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Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[mirror_ubuntu-artful-kernel.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 };
75
76 static const struct inode_operations btrfs_dir_inode_operations;
77 static const struct inode_operations btrfs_symlink_inode_operations;
78 static const struct inode_operations btrfs_dir_ro_inode_operations;
79 static const struct inode_operations btrfs_special_inode_operations;
80 static const struct inode_operations btrfs_file_inode_operations;
81 static const struct address_space_operations btrfs_aops;
82 static const struct address_space_operations btrfs_symlink_aops;
83 static const struct file_operations btrfs_dir_file_operations;
84 static const struct extent_io_ops btrfs_extent_io_ops;
85
86 static struct kmem_cache *btrfs_inode_cachep;
87 struct kmem_cache *btrfs_trans_handle_cachep;
88 struct kmem_cache *btrfs_transaction_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, int *page_started,
109 unsigned long *nr_written, int unlock);
110 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
111 u64 len, u64 orig_start,
112 u64 block_start, u64 block_len,
113 u64 orig_block_len, u64 ram_bytes,
114 int type);
115
116 static int btrfs_dirty_inode(struct inode *inode);
117
118 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
119 void btrfs_test_inode_set_ops(struct inode *inode)
120 {
121 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
122 }
123 #endif
124
125 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
126 struct inode *inode, struct inode *dir,
127 const struct qstr *qstr)
128 {
129 int err;
130
131 err = btrfs_init_acl(trans, inode, dir);
132 if (!err)
133 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
134 return err;
135 }
136
137 /*
138 * this does all the hard work for inserting an inline extent into
139 * the btree. The caller should have done a btrfs_drop_extents so that
140 * no overlapping inline items exist in the btree
141 */
142 static int insert_inline_extent(struct btrfs_trans_handle *trans,
143 struct btrfs_path *path, int extent_inserted,
144 struct btrfs_root *root, struct inode *inode,
145 u64 start, size_t size, size_t compressed_size,
146 int compress_type,
147 struct page **compressed_pages)
148 {
149 struct extent_buffer *leaf;
150 struct page *page = NULL;
151 char *kaddr;
152 unsigned long ptr;
153 struct btrfs_file_extent_item *ei;
154 int err = 0;
155 int ret;
156 size_t cur_size = size;
157 unsigned long offset;
158
159 if (compressed_size && compressed_pages)
160 cur_size = compressed_size;
161
162 inode_add_bytes(inode, size);
163
164 if (!extent_inserted) {
165 struct btrfs_key key;
166 size_t datasize;
167
168 key.objectid = btrfs_ino(inode);
169 key.offset = start;
170 key.type = BTRFS_EXTENT_DATA_KEY;
171
172 datasize = btrfs_file_extent_calc_inline_size(cur_size);
173 path->leave_spinning = 1;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 datasize);
176 if (ret) {
177 err = ret;
178 goto fail;
179 }
180 }
181 leaf = path->nodes[0];
182 ei = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_file_extent_item);
184 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
185 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
186 btrfs_set_file_extent_encryption(leaf, ei, 0);
187 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
188 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
189 ptr = btrfs_file_extent_inline_start(ei);
190
191 if (compress_type != BTRFS_COMPRESS_NONE) {
192 struct page *cpage;
193 int i = 0;
194 while (compressed_size > 0) {
195 cpage = compressed_pages[i];
196 cur_size = min_t(unsigned long, compressed_size,
197 PAGE_CACHE_SIZE);
198
199 kaddr = kmap_atomic(cpage);
200 write_extent_buffer(leaf, kaddr, ptr, cur_size);
201 kunmap_atomic(kaddr);
202
203 i++;
204 ptr += cur_size;
205 compressed_size -= cur_size;
206 }
207 btrfs_set_file_extent_compression(leaf, ei,
208 compress_type);
209 } else {
210 page = find_get_page(inode->i_mapping,
211 start >> PAGE_CACHE_SHIFT);
212 btrfs_set_file_extent_compression(leaf, ei, 0);
213 kaddr = kmap_atomic(page);
214 offset = start & (PAGE_CACHE_SIZE - 1);
215 write_extent_buffer(leaf, kaddr + offset, ptr, size);
216 kunmap_atomic(kaddr);
217 page_cache_release(page);
218 }
219 btrfs_mark_buffer_dirty(leaf);
220 btrfs_release_path(path);
221
222 /*
223 * we're an inline extent, so nobody can
224 * extend the file past i_size without locking
225 * a page we already have locked.
226 *
227 * We must do any isize and inode updates
228 * before we unlock the pages. Otherwise we
229 * could end up racing with unlink.
230 */
231 BTRFS_I(inode)->disk_i_size = inode->i_size;
232 ret = btrfs_update_inode(trans, root, inode);
233
234 return ret;
235 fail:
236 return err;
237 }
238
239
240 /*
241 * conditionally insert an inline extent into the file. This
242 * does the checks required to make sure the data is small enough
243 * to fit as an inline extent.
244 */
245 static noinline int cow_file_range_inline(struct btrfs_root *root,
246 struct inode *inode, u64 start,
247 u64 end, size_t compressed_size,
248 int compress_type,
249 struct page **compressed_pages)
250 {
251 struct btrfs_trans_handle *trans;
252 u64 isize = i_size_read(inode);
253 u64 actual_end = min(end + 1, isize);
254 u64 inline_len = actual_end - start;
255 u64 aligned_end = ALIGN(end, root->sectorsize);
256 u64 data_len = inline_len;
257 int ret;
258 struct btrfs_path *path;
259 int extent_inserted = 0;
260 u32 extent_item_size;
261
262 if (compressed_size)
263 data_len = compressed_size;
264
265 if (start > 0 ||
266 actual_end > PAGE_CACHE_SIZE ||
267 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
268 (!compressed_size &&
269 (actual_end & (root->sectorsize - 1)) == 0) ||
270 end + 1 < isize ||
271 data_len > root->fs_info->max_inline) {
272 return 1;
273 }
274
275 path = btrfs_alloc_path();
276 if (!path)
277 return -ENOMEM;
278
279 trans = btrfs_join_transaction(root);
280 if (IS_ERR(trans)) {
281 btrfs_free_path(path);
282 return PTR_ERR(trans);
283 }
284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
285
286 if (compressed_size && compressed_pages)
287 extent_item_size = btrfs_file_extent_calc_inline_size(
288 compressed_size);
289 else
290 extent_item_size = btrfs_file_extent_calc_inline_size(
291 inline_len);
292
293 ret = __btrfs_drop_extents(trans, root, inode, path,
294 start, aligned_end, NULL,
295 1, 1, extent_item_size, &extent_inserted);
296 if (ret) {
297 btrfs_abort_transaction(trans, root, ret);
298 goto out;
299 }
300
301 if (isize > actual_end)
302 inline_len = min_t(u64, isize, actual_end);
303 ret = insert_inline_extent(trans, path, extent_inserted,
304 root, inode, start,
305 inline_len, compressed_size,
306 compress_type, compressed_pages);
307 if (ret && ret != -ENOSPC) {
308 btrfs_abort_transaction(trans, root, ret);
309 goto out;
310 } else if (ret == -ENOSPC) {
311 ret = 1;
312 goto out;
313 }
314
315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
316 btrfs_delalloc_release_metadata(inode, end + 1 - start);
317 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
318 out:
319 /*
320 * Don't forget to free the reserved space, as for inlined extent
321 * it won't count as data extent, free them directly here.
322 * And at reserve time, it's always aligned to page size, so
323 * just free one page here.
324 */
325 btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
326 btrfs_free_path(path);
327 btrfs_end_transaction(trans, root);
328 return ret;
329 }
330
331 struct async_extent {
332 u64 start;
333 u64 ram_size;
334 u64 compressed_size;
335 struct page **pages;
336 unsigned long nr_pages;
337 int compress_type;
338 struct list_head list;
339 };
340
341 struct async_cow {
342 struct inode *inode;
343 struct btrfs_root *root;
344 struct page *locked_page;
345 u64 start;
346 u64 end;
347 struct list_head extents;
348 struct btrfs_work work;
349 };
350
351 static noinline int add_async_extent(struct async_cow *cow,
352 u64 start, u64 ram_size,
353 u64 compressed_size,
354 struct page **pages,
355 unsigned long nr_pages,
356 int compress_type)
357 {
358 struct async_extent *async_extent;
359
360 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
361 BUG_ON(!async_extent); /* -ENOMEM */
362 async_extent->start = start;
363 async_extent->ram_size = ram_size;
364 async_extent->compressed_size = compressed_size;
365 async_extent->pages = pages;
366 async_extent->nr_pages = nr_pages;
367 async_extent->compress_type = compress_type;
368 list_add_tail(&async_extent->list, &cow->extents);
369 return 0;
370 }
371
372 static inline int inode_need_compress(struct inode *inode)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375
376 /* force compress */
377 if (btrfs_test_opt(root, FORCE_COMPRESS))
378 return 1;
379 /* bad compression ratios */
380 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
381 return 0;
382 if (btrfs_test_opt(root, COMPRESS) ||
383 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
384 BTRFS_I(inode)->force_compress)
385 return 1;
386 return 0;
387 }
388
389 /*
390 * we create compressed extents in two phases. The first
391 * phase compresses a range of pages that have already been
392 * locked (both pages and state bits are locked).
393 *
394 * This is done inside an ordered work queue, and the compression
395 * is spread across many cpus. The actual IO submission is step
396 * two, and the ordered work queue takes care of making sure that
397 * happens in the same order things were put onto the queue by
398 * writepages and friends.
399 *
400 * If this code finds it can't get good compression, it puts an
401 * entry onto the work queue to write the uncompressed bytes. This
402 * makes sure that both compressed inodes and uncompressed inodes
403 * are written in the same order that the flusher thread sent them
404 * down.
405 */
406 static noinline void compress_file_range(struct inode *inode,
407 struct page *locked_page,
408 u64 start, u64 end,
409 struct async_cow *async_cow,
410 int *num_added)
411 {
412 struct btrfs_root *root = BTRFS_I(inode)->root;
413 u64 num_bytes;
414 u64 blocksize = root->sectorsize;
415 u64 actual_end;
416 u64 isize = i_size_read(inode);
417 int ret = 0;
418 struct page **pages = NULL;
419 unsigned long nr_pages;
420 unsigned long nr_pages_ret = 0;
421 unsigned long total_compressed = 0;
422 unsigned long total_in = 0;
423 unsigned long max_compressed = SZ_128K;
424 unsigned long max_uncompressed = SZ_128K;
425 int i;
426 int will_compress;
427 int compress_type = root->fs_info->compress_type;
428 int redirty = 0;
429
430 /* if this is a small write inside eof, kick off a defrag */
431 if ((end - start + 1) < SZ_16K &&
432 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
433 btrfs_add_inode_defrag(NULL, inode);
434
435 actual_end = min_t(u64, isize, end + 1);
436 again:
437 will_compress = 0;
438 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
439 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE);
440
441 /*
442 * we don't want to send crud past the end of i_size through
443 * compression, that's just a waste of CPU time. So, if the
444 * end of the file is before the start of our current
445 * requested range of bytes, we bail out to the uncompressed
446 * cleanup code that can deal with all of this.
447 *
448 * It isn't really the fastest way to fix things, but this is a
449 * very uncommon corner.
450 */
451 if (actual_end <= start)
452 goto cleanup_and_bail_uncompressed;
453
454 total_compressed = actual_end - start;
455
456 /*
457 * skip compression for a small file range(<=blocksize) that
458 * isn't an inline extent, since it dosen't save disk space at all.
459 */
460 if (total_compressed <= blocksize &&
461 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
462 goto cleanup_and_bail_uncompressed;
463
464 /* we want to make sure that amount of ram required to uncompress
465 * an extent is reasonable, so we limit the total size in ram
466 * of a compressed extent to 128k. This is a crucial number
467 * because it also controls how easily we can spread reads across
468 * cpus for decompression.
469 *
470 * We also want to make sure the amount of IO required to do
471 * a random read is reasonably small, so we limit the size of
472 * a compressed extent to 128k.
473 */
474 total_compressed = min(total_compressed, max_uncompressed);
475 num_bytes = ALIGN(end - start + 1, blocksize);
476 num_bytes = max(blocksize, num_bytes);
477 total_in = 0;
478 ret = 0;
479
480 /*
481 * we do compression for mount -o compress and when the
482 * inode has not been flagged as nocompress. This flag can
483 * change at any time if we discover bad compression ratios.
484 */
485 if (inode_need_compress(inode)) {
486 WARN_ON(pages);
487 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
488 if (!pages) {
489 /* just bail out to the uncompressed code */
490 goto cont;
491 }
492
493 if (BTRFS_I(inode)->force_compress)
494 compress_type = BTRFS_I(inode)->force_compress;
495
496 /*
497 * we need to call clear_page_dirty_for_io on each
498 * page in the range. Otherwise applications with the file
499 * mmap'd can wander in and change the page contents while
500 * we are compressing them.
501 *
502 * If the compression fails for any reason, we set the pages
503 * dirty again later on.
504 */
505 extent_range_clear_dirty_for_io(inode, start, end);
506 redirty = 1;
507 ret = btrfs_compress_pages(compress_type,
508 inode->i_mapping, start,
509 total_compressed, pages,
510 nr_pages, &nr_pages_ret,
511 &total_in,
512 &total_compressed,
513 max_compressed);
514
515 if (!ret) {
516 unsigned long offset = total_compressed &
517 (PAGE_CACHE_SIZE - 1);
518 struct page *page = pages[nr_pages_ret - 1];
519 char *kaddr;
520
521 /* zero the tail end of the last page, we might be
522 * sending it down to disk
523 */
524 if (offset) {
525 kaddr = kmap_atomic(page);
526 memset(kaddr + offset, 0,
527 PAGE_CACHE_SIZE - offset);
528 kunmap_atomic(kaddr);
529 }
530 will_compress = 1;
531 }
532 }
533 cont:
534 if (start == 0) {
535 /* lets try to make an inline extent */
536 if (ret || total_in < (actual_end - start)) {
537 /* we didn't compress the entire range, try
538 * to make an uncompressed inline extent.
539 */
540 ret = cow_file_range_inline(root, inode, start, end,
541 0, 0, NULL);
542 } else {
543 /* try making a compressed inline extent */
544 ret = cow_file_range_inline(root, inode, start, end,
545 total_compressed,
546 compress_type, pages);
547 }
548 if (ret <= 0) {
549 unsigned long clear_flags = EXTENT_DELALLOC |
550 EXTENT_DEFRAG;
551 unsigned long page_error_op;
552
553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
555
556 /*
557 * inline extent creation worked or returned error,
558 * we don't need to create any more async work items.
559 * Unlock and free up our temp pages.
560 */
561 extent_clear_unlock_delalloc(inode, start, end, NULL,
562 clear_flags, PAGE_UNLOCK |
563 PAGE_CLEAR_DIRTY |
564 PAGE_SET_WRITEBACK |
565 page_error_op |
566 PAGE_END_WRITEBACK);
567 goto free_pages_out;
568 }
569 }
570
571 if (will_compress) {
572 /*
573 * we aren't doing an inline extent round the compressed size
574 * up to a block size boundary so the allocator does sane
575 * things
576 */
577 total_compressed = ALIGN(total_compressed, blocksize);
578
579 /*
580 * one last check to make sure the compression is really a
581 * win, compare the page count read with the blocks on disk
582 */
583 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
584 if (total_compressed >= total_in) {
585 will_compress = 0;
586 } else {
587 num_bytes = total_in;
588 }
589 }
590 if (!will_compress && pages) {
591 /*
592 * the compression code ran but failed to make things smaller,
593 * free any pages it allocated and our page pointer array
594 */
595 for (i = 0; i < nr_pages_ret; i++) {
596 WARN_ON(pages[i]->mapping);
597 page_cache_release(pages[i]);
598 }
599 kfree(pages);
600 pages = NULL;
601 total_compressed = 0;
602 nr_pages_ret = 0;
603
604 /* flag the file so we don't compress in the future */
605 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
606 !(BTRFS_I(inode)->force_compress)) {
607 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
608 }
609 }
610 if (will_compress) {
611 *num_added += 1;
612
613 /* the async work queues will take care of doing actual
614 * allocation on disk for these compressed pages,
615 * and will submit them to the elevator.
616 */
617 add_async_extent(async_cow, start, num_bytes,
618 total_compressed, pages, nr_pages_ret,
619 compress_type);
620
621 if (start + num_bytes < end) {
622 start += num_bytes;
623 pages = NULL;
624 cond_resched();
625 goto again;
626 }
627 } else {
628 cleanup_and_bail_uncompressed:
629 /*
630 * No compression, but we still need to write the pages in
631 * the file we've been given so far. redirty the locked
632 * page if it corresponds to our extent and set things up
633 * for the async work queue to run cow_file_range to do
634 * the normal delalloc dance
635 */
636 if (page_offset(locked_page) >= start &&
637 page_offset(locked_page) <= end) {
638 __set_page_dirty_nobuffers(locked_page);
639 /* unlocked later on in the async handlers */
640 }
641 if (redirty)
642 extent_range_redirty_for_io(inode, start, end);
643 add_async_extent(async_cow, start, end - start + 1,
644 0, NULL, 0, BTRFS_COMPRESS_NONE);
645 *num_added += 1;
646 }
647
648 return;
649
650 free_pages_out:
651 for (i = 0; i < nr_pages_ret; i++) {
652 WARN_ON(pages[i]->mapping);
653 page_cache_release(pages[i]);
654 }
655 kfree(pages);
656 }
657
658 static void free_async_extent_pages(struct async_extent *async_extent)
659 {
660 int i;
661
662 if (!async_extent->pages)
663 return;
664
665 for (i = 0; i < async_extent->nr_pages; i++) {
666 WARN_ON(async_extent->pages[i]->mapping);
667 page_cache_release(async_extent->pages[i]);
668 }
669 kfree(async_extent->pages);
670 async_extent->nr_pages = 0;
671 async_extent->pages = NULL;
672 }
673
674 /*
675 * phase two of compressed writeback. This is the ordered portion
676 * of the code, which only gets called in the order the work was
677 * queued. We walk all the async extents created by compress_file_range
678 * and send them down to the disk.
679 */
680 static noinline void submit_compressed_extents(struct inode *inode,
681 struct async_cow *async_cow)
682 {
683 struct async_extent *async_extent;
684 u64 alloc_hint = 0;
685 struct btrfs_key ins;
686 struct extent_map *em;
687 struct btrfs_root *root = BTRFS_I(inode)->root;
688 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
689 struct extent_io_tree *io_tree;
690 int ret = 0;
691
692 again:
693 while (!list_empty(&async_cow->extents)) {
694 async_extent = list_entry(async_cow->extents.next,
695 struct async_extent, list);
696 list_del(&async_extent->list);
697
698 io_tree = &BTRFS_I(inode)->io_tree;
699
700 retry:
701 /* did the compression code fall back to uncompressed IO? */
702 if (!async_extent->pages) {
703 int page_started = 0;
704 unsigned long nr_written = 0;
705
706 lock_extent(io_tree, async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1);
709
710 /* allocate blocks */
711 ret = cow_file_range(inode, async_cow->locked_page,
712 async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1,
715 &page_started, &nr_written, 0);
716
717 /* JDM XXX */
718
719 /*
720 * if page_started, cow_file_range inserted an
721 * inline extent and took care of all the unlocking
722 * and IO for us. Otherwise, we need to submit
723 * all those pages down to the drive.
724 */
725 if (!page_started && !ret)
726 extent_write_locked_range(io_tree,
727 inode, async_extent->start,
728 async_extent->start +
729 async_extent->ram_size - 1,
730 btrfs_get_extent,
731 WB_SYNC_ALL);
732 else if (ret)
733 unlock_page(async_cow->locked_page);
734 kfree(async_extent);
735 cond_resched();
736 continue;
737 }
738
739 lock_extent(io_tree, async_extent->start,
740 async_extent->start + async_extent->ram_size - 1);
741
742 ret = btrfs_reserve_extent(root,
743 async_extent->compressed_size,
744 async_extent->compressed_size,
745 0, alloc_hint, &ins, 1, 1);
746 if (ret) {
747 free_async_extent_pages(async_extent);
748
749 if (ret == -ENOSPC) {
750 unlock_extent(io_tree, async_extent->start,
751 async_extent->start +
752 async_extent->ram_size - 1);
753
754 /*
755 * we need to redirty the pages if we decide to
756 * fallback to uncompressed IO, otherwise we
757 * will not submit these pages down to lower
758 * layers.
759 */
760 extent_range_redirty_for_io(inode,
761 async_extent->start,
762 async_extent->start +
763 async_extent->ram_size - 1);
764
765 goto retry;
766 }
767 goto out_free;
768 }
769 /*
770 * here we're doing allocation and writeback of the
771 * compressed pages
772 */
773 btrfs_drop_extent_cache(inode, async_extent->start,
774 async_extent->start +
775 async_extent->ram_size - 1, 0);
776
777 em = alloc_extent_map();
778 if (!em) {
779 ret = -ENOMEM;
780 goto out_free_reserve;
781 }
782 em->start = async_extent->start;
783 em->len = async_extent->ram_size;
784 em->orig_start = em->start;
785 em->mod_start = em->start;
786 em->mod_len = em->len;
787
788 em->block_start = ins.objectid;
789 em->block_len = ins.offset;
790 em->orig_block_len = ins.offset;
791 em->ram_bytes = async_extent->ram_size;
792 em->bdev = root->fs_info->fs_devices->latest_bdev;
793 em->compress_type = async_extent->compress_type;
794 set_bit(EXTENT_FLAG_PINNED, &em->flags);
795 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
796 em->generation = -1;
797
798 while (1) {
799 write_lock(&em_tree->lock);
800 ret = add_extent_mapping(em_tree, em, 1);
801 write_unlock(&em_tree->lock);
802 if (ret != -EEXIST) {
803 free_extent_map(em);
804 break;
805 }
806 btrfs_drop_extent_cache(inode, async_extent->start,
807 async_extent->start +
808 async_extent->ram_size - 1, 0);
809 }
810
811 if (ret)
812 goto out_free_reserve;
813
814 ret = btrfs_add_ordered_extent_compress(inode,
815 async_extent->start,
816 ins.objectid,
817 async_extent->ram_size,
818 ins.offset,
819 BTRFS_ORDERED_COMPRESSED,
820 async_extent->compress_type);
821 if (ret) {
822 btrfs_drop_extent_cache(inode, async_extent->start,
823 async_extent->start +
824 async_extent->ram_size - 1, 0);
825 goto out_free_reserve;
826 }
827
828 /*
829 * clear dirty, set writeback and unlock the pages.
830 */
831 extent_clear_unlock_delalloc(inode, async_extent->start,
832 async_extent->start +
833 async_extent->ram_size - 1,
834 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
835 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
836 PAGE_SET_WRITEBACK);
837 ret = btrfs_submit_compressed_write(inode,
838 async_extent->start,
839 async_extent->ram_size,
840 ins.objectid,
841 ins.offset, async_extent->pages,
842 async_extent->nr_pages);
843 if (ret) {
844 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
845 struct page *p = async_extent->pages[0];
846 const u64 start = async_extent->start;
847 const u64 end = start + async_extent->ram_size - 1;
848
849 p->mapping = inode->i_mapping;
850 tree->ops->writepage_end_io_hook(p, start, end,
851 NULL, 0);
852 p->mapping = NULL;
853 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
854 PAGE_END_WRITEBACK |
855 PAGE_SET_ERROR);
856 free_async_extent_pages(async_extent);
857 }
858 alloc_hint = ins.objectid + ins.offset;
859 kfree(async_extent);
860 cond_resched();
861 }
862 return;
863 out_free_reserve:
864 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
865 out_free:
866 extent_clear_unlock_delalloc(inode, async_extent->start,
867 async_extent->start +
868 async_extent->ram_size - 1,
869 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
870 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
871 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
872 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
873 PAGE_SET_ERROR);
874 free_async_extent_pages(async_extent);
875 kfree(async_extent);
876 goto again;
877 }
878
879 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
880 u64 num_bytes)
881 {
882 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
883 struct extent_map *em;
884 u64 alloc_hint = 0;
885
886 read_lock(&em_tree->lock);
887 em = search_extent_mapping(em_tree, start, num_bytes);
888 if (em) {
889 /*
890 * if block start isn't an actual block number then find the
891 * first block in this inode and use that as a hint. If that
892 * block is also bogus then just don't worry about it.
893 */
894 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
895 free_extent_map(em);
896 em = search_extent_mapping(em_tree, 0, 0);
897 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
898 alloc_hint = em->block_start;
899 if (em)
900 free_extent_map(em);
901 } else {
902 alloc_hint = em->block_start;
903 free_extent_map(em);
904 }
905 }
906 read_unlock(&em_tree->lock);
907
908 return alloc_hint;
909 }
910
911 /*
912 * when extent_io.c finds a delayed allocation range in the file,
913 * the call backs end up in this code. The basic idea is to
914 * allocate extents on disk for the range, and create ordered data structs
915 * in ram to track those extents.
916 *
917 * locked_page is the page that writepage had locked already. We use
918 * it to make sure we don't do extra locks or unlocks.
919 *
920 * *page_started is set to one if we unlock locked_page and do everything
921 * required to start IO on it. It may be clean and already done with
922 * IO when we return.
923 */
924 static noinline int cow_file_range(struct inode *inode,
925 struct page *locked_page,
926 u64 start, u64 end, int *page_started,
927 unsigned long *nr_written,
928 int unlock)
929 {
930 struct btrfs_root *root = BTRFS_I(inode)->root;
931 u64 alloc_hint = 0;
932 u64 num_bytes;
933 unsigned long ram_size;
934 u64 disk_num_bytes;
935 u64 cur_alloc_size;
936 u64 blocksize = root->sectorsize;
937 struct btrfs_key ins;
938 struct extent_map *em;
939 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
940 int ret = 0;
941
942 if (btrfs_is_free_space_inode(inode)) {
943 WARN_ON_ONCE(1);
944 ret = -EINVAL;
945 goto out_unlock;
946 }
947
948 num_bytes = ALIGN(end - start + 1, blocksize);
949 num_bytes = max(blocksize, num_bytes);
950 disk_num_bytes = num_bytes;
951
952 /* if this is a small write inside eof, kick off defrag */
953 if (num_bytes < SZ_64K &&
954 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
955 btrfs_add_inode_defrag(NULL, inode);
956
957 if (start == 0) {
958 /* lets try to make an inline extent */
959 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
960 NULL);
961 if (ret == 0) {
962 extent_clear_unlock_delalloc(inode, start, end, NULL,
963 EXTENT_LOCKED | EXTENT_DELALLOC |
964 EXTENT_DEFRAG, PAGE_UNLOCK |
965 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
966 PAGE_END_WRITEBACK);
967
968 *nr_written = *nr_written +
969 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
970 *page_started = 1;
971 goto out;
972 } else if (ret < 0) {
973 goto out_unlock;
974 }
975 }
976
977 BUG_ON(disk_num_bytes >
978 btrfs_super_total_bytes(root->fs_info->super_copy));
979
980 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
981 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
982
983 while (disk_num_bytes > 0) {
984 unsigned long op;
985
986 cur_alloc_size = disk_num_bytes;
987 ret = btrfs_reserve_extent(root, cur_alloc_size,
988 root->sectorsize, 0, alloc_hint,
989 &ins, 1, 1);
990 if (ret < 0)
991 goto out_unlock;
992
993 em = alloc_extent_map();
994 if (!em) {
995 ret = -ENOMEM;
996 goto out_reserve;
997 }
998 em->start = start;
999 em->orig_start = em->start;
1000 ram_size = ins.offset;
1001 em->len = ins.offset;
1002 em->mod_start = em->start;
1003 em->mod_len = em->len;
1004
1005 em->block_start = ins.objectid;
1006 em->block_len = ins.offset;
1007 em->orig_block_len = ins.offset;
1008 em->ram_bytes = ram_size;
1009 em->bdev = root->fs_info->fs_devices->latest_bdev;
1010 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1011 em->generation = -1;
1012
1013 while (1) {
1014 write_lock(&em_tree->lock);
1015 ret = add_extent_mapping(em_tree, em, 1);
1016 write_unlock(&em_tree->lock);
1017 if (ret != -EEXIST) {
1018 free_extent_map(em);
1019 break;
1020 }
1021 btrfs_drop_extent_cache(inode, start,
1022 start + ram_size - 1, 0);
1023 }
1024 if (ret)
1025 goto out_reserve;
1026
1027 cur_alloc_size = ins.offset;
1028 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1029 ram_size, cur_alloc_size, 0);
1030 if (ret)
1031 goto out_drop_extent_cache;
1032
1033 if (root->root_key.objectid ==
1034 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1035 ret = btrfs_reloc_clone_csums(inode, start,
1036 cur_alloc_size);
1037 if (ret)
1038 goto out_drop_extent_cache;
1039 }
1040
1041 if (disk_num_bytes < cur_alloc_size)
1042 break;
1043
1044 /* we're not doing compressed IO, don't unlock the first
1045 * page (which the caller expects to stay locked), don't
1046 * clear any dirty bits and don't set any writeback bits
1047 *
1048 * Do set the Private2 bit so we know this page was properly
1049 * setup for writepage
1050 */
1051 op = unlock ? PAGE_UNLOCK : 0;
1052 op |= PAGE_SET_PRIVATE2;
1053
1054 extent_clear_unlock_delalloc(inode, start,
1055 start + ram_size - 1, locked_page,
1056 EXTENT_LOCKED | EXTENT_DELALLOC,
1057 op);
1058 disk_num_bytes -= cur_alloc_size;
1059 num_bytes -= cur_alloc_size;
1060 alloc_hint = ins.objectid + ins.offset;
1061 start += cur_alloc_size;
1062 }
1063 out:
1064 return ret;
1065
1066 out_drop_extent_cache:
1067 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1068 out_reserve:
1069 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1070 out_unlock:
1071 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1072 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1073 EXTENT_DELALLOC | EXTENT_DEFRAG,
1074 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1075 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1076 goto out;
1077 }
1078
1079 /*
1080 * work queue call back to started compression on a file and pages
1081 */
1082 static noinline void async_cow_start(struct btrfs_work *work)
1083 {
1084 struct async_cow *async_cow;
1085 int num_added = 0;
1086 async_cow = container_of(work, struct async_cow, work);
1087
1088 compress_file_range(async_cow->inode, async_cow->locked_page,
1089 async_cow->start, async_cow->end, async_cow,
1090 &num_added);
1091 if (num_added == 0) {
1092 btrfs_add_delayed_iput(async_cow->inode);
1093 async_cow->inode = NULL;
1094 }
1095 }
1096
1097 /*
1098 * work queue call back to submit previously compressed pages
1099 */
1100 static noinline void async_cow_submit(struct btrfs_work *work)
1101 {
1102 struct async_cow *async_cow;
1103 struct btrfs_root *root;
1104 unsigned long nr_pages;
1105
1106 async_cow = container_of(work, struct async_cow, work);
1107
1108 root = async_cow->root;
1109 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1110 PAGE_CACHE_SHIFT;
1111
1112 /*
1113 * atomic_sub_return implies a barrier for waitqueue_active
1114 */
1115 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1116 5 * SZ_1M &&
1117 waitqueue_active(&root->fs_info->async_submit_wait))
1118 wake_up(&root->fs_info->async_submit_wait);
1119
1120 if (async_cow->inode)
1121 submit_compressed_extents(async_cow->inode, async_cow);
1122 }
1123
1124 static noinline void async_cow_free(struct btrfs_work *work)
1125 {
1126 struct async_cow *async_cow;
1127 async_cow = container_of(work, struct async_cow, work);
1128 if (async_cow->inode)
1129 btrfs_add_delayed_iput(async_cow->inode);
1130 kfree(async_cow);
1131 }
1132
1133 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1134 u64 start, u64 end, int *page_started,
1135 unsigned long *nr_written)
1136 {
1137 struct async_cow *async_cow;
1138 struct btrfs_root *root = BTRFS_I(inode)->root;
1139 unsigned long nr_pages;
1140 u64 cur_end;
1141 int limit = 10 * SZ_1M;
1142
1143 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1144 1, 0, NULL, GFP_NOFS);
1145 while (start < end) {
1146 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1147 BUG_ON(!async_cow); /* -ENOMEM */
1148 async_cow->inode = igrab(inode);
1149 async_cow->root = root;
1150 async_cow->locked_page = locked_page;
1151 async_cow->start = start;
1152
1153 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1154 !btrfs_test_opt(root, FORCE_COMPRESS))
1155 cur_end = end;
1156 else
1157 cur_end = min(end, start + SZ_512K - 1);
1158
1159 async_cow->end = cur_end;
1160 INIT_LIST_HEAD(&async_cow->extents);
1161
1162 btrfs_init_work(&async_cow->work,
1163 btrfs_delalloc_helper,
1164 async_cow_start, async_cow_submit,
1165 async_cow_free);
1166
1167 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1168 PAGE_CACHE_SHIFT;
1169 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1170
1171 btrfs_queue_work(root->fs_info->delalloc_workers,
1172 &async_cow->work);
1173
1174 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1175 wait_event(root->fs_info->async_submit_wait,
1176 (atomic_read(&root->fs_info->async_delalloc_pages) <
1177 limit));
1178 }
1179
1180 while (atomic_read(&root->fs_info->async_submit_draining) &&
1181 atomic_read(&root->fs_info->async_delalloc_pages)) {
1182 wait_event(root->fs_info->async_submit_wait,
1183 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1184 0));
1185 }
1186
1187 *nr_written += nr_pages;
1188 start = cur_end + 1;
1189 }
1190 *page_started = 1;
1191 return 0;
1192 }
1193
1194 static noinline int csum_exist_in_range(struct btrfs_root *root,
1195 u64 bytenr, u64 num_bytes)
1196 {
1197 int ret;
1198 struct btrfs_ordered_sum *sums;
1199 LIST_HEAD(list);
1200
1201 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1202 bytenr + num_bytes - 1, &list, 0);
1203 if (ret == 0 && list_empty(&list))
1204 return 0;
1205
1206 while (!list_empty(&list)) {
1207 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1208 list_del(&sums->list);
1209 kfree(sums);
1210 }
1211 return 1;
1212 }
1213
1214 /*
1215 * when nowcow writeback call back. This checks for snapshots or COW copies
1216 * of the extents that exist in the file, and COWs the file as required.
1217 *
1218 * If no cow copies or snapshots exist, we write directly to the existing
1219 * blocks on disk
1220 */
1221 static noinline int run_delalloc_nocow(struct inode *inode,
1222 struct page *locked_page,
1223 u64 start, u64 end, int *page_started, int force,
1224 unsigned long *nr_written)
1225 {
1226 struct btrfs_root *root = BTRFS_I(inode)->root;
1227 struct btrfs_trans_handle *trans;
1228 struct extent_buffer *leaf;
1229 struct btrfs_path *path;
1230 struct btrfs_file_extent_item *fi;
1231 struct btrfs_key found_key;
1232 u64 cow_start;
1233 u64 cur_offset;
1234 u64 extent_end;
1235 u64 extent_offset;
1236 u64 disk_bytenr;
1237 u64 num_bytes;
1238 u64 disk_num_bytes;
1239 u64 ram_bytes;
1240 int extent_type;
1241 int ret, err;
1242 int type;
1243 int nocow;
1244 int check_prev = 1;
1245 bool nolock;
1246 u64 ino = btrfs_ino(inode);
1247
1248 path = btrfs_alloc_path();
1249 if (!path) {
1250 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1251 EXTENT_LOCKED | EXTENT_DELALLOC |
1252 EXTENT_DO_ACCOUNTING |
1253 EXTENT_DEFRAG, PAGE_UNLOCK |
1254 PAGE_CLEAR_DIRTY |
1255 PAGE_SET_WRITEBACK |
1256 PAGE_END_WRITEBACK);
1257 return -ENOMEM;
1258 }
1259
1260 nolock = btrfs_is_free_space_inode(inode);
1261
1262 if (nolock)
1263 trans = btrfs_join_transaction_nolock(root);
1264 else
1265 trans = btrfs_join_transaction(root);
1266
1267 if (IS_ERR(trans)) {
1268 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1269 EXTENT_LOCKED | EXTENT_DELALLOC |
1270 EXTENT_DO_ACCOUNTING |
1271 EXTENT_DEFRAG, PAGE_UNLOCK |
1272 PAGE_CLEAR_DIRTY |
1273 PAGE_SET_WRITEBACK |
1274 PAGE_END_WRITEBACK);
1275 btrfs_free_path(path);
1276 return PTR_ERR(trans);
1277 }
1278
1279 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1280
1281 cow_start = (u64)-1;
1282 cur_offset = start;
1283 while (1) {
1284 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1285 cur_offset, 0);
1286 if (ret < 0)
1287 goto error;
1288 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1289 leaf = path->nodes[0];
1290 btrfs_item_key_to_cpu(leaf, &found_key,
1291 path->slots[0] - 1);
1292 if (found_key.objectid == ino &&
1293 found_key.type == BTRFS_EXTENT_DATA_KEY)
1294 path->slots[0]--;
1295 }
1296 check_prev = 0;
1297 next_slot:
1298 leaf = path->nodes[0];
1299 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1300 ret = btrfs_next_leaf(root, path);
1301 if (ret < 0)
1302 goto error;
1303 if (ret > 0)
1304 break;
1305 leaf = path->nodes[0];
1306 }
1307
1308 nocow = 0;
1309 disk_bytenr = 0;
1310 num_bytes = 0;
1311 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1312
1313 if (found_key.objectid > ino)
1314 break;
1315 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1316 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1317 path->slots[0]++;
1318 goto next_slot;
1319 }
1320 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1321 found_key.offset > end)
1322 break;
1323
1324 if (found_key.offset > cur_offset) {
1325 extent_end = found_key.offset;
1326 extent_type = 0;
1327 goto out_check;
1328 }
1329
1330 fi = btrfs_item_ptr(leaf, path->slots[0],
1331 struct btrfs_file_extent_item);
1332 extent_type = btrfs_file_extent_type(leaf, fi);
1333
1334 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1335 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1336 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1337 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1338 extent_offset = btrfs_file_extent_offset(leaf, fi);
1339 extent_end = found_key.offset +
1340 btrfs_file_extent_num_bytes(leaf, fi);
1341 disk_num_bytes =
1342 btrfs_file_extent_disk_num_bytes(leaf, fi);
1343 if (extent_end <= start) {
1344 path->slots[0]++;
1345 goto next_slot;
1346 }
1347 if (disk_bytenr == 0)
1348 goto out_check;
1349 if (btrfs_file_extent_compression(leaf, fi) ||
1350 btrfs_file_extent_encryption(leaf, fi) ||
1351 btrfs_file_extent_other_encoding(leaf, fi))
1352 goto out_check;
1353 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1354 goto out_check;
1355 if (btrfs_extent_readonly(root, disk_bytenr))
1356 goto out_check;
1357 if (btrfs_cross_ref_exist(trans, root, ino,
1358 found_key.offset -
1359 extent_offset, disk_bytenr))
1360 goto out_check;
1361 disk_bytenr += extent_offset;
1362 disk_bytenr += cur_offset - found_key.offset;
1363 num_bytes = min(end + 1, extent_end) - cur_offset;
1364 /*
1365 * if there are pending snapshots for this root,
1366 * we fall into common COW way.
