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Btrfs: fix __MAX_CSUM_ITEMS
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63 #include "dedupe.h"
64
65 struct btrfs_iget_args {
66 struct btrfs_key *location;
67 struct btrfs_root *root;
68 };
69
70 struct btrfs_dio_data {
71 u64 outstanding_extents;
72 u64 reserve;
73 u64 unsubmitted_oe_range_start;
74 u64 unsubmitted_oe_range_end;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_transaction_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
113 u64 len, u64 orig_start,
114 u64 block_start, u64 block_len,
115 u64 orig_block_len, u64 ram_bytes,
116 int type);
117
118 static int btrfs_dirty_inode(struct inode *inode);
119
120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
121 void btrfs_test_inode_set_ops(struct inode *inode)
122 {
123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
124 }
125 #endif
126
127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
128 struct inode *inode, struct inode *dir,
129 const struct qstr *qstr)
130 {
131 int err;
132
133 err = btrfs_init_acl(trans, inode, dir);
134 if (!err)
135 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
136 return err;
137 }
138
139 /*
140 * this does all the hard work for inserting an inline extent into
141 * the btree. The caller should have done a btrfs_drop_extents so that
142 * no overlapping inline items exist in the btree
143 */
144 static int insert_inline_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_path *path, int extent_inserted,
146 struct btrfs_root *root, struct inode *inode,
147 u64 start, size_t size, size_t compressed_size,
148 int compress_type,
149 struct page **compressed_pages)
150 {
151 struct extent_buffer *leaf;
152 struct page *page = NULL;
153 char *kaddr;
154 unsigned long ptr;
155 struct btrfs_file_extent_item *ei;
156 int err = 0;
157 int ret;
158 size_t cur_size = size;
159 unsigned long offset;
160
161 if (compressed_size && compressed_pages)
162 cur_size = compressed_size;
163
164 inode_add_bytes(inode, size);
165
166 if (!extent_inserted) {
167 struct btrfs_key key;
168 size_t datasize;
169
170 key.objectid = btrfs_ino(inode);
171 key.offset = start;
172 key.type = BTRFS_EXTENT_DATA_KEY;
173
174 datasize = btrfs_file_extent_calc_inline_size(cur_size);
175 path->leave_spinning = 1;
176 ret = btrfs_insert_empty_item(trans, root, path, &key,
177 datasize);
178 if (ret) {
179 err = ret;
180 goto fail;
181 }
182 }
183 leaf = path->nodes[0];
184 ei = btrfs_item_ptr(leaf, path->slots[0],
185 struct btrfs_file_extent_item);
186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
188 btrfs_set_file_extent_encryption(leaf, ei, 0);
189 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
190 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
191 ptr = btrfs_file_extent_inline_start(ei);
192
193 if (compress_type != BTRFS_COMPRESS_NONE) {
194 struct page *cpage;
195 int i = 0;
196 while (compressed_size > 0) {
197 cpage = compressed_pages[i];
198 cur_size = min_t(unsigned long, compressed_size,
199 PAGE_SIZE);
200
201 kaddr = kmap_atomic(cpage);
202 write_extent_buffer(leaf, kaddr, ptr, cur_size);
203 kunmap_atomic(kaddr);
204
205 i++;
206 ptr += cur_size;
207 compressed_size -= cur_size;
208 }
209 btrfs_set_file_extent_compression(leaf, ei,
210 compress_type);
211 } else {
212 page = find_get_page(inode->i_mapping,
213 start >> PAGE_SHIFT);
214 btrfs_set_file_extent_compression(leaf, ei, 0);
215 kaddr = kmap_atomic(page);
216 offset = start & (PAGE_SIZE - 1);
217 write_extent_buffer(leaf, kaddr + offset, ptr, size);
218 kunmap_atomic(kaddr);
219 put_page(page);
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 btrfs_release_path(path);
223
224 /*
225 * we're an inline extent, so nobody can
226 * extend the file past i_size without locking
227 * a page we already have locked.
228 *
229 * We must do any isize and inode updates
230 * before we unlock the pages. Otherwise we
231 * could end up racing with unlink.
232 */
233 BTRFS_I(inode)->disk_i_size = inode->i_size;
234 ret = btrfs_update_inode(trans, root, inode);
235
236 return ret;
237 fail:
238 return err;
239 }
240
241
242 /*
243 * conditionally insert an inline extent into the file. This
244 * does the checks required to make sure the data is small enough
245 * to fit as an inline extent.
246 */
247 static noinline int cow_file_range_inline(struct btrfs_root *root,
248 struct inode *inode, u64 start,
249 u64 end, size_t compressed_size,
250 int compress_type,
251 struct page **compressed_pages)
252 {
253 struct btrfs_trans_handle *trans;
254 u64 isize = i_size_read(inode);
255 u64 actual_end = min(end + 1, isize);
256 u64 inline_len = actual_end - start;
257 u64 aligned_end = ALIGN(end, root->sectorsize);
258 u64 data_len = inline_len;
259 int ret;
260 struct btrfs_path *path;
261 int extent_inserted = 0;
262 u32 extent_item_size;
263
264 if (compressed_size)
265 data_len = compressed_size;
266
267 if (start > 0 ||
268 actual_end > root->sectorsize ||
269 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
270 (!compressed_size &&
271 (actual_end & (root->sectorsize - 1)) == 0) ||
272 end + 1 < isize ||
273 data_len > root->fs_info->max_inline) {
274 return 1;
275 }
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 trans = btrfs_join_transaction(root);
282 if (IS_ERR(trans)) {
283 btrfs_free_path(path);
284 return PTR_ERR(trans);
285 }
286 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
287
288 if (compressed_size && compressed_pages)
289 extent_item_size = btrfs_file_extent_calc_inline_size(
290 compressed_size);
291 else
292 extent_item_size = btrfs_file_extent_calc_inline_size(
293 inline_len);
294
295 ret = __btrfs_drop_extents(trans, root, inode, path,
296 start, aligned_end, NULL,
297 1, 1, extent_item_size, &extent_inserted);
298 if (ret) {
299 btrfs_abort_transaction(trans, ret);
300 goto out;
301 }
302
303 if (isize > actual_end)
304 inline_len = min_t(u64, isize, actual_end);
305 ret = insert_inline_extent(trans, path, extent_inserted,
306 root, inode, start,
307 inline_len, compressed_size,
308 compress_type, compressed_pages);
309 if (ret && ret != -ENOSPC) {
310 btrfs_abort_transaction(trans, ret);
311 goto out;
312 } else if (ret == -ENOSPC) {
313 ret = 1;
314 goto out;
315 }
316
317 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
318 btrfs_delalloc_release_metadata(inode, end + 1 - start);
319 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
320 out:
321 /*
322 * Don't forget to free the reserved space, as for inlined extent
323 * it won't count as data extent, free them directly here.
324 * And at reserve time, it's always aligned to page size, so
325 * just free one page here.
326 */
327 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
328 btrfs_free_path(path);
329 btrfs_end_transaction(trans, root);
330 return ret;
331 }
332
333 struct async_extent {
334 u64 start;
335 u64 ram_size;
336 u64 compressed_size;
337 struct page **pages;
338 unsigned long nr_pages;
339 int compress_type;
340 struct list_head list;
341 };
342
343 struct async_cow {
344 struct inode *inode;
345 struct btrfs_root *root;
346 struct page *locked_page;
347 u64 start;
348 u64 end;
349 struct list_head extents;
350 struct btrfs_work work;
351 };
352
353 static noinline int add_async_extent(struct async_cow *cow,
354 u64 start, u64 ram_size,
355 u64 compressed_size,
356 struct page **pages,
357 unsigned long nr_pages,
358 int compress_type)
359 {
360 struct async_extent *async_extent;
361
362 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
363 BUG_ON(!async_extent); /* -ENOMEM */
364 async_extent->start = start;
365 async_extent->ram_size = ram_size;
366 async_extent->compressed_size = compressed_size;
367 async_extent->pages = pages;
368 async_extent->nr_pages = nr_pages;
369 async_extent->compress_type = compress_type;
370 list_add_tail(&async_extent->list, &cow->extents);
371 return 0;
372 }
373
374 static inline int inode_need_compress(struct inode *inode)
375 {
376 struct btrfs_root *root = BTRFS_I(inode)->root;
377
378 /* force compress */
379 if (btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
380 return 1;
381 /* bad compression ratios */
382 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
383 return 0;
384 if (btrfs_test_opt(root->fs_info, COMPRESS) ||
385 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
386 BTRFS_I(inode)->force_compress)
387 return 1;
388 return 0;
389 }
390
391 /*
392 * we create compressed extents in two phases. The first
393 * phase compresses a range of pages that have already been
394 * locked (both pages and state bits are locked).
395 *
396 * This is done inside an ordered work queue, and the compression
397 * is spread across many cpus. The actual IO submission is step
398 * two, and the ordered work queue takes care of making sure that
399 * happens in the same order things were put onto the queue by
400 * writepages and friends.
401 *
402 * If this code finds it can't get good compression, it puts an
403 * entry onto the work queue to write the uncompressed bytes. This
404 * makes sure that both compressed inodes and uncompressed inodes
405 * are written in the same order that the flusher thread sent them
406 * down.
407 */
408 static noinline void compress_file_range(struct inode *inode,
409 struct page *locked_page,
410 u64 start, u64 end,
411 struct async_cow *async_cow,
412 int *num_added)
413 {
414 struct btrfs_root *root = BTRFS_I(inode)->root;
415 u64 num_bytes;
416 u64 blocksize = root->sectorsize;
417 u64 actual_end;
418 u64 isize = i_size_read(inode);
419 int ret = 0;
420 struct page **pages = NULL;
421 unsigned long nr_pages;
422 unsigned long nr_pages_ret = 0;
423 unsigned long total_compressed = 0;
424 unsigned long total_in = 0;
425 unsigned long max_compressed = SZ_128K;
426 unsigned long max_uncompressed = SZ_128K;
427 int i;
428 int will_compress;
429 int compress_type = root->fs_info->compress_type;
430 int redirty = 0;
431
432 /* if this is a small write inside eof, kick off a defrag */
433 if ((end - start + 1) < SZ_16K &&
434 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
435 btrfs_add_inode_defrag(NULL, inode);
436
437 actual_end = min_t(u64, isize, end + 1);
438 again:
439 will_compress = 0;
440 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
441 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
442
443 /*
444 * we don't want to send crud past the end of i_size through
445 * compression, that's just a waste of CPU time. So, if the
446 * end of the file is before the start of our current
447 * requested range of bytes, we bail out to the uncompressed
448 * cleanup code that can deal with all of this.
449 *
450 * It isn't really the fastest way to fix things, but this is a
451 * very uncommon corner.
452 */
453 if (actual_end <= start)
454 goto cleanup_and_bail_uncompressed;
455
456 total_compressed = actual_end - start;
457
458 /*
459 * skip compression for a small file range(<=blocksize) that
460 * isn't an inline extent, since it doesn't save disk space at all.
461 */
462 if (total_compressed <= blocksize &&
463 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
464 goto cleanup_and_bail_uncompressed;
465
466 /* we want to make sure that amount of ram required to uncompress
467 * an extent is reasonable, so we limit the total size in ram
468 * of a compressed extent to 128k. This is a crucial number
469 * because it also controls how easily we can spread reads across
470 * cpus for decompression.
471 *
472 * We also want to make sure the amount of IO required to do
473 * a random read is reasonably small, so we limit the size of
474 * a compressed extent to 128k.
475 */
476 total_compressed = min(total_compressed, max_uncompressed);
477 num_bytes = ALIGN(end - start + 1, blocksize);
478 num_bytes = max(blocksize, num_bytes);
479 total_in = 0;
480 ret = 0;
481
482 /*
483 * we do compression for mount -o compress and when the
484 * inode has not been flagged as nocompress. This flag can
485 * change at any time if we discover bad compression ratios.
486 */
487 if (inode_need_compress(inode)) {
488 WARN_ON(pages);
489 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
490 if (!pages) {
491 /* just bail out to the uncompressed code */
492 goto cont;
493 }
494
495 if (BTRFS_I(inode)->force_compress)
496 compress_type = BTRFS_I(inode)->force_compress;
497
498 /*
499 * we need to call clear_page_dirty_for_io on each
500 * page in the range. Otherwise applications with the file
501 * mmap'd can wander in and change the page contents while
502 * we are compressing them.
503 *
504 * If the compression fails for any reason, we set the pages
505 * dirty again later on.
506 */
507 extent_range_clear_dirty_for_io(inode, start, end);
508 redirty = 1;
509 ret = btrfs_compress_pages(compress_type,
510 inode->i_mapping, start,
511 total_compressed, pages,
512 nr_pages, &nr_pages_ret,
513 &total_in,
514 &total_compressed,
515 max_compressed);
516
517 if (!ret) {
518 unsigned long offset = total_compressed &
519 (PAGE_SIZE - 1);
520 struct page *page = pages[nr_pages_ret - 1];
521 char *kaddr;
522
523 /* zero the tail end of the last page, we might be
524 * sending it down to disk
525 */
526 if (offset) {
527 kaddr = kmap_atomic(page);
528 memset(kaddr + offset, 0,
529 PAGE_SIZE - offset);
530 kunmap_atomic(kaddr);
531 }
532 will_compress = 1;
533 }
534 }
535 cont:
536 if (start == 0) {
537 /* lets try to make an inline extent */
538 if (ret || total_in < (actual_end - start)) {
539 /* we didn't compress the entire range, try
540 * to make an uncompressed inline extent.
541 */
542 ret = cow_file_range_inline(root, inode, start, end,
543 0, 0, NULL);
544 } else {
545 /* try making a compressed inline extent */
546 ret = cow_file_range_inline(root, inode, start, end,
547 total_compressed,
548 compress_type, pages);
549 }
550 if (ret <= 0) {
551 unsigned long clear_flags = EXTENT_DELALLOC |
552 EXTENT_DEFRAG;
553 unsigned long page_error_op;
554
555 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
556 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
557
558 /*
559 * inline extent creation worked or returned error,
560 * we don't need to create any more async work items.
561 * Unlock and free up our temp pages.
562 */
563 extent_clear_unlock_delalloc(inode, start, end, NULL,
564 clear_flags, PAGE_UNLOCK |
565 PAGE_CLEAR_DIRTY |
566 PAGE_SET_WRITEBACK |
567 page_error_op |
568 PAGE_END_WRITEBACK);
569 goto free_pages_out;
570 }
571 }
572
573 if (will_compress) {
574 /*
575 * we aren't doing an inline extent round the compressed size
576 * up to a block size boundary so the allocator does sane
577 * things
578 */
579 total_compressed = ALIGN(total_compressed, blocksize);
580
581 /*
582 * one last check to make sure the compression is really a
583 * win, compare the page count read with the blocks on disk
584 */
585 total_in = ALIGN(total_in, PAGE_SIZE);
586 if (total_compressed >= total_in) {
587 will_compress = 0;
588 } else {
589 num_bytes = total_in;
590 *num_added += 1;
591
592 /*
593 * The async work queues will take care of doing actual
594 * allocation on disk for these compressed pages, and
595 * will submit them to the elevator.
596 */
597 add_async_extent(async_cow, start, num_bytes,
598 total_compressed, pages, nr_pages_ret,
599 compress_type);
600
601 if (start + num_bytes < end) {
602 start += num_bytes;
603 pages = NULL;
604 cond_resched();
605 goto again;
606 }
607 return;
608 }
609 }
610 if (pages) {
611 /*
612 * the compression code ran but failed to make things smaller,
613 * free any pages it allocated and our page pointer array
614 */
615 for (i = 0; i < nr_pages_ret; i++) {
616 WARN_ON(pages[i]->mapping);
617 put_page(pages[i]);
618 }
619 kfree(pages);
620 pages = NULL;
621 total_compressed = 0;
622 nr_pages_ret = 0;
623
624 /* flag the file so we don't compress in the future */
625 if (!btrfs_test_opt(root->fs_info, FORCE_COMPRESS) &&
626 !(BTRFS_I(inode)->force_compress)) {
627 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
628 }
629 }
630 cleanup_and_bail_uncompressed:
631 /*
632 * No compression, but we still need to write the pages in the file
633 * we've been given so far. redirty the locked page if it corresponds
634 * to our extent and set things up for the async work queue to run
635 * cow_file_range to do the normal delalloc dance.
636 */
637 if (page_offset(locked_page) >= start &&
638 page_offset(locked_page) <= end)
639 __set_page_dirty_nobuffers(locked_page);
640 /* unlocked later on in the async handlers */
641
642 if (redirty)
643 extent_range_redirty_for_io(inode, start, end);
644 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
645 BTRFS_COMPRESS_NONE);
646 *num_added += 1;
647
648 return;
649
650 free_pages_out:
651 for (i = 0; i < nr_pages_ret; i++) {
652 WARN_ON(pages[i]->mapping);
653 put_page(pages[i]);
654 }
655 kfree(pages);
656 }
657
658 static void free_async_extent_pages(struct async_extent *async_extent)
659 {
660 int i;
661
662 if (!async_extent->pages)
663 return;
664
665 for (i = 0; i < async_extent->nr_pages; i++) {
666 WARN_ON(async_extent->pages[i]->mapping);
667 put_page(async_extent->pages[i]);
668 }
669 kfree(async_extent->pages);
670 async_extent->nr_pages = 0;
671 async_extent->pages = NULL;
672 }
673
674 /*
675 * phase two of compressed writeback. This is the ordered portion
676 * of the code, which only gets called in the order the work was
677 * queued. We walk all the async extents created by compress_file_range
678 * and send them down to the disk.
679 */
680 static noinline void submit_compressed_extents(struct inode *inode,
681 struct async_cow *async_cow)
682 {
683 struct async_extent *async_extent;
684 u64 alloc_hint = 0;
685 struct btrfs_key ins;
686 struct extent_map *em;
687 struct btrfs_root *root = BTRFS_I(inode)->root;
688 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
689 struct extent_io_tree *io_tree;
690 int ret = 0;
691
692 again:
693 while (!list_empty(&async_cow->extents)) {
694 async_extent = list_entry(async_cow->extents.next,
695 struct async_extent, list);
696 list_del(&async_extent->list);
697
698 io_tree = &BTRFS_I(inode)->io_tree;
699
700 retry:
701 /* did the compression code fall back to uncompressed IO? */
702 if (!async_extent->pages) {
703 int page_started = 0;
704 unsigned long nr_written = 0;
705
706 lock_extent(io_tree, async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1);
709
710 /* allocate blocks */
711 ret = cow_file_range(inode, async_cow->locked_page,
712 async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 &page_started, &nr_written, 0,
718 NULL);
719
720 /* JDM XXX */
721
722 /*
723 * if page_started, cow_file_range inserted an
724 * inline extent and took care of all the unlocking
725 * and IO for us. Otherwise, we need to submit
726 * all those pages down to the drive.
727 */
728 if (!page_started && !ret)
729 extent_write_locked_range(io_tree,
730 inode, async_extent->start,
731 async_extent->start +
732 async_extent->ram_size - 1,
733 btrfs_get_extent,
734 WB_SYNC_ALL);
735 else if (ret)
736 unlock_page(async_cow->locked_page);
737 kfree(async_extent);
738 cond_resched();
739 continue;
740 }
741
742 lock_extent(io_tree, async_extent->start,
743 async_extent->start + async_extent->ram_size - 1);
744
745 ret = btrfs_reserve_extent(root,
746 async_extent->compressed_size,
747 async_extent->compressed_size,
748 0, alloc_hint, &ins, 1, 1);
749 if (ret) {
750 free_async_extent_pages(async_extent);
751
752 if (ret == -ENOSPC) {
753 unlock_extent(io_tree, async_extent->start,
754 async_extent->start +
755 async_extent->ram_size - 1);
756
757 /*
758 * we need to redirty the pages if we decide to
759 * fallback to uncompressed IO, otherwise we
760 * will not submit these pages down to lower
761 * layers.
762 */
763 extent_range_redirty_for_io(inode,
764 async_extent->start,
765 async_extent->start +
766 async_extent->ram_size - 1);
767
768 goto retry;
769 }
770 goto out_free;
771 }
772 /*
773 * here we're doing allocation and writeback of the
774 * compressed pages
775 */
776 btrfs_drop_extent_cache(inode, async_extent->start,
777 async_extent->start +
778 async_extent->ram_size - 1, 0);
779
780 em = alloc_extent_map();
781 if (!em) {
782 ret = -ENOMEM;
783 goto out_free_reserve;
784 }
785 em->start = async_extent->start;
786 em->len = async_extent->ram_size;
787 em->orig_start = em->start;
788 em->mod_start = em->start;
789 em->mod_len = em->len;
790
791 em->block_start = ins.objectid;
792 em->block_len = ins.offset;
793 em->orig_block_len = ins.offset;
794 em->ram_bytes = async_extent->ram_size;
795 em->bdev = root->fs_info->fs_devices->latest_bdev;
796 em->compress_type = async_extent->compress_type;
797 set_bit(EXTENT_FLAG_PINNED, &em->flags);
798 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
799 em->generation = -1;
800
801 while (1) {
802 write_lock(&em_tree->lock);
803 ret = add_extent_mapping(em_tree, em, 1);
804 write_unlock(&em_tree->lock);
805 if (ret != -EEXIST) {
806 free_extent_map(em);
807 break;
808 }
809 btrfs_drop_extent_cache(inode, async_extent->start,
810 async_extent->start +
811 async_extent->ram_size - 1, 0);
812 }
813
814 if (ret)
815 goto out_free_reserve;
816
817 ret = btrfs_add_ordered_extent_compress(inode,
818 async_extent->start,
819 ins.objectid,
820 async_extent->ram_size,
821 ins.offset,
822 BTRFS_ORDERED_COMPRESSED,
823 async_extent->compress_type);
824 if (ret) {
825 btrfs_drop_extent_cache(inode, async_extent->start,
826 async_extent->start +
827 async_extent->ram_size - 1, 0);
828 goto out_free_reserve;
829 }
830 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
831
832 /*
833 * clear dirty, set writeback and unlock the pages.
834 */
835 extent_clear_unlock_delalloc(inode, async_extent->start,
836 async_extent->start +
837 async_extent->ram_size - 1,
838 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
839 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
840 PAGE_SET_WRITEBACK);
841 ret = btrfs_submit_compressed_write(inode,
842 async_extent->start,
843 async_extent->ram_size,
844 ins.objectid,
845 ins.offset, async_extent->pages,
846 async_extent->nr_pages);
847 if (ret) {
848 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
849 struct page *p = async_extent->pages[0];
850 const u64 start = async_extent->start;
851 const u64 end = start + async_extent->ram_size - 1;
852
853 p->mapping = inode->i_mapping;
854 tree->ops->writepage_end_io_hook(p, start, end,
855 NULL, 0);
856 p->mapping = NULL;
857 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
858 PAGE_END_WRITEBACK |
859 PAGE_SET_ERROR);
860 free_async_extent_pages(async_extent);
861 }
862 alloc_hint = ins.objectid + ins.offset;
863 kfree(async_extent);
864 cond_resched();
865 }
866 return;
867 out_free_reserve:
868 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
869 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
870 out_free:
871 extent_clear_unlock_delalloc(inode, async_extent->start,
872 async_extent->start +
873 async_extent->ram_size - 1,
874 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
875 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
876 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
877 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
878 PAGE_SET_ERROR);
879 free_async_extent_pages(async_extent);
880 kfree(async_extent);
881 goto again;
882 }
883
884 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
885 u64 num_bytes)
886 {
887 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
888 struct extent_map *em;
889 u64 alloc_hint = 0;
890
891 read_lock(&em_tree->lock);
892 em = search_extent_mapping(em_tree, start, num_bytes);
893 if (em) {
894 /*
895 * if block start isn't an actual block number then find the
896 * first block in this inode and use that as a hint. If that
897 * block is also bogus then just don't worry about it.
898 */
899 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
900 free_extent_map(em);
901 em = search_extent_mapping(em_tree, 0, 0);
902 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
903 alloc_hint = em->block_start;
904 if (em)
905 free_extent_map(em);
906 } else {
907 alloc_hint = em->block_start;
908 free_extent_map(em);
909 }
910 }
911 read_unlock(&em_tree->lock);
912
913 return alloc_hint;
914 }
915
916 /*
917 * when extent_io.c finds a delayed allocation range in the file,
918 * the call backs end up in this code. The basic idea is to
919 * allocate extents on disk for the range, and create ordered data structs
920 * in ram to track those extents.
921 *
922 * locked_page is the page that writepage had locked already. We use
923 * it to make sure we don't do extra locks or unlocks.
924 *
925 * *page_started is set to one if we unlock locked_page and do everything
926 * required to start IO on it. It may be clean and already done with
927 * IO when we return.
928 */
929 static noinline int cow_file_range(struct inode *inode,
930 struct page *locked_page,
931 u64 start, u64 end, u64 delalloc_end,
932 int *page_started, unsigned long *nr_written,
933 int unlock, struct btrfs_dedupe_hash *hash)
934 {
935 struct btrfs_root *root = BTRFS_I(inode)->root;
936 u64 alloc_hint = 0;
937 u64 num_bytes;
938 unsigned long ram_size;
939 u64 disk_num_bytes;
940 u64 cur_alloc_size;
941 u64 blocksize = root->sectorsize;
942 struct btrfs_key ins;
943 struct extent_map *em;
944 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
945 int ret = 0;
946
947 if (btrfs_is_free_space_inode(inode)) {
948 WARN_ON_ONCE(1);
949 ret = -EINVAL;
950 goto out_unlock;
951 }
952
953 num_bytes = ALIGN(end - start + 1, blocksize);
954 num_bytes = max(blocksize, num_bytes);
955 disk_num_bytes = num_bytes;
956
957 /* if this is a small write inside eof, kick off defrag */
958 if (num_bytes < SZ_64K &&
959 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
960 btrfs_add_inode_defrag(NULL, inode);
961
962 if (start == 0) {
963 /* lets try to make an inline extent */
964 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
965 NULL);
966 if (ret == 0) {
967 extent_clear_unlock_delalloc(inode, start, end, NULL,
968 EXTENT_LOCKED | EXTENT_DELALLOC |
969 EXTENT_DEFRAG, PAGE_UNLOCK |
970 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
971 PAGE_END_WRITEBACK);
972
973 *nr_written = *nr_written +
974 (end - start + PAGE_SIZE) / PAGE_SIZE;
975 *page_started = 1;
976 goto out;
977 } else if (ret < 0) {
978 goto out_unlock;
979 }
980 }
981
982 BUG_ON(disk_num_bytes >
983 btrfs_super_total_bytes(root->fs_info->super_copy));
984
985 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
986 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
987
988 while (disk_num_bytes > 0) {
989 unsigned long op;
990
991 cur_alloc_size = disk_num_bytes;
992 ret = btrfs_reserve_extent(root, cur_alloc_size,
993 root->sectorsize, 0, alloc_hint,
994 &ins, 1, 1);
995 if (ret < 0)
996 goto out_unlock;
997
998 em = alloc_extent_map();
999 if (!em) {
1000 ret = -ENOMEM;
1001 goto out_reserve;
1002 }
1003 em->start = start;
1004 em->orig_start = em->start;
1005 ram_size = ins.offset;
1006 em->len = ins.offset;
1007 em->mod_start = em->start;
1008 em->mod_len = em->len;
1009
1010 em->block_start = ins.objectid;
1011 em->block_len = ins.offset;
1012 em->orig_block_len = ins.offset;
1013 em->ram_bytes = ram_size;
1014 em->bdev = root->fs_info->fs_devices->latest_bdev;
1015 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1016 em->generation = -1;
1017
1018 while (1) {
1019 write_lock(&em_tree->lock);
1020 ret = add_extent_mapping(em_tree, em, 1);
1021 write_unlock(&em_tree->lock);
1022 if (ret != -EEXIST) {
1023 free_extent_map(em);
1024 break;
1025 }
1026 btrfs_drop_extent_cache(inode, start,
1027 start + ram_size - 1, 0);
1028 }
1029 if (ret)
1030 goto out_reserve;
1031
1032 cur_alloc_size = ins.offset;
1033 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1034 ram_size, cur_alloc_size, 0);
1035 if (ret)
1036 goto out_drop_extent_cache;
1037
1038 if (root->root_key.objectid ==
1039 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1040 ret = btrfs_reloc_clone_csums(inode, start,
1041 cur_alloc_size);
1042 if (ret)
1043 goto out_drop_extent_cache;
1044 }
1045
1046 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1047
1048 if (disk_num_bytes < cur_alloc_size)
1049 break;
1050
1051 /* we're not doing compressed IO, don't unlock the first
1052 * page (which the caller expects to stay locked), don't
1053 * clear any dirty bits and don't set any writeback bits
1054 *
1055 * Do set the Private2 bit so we know this page was properly
1056 * setup for writepage
1057 */
1058 op = unlock ? PAGE_UNLOCK : 0;
1059 op |= PAGE_SET_PRIVATE2;
1060
1061 extent_clear_unlock_delalloc(inode, start,
1062 start + ram_size - 1, locked_page,
1063 EXTENT_LOCKED | EXTENT_DELALLOC,
1064 op);
1065 disk_num_bytes -= cur_alloc_size;
1066 num_bytes -= cur_alloc_size;
1067 alloc_hint = ins.objectid + ins.offset;
1068 start += cur_alloc_size;
1069 }
1070 out:
1071 return ret;
1072
1073 out_drop_extent_cache:
1074 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1075 out_reserve:
1076 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1077 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1078 out_unlock:
1079 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1080 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1081 EXTENT_DELALLOC | EXTENT_DEFRAG,
1082 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1083 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1084 goto out;
1085 }
1086
1087 /*
1088 * work queue call back to started compression on a file and pages
1089 */
1090 static noinline void async_cow_start(struct btrfs_work *work)
1091 {
1092 struct async_cow *async_cow;
1093 int num_added = 0;
1094 async_cow = container_of(work, struct async_cow, work);
1095
1096 compress_file_range(async_cow->inode, async_cow->locked_page,
1097 async_cow->start, async_cow->end, async_cow,
1098 &num_added);
1099 if (num_added == 0) {
1100 btrfs_add_delayed_iput(async_cow->inode);
1101 async_cow->inode = NULL;
1102 }
1103 }
1104
1105 /*
1106 * work queue call back to submit previously compressed pages
1107 */
1108 static noinline void async_cow_submit(struct btrfs_work *work)
1109 {
1110 struct async_cow *async_cow;
1111 struct btrfs_root *root;
1112 unsigned long nr_pages;
1113
1114 async_cow = container_of(work, struct async_cow, work);
1115
1116 root = async_cow->root;
1117 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1118 PAGE_SHIFT;
1119
1120 /*
1121 * atomic_sub_return implies a barrier for waitqueue_active
1122 */
1123 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1124 5 * SZ_1M &&
1125 waitqueue_active(&root->fs_info->async_submit_wait))
1126 wake_up(&root->fs_info->async_submit_wait);
1127
1128 if (async_cow->inode)
1129 submit_compressed_extents(async_cow->inode, async_cow);
1130 }
1131
1132 static noinline void async_cow_free(struct btrfs_work *work)
1133 {
1134 struct async_cow *async_cow;
1135 async_cow = container_of(work, struct async_cow, work);
1136 if (async_cow->inode)
1137 btrfs_add_delayed_iput(async_cow->inode);
1138 kfree(async_cow);
1139 }
1140
1141 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1142 u64 start, u64 end, int *page_started,
1143 unsigned long *nr_written)
1144 {
1145 struct async_cow *async_cow;
1146 struct btrfs_root *root = BTRFS_I(inode)->root;
1147 unsigned long nr_pages;
1148 u64 cur_end;
1149 int limit = 10 * SZ_1M;
1150
1151 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1152 1, 0, NULL, GFP_NOFS);
1153 while (start < end) {
1154 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1155 BUG_ON(!async_cow); /* -ENOMEM */
1156 async_cow->inode = igrab(inode);
1157 async_cow->root = root;
1158 async_cow->locked_page = locked_page;
1159 async_cow->start = start;
1160
1161 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1162 !btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
1163 cur_end = end;
1164 else
1165 cur_end = min(end, start + SZ_512K - 1);
1166
1167 async_cow->end = cur_end;
1168 INIT_LIST_HEAD(&async_cow->extents);
1169
1170 btrfs_init_work(&async_cow->work,
1171 btrfs_delalloc_helper,
1172 async_cow_start, async_cow_submit,
1173 async_cow_free);
1174
1175 nr_pages = (cur_end - start + PAGE_SIZE) >>
1176 PAGE_SHIFT;
1177 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1178
1179 btrfs_queue_work(root->fs_info->delalloc_workers,
1180 &async_cow->work);
1181
1182 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1183 wait_event(root->fs_info->async_submit_wait,
1184 (atomic_read(&root->fs_info->async_delalloc_pages) <
1185 limit));
1186 }
1187
1188 while (atomic_read(&root->fs_info->async_submit_draining) &&
1189 atomic_read(&root->fs_info->async_delalloc_pages)) {
1190 wait_event(root->fs_info->async_submit_wait,
1191 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1192 0));
1193 }
1194
1195 *nr_written += nr_pages;
1196 start = cur_end + 1;
1197 }
1198 *page_started = 1;
1199 return 0;
1200 }
1201
1202 static noinline int csum_exist_in_range(struct btrfs_root *root,
1203 u64 bytenr, u64 num_bytes)
1204 {
1205 int ret;
1206 struct btrfs_ordered_sum *sums;
1207 LIST_HEAD(list);
1208
1209 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1210 bytenr + num_bytes - 1, &list, 0);
1211 if (ret == 0 && list_empty(&list))
1212 return 0;
1213
1214 while (!list_empty(&list)) {
1215 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1216 list_del(&sums->list);
1217 kfree(sums);
1218 }
1219 return 1;
1220 }
1221
1222 /*
1223 * when nowcow writeback call back. This checks for snapshots or COW copies
1224 * of the extents that exist in the file, and COWs the file as required.
1225 *
1226 * If no cow copies or snapshots exist, we write directly to the existing
1227 * blocks on disk
1228 */
1229 static noinline int run_delalloc_nocow(struct inode *inode,
1230 struct page *locked_page,
1231 u64 start, u64 end, int *page_started, int force,
1232 unsigned long *nr_written)
1233 {
1234 struct btrfs_root *root = BTRFS_I(inode)->root;
1235 struct btrfs_trans_handle *trans;
1236 struct extent_buffer *leaf;
1237 struct btrfs_path *path;
1238 struct btrfs_file_extent_item *fi;
1239 struct btrfs_key found_key;
1240 u64 cow_start;
1241 u64 cur_offset;
1242 u64 extent_end;
1243 u64 extent_offset;
1244 u64 disk_bytenr;
1245 u64 num_bytes;
1246 u64 disk_num_bytes;
1247 u64 ram_bytes;
1248 int extent_type;
1249 int ret, err;
1250 int type;
1251 int nocow;
1252 int check_prev = 1;
1253 bool nolock;
1254 u64 ino = btrfs_ino(inode);
1255
1256 path = btrfs_alloc_path();
1257 if (!path) {
1258 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1259 EXTENT_LOCKED | EXTENT_DELALLOC |
1260 EXTENT_DO_ACCOUNTING |
1261 EXTENT_DEFRAG, PAGE_UNLOCK |
1262 PAGE_CLEAR_DIRTY |
1263 PAGE_SET_WRITEBACK |
1264 PAGE_END_WRITEBACK);
1265 return -ENOMEM;
1266 }
1267
1268 nolock = btrfs_is_free_space_inode(inode);
1269
1270 if (nolock)
1271 trans = btrfs_join_transaction_nolock(root);
1272 else
1273 trans = btrfs_join_transaction(root);
1274
1275 if (IS_ERR(trans)) {
1276 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1277 EXTENT_LOCKED | EXTENT_DELALLOC |
1278 EXTENT_DO_ACCOUNTING |
1279 EXTENT_DEFRAG, PAGE_UNLOCK |
1280 PAGE_CLEAR_DIRTY |
1281 PAGE_SET_WRITEBACK |
1282 PAGE_END_WRITEBACK);
1283 btrfs_free_path(path);
1284 return PTR_ERR(trans);
1285 }
1286
1287 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1288
1289 cow_start = (u64)-1;
1290 cur_offset = start;
1291 while (1) {
1292 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1293 cur_offset, 0);
1294 if (ret < 0)
1295 goto error;
1296 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1297 leaf = path->nodes[0];
1298 btrfs_item_key_to_cpu(leaf, &found_key,
1299 path->slots[0] - 1);
1300 if (found_key.objectid == ino &&
1301 found_key.type == BTRFS_EXTENT_DATA_KEY)
1302 path->slots[0]--;
1303 }
1304 check_prev = 0;
1305 next_slot:
1306 leaf = path->nodes[0];
1307 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1308 ret = btrfs_next_leaf(root, path);
1309 if (ret < 0)
1310 goto error;
1311 if (ret > 0)
1312 break;
1313 leaf = path->nodes[0];
1314 }
1315
1316 nocow = 0;
1317 disk_bytenr = 0;
1318 num_bytes = 0;
1319 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1320
1321 if (found_key.objectid > ino)
1322 break;
1323 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1324 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1325 path->slots[0]++;
1326 goto next_slot;
1327 }
1328 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1329 found_key.offset > end)
1330 break;
1331
1332 if (found_key.offset > cur_offset) {
1333 extent_end = found_key.offset;
1334 extent_type = 0;
1335 goto out_check;
1336 }
1337
1338 fi = btrfs_item_ptr(leaf, path->slots[0],
1339 struct btrfs_file_extent_item);
1340 extent_type = btrfs_file_extent_type(leaf, fi);
1341
1342 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1343 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1344 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1345 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1346 extent_offset = btrfs_file_extent_offset(leaf, fi);
1347 extent_end = found_key.offset +
1348 btrfs_file_extent_num_bytes(leaf, fi);
1349 disk_num_bytes =
1350 btrfs_file_extent_disk_num_bytes(leaf, fi);
1351 if (extent_end <= start) {
1352 path->slots[0]++;
1353 goto next_slot;
1354 }
1355 if (disk_bytenr == 0)
1356 goto out_check;
1357 if (btrfs_file_extent_compression(leaf, fi) ||
1358 btrfs_file_extent_encryption(leaf, fi) ||
1359 btrfs_file_extent_other_encoding(leaf, fi))
1360 goto out_check;
1361 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1362 goto out_check;
1363 if (btrfs_extent_readonly(root, disk_bytenr))
1364 goto out_check;
1365 if (btrfs_cross_ref_exist(trans, root, ino,
1366 found_key.offset -
1367 extent_offset, disk_bytenr))
1368 goto out_check;
1369 disk_bytenr += extent_offset;
1370 disk_bytenr += cur_offset - found_key.offset;
1371 num_bytes = min(end + 1, extent_end) - cur_offset;
1372 /*
1373 * if there are pending snapshots for this root,
1374 * we fall into common COW way.
1375 */
1376 if (!nolock) {
1377 err = btrfs_start_write_no_snapshoting(root);
1378 if (!err)
1379 goto out_check;
1380 }
1381 /*
1382 * force cow if csum exists in the range.
1383 * this ensure that csum for a given extent are
1384 * either valid or do not exist.
