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1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63 #include "dedupe.h"
64
65 struct btrfs_iget_args {
66 struct btrfs_key *location;
67 struct btrfs_root *root;
68 };
69
70 struct btrfs_dio_data {
71 u64 outstanding_extents;
72 u64 reserve;
73 u64 unsubmitted_oe_range_start;
74 u64 unsubmitted_oe_range_end;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_transaction_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
113 u64 len, u64 orig_start,
114 u64 block_start, u64 block_len,
115 u64 orig_block_len, u64 ram_bytes,
116 int type);
117
118 static int btrfs_dirty_inode(struct inode *inode);
119
120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
121 void btrfs_test_inode_set_ops(struct inode *inode)
122 {
123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
124 }
125 #endif
126
127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
128 struct inode *inode, struct inode *dir,
129 const struct qstr *qstr)
130 {
131 int err;
132
133 err = btrfs_init_acl(trans, inode, dir);
134 if (!err)
135 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
136 return err;
137 }
138
139 /*
140 * this does all the hard work for inserting an inline extent into
141 * the btree. The caller should have done a btrfs_drop_extents so that
142 * no overlapping inline items exist in the btree
143 */
144 static int insert_inline_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_path *path, int extent_inserted,
146 struct btrfs_root *root, struct inode *inode,
147 u64 start, size_t size, size_t compressed_size,
148 int compress_type,
149 struct page **compressed_pages)
150 {
151 struct extent_buffer *leaf;
152 struct page *page = NULL;
153 char *kaddr;
154 unsigned long ptr;
155 struct btrfs_file_extent_item *ei;
156 int err = 0;
157 int ret;
158 size_t cur_size = size;
159 unsigned long offset;
160
161 if (compressed_size && compressed_pages)
162 cur_size = compressed_size;
163
164 inode_add_bytes(inode, size);
165
166 if (!extent_inserted) {
167 struct btrfs_key key;
168 size_t datasize;
169
170 key.objectid = btrfs_ino(inode);
171 key.offset = start;
172 key.type = BTRFS_EXTENT_DATA_KEY;
173
174 datasize = btrfs_file_extent_calc_inline_size(cur_size);
175 path->leave_spinning = 1;
176 ret = btrfs_insert_empty_item(trans, root, path, &key,
177 datasize);
178 if (ret) {
179 err = ret;
180 goto fail;
181 }
182 }
183 leaf = path->nodes[0];
184 ei = btrfs_item_ptr(leaf, path->slots[0],
185 struct btrfs_file_extent_item);
186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
188 btrfs_set_file_extent_encryption(leaf, ei, 0);
189 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
190 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
191 ptr = btrfs_file_extent_inline_start(ei);
192
193 if (compress_type != BTRFS_COMPRESS_NONE) {
194 struct page *cpage;
195 int i = 0;
196 while (compressed_size > 0) {
197 cpage = compressed_pages[i];
198 cur_size = min_t(unsigned long, compressed_size,
199 PAGE_SIZE);
200
201 kaddr = kmap_atomic(cpage);
202 write_extent_buffer(leaf, kaddr, ptr, cur_size);
203 kunmap_atomic(kaddr);
204
205 i++;
206 ptr += cur_size;
207 compressed_size -= cur_size;
208 }
209 btrfs_set_file_extent_compression(leaf, ei,
210 compress_type);
211 } else {
212 page = find_get_page(inode->i_mapping,
213 start >> PAGE_SHIFT);
214 btrfs_set_file_extent_compression(leaf, ei, 0);
215 kaddr = kmap_atomic(page);
216 offset = start & (PAGE_SIZE - 1);
217 write_extent_buffer(leaf, kaddr + offset, ptr, size);
218 kunmap_atomic(kaddr);
219 put_page(page);
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 btrfs_release_path(path);
223
224 /*
225 * we're an inline extent, so nobody can
226 * extend the file past i_size without locking
227 * a page we already have locked.
228 *
229 * We must do any isize and inode updates
230 * before we unlock the pages. Otherwise we
231 * could end up racing with unlink.
232 */
233 BTRFS_I(inode)->disk_i_size = inode->i_size;
234 ret = btrfs_update_inode(trans, root, inode);
235
236 return ret;
237 fail:
238 return err;
239 }
240
241
242 /*
243 * conditionally insert an inline extent into the file. This
244 * does the checks required to make sure the data is small enough
245 * to fit as an inline extent.
246 */
247 static noinline int cow_file_range_inline(struct btrfs_root *root,
248 struct inode *inode, u64 start,
249 u64 end, size_t compressed_size,
250 int compress_type,
251 struct page **compressed_pages)
252 {
253 struct btrfs_trans_handle *trans;
254 u64 isize = i_size_read(inode);
255 u64 actual_end = min(end + 1, isize);
256 u64 inline_len = actual_end - start;
257 u64 aligned_end = ALIGN(end, root->sectorsize);
258 u64 data_len = inline_len;
259 int ret;
260 struct btrfs_path *path;
261 int extent_inserted = 0;
262 u32 extent_item_size;
263
264 if (compressed_size)
265 data_len = compressed_size;
266
267 if (start > 0 ||
268 actual_end > root->sectorsize ||
269 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
270 (!compressed_size &&
271 (actual_end & (root->sectorsize - 1)) == 0) ||
272 end + 1 < isize ||
273 data_len > root->fs_info->max_inline) {
274 return 1;
275 }
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 trans = btrfs_join_transaction(root);
282 if (IS_ERR(trans)) {
283 btrfs_free_path(path);
284 return PTR_ERR(trans);
285 }
286 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
287
288 if (compressed_size && compressed_pages)
289 extent_item_size = btrfs_file_extent_calc_inline_size(
290 compressed_size);
291 else
292 extent_item_size = btrfs_file_extent_calc_inline_size(
293 inline_len);
294
295 ret = __btrfs_drop_extents(trans, root, inode, path,
296 start, aligned_end, NULL,
297 1, 1, extent_item_size, &extent_inserted);
298 if (ret) {
299 btrfs_abort_transaction(trans, ret);
300 goto out;
301 }
302
303 if (isize > actual_end)
304 inline_len = min_t(u64, isize, actual_end);
305 ret = insert_inline_extent(trans, path, extent_inserted,
306 root, inode, start,
307 inline_len, compressed_size,
308 compress_type, compressed_pages);
309 if (ret && ret != -ENOSPC) {
310 btrfs_abort_transaction(trans, ret);
311 goto out;
312 } else if (ret == -ENOSPC) {
313 ret = 1;
314 goto out;
315 }
316
317 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
318 btrfs_delalloc_release_metadata(inode, end + 1 - start);
319 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
320 out:
321 /*
322 * Don't forget to free the reserved space, as for inlined extent
323 * it won't count as data extent, free them directly here.
324 * And at reserve time, it's always aligned to page size, so
325 * just free one page here.
326 */
327 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
328 btrfs_free_path(path);
329 btrfs_end_transaction(trans, root);
330 return ret;
331 }
332
333 struct async_extent {
334 u64 start;
335 u64 ram_size;
336 u64 compressed_size;
337 struct page **pages;
338 unsigned long nr_pages;
339 int compress_type;
340 struct list_head list;
341 };
342
343 struct async_cow {
344 struct inode *inode;
345 struct btrfs_root *root;
346 struct page *locked_page;
347 u64 start;
348 u64 end;
349 struct list_head extents;
350 struct btrfs_work work;
351 };
352
353 static noinline int add_async_extent(struct async_cow *cow,
354 u64 start, u64 ram_size,
355 u64 compressed_size,
356 struct page **pages,
357 unsigned long nr_pages,
358 int compress_type)
359 {
360 struct async_extent *async_extent;
361
362 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
363 BUG_ON(!async_extent); /* -ENOMEM */
364 async_extent->start = start;
365 async_extent->ram_size = ram_size;
366 async_extent->compressed_size = compressed_size;
367 async_extent->pages = pages;
368 async_extent->nr_pages = nr_pages;
369 async_extent->compress_type = compress_type;
370 list_add_tail(&async_extent->list, &cow->extents);
371 return 0;
372 }
373
374 static inline int inode_need_compress(struct inode *inode)
375 {
376 struct btrfs_root *root = BTRFS_I(inode)->root;
377
378 /* force compress */
379 if (btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
380 return 1;
381 /* bad compression ratios */
382 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
383 return 0;
384 if (btrfs_test_opt(root->fs_info, COMPRESS) ||
385 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
386 BTRFS_I(inode)->force_compress)
387 return 1;
388 return 0;
389 }
390
391 /*
392 * we create compressed extents in two phases. The first
393 * phase compresses a range of pages that have already been
394 * locked (both pages and state bits are locked).
395 *
396 * This is done inside an ordered work queue, and the compression
397 * is spread across many cpus. The actual IO submission is step
398 * two, and the ordered work queue takes care of making sure that
399 * happens in the same order things were put onto the queue by
400 * writepages and friends.
401 *
402 * If this code finds it can't get good compression, it puts an
403 * entry onto the work queue to write the uncompressed bytes. This
404 * makes sure that both compressed inodes and uncompressed inodes
405 * are written in the same order that the flusher thread sent them
406 * down.
407 */
408 static noinline void compress_file_range(struct inode *inode,
409 struct page *locked_page,
410 u64 start, u64 end,
411 struct async_cow *async_cow,
412 int *num_added)
413 {
414 struct btrfs_root *root = BTRFS_I(inode)->root;
415 u64 num_bytes;
416 u64 blocksize = root->sectorsize;
417 u64 actual_end;
418 u64 isize = i_size_read(inode);
419 int ret = 0;
420 struct page **pages = NULL;
421 unsigned long nr_pages;
422 unsigned long nr_pages_ret = 0;
423 unsigned long total_compressed = 0;
424 unsigned long total_in = 0;
425 unsigned long max_compressed = SZ_128K;
426 unsigned long max_uncompressed = SZ_128K;
427 int i;
428 int will_compress;
429 int compress_type = root->fs_info->compress_type;
430 int redirty = 0;
431
432 /* if this is a small write inside eof, kick off a defrag */
433 if ((end - start + 1) < SZ_16K &&
434 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
435 btrfs_add_inode_defrag(NULL, inode);
436
437 actual_end = min_t(u64, isize, end + 1);
438 again:
439 will_compress = 0;
440 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
441 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
442
443 /*
444 * we don't want to send crud past the end of i_size through
445 * compression, that's just a waste of CPU time. So, if the
446 * end of the file is before the start of our current
447 * requested range of bytes, we bail out to the uncompressed
448 * cleanup code that can deal with all of this.
449 *
450 * It isn't really the fastest way to fix things, but this is a
451 * very uncommon corner.
452 */
453 if (actual_end <= start)
454 goto cleanup_and_bail_uncompressed;
455
456 total_compressed = actual_end - start;
457
458 /*
459 * skip compression for a small file range(<=blocksize) that
460 * isn't an inline extent, since it doesn't save disk space at all.
461 */
462 if (total_compressed <= blocksize &&
463 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
464 goto cleanup_and_bail_uncompressed;
465
466 /* we want to make sure that amount of ram required to uncompress
467 * an extent is reasonable, so we limit the total size in ram
468 * of a compressed extent to 128k. This is a crucial number
469 * because it also controls how easily we can spread reads across
470 * cpus for decompression.
471 *
472 * We also want to make sure the amount of IO required to do
473 * a random read is reasonably small, so we limit the size of
474 * a compressed extent to 128k.
475 */
476 total_compressed = min(total_compressed, max_uncompressed);
477 num_bytes = ALIGN(end - start + 1, blocksize);
478 num_bytes = max(blocksize, num_bytes);
479 total_in = 0;
480 ret = 0;
481
482 /*
483 * we do compression for mount -o compress and when the
484 * inode has not been flagged as nocompress. This flag can
485 * change at any time if we discover bad compression ratios.
486 */
487 if (inode_need_compress(inode)) {
488 WARN_ON(pages);
489 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
490 if (!pages) {
491 /* just bail out to the uncompressed code */
492 goto cont;
493 }
494
495 if (BTRFS_I(inode)->force_compress)
496 compress_type = BTRFS_I(inode)->force_compress;
497
498 /*
499 * we need to call clear_page_dirty_for_io on each
500 * page in the range. Otherwise applications with the file
501 * mmap'd can wander in and change the page contents while
502 * we are compressing them.
503 *
504 * If the compression fails for any reason, we set the pages
505 * dirty again later on.
506 */
507 extent_range_clear_dirty_for_io(inode, start, end);
508 redirty = 1;
509 ret = btrfs_compress_pages(compress_type,
510 inode->i_mapping, start,
511 total_compressed, pages,
512 nr_pages, &nr_pages_ret,
513 &total_in,
514 &total_compressed,
515 max_compressed);
516
517 if (!ret) {
518 unsigned long offset = total_compressed &
519 (PAGE_SIZE - 1);
520 struct page *page = pages[nr_pages_ret - 1];
521 char *kaddr;
522
523 /* zero the tail end of the last page, we might be
524 * sending it down to disk
525 */
526 if (offset) {
527 kaddr = kmap_atomic(page);
528 memset(kaddr + offset, 0,
529 PAGE_SIZE - offset);
530 kunmap_atomic(kaddr);
531 }
532 will_compress = 1;
533 }
534 }
535 cont:
536 if (start == 0) {
537 /* lets try to make an inline extent */
538 if (ret || total_in < (actual_end - start)) {
539 /* we didn't compress the entire range, try
540 * to make an uncompressed inline extent.
541 */
542 ret = cow_file_range_inline(root, inode, start, end,
543 0, 0, NULL);
544 } else {
545 /* try making a compressed inline extent */
546 ret = cow_file_range_inline(root, inode, start, end,
547 total_compressed,
548 compress_type, pages);
549 }
550 if (ret <= 0) {
551 unsigned long clear_flags = EXTENT_DELALLOC |
552 EXTENT_DEFRAG;
553 unsigned long page_error_op;
554
555 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
556 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
557
558 /*
559 * inline extent creation worked or returned error,
560 * we don't need to create any more async work items.
561 * Unlock and free up our temp pages.
562 */
563 extent_clear_unlock_delalloc(inode, start, end, NULL,
564 clear_flags, PAGE_UNLOCK |
565 PAGE_CLEAR_DIRTY |
566 PAGE_SET_WRITEBACK |
567 page_error_op |
568 PAGE_END_WRITEBACK);
569 btrfs_free_reserved_data_space_noquota(inode, start,
570 end - start + 1);
571 goto free_pages_out;
572 }
573 }
574
575 if (will_compress) {
576 /*
577 * we aren't doing an inline extent round the compressed size
578 * up to a block size boundary so the allocator does sane
579 * things
580 */
581 total_compressed = ALIGN(total_compressed, blocksize);
582
583 /*
584 * one last check to make sure the compression is really a
585 * win, compare the page count read with the blocks on disk
586 */
587 total_in = ALIGN(total_in, PAGE_SIZE);
588 if (total_compressed >= total_in) {
589 will_compress = 0;
590 } else {
591 num_bytes = total_in;
592 *num_added += 1;
593
594 /*
595 * The async work queues will take care of doing actual
596 * allocation on disk for these compressed pages, and
597 * will submit them to the elevator.
598 */
599 add_async_extent(async_cow, start, num_bytes,
600 total_compressed, pages, nr_pages_ret,
601 compress_type);
602
603 if (start + num_bytes < end) {
604 start += num_bytes;
605 pages = NULL;
606 cond_resched();
607 goto again;
608 }
609 return;
610 }
611 }
612 if (pages) {
613 /*
614 * the compression code ran but failed to make things smaller,
615 * free any pages it allocated and our page pointer array
616 */
617 for (i = 0; i < nr_pages_ret; i++) {
618 WARN_ON(pages[i]->mapping);
619 put_page(pages[i]);
620 }
621 kfree(pages);
622 pages = NULL;
623 total_compressed = 0;
624 nr_pages_ret = 0;
625
626 /* flag the file so we don't compress in the future */
627 if (!btrfs_test_opt(root->fs_info, FORCE_COMPRESS) &&
628 !(BTRFS_I(inode)->force_compress)) {
629 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
630 }
631 }
632 cleanup_and_bail_uncompressed:
633 /*
634 * No compression, but we still need to write the pages in the file
635 * we've been given so far. redirty the locked page if it corresponds
636 * to our extent and set things up for the async work queue to run
637 * cow_file_range to do the normal delalloc dance.
638 */
639 if (page_offset(locked_page) >= start &&
640 page_offset(locked_page) <= end)
641 __set_page_dirty_nobuffers(locked_page);
642 /* unlocked later on in the async handlers */
643
644 if (redirty)
645 extent_range_redirty_for_io(inode, start, end);
646 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
647 BTRFS_COMPRESS_NONE);
648 *num_added += 1;
649
650 return;
651
652 free_pages_out:
653 for (i = 0; i < nr_pages_ret; i++) {
654 WARN_ON(pages[i]->mapping);
655 put_page(pages[i]);
656 }
657 kfree(pages);
658 }
659
660 static void free_async_extent_pages(struct async_extent *async_extent)
661 {
662 int i;
663
664 if (!async_extent->pages)
665 return;
666
667 for (i = 0; i < async_extent->nr_pages; i++) {
668 WARN_ON(async_extent->pages[i]->mapping);
669 put_page(async_extent->pages[i]);
670 }
671 kfree(async_extent->pages);
672 async_extent->nr_pages = 0;
673 async_extent->pages = NULL;
674 }
675
676 /*
677 * phase two of compressed writeback. This is the ordered portion
678 * of the code, which only gets called in the order the work was
679 * queued. We walk all the async extents created by compress_file_range
680 * and send them down to the disk.
681 */
682 static noinline void submit_compressed_extents(struct inode *inode,
683 struct async_cow *async_cow)
684 {
685 struct async_extent *async_extent;
686 u64 alloc_hint = 0;
687 struct btrfs_key ins;
688 struct extent_map *em;
689 struct btrfs_root *root = BTRFS_I(inode)->root;
690 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
691 struct extent_io_tree *io_tree;
692 int ret = 0;
693
694 again:
695 while (!list_empty(&async_cow->extents)) {
696 async_extent = list_entry(async_cow->extents.next,
697 struct async_extent, list);
698 list_del(&async_extent->list);
699
700 io_tree = &BTRFS_I(inode)->io_tree;
701
702 retry:
703 /* did the compression code fall back to uncompressed IO? */
704 if (!async_extent->pages) {
705 int page_started = 0;
706 unsigned long nr_written = 0;
707
708 lock_extent(io_tree, async_extent->start,
709 async_extent->start +
710 async_extent->ram_size - 1);
711
712 /* allocate blocks */
713 ret = cow_file_range(inode, async_cow->locked_page,
714 async_extent->start,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 async_extent->start +
718 async_extent->ram_size - 1,
719 &page_started, &nr_written, 0,
720 NULL);
721
722 /* JDM XXX */
723
724 /*
725 * if page_started, cow_file_range inserted an
726 * inline extent and took care of all the unlocking
727 * and IO for us. Otherwise, we need to submit
728 * all those pages down to the drive.
729 */
730 if (!page_started && !ret)
731 extent_write_locked_range(io_tree,
732 inode, async_extent->start,
733 async_extent->start +
734 async_extent->ram_size - 1,
735 btrfs_get_extent,
736 WB_SYNC_ALL);
737 else if (ret)
738 unlock_page(async_cow->locked_page);
739 kfree(async_extent);
740 cond_resched();
741 continue;
742 }
743
744 lock_extent(io_tree, async_extent->start,
745 async_extent->start + async_extent->ram_size - 1);
746
747 ret = btrfs_reserve_extent(root, async_extent->ram_size,
748 async_extent->compressed_size,
749 async_extent->compressed_size,
750 0, alloc_hint, &ins, 1, 1);
751 if (ret) {
752 free_async_extent_pages(async_extent);
753
754 if (ret == -ENOSPC) {
755 unlock_extent(io_tree, async_extent->start,
756 async_extent->start +
757 async_extent->ram_size - 1);
758
759 /*
760 * we need to redirty the pages if we decide to
761 * fallback to uncompressed IO, otherwise we
762 * will not submit these pages down to lower
763 * layers.
764 */
765 extent_range_redirty_for_io(inode,
766 async_extent->start,
767 async_extent->start +
768 async_extent->ram_size - 1);
769
770 goto retry;
771 }
772 goto out_free;
773 }
774 /*
775 * here we're doing allocation and writeback of the
776 * compressed pages
777 */
778 btrfs_drop_extent_cache(inode, async_extent->start,
779 async_extent->start +
780 async_extent->ram_size - 1, 0);
781
782 em = alloc_extent_map();
783 if (!em) {
784 ret = -ENOMEM;
785 goto out_free_reserve;
786 }
787 em->start = async_extent->start;
788 em->len = async_extent->ram_size;
789 em->orig_start = em->start;
790 em->mod_start = em->start;
791 em->mod_len = em->len;
792
793 em->block_start = ins.objectid;
794 em->block_len = ins.offset;
795 em->orig_block_len = ins.offset;
796 em->ram_bytes = async_extent->ram_size;
797 em->bdev = root->fs_info->fs_devices->latest_bdev;
798 em->compress_type = async_extent->compress_type;
799 set_bit(EXTENT_FLAG_PINNED, &em->flags);
800 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
801 em->generation = -1;
802
803 while (1) {
804 write_lock(&em_tree->lock);
805 ret = add_extent_mapping(em_tree, em, 1);
806 write_unlock(&em_tree->lock);
807 if (ret != -EEXIST) {
808 free_extent_map(em);
809 break;
810 }
811 btrfs_drop_extent_cache(inode, async_extent->start,
812 async_extent->start +
813 async_extent->ram_size - 1, 0);
814 }
815
816 if (ret)
817 goto out_free_reserve;
818
819 ret = btrfs_add_ordered_extent_compress(inode,
820 async_extent->start,
821 ins.objectid,
822 async_extent->ram_size,
823 ins.offset,
824 BTRFS_ORDERED_COMPRESSED,
825 async_extent->compress_type);
826 if (ret) {
827 btrfs_drop_extent_cache(inode, async_extent->start,
828 async_extent->start +
829 async_extent->ram_size - 1, 0);
830 goto out_free_reserve;
831 }
832 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
833
834 /*
835 * clear dirty, set writeback and unlock the pages.
836 */
837 extent_clear_unlock_delalloc(inode, async_extent->start,
838 async_extent->start +
839 async_extent->ram_size - 1,
840 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
841 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
842 PAGE_SET_WRITEBACK);
843 ret = btrfs_submit_compressed_write(inode,
844 async_extent->start,
845 async_extent->ram_size,
846 ins.objectid,
847 ins.offset, async_extent->pages,
848 async_extent->nr_pages);
849 if (ret) {
850 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
851 struct page *p = async_extent->pages[0];
852 const u64 start = async_extent->start;
853 const u64 end = start + async_extent->ram_size - 1;
854
855 p->mapping = inode->i_mapping;
856 tree->ops->writepage_end_io_hook(p, start, end,
857 NULL, 0);
858 p->mapping = NULL;
859 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
860 PAGE_END_WRITEBACK |
861 PAGE_SET_ERROR);
862 free_async_extent_pages(async_extent);
863 }
864 alloc_hint = ins.objectid + ins.offset;
865 kfree(async_extent);
866 cond_resched();
867 }
868 return;
869 out_free_reserve:
870 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
871 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
872 out_free:
873 extent_clear_unlock_delalloc(inode, async_extent->start,
874 async_extent->start +
875 async_extent->ram_size - 1,
876 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
877 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
878 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
879 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
880 PAGE_SET_ERROR);
881 free_async_extent_pages(async_extent);
882 kfree(async_extent);
883 goto again;
884 }
885
886 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
887 u64 num_bytes)
888 {
889 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
890 struct extent_map *em;
891 u64 alloc_hint = 0;
892
893 read_lock(&em_tree->lock);
894 em = search_extent_mapping(em_tree, start, num_bytes);
895 if (em) {
896 /*
897 * if block start isn't an actual block number then find the
898 * first block in this inode and use that as a hint. If that
899 * block is also bogus then just don't worry about it.
900 */
901 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
902 free_extent_map(em);
903 em = search_extent_mapping(em_tree, 0, 0);
904 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
905 alloc_hint = em->block_start;
906 if (em)
907 free_extent_map(em);
908 } else {
909 alloc_hint = em->block_start;
910 free_extent_map(em);
911 }
912 }
913 read_unlock(&em_tree->lock);
914
915 return alloc_hint;
916 }
917
918 /*
919 * when extent_io.c finds a delayed allocation range in the file,
920 * the call backs end up in this code. The basic idea is to
921 * allocate extents on disk for the range, and create ordered data structs
922 * in ram to track those extents.
923 *
924 * locked_page is the page that writepage had locked already. We use
925 * it to make sure we don't do extra locks or unlocks.
926 *
927 * *page_started is set to one if we unlock locked_page and do everything
928 * required to start IO on it. It may be clean and already done with
929 * IO when we return.
930 */
931 static noinline int cow_file_range(struct inode *inode,
932 struct page *locked_page,
933 u64 start, u64 end, u64 delalloc_end,
934 int *page_started, unsigned long *nr_written,
935 int unlock, struct btrfs_dedupe_hash *hash)
936 {
937 struct btrfs_root *root = BTRFS_I(inode)->root;
938 u64 alloc_hint = 0;
939 u64 num_bytes;
940 unsigned long ram_size;
941 u64 disk_num_bytes;
942 u64 cur_alloc_size;
943 u64 blocksize = root->sectorsize;
944 struct btrfs_key ins;
945 struct extent_map *em;
946 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
947 int ret = 0;
948
949 if (btrfs_is_free_space_inode(inode)) {
950 WARN_ON_ONCE(1);
951 ret = -EINVAL;
952 goto out_unlock;
953 }
954
955 num_bytes = ALIGN(end - start + 1, blocksize);
956 num_bytes = max(blocksize, num_bytes);
957 disk_num_bytes = num_bytes;
958
959 /* if this is a small write inside eof, kick off defrag */
960 if (num_bytes < SZ_64K &&
961 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
962 btrfs_add_inode_defrag(NULL, inode);
963
964 if (start == 0) {
965 /* lets try to make an inline extent */
966 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
967 NULL);
968 if (ret == 0) {
969 extent_clear_unlock_delalloc(inode, start, end, NULL,
970 EXTENT_LOCKED | EXTENT_DELALLOC |
971 EXTENT_DEFRAG, PAGE_UNLOCK |
972 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
973 PAGE_END_WRITEBACK);
974 btrfs_free_reserved_data_space_noquota(inode, start,
975 end - start + 1);
976 *nr_written = *nr_written +
977 (end - start + PAGE_SIZE) / PAGE_SIZE;
978 *page_started = 1;
979 goto out;
980 } else if (ret < 0) {
981 goto out_unlock;
982 }
983 }
984
985 BUG_ON(disk_num_bytes >
986 btrfs_super_total_bytes(root->fs_info->super_copy));
987
988 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
989 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
990
991 while (disk_num_bytes > 0) {
992 unsigned long op;
993
994 cur_alloc_size = disk_num_bytes;
995 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
996 root->sectorsize, 0, alloc_hint,
997 &ins, 1, 1);
998 if (ret < 0)
999 goto out_unlock;
1000
1001 em = alloc_extent_map();
1002 if (!em) {
1003 ret = -ENOMEM;
1004 goto out_reserve;
1005 }
1006 em->start = start;
1007 em->orig_start = em->start;
1008 ram_size = ins.offset;
1009 em->len = ins.offset;
1010 em->mod_start = em->start;
1011 em->mod_len = em->len;
1012
1013 em->block_start = ins.objectid;
1014 em->block_len = ins.offset;
1015 em->orig_block_len = ins.offset;
1016 em->ram_bytes = ram_size;
1017 em->bdev = root->fs_info->fs_devices->latest_bdev;
1018 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1019 em->generation = -1;
1020
1021 while (1) {
1022 write_lock(&em_tree->lock);
1023 ret = add_extent_mapping(em_tree, em, 1);
1024 write_unlock(&em_tree->lock);
1025 if (ret != -EEXIST) {
1026 free_extent_map(em);
1027 break;
1028 }
1029 btrfs_drop_extent_cache(inode, start,
1030 start + ram_size - 1, 0);
1031 }
1032 if (ret)
1033 goto out_reserve;
1034
1035 cur_alloc_size = ins.offset;
1036 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1037 ram_size, cur_alloc_size, 0);
1038 if (ret)
1039 goto out_drop_extent_cache;
1040
1041 if (root->root_key.objectid ==
1042 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1043 ret = btrfs_reloc_clone_csums(inode, start,
1044 cur_alloc_size);
1045 if (ret)
1046 goto out_drop_extent_cache;
1047 }
1048
1049 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1050
1051 if (disk_num_bytes < cur_alloc_size)
1052 break;
1053
1054 /* we're not doing compressed IO, don't unlock the first
1055 * page (which the caller expects to stay locked), don't
1056 * clear any dirty bits and don't set any writeback bits
1057 *
1058 * Do set the Private2 bit so we know this page was properly
1059 * setup for writepage
1060 */
1061 op = unlock ? PAGE_UNLOCK : 0;
1062 op |= PAGE_SET_PRIVATE2;
1063
1064 extent_clear_unlock_delalloc(inode, start,
1065 start + ram_size - 1, locked_page,
1066 EXTENT_LOCKED | EXTENT_DELALLOC,
1067 op);
1068 disk_num_bytes -= cur_alloc_size;
1069 num_bytes -= cur_alloc_size;
1070 alloc_hint = ins.objectid + ins.offset;
1071 start += cur_alloc_size;
1072 }
1073 out:
1074 return ret;
1075
1076 out_drop_extent_cache:
1077 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1078 out_reserve:
1079 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1080 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1081 out_unlock:
1082 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1083 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1084 EXTENT_DELALLOC | EXTENT_DEFRAG,
1085 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1086 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1087 goto out;
1088 }
1089
1090 /*
1091 * work queue call back to started compression on a file and pages
1092 */
1093 static noinline void async_cow_start(struct btrfs_work *work)
1094 {
1095 struct async_cow *async_cow;
1096 int num_added = 0;
1097 async_cow = container_of(work, struct async_cow, work);
1098
1099 compress_file_range(async_cow->inode, async_cow->locked_page,
1100 async_cow->start, async_cow->end, async_cow,
1101 &num_added);
1102 if (num_added == 0) {
1103 btrfs_add_delayed_iput(async_cow->inode);
1104 async_cow->inode = NULL;
1105 }
1106 }
1107
1108 /*
1109 * work queue call back to submit previously compressed pages
1110 */
1111 static noinline void async_cow_submit(struct btrfs_work *work)
1112 {
1113 struct async_cow *async_cow;
1114 struct btrfs_root *root;
1115 unsigned long nr_pages;
1116
1117 async_cow = container_of(work, struct async_cow, work);
1118
1119 root = async_cow->root;
1120 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1121 PAGE_SHIFT;
1122
1123 /*
1124 * atomic_sub_return implies a barrier for waitqueue_active
1125 */
1126 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1127 5 * SZ_1M &&
1128 waitqueue_active(&root->fs_info->async_submit_wait))
1129 wake_up(&root->fs_info->async_submit_wait);
1130
1131 if (async_cow->inode)
1132 submit_compressed_extents(async_cow->inode, async_cow);
1133 }
1134
1135 static noinline void async_cow_free(struct btrfs_work *work)
1136 {
1137 struct async_cow *async_cow;
1138 async_cow = container_of(work, struct async_cow, work);
1139 if (async_cow->inode)
1140 btrfs_add_delayed_iput(async_cow->inode);
1141 kfree(async_cow);
1142 }
1143
1144 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1145 u64 start, u64 end, int *page_started,
1146 unsigned long *nr_written)
1147 {
1148 struct async_cow *async_cow;
1149 struct btrfs_root *root = BTRFS_I(inode)->root;
1150 unsigned long nr_pages;
1151 u64 cur_end;
1152 int limit = 10 * SZ_1M;
1153
1154 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1155 1, 0, NULL, GFP_NOFS);
1156 while (start < end) {
1157 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1158 BUG_ON(!async_cow); /* -ENOMEM */
1159 async_cow->inode = igrab(inode);
1160 async_cow->root = root;
1161 async_cow->locked_page = locked_page;
1162 async_cow->start = start;
1163
1164 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1165 !btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
1166 cur_end = end;
1167 else
1168 cur_end = min(end, start + SZ_512K - 1);
1169
1170 async_cow->end = cur_end;
1171 INIT_LIST_HEAD(&async_cow->extents);
1172
1173 btrfs_init_work(&async_cow->work,
1174 btrfs_delalloc_helper,
1175 async_cow_start, async_cow_submit,
1176 async_cow_free);
1177
1178 nr_pages = (cur_end - start + PAGE_SIZE) >>
1179 PAGE_SHIFT;
1180 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1181
1182 btrfs_queue_work(root->fs_info->delalloc_workers,
1183 &async_cow->work);
1184
1185 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1186 wait_event(root->fs_info->async_submit_wait,
1187 (atomic_read(&root->fs_info->async_delalloc_pages) <
1188 limit));
1189 }
1190
1191 while (atomic_read(&root->fs_info->async_submit_draining) &&
1192 atomic_read(&root->fs_info->async_delalloc_pages)) {
1193 wait_event(root->fs_info->async_submit_wait,
1194 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1195 0));
1196 }
1197
1198 *nr_written += nr_pages;
1199 start = cur_end + 1;
1200 }
1201 *page_started = 1;
1202 return 0;
1203 }
1204
1205 static noinline int csum_exist_in_range(struct btrfs_root *root,
1206 u64 bytenr, u64 num_bytes)
1207 {
1208 int ret;
1209 struct btrfs_ordered_sum *sums;
1210 LIST_HEAD(list);
1211
1212 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1213 bytenr + num_bytes - 1, &list, 0);
1214 if (ret == 0 && list_empty(&list))
1215 return 0;
1216
1217 while (!list_empty(&list)) {
1218 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1219 list_del(&sums->list);
1220 kfree(sums);
1221 }
1222 return 1;
1223 }
1224
1225 /*
1226 * when nowcow writeback call back. This checks for snapshots or COW copies
1227 * of the extents that exist in the file, and COWs the file as required.
1228 *
1229 * If no cow copies or snapshots exist, we write directly to the existing
1230 * blocks on disk
1231 */
1232 static noinline int run_delalloc_nocow(struct inode *inode,
1233 struct page *locked_page,
1234 u64 start, u64 end, int *page_started, int force,
1235 unsigned long *nr_written)
1236 {
1237 struct btrfs_root *root = BTRFS_I(inode)->root;
1238 struct btrfs_trans_handle *trans;
1239 struct extent_buffer *leaf;
1240 struct btrfs_path *path;
1241 struct btrfs_file_extent_item *fi;
1242 struct btrfs_key found_key;
1243 u64 cow_start;
1244 u64 cur_offset;
1245 u64 extent_end;
1246 u64 extent_offset;
1247 u64 disk_bytenr;
1248 u64 num_bytes;
1249 u64 disk_num_bytes;
1250 u64 ram_bytes;
1251 int extent_type;
1252 int ret, err;
1253 int type;
1254 int nocow;
1255 int check_prev = 1;
1256 bool nolock;
1257 u64 ino = btrfs_ino(inode);
1258
1259 path = btrfs_alloc_path();
1260 if (!path) {
1261 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1262 EXTENT_LOCKED | EXTENT_DELALLOC |
1263 EXTENT_DO_ACCOUNTING |
1264 EXTENT_DEFRAG, PAGE_UNLOCK |
1265 PAGE_CLEAR_DIRTY |
1266 PAGE_SET_WRITEBACK |
1267 PAGE_END_WRITEBACK);
1268 return -ENOMEM;
1269 }
1270
1271 nolock = btrfs_is_free_space_inode(inode);
1272
1273 if (nolock)
1274 trans = btrfs_join_transaction_nolock(root);
1275 else
1276 trans = btrfs_join_transaction(root);
1277
1278 if (IS_ERR(trans)) {
1279 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1280 EXTENT_LOCKED | EXTENT_DELALLOC |
1281 EXTENT_DO_ACCOUNTING |
1282 EXTENT_DEFRAG, PAGE_UNLOCK |
1283 PAGE_CLEAR_DIRTY |
1284 PAGE_SET_WRITEBACK |
1285 PAGE_END_WRITEBACK);
1286 btrfs_free_path(path);
1287 return PTR_ERR(trans);
1288 }
1289
1290 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1291
1292 cow_start = (u64)-1;
1293 cur_offset = start;
1294 while (1) {
1295 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1296 cur_offset, 0);
1297 if (ret < 0)
1298 goto error;
1299 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1300 leaf = path->nodes[0];
1301 btrfs_item_key_to_cpu(leaf, &found_key,
1302 path->slots[0] - 1);
1303 if (found_key.objectid == ino &&
1304 found_key.type == BTRFS_EXTENT_DATA_KEY)
1305 path->slots[0]--;
1306 }
1307 check_prev = 0;
1308 next_slot:
1309 leaf = path->nodes[0];
1310 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1311 ret = btrfs_next_leaf(root, path);
1312 if (ret < 0)
1313 goto error;
1314 if (ret > 0)
1315 break;
1316 leaf = path->nodes[0];
1317 }
1318
1319 nocow = 0;
1320 disk_bytenr = 0;
1321 num_bytes = 0;
1322 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1323
1324 if (found_key.objectid > ino)
1325 break;
1326 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1327 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1328 path->slots[0]++;
1329 goto next_slot;
1330 }
1331 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1332 found_key.offset > end)
1333 break;
1334
1335 if (found_key.offset > cur_offset) {
1336 extent_end = found_key.offset;
1337 extent_type = 0;
1338 goto out_check;
1339 }
1340
1341 fi = btrfs_item_ptr(leaf, path->slots[0],
1342 struct btrfs_file_extent_item);
1343 extent_type = btrfs_file_extent_type(leaf, fi);
1344
1345 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1346 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1347 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1348 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1349 extent_offset = btrfs_file_extent_offset(leaf, fi);
1350 extent_end = found_key.offset +
1351 btrfs_file_extent_num_bytes(leaf, fi);
1352 disk_num_bytes =
1353 btrfs_file_extent_disk_num_bytes(leaf, fi);
1354 if (extent_end <= start) {
1355 path->slots[0]++;
1356 goto next_slot;
1357 }
1358 if (disk_bytenr == 0)
1359 goto out_check;
1360 if (btrfs_file_extent_compression(leaf, fi) ||
1361 btrfs_file_extent_encryption(leaf, fi) ||
1362 btrfs_file_extent_other_encoding(leaf, fi))
1363 goto out_check;
1364 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1365 goto out_check;
1366 if (btrfs_extent_readonly(root, disk_bytenr))
1367 goto out_check;
1368 if (btrfs_cross_ref_exist(trans, root, ino,
1369 found_key.offset -
1370 extent_offset, disk_bytenr))
1371 goto out_check;
1372 disk_bytenr += extent_offset;
1373 disk_bytenr += cur_offset - found_key.offset;
1374 num_bytes = min(end + 1, extent_end) - cur_offset;
1375 /*
1376 * if there are pending snapshots for this root,
1377 * we fall into common COW way.
1378 */
1379 if (!nolock) {
1380 err = btrfs_start_write_no_snapshoting(root);
1381 if (!err)
1382 goto out_check;
1383 }
1384 /*
1385 * force cow if csum exists in the range.
1386 * this ensure that csum for a given extent are
1387 * either valid or do not exist.
