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Merge branch 'for-4.7-zac' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
[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
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 };
75
76 static const struct inode_operations btrfs_dir_inode_operations;
77 static const struct inode_operations btrfs_symlink_inode_operations;
78 static const struct inode_operations btrfs_dir_ro_inode_operations;
79 static const struct inode_operations btrfs_special_inode_operations;
80 static const struct inode_operations btrfs_file_inode_operations;
81 static const struct address_space_operations btrfs_aops;
82 static const struct address_space_operations btrfs_symlink_aops;
83 static const struct file_operations btrfs_dir_file_operations;
84 static const struct extent_io_ops btrfs_extent_io_ops;
85
86 static struct kmem_cache *btrfs_inode_cachep;
87 struct kmem_cache *btrfs_trans_handle_cachep;
88 struct kmem_cache *btrfs_transaction_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, int *page_started,
109 unsigned long *nr_written, int unlock);
110 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
111 u64 len, u64 orig_start,
112 u64 block_start, u64 block_len,
113 u64 orig_block_len, u64 ram_bytes,
114 int type);
115
116 static int btrfs_dirty_inode(struct inode *inode);
117
118 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
119 void btrfs_test_inode_set_ops(struct inode *inode)
120 {
121 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
122 }
123 #endif
124
125 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
126 struct inode *inode, struct inode *dir,
127 const struct qstr *qstr)
128 {
129 int err;
130
131 err = btrfs_init_acl(trans, inode, dir);
132 if (!err)
133 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
134 return err;
135 }
136
137 /*
138 * this does all the hard work for inserting an inline extent into
139 * the btree. The caller should have done a btrfs_drop_extents so that
140 * no overlapping inline items exist in the btree
141 */
142 static int insert_inline_extent(struct btrfs_trans_handle *trans,
143 struct btrfs_path *path, int extent_inserted,
144 struct btrfs_root *root, struct inode *inode,
145 u64 start, size_t size, size_t compressed_size,
146 int compress_type,
147 struct page **compressed_pages)
148 {
149 struct extent_buffer *leaf;
150 struct page *page = NULL;
151 char *kaddr;
152 unsigned long ptr;
153 struct btrfs_file_extent_item *ei;
154 int err = 0;
155 int ret;
156 size_t cur_size = size;
157 unsigned long offset;
158
159 if (compressed_size && compressed_pages)
160 cur_size = compressed_size;
161
162 inode_add_bytes(inode, size);
163
164 if (!extent_inserted) {
165 struct btrfs_key key;
166 size_t datasize;
167
168 key.objectid = btrfs_ino(inode);
169 key.offset = start;
170 key.type = BTRFS_EXTENT_DATA_KEY;
171
172 datasize = btrfs_file_extent_calc_inline_size(cur_size);
173 path->leave_spinning = 1;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 datasize);
176 if (ret) {
177 err = ret;
178 goto fail;
179 }
180 }
181 leaf = path->nodes[0];
182 ei = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_file_extent_item);
184 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
185 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
186 btrfs_set_file_extent_encryption(leaf, ei, 0);
187 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
188 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
189 ptr = btrfs_file_extent_inline_start(ei);
190
191 if (compress_type != BTRFS_COMPRESS_NONE) {
192 struct page *cpage;
193 int i = 0;
194 while (compressed_size > 0) {
195 cpage = compressed_pages[i];
196 cur_size = min_t(unsigned long, compressed_size,
197 PAGE_SIZE);
198
199 kaddr = kmap_atomic(cpage);
200 write_extent_buffer(leaf, kaddr, ptr, cur_size);
201 kunmap_atomic(kaddr);
202
203 i++;
204 ptr += cur_size;
205 compressed_size -= cur_size;
206 }
207 btrfs_set_file_extent_compression(leaf, ei,
208 compress_type);
209 } else {
210 page = find_get_page(inode->i_mapping,
211 start >> PAGE_SHIFT);
212 btrfs_set_file_extent_compression(leaf, ei, 0);
213 kaddr = kmap_atomic(page);
214 offset = start & (PAGE_SIZE - 1);
215 write_extent_buffer(leaf, kaddr + offset, ptr, size);
216 kunmap_atomic(kaddr);
217 put_page(page);
218 }
219 btrfs_mark_buffer_dirty(leaf);
220 btrfs_release_path(path);
221
222 /*
223 * we're an inline extent, so nobody can
224 * extend the file past i_size without locking
225 * a page we already have locked.
226 *
227 * We must do any isize and inode updates
228 * before we unlock the pages. Otherwise we
229 * could end up racing with unlink.
230 */
231 BTRFS_I(inode)->disk_i_size = inode->i_size;
232 ret = btrfs_update_inode(trans, root, inode);
233
234 return ret;
235 fail:
236 return err;
237 }
238
239
240 /*
241 * conditionally insert an inline extent into the file. This
242 * does the checks required to make sure the data is small enough
243 * to fit as an inline extent.
244 */
245 static noinline int cow_file_range_inline(struct btrfs_root *root,
246 struct inode *inode, u64 start,
247 u64 end, size_t compressed_size,
248 int compress_type,
249 struct page **compressed_pages)
250 {
251 struct btrfs_trans_handle *trans;
252 u64 isize = i_size_read(inode);
253 u64 actual_end = min(end + 1, isize);
254 u64 inline_len = actual_end - start;
255 u64 aligned_end = ALIGN(end, root->sectorsize);
256 u64 data_len = inline_len;
257 int ret;
258 struct btrfs_path *path;
259 int extent_inserted = 0;
260 u32 extent_item_size;
261
262 if (compressed_size)
263 data_len = compressed_size;
264
265 if (start > 0 ||
266 actual_end > root->sectorsize ||
267 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
268 (!compressed_size &&
269 (actual_end & (root->sectorsize - 1)) == 0) ||
270 end + 1 < isize ||
271 data_len > root->fs_info->max_inline) {
272 return 1;
273 }
274
275 path = btrfs_alloc_path();
276 if (!path)
277 return -ENOMEM;
278
279 trans = btrfs_join_transaction(root);
280 if (IS_ERR(trans)) {
281 btrfs_free_path(path);
282 return PTR_ERR(trans);
283 }
284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
285
286 if (compressed_size && compressed_pages)
287 extent_item_size = btrfs_file_extent_calc_inline_size(
288 compressed_size);
289 else
290 extent_item_size = btrfs_file_extent_calc_inline_size(
291 inline_len);
292
293 ret = __btrfs_drop_extents(trans, root, inode, path,
294 start, aligned_end, NULL,
295 1, 1, extent_item_size, &extent_inserted);
296 if (ret) {
297 btrfs_abort_transaction(trans, root, ret);
298 goto out;
299 }
300
301 if (isize > actual_end)
302 inline_len = min_t(u64, isize, actual_end);
303 ret = insert_inline_extent(trans, path, extent_inserted,
304 root, inode, start,
305 inline_len, compressed_size,
306 compress_type, compressed_pages);
307 if (ret && ret != -ENOSPC) {
308 btrfs_abort_transaction(trans, root, ret);
309 goto out;
310 } else if (ret == -ENOSPC) {
311 ret = 1;
312 goto out;
313 }
314
315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
316 btrfs_delalloc_release_metadata(inode, end + 1 - start);
317 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
318 out:
319 /*
320 * Don't forget to free the reserved space, as for inlined extent
321 * it won't count as data extent, free them directly here.
322 * And at reserve time, it's always aligned to page size, so
323 * just free one page here.
324 */
325 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
326 btrfs_free_path(path);
327 btrfs_end_transaction(trans, root);
328 return ret;
329 }
330
331 struct async_extent {
332 u64 start;
333 u64 ram_size;
334 u64 compressed_size;
335 struct page **pages;
336 unsigned long nr_pages;
337 int compress_type;
338 struct list_head list;
339 };
340
341 struct async_cow {
342 struct inode *inode;
343 struct btrfs_root *root;
344 struct page *locked_page;
345 u64 start;
346 u64 end;
347 struct list_head extents;
348 struct btrfs_work work;
349 };
350
351 static noinline int add_async_extent(struct async_cow *cow,
352 u64 start, u64 ram_size,
353 u64 compressed_size,
354 struct page **pages,
355 unsigned long nr_pages,
356 int compress_type)
357 {
358 struct async_extent *async_extent;
359
360 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
361 BUG_ON(!async_extent); /* -ENOMEM */
362 async_extent->start = start;
363 async_extent->ram_size = ram_size;
364 async_extent->compressed_size = compressed_size;
365 async_extent->pages = pages;
366 async_extent->nr_pages = nr_pages;
367 async_extent->compress_type = compress_type;
368 list_add_tail(&async_extent->list, &cow->extents);
369 return 0;
370 }
371
372 static inline int inode_need_compress(struct inode *inode)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375
376 /* force compress */
377 if (btrfs_test_opt(root, FORCE_COMPRESS))
378 return 1;
379 /* bad compression ratios */
380 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
381 return 0;
382 if (btrfs_test_opt(root, COMPRESS) ||
383 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
384 BTRFS_I(inode)->force_compress)
385 return 1;
386 return 0;
387 }
388
389 /*
390 * we create compressed extents in two phases. The first
391 * phase compresses a range of pages that have already been
392 * locked (both pages and state bits are locked).
393 *
394 * This is done inside an ordered work queue, and the compression
395 * is spread across many cpus. The actual IO submission is step
396 * two, and the ordered work queue takes care of making sure that
397 * happens in the same order things were put onto the queue by
398 * writepages and friends.
399 *
400 * If this code finds it can't get good compression, it puts an
401 * entry onto the work queue to write the uncompressed bytes. This
402 * makes sure that both compressed inodes and uncompressed inodes
403 * are written in the same order that the flusher thread sent them
404 * down.
405 */
406 static noinline void compress_file_range(struct inode *inode,
407 struct page *locked_page,
408 u64 start, u64 end,
409 struct async_cow *async_cow,
410 int *num_added)
411 {
412 struct btrfs_root *root = BTRFS_I(inode)->root;
413 u64 num_bytes;
414 u64 blocksize = root->sectorsize;
415 u64 actual_end;
416 u64 isize = i_size_read(inode);
417 int ret = 0;
418 struct page **pages = NULL;
419 unsigned long nr_pages;
420 unsigned long nr_pages_ret = 0;
421 unsigned long total_compressed = 0;
422 unsigned long total_in = 0;
423 unsigned long max_compressed = SZ_128K;
424 unsigned long max_uncompressed = SZ_128K;
425 int i;
426 int will_compress;
427 int compress_type = root->fs_info->compress_type;
428 int redirty = 0;
429
430 /* if this is a small write inside eof, kick off a defrag */
431 if ((end - start + 1) < SZ_16K &&
432 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
433 btrfs_add_inode_defrag(NULL, inode);
434
435 actual_end = min_t(u64, isize, end + 1);
436 again:
437 will_compress = 0;
438 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
439 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
440
441 /*
442 * we don't want to send crud past the end of i_size through
443 * compression, that's just a waste of CPU time. So, if the
444 * end of the file is before the start of our current
445 * requested range of bytes, we bail out to the uncompressed
446 * cleanup code that can deal with all of this.
447 *
448 * It isn't really the fastest way to fix things, but this is a
449 * very uncommon corner.
450 */
451 if (actual_end <= start)
452 goto cleanup_and_bail_uncompressed;
453
454 total_compressed = actual_end - start;
455
456 /*
457 * skip compression for a small file range(<=blocksize) that
458 * isn't an inline extent, since it dosen't save disk space at all.
459 */
460 if (total_compressed <= blocksize &&
461 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
462 goto cleanup_and_bail_uncompressed;
463
464 /* we want to make sure that amount of ram required to uncompress
465 * an extent is reasonable, so we limit the total size in ram
466 * of a compressed extent to 128k. This is a crucial number
467 * because it also controls how easily we can spread reads across
468 * cpus for decompression.
469 *
470 * We also want to make sure the amount of IO required to do
471 * a random read is reasonably small, so we limit the size of
472 * a compressed extent to 128k.
473 */
474 total_compressed = min(total_compressed, max_uncompressed);
475 num_bytes = ALIGN(end - start + 1, blocksize);
476 num_bytes = max(blocksize, num_bytes);
477 total_in = 0;
478 ret = 0;
479
480 /*
481 * we do compression for mount -o compress and when the
482 * inode has not been flagged as nocompress. This flag can
483 * change at any time if we discover bad compression ratios.
484 */
485 if (inode_need_compress(inode)) {
486 WARN_ON(pages);
487 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
488 if (!pages) {
489 /* just bail out to the uncompressed code */
490 goto cont;
491 }
492
493 if (BTRFS_I(inode)->force_compress)
494 compress_type = BTRFS_I(inode)->force_compress;
495
496 /*
497 * we need to call clear_page_dirty_for_io on each
498 * page in the range. Otherwise applications with the file
499 * mmap'd can wander in and change the page contents while
500 * we are compressing them.
501 *
502 * If the compression fails for any reason, we set the pages
503 * dirty again later on.
504 */
505 extent_range_clear_dirty_for_io(inode, start, end);
506 redirty = 1;
507 ret = btrfs_compress_pages(compress_type,
508 inode->i_mapping, start,
509 total_compressed, pages,
510 nr_pages, &nr_pages_ret,
511 &total_in,
512 &total_compressed,
513 max_compressed);
514
515 if (!ret) {
516 unsigned long offset = total_compressed &
517 (PAGE_SIZE - 1);
518 struct page *page = pages[nr_pages_ret - 1];
519 char *kaddr;
520
521 /* zero the tail end of the last page, we might be
522 * sending it down to disk
523 */
524 if (offset) {
525 kaddr = kmap_atomic(page);
526 memset(kaddr + offset, 0,
527 PAGE_SIZE - offset);
528 kunmap_atomic(kaddr);
529 }
530 will_compress = 1;
531 }
532 }
533 cont:
534 if (start == 0) {
535 /* lets try to make an inline extent */
536 if (ret || total_in < (actual_end - start)) {
537 /* we didn't compress the entire range, try
538 * to make an uncompressed inline extent.
539 */
540 ret = cow_file_range_inline(root, inode, start, end,
541 0, 0, NULL);
542 } else {
543 /* try making a compressed inline extent */
544 ret = cow_file_range_inline(root, inode, start, end,
545 total_compressed,
546 compress_type, pages);
547 }
548 if (ret <= 0) {
549 unsigned long clear_flags = EXTENT_DELALLOC |
550 EXTENT_DEFRAG;
551 unsigned long page_error_op;
552
553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
555
556 /*
557 * inline extent creation worked or returned error,
558 * we don't need to create any more async work items.
559 * Unlock and free up our temp pages.
560 */
561 extent_clear_unlock_delalloc(inode, start, end, NULL,
562 clear_flags, PAGE_UNLOCK |
563 PAGE_CLEAR_DIRTY |
564 PAGE_SET_WRITEBACK |
565 page_error_op |
566 PAGE_END_WRITEBACK);
567 goto free_pages_out;
568 }
569 }
570
571 if (will_compress) {
572 /*
573 * we aren't doing an inline extent round the compressed size
574 * up to a block size boundary so the allocator does sane
575 * things
576 */
577 total_compressed = ALIGN(total_compressed, blocksize);
578
579 /*
580 * one last check to make sure the compression is really a
581 * win, compare the page count read with the blocks on disk
582 */
583 total_in = ALIGN(total_in, PAGE_SIZE);
584 if (total_compressed >= total_in) {
585 will_compress = 0;
586 } else {
587 num_bytes = total_in;
588 }
589 }
590 if (!will_compress && pages) {
591 /*
592 * the compression code ran but failed to make things smaller,
593 * free any pages it allocated and our page pointer array
594 */
595 for (i = 0; i < nr_pages_ret; i++) {
596 WARN_ON(pages[i]->mapping);
597 put_page(pages[i]);
598 }
599 kfree(pages);
600 pages = NULL;
601 total_compressed = 0;
602 nr_pages_ret = 0;
603
604 /* flag the file so we don't compress in the future */
605 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
606 !(BTRFS_I(inode)->force_compress)) {
607 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
608 }
609 }
610 if (will_compress) {
611 *num_added += 1;
612
613 /* the async work queues will take care of doing actual
614 * allocation on disk for these compressed pages,
615 * and will submit them to the elevator.
616 */
617 add_async_extent(async_cow, start, num_bytes,
618 total_compressed, pages, nr_pages_ret,
619 compress_type);
620
621 if (start + num_bytes < end) {
622 start += num_bytes;
623 pages = NULL;
624 cond_resched();
625 goto again;
626 }
627 } else {
628 cleanup_and_bail_uncompressed:
629 /*
630 * No compression, but we still need to write the pages in
631 * the file we've been given so far. redirty the locked
632 * page if it corresponds to our extent and set things up
633 * for the async work queue to run cow_file_range to do
634 * the normal delalloc dance
635 */
636 if (page_offset(locked_page) >= start &&
637 page_offset(locked_page) <= end) {
638 __set_page_dirty_nobuffers(locked_page);
639 /* unlocked later on in the async handlers */
640 }
641 if (redirty)
642 extent_range_redirty_for_io(inode, start, end);
643 add_async_extent(async_cow, start, end - start + 1,
644 0, NULL, 0, BTRFS_COMPRESS_NONE);
645 *num_added += 1;
646 }
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 &page_started, &nr_written, 0);
716
717 /* JDM XXX */
718
719 /*
720 * if page_started, cow_file_range inserted an
721 * inline extent and took care of all the unlocking
722 * and IO for us. Otherwise, we need to submit
723 * all those pages down to the drive.
724 */
725 if (!page_started && !ret)
726 extent_write_locked_range(io_tree,
727 inode, async_extent->start,
728 async_extent->start +
729 async_extent->ram_size - 1,
730 btrfs_get_extent,
731 WB_SYNC_ALL);
732 else if (ret)
733 unlock_page(async_cow->locked_page);
734 kfree(async_extent);
735 cond_resched();
736 continue;
737 }
738
739 lock_extent(io_tree, async_extent->start,
740 async_extent->start + async_extent->ram_size - 1);
741
742 ret = btrfs_reserve_extent(root,
743 async_extent->compressed_size,
744 async_extent->compressed_size,
745 0, alloc_hint, &ins, 1, 1);
746 if (ret) {
747 free_async_extent_pages(async_extent);
748
749 if (ret == -ENOSPC) {
750 unlock_extent(io_tree, async_extent->start,
751 async_extent->start +
752 async_extent->ram_size - 1);
753
754 /*
755 * we need to redirty the pages if we decide to
756 * fallback to uncompressed IO, otherwise we
757 * will not submit these pages down to lower
758 * layers.
759 */
760 extent_range_redirty_for_io(inode,
761 async_extent->start,
762 async_extent->start +
763 async_extent->ram_size - 1);
764
765 goto retry;
766 }
767 goto out_free;
768 }
769 /*
770 * here we're doing allocation and writeback of the
771 * compressed pages
772 */
773 btrfs_drop_extent_cache(inode, async_extent->start,
774 async_extent->start +
775 async_extent->ram_size - 1, 0);
776
777 em = alloc_extent_map();
778 if (!em) {
779 ret = -ENOMEM;
780 goto out_free_reserve;
781 }
782 em->start = async_extent->start;
783 em->len = async_extent->ram_size;
784 em->orig_start = em->start;
785 em->mod_start = em->start;
786 em->mod_len = em->len;
787
788 em->block_start = ins.objectid;
789 em->block_len = ins.offset;
790 em->orig_block_len = ins.offset;
791 em->ram_bytes = async_extent->ram_size;
792 em->bdev = root->fs_info->fs_devices->latest_bdev;
793 em->compress_type = async_extent->compress_type;
794 set_bit(EXTENT_FLAG_PINNED, &em->flags);
795 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
796 em->generation = -1;
797
798 while (1) {
799 write_lock(&em_tree->lock);
800 ret = add_extent_mapping(em_tree, em, 1);
801 write_unlock(&em_tree->lock);
802 if (ret != -EEXIST) {
803 free_extent_map(em);
804 break;
805 }
806 btrfs_drop_extent_cache(inode, async_extent->start,
807 async_extent->start +
808 async_extent->ram_size - 1, 0);
809 }
810
811 if (ret)
812 goto out_free_reserve;
813
814 ret = btrfs_add_ordered_extent_compress(inode,
815 async_extent->start,
816 ins.objectid,
817 async_extent->ram_size,
818 ins.offset,
819 BTRFS_ORDERED_COMPRESSED,
820 async_extent->compress_type);
821 if (ret) {
822 btrfs_drop_extent_cache(inode, async_extent->start,
823 async_extent->start +
824 async_extent->ram_size - 1, 0);
825 goto out_free_reserve;
826 }
827 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
828
829 /*
830 * clear dirty, set writeback and unlock the pages.
831 */
832 extent_clear_unlock_delalloc(inode, async_extent->start,
833 async_extent->start +
834 async_extent->ram_size - 1,
835 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
836 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
837 PAGE_SET_WRITEBACK);
838 ret = btrfs_submit_compressed_write(inode,
839 async_extent->start,
840 async_extent->ram_size,
841 ins.objectid,
842 ins.offset, async_extent->pages,
843 async_extent->nr_pages);
844 if (ret) {
845 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
846 struct page *p = async_extent->pages[0];
847 const u64 start = async_extent->start;
848 const u64 end = start + async_extent->ram_size - 1;
849
850 p->mapping = inode->i_mapping;
851 tree->ops->writepage_end_io_hook(p, start, end,
852 NULL, 0);
853 p->mapping = NULL;
854 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
855 PAGE_END_WRITEBACK |
856 PAGE_SET_ERROR);
857 free_async_extent_pages(async_extent);
858 }
859 alloc_hint = ins.objectid + ins.offset;
860 kfree(async_extent);
861 cond_resched();
862 }
863 return;
864 out_free_reserve:
865 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
866 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
867 out_free:
868 extent_clear_unlock_delalloc(inode, async_extent->start,
869 async_extent->start +
870 async_extent->ram_size - 1,
871 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
872 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
873 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
874 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
875 PAGE_SET_ERROR);
876 free_async_extent_pages(async_extent);
877 kfree(async_extent);
878 goto again;
879 }
880
881 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
882 u64 num_bytes)
883 {
884 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
885 struct extent_map *em;
886 u64 alloc_hint = 0;
887
888 read_lock(&em_tree->lock);
889 em = search_extent_mapping(em_tree, start, num_bytes);
890 if (em) {
891 /*
892 * if block start isn't an actual block number then find the
893 * first block in this inode and use that as a hint. If that
894 * block is also bogus then just don't worry about it.
895 */
896 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
897 free_extent_map(em);
898 em = search_extent_mapping(em_tree, 0, 0);
899 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
900 alloc_hint = em->block_start;
901 if (em)
902 free_extent_map(em);
903 } else {
904 alloc_hint = em->block_start;
905 free_extent_map(em);
906 }
907 }
908 read_unlock(&em_tree->lock);
909
910 return alloc_hint;
911 }
912
913 /*
914 * when extent_io.c finds a delayed allocation range in the file,
915 * the call backs end up in this code. The basic idea is to
916 * allocate extents on disk for the range, and create ordered data structs
917 * in ram to track those extents.
918 *
919 * locked_page is the page that writepage had locked already. We use
920 * it to make sure we don't do extra locks or unlocks.
921 *
922 * *page_started is set to one if we unlock locked_page and do everything
923 * required to start IO on it. It may be clean and already done with
924 * IO when we return.
925 */
926 static noinline int cow_file_range(struct inode *inode,
927 struct page *locked_page,
928 u64 start, u64 end, int *page_started,
929 unsigned long *nr_written,
930 int unlock)
931 {
932 struct btrfs_root *root = BTRFS_I(inode)->root;
933 u64 alloc_hint = 0;
934 u64 num_bytes;
935 unsigned long ram_size;
936 u64 disk_num_bytes;
937 u64 cur_alloc_size;
938 u64 blocksize = root->sectorsize;
939 struct btrfs_key ins;
940 struct extent_map *em;
941 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
942 int ret = 0;
943
944 if (btrfs_is_free_space_inode(inode)) {
945 WARN_ON_ONCE(1);
946 ret = -EINVAL;
947 goto out_unlock;
948 }
949
950 num_bytes = ALIGN(end - start + 1, blocksize);
951 num_bytes = max(blocksize, num_bytes);
952 disk_num_bytes = num_bytes;
953
954 /* if this is a small write inside eof, kick off defrag */
955 if (num_bytes < SZ_64K &&
956 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
957 btrfs_add_inode_defrag(NULL, inode);
958
959 if (start == 0) {
960 /* lets try to make an inline extent */
961 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
962 NULL);
963 if (ret == 0) {
964 extent_clear_unlock_delalloc(inode, start, end, NULL,
965 EXTENT_LOCKED | EXTENT_DELALLOC |
966 EXTENT_DEFRAG, PAGE_UNLOCK |
967 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
968 PAGE_END_WRITEBACK);
969
970 *nr_written = *nr_written +
971 (end - start + PAGE_SIZE) / PAGE_SIZE;
972 *page_started = 1;
973 goto out;
974 } else if (ret < 0) {
975 goto out_unlock;
976 }
977 }
978
979 BUG_ON(disk_num_bytes >
980 btrfs_super_total_bytes(root->fs_info->super_copy));
981
982 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
983 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
984
985 while (disk_num_bytes > 0) {
986 unsigned long op;
987
988 cur_alloc_size = disk_num_bytes;
989 ret = btrfs_reserve_extent(root, cur_alloc_size,
990 root->sectorsize, 0, alloc_hint,
991 &ins, 1, 1);
992 if (ret < 0)
993 goto out_unlock;
994
995 em = alloc_extent_map();
996 if (!em) {
997 ret = -ENOMEM;
998 goto out_reserve;
999 }
1000 em->start = start;
1001 em->orig_start = em->start;
1002 ram_size = ins.offset;
1003 em->len = ins.offset;
1004 em->mod_start = em->start;
1005 em->mod_len = em->len;
1006
1007 em->block_start = ins.objectid;
1008 em->block_len = ins.offset;
1009 em->orig_block_len = ins.offset;
1010 em->ram_bytes = ram_size;
1011 em->bdev = root->fs_info->fs_devices->latest_bdev;
1012 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1013 em->generation = -1;
1014
1015 while (1) {
1016 write_lock(&em_tree->lock);
1017 ret = add_extent_mapping(em_tree, em, 1);
1018 write_unlock(&em_tree->lock);
1019 if (ret != -EEXIST) {
1020 free_extent_map(em);
1021 break;
1022 }
1023 btrfs_drop_extent_cache(inode, start,
1024 start + ram_size - 1, 0);
1025 }
1026 if (ret)
1027 goto out_reserve;
1028
1029 cur_alloc_size = ins.offset;
1030 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1031 ram_size, cur_alloc_size, 0);
1032 if (ret)
1033 goto out_drop_extent_cache;
1034
1035 if (root->root_key.objectid ==
1036 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1037 ret = btrfs_reloc_clone_csums(inode, start,
1038 cur_alloc_size);
1039 if (ret)
1040 goto out_drop_extent_cache;
1041 }
1042
1043 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1044
1045 if (disk_num_bytes < cur_alloc_size)
1046 break;
1047
1048 /* we're not doing compressed IO, don't unlock the first
1049 * page (which the caller expects to stay locked), don't
1050 * clear any dirty bits and don't set any writeback bits
1051 *
1052 * Do set the Private2 bit so we know this page was properly
1053 * setup for writepage
1054 */
1055 op = unlock ? PAGE_UNLOCK : 0;
1056 op |= PAGE_SET_PRIVATE2;
1057
1058 extent_clear_unlock_delalloc(inode, start,
1059 start + ram_size - 1, locked_page,
1060 EXTENT_LOCKED | EXTENT_DELALLOC,
1061 op);
1062 disk_num_bytes -= cur_alloc_size;
1063 num_bytes -= cur_alloc_size;
1064 alloc_hint = ins.objectid + ins.offset;
1065 start += cur_alloc_size;
1066 }
1067 out:
1068 return ret;
1069
1070 out_drop_extent_cache:
1071 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1072 out_reserve:
1073 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1074 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1075 out_unlock:
1076 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1077 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1078 EXTENT_DELALLOC | EXTENT_DEFRAG,
1079 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1080 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1081 goto out;
1082 }
1083
1084 /*
1085 * work queue call back to started compression on a file and pages
1086 */
1087 static noinline void async_cow_start(struct btrfs_work *work)
1088 {
1089 struct async_cow *async_cow;
1090 int num_added = 0;
1091 async_cow = container_of(work, struct async_cow, work);
1092
1093 compress_file_range(async_cow->inode, async_cow->locked_page,
1094 async_cow->start, async_cow->end, async_cow,
1095 &num_added);
1096 if (num_added == 0) {
1097 btrfs_add_delayed_iput(async_cow->inode);
1098 async_cow->inode = NULL;
1099 }
1100 }
1101
1102 /*
1103 * work queue call back to submit previously compressed pages
1104 */
1105 static noinline void async_cow_submit(struct btrfs_work *work)
1106 {
1107 struct async_cow *async_cow;
1108 struct btrfs_root *root;
1109 unsigned long nr_pages;
1110
1111 async_cow = container_of(work, struct async_cow, work);
1112
1113 root = async_cow->root;
1114 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1115 PAGE_SHIFT;
1116
1117 /*
1118 * atomic_sub_return implies a barrier for waitqueue_active
1119 */
1120 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1121 5 * SZ_1M &&
1122 waitqueue_active(&root->fs_info->async_submit_wait))
1123 wake_up(&root->fs_info->async_submit_wait);
1124
1125 if (async_cow->inode)
1126 submit_compressed_extents(async_cow->inode, async_cow);
1127 }
1128
1129 static noinline void async_cow_free(struct btrfs_work *work)
1130 {
1131 struct async_cow *async_cow;
1132 async_cow = container_of(work, struct async_cow, work);
1133 if (async_cow->inode)
1134 btrfs_add_delayed_iput(async_cow->inode);
1135 kfree(async_cow);
1136 }
1137
1138 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1139 u64 start, u64 end, int *page_started,
1140 unsigned long *nr_written)
1141 {
1142 struct async_cow *async_cow;
1143 struct btrfs_root *root = BTRFS_I(inode)->root;
1144 unsigned long nr_pages;
1145 u64 cur_end;
1146 int limit = 10 * SZ_1M;
1147
1148 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1149 1, 0, NULL, GFP_NOFS);
1150 while (start < end) {
1151 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1152 BUG_ON(!async_cow); /* -ENOMEM */
1153 async_cow->inode = igrab(inode);
1154 async_cow->root = root;
1155 async_cow->locked_page = locked_page;
1156 async_cow->start = start;
1157
1158 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1159 !btrfs_test_opt(root, FORCE_COMPRESS))
1160 cur_end = end;
1161 else
1162 cur_end = min(end, start + SZ_512K - 1);
1163
1164 async_cow->end = cur_end;
1165 INIT_LIST_HEAD(&async_cow->extents);
1166
1167 btrfs_init_work(&async_cow->work,
1168 btrfs_delalloc_helper,
1169 async_cow_start, async_cow_submit,
1170 async_cow_free);
1171
1172 nr_pages = (cur_end - start + PAGE_SIZE) >>
1173 PAGE_SHIFT;
1174 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1175
1176 btrfs_queue_work(root->fs_info->delalloc_workers,
1177 &async_cow->work);
1178
1179 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1180 wait_event(root->fs_info->async_submit_wait,
1181 (atomic_read(&root->fs_info->async_delalloc_pages) <
1182 limit));
1183 }
1184
1185 while (atomic_read(&root->fs_info->async_submit_draining) &&
1186 atomic_read(&root->fs_info->async_delalloc_pages)) {
1187 wait_event(root->fs_info->async_submit_wait,
1188 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1189 0));
1190 }
1191
1192 *nr_written += nr_pages;
1193 start = cur_end + 1;
1194 }
1195 *page_started = 1;
1196 return 0;
1197 }
1198
1199 static noinline int csum_exist_in_range(struct btrfs_root *root,
1200 u64 bytenr, u64 num_bytes)
1201 {
1202 int ret;
1203 struct btrfs_ordered_sum *sums;
1204 LIST_HEAD(list);
1205
1206 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1207 bytenr + num_bytes - 1, &list, 0);
1208 if (ret == 0 && list_empty(&list))
1209 return 0;
1210
1211 while (!list_empty(&list)) {
1212 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1213 list_del(&sums->list);
1214 kfree(sums);
1215 }
1216 return 1;
1217 }
1218
1219 /*
1220 * when nowcow writeback call back. This checks for snapshots or COW copies
1221 * of the extents that exist in the file, and COWs the file as required.
1222 *
1223 * If no cow copies or snapshots exist, we write directly to the existing
1224 * blocks on disk
1225 */
1226 static noinline int run_delalloc_nocow(struct inode *inode,
1227 struct page *locked_page,
1228 u64 start, u64 end, int *page_started, int force,
1229 unsigned long *nr_written)
1230 {
1231 struct btrfs_root *root = BTRFS_I(inode)->root;
1232 struct btrfs_trans_handle *trans;
1233 struct extent_buffer *leaf;
1234 struct btrfs_path *path;
1235 struct btrfs_file_extent_item *fi;
1236 struct btrfs_key found_key;
1237 u64 cow_start;
1238 u64 cur_offset;
1239 u64 extent_end;
1240 u64 extent_offset;
1241 u64 disk_bytenr;
1242 u64 num_bytes;
1243 u64 disk_num_bytes;
1244 u64 ram_bytes;
1245 int extent_type;
1246 int ret, err;
1247 int type;
1248 int nocow;
1249 int check_prev = 1;
1250 bool nolock;
1251 u64 ino = btrfs_ino(inode);
1252
1253 path = btrfs_alloc_path();
1254 if (!path) {
1255 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1256 EXTENT_LOCKED | EXTENT_DELALLOC |
1257 EXTENT_DO_ACCOUNTING |
1258 EXTENT_DEFRAG, PAGE_UNLOCK |
1259 PAGE_CLEAR_DIRTY |
1260 PAGE_SET_WRITEBACK |
1261 PAGE_END_WRITEBACK);
1262 return -ENOMEM;
1263 }
1264
1265 nolock = btrfs_is_free_space_inode(inode);
1266
1267 if (nolock)
1268 trans = btrfs_join_transaction_nolock(root);
1269 else
1270 trans = btrfs_join_transaction(root);
1271
1272 if (IS_ERR(trans)) {
1273 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1274 EXTENT_LOCKED | EXTENT_DELALLOC |
1275 EXTENT_DO_ACCOUNTING |
1276 EXTENT_DEFRAG, PAGE_UNLOCK |
1277 PAGE_CLEAR_DIRTY |
1278 PAGE_SET_WRITEBACK |
1279 PAGE_END_WRITEBACK);
1280 btrfs_free_path(path);
1281 return PTR_ERR(trans);
1282 }
1283
1284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1285
1286 cow_start = (u64)-1;
1287 cur_offset = start;
1288 while (1) {
1289 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1290 cur_offset, 0);
1291 if (ret < 0)
1292 goto error;
1293 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1294 leaf = path->nodes[0];
1295 btrfs_item_key_to_cpu(leaf, &found_key,
1296 path->slots[0] - 1);
1297 if (found_key.objectid == ino &&
1298 found_key.type == BTRFS_EXTENT_DATA_KEY)
1299 path->slots[0]--;
1300 }
1301 check_prev = 0;
1302 next_slot:
1303 leaf = path->nodes[0];
1304 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1305 ret = btrfs_next_leaf(root, path);
1306 if (ret < 0)
1307 goto error;
1308 if (ret > 0)
1309 break;
1310 leaf = path->nodes[0];
1311 }
1312
1313 nocow = 0;
1314 disk_bytenr = 0;
1315 num_bytes = 0;
1316 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1317
1318 if (found_key.objectid > ino)
1319 break;
1320 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1321 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1322 path->slots[0]++;
1323 goto next_slot;
1324 }
1325 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1326 found_key.offset > end)
1327 break;
1328
1329 if (found_key.offset > cur_offset) {
1330 extent_end = found_key.offset;
1331 extent_type = 0;
1332 goto out_check;
1333 }
1334
1335 fi = btrfs_item_ptr(leaf, path->slots[0],
1336 struct btrfs_file_extent_item);
1337 extent_type = btrfs_file_extent_type(leaf, fi);
1338
1339 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1340 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1341 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1342 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1343 extent_offset = btrfs_file_extent_offset(leaf, fi);
1344 extent_end = found_key.offset +
1345 btrfs_file_extent_num_bytes(leaf, fi);
1346 disk_num_bytes =
1347 btrfs_file_extent_disk_num_bytes(leaf, fi);
1348 if (extent_end <= start) {
1349 path->slots[0]++;
1350 goto next_slot;
1351 }
1352 if (disk_bytenr == 0)
1353 goto out_check;
1354 if (btrfs_file_extent_compression(leaf, fi) ||
1355 btrfs_file_extent_encryption(leaf, fi) ||
1356 btrfs_file_extent_other_encoding(leaf, fi))
1357 goto out_check;
1358 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1359 goto out_check;
1360 if (btrfs_extent_readonly(root, disk_bytenr))
1361 goto out_check;
1362 if (btrfs_cross_ref_exist(trans, root, ino,
1363 found_key.offset -
1364 extent_offset, disk_bytenr))
1365 goto out_check;
1366 disk_bytenr += extent_offset;
1367 disk_bytenr += cur_offset - found_key.offset;
1368 num_bytes = min(end + 1, extent_end) - cur_offset;
1369 /*
1370 * if there are pending snapshots for this root,
1371 * we fall into common COW way.
1372 */
1373 if (!nolock) {
1374 err = btrfs_start_write_no_snapshoting(root);
1375 if (!err)
1376 goto out_check;
1377 }
1378 /*
1379 * force cow if csum exists in the range.
1380 * this ensure that csum for a given extent are
1381 * either valid or do not exist.
