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Merge branch 'kvm-mips-fixes' into HEAD
[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 doesn'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);
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 return 0;
3124 }
3125
3126 phy_offset >>= inode->i_sb->s_blocksize_bits;
3127 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3128 start, (size_t)(end - start + 1));
3129 }
3130
3131 void btrfs_add_delayed_iput(struct inode *inode)
3132 {
3133 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3134 struct btrfs_inode *binode = BTRFS_I(inode);
3135
3136 if (atomic_add_unless(&inode->i_count, -1, 1))
3137 return;
3138
3139 spin_lock(&fs_info->delayed_iput_lock);
3140 if (binode->delayed_iput_count == 0) {
3141 ASSERT(list_empty(&binode->delayed_iput));
3142 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3143 } else {
3144 binode->delayed_iput_count++;
3145 }
3146 spin_unlock(&fs_info->delayed_iput_lock);
3147 }
3148
3149 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3150 {
3151 struct btrfs_fs_info *fs_info = root->fs_info;
3152
3153 spin_lock(&fs_info->delayed_iput_lock);
3154 while (!list_empty(&fs_info->delayed_iputs)) {
3155 struct btrfs_inode *inode;
3156
3157 inode = list_first_entry(&fs_info->delayed_iputs,
3158 struct btrfs_inode, delayed_iput);
3159 if (inode->delayed_iput_count) {
3160 inode->delayed_iput_count--;
3161 list_move_tail(&inode->delayed_iput,
3162 &fs_info->delayed_iputs);
3163 } else {
3164 list_del_init(&inode->delayed_iput);
3165 }
3166 spin_unlock(&fs_info->delayed_iput_lock);
3167 iput(&inode->vfs_inode);
3168 spin_lock(&fs_info->delayed_iput_lock);
3169 }
3170 spin_unlock(&fs_info->delayed_iput_lock);
3171 }
3172
3173 /*
3174 * This is called in transaction commit time. If there are no orphan
3175 * files in the subvolume, it removes orphan item and frees block_rsv
3176 * structure.
3177 */
3178 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3179 struct btrfs_root *root)
3180 {
3181 struct btrfs_block_rsv *block_rsv;
3182 int ret;
3183
3184 if (atomic_read(&root->orphan_inodes) ||
3185 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3186 return;
3187
3188 spin_lock(&root->orphan_lock);
3189 if (atomic_read(&root->orphan_inodes)) {
3190 spin_unlock(&root->orphan_lock);
3191 return;
3192 }
3193
3194 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3195 spin_unlock(&root->orphan_lock);
3196 return;
3197 }
3198
3199 block_rsv = root->orphan_block_rsv;
3200 root->orphan_block_rsv = NULL;
3201 spin_unlock(&root->orphan_lock);
3202
3203 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3204 btrfs_root_refs(&root->root_item) > 0) {
3205 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3206 root->root_key.objectid);
3207 if (ret)
3208 btrfs_abort_transaction(trans, root, ret);
3209 else
3210 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3211 &root->state);
3212 }
3213
3214 if (block_rsv) {
3215 WARN_ON(block_rsv->size > 0);
3216 btrfs_free_block_rsv(root, block_rsv);
3217 }
3218 }
3219
3220 /*
3221 * This creates an orphan entry for the given inode in case something goes
3222 * wrong in the middle of an unlink/truncate.
3223 *
3224 * NOTE: caller of this function should reserve 5 units of metadata for
3225 * this function.
3226 */
3227 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3228 {
3229 struct btrfs_root *root = BTRFS_I(inode)->root;
3230 struct btrfs_block_rsv *block_rsv = NULL;
3231 int reserve = 0;
3232 int insert = 0;
3233 int ret;
3234
3235 if (!root->orphan_block_rsv) {
3236 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3237 if (!block_rsv)
3238 return -ENOMEM;
3239 }
3240
3241 spin_lock(&root->orphan_lock);
3242 if (!root->orphan_block_rsv) {
3243 root->orphan_block_rsv = block_rsv;
3244 } else if (block_rsv) {
3245 btrfs_free_block_rsv(root, block_rsv);
3246 block_rsv = NULL;
3247 }
3248
3249 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3250 &BTRFS_I(inode)->runtime_flags)) {
3251 #if 0
3252 /*
3253 * For proper ENOSPC handling, we should do orphan
3254 * cleanup when mounting. But this introduces backward
3255 * compatibility issue.
3256 */
3257 if (!xchg(&root->orphan_item_inserted, 1))
3258 insert = 2;
3259 else
3260 insert = 1;
3261 #endif
3262 insert = 1;
3263 atomic_inc(&root->orphan_inodes);
3264 }
3265
3266 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3267 &BTRFS_I(inode)->runtime_flags))
3268 reserve = 1;
3269 spin_unlock(&root->orphan_lock);
3270
3271 /* grab metadata reservation from transaction handle */
3272 if (reserve) {
3273 ret = btrfs_orphan_reserve_metadata(trans, inode);
3274 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3275 }
3276
3277 /* insert an orphan item to track this unlinked/truncated file */
3278 if (insert >= 1) {
3279 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3280 if (ret) {
3281 atomic_dec(&root->orphan_inodes);
3282 if (reserve) {
3283 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3284 &BTRFS_I(inode)->runtime_flags);
3285 btrfs_orphan_release_metadata(inode);
3286 }
3287 if (ret != -EEXIST) {
3288 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3289 &BTRFS_I(inode)->runtime_flags);
3290 btrfs_abort_transaction(trans, root, ret);
3291 return ret;
3292 }
3293 }
3294 ret = 0;
3295 }
3296
3297 /* insert an orphan item to track subvolume contains orphan files */
3298 if (insert >= 2) {
3299 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3300 root->root_key.objectid);
3301 if (ret && ret != -EEXIST) {
3302 btrfs_abort_transaction(trans, root, ret);
3303 return ret;
3304 }
3305 }
3306 return 0;
3307 }
3308
3309 /*
3310 * We have done the truncate/delete so we can go ahead and remove the orphan
3311 * item for this particular inode.
3312 */
3313 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3314 struct inode *inode)
3315 {
3316 struct btrfs_root *root = BTRFS_I(inode)->root;
3317 int delete_item = 0;
3318 int release_rsv = 0;
3319 int ret = 0;
3320
3321 spin_lock(&root->orphan_lock);
3322 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3323 &BTRFS_I(inode)->runtime_flags))
3324 delete_item = 1;
3325
3326 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3327 &BTRFS_I(inode)->runtime_flags))
3328 release_rsv = 1;
3329 spin_unlock(&root->orphan_lock);
3330
3331 if (delete_item) {
3332 atomic_dec(&root->orphan_inodes);
3333 if (trans)
3334 ret = btrfs_del_orphan_item(trans, root,
3335 btrfs_ino(inode));
3336 }
3337
3338 if (release_rsv)
3339 btrfs_orphan_release_metadata(inode);
3340
3341 return ret;
3342 }
3343
3344 /*
3345 * this cleans up any orphans that may be left on the list from the last use
3346 * of this root.
3347 */
3348 int btrfs_orphan_cleanup(struct btrfs_root *root)
3349 {
3350 struct btrfs_path *path;
3351 struct extent_buffer *leaf;
3352 struct btrfs_key key, found_key;
3353 struct btrfs_trans_handle *trans;
3354 struct inode *inode;
3355 u64 last_objectid = 0;
3356 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3357
3358 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3359 return 0;
3360
3361 path = btrfs_alloc_path();
3362 if (!path) {
3363 ret = -ENOMEM;
3364 goto out;
3365 }
3366 path->reada = READA_BACK;
3367
3368 key.objectid = BTRFS_ORPHAN_OBJECTID;
3369 key.type = BTRFS_ORPHAN_ITEM_KEY;
3370 key.offset = (u64)-1;
3371
3372 while (1) {
3373 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3374 if (ret < 0)
3375 goto out;
3376
3377 /*
3378 * if ret == 0 means we found what we were searching for, which
3379 * is weird, but possible, so only screw with path if we didn't
3380 * find the key and see if we have stuff that matches
3381 */
3382 if (ret > 0) {
3383 ret = 0;
3384 if (path->slots[0] == 0)
3385 break;
3386 path->slots[0]--;
3387 }
3388
3389 /* pull out the item */
3390 leaf = path->nodes[0];
3391 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3392
3393 /* make sure the item matches what we want */
3394 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3395 break;
3396 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3397 break;
3398
3399 /* release the path since we're done with it */
3400 btrfs_release_path(path);
3401
3402 /*
3403 * this is where we are basically btrfs_lookup, without the
3404 * crossing root thing. we store the inode number in the
3405 * offset of the orphan item.
3406 */
3407
3408 if (found_key.offset == last_objectid) {
3409 btrfs_err(root->fs_info,
3410 "Error removing orphan entry, stopping orphan cleanup");
3411 ret = -EINVAL;
3412 goto out;
3413 }
3414
3415 last_objectid = found_key.offset;
3416
3417 found_key.objectid = found_key.offset;
3418 found_key.type = BTRFS_INODE_ITEM_KEY;
3419 found_key.offset = 0;
3420 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3421 ret = PTR_ERR_OR_ZERO(inode);
3422 if (ret && ret != -ESTALE)
3423 goto out;
3424
3425 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3426 struct btrfs_root *dead_root;
3427 struct btrfs_fs_info *fs_info = root->fs_info;
3428 int is_dead_root = 0;
3429
3430 /*
3431 * this is an orphan in the tree root. Currently these
3432 * could come from 2 sources:
3433 * a) a snapshot deletion in progress
3434 * b) a free space cache inode
3435 * We need to distinguish those two, as the snapshot
3436 * orphan must not get deleted.
3437 * find_dead_roots already ran before us, so if this
3438 * is a snapshot deletion, we should find the root
3439 * in the dead_roots list
3440 */
3441 spin_lock(&fs_info->trans_lock);
3442 list_for_each_entry(dead_root, &fs_info->dead_roots,
3443 root_list) {
3444 if (dead_root->root_key.objectid ==
3445 found_key.objectid) {
3446 is_dead_root = 1;
3447 break;
3448 }
3449 }
3450 spin_unlock(&fs_info->trans_lock);
3451 if (is_dead_root) {
3452 /* prevent this orphan from being found again */
3453 key.offset = found_key.objectid - 1;
3454 continue;
3455 }
3456 }
3457 /*
3458 * Inode is already gone but the orphan item is still there,
3459 * kill the orphan item.
3460 */
3461 if (ret == -ESTALE) {
3462 trans = btrfs_start_transaction(root, 1);
3463 if (IS_ERR(trans)) {
3464 ret = PTR_ERR(trans);
3465 goto out;
3466 }
3467 btrfs_debug(root->fs_info, "auto deleting %Lu",
3468 found_key.objectid);
3469 ret = btrfs_del_orphan_item(trans, root,
3470 found_key.objectid);
3471 btrfs_end_transaction(trans, root);
3472 if (ret)
3473 goto out;
3474 continue;
3475 }
3476
3477 /*
3478 * add this inode to the orphan list so btrfs_orphan_del does
3479 * the proper thing when we hit it
3480 */
3481 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3482 &BTRFS_I(inode)->runtime_flags);
3483 atomic_inc(&root->orphan_inodes);
3484
3485 /* if we have links, this was a truncate, lets do that */
3486 if (inode->i_nlink) {
3487 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3488 iput(inode);
3489 continue;
3490 }
3491 nr_truncate++;
3492
3493 /* 1 for the orphan item deletion. */
3494 trans = btrfs_start_transaction(root, 1);
3495 if (IS_ERR(trans)) {
3496 iput(inode);
3497 ret = PTR_ERR(trans);
3498 goto out;
3499 }
3500 ret = btrfs_orphan_add(trans, inode);
3501 btrfs_end_transaction(trans, root);
3502 if (ret) {
3503 iput(inode);
3504 goto out;
3505 }
3506
3507 ret = btrfs_truncate(inode);
3508 if (ret)
3509 btrfs_orphan_del(NULL, inode);
3510 } else {
3511 nr_unlink++;
3512 }
3513
3514 /* this will do delete_inode and everything for us */
3515 iput(inode);
3516 if (ret)
3517 goto out;
3518 }
3519 /* release the path since we're done with it */
3520 btrfs_release_path(path);
3521
3522 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3523
3524 if (root->orphan_block_rsv)
3525 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3526 (u64)-1);
3527
3528 if (root->orphan_block_rsv ||
3529 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3530 trans = btrfs_join_transaction(root);
3531 if (!IS_ERR(trans))
3532 btrfs_end_transaction(trans, root);
3533 }
3534
3535 if (nr_unlink)
3536 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3537 if (nr_truncate)
3538 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3539
3540 out:
3541 if (ret)
3542 btrfs_err(root->fs_info,
3543 "could not do orphan cleanup %d", ret);
3544 btrfs_free_path(path);
3545 return ret;
3546 }
3547
3548 /*
3549 * very simple check to peek ahead in the leaf looking for xattrs. If we
3550 * don't find any xattrs, we know there can't be any acls.
3551 *
3552 * slot is the slot the inode is in, objectid is the objectid of the inode
3553 */
3554 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3555 int slot, u64 objectid,
3556 int *first_xattr_slot)
3557 {
3558 u32 nritems = btrfs_header_nritems(leaf);
3559 struct btrfs_key found_key;
3560 static u64 xattr_access = 0;
3561 static u64 xattr_default = 0;
3562 int scanned = 0;
3563
3564 if (!xattr_access) {
3565 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3566 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3567 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3568 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3569 }
3570
3571 slot++;
3572 *first_xattr_slot = -1;
3573 while (slot < nritems) {
3574 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3575
3576 /* we found a different objectid, there must not be acls */
3577 if (found_key.objectid != objectid)
3578 return 0;
3579
3580 /* we found an xattr, assume we've got an acl */
3581 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3582 if (*first_xattr_slot == -1)
3583 *first_xattr_slot = slot;
3584 if (found_key.offset == xattr_access ||
3585 found_key.offset == xattr_default)
3586 return 1;
3587 }
3588
3589 /*
3590 * we found a key greater than an xattr key, there can't
3591 * be any acls later on
3592 */
3593 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3594 return 0;
3595
3596 slot++;
3597 scanned++;
3598
3599 /*
3600 * it goes inode, inode backrefs, xattrs, extents,
3601 * so if there are a ton of hard links to an inode there can
3602 * be a lot of backrefs. Don't waste time searching too hard,
3603 * this is just an optimization
3604 */
3605 if (scanned >= 8)
3606 break;
3607 }
3608 /* we hit the end of the leaf before we found an xattr or
3609 * something larger than an xattr. We have to assume the inode
3610 * has acls
3611 */
3612 if (*first_xattr_slot == -1)
3613 *first_xattr_slot = slot;
3614 return 1;
3615 }
3616
3617 /*
3618 * read an inode from the btree into the in-memory inode
3619 */
3620 static void btrfs_read_locked_inode(struct inode *inode)
3621 {
3622 struct btrfs_path *path;
3623 struct extent_buffer *leaf;
3624 struct btrfs_inode_item *inode_item;
3625 struct btrfs_root *root = BTRFS_I(inode)->root;
3626 struct btrfs_key location;
3627 unsigned long ptr;
3628 int maybe_acls;
3629 u32 rdev;
3630 int ret;
3631 bool filled = false;
3632 int first_xattr_slot;
3633
3634 ret = btrfs_fill_inode(inode, &rdev);
3635 if (!ret)
3636 filled = true;
3637
3638 path = btrfs_alloc_path();
3639 if (!path)
3640 goto make_bad;
3641
3642 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3643
3644 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3645 if (ret)
3646 goto make_bad;
3647
3648 leaf = path->nodes[0];
3649
3650 if (filled)
3651 goto cache_index;
3652
3653 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3654 struct btrfs_inode_item);
3655 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3656 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3657 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3658 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3659 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3660
3661 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3662 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3663
3664 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3665 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3666
3667 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3668 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3669
3670 BTRFS_I(inode)->i_otime.tv_sec =
3671 btrfs_timespec_sec(leaf, &inode_item->otime);
3672 BTRFS_I(inode)->i_otime.tv_nsec =
3673 btrfs_timespec_nsec(leaf, &inode_item->otime);
3674
3675 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3676 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3677 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3678
3679 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3680 inode->i_generation = BTRFS_I(inode)->generation;
3681 inode->i_rdev = 0;
3682 rdev = btrfs_inode_rdev(leaf, inode_item);
3683
3684 BTRFS_I(inode)->index_cnt = (u64)-1;
3685 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3686
3687 cache_index:
3688 /*
3689 * If we were modified in the current generation and evicted from memory
3690 * and then re-read we need to do a full sync since we don't have any
3691 * idea about which extents were modified before we were evicted from
3692 * cache.
3693 *
3694 * This is required for both inode re-read from disk and delayed inode
3695 * in delayed_nodes_tree.
3696 */
3697 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3698 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3699 &BTRFS_I(inode)->runtime_flags);
3700
3701 /*
3702 * We don't persist the id of the transaction where an unlink operation
3703 * against the inode was last made. So here we assume the inode might
3704 * have been evicted, and therefore the exact value of last_unlink_trans
3705 * lost, and set it to last_trans to avoid metadata inconsistencies
3706 * between the inode and its parent if the inode is fsync'ed and the log
3707 * replayed. For example, in the scenario:
3708 *
3709 * touch mydir/foo
3710 * ln mydir/foo mydir/bar
3711 * sync
3712 * unlink mydir/bar
3713 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3714 * xfs_io -c fsync mydir/foo
3715 * <power failure>
3716 * mount fs, triggers fsync log replay
3717 *
3718 * We must make sure that when we fsync our inode foo we also log its
3719 * parent inode, otherwise after log replay the parent still has the
3720 * dentry with the "bar" name but our inode foo has a link count of 1
3721 * and doesn't have an inode ref with the name "bar" anymore.
3722 *
3723 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3724 * but it guarantees correctness at the expense of occasional full
3725 * transaction commits on fsync if our inode is a directory, or if our
3726 * inode is not a directory, logging its parent unnecessarily.
3727 */
3728 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3729
3730 path->slots[0]++;
3731 if (inode->i_nlink != 1 ||
3732 path->slots[0] >= btrfs_header_nritems(leaf))
3733 goto cache_acl;
3734
3735 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3736 if (location.objectid != btrfs_ino(inode))
3737 goto cache_acl;
3738
3739 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3740 if (location.type == BTRFS_INODE_REF_KEY) {
3741 struct btrfs_inode_ref *ref;
3742
3743 ref = (struct btrfs_inode_ref *)ptr;
3744 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3745 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3746 struct btrfs_inode_extref *extref;
3747
3748 extref = (struct btrfs_inode_extref *)ptr;
3749 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3750 extref);
3751 }
3752 cache_acl:
3753 /*
3754 * try to precache a NULL acl entry for files that don't have
3755 * any xattrs or acls
3756 */
3757 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3758 btrfs_ino(inode), &first_xattr_slot);
3759 if (first_xattr_slot != -1) {
3760 path->slots[0] = first_xattr_slot;
3761 ret = btrfs_load_inode_props(inode, path);
3762 if (ret)
3763 btrfs_err(root->fs_info,
3764 "error loading props for ino %llu (root %llu): %d",
3765 btrfs_ino(inode),
3766 root->root_key.objectid, ret);
3767 }
3768 btrfs_free_path(path);
3769
3770 if (!maybe_acls)
3771 cache_no_acl(inode);
3772
3773 switch (inode->i_mode & S_IFMT) {
3774 case S_IFREG:
3775 inode->i_mapping->a_ops = &btrfs_aops;
3776 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3777 inode->i_fop = &btrfs_file_operations;
3778 inode->i_op = &btrfs_file_inode_operations;
3779 break;
3780 case S_IFDIR:
3781 inode->i_fop = &btrfs_dir_file_operations;
3782 if (root == root->fs_info->tree_root)
3783 inode->i_op = &btrfs_dir_ro_inode_operations;
3784 else
3785 inode->i_op = &btrfs_dir_inode_operations;
3786 break;
3787 case S_IFLNK:
3788 inode->i_op = &btrfs_symlink_inode_operations;
3789 inode_nohighmem(inode);
3790 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3791 break;
3792 default:
3793 inode->i_op = &btrfs_special_inode_operations;
3794 init_special_inode(inode, inode->i_mode, rdev);
3795 break;
3796 }
3797
3798 btrfs_update_iflags(inode);
3799 return;
3800
3801 make_bad:
3802 btrfs_free_path(path);
3803 make_bad_inode(inode);
3804 }
3805
3806 /*
3807 * given a leaf and an inode, copy the inode fields into the leaf
3808 */
3809 static void fill_inode_item(struct btrfs_trans_handle *trans,
3810 struct extent_buffer *leaf,
3811 struct btrfs_inode_item *item,
3812 struct inode *inode)
3813 {
3814 struct btrfs_map_token token;
3815
3816 btrfs_init_map_token(&token);
3817
3818 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3819 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3820 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3821 &token);
3822 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3823 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3824
3825 btrfs_set_token_timespec_sec(leaf, &item->atime,
3826 inode->i_atime.tv_sec, &token);
3827 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3828 inode->i_atime.tv_nsec, &token);
3829
3830 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3831 inode->i_mtime.tv_sec, &token);
3832 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3833 inode->i_mtime.tv_nsec, &token);
3834
3835 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3836 inode->i_ctime.tv_sec, &token);
3837 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3838 inode->i_ctime.tv_nsec, &token);
3839
3840 btrfs_set_token_timespec_sec(leaf, &item->otime,
3841 BTRFS_I(inode)->i_otime.tv_sec, &token);
3842 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3843 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3844
3845 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3846 &token);
3847 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3848 &token);
3849 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3850 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3851 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3852 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3853 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3854 }
3855
3856 /*
3857 * copy everything in the in-memory inode into the btree.
3858 */
3859 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3860 struct btrfs_root *root, struct inode *inode)
3861 {
3862 struct btrfs_inode_item *inode_item;
3863 struct btrfs_path *path;
3864 struct extent_buffer *leaf;
3865 int ret;
3866
3867 path = btrfs_alloc_path();
3868 if (!path)
3869 return -ENOMEM;
3870
3871 path->leave_spinning = 1;
3872 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3873 1);
3874 if (ret) {
3875 if (ret > 0)
3876 ret = -ENOENT;
3877 goto failed;
3878 }
3879
3880 leaf = path->nodes[0];
3881 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3882 struct btrfs_inode_item);
3883
3884 fill_inode_item(trans, leaf, inode_item, inode);
3885 btrfs_mark_buffer_dirty(leaf);
3886 btrfs_set_inode_last_trans(trans, inode);
3887 ret = 0;
3888 failed:
3889 btrfs_free_path(path);
3890 return ret;
3891 }
3892
3893 /*
3894 * copy everything in the in-memory inode into the btree.
3895 */
3896 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3897 struct btrfs_root *root, struct inode *inode)
3898 {
3899 int ret;
3900
3901 /*
3902 * If the inode is a free space inode, we can deadlock during commit
3903 * if we put it into the delayed code.
3904 *
3905 * The data relocation inode should also be directly updated
3906 * without delay
3907 */
3908 if (!btrfs_is_free_space_inode(inode)
3909 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3910 && !root->fs_info->log_root_recovering) {
3911 btrfs_update_root_times(trans, root);
3912
3913 ret = btrfs_delayed_update_inode(trans, root, inode);
3914 if (!ret)
3915 btrfs_set_inode_last_trans(trans, inode);
3916 return ret;
3917 }
3918
3919 return btrfs_update_inode_item(trans, root, inode);
3920 }
3921
3922 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3923 struct btrfs_root *root,
3924 struct inode *inode)
3925 {
3926 int ret;
3927
3928 ret = btrfs_update_inode(trans, root, inode);
3929 if (ret == -ENOSPC)
3930 return btrfs_update_inode_item(trans, root, inode);
3931 return ret;
3932 }
3933
3934 /*
3935 * unlink helper that gets used here in inode.c and in the tree logging
3936 * recovery code. It remove a link in a directory with a given name, and
3937 * also drops the back refs in the inode to the directory
3938 */
3939 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3940 struct btrfs_root *root,
3941 struct inode *dir, struct inode *inode,
3942 const char *name, int name_len)
3943 {
3944 struct btrfs_path *path;
3945 int ret = 0;
3946 struct extent_buffer *leaf;
3947 struct btrfs_dir_item *di;
3948 struct btrfs_key key;
3949 u64 index;
3950 u64 ino = btrfs_ino(inode);
3951 u64 dir_ino = btrfs_ino(dir);
3952
3953 path = btrfs_alloc_path();
3954 if (!path) {
3955 ret = -ENOMEM;
3956 goto out;
3957 }
3958
3959 path->leave_spinning = 1;
3960 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3961 name, name_len, -1);
3962 if (IS_ERR(di)) {
3963 ret = PTR_ERR(di);
3964 goto err;
3965 }
3966 if (!di) {
3967 ret = -ENOENT;
3968 goto err;
3969 }
3970 leaf = path->nodes[0];
3971 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3972 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3973 if (ret)
3974 goto err;
3975 btrfs_release_path(path);
3976
3977 /*
3978 * If we don't have dir index, we have to get it by looking up
3979 * the inode ref, since we get the inode ref, remove it directly,
3980 * it is unnecessary to do delayed deletion.
3981 *
3982 * But if we have dir index, needn't search inode ref to get it.
3983 * Since the inode ref is close to the inode item, it is better
3984 * that we delay to delete it, and just do this deletion when
3985 * we update the inode item.
3986 */
3987 if (BTRFS_I(inode)->dir_index) {
3988 ret = btrfs_delayed_delete_inode_ref(inode);
3989 if (!ret) {
3990 index = BTRFS_I(inode)->dir_index;
3991 goto skip_backref;
3992 }
3993 }
3994
3995 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3996 dir_ino, &index);
3997 if (ret) {
3998 btrfs_info(root->fs_info,
3999 "failed to delete reference to %.*s, inode %llu parent %llu",
4000 name_len, name, ino, dir_ino);
4001 btrfs_abort_transaction(trans, root, ret);
4002 goto err;
4003 }
4004 skip_backref:
4005 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4006 if (ret) {
4007 btrfs_abort_transaction(trans, root, ret);
4008 goto err;
4009 }
4010
4011 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4012 inode, dir_ino);
4013 if (ret != 0 && ret != -ENOENT) {
4014 btrfs_abort_transaction(trans, root, ret);
4015 goto err;
4016 }
4017
4018 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4019 dir, index);
4020 if (ret == -ENOENT)
4021 ret = 0;
4022 else if (ret)
4023 btrfs_abort_transaction(trans, root, ret);
4024 err:
4025 btrfs_free_path(path);
4026 if (ret)
4027 goto out;
4028
4029 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4030 inode_inc_iversion(inode);
4031 inode_inc_iversion(dir);
4032 inode->i_ctime = dir->i_mtime =
4033 dir->i_ctime = current_fs_time(inode->i_sb);
4034 ret = btrfs_update_inode(trans, root, dir);
4035 out:
4036 return ret;
4037 }
4038
4039 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4040 struct btrfs_root *root,
4041 struct inode *dir, struct inode *inode,
4042 const char *name, int name_len)
4043 {
4044 int ret;
4045 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4046 if (!ret) {
4047 drop_nlink(inode);
4048 ret = btrfs_update_inode(trans, root, inode);
4049 }
4050 return ret;
4051 }
4052
4053 /*
4054 * helper to start transaction for unlink and rmdir.
4055 *
4056 * unlink and rmdir are special in btrfs, they do not always free space, so
4057 * if we cannot make our reservations the normal way try and see if there is
4058 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4059 * allow the unlink to occur.