1388 */
1389 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1390 goto out_check;
1391 if (!btrfs_inc_nocow_writers(root->fs_info,
1392 disk_bytenr))
1393 goto out_check;
1394 nocow = 1;
1395 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1396 extent_end = found_key.offset +
1397 btrfs_file_extent_inline_len(leaf,
1398 path->slots[0], fi);
1399 extent_end = ALIGN(extent_end, root->sectorsize);
1400 } else {
1401 BUG_ON(1);
1402 }
1403 out_check:
1404 if (extent_end <= start) {
1405 path->slots[0]++;
1406 if (!nolock && nocow)
1407 btrfs_end_write_no_snapshoting(root);
1408 if (nocow)
1409 btrfs_dec_nocow_writers(root->fs_info,
1410 disk_bytenr);
1411 goto next_slot;
1412 }
1413 if (!nocow) {
1414 if (cow_start == (u64)-1)
1415 cow_start = cur_offset;
1416 cur_offset = extent_end;
1417 if (cur_offset > end)
1418 break;
1419 path->slots[0]++;
1420 goto next_slot;
1421 }
1422
1423 btrfs_release_path(path);
1424 if (cow_start != (u64)-1) {
1425 ret = cow_file_range(inode, locked_page,
1426 cow_start, found_key.offset - 1,
1427 end, page_started, nr_written, 1,
1428 NULL);
1429 if (ret) {
1430 if (!nolock && nocow)
1431 btrfs_end_write_no_snapshoting(root);
1432 if (nocow)
1433 btrfs_dec_nocow_writers(root->fs_info,
1434 disk_bytenr);
1435 goto error;
1436 }
1437 cow_start = (u64)-1;
1438 }
1439
1440 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1441 struct extent_map *em;
1442 struct extent_map_tree *em_tree;
1443 em_tree = &BTRFS_I(inode)->extent_tree;
1444 em = alloc_extent_map();
1445 BUG_ON(!em); /* -ENOMEM */
1446 em->start = cur_offset;
1447 em->orig_start = found_key.offset - extent_offset;
1448 em->len = num_bytes;
1449 em->block_len = num_bytes;
1450 em->block_start = disk_bytenr;
1451 em->orig_block_len = disk_num_bytes;
1452 em->ram_bytes = ram_bytes;
1453 em->bdev = root->fs_info->fs_devices->latest_bdev;
1454 em->mod_start = em->start;
1455 em->mod_len = em->len;
1456 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1457 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1458 em->generation = -1;
1459 while (1) {
1460 write_lock(&em_tree->lock);
1461 ret = add_extent_mapping(em_tree, em, 1);
1462 write_unlock(&em_tree->lock);
1463 if (ret != -EEXIST) {
1464 free_extent_map(em);
1465 break;
1466 }
1467 btrfs_drop_extent_cache(inode, em->start,
1468 em->start + em->len - 1, 0);
1469 }
1470 type = BTRFS_ORDERED_PREALLOC;
1471 } else {
1472 type = BTRFS_ORDERED_NOCOW;
1473 }
1474
1475 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1476 num_bytes, num_bytes, type);
1477 if (nocow)
1478 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1479 BUG_ON(ret); /* -ENOMEM */
1480
1481 if (root->root_key.objectid ==
1482 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1483 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1484 num_bytes);
1485 if (ret) {
1486 if (!nolock && nocow)
1487 btrfs_end_write_no_snapshoting(root);
1488 goto error;
1489 }
1490 }
1491
1492 extent_clear_unlock_delalloc(inode, cur_offset,
1493 cur_offset + num_bytes - 1,
1494 locked_page, EXTENT_LOCKED |
1495 EXTENT_DELALLOC |
1496 EXTENT_CLEAR_DATA_RESV,
1497 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1498
1499 if (!nolock && nocow)
1500 btrfs_end_write_no_snapshoting(root);
1501 cur_offset = extent_end;
1502 if (cur_offset > end)
1503 break;
1504 }
1505 btrfs_release_path(path);
1506
1507 if (cur_offset <= end && cow_start == (u64)-1) {
1508 cow_start = cur_offset;
1509 cur_offset = end;
1510 }
1511
1512 if (cow_start != (u64)-1) {
1513 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1514 page_started, nr_written, 1, NULL);
1515 if (ret)
1516 goto error;
1517 }
1518
1519 error:
1520 err = btrfs_end_transaction(trans, root);
1521 if (!ret)
1522 ret = err;
1523
1524 if (ret && cur_offset < end)
1525 extent_clear_unlock_delalloc(inode, cur_offset, end,
1526 locked_page, EXTENT_LOCKED |
1527 EXTENT_DELALLOC | EXTENT_DEFRAG |
1528 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1529 PAGE_CLEAR_DIRTY |
1530 PAGE_SET_WRITEBACK |
1531 PAGE_END_WRITEBACK);
1532 btrfs_free_path(path);
1533 return ret;
1534 }
1535
1536 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1537 {
1538
1539 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1540 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1541 return 0;
1542
1543 /*
1544 * @defrag_bytes is a hint value, no spinlock held here,
1545 * if is not zero, it means the file is defragging.
1546 * Force cow if given extent needs to be defragged.
1547 */
1548 if (BTRFS_I(inode)->defrag_bytes &&
1549 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1550 EXTENT_DEFRAG, 0, NULL))
1551 return 1;
1552
1553 return 0;
1554 }
1555
1556 /*
1557 * extent_io.c call back to do delayed allocation processing
1558 */
1559 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1560 u64 start, u64 end, int *page_started,
1561 unsigned long *nr_written)
1562 {
1563 int ret;
1564 int force_cow = need_force_cow(inode, start, end);
1565
1566 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1567 ret = run_delalloc_nocow(inode, locked_page, start, end,
1568 page_started, 1, nr_written);
1569 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1570 ret = run_delalloc_nocow(inode, locked_page, start, end,
1571 page_started, 0, nr_written);
1572 } else if (!inode_need_compress(inode)) {
1573 ret = cow_file_range(inode, locked_page, start, end, end,
1574 page_started, nr_written, 1, NULL);
1575 } else {
1576 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1577 &BTRFS_I(inode)->runtime_flags);
1578 ret = cow_file_range_async(inode, locked_page, start, end,
1579 page_started, nr_written);
1580 }
1581 return ret;
1582 }
1583
1584 static void btrfs_split_extent_hook(struct inode *inode,
1585 struct extent_state *orig, u64 split)
1586 {
1587 u64 size;
1588
1589 /* not delalloc, ignore it */
1590 if (!(orig->state & EXTENT_DELALLOC))
1591 return;
1592
1593 size = orig->end - orig->start + 1;
1594 if (size > BTRFS_MAX_EXTENT_SIZE) {
1595 u64 num_extents;
1596 u64 new_size;
1597
1598 /*
1599 * See the explanation in btrfs_merge_extent_hook, the same
1600 * applies here, just in reverse.
1601 */
1602 new_size = orig->end - split + 1;
1603 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1604 BTRFS_MAX_EXTENT_SIZE);
1605 new_size = split - orig->start;
1606 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1607 BTRFS_MAX_EXTENT_SIZE);
1608 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1609 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1610 return;
1611 }
1612
1613 spin_lock(&BTRFS_I(inode)->lock);
1614 BTRFS_I(inode)->outstanding_extents++;
1615 spin_unlock(&BTRFS_I(inode)->lock);
1616 }
1617
1618 /*
1619 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1620 * extents so we can keep track of new extents that are just merged onto old
1621 * extents, such as when we are doing sequential writes, so we can properly
1622 * account for the metadata space we'll need.
1623 */
1624 static void btrfs_merge_extent_hook(struct inode *inode,
1625 struct extent_state *new,
1626 struct extent_state *other)
1627 {
1628 u64 new_size, old_size;
1629 u64 num_extents;
1630
1631 /* not delalloc, ignore it */
1632 if (!(other->state & EXTENT_DELALLOC))
1633 return;
1634
1635 if (new->start > other->start)
1636 new_size = new->end - other->start + 1;
1637 else
1638 new_size = other->end - new->start + 1;
1639
1640 /* we're not bigger than the max, unreserve the space and go */
1641 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1642 spin_lock(&BTRFS_I(inode)->lock);
1643 BTRFS_I(inode)->outstanding_extents--;
1644 spin_unlock(&BTRFS_I(inode)->lock);
1645 return;
1646 }
1647
1648 /*
1649 * We have to add up either side to figure out how many extents were
1650 * accounted for before we merged into one big extent. If the number of
1651 * extents we accounted for is <= the amount we need for the new range
1652 * then we can return, otherwise drop. Think of it like this
1653 *
1654 * [ 4k][MAX_SIZE]
1655 *
1656 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1657 * need 2 outstanding extents, on one side we have 1 and the other side
1658 * we have 1 so they are == and we can return. But in this case
1659 *
1660 * [MAX_SIZE+4k][MAX_SIZE+4k]
1661 *
1662 * Each range on their own accounts for 2 extents, but merged together
1663 * they are only 3 extents worth of accounting, so we need to drop in
1664 * this case.
1665 */
1666 old_size = other->end - other->start + 1;
1667 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1668 BTRFS_MAX_EXTENT_SIZE);
1669 old_size = new->end - new->start + 1;
1670 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1671 BTRFS_MAX_EXTENT_SIZE);
1672
1673 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1674 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1675 return;
1676
1677 spin_lock(&BTRFS_I(inode)->lock);
1678 BTRFS_I(inode)->outstanding_extents--;
1679 spin_unlock(&BTRFS_I(inode)->lock);
1680 }
1681
1682 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1683 struct inode *inode)
1684 {
1685 spin_lock(&root->delalloc_lock);
1686 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1687 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1688 &root->delalloc_inodes);
1689 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1690 &BTRFS_I(inode)->runtime_flags);
1691 root->nr_delalloc_inodes++;
1692 if (root->nr_delalloc_inodes == 1) {
1693 spin_lock(&root->fs_info->delalloc_root_lock);
1694 BUG_ON(!list_empty(&root->delalloc_root));
1695 list_add_tail(&root->delalloc_root,
1696 &root->fs_info->delalloc_roots);
1697 spin_unlock(&root->fs_info->delalloc_root_lock);
1698 }
1699 }
1700 spin_unlock(&root->delalloc_lock);
1701 }
1702
1703 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1704 struct inode *inode)
1705 {
1706 spin_lock(&root->delalloc_lock);
1707 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1708 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1709 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1710 &BTRFS_I(inode)->runtime_flags);
1711 root->nr_delalloc_inodes--;
1712 if (!root->nr_delalloc_inodes) {
1713 spin_lock(&root->fs_info->delalloc_root_lock);
1714 BUG_ON(list_empty(&root->delalloc_root));
1715 list_del_init(&root->delalloc_root);
1716 spin_unlock(&root->fs_info->delalloc_root_lock);
1717 }
1718 }
1719 spin_unlock(&root->delalloc_lock);
1720 }
1721
1722 /*
1723 * extent_io.c set_bit_hook, used to track delayed allocation
1724 * bytes in this file, and to maintain the list of inodes that
1725 * have pending delalloc work to be done.
1726 */
1727 static void btrfs_set_bit_hook(struct inode *inode,
1728 struct extent_state *state, unsigned *bits)
1729 {
1730
1731 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1732 WARN_ON(1);
1733 /*
1734 * set_bit and clear bit hooks normally require _irqsave/restore
1735 * but in this case, we are only testing for the DELALLOC
1736 * bit, which is only set or cleared with irqs on
1737 */
1738 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1739 struct btrfs_root *root = BTRFS_I(inode)->root;
1740 u64 len = state->end + 1 - state->start;
1741 bool do_list = !btrfs_is_free_space_inode(inode);
1742
1743 if (*bits & EXTENT_FIRST_DELALLOC) {
1744 *bits &= ~EXTENT_FIRST_DELALLOC;
1745 } else {
1746 spin_lock(&BTRFS_I(inode)->lock);
1747 BTRFS_I(inode)->outstanding_extents++;
1748 spin_unlock(&BTRFS_I(inode)->lock);
1749 }
1750
1751 /* For sanity tests */
1752 if (btrfs_is_testing(root->fs_info))
1753 return;
1754
1755 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1756 root->fs_info->delalloc_batch);
1757 spin_lock(&BTRFS_I(inode)->lock);
1758 BTRFS_I(inode)->delalloc_bytes += len;
1759 if (*bits & EXTENT_DEFRAG)
1760 BTRFS_I(inode)->defrag_bytes += len;
1761 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1762 &BTRFS_I(inode)->runtime_flags))
1763 btrfs_add_delalloc_inodes(root, inode);
1764 spin_unlock(&BTRFS_I(inode)->lock);
1765 }
1766 }
1767
1768 /*
1769 * extent_io.c clear_bit_hook, see set_bit_hook for why
1770 */
1771 static void btrfs_clear_bit_hook(struct inode *inode,
1772 struct extent_state *state,
1773 unsigned *bits)
1774 {
1775 u64 len = state->end + 1 - state->start;
1776 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1777 BTRFS_MAX_EXTENT_SIZE);
1778
1779 spin_lock(&BTRFS_I(inode)->lock);
1780 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1781 BTRFS_I(inode)->defrag_bytes -= len;
1782 spin_unlock(&BTRFS_I(inode)->lock);
1783
1784 /*
1785 * set_bit and clear bit hooks normally require _irqsave/restore
1786 * but in this case, we are only testing for the DELALLOC
1787 * bit, which is only set or cleared with irqs on
1788 */
1789 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1790 struct btrfs_root *root = BTRFS_I(inode)->root;
1791 bool do_list = !btrfs_is_free_space_inode(inode);
1792
1793 if (*bits & EXTENT_FIRST_DELALLOC) {
1794 *bits &= ~EXTENT_FIRST_DELALLOC;
1795 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1796 spin_lock(&BTRFS_I(inode)->lock);
1797 BTRFS_I(inode)->outstanding_extents -= num_extents;
1798 spin_unlock(&BTRFS_I(inode)->lock);
1799 }
1800
1801 /*
1802 * We don't reserve metadata space for space cache inodes so we
1803 * don't need to call dellalloc_release_metadata if there is an
1804 * error.
1805 */
1806 if (*bits & EXTENT_DO_ACCOUNTING &&
1807 root != root->fs_info->tree_root)
1808 btrfs_delalloc_release_metadata(inode, len);
1809
1810 /* For sanity tests. */
1811 if (btrfs_is_testing(root->fs_info))
1812 return;
1813
1814 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1815 && do_list && !(state->state & EXTENT_NORESERVE)
1816 && (*bits & (EXTENT_DO_ACCOUNTING |
1817 EXTENT_CLEAR_DATA_RESV)))
1818 btrfs_free_reserved_data_space_noquota(inode,
1819 state->start, len);
1820
1821 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1822 root->fs_info->delalloc_batch);
1823 spin_lock(&BTRFS_I(inode)->lock);
1824 BTRFS_I(inode)->delalloc_bytes -= len;
1825 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1826 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1827 &BTRFS_I(inode)->runtime_flags))
1828 btrfs_del_delalloc_inode(root, inode);
1829 spin_unlock(&BTRFS_I(inode)->lock);
1830 }
1831 }
1832
1833 /*
1834 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1835 * we don't create bios that span stripes or chunks
1836 *
1837 * return 1 if page cannot be merged to bio
1838 * return 0 if page can be merged to bio
1839 * return error otherwise
1840 */
1841 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1842 size_t size, struct bio *bio,
1843 unsigned long bio_flags)
1844 {
1845 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1846 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1847 u64 length = 0;
1848 u64 map_length;
1849 int ret;
1850
1851 if (bio_flags & EXTENT_BIO_COMPRESSED)
1852 return 0;
1853
1854 length = bio->bi_iter.bi_size;
1855 map_length = length;
1856 ret = btrfs_map_block(root->fs_info, bio_op(bio), logical,
1857 &map_length, NULL, 0);
1858 if (ret < 0)
1859 return ret;
1860 if (map_length < length + size)
1861 return 1;
1862 return 0;
1863 }
1864
1865 /*
1866 * in order to insert checksums into the metadata in large chunks,
1867 * we wait until bio submission time. All the pages in the bio are
1868 * checksummed and sums are attached onto the ordered extent record.
1869 *
1870 * At IO completion time the cums attached on the ordered extent record
1871 * are inserted into the btree
1872 */
1873 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
1874 int mirror_num, unsigned long bio_flags,
1875 u64 bio_offset)
1876 {
1877 struct btrfs_root *root = BTRFS_I(inode)->root;
1878 int ret = 0;
1879
1880 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1881 BUG_ON(ret); /* -ENOMEM */
1882 return 0;
1883 }
1884
1885 /*
1886 * in order to insert checksums into the metadata in large chunks,
1887 * we wait until bio submission time. All the pages in the bio are
1888 * checksummed and sums are attached onto the ordered extent record.
1889 *
1890 * At IO completion time the cums attached on the ordered extent record
1891 * are inserted into the btree
1892 */
1893 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio,
1894 int mirror_num, unsigned long bio_flags,
1895 u64 bio_offset)
1896 {
1897 struct btrfs_root *root = BTRFS_I(inode)->root;
1898 int ret;
1899
1900 ret = btrfs_map_bio(root, bio, mirror_num, 1);
1901 if (ret) {
1902 bio->bi_error = ret;
1903 bio_endio(bio);
1904 }
1905 return ret;
1906 }
1907
1908 /*
1909 * extent_io.c submission hook. This does the right thing for csum calculation
1910 * on write, or reading the csums from the tree before a read
1911 */
1912 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
1913 int mirror_num, unsigned long bio_flags,
1914 u64 bio_offset)
1915 {
1916 struct btrfs_root *root = BTRFS_I(inode)->root;
1917 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1918 int ret = 0;
1919 int skip_sum;
1920 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1921
1922 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1923
1924 if (btrfs_is_free_space_inode(inode))
1925 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1926
1927 if (bio_op(bio) != REQ_OP_WRITE) {
1928 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1929 if (ret)
1930 goto out;
1931
1932 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1933 ret = btrfs_submit_compressed_read(inode, bio,
1934 mirror_num,
1935 bio_flags);
1936 goto out;
1937 } else if (!skip_sum) {
1938 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1939 if (ret)
1940 goto out;
1941 }
1942 goto mapit;
1943 } else if (async && !skip_sum) {
1944 /* csum items have already been cloned */
1945 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1946 goto mapit;
1947 /* we're doing a write, do the async checksumming */
1948 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1949 inode, bio, mirror_num,
1950 bio_flags, bio_offset,
1951 __btrfs_submit_bio_start,
1952 __btrfs_submit_bio_done);
1953 goto out;
1954 } else if (!skip_sum) {
1955 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1956 if (ret)
1957 goto out;
1958 }
1959
1960 mapit:
1961 ret = btrfs_map_bio(root, bio, mirror_num, 0);
1962
1963 out:
1964 if (ret < 0) {
1965 bio->bi_error = ret;
1966 bio_endio(bio);
1967 }
1968 return ret;
1969 }
1970
1971 /*
1972 * given a list of ordered sums record them in the inode. This happens
1973 * at IO completion time based on sums calculated at bio submission time.
1974 */
1975 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1976 struct inode *inode, u64 file_offset,
1977 struct list_head *list)
1978 {
1979 struct btrfs_ordered_sum *sum;
1980
1981 list_for_each_entry(sum, list, list) {
1982 trans->adding_csums = 1;
1983 btrfs_csum_file_blocks(trans,
1984 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1985 trans->adding_csums = 0;
1986 }
1987 return 0;
1988 }
1989
1990 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1991 struct extent_state **cached_state)
1992 {
1993 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1994 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1995 cached_state);
1996 }
1997
1998 /* see btrfs_writepage_start_hook for details on why this is required */
1999 struct btrfs_writepage_fixup {
2000 struct page *page;
2001 struct btrfs_work work;
2002 };
2003
2004 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2005 {
2006 struct btrfs_writepage_fixup *fixup;
2007 struct btrfs_ordered_extent *ordered;
2008 struct extent_state *cached_state = NULL;
2009 struct page *page;
2010 struct inode *inode;
2011 u64 page_start;
2012 u64 page_end;
2013 int ret;
2014
2015 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2016 page = fixup->page;
2017 again:
2018 lock_page(page);
2019 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2020 ClearPageChecked(page);
2021 goto out_page;
2022 }
2023
2024 inode = page->mapping->host;
2025 page_start = page_offset(page);
2026 page_end = page_offset(page) + PAGE_SIZE - 1;
2027
2028 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2029 &cached_state);
2030
2031 /* already ordered? We're done */
2032 if (PagePrivate2(page))
2033 goto out;
2034
2035 ordered = btrfs_lookup_ordered_range(inode, page_start,
2036 PAGE_SIZE);
2037 if (ordered) {
2038 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2039 page_end, &cached_state, GFP_NOFS);
2040 unlock_page(page);
2041 btrfs_start_ordered_extent(inode, ordered, 1);
2042 btrfs_put_ordered_extent(ordered);
2043 goto again;
2044 }
2045
2046 ret = btrfs_delalloc_reserve_space(inode, page_start,
2047 PAGE_SIZE);
2048 if (ret) {
2049 mapping_set_error(page->mapping, ret);
2050 end_extent_writepage(page, ret, page_start, page_end);
2051 ClearPageChecked(page);
2052 goto out;
2053 }
2054
2055 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2056 ClearPageChecked(page);
2057 set_page_dirty(page);
2058 out:
2059 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2060 &cached_state, GFP_NOFS);
2061 out_page:
2062 unlock_page(page);
2063 put_page(page);
2064 kfree(fixup);
2065 }
2066
2067 /*
2068 * There are a few paths in the higher layers of the kernel that directly
2069 * set the page dirty bit without asking the filesystem if it is a
2070 * good idea. This causes problems because we want to make sure COW
2071 * properly happens and the data=ordered rules are followed.
2072 *
2073 * In our case any range that doesn't have the ORDERED bit set
2074 * hasn't been properly setup for IO. We kick off an async process
2075 * to fix it up. The async helper will wait for ordered extents, set
2076 * the delalloc bit and make it safe to write the page.
2077 */
2078 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2079 {
2080 struct inode *inode = page->mapping->host;
2081 struct btrfs_writepage_fixup *fixup;
2082 struct btrfs_root *root = BTRFS_I(inode)->root;
2083
2084 /* this page is properly in the ordered list */
2085 if (TestClearPagePrivate2(page))
2086 return 0;
2087
2088 if (PageChecked(page))
2089 return -EAGAIN;
2090
2091 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2092 if (!fixup)
2093 return -EAGAIN;
2094
2095 SetPageChecked(page);
2096 get_page(page);
2097 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2098 btrfs_writepage_fixup_worker, NULL, NULL);
2099 fixup->page = page;
2100 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2101 return -EBUSY;
2102 }
2103
2104 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2105 struct inode *inode, u64 file_pos,
2106 u64 disk_bytenr, u64 disk_num_bytes,
2107 u64 num_bytes, u64 ram_bytes,
2108 u8 compression, u8 encryption,
2109 u16 other_encoding, int extent_type)
2110 {
2111 struct btrfs_root *root = BTRFS_I(inode)->root;
2112 struct btrfs_file_extent_item *fi;
2113 struct btrfs_path *path;
2114 struct extent_buffer *leaf;
2115 struct btrfs_key ins;
2116 int extent_inserted = 0;
2117 int ret;
2118
2119 path = btrfs_alloc_path();
2120 if (!path)
2121 return -ENOMEM;
2122
2123 /*
2124 * we may be replacing one extent in the tree with another.
2125 * The new extent is pinned in the extent map, and we don't want
2126 * to drop it from the cache until it is completely in the btree.
2127 *
2128 * So, tell btrfs_drop_extents to leave this extent in the cache.
2129 * the caller is expected to unpin it and allow it to be merged
2130 * with the others.
2131 */
2132 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2133 file_pos + num_bytes, NULL, 0,
2134 1, sizeof(*fi), &extent_inserted);
2135 if (ret)
2136 goto out;
2137
2138 if (!extent_inserted) {
2139 ins.objectid = btrfs_ino(inode);
2140 ins.offset = file_pos;
2141 ins.type = BTRFS_EXTENT_DATA_KEY;
2142
2143 path->leave_spinning = 1;
2144 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2145 sizeof(*fi));
2146 if (ret)
2147 goto out;
2148 }
2149 leaf = path->nodes[0];
2150 fi = btrfs_item_ptr(leaf, path->slots[0],
2151 struct btrfs_file_extent_item);
2152 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2153 btrfs_set_file_extent_type(leaf, fi, extent_type);
2154 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2155 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2156 btrfs_set_file_extent_offset(leaf, fi, 0);
2157 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2158 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2159 btrfs_set_file_extent_compression(leaf, fi, compression);
2160 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2161 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2162
2163 btrfs_mark_buffer_dirty(leaf);
2164 btrfs_release_path(path);
2165
2166 inode_add_bytes(inode, num_bytes);
2167
2168 ins.objectid = disk_bytenr;
2169 ins.offset = disk_num_bytes;
2170 ins.type = BTRFS_EXTENT_ITEM_KEY;
2171 ret = btrfs_alloc_reserved_file_extent(trans, root,
2172 root->root_key.objectid,
2173 btrfs_ino(inode), file_pos,
2174 ram_bytes, &ins);
2175 /*
2176 * Release the reserved range from inode dirty range map, as it is
2177 * already moved into delayed_ref_head
2178 */
2179 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2180 out:
2181 btrfs_free_path(path);
2182
2183 return ret;
2184 }
2185
2186 /* snapshot-aware defrag */
2187 struct sa_defrag_extent_backref {
2188 struct rb_node node;
2189 struct old_sa_defrag_extent *old;
2190 u64 root_id;
2191 u64 inum;
2192 u64 file_pos;
2193 u64 extent_offset;
2194 u64 num_bytes;
2195 u64 generation;
2196 };
2197
2198 struct old_sa_defrag_extent {
2199 struct list_head list;
2200 struct new_sa_defrag_extent *new;
2201
2202 u64 extent_offset;
2203 u64 bytenr;
2204 u64 offset;
2205 u64 len;
2206 int count;
2207 };
2208
2209 struct new_sa_defrag_extent {
2210 struct rb_root root;
2211 struct list_head head;
2212 struct btrfs_path *path;
2213 struct inode *inode;
2214 u64 file_pos;
2215 u64 len;
2216 u64 bytenr;
2217 u64 disk_len;
2218 u8 compress_type;
2219 };
2220
2221 static int backref_comp(struct sa_defrag_extent_backref *b1,
2222 struct sa_defrag_extent_backref *b2)
2223 {
2224 if (b1->root_id < b2->root_id)
2225 return -1;
2226 else if (b1->root_id > b2->root_id)
2227 return 1;
2228
2229 if (b1->inum < b2->inum)
2230 return -1;
2231 else if (b1->inum > b2->inum)
2232 return 1;
2233
2234 if (b1->file_pos < b2->file_pos)
2235 return -1;
2236 else if (b1->file_pos > b2->file_pos)
2237 return 1;
2238
2239 /*
2240 * [------------------------------] ===> (a range of space)
2241 * |<--->| |<---->| =============> (fs/file tree A)
2242 * |<---------------------------->| ===> (fs/file tree B)
2243 *
2244 * A range of space can refer to two file extents in one tree while
2245 * refer to only one file extent in another tree.
2246 *
2247 * So we may process a disk offset more than one time(two extents in A)
2248 * and locate at the same extent(one extent in B), then insert two same
2249 * backrefs(both refer to the extent in B).
2250 */
2251 return 0;
2252 }
2253
2254 static void backref_insert(struct rb_root *root,
2255 struct sa_defrag_extent_backref *backref)
2256 {
2257 struct rb_node **p = &root->rb_node;
2258 struct rb_node *parent = NULL;
2259 struct sa_defrag_extent_backref *entry;
2260 int ret;
2261
2262 while (*p) {
2263 parent = *p;
2264 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2265
2266 ret = backref_comp(backref, entry);
2267 if (ret < 0)
2268 p = &(*p)->rb_left;
2269 else
2270 p = &(*p)->rb_right;
2271 }
2272
2273 rb_link_node(&backref->node, parent, p);
2274 rb_insert_color(&backref->node, root);
2275 }
2276
2277 /*
2278 * Note the backref might has changed, and in this case we just return 0.
2279 */
2280 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2281 void *ctx)
2282 {
2283 struct btrfs_file_extent_item *extent;
2284 struct btrfs_fs_info *fs_info;
2285 struct old_sa_defrag_extent *old = ctx;
2286 struct new_sa_defrag_extent *new = old->new;
2287 struct btrfs_path *path = new->path;
2288 struct btrfs_key key;
2289 struct btrfs_root *root;
2290 struct sa_defrag_extent_backref *backref;
2291 struct extent_buffer *leaf;
2292 struct inode *inode = new->inode;
2293 int slot;
2294 int ret;
2295 u64 extent_offset;
2296 u64 num_bytes;
2297
2298 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2299 inum == btrfs_ino(inode))
2300 return 0;
2301
2302 key.objectid = root_id;
2303 key.type = BTRFS_ROOT_ITEM_KEY;
2304 key.offset = (u64)-1;
2305
2306 fs_info = BTRFS_I(inode)->root->fs_info;
2307 root = btrfs_read_fs_root_no_name(fs_info, &key);
2308 if (IS_ERR(root)) {
2309 if (PTR_ERR(root) == -ENOENT)
2310 return 0;
2311 WARN_ON(1);
2312 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2313 inum, offset, root_id);
2314 return PTR_ERR(root);
2315 }
2316
2317 key.objectid = inum;
2318 key.type = BTRFS_EXTENT_DATA_KEY;
2319 if (offset > (u64)-1 << 32)
2320 key.offset = 0;
2321 else
2322 key.offset = offset;
2323
2324 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2325 if (WARN_ON(ret < 0))
2326 return ret;
2327 ret = 0;
2328
2329 while (1) {
2330 cond_resched();
2331
2332 leaf = path->nodes[0];
2333 slot = path->slots[0];
2334
2335 if (slot >= btrfs_header_nritems(leaf)) {
2336 ret = btrfs_next_leaf(root, path);
2337 if (ret < 0) {
2338 goto out;
2339 } else if (ret > 0) {
2340 ret = 0;
2341 goto out;
2342 }
2343 continue;
2344 }
2345
2346 path->slots[0]++;
2347
2348 btrfs_item_key_to_cpu(leaf, &key, slot);
2349
2350 if (key.objectid > inum)
2351 goto out;
2352
2353 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2354 continue;
2355
2356 extent = btrfs_item_ptr(leaf, slot,
2357 struct btrfs_file_extent_item);
2358
2359 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2360 continue;
2361
2362 /*
2363 * 'offset' refers to the exact key.offset,
2364 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2365 * (key.offset - extent_offset).
2366 */
2367 if (key.offset != offset)
2368 continue;
2369
2370 extent_offset = btrfs_file_extent_offset(leaf, extent);
2371 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2372
2373 if (extent_offset >= old->extent_offset + old->offset +
2374 old->len || extent_offset + num_bytes <=
2375 old->extent_offset + old->offset)
2376 continue;
2377 break;
2378 }
2379
2380 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2381 if (!backref) {
2382 ret = -ENOENT;
2383 goto out;
2384 }
2385
2386 backref->root_id = root_id;
2387 backref->inum = inum;
2388 backref->file_pos = offset;
2389 backref->num_bytes = num_bytes;
2390 backref->extent_offset = extent_offset;
2391 backref->generation = btrfs_file_extent_generation(leaf, extent);
2392 backref->old = old;
2393 backref_insert(&new->root, backref);
2394 old->count++;
2395 out:
2396 btrfs_release_path(path);
2397 WARN_ON(ret);
2398 return ret;
2399 }
2400
2401 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2402 struct new_sa_defrag_extent *new)
2403 {
2404 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2405 struct old_sa_defrag_extent *old, *tmp;
2406 int ret;
2407
2408 new->path = path;
2409
2410 list_for_each_entry_safe(old, tmp, &new->head, list) {
2411 ret = iterate_inodes_from_logical(old->bytenr +
2412 old->extent_offset, fs_info,
2413 path, record_one_backref,
2414 old);
2415 if (ret < 0 && ret != -ENOENT)
2416 return false;
2417
2418 /* no backref to be processed for this extent */
2419 if (!old->count) {
2420 list_del(&old->list);
2421 kfree(old);
2422 }
2423 }
2424
2425 if (list_empty(&new->head))
2426 return false;
2427
2428 return true;
2429 }
2430
2431 static int relink_is_mergable(struct extent_buffer *leaf,
2432 struct btrfs_file_extent_item *fi,
2433 struct new_sa_defrag_extent *new)
2434 {
2435 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2436 return 0;
2437
2438 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2439 return 0;
2440
2441 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2442 return 0;
2443
2444 if (btrfs_file_extent_encryption(leaf, fi) ||
2445 btrfs_file_extent_other_encoding(leaf, fi))
2446 return 0;
2447
2448 return 1;
2449 }
2450
2451 /*
2452 * Note the backref might has changed, and in this case we just return 0.
2453 */
2454 static noinline int relink_extent_backref(struct btrfs_path *path,
2455 struct sa_defrag_extent_backref *prev,
2456 struct sa_defrag_extent_backref *backref)
2457 {
2458 struct btrfs_file_extent_item *extent;
2459 struct btrfs_file_extent_item *item;
2460 struct btrfs_ordered_extent *ordered;
2461 struct btrfs_trans_handle *trans;
2462 struct btrfs_fs_info *fs_info;
2463 struct btrfs_root *root;
2464 struct btrfs_key key;
2465 struct extent_buffer *leaf;
2466 struct old_sa_defrag_extent *old = backref->old;
2467 struct new_sa_defrag_extent *new = old->new;
2468 struct inode *src_inode = new->inode;
2469 struct inode *inode;
2470 struct extent_state *cached = NULL;
2471 int ret = 0;
2472 u64 start;
2473 u64 len;
2474 u64 lock_start;
2475 u64 lock_end;
2476 bool merge = false;
2477 int index;
2478
2479 if (prev && prev->root_id == backref->root_id &&
2480 prev->inum == backref->inum &&
2481 prev->file_pos + prev->num_bytes == backref->file_pos)
2482 merge = true;
2483
2484 /* step 1: get root */
2485 key.objectid = backref->root_id;
2486 key.type = BTRFS_ROOT_ITEM_KEY;
2487 key.offset = (u64)-1;
2488
2489 fs_info = BTRFS_I(src_inode)->root->fs_info;
2490 index = srcu_read_lock(&fs_info->subvol_srcu);
2491
2492 root = btrfs_read_fs_root_no_name(fs_info, &key);
2493 if (IS_ERR(root)) {
2494 srcu_read_unlock(&fs_info->subvol_srcu, index);
2495 if (PTR_ERR(root) == -ENOENT)
2496 return 0;
2497 return PTR_ERR(root);
2498 }
2499
2500 if (btrfs_root_readonly(root)) {
2501 srcu_read_unlock(&fs_info->subvol_srcu, index);
2502 return 0;
2503 }
2504
2505 /* step 2: get inode */
2506 key.objectid = backref->inum;
2507 key.type = BTRFS_INODE_ITEM_KEY;
2508 key.offset = 0;
2509
2510 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2511 if (IS_ERR(inode)) {
2512 srcu_read_unlock(&fs_info->subvol_srcu, index);
2513 return 0;
2514 }
2515
2516 srcu_read_unlock(&fs_info->subvol_srcu, index);
2517
2518 /* step 3: relink backref */
2519 lock_start = backref->file_pos;
2520 lock_end = backref->file_pos + backref->num_bytes - 1;
2521 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2522 &cached);
2523
2524 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2525 if (ordered) {
2526 btrfs_put_ordered_extent(ordered);
2527 goto out_unlock;
2528 }
2529
2530 trans = btrfs_join_transaction(root);
2531 if (IS_ERR(trans)) {
2532 ret = PTR_ERR(trans);
2533 goto out_unlock;
2534 }
2535
2536 key.objectid = backref->inum;
2537 key.type = BTRFS_EXTENT_DATA_KEY;
2538 key.offset = backref->file_pos;
2539
2540 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2541 if (ret < 0) {
2542 goto out_free_path;
2543 } else if (ret > 0) {
2544 ret = 0;
2545 goto out_free_path;
2546 }
2547
2548 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2549 struct btrfs_file_extent_item);
2550
2551 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2552 backref->generation)
2553 goto out_free_path;
2554
2555 btrfs_release_path(path);
2556
2557 start = backref->file_pos;
2558 if (backref->extent_offset < old->extent_offset + old->offset)
2559 start += old->extent_offset + old->offset -
2560 backref->extent_offset;
2561
2562 len = min(backref->extent_offset + backref->num_bytes,
2563 old->extent_offset + old->offset + old->len);
2564 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2565
2566 ret = btrfs_drop_extents(trans, root, inode, start,
2567 start + len, 1);
2568 if (ret)
2569 goto out_free_path;
2570 again:
2571 key.objectid = btrfs_ino(inode);
2572 key.type = BTRFS_EXTENT_DATA_KEY;
2573 key.offset = start;
2574
2575 path->leave_spinning = 1;
2576 if (merge) {
2577 struct btrfs_file_extent_item *fi;
2578 u64 extent_len;
2579 struct btrfs_key found_key;
2580
2581 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2582 if (ret < 0)
2583 goto out_free_path;
2584
2585 path->slots[0]--;
2586 leaf = path->nodes[0];
2587 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2588
2589 fi = btrfs_item_ptr(leaf, path->slots[0],
2590 struct btrfs_file_extent_item);
2591 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2592
2593 if (extent_len + found_key.offset == start &&
2594 relink_is_mergable(leaf, fi, new)) {
2595 btrfs_set_file_extent_num_bytes(leaf, fi,
2596 extent_len + len);
2597 btrfs_mark_buffer_dirty(leaf);
2598 inode_add_bytes(inode, len);
2599
2600 ret = 1;
2601 goto out_free_path;
2602 } else {
2603 merge = false;
2604 btrfs_release_path(path);
2605 goto again;
2606 }
2607 }
2608
2609 ret = btrfs_insert_empty_item(trans, root, path, &key,
2610 sizeof(*extent));
2611 if (ret) {
2612 btrfs_abort_transaction(trans, ret);
2613 goto out_free_path;
2614 }
2615
2616 leaf = path->nodes[0];
2617 item = btrfs_item_ptr(leaf, path->slots[0],
2618 struct btrfs_file_extent_item);
2619 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2620 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2621 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2622 btrfs_set_file_extent_num_bytes(leaf, item, len);
2623 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2624 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2625 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2626 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2627 btrfs_set_file_extent_encryption(leaf, item, 0);
2628 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2629
2630 btrfs_mark_buffer_dirty(leaf);
2631 inode_add_bytes(inode, len);
2632 btrfs_release_path(path);
2633
2634 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2635 new->disk_len, 0,
2636 backref->root_id, backref->inum,
2637 new->file_pos); /* start - extent_offset */
2638 if (ret) {
2639 btrfs_abort_transaction(trans, ret);
2640 goto out_free_path;
2641 }
2642
2643 ret = 1;
2644 out_free_path:
2645 btrfs_release_path(path);
2646 path->leave_spinning = 0;
2647 btrfs_end_transaction(trans, root);
2648 out_unlock:
2649 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2650 &cached, GFP_NOFS);
2651 iput(inode);
2652 return ret;
2653 }
2654
2655 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2656 {
2657 struct old_sa_defrag_extent *old, *tmp;
2658
2659 if (!new)
2660 return;
2661
2662 list_for_each_entry_safe(old, tmp, &new->head, list) {
2663 kfree(old);
2664 }
2665 kfree(new);
2666 }
2667
2668 static void relink_file_extents(struct new_sa_defrag_extent *new)
2669 {
2670 struct btrfs_path *path;
2671 struct sa_defrag_extent_backref *backref;
2672 struct sa_defrag_extent_backref *prev = NULL;
2673 struct inode *inode;
2674 struct btrfs_root *root;
2675 struct rb_node *node;
2676 int ret;
2677
2678 inode = new->inode;
2679 root = BTRFS_I(inode)->root;
2680
2681 path = btrfs_alloc_path();
2682 if (!path)
2683 return;
2684
2685 if (!record_extent_backrefs(path, new)) {
2686 btrfs_free_path(path);
2687 goto out;
2688 }
2689 btrfs_release_path(path);
2690
2691 while (1) {
2692 node = rb_first(&new->root);
2693 if (!node)
2694 break;
2695 rb_erase(node, &new->root);
2696
2697 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2698
2699 ret = relink_extent_backref(path, prev, backref);
2700 WARN_ON(ret < 0);
2701
2702 kfree(prev);
2703
2704 if (ret == 1)
2705 prev = backref;
2706 else
2707 prev = NULL;
2708 cond_resched();
2709 }
2710 kfree(prev);
2711
2712 btrfs_free_path(path);
2713 out:
2714 free_sa_defrag_extent(new);
2715
2716 atomic_dec(&root->fs_info->defrag_running);
2717 wake_up(&root->fs_info->transaction_wait);
2718 }
2719
2720 static struct new_sa_defrag_extent *
2721 record_old_file_extents(struct inode *inode,
2722 struct btrfs_ordered_extent *ordered)
2723 {
2724 struct btrfs_root *root = BTRFS_I(inode)->root;
2725 struct btrfs_path *path;
2726 struct btrfs_key key;
2727 struct old_sa_defrag_extent *old;
2728 struct new_sa_defrag_extent *new;
2729 int ret;
2730
2731 new = kmalloc(sizeof(*new), GFP_NOFS);
2732 if (!new)
2733 return NULL;
2734
2735 new->inode = inode;
2736 new->file_pos = ordered->file_offset;
2737 new->len = ordered->len;
2738 new->bytenr = ordered->start;
2739 new->disk_len = ordered->disk_len;
2740 new->compress_type = ordered->compress_type;
2741 new->root = RB_ROOT;
2742 INIT_LIST_HEAD(&new->head);
2743
2744 path = btrfs_alloc_path();
2745 if (!path)
2746 goto out_kfree;
2747
2748 key.objectid = btrfs_ino(inode);
2749 key.type = BTRFS_EXTENT_DATA_KEY;
2750 key.offset = new->file_pos;
2751
2752 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2753 if (ret < 0)
2754 goto out_free_path;
2755 if (ret > 0 && path->slots[0] > 0)
2756 path->slots[0]--;
2757
2758 /* find out all the old extents for the file range */
2759 while (1) {
2760 struct btrfs_file_extent_item *extent;
2761 struct extent_buffer *l;
2762 int slot;
2763 u64 num_bytes;
2764 u64 offset;
2765 u64 end;
2766 u64 disk_bytenr;
2767 u64 extent_offset;
2768
2769 l = path->nodes[0];
2770 slot = path->slots[0];
2771
2772 if (slot >= btrfs_header_nritems(l)) {
2773 ret = btrfs_next_leaf(root, path);
2774 if (ret < 0)
2775 goto out_free_path;
2776 else if (ret > 0)
2777 break;
2778 continue;
2779 }
2780
2781 btrfs_item_key_to_cpu(l, &key, slot);
2782
2783 if (key.objectid != btrfs_ino(inode))
2784 break;
2785 if (key.type != BTRFS_EXTENT_DATA_KEY)
2786 break;
2787 if (key.offset >= new->file_pos + new->len)
2788 break;
2789
2790 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2791
2792 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2793 if (key.offset + num_bytes < new->file_pos)
2794 goto next;
2795
2796 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2797 if (!disk_bytenr)
2798 goto next;
2799
2800 extent_offset = btrfs_file_extent_offset(l, extent);
2801
2802 old = kmalloc(sizeof(*old), GFP_NOFS);
2803 if (!old)
2804 goto out_free_path;
2805
2806 offset = max(new->file_pos, key.offset);
2807 end = min(new->file_pos + new->len, key.offset + num_bytes);
2808
2809 old->bytenr = disk_bytenr;
2810 old->extent_offset = extent_offset;
2811 old->offset = offset - key.offset;
2812 old->len = end - offset;
2813 old->new = new;
2814 old->count = 0;
2815 list_add_tail(&old->list, &new->head);
2816 next:
2817 path->slots[0]++;
2818 cond_resched();
2819 }
2820
2821 btrfs_free_path(path);
2822 atomic_inc(&root->fs_info->defrag_running);
2823
2824 return new;
2825
2826 out_free_path:
2827 btrfs_free_path(path);
2828 out_kfree:
2829 free_sa_defrag_extent(new);
2830 return NULL;
2831 }
2832
2833 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2834 u64 start, u64 len)
2835 {
2836 struct btrfs_block_group_cache *cache;
2837
2838 cache = btrfs_lookup_block_group(root->fs_info, start);
2839 ASSERT(cache);
2840
2841 spin_lock(&cache->lock);
2842 cache->delalloc_bytes -= len;
2843 spin_unlock(&cache->lock);
2844
2845 btrfs_put_block_group(cache);
2846 }
2847
2848 /* as ordered data IO finishes, this gets called so we can finish
2849 * an ordered extent if the range of bytes in the file it covers are
2850 * fully written.