1382 */
1383 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1384 goto out_check;
1385 if (!btrfs_inc_nocow_writers(root->fs_info,
1386 disk_bytenr))
1387 goto out_check;
1388 nocow = 1;
1389 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1390 extent_end = found_key.offset +
1391 btrfs_file_extent_inline_len(leaf,
1392 path->slots[0], fi);
1393 extent_end = ALIGN(extent_end, root->sectorsize);
1394 } else {
1395 BUG_ON(1);
1396 }
1397 out_check:
1398 if (extent_end <= start) {
1399 path->slots[0]++;
1400 if (!nolock && nocow)
1401 btrfs_end_write_no_snapshoting(root);
1402 if (nocow)
1403 btrfs_dec_nocow_writers(root->fs_info,
1404 disk_bytenr);
1405 goto next_slot;
1406 }
1407 if (!nocow) {
1408 if (cow_start == (u64)-1)
1409 cow_start = cur_offset;
1410 cur_offset = extent_end;
1411 if (cur_offset > end)
1412 break;
1413 path->slots[0]++;
1414 goto next_slot;
1415 }
1416
1417 btrfs_release_path(path);
1418 if (cow_start != (u64)-1) {
1419 ret = cow_file_range(inode, locked_page,
1420 cow_start, found_key.offset - 1,
1421 page_started, nr_written, 1);
1422 if (ret) {
1423 if (!nolock && nocow)
1424 btrfs_end_write_no_snapshoting(root);
1425 if (nocow)
1426 btrfs_dec_nocow_writers(root->fs_info,
1427 disk_bytenr);
1428 goto error;
1429 }
1430 cow_start = (u64)-1;
1431 }
1432
1433 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1434 struct extent_map *em;
1435 struct extent_map_tree *em_tree;
1436 em_tree = &BTRFS_I(inode)->extent_tree;
1437 em = alloc_extent_map();
1438 BUG_ON(!em); /* -ENOMEM */
1439 em->start = cur_offset;
1440 em->orig_start = found_key.offset - extent_offset;
1441 em->len = num_bytes;
1442 em->block_len = num_bytes;
1443 em->block_start = disk_bytenr;
1444 em->orig_block_len = disk_num_bytes;
1445 em->ram_bytes = ram_bytes;
1446 em->bdev = root->fs_info->fs_devices->latest_bdev;
1447 em->mod_start = em->start;
1448 em->mod_len = em->len;
1449 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1450 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1451 em->generation = -1;
1452 while (1) {
1453 write_lock(&em_tree->lock);
1454 ret = add_extent_mapping(em_tree, em, 1);
1455 write_unlock(&em_tree->lock);
1456 if (ret != -EEXIST) {
1457 free_extent_map(em);
1458 break;
1459 }
1460 btrfs_drop_extent_cache(inode, em->start,
1461 em->start + em->len - 1, 0);
1462 }
1463 type = BTRFS_ORDERED_PREALLOC;
1464 } else {
1465 type = BTRFS_ORDERED_NOCOW;
1466 }
1467
1468 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1469 num_bytes, num_bytes, type);
1470 if (nocow)
1471 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1472 BUG_ON(ret); /* -ENOMEM */
1473
1474 if (root->root_key.objectid ==
1475 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1476 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1477 num_bytes);
1478 if (ret) {
1479 if (!nolock && nocow)
1480 btrfs_end_write_no_snapshoting(root);
1481 goto error;
1482 }
1483 }
1484
1485 extent_clear_unlock_delalloc(inode, cur_offset,
1486 cur_offset + num_bytes - 1,
1487 locked_page, EXTENT_LOCKED |
1488 EXTENT_DELALLOC, PAGE_UNLOCK |
1489 PAGE_SET_PRIVATE2);
1490 if (!nolock && nocow)
1491 btrfs_end_write_no_snapshoting(root);
1492 cur_offset = extent_end;
1493 if (cur_offset > end)
1494 break;
1495 }
1496 btrfs_release_path(path);
1497
1498 if (cur_offset <= end && cow_start == (u64)-1) {
1499 cow_start = cur_offset;
1500 cur_offset = end;
1501 }
1502
1503 if (cow_start != (u64)-1) {
1504 ret = cow_file_range(inode, locked_page, cow_start, end,
1505 page_started, nr_written, 1);
1506 if (ret)
1507 goto error;
1508 }
1509
1510 error:
1511 err = btrfs_end_transaction(trans, root);
1512 if (!ret)
1513 ret = err;
1514
1515 if (ret && cur_offset < end)
1516 extent_clear_unlock_delalloc(inode, cur_offset, end,
1517 locked_page, EXTENT_LOCKED |
1518 EXTENT_DELALLOC | EXTENT_DEFRAG |
1519 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1520 PAGE_CLEAR_DIRTY |
1521 PAGE_SET_WRITEBACK |
1522 PAGE_END_WRITEBACK);
1523 btrfs_free_path(path);
1524 return ret;
1525 }
1526
1527 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1528 {
1529
1530 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1531 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1532 return 0;
1533
1534 /*
1535 * @defrag_bytes is a hint value, no spinlock held here,
1536 * if is not zero, it means the file is defragging.
1537 * Force cow if given extent needs to be defragged.
1538 */
1539 if (BTRFS_I(inode)->defrag_bytes &&
1540 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1541 EXTENT_DEFRAG, 0, NULL))
1542 return 1;
1543
1544 return 0;
1545 }
1546
1547 /*
1548 * extent_io.c call back to do delayed allocation processing
1549 */
1550 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1551 u64 start, u64 end, int *page_started,
1552 unsigned long *nr_written)
1553 {
1554 int ret;
1555 int force_cow = need_force_cow(inode, start, end);
1556
1557 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1558 ret = run_delalloc_nocow(inode, locked_page, start, end,
1559 page_started, 1, nr_written);
1560 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1561 ret = run_delalloc_nocow(inode, locked_page, start, end,
1562 page_started, 0, nr_written);
1563 } else if (!inode_need_compress(inode)) {
1564 ret = cow_file_range(inode, locked_page, start, end,
1565 page_started, nr_written, 1);
1566 } else {
1567 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1568 &BTRFS_I(inode)->runtime_flags);
1569 ret = cow_file_range_async(inode, locked_page, start, end,
1570 page_started, nr_written);
1571 }
1572 return ret;
1573 }
1574
1575 static void btrfs_split_extent_hook(struct inode *inode,
1576 struct extent_state *orig, u64 split)
1577 {
1578 u64 size;
1579
1580 /* not delalloc, ignore it */
1581 if (!(orig->state & EXTENT_DELALLOC))
1582 return;
1583
1584 size = orig->end - orig->start + 1;
1585 if (size > BTRFS_MAX_EXTENT_SIZE) {
1586 u64 num_extents;
1587 u64 new_size;
1588
1589 /*
1590 * See the explanation in btrfs_merge_extent_hook, the same
1591 * applies here, just in reverse.
1592 */
1593 new_size = orig->end - split + 1;
1594 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1595 BTRFS_MAX_EXTENT_SIZE);
1596 new_size = split - orig->start;
1597 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1598 BTRFS_MAX_EXTENT_SIZE);
1599 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1600 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1601 return;
1602 }
1603
1604 spin_lock(&BTRFS_I(inode)->lock);
1605 BTRFS_I(inode)->outstanding_extents++;
1606 spin_unlock(&BTRFS_I(inode)->lock);
1607 }
1608
1609 /*
1610 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1611 * extents so we can keep track of new extents that are just merged onto old
1612 * extents, such as when we are doing sequential writes, so we can properly
1613 * account for the metadata space we'll need.
1614 */
1615 static void btrfs_merge_extent_hook(struct inode *inode,
1616 struct extent_state *new,
1617 struct extent_state *other)
1618 {
1619 u64 new_size, old_size;
1620 u64 num_extents;
1621
1622 /* not delalloc, ignore it */
1623 if (!(other->state & EXTENT_DELALLOC))
1624 return;
1625
1626 if (new->start > other->start)
1627 new_size = new->end - other->start + 1;
1628 else
1629 new_size = other->end - new->start + 1;
1630
1631 /* we're not bigger than the max, unreserve the space and go */
1632 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1633 spin_lock(&BTRFS_I(inode)->lock);
1634 BTRFS_I(inode)->outstanding_extents--;
1635 spin_unlock(&BTRFS_I(inode)->lock);
1636 return;
1637 }
1638
1639 /*
1640 * We have to add up either side to figure out how many extents were
1641 * accounted for before we merged into one big extent. If the number of
1642 * extents we accounted for is <= the amount we need for the new range
1643 * then we can return, otherwise drop. Think of it like this
1644 *
1645 * [ 4k][MAX_SIZE]
1646 *
1647 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1648 * need 2 outstanding extents, on one side we have 1 and the other side
1649 * we have 1 so they are == and we can return. But in this case
1650 *
1651 * [MAX_SIZE+4k][MAX_SIZE+4k]
1652 *
1653 * Each range on their own accounts for 2 extents, but merged together
1654 * they are only 3 extents worth of accounting, so we need to drop in
1655 * this case.
1656 */
1657 old_size = other->end - other->start + 1;
1658 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1659 BTRFS_MAX_EXTENT_SIZE);
1660 old_size = new->end - new->start + 1;
1661 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1662 BTRFS_MAX_EXTENT_SIZE);
1663
1664 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1665 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1666 return;
1667
1668 spin_lock(&BTRFS_I(inode)->lock);
1669 BTRFS_I(inode)->outstanding_extents--;
1670 spin_unlock(&BTRFS_I(inode)->lock);
1671 }
1672
1673 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1674 struct inode *inode)
1675 {
1676 spin_lock(&root->delalloc_lock);
1677 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1678 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1679 &root->delalloc_inodes);
1680 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1681 &BTRFS_I(inode)->runtime_flags);
1682 root->nr_delalloc_inodes++;
1683 if (root->nr_delalloc_inodes == 1) {
1684 spin_lock(&root->fs_info->delalloc_root_lock);
1685 BUG_ON(!list_empty(&root->delalloc_root));
1686 list_add_tail(&root->delalloc_root,
1687 &root->fs_info->delalloc_roots);
1688 spin_unlock(&root->fs_info->delalloc_root_lock);
1689 }
1690 }
1691 spin_unlock(&root->delalloc_lock);
1692 }
1693
1694 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1695 struct inode *inode)
1696 {
1697 spin_lock(&root->delalloc_lock);
1698 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1699 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1700 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1701 &BTRFS_I(inode)->runtime_flags);
1702 root->nr_delalloc_inodes--;
1703 if (!root->nr_delalloc_inodes) {
1704 spin_lock(&root->fs_info->delalloc_root_lock);
1705 BUG_ON(list_empty(&root->delalloc_root));
1706 list_del_init(&root->delalloc_root);
1707 spin_unlock(&root->fs_info->delalloc_root_lock);
1708 }
1709 }
1710 spin_unlock(&root->delalloc_lock);
1711 }
1712
1713 /*
1714 * extent_io.c set_bit_hook, used to track delayed allocation
1715 * bytes in this file, and to maintain the list of inodes that
1716 * have pending delalloc work to be done.
1717 */
1718 static void btrfs_set_bit_hook(struct inode *inode,
1719 struct extent_state *state, unsigned *bits)
1720 {
1721
1722 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1723 WARN_ON(1);
1724 /*
1725 * set_bit and clear bit hooks normally require _irqsave/restore
1726 * but in this case, we are only testing for the DELALLOC
1727 * bit, which is only set or cleared with irqs on
1728 */
1729 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1730 struct btrfs_root *root = BTRFS_I(inode)->root;
1731 u64 len = state->end + 1 - state->start;
1732 bool do_list = !btrfs_is_free_space_inode(inode);
1733
1734 if (*bits & EXTENT_FIRST_DELALLOC) {
1735 *bits &= ~EXTENT_FIRST_DELALLOC;
1736 } else {
1737 spin_lock(&BTRFS_I(inode)->lock);
1738 BTRFS_I(inode)->outstanding_extents++;
1739 spin_unlock(&BTRFS_I(inode)->lock);
1740 }
1741
1742 /* For sanity tests */
1743 if (btrfs_test_is_dummy_root(root))
1744 return;
1745
1746 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1747 root->fs_info->delalloc_batch);
1748 spin_lock(&BTRFS_I(inode)->lock);
1749 BTRFS_I(inode)->delalloc_bytes += len;
1750 if (*bits & EXTENT_DEFRAG)
1751 BTRFS_I(inode)->defrag_bytes += len;
1752 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1753 &BTRFS_I(inode)->runtime_flags))
1754 btrfs_add_delalloc_inodes(root, inode);
1755 spin_unlock(&BTRFS_I(inode)->lock);
1756 }
1757 }
1758
1759 /*
1760 * extent_io.c clear_bit_hook, see set_bit_hook for why
1761 */
1762 static void btrfs_clear_bit_hook(struct inode *inode,
1763 struct extent_state *state,
1764 unsigned *bits)
1765 {
1766 u64 len = state->end + 1 - state->start;
1767 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1768 BTRFS_MAX_EXTENT_SIZE);
1769
1770 spin_lock(&BTRFS_I(inode)->lock);
1771 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1772 BTRFS_I(inode)->defrag_bytes -= len;
1773 spin_unlock(&BTRFS_I(inode)->lock);
1774
1775 /*
1776 * set_bit and clear bit hooks normally require _irqsave/restore
1777 * but in this case, we are only testing for the DELALLOC
1778 * bit, which is only set or cleared with irqs on
1779 */
1780 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1781 struct btrfs_root *root = BTRFS_I(inode)->root;
1782 bool do_list = !btrfs_is_free_space_inode(inode);
1783
1784 if (*bits & EXTENT_FIRST_DELALLOC) {
1785 *bits &= ~EXTENT_FIRST_DELALLOC;
1786 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1787 spin_lock(&BTRFS_I(inode)->lock);
1788 BTRFS_I(inode)->outstanding_extents -= num_extents;
1789 spin_unlock(&BTRFS_I(inode)->lock);
1790 }
1791
1792 /*
1793 * We don't reserve metadata space for space cache inodes so we
1794 * don't need to call dellalloc_release_metadata if there is an
1795 * error.
1796 */
1797 if (*bits & EXTENT_DO_ACCOUNTING &&
1798 root != root->fs_info->tree_root)
1799 btrfs_delalloc_release_metadata(inode, len);
1800
1801 /* For sanity tests. */
1802 if (btrfs_test_is_dummy_root(root))
1803 return;
1804
1805 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1806 && do_list && !(state->state & EXTENT_NORESERVE))
1807 btrfs_free_reserved_data_space_noquota(inode,
1808 state->start, len);
1809
1810 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1811 root->fs_info->delalloc_batch);
1812 spin_lock(&BTRFS_I(inode)->lock);
1813 BTRFS_I(inode)->delalloc_bytes -= len;
1814 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1815 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1816 &BTRFS_I(inode)->runtime_flags))
1817 btrfs_del_delalloc_inode(root, inode);
1818 spin_unlock(&BTRFS_I(inode)->lock);
1819 }
1820 }
1821
1822 /*
1823 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1824 * we don't create bios that span stripes or chunks
1825 */
1826 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1827 size_t size, struct bio *bio,
1828 unsigned long bio_flags)
1829 {
1830 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1831 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1832 u64 length = 0;
1833 u64 map_length;
1834 int ret;
1835
1836 if (bio_flags & EXTENT_BIO_COMPRESSED)
1837 return 0;
1838
1839 length = bio->bi_iter.bi_size;
1840 map_length = length;
1841 ret = btrfs_map_block(root->fs_info, rw, logical,
1842 &map_length, NULL, 0);
1843 /* Will always return 0 with map_multi == NULL */
1844 BUG_ON(ret < 0);
1845 if (map_length < length + size)
1846 return 1;
1847 return 0;
1848 }
1849
1850 /*
1851 * in order to insert checksums into the metadata in large chunks,
1852 * we wait until bio submission time. All the pages in the bio are
1853 * checksummed and sums are attached onto the ordered extent record.
1854 *
1855 * At IO completion time the cums attached on the ordered extent record
1856 * are inserted into the btree
1857 */
1858 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1859 struct bio *bio, int mirror_num,
1860 unsigned long bio_flags,
1861 u64 bio_offset)
1862 {
1863 struct btrfs_root *root = BTRFS_I(inode)->root;
1864 int ret = 0;
1865
1866 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1867 BUG_ON(ret); /* -ENOMEM */
1868 return 0;
1869 }
1870
1871 /*
1872 * in order to insert checksums into the metadata in large chunks,
1873 * we wait until bio submission time. All the pages in the bio are
1874 * checksummed and sums are attached onto the ordered extent record.
1875 *
1876 * At IO completion time the cums attached on the ordered extent record
1877 * are inserted into the btree
1878 */
1879 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1880 int mirror_num, unsigned long bio_flags,
1881 u64 bio_offset)
1882 {
1883 struct btrfs_root *root = BTRFS_I(inode)->root;
1884 int ret;
1885
1886 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1887 if (ret) {
1888 bio->bi_error = ret;
1889 bio_endio(bio);
1890 }
1891 return ret;
1892 }
1893
1894 /*
1895 * extent_io.c submission hook. This does the right thing for csum calculation
1896 * on write, or reading the csums from the tree before a read
1897 */
1898 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1899 int mirror_num, unsigned long bio_flags,
1900 u64 bio_offset)
1901 {
1902 struct btrfs_root *root = BTRFS_I(inode)->root;
1903 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1904 int ret = 0;
1905 int skip_sum;
1906 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1907
1908 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1909
1910 if (btrfs_is_free_space_inode(inode))
1911 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1912
1913 if (!(rw & REQ_WRITE)) {
1914 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1915 if (ret)
1916 goto out;
1917
1918 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1919 ret = btrfs_submit_compressed_read(inode, bio,
1920 mirror_num,
1921 bio_flags);
1922 goto out;
1923 } else if (!skip_sum) {
1924 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1925 if (ret)
1926 goto out;
1927 }
1928 goto mapit;
1929 } else if (async && !skip_sum) {
1930 /* csum items have already been cloned */
1931 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1932 goto mapit;
1933 /* we're doing a write, do the async checksumming */
1934 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1935 inode, rw, bio, mirror_num,
1936 bio_flags, bio_offset,
1937 __btrfs_submit_bio_start,
1938 __btrfs_submit_bio_done);
1939 goto out;
1940 } else if (!skip_sum) {
1941 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1942 if (ret)
1943 goto out;
1944 }
1945
1946 mapit:
1947 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1948
1949 out:
1950 if (ret < 0) {
1951 bio->bi_error = ret;
1952 bio_endio(bio);
1953 }
1954 return ret;
1955 }
1956
1957 /*
1958 * given a list of ordered sums record them in the inode. This happens
1959 * at IO completion time based on sums calculated at bio submission time.
1960 */
1961 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1962 struct inode *inode, u64 file_offset,
1963 struct list_head *list)
1964 {
1965 struct btrfs_ordered_sum *sum;
1966
1967 list_for_each_entry(sum, list, list) {
1968 trans->adding_csums = 1;
1969 btrfs_csum_file_blocks(trans,
1970 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1971 trans->adding_csums = 0;
1972 }
1973 return 0;
1974 }
1975
1976 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1977 struct extent_state **cached_state)
1978 {
1979 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1980 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1981 cached_state, GFP_NOFS);
1982 }
1983
1984 /* see btrfs_writepage_start_hook for details on why this is required */
1985 struct btrfs_writepage_fixup {
1986 struct page *page;
1987 struct btrfs_work work;
1988 };
1989
1990 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1991 {
1992 struct btrfs_writepage_fixup *fixup;
1993 struct btrfs_ordered_extent *ordered;
1994 struct extent_state *cached_state = NULL;
1995 struct page *page;
1996 struct inode *inode;
1997 u64 page_start;
1998 u64 page_end;
1999 int ret;
2000
2001 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2002 page = fixup->page;
2003 again:
2004 lock_page(page);
2005 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2006 ClearPageChecked(page);
2007 goto out_page;
2008 }
2009
2010 inode = page->mapping->host;
2011 page_start = page_offset(page);
2012 page_end = page_offset(page) + PAGE_SIZE - 1;
2013
2014 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2015 &cached_state);
2016
2017 /* already ordered? We're done */
2018 if (PagePrivate2(page))
2019 goto out;
2020
2021 ordered = btrfs_lookup_ordered_range(inode, page_start,
2022 PAGE_SIZE);
2023 if (ordered) {
2024 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2025 page_end, &cached_state, GFP_NOFS);
2026 unlock_page(page);
2027 btrfs_start_ordered_extent(inode, ordered, 1);
2028 btrfs_put_ordered_extent(ordered);
2029 goto again;
2030 }
2031
2032 ret = btrfs_delalloc_reserve_space(inode, page_start,
2033 PAGE_SIZE);
2034 if (ret) {
2035 mapping_set_error(page->mapping, ret);
2036 end_extent_writepage(page, ret, page_start, page_end);
2037 ClearPageChecked(page);
2038 goto out;
2039 }
2040
2041 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2042 ClearPageChecked(page);
2043 set_page_dirty(page);
2044 out:
2045 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2046 &cached_state, GFP_NOFS);
2047 out_page:
2048 unlock_page(page);
2049 put_page(page);
2050 kfree(fixup);
2051 }
2052
2053 /*
2054 * There are a few paths in the higher layers of the kernel that directly
2055 * set the page dirty bit without asking the filesystem if it is a
2056 * good idea. This causes problems because we want to make sure COW
2057 * properly happens and the data=ordered rules are followed.
2058 *
2059 * In our case any range that doesn't have the ORDERED bit set
2060 * hasn't been properly setup for IO. We kick off an async process
2061 * to fix it up. The async helper will wait for ordered extents, set
2062 * the delalloc bit and make it safe to write the page.
2063 */
2064 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2065 {
2066 struct inode *inode = page->mapping->host;
2067 struct btrfs_writepage_fixup *fixup;
2068 struct btrfs_root *root = BTRFS_I(inode)->root;
2069
2070 /* this page is properly in the ordered list */
2071 if (TestClearPagePrivate2(page))
2072 return 0;
2073
2074 if (PageChecked(page))
2075 return -EAGAIN;
2076
2077 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2078 if (!fixup)
2079 return -EAGAIN;
2080
2081 SetPageChecked(page);
2082 get_page(page);
2083 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2084 btrfs_writepage_fixup_worker, NULL, NULL);
2085 fixup->page = page;
2086 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2087 return -EBUSY;
2088 }
2089
2090 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2091 struct inode *inode, u64 file_pos,
2092 u64 disk_bytenr, u64 disk_num_bytes,
2093 u64 num_bytes, u64 ram_bytes,
2094 u8 compression, u8 encryption,
2095 u16 other_encoding, int extent_type)
2096 {
2097 struct btrfs_root *root = BTRFS_I(inode)->root;
2098 struct btrfs_file_extent_item *fi;
2099 struct btrfs_path *path;
2100 struct extent_buffer *leaf;
2101 struct btrfs_key ins;
2102 int extent_inserted = 0;
2103 int ret;
2104
2105 path = btrfs_alloc_path();
2106 if (!path)
2107 return -ENOMEM;
2108
2109 /*
2110 * we may be replacing one extent in the tree with another.
2111 * The new extent is pinned in the extent map, and we don't want
2112 * to drop it from the cache until it is completely in the btree.
2113 *
2114 * So, tell btrfs_drop_extents to leave this extent in the cache.
2115 * the caller is expected to unpin it and allow it to be merged
2116 * with the others.
2117 */
2118 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2119 file_pos + num_bytes, NULL, 0,
2120 1, sizeof(*fi), &extent_inserted);
2121 if (ret)
2122 goto out;
2123
2124 if (!extent_inserted) {
2125 ins.objectid = btrfs_ino(inode);
2126 ins.offset = file_pos;
2127 ins.type = BTRFS_EXTENT_DATA_KEY;
2128
2129 path->leave_spinning = 1;
2130 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2131 sizeof(*fi));
2132 if (ret)
2133 goto out;
2134 }
2135 leaf = path->nodes[0];
2136 fi = btrfs_item_ptr(leaf, path->slots[0],
2137 struct btrfs_file_extent_item);
2138 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2139 btrfs_set_file_extent_type(leaf, fi, extent_type);
2140 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2141 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2142 btrfs_set_file_extent_offset(leaf, fi, 0);
2143 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2144 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2145 btrfs_set_file_extent_compression(leaf, fi, compression);
2146 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2147 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2148
2149 btrfs_mark_buffer_dirty(leaf);
2150 btrfs_release_path(path);
2151
2152 inode_add_bytes(inode, num_bytes);
2153
2154 ins.objectid = disk_bytenr;
2155 ins.offset = disk_num_bytes;
2156 ins.type = BTRFS_EXTENT_ITEM_KEY;
2157 ret = btrfs_alloc_reserved_file_extent(trans, root,
2158 root->root_key.objectid,
2159 btrfs_ino(inode), file_pos,
2160 ram_bytes, &ins);
2161 /*
2162 * Release the reserved range from inode dirty range map, as it is
2163 * already moved into delayed_ref_head
2164 */
2165 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2166 out:
2167 btrfs_free_path(path);
2168
2169 return ret;
2170 }
2171
2172 /* snapshot-aware defrag */
2173 struct sa_defrag_extent_backref {
2174 struct rb_node node;
2175 struct old_sa_defrag_extent *old;
2176 u64 root_id;
2177 u64 inum;
2178 u64 file_pos;
2179 u64 extent_offset;
2180 u64 num_bytes;
2181 u64 generation;
2182 };
2183
2184 struct old_sa_defrag_extent {
2185 struct list_head list;
2186 struct new_sa_defrag_extent *new;
2187
2188 u64 extent_offset;
2189 u64 bytenr;
2190 u64 offset;
2191 u64 len;
2192 int count;
2193 };
2194
2195 struct new_sa_defrag_extent {
2196 struct rb_root root;
2197 struct list_head head;
2198 struct btrfs_path *path;
2199 struct inode *inode;
2200 u64 file_pos;
2201 u64 len;
2202 u64 bytenr;
2203 u64 disk_len;
2204 u8 compress_type;
2205 };
2206
2207 static int backref_comp(struct sa_defrag_extent_backref *b1,
2208 struct sa_defrag_extent_backref *b2)
2209 {
2210 if (b1->root_id < b2->root_id)
2211 return -1;
2212 else if (b1->root_id > b2->root_id)
2213 return 1;
2214
2215 if (b1->inum < b2->inum)
2216 return -1;
2217 else if (b1->inum > b2->inum)
2218 return 1;
2219
2220 if (b1->file_pos < b2->file_pos)
2221 return -1;
2222 else if (b1->file_pos > b2->file_pos)
2223 return 1;
2224
2225 /*
2226 * [------------------------------] ===> (a range of space)
2227 * |<--->| |<---->| =============> (fs/file tree A)
2228 * |<---------------------------->| ===> (fs/file tree B)
2229 *
2230 * A range of space can refer to two file extents in one tree while
2231 * refer to only one file extent in another tree.
2232 *
2233 * So we may process a disk offset more than one time(two extents in A)
2234 * and locate at the same extent(one extent in B), then insert two same
2235 * backrefs(both refer to the extent in B).
2236 */
2237 return 0;
2238 }
2239
2240 static void backref_insert(struct rb_root *root,
2241 struct sa_defrag_extent_backref *backref)
2242 {
2243 struct rb_node **p = &root->rb_node;
2244 struct rb_node *parent = NULL;
2245 struct sa_defrag_extent_backref *entry;
2246 int ret;
2247
2248 while (*p) {
2249 parent = *p;
2250 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2251
2252 ret = backref_comp(backref, entry);
2253 if (ret < 0)
2254 p = &(*p)->rb_left;
2255 else
2256 p = &(*p)->rb_right;
2257 }
2258
2259 rb_link_node(&backref->node, parent, p);
2260 rb_insert_color(&backref->node, root);
2261 }
2262
2263 /*
2264 * Note the backref might has changed, and in this case we just return 0.
2265 */
2266 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2267 void *ctx)
2268 {
2269 struct btrfs_file_extent_item *extent;
2270 struct btrfs_fs_info *fs_info;
2271 struct old_sa_defrag_extent *old = ctx;
2272 struct new_sa_defrag_extent *new = old->new;
2273 struct btrfs_path *path = new->path;
2274 struct btrfs_key key;
2275 struct btrfs_root *root;
2276 struct sa_defrag_extent_backref *backref;
2277 struct extent_buffer *leaf;
2278 struct inode *inode = new->inode;
2279 int slot;
2280 int ret;
2281 u64 extent_offset;
2282 u64 num_bytes;
2283
2284 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2285 inum == btrfs_ino(inode))
2286 return 0;
2287
2288 key.objectid = root_id;
2289 key.type = BTRFS_ROOT_ITEM_KEY;
2290 key.offset = (u64)-1;
2291
2292 fs_info = BTRFS_I(inode)->root->fs_info;
2293 root = btrfs_read_fs_root_no_name(fs_info, &key);
2294 if (IS_ERR(root)) {
2295 if (PTR_ERR(root) == -ENOENT)
2296 return 0;
2297 WARN_ON(1);
2298 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2299 inum, offset, root_id);
2300 return PTR_ERR(root);
2301 }
2302
2303 key.objectid = inum;
2304 key.type = BTRFS_EXTENT_DATA_KEY;
2305 if (offset > (u64)-1 << 32)
2306 key.offset = 0;
2307 else
2308 key.offset = offset;
2309
2310 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2311 if (WARN_ON(ret < 0))
2312 return ret;
2313 ret = 0;
2314
2315 while (1) {
2316 cond_resched();
2317
2318 leaf = path->nodes[0];
2319 slot = path->slots[0];
2320
2321 if (slot >= btrfs_header_nritems(leaf)) {
2322 ret = btrfs_next_leaf(root, path);
2323 if (ret < 0) {
2324 goto out;
2325 } else if (ret > 0) {
2326 ret = 0;
2327 goto out;
2328 }
2329 continue;
2330 }
2331
2332 path->slots[0]++;
2333
2334 btrfs_item_key_to_cpu(leaf, &key, slot);
2335
2336 if (key.objectid > inum)
2337 goto out;
2338
2339 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2340 continue;
2341
2342 extent = btrfs_item_ptr(leaf, slot,
2343 struct btrfs_file_extent_item);
2344
2345 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2346 continue;
2347
2348 /*
2349 * 'offset' refers to the exact key.offset,
2350 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2351 * (key.offset - extent_offset).
2352 */
2353 if (key.offset != offset)
2354 continue;
2355
2356 extent_offset = btrfs_file_extent_offset(leaf, extent);
2357 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2358
2359 if (extent_offset >= old->extent_offset + old->offset +
2360 old->len || extent_offset + num_bytes <=
2361 old->extent_offset + old->offset)
2362 continue;
2363 break;
2364 }
2365
2366 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2367 if (!backref) {
2368 ret = -ENOENT;
2369 goto out;
2370 }
2371
2372 backref->root_id = root_id;
2373 backref->inum = inum;
2374 backref->file_pos = offset;
2375 backref->num_bytes = num_bytes;
2376 backref->extent_offset = extent_offset;
2377 backref->generation = btrfs_file_extent_generation(leaf, extent);
2378 backref->old = old;
2379 backref_insert(&new->root, backref);
2380 old->count++;
2381 out:
2382 btrfs_release_path(path);
2383 WARN_ON(ret);
2384 return ret;
2385 }
2386
2387 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2388 struct new_sa_defrag_extent *new)
2389 {
2390 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2391 struct old_sa_defrag_extent *old, *tmp;
2392 int ret;
2393
2394 new->path = path;
2395
2396 list_for_each_entry_safe(old, tmp, &new->head, list) {
2397 ret = iterate_inodes_from_logical(old->bytenr +
2398 old->extent_offset, fs_info,
2399 path, record_one_backref,
2400 old);
2401 if (ret < 0 && ret != -ENOENT)
2402 return false;
2403
2404 /* no backref to be processed for this extent */
2405 if (!old->count) {
2406 list_del(&old->list);
2407 kfree(old);
2408 }
2409 }
2410
2411 if (list_empty(&new->head))
2412 return false;
2413
2414 return true;
2415 }
2416
2417 static int relink_is_mergable(struct extent_buffer *leaf,
2418 struct btrfs_file_extent_item *fi,
2419 struct new_sa_defrag_extent *new)
2420 {
2421 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2422 return 0;
2423
2424 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2425 return 0;
2426
2427 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2428 return 0;
2429
2430 if (btrfs_file_extent_encryption(leaf, fi) ||
2431 btrfs_file_extent_other_encoding(leaf, fi))
2432 return 0;
2433
2434 return 1;
2435 }
2436
2437 /*
2438 * Note the backref might has changed, and in this case we just return 0.
2439 */
2440 static noinline int relink_extent_backref(struct btrfs_path *path,
2441 struct sa_defrag_extent_backref *prev,
2442 struct sa_defrag_extent_backref *backref)
2443 {
2444 struct btrfs_file_extent_item *extent;
2445 struct btrfs_file_extent_item *item;
2446 struct btrfs_ordered_extent *ordered;
2447 struct btrfs_trans_handle *trans;
2448 struct btrfs_fs_info *fs_info;
2449 struct btrfs_root *root;
2450 struct btrfs_key key;
2451 struct extent_buffer *leaf;
2452 struct old_sa_defrag_extent *old = backref->old;
2453 struct new_sa_defrag_extent *new = old->new;
2454 struct inode *src_inode = new->inode;
2455 struct inode *inode;
2456 struct extent_state *cached = NULL;
2457 int ret = 0;
2458 u64 start;
2459 u64 len;
2460 u64 lock_start;
2461 u64 lock_end;
2462 bool merge = false;
2463 int index;
2464
2465 if (prev && prev->root_id == backref->root_id &&
2466 prev->inum == backref->inum &&
2467 prev->file_pos + prev->num_bytes == backref->file_pos)
2468 merge = true;
2469
2470 /* step 1: get root */
2471 key.objectid = backref->root_id;
2472 key.type = BTRFS_ROOT_ITEM_KEY;
2473 key.offset = (u64)-1;
2474
2475 fs_info = BTRFS_I(src_inode)->root->fs_info;
2476 index = srcu_read_lock(&fs_info->subvol_srcu);
2477
2478 root = btrfs_read_fs_root_no_name(fs_info, &key);
2479 if (IS_ERR(root)) {
2480 srcu_read_unlock(&fs_info->subvol_srcu, index);
2481 if (PTR_ERR(root) == -ENOENT)
2482 return 0;
2483 return PTR_ERR(root);
2484 }
2485
2486 if (btrfs_root_readonly(root)) {
2487 srcu_read_unlock(&fs_info->subvol_srcu, index);
2488 return 0;
2489 }
2490
2491 /* step 2: get inode */
2492 key.objectid = backref->inum;
2493 key.type = BTRFS_INODE_ITEM_KEY;
2494 key.offset = 0;
2495
2496 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2497 if (IS_ERR(inode)) {
2498 srcu_read_unlock(&fs_info->subvol_srcu, index);
2499 return 0;
2500 }
2501
2502 srcu_read_unlock(&fs_info->subvol_srcu, index);
2503
2504 /* step 3: relink backref */
2505 lock_start = backref->file_pos;
2506 lock_end = backref->file_pos + backref->num_bytes - 1;
2507 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2508 &cached);
2509
2510 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2511 if (ordered) {
2512 btrfs_put_ordered_extent(ordered);
2513 goto out_unlock;
2514 }
2515
2516 trans = btrfs_join_transaction(root);
2517 if (IS_ERR(trans)) {
2518 ret = PTR_ERR(trans);
2519 goto out_unlock;
2520 }
2521
2522 key.objectid = backref->inum;
2523 key.type = BTRFS_EXTENT_DATA_KEY;
2524 key.offset = backref->file_pos;
2525
2526 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2527 if (ret < 0) {
2528 goto out_free_path;
2529 } else if (ret > 0) {
2530 ret = 0;
2531 goto out_free_path;
2532 }
2533
2534 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2535 struct btrfs_file_extent_item);
2536
2537 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2538 backref->generation)
2539 goto out_free_path;
2540
2541 btrfs_release_path(path);
2542
2543 start = backref->file_pos;
2544 if (backref->extent_offset < old->extent_offset + old->offset)
2545 start += old->extent_offset + old->offset -
2546 backref->extent_offset;
2547
2548 len = min(backref->extent_offset + backref->num_bytes,
2549 old->extent_offset + old->offset + old->len);
2550 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2551
2552 ret = btrfs_drop_extents(trans, root, inode, start,
2553 start + len, 1);
2554 if (ret)
2555 goto out_free_path;
2556 again:
2557 key.objectid = btrfs_ino(inode);
2558 key.type = BTRFS_EXTENT_DATA_KEY;
2559 key.offset = start;
2560
2561 path->leave_spinning = 1;
2562 if (merge) {
2563 struct btrfs_file_extent_item *fi;
2564 u64 extent_len;
2565 struct btrfs_key found_key;
2566
2567 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2568 if (ret < 0)
2569 goto out_free_path;
2570
2571 path->slots[0]--;
2572 leaf = path->nodes[0];
2573 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2574
2575 fi = btrfs_item_ptr(leaf, path->slots[0],
2576 struct btrfs_file_extent_item);
2577 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2578
2579 if (extent_len + found_key.offset == start &&
2580 relink_is_mergable(leaf, fi, new)) {
2581 btrfs_set_file_extent_num_bytes(leaf, fi,
2582 extent_len + len);
2583 btrfs_mark_buffer_dirty(leaf);
2584 inode_add_bytes(inode, len);
2585
2586 ret = 1;
2587 goto out_free_path;
2588 } else {
2589 merge = false;
2590 btrfs_release_path(path);
2591 goto again;
2592 }
2593 }
2594
2595 ret = btrfs_insert_empty_item(trans, root, path, &key,
2596 sizeof(*extent));
2597 if (ret) {
2598 btrfs_abort_transaction(trans, root, ret);
2599 goto out_free_path;
2600 }
2601
2602 leaf = path->nodes[0];
2603 item = btrfs_item_ptr(leaf, path->slots[0],
2604 struct btrfs_file_extent_item);
2605 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2606 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2607 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2608 btrfs_set_file_extent_num_bytes(leaf, item, len);
2609 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2610 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2611 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2612 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2613 btrfs_set_file_extent_encryption(leaf, item, 0);
2614 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2615
2616 btrfs_mark_buffer_dirty(leaf);
2617 inode_add_bytes(inode, len);
2618 btrfs_release_path(path);
2619
2620 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2621 new->disk_len, 0,
2622 backref->root_id, backref->inum,
2623 new->file_pos); /* start - extent_offset */
2624 if (ret) {
2625 btrfs_abort_transaction(trans, root, ret);
2626 goto out_free_path;
2627 }
2628
2629 ret = 1;
2630 out_free_path:
2631 btrfs_release_path(path);
2632 path->leave_spinning = 0;
2633 btrfs_end_transaction(trans, root);
2634 out_unlock:
2635 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2636 &cached, GFP_NOFS);
2637 iput(inode);
2638 return ret;
2639 }
2640
2641 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2642 {
2643 struct old_sa_defrag_extent *old, *tmp;
2644
2645 if (!new)
2646 return;
2647
2648 list_for_each_entry_safe(old, tmp, &new->head, list) {
2649 kfree(old);
2650 }
2651 kfree(new);
2652 }
2653
2654 static void relink_file_extents(struct new_sa_defrag_extent *new)
2655 {
2656 struct btrfs_path *path;
2657 struct sa_defrag_extent_backref *backref;
2658 struct sa_defrag_extent_backref *prev = NULL;
2659 struct inode *inode;
2660 struct btrfs_root *root;
2661 struct rb_node *node;
2662 int ret;
2663
2664 inode = new->inode;
2665 root = BTRFS_I(inode)->root;
2666
2667 path = btrfs_alloc_path();
2668 if (!path)
2669 return;
2670
2671 if (!record_extent_backrefs(path, new)) {
2672 btrfs_free_path(path);
2673 goto out;
2674 }
2675 btrfs_release_path(path);
2676
2677 while (1) {
2678 node = rb_first(&new->root);
2679 if (!node)
2680 break;
2681 rb_erase(node, &new->root);
2682
2683 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2684
2685 ret = relink_extent_backref(path, prev, backref);
2686 WARN_ON(ret < 0);
2687
2688 kfree(prev);
2689
2690 if (ret == 1)
2691 prev = backref;
2692 else
2693 prev = NULL;
2694 cond_resched();
2695 }
2696 kfree(prev);
2697
2698 btrfs_free_path(path);
2699 out:
2700 free_sa_defrag_extent(new);
2701
2702 atomic_dec(&root->fs_info->defrag_running);
2703 wake_up(&root->fs_info->transaction_wait);
2704 }
2705
2706 static struct new_sa_defrag_extent *
2707 record_old_file_extents(struct inode *inode,
2708 struct btrfs_ordered_extent *ordered)
2709 {
2710 struct btrfs_root *root = BTRFS_I(inode)->root;
2711 struct btrfs_path *path;
2712 struct btrfs_key key;
2713 struct old_sa_defrag_extent *old;
2714 struct new_sa_defrag_extent *new;
2715 int ret;
2716
2717 new = kmalloc(sizeof(*new), GFP_NOFS);
2718 if (!new)
2719 return NULL;
2720
2721 new->inode = inode;
2722 new->file_pos = ordered->file_offset;
2723 new->len = ordered->len;
2724 new->bytenr = ordered->start;
2725 new->disk_len = ordered->disk_len;
2726 new->compress_type = ordered->compress_type;
2727 new->root = RB_ROOT;
2728 INIT_LIST_HEAD(&new->head);
2729
2730 path = btrfs_alloc_path();
2731 if (!path)
2732 goto out_kfree;
2733
2734 key.objectid = btrfs_ino(inode);
2735 key.type = BTRFS_EXTENT_DATA_KEY;
2736 key.offset = new->file_pos;
2737
2738 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2739 if (ret < 0)
2740 goto out_free_path;
2741 if (ret > 0 && path->slots[0] > 0)
2742 path->slots[0]--;
2743
2744 /* find out all the old extents for the file range */
2745 while (1) {
2746 struct btrfs_file_extent_item *extent;
2747 struct extent_buffer *l;
2748 int slot;
2749 u64 num_bytes;
2750 u64 offset;
2751 u64 end;
2752 u64 disk_bytenr;
2753 u64 extent_offset;
2754
2755 l = path->nodes[0];
2756 slot = path->slots[0];
2757
2758 if (slot >= btrfs_header_nritems(l)) {
2759 ret = btrfs_next_leaf(root, path);
2760 if (ret < 0)
2761 goto out_free_path;
2762 else if (ret > 0)
2763 break;
2764 continue;
2765 }
2766
2767 btrfs_item_key_to_cpu(l, &key, slot);
2768
2769 if (key.objectid != btrfs_ino(inode))
2770 break;
2771 if (key.type != BTRFS_EXTENT_DATA_KEY)
2772 break;
2773 if (key.offset >= new->file_pos + new->len)
2774 break;
2775
2776 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2777
2778 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2779 if (key.offset + num_bytes < new->file_pos)
2780 goto next;
2781
2782 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2783 if (!disk_bytenr)
2784 goto next;
2785
2786 extent_offset = btrfs_file_extent_offset(l, extent);
2787
2788 old = kmalloc(sizeof(*old), GFP_NOFS);
2789 if (!old)
2790 goto out_free_path;
2791
2792 offset = max(new->file_pos, key.offset);
2793 end = min(new->file_pos + new->len, key.offset + num_bytes);
2794
2795 old->bytenr = disk_bytenr;
2796 old->extent_offset = extent_offset;
2797 old->offset = offset - key.offset;
2798 old->len = end - offset;
2799 old->new = new;
2800 old->count = 0;
2801 list_add_tail(&old->list, &new->head);
2802 next:
2803 path->slots[0]++;
2804 cond_resched();
2805 }
2806
2807 btrfs_free_path(path);
2808 atomic_inc(&root->fs_info->defrag_running);
2809
2810 return new;
2811
2812 out_free_path:
2813 btrfs_free_path(path);
2814 out_kfree:
2815 free_sa_defrag_extent(new);
2816 return NULL;
2817 }
2818
2819 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2820 u64 start, u64 len)
2821 {
2822 struct btrfs_block_group_cache *cache;
2823
2824 cache = btrfs_lookup_block_group(root->fs_info, start);
2825 ASSERT(cache);
2826
2827 spin_lock(&cache->lock);
2828 cache->delalloc_bytes -= len;
2829 spin_unlock(&cache->lock);
2830
2831 btrfs_put_block_group(cache);
2832 }
2833
2834 /* as ordered data IO finishes, this gets called so we can finish
2835 * an ordered extent if the range of bytes in the file it covers are
2836 * fully written.