1367 */
1368 if (!nolock) {
1369 err = btrfs_start_write_no_snapshoting(root);
1370 if (!err)
1371 goto out_check;
1372 }
1373 /*
1374 * force cow if csum exists in the range.
1375 * this ensure that csum for a given extent are
1376 * either valid or do not exist.
1377 */
1378 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1379 goto out_check;
1380 nocow = 1;
1381 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1382 extent_end = found_key.offset +
1383 btrfs_file_extent_inline_len(leaf,
1384 path->slots[0], fi);
1385 extent_end = ALIGN(extent_end, root->sectorsize);
1386 } else {
1387 BUG_ON(1);
1388 }
1389 out_check:
1390 if (extent_end <= start) {
1391 path->slots[0]++;
1392 if (!nolock && nocow)
1393 btrfs_end_write_no_snapshoting(root);
1394 goto next_slot;
1395 }
1396 if (!nocow) {
1397 if (cow_start == (u64)-1)
1398 cow_start = cur_offset;
1399 cur_offset = extent_end;
1400 if (cur_offset > end)
1401 break;
1402 path->slots[0]++;
1403 goto next_slot;
1404 }
1405
1406 btrfs_release_path(path);
1407 if (cow_start != (u64)-1) {
1408 ret = cow_file_range(inode, locked_page,
1409 cow_start, found_key.offset - 1,
1410 page_started, nr_written, 1);
1411 if (ret) {
1412 if (!nolock && nocow)
1413 btrfs_end_write_no_snapshoting(root);
1414 goto error;
1415 }
1416 cow_start = (u64)-1;
1417 }
1418
1419 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1420 struct extent_map *em;
1421 struct extent_map_tree *em_tree;
1422 em_tree = &BTRFS_I(inode)->extent_tree;
1423 em = alloc_extent_map();
1424 BUG_ON(!em); /* -ENOMEM */
1425 em->start = cur_offset;
1426 em->orig_start = found_key.offset - extent_offset;
1427 em->len = num_bytes;
1428 em->block_len = num_bytes;
1429 em->block_start = disk_bytenr;
1430 em->orig_block_len = disk_num_bytes;
1431 em->ram_bytes = ram_bytes;
1432 em->bdev = root->fs_info->fs_devices->latest_bdev;
1433 em->mod_start = em->start;
1434 em->mod_len = em->len;
1435 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1436 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1437 em->generation = -1;
1438 while (1) {
1439 write_lock(&em_tree->lock);
1440 ret = add_extent_mapping(em_tree, em, 1);
1441 write_unlock(&em_tree->lock);
1442 if (ret != -EEXIST) {
1443 free_extent_map(em);
1444 break;
1445 }
1446 btrfs_drop_extent_cache(inode, em->start,
1447 em->start + em->len - 1, 0);
1448 }
1449 type = BTRFS_ORDERED_PREALLOC;
1450 } else {
1451 type = BTRFS_ORDERED_NOCOW;
1452 }
1453
1454 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1455 num_bytes, num_bytes, type);
1456 BUG_ON(ret); /* -ENOMEM */
1457
1458 if (root->root_key.objectid ==
1459 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1460 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1461 num_bytes);
1462 if (ret) {
1463 if (!nolock && nocow)
1464 btrfs_end_write_no_snapshoting(root);
1465 goto error;
1466 }
1467 }
1468
1469 extent_clear_unlock_delalloc(inode, cur_offset,
1470 cur_offset + num_bytes - 1,
1471 locked_page, EXTENT_LOCKED |
1472 EXTENT_DELALLOC, PAGE_UNLOCK |
1473 PAGE_SET_PRIVATE2);
1474 if (!nolock && nocow)
1475 btrfs_end_write_no_snapshoting(root);
1476 cur_offset = extent_end;
1477 if (cur_offset > end)
1478 break;
1479 }
1480 btrfs_release_path(path);
1481
1482 if (cur_offset <= end && cow_start == (u64)-1) {
1483 cow_start = cur_offset;
1484 cur_offset = end;
1485 }
1486
1487 if (cow_start != (u64)-1) {
1488 ret = cow_file_range(inode, locked_page, cow_start, end,
1489 page_started, nr_written, 1);
1490 if (ret)
1491 goto error;
1492 }
1493
1494 error:
1495 err = btrfs_end_transaction(trans, root);
1496 if (!ret)
1497 ret = err;
1498
1499 if (ret && cur_offset < end)
1500 extent_clear_unlock_delalloc(inode, cur_offset, end,
1501 locked_page, EXTENT_LOCKED |
1502 EXTENT_DELALLOC | EXTENT_DEFRAG |
1503 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1504 PAGE_CLEAR_DIRTY |
1505 PAGE_SET_WRITEBACK |
1506 PAGE_END_WRITEBACK);
1507 btrfs_free_path(path);
1508 return ret;
1509 }
1510
1511 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1512 {
1513
1514 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1515 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1516 return 0;
1517
1518 /*
1519 * @defrag_bytes is a hint value, no spinlock held here,
1520 * if is not zero, it means the file is defragging.
1521 * Force cow if given extent needs to be defragged.
1522 */
1523 if (BTRFS_I(inode)->defrag_bytes &&
1524 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1525 EXTENT_DEFRAG, 0, NULL))
1526 return 1;
1527
1528 return 0;
1529 }
1530
1531 /*
1532 * extent_io.c call back to do delayed allocation processing
1533 */
1534 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1535 u64 start, u64 end, int *page_started,
1536 unsigned long *nr_written)
1537 {
1538 int ret;
1539 int force_cow = need_force_cow(inode, start, end);
1540
1541 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1542 ret = run_delalloc_nocow(inode, locked_page, start, end,
1543 page_started, 1, nr_written);
1544 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1545 ret = run_delalloc_nocow(inode, locked_page, start, end,
1546 page_started, 0, nr_written);
1547 } else if (!inode_need_compress(inode)) {
1548 ret = cow_file_range(inode, locked_page, start, end,
1549 page_started, nr_written, 1);
1550 } else {
1551 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1552 &BTRFS_I(inode)->runtime_flags);
1553 ret = cow_file_range_async(inode, locked_page, start, end,
1554 page_started, nr_written);
1555 }
1556 return ret;
1557 }
1558
1559 static void btrfs_split_extent_hook(struct inode *inode,
1560 struct extent_state *orig, u64 split)
1561 {
1562 u64 size;
1563
1564 /* not delalloc, ignore it */
1565 if (!(orig->state & EXTENT_DELALLOC))
1566 return;
1567
1568 size = orig->end - orig->start + 1;
1569 if (size > BTRFS_MAX_EXTENT_SIZE) {
1570 u64 num_extents;
1571 u64 new_size;
1572
1573 /*
1574 * See the explanation in btrfs_merge_extent_hook, the same
1575 * applies here, just in reverse.
1576 */
1577 new_size = orig->end - split + 1;
1578 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1579 BTRFS_MAX_EXTENT_SIZE);
1580 new_size = split - orig->start;
1581 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1582 BTRFS_MAX_EXTENT_SIZE);
1583 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1584 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1585 return;
1586 }
1587
1588 spin_lock(&BTRFS_I(inode)->lock);
1589 BTRFS_I(inode)->outstanding_extents++;
1590 spin_unlock(&BTRFS_I(inode)->lock);
1591 }
1592
1593 /*
1594 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1595 * extents so we can keep track of new extents that are just merged onto old
1596 * extents, such as when we are doing sequential writes, so we can properly
1597 * account for the metadata space we'll need.
1598 */
1599 static void btrfs_merge_extent_hook(struct inode *inode,
1600 struct extent_state *new,
1601 struct extent_state *other)
1602 {
1603 u64 new_size, old_size;
1604 u64 num_extents;
1605
1606 /* not delalloc, ignore it */
1607 if (!(other->state & EXTENT_DELALLOC))
1608 return;
1609
1610 if (new->start > other->start)
1611 new_size = new->end - other->start + 1;
1612 else
1613 new_size = other->end - new->start + 1;
1614
1615 /* we're not bigger than the max, unreserve the space and go */
1616 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1617 spin_lock(&BTRFS_I(inode)->lock);
1618 BTRFS_I(inode)->outstanding_extents--;
1619 spin_unlock(&BTRFS_I(inode)->lock);
1620 return;
1621 }
1622
1623 /*
1624 * We have to add up either side to figure out how many extents were
1625 * accounted for before we merged into one big extent. If the number of
1626 * extents we accounted for is <= the amount we need for the new range
1627 * then we can return, otherwise drop. Think of it like this
1628 *
1629 * [ 4k][MAX_SIZE]
1630 *
1631 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1632 * need 2 outstanding extents, on one side we have 1 and the other side
1633 * we have 1 so they are == and we can return. But in this case
1634 *
1635 * [MAX_SIZE+4k][MAX_SIZE+4k]
1636 *
1637 * Each range on their own accounts for 2 extents, but merged together
1638 * they are only 3 extents worth of accounting, so we need to drop in
1639 * this case.
1640 */
1641 old_size = other->end - other->start + 1;
1642 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1643 BTRFS_MAX_EXTENT_SIZE);
1644 old_size = new->end - new->start + 1;
1645 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1646 BTRFS_MAX_EXTENT_SIZE);
1647
1648 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1649 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1650 return;
1651
1652 spin_lock(&BTRFS_I(inode)->lock);
1653 BTRFS_I(inode)->outstanding_extents--;
1654 spin_unlock(&BTRFS_I(inode)->lock);
1655 }
1656
1657 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1658 struct inode *inode)
1659 {
1660 spin_lock(&root->delalloc_lock);
1661 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1662 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1663 &root->delalloc_inodes);
1664 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1665 &BTRFS_I(inode)->runtime_flags);
1666 root->nr_delalloc_inodes++;
1667 if (root->nr_delalloc_inodes == 1) {
1668 spin_lock(&root->fs_info->delalloc_root_lock);
1669 BUG_ON(!list_empty(&root->delalloc_root));
1670 list_add_tail(&root->delalloc_root,
1671 &root->fs_info->delalloc_roots);
1672 spin_unlock(&root->fs_info->delalloc_root_lock);
1673 }
1674 }
1675 spin_unlock(&root->delalloc_lock);
1676 }
1677
1678 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1679 struct inode *inode)
1680 {
1681 spin_lock(&root->delalloc_lock);
1682 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1683 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1684 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1685 &BTRFS_I(inode)->runtime_flags);
1686 root->nr_delalloc_inodes--;
1687 if (!root->nr_delalloc_inodes) {
1688 spin_lock(&root->fs_info->delalloc_root_lock);
1689 BUG_ON(list_empty(&root->delalloc_root));
1690 list_del_init(&root->delalloc_root);
1691 spin_unlock(&root->fs_info->delalloc_root_lock);
1692 }
1693 }
1694 spin_unlock(&root->delalloc_lock);
1695 }
1696
1697 /*
1698 * extent_io.c set_bit_hook, used to track delayed allocation
1699 * bytes in this file, and to maintain the list of inodes that
1700 * have pending delalloc work to be done.
1701 */
1702 static void btrfs_set_bit_hook(struct inode *inode,
1703 struct extent_state *state, unsigned *bits)
1704 {
1705
1706 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1707 WARN_ON(1);
1708 /*
1709 * set_bit and clear bit hooks normally require _irqsave/restore
1710 * but in this case, we are only testing for the DELALLOC
1711 * bit, which is only set or cleared with irqs on
1712 */
1713 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1714 struct btrfs_root *root = BTRFS_I(inode)->root;
1715 u64 len = state->end + 1 - state->start;
1716 bool do_list = !btrfs_is_free_space_inode(inode);
1717
1718 if (*bits & EXTENT_FIRST_DELALLOC) {
1719 *bits &= ~EXTENT_FIRST_DELALLOC;
1720 } else {
1721 spin_lock(&BTRFS_I(inode)->lock);
1722 BTRFS_I(inode)->outstanding_extents++;
1723 spin_unlock(&BTRFS_I(inode)->lock);
1724 }
1725
1726 /* For sanity tests */
1727 if (btrfs_test_is_dummy_root(root))
1728 return;
1729
1730 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1731 root->fs_info->delalloc_batch);
1732 spin_lock(&BTRFS_I(inode)->lock);
1733 BTRFS_I(inode)->delalloc_bytes += len;
1734 if (*bits & EXTENT_DEFRAG)
1735 BTRFS_I(inode)->defrag_bytes += len;
1736 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1737 &BTRFS_I(inode)->runtime_flags))
1738 btrfs_add_delalloc_inodes(root, inode);
1739 spin_unlock(&BTRFS_I(inode)->lock);
1740 }
1741 }
1742
1743 /*
1744 * extent_io.c clear_bit_hook, see set_bit_hook for why
1745 */
1746 static void btrfs_clear_bit_hook(struct inode *inode,
1747 struct extent_state *state,
1748 unsigned *bits)
1749 {
1750 u64 len = state->end + 1 - state->start;
1751 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1752 BTRFS_MAX_EXTENT_SIZE);
1753
1754 spin_lock(&BTRFS_I(inode)->lock);
1755 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1756 BTRFS_I(inode)->defrag_bytes -= len;
1757 spin_unlock(&BTRFS_I(inode)->lock);
1758
1759 /*
1760 * set_bit and clear bit hooks normally require _irqsave/restore
1761 * but in this case, we are only testing for the DELALLOC
1762 * bit, which is only set or cleared with irqs on
1763 */
1764 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1765 struct btrfs_root *root = BTRFS_I(inode)->root;
1766 bool do_list = !btrfs_is_free_space_inode(inode);
1767
1768 if (*bits & EXTENT_FIRST_DELALLOC) {
1769 *bits &= ~EXTENT_FIRST_DELALLOC;
1770 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1771 spin_lock(&BTRFS_I(inode)->lock);
1772 BTRFS_I(inode)->outstanding_extents -= num_extents;
1773 spin_unlock(&BTRFS_I(inode)->lock);
1774 }
1775
1776 /*
1777 * We don't reserve metadata space for space cache inodes so we
1778 * don't need to call dellalloc_release_metadata if there is an
1779 * error.
1780 */
1781 if (*bits & EXTENT_DO_ACCOUNTING &&
1782 root != root->fs_info->tree_root)
1783 btrfs_delalloc_release_metadata(inode, len);
1784
1785 /* For sanity tests. */
1786 if (btrfs_test_is_dummy_root(root))
1787 return;
1788
1789 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1790 && do_list && !(state->state & EXTENT_NORESERVE))
1791 btrfs_free_reserved_data_space_noquota(inode,
1792 state->start, len);
1793
1794 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1795 root->fs_info->delalloc_batch);
1796 spin_lock(&BTRFS_I(inode)->lock);
1797 BTRFS_I(inode)->delalloc_bytes -= len;
1798 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1799 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1800 &BTRFS_I(inode)->runtime_flags))
1801 btrfs_del_delalloc_inode(root, inode);
1802 spin_unlock(&BTRFS_I(inode)->lock);
1803 }
1804 }
1805
1806 /*
1807 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1808 * we don't create bios that span stripes or chunks
1809 */
1810 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1811 size_t size, struct bio *bio,
1812 unsigned long bio_flags)
1813 {
1814 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1815 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1816 u64 length = 0;
1817 u64 map_length;
1818 int ret;
1819
1820 if (bio_flags & EXTENT_BIO_COMPRESSED)
1821 return 0;
1822
1823 length = bio->bi_iter.bi_size;
1824 map_length = length;
1825 ret = btrfs_map_block(root->fs_info, rw, logical,
1826 &map_length, NULL, 0);
1827 /* Will always return 0 with map_multi == NULL */
1828 BUG_ON(ret < 0);
1829 if (map_length < length + size)
1830 return 1;
1831 return 0;
1832 }
1833
1834 /*
1835 * in order to insert checksums into the metadata in large chunks,
1836 * we wait until bio submission time. All the pages in the bio are
1837 * checksummed and sums are attached onto the ordered extent record.
1838 *
1839 * At IO completion time the cums attached on the ordered extent record
1840 * are inserted into the btree
1841 */
1842 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1843 struct bio *bio, int mirror_num,
1844 unsigned long bio_flags,
1845 u64 bio_offset)
1846 {
1847 struct btrfs_root *root = BTRFS_I(inode)->root;
1848 int ret = 0;
1849
1850 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1851 BUG_ON(ret); /* -ENOMEM */
1852 return 0;
1853 }
1854
1855 /*
1856 * in order to insert checksums into the metadata in large chunks,
1857 * we wait until bio submission time. All the pages in the bio are
1858 * checksummed and sums are attached onto the ordered extent record.
1859 *
1860 * At IO completion time the cums attached on the ordered extent record
1861 * are inserted into the btree
1862 */
1863 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1864 int mirror_num, unsigned long bio_flags,
1865 u64 bio_offset)
1866 {
1867 struct btrfs_root *root = BTRFS_I(inode)->root;
1868 int ret;
1869
1870 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1871 if (ret) {
1872 bio->bi_error = ret;
1873 bio_endio(bio);
1874 }
1875 return ret;
1876 }
1877
1878 /*
1879 * extent_io.c submission hook. This does the right thing for csum calculation
1880 * on write, or reading the csums from the tree before a read
1881 */
1882 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1883 int mirror_num, unsigned long bio_flags,
1884 u64 bio_offset)
1885 {
1886 struct btrfs_root *root = BTRFS_I(inode)->root;
1887 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1888 int ret = 0;
1889 int skip_sum;
1890 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1891
1892 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1893
1894 if (btrfs_is_free_space_inode(inode))
1895 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1896
1897 if (!(rw & REQ_WRITE)) {
1898 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1899 if (ret)
1900 goto out;
1901
1902 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1903 ret = btrfs_submit_compressed_read(inode, bio,
1904 mirror_num,
1905 bio_flags);
1906 goto out;
1907 } else if (!skip_sum) {
1908 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1909 if (ret)
1910 goto out;
1911 }
1912 goto mapit;
1913 } else if (async && !skip_sum) {
1914 /* csum items have already been cloned */
1915 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1916 goto mapit;
1917 /* we're doing a write, do the async checksumming */
1918 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1919 inode, rw, bio, mirror_num,
1920 bio_flags, bio_offset,
1921 __btrfs_submit_bio_start,
1922 __btrfs_submit_bio_done);
1923 goto out;
1924 } else if (!skip_sum) {
1925 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1926 if (ret)
1927 goto out;
1928 }
1929
1930 mapit:
1931 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1932
1933 out:
1934 if (ret < 0) {
1935 bio->bi_error = ret;
1936 bio_endio(bio);
1937 }
1938 return ret;
1939 }
1940
1941 /*
1942 * given a list of ordered sums record them in the inode. This happens
1943 * at IO completion time based on sums calculated at bio submission time.
1944 */
1945 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1946 struct inode *inode, u64 file_offset,
1947 struct list_head *list)
1948 {
1949 struct btrfs_ordered_sum *sum;
1950
1951 list_for_each_entry(sum, list, list) {
1952 trans->adding_csums = 1;
1953 btrfs_csum_file_blocks(trans,
1954 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1955 trans->adding_csums = 0;
1956 }
1957 return 0;
1958 }
1959
1960 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1961 struct extent_state **cached_state)
1962 {
1963 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1964 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1965 cached_state, GFP_NOFS);
1966 }
1967
1968 /* see btrfs_writepage_start_hook for details on why this is required */
1969 struct btrfs_writepage_fixup {
1970 struct page *page;
1971 struct btrfs_work work;
1972 };
1973
1974 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1975 {
1976 struct btrfs_writepage_fixup *fixup;
1977 struct btrfs_ordered_extent *ordered;
1978 struct extent_state *cached_state = NULL;
1979 struct page *page;
1980 struct inode *inode;
1981 u64 page_start;
1982 u64 page_end;
1983 int ret;
1984
1985 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1986 page = fixup->page;
1987 again:
1988 lock_page(page);
1989 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1990 ClearPageChecked(page);
1991 goto out_page;
1992 }
1993
1994 inode = page->mapping->host;
1995 page_start = page_offset(page);
1996 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1997
1998 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
1999 &cached_state);
2000
2001 /* already ordered? We're done */
2002 if (PagePrivate2(page))
2003 goto out;
2004
2005 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2006 if (ordered) {
2007 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2008 page_end, &cached_state, GFP_NOFS);
2009 unlock_page(page);
2010 btrfs_start_ordered_extent(inode, ordered, 1);
2011 btrfs_put_ordered_extent(ordered);
2012 goto again;
2013 }
2014
2015 ret = btrfs_delalloc_reserve_space(inode, page_start,
2016 PAGE_CACHE_SIZE);
2017 if (ret) {
2018 mapping_set_error(page->mapping, ret);
2019 end_extent_writepage(page, ret, page_start, page_end);
2020 ClearPageChecked(page);
2021 goto out;
2022 }
2023
2024 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2025 ClearPageChecked(page);
2026 set_page_dirty(page);
2027 out:
2028 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2029 &cached_state, GFP_NOFS);
2030 out_page:
2031 unlock_page(page);
2032 page_cache_release(page);
2033 kfree(fixup);
2034 }
2035
2036 /*
2037 * There are a few paths in the higher layers of the kernel that directly
2038 * set the page dirty bit without asking the filesystem if it is a
2039 * good idea. This causes problems because we want to make sure COW
2040 * properly happens and the data=ordered rules are followed.
2041 *
2042 * In our case any range that doesn't have the ORDERED bit set
2043 * hasn't been properly setup for IO. We kick off an async process
2044 * to fix it up. The async helper will wait for ordered extents, set
2045 * the delalloc bit and make it safe to write the page.
2046 */
2047 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2048 {
2049 struct inode *inode = page->mapping->host;
2050 struct btrfs_writepage_fixup *fixup;
2051 struct btrfs_root *root = BTRFS_I(inode)->root;
2052
2053 /* this page is properly in the ordered list */
2054 if (TestClearPagePrivate2(page))
2055 return 0;
2056
2057 if (PageChecked(page))
2058 return -EAGAIN;
2059
2060 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2061 if (!fixup)
2062 return -EAGAIN;
2063
2064 SetPageChecked(page);
2065 page_cache_get(page);
2066 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2067 btrfs_writepage_fixup_worker, NULL, NULL);
2068 fixup->page = page;
2069 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2070 return -EBUSY;
2071 }
2072
2073 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2074 struct inode *inode, u64 file_pos,
2075 u64 disk_bytenr, u64 disk_num_bytes,
2076 u64 num_bytes, u64 ram_bytes,
2077 u8 compression, u8 encryption,
2078 u16 other_encoding, int extent_type)
2079 {
2080 struct btrfs_root *root = BTRFS_I(inode)->root;
2081 struct btrfs_file_extent_item *fi;
2082 struct btrfs_path *path;
2083 struct extent_buffer *leaf;
2084 struct btrfs_key ins;
2085 int extent_inserted = 0;
2086 int ret;
2087
2088 path = btrfs_alloc_path();
2089 if (!path)
2090 return -ENOMEM;
2091
2092 /*
2093 * we may be replacing one extent in the tree with another.
2094 * The new extent is pinned in the extent map, and we don't want
2095 * to drop it from the cache until it is completely in the btree.
2096 *
2097 * So, tell btrfs_drop_extents to leave this extent in the cache.
2098 * the caller is expected to unpin it and allow it to be merged
2099 * with the others.
2100 */
2101 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2102 file_pos + num_bytes, NULL, 0,
2103 1, sizeof(*fi), &extent_inserted);
2104 if (ret)
2105 goto out;
2106
2107 if (!extent_inserted) {
2108 ins.objectid = btrfs_ino(inode);
2109 ins.offset = file_pos;
2110 ins.type = BTRFS_EXTENT_DATA_KEY;
2111
2112 path->leave_spinning = 1;
2113 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2114 sizeof(*fi));
2115 if (ret)
2116 goto out;
2117 }
2118 leaf = path->nodes[0];
2119 fi = btrfs_item_ptr(leaf, path->slots[0],
2120 struct btrfs_file_extent_item);
2121 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2122 btrfs_set_file_extent_type(leaf, fi, extent_type);
2123 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2124 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2125 btrfs_set_file_extent_offset(leaf, fi, 0);
2126 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2127 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2128 btrfs_set_file_extent_compression(leaf, fi, compression);
2129 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2130 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2131
2132 btrfs_mark_buffer_dirty(leaf);
2133 btrfs_release_path(path);
2134
2135 inode_add_bytes(inode, num_bytes);
2136
2137 ins.objectid = disk_bytenr;
2138 ins.offset = disk_num_bytes;
2139 ins.type = BTRFS_EXTENT_ITEM_KEY;
2140 ret = btrfs_alloc_reserved_file_extent(trans, root,
2141 root->root_key.objectid,
2142 btrfs_ino(inode), file_pos,
2143 ram_bytes, &ins);
2144 /*
2145 * Release the reserved range from inode dirty range map, as it is
2146 * already moved into delayed_ref_head
2147 */
2148 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2149 out:
2150 btrfs_free_path(path);
2151
2152 return ret;
2153 }
2154
2155 /* snapshot-aware defrag */
2156 struct sa_defrag_extent_backref {
2157 struct rb_node node;
2158 struct old_sa_defrag_extent *old;
2159 u64 root_id;
2160 u64 inum;
2161 u64 file_pos;
2162 u64 extent_offset;
2163 u64 num_bytes;
2164 u64 generation;
2165 };
2166
2167 struct old_sa_defrag_extent {
2168 struct list_head list;
2169 struct new_sa_defrag_extent *new;
2170
2171 u64 extent_offset;
2172 u64 bytenr;
2173 u64 offset;
2174 u64 len;
2175 int count;
2176 };
2177
2178 struct new_sa_defrag_extent {
2179 struct rb_root root;
2180 struct list_head head;
2181 struct btrfs_path *path;
2182 struct inode *inode;
2183 u64 file_pos;
2184 u64 len;
2185 u64 bytenr;
2186 u64 disk_len;
2187 u8 compress_type;
2188 };
2189
2190 static int backref_comp(struct sa_defrag_extent_backref *b1,
2191 struct sa_defrag_extent_backref *b2)
2192 {
2193 if (b1->root_id < b2->root_id)
2194 return -1;
2195 else if (b1->root_id > b2->root_id)
2196 return 1;
2197
2198 if (b1->inum < b2->inum)
2199 return -1;
2200 else if (b1->inum > b2->inum)
2201 return 1;
2202
2203 if (b1->file_pos < b2->file_pos)
2204 return -1;
2205 else if (b1->file_pos > b2->file_pos)
2206 return 1;
2207
2208 /*
2209 * [------------------------------] ===> (a range of space)
2210 * |<--->| |<---->| =============> (fs/file tree A)
2211 * |<---------------------------->| ===> (fs/file tree B)
2212 *
2213 * A range of space can refer to two file extents in one tree while
2214 * refer to only one file extent in another tree.
2215 *
2216 * So we may process a disk offset more than one time(two extents in A)
2217 * and locate at the same extent(one extent in B), then insert two same
2218 * backrefs(both refer to the extent in B).
2219 */
2220 return 0;
2221 }
2222
2223 static void backref_insert(struct rb_root *root,
2224 struct sa_defrag_extent_backref *backref)
2225 {
2226 struct rb_node **p = &root->rb_node;
2227 struct rb_node *parent = NULL;
2228 struct sa_defrag_extent_backref *entry;
2229 int ret;
2230
2231 while (*p) {
2232 parent = *p;
2233 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2234
2235 ret = backref_comp(backref, entry);
2236 if (ret < 0)
2237 p = &(*p)->rb_left;
2238 else
2239 p = &(*p)->rb_right;
2240 }
2241
2242 rb_link_node(&backref->node, parent, p);
2243 rb_insert_color(&backref->node, root);
2244 }
2245
2246 /*
2247 * Note the backref might has changed, and in this case we just return 0.
2248 */
2249 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2250 void *ctx)
2251 {
2252 struct btrfs_file_extent_item *extent;
2253 struct btrfs_fs_info *fs_info;
2254 struct old_sa_defrag_extent *old = ctx;
2255 struct new_sa_defrag_extent *new = old->new;
2256 struct btrfs_path *path = new->path;
2257 struct btrfs_key key;
2258 struct btrfs_root *root;
2259 struct sa_defrag_extent_backref *backref;
2260 struct extent_buffer *leaf;
2261 struct inode *inode = new->inode;
2262 int slot;
2263 int ret;
2264 u64 extent_offset;
2265 u64 num_bytes;
2266
2267 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2268 inum == btrfs_ino(inode))
2269 return 0;
2270
2271 key.objectid = root_id;
2272 key.type = BTRFS_ROOT_ITEM_KEY;
2273 key.offset = (u64)-1;
2274
2275 fs_info = BTRFS_I(inode)->root->fs_info;
2276 root = btrfs_read_fs_root_no_name(fs_info, &key);
2277 if (IS_ERR(root)) {
2278 if (PTR_ERR(root) == -ENOENT)
2279 return 0;
2280 WARN_ON(1);
2281 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2282 inum, offset, root_id);
2283 return PTR_ERR(root);
2284 }
2285
2286 key.objectid = inum;
2287 key.type = BTRFS_EXTENT_DATA_KEY;
2288 if (offset > (u64)-1 << 32)
2289 key.offset = 0;
2290 else
2291 key.offset = offset;
2292
2293 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2294 if (WARN_ON(ret < 0))
2295 return ret;
2296 ret = 0;
2297
2298 while (1) {
2299 cond_resched();
2300
2301 leaf = path->nodes[0];
2302 slot = path->slots[0];
2303
2304 if (slot >= btrfs_header_nritems(leaf)) {
2305 ret = btrfs_next_leaf(root, path);
2306 if (ret < 0) {
2307 goto out;
2308 } else if (ret > 0) {
2309 ret = 0;
2310 goto out;
2311 }
2312 continue;
2313 }
2314
2315 path->slots[0]++;
2316
2317 btrfs_item_key_to_cpu(leaf, &key, slot);
2318
2319 if (key.objectid > inum)
2320 goto out;
2321
2322 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2323 continue;
2324
2325 extent = btrfs_item_ptr(leaf, slot,
2326 struct btrfs_file_extent_item);
2327
2328 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2329 continue;
2330
2331 /*
2332 * 'offset' refers to the exact key.offset,
2333 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2334 * (key.offset - extent_offset).
2335 */
2336 if (key.offset != offset)
2337 continue;
2338
2339 extent_offset = btrfs_file_extent_offset(leaf, extent);
2340 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2341
2342 if (extent_offset >= old->extent_offset + old->offset +
2343 old->len || extent_offset + num_bytes <=
2344 old->extent_offset + old->offset)
2345 continue;
2346 break;
2347 }
2348
2349 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2350 if (!backref) {
2351 ret = -ENOENT;
2352 goto out;
2353 }
2354
2355 backref->root_id = root_id;
2356 backref->inum = inum;
2357 backref->file_pos = offset;
2358 backref->num_bytes = num_bytes;
2359 backref->extent_offset = extent_offset;
2360 backref->generation = btrfs_file_extent_generation(leaf, extent);
2361 backref->old = old;
2362 backref_insert(&new->root, backref);
2363 old->count++;
2364 out:
2365 btrfs_release_path(path);
2366 WARN_ON(ret);
2367 return ret;
2368 }
2369
2370 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2371 struct new_sa_defrag_extent *new)
2372 {
2373 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2374 struct old_sa_defrag_extent *old, *tmp;
2375 int ret;
2376
2377 new->path = path;
2378
2379 list_for_each_entry_safe(old, tmp, &new->head, list) {
2380 ret = iterate_inodes_from_logical(old->bytenr +
2381 old->extent_offset, fs_info,
2382 path, record_one_backref,
2383 old);
2384 if (ret < 0 && ret != -ENOENT)
2385 return false;
2386
2387 /* no backref to be processed for this extent */
2388 if (!old->count) {
2389 list_del(&old->list);
2390 kfree(old);
2391 }
2392 }
2393
2394 if (list_empty(&new->head))
2395 return false;
2396
2397 return true;
2398 }
2399
2400 static int relink_is_mergable(struct extent_buffer *leaf,
2401 struct btrfs_file_extent_item *fi,
2402 struct new_sa_defrag_extent *new)
2403 {
2404 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2405 return 0;
2406
2407 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2408 return 0;
2409
2410 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2411 return 0;
2412
2413 if (btrfs_file_extent_encryption(leaf, fi) ||
2414 btrfs_file_extent_other_encoding(leaf, fi))
2415 return 0;
2416
2417 return 1;
2418 }
2419
2420 /*
2421 * Note the backref might has changed, and in this case we just return 0.