2851 */
2852 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2853 {
2854 struct inode *inode = ordered_extent->inode;
2855 struct btrfs_root *root = BTRFS_I(inode)->root;
2856 struct btrfs_trans_handle *trans = NULL;
2857 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2858 struct extent_state *cached_state = NULL;
2859 struct new_sa_defrag_extent *new = NULL;
2860 int compress_type = 0;
2861 int ret = 0;
2862 u64 logical_len = ordered_extent->len;
2863 bool nolock;
2864 bool truncated = false;
2865
2866 nolock = btrfs_is_free_space_inode(inode);
2867
2868 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2869 ret = -EIO;
2870 goto out;
2871 }
2872
2873 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2874 ordered_extent->file_offset +
2875 ordered_extent->len - 1);
2876
2877 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2878 truncated = true;
2879 logical_len = ordered_extent->truncated_len;
2880 /* Truncated the entire extent, don't bother adding */
2881 if (!logical_len)
2882 goto out;
2883 }
2884
2885 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2886 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2887
2888 /*
2889 * For mwrite(mmap + memset to write) case, we still reserve
2890 * space for NOCOW range.
2891 * As NOCOW won't cause a new delayed ref, just free the space
2892 */
2893 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2894 ordered_extent->len);
2895 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2896 if (nolock)
2897 trans = btrfs_join_transaction_nolock(root);
2898 else
2899 trans = btrfs_join_transaction(root);
2900 if (IS_ERR(trans)) {
2901 ret = PTR_ERR(trans);
2902 trans = NULL;
2903 goto out;
2904 }
2905 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2906 ret = btrfs_update_inode_fallback(trans, root, inode);
2907 if (ret) /* -ENOMEM or corruption */
2908 btrfs_abort_transaction(trans, ret);
2909 goto out;
2910 }
2911
2912 lock_extent_bits(io_tree, ordered_extent->file_offset,
2913 ordered_extent->file_offset + ordered_extent->len - 1,
2914 &cached_state);
2915
2916 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2917 ordered_extent->file_offset + ordered_extent->len - 1,
2918 EXTENT_DEFRAG, 1, cached_state);
2919 if (ret) {
2920 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2921 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2922 /* the inode is shared */
2923 new = record_old_file_extents(inode, ordered_extent);
2924
2925 clear_extent_bit(io_tree, ordered_extent->file_offset,
2926 ordered_extent->file_offset + ordered_extent->len - 1,
2927 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2928 }
2929
2930 if (nolock)
2931 trans = btrfs_join_transaction_nolock(root);
2932 else
2933 trans = btrfs_join_transaction(root);
2934 if (IS_ERR(trans)) {
2935 ret = PTR_ERR(trans);
2936 trans = NULL;
2937 goto out_unlock;
2938 }
2939
2940 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2941
2942 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2943 compress_type = ordered_extent->compress_type;
2944 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2945 BUG_ON(compress_type);
2946 ret = btrfs_mark_extent_written(trans, inode,
2947 ordered_extent->file_offset,
2948 ordered_extent->file_offset +
2949 logical_len);
2950 } else {
2951 BUG_ON(root == root->fs_info->tree_root);
2952 ret = insert_reserved_file_extent(trans, inode,
2953 ordered_extent->file_offset,
2954 ordered_extent->start,
2955 ordered_extent->disk_len,
2956 logical_len, logical_len,
2957 compress_type, 0, 0,
2958 BTRFS_FILE_EXTENT_REG);
2959 if (!ret)
2960 btrfs_release_delalloc_bytes(root,
2961 ordered_extent->start,
2962 ordered_extent->disk_len);
2963 }
2964 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2965 ordered_extent->file_offset, ordered_extent->len,
2966 trans->transid);
2967 if (ret < 0) {
2968 btrfs_abort_transaction(trans, ret);
2969 goto out_unlock;
2970 }
2971
2972 add_pending_csums(trans, inode, ordered_extent->file_offset,
2973 &ordered_extent->list);
2974
2975 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2976 ret = btrfs_update_inode_fallback(trans, root, inode);
2977 if (ret) { /* -ENOMEM or corruption */
2978 btrfs_abort_transaction(trans, ret);
2979 goto out_unlock;
2980 }
2981 ret = 0;
2982 out_unlock:
2983 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2984 ordered_extent->file_offset +
2985 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2986 out:
2987 if (root != root->fs_info->tree_root)
2988 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2989 if (trans)
2990 btrfs_end_transaction(trans, root);
2991
2992 if (ret || truncated) {
2993 u64 start, end;
2994
2995 if (truncated)
2996 start = ordered_extent->file_offset + logical_len;
2997 else
2998 start = ordered_extent->file_offset;
2999 end = ordered_extent->file_offset + ordered_extent->len - 1;
3000 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3001
3002 /* Drop the cache for the part of the extent we didn't write. */
3003 btrfs_drop_extent_cache(inode, start, end, 0);
3004
3005 /*
3006 * If the ordered extent had an IOERR or something else went
3007 * wrong we need to return the space for this ordered extent
3008 * back to the allocator. We only free the extent in the
3009 * truncated case if we didn't write out the extent at all.
3010 */
3011 if ((ret || !logical_len) &&
3012 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3013 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3014 btrfs_free_reserved_extent(root, ordered_extent->start,
3015 ordered_extent->disk_len, 1);
3016 }
3017
3018
3019 /*
3020 * This needs to be done to make sure anybody waiting knows we are done
3021 * updating everything for this ordered extent.
3022 */
3023 btrfs_remove_ordered_extent(inode, ordered_extent);
3024
3025 /* for snapshot-aware defrag */
3026 if (new) {
3027 if (ret) {
3028 free_sa_defrag_extent(new);
3029 atomic_dec(&root->fs_info->defrag_running);
3030 } else {
3031 relink_file_extents(new);
3032 }
3033 }
3034
3035 /* once for us */
3036 btrfs_put_ordered_extent(ordered_extent);
3037 /* once for the tree */
3038 btrfs_put_ordered_extent(ordered_extent);
3039
3040 return ret;
3041 }
3042
3043 static void finish_ordered_fn(struct btrfs_work *work)
3044 {
3045 struct btrfs_ordered_extent *ordered_extent;
3046 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3047 btrfs_finish_ordered_io(ordered_extent);
3048 }
3049
3050 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3051 struct extent_state *state, int uptodate)
3052 {
3053 struct inode *inode = page->mapping->host;
3054 struct btrfs_root *root = BTRFS_I(inode)->root;
3055 struct btrfs_ordered_extent *ordered_extent = NULL;
3056 struct btrfs_workqueue *wq;
3057 btrfs_work_func_t func;
3058
3059 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3060
3061 ClearPagePrivate2(page);
3062 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3063 end - start + 1, uptodate))
3064 return 0;
3065
3066 if (btrfs_is_free_space_inode(inode)) {
3067 wq = root->fs_info->endio_freespace_worker;
3068 func = btrfs_freespace_write_helper;
3069 } else {
3070 wq = root->fs_info->endio_write_workers;
3071 func = btrfs_endio_write_helper;
3072 }
3073
3074 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3075 NULL);
3076 btrfs_queue_work(wq, &ordered_extent->work);
3077
3078 return 0;
3079 }
3080
3081 static int __readpage_endio_check(struct inode *inode,
3082 struct btrfs_io_bio *io_bio,
3083 int icsum, struct page *page,
3084 int pgoff, u64 start, size_t len)
3085 {
3086 char *kaddr;
3087 u32 csum_expected;
3088 u32 csum = ~(u32)0;
3089
3090 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3091
3092 kaddr = kmap_atomic(page);
3093 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3094 btrfs_csum_final(csum, (char *)&csum);
3095 if (csum != csum_expected)
3096 goto zeroit;
3097
3098 kunmap_atomic(kaddr);
3099 return 0;
3100 zeroit:
3101 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3102 "csum failed ino %llu off %llu csum %u expected csum %u",
3103 btrfs_ino(inode), start, csum, csum_expected);
3104 memset(kaddr + pgoff, 1, len);
3105 flush_dcache_page(page);
3106 kunmap_atomic(kaddr);
3107 if (csum_expected == 0)
3108 return 0;
3109 return -EIO;
3110 }
3111
3112 /*
3113 * when reads are done, we need to check csums to verify the data is correct
3114 * if there's a match, we allow the bio to finish. If not, the code in
3115 * extent_io.c will try to find good copies for us.
3116 */
3117 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3118 u64 phy_offset, struct page *page,
3119 u64 start, u64 end, int mirror)
3120 {
3121 size_t offset = start - page_offset(page);
3122 struct inode *inode = page->mapping->host;
3123 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3124 struct btrfs_root *root = BTRFS_I(inode)->root;
3125
3126 if (PageChecked(page)) {
3127 ClearPageChecked(page);
3128 return 0;
3129 }
3130
3131 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3132 return 0;
3133
3134 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3135 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3136 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3137 return 0;
3138 }
3139
3140 phy_offset >>= inode->i_sb->s_blocksize_bits;
3141 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3142 start, (size_t)(end - start + 1));
3143 }
3144
3145 void btrfs_add_delayed_iput(struct inode *inode)
3146 {
3147 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3148 struct btrfs_inode *binode = BTRFS_I(inode);
3149
3150 if (atomic_add_unless(&inode->i_count, -1, 1))
3151 return;
3152
3153 spin_lock(&fs_info->delayed_iput_lock);
3154 if (binode->delayed_iput_count == 0) {
3155 ASSERT(list_empty(&binode->delayed_iput));
3156 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3157 } else {
3158 binode->delayed_iput_count++;
3159 }
3160 spin_unlock(&fs_info->delayed_iput_lock);
3161 }
3162
3163 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3164 {
3165 struct btrfs_fs_info *fs_info = root->fs_info;
3166
3167 spin_lock(&fs_info->delayed_iput_lock);
3168 while (!list_empty(&fs_info->delayed_iputs)) {
3169 struct btrfs_inode *inode;
3170
3171 inode = list_first_entry(&fs_info->delayed_iputs,
3172 struct btrfs_inode, delayed_iput);
3173 if (inode->delayed_iput_count) {
3174 inode->delayed_iput_count--;
3175 list_move_tail(&inode->delayed_iput,
3176 &fs_info->delayed_iputs);
3177 } else {
3178 list_del_init(&inode->delayed_iput);
3179 }
3180 spin_unlock(&fs_info->delayed_iput_lock);
3181 iput(&inode->vfs_inode);
3182 spin_lock(&fs_info->delayed_iput_lock);
3183 }
3184 spin_unlock(&fs_info->delayed_iput_lock);
3185 }
3186
3187 /*
3188 * This is called in transaction commit time. If there are no orphan
3189 * files in the subvolume, it removes orphan item and frees block_rsv
3190 * structure.
3191 */
3192 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3193 struct btrfs_root *root)
3194 {
3195 struct btrfs_block_rsv *block_rsv;
3196 int ret;
3197
3198 if (atomic_read(&root->orphan_inodes) ||
3199 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3200 return;
3201
3202 spin_lock(&root->orphan_lock);
3203 if (atomic_read(&root->orphan_inodes)) {
3204 spin_unlock(&root->orphan_lock);
3205 return;
3206 }
3207
3208 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3209 spin_unlock(&root->orphan_lock);
3210 return;
3211 }
3212
3213 block_rsv = root->orphan_block_rsv;
3214 root->orphan_block_rsv = NULL;
3215 spin_unlock(&root->orphan_lock);
3216
3217 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3218 btrfs_root_refs(&root->root_item) > 0) {
3219 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3220 root->root_key.objectid);
3221 if (ret)
3222 btrfs_abort_transaction(trans, ret);
3223 else
3224 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3225 &root->state);
3226 }
3227
3228 if (block_rsv) {
3229 WARN_ON(block_rsv->size > 0);
3230 btrfs_free_block_rsv(root, block_rsv);
3231 }
3232 }
3233
3234 /*
3235 * This creates an orphan entry for the given inode in case something goes
3236 * wrong in the middle of an unlink/truncate.
3237 *
3238 * NOTE: caller of this function should reserve 5 units of metadata for
3239 * this function.
3240 */
3241 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3242 {
3243 struct btrfs_root *root = BTRFS_I(inode)->root;
3244 struct btrfs_block_rsv *block_rsv = NULL;
3245 int reserve = 0;
3246 int insert = 0;
3247 int ret;
3248
3249 if (!root->orphan_block_rsv) {
3250 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3251 if (!block_rsv)
3252 return -ENOMEM;
3253 }
3254
3255 spin_lock(&root->orphan_lock);
3256 if (!root->orphan_block_rsv) {
3257 root->orphan_block_rsv = block_rsv;
3258 } else if (block_rsv) {
3259 btrfs_free_block_rsv(root, block_rsv);
3260 block_rsv = NULL;
3261 }
3262
3263 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3264 &BTRFS_I(inode)->runtime_flags)) {
3265 #if 0
3266 /*
3267 * For proper ENOSPC handling, we should do orphan
3268 * cleanup when mounting. But this introduces backward
3269 * compatibility issue.
3270 */
3271 if (!xchg(&root->orphan_item_inserted, 1))
3272 insert = 2;
3273 else
3274 insert = 1;
3275 #endif
3276 insert = 1;
3277 atomic_inc(&root->orphan_inodes);
3278 }
3279
3280 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3281 &BTRFS_I(inode)->runtime_flags))
3282 reserve = 1;
3283 spin_unlock(&root->orphan_lock);
3284
3285 /* grab metadata reservation from transaction handle */
3286 if (reserve) {
3287 ret = btrfs_orphan_reserve_metadata(trans, inode);
3288 ASSERT(!ret);
3289 if (ret) {
3290 atomic_dec(&root->orphan_inodes);
3291 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3292 &BTRFS_I(inode)->runtime_flags);
3293 if (insert)
3294 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3295 &BTRFS_I(inode)->runtime_flags);
3296 return ret;
3297 }
3298 }
3299
3300 /* insert an orphan item to track this unlinked/truncated file */
3301 if (insert >= 1) {
3302 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3303 if (ret) {
3304 atomic_dec(&root->orphan_inodes);
3305 if (reserve) {
3306 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3307 &BTRFS_I(inode)->runtime_flags);
3308 btrfs_orphan_release_metadata(inode);
3309 }
3310 if (ret != -EEXIST) {
3311 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3312 &BTRFS_I(inode)->runtime_flags);
3313 btrfs_abort_transaction(trans, ret);
3314 return ret;
3315 }
3316 }
3317 ret = 0;
3318 }
3319
3320 /* insert an orphan item to track subvolume contains orphan files */
3321 if (insert >= 2) {
3322 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3323 root->root_key.objectid);
3324 if (ret && ret != -EEXIST) {
3325 btrfs_abort_transaction(trans, ret);
3326 return ret;
3327 }
3328 }
3329 return 0;
3330 }
3331
3332 /*
3333 * We have done the truncate/delete so we can go ahead and remove the orphan
3334 * item for this particular inode.
3335 */
3336 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3337 struct inode *inode)
3338 {
3339 struct btrfs_root *root = BTRFS_I(inode)->root;
3340 int delete_item = 0;
3341 int release_rsv = 0;
3342 int ret = 0;
3343
3344 spin_lock(&root->orphan_lock);
3345 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3346 &BTRFS_I(inode)->runtime_flags))
3347 delete_item = 1;
3348
3349 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3350 &BTRFS_I(inode)->runtime_flags))
3351 release_rsv = 1;
3352 spin_unlock(&root->orphan_lock);
3353
3354 if (delete_item) {
3355 atomic_dec(&root->orphan_inodes);
3356 if (trans)
3357 ret = btrfs_del_orphan_item(trans, root,
3358 btrfs_ino(inode));
3359 }
3360
3361 if (release_rsv)
3362 btrfs_orphan_release_metadata(inode);
3363
3364 return ret;
3365 }
3366
3367 /*
3368 * this cleans up any orphans that may be left on the list from the last use
3369 * of this root.
3370 */
3371 int btrfs_orphan_cleanup(struct btrfs_root *root)
3372 {
3373 struct btrfs_path *path;
3374 struct extent_buffer *leaf;
3375 struct btrfs_key key, found_key;
3376 struct btrfs_trans_handle *trans;
3377 struct inode *inode;
3378 u64 last_objectid = 0;
3379 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3380
3381 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3382 return 0;
3383
3384 path = btrfs_alloc_path();
3385 if (!path) {
3386 ret = -ENOMEM;
3387 goto out;
3388 }
3389 path->reada = READA_BACK;
3390
3391 key.objectid = BTRFS_ORPHAN_OBJECTID;
3392 key.type = BTRFS_ORPHAN_ITEM_KEY;
3393 key.offset = (u64)-1;
3394
3395 while (1) {
3396 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3397 if (ret < 0)
3398 goto out;
3399
3400 /*
3401 * if ret == 0 means we found what we were searching for, which
3402 * is weird, but possible, so only screw with path if we didn't
3403 * find the key and see if we have stuff that matches
3404 */
3405 if (ret > 0) {
3406 ret = 0;
3407 if (path->slots[0] == 0)
3408 break;
3409 path->slots[0]--;
3410 }
3411
3412 /* pull out the item */
3413 leaf = path->nodes[0];
3414 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3415
3416 /* make sure the item matches what we want */
3417 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3418 break;
3419 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3420 break;
3421
3422 /* release the path since we're done with it */
3423 btrfs_release_path(path);
3424
3425 /*
3426 * this is where we are basically btrfs_lookup, without the
3427 * crossing root thing. we store the inode number in the
3428 * offset of the orphan item.
3429 */
3430
3431 if (found_key.offset == last_objectid) {
3432 btrfs_err(root->fs_info,
3433 "Error removing orphan entry, stopping orphan cleanup");
3434 ret = -EINVAL;
3435 goto out;
3436 }
3437
3438 last_objectid = found_key.offset;
3439
3440 found_key.objectid = found_key.offset;
3441 found_key.type = BTRFS_INODE_ITEM_KEY;
3442 found_key.offset = 0;
3443 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3444 ret = PTR_ERR_OR_ZERO(inode);
3445 if (ret && ret != -ENOENT)
3446 goto out;
3447
3448 if (ret == -ENOENT && root == root->fs_info->tree_root) {
3449 struct btrfs_root *dead_root;
3450 struct btrfs_fs_info *fs_info = root->fs_info;
3451 int is_dead_root = 0;
3452
3453 /*
3454 * this is an orphan in the tree root. Currently these
3455 * could come from 2 sources:
3456 * a) a snapshot deletion in progress
3457 * b) a free space cache inode
3458 * We need to distinguish those two, as the snapshot
3459 * orphan must not get deleted.
3460 * find_dead_roots already ran before us, so if this
3461 * is a snapshot deletion, we should find the root
3462 * in the dead_roots list
3463 */
3464 spin_lock(&fs_info->trans_lock);
3465 list_for_each_entry(dead_root, &fs_info->dead_roots,
3466 root_list) {
3467 if (dead_root->root_key.objectid ==
3468 found_key.objectid) {
3469 is_dead_root = 1;
3470 break;
3471 }
3472 }
3473 spin_unlock(&fs_info->trans_lock);
3474 if (is_dead_root) {
3475 /* prevent this orphan from being found again */
3476 key.offset = found_key.objectid - 1;
3477 continue;
3478 }
3479 }
3480 /*
3481 * Inode is already gone but the orphan item is still there,
3482 * kill the orphan item.
3483 */
3484 if (ret == -ENOENT) {
3485 trans = btrfs_start_transaction(root, 1);
3486 if (IS_ERR(trans)) {
3487 ret = PTR_ERR(trans);
3488 goto out;
3489 }
3490 btrfs_debug(root->fs_info, "auto deleting %Lu",
3491 found_key.objectid);
3492 ret = btrfs_del_orphan_item(trans, root,
3493 found_key.objectid);
3494 btrfs_end_transaction(trans, root);
3495 if (ret)
3496 goto out;
3497 continue;
3498 }
3499
3500 /*
3501 * add this inode to the orphan list so btrfs_orphan_del does
3502 * the proper thing when we hit it
3503 */
3504 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3505 &BTRFS_I(inode)->runtime_flags);
3506 atomic_inc(&root->orphan_inodes);
3507
3508 /* if we have links, this was a truncate, lets do that */
3509 if (inode->i_nlink) {
3510 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3511 iput(inode);
3512 continue;
3513 }
3514 nr_truncate++;
3515
3516 /* 1 for the orphan item deletion. */
3517 trans = btrfs_start_transaction(root, 1);
3518 if (IS_ERR(trans)) {
3519 iput(inode);
3520 ret = PTR_ERR(trans);
3521 goto out;
3522 }
3523 ret = btrfs_orphan_add(trans, inode);
3524 btrfs_end_transaction(trans, root);
3525 if (ret) {
3526 iput(inode);
3527 goto out;
3528 }
3529
3530 ret = btrfs_truncate(inode);
3531 if (ret)
3532 btrfs_orphan_del(NULL, inode);
3533 } else {
3534 nr_unlink++;
3535 }
3536
3537 /* this will do delete_inode and everything for us */
3538 iput(inode);
3539 if (ret)
3540 goto out;
3541 }
3542 /* release the path since we're done with it */
3543 btrfs_release_path(path);
3544
3545 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3546
3547 if (root->orphan_block_rsv)
3548 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3549 (u64)-1);
3550
3551 if (root->orphan_block_rsv ||
3552 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3553 trans = btrfs_join_transaction(root);
3554 if (!IS_ERR(trans))
3555 btrfs_end_transaction(trans, root);
3556 }
3557
3558 if (nr_unlink)
3559 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3560 if (nr_truncate)
3561 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3562
3563 out:
3564 if (ret)
3565 btrfs_err(root->fs_info,
3566 "could not do orphan cleanup %d", ret);
3567 btrfs_free_path(path);
3568 return ret;
3569 }
3570
3571 /*
3572 * very simple check to peek ahead in the leaf looking for xattrs. If we
3573 * don't find any xattrs, we know there can't be any acls.
3574 *
3575 * slot is the slot the inode is in, objectid is the objectid of the inode
3576 */
3577 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3578 int slot, u64 objectid,
3579 int *first_xattr_slot)
3580 {
3581 u32 nritems = btrfs_header_nritems(leaf);
3582 struct btrfs_key found_key;
3583 static u64 xattr_access = 0;
3584 static u64 xattr_default = 0;
3585 int scanned = 0;
3586
3587 if (!xattr_access) {
3588 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3589 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3590 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3591 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3592 }
3593
3594 slot++;
3595 *first_xattr_slot = -1;
3596 while (slot < nritems) {
3597 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3598
3599 /* we found a different objectid, there must not be acls */
3600 if (found_key.objectid != objectid)
3601 return 0;
3602
3603 /* we found an xattr, assume we've got an acl */
3604 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3605 if (*first_xattr_slot == -1)
3606 *first_xattr_slot = slot;
3607 if (found_key.offset == xattr_access ||
3608 found_key.offset == xattr_default)
3609 return 1;
3610 }
3611
3612 /*
3613 * we found a key greater than an xattr key, there can't
3614 * be any acls later on
3615 */
3616 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3617 return 0;
3618
3619 slot++;
3620 scanned++;
3621
3622 /*
3623 * it goes inode, inode backrefs, xattrs, extents,
3624 * so if there are a ton of hard links to an inode there can
3625 * be a lot of backrefs. Don't waste time searching too hard,
3626 * this is just an optimization
3627 */
3628 if (scanned >= 8)
3629 break;
3630 }
3631 /* we hit the end of the leaf before we found an xattr or
3632 * something larger than an xattr. We have to assume the inode
3633 * has acls
3634 */
3635 if (*first_xattr_slot == -1)
3636 *first_xattr_slot = slot;
3637 return 1;
3638 }
3639
3640 /*
3641 * read an inode from the btree into the in-memory inode
3642 */
3643 static int btrfs_read_locked_inode(struct inode *inode)
3644 {
3645 struct btrfs_path *path;
3646 struct extent_buffer *leaf;
3647 struct btrfs_inode_item *inode_item;
3648 struct btrfs_root *root = BTRFS_I(inode)->root;
3649 struct btrfs_key location;
3650 unsigned long ptr;
3651 int maybe_acls;
3652 u32 rdev;
3653 int ret;
3654 bool filled = false;
3655 int first_xattr_slot;
3656
3657 ret = btrfs_fill_inode(inode, &rdev);
3658 if (!ret)
3659 filled = true;
3660
3661 path = btrfs_alloc_path();
3662 if (!path) {
3663 ret = -ENOMEM;
3664 goto make_bad;
3665 }
3666
3667 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3668
3669 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3670 if (ret) {
3671 if (ret > 0)
3672 ret = -ENOENT;
3673 goto make_bad;
3674 }
3675
3676 leaf = path->nodes[0];
3677
3678 if (filled)
3679 goto cache_index;
3680
3681 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3682 struct btrfs_inode_item);
3683 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3684 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3685 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3686 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3687 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3688
3689 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3690 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3691
3692 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3693 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3694
3695 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3696 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3697
3698 BTRFS_I(inode)->i_otime.tv_sec =
3699 btrfs_timespec_sec(leaf, &inode_item->otime);
3700 BTRFS_I(inode)->i_otime.tv_nsec =
3701 btrfs_timespec_nsec(leaf, &inode_item->otime);
3702
3703 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3704 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3705 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3706
3707 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3708 inode->i_generation = BTRFS_I(inode)->generation;
3709 inode->i_rdev = 0;
3710 rdev = btrfs_inode_rdev(leaf, inode_item);
3711
3712 BTRFS_I(inode)->index_cnt = (u64)-1;
3713 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3714
3715 cache_index:
3716 /*
3717 * If we were modified in the current generation and evicted from memory
3718 * and then re-read we need to do a full sync since we don't have any
3719 * idea about which extents were modified before we were evicted from
3720 * cache.
3721 *
3722 * This is required for both inode re-read from disk and delayed inode
3723 * in delayed_nodes_tree.
3724 */
3725 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3726 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3727 &BTRFS_I(inode)->runtime_flags);
3728
3729 /*
3730 * We don't persist the id of the transaction where an unlink operation
3731 * against the inode was last made. So here we assume the inode might
3732 * have been evicted, and therefore the exact value of last_unlink_trans
3733 * lost, and set it to last_trans to avoid metadata inconsistencies
3734 * between the inode and its parent if the inode is fsync'ed and the log
3735 * replayed. For example, in the scenario:
3736 *
3737 * touch mydir/foo
3738 * ln mydir/foo mydir/bar
3739 * sync
3740 * unlink mydir/bar
3741 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3742 * xfs_io -c fsync mydir/foo
3743 * <power failure>
3744 * mount fs, triggers fsync log replay
3745 *
3746 * We must make sure that when we fsync our inode foo we also log its
3747 * parent inode, otherwise after log replay the parent still has the
3748 * dentry with the "bar" name but our inode foo has a link count of 1
3749 * and doesn't have an inode ref with the name "bar" anymore.
3750 *
3751 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3752 * but it guarantees correctness at the expense of occasional full
3753 * transaction commits on fsync if our inode is a directory, or if our
3754 * inode is not a directory, logging its parent unnecessarily.
3755 */
3756 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3757
3758 path->slots[0]++;
3759 if (inode->i_nlink != 1 ||
3760 path->slots[0] >= btrfs_header_nritems(leaf))
3761 goto cache_acl;
3762
3763 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3764 if (location.objectid != btrfs_ino(inode))
3765 goto cache_acl;
3766
3767 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3768 if (location.type == BTRFS_INODE_REF_KEY) {
3769 struct btrfs_inode_ref *ref;
3770
3771 ref = (struct btrfs_inode_ref *)ptr;
3772 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3773 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3774 struct btrfs_inode_extref *extref;
3775
3776 extref = (struct btrfs_inode_extref *)ptr;
3777 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3778 extref);
3779 }
3780 cache_acl:
3781 /*
3782 * try to precache a NULL acl entry for files that don't have
3783 * any xattrs or acls
3784 */
3785 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3786 btrfs_ino(inode), &first_xattr_slot);
3787 if (first_xattr_slot != -1) {
3788 path->slots[0] = first_xattr_slot;
3789 ret = btrfs_load_inode_props(inode, path);
3790 if (ret)
3791 btrfs_err(root->fs_info,
3792 "error loading props for ino %llu (root %llu): %d",
3793 btrfs_ino(inode),
3794 root->root_key.objectid, ret);
3795 }
3796 btrfs_free_path(path);
3797
3798 if (!maybe_acls)
3799 cache_no_acl(inode);
3800
3801 switch (inode->i_mode & S_IFMT) {
3802 case S_IFREG:
3803 inode->i_mapping->a_ops = &btrfs_aops;
3804 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3805 inode->i_fop = &btrfs_file_operations;
3806 inode->i_op = &btrfs_file_inode_operations;
3807 break;
3808 case S_IFDIR:
3809 inode->i_fop = &btrfs_dir_file_operations;
3810 if (root == root->fs_info->tree_root)
3811 inode->i_op = &btrfs_dir_ro_inode_operations;
3812 else
3813 inode->i_op = &btrfs_dir_inode_operations;
3814 break;
3815 case S_IFLNK:
3816 inode->i_op = &btrfs_symlink_inode_operations;
3817 inode_nohighmem(inode);
3818 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3819 break;
3820 default:
3821 inode->i_op = &btrfs_special_inode_operations;
3822 init_special_inode(inode, inode->i_mode, rdev);
3823 break;
3824 }
3825
3826 btrfs_update_iflags(inode);
3827 return 0;
3828
3829 make_bad:
3830 btrfs_free_path(path);
3831 make_bad_inode(inode);
3832 return ret;
3833 }
3834
3835 /*
3836 * given a leaf and an inode, copy the inode fields into the leaf
3837 */
3838 static void fill_inode_item(struct btrfs_trans_handle *trans,
3839 struct extent_buffer *leaf,
3840 struct btrfs_inode_item *item,
3841 struct inode *inode)
3842 {
3843 struct btrfs_map_token token;
3844
3845 btrfs_init_map_token(&token);
3846
3847 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3848 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3849 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3850 &token);
3851 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3852 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3853
3854 btrfs_set_token_timespec_sec(leaf, &item->atime,
3855 inode->i_atime.tv_sec, &token);
3856 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3857 inode->i_atime.tv_nsec, &token);
3858
3859 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3860 inode->i_mtime.tv_sec, &token);
3861 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3862 inode->i_mtime.tv_nsec, &token);
3863
3864 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3865 inode->i_ctime.tv_sec, &token);
3866 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3867 inode->i_ctime.tv_nsec, &token);
3868
3869 btrfs_set_token_timespec_sec(leaf, &item->otime,
3870 BTRFS_I(inode)->i_otime.tv_sec, &token);
3871 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3872 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3873
3874 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3875 &token);
3876 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3877 &token);
3878 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3879 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3880 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3881 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3882 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3883 }
3884
3885 /*
3886 * copy everything in the in-memory inode into the btree.
3887 */
3888 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3889 struct btrfs_root *root, struct inode *inode)
3890 {
3891 struct btrfs_inode_item *inode_item;
3892 struct btrfs_path *path;
3893 struct extent_buffer *leaf;
3894 int ret;
3895
3896 path = btrfs_alloc_path();
3897 if (!path)
3898 return -ENOMEM;
3899
3900 path->leave_spinning = 1;
3901 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3902 1);
3903 if (ret) {
3904 if (ret > 0)
3905 ret = -ENOENT;
3906 goto failed;
3907 }
3908
3909 leaf = path->nodes[0];
3910 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3911 struct btrfs_inode_item);
3912
3913 fill_inode_item(trans, leaf, inode_item, inode);
3914 btrfs_mark_buffer_dirty(leaf);
3915 btrfs_set_inode_last_trans(trans, inode);
3916 ret = 0;
3917 failed:
3918 btrfs_free_path(path);
3919 return ret;
3920 }
3921
3922 /*
3923 * copy everything in the in-memory inode into the btree.
3924 */
3925 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3926 struct btrfs_root *root, struct inode *inode)
3927 {
3928 int ret;
3929
3930 /*
3931 * If the inode is a free space inode, we can deadlock during commit
3932 * if we put it into the delayed code.
3933 *
3934 * The data relocation inode should also be directly updated
3935 * without delay
3936 */
3937 if (!btrfs_is_free_space_inode(inode)
3938 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3939 && !root->fs_info->log_root_recovering) {
3940 btrfs_update_root_times(trans, root);
3941
3942 ret = btrfs_delayed_update_inode(trans, root, inode);
3943 if (!ret)
3944 btrfs_set_inode_last_trans(trans, inode);
3945 return ret;
3946 }
3947
3948 return btrfs_update_inode_item(trans, root, inode);
3949 }
3950
3951 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3952 struct btrfs_root *root,
3953 struct inode *inode)
3954 {
3955 int ret;
3956
3957 ret = btrfs_update_inode(trans, root, inode);
3958 if (ret == -ENOSPC)
3959 return btrfs_update_inode_item(trans, root, inode);
3960 return ret;
3961 }
3962
3963 /*
3964 * unlink helper that gets used here in inode.c and in the tree logging
3965 * recovery code. It remove a link in a directory with a given name, and
3966 * also drops the back refs in the inode to the directory
3967 */
3968 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3969 struct btrfs_root *root,
3970 struct inode *dir, struct inode *inode,
3971 const char *name, int name_len)
3972 {
3973 struct btrfs_path *path;
3974 int ret = 0;
3975 struct extent_buffer *leaf;
3976 struct btrfs_dir_item *di;
3977 struct btrfs_key key;
3978 u64 index;
3979 u64 ino = btrfs_ino(inode);
3980 u64 dir_ino = btrfs_ino(dir);
3981
3982 path = btrfs_alloc_path();
3983 if (!path) {
3984 ret = -ENOMEM;
3985 goto out;
3986 }
3987
3988 path->leave_spinning = 1;
3989 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3990 name, name_len, -1);
3991 if (IS_ERR(di)) {
3992 ret = PTR_ERR(di);
3993 goto err;
3994 }
3995 if (!di) {
3996 ret = -ENOENT;
3997 goto err;
3998 }
3999 leaf = path->nodes[0];
4000 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4001 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4002 if (ret)
4003 goto err;
4004 btrfs_release_path(path);
4005
4006 /*
4007 * If we don't have dir index, we have to get it by looking up
4008 * the inode ref, since we get the inode ref, remove it directly,
4009 * it is unnecessary to do delayed deletion.
4010 *
4011 * But if we have dir index, needn't search inode ref to get it.
4012 * Since the inode ref is close to the inode item, it is better
4013 * that we delay to delete it, and just do this deletion when
4014 * we update the inode item.
4015 */
4016 if (BTRFS_I(inode)->dir_index) {
4017 ret = btrfs_delayed_delete_inode_ref(inode);
4018 if (!ret) {
4019 index = BTRFS_I(inode)->dir_index;
4020 goto skip_backref;
4021 }
4022 }
4023
4024 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4025 dir_ino, &index);
4026 if (ret) {
4027 btrfs_info(root->fs_info,
4028 "failed to delete reference to %.*s, inode %llu parent %llu",
4029 name_len, name, ino, dir_ino);
4030 btrfs_abort_transaction(trans, ret);
4031 goto err;
4032 }
4033 skip_backref:
4034 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4035 if (ret) {
4036 btrfs_abort_transaction(trans, ret);
4037 goto err;
4038 }
4039
4040 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4041 inode, dir_ino);
4042 if (ret != 0 && ret != -ENOENT) {
4043 btrfs_abort_transaction(trans, ret);
4044 goto err;
4045 }
4046
4047 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4048 dir, index);
4049 if (ret == -ENOENT)
4050 ret = 0;
4051 else if (ret)
4052 btrfs_abort_transaction(trans, ret);
4053 err:
4054 btrfs_free_path(path);
4055 if (ret)
4056 goto out;
4057
4058 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4059 inode_inc_iversion(inode);
4060 inode_inc_iversion(dir);
4061 inode->i_ctime = dir->i_mtime =
4062 dir->i_ctime = current_time(inode);
4063 ret = btrfs_update_inode(trans, root, dir);
4064 out:
4065 return ret;
4066 }
4067
4068 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4069 struct btrfs_root *root,
4070 struct inode *dir, struct inode *inode,
4071 const char *name, int name_len)
4072 {
4073 int ret;
4074 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4075 if (!ret) {
4076 drop_nlink(inode);
4077 ret = btrfs_update_inode(trans, root, inode);
4078 }
4079 return ret;
4080 }
4081
4082 /*
4083 * helper to start transaction for unlink and rmdir.
4084 *
4085 * unlink and rmdir are special in btrfs, they do not always free space, so
4086 * if we cannot make our reservations the normal way try and see if there is
4087 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4088 * allow the unlink to occur.
