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Merge tag 'pm+acpi-4.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 static const struct inode_operations btrfs_dir_inode_operations;
70 static const struct inode_operations btrfs_symlink_inode_operations;
71 static const struct inode_operations btrfs_dir_ro_inode_operations;
72 static const struct inode_operations btrfs_special_inode_operations;
73 static const struct inode_operations btrfs_file_inode_operations;
74 static const struct address_space_operations btrfs_aops;
75 static const struct address_space_operations btrfs_symlink_aops;
76 static const struct file_operations btrfs_dir_file_operations;
77 static struct extent_io_ops btrfs_extent_io_ops;
78
79 static struct kmem_cache *btrfs_inode_cachep;
80 static struct kmem_cache *btrfs_delalloc_work_cachep;
81 struct kmem_cache *btrfs_trans_handle_cachep;
82 struct kmem_cache *btrfs_transaction_cachep;
83 struct kmem_cache *btrfs_path_cachep;
84 struct kmem_cache *btrfs_free_space_cachep;
85
86 #define S_SHIFT 12
87 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
88 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
89 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
90 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
91 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
92 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
93 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
94 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
95 };
96
97 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
98 static int btrfs_truncate(struct inode *inode);
99 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
100 static noinline int cow_file_range(struct inode *inode,
101 struct page *locked_page,
102 u64 start, u64 end, int *page_started,
103 unsigned long *nr_written, int unlock);
104 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
105 u64 len, u64 orig_start,
106 u64 block_start, u64 block_len,
107 u64 orig_block_len, u64 ram_bytes,
108 int type);
109
110 static int btrfs_dirty_inode(struct inode *inode);
111
112 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
113 void btrfs_test_inode_set_ops(struct inode *inode)
114 {
115 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
116 }
117 #endif
118
119 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
120 struct inode *inode, struct inode *dir,
121 const struct qstr *qstr)
122 {
123 int err;
124
125 err = btrfs_init_acl(trans, inode, dir);
126 if (!err)
127 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
128 return err;
129 }
130
131 /*
132 * this does all the hard work for inserting an inline extent into
133 * the btree. The caller should have done a btrfs_drop_extents so that
134 * no overlapping inline items exist in the btree
135 */
136 static int insert_inline_extent(struct btrfs_trans_handle *trans,
137 struct btrfs_path *path, int extent_inserted,
138 struct btrfs_root *root, struct inode *inode,
139 u64 start, size_t size, size_t compressed_size,
140 int compress_type,
141 struct page **compressed_pages)
142 {
143 struct extent_buffer *leaf;
144 struct page *page = NULL;
145 char *kaddr;
146 unsigned long ptr;
147 struct btrfs_file_extent_item *ei;
148 int err = 0;
149 int ret;
150 size_t cur_size = size;
151 unsigned long offset;
152
153 if (compressed_size && compressed_pages)
154 cur_size = compressed_size;
155
156 inode_add_bytes(inode, size);
157
158 if (!extent_inserted) {
159 struct btrfs_key key;
160 size_t datasize;
161
162 key.objectid = btrfs_ino(inode);
163 key.offset = start;
164 key.type = BTRFS_EXTENT_DATA_KEY;
165
166 datasize = btrfs_file_extent_calc_inline_size(cur_size);
167 path->leave_spinning = 1;
168 ret = btrfs_insert_empty_item(trans, root, path, &key,
169 datasize);
170 if (ret) {
171 err = ret;
172 goto fail;
173 }
174 }
175 leaf = path->nodes[0];
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_file_extent_item);
178 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
179 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
180 btrfs_set_file_extent_encryption(leaf, ei, 0);
181 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
182 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
183 ptr = btrfs_file_extent_inline_start(ei);
184
185 if (compress_type != BTRFS_COMPRESS_NONE) {
186 struct page *cpage;
187 int i = 0;
188 while (compressed_size > 0) {
189 cpage = compressed_pages[i];
190 cur_size = min_t(unsigned long, compressed_size,
191 PAGE_CACHE_SIZE);
192
193 kaddr = kmap_atomic(cpage);
194 write_extent_buffer(leaf, kaddr, ptr, cur_size);
195 kunmap_atomic(kaddr);
196
197 i++;
198 ptr += cur_size;
199 compressed_size -= cur_size;
200 }
201 btrfs_set_file_extent_compression(leaf, ei,
202 compress_type);
203 } else {
204 page = find_get_page(inode->i_mapping,
205 start >> PAGE_CACHE_SHIFT);
206 btrfs_set_file_extent_compression(leaf, ei, 0);
207 kaddr = kmap_atomic(page);
208 offset = start & (PAGE_CACHE_SIZE - 1);
209 write_extent_buffer(leaf, kaddr + offset, ptr, size);
210 kunmap_atomic(kaddr);
211 page_cache_release(page);
212 }
213 btrfs_mark_buffer_dirty(leaf);
214 btrfs_release_path(path);
215
216 /*
217 * we're an inline extent, so nobody can
218 * extend the file past i_size without locking
219 * a page we already have locked.
220 *
221 * We must do any isize and inode updates
222 * before we unlock the pages. Otherwise we
223 * could end up racing with unlink.
224 */
225 BTRFS_I(inode)->disk_i_size = inode->i_size;
226 ret = btrfs_update_inode(trans, root, inode);
227
228 return ret;
229 fail:
230 return err;
231 }
232
233
234 /*
235 * conditionally insert an inline extent into the file. This
236 * does the checks required to make sure the data is small enough
237 * to fit as an inline extent.
238 */
239 static noinline int cow_file_range_inline(struct btrfs_root *root,
240 struct inode *inode, u64 start,
241 u64 end, size_t compressed_size,
242 int compress_type,
243 struct page **compressed_pages)
244 {
245 struct btrfs_trans_handle *trans;
246 u64 isize = i_size_read(inode);
247 u64 actual_end = min(end + 1, isize);
248 u64 inline_len = actual_end - start;
249 u64 aligned_end = ALIGN(end, root->sectorsize);
250 u64 data_len = inline_len;
251 int ret;
252 struct btrfs_path *path;
253 int extent_inserted = 0;
254 u32 extent_item_size;
255
256 if (compressed_size)
257 data_len = compressed_size;
258
259 if (start > 0 ||
260 actual_end > PAGE_CACHE_SIZE ||
261 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
262 (!compressed_size &&
263 (actual_end & (root->sectorsize - 1)) == 0) ||
264 end + 1 < isize ||
265 data_len > root->fs_info->max_inline) {
266 return 1;
267 }
268
269 path = btrfs_alloc_path();
270 if (!path)
271 return -ENOMEM;
272
273 trans = btrfs_join_transaction(root);
274 if (IS_ERR(trans)) {
275 btrfs_free_path(path);
276 return PTR_ERR(trans);
277 }
278 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
279
280 if (compressed_size && compressed_pages)
281 extent_item_size = btrfs_file_extent_calc_inline_size(
282 compressed_size);
283 else
284 extent_item_size = btrfs_file_extent_calc_inline_size(
285 inline_len);
286
287 ret = __btrfs_drop_extents(trans, root, inode, path,
288 start, aligned_end, NULL,
289 1, 1, extent_item_size, &extent_inserted);
290 if (ret) {
291 btrfs_abort_transaction(trans, root, ret);
292 goto out;
293 }
294
295 if (isize > actual_end)
296 inline_len = min_t(u64, isize, actual_end);
297 ret = insert_inline_extent(trans, path, extent_inserted,
298 root, inode, start,
299 inline_len, compressed_size,
300 compress_type, compressed_pages);
301 if (ret && ret != -ENOSPC) {
302 btrfs_abort_transaction(trans, root, ret);
303 goto out;
304 } else if (ret == -ENOSPC) {
305 ret = 1;
306 goto out;
307 }
308
309 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
310 btrfs_delalloc_release_metadata(inode, end + 1 - start);
311 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
312 out:
313 btrfs_free_path(path);
314 btrfs_end_transaction(trans, root);
315 return ret;
316 }
317
318 struct async_extent {
319 u64 start;
320 u64 ram_size;
321 u64 compressed_size;
322 struct page **pages;
323 unsigned long nr_pages;
324 int compress_type;
325 struct list_head list;
326 };
327
328 struct async_cow {
329 struct inode *inode;
330 struct btrfs_root *root;
331 struct page *locked_page;
332 u64 start;
333 u64 end;
334 struct list_head extents;
335 struct btrfs_work work;
336 };
337
338 static noinline int add_async_extent(struct async_cow *cow,
339 u64 start, u64 ram_size,
340 u64 compressed_size,
341 struct page **pages,
342 unsigned long nr_pages,
343 int compress_type)
344 {
345 struct async_extent *async_extent;
346
347 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
348 BUG_ON(!async_extent); /* -ENOMEM */
349 async_extent->start = start;
350 async_extent->ram_size = ram_size;
351 async_extent->compressed_size = compressed_size;
352 async_extent->pages = pages;
353 async_extent->nr_pages = nr_pages;
354 async_extent->compress_type = compress_type;
355 list_add_tail(&async_extent->list, &cow->extents);
356 return 0;
357 }
358
359 static inline int inode_need_compress(struct inode *inode)
360 {
361 struct btrfs_root *root = BTRFS_I(inode)->root;
362
363 /* force compress */
364 if (btrfs_test_opt(root, FORCE_COMPRESS))
365 return 1;
366 /* bad compression ratios */
367 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
368 return 0;
369 if (btrfs_test_opt(root, COMPRESS) ||
370 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
371 BTRFS_I(inode)->force_compress)
372 return 1;
373 return 0;
374 }
375
376 /*
377 * we create compressed extents in two phases. The first
378 * phase compresses a range of pages that have already been
379 * locked (both pages and state bits are locked).
380 *
381 * This is done inside an ordered work queue, and the compression
382 * is spread across many cpus. The actual IO submission is step
383 * two, and the ordered work queue takes care of making sure that
384 * happens in the same order things were put onto the queue by
385 * writepages and friends.
386 *
387 * If this code finds it can't get good compression, it puts an
388 * entry onto the work queue to write the uncompressed bytes. This
389 * makes sure that both compressed inodes and uncompressed inodes
390 * are written in the same order that the flusher thread sent them
391 * down.
392 */
393 static noinline void compress_file_range(struct inode *inode,
394 struct page *locked_page,
395 u64 start, u64 end,
396 struct async_cow *async_cow,
397 int *num_added)
398 {
399 struct btrfs_root *root = BTRFS_I(inode)->root;
400 u64 num_bytes;
401 u64 blocksize = root->sectorsize;
402 u64 actual_end;
403 u64 isize = i_size_read(inode);
404 int ret = 0;
405 struct page **pages = NULL;
406 unsigned long nr_pages;
407 unsigned long nr_pages_ret = 0;
408 unsigned long total_compressed = 0;
409 unsigned long total_in = 0;
410 unsigned long max_compressed = 128 * 1024;
411 unsigned long max_uncompressed = 128 * 1024;
412 int i;
413 int will_compress;
414 int compress_type = root->fs_info->compress_type;
415 int redirty = 0;
416
417 /* if this is a small write inside eof, kick off a defrag */
418 if ((end - start + 1) < 16 * 1024 &&
419 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
420 btrfs_add_inode_defrag(NULL, inode);
421
422 actual_end = min_t(u64, isize, end + 1);
423 again:
424 will_compress = 0;
425 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
426 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
427
428 /*
429 * we don't want to send crud past the end of i_size through
430 * compression, that's just a waste of CPU time. So, if the
431 * end of the file is before the start of our current
432 * requested range of bytes, we bail out to the uncompressed
433 * cleanup code that can deal with all of this.
434 *
435 * It isn't really the fastest way to fix things, but this is a
436 * very uncommon corner.
437 */
438 if (actual_end <= start)
439 goto cleanup_and_bail_uncompressed;
440
441 total_compressed = actual_end - start;
442
443 /*
444 * skip compression for a small file range(<=blocksize) that
445 * isn't an inline extent, since it dosen't save disk space at all.
446 */
447 if (total_compressed <= blocksize &&
448 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
449 goto cleanup_and_bail_uncompressed;
450
451 /* we want to make sure that amount of ram required to uncompress
452 * an extent is reasonable, so we limit the total size in ram
453 * of a compressed extent to 128k. This is a crucial number
454 * because it also controls how easily we can spread reads across
455 * cpus for decompression.
456 *
457 * We also want to make sure the amount of IO required to do
458 * a random read is reasonably small, so we limit the size of
459 * a compressed extent to 128k.
460 */
461 total_compressed = min(total_compressed, max_uncompressed);
462 num_bytes = ALIGN(end - start + 1, blocksize);
463 num_bytes = max(blocksize, num_bytes);
464 total_in = 0;
465 ret = 0;
466
467 /*
468 * we do compression for mount -o compress and when the
469 * inode has not been flagged as nocompress. This flag can
470 * change at any time if we discover bad compression ratios.
471 */
472 if (inode_need_compress(inode)) {
473 WARN_ON(pages);
474 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
475 if (!pages) {
476 /* just bail out to the uncompressed code */
477 goto cont;
478 }
479
480 if (BTRFS_I(inode)->force_compress)
481 compress_type = BTRFS_I(inode)->force_compress;
482
483 /*
484 * we need to call clear_page_dirty_for_io on each
485 * page in the range. Otherwise applications with the file
486 * mmap'd can wander in and change the page contents while
487 * we are compressing them.
488 *
489 * If the compression fails for any reason, we set the pages
490 * dirty again later on.
491 */
492 extent_range_clear_dirty_for_io(inode, start, end);
493 redirty = 1;
494 ret = btrfs_compress_pages(compress_type,
495 inode->i_mapping, start,
496 total_compressed, pages,
497 nr_pages, &nr_pages_ret,
498 &total_in,
499 &total_compressed,
500 max_compressed);
501
502 if (!ret) {
503 unsigned long offset = total_compressed &
504 (PAGE_CACHE_SIZE - 1);
505 struct page *page = pages[nr_pages_ret - 1];
506 char *kaddr;
507
508 /* zero the tail end of the last page, we might be
509 * sending it down to disk
510 */
511 if (offset) {
512 kaddr = kmap_atomic(page);
513 memset(kaddr + offset, 0,
514 PAGE_CACHE_SIZE - offset);
515 kunmap_atomic(kaddr);
516 }
517 will_compress = 1;
518 }
519 }
520 cont:
521 if (start == 0) {
522 /* lets try to make an inline extent */
523 if (ret || total_in < (actual_end - start)) {
524 /* we didn't compress the entire range, try
525 * to make an uncompressed inline extent.
526 */
527 ret = cow_file_range_inline(root, inode, start, end,
528 0, 0, NULL);
529 } else {
530 /* try making a compressed inline extent */
531 ret = cow_file_range_inline(root, inode, start, end,
532 total_compressed,
533 compress_type, pages);
534 }
535 if (ret <= 0) {
536 unsigned long clear_flags = EXTENT_DELALLOC |
537 EXTENT_DEFRAG;
538 unsigned long page_error_op;
539
540 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
541 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
542
543 /*
544 * inline extent creation worked or returned error,
545 * we don't need to create any more async work items.
546 * Unlock and free up our temp pages.
547 */
548 extent_clear_unlock_delalloc(inode, start, end, NULL,
549 clear_flags, PAGE_UNLOCK |
550 PAGE_CLEAR_DIRTY |
551 PAGE_SET_WRITEBACK |
552 page_error_op |
553 PAGE_END_WRITEBACK);
554 goto free_pages_out;
555 }
556 }
557
558 if (will_compress) {
559 /*
560 * we aren't doing an inline extent round the compressed size
561 * up to a block size boundary so the allocator does sane
562 * things
563 */
564 total_compressed = ALIGN(total_compressed, blocksize);
565
566 /*
567 * one last check to make sure the compression is really a
568 * win, compare the page count read with the blocks on disk
569 */
570 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
571 if (total_compressed >= total_in) {
572 will_compress = 0;
573 } else {
574 num_bytes = total_in;
575 }
576 }
577 if (!will_compress && pages) {
578 /*
579 * the compression code ran but failed to make things smaller,
580 * free any pages it allocated and our page pointer array
581 */
582 for (i = 0; i < nr_pages_ret; i++) {
583 WARN_ON(pages[i]->mapping);
584 page_cache_release(pages[i]);
585 }
586 kfree(pages);
587 pages = NULL;
588 total_compressed = 0;
589 nr_pages_ret = 0;
590
591 /* flag the file so we don't compress in the future */
592 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
593 !(BTRFS_I(inode)->force_compress)) {
594 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
595 }
596 }
597 if (will_compress) {
598 *num_added += 1;
599
600 /* the async work queues will take care of doing actual
601 * allocation on disk for these compressed pages,
602 * and will submit them to the elevator.
603 */
604 add_async_extent(async_cow, start, num_bytes,
605 total_compressed, pages, nr_pages_ret,
606 compress_type);
607
608 if (start + num_bytes < end) {
609 start += num_bytes;
610 pages = NULL;
611 cond_resched();
612 goto again;
613 }
614 } else {
615 cleanup_and_bail_uncompressed:
616 /*
617 * No compression, but we still need to write the pages in
618 * the file we've been given so far. redirty the locked
619 * page if it corresponds to our extent and set things up
620 * for the async work queue to run cow_file_range to do
621 * the normal delalloc dance
622 */
623 if (page_offset(locked_page) >= start &&
624 page_offset(locked_page) <= end) {
625 __set_page_dirty_nobuffers(locked_page);
626 /* unlocked later on in the async handlers */
627 }
628 if (redirty)
629 extent_range_redirty_for_io(inode, start, end);
630 add_async_extent(async_cow, start, end - start + 1,
631 0, NULL, 0, BTRFS_COMPRESS_NONE);
632 *num_added += 1;
633 }
634
635 return;
636
637 free_pages_out:
638 for (i = 0; i < nr_pages_ret; i++) {
639 WARN_ON(pages[i]->mapping);
640 page_cache_release(pages[i]);
641 }
642 kfree(pages);
643 }
644
645 static void free_async_extent_pages(struct async_extent *async_extent)
646 {
647 int i;
648
649 if (!async_extent->pages)
650 return;
651
652 for (i = 0; i < async_extent->nr_pages; i++) {
653 WARN_ON(async_extent->pages[i]->mapping);
654 page_cache_release(async_extent->pages[i]);
655 }
656 kfree(async_extent->pages);
657 async_extent->nr_pages = 0;
658 async_extent->pages = NULL;
659 }
660
661 /*
662 * phase two of compressed writeback. This is the ordered portion
663 * of the code, which only gets called in the order the work was
664 * queued. We walk all the async extents created by compress_file_range
665 * and send them down to the disk.
666 */
667 static noinline void submit_compressed_extents(struct inode *inode,
668 struct async_cow *async_cow)
669 {
670 struct async_extent *async_extent;
671 u64 alloc_hint = 0;
672 struct btrfs_key ins;
673 struct extent_map *em;
674 struct btrfs_root *root = BTRFS_I(inode)->root;
675 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
676 struct extent_io_tree *io_tree;
677 int ret = 0;
678
679 again:
680 while (!list_empty(&async_cow->extents)) {
681 async_extent = list_entry(async_cow->extents.next,
682 struct async_extent, list);
683 list_del(&async_extent->list);
684
685 io_tree = &BTRFS_I(inode)->io_tree;
686
687 retry:
688 /* did the compression code fall back to uncompressed IO? */
689 if (!async_extent->pages) {
690 int page_started = 0;
691 unsigned long nr_written = 0;
692
693 lock_extent(io_tree, async_extent->start,
694 async_extent->start +
695 async_extent->ram_size - 1);
696
697 /* allocate blocks */
698 ret = cow_file_range(inode, async_cow->locked_page,
699 async_extent->start,
700 async_extent->start +
701 async_extent->ram_size - 1,
702 &page_started, &nr_written, 0);
703
704 /* JDM XXX */
705
706 /*
707 * if page_started, cow_file_range inserted an
708 * inline extent and took care of all the unlocking
709 * and IO for us. Otherwise, we need to submit
710 * all those pages down to the drive.
711 */
712 if (!page_started && !ret)
713 extent_write_locked_range(io_tree,
714 inode, async_extent->start,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 btrfs_get_extent,
718 WB_SYNC_ALL);
719 else if (ret)
720 unlock_page(async_cow->locked_page);
721 kfree(async_extent);
722 cond_resched();
723 continue;
724 }
725
726 lock_extent(io_tree, async_extent->start,
727 async_extent->start + async_extent->ram_size - 1);
728
729 ret = btrfs_reserve_extent(root,
730 async_extent->compressed_size,
731 async_extent->compressed_size,
732 0, alloc_hint, &ins, 1, 1);
733 if (ret) {
734 free_async_extent_pages(async_extent);
735
736 if (ret == -ENOSPC) {
737 unlock_extent(io_tree, async_extent->start,
738 async_extent->start +
739 async_extent->ram_size - 1);
740
741 /*
742 * we need to redirty the pages if we decide to
743 * fallback to uncompressed IO, otherwise we
744 * will not submit these pages down to lower
745 * layers.
746 */
747 extent_range_redirty_for_io(inode,
748 async_extent->start,
749 async_extent->start +
750 async_extent->ram_size - 1);
751
752 goto retry;
753 }
754 goto out_free;
755 }
756 /*
757 * here we're doing allocation and writeback of the
758 * compressed pages
759 */
760 btrfs_drop_extent_cache(inode, async_extent->start,
761 async_extent->start +
762 async_extent->ram_size - 1, 0);
763
764 em = alloc_extent_map();
765 if (!em) {
766 ret = -ENOMEM;
767 goto out_free_reserve;
768 }
769 em->start = async_extent->start;
770 em->len = async_extent->ram_size;
771 em->orig_start = em->start;
772 em->mod_start = em->start;
773 em->mod_len = em->len;
774
775 em->block_start = ins.objectid;
776 em->block_len = ins.offset;
777 em->orig_block_len = ins.offset;
778 em->ram_bytes = async_extent->ram_size;
779 em->bdev = root->fs_info->fs_devices->latest_bdev;
780 em->compress_type = async_extent->compress_type;
781 set_bit(EXTENT_FLAG_PINNED, &em->flags);
782 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
783 em->generation = -1;
784
785 while (1) {
786 write_lock(&em_tree->lock);
787 ret = add_extent_mapping(em_tree, em, 1);
788 write_unlock(&em_tree->lock);
789 if (ret != -EEXIST) {
790 free_extent_map(em);
791 break;
792 }
793 btrfs_drop_extent_cache(inode, async_extent->start,
794 async_extent->start +
795 async_extent->ram_size - 1, 0);
796 }
797
798 if (ret)
799 goto out_free_reserve;
800
801 ret = btrfs_add_ordered_extent_compress(inode,
802 async_extent->start,
803 ins.objectid,
804 async_extent->ram_size,
805 ins.offset,
806 BTRFS_ORDERED_COMPRESSED,
807 async_extent->compress_type);
808 if (ret) {
809 btrfs_drop_extent_cache(inode, async_extent->start,
810 async_extent->start +
811 async_extent->ram_size - 1, 0);
812 goto out_free_reserve;
813 }
814
815 /*
816 * clear dirty, set writeback and unlock the pages.
817 */
818 extent_clear_unlock_delalloc(inode, async_extent->start,
819 async_extent->start +
820 async_extent->ram_size - 1,
821 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
822 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
823 PAGE_SET_WRITEBACK);
824 ret = btrfs_submit_compressed_write(inode,
825 async_extent->start,
826 async_extent->ram_size,
827 ins.objectid,
828 ins.offset, async_extent->pages,
829 async_extent->nr_pages);
830 if (ret) {
831 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
832 struct page *p = async_extent->pages[0];
833 const u64 start = async_extent->start;
834 const u64 end = start + async_extent->ram_size - 1;
835
836 p->mapping = inode->i_mapping;
837 tree->ops->writepage_end_io_hook(p, start, end,
838 NULL, 0);
839 p->mapping = NULL;
840 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
841 PAGE_END_WRITEBACK |
842 PAGE_SET_ERROR);
843 free_async_extent_pages(async_extent);
844 }
845 alloc_hint = ins.objectid + ins.offset;
846 kfree(async_extent);
847 cond_resched();
848 }
849 return;
850 out_free_reserve:
851 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
852 out_free:
853 extent_clear_unlock_delalloc(inode, async_extent->start,
854 async_extent->start +
855 async_extent->ram_size - 1,
856 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
857 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
858 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
859 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
860 PAGE_SET_ERROR);
861 free_async_extent_pages(async_extent);
862 kfree(async_extent);
863 goto again;
864 }
865
866 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
867 u64 num_bytes)
868 {
869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
870 struct extent_map *em;
871 u64 alloc_hint = 0;
872
873 read_lock(&em_tree->lock);
874 em = search_extent_mapping(em_tree, start, num_bytes);
875 if (em) {
876 /*
877 * if block start isn't an actual block number then find the
878 * first block in this inode and use that as a hint. If that
879 * block is also bogus then just don't worry about it.
880 */
881 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
882 free_extent_map(em);
883 em = search_extent_mapping(em_tree, 0, 0);
884 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
885 alloc_hint = em->block_start;
886 if (em)
887 free_extent_map(em);
888 } else {
889 alloc_hint = em->block_start;
890 free_extent_map(em);
891 }
892 }
893 read_unlock(&em_tree->lock);
894
895 return alloc_hint;
896 }
897
898 /*
899 * when extent_io.c finds a delayed allocation range in the file,
900 * the call backs end up in this code. The basic idea is to
901 * allocate extents on disk for the range, and create ordered data structs
902 * in ram to track those extents.
903 *
904 * locked_page is the page that writepage had locked already. We use
905 * it to make sure we don't do extra locks or unlocks.
906 *
907 * *page_started is set to one if we unlock locked_page and do everything
908 * required to start IO on it. It may be clean and already done with
909 * IO when we return.