2837 */
2838 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2839 {
2840 struct inode *inode = ordered_extent->inode;
2841 struct btrfs_root *root = BTRFS_I(inode)->root;
2842 struct btrfs_trans_handle *trans = NULL;
2843 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2844 struct extent_state *cached_state = NULL;
2845 struct new_sa_defrag_extent *new = NULL;
2846 int compress_type = 0;
2847 int ret = 0;
2848 u64 logical_len = ordered_extent->len;
2849 bool nolock;
2850 bool truncated = false;
2851
2852 nolock = btrfs_is_free_space_inode(inode);
2853
2854 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2855 ret = -EIO;
2856 goto out;
2857 }
2858
2859 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2860 ordered_extent->file_offset +
2861 ordered_extent->len - 1);
2862
2863 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2864 truncated = true;
2865 logical_len = ordered_extent->truncated_len;
2866 /* Truncated the entire extent, don't bother adding */
2867 if (!logical_len)
2868 goto out;
2869 }
2870
2871 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2872 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2873
2874 /*
2875 * For mwrite(mmap + memset to write) case, we still reserve
2876 * space for NOCOW range.
2877 * As NOCOW won't cause a new delayed ref, just free the space
2878 */
2879 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2880 ordered_extent->len);
2881 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2882 if (nolock)
2883 trans = btrfs_join_transaction_nolock(root);
2884 else
2885 trans = btrfs_join_transaction(root);
2886 if (IS_ERR(trans)) {
2887 ret = PTR_ERR(trans);
2888 trans = NULL;
2889 goto out;
2890 }
2891 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2892 ret = btrfs_update_inode_fallback(trans, root, inode);
2893 if (ret) /* -ENOMEM or corruption */
2894 btrfs_abort_transaction(trans, root, ret);
2895 goto out;
2896 }
2897
2898 lock_extent_bits(io_tree, ordered_extent->file_offset,
2899 ordered_extent->file_offset + ordered_extent->len - 1,
2900 &cached_state);
2901
2902 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2903 ordered_extent->file_offset + ordered_extent->len - 1,
2904 EXTENT_DEFRAG, 1, cached_state);
2905 if (ret) {
2906 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2907 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2908 /* the inode is shared */
2909 new = record_old_file_extents(inode, ordered_extent);
2910
2911 clear_extent_bit(io_tree, ordered_extent->file_offset,
2912 ordered_extent->file_offset + ordered_extent->len - 1,
2913 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2914 }
2915
2916 if (nolock)
2917 trans = btrfs_join_transaction_nolock(root);
2918 else
2919 trans = btrfs_join_transaction(root);
2920 if (IS_ERR(trans)) {
2921 ret = PTR_ERR(trans);
2922 trans = NULL;
2923 goto out_unlock;
2924 }
2925
2926 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2927
2928 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2929 compress_type = ordered_extent->compress_type;
2930 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2931 BUG_ON(compress_type);
2932 ret = btrfs_mark_extent_written(trans, inode,
2933 ordered_extent->file_offset,
2934 ordered_extent->file_offset +
2935 logical_len);
2936 } else {
2937 BUG_ON(root == root->fs_info->tree_root);
2938 ret = insert_reserved_file_extent(trans, inode,
2939 ordered_extent->file_offset,
2940 ordered_extent->start,
2941 ordered_extent->disk_len,
2942 logical_len, logical_len,
2943 compress_type, 0, 0,
2944 BTRFS_FILE_EXTENT_REG);
2945 if (!ret)
2946 btrfs_release_delalloc_bytes(root,
2947 ordered_extent->start,
2948 ordered_extent->disk_len);
2949 }
2950 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2951 ordered_extent->file_offset, ordered_extent->len,
2952 trans->transid);
2953 if (ret < 0) {
2954 btrfs_abort_transaction(trans, root, ret);
2955 goto out_unlock;
2956 }
2957
2958 add_pending_csums(trans, inode, ordered_extent->file_offset,
2959 &ordered_extent->list);
2960
2961 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2962 ret = btrfs_update_inode_fallback(trans, root, inode);
2963 if (ret) { /* -ENOMEM or corruption */
2964 btrfs_abort_transaction(trans, root, ret);
2965 goto out_unlock;
2966 }
2967 ret = 0;
2968 out_unlock:
2969 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2970 ordered_extent->file_offset +
2971 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2972 out:
2973 if (root != root->fs_info->tree_root)
2974 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2975 if (trans)
2976 btrfs_end_transaction(trans, root);
2977
2978 if (ret || truncated) {
2979 u64 start, end;
2980
2981 if (truncated)
2982 start = ordered_extent->file_offset + logical_len;
2983 else
2984 start = ordered_extent->file_offset;
2985 end = ordered_extent->file_offset + ordered_extent->len - 1;
2986 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2987
2988 /* Drop the cache for the part of the extent we didn't write. */
2989 btrfs_drop_extent_cache(inode, start, end, 0);
2990
2991 /*
2992 * If the ordered extent had an IOERR or something else went
2993 * wrong we need to return the space for this ordered extent
2994 * back to the allocator. We only free the extent in the
2995 * truncated case if we didn't write out the extent at all.
2996 */
2997 if ((ret || !logical_len) &&
2998 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2999 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3000 btrfs_free_reserved_extent(root, ordered_extent->start,
3001 ordered_extent->disk_len, 1);
3002 }
3003
3004
3005 /*
3006 * This needs to be done to make sure anybody waiting knows we are done
3007 * updating everything for this ordered extent.
3008 */
3009 btrfs_remove_ordered_extent(inode, ordered_extent);
3010
3011 /* for snapshot-aware defrag */
3012 if (new) {
3013 if (ret) {
3014 free_sa_defrag_extent(new);
3015 atomic_dec(&root->fs_info->defrag_running);
3016 } else {
3017 relink_file_extents(new);
3018 }
3019 }
3020
3021 /* once for us */
3022 btrfs_put_ordered_extent(ordered_extent);
3023 /* once for the tree */
3024 btrfs_put_ordered_extent(ordered_extent);
3025
3026 return ret;
3027 }
3028
3029 static void finish_ordered_fn(struct btrfs_work *work)
3030 {
3031 struct btrfs_ordered_extent *ordered_extent;
3032 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3033 btrfs_finish_ordered_io(ordered_extent);
3034 }
3035
3036 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3037 struct extent_state *state, int uptodate)
3038 {
3039 struct inode *inode = page->mapping->host;
3040 struct btrfs_root *root = BTRFS_I(inode)->root;
3041 struct btrfs_ordered_extent *ordered_extent = NULL;
3042 struct btrfs_workqueue *wq;
3043 btrfs_work_func_t func;
3044
3045 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3046
3047 ClearPagePrivate2(page);
3048 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3049 end - start + 1, uptodate))
3050 return 0;
3051
3052 if (btrfs_is_free_space_inode(inode)) {
3053 wq = root->fs_info->endio_freespace_worker;
3054 func = btrfs_freespace_write_helper;
3055 } else {
3056 wq = root->fs_info->endio_write_workers;
3057 func = btrfs_endio_write_helper;
3058 }
3059
3060 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3061 NULL);
3062 btrfs_queue_work(wq, &ordered_extent->work);
3063
3064 return 0;
3065 }
3066
3067 static int __readpage_endio_check(struct inode *inode,
3068 struct btrfs_io_bio *io_bio,
3069 int icsum, struct page *page,
3070 int pgoff, u64 start, size_t len)
3071 {
3072 char *kaddr;
3073 u32 csum_expected;
3074 u32 csum = ~(u32)0;
3075
3076 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3077
3078 kaddr = kmap_atomic(page);
3079 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3080 btrfs_csum_final(csum, (char *)&csum);
3081 if (csum != csum_expected)
3082 goto zeroit;
3083
3084 kunmap_atomic(kaddr);
3085 return 0;
3086 zeroit:
3087 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3088 "csum failed ino %llu off %llu csum %u expected csum %u",
3089 btrfs_ino(inode), start, csum, csum_expected);
3090 memset(kaddr + pgoff, 1, len);
3091 flush_dcache_page(page);
3092 kunmap_atomic(kaddr);
3093 if (csum_expected == 0)
3094 return 0;
3095 return -EIO;
3096 }
3097
3098 /*
3099 * when reads are done, we need to check csums to verify the data is correct
3100 * if there's a match, we allow the bio to finish. If not, the code in
3101 * extent_io.c will try to find good copies for us.
3102 */
3103 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3104 u64 phy_offset, struct page *page,
3105 u64 start, u64 end, int mirror)
3106 {
3107 size_t offset = start - page_offset(page);
3108 struct inode *inode = page->mapping->host;
3109 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3110 struct btrfs_root *root = BTRFS_I(inode)->root;
3111
3112 if (PageChecked(page)) {
3113 ClearPageChecked(page);
3114 return 0;
3115 }
3116
3117 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3118 return 0;
3119
3120 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3121 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3122 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3123 GFP_NOFS);
3124 return 0;
3125 }
3126
3127 phy_offset >>= inode->i_sb->s_blocksize_bits;
3128 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3129 start, (size_t)(end - start + 1));
3130 }
3131
3132 void btrfs_add_delayed_iput(struct inode *inode)
3133 {
3134 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3135 struct btrfs_inode *binode = BTRFS_I(inode);
3136
3137 if (atomic_add_unless(&inode->i_count, -1, 1))
3138 return;
3139
3140 spin_lock(&fs_info->delayed_iput_lock);
3141 if (binode->delayed_iput_count == 0) {
3142 ASSERT(list_empty(&binode->delayed_iput));
3143 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3144 } else {
3145 binode->delayed_iput_count++;
3146 }
3147 spin_unlock(&fs_info->delayed_iput_lock);
3148 }
3149
3150 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3151 {
3152 struct btrfs_fs_info *fs_info = root->fs_info;
3153
3154 spin_lock(&fs_info->delayed_iput_lock);
3155 while (!list_empty(&fs_info->delayed_iputs)) {
3156 struct btrfs_inode *inode;
3157
3158 inode = list_first_entry(&fs_info->delayed_iputs,
3159 struct btrfs_inode, delayed_iput);
3160 if (inode->delayed_iput_count) {
3161 inode->delayed_iput_count--;
3162 list_move_tail(&inode->delayed_iput,
3163 &fs_info->delayed_iputs);
3164 } else {
3165 list_del_init(&inode->delayed_iput);
3166 }
3167 spin_unlock(&fs_info->delayed_iput_lock);
3168 iput(&inode->vfs_inode);
3169 spin_lock(&fs_info->delayed_iput_lock);
3170 }
3171 spin_unlock(&fs_info->delayed_iput_lock);
3172 }
3173
3174 /*
3175 * This is called in transaction commit time. If there are no orphan
3176 * files in the subvolume, it removes orphan item and frees block_rsv
3177 * structure.
3178 */
3179 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3180 struct btrfs_root *root)
3181 {
3182 struct btrfs_block_rsv *block_rsv;
3183 int ret;
3184
3185 if (atomic_read(&root->orphan_inodes) ||
3186 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3187 return;
3188
3189 spin_lock(&root->orphan_lock);
3190 if (atomic_read(&root->orphan_inodes)) {
3191 spin_unlock(&root->orphan_lock);
3192 return;
3193 }
3194
3195 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3196 spin_unlock(&root->orphan_lock);
3197 return;
3198 }
3199
3200 block_rsv = root->orphan_block_rsv;
3201 root->orphan_block_rsv = NULL;
3202 spin_unlock(&root->orphan_lock);
3203
3204 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3205 btrfs_root_refs(&root->root_item) > 0) {
3206 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3207 root->root_key.objectid);
3208 if (ret)
3209 btrfs_abort_transaction(trans, root, ret);
3210 else
3211 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3212 &root->state);
3213 }
3214
3215 if (block_rsv) {
3216 WARN_ON(block_rsv->size > 0);
3217 btrfs_free_block_rsv(root, block_rsv);
3218 }
3219 }
3220
3221 /*
3222 * This creates an orphan entry for the given inode in case something goes
3223 * wrong in the middle of an unlink/truncate.
3224 *
3225 * NOTE: caller of this function should reserve 5 units of metadata for
3226 * this function.
3227 */
3228 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3229 {
3230 struct btrfs_root *root = BTRFS_I(inode)->root;
3231 struct btrfs_block_rsv *block_rsv = NULL;
3232 int reserve = 0;
3233 int insert = 0;
3234 int ret;
3235
3236 if (!root->orphan_block_rsv) {
3237 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3238 if (!block_rsv)
3239 return -ENOMEM;
3240 }
3241
3242 spin_lock(&root->orphan_lock);
3243 if (!root->orphan_block_rsv) {
3244 root->orphan_block_rsv = block_rsv;
3245 } else if (block_rsv) {
3246 btrfs_free_block_rsv(root, block_rsv);
3247 block_rsv = NULL;
3248 }
3249
3250 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3251 &BTRFS_I(inode)->runtime_flags)) {
3252 #if 0
3253 /*
3254 * For proper ENOSPC handling, we should do orphan
3255 * cleanup when mounting. But this introduces backward
3256 * compatibility issue.
3257 */
3258 if (!xchg(&root->orphan_item_inserted, 1))
3259 insert = 2;
3260 else
3261 insert = 1;
3262 #endif
3263 insert = 1;
3264 atomic_inc(&root->orphan_inodes);
3265 }
3266
3267 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3268 &BTRFS_I(inode)->runtime_flags))
3269 reserve = 1;
3270 spin_unlock(&root->orphan_lock);
3271
3272 /* grab metadata reservation from transaction handle */
3273 if (reserve) {
3274 ret = btrfs_orphan_reserve_metadata(trans, inode);
3275 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3276 }
3277
3278 /* insert an orphan item to track this unlinked/truncated file */
3279 if (insert >= 1) {
3280 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3281 if (ret) {
3282 atomic_dec(&root->orphan_inodes);
3283 if (reserve) {
3284 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3285 &BTRFS_I(inode)->runtime_flags);
3286 btrfs_orphan_release_metadata(inode);
3287 }
3288 if (ret != -EEXIST) {
3289 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3290 &BTRFS_I(inode)->runtime_flags);
3291 btrfs_abort_transaction(trans, root, ret);
3292 return ret;
3293 }
3294 }
3295 ret = 0;
3296 }
3297
3298 /* insert an orphan item to track subvolume contains orphan files */
3299 if (insert >= 2) {
3300 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3301 root->root_key.objectid);
3302 if (ret && ret != -EEXIST) {
3303 btrfs_abort_transaction(trans, root, ret);
3304 return ret;
3305 }
3306 }
3307 return 0;
3308 }
3309
3310 /*
3311 * We have done the truncate/delete so we can go ahead and remove the orphan
3312 * item for this particular inode.
3313 */
3314 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3315 struct inode *inode)
3316 {
3317 struct btrfs_root *root = BTRFS_I(inode)->root;
3318 int delete_item = 0;
3319 int release_rsv = 0;
3320 int ret = 0;
3321
3322 spin_lock(&root->orphan_lock);
3323 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3324 &BTRFS_I(inode)->runtime_flags))
3325 delete_item = 1;
3326
3327 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3328 &BTRFS_I(inode)->runtime_flags))
3329 release_rsv = 1;
3330 spin_unlock(&root->orphan_lock);
3331
3332 if (delete_item) {
3333 atomic_dec(&root->orphan_inodes);
3334 if (trans)
3335 ret = btrfs_del_orphan_item(trans, root,
3336 btrfs_ino(inode));
3337 }
3338
3339 if (release_rsv)
3340 btrfs_orphan_release_metadata(inode);
3341
3342 return ret;
3343 }
3344
3345 /*
3346 * this cleans up any orphans that may be left on the list from the last use
3347 * of this root.
3348 */
3349 int btrfs_orphan_cleanup(struct btrfs_root *root)
3350 {
3351 struct btrfs_path *path;
3352 struct extent_buffer *leaf;
3353 struct btrfs_key key, found_key;
3354 struct btrfs_trans_handle *trans;
3355 struct inode *inode;
3356 u64 last_objectid = 0;
3357 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3358
3359 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3360 return 0;
3361
3362 path = btrfs_alloc_path();
3363 if (!path) {
3364 ret = -ENOMEM;
3365 goto out;
3366 }
3367 path->reada = READA_BACK;
3368
3369 key.objectid = BTRFS_ORPHAN_OBJECTID;
3370 key.type = BTRFS_ORPHAN_ITEM_KEY;
3371 key.offset = (u64)-1;
3372
3373 while (1) {
3374 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3375 if (ret < 0)
3376 goto out;
3377
3378 /*
3379 * if ret == 0 means we found what we were searching for, which
3380 * is weird, but possible, so only screw with path if we didn't
3381 * find the key and see if we have stuff that matches
3382 */
3383 if (ret > 0) {
3384 ret = 0;
3385 if (path->slots[0] == 0)
3386 break;
3387 path->slots[0]--;
3388 }
3389
3390 /* pull out the item */
3391 leaf = path->nodes[0];
3392 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3393
3394 /* make sure the item matches what we want */
3395 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3396 break;
3397 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3398 break;
3399
3400 /* release the path since we're done with it */
3401 btrfs_release_path(path);
3402
3403 /*
3404 * this is where we are basically btrfs_lookup, without the
3405 * crossing root thing. we store the inode number in the
3406 * offset of the orphan item.
3407 */
3408
3409 if (found_key.offset == last_objectid) {
3410 btrfs_err(root->fs_info,
3411 "Error removing orphan entry, stopping orphan cleanup");
3412 ret = -EINVAL;
3413 goto out;
3414 }
3415
3416 last_objectid = found_key.offset;
3417
3418 found_key.objectid = found_key.offset;
3419 found_key.type = BTRFS_INODE_ITEM_KEY;
3420 found_key.offset = 0;
3421 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3422 ret = PTR_ERR_OR_ZERO(inode);
3423 if (ret && ret != -ESTALE)
3424 goto out;
3425
3426 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3427 struct btrfs_root *dead_root;
3428 struct btrfs_fs_info *fs_info = root->fs_info;
3429 int is_dead_root = 0;
3430
3431 /*
3432 * this is an orphan in the tree root. Currently these
3433 * could come from 2 sources:
3434 * a) a snapshot deletion in progress
3435 * b) a free space cache inode
3436 * We need to distinguish those two, as the snapshot
3437 * orphan must not get deleted.
3438 * find_dead_roots already ran before us, so if this
3439 * is a snapshot deletion, we should find the root
3440 * in the dead_roots list
3441 */
3442 spin_lock(&fs_info->trans_lock);
3443 list_for_each_entry(dead_root, &fs_info->dead_roots,
3444 root_list) {
3445 if (dead_root->root_key.objectid ==
3446 found_key.objectid) {
3447 is_dead_root = 1;
3448 break;
3449 }
3450 }
3451 spin_unlock(&fs_info->trans_lock);
3452 if (is_dead_root) {
3453 /* prevent this orphan from being found again */
3454 key.offset = found_key.objectid - 1;
3455 continue;
3456 }
3457 }
3458 /*
3459 * Inode is already gone but the orphan item is still there,
3460 * kill the orphan item.
3461 */
3462 if (ret == -ESTALE) {
3463 trans = btrfs_start_transaction(root, 1);
3464 if (IS_ERR(trans)) {
3465 ret = PTR_ERR(trans);
3466 goto out;
3467 }
3468 btrfs_debug(root->fs_info, "auto deleting %Lu",
3469 found_key.objectid);
3470 ret = btrfs_del_orphan_item(trans, root,
3471 found_key.objectid);
3472 btrfs_end_transaction(trans, root);
3473 if (ret)
3474 goto out;
3475 continue;
3476 }
3477
3478 /*
3479 * add this inode to the orphan list so btrfs_orphan_del does
3480 * the proper thing when we hit it
3481 */
3482 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3483 &BTRFS_I(inode)->runtime_flags);
3484 atomic_inc(&root->orphan_inodes);
3485
3486 /* if we have links, this was a truncate, lets do that */
3487 if (inode->i_nlink) {
3488 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3489 iput(inode);
3490 continue;
3491 }
3492 nr_truncate++;
3493
3494 /* 1 for the orphan item deletion. */
3495 trans = btrfs_start_transaction(root, 1);
3496 if (IS_ERR(trans)) {
3497 iput(inode);
3498 ret = PTR_ERR(trans);
3499 goto out;
3500 }
3501 ret = btrfs_orphan_add(trans, inode);
3502 btrfs_end_transaction(trans, root);
3503 if (ret) {
3504 iput(inode);
3505 goto out;
3506 }
3507
3508 ret = btrfs_truncate(inode);
3509 if (ret)
3510 btrfs_orphan_del(NULL, inode);
3511 } else {
3512 nr_unlink++;
3513 }
3514
3515 /* this will do delete_inode and everything for us */
3516 iput(inode);
3517 if (ret)
3518 goto out;
3519 }
3520 /* release the path since we're done with it */
3521 btrfs_release_path(path);
3522
3523 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3524
3525 if (root->orphan_block_rsv)
3526 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3527 (u64)-1);
3528
3529 if (root->orphan_block_rsv ||
3530 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3531 trans = btrfs_join_transaction(root);
3532 if (!IS_ERR(trans))
3533 btrfs_end_transaction(trans, root);
3534 }
3535
3536 if (nr_unlink)
3537 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3538 if (nr_truncate)
3539 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3540
3541 out:
3542 if (ret)
3543 btrfs_err(root->fs_info,
3544 "could not do orphan cleanup %d", ret);
3545 btrfs_free_path(path);
3546 return ret;
3547 }
3548
3549 /*
3550 * very simple check to peek ahead in the leaf looking for xattrs. If we
3551 * don't find any xattrs, we know there can't be any acls.
3552 *
3553 * slot is the slot the inode is in, objectid is the objectid of the inode
3554 */
3555 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3556 int slot, u64 objectid,
3557 int *first_xattr_slot)
3558 {
3559 u32 nritems = btrfs_header_nritems(leaf);
3560 struct btrfs_key found_key;
3561 static u64 xattr_access = 0;
3562 static u64 xattr_default = 0;
3563 int scanned = 0;
3564
3565 if (!xattr_access) {
3566 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3567 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3568 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3569 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3570 }
3571
3572 slot++;
3573 *first_xattr_slot = -1;
3574 while (slot < nritems) {
3575 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3576
3577 /* we found a different objectid, there must not be acls */
3578 if (found_key.objectid != objectid)
3579 return 0;
3580
3581 /* we found an xattr, assume we've got an acl */
3582 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3583 if (*first_xattr_slot == -1)
3584 *first_xattr_slot = slot;
3585 if (found_key.offset == xattr_access ||
3586 found_key.offset == xattr_default)
3587 return 1;
3588 }
3589
3590 /*
3591 * we found a key greater than an xattr key, there can't
3592 * be any acls later on
3593 */
3594 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3595 return 0;
3596
3597 slot++;
3598 scanned++;
3599
3600 /*
3601 * it goes inode, inode backrefs, xattrs, extents,
3602 * so if there are a ton of hard links to an inode there can
3603 * be a lot of backrefs. Don't waste time searching too hard,
3604 * this is just an optimization
3605 */
3606 if (scanned >= 8)
3607 break;
3608 }
3609 /* we hit the end of the leaf before we found an xattr or
3610 * something larger than an xattr. We have to assume the inode
3611 * has acls
3612 */
3613 if (*first_xattr_slot == -1)
3614 *first_xattr_slot = slot;
3615 return 1;
3616 }
3617
3618 /*
3619 * read an inode from the btree into the in-memory inode
3620 */
3621 static void btrfs_read_locked_inode(struct inode *inode)
3622 {
3623 struct btrfs_path *path;
3624 struct extent_buffer *leaf;
3625 struct btrfs_inode_item *inode_item;
3626 struct btrfs_root *root = BTRFS_I(inode)->root;
3627 struct btrfs_key location;
3628 unsigned long ptr;
3629 int maybe_acls;
3630 u32 rdev;
3631 int ret;
3632 bool filled = false;
3633 int first_xattr_slot;
3634
3635 ret = btrfs_fill_inode(inode, &rdev);
3636 if (!ret)
3637 filled = true;
3638
3639 path = btrfs_alloc_path();
3640 if (!path)
3641 goto make_bad;
3642
3643 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3644
3645 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3646 if (ret)
3647 goto make_bad;
3648
3649 leaf = path->nodes[0];
3650
3651 if (filled)
3652 goto cache_index;
3653
3654 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3655 struct btrfs_inode_item);
3656 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3657 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3658 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3659 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3660 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3661
3662 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3663 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3664
3665 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3666 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3667
3668 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3669 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3670
3671 BTRFS_I(inode)->i_otime.tv_sec =
3672 btrfs_timespec_sec(leaf, &inode_item->otime);
3673 BTRFS_I(inode)->i_otime.tv_nsec =
3674 btrfs_timespec_nsec(leaf, &inode_item->otime);
3675
3676 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3677 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3678 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3679
3680 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3681 inode->i_generation = BTRFS_I(inode)->generation;
3682 inode->i_rdev = 0;
3683 rdev = btrfs_inode_rdev(leaf, inode_item);
3684
3685 BTRFS_I(inode)->index_cnt = (u64)-1;
3686 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3687
3688 cache_index:
3689 /*
3690 * If we were modified in the current generation and evicted from memory
3691 * and then re-read we need to do a full sync since we don't have any
3692 * idea about which extents were modified before we were evicted from
3693 * cache.
3694 *
3695 * This is required for both inode re-read from disk and delayed inode
3696 * in delayed_nodes_tree.
3697 */
3698 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3699 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3700 &BTRFS_I(inode)->runtime_flags);
3701
3702 /*
3703 * We don't persist the id of the transaction where an unlink operation
3704 * against the inode was last made. So here we assume the inode might
3705 * have been evicted, and therefore the exact value of last_unlink_trans
3706 * lost, and set it to last_trans to avoid metadata inconsistencies
3707 * between the inode and its parent if the inode is fsync'ed and the log
3708 * replayed. For example, in the scenario:
3709 *
3710 * touch mydir/foo
3711 * ln mydir/foo mydir/bar
3712 * sync
3713 * unlink mydir/bar
3714 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3715 * xfs_io -c fsync mydir/foo
3716 * <power failure>
3717 * mount fs, triggers fsync log replay
3718 *
3719 * We must make sure that when we fsync our inode foo we also log its
3720 * parent inode, otherwise after log replay the parent still has the
3721 * dentry with the "bar" name but our inode foo has a link count of 1
3722 * and doesn't have an inode ref with the name "bar" anymore.
3723 *
3724 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3725 * but it guarantees correctness at the expense of ocassional full
3726 * transaction commits on fsync if our inode is a directory, or if our
3727 * inode is not a directory, logging its parent unnecessarily.
3728 */
3729 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3730
3731 path->slots[0]++;
3732 if (inode->i_nlink != 1 ||
3733 path->slots[0] >= btrfs_header_nritems(leaf))
3734 goto cache_acl;
3735
3736 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3737 if (location.objectid != btrfs_ino(inode))
3738 goto cache_acl;
3739
3740 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3741 if (location.type == BTRFS_INODE_REF_KEY) {
3742 struct btrfs_inode_ref *ref;
3743
3744 ref = (struct btrfs_inode_ref *)ptr;
3745 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3746 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3747 struct btrfs_inode_extref *extref;
3748
3749 extref = (struct btrfs_inode_extref *)ptr;
3750 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3751 extref);
3752 }
3753 cache_acl:
3754 /*
3755 * try to precache a NULL acl entry for files that don't have
3756 * any xattrs or acls
3757 */
3758 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3759 btrfs_ino(inode), &first_xattr_slot);
3760 if (first_xattr_slot != -1) {
3761 path->slots[0] = first_xattr_slot;
3762 ret = btrfs_load_inode_props(inode, path);
3763 if (ret)
3764 btrfs_err(root->fs_info,
3765 "error loading props for ino %llu (root %llu): %d",
3766 btrfs_ino(inode),
3767 root->root_key.objectid, ret);
3768 }
3769 btrfs_free_path(path);
3770
3771 if (!maybe_acls)
3772 cache_no_acl(inode);
3773
3774 switch (inode->i_mode & S_IFMT) {
3775 case S_IFREG:
3776 inode->i_mapping->a_ops = &btrfs_aops;
3777 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3778 inode->i_fop = &btrfs_file_operations;
3779 inode->i_op = &btrfs_file_inode_operations;
3780 break;
3781 case S_IFDIR:
3782 inode->i_fop = &btrfs_dir_file_operations;
3783 if (root == root->fs_info->tree_root)
3784 inode->i_op = &btrfs_dir_ro_inode_operations;
3785 else
3786 inode->i_op = &btrfs_dir_inode_operations;
3787 break;
3788 case S_IFLNK:
3789 inode->i_op = &btrfs_symlink_inode_operations;
3790 inode_nohighmem(inode);
3791 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3792 break;
3793 default:
3794 inode->i_op = &btrfs_special_inode_operations;
3795 init_special_inode(inode, inode->i_mode, rdev);
3796 break;
3797 }
3798
3799 btrfs_update_iflags(inode);
3800 return;
3801
3802 make_bad:
3803 btrfs_free_path(path);
3804 make_bad_inode(inode);
3805 }
3806
3807 /*
3808 * given a leaf and an inode, copy the inode fields into the leaf
3809 */
3810 static void fill_inode_item(struct btrfs_trans_handle *trans,
3811 struct extent_buffer *leaf,
3812 struct btrfs_inode_item *item,
3813 struct inode *inode)
3814 {
3815 struct btrfs_map_token token;
3816
3817 btrfs_init_map_token(&token);
3818
3819 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3820 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3821 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3822 &token);
3823 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3824 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3825
3826 btrfs_set_token_timespec_sec(leaf, &item->atime,
3827 inode->i_atime.tv_sec, &token);
3828 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3829 inode->i_atime.tv_nsec, &token);
3830
3831 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3832 inode->i_mtime.tv_sec, &token);
3833 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3834 inode->i_mtime.tv_nsec, &token);
3835
3836 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3837 inode->i_ctime.tv_sec, &token);
3838 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3839 inode->i_ctime.tv_nsec, &token);
3840
3841 btrfs_set_token_timespec_sec(leaf, &item->otime,
3842 BTRFS_I(inode)->i_otime.tv_sec, &token);
3843 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3844 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3845
3846 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3847 &token);
3848 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3849 &token);
3850 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3851 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3852 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3853 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3854 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3855 }
3856
3857 /*
3858 * copy everything in the in-memory inode into the btree.
3859 */
3860 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3861 struct btrfs_root *root, struct inode *inode)
3862 {
3863 struct btrfs_inode_item *inode_item;
3864 struct btrfs_path *path;
3865 struct extent_buffer *leaf;
3866 int ret;
3867
3868 path = btrfs_alloc_path();
3869 if (!path)
3870 return -ENOMEM;
3871
3872 path->leave_spinning = 1;
3873 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3874 1);
3875 if (ret) {
3876 if (ret > 0)
3877 ret = -ENOENT;
3878 goto failed;
3879 }
3880
3881 leaf = path->nodes[0];
3882 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3883 struct btrfs_inode_item);
3884
3885 fill_inode_item(trans, leaf, inode_item, inode);
3886 btrfs_mark_buffer_dirty(leaf);
3887 btrfs_set_inode_last_trans(trans, inode);
3888 ret = 0;
3889 failed:
3890 btrfs_free_path(path);
3891 return ret;
3892 }
3893
3894 /*
3895 * copy everything in the in-memory inode into the btree.
3896 */
3897 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3898 struct btrfs_root *root, struct inode *inode)
3899 {
3900 int ret;
3901
3902 /*
3903 * If the inode is a free space inode, we can deadlock during commit
3904 * if we put it into the delayed code.
3905 *
3906 * The data relocation inode should also be directly updated
3907 * without delay
3908 */
3909 if (!btrfs_is_free_space_inode(inode)
3910 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3911 && !root->fs_info->log_root_recovering) {
3912 btrfs_update_root_times(trans, root);
3913
3914 ret = btrfs_delayed_update_inode(trans, root, inode);
3915 if (!ret)
3916 btrfs_set_inode_last_trans(trans, inode);
3917 return ret;
3918 }
3919
3920 return btrfs_update_inode_item(trans, root, inode);
3921 }
3922
3923 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3924 struct btrfs_root *root,
3925 struct inode *inode)
3926 {
3927 int ret;
3928
3929 ret = btrfs_update_inode(trans, root, inode);
3930 if (ret == -ENOSPC)
3931 return btrfs_update_inode_item(trans, root, inode);
3932 return ret;
3933 }
3934
3935 /*
3936 * unlink helper that gets used here in inode.c and in the tree logging
3937 * recovery code. It remove a link in a directory with a given name, and
3938 * also drops the back refs in the inode to the directory
3939 */
3940 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3941 struct btrfs_root *root,
3942 struct inode *dir, struct inode *inode,
3943 const char *name, int name_len)
3944 {
3945 struct btrfs_path *path;
3946 int ret = 0;
3947 struct extent_buffer *leaf;
3948 struct btrfs_dir_item *di;
3949 struct btrfs_key key;
3950 u64 index;
3951 u64 ino = btrfs_ino(inode);
3952 u64 dir_ino = btrfs_ino(dir);
3953
3954 path = btrfs_alloc_path();
3955 if (!path) {
3956 ret = -ENOMEM;
3957 goto out;
3958 }
3959
3960 path->leave_spinning = 1;
3961 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3962 name, name_len, -1);
3963 if (IS_ERR(di)) {
3964 ret = PTR_ERR(di);
3965 goto err;
3966 }
3967 if (!di) {
3968 ret = -ENOENT;
3969 goto err;
3970 }
3971 leaf = path->nodes[0];
3972 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3973 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3974 if (ret)
3975 goto err;
3976 btrfs_release_path(path);
3977
3978 /*
3979 * If we don't have dir index, we have to get it by looking up
3980 * the inode ref, since we get the inode ref, remove it directly,
3981 * it is unnecessary to do delayed deletion.
3982 *
3983 * But if we have dir index, needn't search inode ref to get it.
3984 * Since the inode ref is close to the inode item, it is better
3985 * that we delay to delete it, and just do this deletion when
3986 * we update the inode item.
3987 */
3988 if (BTRFS_I(inode)->dir_index) {
3989 ret = btrfs_delayed_delete_inode_ref(inode);
3990 if (!ret) {
3991 index = BTRFS_I(inode)->dir_index;
3992 goto skip_backref;
3993 }
3994 }
3995
3996 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3997 dir_ino, &index);
3998 if (ret) {
3999 btrfs_info(root->fs_info,
4000 "failed to delete reference to %.*s, inode %llu parent %llu",
4001 name_len, name, ino, dir_ino);
4002 btrfs_abort_transaction(trans, root, ret);
4003 goto err;
4004 }
4005 skip_backref:
4006 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4007 if (ret) {
4008 btrfs_abort_transaction(trans, root, ret);
4009 goto err;
4010 }
4011
4012 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4013 inode, dir_ino);
4014 if (ret != 0 && ret != -ENOENT) {
4015 btrfs_abort_transaction(trans, root, ret);
4016 goto err;
4017 }
4018
4019 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4020 dir, index);
4021 if (ret == -ENOENT)
4022 ret = 0;
4023 else if (ret)
4024 btrfs_abort_transaction(trans, root, ret);
4025 err:
4026 btrfs_free_path(path);
4027 if (ret)
4028 goto out;
4029
4030 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4031 inode_inc_iversion(inode);
4032 inode_inc_iversion(dir);
4033 inode->i_ctime = dir->i_mtime =
4034 dir->i_ctime = current_fs_time(inode->i_sb);
4035 ret = btrfs_update_inode(trans, root, dir);
4036 out:
4037 return ret;
4038 }
4039
4040 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4041 struct btrfs_root *root,
4042 struct inode *dir, struct inode *inode,
4043 const char *name, int name_len)
4044 {
4045 int ret;
4046 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4047 if (!ret) {
4048 drop_nlink(inode);
4049 ret = btrfs_update_inode(trans, root, inode);
4050 }
4051 return ret;
4052 }
4053
4054 /*
4055 * helper to start transaction for unlink and rmdir.
4056 *
4057 * unlink and rmdir are special in btrfs, they do not always free space, so
4058 * if we cannot make our reservations the normal way try and see if there is
4059 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4060 * allow the unlink to occur.