4060 */
4061 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4062 {
4063 struct btrfs_root *root = BTRFS_I(dir)->root;
4064
4065 /*
4066 * 1 for the possible orphan item
4067 * 1 for the dir item
4068 * 1 for the dir index
4069 * 1 for the inode ref
4070 * 1 for the inode
4071 */
4072 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4073 }
4074
4075 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4076 {
4077 struct btrfs_root *root = BTRFS_I(dir)->root;
4078 struct btrfs_trans_handle *trans;
4079 struct inode *inode = d_inode(dentry);
4080 int ret;
4081
4082 trans = __unlink_start_trans(dir);
4083 if (IS_ERR(trans))
4084 return PTR_ERR(trans);
4085
4086 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4087
4088 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4089 dentry->d_name.name, dentry->d_name.len);
4090 if (ret)
4091 goto out;
4092
4093 if (inode->i_nlink == 0) {
4094 ret = btrfs_orphan_add(trans, inode);
4095 if (ret)
4096 goto out;
4097 }
4098
4099 out:
4100 btrfs_end_transaction(trans, root);
4101 btrfs_btree_balance_dirty(root);
4102 return ret;
4103 }
4104
4105 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4106 struct btrfs_root *root,
4107 struct inode *dir, u64 objectid,
4108 const char *name, int name_len)
4109 {
4110 struct btrfs_path *path;
4111 struct extent_buffer *leaf;
4112 struct btrfs_dir_item *di;
4113 struct btrfs_key key;
4114 u64 index;
4115 int ret;
4116 u64 dir_ino = btrfs_ino(dir);
4117
4118 path = btrfs_alloc_path();
4119 if (!path)
4120 return -ENOMEM;
4121
4122 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4123 name, name_len, -1);
4124 if (IS_ERR_OR_NULL(di)) {
4125 if (!di)
4126 ret = -ENOENT;
4127 else
4128 ret = PTR_ERR(di);
4129 goto out;
4130 }
4131
4132 leaf = path->nodes[0];
4133 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4134 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4135 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4136 if (ret) {
4137 btrfs_abort_transaction(trans, root, ret);
4138 goto out;
4139 }
4140 btrfs_release_path(path);
4141
4142 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4143 objectid, root->root_key.objectid,
4144 dir_ino, &index, name, name_len);
4145 if (ret < 0) {
4146 if (ret != -ENOENT) {
4147 btrfs_abort_transaction(trans, root, ret);
4148 goto out;
4149 }
4150 di = btrfs_search_dir_index_item(root, path, dir_ino,
4151 name, name_len);
4152 if (IS_ERR_OR_NULL(di)) {
4153 if (!di)
4154 ret = -ENOENT;
4155 else
4156 ret = PTR_ERR(di);
4157 btrfs_abort_transaction(trans, root, ret);
4158 goto out;
4159 }
4160
4161 leaf = path->nodes[0];
4162 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4163 btrfs_release_path(path);
4164 index = key.offset;
4165 }
4166 btrfs_release_path(path);
4167
4168 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4169 if (ret) {
4170 btrfs_abort_transaction(trans, root, ret);
4171 goto out;
4172 }
4173
4174 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4175 inode_inc_iversion(dir);
4176 dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
4177 ret = btrfs_update_inode_fallback(trans, root, dir);
4178 if (ret)
4179 btrfs_abort_transaction(trans, root, ret);
4180 out:
4181 btrfs_free_path(path);
4182 return ret;
4183 }
4184
4185 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4186 {
4187 struct inode *inode = d_inode(dentry);
4188 int err = 0;
4189 struct btrfs_root *root = BTRFS_I(dir)->root;
4190 struct btrfs_trans_handle *trans;
4191
4192 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4193 return -ENOTEMPTY;
4194 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4195 return -EPERM;
4196
4197 trans = __unlink_start_trans(dir);
4198 if (IS_ERR(trans))
4199 return PTR_ERR(trans);
4200
4201 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4202 err = btrfs_unlink_subvol(trans, root, dir,
4203 BTRFS_I(inode)->location.objectid,
4204 dentry->d_name.name,
4205 dentry->d_name.len);
4206 goto out;
4207 }
4208
4209 err = btrfs_orphan_add(trans, inode);
4210 if (err)
4211 goto out;
4212
4213 /* now the directory is empty */
4214 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4215 dentry->d_name.name, dentry->d_name.len);
4216 if (!err)
4217 btrfs_i_size_write(inode, 0);
4218 out:
4219 btrfs_end_transaction(trans, root);
4220 btrfs_btree_balance_dirty(root);
4221
4222 return err;
4223 }
4224
4225 static int truncate_space_check(struct btrfs_trans_handle *trans,
4226 struct btrfs_root *root,
4227 u64 bytes_deleted)
4228 {
4229 int ret;
4230
4231 /*
4232 * This is only used to apply pressure to the enospc system, we don't
4233 * intend to use this reservation at all.
4234 */
4235 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4236 bytes_deleted *= root->nodesize;
4237 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4238 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4239 if (!ret) {
4240 trace_btrfs_space_reservation(root->fs_info, "transaction",
4241 trans->transid,
4242 bytes_deleted, 1);
4243 trans->bytes_reserved += bytes_deleted;
4244 }
4245 return ret;
4246
4247 }
4248
4249 static int truncate_inline_extent(struct inode *inode,
4250 struct btrfs_path *path,
4251 struct btrfs_key *found_key,
4252 const u64 item_end,
4253 const u64 new_size)
4254 {
4255 struct extent_buffer *leaf = path->nodes[0];
4256 int slot = path->slots[0];
4257 struct btrfs_file_extent_item *fi;
4258 u32 size = (u32)(new_size - found_key->offset);
4259 struct btrfs_root *root = BTRFS_I(inode)->root;
4260
4261 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4262
4263 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4264 loff_t offset = new_size;
4265 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4266
4267 /*
4268 * Zero out the remaining of the last page of our inline extent,
4269 * instead of directly truncating our inline extent here - that
4270 * would be much more complex (decompressing all the data, then
4271 * compressing the truncated data, which might be bigger than
4272 * the size of the inline extent, resize the extent, etc).
4273 * We release the path because to get the page we might need to
4274 * read the extent item from disk (data not in the page cache).
4275 */
4276 btrfs_release_path(path);
4277 return btrfs_truncate_block(inode, offset, page_end - offset,
4278 0);
4279 }
4280
4281 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4282 size = btrfs_file_extent_calc_inline_size(size);
4283 btrfs_truncate_item(root, path, size, 1);
4284
4285 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4286 inode_sub_bytes(inode, item_end + 1 - new_size);
4287
4288 return 0;
4289 }
4290
4291 /*
4292 * this can truncate away extent items, csum items and directory items.
4293 * It starts at a high offset and removes keys until it can't find
4294 * any higher than new_size
4295 *
4296 * csum items that cross the new i_size are truncated to the new size
4297 * as well.
4298 *
4299 * min_type is the minimum key type to truncate down to. If set to 0, this
4300 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4301 */
4302 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4303 struct btrfs_root *root,
4304 struct inode *inode,
4305 u64 new_size, u32 min_type)
4306 {
4307 struct btrfs_path *path;
4308 struct extent_buffer *leaf;
4309 struct btrfs_file_extent_item *fi;
4310 struct btrfs_key key;
4311 struct btrfs_key found_key;
4312 u64 extent_start = 0;
4313 u64 extent_num_bytes = 0;
4314 u64 extent_offset = 0;
4315 u64 item_end = 0;
4316 u64 last_size = new_size;
4317 u32 found_type = (u8)-1;
4318 int found_extent;
4319 int del_item;
4320 int pending_del_nr = 0;
4321 int pending_del_slot = 0;
4322 int extent_type = -1;
4323 int ret;
4324 int err = 0;
4325 u64 ino = btrfs_ino(inode);
4326 u64 bytes_deleted = 0;
4327 bool be_nice = 0;
4328 bool should_throttle = 0;
4329 bool should_end = 0;
4330
4331 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4332
4333 /*
4334 * for non-free space inodes and ref cows, we want to back off from
4335 * time to time
4336 */
4337 if (!btrfs_is_free_space_inode(inode) &&
4338 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4339 be_nice = 1;
4340
4341 path = btrfs_alloc_path();
4342 if (!path)
4343 return -ENOMEM;
4344 path->reada = READA_BACK;
4345
4346 /*
4347 * We want to drop from the next block forward in case this new size is
4348 * not block aligned since we will be keeping the last block of the
4349 * extent just the way it is.
4350 */
4351 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4352 root == root->fs_info->tree_root)
4353 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4354 root->sectorsize), (u64)-1, 0);
4355
4356 /*
4357 * This function is also used to drop the items in the log tree before
4358 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4359 * it is used to drop the loged items. So we shouldn't kill the delayed
4360 * items.
4361 */
4362 if (min_type == 0 && root == BTRFS_I(inode)->root)
4363 btrfs_kill_delayed_inode_items(inode);
4364
4365 key.objectid = ino;
4366 key.offset = (u64)-1;
4367 key.type = (u8)-1;
4368
4369 search_again:
4370 /*
4371 * with a 16K leaf size and 128MB extents, you can actually queue
4372 * up a huge file in a single leaf. Most of the time that
4373 * bytes_deleted is > 0, it will be huge by the time we get here
4374 */
4375 if (be_nice && bytes_deleted > SZ_32M) {
4376 if (btrfs_should_end_transaction(trans, root)) {
4377 err = -EAGAIN;
4378 goto error;
4379 }
4380 }
4381
4382
4383 path->leave_spinning = 1;
4384 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4385 if (ret < 0) {
4386 err = ret;
4387 goto out;
4388 }
4389
4390 if (ret > 0) {
4391 /* there are no items in the tree for us to truncate, we're
4392 * done
4393 */
4394 if (path->slots[0] == 0)
4395 goto out;
4396 path->slots[0]--;
4397 }
4398
4399 while (1) {
4400 fi = NULL;
4401 leaf = path->nodes[0];
4402 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4403 found_type = found_key.type;
4404
4405 if (found_key.objectid != ino)
4406 break;
4407
4408 if (found_type < min_type)
4409 break;
4410
4411 item_end = found_key.offset;
4412 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4413 fi = btrfs_item_ptr(leaf, path->slots[0],
4414 struct btrfs_file_extent_item);
4415 extent_type = btrfs_file_extent_type(leaf, fi);
4416 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4417 item_end +=
4418 btrfs_file_extent_num_bytes(leaf, fi);
4419 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4420 item_end += btrfs_file_extent_inline_len(leaf,
4421 path->slots[0], fi);
4422 }
4423 item_end--;
4424 }
4425 if (found_type > min_type) {
4426 del_item = 1;
4427 } else {
4428 if (item_end < new_size)
4429 break;
4430 if (found_key.offset >= new_size)
4431 del_item = 1;
4432 else
4433 del_item = 0;
4434 }
4435 found_extent = 0;
4436 /* FIXME, shrink the extent if the ref count is only 1 */
4437 if (found_type != BTRFS_EXTENT_DATA_KEY)
4438 goto delete;
4439
4440 if (del_item)
4441 last_size = found_key.offset;
4442 else
4443 last_size = new_size;
4444
4445 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4446 u64 num_dec;
4447 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4448 if (!del_item) {
4449 u64 orig_num_bytes =
4450 btrfs_file_extent_num_bytes(leaf, fi);
4451 extent_num_bytes = ALIGN(new_size -
4452 found_key.offset,
4453 root->sectorsize);
4454 btrfs_set_file_extent_num_bytes(leaf, fi,
4455 extent_num_bytes);
4456 num_dec = (orig_num_bytes -
4457 extent_num_bytes);
4458 if (test_bit(BTRFS_ROOT_REF_COWS,
4459 &root->state) &&
4460 extent_start != 0)
4461 inode_sub_bytes(inode, num_dec);
4462 btrfs_mark_buffer_dirty(leaf);
4463 } else {
4464 extent_num_bytes =
4465 btrfs_file_extent_disk_num_bytes(leaf,
4466 fi);
4467 extent_offset = found_key.offset -
4468 btrfs_file_extent_offset(leaf, fi);
4469
4470 /* FIXME blocksize != 4096 */
4471 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4472 if (extent_start != 0) {
4473 found_extent = 1;
4474 if (test_bit(BTRFS_ROOT_REF_COWS,
4475 &root->state))
4476 inode_sub_bytes(inode, num_dec);
4477 }
4478 }
4479 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4480 /*
4481 * we can't truncate inline items that have had
4482 * special encodings
4483 */
4484 if (!del_item &&
4485 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4486 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4487
4488 /*
4489 * Need to release path in order to truncate a
4490 * compressed extent. So delete any accumulated
4491 * extent items so far.
4492 */
4493 if (btrfs_file_extent_compression(leaf, fi) !=
4494 BTRFS_COMPRESS_NONE && pending_del_nr) {
4495 err = btrfs_del_items(trans, root, path,
4496 pending_del_slot,
4497 pending_del_nr);
4498 if (err) {
4499 btrfs_abort_transaction(trans,
4500 root,
4501 err);
4502 goto error;
4503 }
4504 pending_del_nr = 0;
4505 }
4506
4507 err = truncate_inline_extent(inode, path,
4508 &found_key,
4509 item_end,
4510 new_size);
4511 if (err) {
4512 btrfs_abort_transaction(trans,
4513 root, err);
4514 goto error;
4515 }
4516 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4517 &root->state)) {
4518 inode_sub_bytes(inode, item_end + 1 - new_size);
4519 }
4520 }
4521 delete:
4522 if (del_item) {
4523 if (!pending_del_nr) {
4524 /* no pending yet, add ourselves */
4525 pending_del_slot = path->slots[0];
4526 pending_del_nr = 1;
4527 } else if (pending_del_nr &&
4528 path->slots[0] + 1 == pending_del_slot) {
4529 /* hop on the pending chunk */
4530 pending_del_nr++;
4531 pending_del_slot = path->slots[0];
4532 } else {
4533 BUG();
4534 }
4535 } else {
4536 break;
4537 }
4538 should_throttle = 0;
4539
4540 if (found_extent &&
4541 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4542 root == root->fs_info->tree_root)) {
4543 btrfs_set_path_blocking(path);
4544 bytes_deleted += extent_num_bytes;
4545 ret = btrfs_free_extent(trans, root, extent_start,
4546 extent_num_bytes, 0,
4547 btrfs_header_owner(leaf),
4548 ino, extent_offset);
4549 BUG_ON(ret);
4550 if (btrfs_should_throttle_delayed_refs(trans, root))
4551 btrfs_async_run_delayed_refs(root,
4552 trans->delayed_ref_updates * 2, 0);
4553 if (be_nice) {
4554 if (truncate_space_check(trans, root,
4555 extent_num_bytes)) {
4556 should_end = 1;
4557 }
4558 if (btrfs_should_throttle_delayed_refs(trans,
4559 root)) {
4560 should_throttle = 1;
4561 }
4562 }
4563 }
4564
4565 if (found_type == BTRFS_INODE_ITEM_KEY)
4566 break;
4567
4568 if (path->slots[0] == 0 ||
4569 path->slots[0] != pending_del_slot ||
4570 should_throttle || should_end) {
4571 if (pending_del_nr) {
4572 ret = btrfs_del_items(trans, root, path,
4573 pending_del_slot,
4574 pending_del_nr);
4575 if (ret) {
4576 btrfs_abort_transaction(trans,
4577 root, ret);
4578 goto error;
4579 }
4580 pending_del_nr = 0;
4581 }
4582 btrfs_release_path(path);
4583 if (should_throttle) {
4584 unsigned long updates = trans->delayed_ref_updates;
4585 if (updates) {
4586 trans->delayed_ref_updates = 0;
4587 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4588 if (ret && !err)
4589 err = ret;
4590 }
4591 }
4592 /*
4593 * if we failed to refill our space rsv, bail out
4594 * and let the transaction restart
4595 */
4596 if (should_end) {
4597 err = -EAGAIN;
4598 goto error;
4599 }
4600 goto search_again;
4601 } else {
4602 path->slots[0]--;
4603 }
4604 }
4605 out:
4606 if (pending_del_nr) {
4607 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4608 pending_del_nr);
4609 if (ret)
4610 btrfs_abort_transaction(trans, root, ret);
4611 }
4612 error:
4613 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4614 btrfs_ordered_update_i_size(inode, last_size, NULL);
4615
4616 btrfs_free_path(path);
4617
4618 if (be_nice && bytes_deleted > SZ_32M) {
4619 unsigned long updates = trans->delayed_ref_updates;
4620 if (updates) {
4621 trans->delayed_ref_updates = 0;
4622 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4623 if (ret && !err)
4624 err = ret;
4625 }
4626 }
4627 return err;
4628 }
4629
4630 /*
4631 * btrfs_truncate_block - read, zero a chunk and write a block
4632 * @inode - inode that we're zeroing
4633 * @from - the offset to start zeroing
4634 * @len - the length to zero, 0 to zero the entire range respective to the
4635 * offset
4636 * @front - zero up to the offset instead of from the offset on
4637 *
4638 * This will find the block for the "from" offset and cow the block and zero the
4639 * part we want to zero. This is used with truncate and hole punching.
4640 */
4641 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4642 int front)
4643 {
4644 struct address_space *mapping = inode->i_mapping;
4645 struct btrfs_root *root = BTRFS_I(inode)->root;
4646 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4647 struct btrfs_ordered_extent *ordered;
4648 struct extent_state *cached_state = NULL;
4649 char *kaddr;
4650 u32 blocksize = root->sectorsize;
4651 pgoff_t index = from >> PAGE_SHIFT;
4652 unsigned offset = from & (blocksize - 1);
4653 struct page *page;
4654 gfp_t mask = btrfs_alloc_write_mask(mapping);
4655 int ret = 0;
4656 u64 block_start;
4657 u64 block_end;
4658
4659 if ((offset & (blocksize - 1)) == 0 &&
4660 (!len || ((len & (blocksize - 1)) == 0)))
4661 goto out;
4662
4663 ret = btrfs_delalloc_reserve_space(inode,
4664 round_down(from, blocksize), blocksize);
4665 if (ret)
4666 goto out;
4667
4668 again:
4669 page = find_or_create_page(mapping, index, mask);
4670 if (!page) {
4671 btrfs_delalloc_release_space(inode,
4672 round_down(from, blocksize),
4673 blocksize);
4674 ret = -ENOMEM;
4675 goto out;
4676 }
4677
4678 block_start = round_down(from, blocksize);
4679 block_end = block_start + blocksize - 1;
4680
4681 if (!PageUptodate(page)) {
4682 ret = btrfs_readpage(NULL, page);
4683 lock_page(page);
4684 if (page->mapping != mapping) {
4685 unlock_page(page);
4686 put_page(page);
4687 goto again;
4688 }
4689 if (!PageUptodate(page)) {
4690 ret = -EIO;
4691 goto out_unlock;
4692 }
4693 }
4694 wait_on_page_writeback(page);
4695
4696 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4697 set_page_extent_mapped(page);
4698
4699 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4700 if (ordered) {
4701 unlock_extent_cached(io_tree, block_start, block_end,
4702 &cached_state, GFP_NOFS);
4703 unlock_page(page);
4704 put_page(page);
4705 btrfs_start_ordered_extent(inode, ordered, 1);
4706 btrfs_put_ordered_extent(ordered);
4707 goto again;
4708 }
4709
4710 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4711 EXTENT_DIRTY | EXTENT_DELALLOC |
4712 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4713 0, 0, &cached_state, GFP_NOFS);
4714
4715 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4716 &cached_state);
4717 if (ret) {
4718 unlock_extent_cached(io_tree, block_start, block_end,
4719 &cached_state, GFP_NOFS);
4720 goto out_unlock;
4721 }
4722
4723 if (offset != blocksize) {
4724 if (!len)
4725 len = blocksize - offset;
4726 kaddr = kmap(page);
4727 if (front)
4728 memset(kaddr + (block_start - page_offset(page)),
4729 0, offset);
4730 else
4731 memset(kaddr + (block_start - page_offset(page)) + offset,
4732 0, len);
4733 flush_dcache_page(page);
4734 kunmap(page);
4735 }
4736 ClearPageChecked(page);
4737 set_page_dirty(page);
4738 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4739 GFP_NOFS);
4740
4741 out_unlock:
4742 if (ret)
4743 btrfs_delalloc_release_space(inode, block_start,
4744 blocksize);
4745 unlock_page(page);
4746 put_page(page);
4747 out:
4748 return ret;
4749 }
4750
4751 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4752 u64 offset, u64 len)
4753 {
4754 struct btrfs_trans_handle *trans;
4755 int ret;
4756
4757 /*
4758 * Still need to make sure the inode looks like it's been updated so
4759 * that any holes get logged if we fsync.
4760 */
4761 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4762 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4763 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4764 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4765 return 0;
4766 }
4767
4768 /*
4769 * 1 - for the one we're dropping
4770 * 1 - for the one we're adding
4771 * 1 - for updating the inode.
4772 */
4773 trans = btrfs_start_transaction(root, 3);
4774 if (IS_ERR(trans))
4775 return PTR_ERR(trans);
4776
4777 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4778 if (ret) {
4779 btrfs_abort_transaction(trans, root, ret);
4780 btrfs_end_transaction(trans, root);
4781 return ret;
4782 }
4783
4784 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4785 0, 0, len, 0, len, 0, 0, 0);
4786 if (ret)
4787 btrfs_abort_transaction(trans, root, ret);
4788 else
4789 btrfs_update_inode(trans, root, inode);
4790 btrfs_end_transaction(trans, root);
4791 return ret;
4792 }
4793
4794 /*
4795 * This function puts in dummy file extents for the area we're creating a hole
4796 * for. So if we are truncating this file to a larger size we need to insert
4797 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4798 * the range between oldsize and size
4799 */
4800 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4801 {
4802 struct btrfs_root *root = BTRFS_I(inode)->root;
4803 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4804 struct extent_map *em = NULL;
4805 struct extent_state *cached_state = NULL;
4806 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4807 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4808 u64 block_end = ALIGN(size, root->sectorsize);
4809 u64 last_byte;
4810 u64 cur_offset;
4811 u64 hole_size;
4812 int err = 0;
4813
4814 /*
4815 * If our size started in the middle of a block we need to zero out the
4816 * rest of the block before we expand the i_size, otherwise we could
4817 * expose stale data.
4818 */
4819 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4820 if (err)
4821 return err;
4822
4823 if (size <= hole_start)
4824 return 0;
4825
4826 while (1) {
4827 struct btrfs_ordered_extent *ordered;
4828
4829 lock_extent_bits(io_tree, hole_start, block_end - 1,
4830 &cached_state);
4831 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4832 block_end - hole_start);
4833 if (!ordered)
4834 break;
4835 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4836 &cached_state, GFP_NOFS);
4837 btrfs_start_ordered_extent(inode, ordered, 1);
4838 btrfs_put_ordered_extent(ordered);
4839 }
4840
4841 cur_offset = hole_start;
4842 while (1) {
4843 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4844 block_end - cur_offset, 0);
4845 if (IS_ERR(em)) {
4846 err = PTR_ERR(em);
4847 em = NULL;
4848 break;
4849 }
4850 last_byte = min(extent_map_end(em), block_end);
4851 last_byte = ALIGN(last_byte , root->sectorsize);
4852 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4853 struct extent_map *hole_em;
4854 hole_size = last_byte - cur_offset;
4855
4856 err = maybe_insert_hole(root, inode, cur_offset,
4857 hole_size);
4858 if (err)
4859 break;
4860 btrfs_drop_extent_cache(inode, cur_offset,
4861 cur_offset + hole_size - 1, 0);
4862 hole_em = alloc_extent_map();
4863 if (!hole_em) {
4864 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4865 &BTRFS_I(inode)->runtime_flags);
4866 goto next;
4867 }
4868 hole_em->start = cur_offset;
4869 hole_em->len = hole_size;
4870 hole_em->orig_start = cur_offset;
4871
4872 hole_em->block_start = EXTENT_MAP_HOLE;
4873 hole_em->block_len = 0;
4874 hole_em->orig_block_len = 0;
4875 hole_em->ram_bytes = hole_size;
4876 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4877 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4878 hole_em->generation = root->fs_info->generation;
4879
4880 while (1) {
4881 write_lock(&em_tree->lock);
4882 err = add_extent_mapping(em_tree, hole_em, 1);
4883 write_unlock(&em_tree->lock);
4884 if (err != -EEXIST)
4885 break;
4886 btrfs_drop_extent_cache(inode, cur_offset,
4887 cur_offset +
4888 hole_size - 1, 0);
4889 }
4890 free_extent_map(hole_em);
4891 }
4892 next:
4893 free_extent_map(em);
4894 em = NULL;
4895 cur_offset = last_byte;
4896 if (cur_offset >= block_end)
4897 break;
4898 }
4899 free_extent_map(em);
4900 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4901 GFP_NOFS);
4902 return err;
4903 }
4904
4905 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4906 {
4907 struct btrfs_root *root = BTRFS_I(inode)->root;
4908 struct btrfs_trans_handle *trans;
4909 loff_t oldsize = i_size_read(inode);
4910 loff_t newsize = attr->ia_size;
4911 int mask = attr->ia_valid;
4912 int ret;
4913
4914 /*
4915 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4916 * special case where we need to update the times despite not having
4917 * these flags set. For all other operations the VFS set these flags
4918 * explicitly if it wants a timestamp update.
4919 */
4920 if (newsize != oldsize) {
4921 inode_inc_iversion(inode);
4922 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4923 inode->i_ctime = inode->i_mtime =
4924 current_fs_time(inode->i_sb);
4925 }
4926
4927 if (newsize > oldsize) {
4928 /*
4929 * Don't do an expanding truncate while snapshoting is ongoing.
4930 * This is to ensure the snapshot captures a fully consistent
4931 * state of this file - if the snapshot captures this expanding
4932 * truncation, it must capture all writes that happened before
4933 * this truncation.
4934 */
4935 btrfs_wait_for_snapshot_creation(root);
4936 ret = btrfs_cont_expand(inode, oldsize, newsize);
4937 if (ret) {
4938 btrfs_end_write_no_snapshoting(root);
4939 return ret;
4940 }
4941
4942 trans = btrfs_start_transaction(root, 1);
4943 if (IS_ERR(trans)) {
4944 btrfs_end_write_no_snapshoting(root);
4945 return PTR_ERR(trans);
4946 }
4947
4948 i_size_write(inode, newsize);
4949 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4950 pagecache_isize_extended(inode, oldsize, newsize);
4951 ret = btrfs_update_inode(trans, root, inode);
4952 btrfs_end_write_no_snapshoting(root);
4953 btrfs_end_transaction(trans, root);
4954 } else {
4955
4956 /*
4957 * We're truncating a file that used to have good data down to
4958 * zero. Make sure it gets into the ordered flush list so that
4959 * any new writes get down to disk quickly.
4960 */
4961 if (newsize == 0)
4962 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4963 &BTRFS_I(inode)->runtime_flags);
4964
4965 /*
4966 * 1 for the orphan item we're going to add
4967 * 1 for the orphan item deletion.
4968 */
4969 trans = btrfs_start_transaction(root, 2);
4970 if (IS_ERR(trans))
4971 return PTR_ERR(trans);
4972
4973 /*
4974 * We need to do this in case we fail at _any_ point during the
4975 * actual truncate. Once we do the truncate_setsize we could
4976 * invalidate pages which forces any outstanding ordered io to
4977 * be instantly completed which will give us extents that need
4978 * to be truncated. If we fail to get an orphan inode down we
4979 * could have left over extents that were never meant to live,
4980 * so we need to guarantee from this point on that everything
4981 * will be consistent.
4982 */
4983 ret = btrfs_orphan_add(trans, inode);
4984 btrfs_end_transaction(trans, root);
4985 if (ret)
4986 return ret;
4987
4988 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4989 truncate_setsize(inode, newsize);
4990
4991 /* Disable nonlocked read DIO to avoid the end less truncate */
4992 btrfs_inode_block_unlocked_dio(inode);
4993 inode_dio_wait(inode);
4994 btrfs_inode_resume_unlocked_dio(inode);
4995
4996 ret = btrfs_truncate(inode);
4997 if (ret && inode->i_nlink) {
4998 int err;
4999
5000 /*
5001 * failed to truncate, disk_i_size is only adjusted down
5002 * as we remove extents, so it should represent the true
5003 * size of the inode, so reset the in memory size and
5004 * delete our orphan entry.
5005 */
5006 trans = btrfs_join_transaction(root);
5007 if (IS_ERR(trans)) {
5008 btrfs_orphan_del(NULL, inode);
5009 return ret;
5010 }
5011 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5012 err = btrfs_orphan_del(trans, inode);
5013 if (err)
5014 btrfs_abort_transaction(trans, root, err);
5015 btrfs_end_transaction(trans, root);
5016 }
5017 }
5018
5019 return ret;
5020 }
5021
5022 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5023 {
5024 struct inode *inode = d_inode(dentry);
5025 struct btrfs_root *root = BTRFS_I(inode)->root;
5026 int err;
5027
5028 if (btrfs_root_readonly(root))
5029 return -EROFS;
5030
5031 err = inode_change_ok(inode, attr);
5032 if (err)
5033 return err;
5034
5035 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5036 err = btrfs_setsize(inode, attr);
5037 if (err)
5038 return err;
5039 }
5040
5041 if (attr->ia_valid) {
5042 setattr_copy(inode, attr);
5043 inode_inc_iversion(inode);
5044 err = btrfs_dirty_inode(inode);
5045
5046 if (!err && attr->ia_valid & ATTR_MODE)
5047 err = posix_acl_chmod(inode, inode->i_mode);
5048 }
5049
5050 return err;
5051 }
5052
5053 /*
5054 * While truncating the inode pages during eviction, we get the VFS calling
5055 * btrfs_invalidatepage() against each page of the inode. This is slow because
5056 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5057 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5058 * extent_state structures over and over, wasting lots of time.