2422 */
2423 static noinline int relink_extent_backref(struct btrfs_path *path,
2424 struct sa_defrag_extent_backref *prev,
2425 struct sa_defrag_extent_backref *backref)
2426 {
2427 struct btrfs_file_extent_item *extent;
2428 struct btrfs_file_extent_item *item;
2429 struct btrfs_ordered_extent *ordered;
2430 struct btrfs_trans_handle *trans;
2431 struct btrfs_fs_info *fs_info;
2432 struct btrfs_root *root;
2433 struct btrfs_key key;
2434 struct extent_buffer *leaf;
2435 struct old_sa_defrag_extent *old = backref->old;
2436 struct new_sa_defrag_extent *new = old->new;
2437 struct inode *src_inode = new->inode;
2438 struct inode *inode;
2439 struct extent_state *cached = NULL;
2440 int ret = 0;
2441 u64 start;
2442 u64 len;
2443 u64 lock_start;
2444 u64 lock_end;
2445 bool merge = false;
2446 int index;
2447
2448 if (prev && prev->root_id == backref->root_id &&
2449 prev->inum == backref->inum &&
2450 prev->file_pos + prev->num_bytes == backref->file_pos)
2451 merge = true;
2452
2453 /* step 1: get root */
2454 key.objectid = backref->root_id;
2455 key.type = BTRFS_ROOT_ITEM_KEY;
2456 key.offset = (u64)-1;
2457
2458 fs_info = BTRFS_I(src_inode)->root->fs_info;
2459 index = srcu_read_lock(&fs_info->subvol_srcu);
2460
2461 root = btrfs_read_fs_root_no_name(fs_info, &key);
2462 if (IS_ERR(root)) {
2463 srcu_read_unlock(&fs_info->subvol_srcu, index);
2464 if (PTR_ERR(root) == -ENOENT)
2465 return 0;
2466 return PTR_ERR(root);
2467 }
2468
2469 if (btrfs_root_readonly(root)) {
2470 srcu_read_unlock(&fs_info->subvol_srcu, index);
2471 return 0;
2472 }
2473
2474 /* step 2: get inode */
2475 key.objectid = backref->inum;
2476 key.type = BTRFS_INODE_ITEM_KEY;
2477 key.offset = 0;
2478
2479 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2480 if (IS_ERR(inode)) {
2481 srcu_read_unlock(&fs_info->subvol_srcu, index);
2482 return 0;
2483 }
2484
2485 srcu_read_unlock(&fs_info->subvol_srcu, index);
2486
2487 /* step 3: relink backref */
2488 lock_start = backref->file_pos;
2489 lock_end = backref->file_pos + backref->num_bytes - 1;
2490 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2491 &cached);
2492
2493 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2494 if (ordered) {
2495 btrfs_put_ordered_extent(ordered);
2496 goto out_unlock;
2497 }
2498
2499 trans = btrfs_join_transaction(root);
2500 if (IS_ERR(trans)) {
2501 ret = PTR_ERR(trans);
2502 goto out_unlock;
2503 }
2504
2505 key.objectid = backref->inum;
2506 key.type = BTRFS_EXTENT_DATA_KEY;
2507 key.offset = backref->file_pos;
2508
2509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2510 if (ret < 0) {
2511 goto out_free_path;
2512 } else if (ret > 0) {
2513 ret = 0;
2514 goto out_free_path;
2515 }
2516
2517 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2518 struct btrfs_file_extent_item);
2519
2520 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2521 backref->generation)
2522 goto out_free_path;
2523
2524 btrfs_release_path(path);
2525
2526 start = backref->file_pos;
2527 if (backref->extent_offset < old->extent_offset + old->offset)
2528 start += old->extent_offset + old->offset -
2529 backref->extent_offset;
2530
2531 len = min(backref->extent_offset + backref->num_bytes,
2532 old->extent_offset + old->offset + old->len);
2533 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2534
2535 ret = btrfs_drop_extents(trans, root, inode, start,
2536 start + len, 1);
2537 if (ret)
2538 goto out_free_path;
2539 again:
2540 key.objectid = btrfs_ino(inode);
2541 key.type = BTRFS_EXTENT_DATA_KEY;
2542 key.offset = start;
2543
2544 path->leave_spinning = 1;
2545 if (merge) {
2546 struct btrfs_file_extent_item *fi;
2547 u64 extent_len;
2548 struct btrfs_key found_key;
2549
2550 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2551 if (ret < 0)
2552 goto out_free_path;
2553
2554 path->slots[0]--;
2555 leaf = path->nodes[0];
2556 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2557
2558 fi = btrfs_item_ptr(leaf, path->slots[0],
2559 struct btrfs_file_extent_item);
2560 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2561
2562 if (extent_len + found_key.offset == start &&
2563 relink_is_mergable(leaf, fi, new)) {
2564 btrfs_set_file_extent_num_bytes(leaf, fi,
2565 extent_len + len);
2566 btrfs_mark_buffer_dirty(leaf);
2567 inode_add_bytes(inode, len);
2568
2569 ret = 1;
2570 goto out_free_path;
2571 } else {
2572 merge = false;
2573 btrfs_release_path(path);
2574 goto again;
2575 }
2576 }
2577
2578 ret = btrfs_insert_empty_item(trans, root, path, &key,
2579 sizeof(*extent));
2580 if (ret) {
2581 btrfs_abort_transaction(trans, root, ret);
2582 goto out_free_path;
2583 }
2584
2585 leaf = path->nodes[0];
2586 item = btrfs_item_ptr(leaf, path->slots[0],
2587 struct btrfs_file_extent_item);
2588 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2589 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2590 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2591 btrfs_set_file_extent_num_bytes(leaf, item, len);
2592 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2593 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2594 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2595 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2596 btrfs_set_file_extent_encryption(leaf, item, 0);
2597 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2598
2599 btrfs_mark_buffer_dirty(leaf);
2600 inode_add_bytes(inode, len);
2601 btrfs_release_path(path);
2602
2603 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2604 new->disk_len, 0,
2605 backref->root_id, backref->inum,
2606 new->file_pos); /* start - extent_offset */
2607 if (ret) {
2608 btrfs_abort_transaction(trans, root, ret);
2609 goto out_free_path;
2610 }
2611
2612 ret = 1;
2613 out_free_path:
2614 btrfs_release_path(path);
2615 path->leave_spinning = 0;
2616 btrfs_end_transaction(trans, root);
2617 out_unlock:
2618 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2619 &cached, GFP_NOFS);
2620 iput(inode);
2621 return ret;
2622 }
2623
2624 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2625 {
2626 struct old_sa_defrag_extent *old, *tmp;
2627
2628 if (!new)
2629 return;
2630
2631 list_for_each_entry_safe(old, tmp, &new->head, list) {
2632 kfree(old);
2633 }
2634 kfree(new);
2635 }
2636
2637 static void relink_file_extents(struct new_sa_defrag_extent *new)
2638 {
2639 struct btrfs_path *path;
2640 struct sa_defrag_extent_backref *backref;
2641 struct sa_defrag_extent_backref *prev = NULL;
2642 struct inode *inode;
2643 struct btrfs_root *root;
2644 struct rb_node *node;
2645 int ret;
2646
2647 inode = new->inode;
2648 root = BTRFS_I(inode)->root;
2649
2650 path = btrfs_alloc_path();
2651 if (!path)
2652 return;
2653
2654 if (!record_extent_backrefs(path, new)) {
2655 btrfs_free_path(path);
2656 goto out;
2657 }
2658 btrfs_release_path(path);
2659
2660 while (1) {
2661 node = rb_first(&new->root);
2662 if (!node)
2663 break;
2664 rb_erase(node, &new->root);
2665
2666 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2667
2668 ret = relink_extent_backref(path, prev, backref);
2669 WARN_ON(ret < 0);
2670
2671 kfree(prev);
2672
2673 if (ret == 1)
2674 prev = backref;
2675 else
2676 prev = NULL;
2677 cond_resched();
2678 }
2679 kfree(prev);
2680
2681 btrfs_free_path(path);
2682 out:
2683 free_sa_defrag_extent(new);
2684
2685 atomic_dec(&root->fs_info->defrag_running);
2686 wake_up(&root->fs_info->transaction_wait);
2687 }
2688
2689 static struct new_sa_defrag_extent *
2690 record_old_file_extents(struct inode *inode,
2691 struct btrfs_ordered_extent *ordered)
2692 {
2693 struct btrfs_root *root = BTRFS_I(inode)->root;
2694 struct btrfs_path *path;
2695 struct btrfs_key key;
2696 struct old_sa_defrag_extent *old;
2697 struct new_sa_defrag_extent *new;
2698 int ret;
2699
2700 new = kmalloc(sizeof(*new), GFP_NOFS);
2701 if (!new)
2702 return NULL;
2703
2704 new->inode = inode;
2705 new->file_pos = ordered->file_offset;
2706 new->len = ordered->len;
2707 new->bytenr = ordered->start;
2708 new->disk_len = ordered->disk_len;
2709 new->compress_type = ordered->compress_type;
2710 new->root = RB_ROOT;
2711 INIT_LIST_HEAD(&new->head);
2712
2713 path = btrfs_alloc_path();
2714 if (!path)
2715 goto out_kfree;
2716
2717 key.objectid = btrfs_ino(inode);
2718 key.type = BTRFS_EXTENT_DATA_KEY;
2719 key.offset = new->file_pos;
2720
2721 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2722 if (ret < 0)
2723 goto out_free_path;
2724 if (ret > 0 && path->slots[0] > 0)
2725 path->slots[0]--;
2726
2727 /* find out all the old extents for the file range */
2728 while (1) {
2729 struct btrfs_file_extent_item *extent;
2730 struct extent_buffer *l;
2731 int slot;
2732 u64 num_bytes;
2733 u64 offset;
2734 u64 end;
2735 u64 disk_bytenr;
2736 u64 extent_offset;
2737
2738 l = path->nodes[0];
2739 slot = path->slots[0];
2740
2741 if (slot >= btrfs_header_nritems(l)) {
2742 ret = btrfs_next_leaf(root, path);
2743 if (ret < 0)
2744 goto out_free_path;
2745 else if (ret > 0)
2746 break;
2747 continue;
2748 }
2749
2750 btrfs_item_key_to_cpu(l, &key, slot);
2751
2752 if (key.objectid != btrfs_ino(inode))
2753 break;
2754 if (key.type != BTRFS_EXTENT_DATA_KEY)
2755 break;
2756 if (key.offset >= new->file_pos + new->len)
2757 break;
2758
2759 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2760
2761 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2762 if (key.offset + num_bytes < new->file_pos)
2763 goto next;
2764
2765 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2766 if (!disk_bytenr)
2767 goto next;
2768
2769 extent_offset = btrfs_file_extent_offset(l, extent);
2770
2771 old = kmalloc(sizeof(*old), GFP_NOFS);
2772 if (!old)
2773 goto out_free_path;
2774
2775 offset = max(new->file_pos, key.offset);
2776 end = min(new->file_pos + new->len, key.offset + num_bytes);
2777
2778 old->bytenr = disk_bytenr;
2779 old->extent_offset = extent_offset;
2780 old->offset = offset - key.offset;
2781 old->len = end - offset;
2782 old->new = new;
2783 old->count = 0;
2784 list_add_tail(&old->list, &new->head);
2785 next:
2786 path->slots[0]++;
2787 cond_resched();
2788 }
2789
2790 btrfs_free_path(path);
2791 atomic_inc(&root->fs_info->defrag_running);
2792
2793 return new;
2794
2795 out_free_path:
2796 btrfs_free_path(path);
2797 out_kfree:
2798 free_sa_defrag_extent(new);
2799 return NULL;
2800 }
2801
2802 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2803 u64 start, u64 len)
2804 {
2805 struct btrfs_block_group_cache *cache;
2806
2807 cache = btrfs_lookup_block_group(root->fs_info, start);
2808 ASSERT(cache);
2809
2810 spin_lock(&cache->lock);
2811 cache->delalloc_bytes -= len;
2812 spin_unlock(&cache->lock);
2813
2814 btrfs_put_block_group(cache);
2815 }
2816
2817 /* as ordered data IO finishes, this gets called so we can finish
2818 * an ordered extent if the range of bytes in the file it covers are
2819 * fully written.
2820 */
2821 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2822 {
2823 struct inode *inode = ordered_extent->inode;
2824 struct btrfs_root *root = BTRFS_I(inode)->root;
2825 struct btrfs_trans_handle *trans = NULL;
2826 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2827 struct extent_state *cached_state = NULL;
2828 struct new_sa_defrag_extent *new = NULL;
2829 int compress_type = 0;
2830 int ret = 0;
2831 u64 logical_len = ordered_extent->len;
2832 bool nolock;
2833 bool truncated = false;
2834
2835 nolock = btrfs_is_free_space_inode(inode);
2836
2837 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2838 ret = -EIO;
2839 goto out;
2840 }
2841
2842 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2843 ordered_extent->file_offset +
2844 ordered_extent->len - 1);
2845
2846 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2847 truncated = true;
2848 logical_len = ordered_extent->truncated_len;
2849 /* Truncated the entire extent, don't bother adding */
2850 if (!logical_len)
2851 goto out;
2852 }
2853
2854 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2855 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2856
2857 /*
2858 * For mwrite(mmap + memset to write) case, we still reserve
2859 * space for NOCOW range.
2860 * As NOCOW won't cause a new delayed ref, just free the space
2861 */
2862 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2863 ordered_extent->len);
2864 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2865 if (nolock)
2866 trans = btrfs_join_transaction_nolock(root);
2867 else
2868 trans = btrfs_join_transaction(root);
2869 if (IS_ERR(trans)) {
2870 ret = PTR_ERR(trans);
2871 trans = NULL;
2872 goto out;
2873 }
2874 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2875 ret = btrfs_update_inode_fallback(trans, root, inode);
2876 if (ret) /* -ENOMEM or corruption */
2877 btrfs_abort_transaction(trans, root, ret);
2878 goto out;
2879 }
2880
2881 lock_extent_bits(io_tree, ordered_extent->file_offset,
2882 ordered_extent->file_offset + ordered_extent->len - 1,
2883 &cached_state);
2884
2885 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2886 ordered_extent->file_offset + ordered_extent->len - 1,
2887 EXTENT_DEFRAG, 1, cached_state);
2888 if (ret) {
2889 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2890 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2891 /* the inode is shared */
2892 new = record_old_file_extents(inode, ordered_extent);
2893
2894 clear_extent_bit(io_tree, ordered_extent->file_offset,
2895 ordered_extent->file_offset + ordered_extent->len - 1,
2896 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2897 }
2898
2899 if (nolock)
2900 trans = btrfs_join_transaction_nolock(root);
2901 else
2902 trans = btrfs_join_transaction(root);
2903 if (IS_ERR(trans)) {
2904 ret = PTR_ERR(trans);
2905 trans = NULL;
2906 goto out_unlock;
2907 }
2908
2909 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2910
2911 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2912 compress_type = ordered_extent->compress_type;
2913 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2914 BUG_ON(compress_type);
2915 ret = btrfs_mark_extent_written(trans, inode,
2916 ordered_extent->file_offset,
2917 ordered_extent->file_offset +
2918 logical_len);
2919 } else {
2920 BUG_ON(root == root->fs_info->tree_root);
2921 ret = insert_reserved_file_extent(trans, inode,
2922 ordered_extent->file_offset,
2923 ordered_extent->start,
2924 ordered_extent->disk_len,
2925 logical_len, logical_len,
2926 compress_type, 0, 0,
2927 BTRFS_FILE_EXTENT_REG);
2928 if (!ret)
2929 btrfs_release_delalloc_bytes(root,
2930 ordered_extent->start,
2931 ordered_extent->disk_len);
2932 }
2933 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2934 ordered_extent->file_offset, ordered_extent->len,
2935 trans->transid);
2936 if (ret < 0) {
2937 btrfs_abort_transaction(trans, root, ret);
2938 goto out_unlock;
2939 }
2940
2941 add_pending_csums(trans, inode, ordered_extent->file_offset,
2942 &ordered_extent->list);
2943
2944 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2945 ret = btrfs_update_inode_fallback(trans, root, inode);
2946 if (ret) { /* -ENOMEM or corruption */
2947 btrfs_abort_transaction(trans, root, ret);
2948 goto out_unlock;
2949 }
2950 ret = 0;
2951 out_unlock:
2952 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2953 ordered_extent->file_offset +
2954 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2955 out:
2956 if (root != root->fs_info->tree_root)
2957 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2958 if (trans)
2959 btrfs_end_transaction(trans, root);
2960
2961 if (ret || truncated) {
2962 u64 start, end;
2963
2964 if (truncated)
2965 start = ordered_extent->file_offset + logical_len;
2966 else
2967 start = ordered_extent->file_offset;
2968 end = ordered_extent->file_offset + ordered_extent->len - 1;
2969 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2970
2971 /* Drop the cache for the part of the extent we didn't write. */
2972 btrfs_drop_extent_cache(inode, start, end, 0);
2973
2974 /*
2975 * If the ordered extent had an IOERR or something else went
2976 * wrong we need to return the space for this ordered extent
2977 * back to the allocator. We only free the extent in the
2978 * truncated case if we didn't write out the extent at all.
2979 */
2980 if ((ret || !logical_len) &&
2981 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2982 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2983 btrfs_free_reserved_extent(root, ordered_extent->start,
2984 ordered_extent->disk_len, 1);
2985 }
2986
2987
2988 /*
2989 * This needs to be done to make sure anybody waiting knows we are done
2990 * updating everything for this ordered extent.
2991 */
2992 btrfs_remove_ordered_extent(inode, ordered_extent);
2993
2994 /* for snapshot-aware defrag */
2995 if (new) {
2996 if (ret) {
2997 free_sa_defrag_extent(new);
2998 atomic_dec(&root->fs_info->defrag_running);
2999 } else {
3000 relink_file_extents(new);
3001 }
3002 }
3003
3004 /* once for us */
3005 btrfs_put_ordered_extent(ordered_extent);
3006 /* once for the tree */
3007 btrfs_put_ordered_extent(ordered_extent);
3008
3009 return ret;
3010 }
3011
3012 static void finish_ordered_fn(struct btrfs_work *work)
3013 {
3014 struct btrfs_ordered_extent *ordered_extent;
3015 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3016 btrfs_finish_ordered_io(ordered_extent);
3017 }
3018
3019 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3020 struct extent_state *state, int uptodate)
3021 {
3022 struct inode *inode = page->mapping->host;
3023 struct btrfs_root *root = BTRFS_I(inode)->root;
3024 struct btrfs_ordered_extent *ordered_extent = NULL;
3025 struct btrfs_workqueue *wq;
3026 btrfs_work_func_t func;
3027
3028 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3029
3030 ClearPagePrivate2(page);
3031 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3032 end - start + 1, uptodate))
3033 return 0;
3034
3035 if (btrfs_is_free_space_inode(inode)) {
3036 wq = root->fs_info->endio_freespace_worker;
3037 func = btrfs_freespace_write_helper;
3038 } else {
3039 wq = root->fs_info->endio_write_workers;
3040 func = btrfs_endio_write_helper;
3041 }
3042
3043 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3044 NULL);
3045 btrfs_queue_work(wq, &ordered_extent->work);
3046
3047 return 0;
3048 }
3049
3050 static int __readpage_endio_check(struct inode *inode,
3051 struct btrfs_io_bio *io_bio,
3052 int icsum, struct page *page,
3053 int pgoff, u64 start, size_t len)
3054 {
3055 char *kaddr;
3056 u32 csum_expected;
3057 u32 csum = ~(u32)0;
3058
3059 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3060
3061 kaddr = kmap_atomic(page);
3062 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3063 btrfs_csum_final(csum, (char *)&csum);
3064 if (csum != csum_expected)
3065 goto zeroit;
3066
3067 kunmap_atomic(kaddr);
3068 return 0;
3069 zeroit:
3070 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3071 "csum failed ino %llu off %llu csum %u expected csum %u",
3072 btrfs_ino(inode), start, csum, csum_expected);
3073 memset(kaddr + pgoff, 1, len);
3074 flush_dcache_page(page);
3075 kunmap_atomic(kaddr);
3076 if (csum_expected == 0)
3077 return 0;
3078 return -EIO;
3079 }
3080
3081 /*
3082 * when reads are done, we need to check csums to verify the data is correct
3083 * if there's a match, we allow the bio to finish. If not, the code in
3084 * extent_io.c will try to find good copies for us.
3085 */
3086 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3087 u64 phy_offset, struct page *page,
3088 u64 start, u64 end, int mirror)
3089 {
3090 size_t offset = start - page_offset(page);
3091 struct inode *inode = page->mapping->host;
3092 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3093 struct btrfs_root *root = BTRFS_I(inode)->root;
3094
3095 if (PageChecked(page)) {
3096 ClearPageChecked(page);
3097 return 0;
3098 }
3099
3100 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3101 return 0;
3102
3103 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3104 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3105 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3106 GFP_NOFS);
3107 return 0;
3108 }
3109
3110 phy_offset >>= inode->i_sb->s_blocksize_bits;
3111 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3112 start, (size_t)(end - start + 1));
3113 }
3114
3115 void btrfs_add_delayed_iput(struct inode *inode)
3116 {
3117 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3118 struct btrfs_inode *binode = BTRFS_I(inode);
3119
3120 if (atomic_add_unless(&inode->i_count, -1, 1))
3121 return;
3122
3123 spin_lock(&fs_info->delayed_iput_lock);
3124 if (binode->delayed_iput_count == 0) {
3125 ASSERT(list_empty(&binode->delayed_iput));
3126 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3127 } else {
3128 binode->delayed_iput_count++;
3129 }
3130 spin_unlock(&fs_info->delayed_iput_lock);
3131 }
3132
3133 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3134 {
3135 struct btrfs_fs_info *fs_info = root->fs_info;
3136
3137 down_read(&fs_info->delayed_iput_sem);
3138 spin_lock(&fs_info->delayed_iput_lock);
3139 while (!list_empty(&fs_info->delayed_iputs)) {
3140 struct btrfs_inode *inode;
3141
3142 inode = list_first_entry(&fs_info->delayed_iputs,
3143 struct btrfs_inode, delayed_iput);
3144 if (inode->delayed_iput_count) {
3145 inode->delayed_iput_count--;
3146 list_move_tail(&inode->delayed_iput,
3147 &fs_info->delayed_iputs);
3148 } else {
3149 list_del_init(&inode->delayed_iput);
3150 }
3151 spin_unlock(&fs_info->delayed_iput_lock);
3152 iput(&inode->vfs_inode);
3153 spin_lock(&fs_info->delayed_iput_lock);
3154 }
3155 spin_unlock(&fs_info->delayed_iput_lock);
3156 up_read(&root->fs_info->delayed_iput_sem);
3157 }
3158
3159 /*
3160 * This is called in transaction commit time. If there are no orphan
3161 * files in the subvolume, it removes orphan item and frees block_rsv
3162 * structure.
3163 */
3164 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3165 struct btrfs_root *root)
3166 {
3167 struct btrfs_block_rsv *block_rsv;
3168 int ret;
3169
3170 if (atomic_read(&root->orphan_inodes) ||
3171 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3172 return;
3173
3174 spin_lock(&root->orphan_lock);
3175 if (atomic_read(&root->orphan_inodes)) {
3176 spin_unlock(&root->orphan_lock);
3177 return;
3178 }
3179
3180 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3181 spin_unlock(&root->orphan_lock);
3182 return;
3183 }
3184
3185 block_rsv = root->orphan_block_rsv;
3186 root->orphan_block_rsv = NULL;
3187 spin_unlock(&root->orphan_lock);
3188
3189 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3190 btrfs_root_refs(&root->root_item) > 0) {
3191 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3192 root->root_key.objectid);
3193 if (ret)
3194 btrfs_abort_transaction(trans, root, ret);
3195 else
3196 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3197 &root->state);
3198 }
3199
3200 if (block_rsv) {
3201 WARN_ON(block_rsv->size > 0);
3202 btrfs_free_block_rsv(root, block_rsv);
3203 }
3204 }
3205
3206 /*
3207 * This creates an orphan entry for the given inode in case something goes
3208 * wrong in the middle of an unlink/truncate.
3209 *
3210 * NOTE: caller of this function should reserve 5 units of metadata for
3211 * this function.
3212 */
3213 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3214 {
3215 struct btrfs_root *root = BTRFS_I(inode)->root;
3216 struct btrfs_block_rsv *block_rsv = NULL;
3217 int reserve = 0;
3218 int insert = 0;
3219 int ret;
3220
3221 if (!root->orphan_block_rsv) {
3222 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3223 if (!block_rsv)
3224 return -ENOMEM;
3225 }
3226
3227 spin_lock(&root->orphan_lock);
3228 if (!root->orphan_block_rsv) {
3229 root->orphan_block_rsv = block_rsv;
3230 } else if (block_rsv) {
3231 btrfs_free_block_rsv(root, block_rsv);
3232 block_rsv = NULL;
3233 }
3234
3235 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3236 &BTRFS_I(inode)->runtime_flags)) {
3237 #if 0
3238 /*
3239 * For proper ENOSPC handling, we should do orphan
3240 * cleanup when mounting. But this introduces backward
3241 * compatibility issue.
3242 */
3243 if (!xchg(&root->orphan_item_inserted, 1))
3244 insert = 2;
3245 else
3246 insert = 1;
3247 #endif
3248 insert = 1;
3249 atomic_inc(&root->orphan_inodes);
3250 }
3251
3252 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3253 &BTRFS_I(inode)->runtime_flags))
3254 reserve = 1;
3255 spin_unlock(&root->orphan_lock);
3256
3257 /* grab metadata reservation from transaction handle */
3258 if (reserve) {
3259 ret = btrfs_orphan_reserve_metadata(trans, inode);
3260 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3261 }
3262
3263 /* insert an orphan item to track this unlinked/truncated file */
3264 if (insert >= 1) {
3265 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3266 if (ret) {
3267 atomic_dec(&root->orphan_inodes);
3268 if (reserve) {
3269 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3270 &BTRFS_I(inode)->runtime_flags);
3271 btrfs_orphan_release_metadata(inode);
3272 }
3273 if (ret != -EEXIST) {
3274 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3275 &BTRFS_I(inode)->runtime_flags);
3276 btrfs_abort_transaction(trans, root, ret);
3277 return ret;
3278 }
3279 }
3280 ret = 0;
3281 }
3282
3283 /* insert an orphan item to track subvolume contains orphan files */
3284 if (insert >= 2) {
3285 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3286 root->root_key.objectid);
3287 if (ret && ret != -EEXIST) {
3288 btrfs_abort_transaction(trans, root, ret);
3289 return ret;
3290 }
3291 }
3292 return 0;
3293 }
3294
3295 /*
3296 * We have done the truncate/delete so we can go ahead and remove the orphan
3297 * item for this particular inode.
3298 */
3299 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3300 struct inode *inode)
3301 {
3302 struct btrfs_root *root = BTRFS_I(inode)->root;
3303 int delete_item = 0;
3304 int release_rsv = 0;
3305 int ret = 0;
3306
3307 spin_lock(&root->orphan_lock);
3308 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3309 &BTRFS_I(inode)->runtime_flags))
3310 delete_item = 1;
3311
3312 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3313 &BTRFS_I(inode)->runtime_flags))
3314 release_rsv = 1;
3315 spin_unlock(&root->orphan_lock);
3316
3317 if (delete_item) {
3318 atomic_dec(&root->orphan_inodes);
3319 if (trans)
3320 ret = btrfs_del_orphan_item(trans, root,
3321 btrfs_ino(inode));
3322 }
3323
3324 if (release_rsv)
3325 btrfs_orphan_release_metadata(inode);
3326
3327 return ret;
3328 }
3329
3330 /*
3331 * this cleans up any orphans that may be left on the list from the last use
3332 * of this root.
3333 */
3334 int btrfs_orphan_cleanup(struct btrfs_root *root)
3335 {
3336 struct btrfs_path *path;
3337 struct extent_buffer *leaf;
3338 struct btrfs_key key, found_key;
3339 struct btrfs_trans_handle *trans;
3340 struct inode *inode;
3341 u64 last_objectid = 0;
3342 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3343
3344 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3345 return 0;
3346
3347 path = btrfs_alloc_path();
3348 if (!path) {
3349 ret = -ENOMEM;
3350 goto out;
3351 }
3352 path->reada = READA_BACK;
3353
3354 key.objectid = BTRFS_ORPHAN_OBJECTID;
3355 key.type = BTRFS_ORPHAN_ITEM_KEY;
3356 key.offset = (u64)-1;
3357
3358 while (1) {
3359 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3360 if (ret < 0)
3361 goto out;
3362
3363 /*
3364 * if ret == 0 means we found what we were searching for, which
3365 * is weird, but possible, so only screw with path if we didn't
3366 * find the key and see if we have stuff that matches
3367 */
3368 if (ret > 0) {
3369 ret = 0;
3370 if (path->slots[0] == 0)
3371 break;
3372 path->slots[0]--;
3373 }
3374
3375 /* pull out the item */
3376 leaf = path->nodes[0];
3377 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3378
3379 /* make sure the item matches what we want */
3380 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3381 break;
3382 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3383 break;
3384
3385 /* release the path since we're done with it */
3386 btrfs_release_path(path);
3387
3388 /*
3389 * this is where we are basically btrfs_lookup, without the
3390 * crossing root thing. we store the inode number in the
3391 * offset of the orphan item.
3392 */
3393
3394 if (found_key.offset == last_objectid) {
3395 btrfs_err(root->fs_info,
3396 "Error removing orphan entry, stopping orphan cleanup");
3397 ret = -EINVAL;
3398 goto out;
3399 }
3400
3401 last_objectid = found_key.offset;
3402
3403 found_key.objectid = found_key.offset;
3404 found_key.type = BTRFS_INODE_ITEM_KEY;
3405 found_key.offset = 0;
3406 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3407 ret = PTR_ERR_OR_ZERO(inode);
3408 if (ret && ret != -ESTALE)
3409 goto out;
3410
3411 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3412 struct btrfs_root *dead_root;
3413 struct btrfs_fs_info *fs_info = root->fs_info;
3414 int is_dead_root = 0;
3415
3416 /*
3417 * this is an orphan in the tree root. Currently these
3418 * could come from 2 sources:
3419 * a) a snapshot deletion in progress
3420 * b) a free space cache inode
3421 * We need to distinguish those two, as the snapshot
3422 * orphan must not get deleted.
3423 * find_dead_roots already ran before us, so if this
3424 * is a snapshot deletion, we should find the root
3425 * in the dead_roots list
3426 */
3427 spin_lock(&fs_info->trans_lock);
3428 list_for_each_entry(dead_root, &fs_info->dead_roots,
3429 root_list) {
3430 if (dead_root->root_key.objectid ==
3431 found_key.objectid) {
3432 is_dead_root = 1;
3433 break;
3434 }
3435 }
3436 spin_unlock(&fs_info->trans_lock);
3437 if (is_dead_root) {
3438 /* prevent this orphan from being found again */
3439 key.offset = found_key.objectid - 1;
3440 continue;
3441 }
3442 }
3443 /*
3444 * Inode is already gone but the orphan item is still there,
3445 * kill the orphan item.
3446 */
3447 if (ret == -ESTALE) {
3448 trans = btrfs_start_transaction(root, 1);
3449 if (IS_ERR(trans)) {
3450 ret = PTR_ERR(trans);
3451 goto out;
3452 }
3453 btrfs_debug(root->fs_info, "auto deleting %Lu",
3454 found_key.objectid);
3455 ret = btrfs_del_orphan_item(trans, root,
3456 found_key.objectid);
3457 btrfs_end_transaction(trans, root);
3458 if (ret)
3459 goto out;
3460 continue;
3461 }
3462
3463 /*
3464 * add this inode to the orphan list so btrfs_orphan_del does
3465 * the proper thing when we hit it
3466 */
3467 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3468 &BTRFS_I(inode)->runtime_flags);
3469 atomic_inc(&root->orphan_inodes);
3470
3471 /* if we have links, this was a truncate, lets do that */
3472 if (inode->i_nlink) {
3473 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3474 iput(inode);
3475 continue;
3476 }
3477 nr_truncate++;
3478
3479 /* 1 for the orphan item deletion. */
3480 trans = btrfs_start_transaction(root, 1);
3481 if (IS_ERR(trans)) {
3482 iput(inode);
3483 ret = PTR_ERR(trans);
3484 goto out;
3485 }
3486 ret = btrfs_orphan_add(trans, inode);
3487 btrfs_end_transaction(trans, root);
3488 if (ret) {
3489 iput(inode);
3490 goto out;
3491 }
3492
3493 ret = btrfs_truncate(inode);
3494 if (ret)
3495 btrfs_orphan_del(NULL, inode);
3496 } else {
3497 nr_unlink++;
3498 }
3499
3500 /* this will do delete_inode and everything for us */
3501 iput(inode);
3502 if (ret)
3503 goto out;
3504 }
3505 /* release the path since we're done with it */
3506 btrfs_release_path(path);
3507
3508 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3509
3510 if (root->orphan_block_rsv)
3511 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3512 (u64)-1);
3513
3514 if (root->orphan_block_rsv ||
3515 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3516 trans = btrfs_join_transaction(root);
3517 if (!IS_ERR(trans))
3518 btrfs_end_transaction(trans, root);
3519 }
3520
3521 if (nr_unlink)
3522 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3523 if (nr_truncate)
3524 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3525
3526 out:
3527 if (ret)
3528 btrfs_err(root->fs_info,
3529 "could not do orphan cleanup %d", ret);
3530 btrfs_free_path(path);
3531 return ret;
3532 }
3533
3534 /*
3535 * very simple check to peek ahead in the leaf looking for xattrs. If we
3536 * don't find any xattrs, we know there can't be any acls.
3537 *
3538 * slot is the slot the inode is in, objectid is the objectid of the inode
3539 */
3540 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3541 int slot, u64 objectid,
3542 int *first_xattr_slot)
3543 {
3544 u32 nritems = btrfs_header_nritems(leaf);
3545 struct btrfs_key found_key;
3546 static u64 xattr_access = 0;
3547 static u64 xattr_default = 0;
3548 int scanned = 0;
3549
3550 if (!xattr_access) {
3551 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3552 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3553 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3554 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3555 }
3556
3557 slot++;
3558 *first_xattr_slot = -1;
3559 while (slot < nritems) {
3560 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3561
3562 /* we found a different objectid, there must not be acls */
3563 if (found_key.objectid != objectid)
3564 return 0;
3565
3566 /* we found an xattr, assume we've got an acl */
3567 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3568 if (*first_xattr_slot == -1)
3569 *first_xattr_slot = slot;
3570 if (found_key.offset == xattr_access ||
3571 found_key.offset == xattr_default)
3572 return 1;
3573 }
3574
3575 /*
3576 * we found a key greater than an xattr key, there can't
3577 * be any acls later on
3578 */
3579 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3580 return 0;
3581
3582 slot++;
3583 scanned++;
3584
3585 /*
3586 * it goes inode, inode backrefs, xattrs, extents,
3587 * so if there are a ton of hard links to an inode there can
3588 * be a lot of backrefs. Don't waste time searching too hard,
3589 * this is just an optimization
3590 */
3591 if (scanned >= 8)
3592 break;
3593 }
3594 /* we hit the end of the leaf before we found an xattr or
3595 * something larger than an xattr. We have to assume the inode
3596 * has acls
3597 */
3598 if (*first_xattr_slot == -1)
3599 *first_xattr_slot = slot;
3600 return 1;
3601 }
3602
3603 /*
3604 * read an inode from the btree into the in-memory inode
3605 */
3606 static void btrfs_read_locked_inode(struct inode *inode)
3607 {
3608 struct btrfs_path *path;
3609 struct extent_buffer *leaf;
3610 struct btrfs_inode_item *inode_item;
3611 struct btrfs_root *root = BTRFS_I(inode)->root;
3612 struct btrfs_key location;
3613 unsigned long ptr;
3614 int maybe_acls;
3615 u32 rdev;
3616 int ret;
3617 bool filled = false;
3618 int first_xattr_slot;
3619
3620 ret = btrfs_fill_inode(inode, &rdev);
3621 if (!ret)
3622 filled = true;
3623
3624 path = btrfs_alloc_path();
3625 if (!path)
3626 goto make_bad;
3627
3628 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3629
3630 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3631 if (ret)
3632 goto make_bad;
3633
3634 leaf = path->nodes[0];
3635
3636 if (filled)
3637 goto cache_index;
3638
3639 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3640 struct btrfs_inode_item);
3641 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3642 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3643 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3644 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3645 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3646
3647 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3648 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3649
3650 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3651 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3652
3653 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3654 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3655
3656 BTRFS_I(inode)->i_otime.tv_sec =
3657 btrfs_timespec_sec(leaf, &inode_item->otime);
3658 BTRFS_I(inode)->i_otime.tv_nsec =
3659 btrfs_timespec_nsec(leaf, &inode_item->otime);
3660
3661 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3662 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3663 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3664
3665 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3666 inode->i_generation = BTRFS_I(inode)->generation;
3667 inode->i_rdev = 0;
3668 rdev = btrfs_inode_rdev(leaf, inode_item);
3669
3670 BTRFS_I(inode)->index_cnt = (u64)-1;
3671 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3672
3673 cache_index:
3674 /*
3675 * If we were modified in the current generation and evicted from memory
3676 * and then re-read we need to do a full sync since we don't have any
3677 * idea about which extents were modified before we were evicted from
3678 * cache.
3679 *
3680 * This is required for both inode re-read from disk and delayed inode
3681 * in delayed_nodes_tree.
3682 */
3683 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3684 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3685 &BTRFS_I(inode)->runtime_flags);
3686
3687 /*
3688 * We don't persist the id of the transaction where an unlink operation
3689 * against the inode was last made. So here we assume the inode might
3690 * have been evicted, and therefore the exact value of last_unlink_trans
3691 * lost, and set it to last_trans to avoid metadata inconsistencies
3692 * between the inode and its parent if the inode is fsync'ed and the log
3693 * replayed. For example, in the scenario:
3694 *
3695 * touch mydir/foo
3696 * ln mydir/foo mydir/bar
3697 * sync
3698 * unlink mydir/bar
3699 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3700 * xfs_io -c fsync mydir/foo
3701 * <power failure>
3702 * mount fs, triggers fsync log replay
3703 *
3704 * We must make sure that when we fsync our inode foo we also log its
3705 * parent inode, otherwise after log replay the parent still has the
3706 * dentry with the "bar" name but our inode foo has a link count of 1
3707 * and doesn't have an inode ref with the name "bar" anymore.
3708 *
3709 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3710 * but it guarantees correctness at the expense of ocassional full
3711 * transaction commits on fsync if our inode is a directory, or if our
3712 * inode is not a directory, logging its parent unnecessarily.
3713 */
3714 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3715
3716 path->slots[0]++;
3717 if (inode->i_nlink != 1 ||
3718 path->slots[0] >= btrfs_header_nritems(leaf))
3719 goto cache_acl;
3720
3721 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3722 if (location.objectid != btrfs_ino(inode))
3723 goto cache_acl;
3724
3725 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3726 if (location.type == BTRFS_INODE_REF_KEY) {
3727 struct btrfs_inode_ref *ref;
3728
3729 ref = (struct btrfs_inode_ref *)ptr;
3730 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3731 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3732 struct btrfs_inode_extref *extref;
3733
3734 extref = (struct btrfs_inode_extref *)ptr;
3735 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3736 extref);
3737 }
3738 cache_acl:
3739 /*
3740 * try to precache a NULL acl entry for files that don't have
3741 * any xattrs or acls
3742 */
3743 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3744 btrfs_ino(inode), &first_xattr_slot);
3745 if (first_xattr_slot != -1) {
3746 path->slots[0] = first_xattr_slot;
3747 ret = btrfs_load_inode_props(inode, path);
3748 if (ret)
3749 btrfs_err(root->fs_info,
3750 "error loading props for ino %llu (root %llu): %d",
3751 btrfs_ino(inode),
3752 root->root_key.objectid, ret);
3753 }
3754 btrfs_free_path(path);
3755
3756 if (!maybe_acls)
3757 cache_no_acl(inode);
3758
3759 switch (inode->i_mode & S_IFMT) {
3760 case S_IFREG:
3761 inode->i_mapping->a_ops = &btrfs_aops;
3762 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3763 inode->i_fop = &btrfs_file_operations;
3764 inode->i_op = &btrfs_file_inode_operations;
3765 break;
3766 case S_IFDIR:
3767 inode->i_fop = &btrfs_dir_file_operations;
3768 if (root == root->fs_info->tree_root)
3769 inode->i_op = &btrfs_dir_ro_inode_operations;
3770 else
3771 inode->i_op = &btrfs_dir_inode_operations;
3772 break;
3773 case S_IFLNK:
3774 inode->i_op = &btrfs_symlink_inode_operations;
3775 inode_nohighmem(inode);
3776 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3777 break;
3778 default:
3779 inode->i_op = &btrfs_special_inode_operations;
3780 init_special_inode(inode, inode->i_mode, rdev);
3781 break;
3782 }
3783
3784 btrfs_update_iflags(inode);
3785 return;
3786
3787 make_bad:
3788 btrfs_free_path(path);
3789 make_bad_inode(inode);
3790 }
3791
3792 /*
3793 * given a leaf and an inode, copy the inode fields into the leaf
3794 */
3795 static void fill_inode_item(struct btrfs_trans_handle *trans,
3796 struct extent_buffer *leaf,
3797 struct btrfs_inode_item *item,
3798 struct inode *inode)
3799 {
3800 struct btrfs_map_token token;
3801
3802 btrfs_init_map_token(&token);
3803
3804 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3805 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3806 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3807 &token);
3808 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3809 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3810
3811 btrfs_set_token_timespec_sec(leaf, &item->atime,
3812 inode->i_atime.tv_sec, &token);
3813 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3814 inode->i_atime.tv_nsec, &token);
3815
3816 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3817 inode->i_mtime.tv_sec, &token);
3818 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3819 inode->i_mtime.tv_nsec, &token);
3820
3821 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3822 inode->i_ctime.tv_sec, &token);
3823 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3824 inode->i_ctime.tv_nsec, &token);
3825
3826 btrfs_set_token_timespec_sec(leaf, &item->otime,
3827 BTRFS_I(inode)->i_otime.tv_sec, &token);
3828 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3829 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3830
3831 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3832 &token);
3833 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3834 &token);
3835 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3836 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3837 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3838 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3839 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3840 }
3841
3842 /*
3843 * copy everything in the in-memory inode into the btree.
3844 */
3845 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3846 struct btrfs_root *root, struct inode *inode)
3847 {
3848 struct btrfs_inode_item *inode_item;
3849 struct btrfs_path *path;
3850 struct extent_buffer *leaf;
3851 int ret;
3852
3853 path = btrfs_alloc_path();
3854 if (!path)
3855 return -ENOMEM;
3856
3857 path->leave_spinning = 1;
3858 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3859 1);
3860 if (ret) {
3861 if (ret > 0)
3862 ret = -ENOENT;
3863 goto failed;
3864 }
3865
3866 leaf = path->nodes[0];
3867 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3868 struct btrfs_inode_item);
3869
3870 fill_inode_item(trans, leaf, inode_item, inode);
3871 btrfs_mark_buffer_dirty(leaf);
3872 btrfs_set_inode_last_trans(trans, inode);
3873 ret = 0;
3874 failed:
3875 btrfs_free_path(path);
3876 return ret;
3877 }
3878
3879 /*
3880 * copy everything in the in-memory inode into the btree.