4061 */
4062 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4063 {
4064 struct btrfs_root *root = BTRFS_I(dir)->root;
4065
4066 /*
4067 * 1 for the possible orphan item
4068 * 1 for the dir item
4069 * 1 for the dir index
4070 * 1 for the inode ref
4071 * 1 for the inode
4072 */
4073 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4074 }
4075
4076 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4077 {
4078 struct btrfs_root *root = BTRFS_I(dir)->root;
4079 struct btrfs_trans_handle *trans;
4080 struct inode *inode = d_inode(dentry);
4081 int ret;
4082
4083 trans = __unlink_start_trans(dir);
4084 if (IS_ERR(trans))
4085 return PTR_ERR(trans);
4086
4087 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4088
4089 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4090 dentry->d_name.name, dentry->d_name.len);
4091 if (ret)
4092 goto out;
4093
4094 if (inode->i_nlink == 0) {
4095 ret = btrfs_orphan_add(trans, inode);
4096 if (ret)
4097 goto out;
4098 }
4099
4100 out:
4101 btrfs_end_transaction(trans, root);
4102 btrfs_btree_balance_dirty(root);
4103 return ret;
4104 }
4105
4106 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4107 struct btrfs_root *root,
4108 struct inode *dir, u64 objectid,
4109 const char *name, int name_len)
4110 {
4111 struct btrfs_path *path;
4112 struct extent_buffer *leaf;
4113 struct btrfs_dir_item *di;
4114 struct btrfs_key key;
4115 u64 index;
4116 int ret;
4117 u64 dir_ino = btrfs_ino(dir);
4118
4119 path = btrfs_alloc_path();
4120 if (!path)
4121 return -ENOMEM;
4122
4123 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4124 name, name_len, -1);
4125 if (IS_ERR_OR_NULL(di)) {
4126 if (!di)
4127 ret = -ENOENT;
4128 else
4129 ret = PTR_ERR(di);
4130 goto out;
4131 }
4132
4133 leaf = path->nodes[0];
4134 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4135 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4136 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4137 if (ret) {
4138 btrfs_abort_transaction(trans, root, ret);
4139 goto out;
4140 }
4141 btrfs_release_path(path);
4142
4143 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4144 objectid, root->root_key.objectid,
4145 dir_ino, &index, name, name_len);
4146 if (ret < 0) {
4147 if (ret != -ENOENT) {
4148 btrfs_abort_transaction(trans, root, ret);
4149 goto out;
4150 }
4151 di = btrfs_search_dir_index_item(root, path, dir_ino,
4152 name, name_len);
4153 if (IS_ERR_OR_NULL(di)) {
4154 if (!di)
4155 ret = -ENOENT;
4156 else
4157 ret = PTR_ERR(di);
4158 btrfs_abort_transaction(trans, root, ret);
4159 goto out;
4160 }
4161
4162 leaf = path->nodes[0];
4163 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4164 btrfs_release_path(path);
4165 index = key.offset;
4166 }
4167 btrfs_release_path(path);
4168
4169 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4170 if (ret) {
4171 btrfs_abort_transaction(trans, root, ret);
4172 goto out;
4173 }
4174
4175 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4176 inode_inc_iversion(dir);
4177 dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
4178 ret = btrfs_update_inode_fallback(trans, root, dir);
4179 if (ret)
4180 btrfs_abort_transaction(trans, root, ret);
4181 out:
4182 btrfs_free_path(path);
4183 return ret;
4184 }
4185
4186 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4187 {
4188 struct inode *inode = d_inode(dentry);
4189 int err = 0;
4190 struct btrfs_root *root = BTRFS_I(dir)->root;
4191 struct btrfs_trans_handle *trans;
4192
4193 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4194 return -ENOTEMPTY;
4195 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4196 return -EPERM;
4197
4198 trans = __unlink_start_trans(dir);
4199 if (IS_ERR(trans))
4200 return PTR_ERR(trans);
4201
4202 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4203 err = btrfs_unlink_subvol(trans, root, dir,
4204 BTRFS_I(inode)->location.objectid,
4205 dentry->d_name.name,
4206 dentry->d_name.len);
4207 goto out;
4208 }
4209
4210 err = btrfs_orphan_add(trans, inode);
4211 if (err)
4212 goto out;
4213
4214 /* now the directory is empty */
4215 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4216 dentry->d_name.name, dentry->d_name.len);
4217 if (!err)
4218 btrfs_i_size_write(inode, 0);
4219 out:
4220 btrfs_end_transaction(trans, root);
4221 btrfs_btree_balance_dirty(root);
4222
4223 return err;
4224 }
4225
4226 static int truncate_space_check(struct btrfs_trans_handle *trans,
4227 struct btrfs_root *root,
4228 u64 bytes_deleted)
4229 {
4230 int ret;
4231
4232 /*
4233 * This is only used to apply pressure to the enospc system, we don't
4234 * intend to use this reservation at all.
4235 */
4236 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4237 bytes_deleted *= root->nodesize;
4238 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4239 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4240 if (!ret) {
4241 trace_btrfs_space_reservation(root->fs_info, "transaction",
4242 trans->transid,
4243 bytes_deleted, 1);
4244 trans->bytes_reserved += bytes_deleted;
4245 }
4246 return ret;
4247
4248 }
4249
4250 static int truncate_inline_extent(struct inode *inode,
4251 struct btrfs_path *path,
4252 struct btrfs_key *found_key,
4253 const u64 item_end,
4254 const u64 new_size)
4255 {
4256 struct extent_buffer *leaf = path->nodes[0];
4257 int slot = path->slots[0];
4258 struct btrfs_file_extent_item *fi;
4259 u32 size = (u32)(new_size - found_key->offset);
4260 struct btrfs_root *root = BTRFS_I(inode)->root;
4261
4262 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4263
4264 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4265 loff_t offset = new_size;
4266 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4267
4268 /*
4269 * Zero out the remaining of the last page of our inline extent,
4270 * instead of directly truncating our inline extent here - that
4271 * would be much more complex (decompressing all the data, then
4272 * compressing the truncated data, which might be bigger than
4273 * the size of the inline extent, resize the extent, etc).
4274 * We release the path because to get the page we might need to
4275 * read the extent item from disk (data not in the page cache).
4276 */
4277 btrfs_release_path(path);
4278 return btrfs_truncate_block(inode, offset, page_end - offset,
4279 0);
4280 }
4281
4282 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4283 size = btrfs_file_extent_calc_inline_size(size);
4284 btrfs_truncate_item(root, path, size, 1);
4285
4286 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4287 inode_sub_bytes(inode, item_end + 1 - new_size);
4288
4289 return 0;
4290 }
4291
4292 /*
4293 * this can truncate away extent items, csum items and directory items.
4294 * It starts at a high offset and removes keys until it can't find
4295 * any higher than new_size
4296 *
4297 * csum items that cross the new i_size are truncated to the new size
4298 * as well.
4299 *
4300 * min_type is the minimum key type to truncate down to. If set to 0, this
4301 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4302 */
4303 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4304 struct btrfs_root *root,
4305 struct inode *inode,
4306 u64 new_size, u32 min_type)
4307 {
4308 struct btrfs_path *path;
4309 struct extent_buffer *leaf;
4310 struct btrfs_file_extent_item *fi;
4311 struct btrfs_key key;
4312 struct btrfs_key found_key;
4313 u64 extent_start = 0;
4314 u64 extent_num_bytes = 0;
4315 u64 extent_offset = 0;
4316 u64 item_end = 0;
4317 u64 last_size = new_size;
4318 u32 found_type = (u8)-1;
4319 int found_extent;
4320 int del_item;
4321 int pending_del_nr = 0;
4322 int pending_del_slot = 0;
4323 int extent_type = -1;
4324 int ret;
4325 int err = 0;
4326 u64 ino = btrfs_ino(inode);
4327 u64 bytes_deleted = 0;
4328 bool be_nice = 0;
4329 bool should_throttle = 0;
4330 bool should_end = 0;
4331
4332 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4333
4334 /*
4335 * for non-free space inodes and ref cows, we want to back off from
4336 * time to time
4337 */
4338 if (!btrfs_is_free_space_inode(inode) &&
4339 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4340 be_nice = 1;
4341
4342 path = btrfs_alloc_path();
4343 if (!path)
4344 return -ENOMEM;
4345 path->reada = READA_BACK;
4346
4347 /*
4348 * We want to drop from the next block forward in case this new size is
4349 * not block aligned since we will be keeping the last block of the
4350 * extent just the way it is.
4351 */
4352 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4353 root == root->fs_info->tree_root)
4354 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4355 root->sectorsize), (u64)-1, 0);
4356
4357 /*
4358 * This function is also used to drop the items in the log tree before
4359 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4360 * it is used to drop the loged items. So we shouldn't kill the delayed
4361 * items.
4362 */
4363 if (min_type == 0 && root == BTRFS_I(inode)->root)
4364 btrfs_kill_delayed_inode_items(inode);
4365
4366 key.objectid = ino;
4367 key.offset = (u64)-1;
4368 key.type = (u8)-1;
4369
4370 search_again:
4371 /*
4372 * with a 16K leaf size and 128MB extents, you can actually queue
4373 * up a huge file in a single leaf. Most of the time that
4374 * bytes_deleted is > 0, it will be huge by the time we get here
4375 */
4376 if (be_nice && bytes_deleted > SZ_32M) {
4377 if (btrfs_should_end_transaction(trans, root)) {
4378 err = -EAGAIN;
4379 goto error;
4380 }
4381 }
4382
4383
4384 path->leave_spinning = 1;
4385 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4386 if (ret < 0) {
4387 err = ret;
4388 goto out;
4389 }
4390
4391 if (ret > 0) {
4392 /* there are no items in the tree for us to truncate, we're
4393 * done
4394 */
4395 if (path->slots[0] == 0)
4396 goto out;
4397 path->slots[0]--;
4398 }
4399
4400 while (1) {
4401 fi = NULL;
4402 leaf = path->nodes[0];
4403 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4404 found_type = found_key.type;
4405
4406 if (found_key.objectid != ino)
4407 break;
4408
4409 if (found_type < min_type)
4410 break;
4411
4412 item_end = found_key.offset;
4413 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4414 fi = btrfs_item_ptr(leaf, path->slots[0],
4415 struct btrfs_file_extent_item);
4416 extent_type = btrfs_file_extent_type(leaf, fi);
4417 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4418 item_end +=
4419 btrfs_file_extent_num_bytes(leaf, fi);
4420 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4421 item_end += btrfs_file_extent_inline_len(leaf,
4422 path->slots[0], fi);
4423 }
4424 item_end--;
4425 }
4426 if (found_type > min_type) {
4427 del_item = 1;
4428 } else {
4429 if (item_end < new_size)
4430 break;
4431 if (found_key.offset >= new_size)
4432 del_item = 1;
4433 else
4434 del_item = 0;
4435 }
4436 found_extent = 0;
4437 /* FIXME, shrink the extent if the ref count is only 1 */
4438 if (found_type != BTRFS_EXTENT_DATA_KEY)
4439 goto delete;
4440
4441 if (del_item)
4442 last_size = found_key.offset;
4443 else
4444 last_size = new_size;
4445
4446 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4447 u64 num_dec;
4448 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4449 if (!del_item) {
4450 u64 orig_num_bytes =
4451 btrfs_file_extent_num_bytes(leaf, fi);
4452 extent_num_bytes = ALIGN(new_size -
4453 found_key.offset,
4454 root->sectorsize);
4455 btrfs_set_file_extent_num_bytes(leaf, fi,
4456 extent_num_bytes);
4457 num_dec = (orig_num_bytes -
4458 extent_num_bytes);
4459 if (test_bit(BTRFS_ROOT_REF_COWS,
4460 &root->state) &&
4461 extent_start != 0)
4462 inode_sub_bytes(inode, num_dec);
4463 btrfs_mark_buffer_dirty(leaf);
4464 } else {
4465 extent_num_bytes =
4466 btrfs_file_extent_disk_num_bytes(leaf,
4467 fi);
4468 extent_offset = found_key.offset -
4469 btrfs_file_extent_offset(leaf, fi);
4470
4471 /* FIXME blocksize != 4096 */
4472 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4473 if (extent_start != 0) {
4474 found_extent = 1;
4475 if (test_bit(BTRFS_ROOT_REF_COWS,
4476 &root->state))
4477 inode_sub_bytes(inode, num_dec);
4478 }
4479 }
4480 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4481 /*
4482 * we can't truncate inline items that have had
4483 * special encodings
4484 */
4485 if (!del_item &&
4486 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4487 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4488
4489 /*
4490 * Need to release path in order to truncate a
4491 * compressed extent. So delete any accumulated
4492 * extent items so far.
4493 */
4494 if (btrfs_file_extent_compression(leaf, fi) !=
4495 BTRFS_COMPRESS_NONE && pending_del_nr) {
4496 err = btrfs_del_items(trans, root, path,
4497 pending_del_slot,
4498 pending_del_nr);
4499 if (err) {
4500 btrfs_abort_transaction(trans,
4501 root,
4502 err);
4503 goto error;
4504 }
4505 pending_del_nr = 0;
4506 }
4507
4508 err = truncate_inline_extent(inode, path,
4509 &found_key,
4510 item_end,
4511 new_size);
4512 if (err) {
4513 btrfs_abort_transaction(trans,
4514 root, err);
4515 goto error;
4516 }
4517 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4518 &root->state)) {
4519 inode_sub_bytes(inode, item_end + 1 - new_size);
4520 }
4521 }
4522 delete:
4523 if (del_item) {
4524 if (!pending_del_nr) {
4525 /* no pending yet, add ourselves */
4526 pending_del_slot = path->slots[0];
4527 pending_del_nr = 1;
4528 } else if (pending_del_nr &&
4529 path->slots[0] + 1 == pending_del_slot) {
4530 /* hop on the pending chunk */
4531 pending_del_nr++;
4532 pending_del_slot = path->slots[0];
4533 } else {
4534 BUG();
4535 }
4536 } else {
4537 break;
4538 }
4539 should_throttle = 0;
4540
4541 if (found_extent &&
4542 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4543 root == root->fs_info->tree_root)) {
4544 btrfs_set_path_blocking(path);
4545 bytes_deleted += extent_num_bytes;
4546 ret = btrfs_free_extent(trans, root, extent_start,
4547 extent_num_bytes, 0,
4548 btrfs_header_owner(leaf),
4549 ino, extent_offset);
4550 BUG_ON(ret);
4551 if (btrfs_should_throttle_delayed_refs(trans, root))
4552 btrfs_async_run_delayed_refs(root,
4553 trans->delayed_ref_updates * 2, 0);
4554 if (be_nice) {
4555 if (truncate_space_check(trans, root,
4556 extent_num_bytes)) {
4557 should_end = 1;
4558 }
4559 if (btrfs_should_throttle_delayed_refs(trans,
4560 root)) {
4561 should_throttle = 1;
4562 }
4563 }
4564 }
4565
4566 if (found_type == BTRFS_INODE_ITEM_KEY)
4567 break;
4568
4569 if (path->slots[0] == 0 ||
4570 path->slots[0] != pending_del_slot ||
4571 should_throttle || should_end) {
4572 if (pending_del_nr) {
4573 ret = btrfs_del_items(trans, root, path,
4574 pending_del_slot,
4575 pending_del_nr);
4576 if (ret) {
4577 btrfs_abort_transaction(trans,
4578 root, ret);
4579 goto error;
4580 }
4581 pending_del_nr = 0;
4582 }
4583 btrfs_release_path(path);
4584 if (should_throttle) {
4585 unsigned long updates = trans->delayed_ref_updates;
4586 if (updates) {
4587 trans->delayed_ref_updates = 0;
4588 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4589 if (ret && !err)
4590 err = ret;
4591 }
4592 }
4593 /*
4594 * if we failed to refill our space rsv, bail out
4595 * and let the transaction restart
4596 */
4597 if (should_end) {
4598 err = -EAGAIN;
4599 goto error;
4600 }
4601 goto search_again;
4602 } else {
4603 path->slots[0]--;
4604 }
4605 }
4606 out:
4607 if (pending_del_nr) {
4608 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4609 pending_del_nr);
4610 if (ret)
4611 btrfs_abort_transaction(trans, root, ret);
4612 }
4613 error:
4614 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4615 btrfs_ordered_update_i_size(inode, last_size, NULL);
4616
4617 btrfs_free_path(path);
4618
4619 if (be_nice && bytes_deleted > SZ_32M) {
4620 unsigned long updates = trans->delayed_ref_updates;
4621 if (updates) {
4622 trans->delayed_ref_updates = 0;
4623 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4624 if (ret && !err)
4625 err = ret;
4626 }
4627 }
4628 return err;
4629 }
4630
4631 /*
4632 * btrfs_truncate_block - read, zero a chunk and write a block
4633 * @inode - inode that we're zeroing
4634 * @from - the offset to start zeroing
4635 * @len - the length to zero, 0 to zero the entire range respective to the
4636 * offset
4637 * @front - zero up to the offset instead of from the offset on
4638 *
4639 * This will find the block for the "from" offset and cow the block and zero the
4640 * part we want to zero. This is used with truncate and hole punching.
4641 */
4642 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4643 int front)
4644 {
4645 struct address_space *mapping = inode->i_mapping;
4646 struct btrfs_root *root = BTRFS_I(inode)->root;
4647 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4648 struct btrfs_ordered_extent *ordered;
4649 struct extent_state *cached_state = NULL;
4650 char *kaddr;
4651 u32 blocksize = root->sectorsize;
4652 pgoff_t index = from >> PAGE_SHIFT;
4653 unsigned offset = from & (blocksize - 1);
4654 struct page *page;
4655 gfp_t mask = btrfs_alloc_write_mask(mapping);
4656 int ret = 0;
4657 u64 block_start;
4658 u64 block_end;
4659
4660 if ((offset & (blocksize - 1)) == 0 &&
4661 (!len || ((len & (blocksize - 1)) == 0)))
4662 goto out;
4663
4664 ret = btrfs_delalloc_reserve_space(inode,
4665 round_down(from, blocksize), blocksize);
4666 if (ret)
4667 goto out;
4668
4669 again:
4670 page = find_or_create_page(mapping, index, mask);
4671 if (!page) {
4672 btrfs_delalloc_release_space(inode,
4673 round_down(from, blocksize),
4674 blocksize);
4675 ret = -ENOMEM;
4676 goto out;
4677 }
4678
4679 block_start = round_down(from, blocksize);
4680 block_end = block_start + blocksize - 1;
4681
4682 if (!PageUptodate(page)) {
4683 ret = btrfs_readpage(NULL, page);
4684 lock_page(page);
4685 if (page->mapping != mapping) {
4686 unlock_page(page);
4687 put_page(page);
4688 goto again;
4689 }
4690 if (!PageUptodate(page)) {
4691 ret = -EIO;
4692 goto out_unlock;
4693 }
4694 }
4695 wait_on_page_writeback(page);
4696
4697 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4698 set_page_extent_mapped(page);
4699
4700 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4701 if (ordered) {
4702 unlock_extent_cached(io_tree, block_start, block_end,
4703 &cached_state, GFP_NOFS);
4704 unlock_page(page);
4705 put_page(page);
4706 btrfs_start_ordered_extent(inode, ordered, 1);
4707 btrfs_put_ordered_extent(ordered);
4708 goto again;
4709 }
4710
4711 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4712 EXTENT_DIRTY | EXTENT_DELALLOC |
4713 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4714 0, 0, &cached_state, GFP_NOFS);
4715
4716 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4717 &cached_state);
4718 if (ret) {
4719 unlock_extent_cached(io_tree, block_start, block_end,
4720 &cached_state, GFP_NOFS);
4721 goto out_unlock;
4722 }
4723
4724 if (offset != blocksize) {
4725 if (!len)
4726 len = blocksize - offset;
4727 kaddr = kmap(page);
4728 if (front)
4729 memset(kaddr + (block_start - page_offset(page)),
4730 0, offset);
4731 else
4732 memset(kaddr + (block_start - page_offset(page)) + offset,
4733 0, len);
4734 flush_dcache_page(page);
4735 kunmap(page);
4736 }
4737 ClearPageChecked(page);
4738 set_page_dirty(page);
4739 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4740 GFP_NOFS);
4741
4742 out_unlock:
4743 if (ret)
4744 btrfs_delalloc_release_space(inode, block_start,
4745 blocksize);
4746 unlock_page(page);
4747 put_page(page);
4748 out:
4749 return ret;
4750 }
4751
4752 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4753 u64 offset, u64 len)
4754 {
4755 struct btrfs_trans_handle *trans;
4756 int ret;
4757
4758 /*
4759 * Still need to make sure the inode looks like it's been updated so
4760 * that any holes get logged if we fsync.
4761 */
4762 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4763 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4764 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4765 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4766 return 0;
4767 }
4768
4769 /*
4770 * 1 - for the one we're dropping
4771 * 1 - for the one we're adding
4772 * 1 - for updating the inode.
4773 */
4774 trans = btrfs_start_transaction(root, 3);
4775 if (IS_ERR(trans))
4776 return PTR_ERR(trans);
4777
4778 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4779 if (ret) {
4780 btrfs_abort_transaction(trans, root, ret);
4781 btrfs_end_transaction(trans, root);
4782 return ret;
4783 }
4784
4785 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4786 0, 0, len, 0, len, 0, 0, 0);
4787 if (ret)
4788 btrfs_abort_transaction(trans, root, ret);
4789 else
4790 btrfs_update_inode(trans, root, inode);
4791 btrfs_end_transaction(trans, root);
4792 return ret;
4793 }
4794
4795 /*
4796 * This function puts in dummy file extents for the area we're creating a hole
4797 * for. So if we are truncating this file to a larger size we need to insert
4798 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4799 * the range between oldsize and size
4800 */
4801 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4802 {
4803 struct btrfs_root *root = BTRFS_I(inode)->root;
4804 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4805 struct extent_map *em = NULL;
4806 struct extent_state *cached_state = NULL;
4807 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4808 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4809 u64 block_end = ALIGN(size, root->sectorsize);
4810 u64 last_byte;
4811 u64 cur_offset;
4812 u64 hole_size;
4813 int err = 0;
4814
4815 /*
4816 * If our size started in the middle of a block we need to zero out the
4817 * rest of the block before we expand the i_size, otherwise we could
4818 * expose stale data.
4819 */
4820 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4821 if (err)
4822 return err;
4823
4824 if (size <= hole_start)
4825 return 0;
4826
4827 while (1) {
4828 struct btrfs_ordered_extent *ordered;
4829
4830 lock_extent_bits(io_tree, hole_start, block_end - 1,
4831 &cached_state);
4832 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4833 block_end - hole_start);
4834 if (!ordered)
4835 break;
4836 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4837 &cached_state, GFP_NOFS);
4838 btrfs_start_ordered_extent(inode, ordered, 1);
4839 btrfs_put_ordered_extent(ordered);
4840 }
4841
4842 cur_offset = hole_start;
4843 while (1) {
4844 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4845 block_end - cur_offset, 0);
4846 if (IS_ERR(em)) {
4847 err = PTR_ERR(em);
4848 em = NULL;
4849 break;
4850 }
4851 last_byte = min(extent_map_end(em), block_end);
4852 last_byte = ALIGN(last_byte , root->sectorsize);
4853 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4854 struct extent_map *hole_em;
4855 hole_size = last_byte - cur_offset;
4856
4857 err = maybe_insert_hole(root, inode, cur_offset,
4858 hole_size);
4859 if (err)
4860 break;
4861 btrfs_drop_extent_cache(inode, cur_offset,
4862 cur_offset + hole_size - 1, 0);
4863 hole_em = alloc_extent_map();
4864 if (!hole_em) {
4865 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4866 &BTRFS_I(inode)->runtime_flags);
4867 goto next;
4868 }
4869 hole_em->start = cur_offset;
4870 hole_em->len = hole_size;
4871 hole_em->orig_start = cur_offset;
4872
4873 hole_em->block_start = EXTENT_MAP_HOLE;
4874 hole_em->block_len = 0;
4875 hole_em->orig_block_len = 0;
4876 hole_em->ram_bytes = hole_size;
4877 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4878 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4879 hole_em->generation = root->fs_info->generation;
4880
4881 while (1) {
4882 write_lock(&em_tree->lock);
4883 err = add_extent_mapping(em_tree, hole_em, 1);
4884 write_unlock(&em_tree->lock);
4885 if (err != -EEXIST)
4886 break;
4887 btrfs_drop_extent_cache(inode, cur_offset,
4888 cur_offset +
4889 hole_size - 1, 0);
4890 }
4891 free_extent_map(hole_em);
4892 }
4893 next:
4894 free_extent_map(em);
4895 em = NULL;
4896 cur_offset = last_byte;
4897 if (cur_offset >= block_end)
4898 break;
4899 }
4900 free_extent_map(em);
4901 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4902 GFP_NOFS);
4903 return err;
4904 }
4905
4906 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4907 {
4908 struct btrfs_root *root = BTRFS_I(inode)->root;
4909 struct btrfs_trans_handle *trans;
4910 loff_t oldsize = i_size_read(inode);
4911 loff_t newsize = attr->ia_size;
4912 int mask = attr->ia_valid;
4913 int ret;
4914
4915 /*
4916 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4917 * special case where we need to update the times despite not having
4918 * these flags set. For all other operations the VFS set these flags
4919 * explicitly if it wants a timestamp update.
4920 */
4921 if (newsize != oldsize) {
4922 inode_inc_iversion(inode);
4923 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4924 inode->i_ctime = inode->i_mtime =
4925 current_fs_time(inode->i_sb);
4926 }
4927
4928 if (newsize > oldsize) {
4929 /*
4930 * Don't do an expanding truncate while snapshoting is ongoing.
4931 * This is to ensure the snapshot captures a fully consistent
4932 * state of this file - if the snapshot captures this expanding
4933 * truncation, it must capture all writes that happened before
4934 * this truncation.
4935 */
4936 btrfs_wait_for_snapshot_creation(root);
4937 ret = btrfs_cont_expand(inode, oldsize, newsize);
4938 if (ret) {
4939 btrfs_end_write_no_snapshoting(root);
4940 return ret;
4941 }
4942
4943 trans = btrfs_start_transaction(root, 1);
4944 if (IS_ERR(trans)) {
4945 btrfs_end_write_no_snapshoting(root);
4946 return PTR_ERR(trans);
4947 }
4948
4949 i_size_write(inode, newsize);
4950 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4951 pagecache_isize_extended(inode, oldsize, newsize);
4952 ret = btrfs_update_inode(trans, root, inode);
4953 btrfs_end_write_no_snapshoting(root);
4954 btrfs_end_transaction(trans, root);
4955 } else {
4956
4957 /*
4958 * We're truncating a file that used to have good data down to
4959 * zero. Make sure it gets into the ordered flush list so that
4960 * any new writes get down to disk quickly.
4961 */
4962 if (newsize == 0)
4963 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4964 &BTRFS_I(inode)->runtime_flags);
4965
4966 /*
4967 * 1 for the orphan item we're going to add
4968 * 1 for the orphan item deletion.
4969 */
4970 trans = btrfs_start_transaction(root, 2);
4971 if (IS_ERR(trans))
4972 return PTR_ERR(trans);
4973
4974 /*
4975 * We need to do this in case we fail at _any_ point during the
4976 * actual truncate. Once we do the truncate_setsize we could
4977 * invalidate pages which forces any outstanding ordered io to
4978 * be instantly completed which will give us extents that need
4979 * to be truncated. If we fail to get an orphan inode down we
4980 * could have left over extents that were never meant to live,
4981 * so we need to garuntee from this point on that everything
4982 * will be consistent.
4983 */
4984 ret = btrfs_orphan_add(trans, inode);
4985 btrfs_end_transaction(trans, root);
4986 if (ret)
4987 return ret;
4988
4989 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4990 truncate_setsize(inode, newsize);
4991
4992 /* Disable nonlocked read DIO to avoid the end less truncate */
4993 btrfs_inode_block_unlocked_dio(inode);
4994 inode_dio_wait(inode);
4995 btrfs_inode_resume_unlocked_dio(inode);
4996
4997 ret = btrfs_truncate(inode);
4998 if (ret && inode->i_nlink) {
4999 int err;
5000
5001 /*
5002 * failed to truncate, disk_i_size is only adjusted down
5003 * as we remove extents, so it should represent the true
5004 * size of the inode, so reset the in memory size and
5005 * delete our orphan entry.
5006 */
5007 trans = btrfs_join_transaction(root);
5008 if (IS_ERR(trans)) {
5009 btrfs_orphan_del(NULL, inode);
5010 return ret;
5011 }
5012 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5013 err = btrfs_orphan_del(trans, inode);
5014 if (err)
5015 btrfs_abort_transaction(trans, root, err);
5016 btrfs_end_transaction(trans, root);
5017 }
5018 }
5019
5020 return ret;
5021 }
5022
5023 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5024 {
5025 struct inode *inode = d_inode(dentry);
5026 struct btrfs_root *root = BTRFS_I(inode)->root;
5027 int err;
5028
5029 if (btrfs_root_readonly(root))
5030 return -EROFS;
5031
5032 err = inode_change_ok(inode, attr);
5033 if (err)
5034 return err;
5035
5036 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5037 err = btrfs_setsize(inode, attr);
5038 if (err)
5039 return err;
5040 }
5041
5042 if (attr->ia_valid) {
5043 setattr_copy(inode, attr);
5044 inode_inc_iversion(inode);
5045 err = btrfs_dirty_inode(inode);
5046
5047 if (!err && attr->ia_valid & ATTR_MODE)
5048 err = posix_acl_chmod(inode, inode->i_mode);
5049 }
5050
5051 return err;
5052 }
5053
5054 /*
5055 * While truncating the inode pages during eviction, we get the VFS calling
5056 * btrfs_invalidatepage() against each page of the inode. This is slow because
5057 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5058 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5059 * extent_state structures over and over, wasting lots of time.
5060 *
5061 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5062 * those expensive operations on a per page basis and do only the ordered io
5063 * finishing, while we release here the extent_map and extent_state structures,
5064 * without the excessive merging and splitting.
5065 */
5066 static void evict_inode_truncate_pages(struct inode *inode)
5067 {
5068 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5069 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5070 struct rb_node *node;
5071
5072 ASSERT(inode->i_state & I_FREEING);
5073 truncate_inode_pages_final(&inode->i_data);
5074
5075 write_lock(&map_tree->lock);
5076 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5077 struct extent_map *em;
5078
5079 node = rb_first(&map_tree->map);
5080 em = rb_entry(node, struct extent_map, rb_node);
5081 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5082 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5083 remove_extent_mapping(map_tree, em);
5084 free_extent_map(em);
5085 if (need_resched()) {
5086 write_unlock(&map_tree->lock);
5087 cond_resched();
5088 write_lock(&map_tree->lock);
5089 }
5090 }
5091 write_unlock(&map_tree->lock);
5092
5093 /*
5094 * Keep looping until we have no more ranges in the io tree.
5095 * We can have ongoing bios started by readpages (called from readahead)
5096 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5097 * still in progress (unlocked the pages in the bio but did not yet
5098 * unlocked the ranges in the io tree). Therefore this means some
5099 * ranges can still be locked and eviction started because before
5100 * submitting those bios, which are executed by a separate task (work
5101 * queue kthread), inode references (inode->i_count) were not taken
5102 * (which would be dropped in the end io callback of each bio).
5103 * Therefore here we effectively end up waiting for those bios and
5104 * anyone else holding locked ranges without having bumped the inode's
5105 * reference count - if we don't do it, when they access the inode's
5106 * io_tree to unlock a range it may be too late, leading to an
5107 * use-after-free issue.
5108 */
5109 spin_lock(&io_tree->lock);
5110 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5111 struct extent_state *state;
5112 struct extent_state *cached_state = NULL;
5113 u64 start;
5114 u64 end;
5115
5116 node = rb_first(&io_tree->state);
5117 state = rb_entry(node, struct extent_state, rb_node);
5118 start = state->start;
5119 end = state->end;
5120 spin_unlock(&io_tree->lock);
5121
5122 lock_extent_bits(io_tree, start, end, &cached_state);
5123
5124 /*
5125 * If still has DELALLOC flag, the extent didn't reach disk,
5126 * and its reserved space won't be freed by delayed_ref.
5127 * So we need to free its reserved space here.
5128 * (Refer to comment in btrfs_invalidatepage, case 2)
5129 *
5130 * Note, end is the bytenr of last byte, so we need + 1 here.
5131 */
5132 if (state->state & EXTENT_DELALLOC)
5133 btrfs_qgroup_free_data(inode, start, end - start + 1);
5134
5135 clear_extent_bit(io_tree, start, end,
5136 EXTENT_LOCKED | EXTENT_DIRTY |
5137 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5138 EXTENT_DEFRAG, 1, 1,
5139 &cached_state, GFP_NOFS);
5140
5141 cond_resched();
5142 spin_lock(&io_tree->lock);
5143 }
5144 spin_unlock(&io_tree->lock);
5145 }
5146
5147 void btrfs_evict_inode(struct inode *inode)
5148 {
5149 struct btrfs_trans_handle *trans;
5150 struct btrfs_root *root = BTRFS_I(inode)->root;
5151 struct btrfs_block_rsv *rsv, *global_rsv;
5152 int steal_from_global = 0;
5153 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5154 int ret;
5155
5156 trace_btrfs_inode_evict(inode);
5157
5158 evict_inode_truncate_pages(inode);
5159
5160 if (inode->i_nlink &&
5161 ((btrfs_root_refs(&root->root_item) != 0 &&
5162 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5163 btrfs_is_free_space_inode(inode)))
5164 goto no_delete;
5165
5166 if (is_bad_inode(inode)) {
5167 btrfs_orphan_del(NULL, inode);
5168 goto no_delete;
5169 }
5170 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5171 if (!special_file(inode->i_mode))
5172 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5173
5174 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5175
5176 if (root->fs_info->log_root_recovering) {
5177 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5178 &BTRFS_I(inode)->runtime_flags));
5179 goto no_delete;
5180 }
5181
5182 if (inode->i_nlink > 0) {
5183 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5184 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5185 goto no_delete;
5186 }
5187
5188 ret = btrfs_commit_inode_delayed_inode(inode);
5189 if (ret) {
5190 btrfs_orphan_del(NULL, inode);
5191 goto no_delete;
5192 }
5193
5194 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5195 if (!rsv) {
5196 btrfs_orphan_del(NULL, inode);
5197 goto no_delete;
5198 }
5199 rsv->size = min_size;
5200 rsv->failfast = 1;
5201 global_rsv = &root->fs_info->global_block_rsv;
5202
5203 btrfs_i_size_write(inode, 0);
5204
5205 /*
5206 * This is a bit simpler than btrfs_truncate since we've already
5207 * reserved our space for our orphan item in the unlink, so we just
5208 * need to reserve some slack space in case we add bytes and update
5209 * inode item when doing the truncate.
5210 */
5211 while (1) {
5212 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5213 BTRFS_RESERVE_FLUSH_LIMIT);
5214
5215 /*
5216 * Try and steal from the global reserve since we will
5217 * likely not use this space anyway, we want to try as
5218 * hard as possible to get this to work.
5219 */
5220 if (ret)
5221 steal_from_global++;
5222 else
5223 steal_from_global = 0;
5224 ret = 0;
5225
5226 /*
5227 * steal_from_global == 0: we reserved stuff, hooray!
5228 * steal_from_global == 1: we didn't reserve stuff, boo!
5229 * steal_from_global == 2: we've committed, still not a lot of
5230 * room but maybe we'll have room in the global reserve this
5231 * time.
5232 * steal_from_global == 3: abandon all hope!
5233 */
5234 if (steal_from_global > 2) {
5235 btrfs_warn(root->fs_info,
5236 "Could not get space for a delete, will truncate on mount %d",
5237 ret);
5238 btrfs_orphan_del(NULL, inode);
5239 btrfs_free_block_rsv(root, rsv);
5240 goto no_delete;
5241 }
5242
5243 trans = btrfs_join_transaction(root);
5244 if (IS_ERR(trans)) {
5245 btrfs_orphan_del(NULL, inode);
5246 btrfs_free_block_rsv(root, rsv);
5247 goto no_delete;
5248 }
5249
5250 /*
5251 * We can't just steal from the global reserve, we need tomake
5252 * sure there is room to do it, if not we need to commit and try
5253 * again.
5254 */
5255 if (steal_from_global) {
5256 if (!btrfs_check_space_for_delayed_refs(trans, root))
5257 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5258 min_size);
5259 else
5260 ret = -ENOSPC;
5261 }
5262
5263 /*
5264 * Couldn't steal from the global reserve, we have too much
5265 * pending stuff built up, commit the transaction and try it
5266 * again.
5267 */
5268 if (ret) {
5269 ret = btrfs_commit_transaction(trans, root);
5270 if (ret) {
5271 btrfs_orphan_del(NULL, inode);
5272 btrfs_free_block_rsv(root, rsv);
5273 goto no_delete;
5274 }
5275 continue;
5276 } else {
5277 steal_from_global = 0;
5278 }
5279
5280 trans->block_rsv = rsv;
5281
5282 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5283 if (ret != -ENOSPC && ret != -EAGAIN)
5284 break;
5285
5286 trans->block_rsv = &root->fs_info->trans_block_rsv;
5287 btrfs_end_transaction(trans, root);
5288 trans = NULL;
5289 btrfs_btree_balance_dirty(root);
5290 }
5291
5292 btrfs_free_block_rsv(root, rsv);
5293
5294 /*
5295 * Errors here aren't a big deal, it just means we leave orphan items
5296 * in the tree. They will be cleaned up on the next mount.
5297 */
5298 if (ret == 0) {
5299 trans->block_rsv = root->orphan_block_rsv;
5300 btrfs_orphan_del(trans, inode);
5301 } else {
5302 btrfs_orphan_del(NULL, inode);
5303 }
5304
5305 trans->block_rsv = &root->fs_info->trans_block_rsv;
5306 if (!(root == root->fs_info->tree_root ||
5307 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5308 btrfs_return_ino(root, btrfs_ino(inode));
5309
5310 btrfs_end_transaction(trans, root);
5311 btrfs_btree_balance_dirty(root);
5312 no_delete:
5313 btrfs_remove_delayed_node(inode);
5314 clear_inode(inode);
5315 }
5316
5317 /*
5318 * this returns the key found in the dir entry in the location pointer.
5319 * If no dir entries were found, location->objectid is 0.
5320 */
5321 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5322 struct btrfs_key *location)
5323 {
5324 const char *name = dentry->d_name.name;
5325 int namelen = dentry->d_name.len;
5326 struct btrfs_dir_item *di;
5327 struct btrfs_path *path;
5328 struct btrfs_root *root = BTRFS_I(dir)->root;
5329 int ret = 0;
5330
5331 path = btrfs_alloc_path();
5332 if (!path)
5333 return -ENOMEM;
5334
5335 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5336 namelen, 0);
5337 if (IS_ERR(di))
5338 ret = PTR_ERR(di);
5339
5340 if (IS_ERR_OR_NULL(di))
5341 goto out_err;
5342
5343 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5344 out:
5345 btrfs_free_path(path);
5346 return ret;
5347 out_err:
5348 location->objectid = 0;
5349 goto out;
5350 }
5351
5352 /*
5353 * when we hit a tree root in a directory, the btrfs part of the inode
5354 * needs to be changed to reflect the root directory of the tree root. This
5355 * is kind of like crossing a mount point.