1385 */
1386 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1387 goto out_check;
1388 if (!btrfs_inc_nocow_writers(root->fs_info,
1389 disk_bytenr))
1390 goto out_check;
1391 nocow = 1;
1392 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1393 extent_end = found_key.offset +
1394 btrfs_file_extent_inline_len(leaf,
1395 path->slots[0], fi);
1396 extent_end = ALIGN(extent_end, root->sectorsize);
1397 } else {
1398 BUG_ON(1);
1399 }
1400 out_check:
1401 if (extent_end <= start) {
1402 path->slots[0]++;
1403 if (!nolock && nocow)
1404 btrfs_end_write_no_snapshoting(root);
1405 if (nocow)
1406 btrfs_dec_nocow_writers(root->fs_info,
1407 disk_bytenr);
1408 goto next_slot;
1409 }
1410 if (!nocow) {
1411 if (cow_start == (u64)-1)
1412 cow_start = cur_offset;
1413 cur_offset = extent_end;
1414 if (cur_offset > end)
1415 break;
1416 path->slots[0]++;
1417 goto next_slot;
1418 }
1419
1420 btrfs_release_path(path);
1421 if (cow_start != (u64)-1) {
1422 ret = cow_file_range(inode, locked_page,
1423 cow_start, found_key.offset - 1,
1424 end, page_started, nr_written, 1,
1425 NULL);
1426 if (ret) {
1427 if (!nolock && nocow)
1428 btrfs_end_write_no_snapshoting(root);
1429 if (nocow)
1430 btrfs_dec_nocow_writers(root->fs_info,
1431 disk_bytenr);
1432 goto error;
1433 }
1434 cow_start = (u64)-1;
1435 }
1436
1437 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1438 struct extent_map *em;
1439 struct extent_map_tree *em_tree;
1440 em_tree = &BTRFS_I(inode)->extent_tree;
1441 em = alloc_extent_map();
1442 BUG_ON(!em); /* -ENOMEM */
1443 em->start = cur_offset;
1444 em->orig_start = found_key.offset - extent_offset;
1445 em->len = num_bytes;
1446 em->block_len = num_bytes;
1447 em->block_start = disk_bytenr;
1448 em->orig_block_len = disk_num_bytes;
1449 em->ram_bytes = ram_bytes;
1450 em->bdev = root->fs_info->fs_devices->latest_bdev;
1451 em->mod_start = em->start;
1452 em->mod_len = em->len;
1453 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1454 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1455 em->generation = -1;
1456 while (1) {
1457 write_lock(&em_tree->lock);
1458 ret = add_extent_mapping(em_tree, em, 1);
1459 write_unlock(&em_tree->lock);
1460 if (ret != -EEXIST) {
1461 free_extent_map(em);
1462 break;
1463 }
1464 btrfs_drop_extent_cache(inode, em->start,
1465 em->start + em->len - 1, 0);
1466 }
1467 type = BTRFS_ORDERED_PREALLOC;
1468 } else {
1469 type = BTRFS_ORDERED_NOCOW;
1470 }
1471
1472 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1473 num_bytes, num_bytes, type);
1474 if (nocow)
1475 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1476 BUG_ON(ret); /* -ENOMEM */
1477
1478 if (root->root_key.objectid ==
1479 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1480 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1481 num_bytes);
1482 if (ret) {
1483 if (!nolock && nocow)
1484 btrfs_end_write_no_snapshoting(root);
1485 goto error;
1486 }
1487 }
1488
1489 extent_clear_unlock_delalloc(inode, cur_offset,
1490 cur_offset + num_bytes - 1,
1491 locked_page, EXTENT_LOCKED |
1492 EXTENT_DELALLOC, PAGE_UNLOCK |
1493 PAGE_SET_PRIVATE2);
1494 if (!nolock && nocow)
1495 btrfs_end_write_no_snapshoting(root);
1496 cur_offset = extent_end;
1497 if (cur_offset > end)
1498 break;
1499 }
1500 btrfs_release_path(path);
1501
1502 if (cur_offset <= end && cow_start == (u64)-1) {
1503 cow_start = cur_offset;
1504 cur_offset = end;
1505 }
1506
1507 if (cow_start != (u64)-1) {
1508 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1509 page_started, nr_written, 1, NULL);
1510 if (ret)
1511 goto error;
1512 }
1513
1514 error:
1515 err = btrfs_end_transaction(trans, root);
1516 if (!ret)
1517 ret = err;
1518
1519 if (ret && cur_offset < end)
1520 extent_clear_unlock_delalloc(inode, cur_offset, end,
1521 locked_page, EXTENT_LOCKED |
1522 EXTENT_DELALLOC | EXTENT_DEFRAG |
1523 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1524 PAGE_CLEAR_DIRTY |
1525 PAGE_SET_WRITEBACK |
1526 PAGE_END_WRITEBACK);
1527 btrfs_free_path(path);
1528 return ret;
1529 }
1530
1531 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1532 {
1533
1534 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1535 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1536 return 0;
1537
1538 /*
1539 * @defrag_bytes is a hint value, no spinlock held here,
1540 * if is not zero, it means the file is defragging.
1541 * Force cow if given extent needs to be defragged.
1542 */
1543 if (BTRFS_I(inode)->defrag_bytes &&
1544 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1545 EXTENT_DEFRAG, 0, NULL))
1546 return 1;
1547
1548 return 0;
1549 }
1550
1551 /*
1552 * extent_io.c call back to do delayed allocation processing
1553 */
1554 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1555 u64 start, u64 end, int *page_started,
1556 unsigned long *nr_written)
1557 {
1558 int ret;
1559 int force_cow = need_force_cow(inode, start, end);
1560
1561 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1562 ret = run_delalloc_nocow(inode, locked_page, start, end,
1563 page_started, 1, nr_written);
1564 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1565 ret = run_delalloc_nocow(inode, locked_page, start, end,
1566 page_started, 0, nr_written);
1567 } else if (!inode_need_compress(inode)) {
1568 ret = cow_file_range(inode, locked_page, start, end, end,
1569 page_started, nr_written, 1, NULL);
1570 } else {
1571 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1572 &BTRFS_I(inode)->runtime_flags);
1573 ret = cow_file_range_async(inode, locked_page, start, end,
1574 page_started, nr_written);
1575 }
1576 return ret;
1577 }
1578
1579 static void btrfs_split_extent_hook(struct inode *inode,
1580 struct extent_state *orig, u64 split)
1581 {
1582 u64 size;
1583
1584 /* not delalloc, ignore it */
1585 if (!(orig->state & EXTENT_DELALLOC))
1586 return;
1587
1588 size = orig->end - orig->start + 1;
1589 if (size > BTRFS_MAX_EXTENT_SIZE) {
1590 u64 num_extents;
1591 u64 new_size;
1592
1593 /*
1594 * See the explanation in btrfs_merge_extent_hook, the same
1595 * applies here, just in reverse.
1596 */
1597 new_size = orig->end - split + 1;
1598 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1599 BTRFS_MAX_EXTENT_SIZE);
1600 new_size = split - orig->start;
1601 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1602 BTRFS_MAX_EXTENT_SIZE);
1603 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1604 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1605 return;
1606 }
1607
1608 spin_lock(&BTRFS_I(inode)->lock);
1609 BTRFS_I(inode)->outstanding_extents++;
1610 spin_unlock(&BTRFS_I(inode)->lock);
1611 }
1612
1613 /*
1614 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1615 * extents so we can keep track of new extents that are just merged onto old
1616 * extents, such as when we are doing sequential writes, so we can properly
1617 * account for the metadata space we'll need.
1618 */
1619 static void btrfs_merge_extent_hook(struct inode *inode,
1620 struct extent_state *new,
1621 struct extent_state *other)
1622 {
1623 u64 new_size, old_size;
1624 u64 num_extents;
1625
1626 /* not delalloc, ignore it */
1627 if (!(other->state & EXTENT_DELALLOC))
1628 return;
1629
1630 if (new->start > other->start)
1631 new_size = new->end - other->start + 1;
1632 else
1633 new_size = other->end - new->start + 1;
1634
1635 /* we're not bigger than the max, unreserve the space and go */
1636 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1637 spin_lock(&BTRFS_I(inode)->lock);
1638 BTRFS_I(inode)->outstanding_extents--;
1639 spin_unlock(&BTRFS_I(inode)->lock);
1640 return;
1641 }
1642
1643 /*
1644 * We have to add up either side to figure out how many extents were
1645 * accounted for before we merged into one big extent. If the number of
1646 * extents we accounted for is <= the amount we need for the new range
1647 * then we can return, otherwise drop. Think of it like this
1648 *
1649 * [ 4k][MAX_SIZE]
1650 *
1651 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1652 * need 2 outstanding extents, on one side we have 1 and the other side
1653 * we have 1 so they are == and we can return. But in this case
1654 *
1655 * [MAX_SIZE+4k][MAX_SIZE+4k]
1656 *
1657 * Each range on their own accounts for 2 extents, but merged together
1658 * they are only 3 extents worth of accounting, so we need to drop in
1659 * this case.
1660 */
1661 old_size = other->end - other->start + 1;
1662 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1663 BTRFS_MAX_EXTENT_SIZE);
1664 old_size = new->end - new->start + 1;
1665 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1666 BTRFS_MAX_EXTENT_SIZE);
1667
1668 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1669 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1670 return;
1671
1672 spin_lock(&BTRFS_I(inode)->lock);
1673 BTRFS_I(inode)->outstanding_extents--;
1674 spin_unlock(&BTRFS_I(inode)->lock);
1675 }
1676
1677 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1678 struct inode *inode)
1679 {
1680 spin_lock(&root->delalloc_lock);
1681 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1682 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1683 &root->delalloc_inodes);
1684 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1685 &BTRFS_I(inode)->runtime_flags);
1686 root->nr_delalloc_inodes++;
1687 if (root->nr_delalloc_inodes == 1) {
1688 spin_lock(&root->fs_info->delalloc_root_lock);
1689 BUG_ON(!list_empty(&root->delalloc_root));
1690 list_add_tail(&root->delalloc_root,
1691 &root->fs_info->delalloc_roots);
1692 spin_unlock(&root->fs_info->delalloc_root_lock);
1693 }
1694 }
1695 spin_unlock(&root->delalloc_lock);
1696 }
1697
1698 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1699 struct inode *inode)
1700 {
1701 spin_lock(&root->delalloc_lock);
1702 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1703 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1704 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1705 &BTRFS_I(inode)->runtime_flags);
1706 root->nr_delalloc_inodes--;
1707 if (!root->nr_delalloc_inodes) {
1708 spin_lock(&root->fs_info->delalloc_root_lock);
1709 BUG_ON(list_empty(&root->delalloc_root));
1710 list_del_init(&root->delalloc_root);
1711 spin_unlock(&root->fs_info->delalloc_root_lock);
1712 }
1713 }
1714 spin_unlock(&root->delalloc_lock);
1715 }
1716
1717 /*
1718 * extent_io.c set_bit_hook, used to track delayed allocation
1719 * bytes in this file, and to maintain the list of inodes that
1720 * have pending delalloc work to be done.
1721 */
1722 static void btrfs_set_bit_hook(struct inode *inode,
1723 struct extent_state *state, unsigned *bits)
1724 {
1725
1726 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1727 WARN_ON(1);
1728 /*
1729 * set_bit and clear bit hooks normally require _irqsave/restore
1730 * but in this case, we are only testing for the DELALLOC
1731 * bit, which is only set or cleared with irqs on
1732 */
1733 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1734 struct btrfs_root *root = BTRFS_I(inode)->root;
1735 u64 len = state->end + 1 - state->start;
1736 bool do_list = !btrfs_is_free_space_inode(inode);
1737
1738 if (*bits & EXTENT_FIRST_DELALLOC) {
1739 *bits &= ~EXTENT_FIRST_DELALLOC;
1740 } else {
1741 spin_lock(&BTRFS_I(inode)->lock);
1742 BTRFS_I(inode)->outstanding_extents++;
1743 spin_unlock(&BTRFS_I(inode)->lock);
1744 }
1745
1746 /* For sanity tests */
1747 if (btrfs_is_testing(root->fs_info))
1748 return;
1749
1750 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1751 root->fs_info->delalloc_batch);
1752 spin_lock(&BTRFS_I(inode)->lock);
1753 BTRFS_I(inode)->delalloc_bytes += len;
1754 if (*bits & EXTENT_DEFRAG)
1755 BTRFS_I(inode)->defrag_bytes += len;
1756 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1757 &BTRFS_I(inode)->runtime_flags))
1758 btrfs_add_delalloc_inodes(root, inode);
1759 spin_unlock(&BTRFS_I(inode)->lock);
1760 }
1761 }
1762
1763 /*
1764 * extent_io.c clear_bit_hook, see set_bit_hook for why
1765 */
1766 static void btrfs_clear_bit_hook(struct inode *inode,
1767 struct extent_state *state,
1768 unsigned *bits)
1769 {
1770 u64 len = state->end + 1 - state->start;
1771 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1772 BTRFS_MAX_EXTENT_SIZE);
1773
1774 spin_lock(&BTRFS_I(inode)->lock);
1775 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1776 BTRFS_I(inode)->defrag_bytes -= len;
1777 spin_unlock(&BTRFS_I(inode)->lock);
1778
1779 /*
1780 * set_bit and clear bit hooks normally require _irqsave/restore
1781 * but in this case, we are only testing for the DELALLOC
1782 * bit, which is only set or cleared with irqs on
1783 */
1784 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1785 struct btrfs_root *root = BTRFS_I(inode)->root;
1786 bool do_list = !btrfs_is_free_space_inode(inode);
1787
1788 if (*bits & EXTENT_FIRST_DELALLOC) {
1789 *bits &= ~EXTENT_FIRST_DELALLOC;
1790 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1791 spin_lock(&BTRFS_I(inode)->lock);
1792 BTRFS_I(inode)->outstanding_extents -= num_extents;
1793 spin_unlock(&BTRFS_I(inode)->lock);
1794 }
1795
1796 /*
1797 * We don't reserve metadata space for space cache inodes so we
1798 * don't need to call dellalloc_release_metadata if there is an
1799 * error.
1800 */
1801 if (*bits & EXTENT_DO_ACCOUNTING &&
1802 root != root->fs_info->tree_root)
1803 btrfs_delalloc_release_metadata(inode, len);
1804
1805 /* For sanity tests. */
1806 if (btrfs_is_testing(root->fs_info))
1807 return;
1808
1809 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1810 && do_list && !(state->state & EXTENT_NORESERVE))
1811 btrfs_free_reserved_data_space_noquota(inode,
1812 state->start, len);
1813
1814 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1815 root->fs_info->delalloc_batch);
1816 spin_lock(&BTRFS_I(inode)->lock);
1817 BTRFS_I(inode)->delalloc_bytes -= len;
1818 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1819 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1820 &BTRFS_I(inode)->runtime_flags))
1821 btrfs_del_delalloc_inode(root, inode);
1822 spin_unlock(&BTRFS_I(inode)->lock);
1823 }
1824 }
1825
1826 /*
1827 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1828 * we don't create bios that span stripes or chunks
1829 *
1830 * return 1 if page cannot be merged to bio
1831 * return 0 if page can be merged to bio
1832 * return error otherwise
1833 */
1834 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1835 size_t size, struct bio *bio,
1836 unsigned long bio_flags)
1837 {
1838 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1839 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1840 u64 length = 0;
1841 u64 map_length;
1842 int ret;
1843
1844 if (bio_flags & EXTENT_BIO_COMPRESSED)
1845 return 0;
1846
1847 length = bio->bi_iter.bi_size;
1848 map_length = length;
1849 ret = btrfs_map_block(root->fs_info, rw, logical,
1850 &map_length, NULL, 0);
1851 if (ret < 0)
1852 return ret;
1853 if (map_length < length + size)
1854 return 1;
1855 return 0;
1856 }
1857
1858 /*
1859 * in order to insert checksums into the metadata in large chunks,
1860 * we wait until bio submission time. All the pages in the bio are
1861 * checksummed and sums are attached onto the ordered extent record.
1862 *
1863 * At IO completion time the cums attached on the ordered extent record
1864 * are inserted into the btree
1865 */
1866 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1867 struct bio *bio, int mirror_num,
1868 unsigned long bio_flags,
1869 u64 bio_offset)
1870 {
1871 struct btrfs_root *root = BTRFS_I(inode)->root;
1872 int ret = 0;
1873
1874 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1875 BUG_ON(ret); /* -ENOMEM */
1876 return 0;
1877 }
1878
1879 /*
1880 * in order to insert checksums into the metadata in large chunks,
1881 * we wait until bio submission time. All the pages in the bio are
1882 * checksummed and sums are attached onto the ordered extent record.
1883 *
1884 * At IO completion time the cums attached on the ordered extent record
1885 * are inserted into the btree
1886 */
1887 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1888 int mirror_num, unsigned long bio_flags,
1889 u64 bio_offset)
1890 {
1891 struct btrfs_root *root = BTRFS_I(inode)->root;
1892 int ret;
1893
1894 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1895 if (ret) {
1896 bio->bi_error = ret;
1897 bio_endio(bio);
1898 }
1899 return ret;
1900 }
1901
1902 /*
1903 * extent_io.c submission hook. This does the right thing for csum calculation
1904 * on write, or reading the csums from the tree before a read
1905 */
1906 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1907 int mirror_num, unsigned long bio_flags,
1908 u64 bio_offset)
1909 {
1910 struct btrfs_root *root = BTRFS_I(inode)->root;
1911 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1912 int ret = 0;
1913 int skip_sum;
1914 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1915
1916 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1917
1918 if (btrfs_is_free_space_inode(inode))
1919 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1920
1921 if (!(rw & REQ_WRITE)) {
1922 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1923 if (ret)
1924 goto out;
1925
1926 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1927 ret = btrfs_submit_compressed_read(inode, bio,
1928 mirror_num,
1929 bio_flags);
1930 goto out;
1931 } else if (!skip_sum) {
1932 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1933 if (ret)
1934 goto out;
1935 }
1936 goto mapit;
1937 } else if (async && !skip_sum) {
1938 /* csum items have already been cloned */
1939 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1940 goto mapit;
1941 /* we're doing a write, do the async checksumming */
1942 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1943 inode, rw, bio, mirror_num,
1944 bio_flags, bio_offset,
1945 __btrfs_submit_bio_start,
1946 __btrfs_submit_bio_done);
1947 goto out;
1948 } else if (!skip_sum) {
1949 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1950 if (ret)
1951 goto out;
1952 }
1953
1954 mapit:
1955 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1956
1957 out:
1958 if (ret < 0) {
1959 bio->bi_error = ret;
1960 bio_endio(bio);
1961 }
1962 return ret;
1963 }
1964
1965 /*
1966 * given a list of ordered sums record them in the inode. This happens
1967 * at IO completion time based on sums calculated at bio submission time.
1968 */
1969 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1970 struct inode *inode, u64 file_offset,
1971 struct list_head *list)
1972 {
1973 struct btrfs_ordered_sum *sum;
1974
1975 list_for_each_entry(sum, list, list) {
1976 trans->adding_csums = 1;
1977 btrfs_csum_file_blocks(trans,
1978 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1979 trans->adding_csums = 0;
1980 }
1981 return 0;
1982 }
1983
1984 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1985 struct extent_state **cached_state)
1986 {
1987 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1988 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1989 cached_state);
1990 }
1991
1992 /* see btrfs_writepage_start_hook for details on why this is required */
1993 struct btrfs_writepage_fixup {
1994 struct page *page;
1995 struct btrfs_work work;
1996 };
1997
1998 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1999 {
2000 struct btrfs_writepage_fixup *fixup;
2001 struct btrfs_ordered_extent *ordered;
2002 struct extent_state *cached_state = NULL;
2003 struct page *page;
2004 struct inode *inode;
2005 u64 page_start;
2006 u64 page_end;
2007 int ret;
2008
2009 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2010 page = fixup->page;
2011 again:
2012 lock_page(page);
2013 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2014 ClearPageChecked(page);
2015 goto out_page;
2016 }
2017
2018 inode = page->mapping->host;
2019 page_start = page_offset(page);
2020 page_end = page_offset(page) + PAGE_SIZE - 1;
2021
2022 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2023 &cached_state);
2024
2025 /* already ordered? We're done */
2026 if (PagePrivate2(page))
2027 goto out;
2028
2029 ordered = btrfs_lookup_ordered_range(inode, page_start,
2030 PAGE_SIZE);
2031 if (ordered) {
2032 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2033 page_end, &cached_state, GFP_NOFS);
2034 unlock_page(page);
2035 btrfs_start_ordered_extent(inode, ordered, 1);
2036 btrfs_put_ordered_extent(ordered);
2037 goto again;
2038 }
2039
2040 ret = btrfs_delalloc_reserve_space(inode, page_start,
2041 PAGE_SIZE);
2042 if (ret) {
2043 mapping_set_error(page->mapping, ret);
2044 end_extent_writepage(page, ret, page_start, page_end);
2045 ClearPageChecked(page);
2046 goto out;
2047 }
2048
2049 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2050 ClearPageChecked(page);
2051 set_page_dirty(page);
2052 out:
2053 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2054 &cached_state, GFP_NOFS);
2055 out_page:
2056 unlock_page(page);
2057 put_page(page);
2058 kfree(fixup);
2059 }
2060
2061 /*
2062 * There are a few paths in the higher layers of the kernel that directly
2063 * set the page dirty bit without asking the filesystem if it is a
2064 * good idea. This causes problems because we want to make sure COW
2065 * properly happens and the data=ordered rules are followed.
2066 *
2067 * In our case any range that doesn't have the ORDERED bit set
2068 * hasn't been properly setup for IO. We kick off an async process
2069 * to fix it up. The async helper will wait for ordered extents, set
2070 * the delalloc bit and make it safe to write the page.
2071 */
2072 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2073 {
2074 struct inode *inode = page->mapping->host;
2075 struct btrfs_writepage_fixup *fixup;
2076 struct btrfs_root *root = BTRFS_I(inode)->root;
2077
2078 /* this page is properly in the ordered list */
2079 if (TestClearPagePrivate2(page))
2080 return 0;
2081
2082 if (PageChecked(page))
2083 return -EAGAIN;
2084
2085 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2086 if (!fixup)
2087 return -EAGAIN;
2088
2089 SetPageChecked(page);
2090 get_page(page);
2091 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2092 btrfs_writepage_fixup_worker, NULL, NULL);
2093 fixup->page = page;
2094 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2095 return -EBUSY;
2096 }
2097
2098 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2099 struct inode *inode, u64 file_pos,
2100 u64 disk_bytenr, u64 disk_num_bytes,
2101 u64 num_bytes, u64 ram_bytes,
2102 u8 compression, u8 encryption,
2103 u16 other_encoding, int extent_type)
2104 {
2105 struct btrfs_root *root = BTRFS_I(inode)->root;
2106 struct btrfs_file_extent_item *fi;
2107 struct btrfs_path *path;
2108 struct extent_buffer *leaf;
2109 struct btrfs_key ins;
2110 int extent_inserted = 0;
2111 int ret;
2112
2113 path = btrfs_alloc_path();
2114 if (!path)
2115 return -ENOMEM;
2116
2117 /*
2118 * we may be replacing one extent in the tree with another.
2119 * The new extent is pinned in the extent map, and we don't want
2120 * to drop it from the cache until it is completely in the btree.
2121 *
2122 * So, tell btrfs_drop_extents to leave this extent in the cache.
2123 * the caller is expected to unpin it and allow it to be merged
2124 * with the others.
2125 */
2126 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2127 file_pos + num_bytes, NULL, 0,
2128 1, sizeof(*fi), &extent_inserted);
2129 if (ret)
2130 goto out;
2131
2132 if (!extent_inserted) {
2133 ins.objectid = btrfs_ino(inode);
2134 ins.offset = file_pos;
2135 ins.type = BTRFS_EXTENT_DATA_KEY;
2136
2137 path->leave_spinning = 1;
2138 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2139 sizeof(*fi));
2140 if (ret)
2141 goto out;
2142 }
2143 leaf = path->nodes[0];
2144 fi = btrfs_item_ptr(leaf, path->slots[0],
2145 struct btrfs_file_extent_item);
2146 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2147 btrfs_set_file_extent_type(leaf, fi, extent_type);
2148 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2149 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2150 btrfs_set_file_extent_offset(leaf, fi, 0);
2151 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2152 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2153 btrfs_set_file_extent_compression(leaf, fi, compression);
2154 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2155 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2156
2157 btrfs_mark_buffer_dirty(leaf);
2158 btrfs_release_path(path);
2159
2160 inode_add_bytes(inode, num_bytes);
2161
2162 ins.objectid = disk_bytenr;
2163 ins.offset = disk_num_bytes;
2164 ins.type = BTRFS_EXTENT_ITEM_KEY;
2165 ret = btrfs_alloc_reserved_file_extent(trans, root,
2166 root->root_key.objectid,
2167 btrfs_ino(inode), file_pos,
2168 ram_bytes, &ins);
2169 /*
2170 * Release the reserved range from inode dirty range map, as it is
2171 * already moved into delayed_ref_head
2172 */
2173 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2174 out:
2175 btrfs_free_path(path);
2176
2177 return ret;
2178 }
2179
2180 /* snapshot-aware defrag */
2181 struct sa_defrag_extent_backref {
2182 struct rb_node node;
2183 struct old_sa_defrag_extent *old;
2184 u64 root_id;
2185 u64 inum;
2186 u64 file_pos;
2187 u64 extent_offset;
2188 u64 num_bytes;
2189 u64 generation;
2190 };
2191
2192 struct old_sa_defrag_extent {
2193 struct list_head list;
2194 struct new_sa_defrag_extent *new;
2195
2196 u64 extent_offset;
2197 u64 bytenr;
2198 u64 offset;
2199 u64 len;
2200 int count;
2201 };
2202
2203 struct new_sa_defrag_extent {
2204 struct rb_root root;
2205 struct list_head head;
2206 struct btrfs_path *path;
2207 struct inode *inode;
2208 u64 file_pos;
2209 u64 len;
2210 u64 bytenr;
2211 u64 disk_len;
2212 u8 compress_type;
2213 };
2214
2215 static int backref_comp(struct sa_defrag_extent_backref *b1,
2216 struct sa_defrag_extent_backref *b2)
2217 {
2218 if (b1->root_id < b2->root_id)
2219 return -1;
2220 else if (b1->root_id > b2->root_id)
2221 return 1;
2222
2223 if (b1->inum < b2->inum)
2224 return -1;
2225 else if (b1->inum > b2->inum)
2226 return 1;
2227
2228 if (b1->file_pos < b2->file_pos)
2229 return -1;
2230 else if (b1->file_pos > b2->file_pos)
2231 return 1;
2232
2233 /*
2234 * [------------------------------] ===> (a range of space)
2235 * |<--->| |<---->| =============> (fs/file tree A)
2236 * |<---------------------------->| ===> (fs/file tree B)
2237 *
2238 * A range of space can refer to two file extents in one tree while
2239 * refer to only one file extent in another tree.
2240 *
2241 * So we may process a disk offset more than one time(two extents in A)
2242 * and locate at the same extent(one extent in B), then insert two same
2243 * backrefs(both refer to the extent in B).
2244 */
2245 return 0;
2246 }
2247
2248 static void backref_insert(struct rb_root *root,
2249 struct sa_defrag_extent_backref *backref)
2250 {
2251 struct rb_node **p = &root->rb_node;
2252 struct rb_node *parent = NULL;
2253 struct sa_defrag_extent_backref *entry;
2254 int ret;
2255
2256 while (*p) {
2257 parent = *p;
2258 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2259
2260 ret = backref_comp(backref, entry);
2261 if (ret < 0)
2262 p = &(*p)->rb_left;
2263 else
2264 p = &(*p)->rb_right;
2265 }
2266
2267 rb_link_node(&backref->node, parent, p);
2268 rb_insert_color(&backref->node, root);
2269 }
2270
2271 /*
2272 * Note the backref might has changed, and in this case we just return 0.
2273 */
2274 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2275 void *ctx)
2276 {
2277 struct btrfs_file_extent_item *extent;
2278 struct btrfs_fs_info *fs_info;
2279 struct old_sa_defrag_extent *old = ctx;
2280 struct new_sa_defrag_extent *new = old->new;
2281 struct btrfs_path *path = new->path;
2282 struct btrfs_key key;
2283 struct btrfs_root *root;
2284 struct sa_defrag_extent_backref *backref;
2285 struct extent_buffer *leaf;
2286 struct inode *inode = new->inode;
2287 int slot;
2288 int ret;
2289 u64 extent_offset;
2290 u64 num_bytes;
2291
2292 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2293 inum == btrfs_ino(inode))
2294 return 0;
2295
2296 key.objectid = root_id;
2297 key.type = BTRFS_ROOT_ITEM_KEY;
2298 key.offset = (u64)-1;
2299
2300 fs_info = BTRFS_I(inode)->root->fs_info;
2301 root = btrfs_read_fs_root_no_name(fs_info, &key);
2302 if (IS_ERR(root)) {
2303 if (PTR_ERR(root) == -ENOENT)
2304 return 0;
2305 WARN_ON(1);
2306 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2307 inum, offset, root_id);
2308 return PTR_ERR(root);
2309 }
2310
2311 key.objectid = inum;
2312 key.type = BTRFS_EXTENT_DATA_KEY;
2313 if (offset > (u64)-1 << 32)
2314 key.offset = 0;
2315 else
2316 key.offset = offset;
2317
2318 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2319 if (WARN_ON(ret < 0))
2320 return ret;
2321 ret = 0;
2322
2323 while (1) {
2324 cond_resched();
2325
2326 leaf = path->nodes[0];
2327 slot = path->slots[0];
2328
2329 if (slot >= btrfs_header_nritems(leaf)) {
2330 ret = btrfs_next_leaf(root, path);
2331 if (ret < 0) {
2332 goto out;
2333 } else if (ret > 0) {
2334 ret = 0;
2335 goto out;
2336 }
2337 continue;
2338 }
2339
2340 path->slots[0]++;
2341
2342 btrfs_item_key_to_cpu(leaf, &key, slot);
2343
2344 if (key.objectid > inum)
2345 goto out;
2346
2347 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2348 continue;
2349
2350 extent = btrfs_item_ptr(leaf, slot,
2351 struct btrfs_file_extent_item);
2352
2353 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2354 continue;
2355
2356 /*
2357 * 'offset' refers to the exact key.offset,
2358 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2359 * (key.offset - extent_offset).
2360 */
2361 if (key.offset != offset)
2362 continue;
2363
2364 extent_offset = btrfs_file_extent_offset(leaf, extent);
2365 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2366
2367 if (extent_offset >= old->extent_offset + old->offset +
2368 old->len || extent_offset + num_bytes <=
2369 old->extent_offset + old->offset)
2370 continue;
2371 break;
2372 }
2373
2374 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2375 if (!backref) {
2376 ret = -ENOENT;
2377 goto out;
2378 }
2379
2380 backref->root_id = root_id;
2381 backref->inum = inum;
2382 backref->file_pos = offset;
2383 backref->num_bytes = num_bytes;
2384 backref->extent_offset = extent_offset;
2385 backref->generation = btrfs_file_extent_generation(leaf, extent);
2386 backref->old = old;
2387 backref_insert(&new->root, backref);
2388 old->count++;
2389 out:
2390 btrfs_release_path(path);
2391 WARN_ON(ret);
2392 return ret;
2393 }
2394
2395 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2396 struct new_sa_defrag_extent *new)
2397 {
2398 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2399 struct old_sa_defrag_extent *old, *tmp;
2400 int ret;
2401
2402 new->path = path;
2403
2404 list_for_each_entry_safe(old, tmp, &new->head, list) {
2405 ret = iterate_inodes_from_logical(old->bytenr +
2406 old->extent_offset, fs_info,
2407 path, record_one_backref,
2408 old);
2409 if (ret < 0 && ret != -ENOENT)
2410 return false;
2411
2412 /* no backref to be processed for this extent */
2413 if (!old->count) {
2414 list_del(&old->list);
2415 kfree(old);
2416 }
2417 }
2418
2419 if (list_empty(&new->head))
2420 return false;
2421
2422 return true;
2423 }
2424
2425 static int relink_is_mergable(struct extent_buffer *leaf,
2426 struct btrfs_file_extent_item *fi,
2427 struct new_sa_defrag_extent *new)
2428 {
2429 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2430 return 0;
2431
2432 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2433 return 0;
2434
2435 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2436 return 0;
2437
2438 if (btrfs_file_extent_encryption(leaf, fi) ||
2439 btrfs_file_extent_other_encoding(leaf, fi))
2440 return 0;
2441
2442 return 1;
2443 }
2444
2445 /*
2446 * Note the backref might has changed, and in this case we just return 0.
2447 */
2448 static noinline int relink_extent_backref(struct btrfs_path *path,
2449 struct sa_defrag_extent_backref *prev,
2450 struct sa_defrag_extent_backref *backref)
2451 {
2452 struct btrfs_file_extent_item *extent;
2453 struct btrfs_file_extent_item *item;
2454 struct btrfs_ordered_extent *ordered;
2455 struct btrfs_trans_handle *trans;
2456 struct btrfs_fs_info *fs_info;
2457 struct btrfs_root *root;
2458 struct btrfs_key key;
2459 struct extent_buffer *leaf;
2460 struct old_sa_defrag_extent *old = backref->old;
2461 struct new_sa_defrag_extent *new = old->new;
2462 struct inode *src_inode = new->inode;
2463 struct inode *inode;
2464 struct extent_state *cached = NULL;
2465 int ret = 0;
2466 u64 start;
2467 u64 len;
2468 u64 lock_start;
2469 u64 lock_end;
2470 bool merge = false;
2471 int index;
2472
2473 if (prev && prev->root_id == backref->root_id &&
2474 prev->inum == backref->inum &&
2475 prev->file_pos + prev->num_bytes == backref->file_pos)
2476 merge = true;
2477
2478 /* step 1: get root */
2479 key.objectid = backref->root_id;
2480 key.type = BTRFS_ROOT_ITEM_KEY;
2481 key.offset = (u64)-1;
2482
2483 fs_info = BTRFS_I(src_inode)->root->fs_info;
2484 index = srcu_read_lock(&fs_info->subvol_srcu);
2485
2486 root = btrfs_read_fs_root_no_name(fs_info, &key);
2487 if (IS_ERR(root)) {
2488 srcu_read_unlock(&fs_info->subvol_srcu, index);
2489 if (PTR_ERR(root) == -ENOENT)
2490 return 0;
2491 return PTR_ERR(root);
2492 }
2493
2494 if (btrfs_root_readonly(root)) {
2495 srcu_read_unlock(&fs_info->subvol_srcu, index);
2496 return 0;
2497 }
2498
2499 /* step 2: get inode */
2500 key.objectid = backref->inum;
2501 key.type = BTRFS_INODE_ITEM_KEY;
2502 key.offset = 0;
2503
2504 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2505 if (IS_ERR(inode)) {
2506 srcu_read_unlock(&fs_info->subvol_srcu, index);
2507 return 0;
2508 }
2509
2510 srcu_read_unlock(&fs_info->subvol_srcu, index);
2511
2512 /* step 3: relink backref */
2513 lock_start = backref->file_pos;
2514 lock_end = backref->file_pos + backref->num_bytes - 1;
2515 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2516 &cached);
2517
2518 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2519 if (ordered) {
2520 btrfs_put_ordered_extent(ordered);
2521 goto out_unlock;
2522 }
2523
2524 trans = btrfs_join_transaction(root);
2525 if (IS_ERR(trans)) {
2526 ret = PTR_ERR(trans);
2527 goto out_unlock;
2528 }
2529
2530 key.objectid = backref->inum;
2531 key.type = BTRFS_EXTENT_DATA_KEY;
2532 key.offset = backref->file_pos;
2533
2534 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2535 if (ret < 0) {
2536 goto out_free_path;
2537 } else if (ret > 0) {
2538 ret = 0;
2539 goto out_free_path;
2540 }
2541
2542 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2543 struct btrfs_file_extent_item);
2544
2545 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2546 backref->generation)
2547 goto out_free_path;
2548
2549 btrfs_release_path(path);
2550
2551 start = backref->file_pos;
2552 if (backref->extent_offset < old->extent_offset + old->offset)
2553 start += old->extent_offset + old->offset -
2554 backref->extent_offset;
2555
2556 len = min(backref->extent_offset + backref->num_bytes,
2557 old->extent_offset + old->offset + old->len);
2558 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2559
2560 ret = btrfs_drop_extents(trans, root, inode, start,
2561 start + len, 1);
2562 if (ret)
2563 goto out_free_path;
2564 again:
2565 key.objectid = btrfs_ino(inode);
2566 key.type = BTRFS_EXTENT_DATA_KEY;
2567 key.offset = start;
2568
2569 path->leave_spinning = 1;
2570 if (merge) {
2571 struct btrfs_file_extent_item *fi;
2572 u64 extent_len;
2573 struct btrfs_key found_key;
2574
2575 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2576 if (ret < 0)
2577 goto out_free_path;
2578
2579 path->slots[0]--;
2580 leaf = path->nodes[0];
2581 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2582
2583 fi = btrfs_item_ptr(leaf, path->slots[0],
2584 struct btrfs_file_extent_item);
2585 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2586
2587 if (extent_len + found_key.offset == start &&
2588 relink_is_mergable(leaf, fi, new)) {
2589 btrfs_set_file_extent_num_bytes(leaf, fi,
2590 extent_len + len);
2591 btrfs_mark_buffer_dirty(leaf);
2592 inode_add_bytes(inode, len);
2593
2594 ret = 1;
2595 goto out_free_path;
2596 } else {
2597 merge = false;
2598 btrfs_release_path(path);
2599 goto again;
2600 }
2601 }
2602
2603 ret = btrfs_insert_empty_item(trans, root, path, &key,
2604 sizeof(*extent));
2605 if (ret) {
2606 btrfs_abort_transaction(trans, ret);
2607 goto out_free_path;
2608 }
2609
2610 leaf = path->nodes[0];
2611 item = btrfs_item_ptr(leaf, path->slots[0],
2612 struct btrfs_file_extent_item);
2613 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2614 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2615 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2616 btrfs_set_file_extent_num_bytes(leaf, item, len);
2617 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2618 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2619 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2620 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2621 btrfs_set_file_extent_encryption(leaf, item, 0);
2622 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2623
2624 btrfs_mark_buffer_dirty(leaf);
2625 inode_add_bytes(inode, len);
2626 btrfs_release_path(path);
2627
2628 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2629 new->disk_len, 0,
2630 backref->root_id, backref->inum,
2631 new->file_pos); /* start - extent_offset */
2632 if (ret) {
2633 btrfs_abort_transaction(trans, ret);
2634 goto out_free_path;
2635 }
2636
2637 ret = 1;
2638 out_free_path:
2639 btrfs_release_path(path);
2640 path->leave_spinning = 0;
2641 btrfs_end_transaction(trans, root);
2642 out_unlock:
2643 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2644 &cached, GFP_NOFS);
2645 iput(inode);
2646 return ret;
2647 }
2648
2649 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2650 {
2651 struct old_sa_defrag_extent *old, *tmp;
2652
2653 if (!new)
2654 return;
2655
2656 list_for_each_entry_safe(old, tmp, &new->head, list) {
2657 kfree(old);
2658 }
2659 kfree(new);
2660 }
2661
2662 static void relink_file_extents(struct new_sa_defrag_extent *new)
2663 {
2664 struct btrfs_path *path;
2665 struct sa_defrag_extent_backref *backref;
2666 struct sa_defrag_extent_backref *prev = NULL;
2667 struct inode *inode;
2668 struct btrfs_root *root;
2669 struct rb_node *node;
2670 int ret;
2671
2672 inode = new->inode;
2673 root = BTRFS_I(inode)->root;
2674
2675 path = btrfs_alloc_path();
2676 if (!path)
2677 return;
2678
2679 if (!record_extent_backrefs(path, new)) {
2680 btrfs_free_path(path);
2681 goto out;
2682 }
2683 btrfs_release_path(path);
2684
2685 while (1) {
2686 node = rb_first(&new->root);
2687 if (!node)
2688 break;
2689 rb_erase(node, &new->root);
2690
2691 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2692
2693 ret = relink_extent_backref(path, prev, backref);
2694 WARN_ON(ret < 0);
2695
2696 kfree(prev);
2697
2698 if (ret == 1)
2699 prev = backref;
2700 else
2701 prev = NULL;
2702 cond_resched();
2703 }
2704 kfree(prev);
2705
2706 btrfs_free_path(path);
2707 out:
2708 free_sa_defrag_extent(new);
2709
2710 atomic_dec(&root->fs_info->defrag_running);
2711 wake_up(&root->fs_info->transaction_wait);
2712 }
2713
2714 static struct new_sa_defrag_extent *
2715 record_old_file_extents(struct inode *inode,
2716 struct btrfs_ordered_extent *ordered)
2717 {
2718 struct btrfs_root *root = BTRFS_I(inode)->root;
2719 struct btrfs_path *path;
2720 struct btrfs_key key;
2721 struct old_sa_defrag_extent *old;
2722 struct new_sa_defrag_extent *new;
2723 int ret;
2724
2725 new = kmalloc(sizeof(*new), GFP_NOFS);
2726 if (!new)
2727 return NULL;
2728
2729 new->inode = inode;
2730 new->file_pos = ordered->file_offset;
2731 new->len = ordered->len;
2732 new->bytenr = ordered->start;
2733 new->disk_len = ordered->disk_len;
2734 new->compress_type = ordered->compress_type;
2735 new->root = RB_ROOT;
2736 INIT_LIST_HEAD(&new->head);
2737
2738 path = btrfs_alloc_path();
2739 if (!path)
2740 goto out_kfree;
2741
2742 key.objectid = btrfs_ino(inode);
2743 key.type = BTRFS_EXTENT_DATA_KEY;
2744 key.offset = new->file_pos;
2745
2746 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2747 if (ret < 0)
2748 goto out_free_path;
2749 if (ret > 0 && path->slots[0] > 0)
2750 path->slots[0]--;
2751
2752 /* find out all the old extents for the file range */
2753 while (1) {
2754 struct btrfs_file_extent_item *extent;
2755 struct extent_buffer *l;
2756 int slot;
2757 u64 num_bytes;
2758 u64 offset;
2759 u64 end;
2760 u64 disk_bytenr;
2761 u64 extent_offset;
2762
2763 l = path->nodes[0];
2764 slot = path->slots[0];
2765
2766 if (slot >= btrfs_header_nritems(l)) {
2767 ret = btrfs_next_leaf(root, path);
2768 if (ret < 0)
2769 goto out_free_path;
2770 else if (ret > 0)
2771 break;
2772 continue;
2773 }
2774
2775 btrfs_item_key_to_cpu(l, &key, slot);
2776
2777 if (key.objectid != btrfs_ino(inode))
2778 break;
2779 if (key.type != BTRFS_EXTENT_DATA_KEY)
2780 break;
2781 if (key.offset >= new->file_pos + new->len)
2782 break;
2783
2784 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2785
2786 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2787 if (key.offset + num_bytes < new->file_pos)
2788 goto next;
2789
2790 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2791 if (!disk_bytenr)
2792 goto next;
2793
2794 extent_offset = btrfs_file_extent_offset(l, extent);
2795
2796 old = kmalloc(sizeof(*old), GFP_NOFS);
2797 if (!old)
2798 goto out_free_path;
2799
2800 offset = max(new->file_pos, key.offset);
2801 end = min(new->file_pos + new->len, key.offset + num_bytes);
2802
2803 old->bytenr = disk_bytenr;
2804 old->extent_offset = extent_offset;
2805 old->offset = offset - key.offset;
2806 old->len = end - offset;
2807 old->new = new;
2808 old->count = 0;
2809 list_add_tail(&old->list, &new->head);
2810 next:
2811 path->slots[0]++;
2812 cond_resched();
2813 }
2814
2815 btrfs_free_path(path);
2816 atomic_inc(&root->fs_info->defrag_running);
2817
2818 return new;
2819
2820 out_free_path:
2821 btrfs_free_path(path);
2822 out_kfree:
2823 free_sa_defrag_extent(new);
2824 return NULL;
2825 }
2826
2827 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2828 u64 start, u64 len)
2829 {
2830 struct btrfs_block_group_cache *cache;
2831
2832 cache = btrfs_lookup_block_group(root->fs_info, start);
2833 ASSERT(cache);
2834
2835 spin_lock(&cache->lock);
2836 cache->delalloc_bytes -= len;
2837 spin_unlock(&cache->lock);
2838
2839 btrfs_put_block_group(cache);
2840 }
2841
2842 /* as ordered data IO finishes, this gets called so we can finish
2843 * an ordered extent if the range of bytes in the file it covers are
2844 * fully written.