5059 *
5060 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5061 * those expensive operations on a per page basis and do only the ordered io
5062 * finishing, while we release here the extent_map and extent_state structures,
5063 * without the excessive merging and splitting.
5064 */
5065 static void evict_inode_truncate_pages(struct inode *inode)
5066 {
5067 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5068 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5069 struct rb_node *node;
5070
5071 ASSERT(inode->i_state & I_FREEING);
5072 truncate_inode_pages_final(&inode->i_data);
5073
5074 write_lock(&map_tree->lock);
5075 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5076 struct extent_map *em;
5077
5078 node = rb_first(&map_tree->map);
5079 em = rb_entry(node, struct extent_map, rb_node);
5080 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5081 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5082 remove_extent_mapping(map_tree, em);
5083 free_extent_map(em);
5084 if (need_resched()) {
5085 write_unlock(&map_tree->lock);
5086 cond_resched();
5087 write_lock(&map_tree->lock);
5088 }
5089 }
5090 write_unlock(&map_tree->lock);
5091
5092 /*
5093 * Keep looping until we have no more ranges in the io tree.
5094 * We can have ongoing bios started by readpages (called from readahead)
5095 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5096 * still in progress (unlocked the pages in the bio but did not yet
5097 * unlocked the ranges in the io tree). Therefore this means some
5098 * ranges can still be locked and eviction started because before
5099 * submitting those bios, which are executed by a separate task (work
5100 * queue kthread), inode references (inode->i_count) were not taken
5101 * (which would be dropped in the end io callback of each bio).
5102 * Therefore here we effectively end up waiting for those bios and
5103 * anyone else holding locked ranges without having bumped the inode's
5104 * reference count - if we don't do it, when they access the inode's
5105 * io_tree to unlock a range it may be too late, leading to an
5106 * use-after-free issue.
5107 */
5108 spin_lock(&io_tree->lock);
5109 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5110 struct extent_state *state;
5111 struct extent_state *cached_state = NULL;
5112 u64 start;
5113 u64 end;
5114
5115 node = rb_first(&io_tree->state);
5116 state = rb_entry(node, struct extent_state, rb_node);
5117 start = state->start;
5118 end = state->end;
5119 spin_unlock(&io_tree->lock);
5120
5121 lock_extent_bits(io_tree, start, end, &cached_state);
5122
5123 /*
5124 * If still has DELALLOC flag, the extent didn't reach disk,
5125 * and its reserved space won't be freed by delayed_ref.
5126 * So we need to free its reserved space here.
5127 * (Refer to comment in btrfs_invalidatepage, case 2)
5128 *
5129 * Note, end is the bytenr of last byte, so we need + 1 here.
5130 */
5131 if (state->state & EXTENT_DELALLOC)
5132 btrfs_qgroup_free_data(inode, start, end - start + 1);
5133
5134 clear_extent_bit(io_tree, start, end,
5135 EXTENT_LOCKED | EXTENT_DIRTY |
5136 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5137 EXTENT_DEFRAG, 1, 1,
5138 &cached_state, GFP_NOFS);
5139
5140 cond_resched();
5141 spin_lock(&io_tree->lock);
5142 }
5143 spin_unlock(&io_tree->lock);
5144 }
5145
5146 void btrfs_evict_inode(struct inode *inode)
5147 {
5148 struct btrfs_trans_handle *trans;
5149 struct btrfs_root *root = BTRFS_I(inode)->root;
5150 struct btrfs_block_rsv *rsv, *global_rsv;
5151 int steal_from_global = 0;
5152 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5153 int ret;
5154
5155 trace_btrfs_inode_evict(inode);
5156
5157 evict_inode_truncate_pages(inode);
5158
5159 if (inode->i_nlink &&
5160 ((btrfs_root_refs(&root->root_item) != 0 &&
5161 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5162 btrfs_is_free_space_inode(inode)))
5163 goto no_delete;
5164
5165 if (is_bad_inode(inode)) {
5166 btrfs_orphan_del(NULL, inode);
5167 goto no_delete;
5168 }
5169 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5170 if (!special_file(inode->i_mode))
5171 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5172
5173 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5174
5175 if (root->fs_info->log_root_recovering) {
5176 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5177 &BTRFS_I(inode)->runtime_flags));
5178 goto no_delete;
5179 }
5180
5181 if (inode->i_nlink > 0) {
5182 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5183 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5184 goto no_delete;
5185 }
5186
5187 ret = btrfs_commit_inode_delayed_inode(inode);
5188 if (ret) {
5189 btrfs_orphan_del(NULL, inode);
5190 goto no_delete;
5191 }
5192
5193 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5194 if (!rsv) {
5195 btrfs_orphan_del(NULL, inode);
5196 goto no_delete;
5197 }
5198 rsv->size = min_size;
5199 rsv->failfast = 1;
5200 global_rsv = &root->fs_info->global_block_rsv;
5201
5202 btrfs_i_size_write(inode, 0);
5203
5204 /*
5205 * This is a bit simpler than btrfs_truncate since we've already
5206 * reserved our space for our orphan item in the unlink, so we just
5207 * need to reserve some slack space in case we add bytes and update
5208 * inode item when doing the truncate.
5209 */
5210 while (1) {
5211 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5212 BTRFS_RESERVE_FLUSH_LIMIT);
5213
5214 /*
5215 * Try and steal from the global reserve since we will
5216 * likely not use this space anyway, we want to try as
5217 * hard as possible to get this to work.
5218 */
5219 if (ret)
5220 steal_from_global++;
5221 else
5222 steal_from_global = 0;
5223 ret = 0;
5224
5225 /*
5226 * steal_from_global == 0: we reserved stuff, hooray!
5227 * steal_from_global == 1: we didn't reserve stuff, boo!
5228 * steal_from_global == 2: we've committed, still not a lot of
5229 * room but maybe we'll have room in the global reserve this
5230 * time.
5231 * steal_from_global == 3: abandon all hope!
5232 */
5233 if (steal_from_global > 2) {
5234 btrfs_warn(root->fs_info,
5235 "Could not get space for a delete, will truncate on mount %d",
5236 ret);
5237 btrfs_orphan_del(NULL, inode);
5238 btrfs_free_block_rsv(root, rsv);
5239 goto no_delete;
5240 }
5241
5242 trans = btrfs_join_transaction(root);
5243 if (IS_ERR(trans)) {
5244 btrfs_orphan_del(NULL, inode);
5245 btrfs_free_block_rsv(root, rsv);
5246 goto no_delete;
5247 }
5248
5249 /*
5250 * We can't just steal from the global reserve, we need to make
5251 * sure there is room to do it, if not we need to commit and try
5252 * again.
5253 */
5254 if (steal_from_global) {
5255 if (!btrfs_check_space_for_delayed_refs(trans, root))
5256 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5257 min_size);
5258 else
5259 ret = -ENOSPC;
5260 }
5261
5262 /*
5263 * Couldn't steal from the global reserve, we have too much
5264 * pending stuff built up, commit the transaction and try it
5265 * again.
5266 */
5267 if (ret) {
5268 ret = btrfs_commit_transaction(trans, root);
5269 if (ret) {
5270 btrfs_orphan_del(NULL, inode);
5271 btrfs_free_block_rsv(root, rsv);
5272 goto no_delete;
5273 }
5274 continue;
5275 } else {
5276 steal_from_global = 0;
5277 }
5278
5279 trans->block_rsv = rsv;
5280
5281 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5282 if (ret != -ENOSPC && ret != -EAGAIN)
5283 break;
5284
5285 trans->block_rsv = &root->fs_info->trans_block_rsv;
5286 btrfs_end_transaction(trans, root);
5287 trans = NULL;
5288 btrfs_btree_balance_dirty(root);
5289 }
5290
5291 btrfs_free_block_rsv(root, rsv);
5292
5293 /*
5294 * Errors here aren't a big deal, it just means we leave orphan items
5295 * in the tree. They will be cleaned up on the next mount.
5296 */
5297 if (ret == 0) {
5298 trans->block_rsv = root->orphan_block_rsv;
5299 btrfs_orphan_del(trans, inode);
5300 } else {
5301 btrfs_orphan_del(NULL, inode);
5302 }
5303
5304 trans->block_rsv = &root->fs_info->trans_block_rsv;
5305 if (!(root == root->fs_info->tree_root ||
5306 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5307 btrfs_return_ino(root, btrfs_ino(inode));
5308
5309 btrfs_end_transaction(trans, root);
5310 btrfs_btree_balance_dirty(root);
5311 no_delete:
5312 btrfs_remove_delayed_node(inode);
5313 clear_inode(inode);
5314 }
5315
5316 /*
5317 * this returns the key found in the dir entry in the location pointer.
5318 * If no dir entries were found, location->objectid is 0.
5319 */
5320 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5321 struct btrfs_key *location)
5322 {
5323 const char *name = dentry->d_name.name;
5324 int namelen = dentry->d_name.len;
5325 struct btrfs_dir_item *di;
5326 struct btrfs_path *path;
5327 struct btrfs_root *root = BTRFS_I(dir)->root;
5328 int ret = 0;
5329
5330 path = btrfs_alloc_path();
5331 if (!path)
5332 return -ENOMEM;
5333
5334 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5335 namelen, 0);
5336 if (IS_ERR(di))
5337 ret = PTR_ERR(di);
5338
5339 if (IS_ERR_OR_NULL(di))
5340 goto out_err;
5341
5342 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5343 out:
5344 btrfs_free_path(path);
5345 return ret;
5346 out_err:
5347 location->objectid = 0;
5348 goto out;
5349 }
5350
5351 /*
5352 * when we hit a tree root in a directory, the btrfs part of the inode
5353 * needs to be changed to reflect the root directory of the tree root. This
5354 * is kind of like crossing a mount point.
5355 */
5356 static int fixup_tree_root_location(struct btrfs_root *root,
5357 struct inode *dir,
5358 struct dentry *dentry,
5359 struct btrfs_key *location,
5360 struct btrfs_root **sub_root)
5361 {
5362 struct btrfs_path *path;
5363 struct btrfs_root *new_root;
5364 struct btrfs_root_ref *ref;
5365 struct extent_buffer *leaf;
5366 struct btrfs_key key;
5367 int ret;
5368 int err = 0;
5369
5370 path = btrfs_alloc_path();
5371 if (!path) {
5372 err = -ENOMEM;
5373 goto out;
5374 }
5375
5376 err = -ENOENT;
5377 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5378 key.type = BTRFS_ROOT_REF_KEY;
5379 key.offset = location->objectid;
5380
5381 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5382 0, 0);
5383 if (ret) {
5384 if (ret < 0)
5385 err = ret;
5386 goto out;
5387 }
5388
5389 leaf = path->nodes[0];
5390 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5391 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5392 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5393 goto out;
5394
5395 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5396 (unsigned long)(ref + 1),
5397 dentry->d_name.len);
5398 if (ret)
5399 goto out;
5400
5401 btrfs_release_path(path);
5402
5403 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5404 if (IS_ERR(new_root)) {
5405 err = PTR_ERR(new_root);
5406 goto out;
5407 }
5408
5409 *sub_root = new_root;
5410 location->objectid = btrfs_root_dirid(&new_root->root_item);
5411 location->type = BTRFS_INODE_ITEM_KEY;
5412 location->offset = 0;
5413 err = 0;
5414 out:
5415 btrfs_free_path(path);
5416 return err;
5417 }
5418
5419 static void inode_tree_add(struct inode *inode)
5420 {
5421 struct btrfs_root *root = BTRFS_I(inode)->root;
5422 struct btrfs_inode *entry;
5423 struct rb_node **p;
5424 struct rb_node *parent;
5425 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5426 u64 ino = btrfs_ino(inode);
5427
5428 if (inode_unhashed(inode))
5429 return;
5430 parent = NULL;
5431 spin_lock(&root->inode_lock);
5432 p = &root->inode_tree.rb_node;
5433 while (*p) {
5434 parent = *p;
5435 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5436
5437 if (ino < btrfs_ino(&entry->vfs_inode))
5438 p = &parent->rb_left;
5439 else if (ino > btrfs_ino(&entry->vfs_inode))
5440 p = &parent->rb_right;
5441 else {
5442 WARN_ON(!(entry->vfs_inode.i_state &
5443 (I_WILL_FREE | I_FREEING)));
5444 rb_replace_node(parent, new, &root->inode_tree);
5445 RB_CLEAR_NODE(parent);
5446 spin_unlock(&root->inode_lock);
5447 return;
5448 }
5449 }
5450 rb_link_node(new, parent, p);
5451 rb_insert_color(new, &root->inode_tree);
5452 spin_unlock(&root->inode_lock);
5453 }
5454
5455 static void inode_tree_del(struct inode *inode)
5456 {
5457 struct btrfs_root *root = BTRFS_I(inode)->root;
5458 int empty = 0;
5459
5460 spin_lock(&root->inode_lock);
5461 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5462 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5463 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5464 empty = RB_EMPTY_ROOT(&root->inode_tree);
5465 }
5466 spin_unlock(&root->inode_lock);
5467
5468 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5469 synchronize_srcu(&root->fs_info->subvol_srcu);
5470 spin_lock(&root->inode_lock);
5471 empty = RB_EMPTY_ROOT(&root->inode_tree);
5472 spin_unlock(&root->inode_lock);
5473 if (empty)
5474 btrfs_add_dead_root(root);
5475 }
5476 }
5477
5478 void btrfs_invalidate_inodes(struct btrfs_root *root)
5479 {
5480 struct rb_node *node;
5481 struct rb_node *prev;
5482 struct btrfs_inode *entry;
5483 struct inode *inode;
5484 u64 objectid = 0;
5485
5486 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5487 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5488
5489 spin_lock(&root->inode_lock);
5490 again:
5491 node = root->inode_tree.rb_node;
5492 prev = NULL;
5493 while (node) {
5494 prev = node;
5495 entry = rb_entry(node, struct btrfs_inode, rb_node);
5496
5497 if (objectid < btrfs_ino(&entry->vfs_inode))
5498 node = node->rb_left;
5499 else if (objectid > btrfs_ino(&entry->vfs_inode))
5500 node = node->rb_right;
5501 else
5502 break;
5503 }
5504 if (!node) {
5505 while (prev) {
5506 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5507 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5508 node = prev;
5509 break;
5510 }
5511 prev = rb_next(prev);
5512 }
5513 }
5514 while (node) {
5515 entry = rb_entry(node, struct btrfs_inode, rb_node);
5516 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5517 inode = igrab(&entry->vfs_inode);
5518 if (inode) {
5519 spin_unlock(&root->inode_lock);
5520 if (atomic_read(&inode->i_count) > 1)
5521 d_prune_aliases(inode);
5522 /*
5523 * btrfs_drop_inode will have it removed from
5524 * the inode cache when its usage count
5525 * hits zero.
5526 */
5527 iput(inode);
5528 cond_resched();
5529 spin_lock(&root->inode_lock);
5530 goto again;
5531 }
5532
5533 if (cond_resched_lock(&root->inode_lock))
5534 goto again;
5535
5536 node = rb_next(node);
5537 }
5538 spin_unlock(&root->inode_lock);
5539 }
5540
5541 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5542 {
5543 struct btrfs_iget_args *args = p;
5544 inode->i_ino = args->location->objectid;
5545 memcpy(&BTRFS_I(inode)->location, args->location,
5546 sizeof(*args->location));
5547 BTRFS_I(inode)->root = args->root;
5548 return 0;
5549 }
5550
5551 static int btrfs_find_actor(struct inode *inode, void *opaque)
5552 {
5553 struct btrfs_iget_args *args = opaque;
5554 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5555 args->root == BTRFS_I(inode)->root;
5556 }
5557
5558 static struct inode *btrfs_iget_locked(struct super_block *s,
5559 struct btrfs_key *location,
5560 struct btrfs_root *root)
5561 {
5562 struct inode *inode;
5563 struct btrfs_iget_args args;
5564 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5565
5566 args.location = location;
5567 args.root = root;
5568
5569 inode = iget5_locked(s, hashval, btrfs_find_actor,
5570 btrfs_init_locked_inode,
5571 (void *)&args);
5572 return inode;
5573 }
5574
5575 /* Get an inode object given its location and corresponding root.
5576 * Returns in *is_new if the inode was read from disk
5577 */
5578 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5579 struct btrfs_root *root, int *new)
5580 {
5581 struct inode *inode;
5582
5583 inode = btrfs_iget_locked(s, location, root);
5584 if (!inode)
5585 return ERR_PTR(-ENOMEM);
5586
5587 if (inode->i_state & I_NEW) {
5588 btrfs_read_locked_inode(inode);
5589 if (!is_bad_inode(inode)) {
5590 inode_tree_add(inode);
5591 unlock_new_inode(inode);
5592 if (new)
5593 *new = 1;
5594 } else {
5595 unlock_new_inode(inode);
5596 iput(inode);
5597 inode = ERR_PTR(-ESTALE);
5598 }
5599 }
5600
5601 return inode;
5602 }
5603
5604 static struct inode *new_simple_dir(struct super_block *s,
5605 struct btrfs_key *key,
5606 struct btrfs_root *root)
5607 {
5608 struct inode *inode = new_inode(s);
5609
5610 if (!inode)
5611 return ERR_PTR(-ENOMEM);
5612
5613 BTRFS_I(inode)->root = root;
5614 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5615 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5616
5617 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5618 inode->i_op = &btrfs_dir_ro_inode_operations;
5619 inode->i_fop = &simple_dir_operations;
5620 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5621 inode->i_mtime = current_fs_time(inode->i_sb);
5622 inode->i_atime = inode->i_mtime;
5623 inode->i_ctime = inode->i_mtime;
5624 BTRFS_I(inode)->i_otime = inode->i_mtime;
5625
5626 return inode;
5627 }
5628
5629 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5630 {
5631 struct inode *inode;
5632 struct btrfs_root *root = BTRFS_I(dir)->root;
5633 struct btrfs_root *sub_root = root;
5634 struct btrfs_key location;
5635 int index;
5636 int ret = 0;
5637
5638 if (dentry->d_name.len > BTRFS_NAME_LEN)
5639 return ERR_PTR(-ENAMETOOLONG);
5640
5641 ret = btrfs_inode_by_name(dir, dentry, &location);
5642 if (ret < 0)
5643 return ERR_PTR(ret);
5644
5645 if (location.objectid == 0)
5646 return ERR_PTR(-ENOENT);
5647
5648 if (location.type == BTRFS_INODE_ITEM_KEY) {
5649 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5650 return inode;
5651 }
5652
5653 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5654
5655 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5656 ret = fixup_tree_root_location(root, dir, dentry,
5657 &location, &sub_root);
5658 if (ret < 0) {
5659 if (ret != -ENOENT)
5660 inode = ERR_PTR(ret);
5661 else
5662 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5663 } else {
5664 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5665 }
5666 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5667
5668 if (!IS_ERR(inode) && root != sub_root) {
5669 down_read(&root->fs_info->cleanup_work_sem);
5670 if (!(inode->i_sb->s_flags & MS_RDONLY))
5671 ret = btrfs_orphan_cleanup(sub_root);
5672 up_read(&root->fs_info->cleanup_work_sem);
5673 if (ret) {
5674 iput(inode);
5675 inode = ERR_PTR(ret);
5676 }
5677 }
5678
5679 return inode;
5680 }
5681
5682 static int btrfs_dentry_delete(const struct dentry *dentry)
5683 {
5684 struct btrfs_root *root;
5685 struct inode *inode = d_inode(dentry);
5686
5687 if (!inode && !IS_ROOT(dentry))
5688 inode = d_inode(dentry->d_parent);
5689
5690 if (inode) {
5691 root = BTRFS_I(inode)->root;
5692 if (btrfs_root_refs(&root->root_item) == 0)
5693 return 1;
5694
5695 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5696 return 1;
5697 }
5698 return 0;
5699 }
5700
5701 static void btrfs_dentry_release(struct dentry *dentry)
5702 {
5703 kfree(dentry->d_fsdata);
5704 }
5705
5706 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5707 unsigned int flags)
5708 {
5709 struct inode *inode;
5710
5711 inode = btrfs_lookup_dentry(dir, dentry);
5712 if (IS_ERR(inode)) {
5713 if (PTR_ERR(inode) == -ENOENT)
5714 inode = NULL;
5715 else
5716 return ERR_CAST(inode);
5717 }
5718
5719 return d_splice_alias(inode, dentry);
5720 }
5721
5722 unsigned char btrfs_filetype_table[] = {
5723 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5724 };
5725
5726 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5727 {
5728 struct inode *inode = file_inode(file);
5729 struct btrfs_root *root = BTRFS_I(inode)->root;
5730 struct btrfs_item *item;
5731 struct btrfs_dir_item *di;
5732 struct btrfs_key key;
5733 struct btrfs_key found_key;
5734 struct btrfs_path *path;
5735 struct list_head ins_list;
5736 struct list_head del_list;
5737 int ret;
5738 struct extent_buffer *leaf;
5739 int slot;
5740 unsigned char d_type;
5741 int over = 0;
5742 u32 di_cur;
5743 u32 di_total;
5744 u32 di_len;
5745 int key_type = BTRFS_DIR_INDEX_KEY;
5746 char tmp_name[32];
5747 char *name_ptr;
5748 int name_len;
5749 int is_curr = 0; /* ctx->pos points to the current index? */
5750 bool emitted;
5751
5752 /* FIXME, use a real flag for deciding about the key type */
5753 if (root->fs_info->tree_root == root)
5754 key_type = BTRFS_DIR_ITEM_KEY;
5755
5756 if (!dir_emit_dots(file, ctx))
5757 return 0;
5758
5759 path = btrfs_alloc_path();
5760 if (!path)
5761 return -ENOMEM;
5762
5763 path->reada = READA_FORWARD;
5764
5765 if (key_type == BTRFS_DIR_INDEX_KEY) {
5766 INIT_LIST_HEAD(&ins_list);
5767 INIT_LIST_HEAD(&del_list);
5768 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5769 }
5770
5771 key.type = key_type;
5772 key.offset = ctx->pos;
5773 key.objectid = btrfs_ino(inode);
5774
5775 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5776 if (ret < 0)
5777 goto err;
5778
5779 emitted = false;
5780 while (1) {
5781 leaf = path->nodes[0];
5782 slot = path->slots[0];
5783 if (slot >= btrfs_header_nritems(leaf)) {
5784 ret = btrfs_next_leaf(root, path);
5785 if (ret < 0)
5786 goto err;
5787 else if (ret > 0)
5788 break;
5789 continue;
5790 }
5791
5792 item = btrfs_item_nr(slot);
5793 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5794
5795 if (found_key.objectid != key.objectid)
5796 break;
5797 if (found_key.type != key_type)
5798 break;
5799 if (found_key.offset < ctx->pos)
5800 goto next;
5801 if (key_type == BTRFS_DIR_INDEX_KEY &&
5802 btrfs_should_delete_dir_index(&del_list,
5803 found_key.offset))
5804 goto next;
5805
5806 ctx->pos = found_key.offset;
5807 is_curr = 1;
5808
5809 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5810 di_cur = 0;
5811 di_total = btrfs_item_size(leaf, item);
5812
5813 while (di_cur < di_total) {
5814 struct btrfs_key location;
5815
5816 if (verify_dir_item(root, leaf, di))
5817 break;
5818
5819 name_len = btrfs_dir_name_len(leaf, di);
5820 if (name_len <= sizeof(tmp_name)) {
5821 name_ptr = tmp_name;
5822 } else {
5823 name_ptr = kmalloc(name_len, GFP_KERNEL);
5824 if (!name_ptr) {
5825 ret = -ENOMEM;
5826 goto err;
5827 }
5828 }
5829 read_extent_buffer(leaf, name_ptr,
5830 (unsigned long)(di + 1), name_len);
5831
5832 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5833 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5834
5835
5836 /* is this a reference to our own snapshot? If so
5837 * skip it.
5838 *
5839 * In contrast to old kernels, we insert the snapshot's
5840 * dir item and dir index after it has been created, so
5841 * we won't find a reference to our own snapshot. We
5842 * still keep the following code for backward
5843 * compatibility.
5844 */
5845 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5846 location.objectid == root->root_key.objectid) {
5847 over = 0;
5848 goto skip;
5849 }
5850 over = !dir_emit(ctx, name_ptr, name_len,
5851 location.objectid, d_type);
5852
5853 skip:
5854 if (name_ptr != tmp_name)
5855 kfree(name_ptr);
5856
5857 if (over)
5858 goto nopos;
5859 emitted = true;
5860 di_len = btrfs_dir_name_len(leaf, di) +
5861 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5862 di_cur += di_len;
5863 di = (struct btrfs_dir_item *)((char *)di + di_len);
5864 }
5865 next:
5866 path->slots[0]++;
5867 }
5868
5869 if (key_type == BTRFS_DIR_INDEX_KEY) {
5870 if (is_curr)
5871 ctx->pos++;
5872 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5873 if (ret)
5874 goto nopos;
5875 }
5876
5877 /*
5878 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5879 * it was was set to the termination value in previous call. We assume
5880 * that "." and ".." were emitted if we reach this point and set the
5881 * termination value as well for an empty directory.
5882 */
5883 if (ctx->pos > 2 && !emitted)
5884 goto nopos;
5885
5886 /* Reached end of directory/root. Bump pos past the last item. */
5887 ctx->pos++;
5888
5889 /*
5890 * Stop new entries from being returned after we return the last
5891 * entry.
5892 *
5893 * New directory entries are assigned a strictly increasing
5894 * offset. This means that new entries created during readdir
5895 * are *guaranteed* to be seen in the future by that readdir.
5896 * This has broken buggy programs which operate on names as
5897 * they're returned by readdir. Until we re-use freed offsets
5898 * we have this hack to stop new entries from being returned
5899 * under the assumption that they'll never reach this huge
5900 * offset.
5901 *
5902 * This is being careful not to overflow 32bit loff_t unless the
5903 * last entry requires it because doing so has broken 32bit apps
5904 * in the past.
5905 */
5906 if (key_type == BTRFS_DIR_INDEX_KEY) {
5907 if (ctx->pos >= INT_MAX)
5908 ctx->pos = LLONG_MAX;
5909 else
5910 ctx->pos = INT_MAX;
5911 }
5912 nopos:
5913 ret = 0;
5914 err:
5915 if (key_type == BTRFS_DIR_INDEX_KEY)
5916 btrfs_put_delayed_items(&ins_list, &del_list);
5917 btrfs_free_path(path);
5918 return ret;
5919 }
5920
5921 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5922 {
5923 struct btrfs_root *root = BTRFS_I(inode)->root;
5924 struct btrfs_trans_handle *trans;
5925 int ret = 0;
5926 bool nolock = false;
5927
5928 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5929 return 0;
5930
5931 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5932 nolock = true;
5933
5934 if (wbc->sync_mode == WB_SYNC_ALL) {
5935 if (nolock)
5936 trans = btrfs_join_transaction_nolock(root);
5937 else
5938 trans = btrfs_join_transaction(root);
5939 if (IS_ERR(trans))
5940 return PTR_ERR(trans);
5941 ret = btrfs_commit_transaction(trans, root);
5942 }
5943 return ret;
5944 }
5945
5946 /*
5947 * This is somewhat expensive, updating the tree every time the
5948 * inode changes. But, it is most likely to find the inode in cache.
5949 * FIXME, needs more benchmarking...there are no reasons other than performance
5950 * to keep or drop this code.
5951 */
5952 static int btrfs_dirty_inode(struct inode *inode)
5953 {
5954 struct btrfs_root *root = BTRFS_I(inode)->root;
5955 struct btrfs_trans_handle *trans;
5956 int ret;
5957
5958 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5959 return 0;
5960
5961 trans = btrfs_join_transaction(root);
5962 if (IS_ERR(trans))
5963 return PTR_ERR(trans);
5964
5965 ret = btrfs_update_inode(trans, root, inode);
5966 if (ret && ret == -ENOSPC) {
5967 /* whoops, lets try again with the full transaction */
5968 btrfs_end_transaction(trans, root);
5969 trans = btrfs_start_transaction(root, 1);
5970 if (IS_ERR(trans))
5971 return PTR_ERR(trans);
5972
5973 ret = btrfs_update_inode(trans, root, inode);
5974 }
5975 btrfs_end_transaction(trans, root);
5976 if (BTRFS_I(inode)->delayed_node)
5977 btrfs_balance_delayed_items(root);
5978
5979 return ret;
5980 }
5981
5982 /*
5983 * This is a copy of file_update_time. We need this so we can return error on
5984 * ENOSPC for updating the inode in the case of file write and mmap writes.