3881 */
3882 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3883 struct btrfs_root *root, struct inode *inode)
3884 {
3885 int ret;
3886
3887 /*
3888 * If the inode is a free space inode, we can deadlock during commit
3889 * if we put it into the delayed code.
3890 *
3891 * The data relocation inode should also be directly updated
3892 * without delay
3893 */
3894 if (!btrfs_is_free_space_inode(inode)
3895 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3896 && !root->fs_info->log_root_recovering) {
3897 btrfs_update_root_times(trans, root);
3898
3899 ret = btrfs_delayed_update_inode(trans, root, inode);
3900 if (!ret)
3901 btrfs_set_inode_last_trans(trans, inode);
3902 return ret;
3903 }
3904
3905 return btrfs_update_inode_item(trans, root, inode);
3906 }
3907
3908 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3909 struct btrfs_root *root,
3910 struct inode *inode)
3911 {
3912 int ret;
3913
3914 ret = btrfs_update_inode(trans, root, inode);
3915 if (ret == -ENOSPC)
3916 return btrfs_update_inode_item(trans, root, inode);
3917 return ret;
3918 }
3919
3920 /*
3921 * unlink helper that gets used here in inode.c and in the tree logging
3922 * recovery code. It remove a link in a directory with a given name, and
3923 * also drops the back refs in the inode to the directory
3924 */
3925 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3926 struct btrfs_root *root,
3927 struct inode *dir, struct inode *inode,
3928 const char *name, int name_len)
3929 {
3930 struct btrfs_path *path;
3931 int ret = 0;
3932 struct extent_buffer *leaf;
3933 struct btrfs_dir_item *di;
3934 struct btrfs_key key;
3935 u64 index;
3936 u64 ino = btrfs_ino(inode);
3937 u64 dir_ino = btrfs_ino(dir);
3938
3939 path = btrfs_alloc_path();
3940 if (!path) {
3941 ret = -ENOMEM;
3942 goto out;
3943 }
3944
3945 path->leave_spinning = 1;
3946 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3947 name, name_len, -1);
3948 if (IS_ERR(di)) {
3949 ret = PTR_ERR(di);
3950 goto err;
3951 }
3952 if (!di) {
3953 ret = -ENOENT;
3954 goto err;
3955 }
3956 leaf = path->nodes[0];
3957 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3958 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3959 if (ret)
3960 goto err;
3961 btrfs_release_path(path);
3962
3963 /*
3964 * If we don't have dir index, we have to get it by looking up
3965 * the inode ref, since we get the inode ref, remove it directly,
3966 * it is unnecessary to do delayed deletion.
3967 *
3968 * But if we have dir index, needn't search inode ref to get it.
3969 * Since the inode ref is close to the inode item, it is better
3970 * that we delay to delete it, and just do this deletion when
3971 * we update the inode item.
3972 */
3973 if (BTRFS_I(inode)->dir_index) {
3974 ret = btrfs_delayed_delete_inode_ref(inode);
3975 if (!ret) {
3976 index = BTRFS_I(inode)->dir_index;
3977 goto skip_backref;
3978 }
3979 }
3980
3981 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3982 dir_ino, &index);
3983 if (ret) {
3984 btrfs_info(root->fs_info,
3985 "failed to delete reference to %.*s, inode %llu parent %llu",
3986 name_len, name, ino, dir_ino);
3987 btrfs_abort_transaction(trans, root, ret);
3988 goto err;
3989 }
3990 skip_backref:
3991 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3992 if (ret) {
3993 btrfs_abort_transaction(trans, root, ret);
3994 goto err;
3995 }
3996
3997 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3998 inode, dir_ino);
3999 if (ret != 0 && ret != -ENOENT) {
4000 btrfs_abort_transaction(trans, root, ret);
4001 goto err;
4002 }
4003
4004 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4005 dir, index);
4006 if (ret == -ENOENT)
4007 ret = 0;
4008 else if (ret)
4009 btrfs_abort_transaction(trans, root, ret);
4010 err:
4011 btrfs_free_path(path);
4012 if (ret)
4013 goto out;
4014
4015 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4016 inode_inc_iversion(inode);
4017 inode_inc_iversion(dir);
4018 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4019 ret = btrfs_update_inode(trans, root, dir);
4020 out:
4021 return ret;
4022 }
4023
4024 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4025 struct btrfs_root *root,
4026 struct inode *dir, struct inode *inode,
4027 const char *name, int name_len)
4028 {
4029 int ret;
4030 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4031 if (!ret) {
4032 drop_nlink(inode);
4033 ret = btrfs_update_inode(trans, root, inode);
4034 }
4035 return ret;
4036 }
4037
4038 /*
4039 * helper to start transaction for unlink and rmdir.
4040 *
4041 * unlink and rmdir are special in btrfs, they do not always free space, so
4042 * if we cannot make our reservations the normal way try and see if there is
4043 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4044 * allow the unlink to occur.
4045 */
4046 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4047 {
4048 struct btrfs_root *root = BTRFS_I(dir)->root;
4049
4050 /*
4051 * 1 for the possible orphan item
4052 * 1 for the dir item
4053 * 1 for the dir index
4054 * 1 for the inode ref
4055 * 1 for the inode
4056 */
4057 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4058 }
4059
4060 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4061 {
4062 struct btrfs_root *root = BTRFS_I(dir)->root;
4063 struct btrfs_trans_handle *trans;
4064 struct inode *inode = d_inode(dentry);
4065 int ret;
4066
4067 trans = __unlink_start_trans(dir);
4068 if (IS_ERR(trans))
4069 return PTR_ERR(trans);
4070
4071 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4072
4073 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4074 dentry->d_name.name, dentry->d_name.len);
4075 if (ret)
4076 goto out;
4077
4078 if (inode->i_nlink == 0) {
4079 ret = btrfs_orphan_add(trans, inode);
4080 if (ret)
4081 goto out;
4082 }
4083
4084 out:
4085 btrfs_end_transaction(trans, root);
4086 btrfs_btree_balance_dirty(root);
4087 return ret;
4088 }
4089
4090 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4091 struct btrfs_root *root,
4092 struct inode *dir, u64 objectid,
4093 const char *name, int name_len)
4094 {
4095 struct btrfs_path *path;
4096 struct extent_buffer *leaf;
4097 struct btrfs_dir_item *di;
4098 struct btrfs_key key;
4099 u64 index;
4100 int ret;
4101 u64 dir_ino = btrfs_ino(dir);
4102
4103 path = btrfs_alloc_path();
4104 if (!path)
4105 return -ENOMEM;
4106
4107 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4108 name, name_len, -1);
4109 if (IS_ERR_OR_NULL(di)) {
4110 if (!di)
4111 ret = -ENOENT;
4112 else
4113 ret = PTR_ERR(di);
4114 goto out;
4115 }
4116
4117 leaf = path->nodes[0];
4118 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4119 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4120 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4121 if (ret) {
4122 btrfs_abort_transaction(trans, root, ret);
4123 goto out;
4124 }
4125 btrfs_release_path(path);
4126
4127 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4128 objectid, root->root_key.objectid,
4129 dir_ino, &index, name, name_len);
4130 if (ret < 0) {
4131 if (ret != -ENOENT) {
4132 btrfs_abort_transaction(trans, root, ret);
4133 goto out;
4134 }
4135 di = btrfs_search_dir_index_item(root, path, dir_ino,
4136 name, name_len);
4137 if (IS_ERR_OR_NULL(di)) {
4138 if (!di)
4139 ret = -ENOENT;
4140 else
4141 ret = PTR_ERR(di);
4142 btrfs_abort_transaction(trans, root, ret);
4143 goto out;
4144 }
4145
4146 leaf = path->nodes[0];
4147 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4148 btrfs_release_path(path);
4149 index = key.offset;
4150 }
4151 btrfs_release_path(path);
4152
4153 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4154 if (ret) {
4155 btrfs_abort_transaction(trans, root, ret);
4156 goto out;
4157 }
4158
4159 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4160 inode_inc_iversion(dir);
4161 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4162 ret = btrfs_update_inode_fallback(trans, root, dir);
4163 if (ret)
4164 btrfs_abort_transaction(trans, root, ret);
4165 out:
4166 btrfs_free_path(path);
4167 return ret;
4168 }
4169
4170 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4171 {
4172 struct inode *inode = d_inode(dentry);
4173 int err = 0;
4174 struct btrfs_root *root = BTRFS_I(dir)->root;
4175 struct btrfs_trans_handle *trans;
4176
4177 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4178 return -ENOTEMPTY;
4179 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4180 return -EPERM;
4181
4182 trans = __unlink_start_trans(dir);
4183 if (IS_ERR(trans))
4184 return PTR_ERR(trans);
4185
4186 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4187 err = btrfs_unlink_subvol(trans, root, dir,
4188 BTRFS_I(inode)->location.objectid,
4189 dentry->d_name.name,
4190 dentry->d_name.len);
4191 goto out;
4192 }
4193
4194 err = btrfs_orphan_add(trans, inode);
4195 if (err)
4196 goto out;
4197
4198 /* now the directory is empty */
4199 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4200 dentry->d_name.name, dentry->d_name.len);
4201 if (!err)
4202 btrfs_i_size_write(inode, 0);
4203 out:
4204 btrfs_end_transaction(trans, root);
4205 btrfs_btree_balance_dirty(root);
4206
4207 return err;
4208 }
4209
4210 static int truncate_space_check(struct btrfs_trans_handle *trans,
4211 struct btrfs_root *root,
4212 u64 bytes_deleted)
4213 {
4214 int ret;
4215
4216 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4217 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4218 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4219 if (!ret)
4220 trans->bytes_reserved += bytes_deleted;
4221 return ret;
4222
4223 }
4224
4225 static int truncate_inline_extent(struct inode *inode,
4226 struct btrfs_path *path,
4227 struct btrfs_key *found_key,
4228 const u64 item_end,
4229 const u64 new_size)
4230 {
4231 struct extent_buffer *leaf = path->nodes[0];
4232 int slot = path->slots[0];
4233 struct btrfs_file_extent_item *fi;
4234 u32 size = (u32)(new_size - found_key->offset);
4235 struct btrfs_root *root = BTRFS_I(inode)->root;
4236
4237 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4238
4239 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4240 loff_t offset = new_size;
4241 loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
4242
4243 /*
4244 * Zero out the remaining of the last page of our inline extent,
4245 * instead of directly truncating our inline extent here - that
4246 * would be much more complex (decompressing all the data, then
4247 * compressing the truncated data, which might be bigger than
4248 * the size of the inline extent, resize the extent, etc).
4249 * We release the path because to get the page we might need to
4250 * read the extent item from disk (data not in the page cache).
4251 */
4252 btrfs_release_path(path);
4253 return btrfs_truncate_page(inode, offset, page_end - offset, 0);
4254 }
4255
4256 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4257 size = btrfs_file_extent_calc_inline_size(size);
4258 btrfs_truncate_item(root, path, size, 1);
4259
4260 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4261 inode_sub_bytes(inode, item_end + 1 - new_size);
4262
4263 return 0;
4264 }
4265
4266 /*
4267 * this can truncate away extent items, csum items and directory items.
4268 * It starts at a high offset and removes keys until it can't find
4269 * any higher than new_size
4270 *
4271 * csum items that cross the new i_size are truncated to the new size
4272 * as well.
4273 *
4274 * min_type is the minimum key type to truncate down to. If set to 0, this
4275 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4276 */
4277 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4278 struct btrfs_root *root,
4279 struct inode *inode,
4280 u64 new_size, u32 min_type)
4281 {
4282 struct btrfs_path *path;
4283 struct extent_buffer *leaf;
4284 struct btrfs_file_extent_item *fi;
4285 struct btrfs_key key;
4286 struct btrfs_key found_key;
4287 u64 extent_start = 0;
4288 u64 extent_num_bytes = 0;
4289 u64 extent_offset = 0;
4290 u64 item_end = 0;
4291 u64 last_size = new_size;
4292 u32 found_type = (u8)-1;
4293 int found_extent;
4294 int del_item;
4295 int pending_del_nr = 0;
4296 int pending_del_slot = 0;
4297 int extent_type = -1;
4298 int ret;
4299 int err = 0;
4300 u64 ino = btrfs_ino(inode);
4301 u64 bytes_deleted = 0;
4302 bool be_nice = 0;
4303 bool should_throttle = 0;
4304 bool should_end = 0;
4305
4306 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4307
4308 /*
4309 * for non-free space inodes and ref cows, we want to back off from
4310 * time to time
4311 */
4312 if (!btrfs_is_free_space_inode(inode) &&
4313 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4314 be_nice = 1;
4315
4316 path = btrfs_alloc_path();
4317 if (!path)
4318 return -ENOMEM;
4319 path->reada = READA_BACK;
4320
4321 /*
4322 * We want to drop from the next block forward in case this new size is
4323 * not block aligned since we will be keeping the last block of the
4324 * extent just the way it is.
4325 */
4326 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4327 root == root->fs_info->tree_root)
4328 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4329 root->sectorsize), (u64)-1, 0);
4330
4331 /*
4332 * This function is also used to drop the items in the log tree before
4333 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4334 * it is used to drop the loged items. So we shouldn't kill the delayed
4335 * items.
4336 */
4337 if (min_type == 0 && root == BTRFS_I(inode)->root)
4338 btrfs_kill_delayed_inode_items(inode);
4339
4340 key.objectid = ino;
4341 key.offset = (u64)-1;
4342 key.type = (u8)-1;
4343
4344 search_again:
4345 /*
4346 * with a 16K leaf size and 128MB extents, you can actually queue
4347 * up a huge file in a single leaf. Most of the time that
4348 * bytes_deleted is > 0, it will be huge by the time we get here
4349 */
4350 if (be_nice && bytes_deleted > SZ_32M) {
4351 if (btrfs_should_end_transaction(trans, root)) {
4352 err = -EAGAIN;
4353 goto error;
4354 }
4355 }
4356
4357
4358 path->leave_spinning = 1;
4359 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4360 if (ret < 0) {
4361 err = ret;
4362 goto out;
4363 }
4364
4365 if (ret > 0) {
4366 /* there are no items in the tree for us to truncate, we're
4367 * done
4368 */
4369 if (path->slots[0] == 0)
4370 goto out;
4371 path->slots[0]--;
4372 }
4373
4374 while (1) {
4375 fi = NULL;
4376 leaf = path->nodes[0];
4377 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4378 found_type = found_key.type;
4379
4380 if (found_key.objectid != ino)
4381 break;
4382
4383 if (found_type < min_type)
4384 break;
4385
4386 item_end = found_key.offset;
4387 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4388 fi = btrfs_item_ptr(leaf, path->slots[0],
4389 struct btrfs_file_extent_item);
4390 extent_type = btrfs_file_extent_type(leaf, fi);
4391 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4392 item_end +=
4393 btrfs_file_extent_num_bytes(leaf, fi);
4394 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4395 item_end += btrfs_file_extent_inline_len(leaf,
4396 path->slots[0], fi);
4397 }
4398 item_end--;
4399 }
4400 if (found_type > min_type) {
4401 del_item = 1;
4402 } else {
4403 if (item_end < new_size)
4404 break;
4405 if (found_key.offset >= new_size)
4406 del_item = 1;
4407 else
4408 del_item = 0;
4409 }
4410 found_extent = 0;
4411 /* FIXME, shrink the extent if the ref count is only 1 */
4412 if (found_type != BTRFS_EXTENT_DATA_KEY)
4413 goto delete;
4414
4415 if (del_item)
4416 last_size = found_key.offset;
4417 else
4418 last_size = new_size;
4419
4420 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4421 u64 num_dec;
4422 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4423 if (!del_item) {
4424 u64 orig_num_bytes =
4425 btrfs_file_extent_num_bytes(leaf, fi);
4426 extent_num_bytes = ALIGN(new_size -
4427 found_key.offset,
4428 root->sectorsize);
4429 btrfs_set_file_extent_num_bytes(leaf, fi,
4430 extent_num_bytes);
4431 num_dec = (orig_num_bytes -
4432 extent_num_bytes);
4433 if (test_bit(BTRFS_ROOT_REF_COWS,
4434 &root->state) &&
4435 extent_start != 0)
4436 inode_sub_bytes(inode, num_dec);
4437 btrfs_mark_buffer_dirty(leaf);
4438 } else {
4439 extent_num_bytes =
4440 btrfs_file_extent_disk_num_bytes(leaf,
4441 fi);
4442 extent_offset = found_key.offset -
4443 btrfs_file_extent_offset(leaf, fi);
4444
4445 /* FIXME blocksize != 4096 */
4446 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4447 if (extent_start != 0) {
4448 found_extent = 1;
4449 if (test_bit(BTRFS_ROOT_REF_COWS,
4450 &root->state))
4451 inode_sub_bytes(inode, num_dec);
4452 }
4453 }
4454 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4455 /*
4456 * we can't truncate inline items that have had
4457 * special encodings
4458 */
4459 if (!del_item &&
4460 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4461 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4462
4463 /*
4464 * Need to release path in order to truncate a
4465 * compressed extent. So delete any accumulated
4466 * extent items so far.
4467 */
4468 if (btrfs_file_extent_compression(leaf, fi) !=
4469 BTRFS_COMPRESS_NONE && pending_del_nr) {
4470 err = btrfs_del_items(trans, root, path,
4471 pending_del_slot,
4472 pending_del_nr);
4473 if (err) {
4474 btrfs_abort_transaction(trans,
4475 root,
4476 err);
4477 goto error;
4478 }
4479 pending_del_nr = 0;
4480 }
4481
4482 err = truncate_inline_extent(inode, path,
4483 &found_key,
4484 item_end,
4485 new_size);
4486 if (err) {
4487 btrfs_abort_transaction(trans,
4488 root, err);
4489 goto error;
4490 }
4491 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4492 &root->state)) {
4493 inode_sub_bytes(inode, item_end + 1 - new_size);
4494 }
4495 }
4496 delete:
4497 if (del_item) {
4498 if (!pending_del_nr) {
4499 /* no pending yet, add ourselves */
4500 pending_del_slot = path->slots[0];
4501 pending_del_nr = 1;
4502 } else if (pending_del_nr &&
4503 path->slots[0] + 1 == pending_del_slot) {
4504 /* hop on the pending chunk */
4505 pending_del_nr++;
4506 pending_del_slot = path->slots[0];
4507 } else {
4508 BUG();
4509 }
4510 } else {
4511 break;
4512 }
4513 should_throttle = 0;
4514
4515 if (found_extent &&
4516 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4517 root == root->fs_info->tree_root)) {
4518 btrfs_set_path_blocking(path);
4519 bytes_deleted += extent_num_bytes;
4520 ret = btrfs_free_extent(trans, root, extent_start,
4521 extent_num_bytes, 0,
4522 btrfs_header_owner(leaf),
4523 ino, extent_offset);
4524 BUG_ON(ret);
4525 if (btrfs_should_throttle_delayed_refs(trans, root))
4526 btrfs_async_run_delayed_refs(root,
4527 trans->delayed_ref_updates * 2, 0);
4528 if (be_nice) {
4529 if (truncate_space_check(trans, root,
4530 extent_num_bytes)) {
4531 should_end = 1;
4532 }
4533 if (btrfs_should_throttle_delayed_refs(trans,
4534 root)) {
4535 should_throttle = 1;
4536 }
4537 }
4538 }
4539
4540 if (found_type == BTRFS_INODE_ITEM_KEY)
4541 break;
4542
4543 if (path->slots[0] == 0 ||
4544 path->slots[0] != pending_del_slot ||
4545 should_throttle || should_end) {
4546 if (pending_del_nr) {
4547 ret = btrfs_del_items(trans, root, path,
4548 pending_del_slot,
4549 pending_del_nr);
4550 if (ret) {
4551 btrfs_abort_transaction(trans,
4552 root, ret);
4553 goto error;
4554 }
4555 pending_del_nr = 0;
4556 }
4557 btrfs_release_path(path);
4558 if (should_throttle) {
4559 unsigned long updates = trans->delayed_ref_updates;
4560 if (updates) {
4561 trans->delayed_ref_updates = 0;
4562 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4563 if (ret && !err)
4564 err = ret;
4565 }
4566 }
4567 /*
4568 * if we failed to refill our space rsv, bail out
4569 * and let the transaction restart
4570 */
4571 if (should_end) {
4572 err = -EAGAIN;
4573 goto error;
4574 }
4575 goto search_again;
4576 } else {
4577 path->slots[0]--;
4578 }
4579 }
4580 out:
4581 if (pending_del_nr) {
4582 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4583 pending_del_nr);
4584 if (ret)
4585 btrfs_abort_transaction(trans, root, ret);
4586 }
4587 error:
4588 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4589 btrfs_ordered_update_i_size(inode, last_size, NULL);
4590
4591 btrfs_free_path(path);
4592
4593 if (be_nice && bytes_deleted > SZ_32M) {
4594 unsigned long updates = trans->delayed_ref_updates;
4595 if (updates) {
4596 trans->delayed_ref_updates = 0;
4597 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4598 if (ret && !err)
4599 err = ret;
4600 }
4601 }
4602 return err;
4603 }
4604
4605 /*
4606 * btrfs_truncate_page - read, zero a chunk and write a page
4607 * @inode - inode that we're zeroing
4608 * @from - the offset to start zeroing
4609 * @len - the length to zero, 0 to zero the entire range respective to the
4610 * offset
4611 * @front - zero up to the offset instead of from the offset on
4612 *
4613 * This will find the page for the "from" offset and cow the page and zero the
4614 * part we want to zero. This is used with truncate and hole punching.
4615 */
4616 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4617 int front)
4618 {
4619 struct address_space *mapping = inode->i_mapping;
4620 struct btrfs_root *root = BTRFS_I(inode)->root;
4621 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4622 struct btrfs_ordered_extent *ordered;
4623 struct extent_state *cached_state = NULL;
4624 char *kaddr;
4625 u32 blocksize = root->sectorsize;
4626 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4627 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4628 struct page *page;
4629 gfp_t mask = btrfs_alloc_write_mask(mapping);
4630 int ret = 0;
4631 u64 page_start;
4632 u64 page_end;
4633
4634 if ((offset & (blocksize - 1)) == 0 &&
4635 (!len || ((len & (blocksize - 1)) == 0)))
4636 goto out;
4637 ret = btrfs_delalloc_reserve_space(inode,
4638 round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
4639 if (ret)
4640 goto out;
4641
4642 again:
4643 page = find_or_create_page(mapping, index, mask);
4644 if (!page) {
4645 btrfs_delalloc_release_space(inode,
4646 round_down(from, PAGE_CACHE_SIZE),
4647 PAGE_CACHE_SIZE);
4648 ret = -ENOMEM;
4649 goto out;
4650 }
4651
4652 page_start = page_offset(page);
4653 page_end = page_start + PAGE_CACHE_SIZE - 1;
4654
4655 if (!PageUptodate(page)) {
4656 ret = btrfs_readpage(NULL, page);
4657 lock_page(page);
4658 if (page->mapping != mapping) {
4659 unlock_page(page);
4660 page_cache_release(page);
4661 goto again;
4662 }
4663 if (!PageUptodate(page)) {
4664 ret = -EIO;
4665 goto out_unlock;
4666 }
4667 }
4668 wait_on_page_writeback(page);
4669
4670 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
4671 set_page_extent_mapped(page);
4672
4673 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4674 if (ordered) {
4675 unlock_extent_cached(io_tree, page_start, page_end,
4676 &cached_state, GFP_NOFS);
4677 unlock_page(page);
4678 page_cache_release(page);
4679 btrfs_start_ordered_extent(inode, ordered, 1);
4680 btrfs_put_ordered_extent(ordered);
4681 goto again;
4682 }
4683
4684 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4685 EXTENT_DIRTY | EXTENT_DELALLOC |
4686 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4687 0, 0, &cached_state, GFP_NOFS);
4688
4689 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4690 &cached_state);
4691 if (ret) {
4692 unlock_extent_cached(io_tree, page_start, page_end,
4693 &cached_state, GFP_NOFS);
4694 goto out_unlock;
4695 }
4696
4697 if (offset != PAGE_CACHE_SIZE) {
4698 if (!len)
4699 len = PAGE_CACHE_SIZE - offset;
4700 kaddr = kmap(page);
4701 if (front)
4702 memset(kaddr, 0, offset);
4703 else
4704 memset(kaddr + offset, 0, len);
4705 flush_dcache_page(page);
4706 kunmap(page);
4707 }
4708 ClearPageChecked(page);
4709 set_page_dirty(page);
4710 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4711 GFP_NOFS);
4712
4713 out_unlock:
4714 if (ret)
4715 btrfs_delalloc_release_space(inode, page_start,
4716 PAGE_CACHE_SIZE);
4717 unlock_page(page);
4718 page_cache_release(page);
4719 out:
4720 return ret;
4721 }
4722
4723 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4724 u64 offset, u64 len)
4725 {
4726 struct btrfs_trans_handle *trans;
4727 int ret;
4728
4729 /*
4730 * Still need to make sure the inode looks like it's been updated so
4731 * that any holes get logged if we fsync.
4732 */
4733 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4734 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4735 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4736 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4737 return 0;
4738 }
4739
4740 /*
4741 * 1 - for the one we're dropping
4742 * 1 - for the one we're adding
4743 * 1 - for updating the inode.
4744 */
4745 trans = btrfs_start_transaction(root, 3);
4746 if (IS_ERR(trans))
4747 return PTR_ERR(trans);
4748
4749 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4750 if (ret) {
4751 btrfs_abort_transaction(trans, root, ret);
4752 btrfs_end_transaction(trans, root);
4753 return ret;
4754 }
4755
4756 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4757 0, 0, len, 0, len, 0, 0, 0);
4758 if (ret)
4759 btrfs_abort_transaction(trans, root, ret);
4760 else
4761 btrfs_update_inode(trans, root, inode);
4762 btrfs_end_transaction(trans, root);
4763 return ret;
4764 }
4765
4766 /*
4767 * This function puts in dummy file extents for the area we're creating a hole
4768 * for. So if we are truncating this file to a larger size we need to insert
4769 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4770 * the range between oldsize and size
4771 */
4772 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4773 {
4774 struct btrfs_root *root = BTRFS_I(inode)->root;
4775 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4776 struct extent_map *em = NULL;
4777 struct extent_state *cached_state = NULL;
4778 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4779 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4780 u64 block_end = ALIGN(size, root->sectorsize);
4781 u64 last_byte;
4782 u64 cur_offset;
4783 u64 hole_size;
4784 int err = 0;
4785
4786 /*
4787 * If our size started in the middle of a page we need to zero out the
4788 * rest of the page before we expand the i_size, otherwise we could
4789 * expose stale data.
4790 */
4791 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4792 if (err)
4793 return err;
4794
4795 if (size <= hole_start)
4796 return 0;
4797
4798 while (1) {
4799 struct btrfs_ordered_extent *ordered;
4800
4801 lock_extent_bits(io_tree, hole_start, block_end - 1,
4802 &cached_state);
4803 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4804 block_end - hole_start);
4805 if (!ordered)
4806 break;
4807 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4808 &cached_state, GFP_NOFS);
4809 btrfs_start_ordered_extent(inode, ordered, 1);
4810 btrfs_put_ordered_extent(ordered);
4811 }
4812
4813 cur_offset = hole_start;
4814 while (1) {
4815 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4816 block_end - cur_offset, 0);
4817 if (IS_ERR(em)) {
4818 err = PTR_ERR(em);
4819 em = NULL;
4820 break;
4821 }
4822 last_byte = min(extent_map_end(em), block_end);
4823 last_byte = ALIGN(last_byte , root->sectorsize);
4824 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4825 struct extent_map *hole_em;
4826 hole_size = last_byte - cur_offset;
4827
4828 err = maybe_insert_hole(root, inode, cur_offset,
4829 hole_size);
4830 if (err)
4831 break;
4832 btrfs_drop_extent_cache(inode, cur_offset,
4833 cur_offset + hole_size - 1, 0);
4834 hole_em = alloc_extent_map();
4835 if (!hole_em) {
4836 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4837 &BTRFS_I(inode)->runtime_flags);
4838 goto next;
4839 }
4840 hole_em->start = cur_offset;
4841 hole_em->len = hole_size;
4842 hole_em->orig_start = cur_offset;
4843
4844 hole_em->block_start = EXTENT_MAP_HOLE;
4845 hole_em->block_len = 0;
4846 hole_em->orig_block_len = 0;
4847 hole_em->ram_bytes = hole_size;
4848 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4849 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4850 hole_em->generation = root->fs_info->generation;
4851
4852 while (1) {
4853 write_lock(&em_tree->lock);
4854 err = add_extent_mapping(em_tree, hole_em, 1);
4855 write_unlock(&em_tree->lock);
4856 if (err != -EEXIST)
4857 break;
4858 btrfs_drop_extent_cache(inode, cur_offset,
4859 cur_offset +
4860 hole_size - 1, 0);
4861 }
4862 free_extent_map(hole_em);
4863 }
4864 next:
4865 free_extent_map(em);
4866 em = NULL;
4867 cur_offset = last_byte;
4868 if (cur_offset >= block_end)
4869 break;
4870 }
4871 free_extent_map(em);
4872 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4873 GFP_NOFS);
4874 return err;
4875 }
4876
4877 static int wait_snapshoting_atomic_t(atomic_t *a)
4878 {
4879 schedule();
4880 return 0;
4881 }
4882
4883 static void wait_for_snapshot_creation(struct btrfs_root *root)
4884 {
4885 while (true) {
4886 int ret;
4887
4888 ret = btrfs_start_write_no_snapshoting(root);
4889 if (ret)
4890 break;
4891 wait_on_atomic_t(&root->will_be_snapshoted,
4892 wait_snapshoting_atomic_t,
4893 TASK_UNINTERRUPTIBLE);
4894 }
4895 }
4896
4897 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4898 {
4899 struct btrfs_root *root = BTRFS_I(inode)->root;
4900 struct btrfs_trans_handle *trans;
4901 loff_t oldsize = i_size_read(inode);
4902 loff_t newsize = attr->ia_size;
4903 int mask = attr->ia_valid;
4904 int ret;
4905
4906 /*
4907 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4908 * special case where we need to update the times despite not having
4909 * these flags set. For all other operations the VFS set these flags
4910 * explicitly if it wants a timestamp update.
4911 */
4912 if (newsize != oldsize) {
4913 inode_inc_iversion(inode);
4914 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4915 inode->i_ctime = inode->i_mtime =
4916 current_fs_time(inode->i_sb);
4917 }
4918
4919 if (newsize > oldsize) {
4920 truncate_pagecache(inode, newsize);
4921 /*
4922 * Don't do an expanding truncate while snapshoting is ongoing.
4923 * This is to ensure the snapshot captures a fully consistent
4924 * state of this file - if the snapshot captures this expanding
4925 * truncation, it must capture all writes that happened before
4926 * this truncation.
4927 */
4928 wait_for_snapshot_creation(root);
4929 ret = btrfs_cont_expand(inode, oldsize, newsize);
4930 if (ret) {
4931 btrfs_end_write_no_snapshoting(root);
4932 return ret;
4933 }
4934
4935 trans = btrfs_start_transaction(root, 1);
4936 if (IS_ERR(trans)) {
4937 btrfs_end_write_no_snapshoting(root);
4938 return PTR_ERR(trans);
4939 }
4940
4941 i_size_write(inode, newsize);
4942 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4943 ret = btrfs_update_inode(trans, root, inode);
4944 btrfs_end_write_no_snapshoting(root);
4945 btrfs_end_transaction(trans, root);
4946 } else {
4947
4948 /*
4949 * We're truncating a file that used to have good data down to
4950 * zero. Make sure it gets into the ordered flush list so that
4951 * any new writes get down to disk quickly.
4952 */
4953 if (newsize == 0)
4954 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4955 &BTRFS_I(inode)->runtime_flags);
4956
4957 /*
4958 * 1 for the orphan item we're going to add
4959 * 1 for the orphan item deletion.
4960 */
4961 trans = btrfs_start_transaction(root, 2);
4962 if (IS_ERR(trans))
4963 return PTR_ERR(trans);
4964
4965 /*
4966 * We need to do this in case we fail at _any_ point during the
4967 * actual truncate. Once we do the truncate_setsize we could
4968 * invalidate pages which forces any outstanding ordered io to
4969 * be instantly completed which will give us extents that need
4970 * to be truncated. If we fail to get an orphan inode down we
4971 * could have left over extents that were never meant to live,
4972 * so we need to garuntee from this point on that everything
4973 * will be consistent.
4974 */
4975 ret = btrfs_orphan_add(trans, inode);
4976 btrfs_end_transaction(trans, root);
4977 if (ret)
4978 return ret;
4979
4980 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4981 truncate_setsize(inode, newsize);
4982
4983 /* Disable nonlocked read DIO to avoid the end less truncate */
4984 btrfs_inode_block_unlocked_dio(inode);
4985 inode_dio_wait(inode);
4986 btrfs_inode_resume_unlocked_dio(inode);
4987
4988 ret = btrfs_truncate(inode);
4989 if (ret && inode->i_nlink) {
4990 int err;
4991
4992 /*
4993 * failed to truncate, disk_i_size is only adjusted down
4994 * as we remove extents, so it should represent the true
4995 * size of the inode, so reset the in memory size and
4996 * delete our orphan entry.
4997 */
4998 trans = btrfs_join_transaction(root);
4999 if (IS_ERR(trans)) {
5000 btrfs_orphan_del(NULL, inode);
5001 return ret;
5002 }
5003 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5004 err = btrfs_orphan_del(trans, inode);
5005 if (err)
5006 btrfs_abort_transaction(trans, root, err);
5007 btrfs_end_transaction(trans, root);
5008 }
5009 }
5010
5011 return ret;
5012 }
5013
5014 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5015 {
5016 struct inode *inode = d_inode(dentry);
5017 struct btrfs_root *root = BTRFS_I(inode)->root;
5018 int err;
5019
5020 if (btrfs_root_readonly(root))
5021 return -EROFS;
5022
5023 err = inode_change_ok(inode, attr);
5024 if (err)
5025 return err;
5026
5027 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5028 err = btrfs_setsize(inode, attr);
5029 if (err)
5030 return err;
5031 }
5032
5033 if (attr->ia_valid) {
5034 setattr_copy(inode, attr);
5035 inode_inc_iversion(inode);
5036 err = btrfs_dirty_inode(inode);
5037
5038 if (!err && attr->ia_valid & ATTR_MODE)
5039 err = posix_acl_chmod(inode, inode->i_mode);
5040 }
5041
5042 return err;
5043 }
5044
5045 /*
5046 * While truncating the inode pages during eviction, we get the VFS calling
5047 * btrfs_invalidatepage() against each page of the inode. This is slow because
5048 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5049 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5050 * extent_state structures over and over, wasting lots of time.
5051 *
5052 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5053 * those expensive operations on a per page basis and do only the ordered io
5054 * finishing, while we release here the extent_map and extent_state structures,
5055 * without the excessive merging and splitting.
5056 */
5057 static void evict_inode_truncate_pages(struct inode *inode)
5058 {
5059 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5060 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5061 struct rb_node *node;
5062
5063 ASSERT(inode->i_state & I_FREEING);
5064 truncate_inode_pages_final(&inode->i_data);
5065
5066 write_lock(&map_tree->lock);
5067 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5068 struct extent_map *em;
5069
5070 node = rb_first(&map_tree->map);
5071 em = rb_entry(node, struct extent_map, rb_node);
5072 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5073 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5074 remove_extent_mapping(map_tree, em);
5075 free_extent_map(em);
5076 if (need_resched()) {
5077 write_unlock(&map_tree->lock);
5078 cond_resched();
5079 write_lock(&map_tree->lock);
5080 }
5081 }
5082 write_unlock(&map_tree->lock);
5083
5084 /*
5085 * Keep looping until we have no more ranges in the io tree.
5086 * We can have ongoing bios started by readpages (called from readahead)
5087 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5088 * still in progress (unlocked the pages in the bio but did not yet
5089 * unlocked the ranges in the io tree). Therefore this means some
5090 * ranges can still be locked and eviction started because before
5091 * submitting those bios, which are executed by a separate task (work
5092 * queue kthread), inode references (inode->i_count) were not taken
5093 * (which would be dropped in the end io callback of each bio).
5094 * Therefore here we effectively end up waiting for those bios and
5095 * anyone else holding locked ranges without having bumped the inode's
5096 * reference count - if we don't do it, when they access the inode's
5097 * io_tree to unlock a range it may be too late, leading to an
5098 * use-after-free issue.
5099 */
5100 spin_lock(&io_tree->lock);
5101 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5102 struct extent_state *state;
5103 struct extent_state *cached_state = NULL;
5104 u64 start;
5105 u64 end;
5106
5107 node = rb_first(&io_tree->state);
5108 state = rb_entry(node, struct extent_state, rb_node);
5109 start = state->start;
5110 end = state->end;
5111 spin_unlock(&io_tree->lock);
5112
5113 lock_extent_bits(io_tree, start, end, &cached_state);
5114
5115 /*
5116 * If still has DELALLOC flag, the extent didn't reach disk,
5117 * and its reserved space won't be freed by delayed_ref.
5118 * So we need to free its reserved space here.
5119 * (Refer to comment in btrfs_invalidatepage, case 2)
5120 *
5121 * Note, end is the bytenr of last byte, so we need + 1 here.