4089 */
4090 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4091 {
4092 struct btrfs_root *root = BTRFS_I(dir)->root;
4093
4094 /*
4095 * 1 for the possible orphan item
4096 * 1 for the dir item
4097 * 1 for the dir index
4098 * 1 for the inode ref
4099 * 1 for the inode
4100 */
4101 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4102 }
4103
4104 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4105 {
4106 struct btrfs_root *root = BTRFS_I(dir)->root;
4107 struct btrfs_trans_handle *trans;
4108 struct inode *inode = d_inode(dentry);
4109 int ret;
4110
4111 trans = __unlink_start_trans(dir);
4112 if (IS_ERR(trans))
4113 return PTR_ERR(trans);
4114
4115 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4116
4117 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4118 dentry->d_name.name, dentry->d_name.len);
4119 if (ret)
4120 goto out;
4121
4122 if (inode->i_nlink == 0) {
4123 ret = btrfs_orphan_add(trans, inode);
4124 if (ret)
4125 goto out;
4126 }
4127
4128 out:
4129 btrfs_end_transaction(trans, root);
4130 btrfs_btree_balance_dirty(root);
4131 return ret;
4132 }
4133
4134 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4135 struct btrfs_root *root,
4136 struct inode *dir, u64 objectid,
4137 const char *name, int name_len)
4138 {
4139 struct btrfs_path *path;
4140 struct extent_buffer *leaf;
4141 struct btrfs_dir_item *di;
4142 struct btrfs_key key;
4143 u64 index;
4144 int ret;
4145 u64 dir_ino = btrfs_ino(dir);
4146
4147 path = btrfs_alloc_path();
4148 if (!path)
4149 return -ENOMEM;
4150
4151 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4152 name, name_len, -1);
4153 if (IS_ERR_OR_NULL(di)) {
4154 if (!di)
4155 ret = -ENOENT;
4156 else
4157 ret = PTR_ERR(di);
4158 goto out;
4159 }
4160
4161 leaf = path->nodes[0];
4162 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4163 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4164 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4165 if (ret) {
4166 btrfs_abort_transaction(trans, ret);
4167 goto out;
4168 }
4169 btrfs_release_path(path);
4170
4171 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4172 objectid, root->root_key.objectid,
4173 dir_ino, &index, name, name_len);
4174 if (ret < 0) {
4175 if (ret != -ENOENT) {
4176 btrfs_abort_transaction(trans, ret);
4177 goto out;
4178 }
4179 di = btrfs_search_dir_index_item(root, path, dir_ino,
4180 name, name_len);
4181 if (IS_ERR_OR_NULL(di)) {
4182 if (!di)
4183 ret = -ENOENT;
4184 else
4185 ret = PTR_ERR(di);
4186 btrfs_abort_transaction(trans, ret);
4187 goto out;
4188 }
4189
4190 leaf = path->nodes[0];
4191 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4192 btrfs_release_path(path);
4193 index = key.offset;
4194 }
4195 btrfs_release_path(path);
4196
4197 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4198 if (ret) {
4199 btrfs_abort_transaction(trans, ret);
4200 goto out;
4201 }
4202
4203 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4204 inode_inc_iversion(dir);
4205 dir->i_mtime = dir->i_ctime = current_time(dir);
4206 ret = btrfs_update_inode_fallback(trans, root, dir);
4207 if (ret)
4208 btrfs_abort_transaction(trans, ret);
4209 out:
4210 btrfs_free_path(path);
4211 return ret;
4212 }
4213
4214 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4215 {
4216 struct inode *inode = d_inode(dentry);
4217 int err = 0;
4218 struct btrfs_root *root = BTRFS_I(dir)->root;
4219 struct btrfs_trans_handle *trans;
4220 u64 last_unlink_trans;
4221
4222 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4223 return -ENOTEMPTY;
4224 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4225 return -EPERM;
4226
4227 trans = __unlink_start_trans(dir);
4228 if (IS_ERR(trans))
4229 return PTR_ERR(trans);
4230
4231 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4232 err = btrfs_unlink_subvol(trans, root, dir,
4233 BTRFS_I(inode)->location.objectid,
4234 dentry->d_name.name,
4235 dentry->d_name.len);
4236 goto out;
4237 }
4238
4239 err = btrfs_orphan_add(trans, inode);
4240 if (err)
4241 goto out;
4242
4243 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4244
4245 /* now the directory is empty */
4246 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4247 dentry->d_name.name, dentry->d_name.len);
4248 if (!err) {
4249 btrfs_i_size_write(inode, 0);
4250 /*
4251 * Propagate the last_unlink_trans value of the deleted dir to
4252 * its parent directory. This is to prevent an unrecoverable
4253 * log tree in the case we do something like this:
4254 * 1) create dir foo
4255 * 2) create snapshot under dir foo
4256 * 3) delete the snapshot
4257 * 4) rmdir foo
4258 * 5) mkdir foo
4259 * 6) fsync foo or some file inside foo
4260 */
4261 if (last_unlink_trans >= trans->transid)
4262 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4263 }
4264 out:
4265 btrfs_end_transaction(trans, root);
4266 btrfs_btree_balance_dirty(root);
4267
4268 return err;
4269 }
4270
4271 static int truncate_space_check(struct btrfs_trans_handle *trans,
4272 struct btrfs_root *root,
4273 u64 bytes_deleted)
4274 {
4275 int ret;
4276
4277 /*
4278 * This is only used to apply pressure to the enospc system, we don't
4279 * intend to use this reservation at all.
4280 */
4281 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4282 bytes_deleted *= root->nodesize;
4283 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4284 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4285 if (!ret) {
4286 trace_btrfs_space_reservation(root->fs_info, "transaction",
4287 trans->transid,
4288 bytes_deleted, 1);
4289 trans->bytes_reserved += bytes_deleted;
4290 }
4291 return ret;
4292
4293 }
4294
4295 static int truncate_inline_extent(struct inode *inode,
4296 struct btrfs_path *path,
4297 struct btrfs_key *found_key,
4298 const u64 item_end,
4299 const u64 new_size)
4300 {
4301 struct extent_buffer *leaf = path->nodes[0];
4302 int slot = path->slots[0];
4303 struct btrfs_file_extent_item *fi;
4304 u32 size = (u32)(new_size - found_key->offset);
4305 struct btrfs_root *root = BTRFS_I(inode)->root;
4306
4307 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4308
4309 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4310 loff_t offset = new_size;
4311 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4312
4313 /*
4314 * Zero out the remaining of the last page of our inline extent,
4315 * instead of directly truncating our inline extent here - that
4316 * would be much more complex (decompressing all the data, then
4317 * compressing the truncated data, which might be bigger than
4318 * the size of the inline extent, resize the extent, etc).
4319 * We release the path because to get the page we might need to
4320 * read the extent item from disk (data not in the page cache).
4321 */
4322 btrfs_release_path(path);
4323 return btrfs_truncate_block(inode, offset, page_end - offset,
4324 0);
4325 }
4326
4327 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4328 size = btrfs_file_extent_calc_inline_size(size);
4329 btrfs_truncate_item(root, path, size, 1);
4330
4331 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4332 inode_sub_bytes(inode, item_end + 1 - new_size);
4333
4334 return 0;
4335 }
4336
4337 /*
4338 * this can truncate away extent items, csum items and directory items.
4339 * It starts at a high offset and removes keys until it can't find
4340 * any higher than new_size
4341 *
4342 * csum items that cross the new i_size are truncated to the new size
4343 * as well.
4344 *
4345 * min_type is the minimum key type to truncate down to. If set to 0, this
4346 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4347 */
4348 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4349 struct btrfs_root *root,
4350 struct inode *inode,
4351 u64 new_size, u32 min_type)
4352 {
4353 struct btrfs_path *path;
4354 struct extent_buffer *leaf;
4355 struct btrfs_file_extent_item *fi;
4356 struct btrfs_key key;
4357 struct btrfs_key found_key;
4358 u64 extent_start = 0;
4359 u64 extent_num_bytes = 0;
4360 u64 extent_offset = 0;
4361 u64 item_end = 0;
4362 u64 last_size = new_size;
4363 u32 found_type = (u8)-1;
4364 int found_extent;
4365 int del_item;
4366 int pending_del_nr = 0;
4367 int pending_del_slot = 0;
4368 int extent_type = -1;
4369 int ret;
4370 int err = 0;
4371 u64 ino = btrfs_ino(inode);
4372 u64 bytes_deleted = 0;
4373 bool be_nice = 0;
4374 bool should_throttle = 0;
4375 bool should_end = 0;
4376
4377 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4378
4379 /*
4380 * for non-free space inodes and ref cows, we want to back off from
4381 * time to time
4382 */
4383 if (!btrfs_is_free_space_inode(inode) &&
4384 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4385 be_nice = 1;
4386
4387 path = btrfs_alloc_path();
4388 if (!path)
4389 return -ENOMEM;
4390 path->reada = READA_BACK;
4391
4392 /*
4393 * We want to drop from the next block forward in case this new size is
4394 * not block aligned since we will be keeping the last block of the
4395 * extent just the way it is.
4396 */
4397 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4398 root == root->fs_info->tree_root)
4399 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4400 root->sectorsize), (u64)-1, 0);
4401
4402 /*
4403 * This function is also used to drop the items in the log tree before
4404 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4405 * it is used to drop the loged items. So we shouldn't kill the delayed
4406 * items.
4407 */
4408 if (min_type == 0 && root == BTRFS_I(inode)->root)
4409 btrfs_kill_delayed_inode_items(inode);
4410
4411 key.objectid = ino;
4412 key.offset = (u64)-1;
4413 key.type = (u8)-1;
4414
4415 search_again:
4416 /*
4417 * with a 16K leaf size and 128MB extents, you can actually queue
4418 * up a huge file in a single leaf. Most of the time that
4419 * bytes_deleted is > 0, it will be huge by the time we get here
4420 */
4421 if (be_nice && bytes_deleted > SZ_32M) {
4422 if (btrfs_should_end_transaction(trans, root)) {
4423 err = -EAGAIN;
4424 goto error;
4425 }
4426 }
4427
4428
4429 path->leave_spinning = 1;
4430 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4431 if (ret < 0) {
4432 err = ret;
4433 goto out;
4434 }
4435
4436 if (ret > 0) {
4437 /* there are no items in the tree for us to truncate, we're
4438 * done
4439 */
4440 if (path->slots[0] == 0)
4441 goto out;
4442 path->slots[0]--;
4443 }
4444
4445 while (1) {
4446 fi = NULL;
4447 leaf = path->nodes[0];
4448 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4449 found_type = found_key.type;
4450
4451 if (found_key.objectid != ino)
4452 break;
4453
4454 if (found_type < min_type)
4455 break;
4456
4457 item_end = found_key.offset;
4458 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4459 fi = btrfs_item_ptr(leaf, path->slots[0],
4460 struct btrfs_file_extent_item);
4461 extent_type = btrfs_file_extent_type(leaf, fi);
4462 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4463 item_end +=
4464 btrfs_file_extent_num_bytes(leaf, fi);
4465 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4466 item_end += btrfs_file_extent_inline_len(leaf,
4467 path->slots[0], fi);
4468 }
4469 item_end--;
4470 }
4471 if (found_type > min_type) {
4472 del_item = 1;
4473 } else {
4474 if (item_end < new_size)
4475 break;
4476 if (found_key.offset >= new_size)
4477 del_item = 1;
4478 else
4479 del_item = 0;
4480 }
4481 found_extent = 0;
4482 /* FIXME, shrink the extent if the ref count is only 1 */
4483 if (found_type != BTRFS_EXTENT_DATA_KEY)
4484 goto delete;
4485
4486 if (del_item)
4487 last_size = found_key.offset;
4488 else
4489 last_size = new_size;
4490
4491 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4492 u64 num_dec;
4493 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4494 if (!del_item) {
4495 u64 orig_num_bytes =
4496 btrfs_file_extent_num_bytes(leaf, fi);
4497 extent_num_bytes = ALIGN(new_size -
4498 found_key.offset,
4499 root->sectorsize);
4500 btrfs_set_file_extent_num_bytes(leaf, fi,
4501 extent_num_bytes);
4502 num_dec = (orig_num_bytes -
4503 extent_num_bytes);
4504 if (test_bit(BTRFS_ROOT_REF_COWS,
4505 &root->state) &&
4506 extent_start != 0)
4507 inode_sub_bytes(inode, num_dec);
4508 btrfs_mark_buffer_dirty(leaf);
4509 } else {
4510 extent_num_bytes =
4511 btrfs_file_extent_disk_num_bytes(leaf,
4512 fi);
4513 extent_offset = found_key.offset -
4514 btrfs_file_extent_offset(leaf, fi);
4515
4516 /* FIXME blocksize != 4096 */
4517 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4518 if (extent_start != 0) {
4519 found_extent = 1;
4520 if (test_bit(BTRFS_ROOT_REF_COWS,
4521 &root->state))
4522 inode_sub_bytes(inode, num_dec);
4523 }
4524 }
4525 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4526 /*
4527 * we can't truncate inline items that have had
4528 * special encodings
4529 */
4530 if (!del_item &&
4531 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4532 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4533
4534 /*
4535 * Need to release path in order to truncate a
4536 * compressed extent. So delete any accumulated
4537 * extent items so far.
4538 */
4539 if (btrfs_file_extent_compression(leaf, fi) !=
4540 BTRFS_COMPRESS_NONE && pending_del_nr) {
4541 err = btrfs_del_items(trans, root, path,
4542 pending_del_slot,
4543 pending_del_nr);
4544 if (err) {
4545 btrfs_abort_transaction(trans,
4546 err);
4547 goto error;
4548 }
4549 pending_del_nr = 0;
4550 }
4551
4552 err = truncate_inline_extent(inode, path,
4553 &found_key,
4554 item_end,
4555 new_size);
4556 if (err) {
4557 btrfs_abort_transaction(trans, err);
4558 goto error;
4559 }
4560 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4561 &root->state)) {
4562 inode_sub_bytes(inode, item_end + 1 - new_size);
4563 }
4564 }
4565 delete:
4566 if (del_item) {
4567 if (!pending_del_nr) {
4568 /* no pending yet, add ourselves */
4569 pending_del_slot = path->slots[0];
4570 pending_del_nr = 1;
4571 } else if (pending_del_nr &&
4572 path->slots[0] + 1 == pending_del_slot) {
4573 /* hop on the pending chunk */
4574 pending_del_nr++;
4575 pending_del_slot = path->slots[0];
4576 } else {
4577 BUG();
4578 }
4579 } else {
4580 break;
4581 }
4582 should_throttle = 0;
4583
4584 if (found_extent &&
4585 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4586 root == root->fs_info->tree_root)) {
4587 btrfs_set_path_blocking(path);
4588 bytes_deleted += extent_num_bytes;
4589 ret = btrfs_free_extent(trans, root, extent_start,
4590 extent_num_bytes, 0,
4591 btrfs_header_owner(leaf),
4592 ino, extent_offset);
4593 BUG_ON(ret);
4594 if (btrfs_should_throttle_delayed_refs(trans, root))
4595 btrfs_async_run_delayed_refs(root,
4596 trans->transid,
4597 trans->delayed_ref_updates * 2, 0);
4598 if (be_nice) {
4599 if (truncate_space_check(trans, root,
4600 extent_num_bytes)) {
4601 should_end = 1;
4602 }
4603 if (btrfs_should_throttle_delayed_refs(trans,
4604 root)) {
4605 should_throttle = 1;
4606 }
4607 }
4608 }
4609
4610 if (found_type == BTRFS_INODE_ITEM_KEY)
4611 break;
4612
4613 if (path->slots[0] == 0 ||
4614 path->slots[0] != pending_del_slot ||
4615 should_throttle || should_end) {
4616 if (pending_del_nr) {
4617 ret = btrfs_del_items(trans, root, path,
4618 pending_del_slot,
4619 pending_del_nr);
4620 if (ret) {
4621 btrfs_abort_transaction(trans, ret);
4622 goto error;
4623 }
4624 pending_del_nr = 0;
4625 }
4626 btrfs_release_path(path);
4627 if (should_throttle) {
4628 unsigned long updates = trans->delayed_ref_updates;
4629 if (updates) {
4630 trans->delayed_ref_updates = 0;
4631 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4632 if (ret && !err)
4633 err = ret;
4634 }
4635 }
4636 /*
4637 * if we failed to refill our space rsv, bail out
4638 * and let the transaction restart
4639 */
4640 if (should_end) {
4641 err = -EAGAIN;
4642 goto error;
4643 }
4644 goto search_again;
4645 } else {
4646 path->slots[0]--;
4647 }
4648 }
4649 out:
4650 if (pending_del_nr) {
4651 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4652 pending_del_nr);
4653 if (ret)
4654 btrfs_abort_transaction(trans, ret);
4655 }
4656 error:
4657 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4658 btrfs_ordered_update_i_size(inode, last_size, NULL);
4659
4660 btrfs_free_path(path);
4661
4662 if (be_nice && bytes_deleted > SZ_32M) {
4663 unsigned long updates = trans->delayed_ref_updates;
4664 if (updates) {
4665 trans->delayed_ref_updates = 0;
4666 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4667 if (ret && !err)
4668 err = ret;
4669 }
4670 }
4671 return err;
4672 }
4673
4674 /*
4675 * btrfs_truncate_block - read, zero a chunk and write a block
4676 * @inode - inode that we're zeroing
4677 * @from - the offset to start zeroing
4678 * @len - the length to zero, 0 to zero the entire range respective to the
4679 * offset
4680 * @front - zero up to the offset instead of from the offset on
4681 *
4682 * This will find the block for the "from" offset and cow the block and zero the
4683 * part we want to zero. This is used with truncate and hole punching.
4684 */
4685 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4686 int front)
4687 {
4688 struct address_space *mapping = inode->i_mapping;
4689 struct btrfs_root *root = BTRFS_I(inode)->root;
4690 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4691 struct btrfs_ordered_extent *ordered;
4692 struct extent_state *cached_state = NULL;
4693 char *kaddr;
4694 u32 blocksize = root->sectorsize;
4695 pgoff_t index = from >> PAGE_SHIFT;
4696 unsigned offset = from & (blocksize - 1);
4697 struct page *page;
4698 gfp_t mask = btrfs_alloc_write_mask(mapping);
4699 int ret = 0;
4700 u64 block_start;
4701 u64 block_end;
4702
4703 if ((offset & (blocksize - 1)) == 0 &&
4704 (!len || ((len & (blocksize - 1)) == 0)))
4705 goto out;
4706
4707 ret = btrfs_delalloc_reserve_space(inode,
4708 round_down(from, blocksize), blocksize);
4709 if (ret)
4710 goto out;
4711
4712 again:
4713 page = find_or_create_page(mapping, index, mask);
4714 if (!page) {
4715 btrfs_delalloc_release_space(inode,
4716 round_down(from, blocksize),
4717 blocksize);
4718 ret = -ENOMEM;
4719 goto out;
4720 }
4721
4722 block_start = round_down(from, blocksize);
4723 block_end = block_start + blocksize - 1;
4724
4725 if (!PageUptodate(page)) {
4726 ret = btrfs_readpage(NULL, page);
4727 lock_page(page);
4728 if (page->mapping != mapping) {
4729 unlock_page(page);
4730 put_page(page);
4731 goto again;
4732 }
4733 if (!PageUptodate(page)) {
4734 ret = -EIO;
4735 goto out_unlock;
4736 }
4737 }
4738 wait_on_page_writeback(page);
4739
4740 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4741 set_page_extent_mapped(page);
4742
4743 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4744 if (ordered) {
4745 unlock_extent_cached(io_tree, block_start, block_end,
4746 &cached_state, GFP_NOFS);
4747 unlock_page(page);
4748 put_page(page);
4749 btrfs_start_ordered_extent(inode, ordered, 1);
4750 btrfs_put_ordered_extent(ordered);
4751 goto again;
4752 }
4753
4754 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4755 EXTENT_DIRTY | EXTENT_DELALLOC |
4756 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4757 0, 0, &cached_state, GFP_NOFS);
4758
4759 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4760 &cached_state);
4761 if (ret) {
4762 unlock_extent_cached(io_tree, block_start, block_end,
4763 &cached_state, GFP_NOFS);
4764 goto out_unlock;
4765 }
4766
4767 if (offset != blocksize) {
4768 if (!len)
4769 len = blocksize - offset;
4770 kaddr = kmap(page);
4771 if (front)
4772 memset(kaddr + (block_start - page_offset(page)),
4773 0, offset);
4774 else
4775 memset(kaddr + (block_start - page_offset(page)) + offset,
4776 0, len);
4777 flush_dcache_page(page);
4778 kunmap(page);
4779 }
4780 ClearPageChecked(page);
4781 set_page_dirty(page);
4782 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4783 GFP_NOFS);
4784
4785 out_unlock:
4786 if (ret)
4787 btrfs_delalloc_release_space(inode, block_start,
4788 blocksize);
4789 unlock_page(page);
4790 put_page(page);
4791 out:
4792 return ret;
4793 }
4794
4795 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4796 u64 offset, u64 len)
4797 {
4798 struct btrfs_trans_handle *trans;
4799 int ret;
4800
4801 /*
4802 * Still need to make sure the inode looks like it's been updated so
4803 * that any holes get logged if we fsync.
4804 */
4805 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4806 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4807 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4808 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4809 return 0;
4810 }
4811
4812 /*
4813 * 1 - for the one we're dropping
4814 * 1 - for the one we're adding
4815 * 1 - for updating the inode.
4816 */
4817 trans = btrfs_start_transaction(root, 3);
4818 if (IS_ERR(trans))
4819 return PTR_ERR(trans);
4820
4821 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4822 if (ret) {
4823 btrfs_abort_transaction(trans, ret);
4824 btrfs_end_transaction(trans, root);
4825 return ret;
4826 }
4827
4828 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4829 0, 0, len, 0, len, 0, 0, 0);
4830 if (ret)
4831 btrfs_abort_transaction(trans, ret);
4832 else
4833 btrfs_update_inode(trans, root, inode);
4834 btrfs_end_transaction(trans, root);
4835 return ret;
4836 }
4837
4838 /*
4839 * This function puts in dummy file extents for the area we're creating a hole
4840 * for. So if we are truncating this file to a larger size we need to insert
4841 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4842 * the range between oldsize and size
4843 */
4844 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4845 {
4846 struct btrfs_root *root = BTRFS_I(inode)->root;
4847 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4848 struct extent_map *em = NULL;
4849 struct extent_state *cached_state = NULL;
4850 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4851 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4852 u64 block_end = ALIGN(size, root->sectorsize);
4853 u64 last_byte;
4854 u64 cur_offset;
4855 u64 hole_size;
4856 int err = 0;
4857
4858 /*
4859 * If our size started in the middle of a block we need to zero out the
4860 * rest of the block before we expand the i_size, otherwise we could
4861 * expose stale data.
4862 */
4863 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4864 if (err)
4865 return err;
4866
4867 if (size <= hole_start)
4868 return 0;
4869
4870 while (1) {
4871 struct btrfs_ordered_extent *ordered;
4872
4873 lock_extent_bits(io_tree, hole_start, block_end - 1,
4874 &cached_state);
4875 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4876 block_end - hole_start);
4877 if (!ordered)
4878 break;
4879 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4880 &cached_state, GFP_NOFS);
4881 btrfs_start_ordered_extent(inode, ordered, 1);
4882 btrfs_put_ordered_extent(ordered);
4883 }
4884
4885 cur_offset = hole_start;
4886 while (1) {
4887 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4888 block_end - cur_offset, 0);
4889 if (IS_ERR(em)) {
4890 err = PTR_ERR(em);
4891 em = NULL;
4892 break;
4893 }
4894 last_byte = min(extent_map_end(em), block_end);
4895 last_byte = ALIGN(last_byte , root->sectorsize);
4896 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4897 struct extent_map *hole_em;
4898 hole_size = last_byte - cur_offset;
4899
4900 err = maybe_insert_hole(root, inode, cur_offset,
4901 hole_size);
4902 if (err)
4903 break;
4904 btrfs_drop_extent_cache(inode, cur_offset,
4905 cur_offset + hole_size - 1, 0);
4906 hole_em = alloc_extent_map();
4907 if (!hole_em) {
4908 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4909 &BTRFS_I(inode)->runtime_flags);
4910 goto next;
4911 }
4912 hole_em->start = cur_offset;
4913 hole_em->len = hole_size;
4914 hole_em->orig_start = cur_offset;
4915
4916 hole_em->block_start = EXTENT_MAP_HOLE;
4917 hole_em->block_len = 0;
4918 hole_em->orig_block_len = 0;
4919 hole_em->ram_bytes = hole_size;
4920 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4921 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4922 hole_em->generation = root->fs_info->generation;
4923
4924 while (1) {
4925 write_lock(&em_tree->lock);
4926 err = add_extent_mapping(em_tree, hole_em, 1);
4927 write_unlock(&em_tree->lock);
4928 if (err != -EEXIST)
4929 break;
4930 btrfs_drop_extent_cache(inode, cur_offset,
4931 cur_offset +
4932 hole_size - 1, 0);
4933 }
4934 free_extent_map(hole_em);
4935 }
4936 next:
4937 free_extent_map(em);
4938 em = NULL;
4939 cur_offset = last_byte;
4940 if (cur_offset >= block_end)
4941 break;
4942 }
4943 free_extent_map(em);
4944 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4945 GFP_NOFS);
4946 return err;
4947 }
4948
4949 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4950 {
4951 struct btrfs_root *root = BTRFS_I(inode)->root;
4952 struct btrfs_trans_handle *trans;
4953 loff_t oldsize = i_size_read(inode);
4954 loff_t newsize = attr->ia_size;
4955 int mask = attr->ia_valid;
4956 int ret;
4957
4958 /*
4959 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4960 * special case where we need to update the times despite not having
4961 * these flags set. For all other operations the VFS set these flags
4962 * explicitly if it wants a timestamp update.
4963 */
4964 if (newsize != oldsize) {
4965 inode_inc_iversion(inode);
4966 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4967 inode->i_ctime = inode->i_mtime =
4968 current_time(inode);
4969 }
4970
4971 if (newsize > oldsize) {
4972 /*
4973 * Don't do an expanding truncate while snapshoting is ongoing.
4974 * This is to ensure the snapshot captures a fully consistent
4975 * state of this file - if the snapshot captures this expanding
4976 * truncation, it must capture all writes that happened before
4977 * this truncation.
4978 */
4979 btrfs_wait_for_snapshot_creation(root);
4980 ret = btrfs_cont_expand(inode, oldsize, newsize);
4981 if (ret) {
4982 btrfs_end_write_no_snapshoting(root);
4983 return ret;
4984 }
4985
4986 trans = btrfs_start_transaction(root, 1);
4987 if (IS_ERR(trans)) {
4988 btrfs_end_write_no_snapshoting(root);
4989 return PTR_ERR(trans);
4990 }
4991
4992 i_size_write(inode, newsize);
4993 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4994 pagecache_isize_extended(inode, oldsize, newsize);
4995 ret = btrfs_update_inode(trans, root, inode);
4996 btrfs_end_write_no_snapshoting(root);
4997 btrfs_end_transaction(trans, root);
4998 } else {
4999
5000 /*
5001 * We're truncating a file that used to have good data down to
5002 * zero. Make sure it gets into the ordered flush list so that
5003 * any new writes get down to disk quickly.
5004 */
5005 if (newsize == 0)
5006 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5007 &BTRFS_I(inode)->runtime_flags);
5008
5009 /*
5010 * 1 for the orphan item we're going to add
5011 * 1 for the orphan item deletion.
5012 */
5013 trans = btrfs_start_transaction(root, 2);
5014 if (IS_ERR(trans))
5015 return PTR_ERR(trans);
5016
5017 /*
5018 * We need to do this in case we fail at _any_ point during the
5019 * actual truncate. Once we do the truncate_setsize we could
5020 * invalidate pages which forces any outstanding ordered io to
5021 * be instantly completed which will give us extents that need
5022 * to be truncated. If we fail to get an orphan inode down we
5023 * could have left over extents that were never meant to live,
5024 * so we need to guarantee from this point on that everything
5025 * will be consistent.
5026 */
5027 ret = btrfs_orphan_add(trans, inode);
5028 btrfs_end_transaction(trans, root);
5029 if (ret)
5030 return ret;
5031
5032 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5033 truncate_setsize(inode, newsize);
5034
5035 /* Disable nonlocked read DIO to avoid the end less truncate */
5036 btrfs_inode_block_unlocked_dio(inode);
5037 inode_dio_wait(inode);
5038 btrfs_inode_resume_unlocked_dio(inode);
5039
5040 ret = btrfs_truncate(inode);
5041 if (ret && inode->i_nlink) {
5042 int err;
5043
5044 /*
5045 * failed to truncate, disk_i_size is only adjusted down
5046 * as we remove extents, so it should represent the true
5047 * size of the inode, so reset the in memory size and
5048 * delete our orphan entry.
5049 */
5050 trans = btrfs_join_transaction(root);
5051 if (IS_ERR(trans)) {
5052 btrfs_orphan_del(NULL, inode);
5053 return ret;
5054 }
5055 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5056 err = btrfs_orphan_del(trans, inode);
5057 if (err)
5058 btrfs_abort_transaction(trans, err);
5059 btrfs_end_transaction(trans, root);
5060 }
5061 }
5062
5063 return ret;
5064 }
5065
5066 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5067 {
5068 struct inode *inode = d_inode(dentry);
5069 struct btrfs_root *root = BTRFS_I(inode)->root;
5070 int err;
5071
5072 if (btrfs_root_readonly(root))
5073 return -EROFS;
5074
5075 err = inode_change_ok(inode, attr);
5076 if (err)
5077 return err;
5078
5079 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5080 err = btrfs_setsize(inode, attr);
5081 if (err)
5082 return err;
5083 }
5084
5085 if (attr->ia_valid) {
5086 setattr_copy(inode, attr);
5087 inode_inc_iversion(inode);
5088 err = btrfs_dirty_inode(inode);
5089
5090 if (!err && attr->ia_valid & ATTR_MODE)
5091 err = posix_acl_chmod(inode, inode->i_mode);
5092 }
5093
5094 return err;
5095 }
5096
5097 /*
5098 * While truncating the inode pages during eviction, we get the VFS calling
5099 * btrfs_invalidatepage() against each page of the inode. This is slow because
5100 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5101 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5102 * extent_state structures over and over, wasting lots of time.
5103 *
5104 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5105 * those expensive operations on a per page basis and do only the ordered io
5106 * finishing, while we release here the extent_map and extent_state structures,
5107 * without the excessive merging and splitting.
5108 */
5109 static void evict_inode_truncate_pages(struct inode *inode)
5110 {
5111 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5112 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5113 struct rb_node *node;
5114
5115 ASSERT(inode->i_state & I_FREEING);
5116 truncate_inode_pages_final(&inode->i_data);
5117
5118 write_lock(&map_tree->lock);
5119 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5120 struct extent_map *em;
5121
5122 node = rb_first(&map_tree->map);
5123 em = rb_entry(node, struct extent_map, rb_node);
5124 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5125 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5126 remove_extent_mapping(map_tree, em);
5127 free_extent_map(em);
5128 if (need_resched()) {
5129 write_unlock(&map_tree->lock);
5130 cond_resched();
5131 write_lock(&map_tree->lock);
5132 }
5133 }
5134 write_unlock(&map_tree->lock);
5135
5136 /*
5137 * Keep looping until we have no more ranges in the io tree.
5138 * We can have ongoing bios started by readpages (called from readahead)
5139 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5140 * still in progress (unlocked the pages in the bio but did not yet
5141 * unlocked the ranges in the io tree). Therefore this means some
5142 * ranges can still be locked and eviction started because before
5143 * submitting those bios, which are executed by a separate task (work
5144 * queue kthread), inode references (inode->i_count) were not taken
5145 * (which would be dropped in the end io callback of each bio).
5146 * Therefore here we effectively end up waiting for those bios and
5147 * anyone else holding locked ranges without having bumped the inode's
5148 * reference count - if we don't do it, when they access the inode's
5149 * io_tree to unlock a range it may be too late, leading to an
5150 * use-after-free issue.
5151 */
5152 spin_lock(&io_tree->lock);
5153 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5154 struct extent_state *state;
5155 struct extent_state *cached_state = NULL;
5156 u64 start;
5157 u64 end;
5158
5159 node = rb_first(&io_tree->state);
5160 state = rb_entry(node, struct extent_state, rb_node);
5161 start = state->start;
5162 end = state->end;
5163 spin_unlock(&io_tree->lock);
5164
5165 lock_extent_bits(io_tree, start, end, &cached_state);
5166
5167 /*
5168 * If still has DELALLOC flag, the extent didn't reach disk,
5169 * and its reserved space won't be freed by delayed_ref.
5170 * So we need to free its reserved space here.
5171 * (Refer to comment in btrfs_invalidatepage, case 2)
5172 *
5173 * Note, end is the bytenr of last byte, so we need + 1 here.
5174 */
5175 if (state->state & EXTENT_DELALLOC)
5176 btrfs_qgroup_free_data(inode, start, end - start + 1);
5177
5178 clear_extent_bit(io_tree, start, end,
5179 EXTENT_LOCKED | EXTENT_DIRTY |
5180 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5181 EXTENT_DEFRAG, 1, 1,
5182 &cached_state, GFP_NOFS);
5183
5184 cond_resched();
5185 spin_lock(&io_tree->lock);
5186 }
5187 spin_unlock(&io_tree->lock);
5188 }
5189
5190 void btrfs_evict_inode(struct inode *inode)
5191 {
5192 struct btrfs_trans_handle *trans;
5193 struct btrfs_root *root = BTRFS_I(inode)->root;
5194 struct btrfs_block_rsv *rsv, *global_rsv;
5195 int steal_from_global = 0;
5196 u64 min_size;
5197 int ret;
5198
5199 trace_btrfs_inode_evict(inode);
5200
5201 if (!root) {
5202 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5203 return;
5204 }
5205
5206 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5207
5208 evict_inode_truncate_pages(inode);
5209
5210 if (inode->i_nlink &&
5211 ((btrfs_root_refs(&root->root_item) != 0 &&
5212 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5213 btrfs_is_free_space_inode(inode)))
5214 goto no_delete;
5215
5216 if (is_bad_inode(inode)) {
5217 btrfs_orphan_del(NULL, inode);
5218 goto no_delete;
5219 }
5220 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5221 if (!special_file(inode->i_mode))
5222 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5223
5224 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5225
5226 if (root->fs_info->log_root_recovering) {
5227 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5228 &BTRFS_I(inode)->runtime_flags));
5229 goto no_delete;
5230 }
5231
5232 if (inode->i_nlink > 0) {
5233 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5234 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5235 goto no_delete;
5236 }
5237
5238 ret = btrfs_commit_inode_delayed_inode(inode);
5239 if (ret) {
5240 btrfs_orphan_del(NULL, inode);
5241 goto no_delete;
5242 }
5243
5244 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5245 if (!rsv) {
5246 btrfs_orphan_del(NULL, inode);
5247 goto no_delete;
5248 }
5249 rsv->size = min_size;
5250 rsv->failfast = 1;
5251 global_rsv = &root->fs_info->global_block_rsv;
5252
5253 btrfs_i_size_write(inode, 0);
5254
5255 /*
5256 * This is a bit simpler than btrfs_truncate since we've already
5257 * reserved our space for our orphan item in the unlink, so we just
5258 * need to reserve some slack space in case we add bytes and update
5259 * inode item when doing the truncate.
5260 */
5261 while (1) {
5262 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5263 BTRFS_RESERVE_FLUSH_LIMIT);
5264
5265 /*
5266 * Try and steal from the global reserve since we will
5267 * likely not use this space anyway, we want to try as
5268 * hard as possible to get this to work.
5269 */
5270 if (ret)
5271 steal_from_global++;
5272 else
5273 steal_from_global = 0;
5274 ret = 0;
5275
5276 /*
5277 * steal_from_global == 0: we reserved stuff, hooray!
5278 * steal_from_global == 1: we didn't reserve stuff, boo!
5279 * steal_from_global == 2: we've committed, still not a lot of
5280 * room but maybe we'll have room in the global reserve this
5281 * time.
5282 * steal_from_global == 3: abandon all hope!
5283 */
5284 if (steal_from_global > 2) {
5285 btrfs_warn(root->fs_info,
5286 "Could not get space for a delete, will truncate on mount %d",
5287 ret);
5288 btrfs_orphan_del(NULL, inode);
5289 btrfs_free_block_rsv(root, rsv);
5290 goto no_delete;
5291 }
5292
5293 trans = btrfs_join_transaction(root);
5294 if (IS_ERR(trans)) {
5295 btrfs_orphan_del(NULL, inode);
5296 btrfs_free_block_rsv(root, rsv);
5297 goto no_delete;
5298 }
5299
5300 /*
5301 * We can't just steal from the global reserve, we need to make
5302 * sure there is room to do it, if not we need to commit and try
5303 * again.
5304 */
5305 if (steal_from_global) {
5306 if (!btrfs_check_space_for_delayed_refs(trans, root))
5307 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5308 min_size, 0);
5309 else
5310 ret = -ENOSPC;
5311 }
5312
5313 /*
5314 * Couldn't steal from the global reserve, we have too much
5315 * pending stuff built up, commit the transaction and try it
5316 * again.
5317 */
5318 if (ret) {
5319 ret = btrfs_commit_transaction(trans, root);
5320 if (ret) {
5321 btrfs_orphan_del(NULL, inode);
5322 btrfs_free_block_rsv(root, rsv);
5323 goto no_delete;
5324 }
5325 continue;
5326 } else {
5327 steal_from_global = 0;
5328 }
5329
5330 trans->block_rsv = rsv;
5331
5332 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5333 if (ret != -ENOSPC && ret != -EAGAIN)
5334 break;
5335
5336 trans->block_rsv = &root->fs_info->trans_block_rsv;
5337 btrfs_end_transaction(trans, root);
5338 trans = NULL;
5339 btrfs_btree_balance_dirty(root);
5340 }
5341
5342 btrfs_free_block_rsv(root, rsv);
5343
5344 /*
5345 * Errors here aren't a big deal, it just means we leave orphan items
5346 * in the tree. They will be cleaned up on the next mount.
5347 */
5348 if (ret == 0) {
5349 trans->block_rsv = root->orphan_block_rsv;
5350 btrfs_orphan_del(trans, inode);
5351 } else {
5352 btrfs_orphan_del(NULL, inode);
5353 }
5354
5355 trans->block_rsv = &root->fs_info->trans_block_rsv;
5356 if (!(root == root->fs_info->tree_root ||
5357 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5358 btrfs_return_ino(root, btrfs_ino(inode));
5359
5360 btrfs_end_transaction(trans, root);
5361 btrfs_btree_balance_dirty(root);
5362 no_delete:
5363 btrfs_remove_delayed_node(inode);
5364 clear_inode(inode);
5365 }
5366
5367 /*
5368 * this returns the key found in the dir entry in the location pointer.
5369 * If no dir entries were found, location->objectid is 0.
5370 */
5371 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5372 struct btrfs_key *location)
5373 {
5374 const char *name = dentry->d_name.name;
5375 int namelen = dentry->d_name.len;
5376 struct btrfs_dir_item *di;
5377 struct btrfs_path *path;
5378 struct btrfs_root *root = BTRFS_I(dir)->root;
5379 int ret = 0;
5380
5381 path = btrfs_alloc_path();
5382 if (!path)
5383 return -ENOMEM;
5384
5385 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5386 namelen, 0);
5387 if (IS_ERR(di))
5388 ret = PTR_ERR(di);
5389
5390 if (IS_ERR_OR_NULL(di))
5391 goto out_err;
5392
5393 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5394 out:
5395 btrfs_free_path(path);
5396 return ret;
5397 out_err:
5398 location->objectid = 0;
5399 goto out;
5400 }
5401
5402 /*
5403 * when we hit a tree root in a directory, the btrfs part of the inode
5404 * needs to be changed to reflect the root directory of the tree root. This
5405 * is kind of like crossing a mount point.