5985 */
5986 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5987 int flags)
5988 {
5989 struct btrfs_root *root = BTRFS_I(inode)->root;
5990
5991 if (btrfs_root_readonly(root))
5992 return -EROFS;
5993
5994 if (flags & S_VERSION)
5995 inode_inc_iversion(inode);
5996 if (flags & S_CTIME)
5997 inode->i_ctime = *now;
5998 if (flags & S_MTIME)
5999 inode->i_mtime = *now;
6000 if (flags & S_ATIME)
6001 inode->i_atime = *now;
6002 return btrfs_dirty_inode(inode);
6003 }
6004
6005 /*
6006 * find the highest existing sequence number in a directory
6007 * and then set the in-memory index_cnt variable to reflect
6008 * free sequence numbers
6009 */
6010 static int btrfs_set_inode_index_count(struct inode *inode)
6011 {
6012 struct btrfs_root *root = BTRFS_I(inode)->root;
6013 struct btrfs_key key, found_key;
6014 struct btrfs_path *path;
6015 struct extent_buffer *leaf;
6016 int ret;
6017
6018 key.objectid = btrfs_ino(inode);
6019 key.type = BTRFS_DIR_INDEX_KEY;
6020 key.offset = (u64)-1;
6021
6022 path = btrfs_alloc_path();
6023 if (!path)
6024 return -ENOMEM;
6025
6026 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6027 if (ret < 0)
6028 goto out;
6029 /* FIXME: we should be able to handle this */
6030 if (ret == 0)
6031 goto out;
6032 ret = 0;
6033
6034 /*
6035 * MAGIC NUMBER EXPLANATION:
6036 * since we search a directory based on f_pos we have to start at 2
6037 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6038 * else has to start at 2
6039 */
6040 if (path->slots[0] == 0) {
6041 BTRFS_I(inode)->index_cnt = 2;
6042 goto out;
6043 }
6044
6045 path->slots[0]--;
6046
6047 leaf = path->nodes[0];
6048 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6049
6050 if (found_key.objectid != btrfs_ino(inode) ||
6051 found_key.type != BTRFS_DIR_INDEX_KEY) {
6052 BTRFS_I(inode)->index_cnt = 2;
6053 goto out;
6054 }
6055
6056 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6057 out:
6058 btrfs_free_path(path);
6059 return ret;
6060 }
6061
6062 /*
6063 * helper to find a free sequence number in a given directory. This current
6064 * code is very simple, later versions will do smarter things in the btree
6065 */
6066 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6067 {
6068 int ret = 0;
6069
6070 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6071 ret = btrfs_inode_delayed_dir_index_count(dir);
6072 if (ret) {
6073 ret = btrfs_set_inode_index_count(dir);
6074 if (ret)
6075 return ret;
6076 }
6077 }
6078
6079 *index = BTRFS_I(dir)->index_cnt;
6080 BTRFS_I(dir)->index_cnt++;
6081
6082 return ret;
6083 }
6084
6085 static int btrfs_insert_inode_locked(struct inode *inode)
6086 {
6087 struct btrfs_iget_args args;
6088 args.location = &BTRFS_I(inode)->location;
6089 args.root = BTRFS_I(inode)->root;
6090
6091 return insert_inode_locked4(inode,
6092 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6093 btrfs_find_actor, &args);
6094 }
6095
6096 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6097 struct btrfs_root *root,
6098 struct inode *dir,
6099 const char *name, int name_len,
6100 u64 ref_objectid, u64 objectid,
6101 umode_t mode, u64 *index)
6102 {
6103 struct inode *inode;
6104 struct btrfs_inode_item *inode_item;
6105 struct btrfs_key *location;
6106 struct btrfs_path *path;
6107 struct btrfs_inode_ref *ref;
6108 struct btrfs_key key[2];
6109 u32 sizes[2];
6110 int nitems = name ? 2 : 1;
6111 unsigned long ptr;
6112 int ret;
6113
6114 path = btrfs_alloc_path();
6115 if (!path)
6116 return ERR_PTR(-ENOMEM);
6117
6118 inode = new_inode(root->fs_info->sb);
6119 if (!inode) {
6120 btrfs_free_path(path);
6121 return ERR_PTR(-ENOMEM);
6122 }
6123
6124 /*
6125 * O_TMPFILE, set link count to 0, so that after this point,
6126 * we fill in an inode item with the correct link count.
6127 */
6128 if (!name)
6129 set_nlink(inode, 0);
6130
6131 /*
6132 * we have to initialize this early, so we can reclaim the inode
6133 * number if we fail afterwards in this function.
6134 */
6135 inode->i_ino = objectid;
6136
6137 if (dir && name) {
6138 trace_btrfs_inode_request(dir);
6139
6140 ret = btrfs_set_inode_index(dir, index);
6141 if (ret) {
6142 btrfs_free_path(path);
6143 iput(inode);
6144 return ERR_PTR(ret);
6145 }
6146 } else if (dir) {
6147 *index = 0;
6148 }
6149 /*
6150 * index_cnt is ignored for everything but a dir,
6151 * btrfs_get_inode_index_count has an explanation for the magic
6152 * number
6153 */
6154 BTRFS_I(inode)->index_cnt = 2;
6155 BTRFS_I(inode)->dir_index = *index;
6156 BTRFS_I(inode)->root = root;
6157 BTRFS_I(inode)->generation = trans->transid;
6158 inode->i_generation = BTRFS_I(inode)->generation;
6159
6160 /*
6161 * We could have gotten an inode number from somebody who was fsynced
6162 * and then removed in this same transaction, so let's just set full
6163 * sync since it will be a full sync anyway and this will blow away the
6164 * old info in the log.
6165 */
6166 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6167
6168 key[0].objectid = objectid;
6169 key[0].type = BTRFS_INODE_ITEM_KEY;
6170 key[0].offset = 0;
6171
6172 sizes[0] = sizeof(struct btrfs_inode_item);
6173
6174 if (name) {
6175 /*
6176 * Start new inodes with an inode_ref. This is slightly more
6177 * efficient for small numbers of hard links since they will
6178 * be packed into one item. Extended refs will kick in if we
6179 * add more hard links than can fit in the ref item.
6180 */
6181 key[1].objectid = objectid;
6182 key[1].type = BTRFS_INODE_REF_KEY;
6183 key[1].offset = ref_objectid;
6184
6185 sizes[1] = name_len + sizeof(*ref);
6186 }
6187
6188 location = &BTRFS_I(inode)->location;
6189 location->objectid = objectid;
6190 location->offset = 0;
6191 location->type = BTRFS_INODE_ITEM_KEY;
6192
6193 ret = btrfs_insert_inode_locked(inode);
6194 if (ret < 0)
6195 goto fail;
6196
6197 path->leave_spinning = 1;
6198 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6199 if (ret != 0)
6200 goto fail_unlock;
6201
6202 inode_init_owner(inode, dir, mode);
6203 inode_set_bytes(inode, 0);
6204
6205 inode->i_mtime = current_fs_time(inode->i_sb);
6206 inode->i_atime = inode->i_mtime;
6207 inode->i_ctime = inode->i_mtime;
6208 BTRFS_I(inode)->i_otime = inode->i_mtime;
6209
6210 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6211 struct btrfs_inode_item);
6212 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6213 sizeof(*inode_item));
6214 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6215
6216 if (name) {
6217 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6218 struct btrfs_inode_ref);
6219 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6220 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6221 ptr = (unsigned long)(ref + 1);
6222 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6223 }
6224
6225 btrfs_mark_buffer_dirty(path->nodes[0]);
6226 btrfs_free_path(path);
6227
6228 btrfs_inherit_iflags(inode, dir);
6229
6230 if (S_ISREG(mode)) {
6231 if (btrfs_test_opt(root, NODATASUM))
6232 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6233 if (btrfs_test_opt(root, NODATACOW))
6234 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6235 BTRFS_INODE_NODATASUM;
6236 }
6237
6238 inode_tree_add(inode);
6239
6240 trace_btrfs_inode_new(inode);
6241 btrfs_set_inode_last_trans(trans, inode);
6242
6243 btrfs_update_root_times(trans, root);
6244
6245 ret = btrfs_inode_inherit_props(trans, inode, dir);
6246 if (ret)
6247 btrfs_err(root->fs_info,
6248 "error inheriting props for ino %llu (root %llu): %d",
6249 btrfs_ino(inode), root->root_key.objectid, ret);
6250
6251 return inode;
6252
6253 fail_unlock:
6254 unlock_new_inode(inode);
6255 fail:
6256 if (dir && name)
6257 BTRFS_I(dir)->index_cnt--;
6258 btrfs_free_path(path);
6259 iput(inode);
6260 return ERR_PTR(ret);
6261 }
6262
6263 static inline u8 btrfs_inode_type(struct inode *inode)
6264 {
6265 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6266 }
6267
6268 /*
6269 * utility function to add 'inode' into 'parent_inode' with
6270 * a give name and a given sequence number.
6271 * if 'add_backref' is true, also insert a backref from the
6272 * inode to the parent directory.
6273 */
6274 int btrfs_add_link(struct btrfs_trans_handle *trans,
6275 struct inode *parent_inode, struct inode *inode,
6276 const char *name, int name_len, int add_backref, u64 index)
6277 {
6278 int ret = 0;
6279 struct btrfs_key key;
6280 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6281 u64 ino = btrfs_ino(inode);
6282 u64 parent_ino = btrfs_ino(parent_inode);
6283
6284 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6285 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6286 } else {
6287 key.objectid = ino;
6288 key.type = BTRFS_INODE_ITEM_KEY;
6289 key.offset = 0;
6290 }
6291
6292 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6293 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6294 key.objectid, root->root_key.objectid,
6295 parent_ino, index, name, name_len);
6296 } else if (add_backref) {
6297 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6298 parent_ino, index);
6299 }
6300
6301 /* Nothing to clean up yet */
6302 if (ret)
6303 return ret;
6304
6305 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6306 parent_inode, &key,
6307 btrfs_inode_type(inode), index);
6308 if (ret == -EEXIST || ret == -EOVERFLOW)
6309 goto fail_dir_item;
6310 else if (ret) {
6311 btrfs_abort_transaction(trans, root, ret);
6312 return ret;
6313 }
6314
6315 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6316 name_len * 2);
6317 inode_inc_iversion(parent_inode);
6318 parent_inode->i_mtime = parent_inode->i_ctime =
6319 current_fs_time(parent_inode->i_sb);
6320 ret = btrfs_update_inode(trans, root, parent_inode);
6321 if (ret)
6322 btrfs_abort_transaction(trans, root, ret);
6323 return ret;
6324
6325 fail_dir_item:
6326 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6327 u64 local_index;
6328 int err;
6329 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6330 key.objectid, root->root_key.objectid,
6331 parent_ino, &local_index, name, name_len);
6332
6333 } else if (add_backref) {
6334 u64 local_index;
6335 int err;
6336
6337 err = btrfs_del_inode_ref(trans, root, name, name_len,
6338 ino, parent_ino, &local_index);
6339 }
6340 return ret;
6341 }
6342
6343 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6344 struct inode *dir, struct dentry *dentry,
6345 struct inode *inode, int backref, u64 index)
6346 {
6347 int err = btrfs_add_link(trans, dir, inode,
6348 dentry->d_name.name, dentry->d_name.len,
6349 backref, index);
6350 if (err > 0)
6351 err = -EEXIST;
6352 return err;
6353 }
6354
6355 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6356 umode_t mode, dev_t rdev)
6357 {
6358 struct btrfs_trans_handle *trans;
6359 struct btrfs_root *root = BTRFS_I(dir)->root;
6360 struct inode *inode = NULL;
6361 int err;
6362 int drop_inode = 0;
6363 u64 objectid;
6364 u64 index = 0;
6365
6366 /*
6367 * 2 for inode item and ref
6368 * 2 for dir items
6369 * 1 for xattr if selinux is on
6370 */
6371 trans = btrfs_start_transaction(root, 5);
6372 if (IS_ERR(trans))
6373 return PTR_ERR(trans);
6374
6375 err = btrfs_find_free_ino(root, &objectid);
6376 if (err)
6377 goto out_unlock;
6378
6379 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6380 dentry->d_name.len, btrfs_ino(dir), objectid,
6381 mode, &index);
6382 if (IS_ERR(inode)) {
6383 err = PTR_ERR(inode);
6384 goto out_unlock;
6385 }
6386
6387 /*
6388 * If the active LSM wants to access the inode during
6389 * d_instantiate it needs these. Smack checks to see
6390 * if the filesystem supports xattrs by looking at the
6391 * ops vector.
6392 */
6393 inode->i_op = &btrfs_special_inode_operations;
6394 init_special_inode(inode, inode->i_mode, rdev);
6395
6396 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6397 if (err)
6398 goto out_unlock_inode;
6399
6400 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6401 if (err) {
6402 goto out_unlock_inode;
6403 } else {
6404 btrfs_update_inode(trans, root, inode);
6405 unlock_new_inode(inode);
6406 d_instantiate(dentry, inode);
6407 }
6408
6409 out_unlock:
6410 btrfs_end_transaction(trans, root);
6411 btrfs_balance_delayed_items(root);
6412 btrfs_btree_balance_dirty(root);
6413 if (drop_inode) {
6414 inode_dec_link_count(inode);
6415 iput(inode);
6416 }
6417 return err;
6418
6419 out_unlock_inode:
6420 drop_inode = 1;
6421 unlock_new_inode(inode);
6422 goto out_unlock;
6423
6424 }
6425
6426 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6427 umode_t mode, bool excl)
6428 {
6429 struct btrfs_trans_handle *trans;
6430 struct btrfs_root *root = BTRFS_I(dir)->root;
6431 struct inode *inode = NULL;
6432 int drop_inode_on_err = 0;
6433 int err;
6434 u64 objectid;
6435 u64 index = 0;
6436
6437 /*
6438 * 2 for inode item and ref
6439 * 2 for dir items
6440 * 1 for xattr if selinux is on
6441 */
6442 trans = btrfs_start_transaction(root, 5);
6443 if (IS_ERR(trans))
6444 return PTR_ERR(trans);
6445
6446 err = btrfs_find_free_ino(root, &objectid);
6447 if (err)
6448 goto out_unlock;
6449
6450 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6451 dentry->d_name.len, btrfs_ino(dir), objectid,
6452 mode, &index);
6453 if (IS_ERR(inode)) {
6454 err = PTR_ERR(inode);
6455 goto out_unlock;
6456 }
6457 drop_inode_on_err = 1;
6458 /*
6459 * If the active LSM wants to access the inode during
6460 * d_instantiate it needs these. Smack checks to see
6461 * if the filesystem supports xattrs by looking at the
6462 * ops vector.
6463 */
6464 inode->i_fop = &btrfs_file_operations;
6465 inode->i_op = &btrfs_file_inode_operations;
6466 inode->i_mapping->a_ops = &btrfs_aops;
6467
6468 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6469 if (err)
6470 goto out_unlock_inode;
6471
6472 err = btrfs_update_inode(trans, root, inode);
6473 if (err)
6474 goto out_unlock_inode;
6475
6476 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6477 if (err)
6478 goto out_unlock_inode;
6479
6480 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6481 unlock_new_inode(inode);
6482 d_instantiate(dentry, inode);
6483
6484 out_unlock:
6485 btrfs_end_transaction(trans, root);
6486 if (err && drop_inode_on_err) {
6487 inode_dec_link_count(inode);
6488 iput(inode);
6489 }
6490 btrfs_balance_delayed_items(root);
6491 btrfs_btree_balance_dirty(root);
6492 return err;
6493
6494 out_unlock_inode:
6495 unlock_new_inode(inode);
6496 goto out_unlock;
6497
6498 }
6499
6500 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6501 struct dentry *dentry)
6502 {
6503 struct btrfs_trans_handle *trans = NULL;
6504 struct btrfs_root *root = BTRFS_I(dir)->root;
6505 struct inode *inode = d_inode(old_dentry);
6506 u64 index;
6507 int err;
6508 int drop_inode = 0;
6509
6510 /* do not allow sys_link's with other subvols of the same device */
6511 if (root->objectid != BTRFS_I(inode)->root->objectid)
6512 return -EXDEV;
6513
6514 if (inode->i_nlink >= BTRFS_LINK_MAX)
6515 return -EMLINK;
6516
6517 err = btrfs_set_inode_index(dir, &index);
6518 if (err)
6519 goto fail;
6520
6521 /*
6522 * 2 items for inode and inode ref
6523 * 2 items for dir items
6524 * 1 item for parent inode
6525 */
6526 trans = btrfs_start_transaction(root, 5);
6527 if (IS_ERR(trans)) {
6528 err = PTR_ERR(trans);
6529 trans = NULL;
6530 goto fail;
6531 }
6532
6533 /* There are several dir indexes for this inode, clear the cache. */
6534 BTRFS_I(inode)->dir_index = 0ULL;
6535 inc_nlink(inode);
6536 inode_inc_iversion(inode);
6537 inode->i_ctime = current_fs_time(inode->i_sb);
6538 ihold(inode);
6539 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6540
6541 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6542
6543 if (err) {
6544 drop_inode = 1;
6545 } else {
6546 struct dentry *parent = dentry->d_parent;
6547 err = btrfs_update_inode(trans, root, inode);
6548 if (err)
6549 goto fail;
6550 if (inode->i_nlink == 1) {
6551 /*
6552 * If new hard link count is 1, it's a file created
6553 * with open(2) O_TMPFILE flag.
6554 */
6555 err = btrfs_orphan_del(trans, inode);
6556 if (err)
6557 goto fail;
6558 }
6559 d_instantiate(dentry, inode);
6560 btrfs_log_new_name(trans, inode, NULL, parent);
6561 }
6562
6563 btrfs_balance_delayed_items(root);
6564 fail:
6565 if (trans)
6566 btrfs_end_transaction(trans, root);
6567 if (drop_inode) {
6568 inode_dec_link_count(inode);
6569 iput(inode);
6570 }
6571 btrfs_btree_balance_dirty(root);
6572 return err;
6573 }
6574
6575 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6576 {
6577 struct inode *inode = NULL;
6578 struct btrfs_trans_handle *trans;
6579 struct btrfs_root *root = BTRFS_I(dir)->root;
6580 int err = 0;
6581 int drop_on_err = 0;
6582 u64 objectid = 0;
6583 u64 index = 0;
6584
6585 /*
6586 * 2 items for inode and ref
6587 * 2 items for dir items
6588 * 1 for xattr if selinux is on
6589 */
6590 trans = btrfs_start_transaction(root, 5);
6591 if (IS_ERR(trans))
6592 return PTR_ERR(trans);
6593
6594 err = btrfs_find_free_ino(root, &objectid);
6595 if (err)
6596 goto out_fail;
6597
6598 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6599 dentry->d_name.len, btrfs_ino(dir), objectid,
6600 S_IFDIR | mode, &index);
6601 if (IS_ERR(inode)) {
6602 err = PTR_ERR(inode);
6603 goto out_fail;
6604 }
6605
6606 drop_on_err = 1;
6607 /* these must be set before we unlock the inode */
6608 inode->i_op = &btrfs_dir_inode_operations;
6609 inode->i_fop = &btrfs_dir_file_operations;
6610
6611 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6612 if (err)
6613 goto out_fail_inode;
6614
6615 btrfs_i_size_write(inode, 0);
6616 err = btrfs_update_inode(trans, root, inode);
6617 if (err)
6618 goto out_fail_inode;
6619
6620 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6621 dentry->d_name.len, 0, index);
6622 if (err)
6623 goto out_fail_inode;
6624
6625 d_instantiate(dentry, inode);
6626 /*
6627 * mkdir is special. We're unlocking after we call d_instantiate
6628 * to avoid a race with nfsd calling d_instantiate.
6629 */
6630 unlock_new_inode(inode);
6631 drop_on_err = 0;
6632
6633 out_fail:
6634 btrfs_end_transaction(trans, root);
6635 if (drop_on_err) {
6636 inode_dec_link_count(inode);
6637 iput(inode);
6638 }
6639 btrfs_balance_delayed_items(root);
6640 btrfs_btree_balance_dirty(root);
6641 return err;
6642
6643 out_fail_inode:
6644 unlock_new_inode(inode);
6645 goto out_fail;
6646 }
6647
6648 /* Find next extent map of a given extent map, caller needs to ensure locks */
6649 static struct extent_map *next_extent_map(struct extent_map *em)
6650 {
6651 struct rb_node *next;
6652
6653 next = rb_next(&em->rb_node);
6654 if (!next)
6655 return NULL;
6656 return container_of(next, struct extent_map, rb_node);
6657 }
6658
6659 static struct extent_map *prev_extent_map(struct extent_map *em)
6660 {
6661 struct rb_node *prev;
6662
6663 prev = rb_prev(&em->rb_node);
6664 if (!prev)
6665 return NULL;
6666 return container_of(prev, struct extent_map, rb_node);
6667 }
6668
6669 /* helper for btfs_get_extent. Given an existing extent in the tree,
6670 * the existing extent is the nearest extent to map_start,
6671 * and an extent that you want to insert, deal with overlap and insert
6672 * the best fitted new extent into the tree.
6673 */
6674 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6675 struct extent_map *existing,
6676 struct extent_map *em,
6677 u64 map_start)
6678 {
6679 struct extent_map *prev;
6680 struct extent_map *next;
6681 u64 start;
6682 u64 end;
6683 u64 start_diff;
6684
6685 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6686
6687 if (existing->start > map_start) {
6688 next = existing;
6689 prev = prev_extent_map(next);
6690 } else {
6691 prev = existing;
6692 next = next_extent_map(prev);
6693 }
6694
6695 start = prev ? extent_map_end(prev) : em->start;
6696 start = max_t(u64, start, em->start);
6697 end = next ? next->start : extent_map_end(em);
6698 end = min_t(u64, end, extent_map_end(em));
6699 start_diff = start - em->start;
6700 em->start = start;
6701 em->len = end - start;
6702 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6703 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6704 em->block_start += start_diff;
6705 em->block_len -= start_diff;
6706 }
6707 return add_extent_mapping(em_tree, em, 0);
6708 }
6709
6710 static noinline int uncompress_inline(struct btrfs_path *path,
6711 struct page *page,
6712 size_t pg_offset, u64 extent_offset,
6713 struct btrfs_file_extent_item *item)
6714 {
6715 int ret;
6716 struct extent_buffer *leaf = path->nodes[0];
6717 char *tmp;
6718 size_t max_size;
6719 unsigned long inline_size;
6720 unsigned long ptr;
6721 int compress_type;
6722
6723 WARN_ON(pg_offset != 0);
6724 compress_type = btrfs_file_extent_compression(leaf, item);
6725 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6726 inline_size = btrfs_file_extent_inline_item_len(leaf,
6727 btrfs_item_nr(path->slots[0]));
6728 tmp = kmalloc(inline_size, GFP_NOFS);
6729 if (!tmp)
6730 return -ENOMEM;
6731 ptr = btrfs_file_extent_inline_start(item);
6732
6733 read_extent_buffer(leaf, tmp, ptr, inline_size);
6734
6735 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6736 ret = btrfs_decompress(compress_type, tmp, page,
6737 extent_offset, inline_size, max_size);
6738 kfree(tmp);
6739 return ret;
6740 }
6741
6742 /*
6743 * a bit scary, this does extent mapping from logical file offset to the disk.
6744 * the ugly parts come from merging extents from the disk with the in-ram
6745 * representation. This gets more complex because of the data=ordered code,
6746 * where the in-ram extents might be locked pending data=ordered completion.
6747 *
6748 * This also copies inline extents directly into the page.
6749 */
6750
6751 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6752 size_t pg_offset, u64 start, u64 len,
6753 int create)
6754 {
6755 int ret;
6756 int err = 0;
6757 u64 extent_start = 0;
6758 u64 extent_end = 0;
6759 u64 objectid = btrfs_ino(inode);
6760 u32 found_type;
6761 struct btrfs_path *path = NULL;
6762 struct btrfs_root *root = BTRFS_I(inode)->root;
6763 struct btrfs_file_extent_item *item;
6764 struct extent_buffer *leaf;
6765 struct btrfs_key found_key;
6766 struct extent_map *em = NULL;
6767 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6768 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6769 struct btrfs_trans_handle *trans = NULL;
6770 const bool new_inline = !page || create;
6771
6772 again:
6773 read_lock(&em_tree->lock);
6774 em = lookup_extent_mapping(em_tree, start, len);
6775 if (em)
6776 em->bdev = root->fs_info->fs_devices->latest_bdev;
6777 read_unlock(&em_tree->lock);
6778
6779 if (em) {
6780 if (em->start > start || em->start + em->len <= start)
6781 free_extent_map(em);
6782 else if (em->block_start == EXTENT_MAP_INLINE && page)
6783 free_extent_map(em);
6784 else
6785 goto out;
6786 }
6787 em = alloc_extent_map();
6788 if (!em) {
6789 err = -ENOMEM;
6790 goto out;
6791 }
6792 em->bdev = root->fs_info->fs_devices->latest_bdev;
6793 em->start = EXTENT_MAP_HOLE;
6794 em->orig_start = EXTENT_MAP_HOLE;
6795 em->len = (u64)-1;
6796 em->block_len = (u64)-1;
6797
6798 if (!path) {
6799 path = btrfs_alloc_path();
6800 if (!path) {
6801 err = -ENOMEM;
6802 goto out;
6803 }
6804 /*
6805 * Chances are we'll be called again, so go ahead and do
6806 * readahead
6807 */
6808 path->reada = READA_FORWARD;
6809 }
6810
6811 ret = btrfs_lookup_file_extent(trans, root, path,
6812 objectid, start, trans != NULL);
6813 if (ret < 0) {
6814 err = ret;
6815 goto out;
6816 }
6817
6818 if (ret != 0) {
6819 if (path->slots[0] == 0)
6820 goto not_found;
6821 path->slots[0]--;
6822 }
6823
6824 leaf = path->nodes[0];
6825 item = btrfs_item_ptr(leaf, path->slots[0],
6826 struct btrfs_file_extent_item);
6827 /* are we inside the extent that was found? */
6828 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6829 found_type = found_key.type;
6830 if (found_key.objectid != objectid ||
6831 found_type != BTRFS_EXTENT_DATA_KEY) {
6832 /*
6833 * If we backup past the first extent we want to move forward
6834 * and see if there is an extent in front of us, otherwise we'll
6835 * say there is a hole for our whole search range which can
6836 * cause problems.
6837 */
6838 extent_end = start;
6839 goto next;
6840 }
6841
6842 found_type = btrfs_file_extent_type(leaf, item);
6843 extent_start = found_key.offset;
6844 if (found_type == BTRFS_FILE_EXTENT_REG ||
6845 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6846 extent_end = extent_start +
6847 btrfs_file_extent_num_bytes(leaf, item);
6848 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6849 size_t size;
6850 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6851 extent_end = ALIGN(extent_start + size, root->sectorsize);
6852 }
6853 next:
6854 if (start >= extent_end) {
6855 path->slots[0]++;
6856 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6857 ret = btrfs_next_leaf(root, path);
6858 if (ret < 0) {
6859 err = ret;
6860 goto out;
6861 }
6862 if (ret > 0)
6863 goto not_found;
6864 leaf = path->nodes[0];
6865 }
6866 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6867 if (found_key.objectid != objectid ||
6868 found_key.type != BTRFS_EXTENT_DATA_KEY)
6869 goto not_found;
6870 if (start + len <= found_key.offset)
6871 goto not_found;
6872 if (start > found_key.offset)
6873 goto next;
6874 em->start = start;
6875 em->orig_start = start;
6876 em->len = found_key.offset - start;
6877 goto not_found_em;
6878 }
6879
6880 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6881
6882 if (found_type == BTRFS_FILE_EXTENT_REG ||
6883 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6884 goto insert;
6885 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6886 unsigned long ptr;
6887 char *map;
6888 size_t size;
6889 size_t extent_offset;
6890 size_t copy_size;
6891
6892 if (new_inline)
6893 goto out;
6894
6895 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6896 extent_offset = page_offset(page) + pg_offset - extent_start;
6897 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6898 size - extent_offset);
6899 em->start = extent_start + extent_offset;
6900 em->len = ALIGN(copy_size, root->sectorsize);
6901 em->orig_block_len = em->len;
6902 em->orig_start = em->start;
6903 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6904 if (create == 0 && !PageUptodate(page)) {
6905 if (btrfs_file_extent_compression(leaf, item) !=
6906 BTRFS_COMPRESS_NONE) {
6907 ret = uncompress_inline(path, page, pg_offset,
6908 extent_offset, item);
6909 if (ret) {
6910 err = ret;
6911 goto out;
6912 }
6913 } else {
6914 map = kmap(page);
6915 read_extent_buffer(leaf, map + pg_offset, ptr,
6916 copy_size);
6917 if (pg_offset + copy_size < PAGE_SIZE) {
6918 memset(map + pg_offset + copy_size, 0,
6919 PAGE_SIZE - pg_offset -
6920 copy_size);
6921 }
6922 kunmap(page);
6923 }
6924 flush_dcache_page(page);
6925 } else if (create && PageUptodate(page)) {
6926 BUG();
6927 if (!trans) {
6928 kunmap(page);
6929 free_extent_map(em);
6930 em = NULL;
6931
6932 btrfs_release_path(path);
6933 trans = btrfs_join_transaction(root);
6934
6935 if (IS_ERR(trans))
6936 return ERR_CAST(trans);
6937 goto again;
6938 }
6939 map = kmap(page);
6940 write_extent_buffer(leaf, map + pg_offset, ptr,
6941 copy_size);
6942 kunmap(page);
6943 btrfs_mark_buffer_dirty(leaf);
6944 }
6945 set_extent_uptodate(io_tree, em->start,
6946 extent_map_end(em) - 1, NULL, GFP_NOFS);
6947 goto insert;
6948 }
6949 not_found:
6950 em->start = start;
6951 em->orig_start = start;
6952 em->len = len;
6953 not_found_em:
6954 em->block_start = EXTENT_MAP_HOLE;
6955 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6956 insert:
6957 btrfs_release_path(path);
6958 if (em->start > start || extent_map_end(em) <= start) {
6959 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6960 em->start, em->len, start, len);
6961 err = -EIO;
6962 goto out;
6963 }
6964
6965 err = 0;
6966 write_lock(&em_tree->lock);
6967 ret = add_extent_mapping(em_tree, em, 0);
6968 /* it is possible that someone inserted the extent into the tree
6969 * while we had the lock dropped. It is also possible that
6970 * an overlapping map exists in the tree
6971 */
6972 if (ret == -EEXIST) {
6973 struct extent_map *existing;
6974
6975 ret = 0;
6976
6977 existing = search_extent_mapping(em_tree, start, len);
6978 /*
6979 * existing will always be non-NULL, since there must be
6980 * extent causing the -EEXIST.