5122 */
5123 if (state->state & EXTENT_DELALLOC)
5124 btrfs_qgroup_free_data(inode, start, end - start + 1);
5125
5126 clear_extent_bit(io_tree, start, end,
5127 EXTENT_LOCKED | EXTENT_DIRTY |
5128 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5129 EXTENT_DEFRAG, 1, 1,
5130 &cached_state, GFP_NOFS);
5131
5132 cond_resched();
5133 spin_lock(&io_tree->lock);
5134 }
5135 spin_unlock(&io_tree->lock);
5136 }
5137
5138 void btrfs_evict_inode(struct inode *inode)
5139 {
5140 struct btrfs_trans_handle *trans;
5141 struct btrfs_root *root = BTRFS_I(inode)->root;
5142 struct btrfs_block_rsv *rsv, *global_rsv;
5143 int steal_from_global = 0;
5144 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5145 int ret;
5146
5147 trace_btrfs_inode_evict(inode);
5148
5149 evict_inode_truncate_pages(inode);
5150
5151 if (inode->i_nlink &&
5152 ((btrfs_root_refs(&root->root_item) != 0 &&
5153 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5154 btrfs_is_free_space_inode(inode)))
5155 goto no_delete;
5156
5157 if (is_bad_inode(inode)) {
5158 btrfs_orphan_del(NULL, inode);
5159 goto no_delete;
5160 }
5161 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5162 if (!special_file(inode->i_mode))
5163 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5164
5165 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5166
5167 if (root->fs_info->log_root_recovering) {
5168 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5169 &BTRFS_I(inode)->runtime_flags));
5170 goto no_delete;
5171 }
5172
5173 if (inode->i_nlink > 0) {
5174 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5175 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5176 goto no_delete;
5177 }
5178
5179 ret = btrfs_commit_inode_delayed_inode(inode);
5180 if (ret) {
5181 btrfs_orphan_del(NULL, inode);
5182 goto no_delete;
5183 }
5184
5185 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5186 if (!rsv) {
5187 btrfs_orphan_del(NULL, inode);
5188 goto no_delete;
5189 }
5190 rsv->size = min_size;
5191 rsv->failfast = 1;
5192 global_rsv = &root->fs_info->global_block_rsv;
5193
5194 btrfs_i_size_write(inode, 0);
5195
5196 /*
5197 * This is a bit simpler than btrfs_truncate since we've already
5198 * reserved our space for our orphan item in the unlink, so we just
5199 * need to reserve some slack space in case we add bytes and update
5200 * inode item when doing the truncate.
5201 */
5202 while (1) {
5203 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5204 BTRFS_RESERVE_FLUSH_LIMIT);
5205
5206 /*
5207 * Try and steal from the global reserve since we will
5208 * likely not use this space anyway, we want to try as
5209 * hard as possible to get this to work.
5210 */
5211 if (ret)
5212 steal_from_global++;
5213 else
5214 steal_from_global = 0;
5215 ret = 0;
5216
5217 /*
5218 * steal_from_global == 0: we reserved stuff, hooray!
5219 * steal_from_global == 1: we didn't reserve stuff, boo!
5220 * steal_from_global == 2: we've committed, still not a lot of
5221 * room but maybe we'll have room in the global reserve this
5222 * time.
5223 * steal_from_global == 3: abandon all hope!
5224 */
5225 if (steal_from_global > 2) {
5226 btrfs_warn(root->fs_info,
5227 "Could not get space for a delete, will truncate on mount %d",
5228 ret);
5229 btrfs_orphan_del(NULL, inode);
5230 btrfs_free_block_rsv(root, rsv);
5231 goto no_delete;
5232 }
5233
5234 trans = btrfs_join_transaction(root);
5235 if (IS_ERR(trans)) {
5236 btrfs_orphan_del(NULL, inode);
5237 btrfs_free_block_rsv(root, rsv);
5238 goto no_delete;
5239 }
5240
5241 /*
5242 * We can't just steal from the global reserve, we need tomake
5243 * sure there is room to do it, if not we need to commit and try
5244 * again.
5245 */
5246 if (steal_from_global) {
5247 if (!btrfs_check_space_for_delayed_refs(trans, root))
5248 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5249 min_size);
5250 else
5251 ret = -ENOSPC;
5252 }
5253
5254 /*
5255 * Couldn't steal from the global reserve, we have too much
5256 * pending stuff built up, commit the transaction and try it
5257 * again.
5258 */
5259 if (ret) {
5260 ret = btrfs_commit_transaction(trans, root);
5261 if (ret) {
5262 btrfs_orphan_del(NULL, inode);
5263 btrfs_free_block_rsv(root, rsv);
5264 goto no_delete;
5265 }
5266 continue;
5267 } else {
5268 steal_from_global = 0;
5269 }
5270
5271 trans->block_rsv = rsv;
5272
5273 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5274 if (ret != -ENOSPC && ret != -EAGAIN)
5275 break;
5276
5277 trans->block_rsv = &root->fs_info->trans_block_rsv;
5278 btrfs_end_transaction(trans, root);
5279 trans = NULL;
5280 btrfs_btree_balance_dirty(root);
5281 }
5282
5283 btrfs_free_block_rsv(root, rsv);
5284
5285 /*
5286 * Errors here aren't a big deal, it just means we leave orphan items
5287 * in the tree. They will be cleaned up on the next mount.
5288 */
5289 if (ret == 0) {
5290 trans->block_rsv = root->orphan_block_rsv;
5291 btrfs_orphan_del(trans, inode);
5292 } else {
5293 btrfs_orphan_del(NULL, inode);
5294 }
5295
5296 trans->block_rsv = &root->fs_info->trans_block_rsv;
5297 if (!(root == root->fs_info->tree_root ||
5298 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5299 btrfs_return_ino(root, btrfs_ino(inode));
5300
5301 btrfs_end_transaction(trans, root);
5302 btrfs_btree_balance_dirty(root);
5303 no_delete:
5304 btrfs_remove_delayed_node(inode);
5305 clear_inode(inode);
5306 }
5307
5308 /*
5309 * this returns the key found in the dir entry in the location pointer.
5310 * If no dir entries were found, location->objectid is 0.
5311 */
5312 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5313 struct btrfs_key *location)
5314 {
5315 const char *name = dentry->d_name.name;
5316 int namelen = dentry->d_name.len;
5317 struct btrfs_dir_item *di;
5318 struct btrfs_path *path;
5319 struct btrfs_root *root = BTRFS_I(dir)->root;
5320 int ret = 0;
5321
5322 path = btrfs_alloc_path();
5323 if (!path)
5324 return -ENOMEM;
5325
5326 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5327 namelen, 0);
5328 if (IS_ERR(di))
5329 ret = PTR_ERR(di);
5330
5331 if (IS_ERR_OR_NULL(di))
5332 goto out_err;
5333
5334 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5335 out:
5336 btrfs_free_path(path);
5337 return ret;
5338 out_err:
5339 location->objectid = 0;
5340 goto out;
5341 }
5342
5343 /*
5344 * when we hit a tree root in a directory, the btrfs part of the inode
5345 * needs to be changed to reflect the root directory of the tree root. This
5346 * is kind of like crossing a mount point.
5347 */
5348 static int fixup_tree_root_location(struct btrfs_root *root,
5349 struct inode *dir,
5350 struct dentry *dentry,
5351 struct btrfs_key *location,
5352 struct btrfs_root **sub_root)
5353 {
5354 struct btrfs_path *path;
5355 struct btrfs_root *new_root;
5356 struct btrfs_root_ref *ref;
5357 struct extent_buffer *leaf;
5358 struct btrfs_key key;
5359 int ret;
5360 int err = 0;
5361
5362 path = btrfs_alloc_path();
5363 if (!path) {
5364 err = -ENOMEM;
5365 goto out;
5366 }
5367
5368 err = -ENOENT;
5369 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5370 key.type = BTRFS_ROOT_REF_KEY;
5371 key.offset = location->objectid;
5372
5373 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5374 0, 0);
5375 if (ret) {
5376 if (ret < 0)
5377 err = ret;
5378 goto out;
5379 }
5380
5381 leaf = path->nodes[0];
5382 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5383 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5384 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5385 goto out;
5386
5387 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5388 (unsigned long)(ref + 1),
5389 dentry->d_name.len);
5390 if (ret)
5391 goto out;
5392
5393 btrfs_release_path(path);
5394
5395 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5396 if (IS_ERR(new_root)) {
5397 err = PTR_ERR(new_root);
5398 goto out;
5399 }
5400
5401 *sub_root = new_root;
5402 location->objectid = btrfs_root_dirid(&new_root->root_item);
5403 location->type = BTRFS_INODE_ITEM_KEY;
5404 location->offset = 0;
5405 err = 0;
5406 out:
5407 btrfs_free_path(path);
5408 return err;
5409 }
5410
5411 static void inode_tree_add(struct inode *inode)
5412 {
5413 struct btrfs_root *root = BTRFS_I(inode)->root;
5414 struct btrfs_inode *entry;
5415 struct rb_node **p;
5416 struct rb_node *parent;
5417 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5418 u64 ino = btrfs_ino(inode);
5419
5420 if (inode_unhashed(inode))
5421 return;
5422 parent = NULL;
5423 spin_lock(&root->inode_lock);
5424 p = &root->inode_tree.rb_node;
5425 while (*p) {
5426 parent = *p;
5427 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5428
5429 if (ino < btrfs_ino(&entry->vfs_inode))
5430 p = &parent->rb_left;
5431 else if (ino > btrfs_ino(&entry->vfs_inode))
5432 p = &parent->rb_right;
5433 else {
5434 WARN_ON(!(entry->vfs_inode.i_state &
5435 (I_WILL_FREE | I_FREEING)));
5436 rb_replace_node(parent, new, &root->inode_tree);
5437 RB_CLEAR_NODE(parent);
5438 spin_unlock(&root->inode_lock);
5439 return;
5440 }
5441 }
5442 rb_link_node(new, parent, p);
5443 rb_insert_color(new, &root->inode_tree);
5444 spin_unlock(&root->inode_lock);
5445 }
5446
5447 static void inode_tree_del(struct inode *inode)
5448 {
5449 struct btrfs_root *root = BTRFS_I(inode)->root;
5450 int empty = 0;
5451
5452 spin_lock(&root->inode_lock);
5453 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5454 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5455 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5456 empty = RB_EMPTY_ROOT(&root->inode_tree);
5457 }
5458 spin_unlock(&root->inode_lock);
5459
5460 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5461 synchronize_srcu(&root->fs_info->subvol_srcu);
5462 spin_lock(&root->inode_lock);
5463 empty = RB_EMPTY_ROOT(&root->inode_tree);
5464 spin_unlock(&root->inode_lock);
5465 if (empty)
5466 btrfs_add_dead_root(root);
5467 }
5468 }
5469
5470 void btrfs_invalidate_inodes(struct btrfs_root *root)
5471 {
5472 struct rb_node *node;
5473 struct rb_node *prev;
5474 struct btrfs_inode *entry;
5475 struct inode *inode;
5476 u64 objectid = 0;
5477
5478 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5479 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5480
5481 spin_lock(&root->inode_lock);
5482 again:
5483 node = root->inode_tree.rb_node;
5484 prev = NULL;
5485 while (node) {
5486 prev = node;
5487 entry = rb_entry(node, struct btrfs_inode, rb_node);
5488
5489 if (objectid < btrfs_ino(&entry->vfs_inode))
5490 node = node->rb_left;
5491 else if (objectid > btrfs_ino(&entry->vfs_inode))
5492 node = node->rb_right;
5493 else
5494 break;
5495 }
5496 if (!node) {
5497 while (prev) {
5498 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5499 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5500 node = prev;
5501 break;
5502 }
5503 prev = rb_next(prev);
5504 }
5505 }
5506 while (node) {
5507 entry = rb_entry(node, struct btrfs_inode, rb_node);
5508 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5509 inode = igrab(&entry->vfs_inode);
5510 if (inode) {
5511 spin_unlock(&root->inode_lock);
5512 if (atomic_read(&inode->i_count) > 1)
5513 d_prune_aliases(inode);
5514 /*
5515 * btrfs_drop_inode will have it removed from
5516 * the inode cache when its usage count
5517 * hits zero.
5518 */
5519 iput(inode);
5520 cond_resched();
5521 spin_lock(&root->inode_lock);
5522 goto again;
5523 }
5524
5525 if (cond_resched_lock(&root->inode_lock))
5526 goto again;
5527
5528 node = rb_next(node);
5529 }
5530 spin_unlock(&root->inode_lock);
5531 }
5532
5533 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5534 {
5535 struct btrfs_iget_args *args = p;
5536 inode->i_ino = args->location->objectid;
5537 memcpy(&BTRFS_I(inode)->location, args->location,
5538 sizeof(*args->location));
5539 BTRFS_I(inode)->root = args->root;
5540 return 0;
5541 }
5542
5543 static int btrfs_find_actor(struct inode *inode, void *opaque)
5544 {
5545 struct btrfs_iget_args *args = opaque;
5546 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5547 args->root == BTRFS_I(inode)->root;
5548 }
5549
5550 static struct inode *btrfs_iget_locked(struct super_block *s,
5551 struct btrfs_key *location,
5552 struct btrfs_root *root)
5553 {
5554 struct inode *inode;
5555 struct btrfs_iget_args args;
5556 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5557
5558 args.location = location;
5559 args.root = root;
5560
5561 inode = iget5_locked(s, hashval, btrfs_find_actor,
5562 btrfs_init_locked_inode,
5563 (void *)&args);
5564 return inode;
5565 }
5566
5567 /* Get an inode object given its location and corresponding root.
5568 * Returns in *is_new if the inode was read from disk
5569 */
5570 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5571 struct btrfs_root *root, int *new)
5572 {
5573 struct inode *inode;
5574
5575 inode = btrfs_iget_locked(s, location, root);
5576 if (!inode)
5577 return ERR_PTR(-ENOMEM);
5578
5579 if (inode->i_state & I_NEW) {
5580 btrfs_read_locked_inode(inode);
5581 if (!is_bad_inode(inode)) {
5582 inode_tree_add(inode);
5583 unlock_new_inode(inode);
5584 if (new)
5585 *new = 1;
5586 } else {
5587 unlock_new_inode(inode);
5588 iput(inode);
5589 inode = ERR_PTR(-ESTALE);
5590 }
5591 }
5592
5593 return inode;
5594 }
5595
5596 static struct inode *new_simple_dir(struct super_block *s,
5597 struct btrfs_key *key,
5598 struct btrfs_root *root)
5599 {
5600 struct inode *inode = new_inode(s);
5601
5602 if (!inode)
5603 return ERR_PTR(-ENOMEM);
5604
5605 BTRFS_I(inode)->root = root;
5606 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5607 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5608
5609 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5610 inode->i_op = &btrfs_dir_ro_inode_operations;
5611 inode->i_fop = &simple_dir_operations;
5612 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5613 inode->i_mtime = CURRENT_TIME;
5614 inode->i_atime = inode->i_mtime;
5615 inode->i_ctime = inode->i_mtime;
5616 BTRFS_I(inode)->i_otime = inode->i_mtime;
5617
5618 return inode;
5619 }
5620
5621 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5622 {
5623 struct inode *inode;
5624 struct btrfs_root *root = BTRFS_I(dir)->root;
5625 struct btrfs_root *sub_root = root;
5626 struct btrfs_key location;
5627 int index;
5628 int ret = 0;
5629
5630 if (dentry->d_name.len > BTRFS_NAME_LEN)
5631 return ERR_PTR(-ENAMETOOLONG);
5632
5633 ret = btrfs_inode_by_name(dir, dentry, &location);
5634 if (ret < 0)
5635 return ERR_PTR(ret);
5636
5637 if (location.objectid == 0)
5638 return ERR_PTR(-ENOENT);
5639
5640 if (location.type == BTRFS_INODE_ITEM_KEY) {
5641 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5642 return inode;
5643 }
5644
5645 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5646
5647 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5648 ret = fixup_tree_root_location(root, dir, dentry,
5649 &location, &sub_root);
5650 if (ret < 0) {
5651 if (ret != -ENOENT)
5652 inode = ERR_PTR(ret);
5653 else
5654 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5655 } else {
5656 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5657 }
5658 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5659
5660 if (!IS_ERR(inode) && root != sub_root) {
5661 down_read(&root->fs_info->cleanup_work_sem);
5662 if (!(inode->i_sb->s_flags & MS_RDONLY))
5663 ret = btrfs_orphan_cleanup(sub_root);
5664 up_read(&root->fs_info->cleanup_work_sem);
5665 if (ret) {
5666 iput(inode);
5667 inode = ERR_PTR(ret);
5668 }
5669 }
5670
5671 return inode;
5672 }
5673
5674 static int btrfs_dentry_delete(const struct dentry *dentry)
5675 {
5676 struct btrfs_root *root;
5677 struct inode *inode = d_inode(dentry);
5678
5679 if (!inode && !IS_ROOT(dentry))
5680 inode = d_inode(dentry->d_parent);
5681
5682 if (inode) {
5683 root = BTRFS_I(inode)->root;
5684 if (btrfs_root_refs(&root->root_item) == 0)
5685 return 1;
5686
5687 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5688 return 1;
5689 }
5690 return 0;
5691 }
5692
5693 static void btrfs_dentry_release(struct dentry *dentry)
5694 {
5695 kfree(dentry->d_fsdata);
5696 }
5697
5698 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5699 unsigned int flags)
5700 {
5701 struct inode *inode;
5702
5703 inode = btrfs_lookup_dentry(dir, dentry);
5704 if (IS_ERR(inode)) {
5705 if (PTR_ERR(inode) == -ENOENT)
5706 inode = NULL;
5707 else
5708 return ERR_CAST(inode);
5709 }
5710
5711 return d_splice_alias(inode, dentry);
5712 }
5713
5714 unsigned char btrfs_filetype_table[] = {
5715 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5716 };
5717
5718 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5719 {
5720 struct inode *inode = file_inode(file);
5721 struct btrfs_root *root = BTRFS_I(inode)->root;
5722 struct btrfs_item *item;
5723 struct btrfs_dir_item *di;
5724 struct btrfs_key key;
5725 struct btrfs_key found_key;
5726 struct btrfs_path *path;
5727 struct list_head ins_list;
5728 struct list_head del_list;
5729 int ret;
5730 struct extent_buffer *leaf;
5731 int slot;
5732 unsigned char d_type;
5733 int over = 0;
5734 u32 di_cur;
5735 u32 di_total;
5736 u32 di_len;
5737 int key_type = BTRFS_DIR_INDEX_KEY;
5738 char tmp_name[32];
5739 char *name_ptr;
5740 int name_len;
5741 int is_curr = 0; /* ctx->pos points to the current index? */
5742
5743 /* FIXME, use a real flag for deciding about the key type */
5744 if (root->fs_info->tree_root == root)
5745 key_type = BTRFS_DIR_ITEM_KEY;
5746
5747 if (!dir_emit_dots(file, ctx))
5748 return 0;
5749
5750 path = btrfs_alloc_path();
5751 if (!path)
5752 return -ENOMEM;
5753
5754 path->reada = READA_FORWARD;
5755
5756 if (key_type == BTRFS_DIR_INDEX_KEY) {
5757 INIT_LIST_HEAD(&ins_list);
5758 INIT_LIST_HEAD(&del_list);
5759 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5760 }
5761
5762 key.type = key_type;
5763 key.offset = ctx->pos;
5764 key.objectid = btrfs_ino(inode);
5765
5766 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5767 if (ret < 0)
5768 goto err;
5769
5770 while (1) {
5771 leaf = path->nodes[0];
5772 slot = path->slots[0];
5773 if (slot >= btrfs_header_nritems(leaf)) {
5774 ret = btrfs_next_leaf(root, path);
5775 if (ret < 0)
5776 goto err;
5777 else if (ret > 0)
5778 break;
5779 continue;
5780 }
5781
5782 item = btrfs_item_nr(slot);
5783 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5784
5785 if (found_key.objectid != key.objectid)
5786 break;
5787 if (found_key.type != key_type)
5788 break;
5789 if (found_key.offset < ctx->pos)
5790 goto next;
5791 if (key_type == BTRFS_DIR_INDEX_KEY &&
5792 btrfs_should_delete_dir_index(&del_list,
5793 found_key.offset))
5794 goto next;
5795
5796 ctx->pos = found_key.offset;
5797 is_curr = 1;
5798
5799 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5800 di_cur = 0;
5801 di_total = btrfs_item_size(leaf, item);
5802
5803 while (di_cur < di_total) {
5804 struct btrfs_key location;
5805
5806 if (verify_dir_item(root, leaf, di))
5807 break;
5808
5809 name_len = btrfs_dir_name_len(leaf, di);
5810 if (name_len <= sizeof(tmp_name)) {
5811 name_ptr = tmp_name;
5812 } else {
5813 name_ptr = kmalloc(name_len, GFP_NOFS);
5814 if (!name_ptr) {
5815 ret = -ENOMEM;
5816 goto err;
5817 }
5818 }
5819 read_extent_buffer(leaf, name_ptr,
5820 (unsigned long)(di + 1), name_len);
5821
5822 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5823 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5824
5825
5826 /* is this a reference to our own snapshot? If so
5827 * skip it.
5828 *
5829 * In contrast to old kernels, we insert the snapshot's
5830 * dir item and dir index after it has been created, so
5831 * we won't find a reference to our own snapshot. We
5832 * still keep the following code for backward
5833 * compatibility.
5834 */
5835 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5836 location.objectid == root->root_key.objectid) {
5837 over = 0;
5838 goto skip;
5839 }
5840 over = !dir_emit(ctx, name_ptr, name_len,
5841 location.objectid, d_type);
5842
5843 skip:
5844 if (name_ptr != tmp_name)
5845 kfree(name_ptr);
5846
5847 if (over)
5848 goto nopos;
5849 di_len = btrfs_dir_name_len(leaf, di) +
5850 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5851 di_cur += di_len;
5852 di = (struct btrfs_dir_item *)((char *)di + di_len);
5853 }
5854 next:
5855 path->slots[0]++;
5856 }
5857
5858 if (key_type == BTRFS_DIR_INDEX_KEY) {
5859 if (is_curr)
5860 ctx->pos++;
5861 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5862 if (ret)
5863 goto nopos;
5864 }
5865
5866 /* Reached end of directory/root. Bump pos past the last item. */
5867 ctx->pos++;
5868
5869 /*
5870 * Stop new entries from being returned after we return the last
5871 * entry.
5872 *
5873 * New directory entries are assigned a strictly increasing
5874 * offset. This means that new entries created during readdir
5875 * are *guaranteed* to be seen in the future by that readdir.
5876 * This has broken buggy programs which operate on names as
5877 * they're returned by readdir. Until we re-use freed offsets
5878 * we have this hack to stop new entries from being returned
5879 * under the assumption that they'll never reach this huge
5880 * offset.
5881 *
5882 * This is being careful not to overflow 32bit loff_t unless the
5883 * last entry requires it because doing so has broken 32bit apps
5884 * in the past.
5885 */
5886 if (key_type == BTRFS_DIR_INDEX_KEY) {
5887 if (ctx->pos >= INT_MAX)
5888 ctx->pos = LLONG_MAX;
5889 else
5890 ctx->pos = INT_MAX;
5891 }
5892 nopos:
5893 ret = 0;
5894 err:
5895 if (key_type == BTRFS_DIR_INDEX_KEY)
5896 btrfs_put_delayed_items(&ins_list, &del_list);
5897 btrfs_free_path(path);
5898 return ret;
5899 }
5900
5901 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5902 {
5903 struct btrfs_root *root = BTRFS_I(inode)->root;
5904 struct btrfs_trans_handle *trans;
5905 int ret = 0;
5906 bool nolock = false;
5907
5908 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5909 return 0;
5910
5911 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5912 nolock = true;
5913
5914 if (wbc->sync_mode == WB_SYNC_ALL) {
5915 if (nolock)
5916 trans = btrfs_join_transaction_nolock(root);
5917 else
5918 trans = btrfs_join_transaction(root);
5919 if (IS_ERR(trans))
5920 return PTR_ERR(trans);
5921 ret = btrfs_commit_transaction(trans, root);
5922 }
5923 return ret;
5924 }
5925
5926 /*
5927 * This is somewhat expensive, updating the tree every time the
5928 * inode changes. But, it is most likely to find the inode in cache.
5929 * FIXME, needs more benchmarking...there are no reasons other than performance
5930 * to keep or drop this code.
5931 */
5932 static int btrfs_dirty_inode(struct inode *inode)
5933 {
5934 struct btrfs_root *root = BTRFS_I(inode)->root;
5935 struct btrfs_trans_handle *trans;
5936 int ret;
5937
5938 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5939 return 0;
5940
5941 trans = btrfs_join_transaction(root);
5942 if (IS_ERR(trans))
5943 return PTR_ERR(trans);
5944
5945 ret = btrfs_update_inode(trans, root, inode);
5946 if (ret && ret == -ENOSPC) {
5947 /* whoops, lets try again with the full transaction */
5948 btrfs_end_transaction(trans, root);
5949 trans = btrfs_start_transaction(root, 1);
5950 if (IS_ERR(trans))
5951 return PTR_ERR(trans);
5952
5953 ret = btrfs_update_inode(trans, root, inode);
5954 }
5955 btrfs_end_transaction(trans, root);
5956 if (BTRFS_I(inode)->delayed_node)
5957 btrfs_balance_delayed_items(root);
5958
5959 return ret;
5960 }
5961
5962 /*
5963 * This is a copy of file_update_time. We need this so we can return error on
5964 * ENOSPC for updating the inode in the case of file write and mmap writes.
5965 */
5966 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5967 int flags)
5968 {
5969 struct btrfs_root *root = BTRFS_I(inode)->root;
5970
5971 if (btrfs_root_readonly(root))
5972 return -EROFS;
5973
5974 if (flags & S_VERSION)
5975 inode_inc_iversion(inode);
5976 if (flags & S_CTIME)
5977 inode->i_ctime = *now;
5978 if (flags & S_MTIME)
5979 inode->i_mtime = *now;
5980 if (flags & S_ATIME)
5981 inode->i_atime = *now;
5982 return btrfs_dirty_inode(inode);
5983 }
5984
5985 /*
5986 * find the highest existing sequence number in a directory
5987 * and then set the in-memory index_cnt variable to reflect
5988 * free sequence numbers
5989 */
5990 static int btrfs_set_inode_index_count(struct inode *inode)
5991 {
5992 struct btrfs_root *root = BTRFS_I(inode)->root;
5993 struct btrfs_key key, found_key;
5994 struct btrfs_path *path;
5995 struct extent_buffer *leaf;
5996 int ret;
5997
5998 key.objectid = btrfs_ino(inode);
5999 key.type = BTRFS_DIR_INDEX_KEY;
6000 key.offset = (u64)-1;
6001
6002 path = btrfs_alloc_path();
6003 if (!path)
6004 return -ENOMEM;
6005
6006 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6007 if (ret < 0)
6008 goto out;
6009 /* FIXME: we should be able to handle this */
6010 if (ret == 0)
6011 goto out;
6012 ret = 0;
6013
6014 /*
6015 * MAGIC NUMBER EXPLANATION:
6016 * since we search a directory based on f_pos we have to start at 2
6017 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6018 * else has to start at 2
6019 */
6020 if (path->slots[0] == 0) {
6021 BTRFS_I(inode)->index_cnt = 2;
6022 goto out;
6023 }
6024
6025 path->slots[0]--;
6026
6027 leaf = path->nodes[0];
6028 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6029
6030 if (found_key.objectid != btrfs_ino(inode) ||
6031 found_key.type != BTRFS_DIR_INDEX_KEY) {
6032 BTRFS_I(inode)->index_cnt = 2;
6033 goto out;
6034 }
6035
6036 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6037 out:
6038 btrfs_free_path(path);
6039 return ret;
6040 }
6041
6042 /*
6043 * helper to find a free sequence number in a given directory. This current
6044 * code is very simple, later versions will do smarter things in the btree
6045 */
6046 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6047 {
6048 int ret = 0;
6049
6050 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6051 ret = btrfs_inode_delayed_dir_index_count(dir);
6052 if (ret) {
6053 ret = btrfs_set_inode_index_count(dir);
6054 if (ret)
6055 return ret;
6056 }
6057 }
6058
6059 *index = BTRFS_I(dir)->index_cnt;
6060 BTRFS_I(dir)->index_cnt++;
6061
6062 return ret;
6063 }
6064
6065 static int btrfs_insert_inode_locked(struct inode *inode)
6066 {
6067 struct btrfs_iget_args args;
6068 args.location = &BTRFS_I(inode)->location;
6069 args.root = BTRFS_I(inode)->root;
6070
6071 return insert_inode_locked4(inode,
6072 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6073 btrfs_find_actor, &args);
6074 }
6075
6076 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6077 struct btrfs_root *root,
6078 struct inode *dir,
6079 const char *name, int name_len,
6080 u64 ref_objectid, u64 objectid,
6081 umode_t mode, u64 *index)
6082 {
6083 struct inode *inode;
6084 struct btrfs_inode_item *inode_item;
6085 struct btrfs_key *location;
6086 struct btrfs_path *path;
6087 struct btrfs_inode_ref *ref;
6088 struct btrfs_key key[2];
6089 u32 sizes[2];
6090 int nitems = name ? 2 : 1;
6091 unsigned long ptr;
6092 int ret;
6093
6094 path = btrfs_alloc_path();
6095 if (!path)
6096 return ERR_PTR(-ENOMEM);
6097
6098 inode = new_inode(root->fs_info->sb);
6099 if (!inode) {
6100 btrfs_free_path(path);
6101 return ERR_PTR(-ENOMEM);
6102 }
6103
6104 /*
6105 * O_TMPFILE, set link count to 0, so that after this point,
6106 * we fill in an inode item with the correct link count.
6107 */
6108 if (!name)
6109 set_nlink(inode, 0);
6110
6111 /*
6112 * we have to initialize this early, so we can reclaim the inode
6113 * number if we fail afterwards in this function.
6114 */
6115 inode->i_ino = objectid;
6116
6117 if (dir && name) {
6118 trace_btrfs_inode_request(dir);
6119
6120 ret = btrfs_set_inode_index(dir, index);
6121 if (ret) {
6122 btrfs_free_path(path);
6123 iput(inode);
6124 return ERR_PTR(ret);
6125 }
6126 } else if (dir) {
6127 *index = 0;
6128 }
6129 /*
6130 * index_cnt is ignored for everything but a dir,
6131 * btrfs_get_inode_index_count has an explanation for the magic
6132 * number
6133 */
6134 BTRFS_I(inode)->index_cnt = 2;
6135 BTRFS_I(inode)->dir_index = *index;
6136 BTRFS_I(inode)->root = root;
6137 BTRFS_I(inode)->generation = trans->transid;
6138 inode->i_generation = BTRFS_I(inode)->generation;
6139
6140 /*
6141 * We could have gotten an inode number from somebody who was fsynced
6142 * and then removed in this same transaction, so let's just set full
6143 * sync since it will be a full sync anyway and this will blow away the
6144 * old info in the log.
6145 */
6146 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6147
6148 key[0].objectid = objectid;
6149 key[0].type = BTRFS_INODE_ITEM_KEY;
6150 key[0].offset = 0;
6151
6152 sizes[0] = sizeof(struct btrfs_inode_item);
6153
6154 if (name) {
6155 /*
6156 * Start new inodes with an inode_ref. This is slightly more
6157 * efficient for small numbers of hard links since they will
6158 * be packed into one item. Extended refs will kick in if we
6159 * add more hard links than can fit in the ref item.
6160 */
6161 key[1].objectid = objectid;
6162 key[1].type = BTRFS_INODE_REF_KEY;
6163 key[1].offset = ref_objectid;
6164
6165 sizes[1] = name_len + sizeof(*ref);
6166 }
6167
6168 location = &BTRFS_I(inode)->location;
6169 location->objectid = objectid;
6170 location->offset = 0;
6171 location->type = BTRFS_INODE_ITEM_KEY;
6172
6173 ret = btrfs_insert_inode_locked(inode);
6174 if (ret < 0)
6175 goto fail;
6176
6177 path->leave_spinning = 1;
6178 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6179 if (ret != 0)
6180 goto fail_unlock;
6181
6182 inode_init_owner(inode, dir, mode);
6183 inode_set_bytes(inode, 0);
6184
6185 inode->i_mtime = CURRENT_TIME;
6186 inode->i_atime = inode->i_mtime;
6187 inode->i_ctime = inode->i_mtime;
6188 BTRFS_I(inode)->i_otime = inode->i_mtime;
6189
6190 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6191 struct btrfs_inode_item);
6192 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6193 sizeof(*inode_item));
6194 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6195
6196 if (name) {
6197 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6198 struct btrfs_inode_ref);
6199 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6200 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6201 ptr = (unsigned long)(ref + 1);
6202 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6203 }
6204
6205 btrfs_mark_buffer_dirty(path->nodes[0]);
6206 btrfs_free_path(path);
6207
6208 btrfs_inherit_iflags(inode, dir);
6209
6210 if (S_ISREG(mode)) {
6211 if (btrfs_test_opt(root, NODATASUM))
6212 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6213 if (btrfs_test_opt(root, NODATACOW))
6214 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6215 BTRFS_INODE_NODATASUM;
6216 }
6217
6218 inode_tree_add(inode);
6219
6220 trace_btrfs_inode_new(inode);
6221 btrfs_set_inode_last_trans(trans, inode);
6222
6223 btrfs_update_root_times(trans, root);
6224
6225 ret = btrfs_inode_inherit_props(trans, inode, dir);
6226 if (ret)
6227 btrfs_err(root->fs_info,
6228 "error inheriting props for ino %llu (root %llu): %d",
6229 btrfs_ino(inode), root->root_key.objectid, ret);
6230
6231 return inode;
6232
6233 fail_unlock:
6234 unlock_new_inode(inode);
6235 fail:
6236 if (dir && name)
6237 BTRFS_I(dir)->index_cnt--;
6238 btrfs_free_path(path);
6239 iput(inode);
6240 return ERR_PTR(ret);
6241 }
6242
6243 static inline u8 btrfs_inode_type(struct inode *inode)
6244 {
6245 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6246 }
6247
6248 /*
6249 * utility function to add 'inode' into 'parent_inode' with
6250 * a give name and a given sequence number.
6251 * if 'add_backref' is true, also insert a backref from the
6252 * inode to the parent directory.
6253 */
6254 int btrfs_add_link(struct btrfs_trans_handle *trans,
6255 struct inode *parent_inode, struct inode *inode,
6256 const char *name, int name_len, int add_backref, u64 index)
6257 {
6258 int ret = 0;
6259 struct btrfs_key key;
6260 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6261 u64 ino = btrfs_ino(inode);
6262 u64 parent_ino = btrfs_ino(parent_inode);
6263
6264 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6265 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6266 } else {
6267 key.objectid = ino;
6268 key.type = BTRFS_INODE_ITEM_KEY;
6269 key.offset = 0;
6270 }
6271
6272 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6273 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6274 key.objectid, root->root_key.objectid,
6275 parent_ino, index, name, name_len);
6276 } else if (add_backref) {
6277 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6278 parent_ino, index);
6279 }
6280
6281 /* Nothing to clean up yet */
6282 if (ret)
6283 return ret;
6284
6285 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6286 parent_inode, &key,
6287 btrfs_inode_type(inode), index);
6288 if (ret == -EEXIST || ret == -EOVERFLOW)
6289 goto fail_dir_item;
6290 else if (ret) {
6291 btrfs_abort_transaction(trans, root, ret);
6292 return ret;
6293 }
6294
6295 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6296 name_len * 2);
6297 inode_inc_iversion(parent_inode);
6298 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6299 ret = btrfs_update_inode(trans, root, parent_inode);
6300 if (ret)
6301 btrfs_abort_transaction(trans, root, ret);
6302 return ret;
6303
6304 fail_dir_item:
6305 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6306 u64 local_index;
6307 int err;
6308 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6309 key.objectid, root->root_key.objectid,
6310 parent_ino, &local_index, name, name_len);
6311
6312 } else if (add_backref) {
6313 u64 local_index;
6314 int err;
6315
6316 err = btrfs_del_inode_ref(trans, root, name, name_len,
6317 ino, parent_ino, &local_index);
6318 }
6319 return ret;
6320 }
6321
6322 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6323 struct inode *dir, struct dentry *dentry,
6324 struct inode *inode, int backref, u64 index)
6325 {
6326 int err = btrfs_add_link(trans, dir, inode,
6327 dentry->d_name.name, dentry->d_name.len,
6328 backref, index);
6329 if (err > 0)
6330 err = -EEXIST;
6331 return err;
6332 }
6333
6334 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6335 umode_t mode, dev_t rdev)
6336 {
6337 struct btrfs_trans_handle *trans;
6338 struct btrfs_root *root = BTRFS_I(dir)->root;
6339 struct inode *inode = NULL;
6340 int err;
6341 int drop_inode = 0;
6342 u64 objectid;
6343 u64 index = 0;
6344
6345 /*
6346 * 2 for inode item and ref
6347 * 2 for dir items
6348 * 1 for xattr if selinux is on
6349 */
6350 trans = btrfs_start_transaction(root, 5);
6351 if (IS_ERR(trans))
6352 return PTR_ERR(trans);
6353
6354 err = btrfs_find_free_ino(root, &objectid);
6355 if (err)
6356 goto out_unlock;
6357
6358 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6359 dentry->d_name.len, btrfs_ino(dir), objectid,
6360 mode, &index);
6361 if (IS_ERR(inode)) {
6362 err = PTR_ERR(inode);
6363 goto out_unlock;
6364 }
6365
6366 /*
6367 * If the active LSM wants to access the inode during
6368 * d_instantiate it needs these. Smack checks to see
6369 * if the filesystem supports xattrs by looking at the
6370 * ops vector.
6371 */
6372 inode->i_op = &btrfs_special_inode_operations;
6373 init_special_inode(inode, inode->i_mode, rdev);
6374
6375 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6376 if (err)
6377 goto out_unlock_inode;
6378
6379 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6380 if (err) {
6381 goto out_unlock_inode;
6382 } else {
6383 btrfs_update_inode(trans, root, inode);
6384 unlock_new_inode(inode);
6385 d_instantiate(dentry, inode);
6386 }
6387
6388 out_unlock:
6389 btrfs_end_transaction(trans, root);
6390 btrfs_balance_delayed_items(root);
6391 btrfs_btree_balance_dirty(root);
6392 if (drop_inode) {
6393 inode_dec_link_count(inode);
6394 iput(inode);
6395 }
6396 return err;
6397
6398 out_unlock_inode:
6399 drop_inode = 1;
6400 unlock_new_inode(inode);
6401 goto out_unlock;
6402
6403 }
6404
6405 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6406 umode_t mode, bool excl)
6407 {
6408 struct btrfs_trans_handle *trans;
6409 struct btrfs_root *root = BTRFS_I(dir)->root;
6410 struct inode *inode = NULL;
6411 int drop_inode_on_err = 0;
6412 int err;
6413 u64 objectid;
6414 u64 index = 0;
6415
6416 /*
6417 * 2 for inode item and ref
6418 * 2 for dir items
6419 * 1 for xattr if selinux is on
6420 */
6421 trans = btrfs_start_transaction(root, 5);
6422 if (IS_ERR(trans))
6423 return PTR_ERR(trans);
6424
6425 err = btrfs_find_free_ino(root, &objectid);
6426 if (err)
6427 goto out_unlock;
6428
6429 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6430 dentry->d_name.len, btrfs_ino(dir), objectid,
6431 mode, &index);
6432 if (IS_ERR(inode)) {
6433 err = PTR_ERR(inode);
6434 goto out_unlock;
6435 }
6436 drop_inode_on_err = 1;
6437 /*
6438 * If the active LSM wants to access the inode during
6439 * d_instantiate it needs these. Smack checks to see
6440 * if the filesystem supports xattrs by looking at the
6441 * ops vector.