5406 */
5407 static int fixup_tree_root_location(struct btrfs_root *root,
5408 struct inode *dir,
5409 struct dentry *dentry,
5410 struct btrfs_key *location,
5411 struct btrfs_root **sub_root)
5412 {
5413 struct btrfs_path *path;
5414 struct btrfs_root *new_root;
5415 struct btrfs_root_ref *ref;
5416 struct extent_buffer *leaf;
5417 struct btrfs_key key;
5418 int ret;
5419 int err = 0;
5420
5421 path = btrfs_alloc_path();
5422 if (!path) {
5423 err = -ENOMEM;
5424 goto out;
5425 }
5426
5427 err = -ENOENT;
5428 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5429 key.type = BTRFS_ROOT_REF_KEY;
5430 key.offset = location->objectid;
5431
5432 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5433 0, 0);
5434 if (ret) {
5435 if (ret < 0)
5436 err = ret;
5437 goto out;
5438 }
5439
5440 leaf = path->nodes[0];
5441 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5442 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5443 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5444 goto out;
5445
5446 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5447 (unsigned long)(ref + 1),
5448 dentry->d_name.len);
5449 if (ret)
5450 goto out;
5451
5452 btrfs_release_path(path);
5453
5454 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5455 if (IS_ERR(new_root)) {
5456 err = PTR_ERR(new_root);
5457 goto out;
5458 }
5459
5460 *sub_root = new_root;
5461 location->objectid = btrfs_root_dirid(&new_root->root_item);
5462 location->type = BTRFS_INODE_ITEM_KEY;
5463 location->offset = 0;
5464 err = 0;
5465 out:
5466 btrfs_free_path(path);
5467 return err;
5468 }
5469
5470 static void inode_tree_add(struct inode *inode)
5471 {
5472 struct btrfs_root *root = BTRFS_I(inode)->root;
5473 struct btrfs_inode *entry;
5474 struct rb_node **p;
5475 struct rb_node *parent;
5476 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5477 u64 ino = btrfs_ino(inode);
5478
5479 if (inode_unhashed(inode))
5480 return;
5481 parent = NULL;
5482 spin_lock(&root->inode_lock);
5483 p = &root->inode_tree.rb_node;
5484 while (*p) {
5485 parent = *p;
5486 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5487
5488 if (ino < btrfs_ino(&entry->vfs_inode))
5489 p = &parent->rb_left;
5490 else if (ino > btrfs_ino(&entry->vfs_inode))
5491 p = &parent->rb_right;
5492 else {
5493 WARN_ON(!(entry->vfs_inode.i_state &
5494 (I_WILL_FREE | I_FREEING)));
5495 rb_replace_node(parent, new, &root->inode_tree);
5496 RB_CLEAR_NODE(parent);
5497 spin_unlock(&root->inode_lock);
5498 return;
5499 }
5500 }
5501 rb_link_node(new, parent, p);
5502 rb_insert_color(new, &root->inode_tree);
5503 spin_unlock(&root->inode_lock);
5504 }
5505
5506 static void inode_tree_del(struct inode *inode)
5507 {
5508 struct btrfs_root *root = BTRFS_I(inode)->root;
5509 int empty = 0;
5510
5511 spin_lock(&root->inode_lock);
5512 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5513 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5514 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5515 empty = RB_EMPTY_ROOT(&root->inode_tree);
5516 }
5517 spin_unlock(&root->inode_lock);
5518
5519 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5520 synchronize_srcu(&root->fs_info->subvol_srcu);
5521 spin_lock(&root->inode_lock);
5522 empty = RB_EMPTY_ROOT(&root->inode_tree);
5523 spin_unlock(&root->inode_lock);
5524 if (empty)
5525 btrfs_add_dead_root(root);
5526 }
5527 }
5528
5529 void btrfs_invalidate_inodes(struct btrfs_root *root)
5530 {
5531 struct rb_node *node;
5532 struct rb_node *prev;
5533 struct btrfs_inode *entry;
5534 struct inode *inode;
5535 u64 objectid = 0;
5536
5537 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5538 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5539
5540 spin_lock(&root->inode_lock);
5541 again:
5542 node = root->inode_tree.rb_node;
5543 prev = NULL;
5544 while (node) {
5545 prev = node;
5546 entry = rb_entry(node, struct btrfs_inode, rb_node);
5547
5548 if (objectid < btrfs_ino(&entry->vfs_inode))
5549 node = node->rb_left;
5550 else if (objectid > btrfs_ino(&entry->vfs_inode))
5551 node = node->rb_right;
5552 else
5553 break;
5554 }
5555 if (!node) {
5556 while (prev) {
5557 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5558 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5559 node = prev;
5560 break;
5561 }
5562 prev = rb_next(prev);
5563 }
5564 }
5565 while (node) {
5566 entry = rb_entry(node, struct btrfs_inode, rb_node);
5567 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5568 inode = igrab(&entry->vfs_inode);
5569 if (inode) {
5570 spin_unlock(&root->inode_lock);
5571 if (atomic_read(&inode->i_count) > 1)
5572 d_prune_aliases(inode);
5573 /*
5574 * btrfs_drop_inode will have it removed from
5575 * the inode cache when its usage count
5576 * hits zero.
5577 */
5578 iput(inode);
5579 cond_resched();
5580 spin_lock(&root->inode_lock);
5581 goto again;
5582 }
5583
5584 if (cond_resched_lock(&root->inode_lock))
5585 goto again;
5586
5587 node = rb_next(node);
5588 }
5589 spin_unlock(&root->inode_lock);
5590 }
5591
5592 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5593 {
5594 struct btrfs_iget_args *args = p;
5595 inode->i_ino = args->location->objectid;
5596 memcpy(&BTRFS_I(inode)->location, args->location,
5597 sizeof(*args->location));
5598 BTRFS_I(inode)->root = args->root;
5599 return 0;
5600 }
5601
5602 static int btrfs_find_actor(struct inode *inode, void *opaque)
5603 {
5604 struct btrfs_iget_args *args = opaque;
5605 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5606 args->root == BTRFS_I(inode)->root;
5607 }
5608
5609 static struct inode *btrfs_iget_locked(struct super_block *s,
5610 struct btrfs_key *location,
5611 struct btrfs_root *root)
5612 {
5613 struct inode *inode;
5614 struct btrfs_iget_args args;
5615 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5616
5617 args.location = location;
5618 args.root = root;
5619
5620 inode = iget5_locked(s, hashval, btrfs_find_actor,
5621 btrfs_init_locked_inode,
5622 (void *)&args);
5623 return inode;
5624 }
5625
5626 /* Get an inode object given its location and corresponding root.
5627 * Returns in *is_new if the inode was read from disk
5628 */
5629 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5630 struct btrfs_root *root, int *new)
5631 {
5632 struct inode *inode;
5633
5634 inode = btrfs_iget_locked(s, location, root);
5635 if (!inode)
5636 return ERR_PTR(-ENOMEM);
5637
5638 if (inode->i_state & I_NEW) {
5639 int ret;
5640
5641 ret = btrfs_read_locked_inode(inode);
5642 if (!is_bad_inode(inode)) {
5643 inode_tree_add(inode);
5644 unlock_new_inode(inode);
5645 if (new)
5646 *new = 1;
5647 } else {
5648 unlock_new_inode(inode);
5649 iput(inode);
5650 ASSERT(ret < 0);
5651 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5652 }
5653 }
5654
5655 return inode;
5656 }
5657
5658 static struct inode *new_simple_dir(struct super_block *s,
5659 struct btrfs_key *key,
5660 struct btrfs_root *root)
5661 {
5662 struct inode *inode = new_inode(s);
5663
5664 if (!inode)
5665 return ERR_PTR(-ENOMEM);
5666
5667 BTRFS_I(inode)->root = root;
5668 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5669 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5670
5671 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5672 inode->i_op = &btrfs_dir_ro_inode_operations;
5673 inode->i_fop = &simple_dir_operations;
5674 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5675 inode->i_mtime = current_time(inode);
5676 inode->i_atime = inode->i_mtime;
5677 inode->i_ctime = inode->i_mtime;
5678 BTRFS_I(inode)->i_otime = inode->i_mtime;
5679
5680 return inode;
5681 }
5682
5683 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5684 {
5685 struct inode *inode;
5686 struct btrfs_root *root = BTRFS_I(dir)->root;
5687 struct btrfs_root *sub_root = root;
5688 struct btrfs_key location;
5689 int index;
5690 int ret = 0;
5691
5692 if (dentry->d_name.len > BTRFS_NAME_LEN)
5693 return ERR_PTR(-ENAMETOOLONG);
5694
5695 ret = btrfs_inode_by_name(dir, dentry, &location);
5696 if (ret < 0)
5697 return ERR_PTR(ret);
5698
5699 if (location.objectid == 0)
5700 return ERR_PTR(-ENOENT);
5701
5702 if (location.type == BTRFS_INODE_ITEM_KEY) {
5703 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5704 return inode;
5705 }
5706
5707 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5708
5709 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5710 ret = fixup_tree_root_location(root, dir, dentry,
5711 &location, &sub_root);
5712 if (ret < 0) {
5713 if (ret != -ENOENT)
5714 inode = ERR_PTR(ret);
5715 else
5716 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5717 } else {
5718 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5719 }
5720 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5721
5722 if (!IS_ERR(inode) && root != sub_root) {
5723 down_read(&root->fs_info->cleanup_work_sem);
5724 if (!(inode->i_sb->s_flags & MS_RDONLY))
5725 ret = btrfs_orphan_cleanup(sub_root);
5726 up_read(&root->fs_info->cleanup_work_sem);
5727 if (ret) {
5728 iput(inode);
5729 inode = ERR_PTR(ret);
5730 }
5731 }
5732
5733 return inode;
5734 }
5735
5736 static int btrfs_dentry_delete(const struct dentry *dentry)
5737 {
5738 struct btrfs_root *root;
5739 struct inode *inode = d_inode(dentry);
5740
5741 if (!inode && !IS_ROOT(dentry))
5742 inode = d_inode(dentry->d_parent);
5743
5744 if (inode) {
5745 root = BTRFS_I(inode)->root;
5746 if (btrfs_root_refs(&root->root_item) == 0)
5747 return 1;
5748
5749 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5750 return 1;
5751 }
5752 return 0;
5753 }
5754
5755 static void btrfs_dentry_release(struct dentry *dentry)
5756 {
5757 kfree(dentry->d_fsdata);
5758 }
5759
5760 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5761 unsigned int flags)
5762 {
5763 struct inode *inode;
5764
5765 inode = btrfs_lookup_dentry(dir, dentry);
5766 if (IS_ERR(inode)) {
5767 if (PTR_ERR(inode) == -ENOENT)
5768 inode = NULL;
5769 else
5770 return ERR_CAST(inode);
5771 }
5772
5773 return d_splice_alias(inode, dentry);
5774 }
5775
5776 unsigned char btrfs_filetype_table[] = {
5777 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5778 };
5779
5780 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5781 {
5782 struct inode *inode = file_inode(file);
5783 struct btrfs_root *root = BTRFS_I(inode)->root;
5784 struct btrfs_item *item;
5785 struct btrfs_dir_item *di;
5786 struct btrfs_key key;
5787 struct btrfs_key found_key;
5788 struct btrfs_path *path;
5789 struct list_head ins_list;
5790 struct list_head del_list;
5791 int ret;
5792 struct extent_buffer *leaf;
5793 int slot;
5794 unsigned char d_type;
5795 int over = 0;
5796 u32 di_cur;
5797 u32 di_total;
5798 u32 di_len;
5799 int key_type = BTRFS_DIR_INDEX_KEY;
5800 char tmp_name[32];
5801 char *name_ptr;
5802 int name_len;
5803 int is_curr = 0; /* ctx->pos points to the current index? */
5804 bool emitted;
5805 bool put = false;
5806
5807 /* FIXME, use a real flag for deciding about the key type */
5808 if (root->fs_info->tree_root == root)
5809 key_type = BTRFS_DIR_ITEM_KEY;
5810
5811 if (!dir_emit_dots(file, ctx))
5812 return 0;
5813
5814 path = btrfs_alloc_path();
5815 if (!path)
5816 return -ENOMEM;
5817
5818 path->reada = READA_FORWARD;
5819
5820 if (key_type == BTRFS_DIR_INDEX_KEY) {
5821 INIT_LIST_HEAD(&ins_list);
5822 INIT_LIST_HEAD(&del_list);
5823 put = btrfs_readdir_get_delayed_items(inode, &ins_list,
5824 &del_list);
5825 }
5826
5827 key.type = key_type;
5828 key.offset = ctx->pos;
5829 key.objectid = btrfs_ino(inode);
5830
5831 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5832 if (ret < 0)
5833 goto err;
5834
5835 emitted = false;
5836 while (1) {
5837 leaf = path->nodes[0];
5838 slot = path->slots[0];
5839 if (slot >= btrfs_header_nritems(leaf)) {
5840 ret = btrfs_next_leaf(root, path);
5841 if (ret < 0)
5842 goto err;
5843 else if (ret > 0)
5844 break;
5845 continue;
5846 }
5847
5848 item = btrfs_item_nr(slot);
5849 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5850
5851 if (found_key.objectid != key.objectid)
5852 break;
5853 if (found_key.type != key_type)
5854 break;
5855 if (found_key.offset < ctx->pos)
5856 goto next;
5857 if (key_type == BTRFS_DIR_INDEX_KEY &&
5858 btrfs_should_delete_dir_index(&del_list,
5859 found_key.offset))
5860 goto next;
5861
5862 ctx->pos = found_key.offset;
5863 is_curr = 1;
5864
5865 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5866 di_cur = 0;
5867 di_total = btrfs_item_size(leaf, item);
5868
5869 while (di_cur < di_total) {
5870 struct btrfs_key location;
5871
5872 if (verify_dir_item(root, leaf, di))
5873 break;
5874
5875 name_len = btrfs_dir_name_len(leaf, di);
5876 if (name_len <= sizeof(tmp_name)) {
5877 name_ptr = tmp_name;
5878 } else {
5879 name_ptr = kmalloc(name_len, GFP_KERNEL);
5880 if (!name_ptr) {
5881 ret = -ENOMEM;
5882 goto err;
5883 }
5884 }
5885 read_extent_buffer(leaf, name_ptr,
5886 (unsigned long)(di + 1), name_len);
5887
5888 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5889 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5890
5891
5892 /* is this a reference to our own snapshot? If so
5893 * skip it.
5894 *
5895 * In contrast to old kernels, we insert the snapshot's
5896 * dir item and dir index after it has been created, so
5897 * we won't find a reference to our own snapshot. We
5898 * still keep the following code for backward
5899 * compatibility.
5900 */
5901 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5902 location.objectid == root->root_key.objectid) {
5903 over = 0;
5904 goto skip;
5905 }
5906 over = !dir_emit(ctx, name_ptr, name_len,
5907 location.objectid, d_type);
5908
5909 skip:
5910 if (name_ptr != tmp_name)
5911 kfree(name_ptr);
5912
5913 if (over)
5914 goto nopos;
5915 emitted = true;
5916 di_len = btrfs_dir_name_len(leaf, di) +
5917 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5918 di_cur += di_len;
5919 di = (struct btrfs_dir_item *)((char *)di + di_len);
5920 }
5921 next:
5922 path->slots[0]++;
5923 }
5924
5925 if (key_type == BTRFS_DIR_INDEX_KEY) {
5926 if (is_curr)
5927 ctx->pos++;
5928 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5929 if (ret)
5930 goto nopos;
5931 }
5932
5933 /*
5934 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5935 * it was was set to the termination value in previous call. We assume
5936 * that "." and ".." were emitted if we reach this point and set the
5937 * termination value as well for an empty directory.
5938 */
5939 if (ctx->pos > 2 && !emitted)
5940 goto nopos;
5941
5942 /* Reached end of directory/root. Bump pos past the last item. */
5943 ctx->pos++;
5944
5945 /*
5946 * Stop new entries from being returned after we return the last
5947 * entry.
5948 *
5949 * New directory entries are assigned a strictly increasing
5950 * offset. This means that new entries created during readdir
5951 * are *guaranteed* to be seen in the future by that readdir.
5952 * This has broken buggy programs which operate on names as
5953 * they're returned by readdir. Until we re-use freed offsets
5954 * we have this hack to stop new entries from being returned
5955 * under the assumption that they'll never reach this huge
5956 * offset.
5957 *
5958 * This is being careful not to overflow 32bit loff_t unless the
5959 * last entry requires it because doing so has broken 32bit apps
5960 * in the past.
5961 */
5962 if (key_type == BTRFS_DIR_INDEX_KEY) {
5963 if (ctx->pos >= INT_MAX)
5964 ctx->pos = LLONG_MAX;
5965 else
5966 ctx->pos = INT_MAX;
5967 }
5968 nopos:
5969 ret = 0;
5970 err:
5971 if (put)
5972 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5973 btrfs_free_path(path);
5974 return ret;
5975 }
5976
5977 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5978 {
5979 struct btrfs_root *root = BTRFS_I(inode)->root;
5980 struct btrfs_trans_handle *trans;
5981 int ret = 0;
5982 bool nolock = false;
5983
5984 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5985 return 0;
5986
5987 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5988 nolock = true;
5989
5990 if (wbc->sync_mode == WB_SYNC_ALL) {
5991 if (nolock)
5992 trans = btrfs_join_transaction_nolock(root);
5993 else
5994 trans = btrfs_join_transaction(root);
5995 if (IS_ERR(trans))
5996 return PTR_ERR(trans);
5997 ret = btrfs_commit_transaction(trans, root);
5998 }
5999 return ret;
6000 }
6001
6002 /*
6003 * This is somewhat expensive, updating the tree every time the
6004 * inode changes. But, it is most likely to find the inode in cache.
6005 * FIXME, needs more benchmarking...there are no reasons other than performance
6006 * to keep or drop this code.
6007 */
6008 static int btrfs_dirty_inode(struct inode *inode)
6009 {
6010 struct btrfs_root *root = BTRFS_I(inode)->root;
6011 struct btrfs_trans_handle *trans;
6012 int ret;
6013
6014 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6015 return 0;
6016
6017 trans = btrfs_join_transaction(root);
6018 if (IS_ERR(trans))
6019 return PTR_ERR(trans);
6020
6021 ret = btrfs_update_inode(trans, root, inode);
6022 if (ret && ret == -ENOSPC) {
6023 /* whoops, lets try again with the full transaction */
6024 btrfs_end_transaction(trans, root);
6025 trans = btrfs_start_transaction(root, 1);
6026 if (IS_ERR(trans))
6027 return PTR_ERR(trans);
6028
6029 ret = btrfs_update_inode(trans, root, inode);
6030 }
6031 btrfs_end_transaction(trans, root);
6032 if (BTRFS_I(inode)->delayed_node)
6033 btrfs_balance_delayed_items(root);
6034
6035 return ret;
6036 }
6037
6038 /*
6039 * This is a copy of file_update_time. We need this so we can return error on
6040 * ENOSPC for updating the inode in the case of file write and mmap writes.
6041 */
6042 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6043 int flags)
6044 {
6045 struct btrfs_root *root = BTRFS_I(inode)->root;
6046
6047 if (btrfs_root_readonly(root))
6048 return -EROFS;
6049
6050 if (flags & S_VERSION)
6051 inode_inc_iversion(inode);
6052 if (flags & S_CTIME)
6053 inode->i_ctime = *now;
6054 if (flags & S_MTIME)
6055 inode->i_mtime = *now;
6056 if (flags & S_ATIME)
6057 inode->i_atime = *now;
6058 return btrfs_dirty_inode(inode);
6059 }
6060
6061 /*
6062 * find the highest existing sequence number in a directory
6063 * and then set the in-memory index_cnt variable to reflect
6064 * free sequence numbers
6065 */
6066 static int btrfs_set_inode_index_count(struct inode *inode)
6067 {
6068 struct btrfs_root *root = BTRFS_I(inode)->root;
6069 struct btrfs_key key, found_key;
6070 struct btrfs_path *path;
6071 struct extent_buffer *leaf;
6072 int ret;
6073
6074 key.objectid = btrfs_ino(inode);
6075 key.type = BTRFS_DIR_INDEX_KEY;
6076 key.offset = (u64)-1;
6077
6078 path = btrfs_alloc_path();
6079 if (!path)
6080 return -ENOMEM;
6081
6082 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6083 if (ret < 0)
6084 goto out;
6085 /* FIXME: we should be able to handle this */
6086 if (ret == 0)
6087 goto out;
6088 ret = 0;
6089
6090 /*
6091 * MAGIC NUMBER EXPLANATION:
6092 * since we search a directory based on f_pos we have to start at 2
6093 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6094 * else has to start at 2
6095 */
6096 if (path->slots[0] == 0) {
6097 BTRFS_I(inode)->index_cnt = 2;
6098 goto out;
6099 }
6100
6101 path->slots[0]--;
6102
6103 leaf = path->nodes[0];
6104 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6105
6106 if (found_key.objectid != btrfs_ino(inode) ||
6107 found_key.type != BTRFS_DIR_INDEX_KEY) {
6108 BTRFS_I(inode)->index_cnt = 2;
6109 goto out;
6110 }
6111
6112 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6113 out:
6114 btrfs_free_path(path);
6115 return ret;
6116 }
6117
6118 /*
6119 * helper to find a free sequence number in a given directory. This current
6120 * code is very simple, later versions will do smarter things in the btree
6121 */
6122 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6123 {
6124 int ret = 0;
6125
6126 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6127 ret = btrfs_inode_delayed_dir_index_count(dir);
6128 if (ret) {
6129 ret = btrfs_set_inode_index_count(dir);
6130 if (ret)
6131 return ret;
6132 }
6133 }
6134
6135 *index = BTRFS_I(dir)->index_cnt;
6136 BTRFS_I(dir)->index_cnt++;
6137
6138 return ret;
6139 }
6140
6141 static int btrfs_insert_inode_locked(struct inode *inode)
6142 {
6143 struct btrfs_iget_args args;
6144 args.location = &BTRFS_I(inode)->location;
6145 args.root = BTRFS_I(inode)->root;
6146
6147 return insert_inode_locked4(inode,
6148 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6149 btrfs_find_actor, &args);
6150 }
6151
6152 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6153 struct btrfs_root *root,
6154 struct inode *dir,
6155 const char *name, int name_len,
6156 u64 ref_objectid, u64 objectid,
6157 umode_t mode, u64 *index)
6158 {
6159 struct inode *inode;
6160 struct btrfs_inode_item *inode_item;
6161 struct btrfs_key *location;
6162 struct btrfs_path *path;
6163 struct btrfs_inode_ref *ref;
6164 struct btrfs_key key[2];
6165 u32 sizes[2];
6166 int nitems = name ? 2 : 1;
6167 unsigned long ptr;
6168 int ret;
6169
6170 path = btrfs_alloc_path();
6171 if (!path)
6172 return ERR_PTR(-ENOMEM);
6173
6174 inode = new_inode(root->fs_info->sb);
6175 if (!inode) {
6176 btrfs_free_path(path);
6177 return ERR_PTR(-ENOMEM);
6178 }
6179
6180 /*
6181 * O_TMPFILE, set link count to 0, so that after this point,
6182 * we fill in an inode item with the correct link count.
6183 */
6184 if (!name)
6185 set_nlink(inode, 0);
6186
6187 /*
6188 * we have to initialize this early, so we can reclaim the inode
6189 * number if we fail afterwards in this function.
6190 */
6191 inode->i_ino = objectid;
6192
6193 if (dir && name) {
6194 trace_btrfs_inode_request(dir);
6195
6196 ret = btrfs_set_inode_index(dir, index);
6197 if (ret) {
6198 btrfs_free_path(path);
6199 iput(inode);
6200 return ERR_PTR(ret);
6201 }
6202 } else if (dir) {
6203 *index = 0;
6204 }
6205 /*
6206 * index_cnt is ignored for everything but a dir,
6207 * btrfs_get_inode_index_count has an explanation for the magic
6208 * number
6209 */
6210 BTRFS_I(inode)->index_cnt = 2;
6211 BTRFS_I(inode)->dir_index = *index;
6212 BTRFS_I(inode)->root = root;
6213 BTRFS_I(inode)->generation = trans->transid;
6214 inode->i_generation = BTRFS_I(inode)->generation;
6215
6216 /*
6217 * We could have gotten an inode number from somebody who was fsynced
6218 * and then removed in this same transaction, so let's just set full
6219 * sync since it will be a full sync anyway and this will blow away the
6220 * old info in the log.
6221 */
6222 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6223
6224 key[0].objectid = objectid;
6225 key[0].type = BTRFS_INODE_ITEM_KEY;
6226 key[0].offset = 0;
6227
6228 sizes[0] = sizeof(struct btrfs_inode_item);
6229
6230 if (name) {
6231 /*
6232 * Start new inodes with an inode_ref. This is slightly more
6233 * efficient for small numbers of hard links since they will
6234 * be packed into one item. Extended refs will kick in if we
6235 * add more hard links than can fit in the ref item.
6236 */
6237 key[1].objectid = objectid;
6238 key[1].type = BTRFS_INODE_REF_KEY;
6239 key[1].offset = ref_objectid;
6240
6241 sizes[1] = name_len + sizeof(*ref);
6242 }
6243
6244 location = &BTRFS_I(inode)->location;
6245 location->objectid = objectid;
6246 location->offset = 0;
6247 location->type = BTRFS_INODE_ITEM_KEY;
6248
6249 ret = btrfs_insert_inode_locked(inode);
6250 if (ret < 0)
6251 goto fail;
6252
6253 path->leave_spinning = 1;
6254 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6255 if (ret != 0)
6256 goto fail_unlock;
6257
6258 inode_init_owner(inode, dir, mode);
6259 inode_set_bytes(inode, 0);
6260
6261 inode->i_mtime = current_time(inode);
6262 inode->i_atime = inode->i_mtime;
6263 inode->i_ctime = inode->i_mtime;
6264 BTRFS_I(inode)->i_otime = inode->i_mtime;
6265
6266 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6267 struct btrfs_inode_item);
6268 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6269 sizeof(*inode_item));
6270 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6271
6272 if (name) {
6273 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6274 struct btrfs_inode_ref);
6275 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6276 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6277 ptr = (unsigned long)(ref + 1);
6278 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6279 }
6280
6281 btrfs_mark_buffer_dirty(path->nodes[0]);
6282 btrfs_free_path(path);
6283
6284 btrfs_inherit_iflags(inode, dir);
6285
6286 if (S_ISREG(mode)) {
6287 if (btrfs_test_opt(root->fs_info, NODATASUM))
6288 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6289 if (btrfs_test_opt(root->fs_info, NODATACOW))
6290 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6291 BTRFS_INODE_NODATASUM;
6292 }
6293
6294 inode_tree_add(inode);
6295
6296 trace_btrfs_inode_new(inode);
6297 btrfs_set_inode_last_trans(trans, inode);
6298
6299 btrfs_update_root_times(trans, root);
6300
6301 ret = btrfs_inode_inherit_props(trans, inode, dir);
6302 if (ret)
6303 btrfs_err(root->fs_info,
6304 "error inheriting props for ino %llu (root %llu): %d",
6305 btrfs_ino(inode), root->root_key.objectid, ret);
6306
6307 return inode;
6308
6309 fail_unlock:
6310 unlock_new_inode(inode);
6311 fail:
6312 if (dir && name)
6313 BTRFS_I(dir)->index_cnt--;
6314 btrfs_free_path(path);
6315 iput(inode);
6316 return ERR_PTR(ret);
6317 }
6318
6319 static inline u8 btrfs_inode_type(struct inode *inode)
6320 {
6321 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6322 }
6323
6324 /*
6325 * utility function to add 'inode' into 'parent_inode' with
6326 * a give name and a given sequence number.
6327 * if 'add_backref' is true, also insert a backref from the
6328 * inode to the parent directory.
6329 */
6330 int btrfs_add_link(struct btrfs_trans_handle *trans,
6331 struct inode *parent_inode, struct inode *inode,
6332 const char *name, int name_len, int add_backref, u64 index)
6333 {
6334 int ret = 0;
6335 struct btrfs_key key;
6336 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6337 u64 ino = btrfs_ino(inode);
6338 u64 parent_ino = btrfs_ino(parent_inode);
6339
6340 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6341 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6342 } else {
6343 key.objectid = ino;
6344 key.type = BTRFS_INODE_ITEM_KEY;
6345 key.offset = 0;
6346 }
6347
6348 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6349 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6350 key.objectid, root->root_key.objectid,
6351 parent_ino, index, name, name_len);
6352 } else if (add_backref) {
6353 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6354 parent_ino, index);
6355 }
6356
6357 /* Nothing to clean up yet */
6358 if (ret)
6359 return ret;
6360
6361 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6362 parent_inode, &key,
6363 btrfs_inode_type(inode), index);
6364 if (ret == -EEXIST || ret == -EOVERFLOW)
6365 goto fail_dir_item;
6366 else if (ret) {
6367 btrfs_abort_transaction(trans, ret);
6368 return ret;
6369 }
6370
6371 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6372 name_len * 2);
6373 inode_inc_iversion(parent_inode);
6374 parent_inode->i_mtime = parent_inode->i_ctime =
6375 current_time(parent_inode);
6376 ret = btrfs_update_inode(trans, root, parent_inode);
6377 if (ret)
6378 btrfs_abort_transaction(trans, ret);
6379 return ret;
6380
6381 fail_dir_item:
6382 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6383 u64 local_index;
6384 int err;
6385 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6386 key.objectid, root->root_key.objectid,
6387 parent_ino, &local_index, name, name_len);
6388
6389 } else if (add_backref) {
6390 u64 local_index;
6391 int err;
6392
6393 err = btrfs_del_inode_ref(trans, root, name, name_len,
6394 ino, parent_ino, &local_index);
6395 }
6396 return ret;
6397 }
6398
6399 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6400 struct inode *dir, struct dentry *dentry,
6401 struct inode *inode, int backref, u64 index)
6402 {
6403 int err = btrfs_add_link(trans, dir, inode,
6404 dentry->d_name.name, dentry->d_name.len,
6405 backref, index);
6406 if (err > 0)
6407 err = -EEXIST;
6408 return err;
6409 }
6410
6411 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6412 umode_t mode, dev_t rdev)
6413 {
6414 struct btrfs_trans_handle *trans;
6415 struct btrfs_root *root = BTRFS_I(dir)->root;
6416 struct inode *inode = NULL;
6417 int err;
6418 int drop_inode = 0;
6419 u64 objectid;
6420 u64 index = 0;
6421
6422 /*
6423 * 2 for inode item and ref
6424 * 2 for dir items
6425 * 1 for xattr if selinux is on
6426 */
6427 trans = btrfs_start_transaction(root, 5);
6428 if (IS_ERR(trans))
6429 return PTR_ERR(trans);
6430
6431 err = btrfs_find_free_ino(root, &objectid);
6432 if (err)
6433 goto out_unlock;
6434
6435 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6436 dentry->d_name.len, btrfs_ino(dir), objectid,
6437 mode, &index);
6438 if (IS_ERR(inode)) {
6439 err = PTR_ERR(inode);
6440 goto out_unlock;
6441 }
6442
6443 /*
6444 * If the active LSM wants to access the inode during
6445 * d_instantiate it needs these. Smack checks to see
6446 * if the filesystem supports xattrs by looking at the
6447 * ops vector.
6448 */
6449 inode->i_op = &btrfs_special_inode_operations;
6450 init_special_inode(inode, inode->i_mode, rdev);
6451
6452 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6453 if (err)
6454 goto out_unlock_inode;
6455
6456 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6457 if (err) {
6458 goto out_unlock_inode;
6459 } else {
6460 btrfs_update_inode(trans, root, inode);
6461 unlock_new_inode(inode);
6462 d_instantiate(dentry, inode);
6463 }
6464
6465 out_unlock:
6466 btrfs_end_transaction(trans, root);
6467 btrfs_balance_delayed_items(root);
6468 btrfs_btree_balance_dirty(root);
6469 if (drop_inode) {
6470 inode_dec_link_count(inode);
6471 iput(inode);
6472 }
6473 return err;
6474
6475 out_unlock_inode:
6476 drop_inode = 1;
6477 unlock_new_inode(inode);
6478 goto out_unlock;
6479
6480 }
6481
6482 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6483 umode_t mode, bool excl)
6484 {
6485 struct btrfs_trans_handle *trans;
6486 struct btrfs_root *root = BTRFS_I(dir)->root;
6487 struct inode *inode = NULL;
6488 int drop_inode_on_err = 0;
6489 int err;
6490 u64 objectid;
6491 u64 index = 0;
6492
6493 /*
6494 * 2 for inode item and ref
6495 * 2 for dir items
6496 * 1 for xattr if selinux is on
6497 */
6498 trans = btrfs_start_transaction(root, 5);
6499 if (IS_ERR(trans))
6500 return PTR_ERR(trans);
6501
6502 err = btrfs_find_free_ino(root, &objectid);
6503 if (err)
6504 goto out_unlock;
6505
6506 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6507 dentry->d_name.len, btrfs_ino(dir), objectid,
6508 mode, &index);
6509 if (IS_ERR(inode)) {
6510 err = PTR_ERR(inode);
6511 goto out_unlock;
6512 }
6513 drop_inode_on_err = 1;
6514 /*
6515 * If the active LSM wants to access the inode during
6516 * d_instantiate it needs these. Smack checks to see
6517 * if the filesystem supports xattrs by looking at the
6518 * ops vector.
6519 */
6520 inode->i_fop = &btrfs_file_operations;
6521 inode->i_op = &btrfs_file_inode_operations;
6522 inode->i_mapping->a_ops = &btrfs_aops;
6523
6524 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6525 if (err)
6526 goto out_unlock_inode;
6527
6528 err = btrfs_update_inode(trans, root, inode);
6529 if (err)
6530 goto out_unlock_inode;
6531
6532 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6533 if (err)
6534 goto out_unlock_inode;
6535
6536 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6537 unlock_new_inode(inode);
6538 d_instantiate(dentry, inode);
6539
6540 out_unlock:
6541 btrfs_end_transaction(trans, root);
6542 if (err && drop_inode_on_err) {
6543 inode_dec_link_count(inode);
6544 iput(inode);
6545 }
6546 btrfs_balance_delayed_items(root);
6547 btrfs_btree_balance_dirty(root);
6548 return err;
6549
6550 out_unlock_inode:
6551 unlock_new_inode(inode);
6552 goto out_unlock;
6553
6554 }
6555
6556 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6557 struct dentry *dentry)
6558 {
6559 struct btrfs_trans_handle *trans = NULL;
6560 struct btrfs_root *root = BTRFS_I(dir)->root;
6561 struct inode *inode = d_inode(old_dentry);
6562 u64 index;
6563 int err;
6564 int drop_inode = 0;
6565
6566 /* do not allow sys_link's with other subvols of the same device */
6567 if (root->objectid != BTRFS_I(inode)->root->objectid)
6568 return -EXDEV;
6569
6570 if (inode->i_nlink >= BTRFS_LINK_MAX)
6571 return -EMLINK;
6572
6573 err = btrfs_set_inode_index(dir, &index);
6574 if (err)
6575 goto fail;
6576
6577 /*
6578 * 2 items for inode and inode ref
6579 * 2 items for dir items
6580 * 1 item for parent inode
6581 */
6582 trans = btrfs_start_transaction(root, 5);
6583 if (IS_ERR(trans)) {
6584 err = PTR_ERR(trans);
6585 trans = NULL;
6586 goto fail;
6587 }
6588
6589 /* There are several dir indexes for this inode, clear the cache. */
6590 BTRFS_I(inode)->dir_index = 0ULL;
6591 inc_nlink(inode);
6592 inode_inc_iversion(inode);
6593 inode->i_ctime = current_time(inode);
6594 ihold(inode);
6595 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6596
6597 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6598
6599 if (err) {
6600 drop_inode = 1;
6601 } else {
6602 struct dentry *parent = dentry->d_parent;
6603 err = btrfs_update_inode(trans, root, inode);
6604 if (err)
6605 goto fail;
6606 if (inode->i_nlink == 1) {
6607 /*
6608 * If new hard link count is 1, it's a file created
6609 * with open(2) O_TMPFILE flag.
6610 */
6611 err = btrfs_orphan_del(trans, inode);
6612 if (err)
6613 goto fail;
6614 }
6615 d_instantiate(dentry, inode);
6616 btrfs_log_new_name(trans, inode, NULL, parent);
6617 }
6618
6619 btrfs_balance_delayed_items(root);
6620 fail:
6621 if (trans)
6622 btrfs_end_transaction(trans, root);
6623 if (drop_inode) {
6624 inode_dec_link_count(inode);
6625 iput(inode);
6626 }
6627 btrfs_btree_balance_dirty(root);
6628 return err;
6629 }
6630
6631 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6632 {
6633 struct inode *inode = NULL;
6634 struct btrfs_trans_handle *trans;
6635 struct btrfs_root *root = BTRFS_I(dir)->root;
6636 int err = 0;
6637 int drop_on_err = 0;
6638 u64 objectid = 0;
6639 u64 index = 0;
6640
6641 /*
6642 * 2 items for inode and ref
6643 * 2 items for dir items
6644 * 1 for xattr if selinux is on
6645 */
6646 trans = btrfs_start_transaction(root, 5);
6647 if (IS_ERR(trans))
6648 return PTR_ERR(trans);
6649
6650 err = btrfs_find_free_ino(root, &objectid);
6651 if (err)
6652 goto out_fail;
6653
6654 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6655 dentry->d_name.len, btrfs_ino(dir), objectid,
6656 S_IFDIR | mode, &index);
6657 if (IS_ERR(inode)) {
6658 err = PTR_ERR(inode);
6659 goto out_fail;
6660 }
6661
6662 drop_on_err = 1;
6663 /* these must be set before we unlock the inode */
6664 inode->i_op = &btrfs_dir_inode_operations;
6665 inode->i_fop = &btrfs_dir_file_operations;
6666
6667 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6668 if (err)
6669 goto out_fail_inode;
6670
6671 btrfs_i_size_write(inode, 0);
6672 err = btrfs_update_inode(trans, root, inode);
6673 if (err)
6674 goto out_fail_inode;
6675
6676 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6677 dentry->d_name.len, 0, index);
6678 if (err)
6679 goto out_fail_inode;
6680
6681 d_instantiate(dentry, inode);
6682 /*
6683 * mkdir is special. We're unlocking after we call d_instantiate
6684 * to avoid a race with nfsd calling d_instantiate.
6685 */
6686 unlock_new_inode(inode);
6687 drop_on_err = 0;
6688
6689 out_fail:
6690 btrfs_end_transaction(trans, root);
6691 if (drop_on_err) {
6692 inode_dec_link_count(inode);
6693 iput(inode);
6694 }
6695 btrfs_balance_delayed_items(root);
6696 btrfs_btree_balance_dirty(root);
6697 return err;
6698
6699 out_fail_inode:
6700 unlock_new_inode(inode);
6701 goto out_fail;
6702 }
6703
6704 /* Find next extent map of a given extent map, caller needs to ensure locks */
6705 static struct extent_map *next_extent_map(struct extent_map *em)
6706 {
6707 struct rb_node *next;
6708
6709 next = rb_next(&em->rb_node);
6710 if (!next)
6711 return NULL;
6712 return container_of(next, struct extent_map, rb_node);
6713 }
6714
6715 static struct extent_map *prev_extent_map(struct extent_map *em)
6716 {
6717 struct rb_node *prev;
6718
6719 prev = rb_prev(&em->rb_node);
6720 if (!prev)
6721 return NULL;
6722 return container_of(prev, struct extent_map, rb_node);
6723 }
6724
6725 /* helper for btfs_get_extent. Given an existing extent in the tree,
6726 * the existing extent is the nearest extent to map_start,
6727 * and an extent that you want to insert, deal with overlap and insert
6728 * the best fitted new extent into the tree.
6729 */
6730 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6731 struct extent_map *existing,
6732 struct extent_map *em,
6733 u64 map_start)
6734 {
6735 struct extent_map *prev;
6736 struct extent_map *next;
6737 u64 start;
6738 u64 end;
6739 u64 start_diff;
6740
6741 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6742
6743 if (existing->start > map_start) {
6744 next = existing;
6745 prev = prev_extent_map(next);
6746 } else {
6747 prev = existing;
6748 next = next_extent_map(prev);
6749 }
6750
6751 start = prev ? extent_map_end(prev) : em->start;
6752 start = max_t(u64, start, em->start);
6753 end = next ? next->start : extent_map_end(em);
6754 end = min_t(u64, end, extent_map_end(em));
6755 start_diff = start - em->start;
6756 em->start = start;
6757 em->len = end - start;
6758 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6759 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6760 em->block_start += start_diff;
6761 em->block_len -= start_diff;
6762 }
6763 return add_extent_mapping(em_tree, em, 0);
6764 }
6765
6766 static noinline int uncompress_inline(struct btrfs_path *path,
6767 struct page *page,
6768 size_t pg_offset, u64 extent_offset,
6769 struct btrfs_file_extent_item *item)
6770 {
6771 int ret;
6772 struct extent_buffer *leaf = path->nodes[0];
6773 char *tmp;
6774 size_t max_size;
6775 unsigned long inline_size;
6776 unsigned long ptr;
6777 int compress_type;
6778
6779 WARN_ON(pg_offset != 0);
6780 compress_type = btrfs_file_extent_compression(leaf, item);
6781 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6782 inline_size = btrfs_file_extent_inline_item_len(leaf,
6783 btrfs_item_nr(path->slots[0]));
6784 tmp = kmalloc(inline_size, GFP_NOFS);
6785 if (!tmp)
6786 return -ENOMEM;
6787 ptr = btrfs_file_extent_inline_start(item);
6788
6789 read_extent_buffer(leaf, tmp, ptr, inline_size);
6790
6791 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6792 ret = btrfs_decompress(compress_type, tmp, page,
6793 extent_offset, inline_size, max_size);
6794 kfree(tmp);
6795 return ret;
6796 }
6797
6798 /*
6799 * a bit scary, this does extent mapping from logical file offset to the disk.