910 */
911 static noinline int cow_file_range(struct inode *inode,
912 struct page *locked_page,
913 u64 start, u64 end, int *page_started,
914 unsigned long *nr_written,
915 int unlock)
916 {
917 struct btrfs_root *root = BTRFS_I(inode)->root;
918 u64 alloc_hint = 0;
919 u64 num_bytes;
920 unsigned long ram_size;
921 u64 disk_num_bytes;
922 u64 cur_alloc_size;
923 u64 blocksize = root->sectorsize;
924 struct btrfs_key ins;
925 struct extent_map *em;
926 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
927 int ret = 0;
928
929 if (btrfs_is_free_space_inode(inode)) {
930 WARN_ON_ONCE(1);
931 ret = -EINVAL;
932 goto out_unlock;
933 }
934
935 num_bytes = ALIGN(end - start + 1, blocksize);
936 num_bytes = max(blocksize, num_bytes);
937 disk_num_bytes = num_bytes;
938
939 /* if this is a small write inside eof, kick off defrag */
940 if (num_bytes < 64 * 1024 &&
941 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
942 btrfs_add_inode_defrag(NULL, inode);
943
944 if (start == 0) {
945 /* lets try to make an inline extent */
946 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
947 NULL);
948 if (ret == 0) {
949 extent_clear_unlock_delalloc(inode, start, end, NULL,
950 EXTENT_LOCKED | EXTENT_DELALLOC |
951 EXTENT_DEFRAG, PAGE_UNLOCK |
952 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
953 PAGE_END_WRITEBACK);
954
955 *nr_written = *nr_written +
956 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
957 *page_started = 1;
958 goto out;
959 } else if (ret < 0) {
960 goto out_unlock;
961 }
962 }
963
964 BUG_ON(disk_num_bytes >
965 btrfs_super_total_bytes(root->fs_info->super_copy));
966
967 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
968 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
969
970 while (disk_num_bytes > 0) {
971 unsigned long op;
972
973 cur_alloc_size = disk_num_bytes;
974 ret = btrfs_reserve_extent(root, cur_alloc_size,
975 root->sectorsize, 0, alloc_hint,
976 &ins, 1, 1);
977 if (ret < 0)
978 goto out_unlock;
979
980 em = alloc_extent_map();
981 if (!em) {
982 ret = -ENOMEM;
983 goto out_reserve;
984 }
985 em->start = start;
986 em->orig_start = em->start;
987 ram_size = ins.offset;
988 em->len = ins.offset;
989 em->mod_start = em->start;
990 em->mod_len = em->len;
991
992 em->block_start = ins.objectid;
993 em->block_len = ins.offset;
994 em->orig_block_len = ins.offset;
995 em->ram_bytes = ram_size;
996 em->bdev = root->fs_info->fs_devices->latest_bdev;
997 set_bit(EXTENT_FLAG_PINNED, &em->flags);
998 em->generation = -1;
999
1000 while (1) {
1001 write_lock(&em_tree->lock);
1002 ret = add_extent_mapping(em_tree, em, 1);
1003 write_unlock(&em_tree->lock);
1004 if (ret != -EEXIST) {
1005 free_extent_map(em);
1006 break;
1007 }
1008 btrfs_drop_extent_cache(inode, start,
1009 start + ram_size - 1, 0);
1010 }
1011 if (ret)
1012 goto out_reserve;
1013
1014 cur_alloc_size = ins.offset;
1015 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1016 ram_size, cur_alloc_size, 0);
1017 if (ret)
1018 goto out_drop_extent_cache;
1019
1020 if (root->root_key.objectid ==
1021 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1022 ret = btrfs_reloc_clone_csums(inode, start,
1023 cur_alloc_size);
1024 if (ret)
1025 goto out_drop_extent_cache;
1026 }
1027
1028 if (disk_num_bytes < cur_alloc_size)
1029 break;
1030
1031 /* we're not doing compressed IO, don't unlock the first
1032 * page (which the caller expects to stay locked), don't
1033 * clear any dirty bits and don't set any writeback bits
1034 *
1035 * Do set the Private2 bit so we know this page was properly
1036 * setup for writepage
1037 */
1038 op = unlock ? PAGE_UNLOCK : 0;
1039 op |= PAGE_SET_PRIVATE2;
1040
1041 extent_clear_unlock_delalloc(inode, start,
1042 start + ram_size - 1, locked_page,
1043 EXTENT_LOCKED | EXTENT_DELALLOC,
1044 op);
1045 disk_num_bytes -= cur_alloc_size;
1046 num_bytes -= cur_alloc_size;
1047 alloc_hint = ins.objectid + ins.offset;
1048 start += cur_alloc_size;
1049 }
1050 out:
1051 return ret;
1052
1053 out_drop_extent_cache:
1054 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1055 out_reserve:
1056 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1057 out_unlock:
1058 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1059 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1060 EXTENT_DELALLOC | EXTENT_DEFRAG,
1061 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1062 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1063 goto out;
1064 }
1065
1066 /*
1067 * work queue call back to started compression on a file and pages
1068 */
1069 static noinline void async_cow_start(struct btrfs_work *work)
1070 {
1071 struct async_cow *async_cow;
1072 int num_added = 0;
1073 async_cow = container_of(work, struct async_cow, work);
1074
1075 compress_file_range(async_cow->inode, async_cow->locked_page,
1076 async_cow->start, async_cow->end, async_cow,
1077 &num_added);
1078 if (num_added == 0) {
1079 btrfs_add_delayed_iput(async_cow->inode);
1080 async_cow->inode = NULL;
1081 }
1082 }
1083
1084 /*
1085 * work queue call back to submit previously compressed pages
1086 */
1087 static noinline void async_cow_submit(struct btrfs_work *work)
1088 {
1089 struct async_cow *async_cow;
1090 struct btrfs_root *root;
1091 unsigned long nr_pages;
1092
1093 async_cow = container_of(work, struct async_cow, work);
1094
1095 root = async_cow->root;
1096 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1097 PAGE_CACHE_SHIFT;
1098
1099 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1100 5 * 1024 * 1024 &&
1101 waitqueue_active(&root->fs_info->async_submit_wait))
1102 wake_up(&root->fs_info->async_submit_wait);
1103
1104 if (async_cow->inode)
1105 submit_compressed_extents(async_cow->inode, async_cow);
1106 }
1107
1108 static noinline void async_cow_free(struct btrfs_work *work)
1109 {
1110 struct async_cow *async_cow;
1111 async_cow = container_of(work, struct async_cow, work);
1112 if (async_cow->inode)
1113 btrfs_add_delayed_iput(async_cow->inode);
1114 kfree(async_cow);
1115 }
1116
1117 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1118 u64 start, u64 end, int *page_started,
1119 unsigned long *nr_written)
1120 {
1121 struct async_cow *async_cow;
1122 struct btrfs_root *root = BTRFS_I(inode)->root;
1123 unsigned long nr_pages;
1124 u64 cur_end;
1125 int limit = 10 * 1024 * 1024;
1126
1127 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1128 1, 0, NULL, GFP_NOFS);
1129 while (start < end) {
1130 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1131 BUG_ON(!async_cow); /* -ENOMEM */
1132 async_cow->inode = igrab(inode);
1133 async_cow->root = root;
1134 async_cow->locked_page = locked_page;
1135 async_cow->start = start;
1136
1137 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1138 !btrfs_test_opt(root, FORCE_COMPRESS))
1139 cur_end = end;
1140 else
1141 cur_end = min(end, start + 512 * 1024 - 1);
1142
1143 async_cow->end = cur_end;
1144 INIT_LIST_HEAD(&async_cow->extents);
1145
1146 btrfs_init_work(&async_cow->work,
1147 btrfs_delalloc_helper,
1148 async_cow_start, async_cow_submit,
1149 async_cow_free);
1150
1151 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1152 PAGE_CACHE_SHIFT;
1153 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1154
1155 btrfs_queue_work(root->fs_info->delalloc_workers,
1156 &async_cow->work);
1157
1158 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1159 wait_event(root->fs_info->async_submit_wait,
1160 (atomic_read(&root->fs_info->async_delalloc_pages) <
1161 limit));
1162 }
1163
1164 while (atomic_read(&root->fs_info->async_submit_draining) &&
1165 atomic_read(&root->fs_info->async_delalloc_pages)) {
1166 wait_event(root->fs_info->async_submit_wait,
1167 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1168 0));
1169 }
1170
1171 *nr_written += nr_pages;
1172 start = cur_end + 1;
1173 }
1174 *page_started = 1;
1175 return 0;
1176 }
1177
1178 static noinline int csum_exist_in_range(struct btrfs_root *root,
1179 u64 bytenr, u64 num_bytes)
1180 {
1181 int ret;
1182 struct btrfs_ordered_sum *sums;
1183 LIST_HEAD(list);
1184
1185 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1186 bytenr + num_bytes - 1, &list, 0);
1187 if (ret == 0 && list_empty(&list))
1188 return 0;
1189
1190 while (!list_empty(&list)) {
1191 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1192 list_del(&sums->list);
1193 kfree(sums);
1194 }
1195 return 1;
1196 }
1197
1198 /*
1199 * when nowcow writeback call back. This checks for snapshots or COW copies
1200 * of the extents that exist in the file, and COWs the file as required.
1201 *
1202 * If no cow copies or snapshots exist, we write directly to the existing
1203 * blocks on disk
1204 */
1205 static noinline int run_delalloc_nocow(struct inode *inode,
1206 struct page *locked_page,
1207 u64 start, u64 end, int *page_started, int force,
1208 unsigned long *nr_written)
1209 {
1210 struct btrfs_root *root = BTRFS_I(inode)->root;
1211 struct btrfs_trans_handle *trans;
1212 struct extent_buffer *leaf;
1213 struct btrfs_path *path;
1214 struct btrfs_file_extent_item *fi;
1215 struct btrfs_key found_key;
1216 u64 cow_start;
1217 u64 cur_offset;
1218 u64 extent_end;
1219 u64 extent_offset;
1220 u64 disk_bytenr;
1221 u64 num_bytes;
1222 u64 disk_num_bytes;
1223 u64 ram_bytes;
1224 int extent_type;
1225 int ret, err;
1226 int type;
1227 int nocow;
1228 int check_prev = 1;
1229 bool nolock;
1230 u64 ino = btrfs_ino(inode);
1231
1232 path = btrfs_alloc_path();
1233 if (!path) {
1234 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1235 EXTENT_LOCKED | EXTENT_DELALLOC |
1236 EXTENT_DO_ACCOUNTING |
1237 EXTENT_DEFRAG, PAGE_UNLOCK |
1238 PAGE_CLEAR_DIRTY |
1239 PAGE_SET_WRITEBACK |
1240 PAGE_END_WRITEBACK);
1241 return -ENOMEM;
1242 }
1243
1244 nolock = btrfs_is_free_space_inode(inode);
1245
1246 if (nolock)
1247 trans = btrfs_join_transaction_nolock(root);
1248 else
1249 trans = btrfs_join_transaction(root);
1250
1251 if (IS_ERR(trans)) {
1252 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1253 EXTENT_LOCKED | EXTENT_DELALLOC |
1254 EXTENT_DO_ACCOUNTING |
1255 EXTENT_DEFRAG, PAGE_UNLOCK |
1256 PAGE_CLEAR_DIRTY |
1257 PAGE_SET_WRITEBACK |
1258 PAGE_END_WRITEBACK);
1259 btrfs_free_path(path);
1260 return PTR_ERR(trans);
1261 }
1262
1263 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1264
1265 cow_start = (u64)-1;
1266 cur_offset = start;
1267 while (1) {
1268 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1269 cur_offset, 0);
1270 if (ret < 0)
1271 goto error;
1272 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1273 leaf = path->nodes[0];
1274 btrfs_item_key_to_cpu(leaf, &found_key,
1275 path->slots[0] - 1);
1276 if (found_key.objectid == ino &&
1277 found_key.type == BTRFS_EXTENT_DATA_KEY)
1278 path->slots[0]--;
1279 }
1280 check_prev = 0;
1281 next_slot:
1282 leaf = path->nodes[0];
1283 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1284 ret = btrfs_next_leaf(root, path);
1285 if (ret < 0)
1286 goto error;
1287 if (ret > 0)
1288 break;
1289 leaf = path->nodes[0];
1290 }
1291
1292 nocow = 0;
1293 disk_bytenr = 0;
1294 num_bytes = 0;
1295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1296
1297 if (found_key.objectid > ino ||
1298 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1299 found_key.offset > end)
1300 break;
1301
1302 if (found_key.offset > cur_offset) {
1303 extent_end = found_key.offset;
1304 extent_type = 0;
1305 goto out_check;
1306 }
1307
1308 fi = btrfs_item_ptr(leaf, path->slots[0],
1309 struct btrfs_file_extent_item);
1310 extent_type = btrfs_file_extent_type(leaf, fi);
1311
1312 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1313 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1314 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1315 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1316 extent_offset = btrfs_file_extent_offset(leaf, fi);
1317 extent_end = found_key.offset +
1318 btrfs_file_extent_num_bytes(leaf, fi);
1319 disk_num_bytes =
1320 btrfs_file_extent_disk_num_bytes(leaf, fi);
1321 if (extent_end <= start) {
1322 path->slots[0]++;
1323 goto next_slot;
1324 }
1325 if (disk_bytenr == 0)
1326 goto out_check;
1327 if (btrfs_file_extent_compression(leaf, fi) ||
1328 btrfs_file_extent_encryption(leaf, fi) ||
1329 btrfs_file_extent_other_encoding(leaf, fi))
1330 goto out_check;
1331 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1332 goto out_check;
1333 if (btrfs_extent_readonly(root, disk_bytenr))
1334 goto out_check;
1335 if (btrfs_cross_ref_exist(trans, root, ino,
1336 found_key.offset -
1337 extent_offset, disk_bytenr))
1338 goto out_check;
1339 disk_bytenr += extent_offset;
1340 disk_bytenr += cur_offset - found_key.offset;
1341 num_bytes = min(end + 1, extent_end) - cur_offset;
1342 /*
1343 * if there are pending snapshots for this root,
1344 * we fall into common COW way.
1345 */
1346 if (!nolock) {
1347 err = btrfs_start_write_no_snapshoting(root);
1348 if (!err)
1349 goto out_check;
1350 }
1351 /*
1352 * force cow if csum exists in the range.
1353 * this ensure that csum for a given extent are
1354 * either valid or do not exist.
1355 */
1356 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1357 goto out_check;
1358 nocow = 1;
1359 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1360 extent_end = found_key.offset +
1361 btrfs_file_extent_inline_len(leaf,
1362 path->slots[0], fi);
1363 extent_end = ALIGN(extent_end, root->sectorsize);
1364 } else {
1365 BUG_ON(1);
1366 }
1367 out_check:
1368 if (extent_end <= start) {
1369 path->slots[0]++;
1370 if (!nolock && nocow)
1371 btrfs_end_write_no_snapshoting(root);
1372 goto next_slot;
1373 }
1374 if (!nocow) {
1375 if (cow_start == (u64)-1)
1376 cow_start = cur_offset;
1377 cur_offset = extent_end;
1378 if (cur_offset > end)
1379 break;
1380 path->slots[0]++;
1381 goto next_slot;
1382 }
1383
1384 btrfs_release_path(path);
1385 if (cow_start != (u64)-1) {
1386 ret = cow_file_range(inode, locked_page,
1387 cow_start, found_key.offset - 1,
1388 page_started, nr_written, 1);
1389 if (ret) {
1390 if (!nolock && nocow)
1391 btrfs_end_write_no_snapshoting(root);
1392 goto error;
1393 }
1394 cow_start = (u64)-1;
1395 }
1396
1397 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1398 struct extent_map *em;
1399 struct extent_map_tree *em_tree;
1400 em_tree = &BTRFS_I(inode)->extent_tree;
1401 em = alloc_extent_map();
1402 BUG_ON(!em); /* -ENOMEM */
1403 em->start = cur_offset;
1404 em->orig_start = found_key.offset - extent_offset;
1405 em->len = num_bytes;
1406 em->block_len = num_bytes;
1407 em->block_start = disk_bytenr;
1408 em->orig_block_len = disk_num_bytes;
1409 em->ram_bytes = ram_bytes;
1410 em->bdev = root->fs_info->fs_devices->latest_bdev;
1411 em->mod_start = em->start;
1412 em->mod_len = em->len;
1413 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1414 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1415 em->generation = -1;
1416 while (1) {
1417 write_lock(&em_tree->lock);
1418 ret = add_extent_mapping(em_tree, em, 1);
1419 write_unlock(&em_tree->lock);
1420 if (ret != -EEXIST) {
1421 free_extent_map(em);
1422 break;
1423 }
1424 btrfs_drop_extent_cache(inode, em->start,
1425 em->start + em->len - 1, 0);
1426 }
1427 type = BTRFS_ORDERED_PREALLOC;
1428 } else {
1429 type = BTRFS_ORDERED_NOCOW;
1430 }
1431
1432 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1433 num_bytes, num_bytes, type);
1434 BUG_ON(ret); /* -ENOMEM */
1435
1436 if (root->root_key.objectid ==
1437 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1438 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1439 num_bytes);
1440 if (ret) {
1441 if (!nolock && nocow)
1442 btrfs_end_write_no_snapshoting(root);
1443 goto error;
1444 }
1445 }
1446
1447 extent_clear_unlock_delalloc(inode, cur_offset,
1448 cur_offset + num_bytes - 1,
1449 locked_page, EXTENT_LOCKED |
1450 EXTENT_DELALLOC, PAGE_UNLOCK |
1451 PAGE_SET_PRIVATE2);
1452 if (!nolock && nocow)
1453 btrfs_end_write_no_snapshoting(root);
1454 cur_offset = extent_end;
1455 if (cur_offset > end)
1456 break;
1457 }
1458 btrfs_release_path(path);
1459
1460 if (cur_offset <= end && cow_start == (u64)-1) {
1461 cow_start = cur_offset;
1462 cur_offset = end;
1463 }
1464
1465 if (cow_start != (u64)-1) {
1466 ret = cow_file_range(inode, locked_page, cow_start, end,
1467 page_started, nr_written, 1);
1468 if (ret)
1469 goto error;
1470 }
1471
1472 error:
1473 err = btrfs_end_transaction(trans, root);
1474 if (!ret)
1475 ret = err;
1476
1477 if (ret && cur_offset < end)
1478 extent_clear_unlock_delalloc(inode, cur_offset, end,
1479 locked_page, EXTENT_LOCKED |
1480 EXTENT_DELALLOC | EXTENT_DEFRAG |
1481 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1482 PAGE_CLEAR_DIRTY |
1483 PAGE_SET_WRITEBACK |
1484 PAGE_END_WRITEBACK);
1485 btrfs_free_path(path);
1486 return ret;
1487 }
1488
1489 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1490 {
1491
1492 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1493 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1494 return 0;
1495
1496 /*
1497 * @defrag_bytes is a hint value, no spinlock held here,
1498 * if is not zero, it means the file is defragging.
1499 * Force cow if given extent needs to be defragged.
1500 */
1501 if (BTRFS_I(inode)->defrag_bytes &&
1502 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1503 EXTENT_DEFRAG, 0, NULL))
1504 return 1;
1505
1506 return 0;
1507 }
1508
1509 /*
1510 * extent_io.c call back to do delayed allocation processing
1511 */
1512 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1513 u64 start, u64 end, int *page_started,
1514 unsigned long *nr_written)
1515 {
1516 int ret;
1517 int force_cow = need_force_cow(inode, start, end);
1518
1519 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1520 ret = run_delalloc_nocow(inode, locked_page, start, end,
1521 page_started, 1, nr_written);
1522 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1523 ret = run_delalloc_nocow(inode, locked_page, start, end,
1524 page_started, 0, nr_written);
1525 } else if (!inode_need_compress(inode)) {
1526 ret = cow_file_range(inode, locked_page, start, end,
1527 page_started, nr_written, 1);
1528 } else {
1529 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1530 &BTRFS_I(inode)->runtime_flags);
1531 ret = cow_file_range_async(inode, locked_page, start, end,
1532 page_started, nr_written);
1533 }
1534 return ret;
1535 }
1536
1537 static void btrfs_split_extent_hook(struct inode *inode,
1538 struct extent_state *orig, u64 split)
1539 {
1540 u64 size;
1541
1542 /* not delalloc, ignore it */
1543 if (!(orig->state & EXTENT_DELALLOC))
1544 return;
1545
1546 size = orig->end - orig->start + 1;
1547 if (size > BTRFS_MAX_EXTENT_SIZE) {
1548 u64 num_extents;
1549 u64 new_size;
1550
1551 /*
1552 * See the explanation in btrfs_merge_extent_hook, the same
1553 * applies here, just in reverse.
1554 */
1555 new_size = orig->end - split + 1;
1556 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1557 BTRFS_MAX_EXTENT_SIZE);
1558 new_size = split - orig->start;
1559 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1560 BTRFS_MAX_EXTENT_SIZE);
1561 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1562 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1563 return;
1564 }
1565
1566 spin_lock(&BTRFS_I(inode)->lock);
1567 BTRFS_I(inode)->outstanding_extents++;
1568 spin_unlock(&BTRFS_I(inode)->lock);
1569 }
1570
1571 /*
1572 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1573 * extents so we can keep track of new extents that are just merged onto old
1574 * extents, such as when we are doing sequential writes, so we can properly
1575 * account for the metadata space we'll need.
1576 */
1577 static void btrfs_merge_extent_hook(struct inode *inode,
1578 struct extent_state *new,
1579 struct extent_state *other)
1580 {
1581 u64 new_size, old_size;
1582 u64 num_extents;
1583
1584 /* not delalloc, ignore it */
1585 if (!(other->state & EXTENT_DELALLOC))
1586 return;
1587
1588 if (new->start > other->start)
1589 new_size = new->end - other->start + 1;
1590 else
1591 new_size = other->end - new->start + 1;
1592
1593 /* we're not bigger than the max, unreserve the space and go */
1594 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1595 spin_lock(&BTRFS_I(inode)->lock);
1596 BTRFS_I(inode)->outstanding_extents--;
1597 spin_unlock(&BTRFS_I(inode)->lock);
1598 return;
1599 }
1600
1601 /*
1602 * We have to add up either side to figure out how many extents were
1603 * accounted for before we merged into one big extent. If the number of
1604 * extents we accounted for is <= the amount we need for the new range
1605 * then we can return, otherwise drop. Think of it like this
1606 *
1607 * [ 4k][MAX_SIZE]
1608 *
1609 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1610 * need 2 outstanding extents, on one side we have 1 and the other side
1611 * we have 1 so they are == and we can return. But in this case
1612 *
1613 * [MAX_SIZE+4k][MAX_SIZE+4k]
1614 *
1615 * Each range on their own accounts for 2 extents, but merged together
1616 * they are only 3 extents worth of accounting, so we need to drop in
1617 * this case.
1618 */
1619 old_size = other->end - other->start + 1;
1620 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1621 BTRFS_MAX_EXTENT_SIZE);
1622 old_size = new->end - new->start + 1;
1623 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1624 BTRFS_MAX_EXTENT_SIZE);
1625
1626 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1627 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1628 return;
1629
1630 spin_lock(&BTRFS_I(inode)->lock);
1631 BTRFS_I(inode)->outstanding_extents--;
1632 spin_unlock(&BTRFS_I(inode)->lock);
1633 }
1634
1635 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1636 struct inode *inode)
1637 {
1638 spin_lock(&root->delalloc_lock);
1639 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1640 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1641 &root->delalloc_inodes);
1642 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1643 &BTRFS_I(inode)->runtime_flags);
1644 root->nr_delalloc_inodes++;
1645 if (root->nr_delalloc_inodes == 1) {
1646 spin_lock(&root->fs_info->delalloc_root_lock);
1647 BUG_ON(!list_empty(&root->delalloc_root));
1648 list_add_tail(&root->delalloc_root,
1649 &root->fs_info->delalloc_roots);
1650 spin_unlock(&root->fs_info->delalloc_root_lock);
1651 }
1652 }
1653 spin_unlock(&root->delalloc_lock);
1654 }
1655
1656 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1657 struct inode *inode)
1658 {
1659 spin_lock(&root->delalloc_lock);
1660 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1661 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1662 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1663 &BTRFS_I(inode)->runtime_flags);
1664 root->nr_delalloc_inodes--;
1665 if (!root->nr_delalloc_inodes) {
1666 spin_lock(&root->fs_info->delalloc_root_lock);
1667 BUG_ON(list_empty(&root->delalloc_root));
1668 list_del_init(&root->delalloc_root);
1669 spin_unlock(&root->fs_info->delalloc_root_lock);
1670 }
1671 }
1672 spin_unlock(&root->delalloc_lock);
1673 }
1674
1675 /*
1676 * extent_io.c set_bit_hook, used to track delayed allocation
1677 * bytes in this file, and to maintain the list of inodes that
1678 * have pending delalloc work to be done.
1679 */
1680 static void btrfs_set_bit_hook(struct inode *inode,
1681 struct extent_state *state, unsigned *bits)
1682 {
1683
1684 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1685 WARN_ON(1);
1686 /*
1687 * set_bit and clear bit hooks normally require _irqsave/restore
1688 * but in this case, we are only testing for the DELALLOC
1689 * bit, which is only set or cleared with irqs on
1690 */
1691 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1692 struct btrfs_root *root = BTRFS_I(inode)->root;
1693 u64 len = state->end + 1 - state->start;
1694 bool do_list = !btrfs_is_free_space_inode(inode);
1695
1696 if (*bits & EXTENT_FIRST_DELALLOC) {
1697 *bits &= ~EXTENT_FIRST_DELALLOC;
1698 } else {
1699 spin_lock(&BTRFS_I(inode)->lock);
1700 BTRFS_I(inode)->outstanding_extents++;
1701 spin_unlock(&BTRFS_I(inode)->lock);
1702 }
1703
1704 /* For sanity tests */
1705 if (btrfs_test_is_dummy_root(root))
1706 return;
1707
1708 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1709 root->fs_info->delalloc_batch);
1710 spin_lock(&BTRFS_I(inode)->lock);
1711 BTRFS_I(inode)->delalloc_bytes += len;
1712 if (*bits & EXTENT_DEFRAG)
1713 BTRFS_I(inode)->defrag_bytes += len;
1714 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1715 &BTRFS_I(inode)->runtime_flags))
1716 btrfs_add_delalloc_inodes(root, inode);
1717 spin_unlock(&BTRFS_I(inode)->lock);
1718 }
1719 }
1720
1721 /*
1722 * extent_io.c clear_bit_hook, see set_bit_hook for why
1723 */
1724 static void btrfs_clear_bit_hook(struct inode *inode,
1725 struct extent_state *state,
1726 unsigned *bits)
1727 {
1728 u64 len = state->end + 1 - state->start;
1729 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1730 BTRFS_MAX_EXTENT_SIZE);
1731
1732 spin_lock(&BTRFS_I(inode)->lock);
1733 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1734 BTRFS_I(inode)->defrag_bytes -= len;
1735 spin_unlock(&BTRFS_I(inode)->lock);
1736
1737 /*
1738 * set_bit and clear bit hooks normally require _irqsave/restore
1739 * but in this case, we are only testing for the DELALLOC
1740 * bit, which is only set or cleared with irqs on
1741 */
1742 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1743 struct btrfs_root *root = BTRFS_I(inode)->root;
1744 bool do_list = !btrfs_is_free_space_inode(inode);
1745
1746 if (*bits & EXTENT_FIRST_DELALLOC) {
1747 *bits &= ~EXTENT_FIRST_DELALLOC;
1748 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1749 spin_lock(&BTRFS_I(inode)->lock);
1750 BTRFS_I(inode)->outstanding_extents -= num_extents;
1751 spin_unlock(&BTRFS_I(inode)->lock);
1752 }
1753
1754 /*
1755 * We don't reserve metadata space for space cache inodes so we
1756 * don't need to call dellalloc_release_metadata if there is an
1757 * error.
1758 */
1759 if (*bits & EXTENT_DO_ACCOUNTING &&
1760 root != root->fs_info->tree_root)
1761 btrfs_delalloc_release_metadata(inode, len);
1762
1763 /* For sanity tests. */
1764 if (btrfs_test_is_dummy_root(root))
1765 return;
1766
1767 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1768 && do_list && !(state->state & EXTENT_NORESERVE))
1769 btrfs_free_reserved_data_space(inode, len);
1770
1771 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1772 root->fs_info->delalloc_batch);
1773 spin_lock(&BTRFS_I(inode)->lock);
1774 BTRFS_I(inode)->delalloc_bytes -= len;
1775 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1776 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1777 &BTRFS_I(inode)->runtime_flags))
1778 btrfs_del_delalloc_inode(root, inode);
1779 spin_unlock(&BTRFS_I(inode)->lock);
1780 }
1781 }
1782
1783 /*
1784 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1785 * we don't create bios that span stripes or chunks
1786 */
1787 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1788 size_t size, struct bio *bio,
1789 unsigned long bio_flags)
1790 {
1791 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1792 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1793 u64 length = 0;
1794 u64 map_length;
1795 int ret;
1796
1797 if (bio_flags & EXTENT_BIO_COMPRESSED)
1798 return 0;
1799
1800 length = bio->bi_iter.bi_size;
1801 map_length = length;
1802 ret = btrfs_map_block(root->fs_info, rw, logical,
1803 &map_length, NULL, 0);
1804 /* Will always return 0 with map_multi == NULL */
1805 BUG_ON(ret < 0);
1806 if (map_length < length + size)
1807 return 1;
1808 return 0;
1809 }
1810
1811 /*
1812 * in order to insert checksums into the metadata in large chunks,
1813 * we wait until bio submission time. All the pages in the bio are
1814 * checksummed and sums are attached onto the ordered extent record.
1815 *
1816 * At IO completion time the cums attached on the ordered extent record
1817 * are inserted into the btree
1818 */
1819 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1820 struct bio *bio, int mirror_num,
1821 unsigned long bio_flags,
1822 u64 bio_offset)
1823 {
1824 struct btrfs_root *root = BTRFS_I(inode)->root;
1825 int ret = 0;
1826
1827 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1828 BUG_ON(ret); /* -ENOMEM */
1829 return 0;
1830 }
1831
1832 /*
1833 * in order to insert checksums into the metadata in large chunks,
1834 * we wait until bio submission time. All the pages in the bio are
1835 * checksummed and sums are attached onto the ordered extent record.