6442 */
6443 inode->i_fop = &btrfs_file_operations;
6444 inode->i_op = &btrfs_file_inode_operations;
6445 inode->i_mapping->a_ops = &btrfs_aops;
6446
6447 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6448 if (err)
6449 goto out_unlock_inode;
6450
6451 err = btrfs_update_inode(trans, root, inode);
6452 if (err)
6453 goto out_unlock_inode;
6454
6455 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6456 if (err)
6457 goto out_unlock_inode;
6458
6459 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6460 unlock_new_inode(inode);
6461 d_instantiate(dentry, inode);
6462
6463 out_unlock:
6464 btrfs_end_transaction(trans, root);
6465 if (err && drop_inode_on_err) {
6466 inode_dec_link_count(inode);
6467 iput(inode);
6468 }
6469 btrfs_balance_delayed_items(root);
6470 btrfs_btree_balance_dirty(root);
6471 return err;
6472
6473 out_unlock_inode:
6474 unlock_new_inode(inode);
6475 goto out_unlock;
6476
6477 }
6478
6479 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6480 struct dentry *dentry)
6481 {
6482 struct btrfs_trans_handle *trans = NULL;
6483 struct btrfs_root *root = BTRFS_I(dir)->root;
6484 struct inode *inode = d_inode(old_dentry);
6485 u64 index;
6486 int err;
6487 int drop_inode = 0;
6488
6489 /* do not allow sys_link's with other subvols of the same device */
6490 if (root->objectid != BTRFS_I(inode)->root->objectid)
6491 return -EXDEV;
6492
6493 if (inode->i_nlink >= BTRFS_LINK_MAX)
6494 return -EMLINK;
6495
6496 err = btrfs_set_inode_index(dir, &index);
6497 if (err)
6498 goto fail;
6499
6500 /*
6501 * 2 items for inode and inode ref
6502 * 2 items for dir items
6503 * 1 item for parent inode
6504 */
6505 trans = btrfs_start_transaction(root, 5);
6506 if (IS_ERR(trans)) {
6507 err = PTR_ERR(trans);
6508 trans = NULL;
6509 goto fail;
6510 }
6511
6512 /* There are several dir indexes for this inode, clear the cache. */
6513 BTRFS_I(inode)->dir_index = 0ULL;
6514 inc_nlink(inode);
6515 inode_inc_iversion(inode);
6516 inode->i_ctime = CURRENT_TIME;
6517 ihold(inode);
6518 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6519
6520 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6521
6522 if (err) {
6523 drop_inode = 1;
6524 } else {
6525 struct dentry *parent = dentry->d_parent;
6526 err = btrfs_update_inode(trans, root, inode);
6527 if (err)
6528 goto fail;
6529 if (inode->i_nlink == 1) {
6530 /*
6531 * If new hard link count is 1, it's a file created
6532 * with open(2) O_TMPFILE flag.
6533 */
6534 err = btrfs_orphan_del(trans, inode);
6535 if (err)
6536 goto fail;
6537 }
6538 d_instantiate(dentry, inode);
6539 btrfs_log_new_name(trans, inode, NULL, parent);
6540 }
6541
6542 btrfs_balance_delayed_items(root);
6543 fail:
6544 if (trans)
6545 btrfs_end_transaction(trans, root);
6546 if (drop_inode) {
6547 inode_dec_link_count(inode);
6548 iput(inode);
6549 }
6550 btrfs_btree_balance_dirty(root);
6551 return err;
6552 }
6553
6554 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6555 {
6556 struct inode *inode = NULL;
6557 struct btrfs_trans_handle *trans;
6558 struct btrfs_root *root = BTRFS_I(dir)->root;
6559 int err = 0;
6560 int drop_on_err = 0;
6561 u64 objectid = 0;
6562 u64 index = 0;
6563
6564 /*
6565 * 2 items for inode and ref
6566 * 2 items for dir items
6567 * 1 for xattr if selinux is on
6568 */
6569 trans = btrfs_start_transaction(root, 5);
6570 if (IS_ERR(trans))
6571 return PTR_ERR(trans);
6572
6573 err = btrfs_find_free_ino(root, &objectid);
6574 if (err)
6575 goto out_fail;
6576
6577 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6578 dentry->d_name.len, btrfs_ino(dir), objectid,
6579 S_IFDIR | mode, &index);
6580 if (IS_ERR(inode)) {
6581 err = PTR_ERR(inode);
6582 goto out_fail;
6583 }
6584
6585 drop_on_err = 1;
6586 /* these must be set before we unlock the inode */
6587 inode->i_op = &btrfs_dir_inode_operations;
6588 inode->i_fop = &btrfs_dir_file_operations;
6589
6590 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6591 if (err)
6592 goto out_fail_inode;
6593
6594 btrfs_i_size_write(inode, 0);
6595 err = btrfs_update_inode(trans, root, inode);
6596 if (err)
6597 goto out_fail_inode;
6598
6599 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6600 dentry->d_name.len, 0, index);
6601 if (err)
6602 goto out_fail_inode;
6603
6604 d_instantiate(dentry, inode);
6605 /*
6606 * mkdir is special. We're unlocking after we call d_instantiate
6607 * to avoid a race with nfsd calling d_instantiate.
6608 */
6609 unlock_new_inode(inode);
6610 drop_on_err = 0;
6611
6612 out_fail:
6613 btrfs_end_transaction(trans, root);
6614 if (drop_on_err) {
6615 inode_dec_link_count(inode);
6616 iput(inode);
6617 }
6618 btrfs_balance_delayed_items(root);
6619 btrfs_btree_balance_dirty(root);
6620 return err;
6621
6622 out_fail_inode:
6623 unlock_new_inode(inode);
6624 goto out_fail;
6625 }
6626
6627 /* Find next extent map of a given extent map, caller needs to ensure locks */
6628 static struct extent_map *next_extent_map(struct extent_map *em)
6629 {
6630 struct rb_node *next;
6631
6632 next = rb_next(&em->rb_node);
6633 if (!next)
6634 return NULL;
6635 return container_of(next, struct extent_map, rb_node);
6636 }
6637
6638 static struct extent_map *prev_extent_map(struct extent_map *em)
6639 {
6640 struct rb_node *prev;
6641
6642 prev = rb_prev(&em->rb_node);
6643 if (!prev)
6644 return NULL;
6645 return container_of(prev, struct extent_map, rb_node);
6646 }
6647
6648 /* helper for btfs_get_extent. Given an existing extent in the tree,
6649 * the existing extent is the nearest extent to map_start,
6650 * and an extent that you want to insert, deal with overlap and insert
6651 * the best fitted new extent into the tree.
6652 */
6653 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6654 struct extent_map *existing,
6655 struct extent_map *em,
6656 u64 map_start)
6657 {
6658 struct extent_map *prev;
6659 struct extent_map *next;
6660 u64 start;
6661 u64 end;
6662 u64 start_diff;
6663
6664 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6665
6666 if (existing->start > map_start) {
6667 next = existing;
6668 prev = prev_extent_map(next);
6669 } else {
6670 prev = existing;
6671 next = next_extent_map(prev);
6672 }
6673
6674 start = prev ? extent_map_end(prev) : em->start;
6675 start = max_t(u64, start, em->start);
6676 end = next ? next->start : extent_map_end(em);
6677 end = min_t(u64, end, extent_map_end(em));
6678 start_diff = start - em->start;
6679 em->start = start;
6680 em->len = end - start;
6681 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6682 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6683 em->block_start += start_diff;
6684 em->block_len -= start_diff;
6685 }
6686 return add_extent_mapping(em_tree, em, 0);
6687 }
6688
6689 static noinline int uncompress_inline(struct btrfs_path *path,
6690 struct page *page,
6691 size_t pg_offset, u64 extent_offset,
6692 struct btrfs_file_extent_item *item)
6693 {
6694 int ret;
6695 struct extent_buffer *leaf = path->nodes[0];
6696 char *tmp;
6697 size_t max_size;
6698 unsigned long inline_size;
6699 unsigned long ptr;
6700 int compress_type;
6701
6702 WARN_ON(pg_offset != 0);
6703 compress_type = btrfs_file_extent_compression(leaf, item);
6704 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6705 inline_size = btrfs_file_extent_inline_item_len(leaf,
6706 btrfs_item_nr(path->slots[0]));
6707 tmp = kmalloc(inline_size, GFP_NOFS);
6708 if (!tmp)
6709 return -ENOMEM;
6710 ptr = btrfs_file_extent_inline_start(item);
6711
6712 read_extent_buffer(leaf, tmp, ptr, inline_size);
6713
6714 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6715 ret = btrfs_decompress(compress_type, tmp, page,
6716 extent_offset, inline_size, max_size);
6717 kfree(tmp);
6718 return ret;
6719 }
6720
6721 /*
6722 * a bit scary, this does extent mapping from logical file offset to the disk.
6723 * the ugly parts come from merging extents from the disk with the in-ram
6724 * representation. This gets more complex because of the data=ordered code,
6725 * where the in-ram extents might be locked pending data=ordered completion.
6726 *
6727 * This also copies inline extents directly into the page.
6728 */
6729
6730 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6731 size_t pg_offset, u64 start, u64 len,
6732 int create)
6733 {
6734 int ret;
6735 int err = 0;
6736 u64 extent_start = 0;
6737 u64 extent_end = 0;
6738 u64 objectid = btrfs_ino(inode);
6739 u32 found_type;
6740 struct btrfs_path *path = NULL;
6741 struct btrfs_root *root = BTRFS_I(inode)->root;
6742 struct btrfs_file_extent_item *item;
6743 struct extent_buffer *leaf;
6744 struct btrfs_key found_key;
6745 struct extent_map *em = NULL;
6746 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6747 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6748 struct btrfs_trans_handle *trans = NULL;
6749 const bool new_inline = !page || create;
6750
6751 again:
6752 read_lock(&em_tree->lock);
6753 em = lookup_extent_mapping(em_tree, start, len);
6754 if (em)
6755 em->bdev = root->fs_info->fs_devices->latest_bdev;
6756 read_unlock(&em_tree->lock);
6757
6758 if (em) {
6759 if (em->start > start || em->start + em->len <= start)
6760 free_extent_map(em);
6761 else if (em->block_start == EXTENT_MAP_INLINE && page)
6762 free_extent_map(em);
6763 else
6764 goto out;
6765 }
6766 em = alloc_extent_map();
6767 if (!em) {
6768 err = -ENOMEM;
6769 goto out;
6770 }
6771 em->bdev = root->fs_info->fs_devices->latest_bdev;
6772 em->start = EXTENT_MAP_HOLE;
6773 em->orig_start = EXTENT_MAP_HOLE;
6774 em->len = (u64)-1;
6775 em->block_len = (u64)-1;
6776
6777 if (!path) {
6778 path = btrfs_alloc_path();
6779 if (!path) {
6780 err = -ENOMEM;
6781 goto out;
6782 }
6783 /*
6784 * Chances are we'll be called again, so go ahead and do
6785 * readahead
6786 */
6787 path->reada = READA_FORWARD;
6788 }
6789
6790 ret = btrfs_lookup_file_extent(trans, root, path,
6791 objectid, start, trans != NULL);
6792 if (ret < 0) {
6793 err = ret;
6794 goto out;
6795 }
6796
6797 if (ret != 0) {
6798 if (path->slots[0] == 0)
6799 goto not_found;
6800 path->slots[0]--;
6801 }
6802
6803 leaf = path->nodes[0];
6804 item = btrfs_item_ptr(leaf, path->slots[0],
6805 struct btrfs_file_extent_item);
6806 /* are we inside the extent that was found? */
6807 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6808 found_type = found_key.type;
6809 if (found_key.objectid != objectid ||
6810 found_type != BTRFS_EXTENT_DATA_KEY) {
6811 /*
6812 * If we backup past the first extent we want to move forward
6813 * and see if there is an extent in front of us, otherwise we'll
6814 * say there is a hole for our whole search range which can
6815 * cause problems.
6816 */
6817 extent_end = start;
6818 goto next;
6819 }
6820
6821 found_type = btrfs_file_extent_type(leaf, item);
6822 extent_start = found_key.offset;
6823 if (found_type == BTRFS_FILE_EXTENT_REG ||
6824 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6825 extent_end = extent_start +
6826 btrfs_file_extent_num_bytes(leaf, item);
6827 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6828 size_t size;
6829 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6830 extent_end = ALIGN(extent_start + size, root->sectorsize);
6831 }
6832 next:
6833 if (start >= extent_end) {
6834 path->slots[0]++;
6835 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6836 ret = btrfs_next_leaf(root, path);
6837 if (ret < 0) {
6838 err = ret;
6839 goto out;
6840 }
6841 if (ret > 0)
6842 goto not_found;
6843 leaf = path->nodes[0];
6844 }
6845 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6846 if (found_key.objectid != objectid ||
6847 found_key.type != BTRFS_EXTENT_DATA_KEY)
6848 goto not_found;
6849 if (start + len <= found_key.offset)
6850 goto not_found;
6851 if (start > found_key.offset)
6852 goto next;
6853 em->start = start;
6854 em->orig_start = start;
6855 em->len = found_key.offset - start;
6856 goto not_found_em;
6857 }
6858
6859 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6860
6861 if (found_type == BTRFS_FILE_EXTENT_REG ||
6862 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6863 goto insert;
6864 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6865 unsigned long ptr;
6866 char *map;
6867 size_t size;
6868 size_t extent_offset;
6869 size_t copy_size;
6870
6871 if (new_inline)
6872 goto out;
6873
6874 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6875 extent_offset = page_offset(page) + pg_offset - extent_start;
6876 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6877 size - extent_offset);
6878 em->start = extent_start + extent_offset;
6879 em->len = ALIGN(copy_size, root->sectorsize);
6880 em->orig_block_len = em->len;
6881 em->orig_start = em->start;
6882 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6883 if (create == 0 && !PageUptodate(page)) {
6884 if (btrfs_file_extent_compression(leaf, item) !=
6885 BTRFS_COMPRESS_NONE) {
6886 ret = uncompress_inline(path, page, pg_offset,
6887 extent_offset, item);
6888 if (ret) {
6889 err = ret;
6890 goto out;
6891 }
6892 } else {
6893 map = kmap(page);
6894 read_extent_buffer(leaf, map + pg_offset, ptr,
6895 copy_size);
6896 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6897 memset(map + pg_offset + copy_size, 0,
6898 PAGE_CACHE_SIZE - pg_offset -
6899 copy_size);
6900 }
6901 kunmap(page);
6902 }
6903 flush_dcache_page(page);
6904 } else if (create && PageUptodate(page)) {
6905 BUG();
6906 if (!trans) {
6907 kunmap(page);
6908 free_extent_map(em);
6909 em = NULL;
6910
6911 btrfs_release_path(path);
6912 trans = btrfs_join_transaction(root);
6913
6914 if (IS_ERR(trans))
6915 return ERR_CAST(trans);
6916 goto again;
6917 }
6918 map = kmap(page);
6919 write_extent_buffer(leaf, map + pg_offset, ptr,
6920 copy_size);
6921 kunmap(page);
6922 btrfs_mark_buffer_dirty(leaf);
6923 }
6924 set_extent_uptodate(io_tree, em->start,
6925 extent_map_end(em) - 1, NULL, GFP_NOFS);
6926 goto insert;
6927 }
6928 not_found:
6929 em->start = start;
6930 em->orig_start = start;
6931 em->len = len;
6932 not_found_em:
6933 em->block_start = EXTENT_MAP_HOLE;
6934 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6935 insert:
6936 btrfs_release_path(path);
6937 if (em->start > start || extent_map_end(em) <= start) {
6938 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6939 em->start, em->len, start, len);
6940 err = -EIO;
6941 goto out;
6942 }
6943
6944 err = 0;
6945 write_lock(&em_tree->lock);
6946 ret = add_extent_mapping(em_tree, em, 0);
6947 /* it is possible that someone inserted the extent into the tree
6948 * while we had the lock dropped. It is also possible that
6949 * an overlapping map exists in the tree
6950 */
6951 if (ret == -EEXIST) {
6952 struct extent_map *existing;
6953
6954 ret = 0;
6955
6956 existing = search_extent_mapping(em_tree, start, len);
6957 /*
6958 * existing will always be non-NULL, since there must be
6959 * extent causing the -EEXIST.
6960 */
6961 if (start >= extent_map_end(existing) ||
6962 start <= existing->start) {
6963 /*
6964 * The existing extent map is the one nearest to
6965 * the [start, start + len) range which overlaps
6966 */
6967 err = merge_extent_mapping(em_tree, existing,
6968 em, start);
6969 free_extent_map(existing);
6970 if (err) {
6971 free_extent_map(em);
6972 em = NULL;
6973 }
6974 } else {
6975 free_extent_map(em);
6976 em = existing;
6977 err = 0;
6978 }
6979 }
6980 write_unlock(&em_tree->lock);
6981 out:
6982
6983 trace_btrfs_get_extent(root, em);
6984
6985 btrfs_free_path(path);
6986 if (trans) {
6987 ret = btrfs_end_transaction(trans, root);
6988 if (!err)
6989 err = ret;
6990 }
6991 if (err) {
6992 free_extent_map(em);
6993 return ERR_PTR(err);
6994 }
6995 BUG_ON(!em); /* Error is always set */
6996 return em;
6997 }
6998
6999 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7000 size_t pg_offset, u64 start, u64 len,
7001 int create)
7002 {
7003 struct extent_map *em;
7004 struct extent_map *hole_em = NULL;
7005 u64 range_start = start;
7006 u64 end;
7007 u64 found;
7008 u64 found_end;
7009 int err = 0;
7010
7011 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7012 if (IS_ERR(em))
7013 return em;
7014 if (em) {
7015 /*
7016 * if our em maps to
7017 * - a hole or
7018 * - a pre-alloc extent,
7019 * there might actually be delalloc bytes behind it.
7020 */
7021 if (em->block_start != EXTENT_MAP_HOLE &&
7022 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7023 return em;
7024 else
7025 hole_em = em;
7026 }
7027
7028 /* check to see if we've wrapped (len == -1 or similar) */
7029 end = start + len;
7030 if (end < start)
7031 end = (u64)-1;
7032 else
7033 end -= 1;
7034
7035 em = NULL;
7036
7037 /* ok, we didn't find anything, lets look for delalloc */
7038 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7039 end, len, EXTENT_DELALLOC, 1);
7040 found_end = range_start + found;
7041 if (found_end < range_start)
7042 found_end = (u64)-1;
7043
7044 /*
7045 * we didn't find anything useful, return
7046 * the original results from get_extent()
7047 */
7048 if (range_start > end || found_end <= start) {
7049 em = hole_em;
7050 hole_em = NULL;
7051 goto out;
7052 }
7053
7054 /* adjust the range_start to make sure it doesn't
7055 * go backwards from the start they passed in
7056 */
7057 range_start = max(start, range_start);
7058 found = found_end - range_start;
7059
7060 if (found > 0) {
7061 u64 hole_start = start;
7062 u64 hole_len = len;
7063
7064 em = alloc_extent_map();
7065 if (!em) {
7066 err = -ENOMEM;
7067 goto out;
7068 }
7069 /*
7070 * when btrfs_get_extent can't find anything it
7071 * returns one huge hole
7072 *
7073 * make sure what it found really fits our range, and
7074 * adjust to make sure it is based on the start from
7075 * the caller
7076 */
7077 if (hole_em) {
7078 u64 calc_end = extent_map_end(hole_em);
7079
7080 if (calc_end <= start || (hole_em->start > end)) {
7081 free_extent_map(hole_em);
7082 hole_em = NULL;
7083 } else {
7084 hole_start = max(hole_em->start, start);
7085 hole_len = calc_end - hole_start;
7086 }
7087 }
7088 em->bdev = NULL;
7089 if (hole_em && range_start > hole_start) {
7090 /* our hole starts before our delalloc, so we
7091 * have to return just the parts of the hole
7092 * that go until the delalloc starts
7093 */
7094 em->len = min(hole_len,
7095 range_start - hole_start);
7096 em->start = hole_start;
7097 em->orig_start = hole_start;
7098 /*
7099 * don't adjust block start at all,
7100 * it is fixed at EXTENT_MAP_HOLE
7101 */
7102 em->block_start = hole_em->block_start;
7103 em->block_len = hole_len;
7104 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7105 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7106 } else {
7107 em->start = range_start;
7108 em->len = found;
7109 em->orig_start = range_start;
7110 em->block_start = EXTENT_MAP_DELALLOC;
7111 em->block_len = found;
7112 }
7113 } else if (hole_em) {
7114 return hole_em;
7115 }
7116 out:
7117
7118 free_extent_map(hole_em);
7119 if (err) {
7120 free_extent_map(em);
7121 return ERR_PTR(err);
7122 }
7123 return em;
7124 }
7125
7126 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7127 u64 start, u64 len)
7128 {
7129 struct btrfs_root *root = BTRFS_I(inode)->root;
7130 struct extent_map *em;
7131 struct btrfs_key ins;
7132 u64 alloc_hint;
7133 int ret;
7134
7135 alloc_hint = get_extent_allocation_hint(inode, start, len);
7136 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7137 alloc_hint, &ins, 1, 1);
7138 if (ret)
7139 return ERR_PTR(ret);
7140
7141 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7142 ins.offset, ins.offset, ins.offset, 0);
7143 if (IS_ERR(em)) {
7144 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7145 return em;
7146 }
7147
7148 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7149 ins.offset, ins.offset, 0);
7150 if (ret) {
7151 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7152 free_extent_map(em);
7153 return ERR_PTR(ret);
7154 }
7155
7156 return em;
7157 }
7158
7159 /*
7160 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7161 * block must be cow'd
7162 */
7163 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7164 u64 *orig_start, u64 *orig_block_len,
7165 u64 *ram_bytes)
7166 {
7167 struct btrfs_trans_handle *trans;
7168 struct btrfs_path *path;
7169 int ret;
7170 struct extent_buffer *leaf;
7171 struct btrfs_root *root = BTRFS_I(inode)->root;
7172 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7173 struct btrfs_file_extent_item *fi;
7174 struct btrfs_key key;
7175 u64 disk_bytenr;
7176 u64 backref_offset;
7177 u64 extent_end;
7178 u64 num_bytes;
7179 int slot;
7180 int found_type;
7181 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7182
7183 path = btrfs_alloc_path();
7184 if (!path)
7185 return -ENOMEM;
7186
7187 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7188 offset, 0);
7189 if (ret < 0)
7190 goto out;
7191
7192 slot = path->slots[0];
7193 if (ret == 1) {
7194 if (slot == 0) {
7195 /* can't find the item, must cow */
7196 ret = 0;
7197 goto out;
7198 }
7199 slot--;
7200 }
7201 ret = 0;
7202 leaf = path->nodes[0];
7203 btrfs_item_key_to_cpu(leaf, &key, slot);
7204 if (key.objectid != btrfs_ino(inode) ||
7205 key.type != BTRFS_EXTENT_DATA_KEY) {
7206 /* not our file or wrong item type, must cow */
7207 goto out;
7208 }
7209
7210 if (key.offset > offset) {
7211 /* Wrong offset, must cow */
7212 goto out;
7213 }
7214
7215 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7216 found_type = btrfs_file_extent_type(leaf, fi);
7217 if (found_type != BTRFS_FILE_EXTENT_REG &&
7218 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7219 /* not a regular extent, must cow */
7220 goto out;
7221 }
7222
7223 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7224 goto out;
7225
7226 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7227 if (extent_end <= offset)
7228 goto out;
7229
7230 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7231 if (disk_bytenr == 0)
7232 goto out;
7233
7234 if (btrfs_file_extent_compression(leaf, fi) ||
7235 btrfs_file_extent_encryption(leaf, fi) ||
7236 btrfs_file_extent_other_encoding(leaf, fi))
7237 goto out;
7238
7239 backref_offset = btrfs_file_extent_offset(leaf, fi);
7240
7241 if (orig_start) {
7242 *orig_start = key.offset - backref_offset;
7243 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7244 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7245 }
7246
7247 if (btrfs_extent_readonly(root, disk_bytenr))
7248 goto out;
7249
7250 num_bytes = min(offset + *len, extent_end) - offset;
7251 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7252 u64 range_end;
7253
7254 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7255 ret = test_range_bit(io_tree, offset, range_end,
7256 EXTENT_DELALLOC, 0, NULL);
7257 if (ret) {
7258 ret = -EAGAIN;
7259 goto out;
7260 }
7261 }
7262
7263 btrfs_release_path(path);
7264
7265 /*
7266 * look for other files referencing this extent, if we
7267 * find any we must cow
7268 */
7269 trans = btrfs_join_transaction(root);
7270 if (IS_ERR(trans)) {
7271 ret = 0;
7272 goto out;
7273 }
7274
7275 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7276 key.offset - backref_offset, disk_bytenr);
7277 btrfs_end_transaction(trans, root);
7278 if (ret) {
7279 ret = 0;
7280 goto out;
7281 }
7282
7283 /*
7284 * adjust disk_bytenr and num_bytes to cover just the bytes
7285 * in this extent we are about to write. If there
7286 * are any csums in that range we have to cow in order
7287 * to keep the csums correct
7288 */
7289 disk_bytenr += backref_offset;
7290 disk_bytenr += offset - key.offset;
7291 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7292 goto out;
7293 /*
7294 * all of the above have passed, it is safe to overwrite this extent
7295 * without cow
7296 */
7297 *len = num_bytes;
7298 ret = 1;
7299 out:
7300 btrfs_free_path(path);
7301 return ret;
7302 }
7303
7304 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7305 {
7306 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7307 int found = false;
7308 void **pagep = NULL;
7309 struct page *page = NULL;
7310 int start_idx;
7311 int end_idx;
7312
7313 start_idx = start >> PAGE_CACHE_SHIFT;
7314
7315 /*
7316 * end is the last byte in the last page. end == start is legal
7317 */
7318 end_idx = end >> PAGE_CACHE_SHIFT;
7319
7320 rcu_read_lock();
7321
7322 /* Most of the code in this while loop is lifted from
7323 * find_get_page. It's been modified to begin searching from a
7324 * page and return just the first page found in that range. If the
7325 * found idx is less than or equal to the end idx then we know that
7326 * a page exists. If no pages are found or if those pages are
7327 * outside of the range then we're fine (yay!) */
7328 while (page == NULL &&
7329 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7330 page = radix_tree_deref_slot(pagep);
7331 if (unlikely(!page))
7332 break;
7333
7334 if (radix_tree_exception(page)) {
7335 if (radix_tree_deref_retry(page)) {
7336 page = NULL;
7337 continue;
7338 }
7339 /*
7340 * Otherwise, shmem/tmpfs must be storing a swap entry
7341 * here as an exceptional entry: so return it without
7342 * attempting to raise page count.
7343 */
7344 page = NULL;
7345 break; /* TODO: Is this relevant for this use case? */
7346 }
7347
7348 if (!page_cache_get_speculative(page)) {
7349 page = NULL;
7350 continue;
7351 }
7352
7353 /*
7354 * Has the page moved?
7355 * This is part of the lockless pagecache protocol. See
7356 * include/linux/pagemap.h for details.
7357 */
7358 if (unlikely(page != *pagep)) {
7359 page_cache_release(page);
7360 page = NULL;
7361 }
7362 }
7363
7364 if (page) {
7365 if (page->index <= end_idx)
7366 found = true;
7367 page_cache_release(page);
7368 }
7369
7370 rcu_read_unlock();
7371 return found;
7372 }
7373
7374 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7375 struct extent_state **cached_state, int writing)
7376 {
7377 struct btrfs_ordered_extent *ordered;
7378 int ret = 0;
7379
7380 while (1) {
7381 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7382 cached_state);
7383 /*
7384 * We're concerned with the entire range that we're going to be
7385 * doing DIO to, so we need to make sure theres no ordered
7386 * extents in this range.
7387 */
7388 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7389 lockend - lockstart + 1);
7390
7391 /*
7392 * We need to make sure there are no buffered pages in this
7393 * range either, we could have raced between the invalidate in
7394 * generic_file_direct_write and locking the extent. The
7395 * invalidate needs to happen so that reads after a write do not
7396 * get stale data.
7397 */
7398 if (!ordered &&
7399 (!writing ||
7400 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7401 break;
7402
7403 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7404 cached_state, GFP_NOFS);
7405
7406 if (ordered) {
7407 btrfs_start_ordered_extent(inode, ordered, 1);
7408 btrfs_put_ordered_extent(ordered);
7409 } else {
7410 /*
7411 * We could trigger writeback for this range (and wait
7412 * for it to complete) and then invalidate the pages for
7413 * this range (through invalidate_inode_pages2_range()),
7414 * but that can lead us to a deadlock with a concurrent
7415 * call to readpages() (a buffered read or a defrag call
7416 * triggered a readahead) on a page lock due to an
7417 * ordered dio extent we created before but did not have
7418 * yet a corresponding bio submitted (whence it can not
7419 * complete), which makes readpages() wait for that
7420 * ordered extent to complete while holding a lock on
7421 * that page.
7422 */
7423 ret = -ENOTBLK;
7424 break;
7425 }
7426
7427 cond_resched();
7428 }
7429
7430 return ret;
7431 }
7432
7433 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7434 u64 len, u64 orig_start,
7435 u64 block_start, u64 block_len,
7436 u64 orig_block_len, u64 ram_bytes,
7437 int type)
7438 {
7439 struct extent_map_tree *em_tree;
7440 struct extent_map *em;
7441 struct btrfs_root *root = BTRFS_I(inode)->root;
7442 int ret;
7443
7444 em_tree = &BTRFS_I(inode)->extent_tree;
7445 em = alloc_extent_map();
7446 if (!em)
7447 return ERR_PTR(-ENOMEM);
7448
7449 em->start = start;
7450 em->orig_start = orig_start;
7451 em->mod_start = start;
7452 em->mod_len = len;
7453 em->len = len;
7454 em->block_len = block_len;
7455 em->block_start = block_start;
7456 em->bdev = root->fs_info->fs_devices->latest_bdev;
7457 em->orig_block_len = orig_block_len;
7458 em->ram_bytes = ram_bytes;
7459 em->generation = -1;
7460 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7461 if (type == BTRFS_ORDERED_PREALLOC)
7462 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7463
7464 do {
7465 btrfs_drop_extent_cache(inode, em->start,
7466 em->start + em->len - 1, 0);
7467 write_lock(&em_tree->lock);
7468 ret = add_extent_mapping(em_tree, em, 1);
7469 write_unlock(&em_tree->lock);
7470 } while (ret == -EEXIST);
7471
7472 if (ret) {
7473 free_extent_map(em);
7474 return ERR_PTR(ret);
7475 }
7476
7477 return em;
7478 }
7479
7480 static void adjust_dio_outstanding_extents(struct inode *inode,
7481 struct btrfs_dio_data *dio_data,
7482 const u64 len)
7483 {
7484 unsigned num_extents;
7485
7486 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7487 BTRFS_MAX_EXTENT_SIZE);
7488 /*
7489 * If we have an outstanding_extents count still set then we're
7490 * within our reservation, otherwise we need to adjust our inode
7491 * counter appropriately.
7492 */
7493 if (dio_data->outstanding_extents) {
7494 dio_data->outstanding_extents -= num_extents;
7495 } else {
7496 spin_lock(&BTRFS_I(inode)->lock);
7497 BTRFS_I(inode)->outstanding_extents += num_extents;
7498 spin_unlock(&BTRFS_I(inode)->lock);
7499 }
7500 }
7501
7502 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7503 struct buffer_head *bh_result, int create)
7504 {
7505 struct extent_map *em;
7506 struct btrfs_root *root = BTRFS_I(inode)->root;
7507 struct extent_state *cached_state = NULL;
7508 struct btrfs_dio_data *dio_data = NULL;
7509 u64 start = iblock << inode->i_blkbits;
7510 u64 lockstart, lockend;
7511 u64 len = bh_result->b_size;
7512 int unlock_bits = EXTENT_LOCKED;
7513 int ret = 0;
7514
7515 if (create)
7516 unlock_bits |= EXTENT_DIRTY;
7517 else
7518 len = min_t(u64, len, root->sectorsize);
7519
7520 lockstart = start;
7521 lockend = start + len - 1;
7522
7523 if (current->journal_info) {
7524 /*
7525 * Need to pull our outstanding extents and set journal_info to NULL so
7526 * that anything that needs to check if there's a transction doesn't get
7527 * confused.
7528 */
7529 dio_data = current->journal_info;
7530 current->journal_info = NULL;
7531 }
7532
7533 /*
7534 * If this errors out it's because we couldn't invalidate pagecache for
7535 * this range and we need to fallback to buffered.
7536 */
7537 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7538 create)) {
7539 ret = -ENOTBLK;
7540 goto err;
7541 }
7542
7543 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7544 if (IS_ERR(em)) {
7545 ret = PTR_ERR(em);
7546 goto unlock_err;
7547 }
7548
7549 /*
7550 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7551 * io. INLINE is special, and we could probably kludge it in here, but
7552 * it's still buffered so for safety lets just fall back to the generic
7553 * buffered path.
7554 *
7555 * For COMPRESSED we _have_ to read the entire extent in so we can
7556 * decompress it, so there will be buffering required no matter what we
7557 * do, so go ahead and fallback to buffered.
7558 *
7559 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7560 * to buffered IO. Don't blame me, this is the price we pay for using
7561 * the generic code.
7562 */
7563 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7564 em->block_start == EXTENT_MAP_INLINE) {
7565 free_extent_map(em);
7566 ret = -ENOTBLK;
7567 goto unlock_err;
7568 }
7569
7570 /* Just a good old fashioned hole, return */
7571 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7572 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7573 free_extent_map(em);
7574 goto unlock_err;
7575 }
7576
7577 /*
7578 * We don't allocate a new extent in the following cases
7579 *
7580 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7581 * existing extent.
7582 * 2) The extent is marked as PREALLOC. We're good to go here and can
7583 * just use the extent.
7584 *
7585 */
7586 if (!create) {
7587 len = min(len, em->len - (start - em->start));
7588 lockstart = start + len;
7589 goto unlock;
7590 }
7591
7592 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7593 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7594 em->block_start != EXTENT_MAP_HOLE)) {
7595 int type;
7596 u64 block_start, orig_start, orig_block_len, ram_bytes;
7597
7598 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7599 type = BTRFS_ORDERED_PREALLOC;
7600 else
7601 type = BTRFS_ORDERED_NOCOW;
7602 len = min(len, em->len - (start - em->start));
7603 block_start = em->block_start + (start - em->start);
7604
7605 if (can_nocow_extent(inode, start, &len, &orig_start,
7606 &orig_block_len, &ram_bytes) == 1) {
7607 if (type == BTRFS_ORDERED_PREALLOC) {
7608 free_extent_map(em);
7609 em = create_pinned_em(inode, start, len,
7610 orig_start,
7611 block_start, len,
7612 orig_block_len,
7613 ram_bytes, type);
7614 if (IS_ERR(em)) {
7615 ret = PTR_ERR(em);
7616 goto unlock_err;
7617 }
7618 }
7619
7620 ret = btrfs_add_ordered_extent_dio(inode, start,
7621 block_start, len, len, type);
7622 if (ret) {
7623 free_extent_map(em);
7624 goto unlock_err;
7625 }
7626 goto unlock;
7627 }
7628 }
7629
7630 /*
7631 * this will cow the extent, reset the len in case we changed
7632 * it above
7633 */
7634 len = bh_result->b_size;
7635 free_extent_map(em);
7636 em = btrfs_new_extent_direct(inode, start, len);
7637 if (IS_ERR(em)) {
7638 ret = PTR_ERR(em);
7639 goto unlock_err;
7640 }
7641 len = min(len, em->len - (start - em->start));
7642 unlock:
7643 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7644 inode->i_blkbits;
7645 bh_result->b_size = len;
7646 bh_result->b_bdev = em->bdev;
7647 set_buffer_mapped(bh_result);
7648 if (create) {
7649 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7650 set_buffer_new(bh_result);
7651
7652 /*
7653 * Need to update the i_size under the extent lock so buffered
7654 * readers will get the updated i_size when we unlock.
7655 */
7656 if (start + len > i_size_read(inode))
7657 i_size_write(inode, start + len);
7658
7659 adjust_dio_outstanding_extents(inode, dio_data, len);
7660 btrfs_free_reserved_data_space(inode, start, len);
7661 WARN_ON(dio_data->reserve < len);
7662 dio_data->reserve -= len;
7663 dio_data->unsubmitted_oe_range_end = start + len;
7664 current->journal_info = dio_data;
7665 }
7666
7667 /*
7668 * In the case of write we need to clear and unlock the entire range,
7669 * in the case of read we need to unlock only the end area that we
7670 * aren't using if there is any left over space.
7671 */
7672 if (lockstart < lockend) {
7673 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7674 lockend, unlock_bits, 1, 0,
7675 &cached_state, GFP_NOFS);
7676 } else {
7677 free_extent_state(cached_state);
7678 }
7679
7680 free_extent_map(em);
7681
7682 return 0;
7683
7684 unlock_err:
7685 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7686 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7687 err:
7688 if (dio_data)
7689 current->journal_info = dio_data;
7690 /*
7691 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7692 * write less data then expected, so that we don't underflow our inode's
7693 * outstanding extents counter.