5356 */
5357 static int fixup_tree_root_location(struct btrfs_root *root,
5358 struct inode *dir,
5359 struct dentry *dentry,
5360 struct btrfs_key *location,
5361 struct btrfs_root **sub_root)
5362 {
5363 struct btrfs_path *path;
5364 struct btrfs_root *new_root;
5365 struct btrfs_root_ref *ref;
5366 struct extent_buffer *leaf;
5367 struct btrfs_key key;
5368 int ret;
5369 int err = 0;
5370
5371 path = btrfs_alloc_path();
5372 if (!path) {
5373 err = -ENOMEM;
5374 goto out;
5375 }
5376
5377 err = -ENOENT;
5378 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5379 key.type = BTRFS_ROOT_REF_KEY;
5380 key.offset = location->objectid;
5381
5382 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5383 0, 0);
5384 if (ret) {
5385 if (ret < 0)
5386 err = ret;
5387 goto out;
5388 }
5389
5390 leaf = path->nodes[0];
5391 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5392 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5393 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5394 goto out;
5395
5396 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5397 (unsigned long)(ref + 1),
5398 dentry->d_name.len);
5399 if (ret)
5400 goto out;
5401
5402 btrfs_release_path(path);
5403
5404 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5405 if (IS_ERR(new_root)) {
5406 err = PTR_ERR(new_root);
5407 goto out;
5408 }
5409
5410 *sub_root = new_root;
5411 location->objectid = btrfs_root_dirid(&new_root->root_item);
5412 location->type = BTRFS_INODE_ITEM_KEY;
5413 location->offset = 0;
5414 err = 0;
5415 out:
5416 btrfs_free_path(path);
5417 return err;
5418 }
5419
5420 static void inode_tree_add(struct inode *inode)
5421 {
5422 struct btrfs_root *root = BTRFS_I(inode)->root;
5423 struct btrfs_inode *entry;
5424 struct rb_node **p;
5425 struct rb_node *parent;
5426 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5427 u64 ino = btrfs_ino(inode);
5428
5429 if (inode_unhashed(inode))
5430 return;
5431 parent = NULL;
5432 spin_lock(&root->inode_lock);
5433 p = &root->inode_tree.rb_node;
5434 while (*p) {
5435 parent = *p;
5436 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5437
5438 if (ino < btrfs_ino(&entry->vfs_inode))
5439 p = &parent->rb_left;
5440 else if (ino > btrfs_ino(&entry->vfs_inode))
5441 p = &parent->rb_right;
5442 else {
5443 WARN_ON(!(entry->vfs_inode.i_state &
5444 (I_WILL_FREE | I_FREEING)));
5445 rb_replace_node(parent, new, &root->inode_tree);
5446 RB_CLEAR_NODE(parent);
5447 spin_unlock(&root->inode_lock);
5448 return;
5449 }
5450 }
5451 rb_link_node(new, parent, p);
5452 rb_insert_color(new, &root->inode_tree);
5453 spin_unlock(&root->inode_lock);
5454 }
5455
5456 static void inode_tree_del(struct inode *inode)
5457 {
5458 struct btrfs_root *root = BTRFS_I(inode)->root;
5459 int empty = 0;
5460
5461 spin_lock(&root->inode_lock);
5462 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5463 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5464 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5465 empty = RB_EMPTY_ROOT(&root->inode_tree);
5466 }
5467 spin_unlock(&root->inode_lock);
5468
5469 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5470 synchronize_srcu(&root->fs_info->subvol_srcu);
5471 spin_lock(&root->inode_lock);
5472 empty = RB_EMPTY_ROOT(&root->inode_tree);
5473 spin_unlock(&root->inode_lock);
5474 if (empty)
5475 btrfs_add_dead_root(root);
5476 }
5477 }
5478
5479 void btrfs_invalidate_inodes(struct btrfs_root *root)
5480 {
5481 struct rb_node *node;
5482 struct rb_node *prev;
5483 struct btrfs_inode *entry;
5484 struct inode *inode;
5485 u64 objectid = 0;
5486
5487 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5488 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5489
5490 spin_lock(&root->inode_lock);
5491 again:
5492 node = root->inode_tree.rb_node;
5493 prev = NULL;
5494 while (node) {
5495 prev = node;
5496 entry = rb_entry(node, struct btrfs_inode, rb_node);
5497
5498 if (objectid < btrfs_ino(&entry->vfs_inode))
5499 node = node->rb_left;
5500 else if (objectid > btrfs_ino(&entry->vfs_inode))
5501 node = node->rb_right;
5502 else
5503 break;
5504 }
5505 if (!node) {
5506 while (prev) {
5507 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5508 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5509 node = prev;
5510 break;
5511 }
5512 prev = rb_next(prev);
5513 }
5514 }
5515 while (node) {
5516 entry = rb_entry(node, struct btrfs_inode, rb_node);
5517 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5518 inode = igrab(&entry->vfs_inode);
5519 if (inode) {
5520 spin_unlock(&root->inode_lock);
5521 if (atomic_read(&inode->i_count) > 1)
5522 d_prune_aliases(inode);
5523 /*
5524 * btrfs_drop_inode will have it removed from
5525 * the inode cache when its usage count
5526 * hits zero.
5527 */
5528 iput(inode);
5529 cond_resched();
5530 spin_lock(&root->inode_lock);
5531 goto again;
5532 }
5533
5534 if (cond_resched_lock(&root->inode_lock))
5535 goto again;
5536
5537 node = rb_next(node);
5538 }
5539 spin_unlock(&root->inode_lock);
5540 }
5541
5542 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5543 {
5544 struct btrfs_iget_args *args = p;
5545 inode->i_ino = args->location->objectid;
5546 memcpy(&BTRFS_I(inode)->location, args->location,
5547 sizeof(*args->location));
5548 BTRFS_I(inode)->root = args->root;
5549 return 0;
5550 }
5551
5552 static int btrfs_find_actor(struct inode *inode, void *opaque)
5553 {
5554 struct btrfs_iget_args *args = opaque;
5555 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5556 args->root == BTRFS_I(inode)->root;
5557 }
5558
5559 static struct inode *btrfs_iget_locked(struct super_block *s,
5560 struct btrfs_key *location,
5561 struct btrfs_root *root)
5562 {
5563 struct inode *inode;
5564 struct btrfs_iget_args args;
5565 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5566
5567 args.location = location;
5568 args.root = root;
5569
5570 inode = iget5_locked(s, hashval, btrfs_find_actor,
5571 btrfs_init_locked_inode,
5572 (void *)&args);
5573 return inode;
5574 }
5575
5576 /* Get an inode object given its location and corresponding root.
5577 * Returns in *is_new if the inode was read from disk
5578 */
5579 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5580 struct btrfs_root *root, int *new)
5581 {
5582 struct inode *inode;
5583
5584 inode = btrfs_iget_locked(s, location, root);
5585 if (!inode)
5586 return ERR_PTR(-ENOMEM);
5587
5588 if (inode->i_state & I_NEW) {
5589 btrfs_read_locked_inode(inode);
5590 if (!is_bad_inode(inode)) {
5591 inode_tree_add(inode);
5592 unlock_new_inode(inode);
5593 if (new)
5594 *new = 1;
5595 } else {
5596 unlock_new_inode(inode);
5597 iput(inode);
5598 inode = ERR_PTR(-ESTALE);
5599 }
5600 }
5601
5602 return inode;
5603 }
5604
5605 static struct inode *new_simple_dir(struct super_block *s,
5606 struct btrfs_key *key,
5607 struct btrfs_root *root)
5608 {
5609 struct inode *inode = new_inode(s);
5610
5611 if (!inode)
5612 return ERR_PTR(-ENOMEM);
5613
5614 BTRFS_I(inode)->root = root;
5615 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5616 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5617
5618 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5619 inode->i_op = &btrfs_dir_ro_inode_operations;
5620 inode->i_fop = &simple_dir_operations;
5621 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5622 inode->i_mtime = current_fs_time(inode->i_sb);
5623 inode->i_atime = inode->i_mtime;
5624 inode->i_ctime = inode->i_mtime;
5625 BTRFS_I(inode)->i_otime = inode->i_mtime;
5626
5627 return inode;
5628 }
5629
5630 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5631 {
5632 struct inode *inode;
5633 struct btrfs_root *root = BTRFS_I(dir)->root;
5634 struct btrfs_root *sub_root = root;
5635 struct btrfs_key location;
5636 int index;
5637 int ret = 0;
5638
5639 if (dentry->d_name.len > BTRFS_NAME_LEN)
5640 return ERR_PTR(-ENAMETOOLONG);
5641
5642 ret = btrfs_inode_by_name(dir, dentry, &location);
5643 if (ret < 0)
5644 return ERR_PTR(ret);
5645
5646 if (location.objectid == 0)
5647 return ERR_PTR(-ENOENT);
5648
5649 if (location.type == BTRFS_INODE_ITEM_KEY) {
5650 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5651 return inode;
5652 }
5653
5654 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5655
5656 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5657 ret = fixup_tree_root_location(root, dir, dentry,
5658 &location, &sub_root);
5659 if (ret < 0) {
5660 if (ret != -ENOENT)
5661 inode = ERR_PTR(ret);
5662 else
5663 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5664 } else {
5665 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5666 }
5667 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5668
5669 if (!IS_ERR(inode) && root != sub_root) {
5670 down_read(&root->fs_info->cleanup_work_sem);
5671 if (!(inode->i_sb->s_flags & MS_RDONLY))
5672 ret = btrfs_orphan_cleanup(sub_root);
5673 up_read(&root->fs_info->cleanup_work_sem);
5674 if (ret) {
5675 iput(inode);
5676 inode = ERR_PTR(ret);
5677 }
5678 }
5679
5680 return inode;
5681 }
5682
5683 static int btrfs_dentry_delete(const struct dentry *dentry)
5684 {
5685 struct btrfs_root *root;
5686 struct inode *inode = d_inode(dentry);
5687
5688 if (!inode && !IS_ROOT(dentry))
5689 inode = d_inode(dentry->d_parent);
5690
5691 if (inode) {
5692 root = BTRFS_I(inode)->root;
5693 if (btrfs_root_refs(&root->root_item) == 0)
5694 return 1;
5695
5696 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5697 return 1;
5698 }
5699 return 0;
5700 }
5701
5702 static void btrfs_dentry_release(struct dentry *dentry)
5703 {
5704 kfree(dentry->d_fsdata);
5705 }
5706
5707 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5708 unsigned int flags)
5709 {
5710 struct inode *inode;
5711
5712 inode = btrfs_lookup_dentry(dir, dentry);
5713 if (IS_ERR(inode)) {
5714 if (PTR_ERR(inode) == -ENOENT)
5715 inode = NULL;
5716 else
5717 return ERR_CAST(inode);
5718 }
5719
5720 return d_splice_alias(inode, dentry);
5721 }
5722
5723 unsigned char btrfs_filetype_table[] = {
5724 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5725 };
5726
5727 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5728 {
5729 struct inode *inode = file_inode(file);
5730 struct btrfs_root *root = BTRFS_I(inode)->root;
5731 struct btrfs_item *item;
5732 struct btrfs_dir_item *di;
5733 struct btrfs_key key;
5734 struct btrfs_key found_key;
5735 struct btrfs_path *path;
5736 struct list_head ins_list;
5737 struct list_head del_list;
5738 int ret;
5739 struct extent_buffer *leaf;
5740 int slot;
5741 unsigned char d_type;
5742 int over = 0;
5743 u32 di_cur;
5744 u32 di_total;
5745 u32 di_len;
5746 int key_type = BTRFS_DIR_INDEX_KEY;
5747 char tmp_name[32];
5748 char *name_ptr;
5749 int name_len;
5750 int is_curr = 0; /* ctx->pos points to the current index? */
5751 bool emitted;
5752
5753 /* FIXME, use a real flag for deciding about the key type */
5754 if (root->fs_info->tree_root == root)
5755 key_type = BTRFS_DIR_ITEM_KEY;
5756
5757 if (!dir_emit_dots(file, ctx))
5758 return 0;
5759
5760 path = btrfs_alloc_path();
5761 if (!path)
5762 return -ENOMEM;
5763
5764 path->reada = READA_FORWARD;
5765
5766 if (key_type == BTRFS_DIR_INDEX_KEY) {
5767 INIT_LIST_HEAD(&ins_list);
5768 INIT_LIST_HEAD(&del_list);
5769 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5770 }
5771
5772 key.type = key_type;
5773 key.offset = ctx->pos;
5774 key.objectid = btrfs_ino(inode);
5775
5776 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5777 if (ret < 0)
5778 goto err;
5779
5780 emitted = false;
5781 while (1) {
5782 leaf = path->nodes[0];
5783 slot = path->slots[0];
5784 if (slot >= btrfs_header_nritems(leaf)) {
5785 ret = btrfs_next_leaf(root, path);
5786 if (ret < 0)
5787 goto err;
5788 else if (ret > 0)
5789 break;
5790 continue;
5791 }
5792
5793 item = btrfs_item_nr(slot);
5794 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5795
5796 if (found_key.objectid != key.objectid)
5797 break;
5798 if (found_key.type != key_type)
5799 break;
5800 if (found_key.offset < ctx->pos)
5801 goto next;
5802 if (key_type == BTRFS_DIR_INDEX_KEY &&
5803 btrfs_should_delete_dir_index(&del_list,
5804 found_key.offset))
5805 goto next;
5806
5807 ctx->pos = found_key.offset;
5808 is_curr = 1;
5809
5810 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5811 di_cur = 0;
5812 di_total = btrfs_item_size(leaf, item);
5813
5814 while (di_cur < di_total) {
5815 struct btrfs_key location;
5816
5817 if (verify_dir_item(root, leaf, di))
5818 break;
5819
5820 name_len = btrfs_dir_name_len(leaf, di);
5821 if (name_len <= sizeof(tmp_name)) {
5822 name_ptr = tmp_name;
5823 } else {
5824 name_ptr = kmalloc(name_len, GFP_KERNEL);
5825 if (!name_ptr) {
5826 ret = -ENOMEM;
5827 goto err;
5828 }
5829 }
5830 read_extent_buffer(leaf, name_ptr,
5831 (unsigned long)(di + 1), name_len);
5832
5833 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5834 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5835
5836
5837 /* is this a reference to our own snapshot? If so
5838 * skip it.
5839 *
5840 * In contrast to old kernels, we insert the snapshot's
5841 * dir item and dir index after it has been created, so
5842 * we won't find a reference to our own snapshot. We
5843 * still keep the following code for backward
5844 * compatibility.
5845 */
5846 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5847 location.objectid == root->root_key.objectid) {
5848 over = 0;
5849 goto skip;
5850 }
5851 over = !dir_emit(ctx, name_ptr, name_len,
5852 location.objectid, d_type);
5853
5854 skip:
5855 if (name_ptr != tmp_name)
5856 kfree(name_ptr);
5857
5858 if (over)
5859 goto nopos;
5860 emitted = true;
5861 di_len = btrfs_dir_name_len(leaf, di) +
5862 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5863 di_cur += di_len;
5864 di = (struct btrfs_dir_item *)((char *)di + di_len);
5865 }
5866 next:
5867 path->slots[0]++;
5868 }
5869
5870 if (key_type == BTRFS_DIR_INDEX_KEY) {
5871 if (is_curr)
5872 ctx->pos++;
5873 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5874 if (ret)
5875 goto nopos;
5876 }
5877
5878 /*
5879 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5880 * it was was set to the termination value in previous call. We assume
5881 * that "." and ".." were emitted if we reach this point and set the
5882 * termination value as well for an empty directory.
5883 */
5884 if (ctx->pos > 2 && !emitted)
5885 goto nopos;
5886
5887 /* Reached end of directory/root. Bump pos past the last item. */
5888 ctx->pos++;
5889
5890 /*
5891 * Stop new entries from being returned after we return the last
5892 * entry.
5893 *
5894 * New directory entries are assigned a strictly increasing
5895 * offset. This means that new entries created during readdir
5896 * are *guaranteed* to be seen in the future by that readdir.
5897 * This has broken buggy programs which operate on names as
5898 * they're returned by readdir. Until we re-use freed offsets
5899 * we have this hack to stop new entries from being returned
5900 * under the assumption that they'll never reach this huge
5901 * offset.
5902 *
5903 * This is being careful not to overflow 32bit loff_t unless the
5904 * last entry requires it because doing so has broken 32bit apps
5905 * in the past.
5906 */
5907 if (key_type == BTRFS_DIR_INDEX_KEY) {
5908 if (ctx->pos >= INT_MAX)
5909 ctx->pos = LLONG_MAX;
5910 else
5911 ctx->pos = INT_MAX;
5912 }
5913 nopos:
5914 ret = 0;
5915 err:
5916 if (key_type == BTRFS_DIR_INDEX_KEY)
5917 btrfs_put_delayed_items(&ins_list, &del_list);
5918 btrfs_free_path(path);
5919 return ret;
5920 }
5921
5922 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5923 {
5924 struct btrfs_root *root = BTRFS_I(inode)->root;
5925 struct btrfs_trans_handle *trans;
5926 int ret = 0;
5927 bool nolock = false;
5928
5929 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5930 return 0;
5931
5932 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5933 nolock = true;
5934
5935 if (wbc->sync_mode == WB_SYNC_ALL) {
5936 if (nolock)
5937 trans = btrfs_join_transaction_nolock(root);
5938 else
5939 trans = btrfs_join_transaction(root);
5940 if (IS_ERR(trans))
5941 return PTR_ERR(trans);
5942 ret = btrfs_commit_transaction(trans, root);
5943 }
5944 return ret;
5945 }
5946
5947 /*
5948 * This is somewhat expensive, updating the tree every time the
5949 * inode changes. But, it is most likely to find the inode in cache.
5950 * FIXME, needs more benchmarking...there are no reasons other than performance
5951 * to keep or drop this code.
5952 */
5953 static int btrfs_dirty_inode(struct inode *inode)
5954 {
5955 struct btrfs_root *root = BTRFS_I(inode)->root;
5956 struct btrfs_trans_handle *trans;
5957 int ret;
5958
5959 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5960 return 0;
5961
5962 trans = btrfs_join_transaction(root);
5963 if (IS_ERR(trans))
5964 return PTR_ERR(trans);
5965
5966 ret = btrfs_update_inode(trans, root, inode);
5967 if (ret && ret == -ENOSPC) {
5968 /* whoops, lets try again with the full transaction */
5969 btrfs_end_transaction(trans, root);
5970 trans = btrfs_start_transaction(root, 1);
5971 if (IS_ERR(trans))
5972 return PTR_ERR(trans);
5973
5974 ret = btrfs_update_inode(trans, root, inode);
5975 }
5976 btrfs_end_transaction(trans, root);
5977 if (BTRFS_I(inode)->delayed_node)
5978 btrfs_balance_delayed_items(root);
5979
5980 return ret;
5981 }
5982
5983 /*
5984 * This is a copy of file_update_time. We need this so we can return error on
5985 * ENOSPC for updating the inode in the case of file write and mmap writes.
5986 */
5987 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5988 int flags)
5989 {
5990 struct btrfs_root *root = BTRFS_I(inode)->root;
5991
5992 if (btrfs_root_readonly(root))
5993 return -EROFS;
5994
5995 if (flags & S_VERSION)
5996 inode_inc_iversion(inode);
5997 if (flags & S_CTIME)
5998 inode->i_ctime = *now;
5999 if (flags & S_MTIME)
6000 inode->i_mtime = *now;
6001 if (flags & S_ATIME)
6002 inode->i_atime = *now;
6003 return btrfs_dirty_inode(inode);
6004 }
6005
6006 /*
6007 * find the highest existing sequence number in a directory
6008 * and then set the in-memory index_cnt variable to reflect
6009 * free sequence numbers
6010 */
6011 static int btrfs_set_inode_index_count(struct inode *inode)
6012 {
6013 struct btrfs_root *root = BTRFS_I(inode)->root;
6014 struct btrfs_key key, found_key;
6015 struct btrfs_path *path;
6016 struct extent_buffer *leaf;
6017 int ret;
6018
6019 key.objectid = btrfs_ino(inode);
6020 key.type = BTRFS_DIR_INDEX_KEY;
6021 key.offset = (u64)-1;
6022
6023 path = btrfs_alloc_path();
6024 if (!path)
6025 return -ENOMEM;
6026
6027 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6028 if (ret < 0)
6029 goto out;
6030 /* FIXME: we should be able to handle this */
6031 if (ret == 0)
6032 goto out;
6033 ret = 0;
6034
6035 /*
6036 * MAGIC NUMBER EXPLANATION:
6037 * since we search a directory based on f_pos we have to start at 2
6038 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6039 * else has to start at 2
6040 */
6041 if (path->slots[0] == 0) {
6042 BTRFS_I(inode)->index_cnt = 2;
6043 goto out;
6044 }
6045
6046 path->slots[0]--;
6047
6048 leaf = path->nodes[0];
6049 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6050
6051 if (found_key.objectid != btrfs_ino(inode) ||
6052 found_key.type != BTRFS_DIR_INDEX_KEY) {
6053 BTRFS_I(inode)->index_cnt = 2;
6054 goto out;
6055 }
6056
6057 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6058 out:
6059 btrfs_free_path(path);
6060 return ret;
6061 }
6062
6063 /*
6064 * helper to find a free sequence number in a given directory. This current
6065 * code is very simple, later versions will do smarter things in the btree
6066 */
6067 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6068 {
6069 int ret = 0;
6070
6071 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6072 ret = btrfs_inode_delayed_dir_index_count(dir);
6073 if (ret) {
6074 ret = btrfs_set_inode_index_count(dir);
6075 if (ret)
6076 return ret;
6077 }
6078 }
6079
6080 *index = BTRFS_I(dir)->index_cnt;
6081 BTRFS_I(dir)->index_cnt++;
6082
6083 return ret;
6084 }
6085
6086 static int btrfs_insert_inode_locked(struct inode *inode)
6087 {
6088 struct btrfs_iget_args args;
6089 args.location = &BTRFS_I(inode)->location;
6090 args.root = BTRFS_I(inode)->root;
6091
6092 return insert_inode_locked4(inode,
6093 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6094 btrfs_find_actor, &args);
6095 }
6096
6097 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6098 struct btrfs_root *root,
6099 struct inode *dir,
6100 const char *name, int name_len,
6101 u64 ref_objectid, u64 objectid,
6102 umode_t mode, u64 *index)
6103 {
6104 struct inode *inode;
6105 struct btrfs_inode_item *inode_item;
6106 struct btrfs_key *location;
6107 struct btrfs_path *path;
6108 struct btrfs_inode_ref *ref;
6109 struct btrfs_key key[2];
6110 u32 sizes[2];
6111 int nitems = name ? 2 : 1;
6112 unsigned long ptr;
6113 int ret;
6114
6115 path = btrfs_alloc_path();
6116 if (!path)
6117 return ERR_PTR(-ENOMEM);
6118
6119 inode = new_inode(root->fs_info->sb);
6120 if (!inode) {
6121 btrfs_free_path(path);
6122 return ERR_PTR(-ENOMEM);
6123 }
6124
6125 /*
6126 * O_TMPFILE, set link count to 0, so that after this point,
6127 * we fill in an inode item with the correct link count.
6128 */
6129 if (!name)
6130 set_nlink(inode, 0);
6131
6132 /*
6133 * we have to initialize this early, so we can reclaim the inode
6134 * number if we fail afterwards in this function.
6135 */
6136 inode->i_ino = objectid;
6137
6138 if (dir && name) {
6139 trace_btrfs_inode_request(dir);
6140
6141 ret = btrfs_set_inode_index(dir, index);
6142 if (ret) {
6143 btrfs_free_path(path);
6144 iput(inode);
6145 return ERR_PTR(ret);
6146 }
6147 } else if (dir) {
6148 *index = 0;
6149 }
6150 /*
6151 * index_cnt is ignored for everything but a dir,
6152 * btrfs_get_inode_index_count has an explanation for the magic
6153 * number
6154 */
6155 BTRFS_I(inode)->index_cnt = 2;
6156 BTRFS_I(inode)->dir_index = *index;
6157 BTRFS_I(inode)->root = root;
6158 BTRFS_I(inode)->generation = trans->transid;
6159 inode->i_generation = BTRFS_I(inode)->generation;
6160
6161 /*
6162 * We could have gotten an inode number from somebody who was fsynced
6163 * and then removed in this same transaction, so let's just set full
6164 * sync since it will be a full sync anyway and this will blow away the
6165 * old info in the log.
6166 */
6167 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6168
6169 key[0].objectid = objectid;
6170 key[0].type = BTRFS_INODE_ITEM_KEY;
6171 key[0].offset = 0;
6172
6173 sizes[0] = sizeof(struct btrfs_inode_item);
6174
6175 if (name) {
6176 /*
6177 * Start new inodes with an inode_ref. This is slightly more
6178 * efficient for small numbers of hard links since they will
6179 * be packed into one item. Extended refs will kick in if we
6180 * add more hard links than can fit in the ref item.
6181 */
6182 key[1].objectid = objectid;
6183 key[1].type = BTRFS_INODE_REF_KEY;
6184 key[1].offset = ref_objectid;
6185
6186 sizes[1] = name_len + sizeof(*ref);
6187 }
6188
6189 location = &BTRFS_I(inode)->location;
6190 location->objectid = objectid;
6191 location->offset = 0;
6192 location->type = BTRFS_INODE_ITEM_KEY;
6193
6194 ret = btrfs_insert_inode_locked(inode);
6195 if (ret < 0)
6196 goto fail;
6197
6198 path->leave_spinning = 1;
6199 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6200 if (ret != 0)
6201 goto fail_unlock;
6202
6203 inode_init_owner(inode, dir, mode);
6204 inode_set_bytes(inode, 0);
6205
6206 inode->i_mtime = current_fs_time(inode->i_sb);
6207 inode->i_atime = inode->i_mtime;
6208 inode->i_ctime = inode->i_mtime;
6209 BTRFS_I(inode)->i_otime = inode->i_mtime;
6210
6211 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6212 struct btrfs_inode_item);
6213 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6214 sizeof(*inode_item));
6215 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6216
6217 if (name) {
6218 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6219 struct btrfs_inode_ref);
6220 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6221 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6222 ptr = (unsigned long)(ref + 1);
6223 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6224 }
6225
6226 btrfs_mark_buffer_dirty(path->nodes[0]);
6227 btrfs_free_path(path);
6228
6229 btrfs_inherit_iflags(inode, dir);
6230
6231 if (S_ISREG(mode)) {
6232 if (btrfs_test_opt(root, NODATASUM))
6233 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6234 if (btrfs_test_opt(root, NODATACOW))
6235 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6236 BTRFS_INODE_NODATASUM;
6237 }
6238
6239 inode_tree_add(inode);
6240
6241 trace_btrfs_inode_new(inode);
6242 btrfs_set_inode_last_trans(trans, inode);
6243
6244 btrfs_update_root_times(trans, root);
6245
6246 ret = btrfs_inode_inherit_props(trans, inode, dir);
6247 if (ret)
6248 btrfs_err(root->fs_info,
6249 "error inheriting props for ino %llu (root %llu): %d",
6250 btrfs_ino(inode), root->root_key.objectid, ret);
6251
6252 return inode;
6253
6254 fail_unlock:
6255 unlock_new_inode(inode);
6256 fail:
6257 if (dir && name)
6258 BTRFS_I(dir)->index_cnt--;
6259 btrfs_free_path(path);
6260 iput(inode);
6261 return ERR_PTR(ret);
6262 }
6263
6264 static inline u8 btrfs_inode_type(struct inode *inode)
6265 {
6266 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6267 }
6268
6269 /*
6270 * utility function to add 'inode' into 'parent_inode' with
6271 * a give name and a given sequence number.
6272 * if 'add_backref' is true, also insert a backref from the
6273 * inode to the parent directory.
6274 */
6275 int btrfs_add_link(struct btrfs_trans_handle *trans,
6276 struct inode *parent_inode, struct inode *inode,
6277 const char *name, int name_len, int add_backref, u64 index)
6278 {
6279 int ret = 0;
6280 struct btrfs_key key;
6281 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6282 u64 ino = btrfs_ino(inode);
6283 u64 parent_ino = btrfs_ino(parent_inode);
6284
6285 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6286 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6287 } else {
6288 key.objectid = ino;
6289 key.type = BTRFS_INODE_ITEM_KEY;
6290 key.offset = 0;
6291 }
6292
6293 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6294 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6295 key.objectid, root->root_key.objectid,
6296 parent_ino, index, name, name_len);
6297 } else if (add_backref) {
6298 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6299 parent_ino, index);
6300 }
6301
6302 /* Nothing to clean up yet */
6303 if (ret)
6304 return ret;
6305
6306 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6307 parent_inode, &key,
6308 btrfs_inode_type(inode), index);
6309 if (ret == -EEXIST || ret == -EOVERFLOW)
6310 goto fail_dir_item;
6311 else if (ret) {
6312 btrfs_abort_transaction(trans, root, ret);
6313 return ret;
6314 }
6315
6316 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6317 name_len * 2);
6318 inode_inc_iversion(parent_inode);
6319 parent_inode->i_mtime = parent_inode->i_ctime =
6320 current_fs_time(parent_inode->i_sb);
6321 ret = btrfs_update_inode(trans, root, parent_inode);
6322 if (ret)
6323 btrfs_abort_transaction(trans, root, ret);
6324 return ret;
6325
6326 fail_dir_item:
6327 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6328 u64 local_index;
6329 int err;
6330 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6331 key.objectid, root->root_key.objectid,
6332 parent_ino, &local_index, name, name_len);
6333
6334 } else if (add_backref) {
6335 u64 local_index;
6336 int err;
6337
6338 err = btrfs_del_inode_ref(trans, root, name, name_len,
6339 ino, parent_ino, &local_index);
6340 }
6341 return ret;
6342 }
6343
6344 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6345 struct inode *dir, struct dentry *dentry,
6346 struct inode *inode, int backref, u64 index)
6347 {
6348 int err = btrfs_add_link(trans, dir, inode,
6349 dentry->d_name.name, dentry->d_name.len,
6350 backref, index);
6351 if (err > 0)
6352 err = -EEXIST;
6353 return err;
6354 }
6355
6356 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6357 umode_t mode, dev_t rdev)
6358 {
6359 struct btrfs_trans_handle *trans;
6360 struct btrfs_root *root = BTRFS_I(dir)->root;
6361 struct inode *inode = NULL;
6362 int err;
6363 int drop_inode = 0;
6364 u64 objectid;
6365 u64 index = 0;
6366
6367 /*
6368 * 2 for inode item and ref
6369 * 2 for dir items
6370 * 1 for xattr if selinux is on
6371 */
6372 trans = btrfs_start_transaction(root, 5);
6373 if (IS_ERR(trans))
6374 return PTR_ERR(trans);
6375
6376 err = btrfs_find_free_ino(root, &objectid);
6377 if (err)
6378 goto out_unlock;
6379
6380 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6381 dentry->d_name.len, btrfs_ino(dir), objectid,
6382 mode, &index);
6383 if (IS_ERR(inode)) {
6384 err = PTR_ERR(inode);
6385 goto out_unlock;
6386 }
6387
6388 /*
6389 * If the active LSM wants to access the inode during
6390 * d_instantiate it needs these. Smack checks to see
6391 * if the filesystem supports xattrs by looking at the
6392 * ops vector.
6393 */
6394 inode->i_op = &btrfs_special_inode_operations;
6395 init_special_inode(inode, inode->i_mode, rdev);
6396
6397 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6398 if (err)
6399 goto out_unlock_inode;
6400
6401 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6402 if (err) {
6403 goto out_unlock_inode;
6404 } else {
6405 btrfs_update_inode(trans, root, inode);
6406 unlock_new_inode(inode);
6407 d_instantiate(dentry, inode);
6408 }
6409
6410 out_unlock:
6411 btrfs_end_transaction(trans, root);
6412 btrfs_balance_delayed_items(root);
6413 btrfs_btree_balance_dirty(root);
6414 if (drop_inode) {
6415 inode_dec_link_count(inode);
6416 iput(inode);
6417 }
6418 return err;
6419
6420 out_unlock_inode:
6421 drop_inode = 1;
6422 unlock_new_inode(inode);
6423 goto out_unlock;
6424
6425 }
6426
6427 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6428 umode_t mode, bool excl)
6429 {
6430 struct btrfs_trans_handle *trans;
6431 struct btrfs_root *root = BTRFS_I(dir)->root;
6432 struct inode *inode = NULL;
6433 int drop_inode_on_err = 0;
6434 int err;
6435 u64 objectid;
6436 u64 index = 0;
6437
6438 /*
6439 * 2 for inode item and ref
6440 * 2 for dir items
6441 * 1 for xattr if selinux is on
6442 */
6443 trans = btrfs_start_transaction(root, 5);
6444 if (IS_ERR(trans))
6445 return PTR_ERR(trans);
6446
6447 err = btrfs_find_free_ino(root, &objectid);
6448 if (err)
6449 goto out_unlock;
6450
6451 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6452 dentry->d_name.len, btrfs_ino(dir), objectid,
6453 mode, &index);
6454 if (IS_ERR(inode)) {
6455 err = PTR_ERR(inode);
6456 goto out_unlock;
6457 }
6458 drop_inode_on_err = 1;
6459 /*
6460 * If the active LSM wants to access the inode during
6461 * d_instantiate it needs these. Smack checks to see
6462 * if the filesystem supports xattrs by looking at the
6463 * ops vector.
6464 */
6465 inode->i_fop = &btrfs_file_operations;
6466 inode->i_op = &btrfs_file_inode_operations;
6467 inode->i_mapping->a_ops = &btrfs_aops;
6468
6469 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6470 if (err)
6471 goto out_unlock_inode;
6472
6473 err = btrfs_update_inode(trans, root, inode);
6474 if (err)
6475 goto out_unlock_inode;
6476
6477 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6478 if (err)
6479 goto out_unlock_inode;
6480
6481 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6482 unlock_new_inode(inode);
6483 d_instantiate(dentry, inode);
6484
6485 out_unlock:
6486 btrfs_end_transaction(trans, root);
6487 if (err && drop_inode_on_err) {
6488 inode_dec_link_count(inode);
6489 iput(inode);
6490 }
6491 btrfs_balance_delayed_items(root);
6492 btrfs_btree_balance_dirty(root);
6493 return err;
6494
6495 out_unlock_inode:
6496 unlock_new_inode(inode);
6497 goto out_unlock;
6498
6499 }
6500
6501 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6502 struct dentry *dentry)
6503 {
6504 struct btrfs_trans_handle *trans = NULL;
6505 struct btrfs_root *root = BTRFS_I(dir)->root;
6506 struct inode *inode = d_inode(old_dentry);
6507 u64 index;
6508 int err;
6509 int drop_inode = 0;
6510
6511 /* do not allow sys_link's with other subvols of the same device */
6512 if (root->objectid != BTRFS_I(inode)->root->objectid)
6513 return -EXDEV;
6514
6515 if (inode->i_nlink >= BTRFS_LINK_MAX)
6516 return -EMLINK;
6517
6518 err = btrfs_set_inode_index(dir, &index);
6519 if (err)
6520 goto fail;
6521
6522 /*
6523 * 2 items for inode and inode ref
6524 * 2 items for dir items
6525 * 1 item for parent inode
6526 */
6527 trans = btrfs_start_transaction(root, 5);
6528 if (IS_ERR(trans)) {
6529 err = PTR_ERR(trans);
6530 trans = NULL;
6531 goto fail;
6532 }
6533
6534 /* There are several dir indexes for this inode, clear the cache. */
6535 BTRFS_I(inode)->dir_index = 0ULL;
6536 inc_nlink(inode);
6537 inode_inc_iversion(inode);
6538 inode->i_ctime = current_fs_time(inode->i_sb);
6539 ihold(inode);
6540 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6541
6542 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6543
6544 if (err) {
6545 drop_inode = 1;
6546 } else {
6547 struct dentry *parent = dentry->d_parent;
6548 err = btrfs_update_inode(trans, root, inode);
6549 if (err)
6550 goto fail;
6551 if (inode->i_nlink == 1) {
6552 /*
6553 * If new hard link count is 1, it's a file created
6554 * with open(2) O_TMPFILE flag.
6555 */
6556 err = btrfs_orphan_del(trans, inode);
6557 if (err)
6558 goto fail;
6559 }
6560 d_instantiate(dentry, inode);
6561 btrfs_log_new_name(trans, inode, NULL, parent);
6562 }
6563
6564 btrfs_balance_delayed_items(root);
6565 fail:
6566 if (trans)
6567 btrfs_end_transaction(trans, root);
6568 if (drop_inode) {
6569 inode_dec_link_count(inode);
6570 iput(inode);
6571 }
6572 btrfs_btree_balance_dirty(root);
6573 return err;
6574 }
6575
6576 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6577 {
6578 struct inode *inode = NULL;
6579 struct btrfs_trans_handle *trans;
6580 struct btrfs_root *root = BTRFS_I(dir)->root;
6581 int err = 0;
6582 int drop_on_err = 0;
6583 u64 objectid = 0;
6584 u64 index = 0;
6585
6586 /*
6587 * 2 items for inode and ref
6588 * 2 items for dir items
6589 * 1 for xattr if selinux is on
6590 */
6591 trans = btrfs_start_transaction(root, 5);
6592 if (IS_ERR(trans))
6593 return PTR_ERR(trans);
6594
6595 err = btrfs_find_free_ino(root, &objectid);
6596 if (err)
6597 goto out_fail;
6598
6599 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6600 dentry->d_name.len, btrfs_ino(dir), objectid,
6601 S_IFDIR | mode, &index);
6602 if (IS_ERR(inode)) {
6603 err = PTR_ERR(inode);
6604 goto out_fail;
6605 }
6606
6607 drop_on_err = 1;
6608 /* these must be set before we unlock the inode */
6609 inode->i_op = &btrfs_dir_inode_operations;
6610 inode->i_fop = &btrfs_dir_file_operations;
6611
6612 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6613 if (err)
6614 goto out_fail_inode;
6615
6616 btrfs_i_size_write(inode, 0);
6617 err = btrfs_update_inode(trans, root, inode);
6618 if (err)
6619 goto out_fail_inode;
6620
6621 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6622 dentry->d_name.len, 0, index);
6623 if (err)
6624 goto out_fail_inode;
6625
6626 d_instantiate(dentry, inode);
6627 /*
6628 * mkdir is special. We're unlocking after we call d_instantiate
6629 * to avoid a race with nfsd calling d_instantiate.
6630 */
6631 unlock_new_inode(inode);
6632 drop_on_err = 0;
6633
6634 out_fail:
6635 btrfs_end_transaction(trans, root);
6636 if (drop_on_err) {
6637 inode_dec_link_count(inode);
6638 iput(inode);
6639 }
6640 btrfs_balance_delayed_items(root);
6641 btrfs_btree_balance_dirty(root);
6642 return err;
6643
6644 out_fail_inode:
6645 unlock_new_inode(inode);
6646 goto out_fail;
6647 }
6648
6649 /* Find next extent map of a given extent map, caller needs to ensure locks */
6650 static struct extent_map *next_extent_map(struct extent_map *em)
6651 {
6652 struct rb_node *next;
6653
6654 next = rb_next(&em->rb_node);
6655 if (!next)
6656 return NULL;
6657 return container_of(next, struct extent_map, rb_node);
6658 }
6659
6660 static struct extent_map *prev_extent_map(struct extent_map *em)
6661 {
6662 struct rb_node *prev;
6663
6664 prev = rb_prev(&em->rb_node);
6665 if (!prev)
6666 return NULL;
6667 return container_of(prev, struct extent_map, rb_node);
6668 }
6669
6670 /* helper for btfs_get_extent. Given an existing extent in the tree,
6671 * the existing extent is the nearest extent to map_start,
6672 * and an extent that you want to insert, deal with overlap and insert
6673 * the best fitted new extent into the tree.
6674 */
6675 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6676 struct extent_map *existing,
6677 struct extent_map *em,
6678 u64 map_start)
6679 {
6680 struct extent_map *prev;
6681 struct extent_map *next;
6682 u64 start;
6683 u64 end;
6684 u64 start_diff;
6685
6686 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6687
6688 if (existing->start > map_start) {
6689 next = existing;
6690 prev = prev_extent_map(next);
6691 } else {
6692 prev = existing;
6693 next = next_extent_map(prev);
6694 }
6695
6696 start = prev ? extent_map_end(prev) : em->start;
6697 start = max_t(u64, start, em->start);
6698 end = next ? next->start : extent_map_end(em);
6699 end = min_t(u64, end, extent_map_end(em));
6700 start_diff = start - em->start;
6701 em->start = start;
6702 em->len = end - start;
6703 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6704 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6705 em->block_start += start_diff;
6706 em->block_len -= start_diff;
6707 }
6708 return add_extent_mapping(em_tree, em, 0);
6709 }
6710
6711 static noinline int uncompress_inline(struct btrfs_path *path,
6712 struct page *page,
6713 size_t pg_offset, u64 extent_offset,
6714 struct btrfs_file_extent_item *item)
6715 {
6716 int ret;
6717 struct extent_buffer *leaf = path->nodes[0];
6718 char *tmp;
6719 size_t max_size;
6720 unsigned long inline_size;
6721 unsigned long ptr;
6722 int compress_type;
6723
6724 WARN_ON(pg_offset != 0);
6725 compress_type = btrfs_file_extent_compression(leaf, item);
6726 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6727 inline_size = btrfs_file_extent_inline_item_len(leaf,
6728 btrfs_item_nr(path->slots[0]));
6729 tmp = kmalloc(inline_size, GFP_NOFS);
6730 if (!tmp)
6731 return -ENOMEM;
6732 ptr = btrfs_file_extent_inline_start(item);
6733
6734 read_extent_buffer(leaf, tmp, ptr, inline_size);
6735
6736 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6737 ret = btrfs_decompress(compress_type, tmp, page,
6738 extent_offset, inline_size, max_size);
6739 kfree(tmp);
6740 return ret;
6741 }
6742
6743 /*
6744 * a bit scary, this does extent mapping from logical file offset to the disk.