6800 * the ugly parts come from merging extents from the disk with the in-ram
6801 * representation. This gets more complex because of the data=ordered code,
6802 * where the in-ram extents might be locked pending data=ordered completion.
6803 *
6804 * This also copies inline extents directly into the page.
6805 */
6806
6807 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6808 size_t pg_offset, u64 start, u64 len,
6809 int create)
6810 {
6811 int ret;
6812 int err = 0;
6813 u64 extent_start = 0;
6814 u64 extent_end = 0;
6815 u64 objectid = btrfs_ino(inode);
6816 u32 found_type;
6817 struct btrfs_path *path = NULL;
6818 struct btrfs_root *root = BTRFS_I(inode)->root;
6819 struct btrfs_file_extent_item *item;
6820 struct extent_buffer *leaf;
6821 struct btrfs_key found_key;
6822 struct extent_map *em = NULL;
6823 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6824 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6825 struct btrfs_trans_handle *trans = NULL;
6826 const bool new_inline = !page || create;
6827
6828 again:
6829 read_lock(&em_tree->lock);
6830 em = lookup_extent_mapping(em_tree, start, len);
6831 if (em)
6832 em->bdev = root->fs_info->fs_devices->latest_bdev;
6833 read_unlock(&em_tree->lock);
6834
6835 if (em) {
6836 if (em->start > start || em->start + em->len <= start)
6837 free_extent_map(em);
6838 else if (em->block_start == EXTENT_MAP_INLINE && page)
6839 free_extent_map(em);
6840 else
6841 goto out;
6842 }
6843 em = alloc_extent_map();
6844 if (!em) {
6845 err = -ENOMEM;
6846 goto out;
6847 }
6848 em->bdev = root->fs_info->fs_devices->latest_bdev;
6849 em->start = EXTENT_MAP_HOLE;
6850 em->orig_start = EXTENT_MAP_HOLE;
6851 em->len = (u64)-1;
6852 em->block_len = (u64)-1;
6853
6854 if (!path) {
6855 path = btrfs_alloc_path();
6856 if (!path) {
6857 err = -ENOMEM;
6858 goto out;
6859 }
6860 /*
6861 * Chances are we'll be called again, so go ahead and do
6862 * readahead
6863 */
6864 path->reada = READA_FORWARD;
6865 }
6866
6867 ret = btrfs_lookup_file_extent(trans, root, path,
6868 objectid, start, trans != NULL);
6869 if (ret < 0) {
6870 err = ret;
6871 goto out;
6872 }
6873
6874 if (ret != 0) {
6875 if (path->slots[0] == 0)
6876 goto not_found;
6877 path->slots[0]--;
6878 }
6879
6880 leaf = path->nodes[0];
6881 item = btrfs_item_ptr(leaf, path->slots[0],
6882 struct btrfs_file_extent_item);
6883 /* are we inside the extent that was found? */
6884 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6885 found_type = found_key.type;
6886 if (found_key.objectid != objectid ||
6887 found_type != BTRFS_EXTENT_DATA_KEY) {
6888 /*
6889 * If we backup past the first extent we want to move forward
6890 * and see if there is an extent in front of us, otherwise we'll
6891 * say there is a hole for our whole search range which can
6892 * cause problems.
6893 */
6894 extent_end = start;
6895 goto next;
6896 }
6897
6898 found_type = btrfs_file_extent_type(leaf, item);
6899 extent_start = found_key.offset;
6900 if (found_type == BTRFS_FILE_EXTENT_REG ||
6901 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6902 extent_end = extent_start +
6903 btrfs_file_extent_num_bytes(leaf, item);
6904 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6905 size_t size;
6906 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6907 extent_end = ALIGN(extent_start + size, root->sectorsize);
6908 }
6909 next:
6910 if (start >= extent_end) {
6911 path->slots[0]++;
6912 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6913 ret = btrfs_next_leaf(root, path);
6914 if (ret < 0) {
6915 err = ret;
6916 goto out;
6917 }
6918 if (ret > 0)
6919 goto not_found;
6920 leaf = path->nodes[0];
6921 }
6922 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6923 if (found_key.objectid != objectid ||
6924 found_key.type != BTRFS_EXTENT_DATA_KEY)
6925 goto not_found;
6926 if (start + len <= found_key.offset)
6927 goto not_found;
6928 if (start > found_key.offset)
6929 goto next;
6930 em->start = start;
6931 em->orig_start = start;
6932 em->len = found_key.offset - start;
6933 goto not_found_em;
6934 }
6935
6936 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6937
6938 if (found_type == BTRFS_FILE_EXTENT_REG ||
6939 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6940 goto insert;
6941 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6942 unsigned long ptr;
6943 char *map;
6944 size_t size;
6945 size_t extent_offset;
6946 size_t copy_size;
6947
6948 if (new_inline)
6949 goto out;
6950
6951 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6952 extent_offset = page_offset(page) + pg_offset - extent_start;
6953 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6954 size - extent_offset);
6955 em->start = extent_start + extent_offset;
6956 em->len = ALIGN(copy_size, root->sectorsize);
6957 em->orig_block_len = em->len;
6958 em->orig_start = em->start;
6959 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6960 if (create == 0 && !PageUptodate(page)) {
6961 if (btrfs_file_extent_compression(leaf, item) !=
6962 BTRFS_COMPRESS_NONE) {
6963 ret = uncompress_inline(path, page, pg_offset,
6964 extent_offset, item);
6965 if (ret) {
6966 err = ret;
6967 goto out;
6968 }
6969 } else {
6970 map = kmap(page);
6971 read_extent_buffer(leaf, map + pg_offset, ptr,
6972 copy_size);
6973 if (pg_offset + copy_size < PAGE_SIZE) {
6974 memset(map + pg_offset + copy_size, 0,
6975 PAGE_SIZE - pg_offset -
6976 copy_size);
6977 }
6978 kunmap(page);
6979 }
6980 flush_dcache_page(page);
6981 } else if (create && PageUptodate(page)) {
6982 BUG();
6983 if (!trans) {
6984 kunmap(page);
6985 free_extent_map(em);
6986 em = NULL;
6987
6988 btrfs_release_path(path);
6989 trans = btrfs_join_transaction(root);
6990
6991 if (IS_ERR(trans))
6992 return ERR_CAST(trans);
6993 goto again;
6994 }
6995 map = kmap(page);
6996 write_extent_buffer(leaf, map + pg_offset, ptr,
6997 copy_size);
6998 kunmap(page);
6999 btrfs_mark_buffer_dirty(leaf);
7000 }
7001 set_extent_uptodate(io_tree, em->start,
7002 extent_map_end(em) - 1, NULL, GFP_NOFS);
7003 goto insert;
7004 }
7005 not_found:
7006 em->start = start;
7007 em->orig_start = start;
7008 em->len = len;
7009 not_found_em:
7010 em->block_start = EXTENT_MAP_HOLE;
7011 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7012 insert:
7013 btrfs_release_path(path);
7014 if (em->start > start || extent_map_end(em) <= start) {
7015 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
7016 em->start, em->len, start, len);
7017 err = -EIO;
7018 goto out;
7019 }
7020
7021 err = 0;
7022 write_lock(&em_tree->lock);
7023 ret = add_extent_mapping(em_tree, em, 0);
7024 /* it is possible that someone inserted the extent into the tree
7025 * while we had the lock dropped. It is also possible that
7026 * an overlapping map exists in the tree
7027 */
7028 if (ret == -EEXIST) {
7029 struct extent_map *existing;
7030
7031 ret = 0;
7032
7033 existing = search_extent_mapping(em_tree, start, len);
7034 /*
7035 * existing will always be non-NULL, since there must be
7036 * extent causing the -EEXIST.
7037 */
7038 if (existing->start == em->start &&
7039 extent_map_end(existing) == extent_map_end(em) &&
7040 em->block_start == existing->block_start) {
7041 /*
7042 * these two extents are the same, it happens
7043 * with inlines especially
7044 */
7045 free_extent_map(em);
7046 em = existing;
7047 err = 0;
7048
7049 } else if (start >= extent_map_end(existing) ||
7050 start <= existing->start) {
7051 /*
7052 * The existing extent map is the one nearest to
7053 * the [start, start + len) range which overlaps
7054 */
7055 err = merge_extent_mapping(em_tree, existing,
7056 em, start);
7057 free_extent_map(existing);
7058 if (err) {
7059 free_extent_map(em);
7060 em = NULL;
7061 }
7062 } else {
7063 free_extent_map(em);
7064 em = existing;
7065 err = 0;
7066 }
7067 }
7068 write_unlock(&em_tree->lock);
7069 out:
7070
7071 trace_btrfs_get_extent(root, em);
7072
7073 btrfs_free_path(path);
7074 if (trans) {
7075 ret = btrfs_end_transaction(trans, root);
7076 if (!err)
7077 err = ret;
7078 }
7079 if (err) {
7080 free_extent_map(em);
7081 return ERR_PTR(err);
7082 }
7083 BUG_ON(!em); /* Error is always set */
7084 return em;
7085 }
7086
7087 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7088 size_t pg_offset, u64 start, u64 len,
7089 int create)
7090 {
7091 struct extent_map *em;
7092 struct extent_map *hole_em = NULL;
7093 u64 range_start = start;
7094 u64 end;
7095 u64 found;
7096 u64 found_end;
7097 int err = 0;
7098
7099 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7100 if (IS_ERR(em))
7101 return em;
7102 if (em) {
7103 /*
7104 * if our em maps to
7105 * - a hole or
7106 * - a pre-alloc extent,
7107 * there might actually be delalloc bytes behind it.
7108 */
7109 if (em->block_start != EXTENT_MAP_HOLE &&
7110 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7111 return em;
7112 else
7113 hole_em = em;
7114 }
7115
7116 /* check to see if we've wrapped (len == -1 or similar) */
7117 end = start + len;
7118 if (end < start)
7119 end = (u64)-1;
7120 else
7121 end -= 1;
7122
7123 em = NULL;
7124
7125 /* ok, we didn't find anything, lets look for delalloc */
7126 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7127 end, len, EXTENT_DELALLOC, 1);
7128 found_end = range_start + found;
7129 if (found_end < range_start)
7130 found_end = (u64)-1;
7131
7132 /*
7133 * we didn't find anything useful, return
7134 * the original results from get_extent()
7135 */
7136 if (range_start > end || found_end <= start) {
7137 em = hole_em;
7138 hole_em = NULL;
7139 goto out;
7140 }
7141
7142 /* adjust the range_start to make sure it doesn't
7143 * go backwards from the start they passed in
7144 */
7145 range_start = max(start, range_start);
7146 found = found_end - range_start;
7147
7148 if (found > 0) {
7149 u64 hole_start = start;
7150 u64 hole_len = len;
7151
7152 em = alloc_extent_map();
7153 if (!em) {
7154 err = -ENOMEM;
7155 goto out;
7156 }
7157 /*
7158 * when btrfs_get_extent can't find anything it
7159 * returns one huge hole
7160 *
7161 * make sure what it found really fits our range, and
7162 * adjust to make sure it is based on the start from
7163 * the caller
7164 */
7165 if (hole_em) {
7166 u64 calc_end = extent_map_end(hole_em);
7167
7168 if (calc_end <= start || (hole_em->start > end)) {
7169 free_extent_map(hole_em);
7170 hole_em = NULL;
7171 } else {
7172 hole_start = max(hole_em->start, start);
7173 hole_len = calc_end - hole_start;
7174 }
7175 }
7176 em->bdev = NULL;
7177 if (hole_em && range_start > hole_start) {
7178 /* our hole starts before our delalloc, so we
7179 * have to return just the parts of the hole
7180 * that go until the delalloc starts
7181 */
7182 em->len = min(hole_len,
7183 range_start - hole_start);
7184 em->start = hole_start;
7185 em->orig_start = hole_start;
7186 /*
7187 * don't adjust block start at all,
7188 * it is fixed at EXTENT_MAP_HOLE
7189 */
7190 em->block_start = hole_em->block_start;
7191 em->block_len = hole_len;
7192 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7193 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7194 } else {
7195 em->start = range_start;
7196 em->len = found;
7197 em->orig_start = range_start;
7198 em->block_start = EXTENT_MAP_DELALLOC;
7199 em->block_len = found;
7200 }
7201 } else if (hole_em) {
7202 return hole_em;
7203 }
7204 out:
7205
7206 free_extent_map(hole_em);
7207 if (err) {
7208 free_extent_map(em);
7209 return ERR_PTR(err);
7210 }
7211 return em;
7212 }
7213
7214 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7215 const u64 start,
7216 const u64 len,
7217 const u64 orig_start,
7218 const u64 block_start,
7219 const u64 block_len,
7220 const u64 orig_block_len,
7221 const u64 ram_bytes,
7222 const int type)
7223 {
7224 struct extent_map *em = NULL;
7225 int ret;
7226
7227 down_read(&BTRFS_I(inode)->dio_sem);
7228 if (type != BTRFS_ORDERED_NOCOW) {
7229 em = create_pinned_em(inode, start, len, orig_start,
7230 block_start, block_len, orig_block_len,
7231 ram_bytes, type);
7232 if (IS_ERR(em))
7233 goto out;
7234 }
7235 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7236 len, block_len, type);
7237 if (ret) {
7238 if (em) {
7239 free_extent_map(em);
7240 btrfs_drop_extent_cache(inode, start,
7241 start + len - 1, 0);
7242 }
7243 em = ERR_PTR(ret);
7244 }
7245 out:
7246 up_read(&BTRFS_I(inode)->dio_sem);
7247
7248 return em;
7249 }
7250
7251 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7252 u64 start, u64 len)
7253 {
7254 struct btrfs_root *root = BTRFS_I(inode)->root;
7255 struct extent_map *em;
7256 struct btrfs_key ins;
7257 u64 alloc_hint;
7258 int ret;
7259
7260 alloc_hint = get_extent_allocation_hint(inode, start, len);
7261 ret = btrfs_reserve_extent(root, len, len, root->sectorsize, 0,
7262 alloc_hint, &ins, 1, 1);
7263 if (ret)
7264 return ERR_PTR(ret);
7265
7266 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7267 ins.objectid, ins.offset, ins.offset,
7268 ins.offset, 0);
7269 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7270 if (IS_ERR(em))
7271 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7272
7273 return em;
7274 }
7275
7276 /*
7277 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7278 * block must be cow'd
7279 */
7280 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7281 u64 *orig_start, u64 *orig_block_len,
7282 u64 *ram_bytes)
7283 {
7284 struct btrfs_trans_handle *trans;
7285 struct btrfs_path *path;
7286 int ret;
7287 struct extent_buffer *leaf;
7288 struct btrfs_root *root = BTRFS_I(inode)->root;
7289 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7290 struct btrfs_file_extent_item *fi;
7291 struct btrfs_key key;
7292 u64 disk_bytenr;
7293 u64 backref_offset;
7294 u64 extent_end;
7295 u64 num_bytes;
7296 int slot;
7297 int found_type;
7298 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7299
7300 path = btrfs_alloc_path();
7301 if (!path)
7302 return -ENOMEM;
7303
7304 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7305 offset, 0);
7306 if (ret < 0)
7307 goto out;
7308
7309 slot = path->slots[0];
7310 if (ret == 1) {
7311 if (slot == 0) {
7312 /* can't find the item, must cow */
7313 ret = 0;
7314 goto out;
7315 }
7316 slot--;
7317 }
7318 ret = 0;
7319 leaf = path->nodes[0];
7320 btrfs_item_key_to_cpu(leaf, &key, slot);
7321 if (key.objectid != btrfs_ino(inode) ||
7322 key.type != BTRFS_EXTENT_DATA_KEY) {
7323 /* not our file or wrong item type, must cow */
7324 goto out;
7325 }
7326
7327 if (key.offset > offset) {
7328 /* Wrong offset, must cow */
7329 goto out;
7330 }
7331
7332 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7333 found_type = btrfs_file_extent_type(leaf, fi);
7334 if (found_type != BTRFS_FILE_EXTENT_REG &&
7335 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7336 /* not a regular extent, must cow */
7337 goto out;
7338 }
7339
7340 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7341 goto out;
7342
7343 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7344 if (extent_end <= offset)
7345 goto out;
7346
7347 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7348 if (disk_bytenr == 0)
7349 goto out;
7350
7351 if (btrfs_file_extent_compression(leaf, fi) ||
7352 btrfs_file_extent_encryption(leaf, fi) ||
7353 btrfs_file_extent_other_encoding(leaf, fi))
7354 goto out;
7355
7356 backref_offset = btrfs_file_extent_offset(leaf, fi);
7357
7358 if (orig_start) {
7359 *orig_start = key.offset - backref_offset;
7360 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7361 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7362 }
7363
7364 if (btrfs_extent_readonly(root, disk_bytenr))
7365 goto out;
7366
7367 num_bytes = min(offset + *len, extent_end) - offset;
7368 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7369 u64 range_end;
7370
7371 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7372 ret = test_range_bit(io_tree, offset, range_end,
7373 EXTENT_DELALLOC, 0, NULL);
7374 if (ret) {
7375 ret = -EAGAIN;
7376 goto out;
7377 }
7378 }
7379
7380 btrfs_release_path(path);
7381
7382 /*
7383 * look for other files referencing this extent, if we
7384 * find any we must cow
7385 */
7386 trans = btrfs_join_transaction(root);
7387 if (IS_ERR(trans)) {
7388 ret = 0;
7389 goto out;
7390 }
7391
7392 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7393 key.offset - backref_offset, disk_bytenr);
7394 btrfs_end_transaction(trans, root);
7395 if (ret) {
7396 ret = 0;
7397 goto out;
7398 }
7399
7400 /*
7401 * adjust disk_bytenr and num_bytes to cover just the bytes
7402 * in this extent we are about to write. If there
7403 * are any csums in that range we have to cow in order
7404 * to keep the csums correct
7405 */
7406 disk_bytenr += backref_offset;
7407 disk_bytenr += offset - key.offset;
7408 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7409 goto out;
7410 /*
7411 * all of the above have passed, it is safe to overwrite this extent
7412 * without cow
7413 */
7414 *len = num_bytes;
7415 ret = 1;
7416 out:
7417 btrfs_free_path(path);
7418 return ret;
7419 }
7420
7421 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7422 {
7423 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7424 int found = false;
7425 void **pagep = NULL;
7426 struct page *page = NULL;
7427 int start_idx;
7428 int end_idx;
7429
7430 start_idx = start >> PAGE_SHIFT;
7431
7432 /*
7433 * end is the last byte in the last page. end == start is legal
7434 */
7435 end_idx = end >> PAGE_SHIFT;
7436
7437 rcu_read_lock();
7438
7439 /* Most of the code in this while loop is lifted from
7440 * find_get_page. It's been modified to begin searching from a
7441 * page and return just the first page found in that range. If the
7442 * found idx is less than or equal to the end idx then we know that
7443 * a page exists. If no pages are found or if those pages are
7444 * outside of the range then we're fine (yay!) */
7445 while (page == NULL &&
7446 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7447 page = radix_tree_deref_slot(pagep);
7448 if (unlikely(!page))
7449 break;
7450
7451 if (radix_tree_exception(page)) {
7452 if (radix_tree_deref_retry(page)) {
7453 page = NULL;
7454 continue;
7455 }
7456 /*
7457 * Otherwise, shmem/tmpfs must be storing a swap entry
7458 * here as an exceptional entry: so return it without
7459 * attempting to raise page count.
7460 */
7461 page = NULL;
7462 break; /* TODO: Is this relevant for this use case? */
7463 }
7464
7465 if (!page_cache_get_speculative(page)) {
7466 page = NULL;
7467 continue;
7468 }
7469
7470 /*
7471 * Has the page moved?
7472 * This is part of the lockless pagecache protocol. See
7473 * include/linux/pagemap.h for details.
7474 */
7475 if (unlikely(page != *pagep)) {
7476 put_page(page);
7477 page = NULL;
7478 }
7479 }
7480
7481 if (page) {
7482 if (page->index <= end_idx)
7483 found = true;
7484 put_page(page);
7485 }
7486
7487 rcu_read_unlock();
7488 return found;
7489 }
7490
7491 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7492 struct extent_state **cached_state, int writing)
7493 {
7494 struct btrfs_ordered_extent *ordered;
7495 int ret = 0;
7496
7497 while (1) {
7498 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7499 cached_state);
7500 /*
7501 * We're concerned with the entire range that we're going to be
7502 * doing DIO to, so we need to make sure there's no ordered
7503 * extents in this range.
7504 */
7505 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7506 lockend - lockstart + 1);
7507
7508 /*
7509 * We need to make sure there are no buffered pages in this
7510 * range either, we could have raced between the invalidate in
7511 * generic_file_direct_write and locking the extent. The
7512 * invalidate needs to happen so that reads after a write do not
7513 * get stale data.
7514 */
7515 if (!ordered &&
7516 (!writing ||
7517 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7518 break;
7519
7520 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7521 cached_state, GFP_NOFS);
7522
7523 if (ordered) {
7524 /*
7525 * If we are doing a DIO read and the ordered extent we
7526 * found is for a buffered write, we can not wait for it
7527 * to complete and retry, because if we do so we can
7528 * deadlock with concurrent buffered writes on page
7529 * locks. This happens only if our DIO read covers more
7530 * than one extent map, if at this point has already
7531 * created an ordered extent for a previous extent map
7532 * and locked its range in the inode's io tree, and a
7533 * concurrent write against that previous extent map's
7534 * range and this range started (we unlock the ranges
7535 * in the io tree only when the bios complete and
7536 * buffered writes always lock pages before attempting
7537 * to lock range in the io tree).
7538 */
7539 if (writing ||
7540 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7541 btrfs_start_ordered_extent(inode, ordered, 1);
7542 else
7543 ret = -ENOTBLK;
7544 btrfs_put_ordered_extent(ordered);
7545 } else {
7546 /*
7547 * We could trigger writeback for this range (and wait
7548 * for it to complete) and then invalidate the pages for
7549 * this range (through invalidate_inode_pages2_range()),
7550 * but that can lead us to a deadlock with a concurrent
7551 * call to readpages() (a buffered read or a defrag call
7552 * triggered a readahead) on a page lock due to an
7553 * ordered dio extent we created before but did not have
7554 * yet a corresponding bio submitted (whence it can not
7555 * complete), which makes readpages() wait for that
7556 * ordered extent to complete while holding a lock on
7557 * that page.
7558 */
7559 ret = -ENOTBLK;
7560 }
7561
7562 if (ret)
7563 break;
7564
7565 cond_resched();
7566 }
7567
7568 return ret;
7569 }
7570
7571 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7572 u64 len, u64 orig_start,
7573 u64 block_start, u64 block_len,
7574 u64 orig_block_len, u64 ram_bytes,
7575 int type)
7576 {
7577 struct extent_map_tree *em_tree;
7578 struct extent_map *em;
7579 struct btrfs_root *root = BTRFS_I(inode)->root;
7580 int ret;
7581
7582 em_tree = &BTRFS_I(inode)->extent_tree;
7583 em = alloc_extent_map();
7584 if (!em)
7585 return ERR_PTR(-ENOMEM);
7586
7587 em->start = start;
7588 em->orig_start = orig_start;
7589 em->mod_start = start;
7590 em->mod_len = len;
7591 em->len = len;
7592 em->block_len = block_len;
7593 em->block_start = block_start;
7594 em->bdev = root->fs_info->fs_devices->latest_bdev;
7595 em->orig_block_len = orig_block_len;
7596 em->ram_bytes = ram_bytes;
7597 em->generation = -1;
7598 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7599 if (type == BTRFS_ORDERED_PREALLOC)
7600 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7601
7602 do {
7603 btrfs_drop_extent_cache(inode, em->start,
7604 em->start + em->len - 1, 0);
7605 write_lock(&em_tree->lock);
7606 ret = add_extent_mapping(em_tree, em, 1);
7607 write_unlock(&em_tree->lock);
7608 } while (ret == -EEXIST);
7609
7610 if (ret) {
7611 free_extent_map(em);
7612 return ERR_PTR(ret);
7613 }
7614
7615 return em;
7616 }
7617
7618 static void adjust_dio_outstanding_extents(struct inode *inode,
7619 struct btrfs_dio_data *dio_data,
7620 const u64 len)
7621 {
7622 unsigned num_extents;
7623
7624 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7625 BTRFS_MAX_EXTENT_SIZE);
7626 /*
7627 * If we have an outstanding_extents count still set then we're
7628 * within our reservation, otherwise we need to adjust our inode
7629 * counter appropriately.
7630 */
7631 if (dio_data->outstanding_extents) {
7632 dio_data->outstanding_extents -= num_extents;
7633 } else {
7634 spin_lock(&BTRFS_I(inode)->lock);
7635 BTRFS_I(inode)->outstanding_extents += num_extents;
7636 spin_unlock(&BTRFS_I(inode)->lock);
7637 }
7638 }
7639
7640 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7641 struct buffer_head *bh_result, int create)
7642 {
7643 struct extent_map *em;
7644 struct btrfs_root *root = BTRFS_I(inode)->root;
7645 struct extent_state *cached_state = NULL;
7646 struct btrfs_dio_data *dio_data = NULL;
7647 u64 start = iblock << inode->i_blkbits;
7648 u64 lockstart, lockend;
7649 u64 len = bh_result->b_size;
7650 int unlock_bits = EXTENT_LOCKED;
7651 int ret = 0;
7652
7653 if (create)
7654 unlock_bits |= EXTENT_DIRTY;
7655 else
7656 len = min_t(u64, len, root->sectorsize);
7657
7658 lockstart = start;
7659 lockend = start + len - 1;
7660
7661 if (current->journal_info) {
7662 /*
7663 * Need to pull our outstanding extents and set journal_info to NULL so
7664 * that anything that needs to check if there's a transaction doesn't get
7665 * confused.
7666 */
7667 dio_data = current->journal_info;
7668 current->journal_info = NULL;
7669 }
7670
7671 /*
7672 * If this errors out it's because we couldn't invalidate pagecache for
7673 * this range and we need to fallback to buffered.
7674 */
7675 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7676 create)) {
7677 ret = -ENOTBLK;
7678 goto err;
7679 }
7680
7681 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7682 if (IS_ERR(em)) {
7683 ret = PTR_ERR(em);
7684 goto unlock_err;
7685 }
7686
7687 /*
7688 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7689 * io. INLINE is special, and we could probably kludge it in here, but
7690 * it's still buffered so for safety lets just fall back to the generic
7691 * buffered path.
7692 *
7693 * For COMPRESSED we _have_ to read the entire extent in so we can
7694 * decompress it, so there will be buffering required no matter what we
7695 * do, so go ahead and fallback to buffered.
7696 *
7697 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7698 * to buffered IO. Don't blame me, this is the price we pay for using
7699 * the generic code.
7700 */
7701 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7702 em->block_start == EXTENT_MAP_INLINE) {
7703 free_extent_map(em);
7704 ret = -ENOTBLK;
7705 goto unlock_err;
7706 }
7707
7708 /* Just a good old fashioned hole, return */
7709 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7710 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7711 free_extent_map(em);
7712 goto unlock_err;
7713 }
7714
7715 /*
7716 * We don't allocate a new extent in the following cases
7717 *
7718 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7719 * existing extent.
7720 * 2) The extent is marked as PREALLOC. We're good to go here and can
7721 * just use the extent.
7722 *
7723 */
7724 if (!create) {
7725 len = min(len, em->len - (start - em->start));
7726 lockstart = start + len;
7727 goto unlock;
7728 }
7729
7730 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7731 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7732 em->block_start != EXTENT_MAP_HOLE)) {
7733 int type;
7734 u64 block_start, orig_start, orig_block_len, ram_bytes;
7735
7736 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7737 type = BTRFS_ORDERED_PREALLOC;
7738 else
7739 type = BTRFS_ORDERED_NOCOW;
7740 len = min(len, em->len - (start - em->start));
7741 block_start = em->block_start + (start - em->start);
7742
7743 if (can_nocow_extent(inode, start, &len, &orig_start,
7744 &orig_block_len, &ram_bytes) == 1 &&
7745 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7746 struct extent_map *em2;
7747
7748 em2 = btrfs_create_dio_extent(inode, start, len,
7749 orig_start, block_start,
7750 len, orig_block_len,
7751 ram_bytes, type);
7752 btrfs_dec_nocow_writers(root->fs_info, block_start);
7753 if (type == BTRFS_ORDERED_PREALLOC) {
7754 free_extent_map(em);
7755 em = em2;
7756 }
7757 if (em2 && IS_ERR(em2)) {
7758 ret = PTR_ERR(em2);
7759 goto unlock_err;
7760 }
7761 /*
7762 * For inode marked NODATACOW or extent marked PREALLOC,
7763 * use the existing or preallocated extent, so does not
7764 * need to adjust btrfs_space_info's bytes_may_use.
7765 */
7766 btrfs_free_reserved_data_space_noquota(inode,
7767 start, len);
7768 goto unlock;
7769 }
7770 }
7771
7772 /*
7773 * this will cow the extent, reset the len in case we changed
7774 * it above
7775 */
7776 len = bh_result->b_size;
7777 free_extent_map(em);
7778 em = btrfs_new_extent_direct(inode, start, len);
7779 if (IS_ERR(em)) {
7780 ret = PTR_ERR(em);
7781 goto unlock_err;
7782 }
7783 len = min(len, em->len - (start - em->start));
7784 unlock:
7785 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7786 inode->i_blkbits;
7787 bh_result->b_size = len;
7788 bh_result->b_bdev = em->bdev;
7789 set_buffer_mapped(bh_result);
7790 if (create) {
7791 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7792 set_buffer_new(bh_result);
7793
7794 /*
7795 * Need to update the i_size under the extent lock so buffered
7796 * readers will get the updated i_size when we unlock.
7797 */
7798 if (start + len > i_size_read(inode))
7799 i_size_write(inode, start + len);
7800
7801 adjust_dio_outstanding_extents(inode, dio_data, len);
7802 WARN_ON(dio_data->reserve < len);
7803 dio_data->reserve -= len;
7804 dio_data->unsubmitted_oe_range_end = start + len;
7805 current->journal_info = dio_data;
7806 }
7807
7808 /*
7809 * In the case of write we need to clear and unlock the entire range,
7810 * in the case of read we need to unlock only the end area that we
7811 * aren't using if there is any left over space.
7812 */
7813 if (lockstart < lockend) {
7814 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7815 lockend, unlock_bits, 1, 0,
7816 &cached_state, GFP_NOFS);
7817 } else {
7818 free_extent_state(cached_state);
7819 }
7820
7821 free_extent_map(em);
7822
7823 return 0;
7824
7825 unlock_err:
7826 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7827 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7828 err:
7829 if (dio_data)
7830 current->journal_info = dio_data;
7831 /*
7832 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7833 * write less data then expected, so that we don't underflow our inode's
7834 * outstanding extents counter.
7835 */
7836 if (create && dio_data)
7837 adjust_dio_outstanding_extents(inode, dio_data, len);
7838
7839 return ret;
7840 }
7841
7842 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7843 int mirror_num)
7844 {
7845 struct btrfs_root *root = BTRFS_I(inode)->root;
7846 int ret;
7847
7848 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7849
7850 bio_get(bio);
7851
7852 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7853 BTRFS_WQ_ENDIO_DIO_REPAIR);
7854 if (ret)
7855 goto err;
7856
7857 ret = btrfs_map_bio(root, bio, mirror_num, 0);
7858 err:
7859 bio_put(bio);
7860 return ret;
7861 }
7862
7863 static int btrfs_check_dio_repairable(struct inode *inode,
7864 struct bio *failed_bio,
7865 struct io_failure_record *failrec,
7866 int failed_mirror)
7867 {
7868 int num_copies;
7869
7870 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7871 failrec->logical, failrec->len);
7872 if (num_copies == 1) {
7873 /*
7874 * we only have a single copy of the data, so don't bother with
7875 * all the retry and error correction code that follows. no
7876 * matter what the error is, it is very likely to persist.
7877 */
7878 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7879 num_copies, failrec->this_mirror, failed_mirror);
7880 return 0;
7881 }
7882
7883 failrec->failed_mirror = failed_mirror;
7884 failrec->this_mirror++;
7885 if (failrec->this_mirror == failed_mirror)
7886 failrec->this_mirror++;
7887
7888 if (failrec->this_mirror > num_copies) {
7889 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7890 num_copies, failrec->this_mirror, failed_mirror);
7891 return 0;
7892 }
7893
7894 return 1;
7895 }
7896
7897 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7898 struct page *page, unsigned int pgoff,
7899 u64 start, u64 end, int failed_mirror,
7900 bio_end_io_t *repair_endio, void *repair_arg)
7901 {
7902 struct io_failure_record *failrec;
7903 struct bio *bio;
7904 int isector;
7905 int read_mode;
7906 int ret;
7907
7908 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7909
7910 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7911 if (ret)
7912 return ret;
7913
7914 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7915 failed_mirror);
7916 if (!ret) {
7917 free_io_failure(inode, failrec);
7918 return -EIO;
7919 }
7920
7921 if ((failed_bio->bi_vcnt > 1)
7922 || (failed_bio->bi_io_vec->bv_len
7923 > BTRFS_I(inode)->root->sectorsize))
7924 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7925 else
7926 read_mode = READ_SYNC;
7927
7928 isector = start - btrfs_io_bio(failed_bio)->logical;
7929 isector >>= inode->i_sb->s_blocksize_bits;
7930 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7931 pgoff, isector, repair_endio, repair_arg);
7932 if (!bio) {
7933 free_io_failure(inode, failrec);
7934 return -EIO;
7935 }
7936 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7937
7938 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7939 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7940 read_mode, failrec->this_mirror, failrec->in_validation);
7941
7942 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7943 if (ret) {
7944 free_io_failure(inode, failrec);
7945 bio_put(bio);
7946 }
7947
7948 return ret;
7949 }
7950
7951 struct btrfs_retry_complete {
7952 struct completion done;
7953 struct inode *inode;
7954 u64 start;
7955 int uptodate;
7956 };
7957
7958 static void btrfs_retry_endio_nocsum(struct bio *bio)
7959 {
7960 struct btrfs_retry_complete *done = bio->bi_private;
7961 struct inode *inode;
7962 struct bio_vec *bvec;
7963 int i;
7964
7965 if (bio->bi_error)
7966 goto end;
7967
7968 ASSERT(bio->bi_vcnt == 1);
7969 inode = bio->bi_io_vec->bv_page->mapping->host;
7970 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7971
7972 done->uptodate = 1;
7973 bio_for_each_segment_all(bvec, bio, i)
7974 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7975 end:
7976 complete(&done->done);
7977 bio_put(bio);
7978 }
7979
7980 static int __btrfs_correct_data_nocsum(struct inode *inode,
7981 struct btrfs_io_bio *io_bio)
7982 {
7983 struct btrfs_fs_info *fs_info;
7984 struct bio_vec *bvec;
7985 struct btrfs_retry_complete done;
7986 u64 start;
7987 unsigned int pgoff;
7988 u32 sectorsize;
7989 int nr_sectors;
7990 int i;
7991 int ret;
7992
7993 fs_info = BTRFS_I(inode)->root->fs_info;
7994 sectorsize = BTRFS_I(inode)->root->sectorsize;
7995
7996 start = io_bio->logical;
7997 done.inode = inode;
7998
7999 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8000 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8001 pgoff = bvec->bv_offset;
8002
8003 next_block_or_try_again:
8004 done.uptodate = 0;
8005 done.start = start;
8006 init_completion(&done.done);
8007
8008 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8009 pgoff, start, start + sectorsize - 1,
8010 io_bio->mirror_num,
8011 btrfs_retry_endio_nocsum, &done);
8012 if (ret)
8013 return ret;
8014
8015 wait_for_completion(&done.done);
8016
8017 if (!done.uptodate) {
8018 /* We might have another mirror, so try again */
8019 goto next_block_or_try_again;
8020 }
8021
8022 start += sectorsize;
8023
8024 if (nr_sectors--) {
8025 pgoff += sectorsize;
8026 goto next_block_or_try_again;
8027 }
8028 }
8029
8030 return 0;
8031 }
8032
8033 static void btrfs_retry_endio(struct bio *bio)
8034 {
8035 struct btrfs_retry_complete *done = bio->bi_private;
8036 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8037 struct inode *inode;
8038 struct bio_vec *bvec;
8039 u64 start;
8040 int uptodate;
8041 int ret;
8042 int i;
8043
8044 if (bio->bi_error)
8045 goto end;
8046
8047 uptodate = 1;
8048
8049 start = done->start;
8050
8051 ASSERT(bio->bi_vcnt == 1);
8052 inode = bio->bi_io_vec->bv_page->mapping->host;
8053 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
8054
8055 bio_for_each_segment_all(bvec, bio, i) {
8056 ret = __readpage_endio_check(done->inode, io_bio, i,
8057 bvec->bv_page, bvec->bv_offset,
8058 done->start, bvec->bv_len);
8059 if (!ret)
8060 clean_io_failure(done->inode, done->start,
8061 bvec->bv_page, bvec->bv_offset);
8062 else
8063 uptodate = 0;
8064 }
8065
8066 done->uptodate = uptodate;
8067 end:
8068 complete(&done->done);
8069 bio_put(bio);
8070 }
8071
8072 static int __btrfs_subio_endio_read(struct inode *inode,
8073 struct btrfs_io_bio *io_bio, int err)
8074 {
8075 struct btrfs_fs_info *fs_info;
8076 struct bio_vec *bvec;
8077 struct btrfs_retry_complete done;
8078 u64 start;
8079 u64 offset = 0;
8080 u32 sectorsize;
8081 int nr_sectors;
8082 unsigned int pgoff;
8083 int csum_pos;
8084 int i;
8085 int ret;
8086
8087 fs_info = BTRFS_I(inode)->root->fs_info;
8088 sectorsize = BTRFS_I(inode)->root->sectorsize;
8089
8090 err = 0;
8091 start = io_bio->logical;
8092 done.inode = inode;
8093
8094 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8095 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8096
8097 pgoff = bvec->bv_offset;
8098 next_block:
8099 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8100 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8101 bvec->bv_page, pgoff, start,
8102 sectorsize);
8103 if (likely(!ret))
8104 goto next;
8105 try_again:
8106 done.uptodate = 0;
8107 done.start = start;
8108 init_completion(&done.done);
8109
8110 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8111 pgoff, start, start + sectorsize - 1,
8112 io_bio->mirror_num,
8113 btrfs_retry_endio, &done);
8114 if (ret) {
8115 err = ret;
8116 goto next;
8117 }
8118
8119 wait_for_completion(&done.done);
8120
8121 if (!done.uptodate) {
8122 /* We might have another mirror, so try again */
8123 goto try_again;
8124 }
8125 next:
8126 offset += sectorsize;
8127 start += sectorsize;
8128
8129 ASSERT(nr_sectors);
8130
8131 if (--nr_sectors) {
8132 pgoff += sectorsize;
8133 goto next_block;
8134 }
8135 }
8136
8137 return err;
8138 }
8139
8140 static int btrfs_subio_endio_read(struct inode *inode,
8141 struct btrfs_io_bio *io_bio, int err)
8142 {
8143 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8144
8145 if (skip_csum) {
8146 if (unlikely(err))
8147 return __btrfs_correct_data_nocsum(inode, io_bio);
8148 else
8149 return 0;
8150 } else {
8151 return __btrfs_subio_endio_read(inode, io_bio, err);
8152 }
8153 }
8154
8155 static void btrfs_endio_direct_read(struct bio *bio)
8156 {
8157 struct btrfs_dio_private *dip = bio->bi_private;
8158 struct inode *inode = dip->inode;
8159 struct bio *dio_bio;
8160 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8161 int err = bio->bi_error;
8162
8163 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8164 err = btrfs_subio_endio_read(inode, io_bio, err);
8165
8166 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8167 dip->logical_offset + dip->bytes - 1);
8168 dio_bio = dip->dio_bio;
8169
8170 kfree(dip);
8171
8172 dio_bio->bi_error = bio->bi_error;
8173 dio_end_io(dio_bio, bio->bi_error);
8174
8175 if (io_bio->end_io)
8176 io_bio->end_io(io_bio, err);
8177 bio_put(bio);
8178 }
8179
8180 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8181 const u64 offset,
8182 const u64 bytes,
8183 const int uptodate)
8184 {
8185 struct btrfs_root *root = BTRFS_I(inode)->root;
8186 struct btrfs_ordered_extent *ordered = NULL;
8187 u64 ordered_offset = offset;
8188 u64 ordered_bytes = bytes;
8189 int ret;
8190
8191 again:
8192 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8193 &ordered_offset,
8194 ordered_bytes,
8195 uptodate);
8196 if (!ret)
8197 goto out_test;
8198
8199 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8200 finish_ordered_fn, NULL, NULL);
8201 btrfs_queue_work(root->fs_info->endio_write_workers,
8202 &ordered->work);
8203 out_test:
8204 /*
8205 * our bio might span multiple ordered extents. If we haven't
8206 * completed the accounting for the whole dio, go back and try again
8207 */
8208 if (ordered_offset < offset + bytes) {
8209 ordered_bytes = offset + bytes - ordered_offset;
8210 ordered = NULL;
8211 goto again;
8212 }
8213 }
8214
8215 static void btrfs_endio_direct_write(struct bio *bio)
8216 {
8217 struct btrfs_dio_private *dip = bio->bi_private;
8218 struct bio *dio_bio = dip->dio_bio;
8219
8220 btrfs_endio_direct_write_update_ordered(dip->inode,
8221 dip->logical_offset,
8222 dip->bytes,
8223 !bio->bi_error);
8224
8225 kfree(dip);
8226
8227 dio_bio->bi_error = bio->bi_error;
8228 dio_end_io(dio_bio, bio->bi_error);
8229 bio_put(bio);
8230 }
8231
8232 static int __btrfs_submit_bio_start_direct_io(struct inode *inode,
8233 struct bio *bio, int mirror_num,
8234 unsigned long bio_flags, u64 offset)
8235 {
8236 int ret;
8237 struct btrfs_root *root = BTRFS_I(inode)->root;
8238 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8239 BUG_ON(ret); /* -ENOMEM */
8240 return 0;
8241 }
8242
8243 static void btrfs_end_dio_bio(struct bio *bio)
8244 {
8245 struct btrfs_dio_private *dip = bio->bi_private;
8246 int err = bio->bi_error;
8247
8248 if (err)
8249 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8250 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8251 btrfs_ino(dip->inode), bio_op(bio), bio->bi_opf,
8252 (unsigned long long)bio->bi_iter.bi_sector,
8253 bio->bi_iter.bi_size, err);
8254
8255 if (dip->subio_endio)
8256 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8257
8258 if (err) {
8259 dip->errors = 1;
8260
8261 /*
8262 * before atomic variable goto zero, we must make sure
8263 * dip->errors is perceived to be set.