2845 */
2846 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2847 {
2848 struct inode *inode = ordered_extent->inode;
2849 struct btrfs_root *root = BTRFS_I(inode)->root;
2850 struct btrfs_trans_handle *trans = NULL;
2851 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2852 struct extent_state *cached_state = NULL;
2853 struct new_sa_defrag_extent *new = NULL;
2854 int compress_type = 0;
2855 int ret = 0;
2856 u64 logical_len = ordered_extent->len;
2857 bool nolock;
2858 bool truncated = false;
2859
2860 nolock = btrfs_is_free_space_inode(inode);
2861
2862 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2863 ret = -EIO;
2864 goto out;
2865 }
2866
2867 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2868 ordered_extent->file_offset +
2869 ordered_extent->len - 1);
2870
2871 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2872 truncated = true;
2873 logical_len = ordered_extent->truncated_len;
2874 /* Truncated the entire extent, don't bother adding */
2875 if (!logical_len)
2876 goto out;
2877 }
2878
2879 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2880 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2881
2882 /*
2883 * For mwrite(mmap + memset to write) case, we still reserve
2884 * space for NOCOW range.
2885 * As NOCOW won't cause a new delayed ref, just free the space
2886 */
2887 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2888 ordered_extent->len);
2889 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2890 if (nolock)
2891 trans = btrfs_join_transaction_nolock(root);
2892 else
2893 trans = btrfs_join_transaction(root);
2894 if (IS_ERR(trans)) {
2895 ret = PTR_ERR(trans);
2896 trans = NULL;
2897 goto out;
2898 }
2899 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2900 ret = btrfs_update_inode_fallback(trans, root, inode);
2901 if (ret) /* -ENOMEM or corruption */
2902 btrfs_abort_transaction(trans, ret);
2903 goto out;
2904 }
2905
2906 lock_extent_bits(io_tree, ordered_extent->file_offset,
2907 ordered_extent->file_offset + ordered_extent->len - 1,
2908 &cached_state);
2909
2910 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2911 ordered_extent->file_offset + ordered_extent->len - 1,
2912 EXTENT_DEFRAG, 1, cached_state);
2913 if (ret) {
2914 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2915 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2916 /* the inode is shared */
2917 new = record_old_file_extents(inode, ordered_extent);
2918
2919 clear_extent_bit(io_tree, ordered_extent->file_offset,
2920 ordered_extent->file_offset + ordered_extent->len - 1,
2921 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2922 }
2923
2924 if (nolock)
2925 trans = btrfs_join_transaction_nolock(root);
2926 else
2927 trans = btrfs_join_transaction(root);
2928 if (IS_ERR(trans)) {
2929 ret = PTR_ERR(trans);
2930 trans = NULL;
2931 goto out_unlock;
2932 }
2933
2934 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2935
2936 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2937 compress_type = ordered_extent->compress_type;
2938 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2939 BUG_ON(compress_type);
2940 ret = btrfs_mark_extent_written(trans, inode,
2941 ordered_extent->file_offset,
2942 ordered_extent->file_offset +
2943 logical_len);
2944 } else {
2945 BUG_ON(root == root->fs_info->tree_root);
2946 ret = insert_reserved_file_extent(trans, inode,
2947 ordered_extent->file_offset,
2948 ordered_extent->start,
2949 ordered_extent->disk_len,
2950 logical_len, logical_len,
2951 compress_type, 0, 0,
2952 BTRFS_FILE_EXTENT_REG);
2953 if (!ret)
2954 btrfs_release_delalloc_bytes(root,
2955 ordered_extent->start,
2956 ordered_extent->disk_len);
2957 }
2958 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2959 ordered_extent->file_offset, ordered_extent->len,
2960 trans->transid);
2961 if (ret < 0) {
2962 btrfs_abort_transaction(trans, ret);
2963 goto out_unlock;
2964 }
2965
2966 add_pending_csums(trans, inode, ordered_extent->file_offset,
2967 &ordered_extent->list);
2968
2969 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2970 ret = btrfs_update_inode_fallback(trans, root, inode);
2971 if (ret) { /* -ENOMEM or corruption */
2972 btrfs_abort_transaction(trans, ret);
2973 goto out_unlock;
2974 }
2975 ret = 0;
2976 out_unlock:
2977 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2978 ordered_extent->file_offset +
2979 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2980 out:
2981 if (root != root->fs_info->tree_root)
2982 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2983 if (trans)
2984 btrfs_end_transaction(trans, root);
2985
2986 if (ret || truncated) {
2987 u64 start, end;
2988
2989 if (truncated)
2990 start = ordered_extent->file_offset + logical_len;
2991 else
2992 start = ordered_extent->file_offset;
2993 end = ordered_extent->file_offset + ordered_extent->len - 1;
2994 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2995
2996 /* Drop the cache for the part of the extent we didn't write. */
2997 btrfs_drop_extent_cache(inode, start, end, 0);
2998
2999 /*
3000 * If the ordered extent had an IOERR or something else went
3001 * wrong we need to return the space for this ordered extent
3002 * back to the allocator. We only free the extent in the
3003 * truncated case if we didn't write out the extent at all.
3004 */
3005 if ((ret || !logical_len) &&
3006 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3007 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3008 btrfs_free_reserved_extent(root, ordered_extent->start,
3009 ordered_extent->disk_len, 1);
3010 }
3011
3012
3013 /*
3014 * This needs to be done to make sure anybody waiting knows we are done
3015 * updating everything for this ordered extent.
3016 */
3017 btrfs_remove_ordered_extent(inode, ordered_extent);
3018
3019 /* for snapshot-aware defrag */
3020 if (new) {
3021 if (ret) {
3022 free_sa_defrag_extent(new);
3023 atomic_dec(&root->fs_info->defrag_running);
3024 } else {
3025 relink_file_extents(new);
3026 }
3027 }
3028
3029 /* once for us */
3030 btrfs_put_ordered_extent(ordered_extent);
3031 /* once for the tree */
3032 btrfs_put_ordered_extent(ordered_extent);
3033
3034 return ret;
3035 }
3036
3037 static void finish_ordered_fn(struct btrfs_work *work)
3038 {
3039 struct btrfs_ordered_extent *ordered_extent;
3040 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3041 btrfs_finish_ordered_io(ordered_extent);
3042 }
3043
3044 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3045 struct extent_state *state, int uptodate)
3046 {
3047 struct inode *inode = page->mapping->host;
3048 struct btrfs_root *root = BTRFS_I(inode)->root;
3049 struct btrfs_ordered_extent *ordered_extent = NULL;
3050 struct btrfs_workqueue *wq;
3051 btrfs_work_func_t func;
3052
3053 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3054
3055 ClearPagePrivate2(page);
3056 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3057 end - start + 1, uptodate))
3058 return 0;
3059
3060 if (btrfs_is_free_space_inode(inode)) {
3061 wq = root->fs_info->endio_freespace_worker;
3062 func = btrfs_freespace_write_helper;
3063 } else {
3064 wq = root->fs_info->endio_write_workers;
3065 func = btrfs_endio_write_helper;
3066 }
3067
3068 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3069 NULL);
3070 btrfs_queue_work(wq, &ordered_extent->work);
3071
3072 return 0;
3073 }
3074
3075 static int __readpage_endio_check(struct inode *inode,
3076 struct btrfs_io_bio *io_bio,
3077 int icsum, struct page *page,
3078 int pgoff, u64 start, size_t len)
3079 {
3080 char *kaddr;
3081 u32 csum_expected;
3082 u32 csum = ~(u32)0;
3083
3084 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3085
3086 kaddr = kmap_atomic(page);
3087 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3088 btrfs_csum_final(csum, (char *)&csum);
3089 if (csum != csum_expected)
3090 goto zeroit;
3091
3092 kunmap_atomic(kaddr);
3093 return 0;
3094 zeroit:
3095 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3096 "csum failed ino %llu off %llu csum %u expected csum %u",
3097 btrfs_ino(inode), start, csum, csum_expected);
3098 memset(kaddr + pgoff, 1, len);
3099 flush_dcache_page(page);
3100 kunmap_atomic(kaddr);
3101 if (csum_expected == 0)
3102 return 0;
3103 return -EIO;
3104 }
3105
3106 /*
3107 * when reads are done, we need to check csums to verify the data is correct
3108 * if there's a match, we allow the bio to finish. If not, the code in
3109 * extent_io.c will try to find good copies for us.
3110 */
3111 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3112 u64 phy_offset, struct page *page,
3113 u64 start, u64 end, int mirror)
3114 {
3115 size_t offset = start - page_offset(page);
3116 struct inode *inode = page->mapping->host;
3117 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3118 struct btrfs_root *root = BTRFS_I(inode)->root;
3119
3120 if (PageChecked(page)) {
3121 ClearPageChecked(page);
3122 return 0;
3123 }
3124
3125 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3126 return 0;
3127
3128 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3129 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3130 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3131 return 0;
3132 }
3133
3134 phy_offset >>= inode->i_sb->s_blocksize_bits;
3135 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3136 start, (size_t)(end - start + 1));
3137 }
3138
3139 void btrfs_add_delayed_iput(struct inode *inode)
3140 {
3141 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3142 struct btrfs_inode *binode = BTRFS_I(inode);
3143
3144 if (atomic_add_unless(&inode->i_count, -1, 1))
3145 return;
3146
3147 spin_lock(&fs_info->delayed_iput_lock);
3148 if (binode->delayed_iput_count == 0) {
3149 ASSERT(list_empty(&binode->delayed_iput));
3150 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3151 } else {
3152 binode->delayed_iput_count++;
3153 }
3154 spin_unlock(&fs_info->delayed_iput_lock);
3155 }
3156
3157 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3158 {
3159 struct btrfs_fs_info *fs_info = root->fs_info;
3160
3161 spin_lock(&fs_info->delayed_iput_lock);
3162 while (!list_empty(&fs_info->delayed_iputs)) {
3163 struct btrfs_inode *inode;
3164
3165 inode = list_first_entry(&fs_info->delayed_iputs,
3166 struct btrfs_inode, delayed_iput);
3167 if (inode->delayed_iput_count) {
3168 inode->delayed_iput_count--;
3169 list_move_tail(&inode->delayed_iput,
3170 &fs_info->delayed_iputs);
3171 } else {
3172 list_del_init(&inode->delayed_iput);
3173 }
3174 spin_unlock(&fs_info->delayed_iput_lock);
3175 iput(&inode->vfs_inode);
3176 spin_lock(&fs_info->delayed_iput_lock);
3177 }
3178 spin_unlock(&fs_info->delayed_iput_lock);
3179 }
3180
3181 /*
3182 * This is called in transaction commit time. If there are no orphan
3183 * files in the subvolume, it removes orphan item and frees block_rsv
3184 * structure.
3185 */
3186 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3187 struct btrfs_root *root)
3188 {
3189 struct btrfs_block_rsv *block_rsv;
3190 int ret;
3191
3192 if (atomic_read(&root->orphan_inodes) ||
3193 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3194 return;
3195
3196 spin_lock(&root->orphan_lock);
3197 if (atomic_read(&root->orphan_inodes)) {
3198 spin_unlock(&root->orphan_lock);
3199 return;
3200 }
3201
3202 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3203 spin_unlock(&root->orphan_lock);
3204 return;
3205 }
3206
3207 block_rsv = root->orphan_block_rsv;
3208 root->orphan_block_rsv = NULL;
3209 spin_unlock(&root->orphan_lock);
3210
3211 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3212 btrfs_root_refs(&root->root_item) > 0) {
3213 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3214 root->root_key.objectid);
3215 if (ret)
3216 btrfs_abort_transaction(trans, ret);
3217 else
3218 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3219 &root->state);
3220 }
3221
3222 if (block_rsv) {
3223 WARN_ON(block_rsv->size > 0);
3224 btrfs_free_block_rsv(root, block_rsv);
3225 }
3226 }
3227
3228 /*
3229 * This creates an orphan entry for the given inode in case something goes
3230 * wrong in the middle of an unlink/truncate.
3231 *
3232 * NOTE: caller of this function should reserve 5 units of metadata for
3233 * this function.
3234 */
3235 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3236 {
3237 struct btrfs_root *root = BTRFS_I(inode)->root;
3238 struct btrfs_block_rsv *block_rsv = NULL;
3239 int reserve = 0;
3240 int insert = 0;
3241 int ret;
3242
3243 if (!root->orphan_block_rsv) {
3244 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3245 if (!block_rsv)
3246 return -ENOMEM;
3247 }
3248
3249 spin_lock(&root->orphan_lock);
3250 if (!root->orphan_block_rsv) {
3251 root->orphan_block_rsv = block_rsv;
3252 } else if (block_rsv) {
3253 btrfs_free_block_rsv(root, block_rsv);
3254 block_rsv = NULL;
3255 }
3256
3257 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3258 &BTRFS_I(inode)->runtime_flags)) {
3259 #if 0
3260 /*
3261 * For proper ENOSPC handling, we should do orphan
3262 * cleanup when mounting. But this introduces backward
3263 * compatibility issue.
3264 */
3265 if (!xchg(&root->orphan_item_inserted, 1))
3266 insert = 2;
3267 else
3268 insert = 1;
3269 #endif
3270 insert = 1;
3271 atomic_inc(&root->orphan_inodes);
3272 }
3273
3274 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3275 &BTRFS_I(inode)->runtime_flags))
3276 reserve = 1;
3277 spin_unlock(&root->orphan_lock);
3278
3279 /* grab metadata reservation from transaction handle */
3280 if (reserve) {
3281 ret = btrfs_orphan_reserve_metadata(trans, inode);
3282 ASSERT(!ret);
3283 if (ret) {
3284 atomic_dec(&root->orphan_inodes);
3285 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3286 &BTRFS_I(inode)->runtime_flags);
3287 if (insert)
3288 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3289 &BTRFS_I(inode)->runtime_flags);
3290 return ret;
3291 }
3292 }
3293
3294 /* insert an orphan item to track this unlinked/truncated file */
3295 if (insert >= 1) {
3296 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3297 if (ret) {
3298 atomic_dec(&root->orphan_inodes);
3299 if (reserve) {
3300 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3301 &BTRFS_I(inode)->runtime_flags);
3302 btrfs_orphan_release_metadata(inode);
3303 }
3304 if (ret != -EEXIST) {
3305 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3306 &BTRFS_I(inode)->runtime_flags);
3307 btrfs_abort_transaction(trans, ret);
3308 return ret;
3309 }
3310 }
3311 ret = 0;
3312 }
3313
3314 /* insert an orphan item to track subvolume contains orphan files */
3315 if (insert >= 2) {
3316 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3317 root->root_key.objectid);
3318 if (ret && ret != -EEXIST) {
3319 btrfs_abort_transaction(trans, ret);
3320 return ret;
3321 }
3322 }
3323 return 0;
3324 }
3325
3326 /*
3327 * We have done the truncate/delete so we can go ahead and remove the orphan
3328 * item for this particular inode.
3329 */
3330 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3331 struct inode *inode)
3332 {
3333 struct btrfs_root *root = BTRFS_I(inode)->root;
3334 int delete_item = 0;
3335 int release_rsv = 0;
3336 int ret = 0;
3337
3338 spin_lock(&root->orphan_lock);
3339 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3340 &BTRFS_I(inode)->runtime_flags))
3341 delete_item = 1;
3342
3343 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3344 &BTRFS_I(inode)->runtime_flags))
3345 release_rsv = 1;
3346 spin_unlock(&root->orphan_lock);
3347
3348 if (delete_item) {
3349 atomic_dec(&root->orphan_inodes);
3350 if (trans)
3351 ret = btrfs_del_orphan_item(trans, root,
3352 btrfs_ino(inode));
3353 }
3354
3355 if (release_rsv)
3356 btrfs_orphan_release_metadata(inode);
3357
3358 return ret;
3359 }
3360
3361 /*
3362 * this cleans up any orphans that may be left on the list from the last use
3363 * of this root.
3364 */
3365 int btrfs_orphan_cleanup(struct btrfs_root *root)
3366 {
3367 struct btrfs_path *path;
3368 struct extent_buffer *leaf;
3369 struct btrfs_key key, found_key;
3370 struct btrfs_trans_handle *trans;
3371 struct inode *inode;
3372 u64 last_objectid = 0;
3373 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3374
3375 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3376 return 0;
3377
3378 path = btrfs_alloc_path();
3379 if (!path) {
3380 ret = -ENOMEM;
3381 goto out;
3382 }
3383 path->reada = READA_BACK;
3384
3385 key.objectid = BTRFS_ORPHAN_OBJECTID;
3386 key.type = BTRFS_ORPHAN_ITEM_KEY;
3387 key.offset = (u64)-1;
3388
3389 while (1) {
3390 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3391 if (ret < 0)
3392 goto out;
3393
3394 /*
3395 * if ret == 0 means we found what we were searching for, which
3396 * is weird, but possible, so only screw with path if we didn't
3397 * find the key and see if we have stuff that matches
3398 */
3399 if (ret > 0) {
3400 ret = 0;
3401 if (path->slots[0] == 0)
3402 break;
3403 path->slots[0]--;
3404 }
3405
3406 /* pull out the item */
3407 leaf = path->nodes[0];
3408 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3409
3410 /* make sure the item matches what we want */
3411 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3412 break;
3413 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3414 break;
3415
3416 /* release the path since we're done with it */
3417 btrfs_release_path(path);
3418
3419 /*
3420 * this is where we are basically btrfs_lookup, without the
3421 * crossing root thing. we store the inode number in the
3422 * offset of the orphan item.
3423 */
3424
3425 if (found_key.offset == last_objectid) {
3426 btrfs_err(root->fs_info,
3427 "Error removing orphan entry, stopping orphan cleanup");
3428 ret = -EINVAL;
3429 goto out;
3430 }
3431
3432 last_objectid = found_key.offset;
3433
3434 found_key.objectid = found_key.offset;
3435 found_key.type = BTRFS_INODE_ITEM_KEY;
3436 found_key.offset = 0;
3437 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3438 ret = PTR_ERR_OR_ZERO(inode);
3439 if (ret && ret != -ESTALE)
3440 goto out;
3441
3442 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3443 struct btrfs_root *dead_root;
3444 struct btrfs_fs_info *fs_info = root->fs_info;
3445 int is_dead_root = 0;
3446
3447 /*
3448 * this is an orphan in the tree root. Currently these
3449 * could come from 2 sources:
3450 * a) a snapshot deletion in progress
3451 * b) a free space cache inode
3452 * We need to distinguish those two, as the snapshot
3453 * orphan must not get deleted.
3454 * find_dead_roots already ran before us, so if this
3455 * is a snapshot deletion, we should find the root
3456 * in the dead_roots list
3457 */
3458 spin_lock(&fs_info->trans_lock);
3459 list_for_each_entry(dead_root, &fs_info->dead_roots,
3460 root_list) {
3461 if (dead_root->root_key.objectid ==
3462 found_key.objectid) {
3463 is_dead_root = 1;
3464 break;
3465 }
3466 }
3467 spin_unlock(&fs_info->trans_lock);
3468 if (is_dead_root) {
3469 /* prevent this orphan from being found again */
3470 key.offset = found_key.objectid - 1;
3471 continue;
3472 }
3473 }
3474 /*
3475 * Inode is already gone but the orphan item is still there,
3476 * kill the orphan item.
3477 */
3478 if (ret == -ESTALE) {
3479 trans = btrfs_start_transaction(root, 1);
3480 if (IS_ERR(trans)) {
3481 ret = PTR_ERR(trans);
3482 goto out;
3483 }
3484 btrfs_debug(root->fs_info, "auto deleting %Lu",
3485 found_key.objectid);
3486 ret = btrfs_del_orphan_item(trans, root,
3487 found_key.objectid);
3488 btrfs_end_transaction(trans, root);
3489 if (ret)
3490 goto out;
3491 continue;
3492 }
3493
3494 /*
3495 * add this inode to the orphan list so btrfs_orphan_del does
3496 * the proper thing when we hit it
3497 */
3498 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3499 &BTRFS_I(inode)->runtime_flags);
3500 atomic_inc(&root->orphan_inodes);
3501
3502 /* if we have links, this was a truncate, lets do that */
3503 if (inode->i_nlink) {
3504 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3505 iput(inode);
3506 continue;
3507 }
3508 nr_truncate++;
3509
3510 /* 1 for the orphan item deletion. */
3511 trans = btrfs_start_transaction(root, 1);
3512 if (IS_ERR(trans)) {
3513 iput(inode);
3514 ret = PTR_ERR(trans);
3515 goto out;
3516 }
3517 ret = btrfs_orphan_add(trans, inode);
3518 btrfs_end_transaction(trans, root);
3519 if (ret) {
3520 iput(inode);
3521 goto out;
3522 }
3523
3524 ret = btrfs_truncate(inode);
3525 if (ret)
3526 btrfs_orphan_del(NULL, inode);
3527 } else {
3528 nr_unlink++;
3529 }
3530
3531 /* this will do delete_inode and everything for us */
3532 iput(inode);
3533 if (ret)
3534 goto out;
3535 }
3536 /* release the path since we're done with it */
3537 btrfs_release_path(path);
3538
3539 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3540
3541 if (root->orphan_block_rsv)
3542 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3543 (u64)-1);
3544
3545 if (root->orphan_block_rsv ||
3546 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3547 trans = btrfs_join_transaction(root);
3548 if (!IS_ERR(trans))
3549 btrfs_end_transaction(trans, root);
3550 }
3551
3552 if (nr_unlink)
3553 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3554 if (nr_truncate)
3555 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3556
3557 out:
3558 if (ret)
3559 btrfs_err(root->fs_info,
3560 "could not do orphan cleanup %d", ret);
3561 btrfs_free_path(path);
3562 return ret;
3563 }
3564
3565 /*
3566 * very simple check to peek ahead in the leaf looking for xattrs. If we
3567 * don't find any xattrs, we know there can't be any acls.
3568 *
3569 * slot is the slot the inode is in, objectid is the objectid of the inode
3570 */
3571 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3572 int slot, u64 objectid,
3573 int *first_xattr_slot)
3574 {
3575 u32 nritems = btrfs_header_nritems(leaf);
3576 struct btrfs_key found_key;
3577 static u64 xattr_access = 0;
3578 static u64 xattr_default = 0;
3579 int scanned = 0;
3580
3581 if (!xattr_access) {
3582 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3583 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3584 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3585 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3586 }
3587
3588 slot++;
3589 *first_xattr_slot = -1;
3590 while (slot < nritems) {
3591 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3592
3593 /* we found a different objectid, there must not be acls */
3594 if (found_key.objectid != objectid)
3595 return 0;
3596
3597 /* we found an xattr, assume we've got an acl */
3598 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3599 if (*first_xattr_slot == -1)
3600 *first_xattr_slot = slot;
3601 if (found_key.offset == xattr_access ||
3602 found_key.offset == xattr_default)
3603 return 1;
3604 }
3605
3606 /*
3607 * we found a key greater than an xattr key, there can't
3608 * be any acls later on
3609 */
3610 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3611 return 0;
3612
3613 slot++;
3614 scanned++;
3615
3616 /*
3617 * it goes inode, inode backrefs, xattrs, extents,
3618 * so if there are a ton of hard links to an inode there can
3619 * be a lot of backrefs. Don't waste time searching too hard,
3620 * this is just an optimization
3621 */
3622 if (scanned >= 8)
3623 break;
3624 }
3625 /* we hit the end of the leaf before we found an xattr or
3626 * something larger than an xattr. We have to assume the inode
3627 * has acls
3628 */
3629 if (*first_xattr_slot == -1)
3630 *first_xattr_slot = slot;
3631 return 1;
3632 }
3633
3634 /*
3635 * read an inode from the btree into the in-memory inode
3636 */
3637 static void btrfs_read_locked_inode(struct inode *inode)
3638 {
3639 struct btrfs_path *path;
3640 struct extent_buffer *leaf;
3641 struct btrfs_inode_item *inode_item;
3642 struct btrfs_root *root = BTRFS_I(inode)->root;
3643 struct btrfs_key location;
3644 unsigned long ptr;
3645 int maybe_acls;
3646 u32 rdev;
3647 int ret;
3648 bool filled = false;
3649 int first_xattr_slot;
3650
3651 ret = btrfs_fill_inode(inode, &rdev);
3652 if (!ret)
3653 filled = true;
3654
3655 path = btrfs_alloc_path();
3656 if (!path)
3657 goto make_bad;
3658
3659 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3660
3661 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3662 if (ret)
3663 goto make_bad;
3664
3665 leaf = path->nodes[0];
3666
3667 if (filled)
3668 goto cache_index;
3669
3670 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3671 struct btrfs_inode_item);
3672 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3673 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3674 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3675 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3676 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3677
3678 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3679 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3680
3681 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3682 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3683
3684 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3685 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3686
3687 BTRFS_I(inode)->i_otime.tv_sec =
3688 btrfs_timespec_sec(leaf, &inode_item->otime);
3689 BTRFS_I(inode)->i_otime.tv_nsec =
3690 btrfs_timespec_nsec(leaf, &inode_item->otime);
3691
3692 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3693 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3694 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3695
3696 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3697 inode->i_generation = BTRFS_I(inode)->generation;
3698 inode->i_rdev = 0;
3699 rdev = btrfs_inode_rdev(leaf, inode_item);
3700
3701 BTRFS_I(inode)->index_cnt = (u64)-1;
3702 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3703
3704 cache_index:
3705 /*
3706 * If we were modified in the current generation and evicted from memory
3707 * and then re-read we need to do a full sync since we don't have any
3708 * idea about which extents were modified before we were evicted from
3709 * cache.
3710 *
3711 * This is required for both inode re-read from disk and delayed inode
3712 * in delayed_nodes_tree.
3713 */
3714 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3715 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3716 &BTRFS_I(inode)->runtime_flags);
3717
3718 /*
3719 * We don't persist the id of the transaction where an unlink operation
3720 * against the inode was last made. So here we assume the inode might
3721 * have been evicted, and therefore the exact value of last_unlink_trans
3722 * lost, and set it to last_trans to avoid metadata inconsistencies
3723 * between the inode and its parent if the inode is fsync'ed and the log
3724 * replayed. For example, in the scenario:
3725 *
3726 * touch mydir/foo
3727 * ln mydir/foo mydir/bar
3728 * sync
3729 * unlink mydir/bar
3730 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3731 * xfs_io -c fsync mydir/foo
3732 * <power failure>
3733 * mount fs, triggers fsync log replay
3734 *
3735 * We must make sure that when we fsync our inode foo we also log its
3736 * parent inode, otherwise after log replay the parent still has the
3737 * dentry with the "bar" name but our inode foo has a link count of 1
3738 * and doesn't have an inode ref with the name "bar" anymore.
3739 *
3740 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3741 * but it guarantees correctness at the expense of occasional full
3742 * transaction commits on fsync if our inode is a directory, or if our
3743 * inode is not a directory, logging its parent unnecessarily.
3744 */
3745 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3746
3747 path->slots[0]++;
3748 if (inode->i_nlink != 1 ||
3749 path->slots[0] >= btrfs_header_nritems(leaf))
3750 goto cache_acl;
3751
3752 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3753 if (location.objectid != btrfs_ino(inode))
3754 goto cache_acl;
3755
3756 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3757 if (location.type == BTRFS_INODE_REF_KEY) {
3758 struct btrfs_inode_ref *ref;
3759
3760 ref = (struct btrfs_inode_ref *)ptr;
3761 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3762 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3763 struct btrfs_inode_extref *extref;
3764
3765 extref = (struct btrfs_inode_extref *)ptr;
3766 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3767 extref);
3768 }
3769 cache_acl:
3770 /*
3771 * try to precache a NULL acl entry for files that don't have
3772 * any xattrs or acls
3773 */
3774 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3775 btrfs_ino(inode), &first_xattr_slot);
3776 if (first_xattr_slot != -1) {
3777 path->slots[0] = first_xattr_slot;
3778 ret = btrfs_load_inode_props(inode, path);
3779 if (ret)
3780 btrfs_err(root->fs_info,
3781 "error loading props for ino %llu (root %llu): %d",
3782 btrfs_ino(inode),
3783 root->root_key.objectid, ret);
3784 }
3785 btrfs_free_path(path);
3786
3787 if (!maybe_acls)
3788 cache_no_acl(inode);
3789
3790 switch (inode->i_mode & S_IFMT) {
3791 case S_IFREG:
3792 inode->i_mapping->a_ops = &btrfs_aops;
3793 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3794 inode->i_fop = &btrfs_file_operations;
3795 inode->i_op = &btrfs_file_inode_operations;
3796 break;
3797 case S_IFDIR:
3798 inode->i_fop = &btrfs_dir_file_operations;
3799 if (root == root->fs_info->tree_root)
3800 inode->i_op = &btrfs_dir_ro_inode_operations;
3801 else
3802 inode->i_op = &btrfs_dir_inode_operations;
3803 break;
3804 case S_IFLNK:
3805 inode->i_op = &btrfs_symlink_inode_operations;
3806 inode_nohighmem(inode);
3807 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3808 break;
3809 default:
3810 inode->i_op = &btrfs_special_inode_operations;
3811 init_special_inode(inode, inode->i_mode, rdev);
3812 break;
3813 }
3814
3815 btrfs_update_iflags(inode);
3816 return;
3817
3818 make_bad:
3819 btrfs_free_path(path);
3820 make_bad_inode(inode);
3821 }
3822
3823 /*
3824 * given a leaf and an inode, copy the inode fields into the leaf
3825 */
3826 static void fill_inode_item(struct btrfs_trans_handle *trans,
3827 struct extent_buffer *leaf,
3828 struct btrfs_inode_item *item,
3829 struct inode *inode)
3830 {
3831 struct btrfs_map_token token;
3832
3833 btrfs_init_map_token(&token);
3834
3835 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3836 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3837 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3838 &token);
3839 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3840 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3841
3842 btrfs_set_token_timespec_sec(leaf, &item->atime,
3843 inode->i_atime.tv_sec, &token);
3844 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3845 inode->i_atime.tv_nsec, &token);
3846
3847 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3848 inode->i_mtime.tv_sec, &token);
3849 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3850 inode->i_mtime.tv_nsec, &token);
3851
3852 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3853 inode->i_ctime.tv_sec, &token);
3854 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3855 inode->i_ctime.tv_nsec, &token);
3856
3857 btrfs_set_token_timespec_sec(leaf, &item->otime,
3858 BTRFS_I(inode)->i_otime.tv_sec, &token);
3859 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3860 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3861
3862 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3863 &token);
3864 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3865 &token);
3866 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3867 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3868 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3869 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3870 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3871 }
3872
3873 /*
3874 * copy everything in the in-memory inode into the btree.
3875 */
3876 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3877 struct btrfs_root *root, struct inode *inode)
3878 {
3879 struct btrfs_inode_item *inode_item;
3880 struct btrfs_path *path;
3881 struct extent_buffer *leaf;
3882 int ret;
3883
3884 path = btrfs_alloc_path();
3885 if (!path)
3886 return -ENOMEM;
3887
3888 path->leave_spinning = 1;
3889 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3890 1);
3891 if (ret) {
3892 if (ret > 0)
3893 ret = -ENOENT;
3894 goto failed;
3895 }
3896
3897 leaf = path->nodes[0];
3898 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3899 struct btrfs_inode_item);
3900
3901 fill_inode_item(trans, leaf, inode_item, inode);
3902 btrfs_mark_buffer_dirty(leaf);
3903 btrfs_set_inode_last_trans(trans, inode);
3904 ret = 0;
3905 failed:
3906 btrfs_free_path(path);
3907 return ret;
3908 }
3909
3910 /*
3911 * copy everything in the in-memory inode into the btree.
3912 */
3913 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3914 struct btrfs_root *root, struct inode *inode)
3915 {
3916 int ret;
3917
3918 /*
3919 * If the inode is a free space inode, we can deadlock during commit
3920 * if we put it into the delayed code.
3921 *
3922 * The data relocation inode should also be directly updated
3923 * without delay
3924 */
3925 if (!btrfs_is_free_space_inode(inode)
3926 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3927 && !root->fs_info->log_root_recovering) {
3928 btrfs_update_root_times(trans, root);
3929
3930 ret = btrfs_delayed_update_inode(trans, root, inode);
3931 if (!ret)
3932 btrfs_set_inode_last_trans(trans, inode);
3933 return ret;
3934 }
3935
3936 return btrfs_update_inode_item(trans, root, inode);
3937 }
3938
3939 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3940 struct btrfs_root *root,
3941 struct inode *inode)
3942 {
3943 int ret;
3944
3945 ret = btrfs_update_inode(trans, root, inode);
3946 if (ret == -ENOSPC)
3947 return btrfs_update_inode_item(trans, root, inode);
3948 return ret;
3949 }
3950
3951 /*
3952 * unlink helper that gets used here in inode.c and in the tree logging
3953 * recovery code. It remove a link in a directory with a given name, and
3954 * also drops the back refs in the inode to the directory
3955 */
3956 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3957 struct btrfs_root *root,
3958 struct inode *dir, struct inode *inode,
3959 const char *name, int name_len)
3960 {
3961 struct btrfs_path *path;
3962 int ret = 0;
3963 struct extent_buffer *leaf;
3964 struct btrfs_dir_item *di;
3965 struct btrfs_key key;
3966 u64 index;
3967 u64 ino = btrfs_ino(inode);
3968 u64 dir_ino = btrfs_ino(dir);
3969
3970 path = btrfs_alloc_path();
3971 if (!path) {
3972 ret = -ENOMEM;
3973 goto out;
3974 }
3975
3976 path->leave_spinning = 1;
3977 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3978 name, name_len, -1);
3979 if (IS_ERR(di)) {
3980 ret = PTR_ERR(di);
3981 goto err;
3982 }
3983 if (!di) {
3984 ret = -ENOENT;
3985 goto err;
3986 }
3987 leaf = path->nodes[0];
3988 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3989 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3990 if (ret)
3991 goto err;
3992 btrfs_release_path(path);
3993
3994 /*
3995 * If we don't have dir index, we have to get it by looking up
3996 * the inode ref, since we get the inode ref, remove it directly,
3997 * it is unnecessary to do delayed deletion.
3998 *
3999 * But if we have dir index, needn't search inode ref to get it.
4000 * Since the inode ref is close to the inode item, it is better
4001 * that we delay to delete it, and just do this deletion when
4002 * we update the inode item.
4003 */
4004 if (BTRFS_I(inode)->dir_index) {
4005 ret = btrfs_delayed_delete_inode_ref(inode);
4006 if (!ret) {
4007 index = BTRFS_I(inode)->dir_index;
4008 goto skip_backref;
4009 }
4010 }
4011
4012 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4013 dir_ino, &index);
4014 if (ret) {
4015 btrfs_info(root->fs_info,
4016 "failed to delete reference to %.*s, inode %llu parent %llu",
4017 name_len, name, ino, dir_ino);
4018 btrfs_abort_transaction(trans, ret);
4019 goto err;
4020 }
4021 skip_backref:
4022 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4023 if (ret) {
4024 btrfs_abort_transaction(trans, ret);
4025 goto err;
4026 }
4027
4028 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4029 inode, dir_ino);
4030 if (ret != 0 && ret != -ENOENT) {
4031 btrfs_abort_transaction(trans, ret);
4032 goto err;
4033 }
4034
4035 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4036 dir, index);
4037 if (ret == -ENOENT)
4038 ret = 0;
4039 else if (ret)
4040 btrfs_abort_transaction(trans, ret);
4041 err:
4042 btrfs_free_path(path);
4043 if (ret)
4044 goto out;
4045
4046 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4047 inode_inc_iversion(inode);
4048 inode_inc_iversion(dir);
4049 inode->i_ctime = dir->i_mtime =
4050 dir->i_ctime = current_fs_time(inode->i_sb);
4051 ret = btrfs_update_inode(trans, root, dir);
4052 out:
4053 return ret;
4054 }
4055
4056 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4057 struct btrfs_root *root,
4058 struct inode *dir, struct inode *inode,
4059 const char *name, int name_len)
4060 {
4061 int ret;
4062 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4063 if (!ret) {
4064 drop_nlink(inode);
4065 ret = btrfs_update_inode(trans, root, inode);
4066 }
4067 return ret;
4068 }
4069
4070 /*
4071 * helper to start transaction for unlink and rmdir.
4072 *
4073 * unlink and rmdir are special in btrfs, they do not always free space, so
4074 * if we cannot make our reservations the normal way try and see if there is
4075 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4076 * allow the unlink to occur.