7694 */
7695 if (create && dio_data)
7696 adjust_dio_outstanding_extents(inode, dio_data, len);
7697
7698 return ret;
7699 }
7700
7701 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7702 int rw, int mirror_num)
7703 {
7704 struct btrfs_root *root = BTRFS_I(inode)->root;
7705 int ret;
7706
7707 BUG_ON(rw & REQ_WRITE);
7708
7709 bio_get(bio);
7710
7711 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7712 BTRFS_WQ_ENDIO_DIO_REPAIR);
7713 if (ret)
7714 goto err;
7715
7716 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7717 err:
7718 bio_put(bio);
7719 return ret;
7720 }
7721
7722 static int btrfs_check_dio_repairable(struct inode *inode,
7723 struct bio *failed_bio,
7724 struct io_failure_record *failrec,
7725 int failed_mirror)
7726 {
7727 int num_copies;
7728
7729 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7730 failrec->logical, failrec->len);
7731 if (num_copies == 1) {
7732 /*
7733 * we only have a single copy of the data, so don't bother with
7734 * all the retry and error correction code that follows. no
7735 * matter what the error is, it is very likely to persist.
7736 */
7737 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7738 num_copies, failrec->this_mirror, failed_mirror);
7739 return 0;
7740 }
7741
7742 failrec->failed_mirror = failed_mirror;
7743 failrec->this_mirror++;
7744 if (failrec->this_mirror == failed_mirror)
7745 failrec->this_mirror++;
7746
7747 if (failrec->this_mirror > num_copies) {
7748 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7749 num_copies, failrec->this_mirror, failed_mirror);
7750 return 0;
7751 }
7752
7753 return 1;
7754 }
7755
7756 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7757 struct page *page, u64 start, u64 end,
7758 int failed_mirror, bio_end_io_t *repair_endio,
7759 void *repair_arg)
7760 {
7761 struct io_failure_record *failrec;
7762 struct bio *bio;
7763 int isector;
7764 int read_mode;
7765 int ret;
7766
7767 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7768
7769 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7770 if (ret)
7771 return ret;
7772
7773 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7774 failed_mirror);
7775 if (!ret) {
7776 free_io_failure(inode, failrec);
7777 return -EIO;
7778 }
7779
7780 if (failed_bio->bi_vcnt > 1)
7781 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7782 else
7783 read_mode = READ_SYNC;
7784
7785 isector = start - btrfs_io_bio(failed_bio)->logical;
7786 isector >>= inode->i_sb->s_blocksize_bits;
7787 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7788 0, isector, repair_endio, repair_arg);
7789 if (!bio) {
7790 free_io_failure(inode, failrec);
7791 return -EIO;
7792 }
7793
7794 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7795 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7796 read_mode, failrec->this_mirror, failrec->in_validation);
7797
7798 ret = submit_dio_repair_bio(inode, bio, read_mode,
7799 failrec->this_mirror);
7800 if (ret) {
7801 free_io_failure(inode, failrec);
7802 bio_put(bio);
7803 }
7804
7805 return ret;
7806 }
7807
7808 struct btrfs_retry_complete {
7809 struct completion done;
7810 struct inode *inode;
7811 u64 start;
7812 int uptodate;
7813 };
7814
7815 static void btrfs_retry_endio_nocsum(struct bio *bio)
7816 {
7817 struct btrfs_retry_complete *done = bio->bi_private;
7818 struct bio_vec *bvec;
7819 int i;
7820
7821 if (bio->bi_error)
7822 goto end;
7823
7824 done->uptodate = 1;
7825 bio_for_each_segment_all(bvec, bio, i)
7826 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7827 end:
7828 complete(&done->done);
7829 bio_put(bio);
7830 }
7831
7832 static int __btrfs_correct_data_nocsum(struct inode *inode,
7833 struct btrfs_io_bio *io_bio)
7834 {
7835 struct bio_vec *bvec;
7836 struct btrfs_retry_complete done;
7837 u64 start;
7838 int i;
7839 int ret;
7840
7841 start = io_bio->logical;
7842 done.inode = inode;
7843
7844 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7845 try_again:
7846 done.uptodate = 0;
7847 done.start = start;
7848 init_completion(&done.done);
7849
7850 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7851 start + bvec->bv_len - 1,
7852 io_bio->mirror_num,
7853 btrfs_retry_endio_nocsum, &done);
7854 if (ret)
7855 return ret;
7856
7857 wait_for_completion(&done.done);
7858
7859 if (!done.uptodate) {
7860 /* We might have another mirror, so try again */
7861 goto try_again;
7862 }
7863
7864 start += bvec->bv_len;
7865 }
7866
7867 return 0;
7868 }
7869
7870 static void btrfs_retry_endio(struct bio *bio)
7871 {
7872 struct btrfs_retry_complete *done = bio->bi_private;
7873 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7874 struct bio_vec *bvec;
7875 int uptodate;
7876 int ret;
7877 int i;
7878
7879 if (bio->bi_error)
7880 goto end;
7881
7882 uptodate = 1;
7883 bio_for_each_segment_all(bvec, bio, i) {
7884 ret = __readpage_endio_check(done->inode, io_bio, i,
7885 bvec->bv_page, 0,
7886 done->start, bvec->bv_len);
7887 if (!ret)
7888 clean_io_failure(done->inode, done->start,
7889 bvec->bv_page, 0);
7890 else
7891 uptodate = 0;
7892 }
7893
7894 done->uptodate = uptodate;
7895 end:
7896 complete(&done->done);
7897 bio_put(bio);
7898 }
7899
7900 static int __btrfs_subio_endio_read(struct inode *inode,
7901 struct btrfs_io_bio *io_bio, int err)
7902 {
7903 struct bio_vec *bvec;
7904 struct btrfs_retry_complete done;
7905 u64 start;
7906 u64 offset = 0;
7907 int i;
7908 int ret;
7909
7910 err = 0;
7911 start = io_bio->logical;
7912 done.inode = inode;
7913
7914 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7915 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7916 0, start, bvec->bv_len);
7917 if (likely(!ret))
7918 goto next;
7919 try_again:
7920 done.uptodate = 0;
7921 done.start = start;
7922 init_completion(&done.done);
7923
7924 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7925 start + bvec->bv_len - 1,
7926 io_bio->mirror_num,
7927 btrfs_retry_endio, &done);
7928 if (ret) {
7929 err = ret;
7930 goto next;
7931 }
7932
7933 wait_for_completion(&done.done);
7934
7935 if (!done.uptodate) {
7936 /* We might have another mirror, so try again */
7937 goto try_again;
7938 }
7939 next:
7940 offset += bvec->bv_len;
7941 start += bvec->bv_len;
7942 }
7943
7944 return err;
7945 }
7946
7947 static int btrfs_subio_endio_read(struct inode *inode,
7948 struct btrfs_io_bio *io_bio, int err)
7949 {
7950 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7951
7952 if (skip_csum) {
7953 if (unlikely(err))
7954 return __btrfs_correct_data_nocsum(inode, io_bio);
7955 else
7956 return 0;
7957 } else {
7958 return __btrfs_subio_endio_read(inode, io_bio, err);
7959 }
7960 }
7961
7962 static void btrfs_endio_direct_read(struct bio *bio)
7963 {
7964 struct btrfs_dio_private *dip = bio->bi_private;
7965 struct inode *inode = dip->inode;
7966 struct bio *dio_bio;
7967 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7968 int err = bio->bi_error;
7969
7970 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
7971 err = btrfs_subio_endio_read(inode, io_bio, err);
7972
7973 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7974 dip->logical_offset + dip->bytes - 1);
7975 dio_bio = dip->dio_bio;
7976
7977 kfree(dip);
7978
7979 dio_end_io(dio_bio, bio->bi_error);
7980
7981 if (io_bio->end_io)
7982 io_bio->end_io(io_bio, err);
7983 bio_put(bio);
7984 }
7985
7986 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
7987 const u64 offset,
7988 const u64 bytes,
7989 const int uptodate)
7990 {
7991 struct btrfs_root *root = BTRFS_I(inode)->root;
7992 struct btrfs_ordered_extent *ordered = NULL;
7993 u64 ordered_offset = offset;
7994 u64 ordered_bytes = bytes;
7995 int ret;
7996
7997 again:
7998 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7999 &ordered_offset,
8000 ordered_bytes,
8001 uptodate);
8002 if (!ret)
8003 goto out_test;
8004
8005 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8006 finish_ordered_fn, NULL, NULL);
8007 btrfs_queue_work(root->fs_info->endio_write_workers,
8008 &ordered->work);
8009 out_test:
8010 /*
8011 * our bio might span multiple ordered extents. If we haven't
8012 * completed the accounting for the whole dio, go back and try again
8013 */
8014 if (ordered_offset < offset + bytes) {
8015 ordered_bytes = offset + bytes - ordered_offset;
8016 ordered = NULL;
8017 goto again;
8018 }
8019 }
8020
8021 static void btrfs_endio_direct_write(struct bio *bio)
8022 {
8023 struct btrfs_dio_private *dip = bio->bi_private;
8024 struct bio *dio_bio = dip->dio_bio;
8025
8026 btrfs_endio_direct_write_update_ordered(dip->inode,
8027 dip->logical_offset,
8028 dip->bytes,
8029 !bio->bi_error);
8030
8031 kfree(dip);
8032
8033 dio_end_io(dio_bio, bio->bi_error);
8034 bio_put(bio);
8035 }
8036
8037 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8038 struct bio *bio, int mirror_num,
8039 unsigned long bio_flags, u64 offset)
8040 {
8041 int ret;
8042 struct btrfs_root *root = BTRFS_I(inode)->root;
8043 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8044 BUG_ON(ret); /* -ENOMEM */
8045 return 0;
8046 }
8047
8048 static void btrfs_end_dio_bio(struct bio *bio)
8049 {
8050 struct btrfs_dio_private *dip = bio->bi_private;
8051 int err = bio->bi_error;
8052
8053 if (err)
8054 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8055 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8056 btrfs_ino(dip->inode), bio->bi_rw,
8057 (unsigned long long)bio->bi_iter.bi_sector,
8058 bio->bi_iter.bi_size, err);
8059
8060 if (dip->subio_endio)
8061 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8062
8063 if (err) {
8064 dip->errors = 1;
8065
8066 /*
8067 * before atomic variable goto zero, we must make sure
8068 * dip->errors is perceived to be set.
8069 */
8070 smp_mb__before_atomic();
8071 }
8072
8073 /* if there are more bios still pending for this dio, just exit */
8074 if (!atomic_dec_and_test(&dip->pending_bios))
8075 goto out;
8076
8077 if (dip->errors) {
8078 bio_io_error(dip->orig_bio);
8079 } else {
8080 dip->dio_bio->bi_error = 0;
8081 bio_endio(dip->orig_bio);
8082 }
8083 out:
8084 bio_put(bio);
8085 }
8086
8087 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8088 u64 first_sector, gfp_t gfp_flags)
8089 {
8090 struct bio *bio;
8091 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8092 if (bio)
8093 bio_associate_current(bio);
8094 return bio;
8095 }
8096
8097 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8098 struct inode *inode,
8099 struct btrfs_dio_private *dip,
8100 struct bio *bio,
8101 u64 file_offset)
8102 {
8103 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8104 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8105 int ret;
8106
8107 /*
8108 * We load all the csum data we need when we submit
8109 * the first bio to reduce the csum tree search and
8110 * contention.
8111 */
8112 if (dip->logical_offset == file_offset) {
8113 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8114 file_offset);
8115 if (ret)
8116 return ret;
8117 }
8118
8119 if (bio == dip->orig_bio)
8120 return 0;
8121
8122 file_offset -= dip->logical_offset;
8123 file_offset >>= inode->i_sb->s_blocksize_bits;
8124 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8125
8126 return 0;
8127 }
8128
8129 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8130 int rw, u64 file_offset, int skip_sum,
8131 int async_submit)
8132 {
8133 struct btrfs_dio_private *dip = bio->bi_private;
8134 int write = rw & REQ_WRITE;
8135 struct btrfs_root *root = BTRFS_I(inode)->root;
8136 int ret;
8137
8138 if (async_submit)
8139 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8140
8141 bio_get(bio);
8142
8143 if (!write) {
8144 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8145 BTRFS_WQ_ENDIO_DATA);
8146 if (ret)
8147 goto err;
8148 }
8149
8150 if (skip_sum)
8151 goto map;
8152
8153 if (write && async_submit) {
8154 ret = btrfs_wq_submit_bio(root->fs_info,
8155 inode, rw, bio, 0, 0,
8156 file_offset,
8157 __btrfs_submit_bio_start_direct_io,
8158 __btrfs_submit_bio_done);
8159 goto err;
8160 } else if (write) {
8161 /*
8162 * If we aren't doing async submit, calculate the csum of the
8163 * bio now.
8164 */
8165 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8166 if (ret)
8167 goto err;
8168 } else {
8169 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8170 file_offset);
8171 if (ret)
8172 goto err;
8173 }
8174 map:
8175 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8176 err:
8177 bio_put(bio);
8178 return ret;
8179 }
8180
8181 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8182 int skip_sum)
8183 {
8184 struct inode *inode = dip->inode;
8185 struct btrfs_root *root = BTRFS_I(inode)->root;
8186 struct bio *bio;
8187 struct bio *orig_bio = dip->orig_bio;
8188 struct bio_vec *bvec = orig_bio->bi_io_vec;
8189 u64 start_sector = orig_bio->bi_iter.bi_sector;
8190 u64 file_offset = dip->logical_offset;
8191 u64 submit_len = 0;
8192 u64 map_length;
8193 int nr_pages = 0;
8194 int ret;
8195 int async_submit = 0;
8196
8197 map_length = orig_bio->bi_iter.bi_size;
8198 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8199 &map_length, NULL, 0);
8200 if (ret)
8201 return -EIO;
8202
8203 if (map_length >= orig_bio->bi_iter.bi_size) {
8204 bio = orig_bio;
8205 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8206 goto submit;
8207 }
8208
8209 /* async crcs make it difficult to collect full stripe writes. */
8210 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8211 async_submit = 0;
8212 else
8213 async_submit = 1;
8214
8215 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8216 if (!bio)
8217 return -ENOMEM;
8218
8219 bio->bi_private = dip;
8220 bio->bi_end_io = btrfs_end_dio_bio;
8221 btrfs_io_bio(bio)->logical = file_offset;
8222 atomic_inc(&dip->pending_bios);
8223
8224 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8225 if (map_length < submit_len + bvec->bv_len ||
8226 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8227 bvec->bv_offset) < bvec->bv_len) {
8228 /*
8229 * inc the count before we submit the bio so
8230 * we know the end IO handler won't happen before
8231 * we inc the count. Otherwise, the dip might get freed
8232 * before we're done setting it up
8233 */
8234 atomic_inc(&dip->pending_bios);
8235 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8236 file_offset, skip_sum,
8237 async_submit);
8238 if (ret) {
8239 bio_put(bio);
8240 atomic_dec(&dip->pending_bios);
8241 goto out_err;
8242 }
8243
8244 start_sector += submit_len >> 9;
8245 file_offset += submit_len;
8246
8247 submit_len = 0;
8248 nr_pages = 0;
8249
8250 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8251 start_sector, GFP_NOFS);
8252 if (!bio)
8253 goto out_err;
8254 bio->bi_private = dip;
8255 bio->bi_end_io = btrfs_end_dio_bio;
8256 btrfs_io_bio(bio)->logical = file_offset;
8257
8258 map_length = orig_bio->bi_iter.bi_size;
8259 ret = btrfs_map_block(root->fs_info, rw,
8260 start_sector << 9,
8261 &map_length, NULL, 0);
8262 if (ret) {
8263 bio_put(bio);
8264 goto out_err;
8265 }
8266 } else {
8267 submit_len += bvec->bv_len;
8268 nr_pages++;
8269 bvec++;
8270 }
8271 }
8272
8273 submit:
8274 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8275 async_submit);
8276 if (!ret)
8277 return 0;
8278
8279 bio_put(bio);
8280 out_err:
8281 dip->errors = 1;
8282 /*
8283 * before atomic variable goto zero, we must
8284 * make sure dip->errors is perceived to be set.
8285 */
8286 smp_mb__before_atomic();
8287 if (atomic_dec_and_test(&dip->pending_bios))
8288 bio_io_error(dip->orig_bio);
8289
8290 /* bio_end_io() will handle error, so we needn't return it */
8291 return 0;
8292 }
8293
8294 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8295 struct inode *inode, loff_t file_offset)
8296 {
8297 struct btrfs_dio_private *dip = NULL;
8298 struct bio *io_bio = NULL;
8299 struct btrfs_io_bio *btrfs_bio;
8300 int skip_sum;
8301 int write = rw & REQ_WRITE;
8302 int ret = 0;
8303
8304 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8305
8306 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8307 if (!io_bio) {
8308 ret = -ENOMEM;
8309 goto free_ordered;
8310 }
8311
8312 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8313 if (!dip) {
8314 ret = -ENOMEM;
8315 goto free_ordered;
8316 }
8317
8318 dip->private = dio_bio->bi_private;
8319 dip->inode = inode;
8320 dip->logical_offset = file_offset;
8321 dip->bytes = dio_bio->bi_iter.bi_size;
8322 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8323 io_bio->bi_private = dip;
8324 dip->orig_bio = io_bio;
8325 dip->dio_bio = dio_bio;
8326 atomic_set(&dip->pending_bios, 0);
8327 btrfs_bio = btrfs_io_bio(io_bio);
8328 btrfs_bio->logical = file_offset;
8329
8330 if (write) {
8331 io_bio->bi_end_io = btrfs_endio_direct_write;
8332 } else {
8333 io_bio->bi_end_io = btrfs_endio_direct_read;
8334 dip->subio_endio = btrfs_subio_endio_read;
8335 }
8336
8337 /*
8338 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8339 * even if we fail to submit a bio, because in such case we do the
8340 * corresponding error handling below and it must not be done a second
8341 * time by btrfs_direct_IO().
8342 */
8343 if (write) {
8344 struct btrfs_dio_data *dio_data = current->journal_info;
8345
8346 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8347 dip->bytes;
8348 dio_data->unsubmitted_oe_range_start =
8349 dio_data->unsubmitted_oe_range_end;
8350 }
8351
8352 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8353 if (!ret)
8354 return;
8355
8356 if (btrfs_bio->end_io)
8357 btrfs_bio->end_io(btrfs_bio, ret);
8358
8359 free_ordered:
8360 /*
8361 * If we arrived here it means either we failed to submit the dip
8362 * or we either failed to clone the dio_bio or failed to allocate the
8363 * dip. If we cloned the dio_bio and allocated the dip, we can just
8364 * call bio_endio against our io_bio so that we get proper resource
8365 * cleanup if we fail to submit the dip, otherwise, we must do the
8366 * same as btrfs_endio_direct_[write|read] because we can't call these
8367 * callbacks - they require an allocated dip and a clone of dio_bio.
8368 */
8369 if (io_bio && dip) {
8370 io_bio->bi_error = -EIO;
8371 bio_endio(io_bio);
8372 /*
8373 * The end io callbacks free our dip, do the final put on io_bio
8374 * and all the cleanup and final put for dio_bio (through
8375 * dio_end_io()).
8376 */
8377 dip = NULL;
8378 io_bio = NULL;
8379 } else {
8380 if (write)
8381 btrfs_endio_direct_write_update_ordered(inode,
8382 file_offset,
8383 dio_bio->bi_iter.bi_size,
8384 0);
8385 else
8386 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8387 file_offset + dio_bio->bi_iter.bi_size - 1);
8388
8389 dio_bio->bi_error = -EIO;
8390 /*
8391 * Releases and cleans up our dio_bio, no need to bio_put()
8392 * nor bio_endio()/bio_io_error() against dio_bio.
8393 */
8394 dio_end_io(dio_bio, ret);
8395 }
8396 if (io_bio)
8397 bio_put(io_bio);
8398 kfree(dip);
8399 }
8400
8401 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8402 const struct iov_iter *iter, loff_t offset)
8403 {
8404 int seg;
8405 int i;
8406 unsigned blocksize_mask = root->sectorsize - 1;
8407 ssize_t retval = -EINVAL;
8408
8409 if (offset & blocksize_mask)
8410 goto out;
8411
8412 if (iov_iter_alignment(iter) & blocksize_mask)
8413 goto out;
8414
8415 /* If this is a write we don't need to check anymore */
8416 if (iov_iter_rw(iter) == WRITE)
8417 return 0;
8418 /*
8419 * Check to make sure we don't have duplicate iov_base's in this
8420 * iovec, if so return EINVAL, otherwise we'll get csum errors
8421 * when reading back.
8422 */
8423 for (seg = 0; seg < iter->nr_segs; seg++) {
8424 for (i = seg + 1; i < iter->nr_segs; i++) {
8425 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8426 goto out;
8427 }
8428 }
8429 retval = 0;
8430 out:
8431 return retval;
8432 }
8433
8434 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8435 loff_t offset)
8436 {
8437 struct file *file = iocb->ki_filp;
8438 struct inode *inode = file->f_mapping->host;
8439 struct btrfs_root *root = BTRFS_I(inode)->root;
8440 struct btrfs_dio_data dio_data = { 0 };
8441 size_t count = 0;
8442 int flags = 0;
8443 bool wakeup = true;
8444 bool relock = false;
8445 ssize_t ret;
8446
8447 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8448 return 0;
8449
8450 inode_dio_begin(inode);
8451 smp_mb__after_atomic();
8452
8453 /*
8454 * The generic stuff only does filemap_write_and_wait_range, which
8455 * isn't enough if we've written compressed pages to this area, so
8456 * we need to flush the dirty pages again to make absolutely sure
8457 * that any outstanding dirty pages are on disk.
8458 */
8459 count = iov_iter_count(iter);
8460 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8461 &BTRFS_I(inode)->runtime_flags))
8462 filemap_fdatawrite_range(inode->i_mapping, offset,
8463 offset + count - 1);
8464
8465 if (iov_iter_rw(iter) == WRITE) {
8466 /*
8467 * If the write DIO is beyond the EOF, we need update
8468 * the isize, but it is protected by i_mutex. So we can
8469 * not unlock the i_mutex at this case.
8470 */
8471 if (offset + count <= inode->i_size) {
8472 mutex_unlock(&inode->i_mutex);
8473 relock = true;
8474 }
8475 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8476 if (ret)
8477 goto out;
8478 dio_data.outstanding_extents = div64_u64(count +
8479 BTRFS_MAX_EXTENT_SIZE - 1,
8480 BTRFS_MAX_EXTENT_SIZE);
8481
8482 /*
8483 * We need to know how many extents we reserved so that we can
8484 * do the accounting properly if we go over the number we
8485 * originally calculated. Abuse current->journal_info for this.
8486 */
8487 dio_data.reserve = round_up(count, root->sectorsize);
8488 dio_data.unsubmitted_oe_range_start = (u64)offset;
8489 dio_data.unsubmitted_oe_range_end = (u64)offset;
8490 current->journal_info = &dio_data;
8491 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8492 &BTRFS_I(inode)->runtime_flags)) {
8493 inode_dio_end(inode);
8494 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8495 wakeup = false;
8496 }
8497
8498 ret = __blockdev_direct_IO(iocb, inode,
8499 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8500 iter, offset, btrfs_get_blocks_direct, NULL,
8501 btrfs_submit_direct, flags);
8502 if (iov_iter_rw(iter) == WRITE) {
8503 current->journal_info = NULL;
8504 if (ret < 0 && ret != -EIOCBQUEUED) {
8505 if (dio_data.reserve)
8506 btrfs_delalloc_release_space(inode, offset,
8507 dio_data.reserve);
8508 /*
8509 * On error we might have left some ordered extents
8510 * without submitting corresponding bios for them, so
8511 * cleanup them up to avoid other tasks getting them
8512 * and waiting for them to complete forever.
8513 */
8514 if (dio_data.unsubmitted_oe_range_start <
8515 dio_data.unsubmitted_oe_range_end)
8516 btrfs_endio_direct_write_update_ordered(inode,
8517 dio_data.unsubmitted_oe_range_start,
8518 dio_data.unsubmitted_oe_range_end -
8519 dio_data.unsubmitted_oe_range_start,
8520 0);
8521 } else if (ret >= 0 && (size_t)ret < count)
8522 btrfs_delalloc_release_space(inode, offset,
8523 count - (size_t)ret);
8524 }
8525 out:
8526 if (wakeup)
8527 inode_dio_end(inode);
8528 if (relock)
8529 mutex_lock(&inode->i_mutex);
8530
8531 return ret;
8532 }
8533
8534 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8535
8536 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8537 __u64 start, __u64 len)
8538 {
8539 int ret;
8540
8541 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8542 if (ret)
8543 return ret;
8544
8545 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8546 }
8547
8548 int btrfs_readpage(struct file *file, struct page *page)
8549 {
8550 struct extent_io_tree *tree;
8551 tree = &BTRFS_I(page->mapping->host)->io_tree;
8552 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8553 }
8554
8555 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8556 {
8557 struct extent_io_tree *tree;
8558 struct inode *inode = page->mapping->host;
8559 int ret;
8560
8561 if (current->flags & PF_MEMALLOC) {
8562 redirty_page_for_writepage(wbc, page);
8563 unlock_page(page);
8564 return 0;
8565 }
8566
8567 /*
8568 * If we are under memory pressure we will call this directly from the
8569 * VM, we need to make sure we have the inode referenced for the ordered
8570 * extent. If not just return like we didn't do anything.
8571 */
8572 if (!igrab(inode)) {
8573 redirty_page_for_writepage(wbc, page);
8574 return AOP_WRITEPAGE_ACTIVATE;
8575 }
8576 tree = &BTRFS_I(page->mapping->host)->io_tree;
8577 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8578 btrfs_add_delayed_iput(inode);
8579 return ret;
8580 }
8581
8582 static int btrfs_writepages(struct address_space *mapping,
8583 struct writeback_control *wbc)
8584 {
8585 struct extent_io_tree *tree;
8586
8587 tree = &BTRFS_I(mapping->host)->io_tree;
8588 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8589 }
8590
8591 static int
8592 btrfs_readpages(struct file *file, struct address_space *mapping,
8593 struct list_head *pages, unsigned nr_pages)
8594 {
8595 struct extent_io_tree *tree;
8596 tree = &BTRFS_I(mapping->host)->io_tree;
8597 return extent_readpages(tree, mapping, pages, nr_pages,
8598 btrfs_get_extent);
8599 }
8600 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8601 {
8602 struct extent_io_tree *tree;
8603 struct extent_map_tree *map;
8604 int ret;
8605
8606 tree = &BTRFS_I(page->mapping->host)->io_tree;
8607 map = &BTRFS_I(page->mapping->host)->extent_tree;
8608 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8609 if (ret == 1) {
8610 ClearPagePrivate(page);
8611 set_page_private(page, 0);
8612 page_cache_release(page);
8613 }
8614 return ret;
8615 }
8616
8617 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8618 {
8619 if (PageWriteback(page) || PageDirty(page))
8620 return 0;
8621 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8622 }
8623
8624 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8625 unsigned int length)
8626 {
8627 struct inode *inode = page->mapping->host;
8628 struct extent_io_tree *tree;
8629 struct btrfs_ordered_extent *ordered;
8630 struct extent_state *cached_state = NULL;
8631 u64 page_start = page_offset(page);
8632 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8633 int inode_evicting = inode->i_state & I_FREEING;
8634
8635 /*
8636 * we have the page locked, so new writeback can't start,
8637 * and the dirty bit won't be cleared while we are here.
8638 *
8639 * Wait for IO on this page so that we can safely clear
8640 * the PagePrivate2 bit and do ordered accounting
8641 */
8642 wait_on_page_writeback(page);
8643
8644 tree = &BTRFS_I(inode)->io_tree;
8645 if (offset) {
8646 btrfs_releasepage(page, GFP_NOFS);
8647 return;
8648 }
8649
8650 if (!inode_evicting)
8651 lock_extent_bits(tree, page_start, page_end, &cached_state);
8652 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8653 if (ordered) {
8654 /*
8655 * IO on this page will never be started, so we need
8656 * to account for any ordered extents now
8657 */
8658 if (!inode_evicting)
8659 clear_extent_bit(tree, page_start, page_end,
8660 EXTENT_DIRTY | EXTENT_DELALLOC |
8661 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8662 EXTENT_DEFRAG, 1, 0, &cached_state,
8663 GFP_NOFS);
8664 /*
8665 * whoever cleared the private bit is responsible
8666 * for the finish_ordered_io
8667 */
8668 if (TestClearPagePrivate2(page)) {
8669 struct btrfs_ordered_inode_tree *tree;
8670 u64 new_len;
8671
8672 tree = &BTRFS_I(inode)->ordered_tree;
8673
8674 spin_lock_irq(&tree->lock);
8675 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8676 new_len = page_start - ordered->file_offset;
8677 if (new_len < ordered->truncated_len)
8678 ordered->truncated_len = new_len;
8679 spin_unlock_irq(&tree->lock);
8680
8681 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8682 page_start,
8683 PAGE_CACHE_SIZE, 1))
8684 btrfs_finish_ordered_io(ordered);
8685 }
8686 btrfs_put_ordered_extent(ordered);
8687 if (!inode_evicting) {
8688 cached_state = NULL;
8689 lock_extent_bits(tree, page_start, page_end,
8690 &cached_state);
8691 }
8692 }
8693
8694 /*
8695 * Qgroup reserved space handler
8696 * Page here will be either
8697 * 1) Already written to disk
8698 * In this case, its reserved space is released from data rsv map
8699 * and will be freed by delayed_ref handler finally.
8700 * So even we call qgroup_free_data(), it won't decrease reserved
8701 * space.
8702 * 2) Not written to disk
8703 * This means the reserved space should be freed here.
8704 */
8705 btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
8706 if (!inode_evicting) {
8707 clear_extent_bit(tree, page_start, page_end,
8708 EXTENT_LOCKED | EXTENT_DIRTY |
8709 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8710 EXTENT_DEFRAG, 1, 1,
8711 &cached_state, GFP_NOFS);
8712
8713 __btrfs_releasepage(page, GFP_NOFS);
8714 }
8715
8716 ClearPageChecked(page);
8717 if (PagePrivate(page)) {
8718 ClearPagePrivate(page);
8719 set_page_private(page, 0);
8720 page_cache_release(page);
8721 }
8722 }
8723
8724 /*
8725 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8726 * called from a page fault handler when a page is first dirtied. Hence we must
8727 * be careful to check for EOF conditions here. We set the page up correctly
8728 * for a written page which means we get ENOSPC checking when writing into
8729 * holes and correct delalloc and unwritten extent mapping on filesystems that
8730 * support these features.
8731 *
8732 * We are not allowed to take the i_mutex here so we have to play games to
8733 * protect against truncate races as the page could now be beyond EOF. Because
8734 * vmtruncate() writes the inode size before removing pages, once we have the
8735 * page lock we can determine safely if the page is beyond EOF. If it is not
8736 * beyond EOF, then the page is guaranteed safe against truncation until we
8737 * unlock the page.
8738 */
8739 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8740 {
8741 struct page *page = vmf->page;
8742 struct inode *inode = file_inode(vma->vm_file);
8743 struct btrfs_root *root = BTRFS_I(inode)->root;
8744 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8745 struct btrfs_ordered_extent *ordered;
8746 struct extent_state *cached_state = NULL;
8747 char *kaddr;
8748 unsigned long zero_start;
8749 loff_t size;
8750 int ret;
8751 int reserved = 0;
8752 u64 page_start;
8753 u64 page_end;
8754
8755 sb_start_pagefault(inode->i_sb);
8756 page_start = page_offset(page);
8757 page_end = page_start + PAGE_CACHE_SIZE - 1;
8758
8759 ret = btrfs_delalloc_reserve_space(inode, page_start,
8760 PAGE_CACHE_SIZE);
8761 if (!ret) {
8762 ret = file_update_time(vma->vm_file);
8763 reserved = 1;
8764 }
8765 if (ret) {
8766 if (ret == -ENOMEM)
8767 ret = VM_FAULT_OOM;
8768 else /* -ENOSPC, -EIO, etc */
8769 ret = VM_FAULT_SIGBUS;
8770 if (reserved)
8771 goto out;
8772 goto out_noreserve;
8773 }
8774
8775 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8776 again:
8777 lock_page(page);
8778 size = i_size_read(inode);
8779
8780 if ((page->mapping != inode->i_mapping) ||
8781 (page_start >= size)) {
8782 /* page got truncated out from underneath us */
8783 goto out_unlock;
8784 }
8785 wait_on_page_writeback(page);
8786
8787 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8788 set_page_extent_mapped(page);
8789
8790 /*
8791 * we can't set the delalloc bits if there are pending ordered
8792 * extents. Drop our locks and wait for them to finish
8793 */
8794 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8795 if (ordered) {
8796 unlock_extent_cached(io_tree, page_start, page_end,
8797 &cached_state, GFP_NOFS);
8798 unlock_page(page);
8799 btrfs_start_ordered_extent(inode, ordered, 1);
8800 btrfs_put_ordered_extent(ordered);
8801 goto again;
8802 }
8803
8804 /*
8805 * XXX - page_mkwrite gets called every time the page is dirtied, even
8806 * if it was already dirty, so for space accounting reasons we need to
8807 * clear any delalloc bits for the range we are fixing to save. There
8808 * is probably a better way to do this, but for now keep consistent with
8809 * prepare_pages in the normal write path.
8810 */
8811 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8812 EXTENT_DIRTY | EXTENT_DELALLOC |
8813 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8814 0, 0, &cached_state, GFP_NOFS);
8815
8816 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8817 &cached_state);
8818 if (ret) {
8819 unlock_extent_cached(io_tree, page_start, page_end,
8820 &cached_state, GFP_NOFS);
8821 ret = VM_FAULT_SIGBUS;
8822 goto out_unlock;
8823 }
8824 ret = 0;
8825
8826 /* page is wholly or partially inside EOF */
8827 if (page_start + PAGE_CACHE_SIZE > size)
8828 zero_start = size & ~PAGE_CACHE_MASK;
8829 else
8830 zero_start = PAGE_CACHE_SIZE;
8831
8832 if (zero_start != PAGE_CACHE_SIZE) {
8833 kaddr = kmap(page);
8834 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8835 flush_dcache_page(page);
8836 kunmap(page);
8837 }
8838 ClearPageChecked(page);
8839 set_page_dirty(page);
8840 SetPageUptodate(page);
8841
8842 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8843 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8844 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8845
8846 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8847
8848 out_unlock:
8849 if (!ret) {
8850 sb_end_pagefault(inode->i_sb);
8851 return VM_FAULT_LOCKED;
8852 }
8853 unlock_page(page);
8854 out:
8855 btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
8856 out_noreserve:
8857 sb_end_pagefault(inode->i_sb);
8858 return ret;
8859 }
8860
8861 static int btrfs_truncate(struct inode *inode)
8862 {
8863 struct btrfs_root *root = BTRFS_I(inode)->root;
8864 struct btrfs_block_rsv *rsv;
8865 int ret = 0;
8866 int err = 0;
8867 struct btrfs_trans_handle *trans;
8868 u64 mask = root->sectorsize - 1;
8869 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8870
8871 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8872 (u64)-1);
8873 if (ret)
8874 return ret;
8875
8876 /*
8877 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8878 * 3 things going on here
8879 *
8880 * 1) We need to reserve space for our orphan item and the space to
8881 * delete our orphan item. Lord knows we don't want to have a dangling
8882 * orphan item because we didn't reserve space to remove it.
8883 *
8884 * 2) We need to reserve space to update our inode.
8885 *
8886 * 3) We need to have something to cache all the space that is going to
8887 * be free'd up by the truncate operation, but also have some slack
8888 * space reserved in case it uses space during the truncate (thank you
8889 * very much snapshotting).
8890 *
8891 * And we need these to all be seperate. The fact is we can use alot of
8892 * space doing the truncate, and we have no earthly idea how much space
8893 * we will use, so we need the truncate reservation to be seperate so it
8894 * doesn't end up using space reserved for updating the inode or
8895 * removing the orphan item. We also need to be able to stop the
8896 * transaction and start a new one, which means we need to be able to
8897 * update the inode several times, and we have no idea of knowing how
8898 * many times that will be, so we can't just reserve 1 item for the
8899 * entirety of the opration, so that has to be done seperately as well.
8900 * Then there is the orphan item, which does indeed need to be held on
8901 * to for the whole operation, and we need nobody to touch this reserved
8902 * space except the orphan code.
8903 *
8904 * So that leaves us with
8905 *
8906 * 1) root->orphan_block_rsv - for the orphan deletion.
8907 * 2) rsv - for the truncate reservation, which we will steal from the
8908 * transaction reservation.
8909 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8910 * updating the inode.
8911 */
8912 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8913 if (!rsv)
8914 return -ENOMEM;
8915 rsv->size = min_size;
8916 rsv->failfast = 1;
8917
8918 /*
8919 * 1 for the truncate slack space
8920 * 1 for updating the inode.
8921 */
8922 trans = btrfs_start_transaction(root, 2);
8923 if (IS_ERR(trans)) {
8924 err = PTR_ERR(trans);
8925 goto out;
8926 }
8927
8928 /* Migrate the slack space for the truncate to our reserve */
8929 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8930 min_size);
8931 BUG_ON(ret);
8932
8933 /*
8934 * So if we truncate and then write and fsync we normally would just
8935 * write the extents that changed, which is a problem if we need to
8936 * first truncate that entire inode. So set this flag so we write out
8937 * all of the extents in the inode to the sync log so we're completely
8938 * safe.
8939 */
8940 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8941 trans->block_rsv = rsv;
8942
8943 while (1) {
8944 ret = btrfs_truncate_inode_items(trans, root, inode,
8945 inode->i_size,
8946 BTRFS_EXTENT_DATA_KEY);
8947 if (ret != -ENOSPC && ret != -EAGAIN) {
8948 err = ret;
8949 break;
8950 }
8951
8952 trans->block_rsv = &root->fs_info->trans_block_rsv;
8953 ret = btrfs_update_inode(trans, root, inode);
8954 if (ret) {
8955 err = ret;
8956 break;
8957 }
8958
8959 btrfs_end_transaction(trans, root);
8960 btrfs_btree_balance_dirty(root);
8961
8962 trans = btrfs_start_transaction(root, 2);
8963 if (IS_ERR(trans)) {
8964 ret = err = PTR_ERR(trans);
8965 trans = NULL;
8966 break;
8967 }
8968
8969 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8970 rsv, min_size);
8971 BUG_ON(ret); /* shouldn't happen */
8972 trans->block_rsv = rsv;
8973 }
8974
8975 if (ret == 0 && inode->i_nlink > 0) {
8976 trans->block_rsv = root->orphan_block_rsv;
8977 ret = btrfs_orphan_del(trans, inode);
8978 if (ret)
8979 err = ret;
8980 }
8981
8982 if (trans) {
8983 trans->block_rsv = &root->fs_info->trans_block_rsv;
8984 ret = btrfs_update_inode(trans, root, inode);
8985 if (ret && !err)
8986 err = ret;
8987
8988 ret = btrfs_end_transaction(trans, root);
8989 btrfs_btree_balance_dirty(root);
8990 }
8991
8992 out:
8993 btrfs_free_block_rsv(root, rsv);
8994
8995 if (ret && !err)
8996 err = ret;
8997
8998 return err;
8999 }
9000
9001 /*
9002 * create a new subvolume directory/inode (helper for the ioctl).