6981 */
6982 if (existing->start == em->start &&
6983 extent_map_end(existing) == extent_map_end(em) &&
6984 em->block_start == existing->block_start) {
6985 /*
6986 * these two extents are the same, it happens
6987 * with inlines especially
6988 */
6989 free_extent_map(em);
6990 em = existing;
6991 err = 0;
6992
6993 } else if (start >= extent_map_end(existing) ||
6994 start <= existing->start) {
6995 /*
6996 * The existing extent map is the one nearest to
6997 * the [start, start + len) range which overlaps
6998 */
6999 err = merge_extent_mapping(em_tree, existing,
7000 em, start);
7001 free_extent_map(existing);
7002 if (err) {
7003 free_extent_map(em);
7004 em = NULL;
7005 }
7006 } else {
7007 free_extent_map(em);
7008 em = existing;
7009 err = 0;
7010 }
7011 }
7012 write_unlock(&em_tree->lock);
7013 out:
7014
7015 trace_btrfs_get_extent(root, em);
7016
7017 btrfs_free_path(path);
7018 if (trans) {
7019 ret = btrfs_end_transaction(trans, root);
7020 if (!err)
7021 err = ret;
7022 }
7023 if (err) {
7024 free_extent_map(em);
7025 return ERR_PTR(err);
7026 }
7027 BUG_ON(!em); /* Error is always set */
7028 return em;
7029 }
7030
7031 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7032 size_t pg_offset, u64 start, u64 len,
7033 int create)
7034 {
7035 struct extent_map *em;
7036 struct extent_map *hole_em = NULL;
7037 u64 range_start = start;
7038 u64 end;
7039 u64 found;
7040 u64 found_end;
7041 int err = 0;
7042
7043 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7044 if (IS_ERR(em))
7045 return em;
7046 if (em) {
7047 /*
7048 * if our em maps to
7049 * - a hole or
7050 * - a pre-alloc extent,
7051 * there might actually be delalloc bytes behind it.
7052 */
7053 if (em->block_start != EXTENT_MAP_HOLE &&
7054 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7055 return em;
7056 else
7057 hole_em = em;
7058 }
7059
7060 /* check to see if we've wrapped (len == -1 or similar) */
7061 end = start + len;
7062 if (end < start)
7063 end = (u64)-1;
7064 else
7065 end -= 1;
7066
7067 em = NULL;
7068
7069 /* ok, we didn't find anything, lets look for delalloc */
7070 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7071 end, len, EXTENT_DELALLOC, 1);
7072 found_end = range_start + found;
7073 if (found_end < range_start)
7074 found_end = (u64)-1;
7075
7076 /*
7077 * we didn't find anything useful, return
7078 * the original results from get_extent()
7079 */
7080 if (range_start > end || found_end <= start) {
7081 em = hole_em;
7082 hole_em = NULL;
7083 goto out;
7084 }
7085
7086 /* adjust the range_start to make sure it doesn't
7087 * go backwards from the start they passed in
7088 */
7089 range_start = max(start, range_start);
7090 found = found_end - range_start;
7091
7092 if (found > 0) {
7093 u64 hole_start = start;
7094 u64 hole_len = len;
7095
7096 em = alloc_extent_map();
7097 if (!em) {
7098 err = -ENOMEM;
7099 goto out;
7100 }
7101 /*
7102 * when btrfs_get_extent can't find anything it
7103 * returns one huge hole
7104 *
7105 * make sure what it found really fits our range, and
7106 * adjust to make sure it is based on the start from
7107 * the caller
7108 */
7109 if (hole_em) {
7110 u64 calc_end = extent_map_end(hole_em);
7111
7112 if (calc_end <= start || (hole_em->start > end)) {
7113 free_extent_map(hole_em);
7114 hole_em = NULL;
7115 } else {
7116 hole_start = max(hole_em->start, start);
7117 hole_len = calc_end - hole_start;
7118 }
7119 }
7120 em->bdev = NULL;
7121 if (hole_em && range_start > hole_start) {
7122 /* our hole starts before our delalloc, so we
7123 * have to return just the parts of the hole
7124 * that go until the delalloc starts
7125 */
7126 em->len = min(hole_len,
7127 range_start - hole_start);
7128 em->start = hole_start;
7129 em->orig_start = hole_start;
7130 /*
7131 * don't adjust block start at all,
7132 * it is fixed at EXTENT_MAP_HOLE
7133 */
7134 em->block_start = hole_em->block_start;
7135 em->block_len = hole_len;
7136 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7137 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7138 } else {
7139 em->start = range_start;
7140 em->len = found;
7141 em->orig_start = range_start;
7142 em->block_start = EXTENT_MAP_DELALLOC;
7143 em->block_len = found;
7144 }
7145 } else if (hole_em) {
7146 return hole_em;
7147 }
7148 out:
7149
7150 free_extent_map(hole_em);
7151 if (err) {
7152 free_extent_map(em);
7153 return ERR_PTR(err);
7154 }
7155 return em;
7156 }
7157
7158 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7159 const u64 start,
7160 const u64 len,
7161 const u64 orig_start,
7162 const u64 block_start,
7163 const u64 block_len,
7164 const u64 orig_block_len,
7165 const u64 ram_bytes,
7166 const int type)
7167 {
7168 struct extent_map *em = NULL;
7169 int ret;
7170
7171 down_read(&BTRFS_I(inode)->dio_sem);
7172 if (type != BTRFS_ORDERED_NOCOW) {
7173 em = create_pinned_em(inode, start, len, orig_start,
7174 block_start, block_len, orig_block_len,
7175 ram_bytes, type);
7176 if (IS_ERR(em))
7177 goto out;
7178 }
7179 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7180 len, block_len, type);
7181 if (ret) {
7182 if (em) {
7183 free_extent_map(em);
7184 btrfs_drop_extent_cache(inode, start,
7185 start + len - 1, 0);
7186 }
7187 em = ERR_PTR(ret);
7188 }
7189 out:
7190 up_read(&BTRFS_I(inode)->dio_sem);
7191
7192 return em;
7193 }
7194
7195 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7196 u64 start, u64 len)
7197 {
7198 struct btrfs_root *root = BTRFS_I(inode)->root;
7199 struct extent_map *em;
7200 struct btrfs_key ins;
7201 u64 alloc_hint;
7202 int ret;
7203
7204 alloc_hint = get_extent_allocation_hint(inode, start, len);
7205 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7206 alloc_hint, &ins, 1, 1);
7207 if (ret)
7208 return ERR_PTR(ret);
7209
7210 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7211 ins.objectid, ins.offset, ins.offset,
7212 ins.offset, 0);
7213 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7214 if (IS_ERR(em))
7215 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7216
7217 return em;
7218 }
7219
7220 /*
7221 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7222 * block must be cow'd
7223 */
7224 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7225 u64 *orig_start, u64 *orig_block_len,
7226 u64 *ram_bytes)
7227 {
7228 struct btrfs_trans_handle *trans;
7229 struct btrfs_path *path;
7230 int ret;
7231 struct extent_buffer *leaf;
7232 struct btrfs_root *root = BTRFS_I(inode)->root;
7233 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7234 struct btrfs_file_extent_item *fi;
7235 struct btrfs_key key;
7236 u64 disk_bytenr;
7237 u64 backref_offset;
7238 u64 extent_end;
7239 u64 num_bytes;
7240 int slot;
7241 int found_type;
7242 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7243
7244 path = btrfs_alloc_path();
7245 if (!path)
7246 return -ENOMEM;
7247
7248 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7249 offset, 0);
7250 if (ret < 0)
7251 goto out;
7252
7253 slot = path->slots[0];
7254 if (ret == 1) {
7255 if (slot == 0) {
7256 /* can't find the item, must cow */
7257 ret = 0;
7258 goto out;
7259 }
7260 slot--;
7261 }
7262 ret = 0;
7263 leaf = path->nodes[0];
7264 btrfs_item_key_to_cpu(leaf, &key, slot);
7265 if (key.objectid != btrfs_ino(inode) ||
7266 key.type != BTRFS_EXTENT_DATA_KEY) {
7267 /* not our file or wrong item type, must cow */
7268 goto out;
7269 }
7270
7271 if (key.offset > offset) {
7272 /* Wrong offset, must cow */
7273 goto out;
7274 }
7275
7276 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7277 found_type = btrfs_file_extent_type(leaf, fi);
7278 if (found_type != BTRFS_FILE_EXTENT_REG &&
7279 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7280 /* not a regular extent, must cow */
7281 goto out;
7282 }
7283
7284 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7285 goto out;
7286
7287 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7288 if (extent_end <= offset)
7289 goto out;
7290
7291 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7292 if (disk_bytenr == 0)
7293 goto out;
7294
7295 if (btrfs_file_extent_compression(leaf, fi) ||
7296 btrfs_file_extent_encryption(leaf, fi) ||
7297 btrfs_file_extent_other_encoding(leaf, fi))
7298 goto out;
7299
7300 backref_offset = btrfs_file_extent_offset(leaf, fi);
7301
7302 if (orig_start) {
7303 *orig_start = key.offset - backref_offset;
7304 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7305 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7306 }
7307
7308 if (btrfs_extent_readonly(root, disk_bytenr))
7309 goto out;
7310
7311 num_bytes = min(offset + *len, extent_end) - offset;
7312 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7313 u64 range_end;
7314
7315 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7316 ret = test_range_bit(io_tree, offset, range_end,
7317 EXTENT_DELALLOC, 0, NULL);
7318 if (ret) {
7319 ret = -EAGAIN;
7320 goto out;
7321 }
7322 }
7323
7324 btrfs_release_path(path);
7325
7326 /*
7327 * look for other files referencing this extent, if we
7328 * find any we must cow
7329 */
7330 trans = btrfs_join_transaction(root);
7331 if (IS_ERR(trans)) {
7332 ret = 0;
7333 goto out;
7334 }
7335
7336 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7337 key.offset - backref_offset, disk_bytenr);
7338 btrfs_end_transaction(trans, root);
7339 if (ret) {
7340 ret = 0;
7341 goto out;
7342 }
7343
7344 /*
7345 * adjust disk_bytenr and num_bytes to cover just the bytes
7346 * in this extent we are about to write. If there
7347 * are any csums in that range we have to cow in order
7348 * to keep the csums correct
7349 */
7350 disk_bytenr += backref_offset;
7351 disk_bytenr += offset - key.offset;
7352 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7353 goto out;
7354 /*
7355 * all of the above have passed, it is safe to overwrite this extent
7356 * without cow
7357 */
7358 *len = num_bytes;
7359 ret = 1;
7360 out:
7361 btrfs_free_path(path);
7362 return ret;
7363 }
7364
7365 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7366 {
7367 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7368 int found = false;
7369 void **pagep = NULL;
7370 struct page *page = NULL;
7371 int start_idx;
7372 int end_idx;
7373
7374 start_idx = start >> PAGE_SHIFT;
7375
7376 /*
7377 * end is the last byte in the last page. end == start is legal
7378 */
7379 end_idx = end >> PAGE_SHIFT;
7380
7381 rcu_read_lock();
7382
7383 /* Most of the code in this while loop is lifted from
7384 * find_get_page. It's been modified to begin searching from a
7385 * page and return just the first page found in that range. If the
7386 * found idx is less than or equal to the end idx then we know that
7387 * a page exists. If no pages are found or if those pages are
7388 * outside of the range then we're fine (yay!) */
7389 while (page == NULL &&
7390 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7391 page = radix_tree_deref_slot(pagep);
7392 if (unlikely(!page))
7393 break;
7394
7395 if (radix_tree_exception(page)) {
7396 if (radix_tree_deref_retry(page)) {
7397 page = NULL;
7398 continue;
7399 }
7400 /*
7401 * Otherwise, shmem/tmpfs must be storing a swap entry
7402 * here as an exceptional entry: so return it without
7403 * attempting to raise page count.
7404 */
7405 page = NULL;
7406 break; /* TODO: Is this relevant for this use case? */
7407 }
7408
7409 if (!page_cache_get_speculative(page)) {
7410 page = NULL;
7411 continue;
7412 }
7413
7414 /*
7415 * Has the page moved?
7416 * This is part of the lockless pagecache protocol. See
7417 * include/linux/pagemap.h for details.
7418 */
7419 if (unlikely(page != *pagep)) {
7420 put_page(page);
7421 page = NULL;
7422 }
7423 }
7424
7425 if (page) {
7426 if (page->index <= end_idx)
7427 found = true;
7428 put_page(page);
7429 }
7430
7431 rcu_read_unlock();
7432 return found;
7433 }
7434
7435 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7436 struct extent_state **cached_state, int writing)
7437 {
7438 struct btrfs_ordered_extent *ordered;
7439 int ret = 0;
7440
7441 while (1) {
7442 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7443 cached_state);
7444 /*
7445 * We're concerned with the entire range that we're going to be
7446 * doing DIO to, so we need to make sure there's no ordered
7447 * extents in this range.
7448 */
7449 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7450 lockend - lockstart + 1);
7451
7452 /*
7453 * We need to make sure there are no buffered pages in this
7454 * range either, we could have raced between the invalidate in
7455 * generic_file_direct_write and locking the extent. The
7456 * invalidate needs to happen so that reads after a write do not
7457 * get stale data.
7458 */
7459 if (!ordered &&
7460 (!writing ||
7461 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7462 break;
7463
7464 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7465 cached_state, GFP_NOFS);
7466
7467 if (ordered) {
7468 /*
7469 * If we are doing a DIO read and the ordered extent we
7470 * found is for a buffered write, we can not wait for it
7471 * to complete and retry, because if we do so we can
7472 * deadlock with concurrent buffered writes on page
7473 * locks. This happens only if our DIO read covers more
7474 * than one extent map, if at this point has already
7475 * created an ordered extent for a previous extent map
7476 * and locked its range in the inode's io tree, and a
7477 * concurrent write against that previous extent map's
7478 * range and this range started (we unlock the ranges
7479 * in the io tree only when the bios complete and
7480 * buffered writes always lock pages before attempting
7481 * to lock range in the io tree).
7482 */
7483 if (writing ||
7484 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7485 btrfs_start_ordered_extent(inode, ordered, 1);
7486 else
7487 ret = -ENOTBLK;
7488 btrfs_put_ordered_extent(ordered);
7489 } else {
7490 /*
7491 * We could trigger writeback for this range (and wait
7492 * for it to complete) and then invalidate the pages for
7493 * this range (through invalidate_inode_pages2_range()),
7494 * but that can lead us to a deadlock with a concurrent
7495 * call to readpages() (a buffered read or a defrag call
7496 * triggered a readahead) on a page lock due to an
7497 * ordered dio extent we created before but did not have
7498 * yet a corresponding bio submitted (whence it can not
7499 * complete), which makes readpages() wait for that
7500 * ordered extent to complete while holding a lock on
7501 * that page.
7502 */
7503 ret = -ENOTBLK;
7504 }
7505
7506 if (ret)
7507 break;
7508
7509 cond_resched();
7510 }
7511
7512 return ret;
7513 }
7514
7515 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7516 u64 len, u64 orig_start,
7517 u64 block_start, u64 block_len,
7518 u64 orig_block_len, u64 ram_bytes,
7519 int type)
7520 {
7521 struct extent_map_tree *em_tree;
7522 struct extent_map *em;
7523 struct btrfs_root *root = BTRFS_I(inode)->root;
7524 int ret;
7525
7526 em_tree = &BTRFS_I(inode)->extent_tree;
7527 em = alloc_extent_map();
7528 if (!em)
7529 return ERR_PTR(-ENOMEM);
7530
7531 em->start = start;
7532 em->orig_start = orig_start;
7533 em->mod_start = start;
7534 em->mod_len = len;
7535 em->len = len;
7536 em->block_len = block_len;
7537 em->block_start = block_start;
7538 em->bdev = root->fs_info->fs_devices->latest_bdev;
7539 em->orig_block_len = orig_block_len;
7540 em->ram_bytes = ram_bytes;
7541 em->generation = -1;
7542 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7543 if (type == BTRFS_ORDERED_PREALLOC)
7544 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7545
7546 do {
7547 btrfs_drop_extent_cache(inode, em->start,
7548 em->start + em->len - 1, 0);
7549 write_lock(&em_tree->lock);
7550 ret = add_extent_mapping(em_tree, em, 1);
7551 write_unlock(&em_tree->lock);
7552 } while (ret == -EEXIST);
7553
7554 if (ret) {
7555 free_extent_map(em);
7556 return ERR_PTR(ret);
7557 }
7558
7559 return em;
7560 }
7561
7562 static void adjust_dio_outstanding_extents(struct inode *inode,
7563 struct btrfs_dio_data *dio_data,
7564 const u64 len)
7565 {
7566 unsigned num_extents;
7567
7568 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7569 BTRFS_MAX_EXTENT_SIZE);
7570 /*
7571 * If we have an outstanding_extents count still set then we're
7572 * within our reservation, otherwise we need to adjust our inode
7573 * counter appropriately.
7574 */
7575 if (dio_data->outstanding_extents) {
7576 dio_data->outstanding_extents -= num_extents;
7577 } else {
7578 spin_lock(&BTRFS_I(inode)->lock);
7579 BTRFS_I(inode)->outstanding_extents += num_extents;
7580 spin_unlock(&BTRFS_I(inode)->lock);
7581 }
7582 }
7583
7584 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7585 struct buffer_head *bh_result, int create)
7586 {
7587 struct extent_map *em;
7588 struct btrfs_root *root = BTRFS_I(inode)->root;
7589 struct extent_state *cached_state = NULL;
7590 struct btrfs_dio_data *dio_data = NULL;
7591 u64 start = iblock << inode->i_blkbits;
7592 u64 lockstart, lockend;
7593 u64 len = bh_result->b_size;
7594 int unlock_bits = EXTENT_LOCKED;
7595 int ret = 0;
7596
7597 if (create)
7598 unlock_bits |= EXTENT_DIRTY;
7599 else
7600 len = min_t(u64, len, root->sectorsize);
7601
7602 lockstart = start;
7603 lockend = start + len - 1;
7604
7605 if (current->journal_info) {
7606 /*
7607 * Need to pull our outstanding extents and set journal_info to NULL so
7608 * that anything that needs to check if there's a transaction doesn't get
7609 * confused.
7610 */
7611 dio_data = current->journal_info;
7612 current->journal_info = NULL;
7613 }
7614
7615 /*
7616 * If this errors out it's because we couldn't invalidate pagecache for
7617 * this range and we need to fallback to buffered.
7618 */
7619 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7620 create)) {
7621 ret = -ENOTBLK;
7622 goto err;
7623 }
7624
7625 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7626 if (IS_ERR(em)) {
7627 ret = PTR_ERR(em);
7628 goto unlock_err;
7629 }
7630
7631 /*
7632 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7633 * io. INLINE is special, and we could probably kludge it in here, but
7634 * it's still buffered so for safety lets just fall back to the generic
7635 * buffered path.
7636 *
7637 * For COMPRESSED we _have_ to read the entire extent in so we can
7638 * decompress it, so there will be buffering required no matter what we
7639 * do, so go ahead and fallback to buffered.
7640 *
7641 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7642 * to buffered IO. Don't blame me, this is the price we pay for using
7643 * the generic code.
7644 */
7645 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7646 em->block_start == EXTENT_MAP_INLINE) {
7647 free_extent_map(em);
7648 ret = -ENOTBLK;
7649 goto unlock_err;
7650 }
7651
7652 /* Just a good old fashioned hole, return */
7653 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7654 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7655 free_extent_map(em);
7656 goto unlock_err;
7657 }
7658
7659 /*
7660 * We don't allocate a new extent in the following cases
7661 *
7662 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7663 * existing extent.
7664 * 2) The extent is marked as PREALLOC. We're good to go here and can
7665 * just use the extent.
7666 *
7667 */
7668 if (!create) {
7669 len = min(len, em->len - (start - em->start));
7670 lockstart = start + len;
7671 goto unlock;
7672 }
7673
7674 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7675 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7676 em->block_start != EXTENT_MAP_HOLE)) {
7677 int type;
7678 u64 block_start, orig_start, orig_block_len, ram_bytes;
7679
7680 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7681 type = BTRFS_ORDERED_PREALLOC;
7682 else
7683 type = BTRFS_ORDERED_NOCOW;
7684 len = min(len, em->len - (start - em->start));
7685 block_start = em->block_start + (start - em->start);
7686
7687 if (can_nocow_extent(inode, start, &len, &orig_start,
7688 &orig_block_len, &ram_bytes) == 1 &&
7689 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7690 struct extent_map *em2;
7691
7692 em2 = btrfs_create_dio_extent(inode, start, len,
7693 orig_start, block_start,
7694 len, orig_block_len,
7695 ram_bytes, type);
7696 btrfs_dec_nocow_writers(root->fs_info, block_start);
7697 if (type == BTRFS_ORDERED_PREALLOC) {
7698 free_extent_map(em);
7699 em = em2;
7700 }
7701 if (em2 && IS_ERR(em2)) {
7702 ret = PTR_ERR(em2);
7703 goto unlock_err;
7704 }
7705 goto unlock;
7706 }
7707 }
7708
7709 /*
7710 * this will cow the extent, reset the len in case we changed
7711 * it above
7712 */
7713 len = bh_result->b_size;
7714 free_extent_map(em);
7715 em = btrfs_new_extent_direct(inode, start, len);
7716 if (IS_ERR(em)) {
7717 ret = PTR_ERR(em);
7718 goto unlock_err;
7719 }
7720 len = min(len, em->len - (start - em->start));
7721 unlock:
7722 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7723 inode->i_blkbits;
7724 bh_result->b_size = len;
7725 bh_result->b_bdev = em->bdev;
7726 set_buffer_mapped(bh_result);
7727 if (create) {
7728 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7729 set_buffer_new(bh_result);
7730
7731 /*
7732 * Need to update the i_size under the extent lock so buffered
7733 * readers will get the updated i_size when we unlock.
7734 */
7735 if (start + len > i_size_read(inode))
7736 i_size_write(inode, start + len);
7737
7738 adjust_dio_outstanding_extents(inode, dio_data, len);
7739 btrfs_free_reserved_data_space(inode, start, len);
7740 WARN_ON(dio_data->reserve < len);
7741 dio_data->reserve -= len;
7742 dio_data->unsubmitted_oe_range_end = start + len;
7743 current->journal_info = dio_data;
7744 }
7745
7746 /*
7747 * In the case of write we need to clear and unlock the entire range,
7748 * in the case of read we need to unlock only the end area that we
7749 * aren't using if there is any left over space.
7750 */
7751 if (lockstart < lockend) {
7752 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7753 lockend, unlock_bits, 1, 0,
7754 &cached_state, GFP_NOFS);
7755 } else {
7756 free_extent_state(cached_state);
7757 }
7758
7759 free_extent_map(em);
7760
7761 return 0;
7762
7763 unlock_err:
7764 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7765 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7766 err:
7767 if (dio_data)
7768 current->journal_info = dio_data;
7769 /*
7770 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7771 * write less data then expected, so that we don't underflow our inode's
7772 * outstanding extents counter.
7773 */
7774 if (create && dio_data)
7775 adjust_dio_outstanding_extents(inode, dio_data, len);
7776
7777 return ret;
7778 }
7779
7780 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7781 int rw, int mirror_num)
7782 {
7783 struct btrfs_root *root = BTRFS_I(inode)->root;
7784 int ret;
7785
7786 BUG_ON(rw & REQ_WRITE);
7787
7788 bio_get(bio);
7789
7790 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7791 BTRFS_WQ_ENDIO_DIO_REPAIR);
7792 if (ret)
7793 goto err;
7794
7795 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7796 err:
7797 bio_put(bio);
7798 return ret;
7799 }
7800
7801 static int btrfs_check_dio_repairable(struct inode *inode,
7802 struct bio *failed_bio,
7803 struct io_failure_record *failrec,
7804 int failed_mirror)
7805 {
7806 int num_copies;
7807
7808 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7809 failrec->logical, failrec->len);
7810 if (num_copies == 1) {
7811 /*
7812 * we only have a single copy of the data, so don't bother with
7813 * all the retry and error correction code that follows. no
7814 * matter what the error is, it is very likely to persist.