4077 */
4078 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4079 {
4080 struct btrfs_root *root = BTRFS_I(dir)->root;
4081
4082 /*
4083 * 1 for the possible orphan item
4084 * 1 for the dir item
4085 * 1 for the dir index
4086 * 1 for the inode ref
4087 * 1 for the inode
4088 */
4089 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4090 }
4091
4092 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4093 {
4094 struct btrfs_root *root = BTRFS_I(dir)->root;
4095 struct btrfs_trans_handle *trans;
4096 struct inode *inode = d_inode(dentry);
4097 int ret;
4098
4099 trans = __unlink_start_trans(dir);
4100 if (IS_ERR(trans))
4101 return PTR_ERR(trans);
4102
4103 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4104
4105 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4106 dentry->d_name.name, dentry->d_name.len);
4107 if (ret)
4108 goto out;
4109
4110 if (inode->i_nlink == 0) {
4111 ret = btrfs_orphan_add(trans, inode);
4112 if (ret)
4113 goto out;
4114 }
4115
4116 out:
4117 btrfs_end_transaction(trans, root);
4118 btrfs_btree_balance_dirty(root);
4119 return ret;
4120 }
4121
4122 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4123 struct btrfs_root *root,
4124 struct inode *dir, u64 objectid,
4125 const char *name, int name_len)
4126 {
4127 struct btrfs_path *path;
4128 struct extent_buffer *leaf;
4129 struct btrfs_dir_item *di;
4130 struct btrfs_key key;
4131 u64 index;
4132 int ret;
4133 u64 dir_ino = btrfs_ino(dir);
4134
4135 path = btrfs_alloc_path();
4136 if (!path)
4137 return -ENOMEM;
4138
4139 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4140 name, name_len, -1);
4141 if (IS_ERR_OR_NULL(di)) {
4142 if (!di)
4143 ret = -ENOENT;
4144 else
4145 ret = PTR_ERR(di);
4146 goto out;
4147 }
4148
4149 leaf = path->nodes[0];
4150 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4151 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4152 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4153 if (ret) {
4154 btrfs_abort_transaction(trans, ret);
4155 goto out;
4156 }
4157 btrfs_release_path(path);
4158
4159 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4160 objectid, root->root_key.objectid,
4161 dir_ino, &index, name, name_len);
4162 if (ret < 0) {
4163 if (ret != -ENOENT) {
4164 btrfs_abort_transaction(trans, ret);
4165 goto out;
4166 }
4167 di = btrfs_search_dir_index_item(root, path, dir_ino,
4168 name, name_len);
4169 if (IS_ERR_OR_NULL(di)) {
4170 if (!di)
4171 ret = -ENOENT;
4172 else
4173 ret = PTR_ERR(di);
4174 btrfs_abort_transaction(trans, ret);
4175 goto out;
4176 }
4177
4178 leaf = path->nodes[0];
4179 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4180 btrfs_release_path(path);
4181 index = key.offset;
4182 }
4183 btrfs_release_path(path);
4184
4185 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4186 if (ret) {
4187 btrfs_abort_transaction(trans, ret);
4188 goto out;
4189 }
4190
4191 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4192 inode_inc_iversion(dir);
4193 dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
4194 ret = btrfs_update_inode_fallback(trans, root, dir);
4195 if (ret)
4196 btrfs_abort_transaction(trans, ret);
4197 out:
4198 btrfs_free_path(path);
4199 return ret;
4200 }
4201
4202 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4203 {
4204 struct inode *inode = d_inode(dentry);
4205 int err = 0;
4206 struct btrfs_root *root = BTRFS_I(dir)->root;
4207 struct btrfs_trans_handle *trans;
4208
4209 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4210 return -ENOTEMPTY;
4211 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4212 return -EPERM;
4213
4214 trans = __unlink_start_trans(dir);
4215 if (IS_ERR(trans))
4216 return PTR_ERR(trans);
4217
4218 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4219 err = btrfs_unlink_subvol(trans, root, dir,
4220 BTRFS_I(inode)->location.objectid,
4221 dentry->d_name.name,
4222 dentry->d_name.len);
4223 goto out;
4224 }
4225
4226 err = btrfs_orphan_add(trans, inode);
4227 if (err)
4228 goto out;
4229
4230 /* now the directory is empty */
4231 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4232 dentry->d_name.name, dentry->d_name.len);
4233 if (!err)
4234 btrfs_i_size_write(inode, 0);
4235 out:
4236 btrfs_end_transaction(trans, root);
4237 btrfs_btree_balance_dirty(root);
4238
4239 return err;
4240 }
4241
4242 static int truncate_space_check(struct btrfs_trans_handle *trans,
4243 struct btrfs_root *root,
4244 u64 bytes_deleted)
4245 {
4246 int ret;
4247
4248 /*
4249 * This is only used to apply pressure to the enospc system, we don't
4250 * intend to use this reservation at all.
4251 */
4252 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4253 bytes_deleted *= root->nodesize;
4254 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4255 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4256 if (!ret) {
4257 trace_btrfs_space_reservation(root->fs_info, "transaction",
4258 trans->transid,
4259 bytes_deleted, 1);
4260 trans->bytes_reserved += bytes_deleted;
4261 }
4262 return ret;
4263
4264 }
4265
4266 static int truncate_inline_extent(struct inode *inode,
4267 struct btrfs_path *path,
4268 struct btrfs_key *found_key,
4269 const u64 item_end,
4270 const u64 new_size)
4271 {
4272 struct extent_buffer *leaf = path->nodes[0];
4273 int slot = path->slots[0];
4274 struct btrfs_file_extent_item *fi;
4275 u32 size = (u32)(new_size - found_key->offset);
4276 struct btrfs_root *root = BTRFS_I(inode)->root;
4277
4278 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4279
4280 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4281 loff_t offset = new_size;
4282 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4283
4284 /*
4285 * Zero out the remaining of the last page of our inline extent,
4286 * instead of directly truncating our inline extent here - that
4287 * would be much more complex (decompressing all the data, then
4288 * compressing the truncated data, which might be bigger than
4289 * the size of the inline extent, resize the extent, etc).
4290 * We release the path because to get the page we might need to
4291 * read the extent item from disk (data not in the page cache).
4292 */
4293 btrfs_release_path(path);
4294 return btrfs_truncate_block(inode, offset, page_end - offset,
4295 0);
4296 }
4297
4298 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4299 size = btrfs_file_extent_calc_inline_size(size);
4300 btrfs_truncate_item(root, path, size, 1);
4301
4302 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4303 inode_sub_bytes(inode, item_end + 1 - new_size);
4304
4305 return 0;
4306 }
4307
4308 /*
4309 * this can truncate away extent items, csum items and directory items.
4310 * It starts at a high offset and removes keys until it can't find
4311 * any higher than new_size
4312 *
4313 * csum items that cross the new i_size are truncated to the new size
4314 * as well.
4315 *
4316 * min_type is the minimum key type to truncate down to. If set to 0, this
4317 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4318 */
4319 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4320 struct btrfs_root *root,
4321 struct inode *inode,
4322 u64 new_size, u32 min_type)
4323 {
4324 struct btrfs_path *path;
4325 struct extent_buffer *leaf;
4326 struct btrfs_file_extent_item *fi;
4327 struct btrfs_key key;
4328 struct btrfs_key found_key;
4329 u64 extent_start = 0;
4330 u64 extent_num_bytes = 0;
4331 u64 extent_offset = 0;
4332 u64 item_end = 0;
4333 u64 last_size = new_size;
4334 u32 found_type = (u8)-1;
4335 int found_extent;
4336 int del_item;
4337 int pending_del_nr = 0;
4338 int pending_del_slot = 0;
4339 int extent_type = -1;
4340 int ret;
4341 int err = 0;
4342 u64 ino = btrfs_ino(inode);
4343 u64 bytes_deleted = 0;
4344 bool be_nice = 0;
4345 bool should_throttle = 0;
4346 bool should_end = 0;
4347
4348 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4349
4350 /*
4351 * for non-free space inodes and ref cows, we want to back off from
4352 * time to time
4353 */
4354 if (!btrfs_is_free_space_inode(inode) &&
4355 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4356 be_nice = 1;
4357
4358 path = btrfs_alloc_path();
4359 if (!path)
4360 return -ENOMEM;
4361 path->reada = READA_BACK;
4362
4363 /*
4364 * We want to drop from the next block forward in case this new size is
4365 * not block aligned since we will be keeping the last block of the
4366 * extent just the way it is.
4367 */
4368 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4369 root == root->fs_info->tree_root)
4370 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4371 root->sectorsize), (u64)-1, 0);
4372
4373 /*
4374 * This function is also used to drop the items in the log tree before
4375 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4376 * it is used to drop the loged items. So we shouldn't kill the delayed
4377 * items.
4378 */
4379 if (min_type == 0 && root == BTRFS_I(inode)->root)
4380 btrfs_kill_delayed_inode_items(inode);
4381
4382 key.objectid = ino;
4383 key.offset = (u64)-1;
4384 key.type = (u8)-1;
4385
4386 search_again:
4387 /*
4388 * with a 16K leaf size and 128MB extents, you can actually queue
4389 * up a huge file in a single leaf. Most of the time that
4390 * bytes_deleted is > 0, it will be huge by the time we get here
4391 */
4392 if (be_nice && bytes_deleted > SZ_32M) {
4393 if (btrfs_should_end_transaction(trans, root)) {
4394 err = -EAGAIN;
4395 goto error;
4396 }
4397 }
4398
4399
4400 path->leave_spinning = 1;
4401 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4402 if (ret < 0) {
4403 err = ret;
4404 goto out;
4405 }
4406
4407 if (ret > 0) {
4408 /* there are no items in the tree for us to truncate, we're
4409 * done
4410 */
4411 if (path->slots[0] == 0)
4412 goto out;
4413 path->slots[0]--;
4414 }
4415
4416 while (1) {
4417 fi = NULL;
4418 leaf = path->nodes[0];
4419 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4420 found_type = found_key.type;
4421
4422 if (found_key.objectid != ino)
4423 break;
4424
4425 if (found_type < min_type)
4426 break;
4427
4428 item_end = found_key.offset;
4429 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4430 fi = btrfs_item_ptr(leaf, path->slots[0],
4431 struct btrfs_file_extent_item);
4432 extent_type = btrfs_file_extent_type(leaf, fi);
4433 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4434 item_end +=
4435 btrfs_file_extent_num_bytes(leaf, fi);
4436 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4437 item_end += btrfs_file_extent_inline_len(leaf,
4438 path->slots[0], fi);
4439 }
4440 item_end--;
4441 }
4442 if (found_type > min_type) {
4443 del_item = 1;
4444 } else {
4445 if (item_end < new_size)
4446 break;
4447 if (found_key.offset >= new_size)
4448 del_item = 1;
4449 else
4450 del_item = 0;
4451 }
4452 found_extent = 0;
4453 /* FIXME, shrink the extent if the ref count is only 1 */
4454 if (found_type != BTRFS_EXTENT_DATA_KEY)
4455 goto delete;
4456
4457 if (del_item)
4458 last_size = found_key.offset;
4459 else
4460 last_size = new_size;
4461
4462 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4463 u64 num_dec;
4464 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4465 if (!del_item) {
4466 u64 orig_num_bytes =
4467 btrfs_file_extent_num_bytes(leaf, fi);
4468 extent_num_bytes = ALIGN(new_size -
4469 found_key.offset,
4470 root->sectorsize);
4471 btrfs_set_file_extent_num_bytes(leaf, fi,
4472 extent_num_bytes);
4473 num_dec = (orig_num_bytes -
4474 extent_num_bytes);
4475 if (test_bit(BTRFS_ROOT_REF_COWS,
4476 &root->state) &&
4477 extent_start != 0)
4478 inode_sub_bytes(inode, num_dec);
4479 btrfs_mark_buffer_dirty(leaf);
4480 } else {
4481 extent_num_bytes =
4482 btrfs_file_extent_disk_num_bytes(leaf,
4483 fi);
4484 extent_offset = found_key.offset -
4485 btrfs_file_extent_offset(leaf, fi);
4486
4487 /* FIXME blocksize != 4096 */
4488 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4489 if (extent_start != 0) {
4490 found_extent = 1;
4491 if (test_bit(BTRFS_ROOT_REF_COWS,
4492 &root->state))
4493 inode_sub_bytes(inode, num_dec);
4494 }
4495 }
4496 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4497 /*
4498 * we can't truncate inline items that have had
4499 * special encodings
4500 */
4501 if (!del_item &&
4502 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4503 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4504
4505 /*
4506 * Need to release path in order to truncate a
4507 * compressed extent. So delete any accumulated
4508 * extent items so far.
4509 */
4510 if (btrfs_file_extent_compression(leaf, fi) !=
4511 BTRFS_COMPRESS_NONE && pending_del_nr) {
4512 err = btrfs_del_items(trans, root, path,
4513 pending_del_slot,
4514 pending_del_nr);
4515 if (err) {
4516 btrfs_abort_transaction(trans,
4517 err);
4518 goto error;
4519 }
4520 pending_del_nr = 0;
4521 }
4522
4523 err = truncate_inline_extent(inode, path,
4524 &found_key,
4525 item_end,
4526 new_size);
4527 if (err) {
4528 btrfs_abort_transaction(trans, err);
4529 goto error;
4530 }
4531 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4532 &root->state)) {
4533 inode_sub_bytes(inode, item_end + 1 - new_size);
4534 }
4535 }
4536 delete:
4537 if (del_item) {
4538 if (!pending_del_nr) {
4539 /* no pending yet, add ourselves */
4540 pending_del_slot = path->slots[0];
4541 pending_del_nr = 1;
4542 } else if (pending_del_nr &&
4543 path->slots[0] + 1 == pending_del_slot) {
4544 /* hop on the pending chunk */
4545 pending_del_nr++;
4546 pending_del_slot = path->slots[0];
4547 } else {
4548 BUG();
4549 }
4550 } else {
4551 break;
4552 }
4553 should_throttle = 0;
4554
4555 if (found_extent &&
4556 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4557 root == root->fs_info->tree_root)) {
4558 btrfs_set_path_blocking(path);
4559 bytes_deleted += extent_num_bytes;
4560 ret = btrfs_free_extent(trans, root, extent_start,
4561 extent_num_bytes, 0,
4562 btrfs_header_owner(leaf),
4563 ino, extent_offset);
4564 BUG_ON(ret);
4565 if (btrfs_should_throttle_delayed_refs(trans, root))
4566 btrfs_async_run_delayed_refs(root,
4567 trans->transid,
4568 trans->delayed_ref_updates * 2, 0);
4569 if (be_nice) {
4570 if (truncate_space_check(trans, root,
4571 extent_num_bytes)) {
4572 should_end = 1;
4573 }
4574 if (btrfs_should_throttle_delayed_refs(trans,
4575 root)) {
4576 should_throttle = 1;
4577 }
4578 }
4579 }
4580
4581 if (found_type == BTRFS_INODE_ITEM_KEY)
4582 break;
4583
4584 if (path->slots[0] == 0 ||
4585 path->slots[0] != pending_del_slot ||
4586 should_throttle || should_end) {
4587 if (pending_del_nr) {
4588 ret = btrfs_del_items(trans, root, path,
4589 pending_del_slot,
4590 pending_del_nr);
4591 if (ret) {
4592 btrfs_abort_transaction(trans, ret);
4593 goto error;
4594 }
4595 pending_del_nr = 0;
4596 }
4597 btrfs_release_path(path);
4598 if (should_throttle) {
4599 unsigned long updates = trans->delayed_ref_updates;
4600 if (updates) {
4601 trans->delayed_ref_updates = 0;
4602 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4603 if (ret && !err)
4604 err = ret;
4605 }
4606 }
4607 /*
4608 * if we failed to refill our space rsv, bail out
4609 * and let the transaction restart
4610 */
4611 if (should_end) {
4612 err = -EAGAIN;
4613 goto error;
4614 }
4615 goto search_again;
4616 } else {
4617 path->slots[0]--;
4618 }
4619 }
4620 out:
4621 if (pending_del_nr) {
4622 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4623 pending_del_nr);
4624 if (ret)
4625 btrfs_abort_transaction(trans, ret);
4626 }
4627 error:
4628 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4629 btrfs_ordered_update_i_size(inode, last_size, NULL);
4630
4631 btrfs_free_path(path);
4632
4633 if (be_nice && bytes_deleted > SZ_32M) {
4634 unsigned long updates = trans->delayed_ref_updates;
4635 if (updates) {
4636 trans->delayed_ref_updates = 0;
4637 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4638 if (ret && !err)
4639 err = ret;
4640 }
4641 }
4642 return err;
4643 }
4644
4645 /*
4646 * btrfs_truncate_block - read, zero a chunk and write a block
4647 * @inode - inode that we're zeroing
4648 * @from - the offset to start zeroing
4649 * @len - the length to zero, 0 to zero the entire range respective to the
4650 * offset
4651 * @front - zero up to the offset instead of from the offset on
4652 *
4653 * This will find the block for the "from" offset and cow the block and zero the
4654 * part we want to zero. This is used with truncate and hole punching.
4655 */
4656 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4657 int front)
4658 {
4659 struct address_space *mapping = inode->i_mapping;
4660 struct btrfs_root *root = BTRFS_I(inode)->root;
4661 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4662 struct btrfs_ordered_extent *ordered;
4663 struct extent_state *cached_state = NULL;
4664 char *kaddr;
4665 u32 blocksize = root->sectorsize;
4666 pgoff_t index = from >> PAGE_SHIFT;
4667 unsigned offset = from & (blocksize - 1);
4668 struct page *page;
4669 gfp_t mask = btrfs_alloc_write_mask(mapping);
4670 int ret = 0;
4671 u64 block_start;
4672 u64 block_end;
4673
4674 if ((offset & (blocksize - 1)) == 0 &&
4675 (!len || ((len & (blocksize - 1)) == 0)))
4676 goto out;
4677
4678 ret = btrfs_delalloc_reserve_space(inode,
4679 round_down(from, blocksize), blocksize);
4680 if (ret)
4681 goto out;
4682
4683 again:
4684 page = find_or_create_page(mapping, index, mask);
4685 if (!page) {
4686 btrfs_delalloc_release_space(inode,
4687 round_down(from, blocksize),
4688 blocksize);
4689 ret = -ENOMEM;
4690 goto out;
4691 }
4692
4693 block_start = round_down(from, blocksize);
4694 block_end = block_start + blocksize - 1;
4695
4696 if (!PageUptodate(page)) {
4697 ret = btrfs_readpage(NULL, page);
4698 lock_page(page);
4699 if (page->mapping != mapping) {
4700 unlock_page(page);
4701 put_page(page);
4702 goto again;
4703 }
4704 if (!PageUptodate(page)) {
4705 ret = -EIO;
4706 goto out_unlock;
4707 }
4708 }
4709 wait_on_page_writeback(page);
4710
4711 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4712 set_page_extent_mapped(page);
4713
4714 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4715 if (ordered) {
4716 unlock_extent_cached(io_tree, block_start, block_end,
4717 &cached_state, GFP_NOFS);
4718 unlock_page(page);
4719 put_page(page);
4720 btrfs_start_ordered_extent(inode, ordered, 1);
4721 btrfs_put_ordered_extent(ordered);
4722 goto again;
4723 }
4724
4725 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4726 EXTENT_DIRTY | EXTENT_DELALLOC |
4727 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4728 0, 0, &cached_state, GFP_NOFS);
4729
4730 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4731 &cached_state);
4732 if (ret) {
4733 unlock_extent_cached(io_tree, block_start, block_end,
4734 &cached_state, GFP_NOFS);
4735 goto out_unlock;
4736 }
4737
4738 if (offset != blocksize) {
4739 if (!len)
4740 len = blocksize - offset;
4741 kaddr = kmap(page);
4742 if (front)
4743 memset(kaddr + (block_start - page_offset(page)),
4744 0, offset);
4745 else
4746 memset(kaddr + (block_start - page_offset(page)) + offset,
4747 0, len);
4748 flush_dcache_page(page);
4749 kunmap(page);
4750 }
4751 ClearPageChecked(page);
4752 set_page_dirty(page);
4753 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4754 GFP_NOFS);
4755
4756 out_unlock:
4757 if (ret)
4758 btrfs_delalloc_release_space(inode, block_start,
4759 blocksize);
4760 unlock_page(page);
4761 put_page(page);
4762 out:
4763 return ret;
4764 }
4765
4766 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4767 u64 offset, u64 len)
4768 {
4769 struct btrfs_trans_handle *trans;
4770 int ret;
4771
4772 /*
4773 * Still need to make sure the inode looks like it's been updated so
4774 * that any holes get logged if we fsync.
4775 */
4776 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4777 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4778 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4779 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4780 return 0;
4781 }
4782
4783 /*
4784 * 1 - for the one we're dropping
4785 * 1 - for the one we're adding
4786 * 1 - for updating the inode.
4787 */
4788 trans = btrfs_start_transaction(root, 3);
4789 if (IS_ERR(trans))
4790 return PTR_ERR(trans);
4791
4792 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4793 if (ret) {
4794 btrfs_abort_transaction(trans, ret);
4795 btrfs_end_transaction(trans, root);
4796 return ret;
4797 }
4798
4799 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4800 0, 0, len, 0, len, 0, 0, 0);
4801 if (ret)
4802 btrfs_abort_transaction(trans, ret);
4803 else
4804 btrfs_update_inode(trans, root, inode);
4805 btrfs_end_transaction(trans, root);
4806 return ret;
4807 }
4808
4809 /*
4810 * This function puts in dummy file extents for the area we're creating a hole
4811 * for. So if we are truncating this file to a larger size we need to insert
4812 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4813 * the range between oldsize and size
4814 */
4815 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4816 {
4817 struct btrfs_root *root = BTRFS_I(inode)->root;
4818 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4819 struct extent_map *em = NULL;
4820 struct extent_state *cached_state = NULL;
4821 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4822 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4823 u64 block_end = ALIGN(size, root->sectorsize);
4824 u64 last_byte;
4825 u64 cur_offset;
4826 u64 hole_size;
4827 int err = 0;
4828
4829 /*
4830 * If our size started in the middle of a block we need to zero out the
4831 * rest of the block before we expand the i_size, otherwise we could
4832 * expose stale data.
4833 */
4834 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4835 if (err)
4836 return err;
4837
4838 if (size <= hole_start)
4839 return 0;
4840
4841 while (1) {
4842 struct btrfs_ordered_extent *ordered;
4843
4844 lock_extent_bits(io_tree, hole_start, block_end - 1,
4845 &cached_state);
4846 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4847 block_end - hole_start);
4848 if (!ordered)
4849 break;
4850 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4851 &cached_state, GFP_NOFS);
4852 btrfs_start_ordered_extent(inode, ordered, 1);
4853 btrfs_put_ordered_extent(ordered);
4854 }
4855
4856 cur_offset = hole_start;
4857 while (1) {
4858 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4859 block_end - cur_offset, 0);
4860 if (IS_ERR(em)) {
4861 err = PTR_ERR(em);
4862 em = NULL;
4863 break;
4864 }
4865 last_byte = min(extent_map_end(em), block_end);
4866 last_byte = ALIGN(last_byte , root->sectorsize);
4867 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4868 struct extent_map *hole_em;
4869 hole_size = last_byte - cur_offset;
4870
4871 err = maybe_insert_hole(root, inode, cur_offset,
4872 hole_size);
4873 if (err)
4874 break;
4875 btrfs_drop_extent_cache(inode, cur_offset,
4876 cur_offset + hole_size - 1, 0);
4877 hole_em = alloc_extent_map();
4878 if (!hole_em) {
4879 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4880 &BTRFS_I(inode)->runtime_flags);
4881 goto next;
4882 }
4883 hole_em->start = cur_offset;
4884 hole_em->len = hole_size;
4885 hole_em->orig_start = cur_offset;
4886
4887 hole_em->block_start = EXTENT_MAP_HOLE;
4888 hole_em->block_len = 0;
4889 hole_em->orig_block_len = 0;
4890 hole_em->ram_bytes = hole_size;
4891 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4892 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4893 hole_em->generation = root->fs_info->generation;
4894
4895 while (1) {
4896 write_lock(&em_tree->lock);
4897 err = add_extent_mapping(em_tree, hole_em, 1);
4898 write_unlock(&em_tree->lock);
4899 if (err != -EEXIST)
4900 break;
4901 btrfs_drop_extent_cache(inode, cur_offset,
4902 cur_offset +
4903 hole_size - 1, 0);
4904 }
4905 free_extent_map(hole_em);
4906 }
4907 next:
4908 free_extent_map(em);
4909 em = NULL;
4910 cur_offset = last_byte;
4911 if (cur_offset >= block_end)
4912 break;
4913 }
4914 free_extent_map(em);
4915 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4916 GFP_NOFS);
4917 return err;
4918 }
4919
4920 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4921 {
4922 struct btrfs_root *root = BTRFS_I(inode)->root;
4923 struct btrfs_trans_handle *trans;
4924 loff_t oldsize = i_size_read(inode);
4925 loff_t newsize = attr->ia_size;
4926 int mask = attr->ia_valid;
4927 int ret;
4928
4929 /*
4930 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4931 * special case where we need to update the times despite not having
4932 * these flags set. For all other operations the VFS set these flags
4933 * explicitly if it wants a timestamp update.
4934 */
4935 if (newsize != oldsize) {
4936 inode_inc_iversion(inode);
4937 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4938 inode->i_ctime = inode->i_mtime =
4939 current_fs_time(inode->i_sb);
4940 }
4941
4942 if (newsize > oldsize) {
4943 /*
4944 * Don't do an expanding truncate while snapshoting is ongoing.
4945 * This is to ensure the snapshot captures a fully consistent
4946 * state of this file - if the snapshot captures this expanding
4947 * truncation, it must capture all writes that happened before
4948 * this truncation.
4949 */
4950 btrfs_wait_for_snapshot_creation(root);
4951 ret = btrfs_cont_expand(inode, oldsize, newsize);
4952 if (ret) {
4953 btrfs_end_write_no_snapshoting(root);
4954 return ret;
4955 }
4956
4957 trans = btrfs_start_transaction(root, 1);
4958 if (IS_ERR(trans)) {
4959 btrfs_end_write_no_snapshoting(root);
4960 return PTR_ERR(trans);
4961 }
4962
4963 i_size_write(inode, newsize);
4964 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4965 pagecache_isize_extended(inode, oldsize, newsize);
4966 ret = btrfs_update_inode(trans, root, inode);
4967 btrfs_end_write_no_snapshoting(root);
4968 btrfs_end_transaction(trans, root);
4969 } else {
4970
4971 /*
4972 * We're truncating a file that used to have good data down to
4973 * zero. Make sure it gets into the ordered flush list so that
4974 * any new writes get down to disk quickly.
4975 */
4976 if (newsize == 0)
4977 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4978 &BTRFS_I(inode)->runtime_flags);
4979
4980 /*
4981 * 1 for the orphan item we're going to add
4982 * 1 for the orphan item deletion.
4983 */
4984 trans = btrfs_start_transaction(root, 2);
4985 if (IS_ERR(trans))
4986 return PTR_ERR(trans);
4987
4988 /*
4989 * We need to do this in case we fail at _any_ point during the
4990 * actual truncate. Once we do the truncate_setsize we could
4991 * invalidate pages which forces any outstanding ordered io to
4992 * be instantly completed which will give us extents that need
4993 * to be truncated. If we fail to get an orphan inode down we
4994 * could have left over extents that were never meant to live,
4995 * so we need to guarantee from this point on that everything
4996 * will be consistent.
4997 */
4998 ret = btrfs_orphan_add(trans, inode);
4999 btrfs_end_transaction(trans, root);
5000 if (ret)
5001 return ret;
5002
5003 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5004 truncate_setsize(inode, newsize);
5005
5006 /* Disable nonlocked read DIO to avoid the end less truncate */
5007 btrfs_inode_block_unlocked_dio(inode);
5008 inode_dio_wait(inode);
5009 btrfs_inode_resume_unlocked_dio(inode);
5010
5011 ret = btrfs_truncate(inode);
5012 if (ret && inode->i_nlink) {
5013 int err;
5014
5015 /*
5016 * failed to truncate, disk_i_size is only adjusted down
5017 * as we remove extents, so it should represent the true
5018 * size of the inode, so reset the in memory size and
5019 * delete our orphan entry.
5020 */
5021 trans = btrfs_join_transaction(root);
5022 if (IS_ERR(trans)) {
5023 btrfs_orphan_del(NULL, inode);
5024 return ret;
5025 }
5026 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5027 err = btrfs_orphan_del(trans, inode);
5028 if (err)
5029 btrfs_abort_transaction(trans, err);
5030 btrfs_end_transaction(trans, root);
5031 }
5032 }
5033
5034 return ret;
5035 }
5036
5037 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5038 {
5039 struct inode *inode = d_inode(dentry);
5040 struct btrfs_root *root = BTRFS_I(inode)->root;
5041 int err;
5042
5043 if (btrfs_root_readonly(root))
5044 return -EROFS;
5045
5046 err = inode_change_ok(inode, attr);
5047 if (err)
5048 return err;
5049
5050 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5051 err = btrfs_setsize(inode, attr);
5052 if (err)
5053 return err;
5054 }
5055
5056 if (attr->ia_valid) {
5057 setattr_copy(inode, attr);
5058 inode_inc_iversion(inode);
5059 err = btrfs_dirty_inode(inode);
5060
5061 if (!err && attr->ia_valid & ATTR_MODE)
5062 err = posix_acl_chmod(inode, inode->i_mode);
5063 }
5064
5065 return err;
5066 }
5067
5068 /*
5069 * While truncating the inode pages during eviction, we get the VFS calling
5070 * btrfs_invalidatepage() against each page of the inode. This is slow because
5071 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5072 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5073 * extent_state structures over and over, wasting lots of time.
5074 *
5075 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5076 * those expensive operations on a per page basis and do only the ordered io
5077 * finishing, while we release here the extent_map and extent_state structures,
5078 * without the excessive merging and splitting.
5079 */
5080 static void evict_inode_truncate_pages(struct inode *inode)
5081 {
5082 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5083 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5084 struct rb_node *node;
5085
5086 ASSERT(inode->i_state & I_FREEING);
5087 truncate_inode_pages_final(&inode->i_data);
5088
5089 write_lock(&map_tree->lock);
5090 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5091 struct extent_map *em;
5092
5093 node = rb_first(&map_tree->map);
5094 em = rb_entry(node, struct extent_map, rb_node);
5095 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5096 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5097 remove_extent_mapping(map_tree, em);
5098 free_extent_map(em);
5099 if (need_resched()) {
5100 write_unlock(&map_tree->lock);
5101 cond_resched();
5102 write_lock(&map_tree->lock);
5103 }
5104 }
5105 write_unlock(&map_tree->lock);
5106
5107 /*
5108 * Keep looping until we have no more ranges in the io tree.
5109 * We can have ongoing bios started by readpages (called from readahead)
5110 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5111 * still in progress (unlocked the pages in the bio but did not yet
5112 * unlocked the ranges in the io tree). Therefore this means some
5113 * ranges can still be locked and eviction started because before
5114 * submitting those bios, which are executed by a separate task (work
5115 * queue kthread), inode references (inode->i_count) were not taken
5116 * (which would be dropped in the end io callback of each bio).
5117 * Therefore here we effectively end up waiting for those bios and
5118 * anyone else holding locked ranges without having bumped the inode's
5119 * reference count - if we don't do it, when they access the inode's
5120 * io_tree to unlock a range it may be too late, leading to an
5121 * use-after-free issue.
5122 */
5123 spin_lock(&io_tree->lock);
5124 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5125 struct extent_state *state;
5126 struct extent_state *cached_state = NULL;
5127 u64 start;
5128 u64 end;
5129
5130 node = rb_first(&io_tree->state);
5131 state = rb_entry(node, struct extent_state, rb_node);
5132 start = state->start;
5133 end = state->end;
5134 spin_unlock(&io_tree->lock);
5135
5136 lock_extent_bits(io_tree, start, end, &cached_state);
5137
5138 /*
5139 * If still has DELALLOC flag, the extent didn't reach disk,
5140 * and its reserved space won't be freed by delayed_ref.
5141 * So we need to free its reserved space here.
5142 * (Refer to comment in btrfs_invalidatepage, case 2)
5143 *
5144 * Note, end is the bytenr of last byte, so we need + 1 here.
5145 */
5146 if (state->state & EXTENT_DELALLOC)
5147 btrfs_qgroup_free_data(inode, start, end - start + 1);
5148
5149 clear_extent_bit(io_tree, start, end,
5150 EXTENT_LOCKED | EXTENT_DIRTY |
5151 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5152 EXTENT_DEFRAG, 1, 1,
5153 &cached_state, GFP_NOFS);
5154
5155 cond_resched();
5156 spin_lock(&io_tree->lock);
5157 }
5158 spin_unlock(&io_tree->lock);
5159 }
5160
5161 void btrfs_evict_inode(struct inode *inode)
5162 {
5163 struct btrfs_trans_handle *trans;
5164 struct btrfs_root *root = BTRFS_I(inode)->root;
5165 struct btrfs_block_rsv *rsv, *global_rsv;
5166 int steal_from_global = 0;
5167 u64 min_size;
5168 int ret;
5169
5170 trace_btrfs_inode_evict(inode);
5171
5172 if (!root) {
5173 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5174 return;
5175 }
5176
5177 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5178
5179 evict_inode_truncate_pages(inode);
5180
5181 if (inode->i_nlink &&
5182 ((btrfs_root_refs(&root->root_item) != 0 &&
5183 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5184 btrfs_is_free_space_inode(inode)))
5185 goto no_delete;
5186
5187 if (is_bad_inode(inode)) {
5188 btrfs_orphan_del(NULL, inode);
5189 goto no_delete;
5190 }
5191 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5192 if (!special_file(inode->i_mode))
5193 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5194
5195 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5196
5197 if (root->fs_info->log_root_recovering) {
5198 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5199 &BTRFS_I(inode)->runtime_flags));
5200 goto no_delete;
5201 }
5202
5203 if (inode->i_nlink > 0) {
5204 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5205 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5206 goto no_delete;
5207 }
5208
5209 ret = btrfs_commit_inode_delayed_inode(inode);
5210 if (ret) {
5211 btrfs_orphan_del(NULL, inode);
5212 goto no_delete;
5213 }
5214
5215 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5216 if (!rsv) {
5217 btrfs_orphan_del(NULL, inode);
5218 goto no_delete;
5219 }
5220 rsv->size = min_size;
5221 rsv->failfast = 1;
5222 global_rsv = &root->fs_info->global_block_rsv;
5223
5224 btrfs_i_size_write(inode, 0);
5225
5226 /*
5227 * This is a bit simpler than btrfs_truncate since we've already
5228 * reserved our space for our orphan item in the unlink, so we just
5229 * need to reserve some slack space in case we add bytes and update
5230 * inode item when doing the truncate.
5231 */
5232 while (1) {
5233 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5234 BTRFS_RESERVE_FLUSH_LIMIT);
5235
5236 /*
5237 * Try and steal from the global reserve since we will
5238 * likely not use this space anyway, we want to try as
5239 * hard as possible to get this to work.
5240 */
5241 if (ret)
5242 steal_from_global++;
5243 else
5244 steal_from_global = 0;
5245 ret = 0;
5246
5247 /*
5248 * steal_from_global == 0: we reserved stuff, hooray!
5249 * steal_from_global == 1: we didn't reserve stuff, boo!
5250 * steal_from_global == 2: we've committed, still not a lot of
5251 * room but maybe we'll have room in the global reserve this
5252 * time.
5253 * steal_from_global == 3: abandon all hope!
5254 */
5255 if (steal_from_global > 2) {
5256 btrfs_warn(root->fs_info,
5257 "Could not get space for a delete, will truncate on mount %d",
5258 ret);
5259 btrfs_orphan_del(NULL, inode);
5260 btrfs_free_block_rsv(root, rsv);
5261 goto no_delete;
5262 }
5263
5264 trans = btrfs_join_transaction(root);
5265 if (IS_ERR(trans)) {
5266 btrfs_orphan_del(NULL, inode);
5267 btrfs_free_block_rsv(root, rsv);
5268 goto no_delete;
5269 }
5270
5271 /*
5272 * We can't just steal from the global reserve, we need to make
5273 * sure there is room to do it, if not we need to commit and try
5274 * again.
5275 */
5276 if (steal_from_global) {
5277 if (!btrfs_check_space_for_delayed_refs(trans, root))
5278 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5279 min_size, 0);
5280 else
5281 ret = -ENOSPC;
5282 }
5283
5284 /*
5285 * Couldn't steal from the global reserve, we have too much
5286 * pending stuff built up, commit the transaction and try it
5287 * again.
5288 */
5289 if (ret) {
5290 ret = btrfs_commit_transaction(trans, root);
5291 if (ret) {
5292 btrfs_orphan_del(NULL, inode);
5293 btrfs_free_block_rsv(root, rsv);
5294 goto no_delete;
5295 }
5296 continue;
5297 } else {
5298 steal_from_global = 0;
5299 }
5300
5301 trans->block_rsv = rsv;
5302
5303 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5304 if (ret != -ENOSPC && ret != -EAGAIN)
5305 break;
5306
5307 trans->block_rsv = &root->fs_info->trans_block_rsv;
5308 btrfs_end_transaction(trans, root);
5309 trans = NULL;
5310 btrfs_btree_balance_dirty(root);
5311 }
5312
5313 btrfs_free_block_rsv(root, rsv);
5314
5315 /*
5316 * Errors here aren't a big deal, it just means we leave orphan items
5317 * in the tree. They will be cleaned up on the next mount.
5318 */
5319 if (ret == 0) {
5320 trans->block_rsv = root->orphan_block_rsv;
5321 btrfs_orphan_del(trans, inode);
5322 } else {
5323 btrfs_orphan_del(NULL, inode);
5324 }
5325
5326 trans->block_rsv = &root->fs_info->trans_block_rsv;
5327 if (!(root == root->fs_info->tree_root ||
5328 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5329 btrfs_return_ino(root, btrfs_ino(inode));
5330
5331 btrfs_end_transaction(trans, root);
5332 btrfs_btree_balance_dirty(root);
5333 no_delete:
5334 btrfs_remove_delayed_node(inode);
5335 clear_inode(inode);
5336 }
5337
5338 /*
5339 * this returns the key found in the dir entry in the location pointer.
5340 * If no dir entries were found, location->objectid is 0.
5341 */
5342 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5343 struct btrfs_key *location)
5344 {
5345 const char *name = dentry->d_name.name;
5346 int namelen = dentry->d_name.len;
5347 struct btrfs_dir_item *di;
5348 struct btrfs_path *path;
5349 struct btrfs_root *root = BTRFS_I(dir)->root;
5350 int ret = 0;
5351
5352 path = btrfs_alloc_path();
5353 if (!path)
5354 return -ENOMEM;
5355
5356 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5357 namelen, 0);
5358 if (IS_ERR(di))
5359 ret = PTR_ERR(di);
5360
5361 if (IS_ERR_OR_NULL(di))
5362 goto out_err;
5363
5364 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5365 out:
5366 btrfs_free_path(path);
5367 return ret;
5368 out_err:
5369 location->objectid = 0;
5370 goto out;
5371 }
5372
5373 /*
5374 * when we hit a tree root in a directory, the btrfs part of the inode
5375 * needs to be changed to reflect the root directory of the tree root. This
5376 * is kind of like crossing a mount point.