8264 */
8265 smp_mb__before_atomic();
8266 }
8267
8268 /* if there are more bios still pending for this dio, just exit */
8269 if (!atomic_dec_and_test(&dip->pending_bios))
8270 goto out;
8271
8272 if (dip->errors) {
8273 bio_io_error(dip->orig_bio);
8274 } else {
8275 dip->dio_bio->bi_error = 0;
8276 bio_endio(dip->orig_bio);
8277 }
8278 out:
8279 bio_put(bio);
8280 }
8281
8282 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8283 u64 first_sector, gfp_t gfp_flags)
8284 {
8285 struct bio *bio;
8286 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8287 if (bio)
8288 bio_associate_current(bio);
8289 return bio;
8290 }
8291
8292 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8293 struct inode *inode,
8294 struct btrfs_dio_private *dip,
8295 struct bio *bio,
8296 u64 file_offset)
8297 {
8298 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8299 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8300 int ret;
8301
8302 /*
8303 * We load all the csum data we need when we submit
8304 * the first bio to reduce the csum tree search and
8305 * contention.
8306 */
8307 if (dip->logical_offset == file_offset) {
8308 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8309 file_offset);
8310 if (ret)
8311 return ret;
8312 }
8313
8314 if (bio == dip->orig_bio)
8315 return 0;
8316
8317 file_offset -= dip->logical_offset;
8318 file_offset >>= inode->i_sb->s_blocksize_bits;
8319 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8320
8321 return 0;
8322 }
8323
8324 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8325 u64 file_offset, int skip_sum,
8326 int async_submit)
8327 {
8328 struct btrfs_dio_private *dip = bio->bi_private;
8329 bool write = bio_op(bio) == REQ_OP_WRITE;
8330 struct btrfs_root *root = BTRFS_I(inode)->root;
8331 int ret;
8332
8333 if (async_submit)
8334 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8335
8336 bio_get(bio);
8337
8338 if (!write) {
8339 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8340 BTRFS_WQ_ENDIO_DATA);
8341 if (ret)
8342 goto err;
8343 }
8344
8345 if (skip_sum)
8346 goto map;
8347
8348 if (write && async_submit) {
8349 ret = btrfs_wq_submit_bio(root->fs_info,
8350 inode, bio, 0, 0, file_offset,
8351 __btrfs_submit_bio_start_direct_io,
8352 __btrfs_submit_bio_done);
8353 goto err;
8354 } else if (write) {
8355 /*
8356 * If we aren't doing async submit, calculate the csum of the
8357 * bio now.
8358 */
8359 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8360 if (ret)
8361 goto err;
8362 } else {
8363 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8364 file_offset);
8365 if (ret)
8366 goto err;
8367 }
8368 map:
8369 ret = btrfs_map_bio(root, bio, 0, async_submit);
8370 err:
8371 bio_put(bio);
8372 return ret;
8373 }
8374
8375 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8376 int skip_sum)
8377 {
8378 struct inode *inode = dip->inode;
8379 struct btrfs_root *root = BTRFS_I(inode)->root;
8380 struct bio *bio;
8381 struct bio *orig_bio = dip->orig_bio;
8382 struct bio_vec *bvec = orig_bio->bi_io_vec;
8383 u64 start_sector = orig_bio->bi_iter.bi_sector;
8384 u64 file_offset = dip->logical_offset;
8385 u64 submit_len = 0;
8386 u64 map_length;
8387 u32 blocksize = root->sectorsize;
8388 int async_submit = 0;
8389 int nr_sectors;
8390 int ret;
8391 int i;
8392
8393 map_length = orig_bio->bi_iter.bi_size;
8394 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8395 start_sector << 9, &map_length, NULL, 0);
8396 if (ret)
8397 return -EIO;
8398
8399 if (map_length >= orig_bio->bi_iter.bi_size) {
8400 bio = orig_bio;
8401 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8402 goto submit;
8403 }
8404
8405 /* async crcs make it difficult to collect full stripe writes. */
8406 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8407 async_submit = 0;
8408 else
8409 async_submit = 1;
8410
8411 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8412 if (!bio)
8413 return -ENOMEM;
8414
8415 bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
8416 bio->bi_private = dip;
8417 bio->bi_end_io = btrfs_end_dio_bio;
8418 btrfs_io_bio(bio)->logical = file_offset;
8419 atomic_inc(&dip->pending_bios);
8420
8421 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8422 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8423 i = 0;
8424 next_block:
8425 if (unlikely(map_length < submit_len + blocksize ||
8426 bio_add_page(bio, bvec->bv_page, blocksize,
8427 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8428 /*
8429 * inc the count before we submit the bio so
8430 * we know the end IO handler won't happen before
8431 * we inc the count. Otherwise, the dip might get freed
8432 * before we're done setting it up
8433 */
8434 atomic_inc(&dip->pending_bios);
8435 ret = __btrfs_submit_dio_bio(bio, inode,
8436 file_offset, skip_sum,
8437 async_submit);
8438 if (ret) {
8439 bio_put(bio);
8440 atomic_dec(&dip->pending_bios);
8441 goto out_err;
8442 }
8443
8444 start_sector += submit_len >> 9;
8445 file_offset += submit_len;
8446
8447 submit_len = 0;
8448
8449 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8450 start_sector, GFP_NOFS);
8451 if (!bio)
8452 goto out_err;
8453 bio_set_op_attrs(bio, bio_op(orig_bio), orig_bio->bi_opf);
8454 bio->bi_private = dip;
8455 bio->bi_end_io = btrfs_end_dio_bio;
8456 btrfs_io_bio(bio)->logical = file_offset;
8457
8458 map_length = orig_bio->bi_iter.bi_size;
8459 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8460 start_sector << 9,
8461 &map_length, NULL, 0);
8462 if (ret) {
8463 bio_put(bio);
8464 goto out_err;
8465 }
8466
8467 goto next_block;
8468 } else {
8469 submit_len += blocksize;
8470 if (--nr_sectors) {
8471 i++;
8472 goto next_block;
8473 }
8474 bvec++;
8475 }
8476 }
8477
8478 submit:
8479 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8480 async_submit);
8481 if (!ret)
8482 return 0;
8483
8484 bio_put(bio);
8485 out_err:
8486 dip->errors = 1;
8487 /*
8488 * before atomic variable goto zero, we must
8489 * make sure dip->errors is perceived to be set.
8490 */
8491 smp_mb__before_atomic();
8492 if (atomic_dec_and_test(&dip->pending_bios))
8493 bio_io_error(dip->orig_bio);
8494
8495 /* bio_end_io() will handle error, so we needn't return it */
8496 return 0;
8497 }
8498
8499 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8500 loff_t file_offset)
8501 {
8502 struct btrfs_dio_private *dip = NULL;
8503 struct bio *io_bio = NULL;
8504 struct btrfs_io_bio *btrfs_bio;
8505 int skip_sum;
8506 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8507 int ret = 0;
8508
8509 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8510
8511 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8512 if (!io_bio) {
8513 ret = -ENOMEM;
8514 goto free_ordered;
8515 }
8516
8517 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8518 if (!dip) {
8519 ret = -ENOMEM;
8520 goto free_ordered;
8521 }
8522
8523 dip->private = dio_bio->bi_private;
8524 dip->inode = inode;
8525 dip->logical_offset = file_offset;
8526 dip->bytes = dio_bio->bi_iter.bi_size;
8527 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8528 io_bio->bi_private = dip;
8529 dip->orig_bio = io_bio;
8530 dip->dio_bio = dio_bio;
8531 atomic_set(&dip->pending_bios, 0);
8532 btrfs_bio = btrfs_io_bio(io_bio);
8533 btrfs_bio->logical = file_offset;
8534
8535 if (write) {
8536 io_bio->bi_end_io = btrfs_endio_direct_write;
8537 } else {
8538 io_bio->bi_end_io = btrfs_endio_direct_read;
8539 dip->subio_endio = btrfs_subio_endio_read;
8540 }
8541
8542 /*
8543 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8544 * even if we fail to submit a bio, because in such case we do the
8545 * corresponding error handling below and it must not be done a second
8546 * time by btrfs_direct_IO().
8547 */
8548 if (write) {
8549 struct btrfs_dio_data *dio_data = current->journal_info;
8550
8551 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8552 dip->bytes;
8553 dio_data->unsubmitted_oe_range_start =
8554 dio_data->unsubmitted_oe_range_end;
8555 }
8556
8557 ret = btrfs_submit_direct_hook(dip, skip_sum);
8558 if (!ret)
8559 return;
8560
8561 if (btrfs_bio->end_io)
8562 btrfs_bio->end_io(btrfs_bio, ret);
8563
8564 free_ordered:
8565 /*
8566 * If we arrived here it means either we failed to submit the dip
8567 * or we either failed to clone the dio_bio or failed to allocate the
8568 * dip. If we cloned the dio_bio and allocated the dip, we can just
8569 * call bio_endio against our io_bio so that we get proper resource
8570 * cleanup if we fail to submit the dip, otherwise, we must do the
8571 * same as btrfs_endio_direct_[write|read] because we can't call these
8572 * callbacks - they require an allocated dip and a clone of dio_bio.
8573 */
8574 if (io_bio && dip) {
8575 io_bio->bi_error = -EIO;
8576 bio_endio(io_bio);
8577 /*
8578 * The end io callbacks free our dip, do the final put on io_bio
8579 * and all the cleanup and final put for dio_bio (through
8580 * dio_end_io()).
8581 */
8582 dip = NULL;
8583 io_bio = NULL;
8584 } else {
8585 if (write)
8586 btrfs_endio_direct_write_update_ordered(inode,
8587 file_offset,
8588 dio_bio->bi_iter.bi_size,
8589 0);
8590 else
8591 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8592 file_offset + dio_bio->bi_iter.bi_size - 1);
8593
8594 dio_bio->bi_error = -EIO;
8595 /*
8596 * Releases and cleans up our dio_bio, no need to bio_put()
8597 * nor bio_endio()/bio_io_error() against dio_bio.
8598 */
8599 dio_end_io(dio_bio, ret);
8600 }
8601 if (io_bio)
8602 bio_put(io_bio);
8603 kfree(dip);
8604 }
8605
8606 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8607 const struct iov_iter *iter, loff_t offset)
8608 {
8609 int seg;
8610 int i;
8611 unsigned blocksize_mask = root->sectorsize - 1;
8612 ssize_t retval = -EINVAL;
8613
8614 if (offset & blocksize_mask)
8615 goto out;
8616
8617 if (iov_iter_alignment(iter) & blocksize_mask)
8618 goto out;
8619
8620 /* If this is a write we don't need to check anymore */
8621 if (iov_iter_rw(iter) == WRITE)
8622 return 0;
8623 /*
8624 * Check to make sure we don't have duplicate iov_base's in this
8625 * iovec, if so return EINVAL, otherwise we'll get csum errors
8626 * when reading back.
8627 */
8628 for (seg = 0; seg < iter->nr_segs; seg++) {
8629 for (i = seg + 1; i < iter->nr_segs; i++) {
8630 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8631 goto out;
8632 }
8633 }
8634 retval = 0;
8635 out:
8636 return retval;
8637 }
8638
8639 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8640 {
8641 struct file *file = iocb->ki_filp;
8642 struct inode *inode = file->f_mapping->host;
8643 struct btrfs_root *root = BTRFS_I(inode)->root;
8644 struct btrfs_dio_data dio_data = { 0 };
8645 loff_t offset = iocb->ki_pos;
8646 size_t count = 0;
8647 int flags = 0;
8648 bool wakeup = true;
8649 bool relock = false;
8650 ssize_t ret;
8651
8652 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8653 return 0;
8654
8655 inode_dio_begin(inode);
8656 smp_mb__after_atomic();
8657
8658 /*
8659 * The generic stuff only does filemap_write_and_wait_range, which
8660 * isn't enough if we've written compressed pages to this area, so
8661 * we need to flush the dirty pages again to make absolutely sure
8662 * that any outstanding dirty pages are on disk.
8663 */
8664 count = iov_iter_count(iter);
8665 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8666 &BTRFS_I(inode)->runtime_flags))
8667 filemap_fdatawrite_range(inode->i_mapping, offset,
8668 offset + count - 1);
8669
8670 if (iov_iter_rw(iter) == WRITE) {
8671 /*
8672 * If the write DIO is beyond the EOF, we need update
8673 * the isize, but it is protected by i_mutex. So we can
8674 * not unlock the i_mutex at this case.
8675 */
8676 if (offset + count <= inode->i_size) {
8677 inode_unlock(inode);
8678 relock = true;
8679 }
8680 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8681 if (ret)
8682 goto out;
8683 dio_data.outstanding_extents = div64_u64(count +
8684 BTRFS_MAX_EXTENT_SIZE - 1,
8685 BTRFS_MAX_EXTENT_SIZE);
8686
8687 /*
8688 * We need to know how many extents we reserved so that we can
8689 * do the accounting properly if we go over the number we
8690 * originally calculated. Abuse current->journal_info for this.
8691 */
8692 dio_data.reserve = round_up(count, root->sectorsize);
8693 dio_data.unsubmitted_oe_range_start = (u64)offset;
8694 dio_data.unsubmitted_oe_range_end = (u64)offset;
8695 current->journal_info = &dio_data;
8696 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8697 &BTRFS_I(inode)->runtime_flags)) {
8698 inode_dio_end(inode);
8699 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8700 wakeup = false;
8701 }
8702
8703 ret = __blockdev_direct_IO(iocb, inode,
8704 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8705 iter, btrfs_get_blocks_direct, NULL,
8706 btrfs_submit_direct, flags);
8707 if (iov_iter_rw(iter) == WRITE) {
8708 current->journal_info = NULL;
8709 if (ret < 0 && ret != -EIOCBQUEUED) {
8710 if (dio_data.reserve)
8711 btrfs_delalloc_release_space(inode, offset,
8712 dio_data.reserve);
8713 /*
8714 * On error we might have left some ordered extents
8715 * without submitting corresponding bios for them, so
8716 * cleanup them up to avoid other tasks getting them
8717 * and waiting for them to complete forever.
8718 */
8719 if (dio_data.unsubmitted_oe_range_start <
8720 dio_data.unsubmitted_oe_range_end)
8721 btrfs_endio_direct_write_update_ordered(inode,
8722 dio_data.unsubmitted_oe_range_start,
8723 dio_data.unsubmitted_oe_range_end -
8724 dio_data.unsubmitted_oe_range_start,
8725 0);
8726 } else if (ret >= 0 && (size_t)ret < count)
8727 btrfs_delalloc_release_space(inode, offset,
8728 count - (size_t)ret);
8729 }
8730 out:
8731 if (wakeup)
8732 inode_dio_end(inode);
8733 if (relock)
8734 inode_lock(inode);
8735
8736 return ret;
8737 }
8738
8739 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8740
8741 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8742 __u64 start, __u64 len)
8743 {
8744 int ret;
8745
8746 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8747 if (ret)
8748 return ret;
8749
8750 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8751 }
8752
8753 int btrfs_readpage(struct file *file, struct page *page)
8754 {
8755 struct extent_io_tree *tree;
8756 tree = &BTRFS_I(page->mapping->host)->io_tree;
8757 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8758 }
8759
8760 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8761 {
8762 struct extent_io_tree *tree;
8763 struct inode *inode = page->mapping->host;
8764 int ret;
8765
8766 if (current->flags & PF_MEMALLOC) {
8767 redirty_page_for_writepage(wbc, page);
8768 unlock_page(page);
8769 return 0;
8770 }
8771
8772 /*
8773 * If we are under memory pressure we will call this directly from the
8774 * VM, we need to make sure we have the inode referenced for the ordered
8775 * extent. If not just return like we didn't do anything.
8776 */
8777 if (!igrab(inode)) {
8778 redirty_page_for_writepage(wbc, page);
8779 return AOP_WRITEPAGE_ACTIVATE;
8780 }
8781 tree = &BTRFS_I(page->mapping->host)->io_tree;
8782 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8783 btrfs_add_delayed_iput(inode);
8784 return ret;
8785 }
8786
8787 static int btrfs_writepages(struct address_space *mapping,
8788 struct writeback_control *wbc)
8789 {
8790 struct extent_io_tree *tree;
8791
8792 tree = &BTRFS_I(mapping->host)->io_tree;
8793 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8794 }
8795
8796 static int
8797 btrfs_readpages(struct file *file, struct address_space *mapping,
8798 struct list_head *pages, unsigned nr_pages)
8799 {
8800 struct extent_io_tree *tree;
8801 tree = &BTRFS_I(mapping->host)->io_tree;
8802 return extent_readpages(tree, mapping, pages, nr_pages,
8803 btrfs_get_extent);
8804 }
8805 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8806 {
8807 struct extent_io_tree *tree;
8808 struct extent_map_tree *map;
8809 int ret;
8810
8811 tree = &BTRFS_I(page->mapping->host)->io_tree;
8812 map = &BTRFS_I(page->mapping->host)->extent_tree;
8813 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8814 if (ret == 1) {
8815 ClearPagePrivate(page);
8816 set_page_private(page, 0);
8817 put_page(page);
8818 }
8819 return ret;
8820 }
8821
8822 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8823 {
8824 if (PageWriteback(page) || PageDirty(page))
8825 return 0;
8826 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8827 }
8828
8829 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8830 unsigned int length)
8831 {
8832 struct inode *inode = page->mapping->host;
8833 struct extent_io_tree *tree;
8834 struct btrfs_ordered_extent *ordered;
8835 struct extent_state *cached_state = NULL;
8836 u64 page_start = page_offset(page);
8837 u64 page_end = page_start + PAGE_SIZE - 1;
8838 u64 start;
8839 u64 end;
8840 int inode_evicting = inode->i_state & I_FREEING;
8841
8842 /*
8843 * we have the page locked, so new writeback can't start,
8844 * and the dirty bit won't be cleared while we are here.
8845 *
8846 * Wait for IO on this page so that we can safely clear
8847 * the PagePrivate2 bit and do ordered accounting
8848 */
8849 wait_on_page_writeback(page);
8850
8851 tree = &BTRFS_I(inode)->io_tree;
8852 if (offset) {
8853 btrfs_releasepage(page, GFP_NOFS);
8854 return;
8855 }
8856
8857 if (!inode_evicting)
8858 lock_extent_bits(tree, page_start, page_end, &cached_state);
8859 again:
8860 start = page_start;
8861 ordered = btrfs_lookup_ordered_range(inode, start,
8862 page_end - start + 1);
8863 if (ordered) {
8864 end = min(page_end, ordered->file_offset + ordered->len - 1);
8865 /*
8866 * IO on this page will never be started, so we need
8867 * to account for any ordered extents now
8868 */
8869 if (!inode_evicting)
8870 clear_extent_bit(tree, start, end,
8871 EXTENT_DIRTY | EXTENT_DELALLOC |
8872 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8873 EXTENT_DEFRAG, 1, 0, &cached_state,
8874 GFP_NOFS);
8875 /*
8876 * whoever cleared the private bit is responsible
8877 * for the finish_ordered_io
8878 */
8879 if (TestClearPagePrivate2(page)) {
8880 struct btrfs_ordered_inode_tree *tree;
8881 u64 new_len;
8882
8883 tree = &BTRFS_I(inode)->ordered_tree;
8884
8885 spin_lock_irq(&tree->lock);
8886 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8887 new_len = start - ordered->file_offset;
8888 if (new_len < ordered->truncated_len)
8889 ordered->truncated_len = new_len;
8890 spin_unlock_irq(&tree->lock);
8891
8892 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8893 start,
8894 end - start + 1, 1))
8895 btrfs_finish_ordered_io(ordered);
8896 }
8897 btrfs_put_ordered_extent(ordered);
8898 if (!inode_evicting) {
8899 cached_state = NULL;
8900 lock_extent_bits(tree, start, end,
8901 &cached_state);
8902 }
8903
8904 start = end + 1;
8905 if (start < page_end)
8906 goto again;
8907 }
8908
8909 /*
8910 * Qgroup reserved space handler
8911 * Page here will be either
8912 * 1) Already written to disk
8913 * In this case, its reserved space is released from data rsv map
8914 * and will be freed by delayed_ref handler finally.
8915 * So even we call qgroup_free_data(), it won't decrease reserved
8916 * space.
8917 * 2) Not written to disk
8918 * This means the reserved space should be freed here.
8919 */
8920 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8921 if (!inode_evicting) {
8922 clear_extent_bit(tree, page_start, page_end,
8923 EXTENT_LOCKED | EXTENT_DIRTY |
8924 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8925 EXTENT_DEFRAG, 1, 1,
8926 &cached_state, GFP_NOFS);
8927
8928 __btrfs_releasepage(page, GFP_NOFS);
8929 }
8930
8931 ClearPageChecked(page);
8932 if (PagePrivate(page)) {
8933 ClearPagePrivate(page);
8934 set_page_private(page, 0);
8935 put_page(page);
8936 }
8937 }
8938
8939 /*
8940 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8941 * called from a page fault handler when a page is first dirtied. Hence we must
8942 * be careful to check for EOF conditions here. We set the page up correctly
8943 * for a written page which means we get ENOSPC checking when writing into
8944 * holes and correct delalloc and unwritten extent mapping on filesystems that
8945 * support these features.
8946 *
8947 * We are not allowed to take the i_mutex here so we have to play games to
8948 * protect against truncate races as the page could now be beyond EOF. Because
8949 * vmtruncate() writes the inode size before removing pages, once we have the
8950 * page lock we can determine safely if the page is beyond EOF. If it is not
8951 * beyond EOF, then the page is guaranteed safe against truncation until we
8952 * unlock the page.
8953 */
8954 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8955 {
8956 struct page *page = vmf->page;
8957 struct inode *inode = file_inode(vma->vm_file);
8958 struct btrfs_root *root = BTRFS_I(inode)->root;
8959 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8960 struct btrfs_ordered_extent *ordered;
8961 struct extent_state *cached_state = NULL;
8962 char *kaddr;
8963 unsigned long zero_start;
8964 loff_t size;
8965 int ret;
8966 int reserved = 0;
8967 u64 reserved_space;
8968 u64 page_start;
8969 u64 page_end;
8970 u64 end;
8971
8972 reserved_space = PAGE_SIZE;
8973
8974 sb_start_pagefault(inode->i_sb);
8975 page_start = page_offset(page);
8976 page_end = page_start + PAGE_SIZE - 1;
8977 end = page_end;
8978
8979 /*
8980 * Reserving delalloc space after obtaining the page lock can lead to
8981 * deadlock. For example, if a dirty page is locked by this function
8982 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8983 * dirty page write out, then the btrfs_writepage() function could
8984 * end up waiting indefinitely to get a lock on the page currently
8985 * being processed by btrfs_page_mkwrite() function.
8986 */
8987 ret = btrfs_delalloc_reserve_space(inode, page_start,
8988 reserved_space);
8989 if (!ret) {
8990 ret = file_update_time(vma->vm_file);
8991 reserved = 1;
8992 }
8993 if (ret) {
8994 if (ret == -ENOMEM)
8995 ret = VM_FAULT_OOM;
8996 else /* -ENOSPC, -EIO, etc */
8997 ret = VM_FAULT_SIGBUS;
8998 if (reserved)
8999 goto out;
9000 goto out_noreserve;
9001 }
9002
9003 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9004 again:
9005 lock_page(page);
9006 size = i_size_read(inode);
9007
9008 if ((page->mapping != inode->i_mapping) ||
9009 (page_start >= size)) {
9010 /* page got truncated out from underneath us */
9011 goto out_unlock;
9012 }
9013 wait_on_page_writeback(page);
9014
9015 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9016 set_page_extent_mapped(page);
9017
9018 /*
9019 * we can't set the delalloc bits if there are pending ordered
9020 * extents. Drop our locks and wait for them to finish
9021 */
9022 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
9023 if (ordered) {
9024 unlock_extent_cached(io_tree, page_start, page_end,
9025 &cached_state, GFP_NOFS);
9026 unlock_page(page);
9027 btrfs_start_ordered_extent(inode, ordered, 1);
9028 btrfs_put_ordered_extent(ordered);
9029 goto again;
9030 }
9031
9032 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9033 reserved_space = round_up(size - page_start, root->sectorsize);
9034 if (reserved_space < PAGE_SIZE) {
9035 end = page_start + reserved_space - 1;
9036 spin_lock(&BTRFS_I(inode)->lock);
9037 BTRFS_I(inode)->outstanding_extents++;
9038 spin_unlock(&BTRFS_I(inode)->lock);
9039 btrfs_delalloc_release_space(inode, page_start,
9040 PAGE_SIZE - reserved_space);
9041 }
9042 }
9043
9044 /*
9045 * XXX - page_mkwrite gets called every time the page is dirtied, even
9046 * if it was already dirty, so for space accounting reasons we need to
9047 * clear any delalloc bits for the range we are fixing to save. There
9048 * is probably a better way to do this, but for now keep consistent with
9049 * prepare_pages in the normal write path.
9050 */
9051 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9052 EXTENT_DIRTY | EXTENT_DELALLOC |
9053 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9054 0, 0, &cached_state, GFP_NOFS);
9055
9056 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9057 &cached_state);
9058 if (ret) {
9059 unlock_extent_cached(io_tree, page_start, page_end,
9060 &cached_state, GFP_NOFS);
9061 ret = VM_FAULT_SIGBUS;
9062 goto out_unlock;
9063 }
9064 ret = 0;
9065
9066 /* page is wholly or partially inside EOF */
9067 if (page_start + PAGE_SIZE > size)
9068 zero_start = size & ~PAGE_MASK;
9069 else
9070 zero_start = PAGE_SIZE;
9071
9072 if (zero_start != PAGE_SIZE) {
9073 kaddr = kmap(page);
9074 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9075 flush_dcache_page(page);
9076 kunmap(page);
9077 }
9078 ClearPageChecked(page);
9079 set_page_dirty(page);
9080 SetPageUptodate(page);
9081
9082 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9083 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9084 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9085
9086 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9087
9088 out_unlock:
9089 if (!ret) {
9090 sb_end_pagefault(inode->i_sb);
9091 return VM_FAULT_LOCKED;
9092 }
9093 unlock_page(page);
9094 out:
9095 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9096 out_noreserve:
9097 sb_end_pagefault(inode->i_sb);
9098 return ret;
9099 }
9100
9101 static int btrfs_truncate(struct inode *inode)
9102 {
9103 struct btrfs_root *root = BTRFS_I(inode)->root;
9104 struct btrfs_block_rsv *rsv;
9105 int ret = 0;
9106 int err = 0;
9107 struct btrfs_trans_handle *trans;
9108 u64 mask = root->sectorsize - 1;
9109 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9110
9111 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9112 (u64)-1);
9113 if (ret)
9114 return ret;
9115
9116 /*
9117 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9118 * 3 things going on here
9119 *
9120 * 1) We need to reserve space for our orphan item and the space to
9121 * delete our orphan item. Lord knows we don't want to have a dangling
9122 * orphan item because we didn't reserve space to remove it.
9123 *
9124 * 2) We need to reserve space to update our inode.
9125 *
9126 * 3) We need to have something to cache all the space that is going to
9127 * be free'd up by the truncate operation, but also have some slack
9128 * space reserved in case it uses space during the truncate (thank you
9129 * very much snapshotting).
9130 *
9131 * And we need these to all be separate. The fact is we can use a lot of
9132 * space doing the truncate, and we have no earthly idea how much space
9133 * we will use, so we need the truncate reservation to be separate so it
9134 * doesn't end up using space reserved for updating the inode or
9135 * removing the orphan item. We also need to be able to stop the
9136 * transaction and start a new one, which means we need to be able to
9137 * update the inode several times, and we have no idea of knowing how
9138 * many times that will be, so we can't just reserve 1 item for the
9139 * entirety of the operation, so that has to be done separately as well.
9140 * Then there is the orphan item, which does indeed need to be held on
9141 * to for the whole operation, and we need nobody to touch this reserved
9142 * space except the orphan code.
9143 *
9144 * So that leaves us with
9145 *
9146 * 1) root->orphan_block_rsv - for the orphan deletion.
9147 * 2) rsv - for the truncate reservation, which we will steal from the
9148 * transaction reservation.
9149 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9150 * updating the inode.
9151 */
9152 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9153 if (!rsv)
9154 return -ENOMEM;
9155 rsv->size = min_size;
9156 rsv->failfast = 1;
9157
9158 /*
9159 * 1 for the truncate slack space
9160 * 1 for updating the inode.
9161 */
9162 trans = btrfs_start_transaction(root, 2);
9163 if (IS_ERR(trans)) {
9164 err = PTR_ERR(trans);
9165 goto out;
9166 }
9167
9168 /* Migrate the slack space for the truncate to our reserve */
9169 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9170 min_size, 0);
9171 BUG_ON(ret);
9172
9173 /*
9174 * So if we truncate and then write and fsync we normally would just
9175 * write the extents that changed, which is a problem if we need to
9176 * first truncate that entire inode. So set this flag so we write out
9177 * all of the extents in the inode to the sync log so we're completely
9178 * safe.
9179 */
9180 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9181 trans->block_rsv = rsv;
9182
9183 while (1) {
9184 ret = btrfs_truncate_inode_items(trans, root, inode,
9185 inode->i_size,
9186 BTRFS_EXTENT_DATA_KEY);
9187 if (ret != -ENOSPC && ret != -EAGAIN) {
9188 err = ret;
9189 break;
9190 }
9191
9192 trans->block_rsv = &root->fs_info->trans_block_rsv;
9193 ret = btrfs_update_inode(trans, root, inode);
9194 if (ret) {
9195 err = ret;
9196 break;
9197 }
9198
9199 btrfs_end_transaction(trans, root);
9200 btrfs_btree_balance_dirty(root);
9201
9202 trans = btrfs_start_transaction(root, 2);
9203 if (IS_ERR(trans)) {
9204 ret = err = PTR_ERR(trans);
9205 trans = NULL;
9206 break;
9207 }
9208
9209 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9210 rsv, min_size, 0);
9211 BUG_ON(ret); /* shouldn't happen */
9212 trans->block_rsv = rsv;
9213 }
9214
9215 if (ret == 0 && inode->i_nlink > 0) {
9216 trans->block_rsv = root->orphan_block_rsv;
9217 ret = btrfs_orphan_del(trans, inode);
9218 if (ret)
9219 err = ret;
9220 }
9221
9222 if (trans) {
9223 trans->block_rsv = &root->fs_info->trans_block_rsv;
9224 ret = btrfs_update_inode(trans, root, inode);
9225 if (ret && !err)
9226 err = ret;
9227
9228 ret = btrfs_end_transaction(trans, root);
9229 btrfs_btree_balance_dirty(root);
9230 }
9231 out:
9232 btrfs_free_block_rsv(root, rsv);
9233
9234 if (ret && !err)
9235 err = ret;
9236
9237 return err;
9238 }
9239
9240 /*
9241 * create a new subvolume directory/inode (helper for the ioctl).
9242 */
9243 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9244 struct btrfs_root *new_root,
9245 struct btrfs_root *parent_root,
9246 u64 new_dirid)
9247 {
9248 struct inode *inode;
9249 int err;
9250 u64 index = 0;
9251
9252 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9253 new_dirid, new_dirid,
9254 S_IFDIR | (~current_umask() & S_IRWXUGO),
9255 &index);
9256 if (IS_ERR(inode))
9257 return PTR_ERR(inode);
9258 inode->i_op = &btrfs_dir_inode_operations;
9259 inode->i_fop = &btrfs_dir_file_operations;
9260
9261 set_nlink(inode, 1);
9262 btrfs_i_size_write(inode, 0);
9263 unlock_new_inode(inode);
9264
9265 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9266 if (err)
9267 btrfs_err(new_root->fs_info,
9268 "error inheriting subvolume %llu properties: %d",
9269 new_root->root_key.objectid, err);
9270
9271 err = btrfs_update_inode(trans, new_root, inode);
9272
9273 iput(inode);
9274 return err;
9275 }
9276
9277 struct inode *btrfs_alloc_inode(struct super_block *sb)
9278 {
9279 struct btrfs_inode *ei;
9280 struct inode *inode;
9281
9282 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9283 if (!ei)
9284 return NULL;
9285
9286 ei->root = NULL;
9287 ei->generation = 0;
9288 ei->last_trans = 0;
9289 ei->last_sub_trans = 0;
9290 ei->logged_trans = 0;
9291 ei->delalloc_bytes = 0;
9292 ei->defrag_bytes = 0;
9293 ei->disk_i_size = 0;
9294 ei->flags = 0;
9295 ei->csum_bytes = 0;
9296 ei->index_cnt = (u64)-1;
9297 ei->dir_index = 0;
9298 ei->last_unlink_trans = 0;
9299 ei->last_log_commit = 0;
9300 ei->delayed_iput_count = 0;
9301
9302 spin_lock_init(&ei->lock);
9303 ei->outstanding_extents = 0;
9304 ei->reserved_extents = 0;
9305
9306 ei->runtime_flags = 0;
9307 ei->force_compress = BTRFS_COMPRESS_NONE;
9308
9309 ei->delayed_node = NULL;
9310
9311 ei->i_otime.tv_sec = 0;
9312 ei->i_otime.tv_nsec = 0;
9313
9314 inode = &ei->vfs_inode;
9315 extent_map_tree_init(&ei->extent_tree);
9316 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9317 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9318 ei->io_tree.track_uptodate = 1;
9319 ei->io_failure_tree.track_uptodate = 1;
9320 atomic_set(&ei->sync_writers, 0);
9321 mutex_init(&ei->log_mutex);
9322 mutex_init(&ei->delalloc_mutex);
9323 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9324 INIT_LIST_HEAD(&ei->delalloc_inodes);
9325 INIT_LIST_HEAD(&ei->delayed_iput);
9326 RB_CLEAR_NODE(&ei->rb_node);
9327 init_rwsem(&ei->dio_sem);
9328
9329 return inode;
9330 }
9331
9332 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9333 void btrfs_test_destroy_inode(struct inode *inode)
9334 {
9335 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9336 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9337 }
9338 #endif
9339
9340 static void btrfs_i_callback(struct rcu_head *head)
9341 {
9342 struct inode *inode = container_of(head, struct inode, i_rcu);
9343 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9344 }
9345
9346 void btrfs_destroy_inode(struct inode *inode)
9347 {
9348 struct btrfs_ordered_extent *ordered;
9349 struct btrfs_root *root = BTRFS_I(inode)->root;
9350
9351 WARN_ON(!hlist_empty(&inode->i_dentry));
9352 WARN_ON(inode->i_data.nrpages);
9353 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9354 WARN_ON(BTRFS_I(inode)->reserved_extents);
9355 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9356 WARN_ON(BTRFS_I(inode)->csum_bytes);
9357 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9358
9359 /*
9360 * This can happen where we create an inode, but somebody else also
9361 * created the same inode and we need to destroy the one we already
9362 * created.
9363 */
9364 if (!root)
9365 goto free;
9366
9367 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9368 &BTRFS_I(inode)->runtime_flags)) {
9369 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9370 btrfs_ino(inode));
9371 atomic_dec(&root->orphan_inodes);
9372 }
9373
9374 while (1) {
9375 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9376 if (!ordered)
9377 break;
9378 else {
9379 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9380 ordered->file_offset, ordered->len);
9381 btrfs_remove_ordered_extent(inode, ordered);
9382 btrfs_put_ordered_extent(ordered);
9383 btrfs_put_ordered_extent(ordered);
9384 }
9385 }
9386 btrfs_qgroup_check_reserved_leak(inode);
9387 inode_tree_del(inode);
9388 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9389 free:
9390 call_rcu(&inode->i_rcu, btrfs_i_callback);
9391 }
9392
9393 int btrfs_drop_inode(struct inode *inode)
9394 {
9395 struct btrfs_root *root = BTRFS_I(inode)->root;
9396
9397 if (root == NULL)
9398 return 1;
9399
9400 /* the snap/subvol tree is on deleting */
9401 if (btrfs_root_refs(&root->root_item) == 0)
9402 return 1;
9403 else
9404 return generic_drop_inode(inode);
9405 }
9406
9407 static void init_once(void *foo)
9408 {
9409 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9410
9411 inode_init_once(&ei->vfs_inode);
9412 }
9413
9414 void btrfs_destroy_cachep(void)
9415 {
9416 /*
9417 * Make sure all delayed rcu free inodes are flushed before we
9418 * destroy cache.