1836 *
1837 * At IO completion time the cums attached on the ordered extent record
1838 * are inserted into the btree
1839 */
1840 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1841 int mirror_num, unsigned long bio_flags,
1842 u64 bio_offset)
1843 {
1844 struct btrfs_root *root = BTRFS_I(inode)->root;
1845 int ret;
1846
1847 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1848 if (ret)
1849 bio_endio(bio, ret);
1850 return ret;
1851 }
1852
1853 /*
1854 * extent_io.c submission hook. This does the right thing for csum calculation
1855 * on write, or reading the csums from the tree before a read
1856 */
1857 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1858 int mirror_num, unsigned long bio_flags,
1859 u64 bio_offset)
1860 {
1861 struct btrfs_root *root = BTRFS_I(inode)->root;
1862 int ret = 0;
1863 int skip_sum;
1864 int metadata = 0;
1865 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1866
1867 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1868
1869 if (btrfs_is_free_space_inode(inode))
1870 metadata = 2;
1871
1872 if (!(rw & REQ_WRITE)) {
1873 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1874 if (ret)
1875 goto out;
1876
1877 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1878 ret = btrfs_submit_compressed_read(inode, bio,
1879 mirror_num,
1880 bio_flags);
1881 goto out;
1882 } else if (!skip_sum) {
1883 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1884 if (ret)
1885 goto out;
1886 }
1887 goto mapit;
1888 } else if (async && !skip_sum) {
1889 /* csum items have already been cloned */
1890 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1891 goto mapit;
1892 /* we're doing a write, do the async checksumming */
1893 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1894 inode, rw, bio, mirror_num,
1895 bio_flags, bio_offset,
1896 __btrfs_submit_bio_start,
1897 __btrfs_submit_bio_done);
1898 goto out;
1899 } else if (!skip_sum) {
1900 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1901 if (ret)
1902 goto out;
1903 }
1904
1905 mapit:
1906 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1907
1908 out:
1909 if (ret < 0)
1910 bio_endio(bio, ret);
1911 return ret;
1912 }
1913
1914 /*
1915 * given a list of ordered sums record them in the inode. This happens
1916 * at IO completion time based on sums calculated at bio submission time.
1917 */
1918 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1919 struct inode *inode, u64 file_offset,
1920 struct list_head *list)
1921 {
1922 struct btrfs_ordered_sum *sum;
1923
1924 list_for_each_entry(sum, list, list) {
1925 trans->adding_csums = 1;
1926 btrfs_csum_file_blocks(trans,
1927 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1928 trans->adding_csums = 0;
1929 }
1930 return 0;
1931 }
1932
1933 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1934 struct extent_state **cached_state)
1935 {
1936 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1937 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1938 cached_state, GFP_NOFS);
1939 }
1940
1941 /* see btrfs_writepage_start_hook for details on why this is required */
1942 struct btrfs_writepage_fixup {
1943 struct page *page;
1944 struct btrfs_work work;
1945 };
1946
1947 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1948 {
1949 struct btrfs_writepage_fixup *fixup;
1950 struct btrfs_ordered_extent *ordered;
1951 struct extent_state *cached_state = NULL;
1952 struct page *page;
1953 struct inode *inode;
1954 u64 page_start;
1955 u64 page_end;
1956 int ret;
1957
1958 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1959 page = fixup->page;
1960 again:
1961 lock_page(page);
1962 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1963 ClearPageChecked(page);
1964 goto out_page;
1965 }
1966
1967 inode = page->mapping->host;
1968 page_start = page_offset(page);
1969 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1970
1971 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1972 &cached_state);
1973
1974 /* already ordered? We're done */
1975 if (PagePrivate2(page))
1976 goto out;
1977
1978 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1979 if (ordered) {
1980 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1981 page_end, &cached_state, GFP_NOFS);
1982 unlock_page(page);
1983 btrfs_start_ordered_extent(inode, ordered, 1);
1984 btrfs_put_ordered_extent(ordered);
1985 goto again;
1986 }
1987
1988 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1989 if (ret) {
1990 mapping_set_error(page->mapping, ret);
1991 end_extent_writepage(page, ret, page_start, page_end);
1992 ClearPageChecked(page);
1993 goto out;
1994 }
1995
1996 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1997 ClearPageChecked(page);
1998 set_page_dirty(page);
1999 out:
2000 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2001 &cached_state, GFP_NOFS);
2002 out_page:
2003 unlock_page(page);
2004 page_cache_release(page);
2005 kfree(fixup);
2006 }
2007
2008 /*
2009 * There are a few paths in the higher layers of the kernel that directly
2010 * set the page dirty bit without asking the filesystem if it is a
2011 * good idea. This causes problems because we want to make sure COW
2012 * properly happens and the data=ordered rules are followed.
2013 *
2014 * In our case any range that doesn't have the ORDERED bit set
2015 * hasn't been properly setup for IO. We kick off an async process
2016 * to fix it up. The async helper will wait for ordered extents, set
2017 * the delalloc bit and make it safe to write the page.
2018 */
2019 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2020 {
2021 struct inode *inode = page->mapping->host;
2022 struct btrfs_writepage_fixup *fixup;
2023 struct btrfs_root *root = BTRFS_I(inode)->root;
2024
2025 /* this page is properly in the ordered list */
2026 if (TestClearPagePrivate2(page))
2027 return 0;
2028
2029 if (PageChecked(page))
2030 return -EAGAIN;
2031
2032 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2033 if (!fixup)
2034 return -EAGAIN;
2035
2036 SetPageChecked(page);
2037 page_cache_get(page);
2038 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2039 btrfs_writepage_fixup_worker, NULL, NULL);
2040 fixup->page = page;
2041 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2042 return -EBUSY;
2043 }
2044
2045 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2046 struct inode *inode, u64 file_pos,
2047 u64 disk_bytenr, u64 disk_num_bytes,
2048 u64 num_bytes, u64 ram_bytes,
2049 u8 compression, u8 encryption,
2050 u16 other_encoding, int extent_type)
2051 {
2052 struct btrfs_root *root = BTRFS_I(inode)->root;
2053 struct btrfs_file_extent_item *fi;
2054 struct btrfs_path *path;
2055 struct extent_buffer *leaf;
2056 struct btrfs_key ins;
2057 int extent_inserted = 0;
2058 int ret;
2059
2060 path = btrfs_alloc_path();
2061 if (!path)
2062 return -ENOMEM;
2063
2064 /*
2065 * we may be replacing one extent in the tree with another.
2066 * The new extent is pinned in the extent map, and we don't want
2067 * to drop it from the cache until it is completely in the btree.
2068 *
2069 * So, tell btrfs_drop_extents to leave this extent in the cache.
2070 * the caller is expected to unpin it and allow it to be merged
2071 * with the others.
2072 */
2073 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2074 file_pos + num_bytes, NULL, 0,
2075 1, sizeof(*fi), &extent_inserted);
2076 if (ret)
2077 goto out;
2078
2079 if (!extent_inserted) {
2080 ins.objectid = btrfs_ino(inode);
2081 ins.offset = file_pos;
2082 ins.type = BTRFS_EXTENT_DATA_KEY;
2083
2084 path->leave_spinning = 1;
2085 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2086 sizeof(*fi));
2087 if (ret)
2088 goto out;
2089 }
2090 leaf = path->nodes[0];
2091 fi = btrfs_item_ptr(leaf, path->slots[0],
2092 struct btrfs_file_extent_item);
2093 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2094 btrfs_set_file_extent_type(leaf, fi, extent_type);
2095 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2096 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2097 btrfs_set_file_extent_offset(leaf, fi, 0);
2098 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2099 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2100 btrfs_set_file_extent_compression(leaf, fi, compression);
2101 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2102 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2103
2104 btrfs_mark_buffer_dirty(leaf);
2105 btrfs_release_path(path);
2106
2107 inode_add_bytes(inode, num_bytes);
2108
2109 ins.objectid = disk_bytenr;
2110 ins.offset = disk_num_bytes;
2111 ins.type = BTRFS_EXTENT_ITEM_KEY;
2112 ret = btrfs_alloc_reserved_file_extent(trans, root,
2113 root->root_key.objectid,
2114 btrfs_ino(inode), file_pos, &ins);
2115 out:
2116 btrfs_free_path(path);
2117
2118 return ret;
2119 }
2120
2121 /* snapshot-aware defrag */
2122 struct sa_defrag_extent_backref {
2123 struct rb_node node;
2124 struct old_sa_defrag_extent *old;
2125 u64 root_id;
2126 u64 inum;
2127 u64 file_pos;
2128 u64 extent_offset;
2129 u64 num_bytes;
2130 u64 generation;
2131 };
2132
2133 struct old_sa_defrag_extent {
2134 struct list_head list;
2135 struct new_sa_defrag_extent *new;
2136
2137 u64 extent_offset;
2138 u64 bytenr;
2139 u64 offset;
2140 u64 len;
2141 int count;
2142 };
2143
2144 struct new_sa_defrag_extent {
2145 struct rb_root root;
2146 struct list_head head;
2147 struct btrfs_path *path;
2148 struct inode *inode;
2149 u64 file_pos;
2150 u64 len;
2151 u64 bytenr;
2152 u64 disk_len;
2153 u8 compress_type;
2154 };
2155
2156 static int backref_comp(struct sa_defrag_extent_backref *b1,
2157 struct sa_defrag_extent_backref *b2)
2158 {
2159 if (b1->root_id < b2->root_id)
2160 return -1;
2161 else if (b1->root_id > b2->root_id)
2162 return 1;
2163
2164 if (b1->inum < b2->inum)
2165 return -1;
2166 else if (b1->inum > b2->inum)
2167 return 1;
2168
2169 if (b1->file_pos < b2->file_pos)
2170 return -1;
2171 else if (b1->file_pos > b2->file_pos)
2172 return 1;
2173
2174 /*
2175 * [------------------------------] ===> (a range of space)
2176 * |<--->| |<---->| =============> (fs/file tree A)
2177 * |<---------------------------->| ===> (fs/file tree B)
2178 *
2179 * A range of space can refer to two file extents in one tree while
2180 * refer to only one file extent in another tree.
2181 *
2182 * So we may process a disk offset more than one time(two extents in A)
2183 * and locate at the same extent(one extent in B), then insert two same
2184 * backrefs(both refer to the extent in B).
2185 */
2186 return 0;
2187 }
2188
2189 static void backref_insert(struct rb_root *root,
2190 struct sa_defrag_extent_backref *backref)
2191 {
2192 struct rb_node **p = &root->rb_node;
2193 struct rb_node *parent = NULL;
2194 struct sa_defrag_extent_backref *entry;
2195 int ret;
2196
2197 while (*p) {
2198 parent = *p;
2199 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2200
2201 ret = backref_comp(backref, entry);
2202 if (ret < 0)
2203 p = &(*p)->rb_left;
2204 else
2205 p = &(*p)->rb_right;
2206 }
2207
2208 rb_link_node(&backref->node, parent, p);
2209 rb_insert_color(&backref->node, root);
2210 }
2211
2212 /*
2213 * Note the backref might has changed, and in this case we just return 0.
2214 */
2215 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2216 void *ctx)
2217 {
2218 struct btrfs_file_extent_item *extent;
2219 struct btrfs_fs_info *fs_info;
2220 struct old_sa_defrag_extent *old = ctx;
2221 struct new_sa_defrag_extent *new = old->new;
2222 struct btrfs_path *path = new->path;
2223 struct btrfs_key key;
2224 struct btrfs_root *root;
2225 struct sa_defrag_extent_backref *backref;
2226 struct extent_buffer *leaf;
2227 struct inode *inode = new->inode;
2228 int slot;
2229 int ret;
2230 u64 extent_offset;
2231 u64 num_bytes;
2232
2233 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2234 inum == btrfs_ino(inode))
2235 return 0;
2236
2237 key.objectid = root_id;
2238 key.type = BTRFS_ROOT_ITEM_KEY;
2239 key.offset = (u64)-1;
2240
2241 fs_info = BTRFS_I(inode)->root->fs_info;
2242 root = btrfs_read_fs_root_no_name(fs_info, &key);
2243 if (IS_ERR(root)) {
2244 if (PTR_ERR(root) == -ENOENT)
2245 return 0;
2246 WARN_ON(1);
2247 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2248 inum, offset, root_id);
2249 return PTR_ERR(root);
2250 }
2251
2252 key.objectid = inum;
2253 key.type = BTRFS_EXTENT_DATA_KEY;
2254 if (offset > (u64)-1 << 32)
2255 key.offset = 0;
2256 else
2257 key.offset = offset;
2258
2259 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2260 if (WARN_ON(ret < 0))
2261 return ret;
2262 ret = 0;
2263
2264 while (1) {
2265 cond_resched();
2266
2267 leaf = path->nodes[0];
2268 slot = path->slots[0];
2269
2270 if (slot >= btrfs_header_nritems(leaf)) {
2271 ret = btrfs_next_leaf(root, path);
2272 if (ret < 0) {
2273 goto out;
2274 } else if (ret > 0) {
2275 ret = 0;
2276 goto out;
2277 }
2278 continue;
2279 }
2280
2281 path->slots[0]++;
2282
2283 btrfs_item_key_to_cpu(leaf, &key, slot);
2284
2285 if (key.objectid > inum)
2286 goto out;
2287
2288 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2289 continue;
2290
2291 extent = btrfs_item_ptr(leaf, slot,
2292 struct btrfs_file_extent_item);
2293
2294 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2295 continue;
2296
2297 /*
2298 * 'offset' refers to the exact key.offset,
2299 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2300 * (key.offset - extent_offset).
2301 */
2302 if (key.offset != offset)
2303 continue;
2304
2305 extent_offset = btrfs_file_extent_offset(leaf, extent);
2306 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2307
2308 if (extent_offset >= old->extent_offset + old->offset +
2309 old->len || extent_offset + num_bytes <=
2310 old->extent_offset + old->offset)
2311 continue;
2312 break;
2313 }
2314
2315 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2316 if (!backref) {
2317 ret = -ENOENT;
2318 goto out;
2319 }
2320
2321 backref->root_id = root_id;
2322 backref->inum = inum;
2323 backref->file_pos = offset;
2324 backref->num_bytes = num_bytes;
2325 backref->extent_offset = extent_offset;
2326 backref->generation = btrfs_file_extent_generation(leaf, extent);
2327 backref->old = old;
2328 backref_insert(&new->root, backref);
2329 old->count++;
2330 out:
2331 btrfs_release_path(path);
2332 WARN_ON(ret);
2333 return ret;
2334 }
2335
2336 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2337 struct new_sa_defrag_extent *new)
2338 {
2339 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2340 struct old_sa_defrag_extent *old, *tmp;
2341 int ret;
2342
2343 new->path = path;
2344
2345 list_for_each_entry_safe(old, tmp, &new->head, list) {
2346 ret = iterate_inodes_from_logical(old->bytenr +
2347 old->extent_offset, fs_info,
2348 path, record_one_backref,
2349 old);
2350 if (ret < 0 && ret != -ENOENT)
2351 return false;
2352
2353 /* no backref to be processed for this extent */
2354 if (!old->count) {
2355 list_del(&old->list);
2356 kfree(old);
2357 }
2358 }
2359
2360 if (list_empty(&new->head))
2361 return false;
2362
2363 return true;
2364 }
2365
2366 static int relink_is_mergable(struct extent_buffer *leaf,
2367 struct btrfs_file_extent_item *fi,
2368 struct new_sa_defrag_extent *new)
2369 {
2370 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2371 return 0;
2372
2373 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2374 return 0;
2375
2376 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2377 return 0;
2378
2379 if (btrfs_file_extent_encryption(leaf, fi) ||
2380 btrfs_file_extent_other_encoding(leaf, fi))
2381 return 0;
2382
2383 return 1;
2384 }
2385
2386 /*
2387 * Note the backref might has changed, and in this case we just return 0.
2388 */
2389 static noinline int relink_extent_backref(struct btrfs_path *path,
2390 struct sa_defrag_extent_backref *prev,
2391 struct sa_defrag_extent_backref *backref)
2392 {
2393 struct btrfs_file_extent_item *extent;
2394 struct btrfs_file_extent_item *item;
2395 struct btrfs_ordered_extent *ordered;
2396 struct btrfs_trans_handle *trans;
2397 struct btrfs_fs_info *fs_info;
2398 struct btrfs_root *root;
2399 struct btrfs_key key;
2400 struct extent_buffer *leaf;
2401 struct old_sa_defrag_extent *old = backref->old;
2402 struct new_sa_defrag_extent *new = old->new;
2403 struct inode *src_inode = new->inode;
2404 struct inode *inode;
2405 struct extent_state *cached = NULL;
2406 int ret = 0;
2407 u64 start;
2408 u64 len;
2409 u64 lock_start;
2410 u64 lock_end;
2411 bool merge = false;
2412 int index;
2413
2414 if (prev && prev->root_id == backref->root_id &&
2415 prev->inum == backref->inum &&
2416 prev->file_pos + prev->num_bytes == backref->file_pos)
2417 merge = true;
2418
2419 /* step 1: get root */
2420 key.objectid = backref->root_id;
2421 key.type = BTRFS_ROOT_ITEM_KEY;
2422 key.offset = (u64)-1;
2423
2424 fs_info = BTRFS_I(src_inode)->root->fs_info;
2425 index = srcu_read_lock(&fs_info->subvol_srcu);
2426
2427 root = btrfs_read_fs_root_no_name(fs_info, &key);
2428 if (IS_ERR(root)) {
2429 srcu_read_unlock(&fs_info->subvol_srcu, index);
2430 if (PTR_ERR(root) == -ENOENT)
2431 return 0;
2432 return PTR_ERR(root);
2433 }
2434
2435 if (btrfs_root_readonly(root)) {
2436 srcu_read_unlock(&fs_info->subvol_srcu, index);
2437 return 0;
2438 }
2439
2440 /* step 2: get inode */
2441 key.objectid = backref->inum;
2442 key.type = BTRFS_INODE_ITEM_KEY;
2443 key.offset = 0;
2444
2445 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2446 if (IS_ERR(inode)) {
2447 srcu_read_unlock(&fs_info->subvol_srcu, index);
2448 return 0;
2449 }
2450
2451 srcu_read_unlock(&fs_info->subvol_srcu, index);
2452
2453 /* step 3: relink backref */
2454 lock_start = backref->file_pos;
2455 lock_end = backref->file_pos + backref->num_bytes - 1;
2456 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2457 0, &cached);
2458
2459 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2460 if (ordered) {
2461 btrfs_put_ordered_extent(ordered);
2462 goto out_unlock;
2463 }
2464
2465 trans = btrfs_join_transaction(root);
2466 if (IS_ERR(trans)) {
2467 ret = PTR_ERR(trans);
2468 goto out_unlock;
2469 }
2470
2471 key.objectid = backref->inum;
2472 key.type = BTRFS_EXTENT_DATA_KEY;
2473 key.offset = backref->file_pos;
2474
2475 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2476 if (ret < 0) {
2477 goto out_free_path;
2478 } else if (ret > 0) {
2479 ret = 0;
2480 goto out_free_path;
2481 }
2482
2483 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2484 struct btrfs_file_extent_item);
2485
2486 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2487 backref->generation)
2488 goto out_free_path;
2489
2490 btrfs_release_path(path);
2491
2492 start = backref->file_pos;
2493 if (backref->extent_offset < old->extent_offset + old->offset)
2494 start += old->extent_offset + old->offset -
2495 backref->extent_offset;
2496
2497 len = min(backref->extent_offset + backref->num_bytes,
2498 old->extent_offset + old->offset + old->len);
2499 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2500
2501 ret = btrfs_drop_extents(trans, root, inode, start,
2502 start + len, 1);
2503 if (ret)
2504 goto out_free_path;
2505 again:
2506 key.objectid = btrfs_ino(inode);
2507 key.type = BTRFS_EXTENT_DATA_KEY;
2508 key.offset = start;
2509
2510 path->leave_spinning = 1;
2511 if (merge) {
2512 struct btrfs_file_extent_item *fi;
2513 u64 extent_len;
2514 struct btrfs_key found_key;
2515
2516 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2517 if (ret < 0)
2518 goto out_free_path;
2519
2520 path->slots[0]--;
2521 leaf = path->nodes[0];
2522 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2523
2524 fi = btrfs_item_ptr(leaf, path->slots[0],
2525 struct btrfs_file_extent_item);
2526 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2527
2528 if (extent_len + found_key.offset == start &&
2529 relink_is_mergable(leaf, fi, new)) {
2530 btrfs_set_file_extent_num_bytes(leaf, fi,
2531 extent_len + len);
2532 btrfs_mark_buffer_dirty(leaf);
2533 inode_add_bytes(inode, len);
2534
2535 ret = 1;
2536 goto out_free_path;
2537 } else {
2538 merge = false;
2539 btrfs_release_path(path);
2540 goto again;
2541 }
2542 }
2543
2544 ret = btrfs_insert_empty_item(trans, root, path, &key,
2545 sizeof(*extent));
2546 if (ret) {
2547 btrfs_abort_transaction(trans, root, ret);
2548 goto out_free_path;
2549 }
2550
2551 leaf = path->nodes[0];
2552 item = btrfs_item_ptr(leaf, path->slots[0],
2553 struct btrfs_file_extent_item);
2554 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2555 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2556 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2557 btrfs_set_file_extent_num_bytes(leaf, item, len);
2558 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2559 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2560 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2561 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2562 btrfs_set_file_extent_encryption(leaf, item, 0);
2563 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2564
2565 btrfs_mark_buffer_dirty(leaf);
2566 inode_add_bytes(inode, len);
2567 btrfs_release_path(path);
2568
2569 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2570 new->disk_len, 0,
2571 backref->root_id, backref->inum,
2572 new->file_pos, 0); /* start - extent_offset */
2573 if (ret) {
2574 btrfs_abort_transaction(trans, root, ret);
2575 goto out_free_path;
2576 }
2577
2578 ret = 1;
2579 out_free_path:
2580 btrfs_release_path(path);
2581 path->leave_spinning = 0;
2582 btrfs_end_transaction(trans, root);
2583 out_unlock:
2584 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2585 &cached, GFP_NOFS);
2586 iput(inode);
2587 return ret;
2588 }
2589
2590 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2591 {
2592 struct old_sa_defrag_extent *old, *tmp;
2593
2594 if (!new)
2595 return;
2596
2597 list_for_each_entry_safe(old, tmp, &new->head, list) {
2598 list_del(&old->list);
2599 kfree(old);
2600 }
2601 kfree(new);
2602 }
2603
2604 static void relink_file_extents(struct new_sa_defrag_extent *new)
2605 {
2606 struct btrfs_path *path;
2607 struct sa_defrag_extent_backref *backref;
2608 struct sa_defrag_extent_backref *prev = NULL;
2609 struct inode *inode;
2610 struct btrfs_root *root;
2611 struct rb_node *node;
2612 int ret;
2613
2614 inode = new->inode;
2615 root = BTRFS_I(inode)->root;
2616
2617 path = btrfs_alloc_path();
2618 if (!path)
2619 return;
2620
2621 if (!record_extent_backrefs(path, new)) {
2622 btrfs_free_path(path);
2623 goto out;
2624 }
2625 btrfs_release_path(path);
2626
2627 while (1) {
2628 node = rb_first(&new->root);
2629 if (!node)
2630 break;
2631 rb_erase(node, &new->root);
2632
2633 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2634
2635 ret = relink_extent_backref(path, prev, backref);
2636 WARN_ON(ret < 0);
2637
2638 kfree(prev);
2639
2640 if (ret == 1)
2641 prev = backref;
2642 else
2643 prev = NULL;
2644 cond_resched();
2645 }
2646 kfree(prev);
2647
2648 btrfs_free_path(path);
2649 out:
2650 free_sa_defrag_extent(new);
2651
2652 atomic_dec(&root->fs_info->defrag_running);
2653 wake_up(&root->fs_info->transaction_wait);
2654 }
2655
2656 static struct new_sa_defrag_extent *
2657 record_old_file_extents(struct inode *inode,
2658 struct btrfs_ordered_extent *ordered)
2659 {
2660 struct btrfs_root *root = BTRFS_I(inode)->root;
2661 struct btrfs_path *path;
2662 struct btrfs_key key;
2663 struct old_sa_defrag_extent *old;
2664 struct new_sa_defrag_extent *new;
2665 int ret;
2666
2667 new = kmalloc(sizeof(*new), GFP_NOFS);
2668 if (!new)
2669 return NULL;
2670
2671 new->inode = inode;
2672 new->file_pos = ordered->file_offset;
2673 new->len = ordered->len;
2674 new->bytenr = ordered->start;
2675 new->disk_len = ordered->disk_len;
2676 new->compress_type = ordered->compress_type;
2677 new->root = RB_ROOT;
2678 INIT_LIST_HEAD(&new->head);
2679
2680 path = btrfs_alloc_path();
2681 if (!path)
2682 goto out_kfree;
2683
2684 key.objectid = btrfs_ino(inode);
2685 key.type = BTRFS_EXTENT_DATA_KEY;
2686 key.offset = new->file_pos;
2687
2688 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2689 if (ret < 0)
2690 goto out_free_path;
2691 if (ret > 0 && path->slots[0] > 0)
2692 path->slots[0]--;
2693
2694 /* find out all the old extents for the file range */
2695 while (1) {
2696 struct btrfs_file_extent_item *extent;
2697 struct extent_buffer *l;
2698 int slot;
2699 u64 num_bytes;
2700 u64 offset;
2701 u64 end;
2702 u64 disk_bytenr;
2703 u64 extent_offset;
2704
2705 l = path->nodes[0];
2706 slot = path->slots[0];
2707
2708 if (slot >= btrfs_header_nritems(l)) {
2709 ret = btrfs_next_leaf(root, path);
2710 if (ret < 0)
2711 goto out_free_path;
2712 else if (ret > 0)
2713 break;
2714 continue;
2715 }
2716
2717 btrfs_item_key_to_cpu(l, &key, slot);
2718
2719 if (key.objectid != btrfs_ino(inode))
2720 break;
2721 if (key.type != BTRFS_EXTENT_DATA_KEY)
2722 break;
2723 if (key.offset >= new->file_pos + new->len)
2724 break;
2725
2726 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2727
2728 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2729 if (key.offset + num_bytes < new->file_pos)
2730 goto next;
2731
2732 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2733 if (!disk_bytenr)
2734 goto next;
2735
2736 extent_offset = btrfs_file_extent_offset(l, extent);
2737
2738 old = kmalloc(sizeof(*old), GFP_NOFS);
2739 if (!old)
2740 goto out_free_path;
2741
2742 offset = max(new->file_pos, key.offset);
2743 end = min(new->file_pos + new->len, key.offset + num_bytes);
2744
2745 old->bytenr = disk_bytenr;
2746 old->extent_offset = extent_offset;
2747 old->offset = offset - key.offset;
2748 old->len = end - offset;
2749 old->new = new;
2750 old->count = 0;
2751 list_add_tail(&old->list, &new->head);
2752 next:
2753 path->slots[0]++;
2754 cond_resched();
2755 }
2756
2757 btrfs_free_path(path);
2758 atomic_inc(&root->fs_info->defrag_running);
2759
2760 return new;
2761
2762 out_free_path:
2763 btrfs_free_path(path);
2764 out_kfree:
2765 free_sa_defrag_extent(new);
2766 return NULL;
2767 }
2768
2769 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2770 u64 start, u64 len)
2771 {
2772 struct btrfs_block_group_cache *cache;
2773
2774 cache = btrfs_lookup_block_group(root->fs_info, start);
2775 ASSERT(cache);
2776
2777 spin_lock(&cache->lock);
2778 cache->delalloc_bytes -= len;
2779 spin_unlock(&cache->lock);
2780
2781 btrfs_put_block_group(cache);
2782 }
2783
2784 /* as ordered data IO finishes, this gets called so we can finish
2785 * an ordered extent if the range of bytes in the file it covers are
2786 * fully written.