5377 */
5378 static int fixup_tree_root_location(struct btrfs_root *root,
5379 struct inode *dir,
5380 struct dentry *dentry,
5381 struct btrfs_key *location,
5382 struct btrfs_root **sub_root)
5383 {
5384 struct btrfs_path *path;
5385 struct btrfs_root *new_root;
5386 struct btrfs_root_ref *ref;
5387 struct extent_buffer *leaf;
5388 struct btrfs_key key;
5389 int ret;
5390 int err = 0;
5391
5392 path = btrfs_alloc_path();
5393 if (!path) {
5394 err = -ENOMEM;
5395 goto out;
5396 }
5397
5398 err = -ENOENT;
5399 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5400 key.type = BTRFS_ROOT_REF_KEY;
5401 key.offset = location->objectid;
5402
5403 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5404 0, 0);
5405 if (ret) {
5406 if (ret < 0)
5407 err = ret;
5408 goto out;
5409 }
5410
5411 leaf = path->nodes[0];
5412 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5413 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5414 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5415 goto out;
5416
5417 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5418 (unsigned long)(ref + 1),
5419 dentry->d_name.len);
5420 if (ret)
5421 goto out;
5422
5423 btrfs_release_path(path);
5424
5425 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5426 if (IS_ERR(new_root)) {
5427 err = PTR_ERR(new_root);
5428 goto out;
5429 }
5430
5431 *sub_root = new_root;
5432 location->objectid = btrfs_root_dirid(&new_root->root_item);
5433 location->type = BTRFS_INODE_ITEM_KEY;
5434 location->offset = 0;
5435 err = 0;
5436 out:
5437 btrfs_free_path(path);
5438 return err;
5439 }
5440
5441 static void inode_tree_add(struct inode *inode)
5442 {
5443 struct btrfs_root *root = BTRFS_I(inode)->root;
5444 struct btrfs_inode *entry;
5445 struct rb_node **p;
5446 struct rb_node *parent;
5447 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5448 u64 ino = btrfs_ino(inode);
5449
5450 if (inode_unhashed(inode))
5451 return;
5452 parent = NULL;
5453 spin_lock(&root->inode_lock);
5454 p = &root->inode_tree.rb_node;
5455 while (*p) {
5456 parent = *p;
5457 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5458
5459 if (ino < btrfs_ino(&entry->vfs_inode))
5460 p = &parent->rb_left;
5461 else if (ino > btrfs_ino(&entry->vfs_inode))
5462 p = &parent->rb_right;
5463 else {
5464 WARN_ON(!(entry->vfs_inode.i_state &
5465 (I_WILL_FREE | I_FREEING)));
5466 rb_replace_node(parent, new, &root->inode_tree);
5467 RB_CLEAR_NODE(parent);
5468 spin_unlock(&root->inode_lock);
5469 return;
5470 }
5471 }
5472 rb_link_node(new, parent, p);
5473 rb_insert_color(new, &root->inode_tree);
5474 spin_unlock(&root->inode_lock);
5475 }
5476
5477 static void inode_tree_del(struct inode *inode)
5478 {
5479 struct btrfs_root *root = BTRFS_I(inode)->root;
5480 int empty = 0;
5481
5482 spin_lock(&root->inode_lock);
5483 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5484 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5485 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5486 empty = RB_EMPTY_ROOT(&root->inode_tree);
5487 }
5488 spin_unlock(&root->inode_lock);
5489
5490 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5491 synchronize_srcu(&root->fs_info->subvol_srcu);
5492 spin_lock(&root->inode_lock);
5493 empty = RB_EMPTY_ROOT(&root->inode_tree);
5494 spin_unlock(&root->inode_lock);
5495 if (empty)
5496 btrfs_add_dead_root(root);
5497 }
5498 }
5499
5500 void btrfs_invalidate_inodes(struct btrfs_root *root)
5501 {
5502 struct rb_node *node;
5503 struct rb_node *prev;
5504 struct btrfs_inode *entry;
5505 struct inode *inode;
5506 u64 objectid = 0;
5507
5508 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5509 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5510
5511 spin_lock(&root->inode_lock);
5512 again:
5513 node = root->inode_tree.rb_node;
5514 prev = NULL;
5515 while (node) {
5516 prev = node;
5517 entry = rb_entry(node, struct btrfs_inode, rb_node);
5518
5519 if (objectid < btrfs_ino(&entry->vfs_inode))
5520 node = node->rb_left;
5521 else if (objectid > btrfs_ino(&entry->vfs_inode))
5522 node = node->rb_right;
5523 else
5524 break;
5525 }
5526 if (!node) {
5527 while (prev) {
5528 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5529 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5530 node = prev;
5531 break;
5532 }
5533 prev = rb_next(prev);
5534 }
5535 }
5536 while (node) {
5537 entry = rb_entry(node, struct btrfs_inode, rb_node);
5538 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5539 inode = igrab(&entry->vfs_inode);
5540 if (inode) {
5541 spin_unlock(&root->inode_lock);
5542 if (atomic_read(&inode->i_count) > 1)
5543 d_prune_aliases(inode);
5544 /*
5545 * btrfs_drop_inode will have it removed from
5546 * the inode cache when its usage count
5547 * hits zero.
5548 */
5549 iput(inode);
5550 cond_resched();
5551 spin_lock(&root->inode_lock);
5552 goto again;
5553 }
5554
5555 if (cond_resched_lock(&root->inode_lock))
5556 goto again;
5557
5558 node = rb_next(node);
5559 }
5560 spin_unlock(&root->inode_lock);
5561 }
5562
5563 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5564 {
5565 struct btrfs_iget_args *args = p;
5566 inode->i_ino = args->location->objectid;
5567 memcpy(&BTRFS_I(inode)->location, args->location,
5568 sizeof(*args->location));
5569 BTRFS_I(inode)->root = args->root;
5570 return 0;
5571 }
5572
5573 static int btrfs_find_actor(struct inode *inode, void *opaque)
5574 {
5575 struct btrfs_iget_args *args = opaque;
5576 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5577 args->root == BTRFS_I(inode)->root;
5578 }
5579
5580 static struct inode *btrfs_iget_locked(struct super_block *s,
5581 struct btrfs_key *location,
5582 struct btrfs_root *root)
5583 {
5584 struct inode *inode;
5585 struct btrfs_iget_args args;
5586 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5587
5588 args.location = location;
5589 args.root = root;
5590
5591 inode = iget5_locked(s, hashval, btrfs_find_actor,
5592 btrfs_init_locked_inode,
5593 (void *)&args);
5594 return inode;
5595 }
5596
5597 /* Get an inode object given its location and corresponding root.
5598 * Returns in *is_new if the inode was read from disk
5599 */
5600 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5601 struct btrfs_root *root, int *new)
5602 {
5603 struct inode *inode;
5604
5605 inode = btrfs_iget_locked(s, location, root);
5606 if (!inode)
5607 return ERR_PTR(-ENOMEM);
5608
5609 if (inode->i_state & I_NEW) {
5610 btrfs_read_locked_inode(inode);
5611 if (!is_bad_inode(inode)) {
5612 inode_tree_add(inode);
5613 unlock_new_inode(inode);
5614 if (new)
5615 *new = 1;
5616 } else {
5617 unlock_new_inode(inode);
5618 iput(inode);
5619 inode = ERR_PTR(-ESTALE);
5620 }
5621 }
5622
5623 return inode;
5624 }
5625
5626 static struct inode *new_simple_dir(struct super_block *s,
5627 struct btrfs_key *key,
5628 struct btrfs_root *root)
5629 {
5630 struct inode *inode = new_inode(s);
5631
5632 if (!inode)
5633 return ERR_PTR(-ENOMEM);
5634
5635 BTRFS_I(inode)->root = root;
5636 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5637 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5638
5639 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5640 inode->i_op = &btrfs_dir_ro_inode_operations;
5641 inode->i_fop = &simple_dir_operations;
5642 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5643 inode->i_mtime = current_fs_time(inode->i_sb);
5644 inode->i_atime = inode->i_mtime;
5645 inode->i_ctime = inode->i_mtime;
5646 BTRFS_I(inode)->i_otime = inode->i_mtime;
5647
5648 return inode;
5649 }
5650
5651 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5652 {
5653 struct inode *inode;
5654 struct btrfs_root *root = BTRFS_I(dir)->root;
5655 struct btrfs_root *sub_root = root;
5656 struct btrfs_key location;
5657 int index;
5658 int ret = 0;
5659
5660 if (dentry->d_name.len > BTRFS_NAME_LEN)
5661 return ERR_PTR(-ENAMETOOLONG);
5662
5663 ret = btrfs_inode_by_name(dir, dentry, &location);
5664 if (ret < 0)
5665 return ERR_PTR(ret);
5666
5667 if (location.objectid == 0)
5668 return ERR_PTR(-ENOENT);
5669
5670 if (location.type == BTRFS_INODE_ITEM_KEY) {
5671 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5672 return inode;
5673 }
5674
5675 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5676
5677 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5678 ret = fixup_tree_root_location(root, dir, dentry,
5679 &location, &sub_root);
5680 if (ret < 0) {
5681 if (ret != -ENOENT)
5682 inode = ERR_PTR(ret);
5683 else
5684 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5685 } else {
5686 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5687 }
5688 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5689
5690 if (!IS_ERR(inode) && root != sub_root) {
5691 down_read(&root->fs_info->cleanup_work_sem);
5692 if (!(inode->i_sb->s_flags & MS_RDONLY))
5693 ret = btrfs_orphan_cleanup(sub_root);
5694 up_read(&root->fs_info->cleanup_work_sem);
5695 if (ret) {
5696 iput(inode);
5697 inode = ERR_PTR(ret);
5698 }
5699 }
5700
5701 return inode;
5702 }
5703
5704 static int btrfs_dentry_delete(const struct dentry *dentry)
5705 {
5706 struct btrfs_root *root;
5707 struct inode *inode = d_inode(dentry);
5708
5709 if (!inode && !IS_ROOT(dentry))
5710 inode = d_inode(dentry->d_parent);
5711
5712 if (inode) {
5713 root = BTRFS_I(inode)->root;
5714 if (btrfs_root_refs(&root->root_item) == 0)
5715 return 1;
5716
5717 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5718 return 1;
5719 }
5720 return 0;
5721 }
5722
5723 static void btrfs_dentry_release(struct dentry *dentry)
5724 {
5725 kfree(dentry->d_fsdata);
5726 }
5727
5728 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5729 unsigned int flags)
5730 {
5731 struct inode *inode;
5732
5733 inode = btrfs_lookup_dentry(dir, dentry);
5734 if (IS_ERR(inode)) {
5735 if (PTR_ERR(inode) == -ENOENT)
5736 inode = NULL;
5737 else
5738 return ERR_CAST(inode);
5739 }
5740
5741 return d_splice_alias(inode, dentry);
5742 }
5743
5744 unsigned char btrfs_filetype_table[] = {
5745 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5746 };
5747
5748 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5749 {
5750 struct inode *inode = file_inode(file);
5751 struct btrfs_root *root = BTRFS_I(inode)->root;
5752 struct btrfs_item *item;
5753 struct btrfs_dir_item *di;
5754 struct btrfs_key key;
5755 struct btrfs_key found_key;
5756 struct btrfs_path *path;
5757 struct list_head ins_list;
5758 struct list_head del_list;
5759 int ret;
5760 struct extent_buffer *leaf;
5761 int slot;
5762 unsigned char d_type;
5763 int over = 0;
5764 u32 di_cur;
5765 u32 di_total;
5766 u32 di_len;
5767 int key_type = BTRFS_DIR_INDEX_KEY;
5768 char tmp_name[32];
5769 char *name_ptr;
5770 int name_len;
5771 int is_curr = 0; /* ctx->pos points to the current index? */
5772 bool emitted;
5773 bool put = false;
5774
5775 /* FIXME, use a real flag for deciding about the key type */
5776 if (root->fs_info->tree_root == root)
5777 key_type = BTRFS_DIR_ITEM_KEY;
5778
5779 if (!dir_emit_dots(file, ctx))
5780 return 0;
5781
5782 path = btrfs_alloc_path();
5783 if (!path)
5784 return -ENOMEM;
5785
5786 path->reada = READA_FORWARD;
5787
5788 if (key_type == BTRFS_DIR_INDEX_KEY) {
5789 INIT_LIST_HEAD(&ins_list);
5790 INIT_LIST_HEAD(&del_list);
5791 put = btrfs_readdir_get_delayed_items(inode, &ins_list,
5792 &del_list);
5793 }
5794
5795 key.type = key_type;
5796 key.offset = ctx->pos;
5797 key.objectid = btrfs_ino(inode);
5798
5799 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5800 if (ret < 0)
5801 goto err;
5802
5803 emitted = false;
5804 while (1) {
5805 leaf = path->nodes[0];
5806 slot = path->slots[0];
5807 if (slot >= btrfs_header_nritems(leaf)) {
5808 ret = btrfs_next_leaf(root, path);
5809 if (ret < 0)
5810 goto err;
5811 else if (ret > 0)
5812 break;
5813 continue;
5814 }
5815
5816 item = btrfs_item_nr(slot);
5817 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5818
5819 if (found_key.objectid != key.objectid)
5820 break;
5821 if (found_key.type != key_type)
5822 break;
5823 if (found_key.offset < ctx->pos)
5824 goto next;
5825 if (key_type == BTRFS_DIR_INDEX_KEY &&
5826 btrfs_should_delete_dir_index(&del_list,
5827 found_key.offset))
5828 goto next;
5829
5830 ctx->pos = found_key.offset;
5831 is_curr = 1;
5832
5833 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5834 di_cur = 0;
5835 di_total = btrfs_item_size(leaf, item);
5836
5837 while (di_cur < di_total) {
5838 struct btrfs_key location;
5839
5840 if (verify_dir_item(root, leaf, di))
5841 break;
5842
5843 name_len = btrfs_dir_name_len(leaf, di);
5844 if (name_len <= sizeof(tmp_name)) {
5845 name_ptr = tmp_name;
5846 } else {
5847 name_ptr = kmalloc(name_len, GFP_KERNEL);
5848 if (!name_ptr) {
5849 ret = -ENOMEM;
5850 goto err;
5851 }
5852 }
5853 read_extent_buffer(leaf, name_ptr,
5854 (unsigned long)(di + 1), name_len);
5855
5856 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5857 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5858
5859
5860 /* is this a reference to our own snapshot? If so
5861 * skip it.
5862 *
5863 * In contrast to old kernels, we insert the snapshot's
5864 * dir item and dir index after it has been created, so
5865 * we won't find a reference to our own snapshot. We
5866 * still keep the following code for backward
5867 * compatibility.
5868 */
5869 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5870 location.objectid == root->root_key.objectid) {
5871 over = 0;
5872 goto skip;
5873 }
5874 over = !dir_emit(ctx, name_ptr, name_len,
5875 location.objectid, d_type);
5876
5877 skip:
5878 if (name_ptr != tmp_name)
5879 kfree(name_ptr);
5880
5881 if (over)
5882 goto nopos;
5883 emitted = true;
5884 di_len = btrfs_dir_name_len(leaf, di) +
5885 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5886 di_cur += di_len;
5887 di = (struct btrfs_dir_item *)((char *)di + di_len);
5888 }
5889 next:
5890 path->slots[0]++;
5891 }
5892
5893 if (key_type == BTRFS_DIR_INDEX_KEY) {
5894 if (is_curr)
5895 ctx->pos++;
5896 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5897 if (ret)
5898 goto nopos;
5899 }
5900
5901 /*
5902 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5903 * it was was set to the termination value in previous call. We assume
5904 * that "." and ".." were emitted if we reach this point and set the
5905 * termination value as well for an empty directory.
5906 */
5907 if (ctx->pos > 2 && !emitted)
5908 goto nopos;
5909
5910 /* Reached end of directory/root. Bump pos past the last item. */
5911 ctx->pos++;
5912
5913 /*
5914 * Stop new entries from being returned after we return the last
5915 * entry.
5916 *
5917 * New directory entries are assigned a strictly increasing
5918 * offset. This means that new entries created during readdir
5919 * are *guaranteed* to be seen in the future by that readdir.
5920 * This has broken buggy programs which operate on names as
5921 * they're returned by readdir. Until we re-use freed offsets
5922 * we have this hack to stop new entries from being returned
5923 * under the assumption that they'll never reach this huge
5924 * offset.
5925 *
5926 * This is being careful not to overflow 32bit loff_t unless the
5927 * last entry requires it because doing so has broken 32bit apps
5928 * in the past.
5929 */
5930 if (key_type == BTRFS_DIR_INDEX_KEY) {
5931 if (ctx->pos >= INT_MAX)
5932 ctx->pos = LLONG_MAX;
5933 else
5934 ctx->pos = INT_MAX;
5935 }
5936 nopos:
5937 ret = 0;
5938 err:
5939 if (put)
5940 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5941 btrfs_free_path(path);
5942 return ret;
5943 }
5944
5945 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5946 {
5947 struct btrfs_root *root = BTRFS_I(inode)->root;
5948 struct btrfs_trans_handle *trans;
5949 int ret = 0;
5950 bool nolock = false;
5951
5952 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5953 return 0;
5954
5955 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5956 nolock = true;
5957
5958 if (wbc->sync_mode == WB_SYNC_ALL) {
5959 if (nolock)
5960 trans = btrfs_join_transaction_nolock(root);
5961 else
5962 trans = btrfs_join_transaction(root);
5963 if (IS_ERR(trans))
5964 return PTR_ERR(trans);
5965 ret = btrfs_commit_transaction(trans, root);
5966 }
5967 return ret;
5968 }
5969
5970 /*
5971 * This is somewhat expensive, updating the tree every time the
5972 * inode changes. But, it is most likely to find the inode in cache.
5973 * FIXME, needs more benchmarking...there are no reasons other than performance
5974 * to keep or drop this code.
5975 */
5976 static int btrfs_dirty_inode(struct inode *inode)
5977 {
5978 struct btrfs_root *root = BTRFS_I(inode)->root;
5979 struct btrfs_trans_handle *trans;
5980 int ret;
5981
5982 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5983 return 0;
5984
5985 trans = btrfs_join_transaction(root);
5986 if (IS_ERR(trans))
5987 return PTR_ERR(trans);
5988
5989 ret = btrfs_update_inode(trans, root, inode);
5990 if (ret && ret == -ENOSPC) {
5991 /* whoops, lets try again with the full transaction */
5992 btrfs_end_transaction(trans, root);
5993 trans = btrfs_start_transaction(root, 1);
5994 if (IS_ERR(trans))
5995 return PTR_ERR(trans);
5996
5997 ret = btrfs_update_inode(trans, root, inode);
5998 }
5999 btrfs_end_transaction(trans, root);
6000 if (BTRFS_I(inode)->delayed_node)
6001 btrfs_balance_delayed_items(root);
6002
6003 return ret;
6004 }
6005
6006 /*
6007 * This is a copy of file_update_time. We need this so we can return error on
6008 * ENOSPC for updating the inode in the case of file write and mmap writes.
6009 */
6010 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6011 int flags)
6012 {
6013 struct btrfs_root *root = BTRFS_I(inode)->root;
6014
6015 if (btrfs_root_readonly(root))
6016 return -EROFS;
6017
6018 if (flags & S_VERSION)
6019 inode_inc_iversion(inode);
6020 if (flags & S_CTIME)
6021 inode->i_ctime = *now;
6022 if (flags & S_MTIME)
6023 inode->i_mtime = *now;
6024 if (flags & S_ATIME)
6025 inode->i_atime = *now;
6026 return btrfs_dirty_inode(inode);
6027 }
6028
6029 /*
6030 * find the highest existing sequence number in a directory
6031 * and then set the in-memory index_cnt variable to reflect
6032 * free sequence numbers
6033 */
6034 static int btrfs_set_inode_index_count(struct inode *inode)
6035 {
6036 struct btrfs_root *root = BTRFS_I(inode)->root;
6037 struct btrfs_key key, found_key;
6038 struct btrfs_path *path;
6039 struct extent_buffer *leaf;
6040 int ret;
6041
6042 key.objectid = btrfs_ino(inode);
6043 key.type = BTRFS_DIR_INDEX_KEY;
6044 key.offset = (u64)-1;
6045
6046 path = btrfs_alloc_path();
6047 if (!path)
6048 return -ENOMEM;
6049
6050 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6051 if (ret < 0)
6052 goto out;
6053 /* FIXME: we should be able to handle this */
6054 if (ret == 0)
6055 goto out;
6056 ret = 0;
6057
6058 /*
6059 * MAGIC NUMBER EXPLANATION:
6060 * since we search a directory based on f_pos we have to start at 2
6061 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6062 * else has to start at 2
6063 */
6064 if (path->slots[0] == 0) {
6065 BTRFS_I(inode)->index_cnt = 2;
6066 goto out;
6067 }
6068
6069 path->slots[0]--;
6070
6071 leaf = path->nodes[0];
6072 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6073
6074 if (found_key.objectid != btrfs_ino(inode) ||
6075 found_key.type != BTRFS_DIR_INDEX_KEY) {
6076 BTRFS_I(inode)->index_cnt = 2;
6077 goto out;
6078 }
6079
6080 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6081 out:
6082 btrfs_free_path(path);
6083 return ret;
6084 }
6085
6086 /*
6087 * helper to find a free sequence number in a given directory. This current
6088 * code is very simple, later versions will do smarter things in the btree
6089 */
6090 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6091 {
6092 int ret = 0;
6093
6094 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6095 ret = btrfs_inode_delayed_dir_index_count(dir);
6096 if (ret) {
6097 ret = btrfs_set_inode_index_count(dir);
6098 if (ret)
6099 return ret;
6100 }
6101 }
6102
6103 *index = BTRFS_I(dir)->index_cnt;
6104 BTRFS_I(dir)->index_cnt++;
6105
6106 return ret;
6107 }
6108
6109 static int btrfs_insert_inode_locked(struct inode *inode)
6110 {
6111 struct btrfs_iget_args args;
6112 args.location = &BTRFS_I(inode)->location;
6113 args.root = BTRFS_I(inode)->root;
6114
6115 return insert_inode_locked4(inode,
6116 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6117 btrfs_find_actor, &args);
6118 }
6119
6120 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6121 struct btrfs_root *root,
6122 struct inode *dir,
6123 const char *name, int name_len,
6124 u64 ref_objectid, u64 objectid,
6125 umode_t mode, u64 *index)
6126 {
6127 struct inode *inode;
6128 struct btrfs_inode_item *inode_item;
6129 struct btrfs_key *location;
6130 struct btrfs_path *path;
6131 struct btrfs_inode_ref *ref;
6132 struct btrfs_key key[2];
6133 u32 sizes[2];
6134 int nitems = name ? 2 : 1;
6135 unsigned long ptr;
6136 int ret;
6137
6138 path = btrfs_alloc_path();
6139 if (!path)
6140 return ERR_PTR(-ENOMEM);
6141
6142 inode = new_inode(root->fs_info->sb);
6143 if (!inode) {
6144 btrfs_free_path(path);
6145 return ERR_PTR(-ENOMEM);
6146 }
6147
6148 /*
6149 * O_TMPFILE, set link count to 0, so that after this point,
6150 * we fill in an inode item with the correct link count.
6151 */
6152 if (!name)
6153 set_nlink(inode, 0);
6154
6155 /*
6156 * we have to initialize this early, so we can reclaim the inode
6157 * number if we fail afterwards in this function.
6158 */
6159 inode->i_ino = objectid;
6160
6161 if (dir && name) {
6162 trace_btrfs_inode_request(dir);
6163
6164 ret = btrfs_set_inode_index(dir, index);
6165 if (ret) {
6166 btrfs_free_path(path);
6167 iput(inode);
6168 return ERR_PTR(ret);
6169 }
6170 } else if (dir) {
6171 *index = 0;
6172 }
6173 /*
6174 * index_cnt is ignored for everything but a dir,
6175 * btrfs_get_inode_index_count has an explanation for the magic
6176 * number
6177 */
6178 BTRFS_I(inode)->index_cnt = 2;
6179 BTRFS_I(inode)->dir_index = *index;
6180 BTRFS_I(inode)->root = root;
6181 BTRFS_I(inode)->generation = trans->transid;
6182 inode->i_generation = BTRFS_I(inode)->generation;
6183
6184 /*
6185 * We could have gotten an inode number from somebody who was fsynced
6186 * and then removed in this same transaction, so let's just set full
6187 * sync since it will be a full sync anyway and this will blow away the
6188 * old info in the log.
6189 */
6190 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6191
6192 key[0].objectid = objectid;
6193 key[0].type = BTRFS_INODE_ITEM_KEY;
6194 key[0].offset = 0;
6195
6196 sizes[0] = sizeof(struct btrfs_inode_item);
6197
6198 if (name) {
6199 /*
6200 * Start new inodes with an inode_ref. This is slightly more
6201 * efficient for small numbers of hard links since they will
6202 * be packed into one item. Extended refs will kick in if we
6203 * add more hard links than can fit in the ref item.
6204 */
6205 key[1].objectid = objectid;
6206 key[1].type = BTRFS_INODE_REF_KEY;
6207 key[1].offset = ref_objectid;
6208
6209 sizes[1] = name_len + sizeof(*ref);
6210 }
6211
6212 location = &BTRFS_I(inode)->location;
6213 location->objectid = objectid;
6214 location->offset = 0;
6215 location->type = BTRFS_INODE_ITEM_KEY;
6216
6217 ret = btrfs_insert_inode_locked(inode);
6218 if (ret < 0)
6219 goto fail;
6220
6221 path->leave_spinning = 1;
6222 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6223 if (ret != 0)
6224 goto fail_unlock;
6225
6226 inode_init_owner(inode, dir, mode);
6227 inode_set_bytes(inode, 0);
6228
6229 inode->i_mtime = current_fs_time(inode->i_sb);
6230 inode->i_atime = inode->i_mtime;
6231 inode->i_ctime = inode->i_mtime;
6232 BTRFS_I(inode)->i_otime = inode->i_mtime;
6233
6234 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6235 struct btrfs_inode_item);
6236 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6237 sizeof(*inode_item));
6238 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6239
6240 if (name) {
6241 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6242 struct btrfs_inode_ref);
6243 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6244 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6245 ptr = (unsigned long)(ref + 1);
6246 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6247 }
6248
6249 btrfs_mark_buffer_dirty(path->nodes[0]);
6250 btrfs_free_path(path);
6251
6252 btrfs_inherit_iflags(inode, dir);
6253
6254 if (S_ISREG(mode)) {
6255 if (btrfs_test_opt(root->fs_info, NODATASUM))
6256 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6257 if (btrfs_test_opt(root->fs_info, NODATACOW))
6258 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6259 BTRFS_INODE_NODATASUM;
6260 }
6261
6262 inode_tree_add(inode);
6263
6264 trace_btrfs_inode_new(inode);
6265 btrfs_set_inode_last_trans(trans, inode);
6266
6267 btrfs_update_root_times(trans, root);
6268
6269 ret = btrfs_inode_inherit_props(trans, inode, dir);
6270 if (ret)
6271 btrfs_err(root->fs_info,
6272 "error inheriting props for ino %llu (root %llu): %d",
6273 btrfs_ino(inode), root->root_key.objectid, ret);
6274
6275 return inode;
6276
6277 fail_unlock:
6278 unlock_new_inode(inode);
6279 fail:
6280 if (dir && name)
6281 BTRFS_I(dir)->index_cnt--;
6282 btrfs_free_path(path);
6283 iput(inode);
6284 return ERR_PTR(ret);
6285 }
6286
6287 static inline u8 btrfs_inode_type(struct inode *inode)
6288 {
6289 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6290 }
6291
6292 /*
6293 * utility function to add 'inode' into 'parent_inode' with
6294 * a give name and a given sequence number.
6295 * if 'add_backref' is true, also insert a backref from the
6296 * inode to the parent directory.
6297 */
6298 int btrfs_add_link(struct btrfs_trans_handle *trans,
6299 struct inode *parent_inode, struct inode *inode,
6300 const char *name, int name_len, int add_backref, u64 index)
6301 {
6302 int ret = 0;
6303 struct btrfs_key key;
6304 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6305 u64 ino = btrfs_ino(inode);
6306 u64 parent_ino = btrfs_ino(parent_inode);
6307
6308 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6309 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6310 } else {
6311 key.objectid = ino;
6312 key.type = BTRFS_INODE_ITEM_KEY;
6313 key.offset = 0;
6314 }
6315
6316 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6317 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6318 key.objectid, root->root_key.objectid,
6319 parent_ino, index, name, name_len);
6320 } else if (add_backref) {
6321 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6322 parent_ino, index);
6323 }
6324
6325 /* Nothing to clean up yet */
6326 if (ret)
6327 return ret;
6328
6329 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6330 parent_inode, &key,
6331 btrfs_inode_type(inode), index);
6332 if (ret == -EEXIST || ret == -EOVERFLOW)
6333 goto fail_dir_item;
6334 else if (ret) {
6335 btrfs_abort_transaction(trans, ret);
6336 return ret;
6337 }
6338
6339 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6340 name_len * 2);
6341 inode_inc_iversion(parent_inode);
6342 parent_inode->i_mtime = parent_inode->i_ctime =
6343 current_fs_time(parent_inode->i_sb);
6344 ret = btrfs_update_inode(trans, root, parent_inode);
6345 if (ret)
6346 btrfs_abort_transaction(trans, ret);
6347 return ret;
6348
6349 fail_dir_item:
6350 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6351 u64 local_index;
6352 int err;
6353 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6354 key.objectid, root->root_key.objectid,
6355 parent_ino, &local_index, name, name_len);
6356
6357 } else if (add_backref) {
6358 u64 local_index;
6359 int err;
6360
6361 err = btrfs_del_inode_ref(trans, root, name, name_len,
6362 ino, parent_ino, &local_index);
6363 }
6364 return ret;
6365 }
6366
6367 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6368 struct inode *dir, struct dentry *dentry,
6369 struct inode *inode, int backref, u64 index)
6370 {
6371 int err = btrfs_add_link(trans, dir, inode,
6372 dentry->d_name.name, dentry->d_name.len,
6373 backref, index);
6374 if (err > 0)
6375 err = -EEXIST;
6376 return err;
6377 }
6378
6379 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6380 umode_t mode, dev_t rdev)
6381 {
6382 struct btrfs_trans_handle *trans;
6383 struct btrfs_root *root = BTRFS_I(dir)->root;
6384 struct inode *inode = NULL;
6385 int err;
6386 int drop_inode = 0;
6387 u64 objectid;
6388 u64 index = 0;
6389
6390 /*
6391 * 2 for inode item and ref
6392 * 2 for dir items
6393 * 1 for xattr if selinux is on
6394 */
6395 trans = btrfs_start_transaction(root, 5);
6396 if (IS_ERR(trans))
6397 return PTR_ERR(trans);
6398
6399 err = btrfs_find_free_ino(root, &objectid);
6400 if (err)
6401 goto out_unlock;
6402
6403 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6404 dentry->d_name.len, btrfs_ino(dir), objectid,
6405 mode, &index);
6406 if (IS_ERR(inode)) {
6407 err = PTR_ERR(inode);
6408 goto out_unlock;
6409 }
6410
6411 /*
6412 * If the active LSM wants to access the inode during
6413 * d_instantiate it needs these. Smack checks to see
6414 * if the filesystem supports xattrs by looking at the
6415 * ops vector.
6416 */
6417 inode->i_op = &btrfs_special_inode_operations;
6418 init_special_inode(inode, inode->i_mode, rdev);
6419
6420 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6421 if (err)
6422 goto out_unlock_inode;
6423
6424 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6425 if (err) {
6426 goto out_unlock_inode;
6427 } else {
6428 btrfs_update_inode(trans, root, inode);
6429 unlock_new_inode(inode);
6430 d_instantiate(dentry, inode);
6431 }
6432
6433 out_unlock:
6434 btrfs_end_transaction(trans, root);
6435 btrfs_balance_delayed_items(root);
6436 btrfs_btree_balance_dirty(root);
6437 if (drop_inode) {
6438 inode_dec_link_count(inode);
6439 iput(inode);
6440 }
6441 return err;
6442
6443 out_unlock_inode:
6444 drop_inode = 1;
6445 unlock_new_inode(inode);
6446 goto out_unlock;
6447
6448 }
6449
6450 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6451 umode_t mode, bool excl)
6452 {
6453 struct btrfs_trans_handle *trans;
6454 struct btrfs_root *root = BTRFS_I(dir)->root;
6455 struct inode *inode = NULL;
6456 int drop_inode_on_err = 0;
6457 int err;
6458 u64 objectid;
6459 u64 index = 0;
6460
6461 /*
6462 * 2 for inode item and ref
6463 * 2 for dir items
6464 * 1 for xattr if selinux is on
6465 */
6466 trans = btrfs_start_transaction(root, 5);
6467 if (IS_ERR(trans))
6468 return PTR_ERR(trans);
6469
6470 err = btrfs_find_free_ino(root, &objectid);
6471 if (err)
6472 goto out_unlock;
6473
6474 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6475 dentry->d_name.len, btrfs_ino(dir), objectid,
6476 mode, &index);
6477 if (IS_ERR(inode)) {
6478 err = PTR_ERR(inode);
6479 goto out_unlock;
6480 }
6481 drop_inode_on_err = 1;
6482 /*
6483 * If the active LSM wants to access the inode during
6484 * d_instantiate it needs these. Smack checks to see
6485 * if the filesystem supports xattrs by looking at the
6486 * ops vector.
6487 */
6488 inode->i_fop = &btrfs_file_operations;
6489 inode->i_op = &btrfs_file_inode_operations;
6490 inode->i_mapping->a_ops = &btrfs_aops;
6491
6492 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6493 if (err)
6494 goto out_unlock_inode;
6495
6496 err = btrfs_update_inode(trans, root, inode);
6497 if (err)
6498 goto out_unlock_inode;
6499
6500 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6501 if (err)
6502 goto out_unlock_inode;
6503
6504 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6505 unlock_new_inode(inode);
6506 d_instantiate(dentry, inode);
6507
6508 out_unlock:
6509 btrfs_end_transaction(trans, root);
6510 if (err && drop_inode_on_err) {
6511 inode_dec_link_count(inode);
6512 iput(inode);
6513 }
6514 btrfs_balance_delayed_items(root);
6515 btrfs_btree_balance_dirty(root);
6516 return err;
6517
6518 out_unlock_inode:
6519 unlock_new_inode(inode);
6520 goto out_unlock;
6521
6522 }
6523
6524 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6525 struct dentry *dentry)
6526 {
6527 struct btrfs_trans_handle *trans = NULL;
6528 struct btrfs_root *root = BTRFS_I(dir)->root;
6529 struct inode *inode = d_inode(old_dentry);
6530 u64 index;
6531 int err;
6532 int drop_inode = 0;
6533
6534 /* do not allow sys_link's with other subvols of the same device */
6535 if (root->objectid != BTRFS_I(inode)->root->objectid)
6536 return -EXDEV;
6537
6538 if (inode->i_nlink >= BTRFS_LINK_MAX)
6539 return -EMLINK;
6540
6541 err = btrfs_set_inode_index(dir, &index);
6542 if (err)
6543 goto fail;
6544
6545 /*
6546 * 2 items for inode and inode ref
6547 * 2 items for dir items
6548 * 1 item for parent inode
6549 */
6550 trans = btrfs_start_transaction(root, 5);
6551 if (IS_ERR(trans)) {
6552 err = PTR_ERR(trans);
6553 trans = NULL;
6554 goto fail;
6555 }
6556
6557 /* There are several dir indexes for this inode, clear the cache. */
6558 BTRFS_I(inode)->dir_index = 0ULL;
6559 inc_nlink(inode);
6560 inode_inc_iversion(inode);
6561 inode->i_ctime = current_fs_time(inode->i_sb);
6562 ihold(inode);
6563 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6564
6565 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6566
6567 if (err) {
6568 drop_inode = 1;
6569 } else {
6570 struct dentry *parent = dentry->d_parent;
6571 err = btrfs_update_inode(trans, root, inode);
6572 if (err)
6573 goto fail;
6574 if (inode->i_nlink == 1) {
6575 /*
6576 * If new hard link count is 1, it's a file created
6577 * with open(2) O_TMPFILE flag.
6578 */
6579 err = btrfs_orphan_del(trans, inode);
6580 if (err)
6581 goto fail;
6582 }
6583 d_instantiate(dentry, inode);
6584 btrfs_log_new_name(trans, inode, NULL, parent);
6585 }
6586
6587 btrfs_balance_delayed_items(root);
6588 fail:
6589 if (trans)
6590 btrfs_end_transaction(trans, root);
6591 if (drop_inode) {
6592 inode_dec_link_count(inode);
6593 iput(inode);
6594 }
6595 btrfs_btree_balance_dirty(root);
6596 return err;
6597 }
6598
6599 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6600 {
6601 struct inode *inode = NULL;
6602 struct btrfs_trans_handle *trans;
6603 struct btrfs_root *root = BTRFS_I(dir)->root;
6604 int err = 0;
6605 int drop_on_err = 0;
6606 u64 objectid = 0;
6607 u64 index = 0;
6608
6609 /*
6610 * 2 items for inode and ref
6611 * 2 items for dir items
6612 * 1 for xattr if selinux is on
6613 */
6614 trans = btrfs_start_transaction(root, 5);
6615 if (IS_ERR(trans))
6616 return PTR_ERR(trans);
6617
6618 err = btrfs_find_free_ino(root, &objectid);
6619 if (err)
6620 goto out_fail;
6621
6622 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6623 dentry->d_name.len, btrfs_ino(dir), objectid,
6624 S_IFDIR | mode, &index);
6625 if (IS_ERR(inode)) {
6626 err = PTR_ERR(inode);
6627 goto out_fail;
6628 }
6629
6630 drop_on_err = 1;
6631 /* these must be set before we unlock the inode */
6632 inode->i_op = &btrfs_dir_inode_operations;
6633 inode->i_fop = &btrfs_dir_file_operations;
6634
6635 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6636 if (err)
6637 goto out_fail_inode;
6638
6639 btrfs_i_size_write(inode, 0);
6640 err = btrfs_update_inode(trans, root, inode);
6641 if (err)
6642 goto out_fail_inode;
6643
6644 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6645 dentry->d_name.len, 0, index);
6646 if (err)
6647 goto out_fail_inode;
6648
6649 d_instantiate(dentry, inode);
6650 /*
6651 * mkdir is special. We're unlocking after we call d_instantiate
6652 * to avoid a race with nfsd calling d_instantiate.
6653 */
6654 unlock_new_inode(inode);
6655 drop_on_err = 0;
6656
6657 out_fail:
6658 btrfs_end_transaction(trans, root);
6659 if (drop_on_err) {
6660 inode_dec_link_count(inode);
6661 iput(inode);
6662 }
6663 btrfs_balance_delayed_items(root);
6664 btrfs_btree_balance_dirty(root);
6665 return err;
6666
6667 out_fail_inode:
6668 unlock_new_inode(inode);
6669 goto out_fail;
6670 }
6671
6672 /* Find next extent map of a given extent map, caller needs to ensure locks */
6673 static struct extent_map *next_extent_map(struct extent_map *em)
6674 {
6675 struct rb_node *next;
6676
6677 next = rb_next(&em->rb_node);
6678 if (!next)
6679 return NULL;
6680 return container_of(next, struct extent_map, rb_node);
6681 }
6682
6683 static struct extent_map *prev_extent_map(struct extent_map *em)
6684 {
6685 struct rb_node *prev;
6686
6687 prev = rb_prev(&em->rb_node);
6688 if (!prev)
6689 return NULL;
6690 return container_of(prev, struct extent_map, rb_node);
6691 }
6692
6693 /* helper for btfs_get_extent. Given an existing extent in the tree,
6694 * the existing extent is the nearest extent to map_start,
6695 * and an extent that you want to insert, deal with overlap and insert
6696 * the best fitted new extent into the tree.
6697 */
6698 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6699 struct extent_map *existing,
6700 struct extent_map *em,
6701 u64 map_start)
6702 {
6703 struct extent_map *prev;
6704 struct extent_map *next;
6705 u64 start;
6706 u64 end;
6707 u64 start_diff;
6708
6709 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6710
6711 if (existing->start > map_start) {
6712 next = existing;
6713 prev = prev_extent_map(next);
6714 } else {
6715 prev = existing;
6716 next = next_extent_map(prev);
6717 }
6718
6719 start = prev ? extent_map_end(prev) : em->start;
6720 start = max_t(u64, start, em->start);
6721 end = next ? next->start : extent_map_end(em);
6722 end = min_t(u64, end, extent_map_end(em));
6723 start_diff = start - em->start;
6724 em->start = start;
6725 em->len = end - start;
6726 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6727 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6728 em->block_start += start_diff;
6729 em->block_len -= start_diff;
6730 }
6731 return add_extent_mapping(em_tree, em, 0);
6732 }
6733
6734 static noinline int uncompress_inline(struct btrfs_path *path,
6735 struct page *page,
6736 size_t pg_offset, u64 extent_offset,
6737 struct btrfs_file_extent_item *item)
6738 {
6739 int ret;
6740 struct extent_buffer *leaf = path->nodes[0];
6741 char *tmp;
6742 size_t max_size;
6743 unsigned long inline_size;
6744 unsigned long ptr;
6745 int compress_type;
6746
6747 WARN_ON(pg_offset != 0);
6748 compress_type = btrfs_file_extent_compression(leaf, item);
6749 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6750 inline_size = btrfs_file_extent_inline_item_len(leaf,
6751 btrfs_item_nr(path->slots[0]));
6752 tmp = kmalloc(inline_size, GFP_NOFS);
6753 if (!tmp)
6754 return -ENOMEM;
6755 ptr = btrfs_file_extent_inline_start(item);
6756
6757 read_extent_buffer(leaf, tmp, ptr, inline_size);
6758
6759 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6760 ret = btrfs_decompress(compress_type, tmp, page,
6761 extent_offset, inline_size, max_size);
6762 kfree(tmp);
6763 return ret;
6764 }
6765
6766 /*
6767 * a bit scary, this does extent mapping from logical file offset to the disk.