9419 */
9420 rcu_barrier();
9421 kmem_cache_destroy(btrfs_inode_cachep);
9422 kmem_cache_destroy(btrfs_trans_handle_cachep);
9423 kmem_cache_destroy(btrfs_transaction_cachep);
9424 kmem_cache_destroy(btrfs_path_cachep);
9425 kmem_cache_destroy(btrfs_free_space_cachep);
9426 }
9427
9428 int btrfs_init_cachep(void)
9429 {
9430 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9431 sizeof(struct btrfs_inode), 0,
9432 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9433 init_once);
9434 if (!btrfs_inode_cachep)
9435 goto fail;
9436
9437 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9438 sizeof(struct btrfs_trans_handle), 0,
9439 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9440 if (!btrfs_trans_handle_cachep)
9441 goto fail;
9442
9443 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9444 sizeof(struct btrfs_transaction), 0,
9445 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9446 if (!btrfs_transaction_cachep)
9447 goto fail;
9448
9449 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9450 sizeof(struct btrfs_path), 0,
9451 SLAB_MEM_SPREAD, NULL);
9452 if (!btrfs_path_cachep)
9453 goto fail;
9454
9455 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9456 sizeof(struct btrfs_free_space), 0,
9457 SLAB_MEM_SPREAD, NULL);
9458 if (!btrfs_free_space_cachep)
9459 goto fail;
9460
9461 return 0;
9462 fail:
9463 btrfs_destroy_cachep();
9464 return -ENOMEM;
9465 }
9466
9467 static int btrfs_getattr(struct vfsmount *mnt,
9468 struct dentry *dentry, struct kstat *stat)
9469 {
9470 u64 delalloc_bytes;
9471 struct inode *inode = d_inode(dentry);
9472 u32 blocksize = inode->i_sb->s_blocksize;
9473
9474 generic_fillattr(inode, stat);
9475 stat->dev = BTRFS_I(inode)->root->anon_dev;
9476
9477 spin_lock(&BTRFS_I(inode)->lock);
9478 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9479 spin_unlock(&BTRFS_I(inode)->lock);
9480 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9481 ALIGN(delalloc_bytes, blocksize)) >> 9;
9482 return 0;
9483 }
9484
9485 static int btrfs_rename_exchange(struct inode *old_dir,
9486 struct dentry *old_dentry,
9487 struct inode *new_dir,
9488 struct dentry *new_dentry)
9489 {
9490 struct btrfs_trans_handle *trans;
9491 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9492 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9493 struct inode *new_inode = new_dentry->d_inode;
9494 struct inode *old_inode = old_dentry->d_inode;
9495 struct timespec ctime = current_time(old_inode);
9496 struct dentry *parent;
9497 u64 old_ino = btrfs_ino(old_inode);
9498 u64 new_ino = btrfs_ino(new_inode);
9499 u64 old_idx = 0;
9500 u64 new_idx = 0;
9501 u64 root_objectid;
9502 int ret;
9503 bool root_log_pinned = false;
9504 bool dest_log_pinned = false;
9505
9506 /* we only allow rename subvolume link between subvolumes */
9507 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9508 return -EXDEV;
9509
9510 /* close the race window with snapshot create/destroy ioctl */
9511 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9512 down_read(&root->fs_info->subvol_sem);
9513 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9514 down_read(&dest->fs_info->subvol_sem);
9515
9516 /*
9517 * We want to reserve the absolute worst case amount of items. So if
9518 * both inodes are subvols and we need to unlink them then that would
9519 * require 4 item modifications, but if they are both normal inodes it
9520 * would require 5 item modifications, so we'll assume their normal
9521 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9522 * should cover the worst case number of items we'll modify.
9523 */
9524 trans = btrfs_start_transaction(root, 12);
9525 if (IS_ERR(trans)) {
9526 ret = PTR_ERR(trans);
9527 goto out_notrans;
9528 }
9529
9530 /*
9531 * We need to find a free sequence number both in the source and
9532 * in the destination directory for the exchange.
9533 */
9534 ret = btrfs_set_inode_index(new_dir, &old_idx);
9535 if (ret)
9536 goto out_fail;
9537 ret = btrfs_set_inode_index(old_dir, &new_idx);
9538 if (ret)
9539 goto out_fail;
9540
9541 BTRFS_I(old_inode)->dir_index = 0ULL;
9542 BTRFS_I(new_inode)->dir_index = 0ULL;
9543
9544 /* Reference for the source. */
9545 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9546 /* force full log commit if subvolume involved. */
9547 btrfs_set_log_full_commit(root->fs_info, trans);
9548 } else {
9549 btrfs_pin_log_trans(root);
9550 root_log_pinned = true;
9551 ret = btrfs_insert_inode_ref(trans, dest,
9552 new_dentry->d_name.name,
9553 new_dentry->d_name.len,
9554 old_ino,
9555 btrfs_ino(new_dir), old_idx);
9556 if (ret)
9557 goto out_fail;
9558 }
9559
9560 /* And now for the dest. */
9561 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9562 /* force full log commit if subvolume involved. */
9563 btrfs_set_log_full_commit(dest->fs_info, trans);
9564 } else {
9565 btrfs_pin_log_trans(dest);
9566 dest_log_pinned = true;
9567 ret = btrfs_insert_inode_ref(trans, root,
9568 old_dentry->d_name.name,
9569 old_dentry->d_name.len,
9570 new_ino,
9571 btrfs_ino(old_dir), new_idx);
9572 if (ret)
9573 goto out_fail;
9574 }
9575
9576 /* Update inode version and ctime/mtime. */
9577 inode_inc_iversion(old_dir);
9578 inode_inc_iversion(new_dir);
9579 inode_inc_iversion(old_inode);
9580 inode_inc_iversion(new_inode);
9581 old_dir->i_ctime = old_dir->i_mtime = ctime;
9582 new_dir->i_ctime = new_dir->i_mtime = ctime;
9583 old_inode->i_ctime = ctime;
9584 new_inode->i_ctime = ctime;
9585
9586 if (old_dentry->d_parent != new_dentry->d_parent) {
9587 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9588 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9589 }
9590
9591 /* src is a subvolume */
9592 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9593 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9594 ret = btrfs_unlink_subvol(trans, root, old_dir,
9595 root_objectid,
9596 old_dentry->d_name.name,
9597 old_dentry->d_name.len);
9598 } else { /* src is an inode */
9599 ret = __btrfs_unlink_inode(trans, root, old_dir,
9600 old_dentry->d_inode,
9601 old_dentry->d_name.name,
9602 old_dentry->d_name.len);
9603 if (!ret)
9604 ret = btrfs_update_inode(trans, root, old_inode);
9605 }
9606 if (ret) {
9607 btrfs_abort_transaction(trans, ret);
9608 goto out_fail;
9609 }
9610
9611 /* dest is a subvolume */
9612 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9613 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9614 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9615 root_objectid,
9616 new_dentry->d_name.name,
9617 new_dentry->d_name.len);
9618 } else { /* dest is an inode */
9619 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9620 new_dentry->d_inode,
9621 new_dentry->d_name.name,
9622 new_dentry->d_name.len);
9623 if (!ret)
9624 ret = btrfs_update_inode(trans, dest, new_inode);
9625 }
9626 if (ret) {
9627 btrfs_abort_transaction(trans, ret);
9628 goto out_fail;
9629 }
9630
9631 ret = btrfs_add_link(trans, new_dir, old_inode,
9632 new_dentry->d_name.name,
9633 new_dentry->d_name.len, 0, old_idx);
9634 if (ret) {
9635 btrfs_abort_transaction(trans, ret);
9636 goto out_fail;
9637 }
9638
9639 ret = btrfs_add_link(trans, old_dir, new_inode,
9640 old_dentry->d_name.name,
9641 old_dentry->d_name.len, 0, new_idx);
9642 if (ret) {
9643 btrfs_abort_transaction(trans, ret);
9644 goto out_fail;
9645 }
9646
9647 if (old_inode->i_nlink == 1)
9648 BTRFS_I(old_inode)->dir_index = old_idx;
9649 if (new_inode->i_nlink == 1)
9650 BTRFS_I(new_inode)->dir_index = new_idx;
9651
9652 if (root_log_pinned) {
9653 parent = new_dentry->d_parent;
9654 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9655 btrfs_end_log_trans(root);
9656 root_log_pinned = false;
9657 }
9658 if (dest_log_pinned) {
9659 parent = old_dentry->d_parent;
9660 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9661 btrfs_end_log_trans(dest);
9662 dest_log_pinned = false;
9663 }
9664 out_fail:
9665 /*
9666 * If we have pinned a log and an error happened, we unpin tasks
9667 * trying to sync the log and force them to fallback to a transaction
9668 * commit if the log currently contains any of the inodes involved in
9669 * this rename operation (to ensure we do not persist a log with an
9670 * inconsistent state for any of these inodes or leading to any
9671 * inconsistencies when replayed). If the transaction was aborted, the
9672 * abortion reason is propagated to userspace when attempting to commit
9673 * the transaction. If the log does not contain any of these inodes, we
9674 * allow the tasks to sync it.
9675 */
9676 if (ret && (root_log_pinned || dest_log_pinned)) {
9677 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9678 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9679 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9680 (new_inode &&
9681 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9682 btrfs_set_log_full_commit(root->fs_info, trans);
9683
9684 if (root_log_pinned) {
9685 btrfs_end_log_trans(root);
9686 root_log_pinned = false;
9687 }
9688 if (dest_log_pinned) {
9689 btrfs_end_log_trans(dest);
9690 dest_log_pinned = false;
9691 }
9692 }
9693 ret = btrfs_end_transaction(trans, root);
9694 out_notrans:
9695 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9696 up_read(&dest->fs_info->subvol_sem);
9697 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9698 up_read(&root->fs_info->subvol_sem);
9699
9700 return ret;
9701 }
9702
9703 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9704 struct btrfs_root *root,
9705 struct inode *dir,
9706 struct dentry *dentry)
9707 {
9708 int ret;
9709 struct inode *inode;
9710 u64 objectid;
9711 u64 index;
9712
9713 ret = btrfs_find_free_ino(root, &objectid);
9714 if (ret)
9715 return ret;
9716
9717 inode = btrfs_new_inode(trans, root, dir,
9718 dentry->d_name.name,
9719 dentry->d_name.len,
9720 btrfs_ino(dir),
9721 objectid,
9722 S_IFCHR | WHITEOUT_MODE,
9723 &index);
9724
9725 if (IS_ERR(inode)) {
9726 ret = PTR_ERR(inode);
9727 return ret;
9728 }
9729
9730 inode->i_op = &btrfs_special_inode_operations;
9731 init_special_inode(inode, inode->i_mode,
9732 WHITEOUT_DEV);
9733
9734 ret = btrfs_init_inode_security(trans, inode, dir,
9735 &dentry->d_name);
9736 if (ret)
9737 goto out;
9738
9739 ret = btrfs_add_nondir(trans, dir, dentry,
9740 inode, 0, index);
9741 if (ret)
9742 goto out;
9743
9744 ret = btrfs_update_inode(trans, root, inode);
9745 out:
9746 unlock_new_inode(inode);
9747 if (ret)
9748 inode_dec_link_count(inode);
9749 iput(inode);
9750
9751 return ret;
9752 }
9753
9754 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9755 struct inode *new_dir, struct dentry *new_dentry,
9756 unsigned int flags)
9757 {
9758 struct btrfs_trans_handle *trans;
9759 unsigned int trans_num_items;
9760 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9761 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9762 struct inode *new_inode = d_inode(new_dentry);
9763 struct inode *old_inode = d_inode(old_dentry);
9764 u64 index = 0;
9765 u64 root_objectid;
9766 int ret;
9767 u64 old_ino = btrfs_ino(old_inode);
9768 bool log_pinned = false;
9769
9770 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9771 return -EPERM;
9772
9773 /* we only allow rename subvolume link between subvolumes */
9774 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9775 return -EXDEV;
9776
9777 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9778 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9779 return -ENOTEMPTY;
9780
9781 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9782 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9783 return -ENOTEMPTY;
9784
9785
9786 /* check for collisions, even if the name isn't there */
9787 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9788 new_dentry->d_name.name,
9789 new_dentry->d_name.len);
9790
9791 if (ret) {
9792 if (ret == -EEXIST) {
9793 /* we shouldn't get
9794 * eexist without a new_inode */
9795 if (WARN_ON(!new_inode)) {
9796 return ret;
9797 }
9798 } else {
9799 /* maybe -EOVERFLOW */
9800 return ret;
9801 }
9802 }
9803 ret = 0;
9804
9805 /*
9806 * we're using rename to replace one file with another. Start IO on it
9807 * now so we don't add too much work to the end of the transaction
9808 */
9809 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9810 filemap_flush(old_inode->i_mapping);
9811
9812 /* close the racy window with snapshot create/destroy ioctl */
9813 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9814 down_read(&root->fs_info->subvol_sem);
9815 /*
9816 * We want to reserve the absolute worst case amount of items. So if
9817 * both inodes are subvols and we need to unlink them then that would
9818 * require 4 item modifications, but if they are both normal inodes it
9819 * would require 5 item modifications, so we'll assume they are normal
9820 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9821 * should cover the worst case number of items we'll modify.
9822 * If our rename has the whiteout flag, we need more 5 units for the
9823 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9824 * when selinux is enabled).
9825 */
9826 trans_num_items = 11;
9827 if (flags & RENAME_WHITEOUT)
9828 trans_num_items += 5;
9829 trans = btrfs_start_transaction(root, trans_num_items);
9830 if (IS_ERR(trans)) {
9831 ret = PTR_ERR(trans);
9832 goto out_notrans;
9833 }
9834
9835 if (dest != root)
9836 btrfs_record_root_in_trans(trans, dest);
9837
9838 ret = btrfs_set_inode_index(new_dir, &index);
9839 if (ret)
9840 goto out_fail;
9841
9842 BTRFS_I(old_inode)->dir_index = 0ULL;
9843 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9844 /* force full log commit if subvolume involved. */
9845 btrfs_set_log_full_commit(root->fs_info, trans);
9846 } else {
9847 btrfs_pin_log_trans(root);
9848 log_pinned = true;
9849 ret = btrfs_insert_inode_ref(trans, dest,
9850 new_dentry->d_name.name,
9851 new_dentry->d_name.len,
9852 old_ino,
9853 btrfs_ino(new_dir), index);
9854 if (ret)
9855 goto out_fail;
9856 }
9857
9858 inode_inc_iversion(old_dir);
9859 inode_inc_iversion(new_dir);
9860 inode_inc_iversion(old_inode);
9861 old_dir->i_ctime = old_dir->i_mtime =
9862 new_dir->i_ctime = new_dir->i_mtime =
9863 old_inode->i_ctime = current_time(old_dir);
9864
9865 if (old_dentry->d_parent != new_dentry->d_parent)
9866 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9867
9868 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9869 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9870 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9871 old_dentry->d_name.name,
9872 old_dentry->d_name.len);
9873 } else {
9874 ret = __btrfs_unlink_inode(trans, root, old_dir,
9875 d_inode(old_dentry),
9876 old_dentry->d_name.name,
9877 old_dentry->d_name.len);
9878 if (!ret)
9879 ret = btrfs_update_inode(trans, root, old_inode);
9880 }
9881 if (ret) {
9882 btrfs_abort_transaction(trans, ret);
9883 goto out_fail;
9884 }
9885
9886 if (new_inode) {
9887 inode_inc_iversion(new_inode);
9888 new_inode->i_ctime = current_time(new_inode);
9889 if (unlikely(btrfs_ino(new_inode) ==
9890 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9891 root_objectid = BTRFS_I(new_inode)->location.objectid;
9892 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9893 root_objectid,
9894 new_dentry->d_name.name,
9895 new_dentry->d_name.len);
9896 BUG_ON(new_inode->i_nlink == 0);
9897 } else {
9898 ret = btrfs_unlink_inode(trans, dest, new_dir,
9899 d_inode(new_dentry),
9900 new_dentry->d_name.name,
9901 new_dentry->d_name.len);
9902 }
9903 if (!ret && new_inode->i_nlink == 0)
9904 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9905 if (ret) {
9906 btrfs_abort_transaction(trans, ret);
9907 goto out_fail;
9908 }
9909 }
9910
9911 ret = btrfs_add_link(trans, new_dir, old_inode,
9912 new_dentry->d_name.name,
9913 new_dentry->d_name.len, 0, index);
9914 if (ret) {
9915 btrfs_abort_transaction(trans, ret);
9916 goto out_fail;
9917 }
9918
9919 if (old_inode->i_nlink == 1)
9920 BTRFS_I(old_inode)->dir_index = index;
9921
9922 if (log_pinned) {
9923 struct dentry *parent = new_dentry->d_parent;
9924
9925 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9926 btrfs_end_log_trans(root);
9927 log_pinned = false;
9928 }
9929
9930 if (flags & RENAME_WHITEOUT) {
9931 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9932 old_dentry);
9933
9934 if (ret) {
9935 btrfs_abort_transaction(trans, ret);
9936 goto out_fail;
9937 }
9938 }
9939 out_fail:
9940 /*
9941 * If we have pinned the log and an error happened, we unpin tasks
9942 * trying to sync the log and force them to fallback to a transaction
9943 * commit if the log currently contains any of the inodes involved in
9944 * this rename operation (to ensure we do not persist a log with an
9945 * inconsistent state for any of these inodes or leading to any
9946 * inconsistencies when replayed). If the transaction was aborted, the
9947 * abortion reason is propagated to userspace when attempting to commit
9948 * the transaction. If the log does not contain any of these inodes, we
9949 * allow the tasks to sync it.
9950 */
9951 if (ret && log_pinned) {
9952 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9953 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9954 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9955 (new_inode &&
9956 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9957 btrfs_set_log_full_commit(root->fs_info, trans);
9958
9959 btrfs_end_log_trans(root);
9960 log_pinned = false;
9961 }
9962 btrfs_end_transaction(trans, root);
9963 out_notrans:
9964 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9965 up_read(&root->fs_info->subvol_sem);
9966
9967 return ret;
9968 }
9969
9970 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9971 struct inode *new_dir, struct dentry *new_dentry,
9972 unsigned int flags)
9973 {
9974 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9975 return -EINVAL;
9976
9977 if (flags & RENAME_EXCHANGE)
9978 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9979 new_dentry);
9980
9981 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9982 }
9983
9984 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9985 {
9986 struct btrfs_delalloc_work *delalloc_work;
9987 struct inode *inode;
9988
9989 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9990 work);
9991 inode = delalloc_work->inode;
9992 filemap_flush(inode->i_mapping);
9993 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9994 &BTRFS_I(inode)->runtime_flags))
9995 filemap_flush(inode->i_mapping);
9996
9997 if (delalloc_work->delay_iput)
9998 btrfs_add_delayed_iput(inode);
9999 else
10000 iput(inode);
10001 complete(&delalloc_work->completion);
10002 }
10003
10004 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10005 int delay_iput)
10006 {
10007 struct btrfs_delalloc_work *work;
10008
10009 work = kmalloc(sizeof(*work), GFP_NOFS);
10010 if (!work)
10011 return NULL;
10012
10013 init_completion(&work->completion);
10014 INIT_LIST_HEAD(&work->list);
10015 work->inode = inode;
10016 work->delay_iput = delay_iput;
10017 WARN_ON_ONCE(!inode);
10018 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10019 btrfs_run_delalloc_work, NULL, NULL);
10020
10021 return work;
10022 }
10023
10024 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10025 {
10026 wait_for_completion(&work->completion);
10027 kfree(work);
10028 }
10029
10030 /*
10031 * some fairly slow code that needs optimization. This walks the list
10032 * of all the inodes with pending delalloc and forces them to disk.
10033 */
10034 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10035 int nr)
10036 {
10037 struct btrfs_inode *binode;
10038 struct inode *inode;
10039 struct btrfs_delalloc_work *work, *next;
10040 struct list_head works;
10041 struct list_head splice;
10042 int ret = 0;
10043
10044 INIT_LIST_HEAD(&works);
10045 INIT_LIST_HEAD(&splice);
10046
10047 mutex_lock(&root->delalloc_mutex);
10048 spin_lock(&root->delalloc_lock);
10049 list_splice_init(&root->delalloc_inodes, &splice);
10050 while (!list_empty(&splice)) {
10051 binode = list_entry(splice.next, struct btrfs_inode,
10052 delalloc_inodes);
10053
10054 list_move_tail(&binode->delalloc_inodes,
10055 &root->delalloc_inodes);
10056 inode = igrab(&binode->vfs_inode);
10057 if (!inode) {
10058 cond_resched_lock(&root->delalloc_lock);
10059 continue;
10060 }
10061 spin_unlock(&root->delalloc_lock);
10062
10063 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10064 if (!work) {
10065 if (delay_iput)
10066 btrfs_add_delayed_iput(inode);
10067 else
10068 iput(inode);
10069 ret = -ENOMEM;
10070 goto out;
10071 }
10072 list_add_tail(&work->list, &works);
10073 btrfs_queue_work(root->fs_info->flush_workers,
10074 &work->work);
10075 ret++;
10076 if (nr != -1 && ret >= nr)
10077 goto out;
10078 cond_resched();
10079 spin_lock(&root->delalloc_lock);
10080 }
10081 spin_unlock(&root->delalloc_lock);
10082
10083 out:
10084 list_for_each_entry_safe(work, next, &works, list) {
10085 list_del_init(&work->list);
10086 btrfs_wait_and_free_delalloc_work(work);
10087 }
10088
10089 if (!list_empty_careful(&splice)) {
10090 spin_lock(&root->delalloc_lock);
10091 list_splice_tail(&splice, &root->delalloc_inodes);
10092 spin_unlock(&root->delalloc_lock);
10093 }
10094 mutex_unlock(&root->delalloc_mutex);
10095 return ret;
10096 }
10097
10098 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10099 {
10100 int ret;
10101
10102 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10103 return -EROFS;
10104
10105 ret = __start_delalloc_inodes(root, delay_iput, -1);
10106 if (ret > 0)
10107 ret = 0;
10108 /*
10109 * the filemap_flush will queue IO into the worker threads, but
10110 * we have to make sure the IO is actually started and that
10111 * ordered extents get created before we return
10112 */
10113 atomic_inc(&root->fs_info->async_submit_draining);
10114 while (atomic_read(&root->fs_info->nr_async_submits) ||
10115 atomic_read(&root->fs_info->async_delalloc_pages)) {
10116 wait_event(root->fs_info->async_submit_wait,
10117 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10118 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10119 }
10120 atomic_dec(&root->fs_info->async_submit_draining);
10121 return ret;
10122 }
10123
10124 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10125 int nr)
10126 {
10127 struct btrfs_root *root;
10128 struct list_head splice;
10129 int ret;
10130
10131 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10132 return -EROFS;
10133
10134 INIT_LIST_HEAD(&splice);
10135
10136 mutex_lock(&fs_info->delalloc_root_mutex);
10137 spin_lock(&fs_info->delalloc_root_lock);
10138 list_splice_init(&fs_info->delalloc_roots, &splice);
10139 while (!list_empty(&splice) && nr) {
10140 root = list_first_entry(&splice, struct btrfs_root,
10141 delalloc_root);
10142 root = btrfs_grab_fs_root(root);
10143 BUG_ON(!root);
10144 list_move_tail(&root->delalloc_root,
10145 &fs_info->delalloc_roots);
10146 spin_unlock(&fs_info->delalloc_root_lock);
10147
10148 ret = __start_delalloc_inodes(root, delay_iput, nr);
10149 btrfs_put_fs_root(root);
10150 if (ret < 0)
10151 goto out;
10152
10153 if (nr != -1) {
10154 nr -= ret;
10155 WARN_ON(nr < 0);
10156 }
10157 spin_lock(&fs_info->delalloc_root_lock);
10158 }
10159 spin_unlock(&fs_info->delalloc_root_lock);
10160
10161 ret = 0;
10162 atomic_inc(&fs_info->async_submit_draining);
10163 while (atomic_read(&fs_info->nr_async_submits) ||
10164 atomic_read(&fs_info->async_delalloc_pages)) {
10165 wait_event(fs_info->async_submit_wait,
10166 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10167 atomic_read(&fs_info->async_delalloc_pages) == 0));
10168 }
10169 atomic_dec(&fs_info->async_submit_draining);
10170 out:
10171 if (!list_empty_careful(&splice)) {
10172 spin_lock(&fs_info->delalloc_root_lock);
10173 list_splice_tail(&splice, &fs_info->delalloc_roots);
10174 spin_unlock(&fs_info->delalloc_root_lock);
10175 }
10176 mutex_unlock(&fs_info->delalloc_root_mutex);
10177 return ret;
10178 }
10179
10180 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10181 const char *symname)
10182 {
10183 struct btrfs_trans_handle *trans;
10184 struct btrfs_root *root = BTRFS_I(dir)->root;
10185 struct btrfs_path *path;
10186 struct btrfs_key key;
10187 struct inode *inode = NULL;
10188 int err;
10189 int drop_inode = 0;
10190 u64 objectid;
10191 u64 index = 0;
10192 int name_len;
10193 int datasize;
10194 unsigned long ptr;
10195 struct btrfs_file_extent_item *ei;
10196 struct extent_buffer *leaf;
10197
10198 name_len = strlen(symname);
10199 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10200 return -ENAMETOOLONG;
10201
10202 /*
10203 * 2 items for inode item and ref
10204 * 2 items for dir items
10205 * 1 item for updating parent inode item
10206 * 1 item for the inline extent item
10207 * 1 item for xattr if selinux is on
10208 */
10209 trans = btrfs_start_transaction(root, 7);
10210 if (IS_ERR(trans))
10211 return PTR_ERR(trans);
10212
10213 err = btrfs_find_free_ino(root, &objectid);
10214 if (err)
10215 goto out_unlock;
10216
10217 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10218 dentry->d_name.len, btrfs_ino(dir), objectid,
10219 S_IFLNK|S_IRWXUGO, &index);
10220 if (IS_ERR(inode)) {
10221 err = PTR_ERR(inode);
10222 goto out_unlock;
10223 }
10224
10225 /*
10226 * If the active LSM wants to access the inode during
10227 * d_instantiate it needs these. Smack checks to see
10228 * if the filesystem supports xattrs by looking at the
10229 * ops vector.
10230 */
10231 inode->i_fop = &btrfs_file_operations;
10232 inode->i_op = &btrfs_file_inode_operations;
10233 inode->i_mapping->a_ops = &btrfs_aops;
10234 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10235
10236 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10237 if (err)
10238 goto out_unlock_inode;
10239
10240 path = btrfs_alloc_path();
10241 if (!path) {
10242 err = -ENOMEM;
10243 goto out_unlock_inode;
10244 }
10245 key.objectid = btrfs_ino(inode);
10246 key.offset = 0;
10247 key.type = BTRFS_EXTENT_DATA_KEY;
10248 datasize = btrfs_file_extent_calc_inline_size(name_len);
10249 err = btrfs_insert_empty_item(trans, root, path, &key,
10250 datasize);
10251 if (err) {
10252 btrfs_free_path(path);
10253 goto out_unlock_inode;
10254 }
10255 leaf = path->nodes[0];
10256 ei = btrfs_item_ptr(leaf, path->slots[0],
10257 struct btrfs_file_extent_item);
10258 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10259 btrfs_set_file_extent_type(leaf, ei,
10260 BTRFS_FILE_EXTENT_INLINE);
10261 btrfs_set_file_extent_encryption(leaf, ei, 0);
10262 btrfs_set_file_extent_compression(leaf, ei, 0);
10263 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10264 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10265
10266 ptr = btrfs_file_extent_inline_start(ei);
10267 write_extent_buffer(leaf, symname, ptr, name_len);
10268 btrfs_mark_buffer_dirty(leaf);
10269 btrfs_free_path(path);
10270
10271 inode->i_op = &btrfs_symlink_inode_operations;
10272 inode_nohighmem(inode);
10273 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10274 inode_set_bytes(inode, name_len);
10275 btrfs_i_size_write(inode, name_len);
10276 err = btrfs_update_inode(trans, root, inode);
10277 /*
10278 * Last step, add directory indexes for our symlink inode. This is the
10279 * last step to avoid extra cleanup of these indexes if an error happens
10280 * elsewhere above.
10281 */
10282 if (!err)
10283 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10284 if (err) {
10285 drop_inode = 1;
10286 goto out_unlock_inode;
10287 }
10288
10289 unlock_new_inode(inode);
10290 d_instantiate(dentry, inode);
10291
10292 out_unlock:
10293 btrfs_end_transaction(trans, root);
10294 if (drop_inode) {
10295 inode_dec_link_count(inode);
10296 iput(inode);
10297 }
10298 btrfs_btree_balance_dirty(root);
10299 return err;
10300
10301 out_unlock_inode:
10302 drop_inode = 1;
10303 unlock_new_inode(inode);
10304 goto out_unlock;
10305 }
10306
10307 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10308 u64 start, u64 num_bytes, u64 min_size,
10309 loff_t actual_len, u64 *alloc_hint,
10310 struct btrfs_trans_handle *trans)
10311 {
10312 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10313 struct extent_map *em;
10314 struct btrfs_root *root = BTRFS_I(inode)->root;
10315 struct btrfs_key ins;
10316 u64 cur_offset = start;
10317 u64 i_size;
10318 u64 cur_bytes;
10319 u64 last_alloc = (u64)-1;
10320 int ret = 0;
10321 bool own_trans = true;
10322 u64 end = start + num_bytes - 1;
10323
10324 if (trans)
10325 own_trans = false;
10326 while (num_bytes > 0) {
10327 if (own_trans) {
10328 trans = btrfs_start_transaction(root, 3);
10329 if (IS_ERR(trans)) {
10330 ret = PTR_ERR(trans);
10331 break;
10332 }
10333 }
10334
10335 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10336 cur_bytes = max(cur_bytes, min_size);
10337 /*
10338 * If we are severely fragmented we could end up with really
10339 * small allocations, so if the allocator is returning small
10340 * chunks lets make its job easier by only searching for those
10341 * sized chunks.
10342 */
10343 cur_bytes = min(cur_bytes, last_alloc);
10344 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10345 min_size, 0, *alloc_hint, &ins, 1, 0);
10346 if (ret) {
10347 if (own_trans)
10348 btrfs_end_transaction(trans, root);
10349 break;
10350 }
10351 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10352
10353 last_alloc = ins.offset;
10354 ret = insert_reserved_file_extent(trans, inode,
10355 cur_offset, ins.objectid,
10356 ins.offset, ins.offset,
10357 ins.offset, 0, 0, 0,
10358 BTRFS_FILE_EXTENT_PREALLOC);
10359 if (ret) {
10360 btrfs_free_reserved_extent(root, ins.objectid,
10361 ins.offset, 0);
10362 btrfs_abort_transaction(trans, ret);
10363 if (own_trans)
10364 btrfs_end_transaction(trans, root);
10365 break;
10366 }
10367
10368 btrfs_drop_extent_cache(inode, cur_offset,
10369 cur_offset + ins.offset -1, 0);
10370
10371 em = alloc_extent_map();
10372 if (!em) {
10373 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10374 &BTRFS_I(inode)->runtime_flags);
10375 goto next;
10376 }
10377
10378 em->start = cur_offset;
10379 em->orig_start = cur_offset;
10380 em->len = ins.offset;
10381 em->block_start = ins.objectid;
10382 em->block_len = ins.offset;
10383 em->orig_block_len = ins.offset;
10384 em->ram_bytes = ins.offset;
10385 em->bdev = root->fs_info->fs_devices->latest_bdev;
10386 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10387 em->generation = trans->transid;
10388
10389 while (1) {
10390 write_lock(&em_tree->lock);
10391 ret = add_extent_mapping(em_tree, em, 1);
10392 write_unlock(&em_tree->lock);
10393 if (ret != -EEXIST)
10394 break;
10395 btrfs_drop_extent_cache(inode, cur_offset,
10396 cur_offset + ins.offset - 1,
10397 0);
10398 }
10399 free_extent_map(em);
10400 next:
10401 num_bytes -= ins.offset;
10402 cur_offset += ins.offset;
10403 *alloc_hint = ins.objectid + ins.offset;
10404
10405 inode_inc_iversion(inode);
10406 inode->i_ctime = current_time(inode);
10407 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10408 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10409 (actual_len > inode->i_size) &&
10410 (cur_offset > inode->i_size)) {
10411 if (cur_offset > actual_len)
10412 i_size = actual_len;
10413 else
10414 i_size = cur_offset;
10415 i_size_write(inode, i_size);
10416 btrfs_ordered_update_i_size(inode, i_size, NULL);
10417 }
10418
10419 ret = btrfs_update_inode(trans, root, inode);
10420
10421 if (ret) {
10422 btrfs_abort_transaction(trans, ret);
10423 if (own_trans)
10424 btrfs_end_transaction(trans, root);
10425 break;
10426 }
10427
10428 if (own_trans)
10429 btrfs_end_transaction(trans, root);
10430 }
10431 if (cur_offset < end)
10432 btrfs_free_reserved_data_space(inode, cur_offset,
10433 end - cur_offset + 1);
10434 return ret;
10435 }
10436
10437 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10438 u64 start, u64 num_bytes, u64 min_size,
10439 loff_t actual_len, u64 *alloc_hint)
10440 {
10441 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10442 min_size, actual_len, alloc_hint,
10443 NULL);
10444 }
10445
10446 int btrfs_prealloc_file_range_trans(struct inode *inode,
10447 struct btrfs_trans_handle *trans, int mode,
10448 u64 start, u64 num_bytes, u64 min_size,
10449 loff_t actual_len, u64 *alloc_hint)
10450 {
10451 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10452 min_size, actual_len, alloc_hint, trans);
10453 }
10454
10455 static int btrfs_set_page_dirty(struct page *page)
10456 {
10457 return __set_page_dirty_nobuffers(page);
10458 }
10459
10460 static int btrfs_permission(struct inode *inode, int mask)
10461 {
10462 struct btrfs_root *root = BTRFS_I(inode)->root;
10463 umode_t mode = inode->i_mode;
10464
10465 if (mask & MAY_WRITE &&
10466 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10467 if (btrfs_root_readonly(root))
10468 return -EROFS;
10469 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10470 return -EACCES;
10471 }
10472 return generic_permission(inode, mask);
10473 }
10474
10475 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10476 {
10477 struct btrfs_trans_handle *trans;
10478 struct btrfs_root *root = BTRFS_I(dir)->root;
10479 struct inode *inode = NULL;
10480 u64 objectid;
10481 u64 index;
10482 int ret = 0;
10483
10484 /*
10485 * 5 units required for adding orphan entry
10486 */
10487 trans = btrfs_start_transaction(root, 5);
10488 if (IS_ERR(trans))
10489 return PTR_ERR(trans);
10490
10491 ret = btrfs_find_free_ino(root, &objectid);
10492 if (ret)
10493 goto out;
10494
10495 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10496 btrfs_ino(dir), objectid, mode, &index);
10497 if (IS_ERR(inode)) {
10498 ret = PTR_ERR(inode);
10499 inode = NULL;
10500 goto out;
10501 }
10502
10503 inode->i_fop = &btrfs_file_operations;
10504 inode->i_op = &btrfs_file_inode_operations;
10505
10506 inode->i_mapping->a_ops = &btrfs_aops;
10507 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10508
10509 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10510 if (ret)
10511 goto out_inode;
10512
10513 ret = btrfs_update_inode(trans, root, inode);
10514 if (ret)
10515 goto out_inode;
10516 ret = btrfs_orphan_add(trans, inode);
10517 if (ret)
10518 goto out_inode;
10519
10520 /*
10521 * We set number of links to 0 in btrfs_new_inode(), and here we set
10522 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10523 * through:
10524 *
10525 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10526 */
10527 set_nlink(inode, 1);
10528 unlock_new_inode(inode);
10529 d_tmpfile(dentry, inode);
10530 mark_inode_dirty(inode);
10531
10532 out:
10533 btrfs_end_transaction(trans, root);
10534 if (ret)
10535 iput(inode);
10536 btrfs_balance_delayed_items(root);
10537 btrfs_btree_balance_dirty(root);
10538 return ret;
10539
10540 out_inode:
10541 unlock_new_inode(inode);
10542 goto out;
10543
10544 }
10545
10546 /* Inspired by filemap_check_errors() */
10547 int btrfs_inode_check_errors(struct inode *inode)
10548 {
10549 int ret = 0;
10550
10551 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10552 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10553 ret = -ENOSPC;
10554 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10555 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10556 ret = -EIO;
10557
10558 return ret;
10559 }
10560
10561 static const struct inode_operations btrfs_dir_inode_operations = {
10562 .getattr = btrfs_getattr,
10563 .lookup = btrfs_lookup,
10564 .create = btrfs_create,
10565 .unlink = btrfs_unlink,
10566 .link = btrfs_link,
10567 .mkdir = btrfs_mkdir,
10568 .rmdir = btrfs_rmdir,
10569 .rename2 = btrfs_rename2,
10570 .symlink = btrfs_symlink,
10571 .setattr = btrfs_setattr,
10572 .mknod = btrfs_mknod,
10573 .setxattr = generic_setxattr,
10574 .getxattr = generic_getxattr,
10575 .listxattr = btrfs_listxattr,
10576 .removexattr = generic_removexattr,
10577 .permission = btrfs_permission,
10578 .get_acl = btrfs_get_acl,
10579 .set_acl = btrfs_set_acl,
10580 .update_time = btrfs_update_time,
10581 .tmpfile = btrfs_tmpfile,
10582 };
10583 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10584 .lookup = btrfs_lookup,
10585 .permission = btrfs_permission,
10586 .get_acl = btrfs_get_acl,
10587 .set_acl = btrfs_set_acl,
10588 .update_time = btrfs_update_time,
10589 };
10590
10591 static const struct file_operations btrfs_dir_file_operations = {
10592 .llseek = generic_file_llseek,
10593 .read = generic_read_dir,
10594 .iterate_shared = btrfs_real_readdir,
10595 .unlocked_ioctl = btrfs_ioctl,
10596 #ifdef CONFIG_COMPAT
10597 .compat_ioctl = btrfs_compat_ioctl,
10598 #endif
10599 .release = btrfs_release_file,
10600 .fsync = btrfs_sync_file,
10601 };
10602
10603 static const struct extent_io_ops btrfs_extent_io_ops = {
10604 .fill_delalloc = run_delalloc_range,
10605 .submit_bio_hook = btrfs_submit_bio_hook,
10606 .merge_bio_hook = btrfs_merge_bio_hook,
10607 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10608 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10609 .writepage_start_hook = btrfs_writepage_start_hook,
10610 .set_bit_hook = btrfs_set_bit_hook,
10611 .clear_bit_hook = btrfs_clear_bit_hook,
10612 .merge_extent_hook = btrfs_merge_extent_hook,
10613 .split_extent_hook = btrfs_split_extent_hook,
10614 };
10615
10616 /*
10617 * btrfs doesn't support the bmap operation because swapfiles
10618 * use bmap to make a mapping of extents in the file. They assume
10619 * these extents won't change over the life of the file and they
10620 * use the bmap result to do IO directly to the drive.
10621 *
10622 * the btrfs bmap call would return logical addresses that aren't
10623 * suitable for IO and they also will change frequently as COW
10624 * operations happen. So, swapfile + btrfs == corruption.
10625 *
10626 * For now we're avoiding this by dropping bmap.
10627 */
10628 static const struct address_space_operations btrfs_aops = {
10629 .readpage = btrfs_readpage,
10630 .writepage = btrfs_writepage,
10631 .writepages = btrfs_writepages,
10632 .readpages = btrfs_readpages,
10633 .direct_IO = btrfs_direct_IO,
10634 .invalidatepage = btrfs_invalidatepage,
10635 .releasepage = btrfs_releasepage,
10636 .set_page_dirty = btrfs_set_page_dirty,
10637 .error_remove_page = generic_error_remove_page,
10638 };
10639
10640 static const struct address_space_operations btrfs_symlink_aops = {
10641 .readpage = btrfs_readpage,
10642 .writepage = btrfs_writepage,
10643 .invalidatepage = btrfs_invalidatepage,
10644 .releasepage = btrfs_releasepage,
10645 };
10646
10647 static const struct inode_operations btrfs_file_inode_operations = {
10648 .getattr = btrfs_getattr,
10649 .setattr = btrfs_setattr,
10650 .setxattr = generic_setxattr,
10651 .getxattr = generic_getxattr,
10652 .listxattr = btrfs_listxattr,
10653 .removexattr = generic_removexattr,
10654 .permission = btrfs_permission,
10655 .fiemap = btrfs_fiemap,
10656 .get_acl = btrfs_get_acl,
10657 .set_acl = btrfs_set_acl,
10658 .update_time = btrfs_update_time,
10659 };
10660 static const struct inode_operations btrfs_special_inode_operations = {
10661 .getattr = btrfs_getattr,
10662 .setattr = btrfs_setattr,
10663 .permission = btrfs_permission,
10664 .setxattr = generic_setxattr,
10665 .getxattr = generic_getxattr,
10666 .listxattr = btrfs_listxattr,
10667 .removexattr = generic_removexattr,
10668 .get_acl = btrfs_get_acl,
10669 .set_acl = btrfs_set_acl,
10670 .update_time = btrfs_update_time,
10671 };
10672 static const struct inode_operations btrfs_symlink_inode_operations = {
10673 .readlink = generic_readlink,
10674 .get_link = page_get_link,
10675 .getattr = btrfs_getattr,
10676 .setattr = btrfs_setattr,
10677 .permission = btrfs_permission,
10678 .setxattr = generic_setxattr,
10679 .getxattr = generic_getxattr,
10680 .listxattr = btrfs_listxattr,
10681 .removexattr = generic_removexattr,
10682 .update_time = btrfs_update_time,
10683 };
10684
10685 const struct dentry_operations btrfs_dentry_operations = {
10686 .d_delete = btrfs_dentry_delete,
10687 .d_release = btrfs_dentry_release,
10688 };
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