2787 */
2788 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2789 {
2790 struct inode *inode = ordered_extent->inode;
2791 struct btrfs_root *root = BTRFS_I(inode)->root;
2792 struct btrfs_trans_handle *trans = NULL;
2793 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2794 struct extent_state *cached_state = NULL;
2795 struct new_sa_defrag_extent *new = NULL;
2796 int compress_type = 0;
2797 int ret = 0;
2798 u64 logical_len = ordered_extent->len;
2799 bool nolock;
2800 bool truncated = false;
2801
2802 nolock = btrfs_is_free_space_inode(inode);
2803
2804 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2805 ret = -EIO;
2806 goto out;
2807 }
2808
2809 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2810 ordered_extent->file_offset +
2811 ordered_extent->len - 1);
2812
2813 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2814 truncated = true;
2815 logical_len = ordered_extent->truncated_len;
2816 /* Truncated the entire extent, don't bother adding */
2817 if (!logical_len)
2818 goto out;
2819 }
2820
2821 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2822 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2823 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2824 if (nolock)
2825 trans = btrfs_join_transaction_nolock(root);
2826 else
2827 trans = btrfs_join_transaction(root);
2828 if (IS_ERR(trans)) {
2829 ret = PTR_ERR(trans);
2830 trans = NULL;
2831 goto out;
2832 }
2833 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2834 ret = btrfs_update_inode_fallback(trans, root, inode);
2835 if (ret) /* -ENOMEM or corruption */
2836 btrfs_abort_transaction(trans, root, ret);
2837 goto out;
2838 }
2839
2840 lock_extent_bits(io_tree, ordered_extent->file_offset,
2841 ordered_extent->file_offset + ordered_extent->len - 1,
2842 0, &cached_state);
2843
2844 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2845 ordered_extent->file_offset + ordered_extent->len - 1,
2846 EXTENT_DEFRAG, 1, cached_state);
2847 if (ret) {
2848 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2849 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2850 /* the inode is shared */
2851 new = record_old_file_extents(inode, ordered_extent);
2852
2853 clear_extent_bit(io_tree, ordered_extent->file_offset,
2854 ordered_extent->file_offset + ordered_extent->len - 1,
2855 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2856 }
2857
2858 if (nolock)
2859 trans = btrfs_join_transaction_nolock(root);
2860 else
2861 trans = btrfs_join_transaction(root);
2862 if (IS_ERR(trans)) {
2863 ret = PTR_ERR(trans);
2864 trans = NULL;
2865 goto out_unlock;
2866 }
2867
2868 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2869
2870 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2871 compress_type = ordered_extent->compress_type;
2872 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2873 BUG_ON(compress_type);
2874 ret = btrfs_mark_extent_written(trans, inode,
2875 ordered_extent->file_offset,
2876 ordered_extent->file_offset +
2877 logical_len);
2878 } else {
2879 BUG_ON(root == root->fs_info->tree_root);
2880 ret = insert_reserved_file_extent(trans, inode,
2881 ordered_extent->file_offset,
2882 ordered_extent->start,
2883 ordered_extent->disk_len,
2884 logical_len, logical_len,
2885 compress_type, 0, 0,
2886 BTRFS_FILE_EXTENT_REG);
2887 if (!ret)
2888 btrfs_release_delalloc_bytes(root,
2889 ordered_extent->start,
2890 ordered_extent->disk_len);
2891 }
2892 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2893 ordered_extent->file_offset, ordered_extent->len,
2894 trans->transid);
2895 if (ret < 0) {
2896 btrfs_abort_transaction(trans, root, ret);
2897 goto out_unlock;
2898 }
2899
2900 add_pending_csums(trans, inode, ordered_extent->file_offset,
2901 &ordered_extent->list);
2902
2903 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2904 ret = btrfs_update_inode_fallback(trans, root, inode);
2905 if (ret) { /* -ENOMEM or corruption */
2906 btrfs_abort_transaction(trans, root, ret);
2907 goto out_unlock;
2908 }
2909 ret = 0;
2910 out_unlock:
2911 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2912 ordered_extent->file_offset +
2913 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2914 out:
2915 if (root != root->fs_info->tree_root)
2916 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2917 if (trans)
2918 btrfs_end_transaction(trans, root);
2919
2920 if (ret || truncated) {
2921 u64 start, end;
2922
2923 if (truncated)
2924 start = ordered_extent->file_offset + logical_len;
2925 else
2926 start = ordered_extent->file_offset;
2927 end = ordered_extent->file_offset + ordered_extent->len - 1;
2928 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2929
2930 /* Drop the cache for the part of the extent we didn't write. */
2931 btrfs_drop_extent_cache(inode, start, end, 0);
2932
2933 /*
2934 * If the ordered extent had an IOERR or something else went
2935 * wrong we need to return the space for this ordered extent
2936 * back to the allocator. We only free the extent in the
2937 * truncated case if we didn't write out the extent at all.
2938 */
2939 if ((ret || !logical_len) &&
2940 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2941 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2942 btrfs_free_reserved_extent(root, ordered_extent->start,
2943 ordered_extent->disk_len, 1);
2944 }
2945
2946
2947 /*
2948 * This needs to be done to make sure anybody waiting knows we are done
2949 * updating everything for this ordered extent.
2950 */
2951 btrfs_remove_ordered_extent(inode, ordered_extent);
2952
2953 /* for snapshot-aware defrag */
2954 if (new) {
2955 if (ret) {
2956 free_sa_defrag_extent(new);
2957 atomic_dec(&root->fs_info->defrag_running);
2958 } else {
2959 relink_file_extents(new);
2960 }
2961 }
2962
2963 /* once for us */
2964 btrfs_put_ordered_extent(ordered_extent);
2965 /* once for the tree */
2966 btrfs_put_ordered_extent(ordered_extent);
2967
2968 return ret;
2969 }
2970
2971 static void finish_ordered_fn(struct btrfs_work *work)
2972 {
2973 struct btrfs_ordered_extent *ordered_extent;
2974 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2975 btrfs_finish_ordered_io(ordered_extent);
2976 }
2977
2978 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2979 struct extent_state *state, int uptodate)
2980 {
2981 struct inode *inode = page->mapping->host;
2982 struct btrfs_root *root = BTRFS_I(inode)->root;
2983 struct btrfs_ordered_extent *ordered_extent = NULL;
2984 struct btrfs_workqueue *wq;
2985 btrfs_work_func_t func;
2986
2987 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2988
2989 ClearPagePrivate2(page);
2990 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2991 end - start + 1, uptodate))
2992 return 0;
2993
2994 if (btrfs_is_free_space_inode(inode)) {
2995 wq = root->fs_info->endio_freespace_worker;
2996 func = btrfs_freespace_write_helper;
2997 } else {
2998 wq = root->fs_info->endio_write_workers;
2999 func = btrfs_endio_write_helper;
3000 }
3001
3002 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3003 NULL);
3004 btrfs_queue_work(wq, &ordered_extent->work);
3005
3006 return 0;
3007 }
3008
3009 static int __readpage_endio_check(struct inode *inode,
3010 struct btrfs_io_bio *io_bio,
3011 int icsum, struct page *page,
3012 int pgoff, u64 start, size_t len)
3013 {
3014 char *kaddr;
3015 u32 csum_expected;
3016 u32 csum = ~(u32)0;
3017 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
3018 DEFAULT_RATELIMIT_BURST);
3019
3020 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3021
3022 kaddr = kmap_atomic(page);
3023 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3024 btrfs_csum_final(csum, (char *)&csum);
3025 if (csum != csum_expected)
3026 goto zeroit;
3027
3028 kunmap_atomic(kaddr);
3029 return 0;
3030 zeroit:
3031 if (__ratelimit(&_rs))
3032 btrfs_warn(BTRFS_I(inode)->root->fs_info,
3033 "csum failed ino %llu off %llu csum %u expected csum %u",
3034 btrfs_ino(inode), start, csum, csum_expected);
3035 memset(kaddr + pgoff, 1, len);
3036 flush_dcache_page(page);
3037 kunmap_atomic(kaddr);
3038 if (csum_expected == 0)
3039 return 0;
3040 return -EIO;
3041 }
3042
3043 /*
3044 * when reads are done, we need to check csums to verify the data is correct
3045 * if there's a match, we allow the bio to finish. If not, the code in
3046 * extent_io.c will try to find good copies for us.
3047 */
3048 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3049 u64 phy_offset, struct page *page,
3050 u64 start, u64 end, int mirror)
3051 {
3052 size_t offset = start - page_offset(page);
3053 struct inode *inode = page->mapping->host;
3054 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3055 struct btrfs_root *root = BTRFS_I(inode)->root;
3056
3057 if (PageChecked(page)) {
3058 ClearPageChecked(page);
3059 return 0;
3060 }
3061
3062 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3063 return 0;
3064
3065 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3066 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3067 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3068 GFP_NOFS);
3069 return 0;
3070 }
3071
3072 phy_offset >>= inode->i_sb->s_blocksize_bits;
3073 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3074 start, (size_t)(end - start + 1));
3075 }
3076
3077 struct delayed_iput {
3078 struct list_head list;
3079 struct inode *inode;
3080 };
3081
3082 /* JDM: If this is fs-wide, why can't we add a pointer to
3083 * btrfs_inode instead and avoid the allocation? */
3084 void btrfs_add_delayed_iput(struct inode *inode)
3085 {
3086 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3087 struct delayed_iput *delayed;
3088
3089 if (atomic_add_unless(&inode->i_count, -1, 1))
3090 return;
3091
3092 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
3093 delayed->inode = inode;
3094
3095 spin_lock(&fs_info->delayed_iput_lock);
3096 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
3097 spin_unlock(&fs_info->delayed_iput_lock);
3098 }
3099
3100 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3101 {
3102 LIST_HEAD(list);
3103 struct btrfs_fs_info *fs_info = root->fs_info;
3104 struct delayed_iput *delayed;
3105 int empty;
3106
3107 spin_lock(&fs_info->delayed_iput_lock);
3108 empty = list_empty(&fs_info->delayed_iputs);
3109 spin_unlock(&fs_info->delayed_iput_lock);
3110 if (empty)
3111 return;
3112
3113 down_read(&fs_info->delayed_iput_sem);
3114
3115 spin_lock(&fs_info->delayed_iput_lock);
3116 list_splice_init(&fs_info->delayed_iputs, &list);
3117 spin_unlock(&fs_info->delayed_iput_lock);
3118
3119 while (!list_empty(&list)) {
3120 delayed = list_entry(list.next, struct delayed_iput, list);
3121 list_del(&delayed->list);
3122 iput(delayed->inode);
3123 kfree(delayed);
3124 }
3125
3126 up_read(&root->fs_info->delayed_iput_sem);
3127 }
3128
3129 /*
3130 * This is called in transaction commit time. If there are no orphan
3131 * files in the subvolume, it removes orphan item and frees block_rsv
3132 * structure.
3133 */
3134 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3135 struct btrfs_root *root)
3136 {
3137 struct btrfs_block_rsv *block_rsv;
3138 int ret;
3139
3140 if (atomic_read(&root->orphan_inodes) ||
3141 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3142 return;
3143
3144 spin_lock(&root->orphan_lock);
3145 if (atomic_read(&root->orphan_inodes)) {
3146 spin_unlock(&root->orphan_lock);
3147 return;
3148 }
3149
3150 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3151 spin_unlock(&root->orphan_lock);
3152 return;
3153 }
3154
3155 block_rsv = root->orphan_block_rsv;
3156 root->orphan_block_rsv = NULL;
3157 spin_unlock(&root->orphan_lock);
3158
3159 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3160 btrfs_root_refs(&root->root_item) > 0) {
3161 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3162 root->root_key.objectid);
3163 if (ret)
3164 btrfs_abort_transaction(trans, root, ret);
3165 else
3166 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3167 &root->state);
3168 }
3169
3170 if (block_rsv) {
3171 WARN_ON(block_rsv->size > 0);
3172 btrfs_free_block_rsv(root, block_rsv);
3173 }
3174 }
3175
3176 /*
3177 * This creates an orphan entry for the given inode in case something goes
3178 * wrong in the middle of an unlink/truncate.
3179 *
3180 * NOTE: caller of this function should reserve 5 units of metadata for
3181 * this function.
3182 */
3183 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3184 {
3185 struct btrfs_root *root = BTRFS_I(inode)->root;
3186 struct btrfs_block_rsv *block_rsv = NULL;
3187 int reserve = 0;
3188 int insert = 0;
3189 int ret;
3190
3191 if (!root->orphan_block_rsv) {
3192 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3193 if (!block_rsv)
3194 return -ENOMEM;
3195 }
3196
3197 spin_lock(&root->orphan_lock);
3198 if (!root->orphan_block_rsv) {
3199 root->orphan_block_rsv = block_rsv;
3200 } else if (block_rsv) {
3201 btrfs_free_block_rsv(root, block_rsv);
3202 block_rsv = NULL;
3203 }
3204
3205 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3206 &BTRFS_I(inode)->runtime_flags)) {
3207 #if 0
3208 /*
3209 * For proper ENOSPC handling, we should do orphan
3210 * cleanup when mounting. But this introduces backward
3211 * compatibility issue.
3212 */
3213 if (!xchg(&root->orphan_item_inserted, 1))
3214 insert = 2;
3215 else
3216 insert = 1;
3217 #endif
3218 insert = 1;
3219 atomic_inc(&root->orphan_inodes);
3220 }
3221
3222 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3223 &BTRFS_I(inode)->runtime_flags))
3224 reserve = 1;
3225 spin_unlock(&root->orphan_lock);
3226
3227 /* grab metadata reservation from transaction handle */
3228 if (reserve) {
3229 ret = btrfs_orphan_reserve_metadata(trans, inode);
3230 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3231 }
3232
3233 /* insert an orphan item to track this unlinked/truncated file */
3234 if (insert >= 1) {
3235 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3236 if (ret) {
3237 atomic_dec(&root->orphan_inodes);
3238 if (reserve) {
3239 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3240 &BTRFS_I(inode)->runtime_flags);
3241 btrfs_orphan_release_metadata(inode);
3242 }
3243 if (ret != -EEXIST) {
3244 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3245 &BTRFS_I(inode)->runtime_flags);
3246 btrfs_abort_transaction(trans, root, ret);
3247 return ret;
3248 }
3249 }
3250 ret = 0;
3251 }
3252
3253 /* insert an orphan item to track subvolume contains orphan files */
3254 if (insert >= 2) {
3255 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3256 root->root_key.objectid);
3257 if (ret && ret != -EEXIST) {
3258 btrfs_abort_transaction(trans, root, ret);
3259 return ret;
3260 }
3261 }
3262 return 0;
3263 }
3264
3265 /*
3266 * We have done the truncate/delete so we can go ahead and remove the orphan
3267 * item for this particular inode.
3268 */
3269 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3270 struct inode *inode)
3271 {
3272 struct btrfs_root *root = BTRFS_I(inode)->root;
3273 int delete_item = 0;
3274 int release_rsv = 0;
3275 int ret = 0;
3276
3277 spin_lock(&root->orphan_lock);
3278 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3279 &BTRFS_I(inode)->runtime_flags))
3280 delete_item = 1;
3281
3282 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3283 &BTRFS_I(inode)->runtime_flags))
3284 release_rsv = 1;
3285 spin_unlock(&root->orphan_lock);
3286
3287 if (delete_item) {
3288 atomic_dec(&root->orphan_inodes);
3289 if (trans)
3290 ret = btrfs_del_orphan_item(trans, root,
3291 btrfs_ino(inode));
3292 }
3293
3294 if (release_rsv)
3295 btrfs_orphan_release_metadata(inode);
3296
3297 return ret;
3298 }
3299
3300 /*
3301 * this cleans up any orphans that may be left on the list from the last use
3302 * of this root.
3303 */
3304 int btrfs_orphan_cleanup(struct btrfs_root *root)
3305 {
3306 struct btrfs_path *path;
3307 struct extent_buffer *leaf;
3308 struct btrfs_key key, found_key;
3309 struct btrfs_trans_handle *trans;
3310 struct inode *inode;
3311 u64 last_objectid = 0;
3312 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3313
3314 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3315 return 0;
3316
3317 path = btrfs_alloc_path();
3318 if (!path) {
3319 ret = -ENOMEM;
3320 goto out;
3321 }
3322 path->reada = -1;
3323
3324 key.objectid = BTRFS_ORPHAN_OBJECTID;
3325 key.type = BTRFS_ORPHAN_ITEM_KEY;
3326 key.offset = (u64)-1;
3327
3328 while (1) {
3329 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3330 if (ret < 0)
3331 goto out;
3332
3333 /*
3334 * if ret == 0 means we found what we were searching for, which
3335 * is weird, but possible, so only screw with path if we didn't
3336 * find the key and see if we have stuff that matches
3337 */
3338 if (ret > 0) {
3339 ret = 0;
3340 if (path->slots[0] == 0)
3341 break;
3342 path->slots[0]--;
3343 }
3344
3345 /* pull out the item */
3346 leaf = path->nodes[0];
3347 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3348
3349 /* make sure the item matches what we want */
3350 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3351 break;
3352 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3353 break;
3354
3355 /* release the path since we're done with it */
3356 btrfs_release_path(path);
3357
3358 /*
3359 * this is where we are basically btrfs_lookup, without the
3360 * crossing root thing. we store the inode number in the
3361 * offset of the orphan item.
3362 */
3363
3364 if (found_key.offset == last_objectid) {
3365 btrfs_err(root->fs_info,
3366 "Error removing orphan entry, stopping orphan cleanup");
3367 ret = -EINVAL;
3368 goto out;
3369 }
3370
3371 last_objectid = found_key.offset;
3372
3373 found_key.objectid = found_key.offset;
3374 found_key.type = BTRFS_INODE_ITEM_KEY;
3375 found_key.offset = 0;
3376 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3377 ret = PTR_ERR_OR_ZERO(inode);
3378 if (ret && ret != -ESTALE)
3379 goto out;
3380
3381 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3382 struct btrfs_root *dead_root;
3383 struct btrfs_fs_info *fs_info = root->fs_info;
3384 int is_dead_root = 0;
3385
3386 /*
3387 * this is an orphan in the tree root. Currently these
3388 * could come from 2 sources:
3389 * a) a snapshot deletion in progress
3390 * b) a free space cache inode
3391 * We need to distinguish those two, as the snapshot
3392 * orphan must not get deleted.
3393 * find_dead_roots already ran before us, so if this
3394 * is a snapshot deletion, we should find the root
3395 * in the dead_roots list
3396 */
3397 spin_lock(&fs_info->trans_lock);
3398 list_for_each_entry(dead_root, &fs_info->dead_roots,
3399 root_list) {
3400 if (dead_root->root_key.objectid ==
3401 found_key.objectid) {
3402 is_dead_root = 1;
3403 break;
3404 }
3405 }
3406 spin_unlock(&fs_info->trans_lock);
3407 if (is_dead_root) {
3408 /* prevent this orphan from being found again */
3409 key.offset = found_key.objectid - 1;
3410 continue;
3411 }
3412 }
3413 /*
3414 * Inode is already gone but the orphan item is still there,
3415 * kill the orphan item.
3416 */
3417 if (ret == -ESTALE) {
3418 trans = btrfs_start_transaction(root, 1);
3419 if (IS_ERR(trans)) {
3420 ret = PTR_ERR(trans);
3421 goto out;
3422 }
3423 btrfs_debug(root->fs_info, "auto deleting %Lu",
3424 found_key.objectid);
3425 ret = btrfs_del_orphan_item(trans, root,
3426 found_key.objectid);
3427 btrfs_end_transaction(trans, root);
3428 if (ret)
3429 goto out;
3430 continue;
3431 }
3432
3433 /*
3434 * add this inode to the orphan list so btrfs_orphan_del does
3435 * the proper thing when we hit it
3436 */
3437 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3438 &BTRFS_I(inode)->runtime_flags);
3439 atomic_inc(&root->orphan_inodes);
3440
3441 /* if we have links, this was a truncate, lets do that */
3442 if (inode->i_nlink) {
3443 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3444 iput(inode);
3445 continue;
3446 }
3447 nr_truncate++;
3448
3449 /* 1 for the orphan item deletion. */
3450 trans = btrfs_start_transaction(root, 1);
3451 if (IS_ERR(trans)) {
3452 iput(inode);
3453 ret = PTR_ERR(trans);
3454 goto out;
3455 }
3456 ret = btrfs_orphan_add(trans, inode);
3457 btrfs_end_transaction(trans, root);
3458 if (ret) {
3459 iput(inode);
3460 goto out;
3461 }
3462
3463 ret = btrfs_truncate(inode);
3464 if (ret)
3465 btrfs_orphan_del(NULL, inode);
3466 } else {
3467 nr_unlink++;
3468 }
3469
3470 /* this will do delete_inode and everything for us */
3471 iput(inode);
3472 if (ret)
3473 goto out;
3474 }
3475 /* release the path since we're done with it */
3476 btrfs_release_path(path);
3477
3478 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3479
3480 if (root->orphan_block_rsv)
3481 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3482 (u64)-1);
3483
3484 if (root->orphan_block_rsv ||
3485 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3486 trans = btrfs_join_transaction(root);
3487 if (!IS_ERR(trans))
3488 btrfs_end_transaction(trans, root);
3489 }
3490
3491 if (nr_unlink)
3492 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3493 if (nr_truncate)
3494 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3495
3496 out:
3497 if (ret)
3498 btrfs_err(root->fs_info,
3499 "could not do orphan cleanup %d", ret);
3500 btrfs_free_path(path);
3501 return ret;
3502 }
3503
3504 /*
3505 * very simple check to peek ahead in the leaf looking for xattrs. If we
3506 * don't find any xattrs, we know there can't be any acls.
3507 *
3508 * slot is the slot the inode is in, objectid is the objectid of the inode
3509 */
3510 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3511 int slot, u64 objectid,
3512 int *first_xattr_slot)
3513 {
3514 u32 nritems = btrfs_header_nritems(leaf);
3515 struct btrfs_key found_key;
3516 static u64 xattr_access = 0;
3517 static u64 xattr_default = 0;
3518 int scanned = 0;
3519
3520 if (!xattr_access) {
3521 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3522 strlen(POSIX_ACL_XATTR_ACCESS));
3523 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3524 strlen(POSIX_ACL_XATTR_DEFAULT));
3525 }
3526
3527 slot++;
3528 *first_xattr_slot = -1;
3529 while (slot < nritems) {
3530 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3531
3532 /* we found a different objectid, there must not be acls */
3533 if (found_key.objectid != objectid)
3534 return 0;
3535
3536 /* we found an xattr, assume we've got an acl */
3537 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3538 if (*first_xattr_slot == -1)
3539 *first_xattr_slot = slot;
3540 if (found_key.offset == xattr_access ||
3541 found_key.offset == xattr_default)
3542 return 1;
3543 }
3544
3545 /*
3546 * we found a key greater than an xattr key, there can't
3547 * be any acls later on
3548 */
3549 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3550 return 0;
3551
3552 slot++;
3553 scanned++;
3554
3555 /*
3556 * it goes inode, inode backrefs, xattrs, extents,
3557 * so if there are a ton of hard links to an inode there can
3558 * be a lot of backrefs. Don't waste time searching too hard,
3559 * this is just an optimization
3560 */
3561 if (scanned >= 8)
3562 break;
3563 }
3564 /* we hit the end of the leaf before we found an xattr or
3565 * something larger than an xattr. We have to assume the inode
3566 * has acls
3567 */
3568 if (*first_xattr_slot == -1)
3569 *first_xattr_slot = slot;
3570 return 1;
3571 }
3572
3573 /*
3574 * read an inode from the btree into the in-memory inode
3575 */
3576 static void btrfs_read_locked_inode(struct inode *inode)
3577 {
3578 struct btrfs_path *path;
3579 struct extent_buffer *leaf;
3580 struct btrfs_inode_item *inode_item;
3581 struct btrfs_root *root = BTRFS_I(inode)->root;
3582 struct btrfs_key location;
3583 unsigned long ptr;
3584 int maybe_acls;
3585 u32 rdev;
3586 int ret;
3587 bool filled = false;
3588 int first_xattr_slot;
3589
3590 ret = btrfs_fill_inode(inode, &rdev);
3591 if (!ret)
3592 filled = true;
3593
3594 path = btrfs_alloc_path();
3595 if (!path)
3596 goto make_bad;
3597
3598 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3599
3600 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3601 if (ret)
3602 goto make_bad;
3603
3604 leaf = path->nodes[0];
3605
3606 if (filled)
3607 goto cache_index;
3608
3609 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3610 struct btrfs_inode_item);
3611 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3612 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3613 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3614 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3615 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3616
3617 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3618 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3619
3620 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3621 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3622
3623 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3624 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3625
3626 BTRFS_I(inode)->i_otime.tv_sec =
3627 btrfs_timespec_sec(leaf, &inode_item->otime);
3628 BTRFS_I(inode)->i_otime.tv_nsec =
3629 btrfs_timespec_nsec(leaf, &inode_item->otime);
3630
3631 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3632 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3633 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3634
3635 /*
3636 * If we were modified in the current generation and evicted from memory
3637 * and then re-read we need to do a full sync since we don't have any
3638 * idea about which extents were modified before we were evicted from
3639 * cache.
3640 */
3641 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3642 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3643 &BTRFS_I(inode)->runtime_flags);
3644
3645 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3646 inode->i_generation = BTRFS_I(inode)->generation;
3647 inode->i_rdev = 0;
3648 rdev = btrfs_inode_rdev(leaf, inode_item);
3649
3650 BTRFS_I(inode)->index_cnt = (u64)-1;
3651 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3652
3653 cache_index:
3654 path->slots[0]++;
3655 if (inode->i_nlink != 1 ||
3656 path->slots[0] >= btrfs_header_nritems(leaf))
3657 goto cache_acl;
3658
3659 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3660 if (location.objectid != btrfs_ino(inode))
3661 goto cache_acl;
3662
3663 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3664 if (location.type == BTRFS_INODE_REF_KEY) {
3665 struct btrfs_inode_ref *ref;
3666
3667 ref = (struct btrfs_inode_ref *)ptr;
3668 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3669 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3670 struct btrfs_inode_extref *extref;
3671
3672 extref = (struct btrfs_inode_extref *)ptr;
3673 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3674 extref);
3675 }
3676 cache_acl:
3677 /*
3678 * try to precache a NULL acl entry for files that don't have
3679 * any xattrs or acls
3680 */
3681 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3682 btrfs_ino(inode), &first_xattr_slot);
3683 if (first_xattr_slot != -1) {
3684 path->slots[0] = first_xattr_slot;
3685 ret = btrfs_load_inode_props(inode, path);
3686 if (ret)
3687 btrfs_err(root->fs_info,
3688 "error loading props for ino %llu (root %llu): %d",
3689 btrfs_ino(inode),
3690 root->root_key.objectid, ret);
3691 }
3692 btrfs_free_path(path);
3693
3694 if (!maybe_acls)
3695 cache_no_acl(inode);
3696
3697 switch (inode->i_mode & S_IFMT) {
3698 case S_IFREG:
3699 inode->i_mapping->a_ops = &btrfs_aops;
3700 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3701 inode->i_fop = &btrfs_file_operations;
3702 inode->i_op = &btrfs_file_inode_operations;
3703 break;
3704 case S_IFDIR:
3705 inode->i_fop = &btrfs_dir_file_operations;
3706 if (root == root->fs_info->tree_root)
3707 inode->i_op = &btrfs_dir_ro_inode_operations;
3708 else
3709 inode->i_op = &btrfs_dir_inode_operations;
3710 break;
3711 case S_IFLNK:
3712 inode->i_op = &btrfs_symlink_inode_operations;
3713 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3714 break;
3715 default:
3716 inode->i_op = &btrfs_special_inode_operations;
3717 init_special_inode(inode, inode->i_mode, rdev);
3718 break;
3719 }
3720
3721 btrfs_update_iflags(inode);
3722 return;
3723
3724 make_bad:
3725 btrfs_free_path(path);
3726 make_bad_inode(inode);
3727 }
3728
3729 /*
3730 * given a leaf and an inode, copy the inode fields into the leaf
3731 */
3732 static void fill_inode_item(struct btrfs_trans_handle *trans,
3733 struct extent_buffer *leaf,
3734 struct btrfs_inode_item *item,
3735 struct inode *inode)
3736 {
3737 struct btrfs_map_token token;
3738
3739 btrfs_init_map_token(&token);
3740
3741 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3742 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3743 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3744 &token);
3745 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3746 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3747
3748 btrfs_set_token_timespec_sec(leaf, &item->atime,
3749 inode->i_atime.tv_sec, &token);
3750 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3751 inode->i_atime.tv_nsec, &token);
3752
3753 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3754 inode->i_mtime.tv_sec, &token);
3755 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3756 inode->i_mtime.tv_nsec, &token);
3757
3758 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3759 inode->i_ctime.tv_sec, &token);
3760 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3761 inode->i_ctime.tv_nsec, &token);
3762
3763 btrfs_set_token_timespec_sec(leaf, &item->otime,
3764 BTRFS_I(inode)->i_otime.tv_sec, &token);
3765 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3766 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3767
3768 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3769 &token);
3770 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3771 &token);
3772 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3773 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3774 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3775 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3776 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3777 }
3778
3779 /*
3780 * copy everything in the in-memory inode into the btree.