7815 */
7816 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7817 num_copies, failrec->this_mirror, failed_mirror);
7818 return 0;
7819 }
7820
7821 failrec->failed_mirror = failed_mirror;
7822 failrec->this_mirror++;
7823 if (failrec->this_mirror == failed_mirror)
7824 failrec->this_mirror++;
7825
7826 if (failrec->this_mirror > num_copies) {
7827 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7828 num_copies, failrec->this_mirror, failed_mirror);
7829 return 0;
7830 }
7831
7832 return 1;
7833 }
7834
7835 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7836 struct page *page, unsigned int pgoff,
7837 u64 start, u64 end, int failed_mirror,
7838 bio_end_io_t *repair_endio, void *repair_arg)
7839 {
7840 struct io_failure_record *failrec;
7841 struct bio *bio;
7842 int isector;
7843 int read_mode;
7844 int ret;
7845
7846 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7847
7848 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7849 if (ret)
7850 return ret;
7851
7852 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7853 failed_mirror);
7854 if (!ret) {
7855 free_io_failure(inode, failrec);
7856 return -EIO;
7857 }
7858
7859 if ((failed_bio->bi_vcnt > 1)
7860 || (failed_bio->bi_io_vec->bv_len
7861 > BTRFS_I(inode)->root->sectorsize))
7862 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7863 else
7864 read_mode = READ_SYNC;
7865
7866 isector = start - btrfs_io_bio(failed_bio)->logical;
7867 isector >>= inode->i_sb->s_blocksize_bits;
7868 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7869 pgoff, isector, repair_endio, repair_arg);
7870 if (!bio) {
7871 free_io_failure(inode, failrec);
7872 return -EIO;
7873 }
7874
7875 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7876 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7877 read_mode, failrec->this_mirror, failrec->in_validation);
7878
7879 ret = submit_dio_repair_bio(inode, bio, read_mode,
7880 failrec->this_mirror);
7881 if (ret) {
7882 free_io_failure(inode, failrec);
7883 bio_put(bio);
7884 }
7885
7886 return ret;
7887 }
7888
7889 struct btrfs_retry_complete {
7890 struct completion done;
7891 struct inode *inode;
7892 u64 start;
7893 int uptodate;
7894 };
7895
7896 static void btrfs_retry_endio_nocsum(struct bio *bio)
7897 {
7898 struct btrfs_retry_complete *done = bio->bi_private;
7899 struct inode *inode;
7900 struct bio_vec *bvec;
7901 int i;
7902
7903 if (bio->bi_error)
7904 goto end;
7905
7906 ASSERT(bio->bi_vcnt == 1);
7907 inode = bio->bi_io_vec->bv_page->mapping->host;
7908 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7909
7910 done->uptodate = 1;
7911 bio_for_each_segment_all(bvec, bio, i)
7912 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7913 end:
7914 complete(&done->done);
7915 bio_put(bio);
7916 }
7917
7918 static int __btrfs_correct_data_nocsum(struct inode *inode,
7919 struct btrfs_io_bio *io_bio)
7920 {
7921 struct btrfs_fs_info *fs_info;
7922 struct bio_vec *bvec;
7923 struct btrfs_retry_complete done;
7924 u64 start;
7925 unsigned int pgoff;
7926 u32 sectorsize;
7927 int nr_sectors;
7928 int i;
7929 int ret;
7930
7931 fs_info = BTRFS_I(inode)->root->fs_info;
7932 sectorsize = BTRFS_I(inode)->root->sectorsize;
7933
7934 start = io_bio->logical;
7935 done.inode = inode;
7936
7937 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7938 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7939 pgoff = bvec->bv_offset;
7940
7941 next_block_or_try_again:
7942 done.uptodate = 0;
7943 done.start = start;
7944 init_completion(&done.done);
7945
7946 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7947 pgoff, start, start + sectorsize - 1,
7948 io_bio->mirror_num,
7949 btrfs_retry_endio_nocsum, &done);
7950 if (ret)
7951 return ret;
7952
7953 wait_for_completion(&done.done);
7954
7955 if (!done.uptodate) {
7956 /* We might have another mirror, so try again */
7957 goto next_block_or_try_again;
7958 }
7959
7960 start += sectorsize;
7961
7962 if (nr_sectors--) {
7963 pgoff += sectorsize;
7964 goto next_block_or_try_again;
7965 }
7966 }
7967
7968 return 0;
7969 }
7970
7971 static void btrfs_retry_endio(struct bio *bio)
7972 {
7973 struct btrfs_retry_complete *done = bio->bi_private;
7974 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7975 struct inode *inode;
7976 struct bio_vec *bvec;
7977 u64 start;
7978 int uptodate;
7979 int ret;
7980 int i;
7981
7982 if (bio->bi_error)
7983 goto end;
7984
7985 uptodate = 1;
7986
7987 start = done->start;
7988
7989 ASSERT(bio->bi_vcnt == 1);
7990 inode = bio->bi_io_vec->bv_page->mapping->host;
7991 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7992
7993 bio_for_each_segment_all(bvec, bio, i) {
7994 ret = __readpage_endio_check(done->inode, io_bio, i,
7995 bvec->bv_page, bvec->bv_offset,
7996 done->start, bvec->bv_len);
7997 if (!ret)
7998 clean_io_failure(done->inode, done->start,
7999 bvec->bv_page, bvec->bv_offset);
8000 else
8001 uptodate = 0;
8002 }
8003
8004 done->uptodate = uptodate;
8005 end:
8006 complete(&done->done);
8007 bio_put(bio);
8008 }
8009
8010 static int __btrfs_subio_endio_read(struct inode *inode,
8011 struct btrfs_io_bio *io_bio, int err)
8012 {
8013 struct btrfs_fs_info *fs_info;
8014 struct bio_vec *bvec;
8015 struct btrfs_retry_complete done;
8016 u64 start;
8017 u64 offset = 0;
8018 u32 sectorsize;
8019 int nr_sectors;
8020 unsigned int pgoff;
8021 int csum_pos;
8022 int i;
8023 int ret;
8024
8025 fs_info = BTRFS_I(inode)->root->fs_info;
8026 sectorsize = BTRFS_I(inode)->root->sectorsize;
8027
8028 err = 0;
8029 start = io_bio->logical;
8030 done.inode = inode;
8031
8032 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8033 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8034
8035 pgoff = bvec->bv_offset;
8036 next_block:
8037 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8038 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8039 bvec->bv_page, pgoff, start,
8040 sectorsize);
8041 if (likely(!ret))
8042 goto next;
8043 try_again:
8044 done.uptodate = 0;
8045 done.start = start;
8046 init_completion(&done.done);
8047
8048 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8049 pgoff, start, start + sectorsize - 1,
8050 io_bio->mirror_num,
8051 btrfs_retry_endio, &done);
8052 if (ret) {
8053 err = ret;
8054 goto next;
8055 }
8056
8057 wait_for_completion(&done.done);
8058
8059 if (!done.uptodate) {
8060 /* We might have another mirror, so try again */
8061 goto try_again;
8062 }
8063 next:
8064 offset += sectorsize;
8065 start += sectorsize;
8066
8067 ASSERT(nr_sectors);
8068
8069 if (--nr_sectors) {
8070 pgoff += sectorsize;
8071 goto next_block;
8072 }
8073 }
8074
8075 return err;
8076 }
8077
8078 static int btrfs_subio_endio_read(struct inode *inode,
8079 struct btrfs_io_bio *io_bio, int err)
8080 {
8081 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8082
8083 if (skip_csum) {
8084 if (unlikely(err))
8085 return __btrfs_correct_data_nocsum(inode, io_bio);
8086 else
8087 return 0;
8088 } else {
8089 return __btrfs_subio_endio_read(inode, io_bio, err);
8090 }
8091 }
8092
8093 static void btrfs_endio_direct_read(struct bio *bio)
8094 {
8095 struct btrfs_dio_private *dip = bio->bi_private;
8096 struct inode *inode = dip->inode;
8097 struct bio *dio_bio;
8098 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8099 int err = bio->bi_error;
8100
8101 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8102 err = btrfs_subio_endio_read(inode, io_bio, err);
8103
8104 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8105 dip->logical_offset + dip->bytes - 1);
8106 dio_bio = dip->dio_bio;
8107
8108 kfree(dip);
8109
8110 dio_bio->bi_error = bio->bi_error;
8111 dio_end_io(dio_bio, bio->bi_error);
8112
8113 if (io_bio->end_io)
8114 io_bio->end_io(io_bio, err);
8115 bio_put(bio);
8116 }
8117
8118 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8119 const u64 offset,
8120 const u64 bytes,
8121 const int uptodate)
8122 {
8123 struct btrfs_root *root = BTRFS_I(inode)->root;
8124 struct btrfs_ordered_extent *ordered = NULL;
8125 u64 ordered_offset = offset;
8126 u64 ordered_bytes = bytes;
8127 int ret;
8128
8129 again:
8130 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8131 &ordered_offset,
8132 ordered_bytes,
8133 uptodate);
8134 if (!ret)
8135 goto out_test;
8136
8137 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8138 finish_ordered_fn, NULL, NULL);
8139 btrfs_queue_work(root->fs_info->endio_write_workers,
8140 &ordered->work);
8141 out_test:
8142 /*
8143 * our bio might span multiple ordered extents. If we haven't
8144 * completed the accounting for the whole dio, go back and try again
8145 */
8146 if (ordered_offset < offset + bytes) {
8147 ordered_bytes = offset + bytes - ordered_offset;
8148 ordered = NULL;
8149 goto again;
8150 }
8151 }
8152
8153 static void btrfs_endio_direct_write(struct bio *bio)
8154 {
8155 struct btrfs_dio_private *dip = bio->bi_private;
8156 struct bio *dio_bio = dip->dio_bio;
8157
8158 btrfs_endio_direct_write_update_ordered(dip->inode,
8159 dip->logical_offset,
8160 dip->bytes,
8161 !bio->bi_error);
8162
8163 kfree(dip);
8164
8165 dio_bio->bi_error = bio->bi_error;
8166 dio_end_io(dio_bio, bio->bi_error);
8167 bio_put(bio);
8168 }
8169
8170 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8171 struct bio *bio, int mirror_num,
8172 unsigned long bio_flags, u64 offset)
8173 {
8174 int ret;
8175 struct btrfs_root *root = BTRFS_I(inode)->root;
8176 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8177 BUG_ON(ret); /* -ENOMEM */
8178 return 0;
8179 }
8180
8181 static void btrfs_end_dio_bio(struct bio *bio)
8182 {
8183 struct btrfs_dio_private *dip = bio->bi_private;
8184 int err = bio->bi_error;
8185
8186 if (err)
8187 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8188 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8189 btrfs_ino(dip->inode), bio->bi_rw,
8190 (unsigned long long)bio->bi_iter.bi_sector,
8191 bio->bi_iter.bi_size, err);
8192
8193 if (dip->subio_endio)
8194 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8195
8196 if (err) {
8197 dip->errors = 1;
8198
8199 /*
8200 * before atomic variable goto zero, we must make sure
8201 * dip->errors is perceived to be set.
8202 */
8203 smp_mb__before_atomic();
8204 }
8205
8206 /* if there are more bios still pending for this dio, just exit */
8207 if (!atomic_dec_and_test(&dip->pending_bios))
8208 goto out;
8209
8210 if (dip->errors) {
8211 bio_io_error(dip->orig_bio);
8212 } else {
8213 dip->dio_bio->bi_error = 0;
8214 bio_endio(dip->orig_bio);
8215 }
8216 out:
8217 bio_put(bio);
8218 }
8219
8220 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8221 u64 first_sector, gfp_t gfp_flags)
8222 {
8223 struct bio *bio;
8224 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8225 if (bio)
8226 bio_associate_current(bio);
8227 return bio;
8228 }
8229
8230 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8231 struct inode *inode,
8232 struct btrfs_dio_private *dip,
8233 struct bio *bio,
8234 u64 file_offset)
8235 {
8236 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8237 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8238 int ret;
8239
8240 /*
8241 * We load all the csum data we need when we submit
8242 * the first bio to reduce the csum tree search and
8243 * contention.
8244 */
8245 if (dip->logical_offset == file_offset) {
8246 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8247 file_offset);
8248 if (ret)
8249 return ret;
8250 }
8251
8252 if (bio == dip->orig_bio)
8253 return 0;
8254
8255 file_offset -= dip->logical_offset;
8256 file_offset >>= inode->i_sb->s_blocksize_bits;
8257 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8258
8259 return 0;
8260 }
8261
8262 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8263 int rw, u64 file_offset, int skip_sum,
8264 int async_submit)
8265 {
8266 struct btrfs_dio_private *dip = bio->bi_private;
8267 int write = rw & REQ_WRITE;
8268 struct btrfs_root *root = BTRFS_I(inode)->root;
8269 int ret;
8270
8271 if (async_submit)
8272 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8273
8274 bio_get(bio);
8275
8276 if (!write) {
8277 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8278 BTRFS_WQ_ENDIO_DATA);
8279 if (ret)
8280 goto err;
8281 }
8282
8283 if (skip_sum)
8284 goto map;
8285
8286 if (write && async_submit) {
8287 ret = btrfs_wq_submit_bio(root->fs_info,
8288 inode, rw, bio, 0, 0,
8289 file_offset,
8290 __btrfs_submit_bio_start_direct_io,
8291 __btrfs_submit_bio_done);
8292 goto err;
8293 } else if (write) {
8294 /*
8295 * If we aren't doing async submit, calculate the csum of the
8296 * bio now.
8297 */
8298 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8299 if (ret)
8300 goto err;
8301 } else {
8302 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8303 file_offset);
8304 if (ret)
8305 goto err;
8306 }
8307 map:
8308 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8309 err:
8310 bio_put(bio);
8311 return ret;
8312 }
8313
8314 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8315 int skip_sum)
8316 {
8317 struct inode *inode = dip->inode;
8318 struct btrfs_root *root = BTRFS_I(inode)->root;
8319 struct bio *bio;
8320 struct bio *orig_bio = dip->orig_bio;
8321 struct bio_vec *bvec = orig_bio->bi_io_vec;
8322 u64 start_sector = orig_bio->bi_iter.bi_sector;
8323 u64 file_offset = dip->logical_offset;
8324 u64 submit_len = 0;
8325 u64 map_length;
8326 u32 blocksize = root->sectorsize;
8327 int async_submit = 0;
8328 int nr_sectors;
8329 int ret;
8330 int i;
8331
8332 map_length = orig_bio->bi_iter.bi_size;
8333 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8334 &map_length, NULL, 0);
8335 if (ret)
8336 return -EIO;
8337
8338 if (map_length >= orig_bio->bi_iter.bi_size) {
8339 bio = orig_bio;
8340 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8341 goto submit;
8342 }
8343
8344 /* async crcs make it difficult to collect full stripe writes. */
8345 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8346 async_submit = 0;
8347 else
8348 async_submit = 1;
8349
8350 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8351 if (!bio)
8352 return -ENOMEM;
8353
8354 bio->bi_private = dip;
8355 bio->bi_end_io = btrfs_end_dio_bio;
8356 btrfs_io_bio(bio)->logical = file_offset;
8357 atomic_inc(&dip->pending_bios);
8358
8359 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8360 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8361 i = 0;
8362 next_block:
8363 if (unlikely(map_length < submit_len + blocksize ||
8364 bio_add_page(bio, bvec->bv_page, blocksize,
8365 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8366 /*
8367 * inc the count before we submit the bio so
8368 * we know the end IO handler won't happen before
8369 * we inc the count. Otherwise, the dip might get freed
8370 * before we're done setting it up
8371 */
8372 atomic_inc(&dip->pending_bios);
8373 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8374 file_offset, skip_sum,
8375 async_submit);
8376 if (ret) {
8377 bio_put(bio);
8378 atomic_dec(&dip->pending_bios);
8379 goto out_err;
8380 }
8381
8382 start_sector += submit_len >> 9;
8383 file_offset += submit_len;
8384
8385 submit_len = 0;
8386
8387 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8388 start_sector, GFP_NOFS);
8389 if (!bio)
8390 goto out_err;
8391 bio->bi_private = dip;
8392 bio->bi_end_io = btrfs_end_dio_bio;
8393 btrfs_io_bio(bio)->logical = file_offset;
8394
8395 map_length = orig_bio->bi_iter.bi_size;
8396 ret = btrfs_map_block(root->fs_info, rw,
8397 start_sector << 9,
8398 &map_length, NULL, 0);
8399 if (ret) {
8400 bio_put(bio);
8401 goto out_err;
8402 }
8403
8404 goto next_block;
8405 } else {
8406 submit_len += blocksize;
8407 if (--nr_sectors) {
8408 i++;
8409 goto next_block;
8410 }
8411 bvec++;
8412 }
8413 }
8414
8415 submit:
8416 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8417 async_submit);
8418 if (!ret)
8419 return 0;
8420
8421 bio_put(bio);
8422 out_err:
8423 dip->errors = 1;
8424 /*
8425 * before atomic variable goto zero, we must
8426 * make sure dip->errors is perceived to be set.
8427 */
8428 smp_mb__before_atomic();
8429 if (atomic_dec_and_test(&dip->pending_bios))
8430 bio_io_error(dip->orig_bio);
8431
8432 /* bio_end_io() will handle error, so we needn't return it */
8433 return 0;
8434 }
8435
8436 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8437 struct inode *inode, loff_t file_offset)
8438 {
8439 struct btrfs_dio_private *dip = NULL;
8440 struct bio *io_bio = NULL;
8441 struct btrfs_io_bio *btrfs_bio;
8442 int skip_sum;
8443 int write = rw & REQ_WRITE;
8444 int ret = 0;
8445
8446 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8447
8448 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8449 if (!io_bio) {
8450 ret = -ENOMEM;
8451 goto free_ordered;
8452 }
8453
8454 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8455 if (!dip) {
8456 ret = -ENOMEM;
8457 goto free_ordered;
8458 }
8459
8460 dip->private = dio_bio->bi_private;
8461 dip->inode = inode;
8462 dip->logical_offset = file_offset;
8463 dip->bytes = dio_bio->bi_iter.bi_size;
8464 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8465 io_bio->bi_private = dip;
8466 dip->orig_bio = io_bio;
8467 dip->dio_bio = dio_bio;
8468 atomic_set(&dip->pending_bios, 0);
8469 btrfs_bio = btrfs_io_bio(io_bio);
8470 btrfs_bio->logical = file_offset;
8471
8472 if (write) {
8473 io_bio->bi_end_io = btrfs_endio_direct_write;
8474 } else {
8475 io_bio->bi_end_io = btrfs_endio_direct_read;
8476 dip->subio_endio = btrfs_subio_endio_read;
8477 }
8478
8479 /*
8480 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8481 * even if we fail to submit a bio, because in such case we do the
8482 * corresponding error handling below and it must not be done a second
8483 * time by btrfs_direct_IO().
8484 */
8485 if (write) {
8486 struct btrfs_dio_data *dio_data = current->journal_info;
8487
8488 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8489 dip->bytes;
8490 dio_data->unsubmitted_oe_range_start =
8491 dio_data->unsubmitted_oe_range_end;
8492 }
8493
8494 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8495 if (!ret)
8496 return;
8497
8498 if (btrfs_bio->end_io)
8499 btrfs_bio->end_io(btrfs_bio, ret);
8500
8501 free_ordered:
8502 /*
8503 * If we arrived here it means either we failed to submit the dip
8504 * or we either failed to clone the dio_bio or failed to allocate the
8505 * dip. If we cloned the dio_bio and allocated the dip, we can just
8506 * call bio_endio against our io_bio so that we get proper resource
8507 * cleanup if we fail to submit the dip, otherwise, we must do the
8508 * same as btrfs_endio_direct_[write|read] because we can't call these
8509 * callbacks - they require an allocated dip and a clone of dio_bio.
8510 */
8511 if (io_bio && dip) {
8512 io_bio->bi_error = -EIO;
8513 bio_endio(io_bio);
8514 /*
8515 * The end io callbacks free our dip, do the final put on io_bio
8516 * and all the cleanup and final put for dio_bio (through
8517 * dio_end_io()).
8518 */
8519 dip = NULL;
8520 io_bio = NULL;
8521 } else {
8522 if (write)
8523 btrfs_endio_direct_write_update_ordered(inode,
8524 file_offset,
8525 dio_bio->bi_iter.bi_size,
8526 0);
8527 else
8528 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8529 file_offset + dio_bio->bi_iter.bi_size - 1);
8530
8531 dio_bio->bi_error = -EIO;
8532 /*
8533 * Releases and cleans up our dio_bio, no need to bio_put()
8534 * nor bio_endio()/bio_io_error() against dio_bio.
8535 */
8536 dio_end_io(dio_bio, ret);
8537 }
8538 if (io_bio)
8539 bio_put(io_bio);
8540 kfree(dip);
8541 }
8542
8543 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8544 const struct iov_iter *iter, loff_t offset)
8545 {
8546 int seg;
8547 int i;
8548 unsigned blocksize_mask = root->sectorsize - 1;
8549 ssize_t retval = -EINVAL;
8550
8551 if (offset & blocksize_mask)
8552 goto out;
8553
8554 if (iov_iter_alignment(iter) & blocksize_mask)
8555 goto out;
8556
8557 /* If this is a write we don't need to check anymore */
8558 if (iov_iter_rw(iter) == WRITE)
8559 return 0;
8560 /*
8561 * Check to make sure we don't have duplicate iov_base's in this
8562 * iovec, if so return EINVAL, otherwise we'll get csum errors
8563 * when reading back.
8564 */
8565 for (seg = 0; seg < iter->nr_segs; seg++) {
8566 for (i = seg + 1; i < iter->nr_segs; i++) {
8567 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8568 goto out;
8569 }
8570 }
8571 retval = 0;
8572 out:
8573 return retval;
8574 }
8575
8576 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8577 {
8578 struct file *file = iocb->ki_filp;
8579 struct inode *inode = file->f_mapping->host;
8580 struct btrfs_root *root = BTRFS_I(inode)->root;
8581 struct btrfs_dio_data dio_data = { 0 };
8582 loff_t offset = iocb->ki_pos;
8583 size_t count = 0;
8584 int flags = 0;
8585 bool wakeup = true;
8586 bool relock = false;
8587 ssize_t ret;
8588
8589 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8590 return 0;
8591
8592 inode_dio_begin(inode);
8593 smp_mb__after_atomic();
8594
8595 /*
8596 * The generic stuff only does filemap_write_and_wait_range, which
8597 * isn't enough if we've written compressed pages to this area, so
8598 * we need to flush the dirty pages again to make absolutely sure
8599 * that any outstanding dirty pages are on disk.
8600 */
8601 count = iov_iter_count(iter);
8602 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8603 &BTRFS_I(inode)->runtime_flags))
8604 filemap_fdatawrite_range(inode->i_mapping, offset,
8605 offset + count - 1);
8606
8607 if (iov_iter_rw(iter) == WRITE) {
8608 /*
8609 * If the write DIO is beyond the EOF, we need update
8610 * the isize, but it is protected by i_mutex. So we can
8611 * not unlock the i_mutex at this case.
8612 */
8613 if (offset + count <= inode->i_size) {
8614 inode_unlock(inode);
8615 relock = true;
8616 }
8617 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8618 if (ret)
8619 goto out;
8620 dio_data.outstanding_extents = div64_u64(count +
8621 BTRFS_MAX_EXTENT_SIZE - 1,
8622 BTRFS_MAX_EXTENT_SIZE);
8623
8624 /*
8625 * We need to know how many extents we reserved so that we can
8626 * do the accounting properly if we go over the number we
8627 * originally calculated. Abuse current->journal_info for this.
8628 */
8629 dio_data.reserve = round_up(count, root->sectorsize);
8630 dio_data.unsubmitted_oe_range_start = (u64)offset;
8631 dio_data.unsubmitted_oe_range_end = (u64)offset;
8632 current->journal_info = &dio_data;
8633 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8634 &BTRFS_I(inode)->runtime_flags)) {
8635 inode_dio_end(inode);
8636 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8637 wakeup = false;
8638 }
8639
8640 ret = __blockdev_direct_IO(iocb, inode,
8641 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8642 iter, btrfs_get_blocks_direct, NULL,
8643 btrfs_submit_direct, flags);
8644 if (iov_iter_rw(iter) == WRITE) {
8645 current->journal_info = NULL;
8646 if (ret < 0 && ret != -EIOCBQUEUED) {
8647 if (dio_data.reserve)
8648 btrfs_delalloc_release_space(inode, offset,
8649 dio_data.reserve);
8650 /*
8651 * On error we might have left some ordered extents
8652 * without submitting corresponding bios for them, so
8653 * cleanup them up to avoid other tasks getting them
8654 * and waiting for them to complete forever.
8655 */
8656 if (dio_data.unsubmitted_oe_range_start <
8657 dio_data.unsubmitted_oe_range_end)
8658 btrfs_endio_direct_write_update_ordered(inode,
8659 dio_data.unsubmitted_oe_range_start,
8660 dio_data.unsubmitted_oe_range_end -
8661 dio_data.unsubmitted_oe_range_start,
8662 0);
8663 } else if (ret >= 0 && (size_t)ret < count)
8664 btrfs_delalloc_release_space(inode, offset,
8665 count - (size_t)ret);
8666 }
8667 out:
8668 if (wakeup)
8669 inode_dio_end(inode);
8670 if (relock)
8671 inode_lock(inode);
8672
8673 return ret;
8674 }
8675
8676 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8677
8678 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8679 __u64 start, __u64 len)
8680 {
8681 int ret;
8682
8683 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8684 if (ret)
8685 return ret;
8686
8687 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8688 }
8689
8690 int btrfs_readpage(struct file *file, struct page *page)
8691 {
8692 struct extent_io_tree *tree;
8693 tree = &BTRFS_I(page->mapping->host)->io_tree;
8694 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8695 }
8696
8697 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8698 {
8699 struct extent_io_tree *tree;
8700 struct inode *inode = page->mapping->host;
8701 int ret;
8702
8703 if (current->flags & PF_MEMALLOC) {
8704 redirty_page_for_writepage(wbc, page);
8705 unlock_page(page);
8706 return 0;
8707 }
8708
8709 /*
8710 * If we are under memory pressure we will call this directly from the
8711 * VM, we need to make sure we have the inode referenced for the ordered
8712 * extent. If not just return like we didn't do anything.
8713 */
8714 if (!igrab(inode)) {
8715 redirty_page_for_writepage(wbc, page);
8716 return AOP_WRITEPAGE_ACTIVATE;
8717 }
8718 tree = &BTRFS_I(page->mapping->host)->io_tree;
8719 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8720 btrfs_add_delayed_iput(inode);
8721 return ret;
8722 }
8723
8724 static int btrfs_writepages(struct address_space *mapping,
8725 struct writeback_control *wbc)
8726 {
8727 struct extent_io_tree *tree;
8728
8729 tree = &BTRFS_I(mapping->host)->io_tree;
8730 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8731 }
8732
8733 static int
8734 btrfs_readpages(struct file *file, struct address_space *mapping,
8735 struct list_head *pages, unsigned nr_pages)
8736 {
8737 struct extent_io_tree *tree;
8738 tree = &BTRFS_I(mapping->host)->io_tree;
8739 return extent_readpages(tree, mapping, pages, nr_pages,
8740 btrfs_get_extent);
8741 }
8742 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8743 {
8744 struct extent_io_tree *tree;
8745 struct extent_map_tree *map;
8746 int ret;
8747
8748 tree = &BTRFS_I(page->mapping->host)->io_tree;
8749 map = &BTRFS_I(page->mapping->host)->extent_tree;
8750 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8751 if (ret == 1) {
8752 ClearPagePrivate(page);
8753 set_page_private(page, 0);
8754 put_page(page);
8755 }
8756 return ret;
8757 }
8758
8759 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8760 {
8761 if (PageWriteback(page) || PageDirty(page))
8762 return 0;
8763 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8764 }
8765
8766 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8767 unsigned int length)
8768 {
8769 struct inode *inode = page->mapping->host;
8770 struct extent_io_tree *tree;
8771 struct btrfs_ordered_extent *ordered;
8772 struct extent_state *cached_state = NULL;
8773 u64 page_start = page_offset(page);
8774 u64 page_end = page_start + PAGE_SIZE - 1;
8775 u64 start;
8776 u64 end;
8777 int inode_evicting = inode->i_state & I_FREEING;
8778
8779 /*
8780 * we have the page locked, so new writeback can't start,
8781 * and the dirty bit won't be cleared while we are here.
8782 *
8783 * Wait for IO on this page so that we can safely clear
8784 * the PagePrivate2 bit and do ordered accounting
8785 */
8786 wait_on_page_writeback(page);
8787
8788 tree = &BTRFS_I(inode)->io_tree;
8789 if (offset) {
8790 btrfs_releasepage(page, GFP_NOFS);
8791 return;
8792 }
8793
8794 if (!inode_evicting)
8795 lock_extent_bits(tree, page_start, page_end, &cached_state);
8796 again:
8797 start = page_start;
8798 ordered = btrfs_lookup_ordered_range(inode, start,
8799 page_end - start + 1);
8800 if (ordered) {
8801 end = min(page_end, ordered->file_offset + ordered->len - 1);
8802 /*
8803 * IO on this page will never be started, so we need
8804 * to account for any ordered extents now
8805 */
8806 if (!inode_evicting)
8807 clear_extent_bit(tree, start, end,
8808 EXTENT_DIRTY | EXTENT_DELALLOC |
8809 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8810 EXTENT_DEFRAG, 1, 0, &cached_state,
8811 GFP_NOFS);
8812 /*
8813 * whoever cleared the private bit is responsible
8814 * for the finish_ordered_io
8815 */
8816 if (TestClearPagePrivate2(page)) {
8817 struct btrfs_ordered_inode_tree *tree;
8818 u64 new_len;
8819
8820 tree = &BTRFS_I(inode)->ordered_tree;
8821
8822 spin_lock_irq(&tree->lock);
8823 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8824 new_len = start - ordered->file_offset;
8825 if (new_len < ordered->truncated_len)
8826 ordered->truncated_len = new_len;
8827 spin_unlock_irq(&tree->lock);
8828
8829 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8830 start,
8831 end - start + 1, 1))
8832 btrfs_finish_ordered_io(ordered);
8833 }
8834 btrfs_put_ordered_extent(ordered);
8835 if (!inode_evicting) {
8836 cached_state = NULL;
8837 lock_extent_bits(tree, start, end,
8838 &cached_state);
8839 }
8840
8841 start = end + 1;
8842 if (start < page_end)
8843 goto again;
8844 }
8845
8846 /*
8847 * Qgroup reserved space handler
8848 * Page here will be either
8849 * 1) Already written to disk
8850 * In this case, its reserved space is released from data rsv map
8851 * and will be freed by delayed_ref handler finally.
8852 * So even we call qgroup_free_data(), it won't decrease reserved
8853 * space.
8854 * 2) Not written to disk
8855 * This means the reserved space should be freed here.
8856 */
8857 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8858 if (!inode_evicting) {
8859 clear_extent_bit(tree, page_start, page_end,
8860 EXTENT_LOCKED | EXTENT_DIRTY |
8861 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8862 EXTENT_DEFRAG, 1, 1,
8863 &cached_state, GFP_NOFS);
8864
8865 __btrfs_releasepage(page, GFP_NOFS);
8866 }
8867
8868 ClearPageChecked(page);
8869 if (PagePrivate(page)) {
8870 ClearPagePrivate(page);
8871 set_page_private(page, 0);
8872 put_page(page);
8873 }
8874 }
8875
8876 /*
8877 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8878 * called from a page fault handler when a page is first dirtied. Hence we must
8879 * be careful to check for EOF conditions here. We set the page up correctly
8880 * for a written page which means we get ENOSPC checking when writing into
8881 * holes and correct delalloc and unwritten extent mapping on filesystems that
8882 * support these features.