6768 * the ugly parts come from merging extents from the disk with the in-ram
6769 * representation. This gets more complex because of the data=ordered code,
6770 * where the in-ram extents might be locked pending data=ordered completion.
6771 *
6772 * This also copies inline extents directly into the page.
6773 */
6774
6775 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6776 size_t pg_offset, u64 start, u64 len,
6777 int create)
6778 {
6779 int ret;
6780 int err = 0;
6781 u64 extent_start = 0;
6782 u64 extent_end = 0;
6783 u64 objectid = btrfs_ino(inode);
6784 u32 found_type;
6785 struct btrfs_path *path = NULL;
6786 struct btrfs_root *root = BTRFS_I(inode)->root;
6787 struct btrfs_file_extent_item *item;
6788 struct extent_buffer *leaf;
6789 struct btrfs_key found_key;
6790 struct extent_map *em = NULL;
6791 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6792 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6793 struct btrfs_trans_handle *trans = NULL;
6794 const bool new_inline = !page || create;
6795
6796 again:
6797 read_lock(&em_tree->lock);
6798 em = lookup_extent_mapping(em_tree, start, len);
6799 if (em)
6800 em->bdev = root->fs_info->fs_devices->latest_bdev;
6801 read_unlock(&em_tree->lock);
6802
6803 if (em) {
6804 if (em->start > start || em->start + em->len <= start)
6805 free_extent_map(em);
6806 else if (em->block_start == EXTENT_MAP_INLINE && page)
6807 free_extent_map(em);
6808 else
6809 goto out;
6810 }
6811 em = alloc_extent_map();
6812 if (!em) {
6813 err = -ENOMEM;
6814 goto out;
6815 }
6816 em->bdev = root->fs_info->fs_devices->latest_bdev;
6817 em->start = EXTENT_MAP_HOLE;
6818 em->orig_start = EXTENT_MAP_HOLE;
6819 em->len = (u64)-1;
6820 em->block_len = (u64)-1;
6821
6822 if (!path) {
6823 path = btrfs_alloc_path();
6824 if (!path) {
6825 err = -ENOMEM;
6826 goto out;
6827 }
6828 /*
6829 * Chances are we'll be called again, so go ahead and do
6830 * readahead
6831 */
6832 path->reada = READA_FORWARD;
6833 }
6834
6835 ret = btrfs_lookup_file_extent(trans, root, path,
6836 objectid, start, trans != NULL);
6837 if (ret < 0) {
6838 err = ret;
6839 goto out;
6840 }
6841
6842 if (ret != 0) {
6843 if (path->slots[0] == 0)
6844 goto not_found;
6845 path->slots[0]--;
6846 }
6847
6848 leaf = path->nodes[0];
6849 item = btrfs_item_ptr(leaf, path->slots[0],
6850 struct btrfs_file_extent_item);
6851 /* are we inside the extent that was found? */
6852 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6853 found_type = found_key.type;
6854 if (found_key.objectid != objectid ||
6855 found_type != BTRFS_EXTENT_DATA_KEY) {
6856 /*
6857 * If we backup past the first extent we want to move forward
6858 * and see if there is an extent in front of us, otherwise we'll
6859 * say there is a hole for our whole search range which can
6860 * cause problems.
6861 */
6862 extent_end = start;
6863 goto next;
6864 }
6865
6866 found_type = btrfs_file_extent_type(leaf, item);
6867 extent_start = found_key.offset;
6868 if (found_type == BTRFS_FILE_EXTENT_REG ||
6869 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6870 extent_end = extent_start +
6871 btrfs_file_extent_num_bytes(leaf, item);
6872 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6873 size_t size;
6874 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6875 extent_end = ALIGN(extent_start + size, root->sectorsize);
6876 }
6877 next:
6878 if (start >= extent_end) {
6879 path->slots[0]++;
6880 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6881 ret = btrfs_next_leaf(root, path);
6882 if (ret < 0) {
6883 err = ret;
6884 goto out;
6885 }
6886 if (ret > 0)
6887 goto not_found;
6888 leaf = path->nodes[0];
6889 }
6890 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6891 if (found_key.objectid != objectid ||
6892 found_key.type != BTRFS_EXTENT_DATA_KEY)
6893 goto not_found;
6894 if (start + len <= found_key.offset)
6895 goto not_found;
6896 if (start > found_key.offset)
6897 goto next;
6898 em->start = start;
6899 em->orig_start = start;
6900 em->len = found_key.offset - start;
6901 goto not_found_em;
6902 }
6903
6904 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6905
6906 if (found_type == BTRFS_FILE_EXTENT_REG ||
6907 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6908 goto insert;
6909 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6910 unsigned long ptr;
6911 char *map;
6912 size_t size;
6913 size_t extent_offset;
6914 size_t copy_size;
6915
6916 if (new_inline)
6917 goto out;
6918
6919 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6920 extent_offset = page_offset(page) + pg_offset - extent_start;
6921 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6922 size - extent_offset);
6923 em->start = extent_start + extent_offset;
6924 em->len = ALIGN(copy_size, root->sectorsize);
6925 em->orig_block_len = em->len;
6926 em->orig_start = em->start;
6927 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6928 if (create == 0 && !PageUptodate(page)) {
6929 if (btrfs_file_extent_compression(leaf, item) !=
6930 BTRFS_COMPRESS_NONE) {
6931 ret = uncompress_inline(path, page, pg_offset,
6932 extent_offset, item);
6933 if (ret) {
6934 err = ret;
6935 goto out;
6936 }
6937 } else {
6938 map = kmap(page);
6939 read_extent_buffer(leaf, map + pg_offset, ptr,
6940 copy_size);
6941 if (pg_offset + copy_size < PAGE_SIZE) {
6942 memset(map + pg_offset + copy_size, 0,
6943 PAGE_SIZE - pg_offset -
6944 copy_size);
6945 }
6946 kunmap(page);
6947 }
6948 flush_dcache_page(page);
6949 } else if (create && PageUptodate(page)) {
6950 BUG();
6951 if (!trans) {
6952 kunmap(page);
6953 free_extent_map(em);
6954 em = NULL;
6955
6956 btrfs_release_path(path);
6957 trans = btrfs_join_transaction(root);
6958
6959 if (IS_ERR(trans))
6960 return ERR_CAST(trans);
6961 goto again;
6962 }
6963 map = kmap(page);
6964 write_extent_buffer(leaf, map + pg_offset, ptr,
6965 copy_size);
6966 kunmap(page);
6967 btrfs_mark_buffer_dirty(leaf);
6968 }
6969 set_extent_uptodate(io_tree, em->start,
6970 extent_map_end(em) - 1, NULL, GFP_NOFS);
6971 goto insert;
6972 }
6973 not_found:
6974 em->start = start;
6975 em->orig_start = start;
6976 em->len = len;
6977 not_found_em:
6978 em->block_start = EXTENT_MAP_HOLE;
6979 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6980 insert:
6981 btrfs_release_path(path);
6982 if (em->start > start || extent_map_end(em) <= start) {
6983 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6984 em->start, em->len, start, len);
6985 err = -EIO;
6986 goto out;
6987 }
6988
6989 err = 0;
6990 write_lock(&em_tree->lock);
6991 ret = add_extent_mapping(em_tree, em, 0);
6992 /* it is possible that someone inserted the extent into the tree
6993 * while we had the lock dropped. It is also possible that
6994 * an overlapping map exists in the tree
6995 */
6996 if (ret == -EEXIST) {
6997 struct extent_map *existing;
6998
6999 ret = 0;
7000
7001 existing = search_extent_mapping(em_tree, start, len);
7002 /*
7003 * existing will always be non-NULL, since there must be
7004 * extent causing the -EEXIST.
7005 */
7006 if (existing->start == em->start &&
7007 extent_map_end(existing) == extent_map_end(em) &&
7008 em->block_start == existing->block_start) {
7009 /*
7010 * these two extents are the same, it happens
7011 * with inlines especially
7012 */
7013 free_extent_map(em);
7014 em = existing;
7015 err = 0;
7016
7017 } else if (start >= extent_map_end(existing) ||
7018 start <= existing->start) {
7019 /*
7020 * The existing extent map is the one nearest to
7021 * the [start, start + len) range which overlaps
7022 */
7023 err = merge_extent_mapping(em_tree, existing,
7024 em, start);
7025 free_extent_map(existing);
7026 if (err) {
7027 free_extent_map(em);
7028 em = NULL;
7029 }
7030 } else {
7031 free_extent_map(em);
7032 em = existing;
7033 err = 0;
7034 }
7035 }
7036 write_unlock(&em_tree->lock);
7037 out:
7038
7039 trace_btrfs_get_extent(root, em);
7040
7041 btrfs_free_path(path);
7042 if (trans) {
7043 ret = btrfs_end_transaction(trans, root);
7044 if (!err)
7045 err = ret;
7046 }
7047 if (err) {
7048 free_extent_map(em);
7049 return ERR_PTR(err);
7050 }
7051 BUG_ON(!em); /* Error is always set */
7052 return em;
7053 }
7054
7055 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7056 size_t pg_offset, u64 start, u64 len,
7057 int create)
7058 {
7059 struct extent_map *em;
7060 struct extent_map *hole_em = NULL;
7061 u64 range_start = start;
7062 u64 end;
7063 u64 found;
7064 u64 found_end;
7065 int err = 0;
7066
7067 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7068 if (IS_ERR(em))
7069 return em;
7070 if (em) {
7071 /*
7072 * if our em maps to
7073 * - a hole or
7074 * - a pre-alloc extent,
7075 * there might actually be delalloc bytes behind it.
7076 */
7077 if (em->block_start != EXTENT_MAP_HOLE &&
7078 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7079 return em;
7080 else
7081 hole_em = em;
7082 }
7083
7084 /* check to see if we've wrapped (len == -1 or similar) */
7085 end = start + len;
7086 if (end < start)
7087 end = (u64)-1;
7088 else
7089 end -= 1;
7090
7091 em = NULL;
7092
7093 /* ok, we didn't find anything, lets look for delalloc */
7094 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7095 end, len, EXTENT_DELALLOC, 1);
7096 found_end = range_start + found;
7097 if (found_end < range_start)
7098 found_end = (u64)-1;
7099
7100 /*
7101 * we didn't find anything useful, return
7102 * the original results from get_extent()
7103 */
7104 if (range_start > end || found_end <= start) {
7105 em = hole_em;
7106 hole_em = NULL;
7107 goto out;
7108 }
7109
7110 /* adjust the range_start to make sure it doesn't
7111 * go backwards from the start they passed in
7112 */
7113 range_start = max(start, range_start);
7114 found = found_end - range_start;
7115
7116 if (found > 0) {
7117 u64 hole_start = start;
7118 u64 hole_len = len;
7119
7120 em = alloc_extent_map();
7121 if (!em) {
7122 err = -ENOMEM;
7123 goto out;
7124 }
7125 /*
7126 * when btrfs_get_extent can't find anything it
7127 * returns one huge hole
7128 *
7129 * make sure what it found really fits our range, and
7130 * adjust to make sure it is based on the start from
7131 * the caller
7132 */
7133 if (hole_em) {
7134 u64 calc_end = extent_map_end(hole_em);
7135
7136 if (calc_end <= start || (hole_em->start > end)) {
7137 free_extent_map(hole_em);
7138 hole_em = NULL;
7139 } else {
7140 hole_start = max(hole_em->start, start);
7141 hole_len = calc_end - hole_start;
7142 }
7143 }
7144 em->bdev = NULL;
7145 if (hole_em && range_start > hole_start) {
7146 /* our hole starts before our delalloc, so we
7147 * have to return just the parts of the hole
7148 * that go until the delalloc starts
7149 */
7150 em->len = min(hole_len,
7151 range_start - hole_start);
7152 em->start = hole_start;
7153 em->orig_start = hole_start;
7154 /*
7155 * don't adjust block start at all,
7156 * it is fixed at EXTENT_MAP_HOLE
7157 */
7158 em->block_start = hole_em->block_start;
7159 em->block_len = hole_len;
7160 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7161 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7162 } else {
7163 em->start = range_start;
7164 em->len = found;
7165 em->orig_start = range_start;
7166 em->block_start = EXTENT_MAP_DELALLOC;
7167 em->block_len = found;
7168 }
7169 } else if (hole_em) {
7170 return hole_em;
7171 }
7172 out:
7173
7174 free_extent_map(hole_em);
7175 if (err) {
7176 free_extent_map(em);
7177 return ERR_PTR(err);
7178 }
7179 return em;
7180 }
7181
7182 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7183 const u64 start,
7184 const u64 len,
7185 const u64 orig_start,
7186 const u64 block_start,
7187 const u64 block_len,
7188 const u64 orig_block_len,
7189 const u64 ram_bytes,
7190 const int type)
7191 {
7192 struct extent_map *em = NULL;
7193 int ret;
7194
7195 down_read(&BTRFS_I(inode)->dio_sem);
7196 if (type != BTRFS_ORDERED_NOCOW) {
7197 em = create_pinned_em(inode, start, len, orig_start,
7198 block_start, block_len, orig_block_len,
7199 ram_bytes, type);
7200 if (IS_ERR(em))
7201 goto out;
7202 }
7203 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7204 len, block_len, type);
7205 if (ret) {
7206 if (em) {
7207 free_extent_map(em);
7208 btrfs_drop_extent_cache(inode, start,
7209 start + len - 1, 0);
7210 }
7211 em = ERR_PTR(ret);
7212 }
7213 out:
7214 up_read(&BTRFS_I(inode)->dio_sem);
7215
7216 return em;
7217 }
7218
7219 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7220 u64 start, u64 len)
7221 {
7222 struct btrfs_root *root = BTRFS_I(inode)->root;
7223 struct extent_map *em;
7224 struct btrfs_key ins;
7225 u64 alloc_hint;
7226 int ret;
7227
7228 alloc_hint = get_extent_allocation_hint(inode, start, len);
7229 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7230 alloc_hint, &ins, 1, 1);
7231 if (ret)
7232 return ERR_PTR(ret);
7233
7234 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7235 ins.objectid, ins.offset, ins.offset,
7236 ins.offset, 0);
7237 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7238 if (IS_ERR(em))
7239 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7240
7241 return em;
7242 }
7243
7244 /*
7245 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7246 * block must be cow'd
7247 */
7248 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7249 u64 *orig_start, u64 *orig_block_len,
7250 u64 *ram_bytes)
7251 {
7252 struct btrfs_trans_handle *trans;
7253 struct btrfs_path *path;
7254 int ret;
7255 struct extent_buffer *leaf;
7256 struct btrfs_root *root = BTRFS_I(inode)->root;
7257 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7258 struct btrfs_file_extent_item *fi;
7259 struct btrfs_key key;
7260 u64 disk_bytenr;
7261 u64 backref_offset;
7262 u64 extent_end;
7263 u64 num_bytes;
7264 int slot;
7265 int found_type;
7266 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7267
7268 path = btrfs_alloc_path();
7269 if (!path)
7270 return -ENOMEM;
7271
7272 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7273 offset, 0);
7274 if (ret < 0)
7275 goto out;
7276
7277 slot = path->slots[0];
7278 if (ret == 1) {
7279 if (slot == 0) {
7280 /* can't find the item, must cow */
7281 ret = 0;
7282 goto out;
7283 }
7284 slot--;
7285 }
7286 ret = 0;
7287 leaf = path->nodes[0];
7288 btrfs_item_key_to_cpu(leaf, &key, slot);
7289 if (key.objectid != btrfs_ino(inode) ||
7290 key.type != BTRFS_EXTENT_DATA_KEY) {
7291 /* not our file or wrong item type, must cow */
7292 goto out;
7293 }
7294
7295 if (key.offset > offset) {
7296 /* Wrong offset, must cow */
7297 goto out;
7298 }
7299
7300 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7301 found_type = btrfs_file_extent_type(leaf, fi);
7302 if (found_type != BTRFS_FILE_EXTENT_REG &&
7303 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7304 /* not a regular extent, must cow */
7305 goto out;
7306 }
7307
7308 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7309 goto out;
7310
7311 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7312 if (extent_end <= offset)
7313 goto out;
7314
7315 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7316 if (disk_bytenr == 0)
7317 goto out;
7318
7319 if (btrfs_file_extent_compression(leaf, fi) ||
7320 btrfs_file_extent_encryption(leaf, fi) ||
7321 btrfs_file_extent_other_encoding(leaf, fi))
7322 goto out;
7323
7324 backref_offset = btrfs_file_extent_offset(leaf, fi);
7325
7326 if (orig_start) {
7327 *orig_start = key.offset - backref_offset;
7328 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7329 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7330 }
7331
7332 if (btrfs_extent_readonly(root, disk_bytenr))
7333 goto out;
7334
7335 num_bytes = min(offset + *len, extent_end) - offset;
7336 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7337 u64 range_end;
7338
7339 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7340 ret = test_range_bit(io_tree, offset, range_end,
7341 EXTENT_DELALLOC, 0, NULL);
7342 if (ret) {
7343 ret = -EAGAIN;
7344 goto out;
7345 }
7346 }
7347
7348 btrfs_release_path(path);
7349
7350 /*
7351 * look for other files referencing this extent, if we
7352 * find any we must cow
7353 */
7354 trans = btrfs_join_transaction(root);
7355 if (IS_ERR(trans)) {
7356 ret = 0;
7357 goto out;
7358 }
7359
7360 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7361 key.offset - backref_offset, disk_bytenr);
7362 btrfs_end_transaction(trans, root);
7363 if (ret) {
7364 ret = 0;
7365 goto out;
7366 }
7367
7368 /*
7369 * adjust disk_bytenr and num_bytes to cover just the bytes
7370 * in this extent we are about to write. If there
7371 * are any csums in that range we have to cow in order
7372 * to keep the csums correct
7373 */
7374 disk_bytenr += backref_offset;
7375 disk_bytenr += offset - key.offset;
7376 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7377 goto out;
7378 /*
7379 * all of the above have passed, it is safe to overwrite this extent
7380 * without cow
7381 */
7382 *len = num_bytes;
7383 ret = 1;
7384 out:
7385 btrfs_free_path(path);
7386 return ret;
7387 }
7388
7389 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7390 {
7391 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7392 int found = false;
7393 void **pagep = NULL;
7394 struct page *page = NULL;
7395 int start_idx;
7396 int end_idx;
7397
7398 start_idx = start >> PAGE_SHIFT;
7399
7400 /*
7401 * end is the last byte in the last page. end == start is legal
7402 */
7403 end_idx = end >> PAGE_SHIFT;
7404
7405 rcu_read_lock();
7406
7407 /* Most of the code in this while loop is lifted from
7408 * find_get_page. It's been modified to begin searching from a
7409 * page and return just the first page found in that range. If the
7410 * found idx is less than or equal to the end idx then we know that
7411 * a page exists. If no pages are found or if those pages are
7412 * outside of the range then we're fine (yay!) */
7413 while (page == NULL &&
7414 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7415 page = radix_tree_deref_slot(pagep);
7416 if (unlikely(!page))
7417 break;
7418
7419 if (radix_tree_exception(page)) {
7420 if (radix_tree_deref_retry(page)) {
7421 page = NULL;
7422 continue;
7423 }
7424 /*
7425 * Otherwise, shmem/tmpfs must be storing a swap entry
7426 * here as an exceptional entry: so return it without
7427 * attempting to raise page count.
7428 */
7429 page = NULL;
7430 break; /* TODO: Is this relevant for this use case? */
7431 }
7432
7433 if (!page_cache_get_speculative(page)) {
7434 page = NULL;
7435 continue;
7436 }
7437
7438 /*
7439 * Has the page moved?
7440 * This is part of the lockless pagecache protocol. See
7441 * include/linux/pagemap.h for details.
7442 */
7443 if (unlikely(page != *pagep)) {
7444 put_page(page);
7445 page = NULL;
7446 }
7447 }
7448
7449 if (page) {
7450 if (page->index <= end_idx)
7451 found = true;
7452 put_page(page);
7453 }
7454
7455 rcu_read_unlock();
7456 return found;
7457 }
7458
7459 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7460 struct extent_state **cached_state, int writing)
7461 {
7462 struct btrfs_ordered_extent *ordered;
7463 int ret = 0;
7464
7465 while (1) {
7466 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7467 cached_state);
7468 /*
7469 * We're concerned with the entire range that we're going to be
7470 * doing DIO to, so we need to make sure there's no ordered
7471 * extents in this range.
7472 */
7473 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7474 lockend - lockstart + 1);
7475
7476 /*
7477 * We need to make sure there are no buffered pages in this
7478 * range either, we could have raced between the invalidate in
7479 * generic_file_direct_write and locking the extent. The
7480 * invalidate needs to happen so that reads after a write do not
7481 * get stale data.
7482 */
7483 if (!ordered &&
7484 (!writing ||
7485 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7486 break;
7487
7488 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7489 cached_state, GFP_NOFS);
7490
7491 if (ordered) {
7492 /*
7493 * If we are doing a DIO read and the ordered extent we
7494 * found is for a buffered write, we can not wait for it
7495 * to complete and retry, because if we do so we can
7496 * deadlock with concurrent buffered writes on page
7497 * locks. This happens only if our DIO read covers more
7498 * than one extent map, if at this point has already
7499 * created an ordered extent for a previous extent map
7500 * and locked its range in the inode's io tree, and a
7501 * concurrent write against that previous extent map's
7502 * range and this range started (we unlock the ranges
7503 * in the io tree only when the bios complete and
7504 * buffered writes always lock pages before attempting
7505 * to lock range in the io tree).
7506 */
7507 if (writing ||
7508 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7509 btrfs_start_ordered_extent(inode, ordered, 1);
7510 else
7511 ret = -ENOTBLK;
7512 btrfs_put_ordered_extent(ordered);
7513 } else {
7514 /*
7515 * We could trigger writeback for this range (and wait
7516 * for it to complete) and then invalidate the pages for
7517 * this range (through invalidate_inode_pages2_range()),
7518 * but that can lead us to a deadlock with a concurrent
7519 * call to readpages() (a buffered read or a defrag call
7520 * triggered a readahead) on a page lock due to an
7521 * ordered dio extent we created before but did not have
7522 * yet a corresponding bio submitted (whence it can not
7523 * complete), which makes readpages() wait for that
7524 * ordered extent to complete while holding a lock on
7525 * that page.
7526 */
7527 ret = -ENOTBLK;
7528 }
7529
7530 if (ret)
7531 break;
7532
7533 cond_resched();
7534 }
7535
7536 return ret;
7537 }
7538
7539 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7540 u64 len, u64 orig_start,
7541 u64 block_start, u64 block_len,
7542 u64 orig_block_len, u64 ram_bytes,
7543 int type)
7544 {
7545 struct extent_map_tree *em_tree;
7546 struct extent_map *em;
7547 struct btrfs_root *root = BTRFS_I(inode)->root;
7548 int ret;
7549
7550 em_tree = &BTRFS_I(inode)->extent_tree;
7551 em = alloc_extent_map();
7552 if (!em)
7553 return ERR_PTR(-ENOMEM);
7554
7555 em->start = start;
7556 em->orig_start = orig_start;
7557 em->mod_start = start;
7558 em->mod_len = len;
7559 em->len = len;
7560 em->block_len = block_len;
7561 em->block_start = block_start;
7562 em->bdev = root->fs_info->fs_devices->latest_bdev;
7563 em->orig_block_len = orig_block_len;
7564 em->ram_bytes = ram_bytes;
7565 em->generation = -1;
7566 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7567 if (type == BTRFS_ORDERED_PREALLOC)
7568 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7569
7570 do {
7571 btrfs_drop_extent_cache(inode, em->start,
7572 em->start + em->len - 1, 0);
7573 write_lock(&em_tree->lock);
7574 ret = add_extent_mapping(em_tree, em, 1);
7575 write_unlock(&em_tree->lock);
7576 } while (ret == -EEXIST);
7577
7578 if (ret) {
7579 free_extent_map(em);
7580 return ERR_PTR(ret);
7581 }
7582
7583 return em;
7584 }
7585
7586 static void adjust_dio_outstanding_extents(struct inode *inode,
7587 struct btrfs_dio_data *dio_data,
7588 const u64 len)
7589 {
7590 unsigned num_extents;
7591
7592 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7593 BTRFS_MAX_EXTENT_SIZE);
7594 /*
7595 * If we have an outstanding_extents count still set then we're
7596 * within our reservation, otherwise we need to adjust our inode
7597 * counter appropriately.
7598 */
7599 if (dio_data->outstanding_extents) {
7600 dio_data->outstanding_extents -= num_extents;
7601 } else {
7602 spin_lock(&BTRFS_I(inode)->lock);
7603 BTRFS_I(inode)->outstanding_extents += num_extents;
7604 spin_unlock(&BTRFS_I(inode)->lock);
7605 }
7606 }
7607
7608 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7609 struct buffer_head *bh_result, int create)
7610 {
7611 struct extent_map *em;
7612 struct btrfs_root *root = BTRFS_I(inode)->root;
7613 struct extent_state *cached_state = NULL;
7614 struct btrfs_dio_data *dio_data = NULL;
7615 u64 start = iblock << inode->i_blkbits;
7616 u64 lockstart, lockend;
7617 u64 len = bh_result->b_size;
7618 int unlock_bits = EXTENT_LOCKED;
7619 int ret = 0;
7620
7621 if (create)
7622 unlock_bits |= EXTENT_DIRTY;
7623 else
7624 len = min_t(u64, len, root->sectorsize);
7625
7626 lockstart = start;
7627 lockend = start + len - 1;
7628
7629 if (current->journal_info) {
7630 /*
7631 * Need to pull our outstanding extents and set journal_info to NULL so
7632 * that anything that needs to check if there's a transaction doesn't get
7633 * confused.
7634 */
7635 dio_data = current->journal_info;
7636 current->journal_info = NULL;
7637 }
7638
7639 /*
7640 * If this errors out it's because we couldn't invalidate pagecache for
7641 * this range and we need to fallback to buffered.
7642 */
7643 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7644 create)) {
7645 ret = -ENOTBLK;
7646 goto err;
7647 }
7648
7649 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7650 if (IS_ERR(em)) {
7651 ret = PTR_ERR(em);
7652 goto unlock_err;
7653 }
7654
7655 /*
7656 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7657 * io. INLINE is special, and we could probably kludge it in here, but
7658 * it's still buffered so for safety lets just fall back to the generic
7659 * buffered path.
7660 *
7661 * For COMPRESSED we _have_ to read the entire extent in so we can
7662 * decompress it, so there will be buffering required no matter what we
7663 * do, so go ahead and fallback to buffered.
7664 *
7665 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7666 * to buffered IO. Don't blame me, this is the price we pay for using
7667 * the generic code.
7668 */
7669 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7670 em->block_start == EXTENT_MAP_INLINE) {
7671 free_extent_map(em);
7672 ret = -ENOTBLK;
7673 goto unlock_err;
7674 }
7675
7676 /* Just a good old fashioned hole, return */
7677 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7678 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7679 free_extent_map(em);
7680 goto unlock_err;
7681 }
7682
7683 /*
7684 * We don't allocate a new extent in the following cases
7685 *
7686 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7687 * existing extent.
7688 * 2) The extent is marked as PREALLOC. We're good to go here and can
7689 * just use the extent.
7690 *
7691 */
7692 if (!create) {
7693 len = min(len, em->len - (start - em->start));
7694 lockstart = start + len;
7695 goto unlock;
7696 }
7697
7698 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7699 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7700 em->block_start != EXTENT_MAP_HOLE)) {
7701 int type;
7702 u64 block_start, orig_start, orig_block_len, ram_bytes;
7703
7704 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7705 type = BTRFS_ORDERED_PREALLOC;
7706 else
7707 type = BTRFS_ORDERED_NOCOW;
7708 len = min(len, em->len - (start - em->start));
7709 block_start = em->block_start + (start - em->start);
7710
7711 if (can_nocow_extent(inode, start, &len, &orig_start,
7712 &orig_block_len, &ram_bytes) == 1 &&
7713 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7714 struct extent_map *em2;
7715
7716 em2 = btrfs_create_dio_extent(inode, start, len,
7717 orig_start, block_start,
7718 len, orig_block_len,
7719 ram_bytes, type);
7720 btrfs_dec_nocow_writers(root->fs_info, block_start);
7721 if (type == BTRFS_ORDERED_PREALLOC) {
7722 free_extent_map(em);
7723 em = em2;
7724 }
7725 if (em2 && IS_ERR(em2)) {
7726 ret = PTR_ERR(em2);
7727 goto unlock_err;
7728 }
7729 goto unlock;
7730 }
7731 }
7732
7733 /*
7734 * this will cow the extent, reset the len in case we changed
7735 * it above
7736 */
7737 len = bh_result->b_size;
7738 free_extent_map(em);
7739 em = btrfs_new_extent_direct(inode, start, len);
7740 if (IS_ERR(em)) {
7741 ret = PTR_ERR(em);
7742 goto unlock_err;
7743 }
7744 len = min(len, em->len - (start - em->start));
7745 unlock:
7746 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7747 inode->i_blkbits;
7748 bh_result->b_size = len;
7749 bh_result->b_bdev = em->bdev;
7750 set_buffer_mapped(bh_result);
7751 if (create) {
7752 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7753 set_buffer_new(bh_result);
7754
7755 /*
7756 * Need to update the i_size under the extent lock so buffered
7757 * readers will get the updated i_size when we unlock.
7758 */
7759 if (start + len > i_size_read(inode))
7760 i_size_write(inode, start + len);
7761
7762 adjust_dio_outstanding_extents(inode, dio_data, len);
7763 btrfs_free_reserved_data_space(inode, start, len);
7764 WARN_ON(dio_data->reserve < len);
7765 dio_data->reserve -= len;
7766 dio_data->unsubmitted_oe_range_end = start + len;
7767 current->journal_info = dio_data;
7768 }
7769
7770 /*
7771 * In the case of write we need to clear and unlock the entire range,
7772 * in the case of read we need to unlock only the end area that we
7773 * aren't using if there is any left over space.
7774 */
7775 if (lockstart < lockend) {
7776 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7777 lockend, unlock_bits, 1, 0,
7778 &cached_state, GFP_NOFS);
7779 } else {
7780 free_extent_state(cached_state);
7781 }
7782
7783 free_extent_map(em);
7784
7785 return 0;
7786
7787 unlock_err:
7788 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7789 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7790 err:
7791 if (dio_data)
7792 current->journal_info = dio_data;
7793 /*
7794 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7795 * write less data then expected, so that we don't underflow our inode's
7796 * outstanding extents counter.
7797 */
7798 if (create && dio_data)
7799 adjust_dio_outstanding_extents(inode, dio_data, len);
7800
7801 return ret;
7802 }
7803
7804 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7805 int rw, int mirror_num)
7806 {
7807 struct btrfs_root *root = BTRFS_I(inode)->root;
7808 int ret;
7809
7810 BUG_ON(rw & REQ_WRITE);
7811
7812 bio_get(bio);
7813
7814 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7815 BTRFS_WQ_ENDIO_DIO_REPAIR);
7816 if (ret)
7817 goto err;
7818
7819 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7820 err:
7821 bio_put(bio);
7822 return ret;
7823 }
7824
7825 static int btrfs_check_dio_repairable(struct inode *inode,
7826 struct bio *failed_bio,
7827 struct io_failure_record *failrec,
7828 int failed_mirror)
7829 {
7830 int num_copies;
7831
7832 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7833 failrec->logical, failrec->len);
7834 if (num_copies == 1) {
7835 /*
7836 * we only have a single copy of the data, so don't bother with
7837 * all the retry and error correction code that follows. no
7838 * matter what the error is, it is very likely to persist.
7839 */
7840 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7841 num_copies, failrec->this_mirror, failed_mirror);
7842 return 0;
7843 }
7844
7845 failrec->failed_mirror = failed_mirror;
7846 failrec->this_mirror++;
7847 if (failrec->this_mirror == failed_mirror)
7848 failrec->this_mirror++;
7849
7850 if (failrec->this_mirror > num_copies) {
7851 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7852 num_copies, failrec->this_mirror, failed_mirror);
7853 return 0;
7854 }
7855
7856 return 1;
7857 }
7858
7859 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7860 struct page *page, unsigned int pgoff,
7861 u64 start, u64 end, int failed_mirror,
7862 bio_end_io_t *repair_endio, void *repair_arg)
7863 {
7864 struct io_failure_record *failrec;
7865 struct bio *bio;
7866 int isector;
7867 int read_mode;
7868 int ret;
7869
7870 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7871
7872 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7873 if (ret)
7874 return ret;
7875
7876 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7877 failed_mirror);
7878 if (!ret) {
7879 free_io_failure(inode, failrec);
7880 return -EIO;
7881 }
7882
7883 if ((failed_bio->bi_vcnt > 1)
7884 || (failed_bio->bi_io_vec->bv_len
7885 > BTRFS_I(inode)->root->sectorsize))
7886 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7887 else
7888 read_mode = READ_SYNC;
7889
7890 isector = start - btrfs_io_bio(failed_bio)->logical;
7891 isector >>= inode->i_sb->s_blocksize_bits;
7892 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7893 pgoff, isector, repair_endio, repair_arg);
7894 if (!bio) {
7895 free_io_failure(inode, failrec);
7896 return -EIO;
7897 }
7898
7899 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7900 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7901 read_mode, failrec->this_mirror, failrec->in_validation);
7902
7903 ret = submit_dio_repair_bio(inode, bio, read_mode,
7904 failrec->this_mirror);
7905 if (ret) {
7906 free_io_failure(inode, failrec);
7907 bio_put(bio);
7908 }
7909
7910 return ret;
7911 }
7912
7913 struct btrfs_retry_complete {
7914 struct completion done;
7915 struct inode *inode;
7916 u64 start;
7917 int uptodate;
7918 };
7919
7920 static void btrfs_retry_endio_nocsum(struct bio *bio)
7921 {
7922 struct btrfs_retry_complete *done = bio->bi_private;
7923 struct inode *inode;
7924 struct bio_vec *bvec;
7925 int i;
7926
7927 if (bio->bi_error)
7928 goto end;
7929
7930 ASSERT(bio->bi_vcnt == 1);
7931 inode = bio->bi_io_vec->bv_page->mapping->host;
7932 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7933
7934 done->uptodate = 1;
7935 bio_for_each_segment_all(bvec, bio, i)
7936 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7937 end:
7938 complete(&done->done);
7939 bio_put(bio);
7940 }
7941
7942 static int __btrfs_correct_data_nocsum(struct inode *inode,
7943 struct btrfs_io_bio *io_bio)
7944 {
7945 struct btrfs_fs_info *fs_info;
7946 struct bio_vec *bvec;
7947 struct btrfs_retry_complete done;
7948 u64 start;
7949 unsigned int pgoff;
7950 u32 sectorsize;
7951 int nr_sectors;
7952 int i;
7953 int ret;
7954
7955 fs_info = BTRFS_I(inode)->root->fs_info;
7956 sectorsize = BTRFS_I(inode)->root->sectorsize;
7957
7958 start = io_bio->logical;
7959 done.inode = inode;
7960
7961 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7962 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7963 pgoff = bvec->bv_offset;
7964
7965 next_block_or_try_again:
7966 done.uptodate = 0;
7967 done.start = start;
7968 init_completion(&done.done);
7969
7970 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7971 pgoff, start, start + sectorsize - 1,
7972 io_bio->mirror_num,
7973 btrfs_retry_endio_nocsum, &done);
7974 if (ret)
7975 return ret;
7976
7977 wait_for_completion(&done.done);
7978
7979 if (!done.uptodate) {
7980 /* We might have another mirror, so try again */
7981 goto next_block_or_try_again;
7982 }
7983
7984 start += sectorsize;
7985
7986 if (nr_sectors--) {
7987 pgoff += sectorsize;
7988 goto next_block_or_try_again;
7989 }
7990 }
7991
7992 return 0;
7993 }
7994
7995 static void btrfs_retry_endio(struct bio *bio)
7996 {
7997 struct btrfs_retry_complete *done = bio->bi_private;
7998 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7999 struct inode *inode;
8000 struct bio_vec *bvec;
8001 u64 start;
8002 int uptodate;
8003 int ret;
8004 int i;
8005
8006 if (bio->bi_error)
8007 goto end;
8008
8009 uptodate = 1;
8010
8011 start = done->start;
8012
8013 ASSERT(bio->bi_vcnt == 1);
8014 inode = bio->bi_io_vec->bv_page->mapping->host;
8015 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
8016
8017 bio_for_each_segment_all(bvec, bio, i) {
8018 ret = __readpage_endio_check(done->inode, io_bio, i,
8019 bvec->bv_page, bvec->bv_offset,
8020 done->start, bvec->bv_len);
8021 if (!ret)
8022 clean_io_failure(done->inode, done->start,
8023 bvec->bv_page, bvec->bv_offset);
8024 else
8025 uptodate = 0;
8026 }
8027
8028 done->uptodate = uptodate;
8029 end:
8030 complete(&done->done);
8031 bio_put(bio);
8032 }
8033
8034 static int __btrfs_subio_endio_read(struct inode *inode,
8035 struct btrfs_io_bio *io_bio, int err)
8036 {
8037 struct btrfs_fs_info *fs_info;
8038 struct bio_vec *bvec;
8039 struct btrfs_retry_complete done;
8040 u64 start;
8041 u64 offset = 0;
8042 u32 sectorsize;
8043 int nr_sectors;
8044 unsigned int pgoff;
8045 int csum_pos;
8046 int i;
8047 int ret;
8048
8049 fs_info = BTRFS_I(inode)->root->fs_info;
8050 sectorsize = BTRFS_I(inode)->root->sectorsize;
8051
8052 err = 0;
8053 start = io_bio->logical;
8054 done.inode = inode;
8055
8056 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8057 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8058
8059 pgoff = bvec->bv_offset;
8060 next_block:
8061 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8062 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8063 bvec->bv_page, pgoff, start,
8064 sectorsize);
8065 if (likely(!ret))
8066 goto next;
8067 try_again:
8068 done.uptodate = 0;
8069 done.start = start;
8070 init_completion(&done.done);
8071
8072 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8073 pgoff, start, start + sectorsize - 1,
8074 io_bio->mirror_num,
8075 btrfs_retry_endio, &done);
8076 if (ret) {
8077 err = ret;
8078 goto next;
8079 }
8080
8081 wait_for_completion(&done.done);
8082
8083 if (!done.uptodate) {
8084 /* We might have another mirror, so try again */
8085 goto try_again;
8086 }
8087 next:
8088 offset += sectorsize;
8089 start += sectorsize;
8090
8091 ASSERT(nr_sectors);
8092
8093 if (--nr_sectors) {
8094 pgoff += sectorsize;
8095 goto next_block;
8096 }
8097 }
8098
8099 return err;
8100 }
8101
8102 static int btrfs_subio_endio_read(struct inode *inode,
8103 struct btrfs_io_bio *io_bio, int err)
8104 {
8105 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8106
8107 if (skip_csum) {
8108 if (unlikely(err))
8109 return __btrfs_correct_data_nocsum(inode, io_bio);
8110 else
8111 return 0;
8112 } else {
8113 return __btrfs_subio_endio_read(inode, io_bio, err);
8114 }
8115 }
8116
8117 static void btrfs_endio_direct_read(struct bio *bio)
8118 {
8119 struct btrfs_dio_private *dip = bio->bi_private;
8120 struct inode *inode = dip->inode;
8121 struct bio *dio_bio;
8122 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8123 int err = bio->bi_error;
8124
8125 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8126 err = btrfs_subio_endio_read(inode, io_bio, err);
8127
8128 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8129 dip->logical_offset + dip->bytes - 1);
8130 dio_bio = dip->dio_bio;
8131
8132 kfree(dip);
8133
8134 dio_bio->bi_error = bio->bi_error;
8135 dio_end_io(dio_bio, bio->bi_error);
8136
8137 if (io_bio->end_io)
8138 io_bio->end_io(io_bio, err);
8139 bio_put(bio);
8140 }
8141
8142 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8143 const u64 offset,
8144 const u64 bytes,
8145 const int uptodate)
8146 {
8147 struct btrfs_root *root = BTRFS_I(inode)->root;
8148 struct btrfs_ordered_extent *ordered = NULL;
8149 u64 ordered_offset = offset;
8150 u64 ordered_bytes = bytes;
8151 int ret;
8152
8153 again:
8154 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8155 &ordered_offset,
8156 ordered_bytes,
8157 uptodate);
8158 if (!ret)
8159 goto out_test;
8160
8161 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8162 finish_ordered_fn, NULL, NULL);
8163 btrfs_queue_work(root->fs_info->endio_write_workers,
8164 &ordered->work);
8165 out_test:
8166 /*
8167 * our bio might span multiple ordered extents. If we haven't
8168 * completed the accounting for the whole dio, go back and try again
8169 */
8170 if (ordered_offset < offset + bytes) {
8171 ordered_bytes = offset + bytes - ordered_offset;
8172 ordered = NULL;
8173 goto again;
8174 }
8175 }
8176
8177 static void btrfs_endio_direct_write(struct bio *bio)
8178 {
8179 struct btrfs_dio_private *dip = bio->bi_private;
8180 struct bio *dio_bio = dip->dio_bio;
8181
8182 btrfs_endio_direct_write_update_ordered(dip->inode,
8183 dip->logical_offset,
8184 dip->bytes,
8185 !bio->bi_error);
8186
8187 kfree(dip);
8188
8189 dio_bio->bi_error = bio->bi_error;
8190 dio_end_io(dio_bio, bio->bi_error);
8191 bio_put(bio);
8192 }
8193
8194 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8195 struct bio *bio, int mirror_num,
8196 unsigned long bio_flags, u64 offset)
8197 {
8198 int ret;
8199 struct btrfs_root *root = BTRFS_I(inode)->root;
8200 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8201 BUG_ON(ret); /* -ENOMEM */
8202 return 0;
8203 }
8204
8205 static void btrfs_end_dio_bio(struct bio *bio)
8206 {
8207 struct btrfs_dio_private *dip = bio->bi_private;
8208 int err = bio->bi_error;
8209
8210 if (err)
8211 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8212 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8213 btrfs_ino(dip->inode), bio->bi_rw,
8214 (unsigned long long)bio->bi_iter.bi_sector,
8215 bio->bi_iter.bi_size, err);
8216
8217 if (dip->subio_endio)
8218 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8219
8220 if (err) {
8221 dip->errors = 1;
8222
8223 /*
8224 * before atomic variable goto zero, we must make sure
8225 * dip->errors is perceived to be set.