3781 */
3782 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3783 struct btrfs_root *root, struct inode *inode)
3784 {
3785 struct btrfs_inode_item *inode_item;
3786 struct btrfs_path *path;
3787 struct extent_buffer *leaf;
3788 int ret;
3789
3790 path = btrfs_alloc_path();
3791 if (!path)
3792 return -ENOMEM;
3793
3794 path->leave_spinning = 1;
3795 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3796 1);
3797 if (ret) {
3798 if (ret > 0)
3799 ret = -ENOENT;
3800 goto failed;
3801 }
3802
3803 leaf = path->nodes[0];
3804 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3805 struct btrfs_inode_item);
3806
3807 fill_inode_item(trans, leaf, inode_item, inode);
3808 btrfs_mark_buffer_dirty(leaf);
3809 btrfs_set_inode_last_trans(trans, inode);
3810 ret = 0;
3811 failed:
3812 btrfs_free_path(path);
3813 return ret;
3814 }
3815
3816 /*
3817 * copy everything in the in-memory inode into the btree.
3818 */
3819 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3820 struct btrfs_root *root, struct inode *inode)
3821 {
3822 int ret;
3823
3824 /*
3825 * If the inode is a free space inode, we can deadlock during commit
3826 * if we put it into the delayed code.
3827 *
3828 * The data relocation inode should also be directly updated
3829 * without delay
3830 */
3831 if (!btrfs_is_free_space_inode(inode)
3832 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3833 && !root->fs_info->log_root_recovering) {
3834 btrfs_update_root_times(trans, root);
3835
3836 ret = btrfs_delayed_update_inode(trans, root, inode);
3837 if (!ret)
3838 btrfs_set_inode_last_trans(trans, inode);
3839 return ret;
3840 }
3841
3842 return btrfs_update_inode_item(trans, root, inode);
3843 }
3844
3845 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3846 struct btrfs_root *root,
3847 struct inode *inode)
3848 {
3849 int ret;
3850
3851 ret = btrfs_update_inode(trans, root, inode);
3852 if (ret == -ENOSPC)
3853 return btrfs_update_inode_item(trans, root, inode);
3854 return ret;
3855 }
3856
3857 /*
3858 * unlink helper that gets used here in inode.c and in the tree logging
3859 * recovery code. It remove a link in a directory with a given name, and
3860 * also drops the back refs in the inode to the directory
3861 */
3862 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3863 struct btrfs_root *root,
3864 struct inode *dir, struct inode *inode,
3865 const char *name, int name_len)
3866 {
3867 struct btrfs_path *path;
3868 int ret = 0;
3869 struct extent_buffer *leaf;
3870 struct btrfs_dir_item *di;
3871 struct btrfs_key key;
3872 u64 index;
3873 u64 ino = btrfs_ino(inode);
3874 u64 dir_ino = btrfs_ino(dir);
3875
3876 path = btrfs_alloc_path();
3877 if (!path) {
3878 ret = -ENOMEM;
3879 goto out;
3880 }
3881
3882 path->leave_spinning = 1;
3883 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3884 name, name_len, -1);
3885 if (IS_ERR(di)) {
3886 ret = PTR_ERR(di);
3887 goto err;
3888 }
3889 if (!di) {
3890 ret = -ENOENT;
3891 goto err;
3892 }
3893 leaf = path->nodes[0];
3894 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3895 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3896 if (ret)
3897 goto err;
3898 btrfs_release_path(path);
3899
3900 /*
3901 * If we don't have dir index, we have to get it by looking up
3902 * the inode ref, since we get the inode ref, remove it directly,
3903 * it is unnecessary to do delayed deletion.
3904 *
3905 * But if we have dir index, needn't search inode ref to get it.
3906 * Since the inode ref is close to the inode item, it is better
3907 * that we delay to delete it, and just do this deletion when
3908 * we update the inode item.
3909 */
3910 if (BTRFS_I(inode)->dir_index) {
3911 ret = btrfs_delayed_delete_inode_ref(inode);
3912 if (!ret) {
3913 index = BTRFS_I(inode)->dir_index;
3914 goto skip_backref;
3915 }
3916 }
3917
3918 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3919 dir_ino, &index);
3920 if (ret) {
3921 btrfs_info(root->fs_info,
3922 "failed to delete reference to %.*s, inode %llu parent %llu",
3923 name_len, name, ino, dir_ino);
3924 btrfs_abort_transaction(trans, root, ret);
3925 goto err;
3926 }
3927 skip_backref:
3928 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3929 if (ret) {
3930 btrfs_abort_transaction(trans, root, ret);
3931 goto err;
3932 }
3933
3934 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3935 inode, dir_ino);
3936 if (ret != 0 && ret != -ENOENT) {
3937 btrfs_abort_transaction(trans, root, ret);
3938 goto err;
3939 }
3940
3941 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3942 dir, index);
3943 if (ret == -ENOENT)
3944 ret = 0;
3945 else if (ret)
3946 btrfs_abort_transaction(trans, root, ret);
3947 err:
3948 btrfs_free_path(path);
3949 if (ret)
3950 goto out;
3951
3952 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3953 inode_inc_iversion(inode);
3954 inode_inc_iversion(dir);
3955 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3956 ret = btrfs_update_inode(trans, root, dir);
3957 out:
3958 return ret;
3959 }
3960
3961 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3962 struct btrfs_root *root,
3963 struct inode *dir, struct inode *inode,
3964 const char *name, int name_len)
3965 {
3966 int ret;
3967 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3968 if (!ret) {
3969 drop_nlink(inode);
3970 ret = btrfs_update_inode(trans, root, inode);
3971 }
3972 return ret;
3973 }
3974
3975 /*
3976 * helper to start transaction for unlink and rmdir.
3977 *
3978 * unlink and rmdir are special in btrfs, they do not always free space, so
3979 * if we cannot make our reservations the normal way try and see if there is
3980 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3981 * allow the unlink to occur.
3982 */
3983 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3984 {
3985 struct btrfs_trans_handle *trans;
3986 struct btrfs_root *root = BTRFS_I(dir)->root;
3987 int ret;
3988
3989 /*
3990 * 1 for the possible orphan item
3991 * 1 for the dir item
3992 * 1 for the dir index
3993 * 1 for the inode ref
3994 * 1 for the inode
3995 */
3996 trans = btrfs_start_transaction(root, 5);
3997 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3998 return trans;
3999
4000 if (PTR_ERR(trans) == -ENOSPC) {
4001 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
4002
4003 trans = btrfs_start_transaction(root, 0);
4004 if (IS_ERR(trans))
4005 return trans;
4006 ret = btrfs_cond_migrate_bytes(root->fs_info,
4007 &root->fs_info->trans_block_rsv,
4008 num_bytes, 5);
4009 if (ret) {
4010 btrfs_end_transaction(trans, root);
4011 return ERR_PTR(ret);
4012 }
4013 trans->block_rsv = &root->fs_info->trans_block_rsv;
4014 trans->bytes_reserved = num_bytes;
4015 }
4016 return trans;
4017 }
4018
4019 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4020 {
4021 struct btrfs_root *root = BTRFS_I(dir)->root;
4022 struct btrfs_trans_handle *trans;
4023 struct inode *inode = dentry->d_inode;
4024 int ret;
4025
4026 trans = __unlink_start_trans(dir);
4027 if (IS_ERR(trans))
4028 return PTR_ERR(trans);
4029
4030 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
4031
4032 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4033 dentry->d_name.name, dentry->d_name.len);
4034 if (ret)
4035 goto out;
4036
4037 if (inode->i_nlink == 0) {
4038 ret = btrfs_orphan_add(trans, inode);
4039 if (ret)
4040 goto out;
4041 }
4042
4043 out:
4044 btrfs_end_transaction(trans, root);
4045 btrfs_btree_balance_dirty(root);
4046 return ret;
4047 }
4048
4049 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4050 struct btrfs_root *root,
4051 struct inode *dir, u64 objectid,
4052 const char *name, int name_len)
4053 {
4054 struct btrfs_path *path;
4055 struct extent_buffer *leaf;
4056 struct btrfs_dir_item *di;
4057 struct btrfs_key key;
4058 u64 index;
4059 int ret;
4060 u64 dir_ino = btrfs_ino(dir);
4061
4062 path = btrfs_alloc_path();
4063 if (!path)
4064 return -ENOMEM;
4065
4066 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4067 name, name_len, -1);
4068 if (IS_ERR_OR_NULL(di)) {
4069 if (!di)
4070 ret = -ENOENT;
4071 else
4072 ret = PTR_ERR(di);
4073 goto out;
4074 }
4075
4076 leaf = path->nodes[0];
4077 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4078 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4079 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4080 if (ret) {
4081 btrfs_abort_transaction(trans, root, ret);
4082 goto out;
4083 }
4084 btrfs_release_path(path);
4085
4086 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4087 objectid, root->root_key.objectid,
4088 dir_ino, &index, name, name_len);
4089 if (ret < 0) {
4090 if (ret != -ENOENT) {
4091 btrfs_abort_transaction(trans, root, ret);
4092 goto out;
4093 }
4094 di = btrfs_search_dir_index_item(root, path, dir_ino,
4095 name, name_len);
4096 if (IS_ERR_OR_NULL(di)) {
4097 if (!di)
4098 ret = -ENOENT;
4099 else
4100 ret = PTR_ERR(di);
4101 btrfs_abort_transaction(trans, root, ret);
4102 goto out;
4103 }
4104
4105 leaf = path->nodes[0];
4106 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4107 btrfs_release_path(path);
4108 index = key.offset;
4109 }
4110 btrfs_release_path(path);
4111
4112 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4113 if (ret) {
4114 btrfs_abort_transaction(trans, root, ret);
4115 goto out;
4116 }
4117
4118 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4119 inode_inc_iversion(dir);
4120 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4121 ret = btrfs_update_inode_fallback(trans, root, dir);
4122 if (ret)
4123 btrfs_abort_transaction(trans, root, ret);
4124 out:
4125 btrfs_free_path(path);
4126 return ret;
4127 }
4128
4129 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4130 {
4131 struct inode *inode = dentry->d_inode;
4132 int err = 0;
4133 struct btrfs_root *root = BTRFS_I(dir)->root;
4134 struct btrfs_trans_handle *trans;
4135
4136 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4137 return -ENOTEMPTY;
4138 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4139 return -EPERM;
4140
4141 trans = __unlink_start_trans(dir);
4142 if (IS_ERR(trans))
4143 return PTR_ERR(trans);
4144
4145 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4146 err = btrfs_unlink_subvol(trans, root, dir,
4147 BTRFS_I(inode)->location.objectid,
4148 dentry->d_name.name,
4149 dentry->d_name.len);
4150 goto out;
4151 }
4152
4153 err = btrfs_orphan_add(trans, inode);
4154 if (err)
4155 goto out;
4156
4157 /* now the directory is empty */
4158 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4159 dentry->d_name.name, dentry->d_name.len);
4160 if (!err)
4161 btrfs_i_size_write(inode, 0);
4162 out:
4163 btrfs_end_transaction(trans, root);
4164 btrfs_btree_balance_dirty(root);
4165
4166 return err;
4167 }
4168
4169 static int truncate_space_check(struct btrfs_trans_handle *trans,
4170 struct btrfs_root *root,
4171 u64 bytes_deleted)
4172 {
4173 int ret;
4174
4175 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4176 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4177 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4178 if (!ret)
4179 trans->bytes_reserved += bytes_deleted;
4180 return ret;
4181
4182 }
4183
4184 /*
4185 * this can truncate away extent items, csum items and directory items.
4186 * It starts at a high offset and removes keys until it can't find
4187 * any higher than new_size
4188 *
4189 * csum items that cross the new i_size are truncated to the new size
4190 * as well.
4191 *
4192 * min_type is the minimum key type to truncate down to. If set to 0, this
4193 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4194 */
4195 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4196 struct btrfs_root *root,
4197 struct inode *inode,
4198 u64 new_size, u32 min_type)
4199 {
4200 struct btrfs_path *path;
4201 struct extent_buffer *leaf;
4202 struct btrfs_file_extent_item *fi;
4203 struct btrfs_key key;
4204 struct btrfs_key found_key;
4205 u64 extent_start = 0;
4206 u64 extent_num_bytes = 0;
4207 u64 extent_offset = 0;
4208 u64 item_end = 0;
4209 u64 last_size = (u64)-1;
4210 u32 found_type = (u8)-1;
4211 int found_extent;
4212 int del_item;
4213 int pending_del_nr = 0;
4214 int pending_del_slot = 0;
4215 int extent_type = -1;
4216 int ret;
4217 int err = 0;
4218 u64 ino = btrfs_ino(inode);
4219 u64 bytes_deleted = 0;
4220 bool be_nice = 0;
4221 bool should_throttle = 0;
4222 bool should_end = 0;
4223
4224 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4225
4226 /*
4227 * for non-free space inodes and ref cows, we want to back off from
4228 * time to time
4229 */
4230 if (!btrfs_is_free_space_inode(inode) &&
4231 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4232 be_nice = 1;
4233
4234 path = btrfs_alloc_path();
4235 if (!path)
4236 return -ENOMEM;
4237 path->reada = -1;
4238
4239 /*
4240 * We want to drop from the next block forward in case this new size is
4241 * not block aligned since we will be keeping the last block of the
4242 * extent just the way it is.
4243 */
4244 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4245 root == root->fs_info->tree_root)
4246 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4247 root->sectorsize), (u64)-1, 0);
4248
4249 /*
4250 * This function is also used to drop the items in the log tree before
4251 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4252 * it is used to drop the loged items. So we shouldn't kill the delayed
4253 * items.
4254 */
4255 if (min_type == 0 && root == BTRFS_I(inode)->root)
4256 btrfs_kill_delayed_inode_items(inode);
4257
4258 key.objectid = ino;
4259 key.offset = (u64)-1;
4260 key.type = (u8)-1;
4261
4262 search_again:
4263 /*
4264 * with a 16K leaf size and 128MB extents, you can actually queue
4265 * up a huge file in a single leaf. Most of the time that
4266 * bytes_deleted is > 0, it will be huge by the time we get here
4267 */
4268 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4269 if (btrfs_should_end_transaction(trans, root)) {
4270 err = -EAGAIN;
4271 goto error;
4272 }
4273 }
4274
4275
4276 path->leave_spinning = 1;
4277 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4278 if (ret < 0) {
4279 err = ret;
4280 goto out;
4281 }
4282
4283 if (ret > 0) {
4284 /* there are no items in the tree for us to truncate, we're
4285 * done
4286 */
4287 if (path->slots[0] == 0)
4288 goto out;
4289 path->slots[0]--;
4290 }
4291
4292 while (1) {
4293 fi = NULL;
4294 leaf = path->nodes[0];
4295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4296 found_type = found_key.type;
4297
4298 if (found_key.objectid != ino)
4299 break;
4300
4301 if (found_type < min_type)
4302 break;
4303
4304 item_end = found_key.offset;
4305 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4306 fi = btrfs_item_ptr(leaf, path->slots[0],
4307 struct btrfs_file_extent_item);
4308 extent_type = btrfs_file_extent_type(leaf, fi);
4309 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4310 item_end +=
4311 btrfs_file_extent_num_bytes(leaf, fi);
4312 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4313 item_end += btrfs_file_extent_inline_len(leaf,
4314 path->slots[0], fi);
4315 }
4316 item_end--;
4317 }
4318 if (found_type > min_type) {
4319 del_item = 1;
4320 } else {
4321 if (item_end < new_size)
4322 break;
4323 if (found_key.offset >= new_size)
4324 del_item = 1;
4325 else
4326 del_item = 0;
4327 }
4328 found_extent = 0;
4329 /* FIXME, shrink the extent if the ref count is only 1 */
4330 if (found_type != BTRFS_EXTENT_DATA_KEY)
4331 goto delete;
4332
4333 if (del_item)
4334 last_size = found_key.offset;
4335 else
4336 last_size = new_size;
4337
4338 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4339 u64 num_dec;
4340 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4341 if (!del_item) {
4342 u64 orig_num_bytes =
4343 btrfs_file_extent_num_bytes(leaf, fi);
4344 extent_num_bytes = ALIGN(new_size -
4345 found_key.offset,
4346 root->sectorsize);
4347 btrfs_set_file_extent_num_bytes(leaf, fi,
4348 extent_num_bytes);
4349 num_dec = (orig_num_bytes -
4350 extent_num_bytes);
4351 if (test_bit(BTRFS_ROOT_REF_COWS,
4352 &root->state) &&
4353 extent_start != 0)
4354 inode_sub_bytes(inode, num_dec);
4355 btrfs_mark_buffer_dirty(leaf);
4356 } else {
4357 extent_num_bytes =
4358 btrfs_file_extent_disk_num_bytes(leaf,
4359 fi);
4360 extent_offset = found_key.offset -
4361 btrfs_file_extent_offset(leaf, fi);
4362
4363 /* FIXME blocksize != 4096 */
4364 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4365 if (extent_start != 0) {
4366 found_extent = 1;
4367 if (test_bit(BTRFS_ROOT_REF_COWS,
4368 &root->state))
4369 inode_sub_bytes(inode, num_dec);
4370 }
4371 }
4372 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4373 /*
4374 * we can't truncate inline items that have had
4375 * special encodings
4376 */
4377 if (!del_item &&
4378 btrfs_file_extent_compression(leaf, fi) == 0 &&
4379 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4380 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4381 u32 size = new_size - found_key.offset;
4382
4383 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4384 inode_sub_bytes(inode, item_end + 1 -
4385 new_size);
4386
4387 /*
4388 * update the ram bytes to properly reflect
4389 * the new size of our item
4390 */
4391 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4392 size =
4393 btrfs_file_extent_calc_inline_size(size);
4394 btrfs_truncate_item(root, path, size, 1);
4395 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4396 &root->state)) {
4397 inode_sub_bytes(inode, item_end + 1 -
4398 found_key.offset);
4399 }
4400 }
4401 delete:
4402 if (del_item) {
4403 if (!pending_del_nr) {
4404 /* no pending yet, add ourselves */
4405 pending_del_slot = path->slots[0];
4406 pending_del_nr = 1;
4407 } else if (pending_del_nr &&
4408 path->slots[0] + 1 == pending_del_slot) {
4409 /* hop on the pending chunk */
4410 pending_del_nr++;
4411 pending_del_slot = path->slots[0];
4412 } else {
4413 BUG();
4414 }
4415 } else {
4416 break;
4417 }
4418 should_throttle = 0;
4419
4420 if (found_extent &&
4421 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4422 root == root->fs_info->tree_root)) {
4423 btrfs_set_path_blocking(path);
4424 bytes_deleted += extent_num_bytes;
4425 ret = btrfs_free_extent(trans, root, extent_start,
4426 extent_num_bytes, 0,
4427 btrfs_header_owner(leaf),
4428 ino, extent_offset, 0);
4429 BUG_ON(ret);
4430 if (btrfs_should_throttle_delayed_refs(trans, root))
4431 btrfs_async_run_delayed_refs(root,
4432 trans->delayed_ref_updates * 2, 0);
4433 if (be_nice) {
4434 if (truncate_space_check(trans, root,
4435 extent_num_bytes)) {
4436 should_end = 1;
4437 }
4438 if (btrfs_should_throttle_delayed_refs(trans,
4439 root)) {
4440 should_throttle = 1;
4441 }
4442 }
4443 }
4444
4445 if (found_type == BTRFS_INODE_ITEM_KEY)
4446 break;
4447
4448 if (path->slots[0] == 0 ||
4449 path->slots[0] != pending_del_slot ||
4450 should_throttle || should_end) {
4451 if (pending_del_nr) {
4452 ret = btrfs_del_items(trans, root, path,
4453 pending_del_slot,
4454 pending_del_nr);
4455 if (ret) {
4456 btrfs_abort_transaction(trans,
4457 root, ret);
4458 goto error;
4459 }
4460 pending_del_nr = 0;
4461 }
4462 btrfs_release_path(path);
4463 if (should_throttle) {
4464 unsigned long updates = trans->delayed_ref_updates;
4465 if (updates) {
4466 trans->delayed_ref_updates = 0;
4467 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4468 if (ret && !err)
4469 err = ret;
4470 }
4471 }
4472 /*
4473 * if we failed to refill our space rsv, bail out
4474 * and let the transaction restart
4475 */
4476 if (should_end) {
4477 err = -EAGAIN;
4478 goto error;
4479 }
4480 goto search_again;
4481 } else {
4482 path->slots[0]--;
4483 }
4484 }
4485 out:
4486 if (pending_del_nr) {
4487 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4488 pending_del_nr);
4489 if (ret)
4490 btrfs_abort_transaction(trans, root, ret);
4491 }
4492 error:
4493 if (last_size != (u64)-1 &&
4494 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4495 btrfs_ordered_update_i_size(inode, last_size, NULL);
4496
4497 btrfs_free_path(path);
4498
4499 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4500 unsigned long updates = trans->delayed_ref_updates;
4501 if (updates) {
4502 trans->delayed_ref_updates = 0;
4503 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4504 if (ret && !err)
4505 err = ret;
4506 }
4507 }
4508 return err;
4509 }
4510
4511 /*
4512 * btrfs_truncate_page - read, zero a chunk and write a page
4513 * @inode - inode that we're zeroing
4514 * @from - the offset to start zeroing
4515 * @len - the length to zero, 0 to zero the entire range respective to the
4516 * offset
4517 * @front - zero up to the offset instead of from the offset on
4518 *
4519 * This will find the page for the "from" offset and cow the page and zero the
4520 * part we want to zero. This is used with truncate and hole punching.
4521 */
4522 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4523 int front)
4524 {
4525 struct address_space *mapping = inode->i_mapping;
4526 struct btrfs_root *root = BTRFS_I(inode)->root;
4527 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4528 struct btrfs_ordered_extent *ordered;
4529 struct extent_state *cached_state = NULL;
4530 char *kaddr;
4531 u32 blocksize = root->sectorsize;
4532 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4533 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4534 struct page *page;
4535 gfp_t mask = btrfs_alloc_write_mask(mapping);
4536 int ret = 0;
4537 u64 page_start;
4538 u64 page_end;
4539
4540 if ((offset & (blocksize - 1)) == 0 &&
4541 (!len || ((len & (blocksize - 1)) == 0)))
4542 goto out;
4543 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4544 if (ret)
4545 goto out;
4546
4547 again:
4548 page = find_or_create_page(mapping, index, mask);
4549 if (!page) {
4550 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4551 ret = -ENOMEM;
4552 goto out;
4553 }
4554
4555 page_start = page_offset(page);
4556 page_end = page_start + PAGE_CACHE_SIZE - 1;
4557
4558 if (!PageUptodate(page)) {
4559 ret = btrfs_readpage(NULL, page);
4560 lock_page(page);
4561 if (page->mapping != mapping) {
4562 unlock_page(page);
4563 page_cache_release(page);
4564 goto again;
4565 }
4566 if (!PageUptodate(page)) {
4567 ret = -EIO;
4568 goto out_unlock;
4569 }
4570 }
4571 wait_on_page_writeback(page);
4572
4573 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4574 set_page_extent_mapped(page);
4575
4576 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4577 if (ordered) {
4578 unlock_extent_cached(io_tree, page_start, page_end,
4579 &cached_state, GFP_NOFS);
4580 unlock_page(page);
4581 page_cache_release(page);
4582 btrfs_start_ordered_extent(inode, ordered, 1);
4583 btrfs_put_ordered_extent(ordered);
4584 goto again;
4585 }
4586
4587 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4588 EXTENT_DIRTY | EXTENT_DELALLOC |
4589 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4590 0, 0, &cached_state, GFP_NOFS);
4591
4592 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4593 &cached_state);
4594 if (ret) {
4595 unlock_extent_cached(io_tree, page_start, page_end,
4596 &cached_state, GFP_NOFS);
4597 goto out_unlock;
4598 }
4599
4600 if (offset != PAGE_CACHE_SIZE) {
4601 if (!len)
4602 len = PAGE_CACHE_SIZE - offset;
4603 kaddr = kmap(page);
4604 if (front)
4605 memset(kaddr, 0, offset);
4606 else
4607 memset(kaddr + offset, 0, len);
4608 flush_dcache_page(page);
4609 kunmap(page);
4610 }
4611 ClearPageChecked(page);
4612 set_page_dirty(page);
4613 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4614 GFP_NOFS);
4615
4616 out_unlock:
4617 if (ret)
4618 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4619 unlock_page(page);
4620 page_cache_release(page);
4621 out:
4622 return ret;
4623 }
4624
4625 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4626 u64 offset, u64 len)
4627 {
4628 struct btrfs_trans_handle *trans;
4629 int ret;
4630
4631 /*
4632 * Still need to make sure the inode looks like it's been updated so
4633 * that any holes get logged if we fsync.
4634 */
4635 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4636 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4637 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4638 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4639 return 0;
4640 }
4641
4642 /*
4643 * 1 - for the one we're dropping
4644 * 1 - for the one we're adding
4645 * 1 - for updating the inode.
4646 */
4647 trans = btrfs_start_transaction(root, 3);
4648 if (IS_ERR(trans))
4649 return PTR_ERR(trans);
4650
4651 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4652 if (ret) {
4653 btrfs_abort_transaction(trans, root, ret);
4654 btrfs_end_transaction(trans, root);
4655 return ret;
4656 }
4657
4658 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4659 0, 0, len, 0, len, 0, 0, 0);
4660 if (ret)
4661 btrfs_abort_transaction(trans, root, ret);
4662 else
4663 btrfs_update_inode(trans, root, inode);
4664 btrfs_end_transaction(trans, root);
4665 return ret;
4666 }
4667
4668 /*
4669 * This function puts in dummy file extents for the area we're creating a hole
4670 * for. So if we are truncating this file to a larger size we need to insert
4671 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4672 * the range between oldsize and size
4673 */
4674 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4675 {
4676 struct btrfs_root *root = BTRFS_I(inode)->root;
4677 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4678 struct extent_map *em = NULL;
4679 struct extent_state *cached_state = NULL;
4680 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4681 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4682 u64 block_end = ALIGN(size, root->sectorsize);
4683 u64 last_byte;
4684 u64 cur_offset;
4685 u64 hole_size;
4686 int err = 0;
4687
4688 /*
4689 * If our size started in the middle of a page we need to zero out the
4690 * rest of the page before we expand the i_size, otherwise we could
4691 * expose stale data.