8883 *
8884 * We are not allowed to take the i_mutex here so we have to play games to
8885 * protect against truncate races as the page could now be beyond EOF. Because
8886 * vmtruncate() writes the inode size before removing pages, once we have the
8887 * page lock we can determine safely if the page is beyond EOF. If it is not
8888 * beyond EOF, then the page is guaranteed safe against truncation until we
8889 * unlock the page.
8890 */
8891 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8892 {
8893 struct page *page = vmf->page;
8894 struct inode *inode = file_inode(vma->vm_file);
8895 struct btrfs_root *root = BTRFS_I(inode)->root;
8896 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8897 struct btrfs_ordered_extent *ordered;
8898 struct extent_state *cached_state = NULL;
8899 char *kaddr;
8900 unsigned long zero_start;
8901 loff_t size;
8902 int ret;
8903 int reserved = 0;
8904 u64 reserved_space;
8905 u64 page_start;
8906 u64 page_end;
8907 u64 end;
8908
8909 reserved_space = PAGE_SIZE;
8910
8911 sb_start_pagefault(inode->i_sb);
8912 page_start = page_offset(page);
8913 page_end = page_start + PAGE_SIZE - 1;
8914 end = page_end;
8915
8916 /*
8917 * Reserving delalloc space after obtaining the page lock can lead to
8918 * deadlock. For example, if a dirty page is locked by this function
8919 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8920 * dirty page write out, then the btrfs_writepage() function could
8921 * end up waiting indefinitely to get a lock on the page currently
8922 * being processed by btrfs_page_mkwrite() function.
8923 */
8924 ret = btrfs_delalloc_reserve_space(inode, page_start,
8925 reserved_space);
8926 if (!ret) {
8927 ret = file_update_time(vma->vm_file);
8928 reserved = 1;
8929 }
8930 if (ret) {
8931 if (ret == -ENOMEM)
8932 ret = VM_FAULT_OOM;
8933 else /* -ENOSPC, -EIO, etc */
8934 ret = VM_FAULT_SIGBUS;
8935 if (reserved)
8936 goto out;
8937 goto out_noreserve;
8938 }
8939
8940 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8941 again:
8942 lock_page(page);
8943 size = i_size_read(inode);
8944
8945 if ((page->mapping != inode->i_mapping) ||
8946 (page_start >= size)) {
8947 /* page got truncated out from underneath us */
8948 goto out_unlock;
8949 }
8950 wait_on_page_writeback(page);
8951
8952 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8953 set_page_extent_mapped(page);
8954
8955 /*
8956 * we can't set the delalloc bits if there are pending ordered
8957 * extents. Drop our locks and wait for them to finish
8958 */
8959 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
8960 if (ordered) {
8961 unlock_extent_cached(io_tree, page_start, page_end,
8962 &cached_state, GFP_NOFS);
8963 unlock_page(page);
8964 btrfs_start_ordered_extent(inode, ordered, 1);
8965 btrfs_put_ordered_extent(ordered);
8966 goto again;
8967 }
8968
8969 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8970 reserved_space = round_up(size - page_start, root->sectorsize);
8971 if (reserved_space < PAGE_SIZE) {
8972 end = page_start + reserved_space - 1;
8973 spin_lock(&BTRFS_I(inode)->lock);
8974 BTRFS_I(inode)->outstanding_extents++;
8975 spin_unlock(&BTRFS_I(inode)->lock);
8976 btrfs_delalloc_release_space(inode, page_start,
8977 PAGE_SIZE - reserved_space);
8978 }
8979 }
8980
8981 /*
8982 * XXX - page_mkwrite gets called every time the page is dirtied, even
8983 * if it was already dirty, so for space accounting reasons we need to
8984 * clear any delalloc bits for the range we are fixing to save. There
8985 * is probably a better way to do this, but for now keep consistent with
8986 * prepare_pages in the normal write path.
8987 */
8988 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8989 EXTENT_DIRTY | EXTENT_DELALLOC |
8990 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8991 0, 0, &cached_state, GFP_NOFS);
8992
8993 ret = btrfs_set_extent_delalloc(inode, page_start, end,
8994 &cached_state);
8995 if (ret) {
8996 unlock_extent_cached(io_tree, page_start, page_end,
8997 &cached_state, GFP_NOFS);
8998 ret = VM_FAULT_SIGBUS;
8999 goto out_unlock;
9000 }
9001 ret = 0;
9002
9003 /* page is wholly or partially inside EOF */
9004 if (page_start + PAGE_SIZE > size)
9005 zero_start = size & ~PAGE_MASK;
9006 else
9007 zero_start = PAGE_SIZE;
9008
9009 if (zero_start != PAGE_SIZE) {
9010 kaddr = kmap(page);
9011 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9012 flush_dcache_page(page);
9013 kunmap(page);
9014 }
9015 ClearPageChecked(page);
9016 set_page_dirty(page);
9017 SetPageUptodate(page);
9018
9019 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9020 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9021 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9022
9023 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9024
9025 out_unlock:
9026 if (!ret) {
9027 sb_end_pagefault(inode->i_sb);
9028 return VM_FAULT_LOCKED;
9029 }
9030 unlock_page(page);
9031 out:
9032 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9033 out_noreserve:
9034 sb_end_pagefault(inode->i_sb);
9035 return ret;
9036 }
9037
9038 static int btrfs_truncate(struct inode *inode)
9039 {
9040 struct btrfs_root *root = BTRFS_I(inode)->root;
9041 struct btrfs_block_rsv *rsv;
9042 int ret = 0;
9043 int err = 0;
9044 struct btrfs_trans_handle *trans;
9045 u64 mask = root->sectorsize - 1;
9046 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9047
9048 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9049 (u64)-1);
9050 if (ret)
9051 return ret;
9052
9053 /*
9054 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9055 * 3 things going on here
9056 *
9057 * 1) We need to reserve space for our orphan item and the space to
9058 * delete our orphan item. Lord knows we don't want to have a dangling
9059 * orphan item because we didn't reserve space to remove it.
9060 *
9061 * 2) We need to reserve space to update our inode.
9062 *
9063 * 3) We need to have something to cache all the space that is going to
9064 * be free'd up by the truncate operation, but also have some slack
9065 * space reserved in case it uses space during the truncate (thank you
9066 * very much snapshotting).
9067 *
9068 * And we need these to all be separate. The fact is we can use a lot of
9069 * space doing the truncate, and we have no earthly idea how much space
9070 * we will use, so we need the truncate reservation to be separate so it
9071 * doesn't end up using space reserved for updating the inode or
9072 * removing the orphan item. We also need to be able to stop the
9073 * transaction and start a new one, which means we need to be able to
9074 * update the inode several times, and we have no idea of knowing how
9075 * many times that will be, so we can't just reserve 1 item for the
9076 * entirety of the operation, so that has to be done separately as well.
9077 * Then there is the orphan item, which does indeed need to be held on
9078 * to for the whole operation, and we need nobody to touch this reserved
9079 * space except the orphan code.
9080 *
9081 * So that leaves us with
9082 *
9083 * 1) root->orphan_block_rsv - for the orphan deletion.
9084 * 2) rsv - for the truncate reservation, which we will steal from the
9085 * transaction reservation.
9086 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9087 * updating the inode.
9088 */
9089 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9090 if (!rsv)
9091 return -ENOMEM;
9092 rsv->size = min_size;
9093 rsv->failfast = 1;
9094
9095 /*
9096 * 1 for the truncate slack space
9097 * 1 for updating the inode.
9098 */
9099 trans = btrfs_start_transaction(root, 2);
9100 if (IS_ERR(trans)) {
9101 err = PTR_ERR(trans);
9102 goto out;
9103 }
9104
9105 /* Migrate the slack space for the truncate to our reserve */
9106 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9107 min_size);
9108 BUG_ON(ret);
9109
9110 /*
9111 * So if we truncate and then write and fsync we normally would just
9112 * write the extents that changed, which is a problem if we need to
9113 * first truncate that entire inode. So set this flag so we write out
9114 * all of the extents in the inode to the sync log so we're completely
9115 * safe.
9116 */
9117 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9118 trans->block_rsv = rsv;
9119
9120 while (1) {
9121 ret = btrfs_truncate_inode_items(trans, root, inode,
9122 inode->i_size,
9123 BTRFS_EXTENT_DATA_KEY);
9124 if (ret != -ENOSPC && ret != -EAGAIN) {
9125 err = ret;
9126 break;
9127 }
9128
9129 trans->block_rsv = &root->fs_info->trans_block_rsv;
9130 ret = btrfs_update_inode(trans, root, inode);
9131 if (ret) {
9132 err = ret;
9133 break;
9134 }
9135
9136 btrfs_end_transaction(trans, root);
9137 btrfs_btree_balance_dirty(root);
9138
9139 trans = btrfs_start_transaction(root, 2);
9140 if (IS_ERR(trans)) {
9141 ret = err = PTR_ERR(trans);
9142 trans = NULL;
9143 break;
9144 }
9145
9146 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9147 rsv, min_size);
9148 BUG_ON(ret); /* shouldn't happen */
9149 trans->block_rsv = rsv;
9150 }
9151
9152 if (ret == 0 && inode->i_nlink > 0) {
9153 trans->block_rsv = root->orphan_block_rsv;
9154 ret = btrfs_orphan_del(trans, inode);
9155 if (ret)
9156 err = ret;
9157 }
9158
9159 if (trans) {
9160 trans->block_rsv = &root->fs_info->trans_block_rsv;
9161 ret = btrfs_update_inode(trans, root, inode);
9162 if (ret && !err)
9163 err = ret;
9164
9165 ret = btrfs_end_transaction(trans, root);
9166 btrfs_btree_balance_dirty(root);
9167 }
9168
9169 out:
9170 btrfs_free_block_rsv(root, rsv);
9171
9172 if (ret && !err)
9173 err = ret;
9174
9175 return err;
9176 }
9177
9178 /*
9179 * create a new subvolume directory/inode (helper for the ioctl).
9180 */
9181 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9182 struct btrfs_root *new_root,
9183 struct btrfs_root *parent_root,
9184 u64 new_dirid)
9185 {
9186 struct inode *inode;
9187 int err;
9188 u64 index = 0;
9189
9190 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9191 new_dirid, new_dirid,
9192 S_IFDIR | (~current_umask() & S_IRWXUGO),
9193 &index);
9194 if (IS_ERR(inode))
9195 return PTR_ERR(inode);
9196 inode->i_op = &btrfs_dir_inode_operations;
9197 inode->i_fop = &btrfs_dir_file_operations;
9198
9199 set_nlink(inode, 1);
9200 btrfs_i_size_write(inode, 0);
9201 unlock_new_inode(inode);
9202
9203 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9204 if (err)
9205 btrfs_err(new_root->fs_info,
9206 "error inheriting subvolume %llu properties: %d",
9207 new_root->root_key.objectid, err);
9208
9209 err = btrfs_update_inode(trans, new_root, inode);
9210
9211 iput(inode);
9212 return err;
9213 }
9214
9215 struct inode *btrfs_alloc_inode(struct super_block *sb)
9216 {
9217 struct btrfs_inode *ei;
9218 struct inode *inode;
9219
9220 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9221 if (!ei)
9222 return NULL;
9223
9224 ei->root = NULL;
9225 ei->generation = 0;
9226 ei->last_trans = 0;
9227 ei->last_sub_trans = 0;
9228 ei->logged_trans = 0;
9229 ei->delalloc_bytes = 0;
9230 ei->defrag_bytes = 0;
9231 ei->disk_i_size = 0;
9232 ei->flags = 0;
9233 ei->csum_bytes = 0;
9234 ei->index_cnt = (u64)-1;
9235 ei->dir_index = 0;
9236 ei->last_unlink_trans = 0;
9237 ei->last_log_commit = 0;
9238 ei->delayed_iput_count = 0;
9239
9240 spin_lock_init(&ei->lock);
9241 ei->outstanding_extents = 0;
9242 ei->reserved_extents = 0;
9243
9244 ei->runtime_flags = 0;
9245 ei->force_compress = BTRFS_COMPRESS_NONE;
9246
9247 ei->delayed_node = NULL;
9248
9249 ei->i_otime.tv_sec = 0;
9250 ei->i_otime.tv_nsec = 0;
9251
9252 inode = &ei->vfs_inode;
9253 extent_map_tree_init(&ei->extent_tree);
9254 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9255 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9256 ei->io_tree.track_uptodate = 1;
9257 ei->io_failure_tree.track_uptodate = 1;
9258 atomic_set(&ei->sync_writers, 0);
9259 mutex_init(&ei->log_mutex);
9260 mutex_init(&ei->delalloc_mutex);
9261 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9262 INIT_LIST_HEAD(&ei->delalloc_inodes);
9263 INIT_LIST_HEAD(&ei->delayed_iput);
9264 RB_CLEAR_NODE(&ei->rb_node);
9265 init_rwsem(&ei->dio_sem);
9266
9267 return inode;
9268 }
9269
9270 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9271 void btrfs_test_destroy_inode(struct inode *inode)
9272 {
9273 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9274 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9275 }
9276 #endif
9277
9278 static void btrfs_i_callback(struct rcu_head *head)
9279 {
9280 struct inode *inode = container_of(head, struct inode, i_rcu);
9281 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9282 }
9283
9284 void btrfs_destroy_inode(struct inode *inode)
9285 {
9286 struct btrfs_ordered_extent *ordered;
9287 struct btrfs_root *root = BTRFS_I(inode)->root;
9288
9289 WARN_ON(!hlist_empty(&inode->i_dentry));
9290 WARN_ON(inode->i_data.nrpages);
9291 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9292 WARN_ON(BTRFS_I(inode)->reserved_extents);
9293 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9294 WARN_ON(BTRFS_I(inode)->csum_bytes);
9295 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9296
9297 /*
9298 * This can happen where we create an inode, but somebody else also
9299 * created the same inode and we need to destroy the one we already
9300 * created.
9301 */
9302 if (!root)
9303 goto free;
9304
9305 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9306 &BTRFS_I(inode)->runtime_flags)) {
9307 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9308 btrfs_ino(inode));
9309 atomic_dec(&root->orphan_inodes);
9310 }
9311
9312 while (1) {
9313 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9314 if (!ordered)
9315 break;
9316 else {
9317 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9318 ordered->file_offset, ordered->len);
9319 btrfs_remove_ordered_extent(inode, ordered);
9320 btrfs_put_ordered_extent(ordered);
9321 btrfs_put_ordered_extent(ordered);
9322 }
9323 }
9324 btrfs_qgroup_check_reserved_leak(inode);
9325 inode_tree_del(inode);
9326 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9327 free:
9328 call_rcu(&inode->i_rcu, btrfs_i_callback);
9329 }
9330
9331 int btrfs_drop_inode(struct inode *inode)
9332 {
9333 struct btrfs_root *root = BTRFS_I(inode)->root;
9334
9335 if (root == NULL)
9336 return 1;
9337
9338 /* the snap/subvol tree is on deleting */
9339 if (btrfs_root_refs(&root->root_item) == 0)
9340 return 1;
9341 else
9342 return generic_drop_inode(inode);
9343 }
9344
9345 static void init_once(void *foo)
9346 {
9347 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9348
9349 inode_init_once(&ei->vfs_inode);
9350 }
9351
9352 void btrfs_destroy_cachep(void)
9353 {
9354 /*
9355 * Make sure all delayed rcu free inodes are flushed before we
9356 * destroy cache.
9357 */
9358 rcu_barrier();
9359 kmem_cache_destroy(btrfs_inode_cachep);
9360 kmem_cache_destroy(btrfs_trans_handle_cachep);
9361 kmem_cache_destroy(btrfs_transaction_cachep);
9362 kmem_cache_destroy(btrfs_path_cachep);
9363 kmem_cache_destroy(btrfs_free_space_cachep);
9364 }
9365
9366 int btrfs_init_cachep(void)
9367 {
9368 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9369 sizeof(struct btrfs_inode), 0,
9370 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9371 init_once);
9372 if (!btrfs_inode_cachep)
9373 goto fail;
9374
9375 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9376 sizeof(struct btrfs_trans_handle), 0,
9377 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9378 if (!btrfs_trans_handle_cachep)
9379 goto fail;
9380
9381 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9382 sizeof(struct btrfs_transaction), 0,
9383 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9384 if (!btrfs_transaction_cachep)
9385 goto fail;
9386
9387 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9388 sizeof(struct btrfs_path), 0,
9389 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9390 if (!btrfs_path_cachep)
9391 goto fail;
9392
9393 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9394 sizeof(struct btrfs_free_space), 0,
9395 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9396 if (!btrfs_free_space_cachep)
9397 goto fail;
9398
9399 return 0;
9400 fail:
9401 btrfs_destroy_cachep();
9402 return -ENOMEM;
9403 }
9404
9405 static int btrfs_getattr(struct vfsmount *mnt,
9406 struct dentry *dentry, struct kstat *stat)
9407 {
9408 u64 delalloc_bytes;
9409 struct inode *inode = d_inode(dentry);
9410 u32 blocksize = inode->i_sb->s_blocksize;
9411
9412 generic_fillattr(inode, stat);
9413 stat->dev = BTRFS_I(inode)->root->anon_dev;
9414
9415 spin_lock(&BTRFS_I(inode)->lock);
9416 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9417 spin_unlock(&BTRFS_I(inode)->lock);
9418 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9419 ALIGN(delalloc_bytes, blocksize)) >> 9;
9420 return 0;
9421 }
9422
9423 static int btrfs_rename_exchange(struct inode *old_dir,
9424 struct dentry *old_dentry,
9425 struct inode *new_dir,
9426 struct dentry *new_dentry)
9427 {
9428 struct btrfs_trans_handle *trans;
9429 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9430 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9431 struct inode *new_inode = new_dentry->d_inode;
9432 struct inode *old_inode = old_dentry->d_inode;
9433 struct timespec ctime = CURRENT_TIME;
9434 struct dentry *parent;
9435 u64 old_ino = btrfs_ino(old_inode);
9436 u64 new_ino = btrfs_ino(new_inode);
9437 u64 old_idx = 0;
9438 u64 new_idx = 0;
9439 u64 root_objectid;
9440 int ret;
9441 bool root_log_pinned = false;
9442 bool dest_log_pinned = false;
9443
9444 /* we only allow rename subvolume link between subvolumes */
9445 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9446 return -EXDEV;
9447
9448 /* close the race window with snapshot create/destroy ioctl */
9449 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9450 down_read(&root->fs_info->subvol_sem);
9451 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9452 down_read(&dest->fs_info->subvol_sem);
9453
9454 /*
9455 * We want to reserve the absolute worst case amount of items. So if
9456 * both inodes are subvols and we need to unlink them then that would
9457 * require 4 item modifications, but if they are both normal inodes it
9458 * would require 5 item modifications, so we'll assume their normal
9459 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9460 * should cover the worst case number of items we'll modify.
9461 */
9462 trans = btrfs_start_transaction(root, 12);
9463 if (IS_ERR(trans)) {
9464 ret = PTR_ERR(trans);
9465 goto out_notrans;
9466 }
9467
9468 /*
9469 * We need to find a free sequence number both in the source and
9470 * in the destination directory for the exchange.
9471 */
9472 ret = btrfs_set_inode_index(new_dir, &old_idx);
9473 if (ret)
9474 goto out_fail;
9475 ret = btrfs_set_inode_index(old_dir, &new_idx);
9476 if (ret)
9477 goto out_fail;
9478
9479 BTRFS_I(old_inode)->dir_index = 0ULL;
9480 BTRFS_I(new_inode)->dir_index = 0ULL;
9481
9482 /* Reference for the source. */
9483 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9484 /* force full log commit if subvolume involved. */
9485 btrfs_set_log_full_commit(root->fs_info, trans);
9486 } else {
9487 btrfs_pin_log_trans(root);
9488 root_log_pinned = true;
9489 ret = btrfs_insert_inode_ref(trans, dest,
9490 new_dentry->d_name.name,
9491 new_dentry->d_name.len,
9492 old_ino,
9493 btrfs_ino(new_dir), old_idx);
9494 if (ret)
9495 goto out_fail;
9496 }
9497
9498 /* And now for the dest. */
9499 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9500 /* force full log commit if subvolume involved. */
9501 btrfs_set_log_full_commit(dest->fs_info, trans);
9502 } else {
9503 btrfs_pin_log_trans(dest);
9504 dest_log_pinned = true;
9505 ret = btrfs_insert_inode_ref(trans, root,
9506 old_dentry->d_name.name,
9507 old_dentry->d_name.len,
9508 new_ino,
9509 btrfs_ino(old_dir), new_idx);
9510 if (ret)
9511 goto out_fail;
9512 }
9513
9514 /* Update inode version and ctime/mtime. */
9515 inode_inc_iversion(old_dir);
9516 inode_inc_iversion(new_dir);
9517 inode_inc_iversion(old_inode);
9518 inode_inc_iversion(new_inode);
9519 old_dir->i_ctime = old_dir->i_mtime = ctime;
9520 new_dir->i_ctime = new_dir->i_mtime = ctime;
9521 old_inode->i_ctime = ctime;
9522 new_inode->i_ctime = ctime;
9523
9524 if (old_dentry->d_parent != new_dentry->d_parent) {
9525 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9526 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9527 }
9528
9529 /* src is a subvolume */
9530 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9531 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9532 ret = btrfs_unlink_subvol(trans, root, old_dir,
9533 root_objectid,
9534 old_dentry->d_name.name,
9535 old_dentry->d_name.len);
9536 } else { /* src is an inode */
9537 ret = __btrfs_unlink_inode(trans, root, old_dir,
9538 old_dentry->d_inode,
9539 old_dentry->d_name.name,
9540 old_dentry->d_name.len);
9541 if (!ret)
9542 ret = btrfs_update_inode(trans, root, old_inode);
9543 }
9544 if (ret) {
9545 btrfs_abort_transaction(trans, root, ret);
9546 goto out_fail;
9547 }
9548
9549 /* dest is a subvolume */
9550 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9551 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9552 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9553 root_objectid,
9554 new_dentry->d_name.name,
9555 new_dentry->d_name.len);
9556 } else { /* dest is an inode */
9557 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9558 new_dentry->d_inode,
9559 new_dentry->d_name.name,
9560 new_dentry->d_name.len);
9561 if (!ret)
9562 ret = btrfs_update_inode(trans, dest, new_inode);
9563 }
9564 if (ret) {
9565 btrfs_abort_transaction(trans, root, ret);
9566 goto out_fail;
9567 }
9568
9569 ret = btrfs_add_link(trans, new_dir, old_inode,
9570 new_dentry->d_name.name,
9571 new_dentry->d_name.len, 0, old_idx);
9572 if (ret) {
9573 btrfs_abort_transaction(trans, root, ret);
9574 goto out_fail;
9575 }
9576
9577 ret = btrfs_add_link(trans, old_dir, new_inode,
9578 old_dentry->d_name.name,
9579 old_dentry->d_name.len, 0, new_idx);
9580 if (ret) {
9581 btrfs_abort_transaction(trans, root, ret);
9582 goto out_fail;
9583 }
9584
9585 if (old_inode->i_nlink == 1)
9586 BTRFS_I(old_inode)->dir_index = old_idx;
9587 if (new_inode->i_nlink == 1)
9588 BTRFS_I(new_inode)->dir_index = new_idx;
9589
9590 if (root_log_pinned) {
9591 parent = new_dentry->d_parent;
9592 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9593 btrfs_end_log_trans(root);
9594 root_log_pinned = false;
9595 }
9596 if (dest_log_pinned) {
9597 parent = old_dentry->d_parent;
9598 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9599 btrfs_end_log_trans(dest);
9600 dest_log_pinned = false;
9601 }
9602 out_fail:
9603 /*
9604 * If we have pinned a log and an error happened, we unpin tasks
9605 * trying to sync the log and force them to fallback to a transaction
9606 * commit if the log currently contains any of the inodes involved in
9607 * this rename operation (to ensure we do not persist a log with an
9608 * inconsistent state for any of these inodes or leading to any
9609 * inconsistencies when replayed). If the transaction was aborted, the
9610 * abortion reason is propagated to userspace when attempting to commit
9611 * the transaction. If the log does not contain any of these inodes, we
9612 * allow the tasks to sync it.
9613 */
9614 if (ret && (root_log_pinned || dest_log_pinned)) {
9615 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9616 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9617 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9618 (new_inode &&
9619 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9620 btrfs_set_log_full_commit(root->fs_info, trans);
9621
9622 if (root_log_pinned) {
9623 btrfs_end_log_trans(root);
9624 root_log_pinned = false;
9625 }
9626 if (dest_log_pinned) {
9627 btrfs_end_log_trans(dest);
9628 dest_log_pinned = false;
9629 }
9630 }
9631 ret = btrfs_end_transaction(trans, root);
9632 out_notrans:
9633 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9634 up_read(&dest->fs_info->subvol_sem);
9635 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9636 up_read(&root->fs_info->subvol_sem);
9637
9638 return ret;
9639 }
9640
9641 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9642 struct btrfs_root *root,
9643 struct inode *dir,
9644 struct dentry *dentry)
9645 {
9646 int ret;
9647 struct inode *inode;
9648 u64 objectid;
9649 u64 index;
9650
9651 ret = btrfs_find_free_ino(root, &objectid);
9652 if (ret)
9653 return ret;
9654
9655 inode = btrfs_new_inode(trans, root, dir,
9656 dentry->d_name.name,
9657 dentry->d_name.len,
9658 btrfs_ino(dir),
9659 objectid,
9660 S_IFCHR | WHITEOUT_MODE,
9661 &index);
9662
9663 if (IS_ERR(inode)) {
9664 ret = PTR_ERR(inode);
9665 return ret;
9666 }
9667
9668 inode->i_op = &btrfs_special_inode_operations;
9669 init_special_inode(inode, inode->i_mode,
9670 WHITEOUT_DEV);
9671
9672 ret = btrfs_init_inode_security(trans, inode, dir,
9673 &dentry->d_name);
9674 if (ret)
9675 goto out;
9676
9677 ret = btrfs_add_nondir(trans, dir, dentry,
9678 inode, 0, index);
9679 if (ret)
9680 goto out;
9681
9682 ret = btrfs_update_inode(trans, root, inode);
9683 out:
9684 unlock_new_inode(inode);
9685 if (ret)
9686 inode_dec_link_count(inode);
9687 iput(inode);
9688
9689 return ret;
9690 }
9691
9692 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9693 struct inode *new_dir, struct dentry *new_dentry,
9694 unsigned int flags)
9695 {
9696 struct btrfs_trans_handle *trans;
9697 unsigned int trans_num_items;
9698 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9699 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9700 struct inode *new_inode = d_inode(new_dentry);
9701 struct inode *old_inode = d_inode(old_dentry);
9702 u64 index = 0;
9703 u64 root_objectid;
9704 int ret;
9705 u64 old_ino = btrfs_ino(old_inode);
9706 bool log_pinned = false;
9707
9708 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9709 return -EPERM;
9710
9711 /* we only allow rename subvolume link between subvolumes */
9712 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9713 return -EXDEV;
9714
9715 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9716 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9717 return -ENOTEMPTY;
9718
9719 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9720 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9721 return -ENOTEMPTY;
9722
9723
9724 /* check for collisions, even if the name isn't there */
9725 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9726 new_dentry->d_name.name,
9727 new_dentry->d_name.len);
9728
9729 if (ret) {
9730 if (ret == -EEXIST) {
9731 /* we shouldn't get
9732 * eexist without a new_inode */
9733 if (WARN_ON(!new_inode)) {
9734 return ret;
9735 }
9736 } else {
9737 /* maybe -EOVERFLOW */
9738 return ret;
9739 }
9740 }
9741 ret = 0;
9742
9743 /*
9744 * we're using rename to replace one file with another. Start IO on it
9745 * now so we don't add too much work to the end of the transaction
9746 */
9747 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9748 filemap_flush(old_inode->i_mapping);
9749
9750 /* close the racy window with snapshot create/destroy ioctl */
9751 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9752 down_read(&root->fs_info->subvol_sem);
9753 /*
9754 * We want to reserve the absolute worst case amount of items. So if
9755 * both inodes are subvols and we need to unlink them then that would
9756 * require 4 item modifications, but if they are both normal inodes it
9757 * would require 5 item modifications, so we'll assume they are normal
9758 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9759 * should cover the worst case number of items we'll modify.