6745 * the ugly parts come from merging extents from the disk with the in-ram
6746 * representation. This gets more complex because of the data=ordered code,
6747 * where the in-ram extents might be locked pending data=ordered completion.
6748 *
6749 * This also copies inline extents directly into the page.
6750 */
6751
6752 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6753 size_t pg_offset, u64 start, u64 len,
6754 int create)
6755 {
6756 int ret;
6757 int err = 0;
6758 u64 extent_start = 0;
6759 u64 extent_end = 0;
6760 u64 objectid = btrfs_ino(inode);
6761 u32 found_type;
6762 struct btrfs_path *path = NULL;
6763 struct btrfs_root *root = BTRFS_I(inode)->root;
6764 struct btrfs_file_extent_item *item;
6765 struct extent_buffer *leaf;
6766 struct btrfs_key found_key;
6767 struct extent_map *em = NULL;
6768 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6769 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6770 struct btrfs_trans_handle *trans = NULL;
6771 const bool new_inline = !page || create;
6772
6773 again:
6774 read_lock(&em_tree->lock);
6775 em = lookup_extent_mapping(em_tree, start, len);
6776 if (em)
6777 em->bdev = root->fs_info->fs_devices->latest_bdev;
6778 read_unlock(&em_tree->lock);
6779
6780 if (em) {
6781 if (em->start > start || em->start + em->len <= start)
6782 free_extent_map(em);
6783 else if (em->block_start == EXTENT_MAP_INLINE && page)
6784 free_extent_map(em);
6785 else
6786 goto out;
6787 }
6788 em = alloc_extent_map();
6789 if (!em) {
6790 err = -ENOMEM;
6791 goto out;
6792 }
6793 em->bdev = root->fs_info->fs_devices->latest_bdev;
6794 em->start = EXTENT_MAP_HOLE;
6795 em->orig_start = EXTENT_MAP_HOLE;
6796 em->len = (u64)-1;
6797 em->block_len = (u64)-1;
6798
6799 if (!path) {
6800 path = btrfs_alloc_path();
6801 if (!path) {
6802 err = -ENOMEM;
6803 goto out;
6804 }
6805 /*
6806 * Chances are we'll be called again, so go ahead and do
6807 * readahead
6808 */
6809 path->reada = READA_FORWARD;
6810 }
6811
6812 ret = btrfs_lookup_file_extent(trans, root, path,
6813 objectid, start, trans != NULL);
6814 if (ret < 0) {
6815 err = ret;
6816 goto out;
6817 }
6818
6819 if (ret != 0) {
6820 if (path->slots[0] == 0)
6821 goto not_found;
6822 path->slots[0]--;
6823 }
6824
6825 leaf = path->nodes[0];
6826 item = btrfs_item_ptr(leaf, path->slots[0],
6827 struct btrfs_file_extent_item);
6828 /* are we inside the extent that was found? */
6829 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6830 found_type = found_key.type;
6831 if (found_key.objectid != objectid ||
6832 found_type != BTRFS_EXTENT_DATA_KEY) {
6833 /*
6834 * If we backup past the first extent we want to move forward
6835 * and see if there is an extent in front of us, otherwise we'll
6836 * say there is a hole for our whole search range which can
6837 * cause problems.
6838 */
6839 extent_end = start;
6840 goto next;
6841 }
6842
6843 found_type = btrfs_file_extent_type(leaf, item);
6844 extent_start = found_key.offset;
6845 if (found_type == BTRFS_FILE_EXTENT_REG ||
6846 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6847 extent_end = extent_start +
6848 btrfs_file_extent_num_bytes(leaf, item);
6849 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6850 size_t size;
6851 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6852 extent_end = ALIGN(extent_start + size, root->sectorsize);
6853 }
6854 next:
6855 if (start >= extent_end) {
6856 path->slots[0]++;
6857 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6858 ret = btrfs_next_leaf(root, path);
6859 if (ret < 0) {
6860 err = ret;
6861 goto out;
6862 }
6863 if (ret > 0)
6864 goto not_found;
6865 leaf = path->nodes[0];
6866 }
6867 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6868 if (found_key.objectid != objectid ||
6869 found_key.type != BTRFS_EXTENT_DATA_KEY)
6870 goto not_found;
6871 if (start + len <= found_key.offset)
6872 goto not_found;
6873 if (start > found_key.offset)
6874 goto next;
6875 em->start = start;
6876 em->orig_start = start;
6877 em->len = found_key.offset - start;
6878 goto not_found_em;
6879 }
6880
6881 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6882
6883 if (found_type == BTRFS_FILE_EXTENT_REG ||
6884 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6885 goto insert;
6886 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6887 unsigned long ptr;
6888 char *map;
6889 size_t size;
6890 size_t extent_offset;
6891 size_t copy_size;
6892
6893 if (new_inline)
6894 goto out;
6895
6896 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6897 extent_offset = page_offset(page) + pg_offset - extent_start;
6898 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6899 size - extent_offset);
6900 em->start = extent_start + extent_offset;
6901 em->len = ALIGN(copy_size, root->sectorsize);
6902 em->orig_block_len = em->len;
6903 em->orig_start = em->start;
6904 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6905 if (create == 0 && !PageUptodate(page)) {
6906 if (btrfs_file_extent_compression(leaf, item) !=
6907 BTRFS_COMPRESS_NONE) {
6908 ret = uncompress_inline(path, page, pg_offset,
6909 extent_offset, item);
6910 if (ret) {
6911 err = ret;
6912 goto out;
6913 }
6914 } else {
6915 map = kmap(page);
6916 read_extent_buffer(leaf, map + pg_offset, ptr,
6917 copy_size);
6918 if (pg_offset + copy_size < PAGE_SIZE) {
6919 memset(map + pg_offset + copy_size, 0,
6920 PAGE_SIZE - pg_offset -
6921 copy_size);
6922 }
6923 kunmap(page);
6924 }
6925 flush_dcache_page(page);
6926 } else if (create && PageUptodate(page)) {
6927 BUG();
6928 if (!trans) {
6929 kunmap(page);
6930 free_extent_map(em);
6931 em = NULL;
6932
6933 btrfs_release_path(path);
6934 trans = btrfs_join_transaction(root);
6935
6936 if (IS_ERR(trans))
6937 return ERR_CAST(trans);
6938 goto again;
6939 }
6940 map = kmap(page);
6941 write_extent_buffer(leaf, map + pg_offset, ptr,
6942 copy_size);
6943 kunmap(page);
6944 btrfs_mark_buffer_dirty(leaf);
6945 }
6946 set_extent_uptodate(io_tree, em->start,
6947 extent_map_end(em) - 1, NULL, GFP_NOFS);
6948 goto insert;
6949 }
6950 not_found:
6951 em->start = start;
6952 em->orig_start = start;
6953 em->len = len;
6954 not_found_em:
6955 em->block_start = EXTENT_MAP_HOLE;
6956 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6957 insert:
6958 btrfs_release_path(path);
6959 if (em->start > start || extent_map_end(em) <= start) {
6960 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6961 em->start, em->len, start, len);
6962 err = -EIO;
6963 goto out;
6964 }
6965
6966 err = 0;
6967 write_lock(&em_tree->lock);
6968 ret = add_extent_mapping(em_tree, em, 0);
6969 /* it is possible that someone inserted the extent into the tree
6970 * while we had the lock dropped. It is also possible that
6971 * an overlapping map exists in the tree
6972 */
6973 if (ret == -EEXIST) {
6974 struct extent_map *existing;
6975
6976 ret = 0;
6977
6978 existing = search_extent_mapping(em_tree, start, len);
6979 /*
6980 * existing will always be non-NULL, since there must be
6981 * extent causing the -EEXIST.
6982 */
6983 if (start >= extent_map_end(existing) ||
6984 start <= existing->start) {
6985 /*
6986 * The existing extent map is the one nearest to
6987 * the [start, start + len) range which overlaps
6988 */
6989 err = merge_extent_mapping(em_tree, existing,
6990 em, start);
6991 free_extent_map(existing);
6992 if (err) {
6993 free_extent_map(em);
6994 em = NULL;
6995 }
6996 } else {
6997 free_extent_map(em);
6998 em = existing;
6999 err = 0;
7000 }
7001 }
7002 write_unlock(&em_tree->lock);
7003 out:
7004
7005 trace_btrfs_get_extent(root, em);
7006
7007 btrfs_free_path(path);
7008 if (trans) {
7009 ret = btrfs_end_transaction(trans, root);
7010 if (!err)
7011 err = ret;
7012 }
7013 if (err) {
7014 free_extent_map(em);
7015 return ERR_PTR(err);
7016 }
7017 BUG_ON(!em); /* Error is always set */
7018 return em;
7019 }
7020
7021 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7022 size_t pg_offset, u64 start, u64 len,
7023 int create)
7024 {
7025 struct extent_map *em;
7026 struct extent_map *hole_em = NULL;
7027 u64 range_start = start;
7028 u64 end;
7029 u64 found;
7030 u64 found_end;
7031 int err = 0;
7032
7033 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7034 if (IS_ERR(em))
7035 return em;
7036 if (em) {
7037 /*
7038 * if our em maps to
7039 * - a hole or
7040 * - a pre-alloc extent,
7041 * there might actually be delalloc bytes behind it.
7042 */
7043 if (em->block_start != EXTENT_MAP_HOLE &&
7044 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7045 return em;
7046 else
7047 hole_em = em;
7048 }
7049
7050 /* check to see if we've wrapped (len == -1 or similar) */
7051 end = start + len;
7052 if (end < start)
7053 end = (u64)-1;
7054 else
7055 end -= 1;
7056
7057 em = NULL;
7058
7059 /* ok, we didn't find anything, lets look for delalloc */
7060 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7061 end, len, EXTENT_DELALLOC, 1);
7062 found_end = range_start + found;
7063 if (found_end < range_start)
7064 found_end = (u64)-1;
7065
7066 /*
7067 * we didn't find anything useful, return
7068 * the original results from get_extent()
7069 */
7070 if (range_start > end || found_end <= start) {
7071 em = hole_em;
7072 hole_em = NULL;
7073 goto out;
7074 }
7075
7076 /* adjust the range_start to make sure it doesn't
7077 * go backwards from the start they passed in
7078 */
7079 range_start = max(start, range_start);
7080 found = found_end - range_start;
7081
7082 if (found > 0) {
7083 u64 hole_start = start;
7084 u64 hole_len = len;
7085
7086 em = alloc_extent_map();
7087 if (!em) {
7088 err = -ENOMEM;
7089 goto out;
7090 }
7091 /*
7092 * when btrfs_get_extent can't find anything it
7093 * returns one huge hole
7094 *
7095 * make sure what it found really fits our range, and
7096 * adjust to make sure it is based on the start from
7097 * the caller
7098 */
7099 if (hole_em) {
7100 u64 calc_end = extent_map_end(hole_em);
7101
7102 if (calc_end <= start || (hole_em->start > end)) {
7103 free_extent_map(hole_em);
7104 hole_em = NULL;
7105 } else {
7106 hole_start = max(hole_em->start, start);
7107 hole_len = calc_end - hole_start;
7108 }
7109 }
7110 em->bdev = NULL;
7111 if (hole_em && range_start > hole_start) {
7112 /* our hole starts before our delalloc, so we
7113 * have to return just the parts of the hole
7114 * that go until the delalloc starts
7115 */
7116 em->len = min(hole_len,
7117 range_start - hole_start);
7118 em->start = hole_start;
7119 em->orig_start = hole_start;
7120 /*
7121 * don't adjust block start at all,
7122 * it is fixed at EXTENT_MAP_HOLE
7123 */
7124 em->block_start = hole_em->block_start;
7125 em->block_len = hole_len;
7126 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7127 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7128 } else {
7129 em->start = range_start;
7130 em->len = found;
7131 em->orig_start = range_start;
7132 em->block_start = EXTENT_MAP_DELALLOC;
7133 em->block_len = found;
7134 }
7135 } else if (hole_em) {
7136 return hole_em;
7137 }
7138 out:
7139
7140 free_extent_map(hole_em);
7141 if (err) {
7142 free_extent_map(em);
7143 return ERR_PTR(err);
7144 }
7145 return em;
7146 }
7147
7148 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7149 const u64 start,
7150 const u64 len,
7151 const u64 orig_start,
7152 const u64 block_start,
7153 const u64 block_len,
7154 const u64 orig_block_len,
7155 const u64 ram_bytes,
7156 const int type)
7157 {
7158 struct extent_map *em = NULL;
7159 int ret;
7160
7161 down_read(&BTRFS_I(inode)->dio_sem);
7162 if (type != BTRFS_ORDERED_NOCOW) {
7163 em = create_pinned_em(inode, start, len, orig_start,
7164 block_start, block_len, orig_block_len,
7165 ram_bytes, type);
7166 if (IS_ERR(em))
7167 goto out;
7168 }
7169 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7170 len, block_len, type);
7171 if (ret) {
7172 if (em) {
7173 free_extent_map(em);
7174 btrfs_drop_extent_cache(inode, start,
7175 start + len - 1, 0);
7176 }
7177 em = ERR_PTR(ret);
7178 }
7179 out:
7180 up_read(&BTRFS_I(inode)->dio_sem);
7181
7182 return em;
7183 }
7184
7185 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7186 u64 start, u64 len)
7187 {
7188 struct btrfs_root *root = BTRFS_I(inode)->root;
7189 struct extent_map *em;
7190 struct btrfs_key ins;
7191 u64 alloc_hint;
7192 int ret;
7193
7194 alloc_hint = get_extent_allocation_hint(inode, start, len);
7195 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7196 alloc_hint, &ins, 1, 1);
7197 if (ret)
7198 return ERR_PTR(ret);
7199
7200 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7201 ins.objectid, ins.offset, ins.offset,
7202 ins.offset, 0);
7203 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7204 if (IS_ERR(em))
7205 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7206
7207 return em;
7208 }
7209
7210 /*
7211 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7212 * block must be cow'd
7213 */
7214 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7215 u64 *orig_start, u64 *orig_block_len,
7216 u64 *ram_bytes)
7217 {
7218 struct btrfs_trans_handle *trans;
7219 struct btrfs_path *path;
7220 int ret;
7221 struct extent_buffer *leaf;
7222 struct btrfs_root *root = BTRFS_I(inode)->root;
7223 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7224 struct btrfs_file_extent_item *fi;
7225 struct btrfs_key key;
7226 u64 disk_bytenr;
7227 u64 backref_offset;
7228 u64 extent_end;
7229 u64 num_bytes;
7230 int slot;
7231 int found_type;
7232 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7233
7234 path = btrfs_alloc_path();
7235 if (!path)
7236 return -ENOMEM;
7237
7238 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7239 offset, 0);
7240 if (ret < 0)
7241 goto out;
7242
7243 slot = path->slots[0];
7244 if (ret == 1) {
7245 if (slot == 0) {
7246 /* can't find the item, must cow */
7247 ret = 0;
7248 goto out;
7249 }
7250 slot--;
7251 }
7252 ret = 0;
7253 leaf = path->nodes[0];
7254 btrfs_item_key_to_cpu(leaf, &key, slot);
7255 if (key.objectid != btrfs_ino(inode) ||
7256 key.type != BTRFS_EXTENT_DATA_KEY) {
7257 /* not our file or wrong item type, must cow */
7258 goto out;
7259 }
7260
7261 if (key.offset > offset) {
7262 /* Wrong offset, must cow */
7263 goto out;
7264 }
7265
7266 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7267 found_type = btrfs_file_extent_type(leaf, fi);
7268 if (found_type != BTRFS_FILE_EXTENT_REG &&
7269 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7270 /* not a regular extent, must cow */
7271 goto out;
7272 }
7273
7274 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7275 goto out;
7276
7277 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7278 if (extent_end <= offset)
7279 goto out;
7280
7281 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7282 if (disk_bytenr == 0)
7283 goto out;
7284
7285 if (btrfs_file_extent_compression(leaf, fi) ||
7286 btrfs_file_extent_encryption(leaf, fi) ||
7287 btrfs_file_extent_other_encoding(leaf, fi))
7288 goto out;
7289
7290 backref_offset = btrfs_file_extent_offset(leaf, fi);
7291
7292 if (orig_start) {
7293 *orig_start = key.offset - backref_offset;
7294 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7295 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7296 }
7297
7298 if (btrfs_extent_readonly(root, disk_bytenr))
7299 goto out;
7300
7301 num_bytes = min(offset + *len, extent_end) - offset;
7302 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7303 u64 range_end;
7304
7305 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7306 ret = test_range_bit(io_tree, offset, range_end,
7307 EXTENT_DELALLOC, 0, NULL);
7308 if (ret) {
7309 ret = -EAGAIN;
7310 goto out;
7311 }
7312 }
7313
7314 btrfs_release_path(path);
7315
7316 /*
7317 * look for other files referencing this extent, if we
7318 * find any we must cow
7319 */
7320 trans = btrfs_join_transaction(root);
7321 if (IS_ERR(trans)) {
7322 ret = 0;
7323 goto out;
7324 }
7325
7326 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7327 key.offset - backref_offset, disk_bytenr);
7328 btrfs_end_transaction(trans, root);
7329 if (ret) {
7330 ret = 0;
7331 goto out;
7332 }
7333
7334 /*
7335 * adjust disk_bytenr and num_bytes to cover just the bytes
7336 * in this extent we are about to write. If there
7337 * are any csums in that range we have to cow in order
7338 * to keep the csums correct
7339 */
7340 disk_bytenr += backref_offset;
7341 disk_bytenr += offset - key.offset;
7342 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7343 goto out;
7344 /*
7345 * all of the above have passed, it is safe to overwrite this extent
7346 * without cow
7347 */
7348 *len = num_bytes;
7349 ret = 1;
7350 out:
7351 btrfs_free_path(path);
7352 return ret;
7353 }
7354
7355 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7356 {
7357 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7358 int found = false;
7359 void **pagep = NULL;
7360 struct page *page = NULL;
7361 int start_idx;
7362 int end_idx;
7363
7364 start_idx = start >> PAGE_SHIFT;
7365
7366 /*
7367 * end is the last byte in the last page. end == start is legal
7368 */
7369 end_idx = end >> PAGE_SHIFT;
7370
7371 rcu_read_lock();
7372
7373 /* Most of the code in this while loop is lifted from
7374 * find_get_page. It's been modified to begin searching from a
7375 * page and return just the first page found in that range. If the
7376 * found idx is less than or equal to the end idx then we know that
7377 * a page exists. If no pages are found or if those pages are
7378 * outside of the range then we're fine (yay!) */
7379 while (page == NULL &&
7380 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7381 page = radix_tree_deref_slot(pagep);
7382 if (unlikely(!page))
7383 break;
7384
7385 if (radix_tree_exception(page)) {
7386 if (radix_tree_deref_retry(page)) {
7387 page = NULL;
7388 continue;
7389 }
7390 /*
7391 * Otherwise, shmem/tmpfs must be storing a swap entry
7392 * here as an exceptional entry: so return it without
7393 * attempting to raise page count.
7394 */
7395 page = NULL;
7396 break; /* TODO: Is this relevant for this use case? */
7397 }
7398
7399 if (!page_cache_get_speculative(page)) {
7400 page = NULL;
7401 continue;
7402 }
7403
7404 /*
7405 * Has the page moved?
7406 * This is part of the lockless pagecache protocol. See
7407 * include/linux/pagemap.h for details.
7408 */
7409 if (unlikely(page != *pagep)) {
7410 put_page(page);
7411 page = NULL;
7412 }
7413 }
7414
7415 if (page) {
7416 if (page->index <= end_idx)
7417 found = true;
7418 put_page(page);
7419 }
7420
7421 rcu_read_unlock();
7422 return found;
7423 }
7424
7425 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7426 struct extent_state **cached_state, int writing)
7427 {
7428 struct btrfs_ordered_extent *ordered;
7429 int ret = 0;
7430
7431 while (1) {
7432 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7433 cached_state);
7434 /*
7435 * We're concerned with the entire range that we're going to be
7436 * doing DIO to, so we need to make sure theres no ordered
7437 * extents in this range.
7438 */
7439 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7440 lockend - lockstart + 1);
7441
7442 /*
7443 * We need to make sure there are no buffered pages in this
7444 * range either, we could have raced between the invalidate in
7445 * generic_file_direct_write and locking the extent. The
7446 * invalidate needs to happen so that reads after a write do not
7447 * get stale data.
7448 */
7449 if (!ordered &&
7450 (!writing ||
7451 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7452 break;
7453
7454 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7455 cached_state, GFP_NOFS);
7456
7457 if (ordered) {
7458 /*
7459 * If we are doing a DIO read and the ordered extent we
7460 * found is for a buffered write, we can not wait for it
7461 * to complete and retry, because if we do so we can
7462 * deadlock with concurrent buffered writes on page
7463 * locks. This happens only if our DIO read covers more
7464 * than one extent map, if at this point has already
7465 * created an ordered extent for a previous extent map
7466 * and locked its range in the inode's io tree, and a
7467 * concurrent write against that previous extent map's
7468 * range and this range started (we unlock the ranges
7469 * in the io tree only when the bios complete and
7470 * buffered writes always lock pages before attempting
7471 * to lock range in the io tree).
7472 */
7473 if (writing ||
7474 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7475 btrfs_start_ordered_extent(inode, ordered, 1);
7476 else
7477 ret = -ENOTBLK;
7478 btrfs_put_ordered_extent(ordered);
7479 } else {
7480 /*
7481 * We could trigger writeback for this range (and wait
7482 * for it to complete) and then invalidate the pages for
7483 * this range (through invalidate_inode_pages2_range()),
7484 * but that can lead us to a deadlock with a concurrent
7485 * call to readpages() (a buffered read or a defrag call
7486 * triggered a readahead) on a page lock due to an
7487 * ordered dio extent we created before but did not have
7488 * yet a corresponding bio submitted (whence it can not
7489 * complete), which makes readpages() wait for that
7490 * ordered extent to complete while holding a lock on
7491 * that page.
7492 */
7493 ret = -ENOTBLK;
7494 }
7495
7496 if (ret)
7497 break;
7498
7499 cond_resched();
7500 }
7501
7502 return ret;
7503 }
7504
7505 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7506 u64 len, u64 orig_start,
7507 u64 block_start, u64 block_len,
7508 u64 orig_block_len, u64 ram_bytes,
7509 int type)
7510 {
7511 struct extent_map_tree *em_tree;
7512 struct extent_map *em;
7513 struct btrfs_root *root = BTRFS_I(inode)->root;
7514 int ret;
7515
7516 em_tree = &BTRFS_I(inode)->extent_tree;
7517 em = alloc_extent_map();
7518 if (!em)
7519 return ERR_PTR(-ENOMEM);
7520
7521 em->start = start;
7522 em->orig_start = orig_start;
7523 em->mod_start = start;
7524 em->mod_len = len;
7525 em->len = len;
7526 em->block_len = block_len;
7527 em->block_start = block_start;
7528 em->bdev = root->fs_info->fs_devices->latest_bdev;
7529 em->orig_block_len = orig_block_len;
7530 em->ram_bytes = ram_bytes;
7531 em->generation = -1;
7532 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7533 if (type == BTRFS_ORDERED_PREALLOC)
7534 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7535
7536 do {
7537 btrfs_drop_extent_cache(inode, em->start,
7538 em->start + em->len - 1, 0);
7539 write_lock(&em_tree->lock);
7540 ret = add_extent_mapping(em_tree, em, 1);
7541 write_unlock(&em_tree->lock);
7542 } while (ret == -EEXIST);
7543
7544 if (ret) {
7545 free_extent_map(em);
7546 return ERR_PTR(ret);
7547 }
7548
7549 return em;
7550 }
7551
7552 static void adjust_dio_outstanding_extents(struct inode *inode,
7553 struct btrfs_dio_data *dio_data,
7554 const u64 len)
7555 {
7556 unsigned num_extents;
7557
7558 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7559 BTRFS_MAX_EXTENT_SIZE);
7560 /*
7561 * If we have an outstanding_extents count still set then we're
7562 * within our reservation, otherwise we need to adjust our inode
7563 * counter appropriately.
7564 */
7565 if (dio_data->outstanding_extents) {
7566 dio_data->outstanding_extents -= num_extents;
7567 } else {
7568 spin_lock(&BTRFS_I(inode)->lock);
7569 BTRFS_I(inode)->outstanding_extents += num_extents;
7570 spin_unlock(&BTRFS_I(inode)->lock);
7571 }
7572 }
7573
7574 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7575 struct buffer_head *bh_result, int create)
7576 {
7577 struct extent_map *em;
7578 struct btrfs_root *root = BTRFS_I(inode)->root;
7579 struct extent_state *cached_state = NULL;
7580 struct btrfs_dio_data *dio_data = NULL;
7581 u64 start = iblock << inode->i_blkbits;
7582 u64 lockstart, lockend;
7583 u64 len = bh_result->b_size;
7584 int unlock_bits = EXTENT_LOCKED;
7585 int ret = 0;
7586
7587 if (create)
7588 unlock_bits |= EXTENT_DIRTY;
7589 else
7590 len = min_t(u64, len, root->sectorsize);
7591
7592 lockstart = start;
7593 lockend = start + len - 1;
7594
7595 if (current->journal_info) {
7596 /*
7597 * Need to pull our outstanding extents and set journal_info to NULL so
7598 * that anything that needs to check if there's a transction doesn't get
7599 * confused.
7600 */
7601 dio_data = current->journal_info;
7602 current->journal_info = NULL;
7603 }
7604
7605 /*
7606 * If this errors out it's because we couldn't invalidate pagecache for
7607 * this range and we need to fallback to buffered.
7608 */
7609 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7610 create)) {
7611 ret = -ENOTBLK;
7612 goto err;
7613 }
7614
7615 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7616 if (IS_ERR(em)) {
7617 ret = PTR_ERR(em);
7618 goto unlock_err;
7619 }
7620
7621 /*
7622 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7623 * io. INLINE is special, and we could probably kludge it in here, but
7624 * it's still buffered so for safety lets just fall back to the generic
7625 * buffered path.
7626 *
7627 * For COMPRESSED we _have_ to read the entire extent in so we can
7628 * decompress it, so there will be buffering required no matter what we
7629 * do, so go ahead and fallback to buffered.
7630 *
7631 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7632 * to buffered IO. Don't blame me, this is the price we pay for using
7633 * the generic code.
7634 */
7635 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7636 em->block_start == EXTENT_MAP_INLINE) {
7637 free_extent_map(em);
7638 ret = -ENOTBLK;
7639 goto unlock_err;
7640 }
7641
7642 /* Just a good old fashioned hole, return */
7643 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7644 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7645 free_extent_map(em);
7646 goto unlock_err;
7647 }
7648
7649 /*
7650 * We don't allocate a new extent in the following cases
7651 *
7652 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7653 * existing extent.
7654 * 2) The extent is marked as PREALLOC. We're good to go here and can
7655 * just use the extent.
7656 *
7657 */
7658 if (!create) {
7659 len = min(len, em->len - (start - em->start));
7660 lockstart = start + len;
7661 goto unlock;
7662 }
7663
7664 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7665 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7666 em->block_start != EXTENT_MAP_HOLE)) {
7667 int type;
7668 u64 block_start, orig_start, orig_block_len, ram_bytes;
7669
7670 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7671 type = BTRFS_ORDERED_PREALLOC;
7672 else
7673 type = BTRFS_ORDERED_NOCOW;
7674 len = min(len, em->len - (start - em->start));
7675 block_start = em->block_start + (start - em->start);
7676
7677 if (can_nocow_extent(inode, start, &len, &orig_start,
7678 &orig_block_len, &ram_bytes) == 1 &&
7679 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7680 struct extent_map *em2;
7681
7682 em2 = btrfs_create_dio_extent(inode, start, len,
7683 orig_start, block_start,
7684 len, orig_block_len,
7685 ram_bytes, type);
7686 btrfs_dec_nocow_writers(root->fs_info, block_start);
7687 if (type == BTRFS_ORDERED_PREALLOC) {
7688 free_extent_map(em);
7689 em = em2;
7690 }
7691 if (em2 && IS_ERR(em2)) {
7692 ret = PTR_ERR(em2);
7693 goto unlock_err;
7694 }
7695 goto unlock;
7696 }
7697 }
7698
7699 /*
7700 * this will cow the extent, reset the len in case we changed
7701 * it above
7702 */
7703 len = bh_result->b_size;
7704 free_extent_map(em);
7705 em = btrfs_new_extent_direct(inode, start, len);
7706 if (IS_ERR(em)) {
7707 ret = PTR_ERR(em);
7708 goto unlock_err;
7709 }
7710 len = min(len, em->len - (start - em->start));
7711 unlock:
7712 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7713 inode->i_blkbits;
7714 bh_result->b_size = len;
7715 bh_result->b_bdev = em->bdev;
7716 set_buffer_mapped(bh_result);
7717 if (create) {
7718 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7719 set_buffer_new(bh_result);
7720
7721 /*
7722 * Need to update the i_size under the extent lock so buffered
7723 * readers will get the updated i_size when we unlock.
7724 */
7725 if (start + len > i_size_read(inode))
7726 i_size_write(inode, start + len);
7727
7728 adjust_dio_outstanding_extents(inode, dio_data, len);
7729 btrfs_free_reserved_data_space(inode, start, len);
7730 WARN_ON(dio_data->reserve < len);
7731 dio_data->reserve -= len;
7732 dio_data->unsubmitted_oe_range_end = start + len;
7733 current->journal_info = dio_data;
7734 }
7735
7736 /*
7737 * In the case of write we need to clear and unlock the entire range,
7738 * in the case of read we need to unlock only the end area that we
7739 * aren't using if there is any left over space.
7740 */
7741 if (lockstart < lockend) {
7742 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7743 lockend, unlock_bits, 1, 0,
7744 &cached_state, GFP_NOFS);
7745 } else {
7746 free_extent_state(cached_state);
7747 }
7748
7749 free_extent_map(em);
7750
7751 return 0;
7752
7753 unlock_err:
7754 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7755 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7756 err:
7757 if (dio_data)
7758 current->journal_info = dio_data;
7759 /*
7760 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7761 * write less data then expected, so that we don't underflow our inode's
7762 * outstanding extents counter.
7763 */
7764 if (create && dio_data)
7765 adjust_dio_outstanding_extents(inode, dio_data, len);
7766
7767 return ret;
7768 }
7769
7770 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7771 int rw, int mirror_num)
7772 {
7773 struct btrfs_root *root = BTRFS_I(inode)->root;
7774 int ret;
7775
7776 BUG_ON(rw & REQ_WRITE);
7777
7778 bio_get(bio);
7779
7780 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7781 BTRFS_WQ_ENDIO_DIO_REPAIR);
7782 if (ret)
7783 goto err;
7784
7785 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7786 err:
7787 bio_put(bio);
7788 return ret;
7789 }
7790
7791 static int btrfs_check_dio_repairable(struct inode *inode,
7792 struct bio *failed_bio,
7793 struct io_failure_record *failrec,
7794 int failed_mirror)
7795 {
7796 int num_copies;
7797
7798 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7799 failrec->logical, failrec->len);
7800 if (num_copies == 1) {
7801 /*
7802 * we only have a single copy of the data, so don't bother with
7803 * all the retry and error correction code that follows. no
7804 * matter what the error is, it is very likely to persist.
7805 */
7806 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7807 num_copies, failrec->this_mirror, failed_mirror);
7808 return 0;
7809 }
7810
7811 failrec->failed_mirror = failed_mirror;
7812 failrec->this_mirror++;
7813 if (failrec->this_mirror == failed_mirror)
7814 failrec->this_mirror++;
7815
7816 if (failrec->this_mirror > num_copies) {
7817 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7818 num_copies, failrec->this_mirror, failed_mirror);
7819 return 0;
7820 }
7821
7822 return 1;
7823 }
7824
7825 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7826 struct page *page, unsigned int pgoff,
7827 u64 start, u64 end, int failed_mirror,
7828 bio_end_io_t *repair_endio, void *repair_arg)
7829 {
7830 struct io_failure_record *failrec;
7831 struct bio *bio;
7832 int isector;
7833 int read_mode;
7834 int ret;
7835
7836 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7837
7838 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7839 if (ret)
7840 return ret;
7841
7842 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7843 failed_mirror);
7844 if (!ret) {
7845 free_io_failure(inode, failrec);
7846 return -EIO;
7847 }
7848
7849 if ((failed_bio->bi_vcnt > 1)
7850 || (failed_bio->bi_io_vec->bv_len
7851 > BTRFS_I(inode)->root->sectorsize))
7852 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7853 else
7854 read_mode = READ_SYNC;
7855
7856 isector = start - btrfs_io_bio(failed_bio)->logical;
7857 isector >>= inode->i_sb->s_blocksize_bits;
7858 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7859 pgoff, isector, repair_endio, repair_arg);
7860 if (!bio) {
7861 free_io_failure(inode, failrec);
7862 return -EIO;
7863 }
7864
7865 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7866 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7867 read_mode, failrec->this_mirror, failrec->in_validation);
7868
7869 ret = submit_dio_repair_bio(inode, bio, read_mode,
7870 failrec->this_mirror);
7871 if (ret) {
7872 free_io_failure(inode, failrec);
7873 bio_put(bio);
7874 }
7875
7876 return ret;
7877 }
7878
7879 struct btrfs_retry_complete {
7880 struct completion done;
7881 struct inode *inode;
7882 u64 start;
7883 int uptodate;
7884 };
7885
7886 static void btrfs_retry_endio_nocsum(struct bio *bio)
7887 {
7888 struct btrfs_retry_complete *done = bio->bi_private;
7889 struct inode *inode;
7890 struct bio_vec *bvec;
7891 int i;
7892
7893 if (bio->bi_error)
7894 goto end;
7895
7896 ASSERT(bio->bi_vcnt == 1);
7897 inode = bio->bi_io_vec->bv_page->mapping->host;
7898 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7899
7900 done->uptodate = 1;
7901 bio_for_each_segment_all(bvec, bio, i)
7902 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7903 end:
7904 complete(&done->done);
7905 bio_put(bio);
7906 }
7907
7908 static int __btrfs_correct_data_nocsum(struct inode *inode,
7909 struct btrfs_io_bio *io_bio)
7910 {
7911 struct btrfs_fs_info *fs_info;
7912 struct bio_vec *bvec;
7913 struct btrfs_retry_complete done;
7914 u64 start;
7915 unsigned int pgoff;
7916 u32 sectorsize;
7917 int nr_sectors;
7918 int i;
7919 int ret;
7920
7921 fs_info = BTRFS_I(inode)->root->fs_info;
7922 sectorsize = BTRFS_I(inode)->root->sectorsize;
7923
7924 start = io_bio->logical;
7925 done.inode = inode;
7926
7927 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7928 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7929 pgoff = bvec->bv_offset;
7930
7931 next_block_or_try_again:
7932 done.uptodate = 0;
7933 done.start = start;
7934 init_completion(&done.done);
7935
7936 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7937 pgoff, start, start + sectorsize - 1,
7938 io_bio->mirror_num,
7939 btrfs_retry_endio_nocsum, &done);
7940 if (ret)
7941 return ret;
7942
7943 wait_for_completion(&done.done);
7944
7945 if (!done.uptodate) {
7946 /* We might have another mirror, so try again */
7947 goto next_block_or_try_again;
7948 }
7949
7950 start += sectorsize;
7951
7952 if (nr_sectors--) {
7953 pgoff += sectorsize;
7954 goto next_block_or_try_again;
7955 }
7956 }
7957
7958 return 0;
7959 }
7960
7961 static void btrfs_retry_endio(struct bio *bio)
7962 {
7963 struct btrfs_retry_complete *done = bio->bi_private;
7964 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7965 struct inode *inode;
7966 struct bio_vec *bvec;
7967 u64 start;
7968 int uptodate;
7969 int ret;
7970 int i;
7971
7972 if (bio->bi_error)
7973 goto end;
7974
7975 uptodate = 1;
7976
7977 start = done->start;
7978
7979 ASSERT(bio->bi_vcnt == 1);
7980 inode = bio->bi_io_vec->bv_page->mapping->host;
7981 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7982
7983 bio_for_each_segment_all(bvec, bio, i) {
7984 ret = __readpage_endio_check(done->inode, io_bio, i,
7985 bvec->bv_page, bvec->bv_offset,
7986 done->start, bvec->bv_len);
7987 if (!ret)
7988 clean_io_failure(done->inode, done->start,
7989 bvec->bv_page, bvec->bv_offset);
7990 else
7991 uptodate = 0;
7992 }
7993
7994 done->uptodate = uptodate;
7995 end:
7996 complete(&done->done);
7997 bio_put(bio);
7998 }
7999
8000 static int __btrfs_subio_endio_read(struct inode *inode,
8001 struct btrfs_io_bio *io_bio, int err)
8002 {
8003 struct btrfs_fs_info *fs_info;
8004 struct bio_vec *bvec;
8005 struct btrfs_retry_complete done;
8006 u64 start;
8007 u64 offset = 0;
8008 u32 sectorsize;
8009 int nr_sectors;
8010 unsigned int pgoff;
8011 int csum_pos;
8012 int i;
8013 int ret;
8014
8015 fs_info = BTRFS_I(inode)->root->fs_info;
8016 sectorsize = BTRFS_I(inode)->root->sectorsize;
8017
8018 err = 0;
8019 start = io_bio->logical;
8020 done.inode = inode;
8021
8022 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8023 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8024
8025 pgoff = bvec->bv_offset;
8026 next_block:
8027 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8028 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8029 bvec->bv_page, pgoff, start,
8030 sectorsize);
8031 if (likely(!ret))
8032 goto next;
8033 try_again:
8034 done.uptodate = 0;
8035 done.start = start;
8036 init_completion(&done.done);
8037
8038 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8039 pgoff, start, start + sectorsize - 1,
8040 io_bio->mirror_num,
8041 btrfs_retry_endio, &done);
8042 if (ret) {
8043 err = ret;
8044 goto next;
8045 }
8046
8047 wait_for_completion(&done.done);
8048
8049 if (!done.uptodate) {
8050 /* We might have another mirror, so try again */
8051 goto try_again;
8052 }
8053 next:
8054 offset += sectorsize;
8055 start += sectorsize;
8056
8057 ASSERT(nr_sectors);
8058
8059 if (--nr_sectors) {
8060 pgoff += sectorsize;
8061 goto next_block;
8062 }
8063 }
8064
8065 return err;
8066 }
8067
8068 static int btrfs_subio_endio_read(struct inode *inode,
8069 struct btrfs_io_bio *io_bio, int err)
8070 {
8071 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8072
8073 if (skip_csum) {
8074 if (unlikely(err))
8075 return __btrfs_correct_data_nocsum(inode, io_bio);
8076 else
8077 return 0;
8078 } else {
8079 return __btrfs_subio_endio_read(inode, io_bio, err);
8080 }
8081 }
8082
8083 static void btrfs_endio_direct_read(struct bio *bio)
8084 {
8085 struct btrfs_dio_private *dip = bio->bi_private;
8086 struct inode *inode = dip->inode;
8087 struct bio *dio_bio;
8088 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8089 int err = bio->bi_error;
8090
8091 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8092 err = btrfs_subio_endio_read(inode, io_bio, err);
8093
8094 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8095 dip->logical_offset + dip->bytes - 1);
8096 dio_bio = dip->dio_bio;
8097
8098 kfree(dip);
8099
8100 dio_bio->bi_error = bio->bi_error;
8101 dio_end_io(dio_bio, bio->bi_error);
8102
8103 if (io_bio->end_io)
8104 io_bio->end_io(io_bio, err);
8105 bio_put(bio);
8106 }
8107
8108 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8109 const u64 offset,
8110 const u64 bytes,
8111 const int uptodate)
8112 {
8113 struct btrfs_root *root = BTRFS_I(inode)->root;
8114 struct btrfs_ordered_extent *ordered = NULL;
8115 u64 ordered_offset = offset;
8116 u64 ordered_bytes = bytes;
8117 int ret;
8118
8119 again:
8120 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8121 &ordered_offset,
8122 ordered_bytes,
8123 uptodate);
8124 if (!ret)
8125 goto out_test;
8126
8127 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8128 finish_ordered_fn, NULL, NULL);
8129 btrfs_queue_work(root->fs_info->endio_write_workers,
8130 &ordered->work);
8131 out_test:
8132 /*
8133 * our bio might span multiple ordered extents. If we haven't
8134 * completed the accounting for the whole dio, go back and try again
8135 */
8136 if (ordered_offset < offset + bytes) {
8137 ordered_bytes = offset + bytes - ordered_offset;
8138 ordered = NULL;
8139 goto again;
8140 }
8141 }
8142
8143 static void btrfs_endio_direct_write(struct bio *bio)
8144 {
8145 struct btrfs_dio_private *dip = bio->bi_private;
8146 struct bio *dio_bio = dip->dio_bio;
8147
8148 btrfs_endio_direct_write_update_ordered(dip->inode,
8149 dip->logical_offset,
8150 dip->bytes,
8151 !bio->bi_error);
8152
8153 kfree(dip);
8154
8155 dio_bio->bi_error = bio->bi_error;
8156 dio_end_io(dio_bio, bio->bi_error);
8157 bio_put(bio);
8158 }
8159
8160 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8161 struct bio *bio, int mirror_num,
8162 unsigned long bio_flags, u64 offset)
8163 {
8164 int ret;
8165 struct btrfs_root *root = BTRFS_I(inode)->root;
8166 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8167 BUG_ON(ret); /* -ENOMEM */
8168 return 0;
8169 }
8170
8171 static void btrfs_end_dio_bio(struct bio *bio)
8172 {
8173 struct btrfs_dio_private *dip = bio->bi_private;
8174 int err = bio->bi_error;
8175
8176 if (err)
8177 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8178 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8179 btrfs_ino(dip->inode), bio->bi_rw,
8180 (unsigned long long)bio->bi_iter.bi_sector,
8181 bio->bi_iter.bi_size, err);
8182
8183 if (dip->subio_endio)
8184 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8185
8186 if (err) {
8187 dip->errors = 1;
8188
8189 /*
8190 * before atomic variable goto zero, we must make sure
8191 * dip->errors is perceived to be set.