4692 */
4693 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4694 if (err)
4695 return err;
4696
4697 if (size <= hole_start)
4698 return 0;
4699
4700 while (1) {
4701 struct btrfs_ordered_extent *ordered;
4702
4703 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4704 &cached_state);
4705 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4706 block_end - hole_start);
4707 if (!ordered)
4708 break;
4709 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4710 &cached_state, GFP_NOFS);
4711 btrfs_start_ordered_extent(inode, ordered, 1);
4712 btrfs_put_ordered_extent(ordered);
4713 }
4714
4715 cur_offset = hole_start;
4716 while (1) {
4717 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4718 block_end - cur_offset, 0);
4719 if (IS_ERR(em)) {
4720 err = PTR_ERR(em);
4721 em = NULL;
4722 break;
4723 }
4724 last_byte = min(extent_map_end(em), block_end);
4725 last_byte = ALIGN(last_byte , root->sectorsize);
4726 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4727 struct extent_map *hole_em;
4728 hole_size = last_byte - cur_offset;
4729
4730 err = maybe_insert_hole(root, inode, cur_offset,
4731 hole_size);
4732 if (err)
4733 break;
4734 btrfs_drop_extent_cache(inode, cur_offset,
4735 cur_offset + hole_size - 1, 0);
4736 hole_em = alloc_extent_map();
4737 if (!hole_em) {
4738 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4739 &BTRFS_I(inode)->runtime_flags);
4740 goto next;
4741 }
4742 hole_em->start = cur_offset;
4743 hole_em->len = hole_size;
4744 hole_em->orig_start = cur_offset;
4745
4746 hole_em->block_start = EXTENT_MAP_HOLE;
4747 hole_em->block_len = 0;
4748 hole_em->orig_block_len = 0;
4749 hole_em->ram_bytes = hole_size;
4750 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4751 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4752 hole_em->generation = root->fs_info->generation;
4753
4754 while (1) {
4755 write_lock(&em_tree->lock);
4756 err = add_extent_mapping(em_tree, hole_em, 1);
4757 write_unlock(&em_tree->lock);
4758 if (err != -EEXIST)
4759 break;
4760 btrfs_drop_extent_cache(inode, cur_offset,
4761 cur_offset +
4762 hole_size - 1, 0);
4763 }
4764 free_extent_map(hole_em);
4765 }
4766 next:
4767 free_extent_map(em);
4768 em = NULL;
4769 cur_offset = last_byte;
4770 if (cur_offset >= block_end)
4771 break;
4772 }
4773 free_extent_map(em);
4774 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4775 GFP_NOFS);
4776 return err;
4777 }
4778
4779 static int wait_snapshoting_atomic_t(atomic_t *a)
4780 {
4781 schedule();
4782 return 0;
4783 }
4784
4785 static void wait_for_snapshot_creation(struct btrfs_root *root)
4786 {
4787 while (true) {
4788 int ret;
4789
4790 ret = btrfs_start_write_no_snapshoting(root);
4791 if (ret)
4792 break;
4793 wait_on_atomic_t(&root->will_be_snapshoted,
4794 wait_snapshoting_atomic_t,
4795 TASK_UNINTERRUPTIBLE);
4796 }
4797 }
4798
4799 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4800 {
4801 struct btrfs_root *root = BTRFS_I(inode)->root;
4802 struct btrfs_trans_handle *trans;
4803 loff_t oldsize = i_size_read(inode);
4804 loff_t newsize = attr->ia_size;
4805 int mask = attr->ia_valid;
4806 int ret;
4807
4808 /*
4809 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4810 * special case where we need to update the times despite not having
4811 * these flags set. For all other operations the VFS set these flags
4812 * explicitly if it wants a timestamp update.
4813 */
4814 if (newsize != oldsize) {
4815 inode_inc_iversion(inode);
4816 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4817 inode->i_ctime = inode->i_mtime =
4818 current_fs_time(inode->i_sb);
4819 }
4820
4821 if (newsize > oldsize) {
4822 truncate_pagecache(inode, newsize);
4823 /*
4824 * Don't do an expanding truncate while snapshoting is ongoing.
4825 * This is to ensure the snapshot captures a fully consistent
4826 * state of this file - if the snapshot captures this expanding
4827 * truncation, it must capture all writes that happened before
4828 * this truncation.
4829 */
4830 wait_for_snapshot_creation(root);
4831 ret = btrfs_cont_expand(inode, oldsize, newsize);
4832 if (ret) {
4833 btrfs_end_write_no_snapshoting(root);
4834 return ret;
4835 }
4836
4837 trans = btrfs_start_transaction(root, 1);
4838 if (IS_ERR(trans)) {
4839 btrfs_end_write_no_snapshoting(root);
4840 return PTR_ERR(trans);
4841 }
4842
4843 i_size_write(inode, newsize);
4844 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4845 ret = btrfs_update_inode(trans, root, inode);
4846 btrfs_end_write_no_snapshoting(root);
4847 btrfs_end_transaction(trans, root);
4848 } else {
4849
4850 /*
4851 * We're truncating a file that used to have good data down to
4852 * zero. Make sure it gets into the ordered flush list so that
4853 * any new writes get down to disk quickly.
4854 */
4855 if (newsize == 0)
4856 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4857 &BTRFS_I(inode)->runtime_flags);
4858
4859 /*
4860 * 1 for the orphan item we're going to add
4861 * 1 for the orphan item deletion.
4862 */
4863 trans = btrfs_start_transaction(root, 2);
4864 if (IS_ERR(trans))
4865 return PTR_ERR(trans);
4866
4867 /*
4868 * We need to do this in case we fail at _any_ point during the
4869 * actual truncate. Once we do the truncate_setsize we could
4870 * invalidate pages which forces any outstanding ordered io to
4871 * be instantly completed which will give us extents that need
4872 * to be truncated. If we fail to get an orphan inode down we
4873 * could have left over extents that were never meant to live,
4874 * so we need to garuntee from this point on that everything
4875 * will be consistent.
4876 */
4877 ret = btrfs_orphan_add(trans, inode);
4878 btrfs_end_transaction(trans, root);
4879 if (ret)
4880 return ret;
4881
4882 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4883 truncate_setsize(inode, newsize);
4884
4885 /* Disable nonlocked read DIO to avoid the end less truncate */
4886 btrfs_inode_block_unlocked_dio(inode);
4887 inode_dio_wait(inode);
4888 btrfs_inode_resume_unlocked_dio(inode);
4889
4890 ret = btrfs_truncate(inode);
4891 if (ret && inode->i_nlink) {
4892 int err;
4893
4894 /*
4895 * failed to truncate, disk_i_size is only adjusted down
4896 * as we remove extents, so it should represent the true
4897 * size of the inode, so reset the in memory size and
4898 * delete our orphan entry.
4899 */
4900 trans = btrfs_join_transaction(root);
4901 if (IS_ERR(trans)) {
4902 btrfs_orphan_del(NULL, inode);
4903 return ret;
4904 }
4905 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4906 err = btrfs_orphan_del(trans, inode);
4907 if (err)
4908 btrfs_abort_transaction(trans, root, err);
4909 btrfs_end_transaction(trans, root);
4910 }
4911 }
4912
4913 return ret;
4914 }
4915
4916 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4917 {
4918 struct inode *inode = dentry->d_inode;
4919 struct btrfs_root *root = BTRFS_I(inode)->root;
4920 int err;
4921
4922 if (btrfs_root_readonly(root))
4923 return -EROFS;
4924
4925 err = inode_change_ok(inode, attr);
4926 if (err)
4927 return err;
4928
4929 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4930 err = btrfs_setsize(inode, attr);
4931 if (err)
4932 return err;
4933 }
4934
4935 if (attr->ia_valid) {
4936 setattr_copy(inode, attr);
4937 inode_inc_iversion(inode);
4938 err = btrfs_dirty_inode(inode);
4939
4940 if (!err && attr->ia_valid & ATTR_MODE)
4941 err = posix_acl_chmod(inode, inode->i_mode);
4942 }
4943
4944 return err;
4945 }
4946
4947 /*
4948 * While truncating the inode pages during eviction, we get the VFS calling
4949 * btrfs_invalidatepage() against each page of the inode. This is slow because
4950 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4951 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4952 * extent_state structures over and over, wasting lots of time.
4953 *
4954 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4955 * those expensive operations on a per page basis and do only the ordered io
4956 * finishing, while we release here the extent_map and extent_state structures,
4957 * without the excessive merging and splitting.
4958 */
4959 static void evict_inode_truncate_pages(struct inode *inode)
4960 {
4961 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4962 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4963 struct rb_node *node;
4964
4965 ASSERT(inode->i_state & I_FREEING);
4966 truncate_inode_pages_final(&inode->i_data);
4967
4968 write_lock(&map_tree->lock);
4969 while (!RB_EMPTY_ROOT(&map_tree->map)) {
4970 struct extent_map *em;
4971
4972 node = rb_first(&map_tree->map);
4973 em = rb_entry(node, struct extent_map, rb_node);
4974 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
4975 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
4976 remove_extent_mapping(map_tree, em);
4977 free_extent_map(em);
4978 if (need_resched()) {
4979 write_unlock(&map_tree->lock);
4980 cond_resched();
4981 write_lock(&map_tree->lock);
4982 }
4983 }
4984 write_unlock(&map_tree->lock);
4985
4986 spin_lock(&io_tree->lock);
4987 while (!RB_EMPTY_ROOT(&io_tree->state)) {
4988 struct extent_state *state;
4989 struct extent_state *cached_state = NULL;
4990
4991 node = rb_first(&io_tree->state);
4992 state = rb_entry(node, struct extent_state, rb_node);
4993 atomic_inc(&state->refs);
4994 spin_unlock(&io_tree->lock);
4995
4996 lock_extent_bits(io_tree, state->start, state->end,
4997 0, &cached_state);
4998 clear_extent_bit(io_tree, state->start, state->end,
4999 EXTENT_LOCKED | EXTENT_DIRTY |
5000 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5001 EXTENT_DEFRAG, 1, 1,
5002 &cached_state, GFP_NOFS);
5003 free_extent_state(state);
5004
5005 cond_resched();
5006 spin_lock(&io_tree->lock);
5007 }
5008 spin_unlock(&io_tree->lock);
5009 }
5010
5011 void btrfs_evict_inode(struct inode *inode)
5012 {
5013 struct btrfs_trans_handle *trans;
5014 struct btrfs_root *root = BTRFS_I(inode)->root;
5015 struct btrfs_block_rsv *rsv, *global_rsv;
5016 int steal_from_global = 0;
5017 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5018 int ret;
5019
5020 trace_btrfs_inode_evict(inode);
5021
5022 evict_inode_truncate_pages(inode);
5023
5024 if (inode->i_nlink &&
5025 ((btrfs_root_refs(&root->root_item) != 0 &&
5026 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5027 btrfs_is_free_space_inode(inode)))
5028 goto no_delete;
5029
5030 if (is_bad_inode(inode)) {
5031 btrfs_orphan_del(NULL, inode);
5032 goto no_delete;
5033 }
5034 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5035 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5036
5037 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5038
5039 if (root->fs_info->log_root_recovering) {
5040 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5041 &BTRFS_I(inode)->runtime_flags));
5042 goto no_delete;
5043 }
5044
5045 if (inode->i_nlink > 0) {
5046 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5047 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5048 goto no_delete;
5049 }
5050
5051 ret = btrfs_commit_inode_delayed_inode(inode);
5052 if (ret) {
5053 btrfs_orphan_del(NULL, inode);
5054 goto no_delete;
5055 }
5056
5057 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5058 if (!rsv) {
5059 btrfs_orphan_del(NULL, inode);
5060 goto no_delete;
5061 }
5062 rsv->size = min_size;
5063 rsv->failfast = 1;
5064 global_rsv = &root->fs_info->global_block_rsv;
5065
5066 btrfs_i_size_write(inode, 0);
5067
5068 /*
5069 * This is a bit simpler than btrfs_truncate since we've already
5070 * reserved our space for our orphan item in the unlink, so we just
5071 * need to reserve some slack space in case we add bytes and update
5072 * inode item when doing the truncate.
5073 */
5074 while (1) {
5075 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5076 BTRFS_RESERVE_FLUSH_LIMIT);
5077
5078 /*
5079 * Try and steal from the global reserve since we will
5080 * likely not use this space anyway, we want to try as
5081 * hard as possible to get this to work.
5082 */
5083 if (ret)
5084 steal_from_global++;
5085 else
5086 steal_from_global = 0;
5087 ret = 0;
5088
5089 /*
5090 * steal_from_global == 0: we reserved stuff, hooray!
5091 * steal_from_global == 1: we didn't reserve stuff, boo!
5092 * steal_from_global == 2: we've committed, still not a lot of
5093 * room but maybe we'll have room in the global reserve this
5094 * time.
5095 * steal_from_global == 3: abandon all hope!
5096 */
5097 if (steal_from_global > 2) {
5098 btrfs_warn(root->fs_info,
5099 "Could not get space for a delete, will truncate on mount %d",
5100 ret);
5101 btrfs_orphan_del(NULL, inode);
5102 btrfs_free_block_rsv(root, rsv);
5103 goto no_delete;
5104 }
5105
5106 trans = btrfs_join_transaction(root);
5107 if (IS_ERR(trans)) {
5108 btrfs_orphan_del(NULL, inode);
5109 btrfs_free_block_rsv(root, rsv);
5110 goto no_delete;
5111 }
5112
5113 /*
5114 * We can't just steal from the global reserve, we need tomake
5115 * sure there is room to do it, if not we need to commit and try
5116 * again.
5117 */
5118 if (steal_from_global) {
5119 if (!btrfs_check_space_for_delayed_refs(trans, root))
5120 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5121 min_size);
5122 else
5123 ret = -ENOSPC;
5124 }
5125
5126 /*
5127 * Couldn't steal from the global reserve, we have too much
5128 * pending stuff built up, commit the transaction and try it
5129 * again.
5130 */
5131 if (ret) {
5132 ret = btrfs_commit_transaction(trans, root);
5133 if (ret) {
5134 btrfs_orphan_del(NULL, inode);
5135 btrfs_free_block_rsv(root, rsv);
5136 goto no_delete;
5137 }
5138 continue;
5139 } else {
5140 steal_from_global = 0;
5141 }
5142
5143 trans->block_rsv = rsv;
5144
5145 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5146 if (ret != -ENOSPC && ret != -EAGAIN)
5147 break;
5148
5149 trans->block_rsv = &root->fs_info->trans_block_rsv;
5150 btrfs_end_transaction(trans, root);
5151 trans = NULL;
5152 btrfs_btree_balance_dirty(root);
5153 }
5154
5155 btrfs_free_block_rsv(root, rsv);
5156
5157 /*
5158 * Errors here aren't a big deal, it just means we leave orphan items
5159 * in the tree. They will be cleaned up on the next mount.
5160 */
5161 if (ret == 0) {
5162 trans->block_rsv = root->orphan_block_rsv;
5163 btrfs_orphan_del(trans, inode);
5164 } else {
5165 btrfs_orphan_del(NULL, inode);
5166 }
5167
5168 trans->block_rsv = &root->fs_info->trans_block_rsv;
5169 if (!(root == root->fs_info->tree_root ||
5170 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5171 btrfs_return_ino(root, btrfs_ino(inode));
5172
5173 btrfs_end_transaction(trans, root);
5174 btrfs_btree_balance_dirty(root);
5175 no_delete:
5176 btrfs_remove_delayed_node(inode);
5177 clear_inode(inode);
5178 return;
5179 }
5180
5181 /*
5182 * this returns the key found in the dir entry in the location pointer.
5183 * If no dir entries were found, location->objectid is 0.
5184 */
5185 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5186 struct btrfs_key *location)
5187 {
5188 const char *name = dentry->d_name.name;
5189 int namelen = dentry->d_name.len;
5190 struct btrfs_dir_item *di;
5191 struct btrfs_path *path;
5192 struct btrfs_root *root = BTRFS_I(dir)->root;
5193 int ret = 0;
5194
5195 path = btrfs_alloc_path();
5196 if (!path)
5197 return -ENOMEM;
5198
5199 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5200 namelen, 0);
5201 if (IS_ERR(di))
5202 ret = PTR_ERR(di);
5203
5204 if (IS_ERR_OR_NULL(di))
5205 goto out_err;
5206
5207 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5208 out:
5209 btrfs_free_path(path);
5210 return ret;
5211 out_err:
5212 location->objectid = 0;
5213 goto out;
5214 }
5215
5216 /*
5217 * when we hit a tree root in a directory, the btrfs part of the inode
5218 * needs to be changed to reflect the root directory of the tree root. This
5219 * is kind of like crossing a mount point.
5220 */
5221 static int fixup_tree_root_location(struct btrfs_root *root,
5222 struct inode *dir,
5223 struct dentry *dentry,
5224 struct btrfs_key *location,
5225 struct btrfs_root **sub_root)
5226 {
5227 struct btrfs_path *path;
5228 struct btrfs_root *new_root;
5229 struct btrfs_root_ref *ref;
5230 struct extent_buffer *leaf;
5231 struct btrfs_key key;
5232 int ret;
5233 int err = 0;
5234
5235 path = btrfs_alloc_path();
5236 if (!path) {
5237 err = -ENOMEM;
5238 goto out;
5239 }
5240
5241 err = -ENOENT;
5242 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5243 key.type = BTRFS_ROOT_REF_KEY;
5244 key.offset = location->objectid;
5245
5246 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5247 0, 0);
5248 if (ret) {
5249 if (ret < 0)
5250 err = ret;
5251 goto out;
5252 }
5253
5254 leaf = path->nodes[0];
5255 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5256 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5257 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5258 goto out;
5259
5260 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5261 (unsigned long)(ref + 1),
5262 dentry->d_name.len);
5263 if (ret)
5264 goto out;
5265
5266 btrfs_release_path(path);
5267
5268 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5269 if (IS_ERR(new_root)) {
5270 err = PTR_ERR(new_root);
5271 goto out;
5272 }
5273
5274 *sub_root = new_root;
5275 location->objectid = btrfs_root_dirid(&new_root->root_item);
5276 location->type = BTRFS_INODE_ITEM_KEY;
5277 location->offset = 0;
5278 err = 0;
5279 out:
5280 btrfs_free_path(path);
5281 return err;
5282 }
5283
5284 static void inode_tree_add(struct inode *inode)
5285 {
5286 struct btrfs_root *root = BTRFS_I(inode)->root;
5287 struct btrfs_inode *entry;
5288 struct rb_node **p;
5289 struct rb_node *parent;
5290 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5291 u64 ino = btrfs_ino(inode);
5292
5293 if (inode_unhashed(inode))
5294 return;
5295 parent = NULL;
5296 spin_lock(&root->inode_lock);
5297 p = &root->inode_tree.rb_node;
5298 while (*p) {
5299 parent = *p;
5300 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5301
5302 if (ino < btrfs_ino(&entry->vfs_inode))
5303 p = &parent->rb_left;
5304 else if (ino > btrfs_ino(&entry->vfs_inode))
5305 p = &parent->rb_right;
5306 else {
5307 WARN_ON(!(entry->vfs_inode.i_state &
5308 (I_WILL_FREE | I_FREEING)));
5309 rb_replace_node(parent, new, &root->inode_tree);
5310 RB_CLEAR_NODE(parent);
5311 spin_unlock(&root->inode_lock);
5312 return;
5313 }
5314 }
5315 rb_link_node(new, parent, p);
5316 rb_insert_color(new, &root->inode_tree);
5317 spin_unlock(&root->inode_lock);
5318 }
5319
5320 static void inode_tree_del(struct inode *inode)
5321 {
5322 struct btrfs_root *root = BTRFS_I(inode)->root;
5323 int empty = 0;
5324
5325 spin_lock(&root->inode_lock);
5326 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5327 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5328 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5329 empty = RB_EMPTY_ROOT(&root->inode_tree);
5330 }
5331 spin_unlock(&root->inode_lock);
5332
5333 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5334 synchronize_srcu(&root->fs_info->subvol_srcu);
5335 spin_lock(&root->inode_lock);
5336 empty = RB_EMPTY_ROOT(&root->inode_tree);
5337 spin_unlock(&root->inode_lock);
5338 if (empty)
5339 btrfs_add_dead_root(root);
5340 }
5341 }
5342
5343 void btrfs_invalidate_inodes(struct btrfs_root *root)
5344 {
5345 struct rb_node *node;
5346 struct rb_node *prev;
5347 struct btrfs_inode *entry;
5348 struct inode *inode;
5349 u64 objectid = 0;
5350
5351 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5352 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5353
5354 spin_lock(&root->inode_lock);
5355 again:
5356 node = root->inode_tree.rb_node;
5357 prev = NULL;
5358 while (node) {
5359 prev = node;
5360 entry = rb_entry(node, struct btrfs_inode, rb_node);
5361
5362 if (objectid < btrfs_ino(&entry->vfs_inode))
5363 node = node->rb_left;
5364 else if (objectid > btrfs_ino(&entry->vfs_inode))
5365 node = node->rb_right;
5366 else
5367 break;
5368 }
5369 if (!node) {
5370 while (prev) {
5371 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5372 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5373 node = prev;
5374 break;
5375 }
5376 prev = rb_next(prev);
5377 }
5378 }
5379 while (node) {
5380 entry = rb_entry(node, struct btrfs_inode, rb_node);
5381 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5382 inode = igrab(&entry->vfs_inode);
5383 if (inode) {
5384 spin_unlock(&root->inode_lock);
5385 if (atomic_read(&inode->i_count) > 1)
5386 d_prune_aliases(inode);
5387 /*
5388 * btrfs_drop_inode will have it removed from
5389 * the inode cache when its usage count
5390 * hits zero.
5391 */
5392 iput(inode);
5393 cond_resched();
5394 spin_lock(&root->inode_lock);
5395 goto again;
5396 }
5397
5398 if (cond_resched_lock(&root->inode_lock))
5399 goto again;
5400
5401 node = rb_next(node);
5402 }
5403 spin_unlock(&root->inode_lock);
5404 }
5405
5406 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5407 {
5408 struct btrfs_iget_args *args = p;
5409 inode->i_ino = args->location->objectid;
5410 memcpy(&BTRFS_I(inode)->location, args->location,
5411 sizeof(*args->location));
5412 BTRFS_I(inode)->root = args->root;
5413 return 0;
5414 }
5415
5416 static int btrfs_find_actor(struct inode *inode, void *opaque)
5417 {
5418 struct btrfs_iget_args *args = opaque;
5419 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5420 args->root == BTRFS_I(inode)->root;
5421 }
5422
5423 static struct inode *btrfs_iget_locked(struct super_block *s,
5424 struct btrfs_key *location,
5425 struct btrfs_root *root)
5426 {
5427 struct inode *inode;
5428 struct btrfs_iget_args args;
5429 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5430
5431 args.location = location;
5432 args.root = root;
5433
5434 inode = iget5_locked(s, hashval, btrfs_find_actor,
5435 btrfs_init_locked_inode,
5436 (void *)&args);
5437 return inode;
5438 }
5439
5440 /* Get an inode object given its location and corresponding root.
5441 * Returns in *is_new if the inode was read from disk
5442 */
5443 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5444 struct btrfs_root *root, int *new)
5445 {
5446 struct inode *inode;
5447
5448 inode = btrfs_iget_locked(s, location, root);
5449 if (!inode)
5450 return ERR_PTR(-ENOMEM);
5451
5452 if (inode->i_state & I_NEW) {
5453 btrfs_read_locked_inode(inode);
5454 if (!is_bad_inode(inode)) {
5455 inode_tree_add(inode);
5456 unlock_new_inode(inode);
5457 if (new)
5458 *new = 1;
5459 } else {
5460 unlock_new_inode(inode);
5461 iput(inode);
5462 inode = ERR_PTR(-ESTALE);
5463 }
5464 }
5465
5466 return inode;
5467 }
5468
5469 static struct inode *new_simple_dir(struct super_block *s,
5470 struct btrfs_key *key,
5471 struct btrfs_root *root)
5472 {
5473 struct inode *inode = new_inode(s);
5474
5475 if (!inode)
5476 return ERR_PTR(-ENOMEM);
5477
5478 BTRFS_I(inode)->root = root;
5479 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5480 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5481
5482 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5483 inode->i_op = &btrfs_dir_ro_inode_operations;
5484 inode->i_fop = &simple_dir_operations;
5485 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5486 inode->i_mtime = CURRENT_TIME;
5487 inode->i_atime = inode->i_mtime;
5488 inode->i_ctime = inode->i_mtime;
5489 BTRFS_I(inode)->i_otime = inode->i_mtime;
5490
5491 return inode;
5492 }
5493
5494 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5495 {
5496 struct inode *inode;
5497 struct btrfs_root *root = BTRFS_I(dir)->root;
5498 struct btrfs_root *sub_root = root;
5499 struct btrfs_key location;
5500 int index;
5501 int ret = 0;
5502
5503 if (dentry->d_name.len > BTRFS_NAME_LEN)
5504 return ERR_PTR(-ENAMETOOLONG);
5505
5506 ret = btrfs_inode_by_name(dir, dentry, &location);
5507 if (ret < 0)
5508 return ERR_PTR(ret);
5509
5510 if (location.objectid == 0)
5511 return ERR_PTR(-ENOENT);
5512
5513 if (location.type == BTRFS_INODE_ITEM_KEY) {
5514 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5515 return inode;
5516 }
5517
5518 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5519
5520 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5521 ret = fixup_tree_root_location(root, dir, dentry,
5522 &location, &sub_root);
5523 if (ret < 0) {
5524 if (ret != -ENOENT)
5525 inode = ERR_PTR(ret);
5526 else
5527 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5528 } else {
5529 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5530 }
5531 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5532
5533 if (!IS_ERR(inode) && root != sub_root) {
5534 down_read(&root->fs_info->cleanup_work_sem);
5535 if (!(inode->i_sb->s_flags & MS_RDONLY))
5536 ret = btrfs_orphan_cleanup(sub_root);
5537 up_read(&root->fs_info->cleanup_work_sem);
5538 if (ret) {
5539 iput(inode);
5540 inode = ERR_PTR(ret);
5541 }
5542 }
5543
5544 return inode;
5545 }
5546
5547 static int btrfs_dentry_delete(const struct dentry *dentry)
5548 {
5549 struct btrfs_root *root;
5550 struct inode *inode = dentry->d_inode;
5551
5552 if (!inode && !IS_ROOT(dentry))
5553 inode = dentry->d_parent->d_inode;
5554
5555 if (inode) {
5556 root = BTRFS_I(inode)->root;
5557 if (btrfs_root_refs(&root->root_item) == 0)
5558 return 1;
5559
5560 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5561 return 1;
5562 }
5563 return 0;
5564 }
5565
5566 static void btrfs_dentry_release(struct dentry *dentry)
5567 {
5568 kfree(dentry->d_fsdata);
5569 }
5570
5571 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5572 unsigned int flags)
5573 {
5574 struct inode *inode;
5575
5576 inode = btrfs_lookup_dentry(dir, dentry);
5577 if (IS_ERR(inode)) {
5578 if (PTR_ERR(inode) == -ENOENT)
5579 inode = NULL;
5580 else
5581 return ERR_CAST(inode);
5582 }
5583
5584 return d_splice_alias(inode, dentry);
5585 }
5586
5587 unsigned char btrfs_filetype_table[] = {
5588 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5589 };
5590
5591 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5592 {
5593 struct inode *inode = file_inode(file);
5594 struct btrfs_root *root = BTRFS_I(inode)->root;
5595 struct btrfs_item *item;
5596 struct btrfs_dir_item *di;
5597 struct btrfs_key key;
5598 struct btrfs_key found_key;
5599 struct btrfs_path *path;
5600 struct list_head ins_list;
5601 struct list_head del_list;
5602 int ret;
5603 struct extent_buffer *leaf;
5604 int slot;
5605 unsigned char d_type;
5606 int over = 0;
5607 u32 di_cur;
5608 u32 di_total;
5609 u32 di_len;
5610 int key_type = BTRFS_DIR_INDEX_KEY;
5611 char tmp_name[32];
5612 char *name_ptr;
5613 int name_len;
5614 int is_curr = 0; /* ctx->pos points to the current index? */
5615
5616 /* FIXME, use a real flag for deciding about the key type */
5617 if (root->fs_info->tree_root == root)
5618 key_type = BTRFS_DIR_ITEM_KEY;
5619
5620 if (!dir_emit_dots(file, ctx))
5621 return 0;
5622
5623 path = btrfs_alloc_path();
5624 if (!path)
5625 return -ENOMEM;
5626
5627 path->reada = 1;
5628
5629 if (key_type == BTRFS_DIR_INDEX_KEY) {
5630 INIT_LIST_HEAD(&ins_list);
5631 INIT_LIST_HEAD(&del_list);
5632 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5633 }
5634
5635 key.type = key_type;
5636 key.offset = ctx->pos;
5637 key.objectid = btrfs_ino(inode);
5638
5639 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5640 if (ret < 0)
5641 goto err;
5642
5643 while (1) {
5644 leaf = path->nodes[0];
5645 slot = path->slots[0];
5646 if (slot >= btrfs_header_nritems(leaf)) {
5647 ret = btrfs_next_leaf(root, path);
5648 if (ret < 0)
5649 goto err;
5650 else if (ret > 0)
5651 break;
5652 continue;
5653 }
5654
5655 item = btrfs_item_nr(slot);
5656 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5657
5658 if (found_key.objectid != key.objectid)
5659 break;
5660 if (found_key.type != key_type)
5661 break;
5662 if (found_key.offset < ctx->pos)
5663 goto next;
5664 if (key_type == BTRFS_DIR_INDEX_KEY &&
5665 btrfs_should_delete_dir_index(&del_list,
5666 found_key.offset))
5667 goto next;
5668
5669 ctx->pos = found_key.offset;
5670 is_curr = 1;
5671
5672 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5673 di_cur = 0;
5674 di_total = btrfs_item_size(leaf, item);
5675
5676 while (di_cur < di_total) {
5677 struct btrfs_key location;
5678
5679 if (verify_dir_item(root, leaf, di))
5680 break;
5681
5682 name_len = btrfs_dir_name_len(leaf, di);
5683 if (name_len <= sizeof(tmp_name)) {
5684 name_ptr = tmp_name;
5685 } else {
5686 name_ptr = kmalloc(name_len, GFP_NOFS);
5687 if (!name_ptr) {
5688 ret = -ENOMEM;
5689 goto err;
5690 }
5691 }
5692 read_extent_buffer(leaf, name_ptr,
5693 (unsigned long)(di + 1), name_len);
5694
5695 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5696 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5697
5698
5699 /* is this a reference to our own snapshot? If so
5700 * skip it.