8226 */
8227 smp_mb__before_atomic();
8228 }
8229
8230 /* if there are more bios still pending for this dio, just exit */
8231 if (!atomic_dec_and_test(&dip->pending_bios))
8232 goto out;
8233
8234 if (dip->errors) {
8235 bio_io_error(dip->orig_bio);
8236 } else {
8237 dip->dio_bio->bi_error = 0;
8238 bio_endio(dip->orig_bio);
8239 }
8240 out:
8241 bio_put(bio);
8242 }
8243
8244 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8245 u64 first_sector, gfp_t gfp_flags)
8246 {
8247 struct bio *bio;
8248 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8249 if (bio)
8250 bio_associate_current(bio);
8251 return bio;
8252 }
8253
8254 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8255 struct inode *inode,
8256 struct btrfs_dio_private *dip,
8257 struct bio *bio,
8258 u64 file_offset)
8259 {
8260 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8261 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8262 int ret;
8263
8264 /*
8265 * We load all the csum data we need when we submit
8266 * the first bio to reduce the csum tree search and
8267 * contention.
8268 */
8269 if (dip->logical_offset == file_offset) {
8270 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8271 file_offset);
8272 if (ret)
8273 return ret;
8274 }
8275
8276 if (bio == dip->orig_bio)
8277 return 0;
8278
8279 file_offset -= dip->logical_offset;
8280 file_offset >>= inode->i_sb->s_blocksize_bits;
8281 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8282
8283 return 0;
8284 }
8285
8286 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8287 int rw, u64 file_offset, int skip_sum,
8288 int async_submit)
8289 {
8290 struct btrfs_dio_private *dip = bio->bi_private;
8291 int write = rw & REQ_WRITE;
8292 struct btrfs_root *root = BTRFS_I(inode)->root;
8293 int ret;
8294
8295 if (async_submit)
8296 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8297
8298 bio_get(bio);
8299
8300 if (!write) {
8301 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8302 BTRFS_WQ_ENDIO_DATA);
8303 if (ret)
8304 goto err;
8305 }
8306
8307 if (skip_sum)
8308 goto map;
8309
8310 if (write && async_submit) {
8311 ret = btrfs_wq_submit_bio(root->fs_info,
8312 inode, rw, bio, 0, 0,
8313 file_offset,
8314 __btrfs_submit_bio_start_direct_io,
8315 __btrfs_submit_bio_done);
8316 goto err;
8317 } else if (write) {
8318 /*
8319 * If we aren't doing async submit, calculate the csum of the
8320 * bio now.
8321 */
8322 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8323 if (ret)
8324 goto err;
8325 } else {
8326 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8327 file_offset);
8328 if (ret)
8329 goto err;
8330 }
8331 map:
8332 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8333 err:
8334 bio_put(bio);
8335 return ret;
8336 }
8337
8338 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8339 int skip_sum)
8340 {
8341 struct inode *inode = dip->inode;
8342 struct btrfs_root *root = BTRFS_I(inode)->root;
8343 struct bio *bio;
8344 struct bio *orig_bio = dip->orig_bio;
8345 struct bio_vec *bvec = orig_bio->bi_io_vec;
8346 u64 start_sector = orig_bio->bi_iter.bi_sector;
8347 u64 file_offset = dip->logical_offset;
8348 u64 submit_len = 0;
8349 u64 map_length;
8350 u32 blocksize = root->sectorsize;
8351 int async_submit = 0;
8352 int nr_sectors;
8353 int ret;
8354 int i;
8355
8356 map_length = orig_bio->bi_iter.bi_size;
8357 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8358 &map_length, NULL, 0);
8359 if (ret)
8360 return -EIO;
8361
8362 if (map_length >= orig_bio->bi_iter.bi_size) {
8363 bio = orig_bio;
8364 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8365 goto submit;
8366 }
8367
8368 /* async crcs make it difficult to collect full stripe writes. */
8369 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8370 async_submit = 0;
8371 else
8372 async_submit = 1;
8373
8374 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8375 if (!bio)
8376 return -ENOMEM;
8377
8378 bio->bi_private = dip;
8379 bio->bi_end_io = btrfs_end_dio_bio;
8380 btrfs_io_bio(bio)->logical = file_offset;
8381 atomic_inc(&dip->pending_bios);
8382
8383 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8384 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8385 i = 0;
8386 next_block:
8387 if (unlikely(map_length < submit_len + blocksize ||
8388 bio_add_page(bio, bvec->bv_page, blocksize,
8389 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8390 /*
8391 * inc the count before we submit the bio so
8392 * we know the end IO handler won't happen before
8393 * we inc the count. Otherwise, the dip might get freed
8394 * before we're done setting it up
8395 */
8396 atomic_inc(&dip->pending_bios);
8397 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8398 file_offset, skip_sum,
8399 async_submit);
8400 if (ret) {
8401 bio_put(bio);
8402 atomic_dec(&dip->pending_bios);
8403 goto out_err;
8404 }
8405
8406 start_sector += submit_len >> 9;
8407 file_offset += submit_len;
8408
8409 submit_len = 0;
8410
8411 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8412 start_sector, GFP_NOFS);
8413 if (!bio)
8414 goto out_err;
8415 bio->bi_private = dip;
8416 bio->bi_end_io = btrfs_end_dio_bio;
8417 btrfs_io_bio(bio)->logical = file_offset;
8418
8419 map_length = orig_bio->bi_iter.bi_size;
8420 ret = btrfs_map_block(root->fs_info, rw,
8421 start_sector << 9,
8422 &map_length, NULL, 0);
8423 if (ret) {
8424 bio_put(bio);
8425 goto out_err;
8426 }
8427
8428 goto next_block;
8429 } else {
8430 submit_len += blocksize;
8431 if (--nr_sectors) {
8432 i++;
8433 goto next_block;
8434 }
8435 bvec++;
8436 }
8437 }
8438
8439 submit:
8440 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8441 async_submit);
8442 if (!ret)
8443 return 0;
8444
8445 bio_put(bio);
8446 out_err:
8447 dip->errors = 1;
8448 /*
8449 * before atomic variable goto zero, we must
8450 * make sure dip->errors is perceived to be set.
8451 */
8452 smp_mb__before_atomic();
8453 if (atomic_dec_and_test(&dip->pending_bios))
8454 bio_io_error(dip->orig_bio);
8455
8456 /* bio_end_io() will handle error, so we needn't return it */
8457 return 0;
8458 }
8459
8460 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8461 struct inode *inode, loff_t file_offset)
8462 {
8463 struct btrfs_dio_private *dip = NULL;
8464 struct bio *io_bio = NULL;
8465 struct btrfs_io_bio *btrfs_bio;
8466 int skip_sum;
8467 int write = rw & REQ_WRITE;
8468 int ret = 0;
8469
8470 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8471
8472 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8473 if (!io_bio) {
8474 ret = -ENOMEM;
8475 goto free_ordered;
8476 }
8477
8478 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8479 if (!dip) {
8480 ret = -ENOMEM;
8481 goto free_ordered;
8482 }
8483
8484 dip->private = dio_bio->bi_private;
8485 dip->inode = inode;
8486 dip->logical_offset = file_offset;
8487 dip->bytes = dio_bio->bi_iter.bi_size;
8488 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8489 io_bio->bi_private = dip;
8490 dip->orig_bio = io_bio;
8491 dip->dio_bio = dio_bio;
8492 atomic_set(&dip->pending_bios, 0);
8493 btrfs_bio = btrfs_io_bio(io_bio);
8494 btrfs_bio->logical = file_offset;
8495
8496 if (write) {
8497 io_bio->bi_end_io = btrfs_endio_direct_write;
8498 } else {
8499 io_bio->bi_end_io = btrfs_endio_direct_read;
8500 dip->subio_endio = btrfs_subio_endio_read;
8501 }
8502
8503 /*
8504 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8505 * even if we fail to submit a bio, because in such case we do the
8506 * corresponding error handling below and it must not be done a second
8507 * time by btrfs_direct_IO().
8508 */
8509 if (write) {
8510 struct btrfs_dio_data *dio_data = current->journal_info;
8511
8512 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8513 dip->bytes;
8514 dio_data->unsubmitted_oe_range_start =
8515 dio_data->unsubmitted_oe_range_end;
8516 }
8517
8518 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8519 if (!ret)
8520 return;
8521
8522 if (btrfs_bio->end_io)
8523 btrfs_bio->end_io(btrfs_bio, ret);
8524
8525 free_ordered:
8526 /*
8527 * If we arrived here it means either we failed to submit the dip
8528 * or we either failed to clone the dio_bio or failed to allocate the
8529 * dip. If we cloned the dio_bio and allocated the dip, we can just
8530 * call bio_endio against our io_bio so that we get proper resource
8531 * cleanup if we fail to submit the dip, otherwise, we must do the
8532 * same as btrfs_endio_direct_[write|read] because we can't call these
8533 * callbacks - they require an allocated dip and a clone of dio_bio.
8534 */
8535 if (io_bio && dip) {
8536 io_bio->bi_error = -EIO;
8537 bio_endio(io_bio);
8538 /*
8539 * The end io callbacks free our dip, do the final put on io_bio
8540 * and all the cleanup and final put for dio_bio (through
8541 * dio_end_io()).
8542 */
8543 dip = NULL;
8544 io_bio = NULL;
8545 } else {
8546 if (write)
8547 btrfs_endio_direct_write_update_ordered(inode,
8548 file_offset,
8549 dio_bio->bi_iter.bi_size,
8550 0);
8551 else
8552 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8553 file_offset + dio_bio->bi_iter.bi_size - 1);
8554
8555 dio_bio->bi_error = -EIO;
8556 /*
8557 * Releases and cleans up our dio_bio, no need to bio_put()
8558 * nor bio_endio()/bio_io_error() against dio_bio.
8559 */
8560 dio_end_io(dio_bio, ret);
8561 }
8562 if (io_bio)
8563 bio_put(io_bio);
8564 kfree(dip);
8565 }
8566
8567 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8568 const struct iov_iter *iter, loff_t offset)
8569 {
8570 int seg;
8571 int i;
8572 unsigned blocksize_mask = root->sectorsize - 1;
8573 ssize_t retval = -EINVAL;
8574
8575 if (offset & blocksize_mask)
8576 goto out;
8577
8578 if (iov_iter_alignment(iter) & blocksize_mask)
8579 goto out;
8580
8581 /* If this is a write we don't need to check anymore */
8582 if (iov_iter_rw(iter) == WRITE)
8583 return 0;
8584 /*
8585 * Check to make sure we don't have duplicate iov_base's in this
8586 * iovec, if so return EINVAL, otherwise we'll get csum errors
8587 * when reading back.
8588 */
8589 for (seg = 0; seg < iter->nr_segs; seg++) {
8590 for (i = seg + 1; i < iter->nr_segs; i++) {
8591 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8592 goto out;
8593 }
8594 }
8595 retval = 0;
8596 out:
8597 return retval;
8598 }
8599
8600 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8601 {
8602 struct file *file = iocb->ki_filp;
8603 struct inode *inode = file->f_mapping->host;
8604 struct btrfs_root *root = BTRFS_I(inode)->root;
8605 struct btrfs_dio_data dio_data = { 0 };
8606 loff_t offset = iocb->ki_pos;
8607 size_t count = 0;
8608 int flags = 0;
8609 bool wakeup = true;
8610 bool relock = false;
8611 ssize_t ret;
8612
8613 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8614 return 0;
8615
8616 inode_dio_begin(inode);
8617 smp_mb__after_atomic();
8618
8619 /*
8620 * The generic stuff only does filemap_write_and_wait_range, which
8621 * isn't enough if we've written compressed pages to this area, so
8622 * we need to flush the dirty pages again to make absolutely sure
8623 * that any outstanding dirty pages are on disk.
8624 */
8625 count = iov_iter_count(iter);
8626 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8627 &BTRFS_I(inode)->runtime_flags))
8628 filemap_fdatawrite_range(inode->i_mapping, offset,
8629 offset + count - 1);
8630
8631 if (iov_iter_rw(iter) == WRITE) {
8632 /*
8633 * If the write DIO is beyond the EOF, we need update
8634 * the isize, but it is protected by i_mutex. So we can
8635 * not unlock the i_mutex at this case.
8636 */
8637 if (offset + count <= inode->i_size) {
8638 inode_unlock(inode);
8639 relock = true;
8640 }
8641 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8642 if (ret)
8643 goto out;
8644 dio_data.outstanding_extents = div64_u64(count +
8645 BTRFS_MAX_EXTENT_SIZE - 1,
8646 BTRFS_MAX_EXTENT_SIZE);
8647
8648 /*
8649 * We need to know how many extents we reserved so that we can
8650 * do the accounting properly if we go over the number we
8651 * originally calculated. Abuse current->journal_info for this.
8652 */
8653 dio_data.reserve = round_up(count, root->sectorsize);
8654 dio_data.unsubmitted_oe_range_start = (u64)offset;
8655 dio_data.unsubmitted_oe_range_end = (u64)offset;
8656 current->journal_info = &dio_data;
8657 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8658 &BTRFS_I(inode)->runtime_flags)) {
8659 inode_dio_end(inode);
8660 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8661 wakeup = false;
8662 }
8663
8664 ret = __blockdev_direct_IO(iocb, inode,
8665 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8666 iter, btrfs_get_blocks_direct, NULL,
8667 btrfs_submit_direct, flags);
8668 if (iov_iter_rw(iter) == WRITE) {
8669 current->journal_info = NULL;
8670 if (ret < 0 && ret != -EIOCBQUEUED) {
8671 if (dio_data.reserve)
8672 btrfs_delalloc_release_space(inode, offset,
8673 dio_data.reserve);
8674 /*
8675 * On error we might have left some ordered extents
8676 * without submitting corresponding bios for them, so
8677 * cleanup them up to avoid other tasks getting them
8678 * and waiting for them to complete forever.
8679 */
8680 if (dio_data.unsubmitted_oe_range_start <
8681 dio_data.unsubmitted_oe_range_end)
8682 btrfs_endio_direct_write_update_ordered(inode,
8683 dio_data.unsubmitted_oe_range_start,
8684 dio_data.unsubmitted_oe_range_end -
8685 dio_data.unsubmitted_oe_range_start,
8686 0);
8687 } else if (ret >= 0 && (size_t)ret < count)
8688 btrfs_delalloc_release_space(inode, offset,
8689 count - (size_t)ret);
8690 }
8691 out:
8692 if (wakeup)
8693 inode_dio_end(inode);
8694 if (relock)
8695 inode_lock(inode);
8696
8697 return ret;
8698 }
8699
8700 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8701
8702 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8703 __u64 start, __u64 len)
8704 {
8705 int ret;
8706
8707 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8708 if (ret)
8709 return ret;
8710
8711 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8712 }
8713
8714 int btrfs_readpage(struct file *file, struct page *page)
8715 {
8716 struct extent_io_tree *tree;
8717 tree = &BTRFS_I(page->mapping->host)->io_tree;
8718 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8719 }
8720
8721 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8722 {
8723 struct extent_io_tree *tree;
8724 struct inode *inode = page->mapping->host;
8725 int ret;
8726
8727 if (current->flags & PF_MEMALLOC) {
8728 redirty_page_for_writepage(wbc, page);
8729 unlock_page(page);
8730 return 0;
8731 }
8732
8733 /*
8734 * If we are under memory pressure we will call this directly from the
8735 * VM, we need to make sure we have the inode referenced for the ordered
8736 * extent. If not just return like we didn't do anything.
8737 */
8738 if (!igrab(inode)) {
8739 redirty_page_for_writepage(wbc, page);
8740 return AOP_WRITEPAGE_ACTIVATE;
8741 }
8742 tree = &BTRFS_I(page->mapping->host)->io_tree;
8743 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8744 btrfs_add_delayed_iput(inode);
8745 return ret;
8746 }
8747
8748 static int btrfs_writepages(struct address_space *mapping,
8749 struct writeback_control *wbc)
8750 {
8751 struct extent_io_tree *tree;
8752
8753 tree = &BTRFS_I(mapping->host)->io_tree;
8754 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8755 }
8756
8757 static int
8758 btrfs_readpages(struct file *file, struct address_space *mapping,
8759 struct list_head *pages, unsigned nr_pages)
8760 {
8761 struct extent_io_tree *tree;
8762 tree = &BTRFS_I(mapping->host)->io_tree;
8763 return extent_readpages(tree, mapping, pages, nr_pages,
8764 btrfs_get_extent);
8765 }
8766 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8767 {
8768 struct extent_io_tree *tree;
8769 struct extent_map_tree *map;
8770 int ret;
8771
8772 tree = &BTRFS_I(page->mapping->host)->io_tree;
8773 map = &BTRFS_I(page->mapping->host)->extent_tree;
8774 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8775 if (ret == 1) {
8776 ClearPagePrivate(page);
8777 set_page_private(page, 0);
8778 put_page(page);
8779 }
8780 return ret;
8781 }
8782
8783 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8784 {
8785 if (PageWriteback(page) || PageDirty(page))
8786 return 0;
8787 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8788 }
8789
8790 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8791 unsigned int length)
8792 {
8793 struct inode *inode = page->mapping->host;
8794 struct extent_io_tree *tree;
8795 struct btrfs_ordered_extent *ordered;
8796 struct extent_state *cached_state = NULL;
8797 u64 page_start = page_offset(page);
8798 u64 page_end = page_start + PAGE_SIZE - 1;
8799 u64 start;
8800 u64 end;
8801 int inode_evicting = inode->i_state & I_FREEING;
8802
8803 /*
8804 * we have the page locked, so new writeback can't start,
8805 * and the dirty bit won't be cleared while we are here.
8806 *
8807 * Wait for IO on this page so that we can safely clear
8808 * the PagePrivate2 bit and do ordered accounting
8809 */
8810 wait_on_page_writeback(page);
8811
8812 tree = &BTRFS_I(inode)->io_tree;
8813 if (offset) {
8814 btrfs_releasepage(page, GFP_NOFS);
8815 return;
8816 }
8817
8818 if (!inode_evicting)
8819 lock_extent_bits(tree, page_start, page_end, &cached_state);
8820 again:
8821 start = page_start;
8822 ordered = btrfs_lookup_ordered_range(inode, start,
8823 page_end - start + 1);
8824 if (ordered) {
8825 end = min(page_end, ordered->file_offset + ordered->len - 1);
8826 /*
8827 * IO on this page will never be started, so we need
8828 * to account for any ordered extents now
8829 */
8830 if (!inode_evicting)
8831 clear_extent_bit(tree, start, end,
8832 EXTENT_DIRTY | EXTENT_DELALLOC |
8833 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8834 EXTENT_DEFRAG, 1, 0, &cached_state,
8835 GFP_NOFS);
8836 /*
8837 * whoever cleared the private bit is responsible
8838 * for the finish_ordered_io
8839 */
8840 if (TestClearPagePrivate2(page)) {
8841 struct btrfs_ordered_inode_tree *tree;
8842 u64 new_len;
8843
8844 tree = &BTRFS_I(inode)->ordered_tree;
8845
8846 spin_lock_irq(&tree->lock);
8847 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8848 new_len = start - ordered->file_offset;
8849 if (new_len < ordered->truncated_len)
8850 ordered->truncated_len = new_len;
8851 spin_unlock_irq(&tree->lock);
8852
8853 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8854 start,
8855 end - start + 1, 1))
8856 btrfs_finish_ordered_io(ordered);
8857 }
8858 btrfs_put_ordered_extent(ordered);
8859 if (!inode_evicting) {
8860 cached_state = NULL;
8861 lock_extent_bits(tree, start, end,
8862 &cached_state);
8863 }
8864
8865 start = end + 1;
8866 if (start < page_end)
8867 goto again;
8868 }
8869
8870 /*
8871 * Qgroup reserved space handler
8872 * Page here will be either
8873 * 1) Already written to disk
8874 * In this case, its reserved space is released from data rsv map
8875 * and will be freed by delayed_ref handler finally.
8876 * So even we call qgroup_free_data(), it won't decrease reserved
8877 * space.
8878 * 2) Not written to disk
8879 * This means the reserved space should be freed here.
8880 */
8881 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8882 if (!inode_evicting) {
8883 clear_extent_bit(tree, page_start, page_end,
8884 EXTENT_LOCKED | EXTENT_DIRTY |
8885 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8886 EXTENT_DEFRAG, 1, 1,
8887 &cached_state, GFP_NOFS);
8888
8889 __btrfs_releasepage(page, GFP_NOFS);
8890 }
8891
8892 ClearPageChecked(page);
8893 if (PagePrivate(page)) {
8894 ClearPagePrivate(page);
8895 set_page_private(page, 0);
8896 put_page(page);
8897 }
8898 }
8899
8900 /*
8901 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8902 * called from a page fault handler when a page is first dirtied. Hence we must
8903 * be careful to check for EOF conditions here. We set the page up correctly
8904 * for a written page which means we get ENOSPC checking when writing into
8905 * holes and correct delalloc and unwritten extent mapping on filesystems that
8906 * support these features.
8907 *
8908 * We are not allowed to take the i_mutex here so we have to play games to
8909 * protect against truncate races as the page could now be beyond EOF. Because
8910 * vmtruncate() writes the inode size before removing pages, once we have the
8911 * page lock we can determine safely if the page is beyond EOF. If it is not
8912 * beyond EOF, then the page is guaranteed safe against truncation until we
8913 * unlock the page.
8914 */
8915 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8916 {
8917 struct page *page = vmf->page;
8918 struct inode *inode = file_inode(vma->vm_file);
8919 struct btrfs_root *root = BTRFS_I(inode)->root;
8920 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8921 struct btrfs_ordered_extent *ordered;
8922 struct extent_state *cached_state = NULL;
8923 char *kaddr;
8924 unsigned long zero_start;
8925 loff_t size;
8926 int ret;
8927 int reserved = 0;
8928 u64 reserved_space;
8929 u64 page_start;
8930 u64 page_end;
8931 u64 end;
8932
8933 reserved_space = PAGE_SIZE;
8934
8935 sb_start_pagefault(inode->i_sb);
8936 page_start = page_offset(page);
8937 page_end = page_start + PAGE_SIZE - 1;
8938 end = page_end;
8939
8940 /*
8941 * Reserving delalloc space after obtaining the page lock can lead to
8942 * deadlock. For example, if a dirty page is locked by this function
8943 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8944 * dirty page write out, then the btrfs_writepage() function could
8945 * end up waiting indefinitely to get a lock on the page currently
8946 * being processed by btrfs_page_mkwrite() function.
8947 */
8948 ret = btrfs_delalloc_reserve_space(inode, page_start,
8949 reserved_space);
8950 if (!ret) {
8951 ret = file_update_time(vma->vm_file);
8952 reserved = 1;
8953 }
8954 if (ret) {
8955 if (ret == -ENOMEM)
8956 ret = VM_FAULT_OOM;
8957 else /* -ENOSPC, -EIO, etc */
8958 ret = VM_FAULT_SIGBUS;
8959 if (reserved)
8960 goto out;
8961 goto out_noreserve;
8962 }
8963
8964 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8965 again:
8966 lock_page(page);
8967 size = i_size_read(inode);
8968
8969 if ((page->mapping != inode->i_mapping) ||
8970 (page_start >= size)) {
8971 /* page got truncated out from underneath us */
8972 goto out_unlock;
8973 }
8974 wait_on_page_writeback(page);
8975
8976 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8977 set_page_extent_mapped(page);
8978
8979 /*
8980 * we can't set the delalloc bits if there are pending ordered
8981 * extents. Drop our locks and wait for them to finish
8982 */
8983 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
8984 if (ordered) {
8985 unlock_extent_cached(io_tree, page_start, page_end,
8986 &cached_state, GFP_NOFS);
8987 unlock_page(page);
8988 btrfs_start_ordered_extent(inode, ordered, 1);
8989 btrfs_put_ordered_extent(ordered);
8990 goto again;
8991 }
8992
8993 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8994 reserved_space = round_up(size - page_start, root->sectorsize);
8995 if (reserved_space < PAGE_SIZE) {
8996 end = page_start + reserved_space - 1;
8997 spin_lock(&BTRFS_I(inode)->lock);
8998 BTRFS_I(inode)->outstanding_extents++;
8999 spin_unlock(&BTRFS_I(inode)->lock);
9000 btrfs_delalloc_release_space(inode, page_start,
9001 PAGE_SIZE - reserved_space);
9002 }
9003 }
9004
9005 /*
9006 * XXX - page_mkwrite gets called every time the page is dirtied, even
9007 * if it was already dirty, so for space accounting reasons we need to
9008 * clear any delalloc bits for the range we are fixing to save. There
9009 * is probably a better way to do this, but for now keep consistent with
9010 * prepare_pages in the normal write path.
9011 */
9012 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9013 EXTENT_DIRTY | EXTENT_DELALLOC |
9014 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9015 0, 0, &cached_state, GFP_NOFS);
9016
9017 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9018 &cached_state);
9019 if (ret) {
9020 unlock_extent_cached(io_tree, page_start, page_end,
9021 &cached_state, GFP_NOFS);
9022 ret = VM_FAULT_SIGBUS;
9023 goto out_unlock;
9024 }
9025 ret = 0;
9026
9027 /* page is wholly or partially inside EOF */
9028 if (page_start + PAGE_SIZE > size)
9029 zero_start = size & ~PAGE_MASK;
9030 else
9031 zero_start = PAGE_SIZE;
9032
9033 if (zero_start != PAGE_SIZE) {
9034 kaddr = kmap(page);
9035 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9036 flush_dcache_page(page);
9037 kunmap(page);
9038 }
9039 ClearPageChecked(page);
9040 set_page_dirty(page);
9041 SetPageUptodate(page);
9042
9043 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9044 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9045 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9046
9047 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9048
9049 out_unlock:
9050 if (!ret) {
9051 sb_end_pagefault(inode->i_sb);
9052 return VM_FAULT_LOCKED;
9053 }
9054 unlock_page(page);
9055 out:
9056 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9057 out_noreserve:
9058 sb_end_pagefault(inode->i_sb);
9059 return ret;
9060 }
9061
9062 static int btrfs_truncate(struct inode *inode)
9063 {
9064 struct btrfs_root *root = BTRFS_I(inode)->root;
9065 struct btrfs_block_rsv *rsv;
9066 int ret = 0;
9067 int err = 0;
9068 struct btrfs_trans_handle *trans;
9069 u64 mask = root->sectorsize - 1;
9070 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9071
9072 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9073 (u64)-1);
9074 if (ret)
9075 return ret;
9076
9077 /*
9078 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9079 * 3 things going on here
9080 *
9081 * 1) We need to reserve space for our orphan item and the space to
9082 * delete our orphan item. Lord knows we don't want to have a dangling
9083 * orphan item because we didn't reserve space to remove it.
9084 *
9085 * 2) We need to reserve space to update our inode.
9086 *
9087 * 3) We need to have something to cache all the space that is going to
9088 * be free'd up by the truncate operation, but also have some slack
9089 * space reserved in case it uses space during the truncate (thank you
9090 * very much snapshotting).
9091 *
9092 * And we need these to all be separate. The fact is we can use a lot of
9093 * space doing the truncate, and we have no earthly idea how much space
9094 * we will use, so we need the truncate reservation to be separate so it
9095 * doesn't end up using space reserved for updating the inode or
9096 * removing the orphan item. We also need to be able to stop the
9097 * transaction and start a new one, which means we need to be able to
9098 * update the inode several times, and we have no idea of knowing how
9099 * many times that will be, so we can't just reserve 1 item for the
9100 * entirety of the operation, so that has to be done separately as well.
9101 * Then there is the orphan item, which does indeed need to be held on
9102 * to for the whole operation, and we need nobody to touch this reserved
9103 * space except the orphan code.
9104 *
9105 * So that leaves us with
9106 *
9107 * 1) root->orphan_block_rsv - for the orphan deletion.
9108 * 2) rsv - for the truncate reservation, which we will steal from the
9109 * transaction reservation.
9110 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9111 * updating the inode.
9112 */
9113 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9114 if (!rsv)
9115 return -ENOMEM;
9116 rsv->size = min_size;
9117 rsv->failfast = 1;
9118
9119 /*
9120 * 1 for the truncate slack space
9121 * 1 for updating the inode.
9122 */
9123 trans = btrfs_start_transaction(root, 2);
9124 if (IS_ERR(trans)) {
9125 err = PTR_ERR(trans);
9126 goto out;
9127 }
9128
9129 /* Migrate the slack space for the truncate to our reserve */
9130 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9131 min_size, 0);
9132 BUG_ON(ret);
9133
9134 /*
9135 * So if we truncate and then write and fsync we normally would just
9136 * write the extents that changed, which is a problem if we need to
9137 * first truncate that entire inode. So set this flag so we write out
9138 * all of the extents in the inode to the sync log so we're completely
9139 * safe.
9140 */
9141 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9142 trans->block_rsv = rsv;
9143
9144 while (1) {
9145 ret = btrfs_truncate_inode_items(trans, root, inode,
9146 inode->i_size,
9147 BTRFS_EXTENT_DATA_KEY);
9148 if (ret != -ENOSPC && ret != -EAGAIN) {
9149 err = ret;
9150 break;
9151 }
9152
9153 trans->block_rsv = &root->fs_info->trans_block_rsv;
9154 ret = btrfs_update_inode(trans, root, inode);
9155 if (ret) {
9156 err = ret;
9157 break;
9158 }
9159
9160 btrfs_end_transaction(trans, root);
9161 btrfs_btree_balance_dirty(root);
9162
9163 trans = btrfs_start_transaction(root, 2);
9164 if (IS_ERR(trans)) {
9165 ret = err = PTR_ERR(trans);
9166 trans = NULL;
9167 break;
9168 }
9169
9170 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9171 rsv, min_size, 0);
9172 BUG_ON(ret); /* shouldn't happen */
9173 trans->block_rsv = rsv;
9174 }
9175
9176 if (ret == 0 && inode->i_nlink > 0) {
9177 trans->block_rsv = root->orphan_block_rsv;
9178 ret = btrfs_orphan_del(trans, inode);
9179 if (ret)
9180 err = ret;
9181 }
9182
9183 if (trans) {
9184 trans->block_rsv = &root->fs_info->trans_block_rsv;
9185 ret = btrfs_update_inode(trans, root, inode);
9186 if (ret && !err)
9187 err = ret;
9188
9189 ret = btrfs_end_transaction(trans, root);
9190 btrfs_btree_balance_dirty(root);
9191 }
9192 out:
9193 btrfs_free_block_rsv(root, rsv);
9194
9195 if (ret && !err)
9196 err = ret;
9197
9198 return err;
9199 }
9200
9201 /*
9202 * create a new subvolume directory/inode (helper for the ioctl).
9203 */
9204 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9205 struct btrfs_root *new_root,
9206 struct btrfs_root *parent_root,
9207 u64 new_dirid)
9208 {
9209 struct inode *inode;
9210 int err;
9211 u64 index = 0;
9212
9213 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9214 new_dirid, new_dirid,
9215 S_IFDIR | (~current_umask() & S_IRWXUGO),
9216 &index);
9217 if (IS_ERR(inode))
9218 return PTR_ERR(inode);
9219 inode->i_op = &btrfs_dir_inode_operations;
9220 inode->i_fop = &btrfs_dir_file_operations;
9221
9222 set_nlink(inode, 1);
9223 btrfs_i_size_write(inode, 0);
9224 unlock_new_inode(inode);
9225
9226 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9227 if (err)
9228 btrfs_err(new_root->fs_info,
9229 "error inheriting subvolume %llu properties: %d",
9230 new_root->root_key.objectid, err);
9231
9232 err = btrfs_update_inode(trans, new_root, inode);
9233
9234 iput(inode);
9235 return err;
9236 }
9237
9238 struct inode *btrfs_alloc_inode(struct super_block *sb)
9239 {
9240 struct btrfs_inode *ei;
9241 struct inode *inode;
9242
9243 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9244 if (!ei)
9245 return NULL;
9246
9247 ei->root = NULL;
9248 ei->generation = 0;
9249 ei->last_trans = 0;
9250 ei->last_sub_trans = 0;
9251 ei->logged_trans = 0;
9252 ei->delalloc_bytes = 0;
9253 ei->defrag_bytes = 0;
9254 ei->disk_i_size = 0;
9255 ei->flags = 0;
9256 ei->csum_bytes = 0;
9257 ei->index_cnt = (u64)-1;
9258 ei->dir_index = 0;
9259 ei->last_unlink_trans = 0;
9260 ei->last_log_commit = 0;
9261 ei->delayed_iput_count = 0;
9262
9263 spin_lock_init(&ei->lock);
9264 ei->outstanding_extents = 0;
9265 ei->reserved_extents = 0;
9266
9267 ei->runtime_flags = 0;
9268 ei->force_compress = BTRFS_COMPRESS_NONE;
9269
9270 ei->delayed_node = NULL;
9271
9272 ei->i_otime.tv_sec = 0;
9273 ei->i_otime.tv_nsec = 0;
9274
9275 inode = &ei->vfs_inode;
9276 extent_map_tree_init(&ei->extent_tree);
9277 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9278 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9279 ei->io_tree.track_uptodate = 1;
9280 ei->io_failure_tree.track_uptodate = 1;
9281 atomic_set(&ei->sync_writers, 0);
9282 mutex_init(&ei->log_mutex);
9283 mutex_init(&ei->delalloc_mutex);
9284 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9285 INIT_LIST_HEAD(&ei->delalloc_inodes);
9286 INIT_LIST_HEAD(&ei->delayed_iput);
9287 RB_CLEAR_NODE(&ei->rb_node);
9288 init_rwsem(&ei->dio_sem);
9289
9290 return inode;
9291 }
9292
9293 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9294 void btrfs_test_destroy_inode(struct inode *inode)
9295 {
9296 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9297 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9298 }
9299 #endif
9300
9301 static void btrfs_i_callback(struct rcu_head *head)
9302 {
9303 struct inode *inode = container_of(head, struct inode, i_rcu);
9304 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9305 }
9306
9307 void btrfs_destroy_inode(struct inode *inode)
9308 {
9309 struct btrfs_ordered_extent *ordered;
9310 struct btrfs_root *root = BTRFS_I(inode)->root;
9311
9312 WARN_ON(!hlist_empty(&inode->i_dentry));
9313 WARN_ON(inode->i_data.nrpages);
9314 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9315 WARN_ON(BTRFS_I(inode)->reserved_extents);
9316 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9317 WARN_ON(BTRFS_I(inode)->csum_bytes);
9318 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9319
9320 /*
9321 * This can happen where we create an inode, but somebody else also
9322 * created the same inode and we need to destroy the one we already
9323 * created.
9324 */
9325 if (!root)
9326 goto free;
9327
9328 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9329 &BTRFS_I(inode)->runtime_flags)) {
9330 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9331 btrfs_ino(inode));
9332 atomic_dec(&root->orphan_inodes);
9333 }
9334
9335 while (1) {
9336 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9337 if (!ordered)
9338 break;
9339 else {
9340 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9341 ordered->file_offset, ordered->len);
9342 btrfs_remove_ordered_extent(inode, ordered);
9343 btrfs_put_ordered_extent(ordered);
9344 btrfs_put_ordered_extent(ordered);
9345 }
9346 }
9347 btrfs_qgroup_check_reserved_leak(inode);
9348 inode_tree_del(inode);
9349 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9350 free:
9351 call_rcu(&inode->i_rcu, btrfs_i_callback);
9352 }
9353
9354 int btrfs_drop_inode(struct inode *inode)
9355 {
9356 struct btrfs_root *root = BTRFS_I(inode)->root;
9357
9358 if (root == NULL)
9359 return 1;
9360
9361 /* the snap/subvol tree is on deleting */
9362 if (btrfs_root_refs(&root->root_item) == 0)
9363 return 1;
9364 else
9365 return generic_drop_inode(inode);
9366 }
9367
9368 static void init_once(void *foo)
9369 {
9370 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9371
9372 inode_init_once(&ei->vfs_inode);
9373 }
9374
9375 void btrfs_destroy_cachep(void)
9376 {
9377 /*
9378 * Make sure all delayed rcu free inodes are flushed before we
9379 * destroy cache.