8192 */
8193 smp_mb__before_atomic();
8194 }
8195
8196 /* if there are more bios still pending for this dio, just exit */
8197 if (!atomic_dec_and_test(&dip->pending_bios))
8198 goto out;
8199
8200 if (dip->errors) {
8201 bio_io_error(dip->orig_bio);
8202 } else {
8203 dip->dio_bio->bi_error = 0;
8204 bio_endio(dip->orig_bio);
8205 }
8206 out:
8207 bio_put(bio);
8208 }
8209
8210 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8211 u64 first_sector, gfp_t gfp_flags)
8212 {
8213 struct bio *bio;
8214 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8215 if (bio)
8216 bio_associate_current(bio);
8217 return bio;
8218 }
8219
8220 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8221 struct inode *inode,
8222 struct btrfs_dio_private *dip,
8223 struct bio *bio,
8224 u64 file_offset)
8225 {
8226 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8227 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8228 int ret;
8229
8230 /*
8231 * We load all the csum data we need when we submit
8232 * the first bio to reduce the csum tree search and
8233 * contention.
8234 */
8235 if (dip->logical_offset == file_offset) {
8236 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8237 file_offset);
8238 if (ret)
8239 return ret;
8240 }
8241
8242 if (bio == dip->orig_bio)
8243 return 0;
8244
8245 file_offset -= dip->logical_offset;
8246 file_offset >>= inode->i_sb->s_blocksize_bits;
8247 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8248
8249 return 0;
8250 }
8251
8252 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8253 int rw, u64 file_offset, int skip_sum,
8254 int async_submit)
8255 {
8256 struct btrfs_dio_private *dip = bio->bi_private;
8257 int write = rw & REQ_WRITE;
8258 struct btrfs_root *root = BTRFS_I(inode)->root;
8259 int ret;
8260
8261 if (async_submit)
8262 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8263
8264 bio_get(bio);
8265
8266 if (!write) {
8267 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8268 BTRFS_WQ_ENDIO_DATA);
8269 if (ret)
8270 goto err;
8271 }
8272
8273 if (skip_sum)
8274 goto map;
8275
8276 if (write && async_submit) {
8277 ret = btrfs_wq_submit_bio(root->fs_info,
8278 inode, rw, bio, 0, 0,
8279 file_offset,
8280 __btrfs_submit_bio_start_direct_io,
8281 __btrfs_submit_bio_done);
8282 goto err;
8283 } else if (write) {
8284 /*
8285 * If we aren't doing async submit, calculate the csum of the
8286 * bio now.
8287 */
8288 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8289 if (ret)
8290 goto err;
8291 } else {
8292 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8293 file_offset);
8294 if (ret)
8295 goto err;
8296 }
8297 map:
8298 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8299 err:
8300 bio_put(bio);
8301 return ret;
8302 }
8303
8304 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8305 int skip_sum)
8306 {
8307 struct inode *inode = dip->inode;
8308 struct btrfs_root *root = BTRFS_I(inode)->root;
8309 struct bio *bio;
8310 struct bio *orig_bio = dip->orig_bio;
8311 struct bio_vec *bvec = orig_bio->bi_io_vec;
8312 u64 start_sector = orig_bio->bi_iter.bi_sector;
8313 u64 file_offset = dip->logical_offset;
8314 u64 submit_len = 0;
8315 u64 map_length;
8316 u32 blocksize = root->sectorsize;
8317 int async_submit = 0;
8318 int nr_sectors;
8319 int ret;
8320 int i;
8321
8322 map_length = orig_bio->bi_iter.bi_size;
8323 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8324 &map_length, NULL, 0);
8325 if (ret)
8326 return -EIO;
8327
8328 if (map_length >= orig_bio->bi_iter.bi_size) {
8329 bio = orig_bio;
8330 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8331 goto submit;
8332 }
8333
8334 /* async crcs make it difficult to collect full stripe writes. */
8335 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8336 async_submit = 0;
8337 else
8338 async_submit = 1;
8339
8340 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8341 if (!bio)
8342 return -ENOMEM;
8343
8344 bio->bi_private = dip;
8345 bio->bi_end_io = btrfs_end_dio_bio;
8346 btrfs_io_bio(bio)->logical = file_offset;
8347 atomic_inc(&dip->pending_bios);
8348
8349 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8350 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8351 i = 0;
8352 next_block:
8353 if (unlikely(map_length < submit_len + blocksize ||
8354 bio_add_page(bio, bvec->bv_page, blocksize,
8355 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8356 /*
8357 * inc the count before we submit the bio so
8358 * we know the end IO handler won't happen before
8359 * we inc the count. Otherwise, the dip might get freed
8360 * before we're done setting it up
8361 */
8362 atomic_inc(&dip->pending_bios);
8363 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8364 file_offset, skip_sum,
8365 async_submit);
8366 if (ret) {
8367 bio_put(bio);
8368 atomic_dec(&dip->pending_bios);
8369 goto out_err;
8370 }
8371
8372 start_sector += submit_len >> 9;
8373 file_offset += submit_len;
8374
8375 submit_len = 0;
8376
8377 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8378 start_sector, GFP_NOFS);
8379 if (!bio)
8380 goto out_err;
8381 bio->bi_private = dip;
8382 bio->bi_end_io = btrfs_end_dio_bio;
8383 btrfs_io_bio(bio)->logical = file_offset;
8384
8385 map_length = orig_bio->bi_iter.bi_size;
8386 ret = btrfs_map_block(root->fs_info, rw,
8387 start_sector << 9,
8388 &map_length, NULL, 0);
8389 if (ret) {
8390 bio_put(bio);
8391 goto out_err;
8392 }
8393
8394 goto next_block;
8395 } else {
8396 submit_len += blocksize;
8397 if (--nr_sectors) {
8398 i++;
8399 goto next_block;
8400 }
8401 bvec++;
8402 }
8403 }
8404
8405 submit:
8406 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8407 async_submit);
8408 if (!ret)
8409 return 0;
8410
8411 bio_put(bio);
8412 out_err:
8413 dip->errors = 1;
8414 /*
8415 * before atomic variable goto zero, we must
8416 * make sure dip->errors is perceived to be set.
8417 */
8418 smp_mb__before_atomic();
8419 if (atomic_dec_and_test(&dip->pending_bios))
8420 bio_io_error(dip->orig_bio);
8421
8422 /* bio_end_io() will handle error, so we needn't return it */
8423 return 0;
8424 }
8425
8426 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8427 struct inode *inode, loff_t file_offset)
8428 {
8429 struct btrfs_dio_private *dip = NULL;
8430 struct bio *io_bio = NULL;
8431 struct btrfs_io_bio *btrfs_bio;
8432 int skip_sum;
8433 int write = rw & REQ_WRITE;
8434 int ret = 0;
8435
8436 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8437
8438 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8439 if (!io_bio) {
8440 ret = -ENOMEM;
8441 goto free_ordered;
8442 }
8443
8444 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8445 if (!dip) {
8446 ret = -ENOMEM;
8447 goto free_ordered;
8448 }
8449
8450 dip->private = dio_bio->bi_private;
8451 dip->inode = inode;
8452 dip->logical_offset = file_offset;
8453 dip->bytes = dio_bio->bi_iter.bi_size;
8454 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8455 io_bio->bi_private = dip;
8456 dip->orig_bio = io_bio;
8457 dip->dio_bio = dio_bio;
8458 atomic_set(&dip->pending_bios, 0);
8459 btrfs_bio = btrfs_io_bio(io_bio);
8460 btrfs_bio->logical = file_offset;
8461
8462 if (write) {
8463 io_bio->bi_end_io = btrfs_endio_direct_write;
8464 } else {
8465 io_bio->bi_end_io = btrfs_endio_direct_read;
8466 dip->subio_endio = btrfs_subio_endio_read;
8467 }
8468
8469 /*
8470 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8471 * even if we fail to submit a bio, because in such case we do the
8472 * corresponding error handling below and it must not be done a second
8473 * time by btrfs_direct_IO().
8474 */
8475 if (write) {
8476 struct btrfs_dio_data *dio_data = current->journal_info;
8477
8478 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8479 dip->bytes;
8480 dio_data->unsubmitted_oe_range_start =
8481 dio_data->unsubmitted_oe_range_end;
8482 }
8483
8484 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8485 if (!ret)
8486 return;
8487
8488 if (btrfs_bio->end_io)
8489 btrfs_bio->end_io(btrfs_bio, ret);
8490
8491 free_ordered:
8492 /*
8493 * If we arrived here it means either we failed to submit the dip
8494 * or we either failed to clone the dio_bio or failed to allocate the
8495 * dip. If we cloned the dio_bio and allocated the dip, we can just
8496 * call bio_endio against our io_bio so that we get proper resource
8497 * cleanup if we fail to submit the dip, otherwise, we must do the
8498 * same as btrfs_endio_direct_[write|read] because we can't call these
8499 * callbacks - they require an allocated dip and a clone of dio_bio.
8500 */
8501 if (io_bio && dip) {
8502 io_bio->bi_error = -EIO;
8503 bio_endio(io_bio);
8504 /*
8505 * The end io callbacks free our dip, do the final put on io_bio
8506 * and all the cleanup and final put for dio_bio (through
8507 * dio_end_io()).
8508 */
8509 dip = NULL;
8510 io_bio = NULL;
8511 } else {
8512 if (write)
8513 btrfs_endio_direct_write_update_ordered(inode,
8514 file_offset,
8515 dio_bio->bi_iter.bi_size,
8516 0);
8517 else
8518 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8519 file_offset + dio_bio->bi_iter.bi_size - 1);
8520
8521 dio_bio->bi_error = -EIO;
8522 /*
8523 * Releases and cleans up our dio_bio, no need to bio_put()
8524 * nor bio_endio()/bio_io_error() against dio_bio.
8525 */
8526 dio_end_io(dio_bio, ret);
8527 }
8528 if (io_bio)
8529 bio_put(io_bio);
8530 kfree(dip);
8531 }
8532
8533 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8534 const struct iov_iter *iter, loff_t offset)
8535 {
8536 int seg;
8537 int i;
8538 unsigned blocksize_mask = root->sectorsize - 1;
8539 ssize_t retval = -EINVAL;
8540
8541 if (offset & blocksize_mask)
8542 goto out;
8543
8544 if (iov_iter_alignment(iter) & blocksize_mask)
8545 goto out;
8546
8547 /* If this is a write we don't need to check anymore */
8548 if (iov_iter_rw(iter) == WRITE)
8549 return 0;
8550 /*
8551 * Check to make sure we don't have duplicate iov_base's in this
8552 * iovec, if so return EINVAL, otherwise we'll get csum errors
8553 * when reading back.
8554 */
8555 for (seg = 0; seg < iter->nr_segs; seg++) {
8556 for (i = seg + 1; i < iter->nr_segs; i++) {
8557 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8558 goto out;
8559 }
8560 }
8561 retval = 0;
8562 out:
8563 return retval;
8564 }
8565
8566 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8567 {
8568 struct file *file = iocb->ki_filp;
8569 struct inode *inode = file->f_mapping->host;
8570 struct btrfs_root *root = BTRFS_I(inode)->root;
8571 struct btrfs_dio_data dio_data = { 0 };
8572 loff_t offset = iocb->ki_pos;
8573 size_t count = 0;
8574 int flags = 0;
8575 bool wakeup = true;
8576 bool relock = false;
8577 ssize_t ret;
8578
8579 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8580 return 0;
8581
8582 inode_dio_begin(inode);
8583 smp_mb__after_atomic();
8584
8585 /*
8586 * The generic stuff only does filemap_write_and_wait_range, which
8587 * isn't enough if we've written compressed pages to this area, so
8588 * we need to flush the dirty pages again to make absolutely sure
8589 * that any outstanding dirty pages are on disk.
8590 */
8591 count = iov_iter_count(iter);
8592 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8593 &BTRFS_I(inode)->runtime_flags))
8594 filemap_fdatawrite_range(inode->i_mapping, offset,
8595 offset + count - 1);
8596
8597 if (iov_iter_rw(iter) == WRITE) {
8598 /*
8599 * If the write DIO is beyond the EOF, we need update
8600 * the isize, but it is protected by i_mutex. So we can
8601 * not unlock the i_mutex at this case.
8602 */
8603 if (offset + count <= inode->i_size) {
8604 inode_unlock(inode);
8605 relock = true;
8606 }
8607 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8608 if (ret)
8609 goto out;
8610 dio_data.outstanding_extents = div64_u64(count +
8611 BTRFS_MAX_EXTENT_SIZE - 1,
8612 BTRFS_MAX_EXTENT_SIZE);
8613
8614 /*
8615 * We need to know how many extents we reserved so that we can
8616 * do the accounting properly if we go over the number we
8617 * originally calculated. Abuse current->journal_info for this.
8618 */
8619 dio_data.reserve = round_up(count, root->sectorsize);
8620 dio_data.unsubmitted_oe_range_start = (u64)offset;
8621 dio_data.unsubmitted_oe_range_end = (u64)offset;
8622 current->journal_info = &dio_data;
8623 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8624 &BTRFS_I(inode)->runtime_flags)) {
8625 inode_dio_end(inode);
8626 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8627 wakeup = false;
8628 }
8629
8630 ret = __blockdev_direct_IO(iocb, inode,
8631 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8632 iter, btrfs_get_blocks_direct, NULL,
8633 btrfs_submit_direct, flags);
8634 if (iov_iter_rw(iter) == WRITE) {
8635 current->journal_info = NULL;
8636 if (ret < 0 && ret != -EIOCBQUEUED) {
8637 if (dio_data.reserve)
8638 btrfs_delalloc_release_space(inode, offset,
8639 dio_data.reserve);
8640 /*
8641 * On error we might have left some ordered extents
8642 * without submitting corresponding bios for them, so
8643 * cleanup them up to avoid other tasks getting them
8644 * and waiting for them to complete forever.
8645 */
8646 if (dio_data.unsubmitted_oe_range_start <
8647 dio_data.unsubmitted_oe_range_end)
8648 btrfs_endio_direct_write_update_ordered(inode,
8649 dio_data.unsubmitted_oe_range_start,
8650 dio_data.unsubmitted_oe_range_end -
8651 dio_data.unsubmitted_oe_range_start,
8652 0);
8653 } else if (ret >= 0 && (size_t)ret < count)
8654 btrfs_delalloc_release_space(inode, offset,
8655 count - (size_t)ret);
8656 }
8657 out:
8658 if (wakeup)
8659 inode_dio_end(inode);
8660 if (relock)
8661 inode_lock(inode);
8662
8663 return ret;
8664 }
8665
8666 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8667
8668 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8669 __u64 start, __u64 len)
8670 {
8671 int ret;
8672
8673 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8674 if (ret)
8675 return ret;
8676
8677 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8678 }
8679
8680 int btrfs_readpage(struct file *file, struct page *page)
8681 {
8682 struct extent_io_tree *tree;
8683 tree = &BTRFS_I(page->mapping->host)->io_tree;
8684 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8685 }
8686
8687 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8688 {
8689 struct extent_io_tree *tree;
8690 struct inode *inode = page->mapping->host;
8691 int ret;
8692
8693 if (current->flags & PF_MEMALLOC) {
8694 redirty_page_for_writepage(wbc, page);
8695 unlock_page(page);
8696 return 0;
8697 }
8698
8699 /*
8700 * If we are under memory pressure we will call this directly from the
8701 * VM, we need to make sure we have the inode referenced for the ordered
8702 * extent. If not just return like we didn't do anything.
8703 */
8704 if (!igrab(inode)) {
8705 redirty_page_for_writepage(wbc, page);
8706 return AOP_WRITEPAGE_ACTIVATE;
8707 }
8708 tree = &BTRFS_I(page->mapping->host)->io_tree;
8709 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8710 btrfs_add_delayed_iput(inode);
8711 return ret;
8712 }
8713
8714 static int btrfs_writepages(struct address_space *mapping,
8715 struct writeback_control *wbc)
8716 {
8717 struct extent_io_tree *tree;
8718
8719 tree = &BTRFS_I(mapping->host)->io_tree;
8720 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8721 }
8722
8723 static int
8724 btrfs_readpages(struct file *file, struct address_space *mapping,
8725 struct list_head *pages, unsigned nr_pages)
8726 {
8727 struct extent_io_tree *tree;
8728 tree = &BTRFS_I(mapping->host)->io_tree;
8729 return extent_readpages(tree, mapping, pages, nr_pages,
8730 btrfs_get_extent);
8731 }
8732 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8733 {
8734 struct extent_io_tree *tree;
8735 struct extent_map_tree *map;
8736 int ret;
8737
8738 tree = &BTRFS_I(page->mapping->host)->io_tree;
8739 map = &BTRFS_I(page->mapping->host)->extent_tree;
8740 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8741 if (ret == 1) {
8742 ClearPagePrivate(page);
8743 set_page_private(page, 0);
8744 put_page(page);
8745 }
8746 return ret;
8747 }
8748
8749 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8750 {
8751 if (PageWriteback(page) || PageDirty(page))
8752 return 0;
8753 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8754 }
8755
8756 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8757 unsigned int length)
8758 {
8759 struct inode *inode = page->mapping->host;
8760 struct extent_io_tree *tree;
8761 struct btrfs_ordered_extent *ordered;
8762 struct extent_state *cached_state = NULL;
8763 u64 page_start = page_offset(page);
8764 u64 page_end = page_start + PAGE_SIZE - 1;
8765 u64 start;
8766 u64 end;
8767 int inode_evicting = inode->i_state & I_FREEING;
8768
8769 /*
8770 * we have the page locked, so new writeback can't start,
8771 * and the dirty bit won't be cleared while we are here.
8772 *
8773 * Wait for IO on this page so that we can safely clear
8774 * the PagePrivate2 bit and do ordered accounting
8775 */
8776 wait_on_page_writeback(page);
8777
8778 tree = &BTRFS_I(inode)->io_tree;
8779 if (offset) {
8780 btrfs_releasepage(page, GFP_NOFS);
8781 return;
8782 }
8783
8784 if (!inode_evicting)
8785 lock_extent_bits(tree, page_start, page_end, &cached_state);
8786 again:
8787 start = page_start;
8788 ordered = btrfs_lookup_ordered_range(inode, start,
8789 page_end - start + 1);
8790 if (ordered) {
8791 end = min(page_end, ordered->file_offset + ordered->len - 1);
8792 /*
8793 * IO on this page will never be started, so we need
8794 * to account for any ordered extents now
8795 */
8796 if (!inode_evicting)
8797 clear_extent_bit(tree, start, end,
8798 EXTENT_DIRTY | EXTENT_DELALLOC |
8799 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8800 EXTENT_DEFRAG, 1, 0, &cached_state,
8801 GFP_NOFS);
8802 /*
8803 * whoever cleared the private bit is responsible
8804 * for the finish_ordered_io
8805 */
8806 if (TestClearPagePrivate2(page)) {
8807 struct btrfs_ordered_inode_tree *tree;
8808 u64 new_len;
8809
8810 tree = &BTRFS_I(inode)->ordered_tree;
8811
8812 spin_lock_irq(&tree->lock);
8813 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8814 new_len = start - ordered->file_offset;
8815 if (new_len < ordered->truncated_len)
8816 ordered->truncated_len = new_len;
8817 spin_unlock_irq(&tree->lock);
8818
8819 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8820 start,
8821 end - start + 1, 1))
8822 btrfs_finish_ordered_io(ordered);
8823 }
8824 btrfs_put_ordered_extent(ordered);
8825 if (!inode_evicting) {
8826 cached_state = NULL;
8827 lock_extent_bits(tree, start, end,
8828 &cached_state);
8829 }
8830
8831 start = end + 1;
8832 if (start < page_end)
8833 goto again;
8834 }
8835
8836 /*
8837 * Qgroup reserved space handler
8838 * Page here will be either
8839 * 1) Already written to disk
8840 * In this case, its reserved space is released from data rsv map
8841 * and will be freed by delayed_ref handler finally.
8842 * So even we call qgroup_free_data(), it won't decrease reserved
8843 * space.
8844 * 2) Not written to disk
8845 * This means the reserved space should be freed here.
8846 */
8847 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8848 if (!inode_evicting) {
8849 clear_extent_bit(tree, page_start, page_end,
8850 EXTENT_LOCKED | EXTENT_DIRTY |
8851 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8852 EXTENT_DEFRAG, 1, 1,
8853 &cached_state, GFP_NOFS);
8854
8855 __btrfs_releasepage(page, GFP_NOFS);
8856 }
8857
8858 ClearPageChecked(page);
8859 if (PagePrivate(page)) {
8860 ClearPagePrivate(page);
8861 set_page_private(page, 0);
8862 put_page(page);
8863 }
8864 }
8865
8866 /*
8867 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8868 * called from a page fault handler when a page is first dirtied. Hence we must
8869 * be careful to check for EOF conditions here. We set the page up correctly
8870 * for a written page which means we get ENOSPC checking when writing into
8871 * holes and correct delalloc and unwritten extent mapping on filesystems that
8872 * support these features.
8873 *
8874 * We are not allowed to take the i_mutex here so we have to play games to
8875 * protect against truncate races as the page could now be beyond EOF. Because
8876 * vmtruncate() writes the inode size before removing pages, once we have the
8877 * page lock we can determine safely if the page is beyond EOF. If it is not
8878 * beyond EOF, then the page is guaranteed safe against truncation until we
8879 * unlock the page.
8880 */
8881 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8882 {
8883 struct page *page = vmf->page;
8884 struct inode *inode = file_inode(vma->vm_file);
8885 struct btrfs_root *root = BTRFS_I(inode)->root;
8886 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8887 struct btrfs_ordered_extent *ordered;
8888 struct extent_state *cached_state = NULL;
8889 char *kaddr;
8890 unsigned long zero_start;
8891 loff_t size;
8892 int ret;
8893 int reserved = 0;
8894 u64 reserved_space;
8895 u64 page_start;
8896 u64 page_end;
8897 u64 end;
8898
8899 reserved_space = PAGE_SIZE;
8900
8901 sb_start_pagefault(inode->i_sb);
8902 page_start = page_offset(page);
8903 page_end = page_start + PAGE_SIZE - 1;
8904 end = page_end;
8905
8906 /*
8907 * Reserving delalloc space after obtaining the page lock can lead to
8908 * deadlock. For example, if a dirty page is locked by this function
8909 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8910 * dirty page write out, then the btrfs_writepage() function could
8911 * end up waiting indefinitely to get a lock on the page currently
8912 * being processed by btrfs_page_mkwrite() function.
8913 */
8914 ret = btrfs_delalloc_reserve_space(inode, page_start,
8915 reserved_space);
8916 if (!ret) {
8917 ret = file_update_time(vma->vm_file);
8918 reserved = 1;
8919 }
8920 if (ret) {
8921 if (ret == -ENOMEM)
8922 ret = VM_FAULT_OOM;
8923 else /* -ENOSPC, -EIO, etc */
8924 ret = VM_FAULT_SIGBUS;
8925 if (reserved)
8926 goto out;
8927 goto out_noreserve;
8928 }
8929
8930 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8931 again:
8932 lock_page(page);
8933 size = i_size_read(inode);
8934
8935 if ((page->mapping != inode->i_mapping) ||
8936 (page_start >= size)) {
8937 /* page got truncated out from underneath us */
8938 goto out_unlock;
8939 }
8940 wait_on_page_writeback(page);
8941
8942 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8943 set_page_extent_mapped(page);
8944
8945 /*
8946 * we can't set the delalloc bits if there are pending ordered
8947 * extents. Drop our locks and wait for them to finish
8948 */
8949 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
8950 if (ordered) {
8951 unlock_extent_cached(io_tree, page_start, page_end,
8952 &cached_state, GFP_NOFS);
8953 unlock_page(page);
8954 btrfs_start_ordered_extent(inode, ordered, 1);
8955 btrfs_put_ordered_extent(ordered);
8956 goto again;
8957 }
8958
8959 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8960 reserved_space = round_up(size - page_start, root->sectorsize);
8961 if (reserved_space < PAGE_SIZE) {
8962 end = page_start + reserved_space - 1;
8963 spin_lock(&BTRFS_I(inode)->lock);
8964 BTRFS_I(inode)->outstanding_extents++;
8965 spin_unlock(&BTRFS_I(inode)->lock);
8966 btrfs_delalloc_release_space(inode, page_start,
8967 PAGE_SIZE - reserved_space);
8968 }
8969 }
8970
8971 /*
8972 * XXX - page_mkwrite gets called every time the page is dirtied, even
8973 * if it was already dirty, so for space accounting reasons we need to
8974 * clear any delalloc bits for the range we are fixing to save. There
8975 * is probably a better way to do this, but for now keep consistent with
8976 * prepare_pages in the normal write path.
8977 */
8978 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8979 EXTENT_DIRTY | EXTENT_DELALLOC |
8980 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8981 0, 0, &cached_state, GFP_NOFS);
8982
8983 ret = btrfs_set_extent_delalloc(inode, page_start, end,
8984 &cached_state);
8985 if (ret) {
8986 unlock_extent_cached(io_tree, page_start, page_end,
8987 &cached_state, GFP_NOFS);
8988 ret = VM_FAULT_SIGBUS;
8989 goto out_unlock;
8990 }
8991 ret = 0;
8992
8993 /* page is wholly or partially inside EOF */
8994 if (page_start + PAGE_SIZE > size)
8995 zero_start = size & ~PAGE_MASK;
8996 else
8997 zero_start = PAGE_SIZE;
8998
8999 if (zero_start != PAGE_SIZE) {
9000 kaddr = kmap(page);
9001 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9002 flush_dcache_page(page);
9003 kunmap(page);
9004 }
9005 ClearPageChecked(page);
9006 set_page_dirty(page);
9007 SetPageUptodate(page);
9008
9009 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9010 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9011 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9012
9013 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9014
9015 out_unlock:
9016 if (!ret) {
9017 sb_end_pagefault(inode->i_sb);
9018 return VM_FAULT_LOCKED;
9019 }
9020 unlock_page(page);
9021 out:
9022 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9023 out_noreserve:
9024 sb_end_pagefault(inode->i_sb);
9025 return ret;
9026 }
9027
9028 static int btrfs_truncate(struct inode *inode)
9029 {
9030 struct btrfs_root *root = BTRFS_I(inode)->root;
9031 struct btrfs_block_rsv *rsv;
9032 int ret = 0;
9033 int err = 0;
9034 struct btrfs_trans_handle *trans;
9035 u64 mask = root->sectorsize - 1;
9036 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9037
9038 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9039 (u64)-1);
9040 if (ret)
9041 return ret;
9042
9043 /*
9044 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
9045 * 3 things going on here
9046 *
9047 * 1) We need to reserve space for our orphan item and the space to
9048 * delete our orphan item. Lord knows we don't want to have a dangling
9049 * orphan item because we didn't reserve space to remove it.
9050 *
9051 * 2) We need to reserve space to update our inode.
9052 *
9053 * 3) We need to have something to cache all the space that is going to
9054 * be free'd up by the truncate operation, but also have some slack
9055 * space reserved in case it uses space during the truncate (thank you
9056 * very much snapshotting).
9057 *
9058 * And we need these to all be seperate. The fact is we can use alot of
9059 * space doing the truncate, and we have no earthly idea how much space
9060 * we will use, so we need the truncate reservation to be seperate so it
9061 * doesn't end up using space reserved for updating the inode or
9062 * removing the orphan item. We also need to be able to stop the
9063 * transaction and start a new one, which means we need to be able to
9064 * update the inode several times, and we have no idea of knowing how
9065 * many times that will be, so we can't just reserve 1 item for the
9066 * entirety of the opration, so that has to be done seperately as well.
9067 * Then there is the orphan item, which does indeed need to be held on
9068 * to for the whole operation, and we need nobody to touch this reserved
9069 * space except the orphan code.
9070 *
9071 * So that leaves us with
9072 *
9073 * 1) root->orphan_block_rsv - for the orphan deletion.
9074 * 2) rsv - for the truncate reservation, which we will steal from the
9075 * transaction reservation.
9076 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9077 * updating the inode.
9078 */
9079 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9080 if (!rsv)
9081 return -ENOMEM;
9082 rsv->size = min_size;
9083 rsv->failfast = 1;
9084
9085 /*
9086 * 1 for the truncate slack space
9087 * 1 for updating the inode.
9088 */
9089 trans = btrfs_start_transaction(root, 2);
9090 if (IS_ERR(trans)) {
9091 err = PTR_ERR(trans);
9092 goto out;
9093 }
9094
9095 /* Migrate the slack space for the truncate to our reserve */
9096 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9097 min_size);
9098 BUG_ON(ret);
9099
9100 /*
9101 * So if we truncate and then write and fsync we normally would just
9102 * write the extents that changed, which is a problem if we need to
9103 * first truncate that entire inode. So set this flag so we write out
9104 * all of the extents in the inode to the sync log so we're completely
9105 * safe.
9106 */
9107 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9108 trans->block_rsv = rsv;
9109
9110 while (1) {
9111 ret = btrfs_truncate_inode_items(trans, root, inode,
9112 inode->i_size,
9113 BTRFS_EXTENT_DATA_KEY);
9114 if (ret != -ENOSPC && ret != -EAGAIN) {
9115 err = ret;
9116 break;
9117 }
9118
9119 trans->block_rsv = &root->fs_info->trans_block_rsv;
9120 ret = btrfs_update_inode(trans, root, inode);
9121 if (ret) {
9122 err = ret;
9123 break;
9124 }
9125
9126 btrfs_end_transaction(trans, root);
9127 btrfs_btree_balance_dirty(root);
9128
9129 trans = btrfs_start_transaction(root, 2);
9130 if (IS_ERR(trans)) {
9131 ret = err = PTR_ERR(trans);
9132 trans = NULL;
9133 break;
9134 }
9135
9136 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9137 rsv, min_size);
9138 BUG_ON(ret); /* shouldn't happen */
9139 trans->block_rsv = rsv;
9140 }
9141
9142 if (ret == 0 && inode->i_nlink > 0) {
9143 trans->block_rsv = root->orphan_block_rsv;
9144 ret = btrfs_orphan_del(trans, inode);
9145 if (ret)
9146 err = ret;
9147 }
9148
9149 if (trans) {
9150 trans->block_rsv = &root->fs_info->trans_block_rsv;
9151 ret = btrfs_update_inode(trans, root, inode);
9152 if (ret && !err)
9153 err = ret;
9154
9155 ret = btrfs_end_transaction(trans, root);
9156 btrfs_btree_balance_dirty(root);
9157 }
9158
9159 out:
9160 btrfs_free_block_rsv(root, rsv);
9161
9162 if (ret && !err)
9163 err = ret;
9164
9165 return err;
9166 }
9167
9168 /*
9169 * create a new subvolume directory/inode (helper for the ioctl).
9170 */
9171 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9172 struct btrfs_root *new_root,
9173 struct btrfs_root *parent_root,
9174 u64 new_dirid)
9175 {
9176 struct inode *inode;
9177 int err;
9178 u64 index = 0;
9179
9180 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9181 new_dirid, new_dirid,
9182 S_IFDIR | (~current_umask() & S_IRWXUGO),
9183 &index);
9184 if (IS_ERR(inode))
9185 return PTR_ERR(inode);
9186 inode->i_op = &btrfs_dir_inode_operations;
9187 inode->i_fop = &btrfs_dir_file_operations;
9188
9189 set_nlink(inode, 1);
9190 btrfs_i_size_write(inode, 0);
9191 unlock_new_inode(inode);
9192
9193 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9194 if (err)
9195 btrfs_err(new_root->fs_info,
9196 "error inheriting subvolume %llu properties: %d",
9197 new_root->root_key.objectid, err);
9198
9199 err = btrfs_update_inode(trans, new_root, inode);
9200
9201 iput(inode);
9202 return err;
9203 }
9204
9205 struct inode *btrfs_alloc_inode(struct super_block *sb)
9206 {
9207 struct btrfs_inode *ei;
9208 struct inode *inode;
9209
9210 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9211 if (!ei)
9212 return NULL;
9213
9214 ei->root = NULL;
9215 ei->generation = 0;
9216 ei->last_trans = 0;
9217 ei->last_sub_trans = 0;
9218 ei->logged_trans = 0;
9219 ei->delalloc_bytes = 0;
9220 ei->defrag_bytes = 0;
9221 ei->disk_i_size = 0;
9222 ei->flags = 0;
9223 ei->csum_bytes = 0;
9224 ei->index_cnt = (u64)-1;
9225 ei->dir_index = 0;
9226 ei->last_unlink_trans = 0;
9227 ei->last_log_commit = 0;
9228 ei->delayed_iput_count = 0;
9229
9230 spin_lock_init(&ei->lock);
9231 ei->outstanding_extents = 0;
9232 ei->reserved_extents = 0;
9233
9234 ei->runtime_flags = 0;
9235 ei->force_compress = BTRFS_COMPRESS_NONE;
9236
9237 ei->delayed_node = NULL;
9238
9239 ei->i_otime.tv_sec = 0;
9240 ei->i_otime.tv_nsec = 0;
9241
9242 inode = &ei->vfs_inode;
9243 extent_map_tree_init(&ei->extent_tree);
9244 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9245 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9246 ei->io_tree.track_uptodate = 1;
9247 ei->io_failure_tree.track_uptodate = 1;
9248 atomic_set(&ei->sync_writers, 0);
9249 mutex_init(&ei->log_mutex);
9250 mutex_init(&ei->delalloc_mutex);
9251 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9252 INIT_LIST_HEAD(&ei->delalloc_inodes);
9253 INIT_LIST_HEAD(&ei->delayed_iput);
9254 RB_CLEAR_NODE(&ei->rb_node);
9255 init_rwsem(&ei->dio_sem);
9256
9257 return inode;
9258 }
9259
9260 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9261 void btrfs_test_destroy_inode(struct inode *inode)
9262 {
9263 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9264 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9265 }
9266 #endif
9267
9268 static void btrfs_i_callback(struct rcu_head *head)
9269 {
9270 struct inode *inode = container_of(head, struct inode, i_rcu);
9271 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9272 }
9273
9274 void btrfs_destroy_inode(struct inode *inode)
9275 {
9276 struct btrfs_ordered_extent *ordered;
9277 struct btrfs_root *root = BTRFS_I(inode)->root;
9278
9279 WARN_ON(!hlist_empty(&inode->i_dentry));
9280 WARN_ON(inode->i_data.nrpages);
9281 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9282 WARN_ON(BTRFS_I(inode)->reserved_extents);
9283 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9284 WARN_ON(BTRFS_I(inode)->csum_bytes);
9285 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9286
9287 /*
9288 * This can happen where we create an inode, but somebody else also
9289 * created the same inode and we need to destroy the one we already
9290 * created.
9291 */
9292 if (!root)
9293 goto free;
9294
9295 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9296 &BTRFS_I(inode)->runtime_flags)) {
9297 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9298 btrfs_ino(inode));
9299 atomic_dec(&root->orphan_inodes);
9300 }
9301
9302 while (1) {
9303 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9304 if (!ordered)
9305 break;
9306 else {
9307 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9308 ordered->file_offset, ordered->len);
9309 btrfs_remove_ordered_extent(inode, ordered);
9310 btrfs_put_ordered_extent(ordered);
9311 btrfs_put_ordered_extent(ordered);
9312 }
9313 }
9314 btrfs_qgroup_check_reserved_leak(inode);
9315 inode_tree_del(inode);
9316 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9317 free:
9318 call_rcu(&inode->i_rcu, btrfs_i_callback);
9319 }
9320
9321 int btrfs_drop_inode(struct inode *inode)
9322 {
9323 struct btrfs_root *root = BTRFS_I(inode)->root;
9324
9325 if (root == NULL)
9326 return 1;
9327
9328 /* the snap/subvol tree is on deleting */
9329 if (btrfs_root_refs(&root->root_item) == 0)
9330 return 1;
9331 else
9332 return generic_drop_inode(inode);
9333 }
9334
9335 static void init_once(void *foo)
9336 {
9337 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9338
9339 inode_init_once(&ei->vfs_inode);
9340 }
9341
9342 void btrfs_destroy_cachep(void)
9343 {
9344 /*
9345 * Make sure all delayed rcu free inodes are flushed before we
9346 * destroy cache.
9347 */
9348 rcu_barrier();
9349 kmem_cache_destroy(btrfs_inode_cachep);
9350 kmem_cache_destroy(btrfs_trans_handle_cachep);
9351 kmem_cache_destroy(btrfs_transaction_cachep);
9352 kmem_cache_destroy(btrfs_path_cachep);
9353 kmem_cache_destroy(btrfs_free_space_cachep);
9354 }
9355
9356 int btrfs_init_cachep(void)
9357 {
9358 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9359 sizeof(struct btrfs_inode), 0,
9360 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9361 init_once);
9362 if (!btrfs_inode_cachep)
9363 goto fail;
9364
9365 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9366 sizeof(struct btrfs_trans_handle), 0,
9367 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9368 if (!btrfs_trans_handle_cachep)
9369 goto fail;
9370
9371 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9372 sizeof(struct btrfs_transaction), 0,
9373 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9374 if (!btrfs_transaction_cachep)
9375 goto fail;
9376
9377 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9378 sizeof(struct btrfs_path), 0,
9379 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9380 if (!btrfs_path_cachep)
9381 goto fail;
9382
9383 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9384 sizeof(struct btrfs_free_space), 0,
9385 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9386 if (!btrfs_free_space_cachep)
9387 goto fail;
9388
9389 return 0;
9390 fail:
9391 btrfs_destroy_cachep();
9392 return -ENOMEM;
9393 }
9394
9395 static int btrfs_getattr(struct vfsmount *mnt,
9396 struct dentry *dentry, struct kstat *stat)
9397 {
9398 u64 delalloc_bytes;
9399 struct inode *inode = d_inode(dentry);
9400 u32 blocksize = inode->i_sb->s_blocksize;
9401
9402 generic_fillattr(inode, stat);
9403 stat->dev = BTRFS_I(inode)->root->anon_dev;
9404
9405 spin_lock(&BTRFS_I(inode)->lock);
9406 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9407 spin_unlock(&BTRFS_I(inode)->lock);
9408 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9409 ALIGN(delalloc_bytes, blocksize)) >> 9;
9410 return 0;
9411 }
9412
9413 static int btrfs_rename_exchange(struct inode *old_dir,
9414 struct dentry *old_dentry,
9415 struct inode *new_dir,
9416 struct dentry *new_dentry)
9417 {
9418 struct btrfs_trans_handle *trans;
9419 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9420 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9421 struct inode *new_inode = new_dentry->d_inode;
9422 struct inode *old_inode = old_dentry->d_inode;
9423 struct timespec ctime = CURRENT_TIME;
9424 struct dentry *parent;
9425 u64 old_ino = btrfs_ino(old_inode);
9426 u64 new_ino = btrfs_ino(new_inode);
9427 u64 old_idx = 0;
9428 u64 new_idx = 0;
9429 u64 root_objectid;
9430 int ret;
9431 bool root_log_pinned = false;
9432 bool dest_log_pinned = false;
9433
9434 /* we only allow rename subvolume link between subvolumes */
9435 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9436 return -EXDEV;
9437
9438 /* close the race window with snapshot create/destroy ioctl */
9439 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9440 down_read(&root->fs_info->subvol_sem);
9441 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9442 down_read(&dest->fs_info->subvol_sem);
9443
9444 /*
9445 * We want to reserve the absolute worst case amount of items. So if
9446 * both inodes are subvols and we need to unlink them then that would
9447 * require 4 item modifications, but if they are both normal inodes it
9448 * would require 5 item modifications, so we'll assume their normal
9449 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9450 * should cover the worst case number of items we'll modify.