5701 *
5702 * In contrast to old kernels, we insert the snapshot's
5703 * dir item and dir index after it has been created, so
5704 * we won't find a reference to our own snapshot. We
5705 * still keep the following code for backward
5706 * compatibility.
5707 */
5708 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5709 location.objectid == root->root_key.objectid) {
5710 over = 0;
5711 goto skip;
5712 }
5713 over = !dir_emit(ctx, name_ptr, name_len,
5714 location.objectid, d_type);
5715
5716 skip:
5717 if (name_ptr != tmp_name)
5718 kfree(name_ptr);
5719
5720 if (over)
5721 goto nopos;
5722 di_len = btrfs_dir_name_len(leaf, di) +
5723 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5724 di_cur += di_len;
5725 di = (struct btrfs_dir_item *)((char *)di + di_len);
5726 }
5727 next:
5728 path->slots[0]++;
5729 }
5730
5731 if (key_type == BTRFS_DIR_INDEX_KEY) {
5732 if (is_curr)
5733 ctx->pos++;
5734 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5735 if (ret)
5736 goto nopos;
5737 }
5738
5739 /* Reached end of directory/root. Bump pos past the last item. */
5740 ctx->pos++;
5741
5742 /*
5743 * Stop new entries from being returned after we return the last
5744 * entry.
5745 *
5746 * New directory entries are assigned a strictly increasing
5747 * offset. This means that new entries created during readdir
5748 * are *guaranteed* to be seen in the future by that readdir.
5749 * This has broken buggy programs which operate on names as
5750 * they're returned by readdir. Until we re-use freed offsets
5751 * we have this hack to stop new entries from being returned
5752 * under the assumption that they'll never reach this huge
5753 * offset.
5754 *
5755 * This is being careful not to overflow 32bit loff_t unless the
5756 * last entry requires it because doing so has broken 32bit apps
5757 * in the past.
5758 */
5759 if (key_type == BTRFS_DIR_INDEX_KEY) {
5760 if (ctx->pos >= INT_MAX)
5761 ctx->pos = LLONG_MAX;
5762 else
5763 ctx->pos = INT_MAX;
5764 }
5765 nopos:
5766 ret = 0;
5767 err:
5768 if (key_type == BTRFS_DIR_INDEX_KEY)
5769 btrfs_put_delayed_items(&ins_list, &del_list);
5770 btrfs_free_path(path);
5771 return ret;
5772 }
5773
5774 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5775 {
5776 struct btrfs_root *root = BTRFS_I(inode)->root;
5777 struct btrfs_trans_handle *trans;
5778 int ret = 0;
5779 bool nolock = false;
5780
5781 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5782 return 0;
5783
5784 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5785 nolock = true;
5786
5787 if (wbc->sync_mode == WB_SYNC_ALL) {
5788 if (nolock)
5789 trans = btrfs_join_transaction_nolock(root);
5790 else
5791 trans = btrfs_join_transaction(root);
5792 if (IS_ERR(trans))
5793 return PTR_ERR(trans);
5794 ret = btrfs_commit_transaction(trans, root);
5795 }
5796 return ret;
5797 }
5798
5799 /*
5800 * This is somewhat expensive, updating the tree every time the
5801 * inode changes. But, it is most likely to find the inode in cache.
5802 * FIXME, needs more benchmarking...there are no reasons other than performance
5803 * to keep or drop this code.
5804 */
5805 static int btrfs_dirty_inode(struct inode *inode)
5806 {
5807 struct btrfs_root *root = BTRFS_I(inode)->root;
5808 struct btrfs_trans_handle *trans;
5809 int ret;
5810
5811 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5812 return 0;
5813
5814 trans = btrfs_join_transaction(root);
5815 if (IS_ERR(trans))
5816 return PTR_ERR(trans);
5817
5818 ret = btrfs_update_inode(trans, root, inode);
5819 if (ret && ret == -ENOSPC) {
5820 /* whoops, lets try again with the full transaction */
5821 btrfs_end_transaction(trans, root);
5822 trans = btrfs_start_transaction(root, 1);
5823 if (IS_ERR(trans))
5824 return PTR_ERR(trans);
5825
5826 ret = btrfs_update_inode(trans, root, inode);
5827 }
5828 btrfs_end_transaction(trans, root);
5829 if (BTRFS_I(inode)->delayed_node)
5830 btrfs_balance_delayed_items(root);
5831
5832 return ret;
5833 }
5834
5835 /*
5836 * This is a copy of file_update_time. We need this so we can return error on
5837 * ENOSPC for updating the inode in the case of file write and mmap writes.
5838 */
5839 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5840 int flags)
5841 {
5842 struct btrfs_root *root = BTRFS_I(inode)->root;
5843
5844 if (btrfs_root_readonly(root))
5845 return -EROFS;
5846
5847 if (flags & S_VERSION)
5848 inode_inc_iversion(inode);
5849 if (flags & S_CTIME)
5850 inode->i_ctime = *now;
5851 if (flags & S_MTIME)
5852 inode->i_mtime = *now;
5853 if (flags & S_ATIME)
5854 inode->i_atime = *now;
5855 return btrfs_dirty_inode(inode);
5856 }
5857
5858 /*
5859 * find the highest existing sequence number in a directory
5860 * and then set the in-memory index_cnt variable to reflect
5861 * free sequence numbers
5862 */
5863 static int btrfs_set_inode_index_count(struct inode *inode)
5864 {
5865 struct btrfs_root *root = BTRFS_I(inode)->root;
5866 struct btrfs_key key, found_key;
5867 struct btrfs_path *path;
5868 struct extent_buffer *leaf;
5869 int ret;
5870
5871 key.objectid = btrfs_ino(inode);
5872 key.type = BTRFS_DIR_INDEX_KEY;
5873 key.offset = (u64)-1;
5874
5875 path = btrfs_alloc_path();
5876 if (!path)
5877 return -ENOMEM;
5878
5879 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5880 if (ret < 0)
5881 goto out;
5882 /* FIXME: we should be able to handle this */
5883 if (ret == 0)
5884 goto out;
5885 ret = 0;
5886
5887 /*
5888 * MAGIC NUMBER EXPLANATION:
5889 * since we search a directory based on f_pos we have to start at 2
5890 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5891 * else has to start at 2
5892 */
5893 if (path->slots[0] == 0) {
5894 BTRFS_I(inode)->index_cnt = 2;
5895 goto out;
5896 }
5897
5898 path->slots[0]--;
5899
5900 leaf = path->nodes[0];
5901 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5902
5903 if (found_key.objectid != btrfs_ino(inode) ||
5904 found_key.type != BTRFS_DIR_INDEX_KEY) {
5905 BTRFS_I(inode)->index_cnt = 2;
5906 goto out;
5907 }
5908
5909 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5910 out:
5911 btrfs_free_path(path);
5912 return ret;
5913 }
5914
5915 /*
5916 * helper to find a free sequence number in a given directory. This current
5917 * code is very simple, later versions will do smarter things in the btree
5918 */
5919 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5920 {
5921 int ret = 0;
5922
5923 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5924 ret = btrfs_inode_delayed_dir_index_count(dir);
5925 if (ret) {
5926 ret = btrfs_set_inode_index_count(dir);
5927 if (ret)
5928 return ret;
5929 }
5930 }
5931
5932 *index = BTRFS_I(dir)->index_cnt;
5933 BTRFS_I(dir)->index_cnt++;
5934
5935 return ret;
5936 }
5937
5938 static int btrfs_insert_inode_locked(struct inode *inode)
5939 {
5940 struct btrfs_iget_args args;
5941 args.location = &BTRFS_I(inode)->location;
5942 args.root = BTRFS_I(inode)->root;
5943
5944 return insert_inode_locked4(inode,
5945 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
5946 btrfs_find_actor, &args);
5947 }
5948
5949 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5950 struct btrfs_root *root,
5951 struct inode *dir,
5952 const char *name, int name_len,
5953 u64 ref_objectid, u64 objectid,
5954 umode_t mode, u64 *index)
5955 {
5956 struct inode *inode;
5957 struct btrfs_inode_item *inode_item;
5958 struct btrfs_key *location;
5959 struct btrfs_path *path;
5960 struct btrfs_inode_ref *ref;
5961 struct btrfs_key key[2];
5962 u32 sizes[2];
5963 int nitems = name ? 2 : 1;
5964 unsigned long ptr;
5965 int ret;
5966
5967 path = btrfs_alloc_path();
5968 if (!path)
5969 return ERR_PTR(-ENOMEM);
5970
5971 inode = new_inode(root->fs_info->sb);
5972 if (!inode) {
5973 btrfs_free_path(path);
5974 return ERR_PTR(-ENOMEM);
5975 }
5976
5977 /*
5978 * O_TMPFILE, set link count to 0, so that after this point,
5979 * we fill in an inode item with the correct link count.
5980 */
5981 if (!name)
5982 set_nlink(inode, 0);
5983
5984 /*
5985 * we have to initialize this early, so we can reclaim the inode
5986 * number if we fail afterwards in this function.
5987 */
5988 inode->i_ino = objectid;
5989
5990 if (dir && name) {
5991 trace_btrfs_inode_request(dir);
5992
5993 ret = btrfs_set_inode_index(dir, index);
5994 if (ret) {
5995 btrfs_free_path(path);
5996 iput(inode);
5997 return ERR_PTR(ret);
5998 }
5999 } else if (dir) {
6000 *index = 0;
6001 }
6002 /*
6003 * index_cnt is ignored for everything but a dir,
6004 * btrfs_get_inode_index_count has an explanation for the magic
6005 * number
6006 */
6007 BTRFS_I(inode)->index_cnt = 2;
6008 BTRFS_I(inode)->dir_index = *index;
6009 BTRFS_I(inode)->root = root;
6010 BTRFS_I(inode)->generation = trans->transid;
6011 inode->i_generation = BTRFS_I(inode)->generation;
6012
6013 /*
6014 * We could have gotten an inode number from somebody who was fsynced
6015 * and then removed in this same transaction, so let's just set full
6016 * sync since it will be a full sync anyway and this will blow away the
6017 * old info in the log.
6018 */
6019 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6020
6021 key[0].objectid = objectid;
6022 key[0].type = BTRFS_INODE_ITEM_KEY;
6023 key[0].offset = 0;
6024
6025 sizes[0] = sizeof(struct btrfs_inode_item);
6026
6027 if (name) {
6028 /*
6029 * Start new inodes with an inode_ref. This is slightly more
6030 * efficient for small numbers of hard links since they will
6031 * be packed into one item. Extended refs will kick in if we
6032 * add more hard links than can fit in the ref item.
6033 */
6034 key[1].objectid = objectid;
6035 key[1].type = BTRFS_INODE_REF_KEY;
6036 key[1].offset = ref_objectid;
6037
6038 sizes[1] = name_len + sizeof(*ref);
6039 }
6040
6041 location = &BTRFS_I(inode)->location;
6042 location->objectid = objectid;
6043 location->offset = 0;
6044 location->type = BTRFS_INODE_ITEM_KEY;
6045
6046 ret = btrfs_insert_inode_locked(inode);
6047 if (ret < 0)
6048 goto fail;
6049
6050 path->leave_spinning = 1;
6051 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6052 if (ret != 0)
6053 goto fail_unlock;
6054
6055 inode_init_owner(inode, dir, mode);
6056 inode_set_bytes(inode, 0);
6057
6058 inode->i_mtime = CURRENT_TIME;
6059 inode->i_atime = inode->i_mtime;
6060 inode->i_ctime = inode->i_mtime;
6061 BTRFS_I(inode)->i_otime = inode->i_mtime;
6062
6063 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6064 struct btrfs_inode_item);
6065 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6066 sizeof(*inode_item));
6067 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6068
6069 if (name) {
6070 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6071 struct btrfs_inode_ref);
6072 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6073 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6074 ptr = (unsigned long)(ref + 1);
6075 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6076 }
6077
6078 btrfs_mark_buffer_dirty(path->nodes[0]);
6079 btrfs_free_path(path);
6080
6081 btrfs_inherit_iflags(inode, dir);
6082
6083 if (S_ISREG(mode)) {
6084 if (btrfs_test_opt(root, NODATASUM))
6085 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6086 if (btrfs_test_opt(root, NODATACOW))
6087 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6088 BTRFS_INODE_NODATASUM;
6089 }
6090
6091 inode_tree_add(inode);
6092
6093 trace_btrfs_inode_new(inode);
6094 btrfs_set_inode_last_trans(trans, inode);
6095
6096 btrfs_update_root_times(trans, root);
6097
6098 ret = btrfs_inode_inherit_props(trans, inode, dir);
6099 if (ret)
6100 btrfs_err(root->fs_info,
6101 "error inheriting props for ino %llu (root %llu): %d",
6102 btrfs_ino(inode), root->root_key.objectid, ret);
6103
6104 return inode;
6105
6106 fail_unlock:
6107 unlock_new_inode(inode);
6108 fail:
6109 if (dir && name)
6110 BTRFS_I(dir)->index_cnt--;
6111 btrfs_free_path(path);
6112 iput(inode);
6113 return ERR_PTR(ret);
6114 }
6115
6116 static inline u8 btrfs_inode_type(struct inode *inode)
6117 {
6118 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6119 }
6120
6121 /*
6122 * utility function to add 'inode' into 'parent_inode' with
6123 * a give name and a given sequence number.
6124 * if 'add_backref' is true, also insert a backref from the
6125 * inode to the parent directory.
6126 */
6127 int btrfs_add_link(struct btrfs_trans_handle *trans,
6128 struct inode *parent_inode, struct inode *inode,
6129 const char *name, int name_len, int add_backref, u64 index)
6130 {
6131 int ret = 0;
6132 struct btrfs_key key;
6133 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6134 u64 ino = btrfs_ino(inode);
6135 u64 parent_ino = btrfs_ino(parent_inode);
6136
6137 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6138 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6139 } else {
6140 key.objectid = ino;
6141 key.type = BTRFS_INODE_ITEM_KEY;
6142 key.offset = 0;
6143 }
6144
6145 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6146 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6147 key.objectid, root->root_key.objectid,
6148 parent_ino, index, name, name_len);
6149 } else if (add_backref) {
6150 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6151 parent_ino, index);
6152 }
6153
6154 /* Nothing to clean up yet */
6155 if (ret)
6156 return ret;
6157
6158 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6159 parent_inode, &key,
6160 btrfs_inode_type(inode), index);
6161 if (ret == -EEXIST || ret == -EOVERFLOW)
6162 goto fail_dir_item;
6163 else if (ret) {
6164 btrfs_abort_transaction(trans, root, ret);
6165 return ret;
6166 }
6167
6168 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6169 name_len * 2);
6170 inode_inc_iversion(parent_inode);
6171 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6172 ret = btrfs_update_inode(trans, root, parent_inode);
6173 if (ret)
6174 btrfs_abort_transaction(trans, root, ret);
6175 return ret;
6176
6177 fail_dir_item:
6178 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6179 u64 local_index;
6180 int err;
6181 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6182 key.objectid, root->root_key.objectid,
6183 parent_ino, &local_index, name, name_len);
6184
6185 } else if (add_backref) {
6186 u64 local_index;
6187 int err;
6188
6189 err = btrfs_del_inode_ref(trans, root, name, name_len,
6190 ino, parent_ino, &local_index);
6191 }
6192 return ret;
6193 }
6194
6195 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6196 struct inode *dir, struct dentry *dentry,
6197 struct inode *inode, int backref, u64 index)
6198 {
6199 int err = btrfs_add_link(trans, dir, inode,
6200 dentry->d_name.name, dentry->d_name.len,
6201 backref, index);
6202 if (err > 0)
6203 err = -EEXIST;
6204 return err;
6205 }
6206
6207 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6208 umode_t mode, dev_t rdev)
6209 {
6210 struct btrfs_trans_handle *trans;
6211 struct btrfs_root *root = BTRFS_I(dir)->root;
6212 struct inode *inode = NULL;
6213 int err;
6214 int drop_inode = 0;
6215 u64 objectid;
6216 u64 index = 0;
6217
6218 if (!new_valid_dev(rdev))
6219 return -EINVAL;
6220
6221 /*
6222 * 2 for inode item and ref
6223 * 2 for dir items
6224 * 1 for xattr if selinux is on
6225 */
6226 trans = btrfs_start_transaction(root, 5);
6227 if (IS_ERR(trans))
6228 return PTR_ERR(trans);
6229
6230 err = btrfs_find_free_ino(root, &objectid);
6231 if (err)
6232 goto out_unlock;
6233
6234 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6235 dentry->d_name.len, btrfs_ino(dir), objectid,
6236 mode, &index);
6237 if (IS_ERR(inode)) {
6238 err = PTR_ERR(inode);
6239 goto out_unlock;
6240 }
6241
6242 /*
6243 * If the active LSM wants to access the inode during
6244 * d_instantiate it needs these. Smack checks to see
6245 * if the filesystem supports xattrs by looking at the
6246 * ops vector.
6247 */
6248 inode->i_op = &btrfs_special_inode_operations;
6249 init_special_inode(inode, inode->i_mode, rdev);
6250
6251 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6252 if (err)
6253 goto out_unlock_inode;
6254
6255 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6256 if (err) {
6257 goto out_unlock_inode;
6258 } else {
6259 btrfs_update_inode(trans, root, inode);
6260 unlock_new_inode(inode);
6261 d_instantiate(dentry, inode);
6262 }
6263
6264 out_unlock:
6265 btrfs_end_transaction(trans, root);
6266 btrfs_balance_delayed_items(root);
6267 btrfs_btree_balance_dirty(root);
6268 if (drop_inode) {
6269 inode_dec_link_count(inode);
6270 iput(inode);
6271 }
6272 return err;
6273
6274 out_unlock_inode:
6275 drop_inode = 1;
6276 unlock_new_inode(inode);
6277 goto out_unlock;
6278
6279 }
6280
6281 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6282 umode_t mode, bool excl)
6283 {
6284 struct btrfs_trans_handle *trans;
6285 struct btrfs_root *root = BTRFS_I(dir)->root;
6286 struct inode *inode = NULL;
6287 int drop_inode_on_err = 0;
6288 int err;
6289 u64 objectid;
6290 u64 index = 0;
6291
6292 /*
6293 * 2 for inode item and ref
6294 * 2 for dir items
6295 * 1 for xattr if selinux is on
6296 */
6297 trans = btrfs_start_transaction(root, 5);
6298 if (IS_ERR(trans))
6299 return PTR_ERR(trans);
6300
6301 err = btrfs_find_free_ino(root, &objectid);
6302 if (err)
6303 goto out_unlock;
6304
6305 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6306 dentry->d_name.len, btrfs_ino(dir), objectid,
6307 mode, &index);
6308 if (IS_ERR(inode)) {
6309 err = PTR_ERR(inode);
6310 goto out_unlock;
6311 }
6312 drop_inode_on_err = 1;
6313 /*
6314 * If the active LSM wants to access the inode during
6315 * d_instantiate it needs these. Smack checks to see
6316 * if the filesystem supports xattrs by looking at the
6317 * ops vector.
6318 */
6319 inode->i_fop = &btrfs_file_operations;
6320 inode->i_op = &btrfs_file_inode_operations;
6321 inode->i_mapping->a_ops = &btrfs_aops;
6322
6323 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6324 if (err)
6325 goto out_unlock_inode;
6326
6327 err = btrfs_update_inode(trans, root, inode);
6328 if (err)
6329 goto out_unlock_inode;
6330
6331 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6332 if (err)
6333 goto out_unlock_inode;
6334
6335 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6336 unlock_new_inode(inode);
6337 d_instantiate(dentry, inode);
6338
6339 out_unlock:
6340 btrfs_end_transaction(trans, root);
6341 if (err && drop_inode_on_err) {
6342 inode_dec_link_count(inode);
6343 iput(inode);
6344 }
6345 btrfs_balance_delayed_items(root);
6346 btrfs_btree_balance_dirty(root);
6347 return err;
6348
6349 out_unlock_inode:
6350 unlock_new_inode(inode);
6351 goto out_unlock;
6352
6353 }
6354
6355 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6356 struct dentry *dentry)
6357 {
6358 struct btrfs_trans_handle *trans;
6359 struct btrfs_root *root = BTRFS_I(dir)->root;
6360 struct inode *inode = old_dentry->d_inode;
6361 u64 index;
6362 int err;
6363 int drop_inode = 0;
6364
6365 /* do not allow sys_link's with other subvols of the same device */
6366 if (root->objectid != BTRFS_I(inode)->root->objectid)
6367 return -EXDEV;
6368
6369 if (inode->i_nlink >= BTRFS_LINK_MAX)
6370 return -EMLINK;
6371
6372 err = btrfs_set_inode_index(dir, &index);
6373 if (err)
6374 goto fail;
6375
6376 /*
6377 * 2 items for inode and inode ref
6378 * 2 items for dir items
6379 * 1 item for parent inode
6380 */
6381 trans = btrfs_start_transaction(root, 5);
6382 if (IS_ERR(trans)) {
6383 err = PTR_ERR(trans);
6384 goto fail;
6385 }
6386
6387 /* There are several dir indexes for this inode, clear the cache. */
6388 BTRFS_I(inode)->dir_index = 0ULL;
6389 inc_nlink(inode);
6390 inode_inc_iversion(inode);
6391 inode->i_ctime = CURRENT_TIME;
6392 ihold(inode);
6393 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6394
6395 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6396
6397 if (err) {
6398 drop_inode = 1;
6399 } else {
6400 struct dentry *parent = dentry->d_parent;
6401 err = btrfs_update_inode(trans, root, inode);
6402 if (err)
6403 goto fail;
6404 if (inode->i_nlink == 1) {
6405 /*
6406 * If new hard link count is 1, it's a file created
6407 * with open(2) O_TMPFILE flag.
6408 */
6409 err = btrfs_orphan_del(trans, inode);
6410 if (err)
6411 goto fail;
6412 }
6413 d_instantiate(dentry, inode);
6414 btrfs_log_new_name(trans, inode, NULL, parent);
6415 }
6416
6417 btrfs_end_transaction(trans, root);
6418 btrfs_balance_delayed_items(root);
6419 fail:
6420 if (drop_inode) {
6421 inode_dec_link_count(inode);
6422 iput(inode);
6423 }
6424 btrfs_btree_balance_dirty(root);
6425 return err;
6426 }
6427
6428 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6429 {
6430 struct inode *inode = NULL;
6431 struct btrfs_trans_handle *trans;
6432 struct btrfs_root *root = BTRFS_I(dir)->root;
6433 int err = 0;
6434 int drop_on_err = 0;
6435 u64 objectid = 0;
6436 u64 index = 0;
6437
6438 /*
6439 * 2 items for inode and ref
6440 * 2 items for dir items
6441 * 1 for xattr if selinux is on
6442 */
6443 trans = btrfs_start_transaction(root, 5);
6444 if (IS_ERR(trans))
6445 return PTR_ERR(trans);
6446
6447 err = btrfs_find_free_ino(root, &objectid);
6448 if (err)
6449 goto out_fail;
6450
6451 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6452 dentry->d_name.len, btrfs_ino(dir), objectid,
6453 S_IFDIR | mode, &index);
6454 if (IS_ERR(inode)) {
6455 err = PTR_ERR(inode);
6456 goto out_fail;
6457 }
6458
6459 drop_on_err = 1;
6460 /* these must be set before we unlock the inode */
6461 inode->i_op = &btrfs_dir_inode_operations;
6462 inode->i_fop = &btrfs_dir_file_operations;
6463
6464 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6465 if (err)
6466 goto out_fail_inode;
6467
6468 btrfs_i_size_write(inode, 0);
6469 err = btrfs_update_inode(trans, root, inode);
6470 if (err)
6471 goto out_fail_inode;
6472
6473 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6474 dentry->d_name.len, 0, index);
6475 if (err)
6476 goto out_fail_inode;
6477
6478 d_instantiate(dentry, inode);
6479 /*
6480 * mkdir is special. We're unlocking after we call d_instantiate
6481 * to avoid a race with nfsd calling d_instantiate.
6482 */
6483 unlock_new_inode(inode);
6484 drop_on_err = 0;
6485
6486 out_fail:
6487 btrfs_end_transaction(trans, root);
6488 if (drop_on_err) {
6489 inode_dec_link_count(inode);
6490 iput(inode);
6491 }
6492 btrfs_balance_delayed_items(root);
6493 btrfs_btree_balance_dirty(root);
6494 return err;
6495
6496 out_fail_inode:
6497 unlock_new_inode(inode);
6498 goto out_fail;
6499 }
6500
6501 /* Find next extent map of a given extent map, caller needs to ensure locks */
6502 static struct extent_map *next_extent_map(struct extent_map *em)
6503 {
6504 struct rb_node *next;
6505
6506 next = rb_next(&em->rb_node);
6507 if (!next)
6508 return NULL;
6509 return container_of(next, struct extent_map, rb_node);
6510 }
6511
6512 static struct extent_map *prev_extent_map(struct extent_map *em)
6513 {
6514 struct rb_node *prev;
6515
6516 prev = rb_prev(&em->rb_node);
6517 if (!prev)
6518 return NULL;
6519 return container_of(prev, struct extent_map, rb_node);
6520 }
6521
6522 /* helper for btfs_get_extent. Given an existing extent in the tree,
6523 * the existing extent is the nearest extent to map_start,
6524 * and an extent that you want to insert, deal with overlap and insert
6525 * the best fitted new extent into the tree.
6526 */
6527 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6528 struct extent_map *existing,
6529 struct extent_map *em,
6530 u64 map_start)
6531 {
6532 struct extent_map *prev;
6533 struct extent_map *next;
6534 u64 start;
6535 u64 end;
6536 u64 start_diff;
6537
6538 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6539
6540 if (existing->start > map_start) {
6541 next = existing;
6542 prev = prev_extent_map(next);
6543 } else {
6544 prev = existing;
6545 next = next_extent_map(prev);
6546 }
6547
6548 start = prev ? extent_map_end(prev) : em->start;
6549 start = max_t(u64, start, em->start);
6550 end = next ? next->start : extent_map_end(em);
6551 end = min_t(u64, end, extent_map_end(em));
6552 start_diff = start - em->start;
6553 em->start = start;
6554 em->len = end - start;
6555 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6556 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6557 em->block_start += start_diff;
6558 em->block_len -= start_diff;
6559 }
6560 return add_extent_mapping(em_tree, em, 0);
6561 }
6562
6563 static noinline int uncompress_inline(struct btrfs_path *path,
6564 struct inode *inode, struct page *page,
6565 size_t pg_offset, u64 extent_offset,
6566 struct btrfs_file_extent_item *item)
6567 {
6568 int ret;
6569 struct extent_buffer *leaf = path->nodes[0];
6570 char *tmp;
6571 size_t max_size;
6572 unsigned long inline_size;
6573 unsigned long ptr;
6574 int compress_type;
6575
6576 WARN_ON(pg_offset != 0);
6577 compress_type = btrfs_file_extent_compression(leaf, item);
6578 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6579 inline_size = btrfs_file_extent_inline_item_len(leaf,
6580 btrfs_item_nr(path->slots[0]));
6581 tmp = kmalloc(inline_size, GFP_NOFS);
6582 if (!tmp)
6583 return -ENOMEM;
6584 ptr = btrfs_file_extent_inline_start(item);
6585
6586 read_extent_buffer(leaf, tmp, ptr, inline_size);
6587
6588 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6589 ret = btrfs_decompress(compress_type, tmp, page,
6590 extent_offset, inline_size, max_size);
6591 kfree(tmp);
6592 return ret;
6593 }
6594
6595 /*
6596 * a bit scary, this does extent mapping from logical file offset to the disk.