9380 */
9381 rcu_barrier();
9382 kmem_cache_destroy(btrfs_inode_cachep);
9383 kmem_cache_destroy(btrfs_trans_handle_cachep);
9384 kmem_cache_destroy(btrfs_transaction_cachep);
9385 kmem_cache_destroy(btrfs_path_cachep);
9386 kmem_cache_destroy(btrfs_free_space_cachep);
9387 }
9388
9389 int btrfs_init_cachep(void)
9390 {
9391 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9392 sizeof(struct btrfs_inode), 0,
9393 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9394 init_once);
9395 if (!btrfs_inode_cachep)
9396 goto fail;
9397
9398 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9399 sizeof(struct btrfs_trans_handle), 0,
9400 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9401 if (!btrfs_trans_handle_cachep)
9402 goto fail;
9403
9404 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9405 sizeof(struct btrfs_transaction), 0,
9406 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9407 if (!btrfs_transaction_cachep)
9408 goto fail;
9409
9410 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9411 sizeof(struct btrfs_path), 0,
9412 SLAB_MEM_SPREAD, NULL);
9413 if (!btrfs_path_cachep)
9414 goto fail;
9415
9416 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9417 sizeof(struct btrfs_free_space), 0,
9418 SLAB_MEM_SPREAD, NULL);
9419 if (!btrfs_free_space_cachep)
9420 goto fail;
9421
9422 return 0;
9423 fail:
9424 btrfs_destroy_cachep();
9425 return -ENOMEM;
9426 }
9427
9428 static int btrfs_getattr(struct vfsmount *mnt,
9429 struct dentry *dentry, struct kstat *stat)
9430 {
9431 u64 delalloc_bytes;
9432 struct inode *inode = d_inode(dentry);
9433 u32 blocksize = inode->i_sb->s_blocksize;
9434
9435 generic_fillattr(inode, stat);
9436 stat->dev = BTRFS_I(inode)->root->anon_dev;
9437
9438 spin_lock(&BTRFS_I(inode)->lock);
9439 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9440 spin_unlock(&BTRFS_I(inode)->lock);
9441 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9442 ALIGN(delalloc_bytes, blocksize)) >> 9;
9443 return 0;
9444 }
9445
9446 static int btrfs_rename_exchange(struct inode *old_dir,
9447 struct dentry *old_dentry,
9448 struct inode *new_dir,
9449 struct dentry *new_dentry)
9450 {
9451 struct btrfs_trans_handle *trans;
9452 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9453 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9454 struct inode *new_inode = new_dentry->d_inode;
9455 struct inode *old_inode = old_dentry->d_inode;
9456 struct timespec ctime = CURRENT_TIME;
9457 struct dentry *parent;
9458 u64 old_ino = btrfs_ino(old_inode);
9459 u64 new_ino = btrfs_ino(new_inode);
9460 u64 old_idx = 0;
9461 u64 new_idx = 0;
9462 u64 root_objectid;
9463 int ret;
9464 bool root_log_pinned = false;
9465 bool dest_log_pinned = false;
9466
9467 /* we only allow rename subvolume link between subvolumes */
9468 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9469 return -EXDEV;
9470
9471 /* close the race window with snapshot create/destroy ioctl */
9472 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9473 down_read(&root->fs_info->subvol_sem);
9474 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9475 down_read(&dest->fs_info->subvol_sem);
9476
9477 /*
9478 * We want to reserve the absolute worst case amount of items. So if
9479 * both inodes are subvols and we need to unlink them then that would
9480 * require 4 item modifications, but if they are both normal inodes it
9481 * would require 5 item modifications, so we'll assume their normal
9482 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9483 * should cover the worst case number of items we'll modify.
9484 */
9485 trans = btrfs_start_transaction(root, 12);
9486 if (IS_ERR(trans)) {
9487 ret = PTR_ERR(trans);
9488 goto out_notrans;
9489 }
9490
9491 /*
9492 * We need to find a free sequence number both in the source and
9493 * in the destination directory for the exchange.
9494 */
9495 ret = btrfs_set_inode_index(new_dir, &old_idx);
9496 if (ret)
9497 goto out_fail;
9498 ret = btrfs_set_inode_index(old_dir, &new_idx);
9499 if (ret)
9500 goto out_fail;
9501
9502 BTRFS_I(old_inode)->dir_index = 0ULL;
9503 BTRFS_I(new_inode)->dir_index = 0ULL;
9504
9505 /* Reference for the source. */
9506 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9507 /* force full log commit if subvolume involved. */
9508 btrfs_set_log_full_commit(root->fs_info, trans);
9509 } else {
9510 btrfs_pin_log_trans(root);
9511 root_log_pinned = true;
9512 ret = btrfs_insert_inode_ref(trans, dest,
9513 new_dentry->d_name.name,
9514 new_dentry->d_name.len,
9515 old_ino,
9516 btrfs_ino(new_dir), old_idx);
9517 if (ret)
9518 goto out_fail;
9519 }
9520
9521 /* And now for the dest. */
9522 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9523 /* force full log commit if subvolume involved. */
9524 btrfs_set_log_full_commit(dest->fs_info, trans);
9525 } else {
9526 btrfs_pin_log_trans(dest);
9527 dest_log_pinned = true;
9528 ret = btrfs_insert_inode_ref(trans, root,
9529 old_dentry->d_name.name,
9530 old_dentry->d_name.len,
9531 new_ino,
9532 btrfs_ino(old_dir), new_idx);
9533 if (ret)
9534 goto out_fail;
9535 }
9536
9537 /* Update inode version and ctime/mtime. */
9538 inode_inc_iversion(old_dir);
9539 inode_inc_iversion(new_dir);
9540 inode_inc_iversion(old_inode);
9541 inode_inc_iversion(new_inode);
9542 old_dir->i_ctime = old_dir->i_mtime = ctime;
9543 new_dir->i_ctime = new_dir->i_mtime = ctime;
9544 old_inode->i_ctime = ctime;
9545 new_inode->i_ctime = ctime;
9546
9547 if (old_dentry->d_parent != new_dentry->d_parent) {
9548 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9549 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9550 }
9551
9552 /* src is a subvolume */
9553 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9554 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9555 ret = btrfs_unlink_subvol(trans, root, old_dir,
9556 root_objectid,
9557 old_dentry->d_name.name,
9558 old_dentry->d_name.len);
9559 } else { /* src is an inode */
9560 ret = __btrfs_unlink_inode(trans, root, old_dir,
9561 old_dentry->d_inode,
9562 old_dentry->d_name.name,
9563 old_dentry->d_name.len);
9564 if (!ret)
9565 ret = btrfs_update_inode(trans, root, old_inode);
9566 }
9567 if (ret) {
9568 btrfs_abort_transaction(trans, ret);
9569 goto out_fail;
9570 }
9571
9572 /* dest is a subvolume */
9573 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9574 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9575 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9576 root_objectid,
9577 new_dentry->d_name.name,
9578 new_dentry->d_name.len);
9579 } else { /* dest is an inode */
9580 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9581 new_dentry->d_inode,
9582 new_dentry->d_name.name,
9583 new_dentry->d_name.len);
9584 if (!ret)
9585 ret = btrfs_update_inode(trans, dest, new_inode);
9586 }
9587 if (ret) {
9588 btrfs_abort_transaction(trans, ret);
9589 goto out_fail;
9590 }
9591
9592 ret = btrfs_add_link(trans, new_dir, old_inode,
9593 new_dentry->d_name.name,
9594 new_dentry->d_name.len, 0, old_idx);
9595 if (ret) {
9596 btrfs_abort_transaction(trans, ret);
9597 goto out_fail;
9598 }
9599
9600 ret = btrfs_add_link(trans, old_dir, new_inode,
9601 old_dentry->d_name.name,
9602 old_dentry->d_name.len, 0, new_idx);
9603 if (ret) {
9604 btrfs_abort_transaction(trans, ret);
9605 goto out_fail;
9606 }
9607
9608 if (old_inode->i_nlink == 1)
9609 BTRFS_I(old_inode)->dir_index = old_idx;
9610 if (new_inode->i_nlink == 1)
9611 BTRFS_I(new_inode)->dir_index = new_idx;
9612
9613 if (root_log_pinned) {
9614 parent = new_dentry->d_parent;
9615 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9616 btrfs_end_log_trans(root);
9617 root_log_pinned = false;
9618 }
9619 if (dest_log_pinned) {
9620 parent = old_dentry->d_parent;
9621 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9622 btrfs_end_log_trans(dest);
9623 dest_log_pinned = false;
9624 }
9625 out_fail:
9626 /*
9627 * If we have pinned a log and an error happened, we unpin tasks
9628 * trying to sync the log and force them to fallback to a transaction
9629 * commit if the log currently contains any of the inodes involved in
9630 * this rename operation (to ensure we do not persist a log with an
9631 * inconsistent state for any of these inodes or leading to any
9632 * inconsistencies when replayed). If the transaction was aborted, the
9633 * abortion reason is propagated to userspace when attempting to commit
9634 * the transaction. If the log does not contain any of these inodes, we
9635 * allow the tasks to sync it.
9636 */
9637 if (ret && (root_log_pinned || dest_log_pinned)) {
9638 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9639 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9640 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9641 (new_inode &&
9642 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9643 btrfs_set_log_full_commit(root->fs_info, trans);
9644
9645 if (root_log_pinned) {
9646 btrfs_end_log_trans(root);
9647 root_log_pinned = false;
9648 }
9649 if (dest_log_pinned) {
9650 btrfs_end_log_trans(dest);
9651 dest_log_pinned = false;
9652 }
9653 }
9654 ret = btrfs_end_transaction(trans, root);
9655 out_notrans:
9656 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9657 up_read(&dest->fs_info->subvol_sem);
9658 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9659 up_read(&root->fs_info->subvol_sem);
9660
9661 return ret;
9662 }
9663
9664 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9665 struct btrfs_root *root,
9666 struct inode *dir,
9667 struct dentry *dentry)
9668 {
9669 int ret;
9670 struct inode *inode;
9671 u64 objectid;
9672 u64 index;
9673
9674 ret = btrfs_find_free_ino(root, &objectid);
9675 if (ret)
9676 return ret;
9677
9678 inode = btrfs_new_inode(trans, root, dir,
9679 dentry->d_name.name,
9680 dentry->d_name.len,
9681 btrfs_ino(dir),
9682 objectid,
9683 S_IFCHR | WHITEOUT_MODE,
9684 &index);
9685
9686 if (IS_ERR(inode)) {
9687 ret = PTR_ERR(inode);
9688 return ret;
9689 }
9690
9691 inode->i_op = &btrfs_special_inode_operations;
9692 init_special_inode(inode, inode->i_mode,
9693 WHITEOUT_DEV);
9694
9695 ret = btrfs_init_inode_security(trans, inode, dir,
9696 &dentry->d_name);
9697 if (ret)
9698 goto out;
9699
9700 ret = btrfs_add_nondir(trans, dir, dentry,
9701 inode, 0, index);
9702 if (ret)
9703 goto out;
9704
9705 ret = btrfs_update_inode(trans, root, inode);
9706 out:
9707 unlock_new_inode(inode);
9708 if (ret)
9709 inode_dec_link_count(inode);
9710 iput(inode);
9711
9712 return ret;
9713 }
9714
9715 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9716 struct inode *new_dir, struct dentry *new_dentry,
9717 unsigned int flags)
9718 {
9719 struct btrfs_trans_handle *trans;
9720 unsigned int trans_num_items;
9721 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9722 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9723 struct inode *new_inode = d_inode(new_dentry);
9724 struct inode *old_inode = d_inode(old_dentry);
9725 u64 index = 0;
9726 u64 root_objectid;
9727 int ret;
9728 u64 old_ino = btrfs_ino(old_inode);
9729 bool log_pinned = false;
9730
9731 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9732 return -EPERM;
9733
9734 /* we only allow rename subvolume link between subvolumes */
9735 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9736 return -EXDEV;
9737
9738 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9739 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9740 return -ENOTEMPTY;
9741
9742 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9743 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9744 return -ENOTEMPTY;
9745
9746
9747 /* check for collisions, even if the name isn't there */
9748 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9749 new_dentry->d_name.name,
9750 new_dentry->d_name.len);
9751
9752 if (ret) {
9753 if (ret == -EEXIST) {
9754 /* we shouldn't get
9755 * eexist without a new_inode */
9756 if (WARN_ON(!new_inode)) {
9757 return ret;
9758 }
9759 } else {
9760 /* maybe -EOVERFLOW */
9761 return ret;
9762 }
9763 }
9764 ret = 0;
9765
9766 /*
9767 * we're using rename to replace one file with another. Start IO on it
9768 * now so we don't add too much work to the end of the transaction
9769 */
9770 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9771 filemap_flush(old_inode->i_mapping);
9772
9773 /* close the racy window with snapshot create/destroy ioctl */
9774 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9775 down_read(&root->fs_info->subvol_sem);
9776 /*
9777 * We want to reserve the absolute worst case amount of items. So if
9778 * both inodes are subvols and we need to unlink them then that would
9779 * require 4 item modifications, but if they are both normal inodes it
9780 * would require 5 item modifications, so we'll assume they are normal
9781 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9782 * should cover the worst case number of items we'll modify.
9783 * If our rename has the whiteout flag, we need more 5 units for the
9784 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9785 * when selinux is enabled).
9786 */
9787 trans_num_items = 11;
9788 if (flags & RENAME_WHITEOUT)
9789 trans_num_items += 5;
9790 trans = btrfs_start_transaction(root, trans_num_items);
9791 if (IS_ERR(trans)) {
9792 ret = PTR_ERR(trans);
9793 goto out_notrans;
9794 }
9795
9796 if (dest != root)
9797 btrfs_record_root_in_trans(trans, dest);
9798
9799 ret = btrfs_set_inode_index(new_dir, &index);
9800 if (ret)
9801 goto out_fail;
9802
9803 BTRFS_I(old_inode)->dir_index = 0ULL;
9804 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9805 /* force full log commit if subvolume involved. */
9806 btrfs_set_log_full_commit(root->fs_info, trans);
9807 } else {
9808 btrfs_pin_log_trans(root);
9809 log_pinned = true;
9810 ret = btrfs_insert_inode_ref(trans, dest,
9811 new_dentry->d_name.name,
9812 new_dentry->d_name.len,
9813 old_ino,
9814 btrfs_ino(new_dir), index);
9815 if (ret)
9816 goto out_fail;
9817 }
9818
9819 inode_inc_iversion(old_dir);
9820 inode_inc_iversion(new_dir);
9821 inode_inc_iversion(old_inode);
9822 old_dir->i_ctime = old_dir->i_mtime =
9823 new_dir->i_ctime = new_dir->i_mtime =
9824 old_inode->i_ctime = current_fs_time(old_dir->i_sb);
9825
9826 if (old_dentry->d_parent != new_dentry->d_parent)
9827 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9828
9829 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9830 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9831 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9832 old_dentry->d_name.name,
9833 old_dentry->d_name.len);
9834 } else {
9835 ret = __btrfs_unlink_inode(trans, root, old_dir,
9836 d_inode(old_dentry),
9837 old_dentry->d_name.name,
9838 old_dentry->d_name.len);
9839 if (!ret)
9840 ret = btrfs_update_inode(trans, root, old_inode);
9841 }
9842 if (ret) {
9843 btrfs_abort_transaction(trans, ret);
9844 goto out_fail;
9845 }
9846
9847 if (new_inode) {
9848 inode_inc_iversion(new_inode);
9849 new_inode->i_ctime = current_fs_time(new_inode->i_sb);
9850 if (unlikely(btrfs_ino(new_inode) ==
9851 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9852 root_objectid = BTRFS_I(new_inode)->location.objectid;
9853 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9854 root_objectid,
9855 new_dentry->d_name.name,
9856 new_dentry->d_name.len);
9857 BUG_ON(new_inode->i_nlink == 0);
9858 } else {
9859 ret = btrfs_unlink_inode(trans, dest, new_dir,
9860 d_inode(new_dentry),
9861 new_dentry->d_name.name,
9862 new_dentry->d_name.len);
9863 }
9864 if (!ret && new_inode->i_nlink == 0)
9865 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9866 if (ret) {
9867 btrfs_abort_transaction(trans, ret);
9868 goto out_fail;
9869 }
9870 }
9871
9872 ret = btrfs_add_link(trans, new_dir, old_inode,
9873 new_dentry->d_name.name,
9874 new_dentry->d_name.len, 0, index);
9875 if (ret) {
9876 btrfs_abort_transaction(trans, ret);
9877 goto out_fail;
9878 }
9879
9880 if (old_inode->i_nlink == 1)
9881 BTRFS_I(old_inode)->dir_index = index;
9882
9883 if (log_pinned) {
9884 struct dentry *parent = new_dentry->d_parent;
9885
9886 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9887 btrfs_end_log_trans(root);
9888 log_pinned = false;
9889 }
9890
9891 if (flags & RENAME_WHITEOUT) {
9892 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9893 old_dentry);
9894
9895 if (ret) {
9896 btrfs_abort_transaction(trans, ret);
9897 goto out_fail;
9898 }
9899 }
9900 out_fail:
9901 /*
9902 * If we have pinned the log and an error happened, we unpin tasks
9903 * trying to sync the log and force them to fallback to a transaction
9904 * commit if the log currently contains any of the inodes involved in
9905 * this rename operation (to ensure we do not persist a log with an
9906 * inconsistent state for any of these inodes or leading to any
9907 * inconsistencies when replayed). If the transaction was aborted, the
9908 * abortion reason is propagated to userspace when attempting to commit
9909 * the transaction. If the log does not contain any of these inodes, we
9910 * allow the tasks to sync it.
9911 */
9912 if (ret && log_pinned) {
9913 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9914 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9915 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9916 (new_inode &&
9917 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9918 btrfs_set_log_full_commit(root->fs_info, trans);
9919
9920 btrfs_end_log_trans(root);
9921 log_pinned = false;
9922 }
9923 btrfs_end_transaction(trans, root);
9924 out_notrans:
9925 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9926 up_read(&root->fs_info->subvol_sem);
9927
9928 return ret;
9929 }
9930
9931 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9932 struct inode *new_dir, struct dentry *new_dentry,
9933 unsigned int flags)
9934 {
9935 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9936 return -EINVAL;
9937
9938 if (flags & RENAME_EXCHANGE)
9939 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9940 new_dentry);
9941
9942 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9943 }
9944
9945 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9946 {
9947 struct btrfs_delalloc_work *delalloc_work;
9948 struct inode *inode;
9949
9950 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9951 work);
9952 inode = delalloc_work->inode;
9953 filemap_flush(inode->i_mapping);
9954 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9955 &BTRFS_I(inode)->runtime_flags))
9956 filemap_flush(inode->i_mapping);
9957
9958 if (delalloc_work->delay_iput)
9959 btrfs_add_delayed_iput(inode);
9960 else
9961 iput(inode);
9962 complete(&delalloc_work->completion);
9963 }
9964
9965 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9966 int delay_iput)
9967 {
9968 struct btrfs_delalloc_work *work;
9969
9970 work = kmalloc(sizeof(*work), GFP_NOFS);
9971 if (!work)
9972 return NULL;
9973
9974 init_completion(&work->completion);
9975 INIT_LIST_HEAD(&work->list);
9976 work->inode = inode;
9977 work->delay_iput = delay_iput;
9978 WARN_ON_ONCE(!inode);
9979 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9980 btrfs_run_delalloc_work, NULL, NULL);
9981
9982 return work;
9983 }
9984
9985 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9986 {
9987 wait_for_completion(&work->completion);
9988 kfree(work);
9989 }
9990
9991 /*
9992 * some fairly slow code that needs optimization. This walks the list
9993 * of all the inodes with pending delalloc and forces them to disk.
9994 */
9995 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9996 int nr)
9997 {
9998 struct btrfs_inode *binode;
9999 struct inode *inode;
10000 struct btrfs_delalloc_work *work, *next;
10001 struct list_head works;
10002 struct list_head splice;
10003 int ret = 0;
10004
10005 INIT_LIST_HEAD(&works);
10006 INIT_LIST_HEAD(&splice);
10007
10008 mutex_lock(&root->delalloc_mutex);
10009 spin_lock(&root->delalloc_lock);
10010 list_splice_init(&root->delalloc_inodes, &splice);
10011 while (!list_empty(&splice)) {
10012 binode = list_entry(splice.next, struct btrfs_inode,
10013 delalloc_inodes);
10014
10015 list_move_tail(&binode->delalloc_inodes,
10016 &root->delalloc_inodes);
10017 inode = igrab(&binode->vfs_inode);
10018 if (!inode) {
10019 cond_resched_lock(&root->delalloc_lock);
10020 continue;
10021 }
10022 spin_unlock(&root->delalloc_lock);
10023
10024 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10025 if (!work) {
10026 if (delay_iput)
10027 btrfs_add_delayed_iput(inode);
10028 else
10029 iput(inode);
10030 ret = -ENOMEM;
10031 goto out;
10032 }
10033 list_add_tail(&work->list, &works);
10034 btrfs_queue_work(root->fs_info->flush_workers,
10035 &work->work);
10036 ret++;
10037 if (nr != -1 && ret >= nr)
10038 goto out;
10039 cond_resched();
10040 spin_lock(&root->delalloc_lock);
10041 }
10042 spin_unlock(&root->delalloc_lock);
10043
10044 out:
10045 list_for_each_entry_safe(work, next, &works, list) {
10046 list_del_init(&work->list);
10047 btrfs_wait_and_free_delalloc_work(work);
10048 }
10049
10050 if (!list_empty_careful(&splice)) {
10051 spin_lock(&root->delalloc_lock);
10052 list_splice_tail(&splice, &root->delalloc_inodes);
10053 spin_unlock(&root->delalloc_lock);
10054 }
10055 mutex_unlock(&root->delalloc_mutex);
10056 return ret;
10057 }
10058
10059 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10060 {
10061 int ret;
10062
10063 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10064 return -EROFS;
10065
10066 ret = __start_delalloc_inodes(root, delay_iput, -1);
10067 if (ret > 0)
10068 ret = 0;
10069 /*
10070 * the filemap_flush will queue IO into the worker threads, but
10071 * we have to make sure the IO is actually started and that
10072 * ordered extents get created before we return
10073 */
10074 atomic_inc(&root->fs_info->async_submit_draining);
10075 while (atomic_read(&root->fs_info->nr_async_submits) ||
10076 atomic_read(&root->fs_info->async_delalloc_pages)) {
10077 wait_event(root->fs_info->async_submit_wait,
10078 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10079 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10080 }
10081 atomic_dec(&root->fs_info->async_submit_draining);
10082 return ret;
10083 }
10084
10085 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10086 int nr)
10087 {
10088 struct btrfs_root *root;
10089 struct list_head splice;
10090 int ret;
10091
10092 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10093 return -EROFS;
10094
10095 INIT_LIST_HEAD(&splice);
10096
10097 mutex_lock(&fs_info->delalloc_root_mutex);
10098 spin_lock(&fs_info->delalloc_root_lock);
10099 list_splice_init(&fs_info->delalloc_roots, &splice);
10100 while (!list_empty(&splice) && nr) {
10101 root = list_first_entry(&splice, struct btrfs_root,
10102 delalloc_root);
10103 root = btrfs_grab_fs_root(root);
10104 BUG_ON(!root);
10105 list_move_tail(&root->delalloc_root,
10106 &fs_info->delalloc_roots);
10107 spin_unlock(&fs_info->delalloc_root_lock);
10108
10109 ret = __start_delalloc_inodes(root, delay_iput, nr);
10110 btrfs_put_fs_root(root);
10111 if (ret < 0)
10112 goto out;
10113
10114 if (nr != -1) {
10115 nr -= ret;
10116 WARN_ON(nr < 0);
10117 }
10118 spin_lock(&fs_info->delalloc_root_lock);
10119 }
10120 spin_unlock(&fs_info->delalloc_root_lock);
10121
10122 ret = 0;
10123 atomic_inc(&fs_info->async_submit_draining);
10124 while (atomic_read(&fs_info->nr_async_submits) ||
10125 atomic_read(&fs_info->async_delalloc_pages)) {
10126 wait_event(fs_info->async_submit_wait,
10127 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10128 atomic_read(&fs_info->async_delalloc_pages) == 0));
10129 }
10130 atomic_dec(&fs_info->async_submit_draining);
10131 out:
10132 if (!list_empty_careful(&splice)) {
10133 spin_lock(&fs_info->delalloc_root_lock);
10134 list_splice_tail(&splice, &fs_info->delalloc_roots);
10135 spin_unlock(&fs_info->delalloc_root_lock);
10136 }
10137 mutex_unlock(&fs_info->delalloc_root_mutex);
10138 return ret;
10139 }
10140
10141 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10142 const char *symname)
10143 {
10144 struct btrfs_trans_handle *trans;
10145 struct btrfs_root *root = BTRFS_I(dir)->root;
10146 struct btrfs_path *path;
10147 struct btrfs_key key;
10148 struct inode *inode = NULL;
10149 int err;
10150 int drop_inode = 0;
10151 u64 objectid;
10152 u64 index = 0;
10153 int name_len;
10154 int datasize;
10155 unsigned long ptr;
10156 struct btrfs_file_extent_item *ei;
10157 struct extent_buffer *leaf;
10158
10159 name_len = strlen(symname);
10160 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10161 return -ENAMETOOLONG;
10162
10163 /*
10164 * 2 items for inode item and ref
10165 * 2 items for dir items
10166 * 1 item for updating parent inode item
10167 * 1 item for the inline extent item
10168 * 1 item for xattr if selinux is on
10169 */
10170 trans = btrfs_start_transaction(root, 7);
10171 if (IS_ERR(trans))
10172 return PTR_ERR(trans);
10173
10174 err = btrfs_find_free_ino(root, &objectid);
10175 if (err)
10176 goto out_unlock;
10177
10178 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10179 dentry->d_name.len, btrfs_ino(dir), objectid,
10180 S_IFLNK|S_IRWXUGO, &index);
10181 if (IS_ERR(inode)) {
10182 err = PTR_ERR(inode);
10183 goto out_unlock;
10184 }
10185
10186 /*
10187 * If the active LSM wants to access the inode during
10188 * d_instantiate it needs these. Smack checks to see
10189 * if the filesystem supports xattrs by looking at the
10190 * ops vector.
10191 */
10192 inode->i_fop = &btrfs_file_operations;
10193 inode->i_op = &btrfs_file_inode_operations;
10194 inode->i_mapping->a_ops = &btrfs_aops;
10195 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10196
10197 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10198 if (err)
10199 goto out_unlock_inode;
10200
10201 path = btrfs_alloc_path();
10202 if (!path) {
10203 err = -ENOMEM;
10204 goto out_unlock_inode;
10205 }
10206 key.objectid = btrfs_ino(inode);
10207 key.offset = 0;
10208 key.type = BTRFS_EXTENT_DATA_KEY;
10209 datasize = btrfs_file_extent_calc_inline_size(name_len);
10210 err = btrfs_insert_empty_item(trans, root, path, &key,
10211 datasize);
10212 if (err) {
10213 btrfs_free_path(path);
10214 goto out_unlock_inode;
10215 }
10216 leaf = path->nodes[0];
10217 ei = btrfs_item_ptr(leaf, path->slots[0],
10218 struct btrfs_file_extent_item);
10219 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10220 btrfs_set_file_extent_type(leaf, ei,
10221 BTRFS_FILE_EXTENT_INLINE);
10222 btrfs_set_file_extent_encryption(leaf, ei, 0);
10223 btrfs_set_file_extent_compression(leaf, ei, 0);
10224 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10225 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10226
10227 ptr = btrfs_file_extent_inline_start(ei);
10228 write_extent_buffer(leaf, symname, ptr, name_len);
10229 btrfs_mark_buffer_dirty(leaf);
10230 btrfs_free_path(path);
10231
10232 inode->i_op = &btrfs_symlink_inode_operations;
10233 inode_nohighmem(inode);
10234 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10235 inode_set_bytes(inode, name_len);
10236 btrfs_i_size_write(inode, name_len);
10237 err = btrfs_update_inode(trans, root, inode);
10238 /*
10239 * Last step, add directory indexes for our symlink inode. This is the
10240 * last step to avoid extra cleanup of these indexes if an error happens
10241 * elsewhere above.
10242 */
10243 if (!err)
10244 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10245 if (err) {
10246 drop_inode = 1;
10247 goto out_unlock_inode;
10248 }
10249
10250 unlock_new_inode(inode);
10251 d_instantiate(dentry, inode);
10252
10253 out_unlock:
10254 btrfs_end_transaction(trans, root);
10255 if (drop_inode) {
10256 inode_dec_link_count(inode);
10257 iput(inode);
10258 }
10259 btrfs_btree_balance_dirty(root);
10260 return err;
10261
10262 out_unlock_inode:
10263 drop_inode = 1;
10264 unlock_new_inode(inode);
10265 goto out_unlock;
10266 }
10267
10268 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10269 u64 start, u64 num_bytes, u64 min_size,
10270 loff_t actual_len, u64 *alloc_hint,
10271 struct btrfs_trans_handle *trans)
10272 {
10273 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10274 struct extent_map *em;
10275 struct btrfs_root *root = BTRFS_I(inode)->root;
10276 struct btrfs_key ins;
10277 u64 cur_offset = start;
10278 u64 i_size;
10279 u64 cur_bytes;
10280 u64 last_alloc = (u64)-1;
10281 int ret = 0;
10282 bool own_trans = true;
10283
10284 if (trans)
10285 own_trans = false;
10286 while (num_bytes > 0) {
10287 if (own_trans) {
10288 trans = btrfs_start_transaction(root, 3);
10289 if (IS_ERR(trans)) {
10290 ret = PTR_ERR(trans);
10291 break;
10292 }
10293 }
10294
10295 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10296 cur_bytes = max(cur_bytes, min_size);
10297 /*
10298 * If we are severely fragmented we could end up with really
10299 * small allocations, so if the allocator is returning small
10300 * chunks lets make its job easier by only searching for those
10301 * sized chunks.
10302 */
10303 cur_bytes = min(cur_bytes, last_alloc);
10304 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
10305 *alloc_hint, &ins, 1, 0);
10306 if (ret) {
10307 if (own_trans)
10308 btrfs_end_transaction(trans, root);
10309 break;
10310 }
10311 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10312
10313 last_alloc = ins.offset;
10314 ret = insert_reserved_file_extent(trans, inode,
10315 cur_offset, ins.objectid,
10316 ins.offset, ins.offset,
10317 ins.offset, 0, 0, 0,
10318 BTRFS_FILE_EXTENT_PREALLOC);
10319 if (ret) {
10320 btrfs_free_reserved_extent(root, ins.objectid,
10321 ins.offset, 0);
10322 btrfs_abort_transaction(trans, ret);
10323 if (own_trans)
10324 btrfs_end_transaction(trans, root);
10325 break;
10326 }
10327
10328 btrfs_drop_extent_cache(inode, cur_offset,
10329 cur_offset + ins.offset -1, 0);
10330
10331 em = alloc_extent_map();
10332 if (!em) {
10333 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10334 &BTRFS_I(inode)->runtime_flags);
10335 goto next;
10336 }
10337
10338 em->start = cur_offset;
10339 em->orig_start = cur_offset;
10340 em->len = ins.offset;
10341 em->block_start = ins.objectid;
10342 em->block_len = ins.offset;
10343 em->orig_block_len = ins.offset;
10344 em->ram_bytes = ins.offset;
10345 em->bdev = root->fs_info->fs_devices->latest_bdev;
10346 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10347 em->generation = trans->transid;
10348
10349 while (1) {
10350 write_lock(&em_tree->lock);
10351 ret = add_extent_mapping(em_tree, em, 1);
10352 write_unlock(&em_tree->lock);
10353 if (ret != -EEXIST)
10354 break;
10355 btrfs_drop_extent_cache(inode, cur_offset,
10356 cur_offset + ins.offset - 1,
10357 0);
10358 }
10359 free_extent_map(em);
10360 next:
10361 num_bytes -= ins.offset;
10362 cur_offset += ins.offset;
10363 *alloc_hint = ins.objectid + ins.offset;
10364
10365 inode_inc_iversion(inode);
10366 inode->i_ctime = current_fs_time(inode->i_sb);
10367 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10368 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10369 (actual_len > inode->i_size) &&
10370 (cur_offset > inode->i_size)) {
10371 if (cur_offset > actual_len)
10372 i_size = actual_len;
10373 else
10374 i_size = cur_offset;
10375 i_size_write(inode, i_size);
10376 btrfs_ordered_update_i_size(inode, i_size, NULL);
10377 }
10378
10379 ret = btrfs_update_inode(trans, root, inode);
10380
10381 if (ret) {
10382 btrfs_abort_transaction(trans, ret);
10383 if (own_trans)
10384 btrfs_end_transaction(trans, root);
10385 break;
10386 }
10387
10388 if (own_trans)
10389 btrfs_end_transaction(trans, root);
10390 }
10391 return ret;
10392 }
10393
10394 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10395 u64 start, u64 num_bytes, u64 min_size,
10396 loff_t actual_len, u64 *alloc_hint)
10397 {
10398 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10399 min_size, actual_len, alloc_hint,
10400 NULL);
10401 }
10402
10403 int btrfs_prealloc_file_range_trans(struct inode *inode,
10404 struct btrfs_trans_handle *trans, int mode,
10405 u64 start, u64 num_bytes, u64 min_size,
10406 loff_t actual_len, u64 *alloc_hint)
10407 {
10408 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10409 min_size, actual_len, alloc_hint, trans);
10410 }
10411
10412 static int btrfs_set_page_dirty(struct page *page)
10413 {
10414 return __set_page_dirty_nobuffers(page);
10415 }
10416
10417 static int btrfs_permission(struct inode *inode, int mask)
10418 {
10419 struct btrfs_root *root = BTRFS_I(inode)->root;
10420 umode_t mode = inode->i_mode;
10421
10422 if (mask & MAY_WRITE &&
10423 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10424 if (btrfs_root_readonly(root))
10425 return -EROFS;
10426 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10427 return -EACCES;
10428 }
10429 return generic_permission(inode, mask);
10430 }
10431
10432 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10433 {
10434 struct btrfs_trans_handle *trans;
10435 struct btrfs_root *root = BTRFS_I(dir)->root;
10436 struct inode *inode = NULL;
10437 u64 objectid;
10438 u64 index;
10439 int ret = 0;
10440
10441 /*
10442 * 5 units required for adding orphan entry
10443 */
10444 trans = btrfs_start_transaction(root, 5);
10445 if (IS_ERR(trans))
10446 return PTR_ERR(trans);
10447
10448 ret = btrfs_find_free_ino(root, &objectid);
10449 if (ret)
10450 goto out;
10451
10452 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10453 btrfs_ino(dir), objectid, mode, &index);
10454 if (IS_ERR(inode)) {
10455 ret = PTR_ERR(inode);
10456 inode = NULL;
10457 goto out;
10458 }
10459
10460 inode->i_fop = &btrfs_file_operations;
10461 inode->i_op = &btrfs_file_inode_operations;
10462
10463 inode->i_mapping->a_ops = &btrfs_aops;
10464 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10465
10466 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10467 if (ret)
10468 goto out_inode;
10469
10470 ret = btrfs_update_inode(trans, root, inode);
10471 if (ret)
10472 goto out_inode;
10473 ret = btrfs_orphan_add(trans, inode);
10474 if (ret)
10475 goto out_inode;
10476
10477 /*
10478 * We set number of links to 0 in btrfs_new_inode(), and here we set
10479 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10480 * through:
10481 *
10482 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10483 */
10484 set_nlink(inode, 1);
10485 unlock_new_inode(inode);
10486 d_tmpfile(dentry, inode);
10487 mark_inode_dirty(inode);
10488
10489 out:
10490 btrfs_end_transaction(trans, root);
10491 if (ret)
10492 iput(inode);
10493 btrfs_balance_delayed_items(root);
10494 btrfs_btree_balance_dirty(root);
10495 return ret;
10496
10497 out_inode:
10498 unlock_new_inode(inode);
10499 goto out;
10500
10501 }
10502
10503 /* Inspired by filemap_check_errors() */
10504 int btrfs_inode_check_errors(struct inode *inode)
10505 {
10506 int ret = 0;
10507
10508 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10509 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10510 ret = -ENOSPC;
10511 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10512 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10513 ret = -EIO;
10514
10515 return ret;
10516 }
10517
10518 static const struct inode_operations btrfs_dir_inode_operations = {
10519 .getattr = btrfs_getattr,
10520 .lookup = btrfs_lookup,
10521 .create = btrfs_create,
10522 .unlink = btrfs_unlink,
10523 .link = btrfs_link,
10524 .mkdir = btrfs_mkdir,
10525 .rmdir = btrfs_rmdir,
10526 .rename2 = btrfs_rename2,
10527 .symlink = btrfs_symlink,
10528 .setattr = btrfs_setattr,
10529 .mknod = btrfs_mknod,
10530 .setxattr = generic_setxattr,
10531 .getxattr = generic_getxattr,
10532 .listxattr = btrfs_listxattr,
10533 .removexattr = generic_removexattr,
10534 .permission = btrfs_permission,
10535 .get_acl = btrfs_get_acl,
10536 .set_acl = btrfs_set_acl,
10537 .update_time = btrfs_update_time,
10538 .tmpfile = btrfs_tmpfile,
10539 };
10540 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10541 .lookup = btrfs_lookup,
10542 .permission = btrfs_permission,
10543 .get_acl = btrfs_get_acl,
10544 .set_acl = btrfs_set_acl,
10545 .update_time = btrfs_update_time,
10546 };
10547
10548 static const struct file_operations btrfs_dir_file_operations = {
10549 .llseek = generic_file_llseek,
10550 .read = generic_read_dir,
10551 .iterate_shared = btrfs_real_readdir,
10552 .unlocked_ioctl = btrfs_ioctl,
10553 #ifdef CONFIG_COMPAT
10554 .compat_ioctl = btrfs_compat_ioctl,
10555 #endif
10556 .release = btrfs_release_file,
10557 .fsync = btrfs_sync_file,
10558 };
10559
10560 static const struct extent_io_ops btrfs_extent_io_ops = {
10561 .fill_delalloc = run_delalloc_range,
10562 .submit_bio_hook = btrfs_submit_bio_hook,
10563 .merge_bio_hook = btrfs_merge_bio_hook,
10564 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10565 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10566 .writepage_start_hook = btrfs_writepage_start_hook,
10567 .set_bit_hook = btrfs_set_bit_hook,
10568 .clear_bit_hook = btrfs_clear_bit_hook,
10569 .merge_extent_hook = btrfs_merge_extent_hook,
10570 .split_extent_hook = btrfs_split_extent_hook,
10571 };
10572
10573 /*
10574 * btrfs doesn't support the bmap operation because swapfiles
10575 * use bmap to make a mapping of extents in the file. They assume
10576 * these extents won't change over the life of the file and they
10577 * use the bmap result to do IO directly to the drive.
10578 *
10579 * the btrfs bmap call would return logical addresses that aren't
10580 * suitable for IO and they also will change frequently as COW
10581 * operations happen. So, swapfile + btrfs == corruption.
10582 *
10583 * For now we're avoiding this by dropping bmap.
10584 */
10585 static const struct address_space_operations btrfs_aops = {
10586 .readpage = btrfs_readpage,
10587 .writepage = btrfs_writepage,
10588 .writepages = btrfs_writepages,
10589 .readpages = btrfs_readpages,
10590 .direct_IO = btrfs_direct_IO,
10591 .invalidatepage = btrfs_invalidatepage,
10592 .releasepage = btrfs_releasepage,
10593 .set_page_dirty = btrfs_set_page_dirty,
10594 .error_remove_page = generic_error_remove_page,
10595 };
10596
10597 static const struct address_space_operations btrfs_symlink_aops = {
10598 .readpage = btrfs_readpage,
10599 .writepage = btrfs_writepage,
10600 .invalidatepage = btrfs_invalidatepage,
10601 .releasepage = btrfs_releasepage,
10602 };
10603
10604 static const struct inode_operations btrfs_file_inode_operations = {
10605 .getattr = btrfs_getattr,
10606 .setattr = btrfs_setattr,
10607 .setxattr = generic_setxattr,
10608 .getxattr = generic_getxattr,
10609 .listxattr = btrfs_listxattr,
10610 .removexattr = generic_removexattr,
10611 .permission = btrfs_permission,
10612 .fiemap = btrfs_fiemap,
10613 .get_acl = btrfs_get_acl,
10614 .set_acl = btrfs_set_acl,
10615 .update_time = btrfs_update_time,
10616 };
10617 static const struct inode_operations btrfs_special_inode_operations = {
10618 .getattr = btrfs_getattr,
10619 .setattr = btrfs_setattr,
10620 .permission = btrfs_permission,
10621 .setxattr = generic_setxattr,
10622 .getxattr = generic_getxattr,
10623 .listxattr = btrfs_listxattr,
10624 .removexattr = generic_removexattr,
10625 .get_acl = btrfs_get_acl,
10626 .set_acl = btrfs_set_acl,
10627 .update_time = btrfs_update_time,
10628 };
10629 static const struct inode_operations btrfs_symlink_inode_operations = {
10630 .readlink = generic_readlink,
10631 .get_link = page_get_link,
10632 .getattr = btrfs_getattr,
10633 .setattr = btrfs_setattr,
10634 .permission = btrfs_permission,
10635 .setxattr = generic_setxattr,
10636 .getxattr = generic_getxattr,
10637 .listxattr = btrfs_listxattr,
10638 .removexattr = generic_removexattr,
10639 .update_time = btrfs_update_time,
10640 };
10641
10642 const struct dentry_operations btrfs_dentry_operations = {
10643 .d_delete = btrfs_dentry_delete,
10644 .d_release = btrfs_dentry_release,
10645 };
Linux kernel - Deliverables
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