9451 */
9452 trans = btrfs_start_transaction(root, 12);
9453 if (IS_ERR(trans)) {
9454 ret = PTR_ERR(trans);
9455 goto out_notrans;
9456 }
9457
9458 /*
9459 * We need to find a free sequence number both in the source and
9460 * in the destination directory for the exchange.
9461 */
9462 ret = btrfs_set_inode_index(new_dir, &old_idx);
9463 if (ret)
9464 goto out_fail;
9465 ret = btrfs_set_inode_index(old_dir, &new_idx);
9466 if (ret)
9467 goto out_fail;
9468
9469 BTRFS_I(old_inode)->dir_index = 0ULL;
9470 BTRFS_I(new_inode)->dir_index = 0ULL;
9471
9472 /* Reference for the source. */
9473 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9474 /* force full log commit if subvolume involved. */
9475 btrfs_set_log_full_commit(root->fs_info, trans);
9476 } else {
9477 btrfs_pin_log_trans(root);
9478 root_log_pinned = true;
9479 ret = btrfs_insert_inode_ref(trans, dest,
9480 new_dentry->d_name.name,
9481 new_dentry->d_name.len,
9482 old_ino,
9483 btrfs_ino(new_dir), old_idx);
9484 if (ret)
9485 goto out_fail;
9486 }
9487
9488 /* And now for the dest. */
9489 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9490 /* force full log commit if subvolume involved. */
9491 btrfs_set_log_full_commit(dest->fs_info, trans);
9492 } else {
9493 btrfs_pin_log_trans(dest);
9494 dest_log_pinned = true;
9495 ret = btrfs_insert_inode_ref(trans, root,
9496 old_dentry->d_name.name,
9497 old_dentry->d_name.len,
9498 new_ino,
9499 btrfs_ino(old_dir), new_idx);
9500 if (ret)
9501 goto out_fail;
9502 }
9503
9504 /* Update inode version and ctime/mtime. */
9505 inode_inc_iversion(old_dir);
9506 inode_inc_iversion(new_dir);
9507 inode_inc_iversion(old_inode);
9508 inode_inc_iversion(new_inode);
9509 old_dir->i_ctime = old_dir->i_mtime = ctime;
9510 new_dir->i_ctime = new_dir->i_mtime = ctime;
9511 old_inode->i_ctime = ctime;
9512 new_inode->i_ctime = ctime;
9513
9514 if (old_dentry->d_parent != new_dentry->d_parent) {
9515 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9516 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9517 }
9518
9519 /* src is a subvolume */
9520 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9521 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9522 ret = btrfs_unlink_subvol(trans, root, old_dir,
9523 root_objectid,
9524 old_dentry->d_name.name,
9525 old_dentry->d_name.len);
9526 } else { /* src is an inode */
9527 ret = __btrfs_unlink_inode(trans, root, old_dir,
9528 old_dentry->d_inode,
9529 old_dentry->d_name.name,
9530 old_dentry->d_name.len);
9531 if (!ret)
9532 ret = btrfs_update_inode(trans, root, old_inode);
9533 }
9534 if (ret) {
9535 btrfs_abort_transaction(trans, root, ret);
9536 goto out_fail;
9537 }
9538
9539 /* dest is a subvolume */
9540 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9541 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9542 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9543 root_objectid,
9544 new_dentry->d_name.name,
9545 new_dentry->d_name.len);
9546 } else { /* dest is an inode */
9547 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9548 new_dentry->d_inode,
9549 new_dentry->d_name.name,
9550 new_dentry->d_name.len);
9551 if (!ret)
9552 ret = btrfs_update_inode(trans, dest, new_inode);
9553 }
9554 if (ret) {
9555 btrfs_abort_transaction(trans, root, ret);
9556 goto out_fail;
9557 }
9558
9559 ret = btrfs_add_link(trans, new_dir, old_inode,
9560 new_dentry->d_name.name,
9561 new_dentry->d_name.len, 0, old_idx);
9562 if (ret) {
9563 btrfs_abort_transaction(trans, root, ret);
9564 goto out_fail;
9565 }
9566
9567 ret = btrfs_add_link(trans, old_dir, new_inode,
9568 old_dentry->d_name.name,
9569 old_dentry->d_name.len, 0, new_idx);
9570 if (ret) {
9571 btrfs_abort_transaction(trans, root, ret);
9572 goto out_fail;
9573 }
9574
9575 if (old_inode->i_nlink == 1)
9576 BTRFS_I(old_inode)->dir_index = old_idx;
9577 if (new_inode->i_nlink == 1)
9578 BTRFS_I(new_inode)->dir_index = new_idx;
9579
9580 if (root_log_pinned) {
9581 parent = new_dentry->d_parent;
9582 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9583 btrfs_end_log_trans(root);
9584 root_log_pinned = false;
9585 }
9586 if (dest_log_pinned) {
9587 parent = old_dentry->d_parent;
9588 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9589 btrfs_end_log_trans(dest);
9590 dest_log_pinned = false;
9591 }
9592 out_fail:
9593 /*
9594 * If we have pinned a log and an error happened, we unpin tasks
9595 * trying to sync the log and force them to fallback to a transaction
9596 * commit if the log currently contains any of the inodes involved in
9597 * this rename operation (to ensure we do not persist a log with an
9598 * inconsistent state for any of these inodes or leading to any
9599 * inconsistencies when replayed). If the transaction was aborted, the
9600 * abortion reason is propagated to userspace when attempting to commit
9601 * the transaction. If the log does not contain any of these inodes, we
9602 * allow the tasks to sync it.
9603 */
9604 if (ret && (root_log_pinned || dest_log_pinned)) {
9605 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9606 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9607 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9608 (new_inode &&
9609 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9610 btrfs_set_log_full_commit(root->fs_info, trans);
9611
9612 if (root_log_pinned) {
9613 btrfs_end_log_trans(root);
9614 root_log_pinned = false;
9615 }
9616 if (dest_log_pinned) {
9617 btrfs_end_log_trans(dest);
9618 dest_log_pinned = false;
9619 }
9620 }
9621 ret = btrfs_end_transaction(trans, root);
9622 out_notrans:
9623 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9624 up_read(&dest->fs_info->subvol_sem);
9625 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9626 up_read(&root->fs_info->subvol_sem);
9627
9628 return ret;
9629 }
9630
9631 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9632 struct btrfs_root *root,
9633 struct inode *dir,
9634 struct dentry *dentry)
9635 {
9636 int ret;
9637 struct inode *inode;
9638 u64 objectid;
9639 u64 index;
9640
9641 ret = btrfs_find_free_ino(root, &objectid);
9642 if (ret)
9643 return ret;
9644
9645 inode = btrfs_new_inode(trans, root, dir,
9646 dentry->d_name.name,
9647 dentry->d_name.len,
9648 btrfs_ino(dir),
9649 objectid,
9650 S_IFCHR | WHITEOUT_MODE,
9651 &index);
9652
9653 if (IS_ERR(inode)) {
9654 ret = PTR_ERR(inode);
9655 return ret;
9656 }
9657
9658 inode->i_op = &btrfs_special_inode_operations;
9659 init_special_inode(inode, inode->i_mode,
9660 WHITEOUT_DEV);
9661
9662 ret = btrfs_init_inode_security(trans, inode, dir,
9663 &dentry->d_name);
9664 if (ret)
9665 goto out;
9666
9667 ret = btrfs_add_nondir(trans, dir, dentry,
9668 inode, 0, index);
9669 if (ret)
9670 goto out;
9671
9672 ret = btrfs_update_inode(trans, root, inode);
9673 out:
9674 unlock_new_inode(inode);
9675 if (ret)
9676 inode_dec_link_count(inode);
9677 iput(inode);
9678
9679 return ret;
9680 }
9681
9682 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9683 struct inode *new_dir, struct dentry *new_dentry,
9684 unsigned int flags)
9685 {
9686 struct btrfs_trans_handle *trans;
9687 unsigned int trans_num_items;
9688 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9689 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9690 struct inode *new_inode = d_inode(new_dentry);
9691 struct inode *old_inode = d_inode(old_dentry);
9692 u64 index = 0;
9693 u64 root_objectid;
9694 int ret;
9695 u64 old_ino = btrfs_ino(old_inode);
9696 bool log_pinned = false;
9697
9698 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9699 return -EPERM;
9700
9701 /* we only allow rename subvolume link between subvolumes */
9702 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9703 return -EXDEV;
9704
9705 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9706 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9707 return -ENOTEMPTY;
9708
9709 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9710 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9711 return -ENOTEMPTY;
9712
9713
9714 /* check for collisions, even if the name isn't there */
9715 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9716 new_dentry->d_name.name,
9717 new_dentry->d_name.len);
9718
9719 if (ret) {
9720 if (ret == -EEXIST) {
9721 /* we shouldn't get
9722 * eexist without a new_inode */
9723 if (WARN_ON(!new_inode)) {
9724 return ret;
9725 }
9726 } else {
9727 /* maybe -EOVERFLOW */
9728 return ret;
9729 }
9730 }
9731 ret = 0;
9732
9733 /*
9734 * we're using rename to replace one file with another. Start IO on it
9735 * now so we don't add too much work to the end of the transaction
9736 */
9737 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9738 filemap_flush(old_inode->i_mapping);
9739
9740 /* close the racy window with snapshot create/destroy ioctl */
9741 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9742 down_read(&root->fs_info->subvol_sem);
9743 /*
9744 * We want to reserve the absolute worst case amount of items. So if
9745 * both inodes are subvols and we need to unlink them then that would
9746 * require 4 item modifications, but if they are both normal inodes it
9747 * would require 5 item modifications, so we'll assume they are normal
9748 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9749 * should cover the worst case number of items we'll modify.
9750 * If our rename has the whiteout flag, we need more 5 units for the
9751 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9752 * when selinux is enabled).
9753 */
9754 trans_num_items = 11;
9755 if (flags & RENAME_WHITEOUT)
9756 trans_num_items += 5;
9757 trans = btrfs_start_transaction(root, trans_num_items);
9758 if (IS_ERR(trans)) {
9759 ret = PTR_ERR(trans);
9760 goto out_notrans;
9761 }
9762
9763 if (dest != root)
9764 btrfs_record_root_in_trans(trans, dest);
9765
9766 ret = btrfs_set_inode_index(new_dir, &index);
9767 if (ret)
9768 goto out_fail;
9769
9770 BTRFS_I(old_inode)->dir_index = 0ULL;
9771 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9772 /* force full log commit if subvolume involved. */
9773 btrfs_set_log_full_commit(root->fs_info, trans);
9774 } else {
9775 btrfs_pin_log_trans(root);
9776 log_pinned = true;
9777 ret = btrfs_insert_inode_ref(trans, dest,
9778 new_dentry->d_name.name,
9779 new_dentry->d_name.len,
9780 old_ino,
9781 btrfs_ino(new_dir), index);
9782 if (ret)
9783 goto out_fail;
9784 }
9785
9786 inode_inc_iversion(old_dir);
9787 inode_inc_iversion(new_dir);
9788 inode_inc_iversion(old_inode);
9789 old_dir->i_ctime = old_dir->i_mtime =
9790 new_dir->i_ctime = new_dir->i_mtime =
9791 old_inode->i_ctime = current_fs_time(old_dir->i_sb);
9792
9793 if (old_dentry->d_parent != new_dentry->d_parent)
9794 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9795
9796 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9797 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9798 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9799 old_dentry->d_name.name,
9800 old_dentry->d_name.len);
9801 } else {
9802 ret = __btrfs_unlink_inode(trans, root, old_dir,
9803 d_inode(old_dentry),
9804 old_dentry->d_name.name,
9805 old_dentry->d_name.len);
9806 if (!ret)
9807 ret = btrfs_update_inode(trans, root, old_inode);
9808 }
9809 if (ret) {
9810 btrfs_abort_transaction(trans, root, ret);
9811 goto out_fail;
9812 }
9813
9814 if (new_inode) {
9815 inode_inc_iversion(new_inode);
9816 new_inode->i_ctime = current_fs_time(new_inode->i_sb);
9817 if (unlikely(btrfs_ino(new_inode) ==
9818 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9819 root_objectid = BTRFS_I(new_inode)->location.objectid;
9820 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9821 root_objectid,
9822 new_dentry->d_name.name,
9823 new_dentry->d_name.len);
9824 BUG_ON(new_inode->i_nlink == 0);
9825 } else {
9826 ret = btrfs_unlink_inode(trans, dest, new_dir,
9827 d_inode(new_dentry),
9828 new_dentry->d_name.name,
9829 new_dentry->d_name.len);
9830 }
9831 if (!ret && new_inode->i_nlink == 0)
9832 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9833 if (ret) {
9834 btrfs_abort_transaction(trans, root, ret);
9835 goto out_fail;
9836 }
9837 }
9838
9839 ret = btrfs_add_link(trans, new_dir, old_inode,
9840 new_dentry->d_name.name,
9841 new_dentry->d_name.len, 0, index);
9842 if (ret) {
9843 btrfs_abort_transaction(trans, root, ret);
9844 goto out_fail;
9845 }
9846
9847 if (old_inode->i_nlink == 1)
9848 BTRFS_I(old_inode)->dir_index = index;
9849
9850 if (log_pinned) {
9851 struct dentry *parent = new_dentry->d_parent;
9852
9853 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9854 btrfs_end_log_trans(root);
9855 log_pinned = false;
9856 }
9857
9858 if (flags & RENAME_WHITEOUT) {
9859 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9860 old_dentry);
9861
9862 if (ret) {
9863 btrfs_abort_transaction(trans, root, ret);
9864 goto out_fail;
9865 }
9866 }
9867 out_fail:
9868 /*
9869 * If we have pinned the log and an error happened, we unpin tasks
9870 * trying to sync the log and force them to fallback to a transaction
9871 * commit if the log currently contains any of the inodes involved in
9872 * this rename operation (to ensure we do not persist a log with an
9873 * inconsistent state for any of these inodes or leading to any
9874 * inconsistencies when replayed). If the transaction was aborted, the
9875 * abortion reason is propagated to userspace when attempting to commit
9876 * the transaction. If the log does not contain any of these inodes, we
9877 * allow the tasks to sync it.
9878 */
9879 if (ret && log_pinned) {
9880 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9881 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9882 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9883 (new_inode &&
9884 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9885 btrfs_set_log_full_commit(root->fs_info, trans);
9886
9887 btrfs_end_log_trans(root);
9888 log_pinned = false;
9889 }
9890 btrfs_end_transaction(trans, root);
9891 out_notrans:
9892 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9893 up_read(&root->fs_info->subvol_sem);
9894
9895 return ret;
9896 }
9897
9898 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9899 struct inode *new_dir, struct dentry *new_dentry,
9900 unsigned int flags)
9901 {
9902 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9903 return -EINVAL;
9904
9905 if (flags & RENAME_EXCHANGE)
9906 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9907 new_dentry);
9908
9909 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9910 }
9911
9912 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9913 {
9914 struct btrfs_delalloc_work *delalloc_work;
9915 struct inode *inode;
9916
9917 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9918 work);
9919 inode = delalloc_work->inode;
9920 filemap_flush(inode->i_mapping);
9921 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9922 &BTRFS_I(inode)->runtime_flags))
9923 filemap_flush(inode->i_mapping);
9924
9925 if (delalloc_work->delay_iput)
9926 btrfs_add_delayed_iput(inode);
9927 else
9928 iput(inode);
9929 complete(&delalloc_work->completion);
9930 }
9931
9932 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9933 int delay_iput)
9934 {
9935 struct btrfs_delalloc_work *work;
9936
9937 work = kmalloc(sizeof(*work), GFP_NOFS);
9938 if (!work)
9939 return NULL;
9940
9941 init_completion(&work->completion);
9942 INIT_LIST_HEAD(&work->list);
9943 work->inode = inode;
9944 work->delay_iput = delay_iput;
9945 WARN_ON_ONCE(!inode);
9946 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9947 btrfs_run_delalloc_work, NULL, NULL);
9948
9949 return work;
9950 }
9951
9952 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9953 {
9954 wait_for_completion(&work->completion);
9955 kfree(work);
9956 }
9957
9958 /*
9959 * some fairly slow code that needs optimization. This walks the list
9960 * of all the inodes with pending delalloc and forces them to disk.
9961 */
9962 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9963 int nr)
9964 {
9965 struct btrfs_inode *binode;
9966 struct inode *inode;
9967 struct btrfs_delalloc_work *work, *next;
9968 struct list_head works;
9969 struct list_head splice;
9970 int ret = 0;
9971
9972 INIT_LIST_HEAD(&works);
9973 INIT_LIST_HEAD(&splice);
9974
9975 mutex_lock(&root->delalloc_mutex);
9976 spin_lock(&root->delalloc_lock);
9977 list_splice_init(&root->delalloc_inodes, &splice);
9978 while (!list_empty(&splice)) {
9979 binode = list_entry(splice.next, struct btrfs_inode,
9980 delalloc_inodes);
9981
9982 list_move_tail(&binode->delalloc_inodes,
9983 &root->delalloc_inodes);
9984 inode = igrab(&binode->vfs_inode);
9985 if (!inode) {
9986 cond_resched_lock(&root->delalloc_lock);
9987 continue;
9988 }
9989 spin_unlock(&root->delalloc_lock);
9990
9991 work = btrfs_alloc_delalloc_work(inode, delay_iput);
9992 if (!work) {
9993 if (delay_iput)
9994 btrfs_add_delayed_iput(inode);
9995 else
9996 iput(inode);
9997 ret = -ENOMEM;
9998 goto out;
9999 }
10000 list_add_tail(&work->list, &works);
10001 btrfs_queue_work(root->fs_info->flush_workers,
10002 &work->work);
10003 ret++;
10004 if (nr != -1 && ret >= nr)
10005 goto out;
10006 cond_resched();
10007 spin_lock(&root->delalloc_lock);
10008 }
10009 spin_unlock(&root->delalloc_lock);
10010
10011 out:
10012 list_for_each_entry_safe(work, next, &works, list) {
10013 list_del_init(&work->list);
10014 btrfs_wait_and_free_delalloc_work(work);
10015 }
10016
10017 if (!list_empty_careful(&splice)) {
10018 spin_lock(&root->delalloc_lock);
10019 list_splice_tail(&splice, &root->delalloc_inodes);
10020 spin_unlock(&root->delalloc_lock);
10021 }
10022 mutex_unlock(&root->delalloc_mutex);
10023 return ret;
10024 }
10025
10026 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10027 {
10028 int ret;
10029
10030 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10031 return -EROFS;
10032
10033 ret = __start_delalloc_inodes(root, delay_iput, -1);
10034 if (ret > 0)
10035 ret = 0;
10036 /*
10037 * the filemap_flush will queue IO into the worker threads, but
10038 * we have to make sure the IO is actually started and that
10039 * ordered extents get created before we return
10040 */
10041 atomic_inc(&root->fs_info->async_submit_draining);
10042 while (atomic_read(&root->fs_info->nr_async_submits) ||
10043 atomic_read(&root->fs_info->async_delalloc_pages)) {
10044 wait_event(root->fs_info->async_submit_wait,
10045 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10046 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10047 }
10048 atomic_dec(&root->fs_info->async_submit_draining);
10049 return ret;
10050 }
10051
10052 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10053 int nr)
10054 {
10055 struct btrfs_root *root;
10056 struct list_head splice;
10057 int ret;
10058
10059 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10060 return -EROFS;
10061
10062 INIT_LIST_HEAD(&splice);
10063
10064 mutex_lock(&fs_info->delalloc_root_mutex);
10065 spin_lock(&fs_info->delalloc_root_lock);
10066 list_splice_init(&fs_info->delalloc_roots, &splice);
10067 while (!list_empty(&splice) && nr) {
10068 root = list_first_entry(&splice, struct btrfs_root,
10069 delalloc_root);
10070 root = btrfs_grab_fs_root(root);
10071 BUG_ON(!root);
10072 list_move_tail(&root->delalloc_root,
10073 &fs_info->delalloc_roots);
10074 spin_unlock(&fs_info->delalloc_root_lock);
10075
10076 ret = __start_delalloc_inodes(root, delay_iput, nr);
10077 btrfs_put_fs_root(root);
10078 if (ret < 0)
10079 goto out;
10080
10081 if (nr != -1) {
10082 nr -= ret;
10083 WARN_ON(nr < 0);
10084 }
10085 spin_lock(&fs_info->delalloc_root_lock);
10086 }
10087 spin_unlock(&fs_info->delalloc_root_lock);
10088
10089 ret = 0;
10090 atomic_inc(&fs_info->async_submit_draining);
10091 while (atomic_read(&fs_info->nr_async_submits) ||
10092 atomic_read(&fs_info->async_delalloc_pages)) {
10093 wait_event(fs_info->async_submit_wait,
10094 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10095 atomic_read(&fs_info->async_delalloc_pages) == 0));
10096 }
10097 atomic_dec(&fs_info->async_submit_draining);
10098 out:
10099 if (!list_empty_careful(&splice)) {
10100 spin_lock(&fs_info->delalloc_root_lock);
10101 list_splice_tail(&splice, &fs_info->delalloc_roots);
10102 spin_unlock(&fs_info->delalloc_root_lock);
10103 }
10104 mutex_unlock(&fs_info->delalloc_root_mutex);
10105 return ret;
10106 }
10107
10108 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10109 const char *symname)
10110 {
10111 struct btrfs_trans_handle *trans;
10112 struct btrfs_root *root = BTRFS_I(dir)->root;
10113 struct btrfs_path *path;
10114 struct btrfs_key key;
10115 struct inode *inode = NULL;
10116 int err;
10117 int drop_inode = 0;
10118 u64 objectid;
10119 u64 index = 0;
10120 int name_len;
10121 int datasize;
10122 unsigned long ptr;
10123 struct btrfs_file_extent_item *ei;
10124 struct extent_buffer *leaf;
10125
10126 name_len = strlen(symname);
10127 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10128 return -ENAMETOOLONG;
10129
10130 /*
10131 * 2 items for inode item and ref
10132 * 2 items for dir items
10133 * 1 item for updating parent inode item
10134 * 1 item for the inline extent item
10135 * 1 item for xattr if selinux is on
10136 */
10137 trans = btrfs_start_transaction(root, 7);
10138 if (IS_ERR(trans))
10139 return PTR_ERR(trans);
10140
10141 err = btrfs_find_free_ino(root, &objectid);
10142 if (err)
10143 goto out_unlock;
10144
10145 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10146 dentry->d_name.len, btrfs_ino(dir), objectid,
10147 S_IFLNK|S_IRWXUGO, &index);
10148 if (IS_ERR(inode)) {
10149 err = PTR_ERR(inode);
10150 goto out_unlock;
10151 }
10152
10153 /*
10154 * If the active LSM wants to access the inode during
10155 * d_instantiate it needs these. Smack checks to see
10156 * if the filesystem supports xattrs by looking at the
10157 * ops vector.
10158 */
10159 inode->i_fop = &btrfs_file_operations;
10160 inode->i_op = &btrfs_file_inode_operations;
10161 inode->i_mapping->a_ops = &btrfs_aops;
10162 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10163
10164 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10165 if (err)
10166 goto out_unlock_inode;
10167
10168 path = btrfs_alloc_path();
10169 if (!path) {
10170 err = -ENOMEM;
10171 goto out_unlock_inode;
10172 }
10173 key.objectid = btrfs_ino(inode);
10174 key.offset = 0;
10175 key.type = BTRFS_EXTENT_DATA_KEY;
10176 datasize = btrfs_file_extent_calc_inline_size(name_len);
10177 err = btrfs_insert_empty_item(trans, root, path, &key,
10178 datasize);
10179 if (err) {
10180 btrfs_free_path(path);
10181 goto out_unlock_inode;
10182 }
10183 leaf = path->nodes[0];
10184 ei = btrfs_item_ptr(leaf, path->slots[0],
10185 struct btrfs_file_extent_item);
10186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10187 btrfs_set_file_extent_type(leaf, ei,
10188 BTRFS_FILE_EXTENT_INLINE);
10189 btrfs_set_file_extent_encryption(leaf, ei, 0);
10190 btrfs_set_file_extent_compression(leaf, ei, 0);
10191 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10192 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10193
10194 ptr = btrfs_file_extent_inline_start(ei);
10195 write_extent_buffer(leaf, symname, ptr, name_len);
10196 btrfs_mark_buffer_dirty(leaf);
10197 btrfs_free_path(path);
10198
10199 inode->i_op = &btrfs_symlink_inode_operations;
10200 inode_nohighmem(inode);
10201 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10202 inode_set_bytes(inode, name_len);
10203 btrfs_i_size_write(inode, name_len);
10204 err = btrfs_update_inode(trans, root, inode);
10205 /*
10206 * Last step, add directory indexes for our symlink inode. This is the
10207 * last step to avoid extra cleanup of these indexes if an error happens
10208 * elsewhere above.
10209 */
10210 if (!err)
10211 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10212 if (err) {
10213 drop_inode = 1;
10214 goto out_unlock_inode;
10215 }
10216
10217 unlock_new_inode(inode);
10218 d_instantiate(dentry, inode);
10219
10220 out_unlock:
10221 btrfs_end_transaction(trans, root);
10222 if (drop_inode) {
10223 inode_dec_link_count(inode);
10224 iput(inode);
10225 }
10226 btrfs_btree_balance_dirty(root);
10227 return err;
10228
10229 out_unlock_inode:
10230 drop_inode = 1;
10231 unlock_new_inode(inode);
10232 goto out_unlock;
10233 }
10234
10235 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10236 u64 start, u64 num_bytes, u64 min_size,
10237 loff_t actual_len, u64 *alloc_hint,
10238 struct btrfs_trans_handle *trans)
10239 {
10240 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10241 struct extent_map *em;
10242 struct btrfs_root *root = BTRFS_I(inode)->root;
10243 struct btrfs_key ins;
10244 u64 cur_offset = start;
10245 u64 i_size;
10246 u64 cur_bytes;
10247 u64 last_alloc = (u64)-1;
10248 int ret = 0;
10249 bool own_trans = true;
10250
10251 if (trans)
10252 own_trans = false;
10253 while (num_bytes > 0) {
10254 if (own_trans) {
10255 trans = btrfs_start_transaction(root, 3);
10256 if (IS_ERR(trans)) {
10257 ret = PTR_ERR(trans);
10258 break;
10259 }
10260 }
10261
10262 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10263 cur_bytes = max(cur_bytes, min_size);
10264 /*
10265 * If we are severely fragmented we could end up with really
10266 * small allocations, so if the allocator is returning small
10267 * chunks lets make its job easier by only searching for those
10268 * sized chunks.
10269 */
10270 cur_bytes = min(cur_bytes, last_alloc);
10271 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
10272 *alloc_hint, &ins, 1, 0);
10273 if (ret) {
10274 if (own_trans)
10275 btrfs_end_transaction(trans, root);
10276 break;
10277 }
10278 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10279
10280 last_alloc = ins.offset;
10281 ret = insert_reserved_file_extent(trans, inode,
10282 cur_offset, ins.objectid,
10283 ins.offset, ins.offset,
10284 ins.offset, 0, 0, 0,
10285 BTRFS_FILE_EXTENT_PREALLOC);
10286 if (ret) {
10287 btrfs_free_reserved_extent(root, ins.objectid,
10288 ins.offset, 0);
10289 btrfs_abort_transaction(trans, root, ret);
10290 if (own_trans)
10291 btrfs_end_transaction(trans, root);
10292 break;
10293 }
10294
10295 btrfs_drop_extent_cache(inode, cur_offset,
10296 cur_offset + ins.offset -1, 0);
10297
10298 em = alloc_extent_map();
10299 if (!em) {
10300 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10301 &BTRFS_I(inode)->runtime_flags);
10302 goto next;
10303 }
10304
10305 em->start = cur_offset;
10306 em->orig_start = cur_offset;
10307 em->len = ins.offset;
10308 em->block_start = ins.objectid;
10309 em->block_len = ins.offset;
10310 em->orig_block_len = ins.offset;
10311 em->ram_bytes = ins.offset;
10312 em->bdev = root->fs_info->fs_devices->latest_bdev;
10313 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10314 em->generation = trans->transid;
10315
10316 while (1) {
10317 write_lock(&em_tree->lock);
10318 ret = add_extent_mapping(em_tree, em, 1);
10319 write_unlock(&em_tree->lock);
10320 if (ret != -EEXIST)
10321 break;
10322 btrfs_drop_extent_cache(inode, cur_offset,
10323 cur_offset + ins.offset - 1,
10324 0);
10325 }
10326 free_extent_map(em);
10327 next:
10328 num_bytes -= ins.offset;
10329 cur_offset += ins.offset;
10330 *alloc_hint = ins.objectid + ins.offset;
10331
10332 inode_inc_iversion(inode);
10333 inode->i_ctime = current_fs_time(inode->i_sb);
10334 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10335 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10336 (actual_len > inode->i_size) &&
10337 (cur_offset > inode->i_size)) {
10338 if (cur_offset > actual_len)
10339 i_size = actual_len;
10340 else
10341 i_size = cur_offset;
10342 i_size_write(inode, i_size);
10343 btrfs_ordered_update_i_size(inode, i_size, NULL);
10344 }
10345
10346 ret = btrfs_update_inode(trans, root, inode);
10347
10348 if (ret) {
10349 btrfs_abort_transaction(trans, root, ret);
10350 if (own_trans)
10351 btrfs_end_transaction(trans, root);
10352 break;
10353 }
10354
10355 if (own_trans)
10356 btrfs_end_transaction(trans, root);
10357 }
10358 return ret;
10359 }
10360
10361 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10362 u64 start, u64 num_bytes, u64 min_size,
10363 loff_t actual_len, u64 *alloc_hint)
10364 {
10365 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10366 min_size, actual_len, alloc_hint,
10367 NULL);
10368 }
10369
10370 int btrfs_prealloc_file_range_trans(struct inode *inode,
10371 struct btrfs_trans_handle *trans, int mode,
10372 u64 start, u64 num_bytes, u64 min_size,
10373 loff_t actual_len, u64 *alloc_hint)
10374 {
10375 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10376 min_size, actual_len, alloc_hint, trans);
10377 }
10378
10379 static int btrfs_set_page_dirty(struct page *page)
10380 {
10381 return __set_page_dirty_nobuffers(page);
10382 }
10383
10384 static int btrfs_permission(struct inode *inode, int mask)
10385 {
10386 struct btrfs_root *root = BTRFS_I(inode)->root;
10387 umode_t mode = inode->i_mode;
10388
10389 if (mask & MAY_WRITE &&
10390 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10391 if (btrfs_root_readonly(root))
10392 return -EROFS;
10393 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10394 return -EACCES;
10395 }
10396 return generic_permission(inode, mask);
10397 }
10398
10399 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10400 {
10401 struct btrfs_trans_handle *trans;
10402 struct btrfs_root *root = BTRFS_I(dir)->root;
10403 struct inode *inode = NULL;
10404 u64 objectid;
10405 u64 index;
10406 int ret = 0;
10407
10408 /*
10409 * 5 units required for adding orphan entry
10410 */
10411 trans = btrfs_start_transaction(root, 5);
10412 if (IS_ERR(trans))
10413 return PTR_ERR(trans);
10414
10415 ret = btrfs_find_free_ino(root, &objectid);
10416 if (ret)
10417 goto out;
10418
10419 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10420 btrfs_ino(dir), objectid, mode, &index);
10421 if (IS_ERR(inode)) {
10422 ret = PTR_ERR(inode);
10423 inode = NULL;
10424 goto out;
10425 }
10426
10427 inode->i_fop = &btrfs_file_operations;
10428 inode->i_op = &btrfs_file_inode_operations;
10429
10430 inode->i_mapping->a_ops = &btrfs_aops;
10431 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10432
10433 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10434 if (ret)
10435 goto out_inode;
10436
10437 ret = btrfs_update_inode(trans, root, inode);
10438 if (ret)
10439 goto out_inode;
10440 ret = btrfs_orphan_add(trans, inode);
10441 if (ret)
10442 goto out_inode;
10443
10444 /*
10445 * We set number of links to 0 in btrfs_new_inode(), and here we set
10446 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10447 * through:
10448 *
10449 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10450 */
10451 set_nlink(inode, 1);
10452 unlock_new_inode(inode);
10453 d_tmpfile(dentry, inode);
10454 mark_inode_dirty(inode);
10455
10456 out:
10457 btrfs_end_transaction(trans, root);
10458 if (ret)
10459 iput(inode);
10460 btrfs_balance_delayed_items(root);
10461 btrfs_btree_balance_dirty(root);
10462 return ret;
10463
10464 out_inode:
10465 unlock_new_inode(inode);
10466 goto out;
10467
10468 }
10469
10470 /* Inspired by filemap_check_errors() */
10471 int btrfs_inode_check_errors(struct inode *inode)
10472 {
10473 int ret = 0;
10474
10475 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10476 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10477 ret = -ENOSPC;
10478 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10479 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10480 ret = -EIO;
10481
10482 return ret;
10483 }
10484
10485 static const struct inode_operations btrfs_dir_inode_operations = {
10486 .getattr = btrfs_getattr,
10487 .lookup = btrfs_lookup,
10488 .create = btrfs_create,
10489 .unlink = btrfs_unlink,
10490 .link = btrfs_link,
10491 .mkdir = btrfs_mkdir,
10492 .rmdir = btrfs_rmdir,
10493 .rename2 = btrfs_rename2,
10494 .symlink = btrfs_symlink,
10495 .setattr = btrfs_setattr,
10496 .mknod = btrfs_mknod,
10497 .setxattr = generic_setxattr,
10498 .getxattr = generic_getxattr,
10499 .listxattr = btrfs_listxattr,
10500 .removexattr = generic_removexattr,
10501 .permission = btrfs_permission,
10502 .get_acl = btrfs_get_acl,
10503 .set_acl = btrfs_set_acl,
10504 .update_time = btrfs_update_time,
10505 .tmpfile = btrfs_tmpfile,
10506 };
10507 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10508 .lookup = btrfs_lookup,
10509 .permission = btrfs_permission,
10510 .get_acl = btrfs_get_acl,
10511 .set_acl = btrfs_set_acl,
10512 .update_time = btrfs_update_time,
10513 };
10514
10515 static const struct file_operations btrfs_dir_file_operations = {
10516 .llseek = generic_file_llseek,
10517 .read = generic_read_dir,
10518 .iterate = btrfs_real_readdir,
10519 .unlocked_ioctl = btrfs_ioctl,
10520 #ifdef CONFIG_COMPAT
10521 .compat_ioctl = btrfs_compat_ioctl,
10522 #endif
10523 .release = btrfs_release_file,
10524 .fsync = btrfs_sync_file,
10525 };
10526
10527 static const struct extent_io_ops btrfs_extent_io_ops = {
10528 .fill_delalloc = run_delalloc_range,
10529 .submit_bio_hook = btrfs_submit_bio_hook,
10530 .merge_bio_hook = btrfs_merge_bio_hook,
10531 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10532 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10533 .writepage_start_hook = btrfs_writepage_start_hook,
10534 .set_bit_hook = btrfs_set_bit_hook,
10535 .clear_bit_hook = btrfs_clear_bit_hook,
10536 .merge_extent_hook = btrfs_merge_extent_hook,
10537 .split_extent_hook = btrfs_split_extent_hook,
10538 };
10539
10540 /*
10541 * btrfs doesn't support the bmap operation because swapfiles
10542 * use bmap to make a mapping of extents in the file. They assume
10543 * these extents won't change over the life of the file and they
10544 * use the bmap result to do IO directly to the drive.
10545 *
10546 * the btrfs bmap call would return logical addresses that aren't
10547 * suitable for IO and they also will change frequently as COW
10548 * operations happen. So, swapfile + btrfs == corruption.
10549 *
10550 * For now we're avoiding this by dropping bmap.
10551 */
10552 static const struct address_space_operations btrfs_aops = {
10553 .readpage = btrfs_readpage,
10554 .writepage = btrfs_writepage,
10555 .writepages = btrfs_writepages,
10556 .readpages = btrfs_readpages,
10557 .direct_IO = btrfs_direct_IO,
10558 .invalidatepage = btrfs_invalidatepage,
10559 .releasepage = btrfs_releasepage,
10560 .set_page_dirty = btrfs_set_page_dirty,
10561 .error_remove_page = generic_error_remove_page,
10562 };
10563
10564 static const struct address_space_operations btrfs_symlink_aops = {
10565 .readpage = btrfs_readpage,
10566 .writepage = btrfs_writepage,
10567 .invalidatepage = btrfs_invalidatepage,
10568 .releasepage = btrfs_releasepage,
10569 };
10570
10571 static const struct inode_operations btrfs_file_inode_operations = {
10572 .getattr = btrfs_getattr,
10573 .setattr = btrfs_setattr,
10574 .setxattr = generic_setxattr,
10575 .getxattr = generic_getxattr,
10576 .listxattr = btrfs_listxattr,
10577 .removexattr = generic_removexattr,
10578 .permission = btrfs_permission,
10579 .fiemap = btrfs_fiemap,
10580 .get_acl = btrfs_get_acl,
10581 .set_acl = btrfs_set_acl,
10582 .update_time = btrfs_update_time,
10583 };
10584 static const struct inode_operations btrfs_special_inode_operations = {
10585 .getattr = btrfs_getattr,
10586 .setattr = btrfs_setattr,
10587 .permission = btrfs_permission,
10588 .setxattr = generic_setxattr,
10589 .getxattr = generic_getxattr,
10590 .listxattr = btrfs_listxattr,
10591 .removexattr = generic_removexattr,
10592 .get_acl = btrfs_get_acl,
10593 .set_acl = btrfs_set_acl,
10594 .update_time = btrfs_update_time,
10595 };
10596 static const struct inode_operations btrfs_symlink_inode_operations = {
10597 .readlink = generic_readlink,
10598 .get_link = page_get_link,
10599 .getattr = btrfs_getattr,
10600 .setattr = btrfs_setattr,
10601 .permission = btrfs_permission,
10602 .setxattr = generic_setxattr,
10603 .getxattr = generic_getxattr,
10604 .listxattr = btrfs_listxattr,
10605 .removexattr = generic_removexattr,
10606 .update_time = btrfs_update_time,
10607 };
10608
10609 const struct dentry_operations btrfs_dentry_operations = {
10610 .d_delete = btrfs_dentry_delete,
10611 .d_release = btrfs_dentry_release,
10612 };
Linux kernel - Deliverables
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