9003 */
9004 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9005 struct btrfs_root *new_root,
9006 struct btrfs_root *parent_root,
9007 u64 new_dirid)
9008 {
9009 struct inode *inode;
9010 int err;
9011 u64 index = 0;
9012
9013 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9014 new_dirid, new_dirid,
9015 S_IFDIR | (~current_umask() & S_IRWXUGO),
9016 &index);
9017 if (IS_ERR(inode))
9018 return PTR_ERR(inode);
9019 inode->i_op = &btrfs_dir_inode_operations;
9020 inode->i_fop = &btrfs_dir_file_operations;
9021
9022 set_nlink(inode, 1);
9023 btrfs_i_size_write(inode, 0);
9024 unlock_new_inode(inode);
9025
9026 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9027 if (err)
9028 btrfs_err(new_root->fs_info,
9029 "error inheriting subvolume %llu properties: %d",
9030 new_root->root_key.objectid, err);
9031
9032 err = btrfs_update_inode(trans, new_root, inode);
9033
9034 iput(inode);
9035 return err;
9036 }
9037
9038 struct inode *btrfs_alloc_inode(struct super_block *sb)
9039 {
9040 struct btrfs_inode *ei;
9041 struct inode *inode;
9042
9043 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9044 if (!ei)
9045 return NULL;
9046
9047 ei->root = NULL;
9048 ei->generation = 0;
9049 ei->last_trans = 0;
9050 ei->last_sub_trans = 0;
9051 ei->logged_trans = 0;
9052 ei->delalloc_bytes = 0;
9053 ei->defrag_bytes = 0;
9054 ei->disk_i_size = 0;
9055 ei->flags = 0;
9056 ei->csum_bytes = 0;
9057 ei->index_cnt = (u64)-1;
9058 ei->dir_index = 0;
9059 ei->last_unlink_trans = 0;
9060 ei->last_log_commit = 0;
9061 ei->delayed_iput_count = 0;
9062
9063 spin_lock_init(&ei->lock);
9064 ei->outstanding_extents = 0;
9065 ei->reserved_extents = 0;
9066
9067 ei->runtime_flags = 0;
9068 ei->force_compress = BTRFS_COMPRESS_NONE;
9069
9070 ei->delayed_node = NULL;
9071
9072 ei->i_otime.tv_sec = 0;
9073 ei->i_otime.tv_nsec = 0;
9074
9075 inode = &ei->vfs_inode;
9076 extent_map_tree_init(&ei->extent_tree);
9077 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9078 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9079 ei->io_tree.track_uptodate = 1;
9080 ei->io_failure_tree.track_uptodate = 1;
9081 atomic_set(&ei->sync_writers, 0);
9082 mutex_init(&ei->log_mutex);
9083 mutex_init(&ei->delalloc_mutex);
9084 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9085 INIT_LIST_HEAD(&ei->delalloc_inodes);
9086 INIT_LIST_HEAD(&ei->delayed_iput);
9087 RB_CLEAR_NODE(&ei->rb_node);
9088
9089 return inode;
9090 }
9091
9092 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9093 void btrfs_test_destroy_inode(struct inode *inode)
9094 {
9095 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9096 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9097 }
9098 #endif
9099
9100 static void btrfs_i_callback(struct rcu_head *head)
9101 {
9102 struct inode *inode = container_of(head, struct inode, i_rcu);
9103 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9104 }
9105
9106 void btrfs_destroy_inode(struct inode *inode)
9107 {
9108 struct btrfs_ordered_extent *ordered;
9109 struct btrfs_root *root = BTRFS_I(inode)->root;
9110
9111 WARN_ON(!hlist_empty(&inode->i_dentry));
9112 WARN_ON(inode->i_data.nrpages);
9113 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9114 WARN_ON(BTRFS_I(inode)->reserved_extents);
9115 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9116 WARN_ON(BTRFS_I(inode)->csum_bytes);
9117 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9118
9119 /*
9120 * This can happen where we create an inode, but somebody else also
9121 * created the same inode and we need to destroy the one we already
9122 * created.
9123 */
9124 if (!root)
9125 goto free;
9126
9127 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9128 &BTRFS_I(inode)->runtime_flags)) {
9129 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9130 btrfs_ino(inode));
9131 atomic_dec(&root->orphan_inodes);
9132 }
9133
9134 while (1) {
9135 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9136 if (!ordered)
9137 break;
9138 else {
9139 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9140 ordered->file_offset, ordered->len);
9141 btrfs_remove_ordered_extent(inode, ordered);
9142 btrfs_put_ordered_extent(ordered);
9143 btrfs_put_ordered_extent(ordered);
9144 }
9145 }
9146 btrfs_qgroup_check_reserved_leak(inode);
9147 inode_tree_del(inode);
9148 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9149 free:
9150 call_rcu(&inode->i_rcu, btrfs_i_callback);
9151 }
9152
9153 int btrfs_drop_inode(struct inode *inode)
9154 {
9155 struct btrfs_root *root = BTRFS_I(inode)->root;
9156
9157 if (root == NULL)
9158 return 1;
9159
9160 /* the snap/subvol tree is on deleting */
9161 if (btrfs_root_refs(&root->root_item) == 0)
9162 return 1;
9163 else
9164 return generic_drop_inode(inode);
9165 }
9166
9167 static void init_once(void *foo)
9168 {
9169 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9170
9171 inode_init_once(&ei->vfs_inode);
9172 }
9173
9174 void btrfs_destroy_cachep(void)
9175 {
9176 /*
9177 * Make sure all delayed rcu free inodes are flushed before we
9178 * destroy cache.
9179 */
9180 rcu_barrier();
9181 if (btrfs_inode_cachep)
9182 kmem_cache_destroy(btrfs_inode_cachep);
9183 if (btrfs_trans_handle_cachep)
9184 kmem_cache_destroy(btrfs_trans_handle_cachep);
9185 if (btrfs_transaction_cachep)
9186 kmem_cache_destroy(btrfs_transaction_cachep);
9187 if (btrfs_path_cachep)
9188 kmem_cache_destroy(btrfs_path_cachep);
9189 if (btrfs_free_space_cachep)
9190 kmem_cache_destroy(btrfs_free_space_cachep);
9191 }
9192
9193 int btrfs_init_cachep(void)
9194 {
9195 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9196 sizeof(struct btrfs_inode), 0,
9197 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9198 init_once);
9199 if (!btrfs_inode_cachep)
9200 goto fail;
9201
9202 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9203 sizeof(struct btrfs_trans_handle), 0,
9204 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9205 if (!btrfs_trans_handle_cachep)
9206 goto fail;
9207
9208 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9209 sizeof(struct btrfs_transaction), 0,
9210 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9211 if (!btrfs_transaction_cachep)
9212 goto fail;
9213
9214 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9215 sizeof(struct btrfs_path), 0,
9216 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9217 if (!btrfs_path_cachep)
9218 goto fail;
9219
9220 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9221 sizeof(struct btrfs_free_space), 0,
9222 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9223 if (!btrfs_free_space_cachep)
9224 goto fail;
9225
9226 return 0;
9227 fail:
9228 btrfs_destroy_cachep();
9229 return -ENOMEM;
9230 }
9231
9232 static int btrfs_getattr(struct vfsmount *mnt,
9233 struct dentry *dentry, struct kstat *stat)
9234 {
9235 u64 delalloc_bytes;
9236 struct inode *inode = d_inode(dentry);
9237 u32 blocksize = inode->i_sb->s_blocksize;
9238
9239 generic_fillattr(inode, stat);
9240 stat->dev = BTRFS_I(inode)->root->anon_dev;
9241 stat->blksize = PAGE_CACHE_SIZE;
9242
9243 spin_lock(&BTRFS_I(inode)->lock);
9244 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9245 spin_unlock(&BTRFS_I(inode)->lock);
9246 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9247 ALIGN(delalloc_bytes, blocksize)) >> 9;
9248 return 0;
9249 }
9250
9251 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9252 struct inode *new_dir, struct dentry *new_dentry)
9253 {
9254 struct btrfs_trans_handle *trans;
9255 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9256 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9257 struct inode *new_inode = d_inode(new_dentry);
9258 struct inode *old_inode = d_inode(old_dentry);
9259 struct timespec ctime = CURRENT_TIME;
9260 u64 index = 0;
9261 u64 root_objectid;
9262 int ret;
9263 u64 old_ino = btrfs_ino(old_inode);
9264
9265 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9266 return -EPERM;
9267
9268 /* we only allow rename subvolume link between subvolumes */
9269 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9270 return -EXDEV;
9271
9272 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9273 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9274 return -ENOTEMPTY;
9275
9276 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9277 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9278 return -ENOTEMPTY;
9279
9280
9281 /* check for collisions, even if the name isn't there */
9282 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9283 new_dentry->d_name.name,
9284 new_dentry->d_name.len);
9285
9286 if (ret) {
9287 if (ret == -EEXIST) {
9288 /* we shouldn't get
9289 * eexist without a new_inode */
9290 if (WARN_ON(!new_inode)) {
9291 return ret;
9292 }
9293 } else {
9294 /* maybe -EOVERFLOW */
9295 return ret;
9296 }
9297 }
9298 ret = 0;
9299
9300 /*
9301 * we're using rename to replace one file with another. Start IO on it
9302 * now so we don't add too much work to the end of the transaction
9303 */
9304 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9305 filemap_flush(old_inode->i_mapping);
9306
9307 /* close the racy window with snapshot create/destroy ioctl */
9308 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9309 down_read(&root->fs_info->subvol_sem);
9310 /*
9311 * We want to reserve the absolute worst case amount of items. So if
9312 * both inodes are subvols and we need to unlink them then that would
9313 * require 4 item modifications, but if they are both normal inodes it
9314 * would require 5 item modifications, so we'll assume their normal
9315 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9316 * should cover the worst case number of items we'll modify.
9317 */
9318 trans = btrfs_start_transaction(root, 11);
9319 if (IS_ERR(trans)) {
9320 ret = PTR_ERR(trans);
9321 goto out_notrans;
9322 }
9323
9324 if (dest != root)
9325 btrfs_record_root_in_trans(trans, dest);
9326
9327 ret = btrfs_set_inode_index(new_dir, &index);
9328 if (ret)
9329 goto out_fail;
9330
9331 BTRFS_I(old_inode)->dir_index = 0ULL;
9332 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9333 /* force full log commit if subvolume involved. */
9334 btrfs_set_log_full_commit(root->fs_info, trans);
9335 } else {
9336 ret = btrfs_insert_inode_ref(trans, dest,
9337 new_dentry->d_name.name,
9338 new_dentry->d_name.len,
9339 old_ino,
9340 btrfs_ino(new_dir), index);
9341 if (ret)
9342 goto out_fail;
9343 /*
9344 * this is an ugly little race, but the rename is required
9345 * to make sure that if we crash, the inode is either at the
9346 * old name or the new one. pinning the log transaction lets
9347 * us make sure we don't allow a log commit to come in after
9348 * we unlink the name but before we add the new name back in.
9349 */
9350 btrfs_pin_log_trans(root);
9351 }
9352
9353 inode_inc_iversion(old_dir);
9354 inode_inc_iversion(new_dir);
9355 inode_inc_iversion(old_inode);
9356 old_dir->i_ctime = old_dir->i_mtime = ctime;
9357 new_dir->i_ctime = new_dir->i_mtime = ctime;
9358 old_inode->i_ctime = ctime;
9359
9360 if (old_dentry->d_parent != new_dentry->d_parent)
9361 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9362
9363 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9364 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9365 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9366 old_dentry->d_name.name,
9367 old_dentry->d_name.len);
9368 } else {
9369 ret = __btrfs_unlink_inode(trans, root, old_dir,
9370 d_inode(old_dentry),
9371 old_dentry->d_name.name,
9372 old_dentry->d_name.len);
9373 if (!ret)
9374 ret = btrfs_update_inode(trans, root, old_inode);
9375 }
9376 if (ret) {
9377 btrfs_abort_transaction(trans, root, ret);
9378 goto out_fail;
9379 }
9380
9381 if (new_inode) {
9382 inode_inc_iversion(new_inode);
9383 new_inode->i_ctime = CURRENT_TIME;
9384 if (unlikely(btrfs_ino(new_inode) ==
9385 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9386 root_objectid = BTRFS_I(new_inode)->location.objectid;
9387 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9388 root_objectid,
9389 new_dentry->d_name.name,
9390 new_dentry->d_name.len);
9391 BUG_ON(new_inode->i_nlink == 0);
9392 } else {
9393 ret = btrfs_unlink_inode(trans, dest, new_dir,
9394 d_inode(new_dentry),
9395 new_dentry->d_name.name,
9396 new_dentry->d_name.len);
9397 }
9398 if (!ret && new_inode->i_nlink == 0)
9399 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9400 if (ret) {
9401 btrfs_abort_transaction(trans, root, ret);
9402 goto out_fail;
9403 }
9404 }
9405
9406 ret = btrfs_add_link(trans, new_dir, old_inode,
9407 new_dentry->d_name.name,
9408 new_dentry->d_name.len, 0, index);
9409 if (ret) {
9410 btrfs_abort_transaction(trans, root, ret);
9411 goto out_fail;
9412 }
9413
9414 if (old_inode->i_nlink == 1)
9415 BTRFS_I(old_inode)->dir_index = index;
9416
9417 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9418 struct dentry *parent = new_dentry->d_parent;
9419 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9420 btrfs_end_log_trans(root);
9421 }
9422 out_fail:
9423 btrfs_end_transaction(trans, root);
9424 out_notrans:
9425 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9426 up_read(&root->fs_info->subvol_sem);
9427
9428 return ret;
9429 }
9430
9431 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9432 struct inode *new_dir, struct dentry *new_dentry,
9433 unsigned int flags)
9434 {
9435 if (flags & ~RENAME_NOREPLACE)
9436 return -EINVAL;
9437
9438 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9439 }
9440
9441 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9442 {
9443 struct btrfs_delalloc_work *delalloc_work;
9444 struct inode *inode;
9445
9446 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9447 work);
9448 inode = delalloc_work->inode;
9449 filemap_flush(inode->i_mapping);
9450 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9451 &BTRFS_I(inode)->runtime_flags))
9452 filemap_flush(inode->i_mapping);
9453
9454 if (delalloc_work->delay_iput)
9455 btrfs_add_delayed_iput(inode);
9456 else
9457 iput(inode);
9458 complete(&delalloc_work->completion);
9459 }
9460
9461 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9462 int delay_iput)
9463 {
9464 struct btrfs_delalloc_work *work;
9465
9466 work = kmalloc(sizeof(*work), GFP_NOFS);
9467 if (!work)
9468 return NULL;
9469
9470 init_completion(&work->completion);
9471 INIT_LIST_HEAD(&work->list);
9472 work->inode = inode;
9473 work->delay_iput = delay_iput;
9474 WARN_ON_ONCE(!inode);
9475 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9476 btrfs_run_delalloc_work, NULL, NULL);
9477
9478 return work;
9479 }
9480
9481 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9482 {
9483 wait_for_completion(&work->completion);
9484 kfree(work);
9485 }
9486
9487 /*
9488 * some fairly slow code that needs optimization. This walks the list
9489 * of all the inodes with pending delalloc and forces them to disk.
9490 */
9491 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9492 int nr)
9493 {
9494 struct btrfs_inode *binode;
9495 struct inode *inode;
9496 struct btrfs_delalloc_work *work, *next;
9497 struct list_head works;
9498 struct list_head splice;
9499 int ret = 0;
9500
9501 INIT_LIST_HEAD(&works);
9502 INIT_LIST_HEAD(&splice);
9503
9504 mutex_lock(&root->delalloc_mutex);
9505 spin_lock(&root->delalloc_lock);
9506 list_splice_init(&root->delalloc_inodes, &splice);
9507 while (!list_empty(&splice)) {
9508 binode = list_entry(splice.next, struct btrfs_inode,
9509 delalloc_inodes);
9510
9511 list_move_tail(&binode->delalloc_inodes,
9512 &root->delalloc_inodes);
9513 inode = igrab(&binode->vfs_inode);
9514 if (!inode) {
9515 cond_resched_lock(&root->delalloc_lock);
9516 continue;
9517 }
9518 spin_unlock(&root->delalloc_lock);
9519
9520 work = btrfs_alloc_delalloc_work(inode, delay_iput);
9521 if (!work) {
9522 if (delay_iput)
9523 btrfs_add_delayed_iput(inode);
9524 else
9525 iput(inode);
9526 ret = -ENOMEM;
9527 goto out;
9528 }
9529 list_add_tail(&work->list, &works);
9530 btrfs_queue_work(root->fs_info->flush_workers,
9531 &work->work);
9532 ret++;
9533 if (nr != -1 && ret >= nr)
9534 goto out;
9535 cond_resched();
9536 spin_lock(&root->delalloc_lock);
9537 }
9538 spin_unlock(&root->delalloc_lock);
9539
9540 out:
9541 list_for_each_entry_safe(work, next, &works, list) {
9542 list_del_init(&work->list);
9543 btrfs_wait_and_free_delalloc_work(work);
9544 }
9545
9546 if (!list_empty_careful(&splice)) {
9547 spin_lock(&root->delalloc_lock);
9548 list_splice_tail(&splice, &root->delalloc_inodes);
9549 spin_unlock(&root->delalloc_lock);
9550 }
9551 mutex_unlock(&root->delalloc_mutex);
9552 return ret;
9553 }
9554
9555 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9556 {
9557 int ret;
9558
9559 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9560 return -EROFS;
9561
9562 ret = __start_delalloc_inodes(root, delay_iput, -1);
9563 if (ret > 0)
9564 ret = 0;
9565 /*
9566 * the filemap_flush will queue IO into the worker threads, but
9567 * we have to make sure the IO is actually started and that
9568 * ordered extents get created before we return
9569 */
9570 atomic_inc(&root->fs_info->async_submit_draining);
9571 while (atomic_read(&root->fs_info->nr_async_submits) ||
9572 atomic_read(&root->fs_info->async_delalloc_pages)) {
9573 wait_event(root->fs_info->async_submit_wait,
9574 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9575 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9576 }
9577 atomic_dec(&root->fs_info->async_submit_draining);
9578 return ret;
9579 }
9580
9581 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9582 int nr)
9583 {
9584 struct btrfs_root *root;
9585 struct list_head splice;
9586 int ret;
9587
9588 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9589 return -EROFS;
9590
9591 INIT_LIST_HEAD(&splice);
9592
9593 mutex_lock(&fs_info->delalloc_root_mutex);
9594 spin_lock(&fs_info->delalloc_root_lock);
9595 list_splice_init(&fs_info->delalloc_roots, &splice);
9596 while (!list_empty(&splice) && nr) {
9597 root = list_first_entry(&splice, struct btrfs_root,
9598 delalloc_root);
9599 root = btrfs_grab_fs_root(root);
9600 BUG_ON(!root);
9601 list_move_tail(&root->delalloc_root,
9602 &fs_info->delalloc_roots);
9603 spin_unlock(&fs_info->delalloc_root_lock);
9604
9605 ret = __start_delalloc_inodes(root, delay_iput, nr);
9606 btrfs_put_fs_root(root);
9607 if (ret < 0)
9608 goto out;
9609
9610 if (nr != -1) {
9611 nr -= ret;
9612 WARN_ON(nr < 0);
9613 }
9614 spin_lock(&fs_info->delalloc_root_lock);
9615 }
9616 spin_unlock(&fs_info->delalloc_root_lock);
9617
9618 ret = 0;
9619 atomic_inc(&fs_info->async_submit_draining);
9620 while (atomic_read(&fs_info->nr_async_submits) ||
9621 atomic_read(&fs_info->async_delalloc_pages)) {
9622 wait_event(fs_info->async_submit_wait,
9623 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9624 atomic_read(&fs_info->async_delalloc_pages) == 0));
9625 }
9626 atomic_dec(&fs_info->async_submit_draining);
9627 out:
9628 if (!list_empty_careful(&splice)) {
9629 spin_lock(&fs_info->delalloc_root_lock);
9630 list_splice_tail(&splice, &fs_info->delalloc_roots);
9631 spin_unlock(&fs_info->delalloc_root_lock);
9632 }
9633 mutex_unlock(&fs_info->delalloc_root_mutex);
9634 return ret;
9635 }
9636
9637 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9638 const char *symname)
9639 {
9640 struct btrfs_trans_handle *trans;
9641 struct btrfs_root *root = BTRFS_I(dir)->root;
9642 struct btrfs_path *path;
9643 struct btrfs_key key;
9644 struct inode *inode = NULL;
9645 int err;
9646 int drop_inode = 0;
9647 u64 objectid;
9648 u64 index = 0;
9649 int name_len;
9650 int datasize;
9651 unsigned long ptr;
9652 struct btrfs_file_extent_item *ei;
9653 struct extent_buffer *leaf;
9654
9655 name_len = strlen(symname);
9656 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9657 return -ENAMETOOLONG;
9658
9659 /*
9660 * 2 items for inode item and ref
9661 * 2 items for dir items
9662 * 1 item for updating parent inode item
9663 * 1 item for the inline extent item
9664 * 1 item for xattr if selinux is on
9665 */
9666 trans = btrfs_start_transaction(root, 7);
9667 if (IS_ERR(trans))
9668 return PTR_ERR(trans);
9669
9670 err = btrfs_find_free_ino(root, &objectid);
9671 if (err)
9672 goto out_unlock;
9673
9674 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9675 dentry->d_name.len, btrfs_ino(dir), objectid,
9676 S_IFLNK|S_IRWXUGO, &index);
9677 if (IS_ERR(inode)) {
9678 err = PTR_ERR(inode);
9679 goto out_unlock;
9680 }
9681
9682 /*
9683 * If the active LSM wants to access the inode during
9684 * d_instantiate it needs these. Smack checks to see
9685 * if the filesystem supports xattrs by looking at the
9686 * ops vector.
9687 */
9688 inode->i_fop = &btrfs_file_operations;
9689 inode->i_op = &btrfs_file_inode_operations;
9690 inode->i_mapping->a_ops = &btrfs_aops;
9691 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9692
9693 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9694 if (err)
9695 goto out_unlock_inode;
9696
9697 path = btrfs_alloc_path();
9698 if (!path) {
9699 err = -ENOMEM;
9700 goto out_unlock_inode;
9701 }
9702 key.objectid = btrfs_ino(inode);
9703 key.offset = 0;
9704 key.type = BTRFS_EXTENT_DATA_KEY;
9705 datasize = btrfs_file_extent_calc_inline_size(name_len);
9706 err = btrfs_insert_empty_item(trans, root, path, &key,
9707 datasize);
9708 if (err) {
9709 btrfs_free_path(path);
9710 goto out_unlock_inode;
9711 }
9712 leaf = path->nodes[0];
9713 ei = btrfs_item_ptr(leaf, path->slots[0],
9714 struct btrfs_file_extent_item);
9715 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9716 btrfs_set_file_extent_type(leaf, ei,
9717 BTRFS_FILE_EXTENT_INLINE);
9718 btrfs_set_file_extent_encryption(leaf, ei, 0);
9719 btrfs_set_file_extent_compression(leaf, ei, 0);
9720 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9721 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9722
9723 ptr = btrfs_file_extent_inline_start(ei);
9724 write_extent_buffer(leaf, symname, ptr, name_len);
9725 btrfs_mark_buffer_dirty(leaf);
9726 btrfs_free_path(path);
9727
9728 inode->i_op = &btrfs_symlink_inode_operations;
9729 inode_nohighmem(inode);
9730 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9731 inode_set_bytes(inode, name_len);
9732 btrfs_i_size_write(inode, name_len);
9733 err = btrfs_update_inode(trans, root, inode);
9734 /*
9735 * Last step, add directory indexes for our symlink inode. This is the
9736 * last step to avoid extra cleanup of these indexes if an error happens
9737 * elsewhere above.
9738 */
9739 if (!err)
9740 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9741 if (err) {
9742 drop_inode = 1;
9743 goto out_unlock_inode;
9744 }
9745
9746 unlock_new_inode(inode);
9747 d_instantiate(dentry, inode);
9748
9749 out_unlock:
9750 btrfs_end_transaction(trans, root);
9751 if (drop_inode) {
9752 inode_dec_link_count(inode);
9753 iput(inode);
9754 }
9755 btrfs_btree_balance_dirty(root);
9756 return err;
9757
9758 out_unlock_inode:
9759 drop_inode = 1;
9760 unlock_new_inode(inode);
9761 goto out_unlock;
9762 }
9763
9764 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9765 u64 start, u64 num_bytes, u64 min_size,
9766 loff_t actual_len, u64 *alloc_hint,
9767 struct btrfs_trans_handle *trans)
9768 {
9769 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9770 struct extent_map *em;
9771 struct btrfs_root *root = BTRFS_I(inode)->root;
9772 struct btrfs_key ins;
9773 u64 cur_offset = start;
9774 u64 i_size;
9775 u64 cur_bytes;
9776 u64 last_alloc = (u64)-1;
9777 int ret = 0;
9778 bool own_trans = true;
9779
9780 if (trans)
9781 own_trans = false;
9782 while (num_bytes > 0) {
9783 if (own_trans) {
9784 trans = btrfs_start_transaction(root, 3);
9785 if (IS_ERR(trans)) {
9786 ret = PTR_ERR(trans);
9787 break;
9788 }
9789 }
9790
9791 cur_bytes = min_t(u64, num_bytes, SZ_256M);
9792 cur_bytes = max(cur_bytes, min_size);
9793 /*
9794 * If we are severely fragmented we could end up with really
9795 * small allocations, so if the allocator is returning small
9796 * chunks lets make its job easier by only searching for those
9797 * sized chunks.
9798 */
9799 cur_bytes = min(cur_bytes, last_alloc);
9800 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9801 *alloc_hint, &ins, 1, 0);
9802 if (ret) {
9803 if (own_trans)
9804 btrfs_end_transaction(trans, root);
9805 break;
9806 }
9807
9808 last_alloc = ins.offset;
9809 ret = insert_reserved_file_extent(trans, inode,
9810 cur_offset, ins.objectid,
9811 ins.offset, ins.offset,
9812 ins.offset, 0, 0, 0,
9813 BTRFS_FILE_EXTENT_PREALLOC);
9814 if (ret) {
9815 btrfs_free_reserved_extent(root, ins.objectid,
9816 ins.offset, 0);
9817 btrfs_abort_transaction(trans, root, ret);
9818 if (own_trans)
9819 btrfs_end_transaction(trans, root);
9820 break;
9821 }
9822
9823 btrfs_drop_extent_cache(inode, cur_offset,
9824 cur_offset + ins.offset -1, 0);
9825
9826 em = alloc_extent_map();
9827 if (!em) {
9828 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9829 &BTRFS_I(inode)->runtime_flags);
9830 goto next;
9831 }
9832
9833 em->start = cur_offset;
9834 em->orig_start = cur_offset;
9835 em->len = ins.offset;
9836 em->block_start = ins.objectid;
9837 em->block_len = ins.offset;
9838 em->orig_block_len = ins.offset;
9839 em->ram_bytes = ins.offset;
9840 em->bdev = root->fs_info->fs_devices->latest_bdev;
9841 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9842 em->generation = trans->transid;
9843
9844 while (1) {
9845 write_lock(&em_tree->lock);
9846 ret = add_extent_mapping(em_tree, em, 1);
9847 write_unlock(&em_tree->lock);
9848 if (ret != -EEXIST)
9849 break;
9850 btrfs_drop_extent_cache(inode, cur_offset,
9851 cur_offset + ins.offset - 1,
9852 0);
9853 }
9854 free_extent_map(em);
9855 next:
9856 num_bytes -= ins.offset;
9857 cur_offset += ins.offset;
9858 *alloc_hint = ins.objectid + ins.offset;
9859
9860 inode_inc_iversion(inode);
9861 inode->i_ctime = CURRENT_TIME;
9862 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9863 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9864 (actual_len > inode->i_size) &&
9865 (cur_offset > inode->i_size)) {
9866 if (cur_offset > actual_len)
9867 i_size = actual_len;
9868 else
9869 i_size = cur_offset;
9870 i_size_write(inode, i_size);
9871 btrfs_ordered_update_i_size(inode, i_size, NULL);
9872 }
9873
9874 ret = btrfs_update_inode(trans, root, inode);
9875
9876 if (ret) {
9877 btrfs_abort_transaction(trans, root, ret);
9878 if (own_trans)
9879 btrfs_end_transaction(trans, root);
9880 break;
9881 }
9882
9883 if (own_trans)
9884 btrfs_end_transaction(trans, root);
9885 }
9886 return ret;
9887 }
9888
9889 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9890 u64 start, u64 num_bytes, u64 min_size,
9891 loff_t actual_len, u64 *alloc_hint)
9892 {
9893 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9894 min_size, actual_len, alloc_hint,
9895 NULL);
9896 }
9897
9898 int btrfs_prealloc_file_range_trans(struct inode *inode,
9899 struct btrfs_trans_handle *trans, int mode,
9900 u64 start, u64 num_bytes, u64 min_size,
9901 loff_t actual_len, u64 *alloc_hint)
9902 {
9903 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9904 min_size, actual_len, alloc_hint, trans);
9905 }
9906
9907 static int btrfs_set_page_dirty(struct page *page)
9908 {
9909 return __set_page_dirty_nobuffers(page);
9910 }
9911
9912 static int btrfs_permission(struct inode *inode, int mask)
9913 {
9914 struct btrfs_root *root = BTRFS_I(inode)->root;
9915 umode_t mode = inode->i_mode;
9916
9917 if (mask & MAY_WRITE &&
9918 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9919 if (btrfs_root_readonly(root))
9920 return -EROFS;
9921 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9922 return -EACCES;
9923 }
9924 return generic_permission(inode, mask);
9925 }
9926
9927 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9928 {
9929 struct btrfs_trans_handle *trans;
9930 struct btrfs_root *root = BTRFS_I(dir)->root;
9931 struct inode *inode = NULL;
9932 u64 objectid;
9933 u64 index;
9934 int ret = 0;
9935
9936 /*
9937 * 5 units required for adding orphan entry
9938 */
9939 trans = btrfs_start_transaction(root, 5);
9940 if (IS_ERR(trans))
9941 return PTR_ERR(trans);
9942
9943 ret = btrfs_find_free_ino(root, &objectid);
9944 if (ret)
9945 goto out;
9946
9947 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9948 btrfs_ino(dir), objectid, mode, &index);
9949 if (IS_ERR(inode)) {
9950 ret = PTR_ERR(inode);
9951 inode = NULL;
9952 goto out;
9953 }
9954
9955 inode->i_fop = &btrfs_file_operations;
9956 inode->i_op = &btrfs_file_inode_operations;
9957
9958 inode->i_mapping->a_ops = &btrfs_aops;
9959 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9960
9961 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9962 if (ret)
9963 goto out_inode;
9964
9965 ret = btrfs_update_inode(trans, root, inode);
9966 if (ret)
9967 goto out_inode;
9968 ret = btrfs_orphan_add(trans, inode);
9969 if (ret)
9970 goto out_inode;
9971
9972 /*
9973 * We set number of links to 0 in btrfs_new_inode(), and here we set
9974 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9975 * through:
9976 *
9977 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9978 */
9979 set_nlink(inode, 1);
9980 unlock_new_inode(inode);
9981 d_tmpfile(dentry, inode);
9982 mark_inode_dirty(inode);
9983
9984 out:
9985 btrfs_end_transaction(trans, root);
9986 if (ret)
9987 iput(inode);
9988 btrfs_balance_delayed_items(root);
9989 btrfs_btree_balance_dirty(root);
9990 return ret;
9991
9992 out_inode:
9993 unlock_new_inode(inode);
9994 goto out;
9995
9996 }
9997
9998 /* Inspired by filemap_check_errors() */
9999 int btrfs_inode_check_errors(struct inode *inode)
10000 {
10001 int ret = 0;
10002
10003 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10004 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10005 ret = -ENOSPC;
10006 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10007 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10008 ret = -EIO;
10009
10010 return ret;
10011 }
10012
10013 static const struct inode_operations btrfs_dir_inode_operations = {
10014 .getattr = btrfs_getattr,
10015 .lookup = btrfs_lookup,
10016 .create = btrfs_create,
10017 .unlink = btrfs_unlink,
10018 .link = btrfs_link,
10019 .mkdir = btrfs_mkdir,
10020 .rmdir = btrfs_rmdir,
10021 .rename2 = btrfs_rename2,
10022 .symlink = btrfs_symlink,
10023 .setattr = btrfs_setattr,
10024 .mknod = btrfs_mknod,
10025 .setxattr = btrfs_setxattr,
10026 .getxattr = generic_getxattr,
10027 .listxattr = btrfs_listxattr,
10028 .removexattr = btrfs_removexattr,
10029 .permission = btrfs_permission,
10030 .get_acl = btrfs_get_acl,
10031 .set_acl = btrfs_set_acl,
10032 .update_time = btrfs_update_time,
10033 .tmpfile = btrfs_tmpfile,
10034 };
10035 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10036 .lookup = btrfs_lookup,
10037 .permission = btrfs_permission,
10038 .get_acl = btrfs_get_acl,
10039 .set_acl = btrfs_set_acl,
10040 .update_time = btrfs_update_time,
10041 };
10042
10043 static const struct file_operations btrfs_dir_file_operations = {
10044 .llseek = generic_file_llseek,
10045 .read = generic_read_dir,
10046 .iterate = btrfs_real_readdir,
10047 .unlocked_ioctl = btrfs_ioctl,
10048 #ifdef CONFIG_COMPAT
10049 .compat_ioctl = btrfs_ioctl,
10050 #endif
10051 .release = btrfs_release_file,
10052 .fsync = btrfs_sync_file,
10053 };
10054
10055 static const struct extent_io_ops btrfs_extent_io_ops = {
10056 .fill_delalloc = run_delalloc_range,
10057 .submit_bio_hook = btrfs_submit_bio_hook,
10058 .merge_bio_hook = btrfs_merge_bio_hook,
10059 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10060 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10061 .writepage_start_hook = btrfs_writepage_start_hook,
10062 .set_bit_hook = btrfs_set_bit_hook,
10063 .clear_bit_hook = btrfs_clear_bit_hook,
10064 .merge_extent_hook = btrfs_merge_extent_hook,
10065 .split_extent_hook = btrfs_split_extent_hook,
10066 };
10067
10068 /*
10069 * btrfs doesn't support the bmap operation because swapfiles
10070 * use bmap to make a mapping of extents in the file. They assume
10071 * these extents won't change over the life of the file and they
10072 * use the bmap result to do IO directly to the drive.
10073 *
10074 * the btrfs bmap call would return logical addresses that aren't
10075 * suitable for IO and they also will change frequently as COW
10076 * operations happen. So, swapfile + btrfs == corruption.
10077 *
10078 * For now we're avoiding this by dropping bmap.
10079 */
10080 static const struct address_space_operations btrfs_aops = {
10081 .readpage = btrfs_readpage,
10082 .writepage = btrfs_writepage,
10083 .writepages = btrfs_writepages,
10084 .readpages = btrfs_readpages,
10085 .direct_IO = btrfs_direct_IO,
10086 .invalidatepage = btrfs_invalidatepage,
10087 .releasepage = btrfs_releasepage,
10088 .set_page_dirty = btrfs_set_page_dirty,
10089 .error_remove_page = generic_error_remove_page,
10090 };
10091
10092 static const struct address_space_operations btrfs_symlink_aops = {
10093 .readpage = btrfs_readpage,
10094 .writepage = btrfs_writepage,
10095 .invalidatepage = btrfs_invalidatepage,
10096 .releasepage = btrfs_releasepage,
10097 };
10098
10099 static const struct inode_operations btrfs_file_inode_operations = {
10100 .getattr = btrfs_getattr,
10101 .setattr = btrfs_setattr,
10102 .setxattr = btrfs_setxattr,
10103 .getxattr = generic_getxattr,
10104 .listxattr = btrfs_listxattr,
10105 .removexattr = btrfs_removexattr,
10106 .permission = btrfs_permission,
10107 .fiemap = btrfs_fiemap,
10108 .get_acl = btrfs_get_acl,
10109 .set_acl = btrfs_set_acl,
10110 .update_time = btrfs_update_time,
10111 };
10112 static const struct inode_operations btrfs_special_inode_operations = {
10113 .getattr = btrfs_getattr,
10114 .setattr = btrfs_setattr,
10115 .permission = btrfs_permission,
10116 .setxattr = btrfs_setxattr,
10117 .getxattr = generic_getxattr,
10118 .listxattr = btrfs_listxattr,
10119 .removexattr = btrfs_removexattr,
10120 .get_acl = btrfs_get_acl,
10121 .set_acl = btrfs_set_acl,
10122 .update_time = btrfs_update_time,
10123 };
10124 static const struct inode_operations btrfs_symlink_inode_operations = {
10125 .readlink = generic_readlink,
10126 .get_link = page_get_link,
10127 .getattr = btrfs_getattr,
10128 .setattr = btrfs_setattr,
10129 .permission = btrfs_permission,
10130 .setxattr = btrfs_setxattr,
10131 .getxattr = generic_getxattr,
10132 .listxattr = btrfs_listxattr,
10133 .removexattr = btrfs_removexattr,
10134 .update_time = btrfs_update_time,
10135 };
10136
10137 const struct dentry_operations btrfs_dentry_operations = {
10138 .d_delete = btrfs_dentry_delete,
10139 .d_release = btrfs_dentry_release,
10140 };
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