9760 * If our rename has the whiteout flag, we need more 5 units for the
9761 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9762 * when selinux is enabled).
9763 */
9764 trans_num_items = 11;
9765 if (flags & RENAME_WHITEOUT)
9766 trans_num_items += 5;
9767 trans = btrfs_start_transaction(root, trans_num_items);
9768 if (IS_ERR(trans)) {
9769 ret = PTR_ERR(trans);
9770 goto out_notrans;
9771 }
9772
9773 if (dest != root)
9774 btrfs_record_root_in_trans(trans, dest);
9775
9776 ret = btrfs_set_inode_index(new_dir, &index);
9777 if (ret)
9778 goto out_fail;
9779
9780 BTRFS_I(old_inode)->dir_index = 0ULL;
9781 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9782 /* force full log commit if subvolume involved. */
9783 btrfs_set_log_full_commit(root->fs_info, trans);
9784 } else {
9785 btrfs_pin_log_trans(root);
9786 log_pinned = true;
9787 ret = btrfs_insert_inode_ref(trans, dest,
9788 new_dentry->d_name.name,
9789 new_dentry->d_name.len,
9790 old_ino,
9791 btrfs_ino(new_dir), index);
9792 if (ret)
9793 goto out_fail;
9794 }
9795
9796 inode_inc_iversion(old_dir);
9797 inode_inc_iversion(new_dir);
9798 inode_inc_iversion(old_inode);
9799 old_dir->i_ctime = old_dir->i_mtime =
9800 new_dir->i_ctime = new_dir->i_mtime =
9801 old_inode->i_ctime = current_fs_time(old_dir->i_sb);
9802
9803 if (old_dentry->d_parent != new_dentry->d_parent)
9804 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9805
9806 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9807 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9808 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9809 old_dentry->d_name.name,
9810 old_dentry->d_name.len);
9811 } else {
9812 ret = __btrfs_unlink_inode(trans, root, old_dir,
9813 d_inode(old_dentry),
9814 old_dentry->d_name.name,
9815 old_dentry->d_name.len);
9816 if (!ret)
9817 ret = btrfs_update_inode(trans, root, old_inode);
9818 }
9819 if (ret) {
9820 btrfs_abort_transaction(trans, root, ret);
9821 goto out_fail;
9822 }
9823
9824 if (new_inode) {
9825 inode_inc_iversion(new_inode);
9826 new_inode->i_ctime = current_fs_time(new_inode->i_sb);
9827 if (unlikely(btrfs_ino(new_inode) ==
9828 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9829 root_objectid = BTRFS_I(new_inode)->location.objectid;
9830 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9831 root_objectid,
9832 new_dentry->d_name.name,
9833 new_dentry->d_name.len);
9834 BUG_ON(new_inode->i_nlink == 0);
9835 } else {
9836 ret = btrfs_unlink_inode(trans, dest, new_dir,
9837 d_inode(new_dentry),
9838 new_dentry->d_name.name,
9839 new_dentry->d_name.len);
9840 }
9841 if (!ret && new_inode->i_nlink == 0)
9842 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9843 if (ret) {
9844 btrfs_abort_transaction(trans, root, ret);
9845 goto out_fail;
9846 }
9847 }
9848
9849 ret = btrfs_add_link(trans, new_dir, old_inode,
9850 new_dentry->d_name.name,
9851 new_dentry->d_name.len, 0, index);
9852 if (ret) {
9853 btrfs_abort_transaction(trans, root, ret);
9854 goto out_fail;
9855 }
9856
9857 if (old_inode->i_nlink == 1)
9858 BTRFS_I(old_inode)->dir_index = index;
9859
9860 if (log_pinned) {
9861 struct dentry *parent = new_dentry->d_parent;
9862
9863 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9864 btrfs_end_log_trans(root);
9865 log_pinned = false;
9866 }
9867
9868 if (flags & RENAME_WHITEOUT) {
9869 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9870 old_dentry);
9871
9872 if (ret) {
9873 btrfs_abort_transaction(trans, root, ret);
9874 goto out_fail;
9875 }
9876 }
9877 out_fail:
9878 /*
9879 * If we have pinned the log and an error happened, we unpin tasks
9880 * trying to sync the log and force them to fallback to a transaction
9881 * commit if the log currently contains any of the inodes involved in
9882 * this rename operation (to ensure we do not persist a log with an
9883 * inconsistent state for any of these inodes or leading to any
9884 * inconsistencies when replayed). If the transaction was aborted, the
9885 * abortion reason is propagated to userspace when attempting to commit
9886 * the transaction. If the log does not contain any of these inodes, we
9887 * allow the tasks to sync it.
9888 */
9889 if (ret && log_pinned) {
9890 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9891 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9892 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9893 (new_inode &&
9894 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9895 btrfs_set_log_full_commit(root->fs_info, trans);
9896
9897 btrfs_end_log_trans(root);
9898 log_pinned = false;
9899 }
9900 btrfs_end_transaction(trans, root);
9901 out_notrans:
9902 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9903 up_read(&root->fs_info->subvol_sem);
9904
9905 return ret;
9906 }
9907
9908 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9909 struct inode *new_dir, struct dentry *new_dentry,
9910 unsigned int flags)
9911 {
9912 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9913 return -EINVAL;
9914
9915 if (flags & RENAME_EXCHANGE)
9916 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9917 new_dentry);
9918
9919 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9920 }
9921
9922 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9923 {
9924 struct btrfs_delalloc_work *delalloc_work;
9925 struct inode *inode;
9926
9927 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9928 work);
9929 inode = delalloc_work->inode;
9930 filemap_flush(inode->i_mapping);
9931 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9932 &BTRFS_I(inode)->runtime_flags))
9933 filemap_flush(inode->i_mapping);
9934
9935 if (delalloc_work->delay_iput)
9936 btrfs_add_delayed_iput(inode);
9937 else
9938 iput(inode);
9939 complete(&delalloc_work->completion);
9940 }
9941
9942 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9943 int delay_iput)
9944 {
9945 struct btrfs_delalloc_work *work;
9946
9947 work = kmalloc(sizeof(*work), GFP_NOFS);
9948 if (!work)
9949 return NULL;
9950
9951 init_completion(&work->completion);
9952 INIT_LIST_HEAD(&work->list);
9953 work->inode = inode;
9954 work->delay_iput = delay_iput;
9955 WARN_ON_ONCE(!inode);
9956 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9957 btrfs_run_delalloc_work, NULL, NULL);
9958
9959 return work;
9960 }
9961
9962 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9963 {
9964 wait_for_completion(&work->completion);
9965 kfree(work);
9966 }
9967
9968 /*
9969 * some fairly slow code that needs optimization. This walks the list
9970 * of all the inodes with pending delalloc and forces them to disk.
9971 */
9972 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9973 int nr)
9974 {
9975 struct btrfs_inode *binode;
9976 struct inode *inode;
9977 struct btrfs_delalloc_work *work, *next;
9978 struct list_head works;
9979 struct list_head splice;
9980 int ret = 0;
9981
9982 INIT_LIST_HEAD(&works);
9983 INIT_LIST_HEAD(&splice);
9984
9985 mutex_lock(&root->delalloc_mutex);
9986 spin_lock(&root->delalloc_lock);
9987 list_splice_init(&root->delalloc_inodes, &splice);
9988 while (!list_empty(&splice)) {
9989 binode = list_entry(splice.next, struct btrfs_inode,
9990 delalloc_inodes);
9991
9992 list_move_tail(&binode->delalloc_inodes,
9993 &root->delalloc_inodes);
9994 inode = igrab(&binode->vfs_inode);
9995 if (!inode) {
9996 cond_resched_lock(&root->delalloc_lock);
9997 continue;
9998 }
9999 spin_unlock(&root->delalloc_lock);
10000
10001 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10002 if (!work) {
10003 if (delay_iput)
10004 btrfs_add_delayed_iput(inode);
10005 else
10006 iput(inode);
10007 ret = -ENOMEM;
10008 goto out;
10009 }
10010 list_add_tail(&work->list, &works);
10011 btrfs_queue_work(root->fs_info->flush_workers,
10012 &work->work);
10013 ret++;
10014 if (nr != -1 && ret >= nr)
10015 goto out;
10016 cond_resched();
10017 spin_lock(&root->delalloc_lock);
10018 }
10019 spin_unlock(&root->delalloc_lock);
10020
10021 out:
10022 list_for_each_entry_safe(work, next, &works, list) {
10023 list_del_init(&work->list);
10024 btrfs_wait_and_free_delalloc_work(work);
10025 }
10026
10027 if (!list_empty_careful(&splice)) {
10028 spin_lock(&root->delalloc_lock);
10029 list_splice_tail(&splice, &root->delalloc_inodes);
10030 spin_unlock(&root->delalloc_lock);
10031 }
10032 mutex_unlock(&root->delalloc_mutex);
10033 return ret;
10034 }
10035
10036 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10037 {
10038 int ret;
10039
10040 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10041 return -EROFS;
10042
10043 ret = __start_delalloc_inodes(root, delay_iput, -1);
10044 if (ret > 0)
10045 ret = 0;
10046 /*
10047 * the filemap_flush will queue IO into the worker threads, but
10048 * we have to make sure the IO is actually started and that
10049 * ordered extents get created before we return
10050 */
10051 atomic_inc(&root->fs_info->async_submit_draining);
10052 while (atomic_read(&root->fs_info->nr_async_submits) ||
10053 atomic_read(&root->fs_info->async_delalloc_pages)) {
10054 wait_event(root->fs_info->async_submit_wait,
10055 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10056 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10057 }
10058 atomic_dec(&root->fs_info->async_submit_draining);
10059 return ret;
10060 }
10061
10062 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10063 int nr)
10064 {
10065 struct btrfs_root *root;
10066 struct list_head splice;
10067 int ret;
10068
10069 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10070 return -EROFS;
10071
10072 INIT_LIST_HEAD(&splice);
10073
10074 mutex_lock(&fs_info->delalloc_root_mutex);
10075 spin_lock(&fs_info->delalloc_root_lock);
10076 list_splice_init(&fs_info->delalloc_roots, &splice);
10077 while (!list_empty(&splice) && nr) {
10078 root = list_first_entry(&splice, struct btrfs_root,
10079 delalloc_root);
10080 root = btrfs_grab_fs_root(root);
10081 BUG_ON(!root);
10082 list_move_tail(&root->delalloc_root,
10083 &fs_info->delalloc_roots);
10084 spin_unlock(&fs_info->delalloc_root_lock);
10085
10086 ret = __start_delalloc_inodes(root, delay_iput, nr);
10087 btrfs_put_fs_root(root);
10088 if (ret < 0)
10089 goto out;
10090
10091 if (nr != -1) {
10092 nr -= ret;
10093 WARN_ON(nr < 0);
10094 }
10095 spin_lock(&fs_info->delalloc_root_lock);
10096 }
10097 spin_unlock(&fs_info->delalloc_root_lock);
10098
10099 ret = 0;
10100 atomic_inc(&fs_info->async_submit_draining);
10101 while (atomic_read(&fs_info->nr_async_submits) ||
10102 atomic_read(&fs_info->async_delalloc_pages)) {
10103 wait_event(fs_info->async_submit_wait,
10104 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10105 atomic_read(&fs_info->async_delalloc_pages) == 0));
10106 }
10107 atomic_dec(&fs_info->async_submit_draining);
10108 out:
10109 if (!list_empty_careful(&splice)) {
10110 spin_lock(&fs_info->delalloc_root_lock);
10111 list_splice_tail(&splice, &fs_info->delalloc_roots);
10112 spin_unlock(&fs_info->delalloc_root_lock);
10113 }
10114 mutex_unlock(&fs_info->delalloc_root_mutex);
10115 return ret;
10116 }
10117
10118 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10119 const char *symname)
10120 {
10121 struct btrfs_trans_handle *trans;
10122 struct btrfs_root *root = BTRFS_I(dir)->root;
10123 struct btrfs_path *path;
10124 struct btrfs_key key;
10125 struct inode *inode = NULL;
10126 int err;
10127 int drop_inode = 0;
10128 u64 objectid;
10129 u64 index = 0;
10130 int name_len;
10131 int datasize;
10132 unsigned long ptr;
10133 struct btrfs_file_extent_item *ei;
10134 struct extent_buffer *leaf;
10135
10136 name_len = strlen(symname);
10137 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10138 return -ENAMETOOLONG;
10139
10140 /*
10141 * 2 items for inode item and ref
10142 * 2 items for dir items
10143 * 1 item for updating parent inode item
10144 * 1 item for the inline extent item
10145 * 1 item for xattr if selinux is on
10146 */
10147 trans = btrfs_start_transaction(root, 7);
10148 if (IS_ERR(trans))
10149 return PTR_ERR(trans);
10150
10151 err = btrfs_find_free_ino(root, &objectid);
10152 if (err)
10153 goto out_unlock;
10154
10155 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10156 dentry->d_name.len, btrfs_ino(dir), objectid,
10157 S_IFLNK|S_IRWXUGO, &index);
10158 if (IS_ERR(inode)) {
10159 err = PTR_ERR(inode);
10160 goto out_unlock;
10161 }
10162
10163 /*
10164 * If the active LSM wants to access the inode during
10165 * d_instantiate it needs these. Smack checks to see
10166 * if the filesystem supports xattrs by looking at the
10167 * ops vector.
10168 */
10169 inode->i_fop = &btrfs_file_operations;
10170 inode->i_op = &btrfs_file_inode_operations;
10171 inode->i_mapping->a_ops = &btrfs_aops;
10172 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10173
10174 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10175 if (err)
10176 goto out_unlock_inode;
10177
10178 path = btrfs_alloc_path();
10179 if (!path) {
10180 err = -ENOMEM;
10181 goto out_unlock_inode;
10182 }
10183 key.objectid = btrfs_ino(inode);
10184 key.offset = 0;
10185 key.type = BTRFS_EXTENT_DATA_KEY;
10186 datasize = btrfs_file_extent_calc_inline_size(name_len);
10187 err = btrfs_insert_empty_item(trans, root, path, &key,
10188 datasize);
10189 if (err) {
10190 btrfs_free_path(path);
10191 goto out_unlock_inode;
10192 }
10193 leaf = path->nodes[0];
10194 ei = btrfs_item_ptr(leaf, path->slots[0],
10195 struct btrfs_file_extent_item);
10196 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10197 btrfs_set_file_extent_type(leaf, ei,
10198 BTRFS_FILE_EXTENT_INLINE);
10199 btrfs_set_file_extent_encryption(leaf, ei, 0);
10200 btrfs_set_file_extent_compression(leaf, ei, 0);
10201 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10202 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10203
10204 ptr = btrfs_file_extent_inline_start(ei);
10205 write_extent_buffer(leaf, symname, ptr, name_len);
10206 btrfs_mark_buffer_dirty(leaf);
10207 btrfs_free_path(path);
10208
10209 inode->i_op = &btrfs_symlink_inode_operations;
10210 inode_nohighmem(inode);
10211 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10212 inode_set_bytes(inode, name_len);
10213 btrfs_i_size_write(inode, name_len);
10214 err = btrfs_update_inode(trans, root, inode);
10215 /*
10216 * Last step, add directory indexes for our symlink inode. This is the
10217 * last step to avoid extra cleanup of these indexes if an error happens
10218 * elsewhere above.
10219 */
10220 if (!err)
10221 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10222 if (err) {
10223 drop_inode = 1;
10224 goto out_unlock_inode;
10225 }
10226
10227 unlock_new_inode(inode);
10228 d_instantiate(dentry, inode);
10229
10230 out_unlock:
10231 btrfs_end_transaction(trans, root);
10232 if (drop_inode) {
10233 inode_dec_link_count(inode);
10234 iput(inode);
10235 }
10236 btrfs_btree_balance_dirty(root);
10237 return err;
10238
10239 out_unlock_inode:
10240 drop_inode = 1;
10241 unlock_new_inode(inode);
10242 goto out_unlock;
10243 }
10244
10245 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10246 u64 start, u64 num_bytes, u64 min_size,
10247 loff_t actual_len, u64 *alloc_hint,
10248 struct btrfs_trans_handle *trans)
10249 {
10250 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10251 struct extent_map *em;
10252 struct btrfs_root *root = BTRFS_I(inode)->root;
10253 struct btrfs_key ins;
10254 u64 cur_offset = start;
10255 u64 i_size;
10256 u64 cur_bytes;
10257 u64 last_alloc = (u64)-1;
10258 int ret = 0;
10259 bool own_trans = true;
10260
10261 if (trans)
10262 own_trans = false;
10263 while (num_bytes > 0) {
10264 if (own_trans) {
10265 trans = btrfs_start_transaction(root, 3);
10266 if (IS_ERR(trans)) {
10267 ret = PTR_ERR(trans);
10268 break;
10269 }
10270 }
10271
10272 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10273 cur_bytes = max(cur_bytes, min_size);
10274 /*
10275 * If we are severely fragmented we could end up with really
10276 * small allocations, so if the allocator is returning small
10277 * chunks lets make its job easier by only searching for those
10278 * sized chunks.
10279 */
10280 cur_bytes = min(cur_bytes, last_alloc);
10281 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
10282 *alloc_hint, &ins, 1, 0);
10283 if (ret) {
10284 if (own_trans)
10285 btrfs_end_transaction(trans, root);
10286 break;
10287 }
10288 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10289
10290 last_alloc = ins.offset;
10291 ret = insert_reserved_file_extent(trans, inode,
10292 cur_offset, ins.objectid,
10293 ins.offset, ins.offset,
10294 ins.offset, 0, 0, 0,
10295 BTRFS_FILE_EXTENT_PREALLOC);
10296 if (ret) {
10297 btrfs_free_reserved_extent(root, ins.objectid,
10298 ins.offset, 0);
10299 btrfs_abort_transaction(trans, root, ret);
10300 if (own_trans)
10301 btrfs_end_transaction(trans, root);
10302 break;
10303 }
10304
10305 btrfs_drop_extent_cache(inode, cur_offset,
10306 cur_offset + ins.offset -1, 0);
10307
10308 em = alloc_extent_map();
10309 if (!em) {
10310 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10311 &BTRFS_I(inode)->runtime_flags);
10312 goto next;
10313 }
10314
10315 em->start = cur_offset;
10316 em->orig_start = cur_offset;
10317 em->len = ins.offset;
10318 em->block_start = ins.objectid;
10319 em->block_len = ins.offset;
10320 em->orig_block_len = ins.offset;
10321 em->ram_bytes = ins.offset;
10322 em->bdev = root->fs_info->fs_devices->latest_bdev;
10323 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10324 em->generation = trans->transid;
10325
10326 while (1) {
10327 write_lock(&em_tree->lock);
10328 ret = add_extent_mapping(em_tree, em, 1);
10329 write_unlock(&em_tree->lock);
10330 if (ret != -EEXIST)
10331 break;
10332 btrfs_drop_extent_cache(inode, cur_offset,
10333 cur_offset + ins.offset - 1,
10334 0);
10335 }
10336 free_extent_map(em);
10337 next:
10338 num_bytes -= ins.offset;
10339 cur_offset += ins.offset;
10340 *alloc_hint = ins.objectid + ins.offset;
10341
10342 inode_inc_iversion(inode);
10343 inode->i_ctime = current_fs_time(inode->i_sb);
10344 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10345 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10346 (actual_len > inode->i_size) &&
10347 (cur_offset > inode->i_size)) {
10348 if (cur_offset > actual_len)
10349 i_size = actual_len;
10350 else
10351 i_size = cur_offset;
10352 i_size_write(inode, i_size);
10353 btrfs_ordered_update_i_size(inode, i_size, NULL);
10354 }
10355
10356 ret = btrfs_update_inode(trans, root, inode);
10357
10358 if (ret) {
10359 btrfs_abort_transaction(trans, root, ret);
10360 if (own_trans)
10361 btrfs_end_transaction(trans, root);
10362 break;
10363 }
10364
10365 if (own_trans)
10366 btrfs_end_transaction(trans, root);
10367 }
10368 return ret;
10369 }
10370
10371 int btrfs_prealloc_file_range(struct inode *inode, 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,
10377 NULL);
10378 }
10379
10380 int btrfs_prealloc_file_range_trans(struct inode *inode,
10381 struct btrfs_trans_handle *trans, int mode,
10382 u64 start, u64 num_bytes, u64 min_size,
10383 loff_t actual_len, u64 *alloc_hint)
10384 {
10385 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10386 min_size, actual_len, alloc_hint, trans);
10387 }
10388
10389 static int btrfs_set_page_dirty(struct page *page)
10390 {
10391 return __set_page_dirty_nobuffers(page);
10392 }
10393
10394 static int btrfs_permission(struct inode *inode, int mask)
10395 {
10396 struct btrfs_root *root = BTRFS_I(inode)->root;
10397 umode_t mode = inode->i_mode;
10398
10399 if (mask & MAY_WRITE &&
10400 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10401 if (btrfs_root_readonly(root))
10402 return -EROFS;
10403 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10404 return -EACCES;
10405 }
10406 return generic_permission(inode, mask);
10407 }
10408
10409 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10410 {
10411 struct btrfs_trans_handle *trans;
10412 struct btrfs_root *root = BTRFS_I(dir)->root;
10413 struct inode *inode = NULL;
10414 u64 objectid;
10415 u64 index;
10416 int ret = 0;
10417
10418 /*
10419 * 5 units required for adding orphan entry
10420 */
10421 trans = btrfs_start_transaction(root, 5);
10422 if (IS_ERR(trans))
10423 return PTR_ERR(trans);
10424
10425 ret = btrfs_find_free_ino(root, &objectid);
10426 if (ret)
10427 goto out;
10428
10429 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10430 btrfs_ino(dir), objectid, mode, &index);
10431 if (IS_ERR(inode)) {
10432 ret = PTR_ERR(inode);
10433 inode = NULL;
10434 goto out;
10435 }
10436
10437 inode->i_fop = &btrfs_file_operations;
10438 inode->i_op = &btrfs_file_inode_operations;
10439
10440 inode->i_mapping->a_ops = &btrfs_aops;
10441 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10442
10443 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10444 if (ret)
10445 goto out_inode;
10446
10447 ret = btrfs_update_inode(trans, root, inode);
10448 if (ret)
10449 goto out_inode;
10450 ret = btrfs_orphan_add(trans, inode);
10451 if (ret)
10452 goto out_inode;
10453
10454 /*
10455 * We set number of links to 0 in btrfs_new_inode(), and here we set
10456 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10457 * through:
10458 *
10459 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10460 */
10461 set_nlink(inode, 1);
10462 unlock_new_inode(inode);
10463 d_tmpfile(dentry, inode);
10464 mark_inode_dirty(inode);
10465
10466 out:
10467 btrfs_end_transaction(trans, root);
10468 if (ret)
10469 iput(inode);
10470 btrfs_balance_delayed_items(root);
10471 btrfs_btree_balance_dirty(root);
10472 return ret;
10473
10474 out_inode:
10475 unlock_new_inode(inode);
10476 goto out;
10477
10478 }
10479
10480 /* Inspired by filemap_check_errors() */
10481 int btrfs_inode_check_errors(struct inode *inode)
10482 {
10483 int ret = 0;
10484
10485 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10486 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10487 ret = -ENOSPC;
10488 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10489 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10490 ret = -EIO;
10491
10492 return ret;
10493 }
10494
10495 static const struct inode_operations btrfs_dir_inode_operations = {
10496 .getattr = btrfs_getattr,
10497 .lookup = btrfs_lookup,
10498 .create = btrfs_create,
10499 .unlink = btrfs_unlink,
10500 .link = btrfs_link,
10501 .mkdir = btrfs_mkdir,
10502 .rmdir = btrfs_rmdir,
10503 .rename2 = btrfs_rename2,
10504 .symlink = btrfs_symlink,
10505 .setattr = btrfs_setattr,
10506 .mknod = btrfs_mknod,
10507 .setxattr = generic_setxattr,
10508 .getxattr = generic_getxattr,
10509 .listxattr = btrfs_listxattr,
10510 .removexattr = generic_removexattr,
10511 .permission = btrfs_permission,
10512 .get_acl = btrfs_get_acl,
10513 .set_acl = btrfs_set_acl,
10514 .update_time = btrfs_update_time,
10515 .tmpfile = btrfs_tmpfile,
10516 };
10517 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10518 .lookup = btrfs_lookup,
10519 .permission = btrfs_permission,
10520 .get_acl = btrfs_get_acl,
10521 .set_acl = btrfs_set_acl,
10522 .update_time = btrfs_update_time,
10523 };
10524
10525 static const struct file_operations btrfs_dir_file_operations = {
10526 .llseek = generic_file_llseek,
10527 .read = generic_read_dir,
10528 .iterate = btrfs_real_readdir,
10529 .unlocked_ioctl = btrfs_ioctl,
10530 #ifdef CONFIG_COMPAT
10531 .compat_ioctl = btrfs_compat_ioctl,
10532 #endif
10533 .release = btrfs_release_file,
10534 .fsync = btrfs_sync_file,
10535 };
10536
10537 static const struct extent_io_ops btrfs_extent_io_ops = {
10538 .fill_delalloc = run_delalloc_range,
10539 .submit_bio_hook = btrfs_submit_bio_hook,
10540 .merge_bio_hook = btrfs_merge_bio_hook,
10541 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10542 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10543 .writepage_start_hook = btrfs_writepage_start_hook,
10544 .set_bit_hook = btrfs_set_bit_hook,
10545 .clear_bit_hook = btrfs_clear_bit_hook,
10546 .merge_extent_hook = btrfs_merge_extent_hook,
10547 .split_extent_hook = btrfs_split_extent_hook,
10548 };
10549
10550 /*
10551 * btrfs doesn't support the bmap operation because swapfiles
10552 * use bmap to make a mapping of extents in the file. They assume
10553 * these extents won't change over the life of the file and they
10554 * use the bmap result to do IO directly to the drive.
10555 *
10556 * the btrfs bmap call would return logical addresses that aren't
10557 * suitable for IO and they also will change frequently as COW
10558 * operations happen. So, swapfile + btrfs == corruption.
10559 *
10560 * For now we're avoiding this by dropping bmap.
10561 */
10562 static const struct address_space_operations btrfs_aops = {
10563 .readpage = btrfs_readpage,
10564 .writepage = btrfs_writepage,
10565 .writepages = btrfs_writepages,
10566 .readpages = btrfs_readpages,
10567 .direct_IO = btrfs_direct_IO,
10568 .invalidatepage = btrfs_invalidatepage,
10569 .releasepage = btrfs_releasepage,
10570 .set_page_dirty = btrfs_set_page_dirty,
10571 .error_remove_page = generic_error_remove_page,
10572 };
10573
10574 static const struct address_space_operations btrfs_symlink_aops = {
10575 .readpage = btrfs_readpage,
10576 .writepage = btrfs_writepage,
10577 .invalidatepage = btrfs_invalidatepage,
10578 .releasepage = btrfs_releasepage,
10579 };
10580
10581 static const struct inode_operations btrfs_file_inode_operations = {
10582 .getattr = btrfs_getattr,
10583 .setattr = btrfs_setattr,
10584 .setxattr = generic_setxattr,
10585 .getxattr = generic_getxattr,
10586 .listxattr = btrfs_listxattr,
10587 .removexattr = generic_removexattr,
10588 .permission = btrfs_permission,
10589 .fiemap = btrfs_fiemap,
10590 .get_acl = btrfs_get_acl,
10591 .set_acl = btrfs_set_acl,
10592 .update_time = btrfs_update_time,
10593 };
10594 static const struct inode_operations btrfs_special_inode_operations = {
10595 .getattr = btrfs_getattr,
10596 .setattr = btrfs_setattr,
10597 .permission = btrfs_permission,
10598 .setxattr = generic_setxattr,
10599 .getxattr = generic_getxattr,
10600 .listxattr = btrfs_listxattr,
10601 .removexattr = generic_removexattr,
10602 .get_acl = btrfs_get_acl,
10603 .set_acl = btrfs_set_acl,
10604 .update_time = btrfs_update_time,
10605 };
10606 static const struct inode_operations btrfs_symlink_inode_operations = {
10607 .readlink = generic_readlink,
10608 .get_link = page_get_link,
10609 .getattr = btrfs_getattr,
10610 .setattr = btrfs_setattr,
10611 .permission = btrfs_permission,
10612 .setxattr = generic_setxattr,
10613 .getxattr = generic_getxattr,
10614 .listxattr = btrfs_listxattr,
10615 .removexattr = generic_removexattr,
10616 .update_time = btrfs_update_time,
10617 };
10618
10619 const struct dentry_operations btrfs_dentry_operations = {
10620 .d_delete = btrfs_dentry_delete,
10621 .d_release = btrfs_dentry_release,
10622 };
Linux kernel - Deliverables
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