6597 * the ugly parts come from merging extents from the disk with the in-ram
6598 * representation. This gets more complex because of the data=ordered code,
6599 * where the in-ram extents might be locked pending data=ordered completion.
6600 *
6601 * This also copies inline extents directly into the page.
6602 */
6603
6604 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6605 size_t pg_offset, u64 start, u64 len,
6606 int create)
6607 {
6608 int ret;
6609 int err = 0;
6610 u64 extent_start = 0;
6611 u64 extent_end = 0;
6612 u64 objectid = btrfs_ino(inode);
6613 u32 found_type;
6614 struct btrfs_path *path = NULL;
6615 struct btrfs_root *root = BTRFS_I(inode)->root;
6616 struct btrfs_file_extent_item *item;
6617 struct extent_buffer *leaf;
6618 struct btrfs_key found_key;
6619 struct extent_map *em = NULL;
6620 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6621 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6622 struct btrfs_trans_handle *trans = NULL;
6623 const bool new_inline = !page || create;
6624
6625 again:
6626 read_lock(&em_tree->lock);
6627 em = lookup_extent_mapping(em_tree, start, len);
6628 if (em)
6629 em->bdev = root->fs_info->fs_devices->latest_bdev;
6630 read_unlock(&em_tree->lock);
6631
6632 if (em) {
6633 if (em->start > start || em->start + em->len <= start)
6634 free_extent_map(em);
6635 else if (em->block_start == EXTENT_MAP_INLINE && page)
6636 free_extent_map(em);
6637 else
6638 goto out;
6639 }
6640 em = alloc_extent_map();
6641 if (!em) {
6642 err = -ENOMEM;
6643 goto out;
6644 }
6645 em->bdev = root->fs_info->fs_devices->latest_bdev;
6646 em->start = EXTENT_MAP_HOLE;
6647 em->orig_start = EXTENT_MAP_HOLE;
6648 em->len = (u64)-1;
6649 em->block_len = (u64)-1;
6650
6651 if (!path) {
6652 path = btrfs_alloc_path();
6653 if (!path) {
6654 err = -ENOMEM;
6655 goto out;
6656 }
6657 /*
6658 * Chances are we'll be called again, so go ahead and do
6659 * readahead
6660 */
6661 path->reada = 1;
6662 }
6663
6664 ret = btrfs_lookup_file_extent(trans, root, path,
6665 objectid, start, trans != NULL);
6666 if (ret < 0) {
6667 err = ret;
6668 goto out;
6669 }
6670
6671 if (ret != 0) {
6672 if (path->slots[0] == 0)
6673 goto not_found;
6674 path->slots[0]--;
6675 }
6676
6677 leaf = path->nodes[0];
6678 item = btrfs_item_ptr(leaf, path->slots[0],
6679 struct btrfs_file_extent_item);
6680 /* are we inside the extent that was found? */
6681 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6682 found_type = found_key.type;
6683 if (found_key.objectid != objectid ||
6684 found_type != BTRFS_EXTENT_DATA_KEY) {
6685 /*
6686 * If we backup past the first extent we want to move forward
6687 * and see if there is an extent in front of us, otherwise we'll
6688 * say there is a hole for our whole search range which can
6689 * cause problems.
6690 */
6691 extent_end = start;
6692 goto next;
6693 }
6694
6695 found_type = btrfs_file_extent_type(leaf, item);
6696 extent_start = found_key.offset;
6697 if (found_type == BTRFS_FILE_EXTENT_REG ||
6698 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6699 extent_end = extent_start +
6700 btrfs_file_extent_num_bytes(leaf, item);
6701 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6702 size_t size;
6703 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6704 extent_end = ALIGN(extent_start + size, root->sectorsize);
6705 }
6706 next:
6707 if (start >= extent_end) {
6708 path->slots[0]++;
6709 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6710 ret = btrfs_next_leaf(root, path);
6711 if (ret < 0) {
6712 err = ret;
6713 goto out;
6714 }
6715 if (ret > 0)
6716 goto not_found;
6717 leaf = path->nodes[0];
6718 }
6719 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6720 if (found_key.objectid != objectid ||
6721 found_key.type != BTRFS_EXTENT_DATA_KEY)
6722 goto not_found;
6723 if (start + len <= found_key.offset)
6724 goto not_found;
6725 if (start > found_key.offset)
6726 goto next;
6727 em->start = start;
6728 em->orig_start = start;
6729 em->len = found_key.offset - start;
6730 goto not_found_em;
6731 }
6732
6733 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6734
6735 if (found_type == BTRFS_FILE_EXTENT_REG ||
6736 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6737 goto insert;
6738 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6739 unsigned long ptr;
6740 char *map;
6741 size_t size;
6742 size_t extent_offset;
6743 size_t copy_size;
6744
6745 if (new_inline)
6746 goto out;
6747
6748 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6749 extent_offset = page_offset(page) + pg_offset - extent_start;
6750 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6751 size - extent_offset);
6752 em->start = extent_start + extent_offset;
6753 em->len = ALIGN(copy_size, root->sectorsize);
6754 em->orig_block_len = em->len;
6755 em->orig_start = em->start;
6756 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6757 if (create == 0 && !PageUptodate(page)) {
6758 if (btrfs_file_extent_compression(leaf, item) !=
6759 BTRFS_COMPRESS_NONE) {
6760 ret = uncompress_inline(path, inode, page,
6761 pg_offset,
6762 extent_offset, item);
6763 if (ret) {
6764 err = ret;
6765 goto out;
6766 }
6767 } else {
6768 map = kmap(page);
6769 read_extent_buffer(leaf, map + pg_offset, ptr,
6770 copy_size);
6771 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6772 memset(map + pg_offset + copy_size, 0,
6773 PAGE_CACHE_SIZE - pg_offset -
6774 copy_size);
6775 }
6776 kunmap(page);
6777 }
6778 flush_dcache_page(page);
6779 } else if (create && PageUptodate(page)) {
6780 BUG();
6781 if (!trans) {
6782 kunmap(page);
6783 free_extent_map(em);
6784 em = NULL;
6785
6786 btrfs_release_path(path);
6787 trans = btrfs_join_transaction(root);
6788
6789 if (IS_ERR(trans))
6790 return ERR_CAST(trans);
6791 goto again;
6792 }
6793 map = kmap(page);
6794 write_extent_buffer(leaf, map + pg_offset, ptr,
6795 copy_size);
6796 kunmap(page);
6797 btrfs_mark_buffer_dirty(leaf);
6798 }
6799 set_extent_uptodate(io_tree, em->start,
6800 extent_map_end(em) - 1, NULL, GFP_NOFS);
6801 goto insert;
6802 }
6803 not_found:
6804 em->start = start;
6805 em->orig_start = start;
6806 em->len = len;
6807 not_found_em:
6808 em->block_start = EXTENT_MAP_HOLE;
6809 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6810 insert:
6811 btrfs_release_path(path);
6812 if (em->start > start || extent_map_end(em) <= start) {
6813 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6814 em->start, em->len, start, len);
6815 err = -EIO;
6816 goto out;
6817 }
6818
6819 err = 0;
6820 write_lock(&em_tree->lock);
6821 ret = add_extent_mapping(em_tree, em, 0);
6822 /* it is possible that someone inserted the extent into the tree
6823 * while we had the lock dropped. It is also possible that
6824 * an overlapping map exists in the tree
6825 */
6826 if (ret == -EEXIST) {
6827 struct extent_map *existing;
6828
6829 ret = 0;
6830
6831 existing = search_extent_mapping(em_tree, start, len);
6832 /*
6833 * existing will always be non-NULL, since there must be
6834 * extent causing the -EEXIST.
6835 */
6836 if (start >= extent_map_end(existing) ||
6837 start <= existing->start) {
6838 /*
6839 * The existing extent map is the one nearest to
6840 * the [start, start + len) range which overlaps
6841 */
6842 err = merge_extent_mapping(em_tree, existing,
6843 em, start);
6844 free_extent_map(existing);
6845 if (err) {
6846 free_extent_map(em);
6847 em = NULL;
6848 }
6849 } else {
6850 free_extent_map(em);
6851 em = existing;
6852 err = 0;
6853 }
6854 }
6855 write_unlock(&em_tree->lock);
6856 out:
6857
6858 trace_btrfs_get_extent(root, em);
6859
6860 if (path)
6861 btrfs_free_path(path);
6862 if (trans) {
6863 ret = btrfs_end_transaction(trans, root);
6864 if (!err)
6865 err = ret;
6866 }
6867 if (err) {
6868 free_extent_map(em);
6869 return ERR_PTR(err);
6870 }
6871 BUG_ON(!em); /* Error is always set */
6872 return em;
6873 }
6874
6875 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6876 size_t pg_offset, u64 start, u64 len,
6877 int create)
6878 {
6879 struct extent_map *em;
6880 struct extent_map *hole_em = NULL;
6881 u64 range_start = start;
6882 u64 end;
6883 u64 found;
6884 u64 found_end;
6885 int err = 0;
6886
6887 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6888 if (IS_ERR(em))
6889 return em;
6890 if (em) {
6891 /*
6892 * if our em maps to
6893 * - a hole or
6894 * - a pre-alloc extent,
6895 * there might actually be delalloc bytes behind it.
6896 */
6897 if (em->block_start != EXTENT_MAP_HOLE &&
6898 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6899 return em;
6900 else
6901 hole_em = em;
6902 }
6903
6904 /* check to see if we've wrapped (len == -1 or similar) */
6905 end = start + len;
6906 if (end < start)
6907 end = (u64)-1;
6908 else
6909 end -= 1;
6910
6911 em = NULL;
6912
6913 /* ok, we didn't find anything, lets look for delalloc */
6914 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6915 end, len, EXTENT_DELALLOC, 1);
6916 found_end = range_start + found;
6917 if (found_end < range_start)
6918 found_end = (u64)-1;
6919
6920 /*
6921 * we didn't find anything useful, return
6922 * the original results from get_extent()
6923 */
6924 if (range_start > end || found_end <= start) {
6925 em = hole_em;
6926 hole_em = NULL;
6927 goto out;
6928 }
6929
6930 /* adjust the range_start to make sure it doesn't
6931 * go backwards from the start they passed in
6932 */
6933 range_start = max(start, range_start);
6934 found = found_end - range_start;
6935
6936 if (found > 0) {
6937 u64 hole_start = start;
6938 u64 hole_len = len;
6939
6940 em = alloc_extent_map();
6941 if (!em) {
6942 err = -ENOMEM;
6943 goto out;
6944 }
6945 /*
6946 * when btrfs_get_extent can't find anything it
6947 * returns one huge hole
6948 *
6949 * make sure what it found really fits our range, and
6950 * adjust to make sure it is based on the start from
6951 * the caller
6952 */
6953 if (hole_em) {
6954 u64 calc_end = extent_map_end(hole_em);
6955
6956 if (calc_end <= start || (hole_em->start > end)) {
6957 free_extent_map(hole_em);
6958 hole_em = NULL;
6959 } else {
6960 hole_start = max(hole_em->start, start);
6961 hole_len = calc_end - hole_start;
6962 }
6963 }
6964 em->bdev = NULL;
6965 if (hole_em && range_start > hole_start) {
6966 /* our hole starts before our delalloc, so we
6967 * have to return just the parts of the hole
6968 * that go until the delalloc starts
6969 */
6970 em->len = min(hole_len,
6971 range_start - hole_start);
6972 em->start = hole_start;
6973 em->orig_start = hole_start;
6974 /*
6975 * don't adjust block start at all,
6976 * it is fixed at EXTENT_MAP_HOLE
6977 */
6978 em->block_start = hole_em->block_start;
6979 em->block_len = hole_len;
6980 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6981 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6982 } else {
6983 em->start = range_start;
6984 em->len = found;
6985 em->orig_start = range_start;
6986 em->block_start = EXTENT_MAP_DELALLOC;
6987 em->block_len = found;
6988 }
6989 } else if (hole_em) {
6990 return hole_em;
6991 }
6992 out:
6993
6994 free_extent_map(hole_em);
6995 if (err) {
6996 free_extent_map(em);
6997 return ERR_PTR(err);
6998 }
6999 return em;
7000 }
7001
7002 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7003 u64 start, u64 len)
7004 {
7005 struct btrfs_root *root = BTRFS_I(inode)->root;
7006 struct extent_map *em;
7007 struct btrfs_key ins;
7008 u64 alloc_hint;
7009 int ret;
7010
7011 alloc_hint = get_extent_allocation_hint(inode, start, len);
7012 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7013 alloc_hint, &ins, 1, 1);
7014 if (ret)
7015 return ERR_PTR(ret);
7016
7017 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7018 ins.offset, ins.offset, ins.offset, 0);
7019 if (IS_ERR(em)) {
7020 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7021 return em;
7022 }
7023
7024 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7025 ins.offset, ins.offset, 0);
7026 if (ret) {
7027 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7028 free_extent_map(em);
7029 return ERR_PTR(ret);
7030 }
7031
7032 return em;
7033 }
7034
7035 /*
7036 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7037 * block must be cow'd
7038 */
7039 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7040 u64 *orig_start, u64 *orig_block_len,
7041 u64 *ram_bytes)
7042 {
7043 struct btrfs_trans_handle *trans;
7044 struct btrfs_path *path;
7045 int ret;
7046 struct extent_buffer *leaf;
7047 struct btrfs_root *root = BTRFS_I(inode)->root;
7048 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7049 struct btrfs_file_extent_item *fi;
7050 struct btrfs_key key;
7051 u64 disk_bytenr;
7052 u64 backref_offset;
7053 u64 extent_end;
7054 u64 num_bytes;
7055 int slot;
7056 int found_type;
7057 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7058
7059 path = btrfs_alloc_path();
7060 if (!path)
7061 return -ENOMEM;
7062
7063 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7064 offset, 0);
7065 if (ret < 0)
7066 goto out;
7067
7068 slot = path->slots[0];
7069 if (ret == 1) {
7070 if (slot == 0) {
7071 /* can't find the item, must cow */
7072 ret = 0;
7073 goto out;
7074 }
7075 slot--;
7076 }
7077 ret = 0;
7078 leaf = path->nodes[0];
7079 btrfs_item_key_to_cpu(leaf, &key, slot);
7080 if (key.objectid != btrfs_ino(inode) ||
7081 key.type != BTRFS_EXTENT_DATA_KEY) {
7082 /* not our file or wrong item type, must cow */
7083 goto out;
7084 }
7085
7086 if (key.offset > offset) {
7087 /* Wrong offset, must cow */
7088 goto out;
7089 }
7090
7091 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7092 found_type = btrfs_file_extent_type(leaf, fi);
7093 if (found_type != BTRFS_FILE_EXTENT_REG &&
7094 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7095 /* not a regular extent, must cow */
7096 goto out;
7097 }
7098
7099 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7100 goto out;
7101
7102 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7103 if (extent_end <= offset)
7104 goto out;
7105
7106 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7107 if (disk_bytenr == 0)
7108 goto out;
7109
7110 if (btrfs_file_extent_compression(leaf, fi) ||
7111 btrfs_file_extent_encryption(leaf, fi) ||
7112 btrfs_file_extent_other_encoding(leaf, fi))
7113 goto out;
7114
7115 backref_offset = btrfs_file_extent_offset(leaf, fi);
7116
7117 if (orig_start) {
7118 *orig_start = key.offset - backref_offset;
7119 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7120 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7121 }
7122
7123 if (btrfs_extent_readonly(root, disk_bytenr))
7124 goto out;
7125
7126 num_bytes = min(offset + *len, extent_end) - offset;
7127 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7128 u64 range_end;
7129
7130 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7131 ret = test_range_bit(io_tree, offset, range_end,
7132 EXTENT_DELALLOC, 0, NULL);
7133 if (ret) {
7134 ret = -EAGAIN;
7135 goto out;
7136 }
7137 }
7138
7139 btrfs_release_path(path);
7140
7141 /*
7142 * look for other files referencing this extent, if we
7143 * find any we must cow
7144 */
7145 trans = btrfs_join_transaction(root);
7146 if (IS_ERR(trans)) {
7147 ret = 0;
7148 goto out;
7149 }
7150
7151 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7152 key.offset - backref_offset, disk_bytenr);
7153 btrfs_end_transaction(trans, root);
7154 if (ret) {
7155 ret = 0;
7156 goto out;
7157 }
7158
7159 /*
7160 * adjust disk_bytenr and num_bytes to cover just the bytes
7161 * in this extent we are about to write. If there
7162 * are any csums in that range we have to cow in order
7163 * to keep the csums correct
7164 */
7165 disk_bytenr += backref_offset;
7166 disk_bytenr += offset - key.offset;
7167 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7168 goto out;
7169 /*
7170 * all of the above have passed, it is safe to overwrite this extent
7171 * without cow
7172 */
7173 *len = num_bytes;
7174 ret = 1;
7175 out:
7176 btrfs_free_path(path);
7177 return ret;
7178 }
7179
7180 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7181 {
7182 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7183 int found = false;
7184 void **pagep = NULL;
7185 struct page *page = NULL;
7186 int start_idx;
7187 int end_idx;
7188
7189 start_idx = start >> PAGE_CACHE_SHIFT;
7190
7191 /*
7192 * end is the last byte in the last page. end == start is legal
7193 */
7194 end_idx = end >> PAGE_CACHE_SHIFT;
7195
7196 rcu_read_lock();
7197
7198 /* Most of the code in this while loop is lifted from
7199 * find_get_page. It's been modified to begin searching from a
7200 * page and return just the first page found in that range. If the
7201 * found idx is less than or equal to the end idx then we know that
7202 * a page exists. If no pages are found or if those pages are
7203 * outside of the range then we're fine (yay!) */
7204 while (page == NULL &&
7205 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7206 page = radix_tree_deref_slot(pagep);
7207 if (unlikely(!page))
7208 break;
7209
7210 if (radix_tree_exception(page)) {
7211 if (radix_tree_deref_retry(page)) {
7212 page = NULL;
7213 continue;
7214 }
7215 /*
7216 * Otherwise, shmem/tmpfs must be storing a swap entry
7217 * here as an exceptional entry: so return it without
7218 * attempting to raise page count.
7219 */
7220 page = NULL;
7221 break; /* TODO: Is this relevant for this use case? */
7222 }
7223
7224 if (!page_cache_get_speculative(page)) {
7225 page = NULL;
7226 continue;
7227 }
7228
7229 /*
7230 * Has the page moved?
7231 * This is part of the lockless pagecache protocol. See
7232 * include/linux/pagemap.h for details.
7233 */
7234 if (unlikely(page != *pagep)) {
7235 page_cache_release(page);
7236 page = NULL;
7237 }
7238 }
7239
7240 if (page) {
7241 if (page->index <= end_idx)
7242 found = true;
7243 page_cache_release(page);
7244 }
7245
7246 rcu_read_unlock();
7247 return found;
7248 }
7249
7250 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7251 struct extent_state **cached_state, int writing)
7252 {
7253 struct btrfs_ordered_extent *ordered;
7254 int ret = 0;
7255
7256 while (1) {
7257 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7258 0, cached_state);
7259 /*
7260 * We're concerned with the entire range that we're going to be
7261 * doing DIO to, so we need to make sure theres no ordered
7262 * extents in this range.
7263 */
7264 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7265 lockend - lockstart + 1);
7266
7267 /*
7268 * We need to make sure there are no buffered pages in this
7269 * range either, we could have raced between the invalidate in
7270 * generic_file_direct_write and locking the extent. The
7271 * invalidate needs to happen so that reads after a write do not
7272 * get stale data.
7273 */
7274 if (!ordered &&
7275 (!writing ||
7276 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7277 break;
7278
7279 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7280 cached_state, GFP_NOFS);
7281
7282 if (ordered) {
7283 btrfs_start_ordered_extent(inode, ordered, 1);
7284 btrfs_put_ordered_extent(ordered);
7285 } else {
7286 /* Screw you mmap */
7287 ret = btrfs_fdatawrite_range(inode, lockstart, lockend);
7288 if (ret)
7289 break;
7290 ret = filemap_fdatawait_range(inode->i_mapping,
7291 lockstart,
7292 lockend);
7293 if (ret)
7294 break;
7295
7296 /*
7297 * If we found a page that couldn't be invalidated just
7298 * fall back to buffered.
7299 */
7300 ret = invalidate_inode_pages2_range(inode->i_mapping,
7301 lockstart >> PAGE_CACHE_SHIFT,
7302 lockend >> PAGE_CACHE_SHIFT);
7303 if (ret)
7304 break;
7305 }
7306
7307 cond_resched();
7308 }
7309
7310 return ret;
7311 }
7312
7313 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7314 u64 len, u64 orig_start,
7315 u64 block_start, u64 block_len,
7316 u64 orig_block_len, u64 ram_bytes,
7317 int type)
7318 {
7319 struct extent_map_tree *em_tree;
7320 struct extent_map *em;
7321 struct btrfs_root *root = BTRFS_I(inode)->root;
7322 int ret;
7323
7324 em_tree = &BTRFS_I(inode)->extent_tree;
7325 em = alloc_extent_map();
7326 if (!em)
7327 return ERR_PTR(-ENOMEM);
7328
7329 em->start = start;
7330 em->orig_start = orig_start;
7331 em->mod_start = start;
7332 em->mod_len = len;
7333 em->len = len;
7334 em->block_len = block_len;
7335 em->block_start = block_start;
7336 em->bdev = root->fs_info->fs_devices->latest_bdev;
7337 em->orig_block_len = orig_block_len;
7338 em->ram_bytes = ram_bytes;
7339 em->generation = -1;
7340 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7341 if (type == BTRFS_ORDERED_PREALLOC)
7342 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7343
7344 do {
7345 btrfs_drop_extent_cache(inode, em->start,
7346 em->start + em->len - 1, 0);
7347 write_lock(&em_tree->lock);
7348 ret = add_extent_mapping(em_tree, em, 1);
7349 write_unlock(&em_tree->lock);
7350 } while (ret == -EEXIST);
7351
7352 if (ret) {
7353 free_extent_map(em);
7354 return ERR_PTR(ret);
7355 }
7356
7357 return em;
7358 }
7359
7360
7361 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7362 struct buffer_head *bh_result, int create)
7363 {
7364 struct extent_map *em;
7365 struct btrfs_root *root = BTRFS_I(inode)->root;
7366 struct extent_state *cached_state = NULL;
7367 u64 start = iblock << inode->i_blkbits;
7368 u64 lockstart, lockend;
7369 u64 len = bh_result->b_size;
7370 u64 *outstanding_extents = NULL;
7371 int unlock_bits = EXTENT_LOCKED;
7372 int ret = 0;
7373
7374 if (create)
7375 unlock_bits |= EXTENT_DIRTY;
7376 else
7377 len = min_t(u64, len, root->sectorsize);
7378
7379 lockstart = start;
7380 lockend = start + len - 1;
7381
7382 if (current->journal_info) {
7383 /*
7384 * Need to pull our outstanding extents and set journal_info to NULL so
7385 * that anything that needs to check if there's a transction doesn't get
7386 * confused.
7387 */
7388 outstanding_extents = current->journal_info;
7389 current->journal_info = NULL;
7390 }
7391
7392 /*
7393 * If this errors out it's because we couldn't invalidate pagecache for
7394 * this range and we need to fallback to buffered.
7395 */
7396 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
7397 return -ENOTBLK;
7398
7399 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7400 if (IS_ERR(em)) {
7401 ret = PTR_ERR(em);
7402 goto unlock_err;
7403 }
7404
7405 /*
7406 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7407 * io. INLINE is special, and we could probably kludge it in here, but
7408 * it's still buffered so for safety lets just fall back to the generic
7409 * buffered path.
7410 *
7411 * For COMPRESSED we _have_ to read the entire extent in so we can
7412 * decompress it, so there will be buffering required no matter what we
7413 * do, so go ahead and fallback to buffered.
7414 *
7415 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7416 * to buffered IO. Don't blame me, this is the price we pay for using
7417 * the generic code.
7418 */
7419 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7420 em->block_start == EXTENT_MAP_INLINE) {
7421 free_extent_map(em);
7422 ret = -ENOTBLK;
7423 goto unlock_err;
7424 }
7425
7426 /* Just a good old fashioned hole, return */
7427 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7428 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7429 free_extent_map(em);
7430 goto unlock_err;
7431 }
7432
7433 /*
7434 * We don't allocate a new extent in the following cases
7435 *
7436 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7437 * existing extent.
7438 * 2) The extent is marked as PREALLOC. We're good to go here and can
7439 * just use the extent.
7440 *
7441 */
7442 if (!create) {
7443 len = min(len, em->len - (start - em->start));
7444 lockstart = start + len;
7445 goto unlock;
7446 }
7447
7448 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7449 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7450 em->block_start != EXTENT_MAP_HOLE)) {
7451 int type;
7452 u64 block_start, orig_start, orig_block_len, ram_bytes;
7453
7454 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7455 type = BTRFS_ORDERED_PREALLOC;
7456 else
7457 type = BTRFS_ORDERED_NOCOW;
7458 len = min(len, em->len - (start - em->start));
7459 block_start = em->block_start + (start - em->start);
7460
7461 if (can_nocow_extent(inode, start, &len, &orig_start,
7462 &orig_block_len, &ram_bytes) == 1) {
7463 if (type == BTRFS_ORDERED_PREALLOC) {
7464 free_extent_map(em);
7465 em = create_pinned_em(inode, start, len,
7466 orig_start,
7467 block_start, len,
7468 orig_block_len,
7469 ram_bytes, type);
7470 if (IS_ERR(em)) {
7471 ret = PTR_ERR(em);
7472 goto unlock_err;
7473 }
7474 }
7475
7476 ret = btrfs_add_ordered_extent_dio(inode, start,
7477 block_start, len, len, type);
7478 if (ret) {
7479 free_extent_map(em);
7480 goto unlock_err;
7481 }
7482 goto unlock;
7483 }
7484 }
7485
7486 /*
7487 * this will cow the extent, reset the len in case we changed
7488 * it above
7489 */
7490 len = bh_result->b_size;
7491 free_extent_map(em);
7492 em = btrfs_new_extent_direct(inode, start, len);
7493 if (IS_ERR(em)) {
7494 ret = PTR_ERR(em);
7495 goto unlock_err;
7496 }
7497 len = min(len, em->len - (start - em->start));
7498 unlock:
7499 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7500 inode->i_blkbits;
7501 bh_result->b_size = len;
7502 bh_result->b_bdev = em->bdev;
7503 set_buffer_mapped(bh_result);
7504 if (create) {
7505 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7506 set_buffer_new(bh_result);
7507
7508 /*
7509 * Need to update the i_size under the extent lock so buffered
7510 * readers will get the updated i_size when we unlock.
7511 */
7512 if (start + len > i_size_read(inode))
7513 i_size_write(inode, start + len);
7514
7515 /*
7516 * If we have an outstanding_extents count still set then we're
7517 * within our reservation, otherwise we need to adjust our inode
7518 * counter appropriately.
7519 */
7520 if (*outstanding_extents) {
7521 (*outstanding_extents)--;
7522 } else {
7523 spin_lock(&BTRFS_I(inode)->lock);
7524 BTRFS_I(inode)->outstanding_extents++;
7525 spin_unlock(&BTRFS_I(inode)->lock);
7526 }
7527
7528 current->journal_info = outstanding_extents;
7529 btrfs_free_reserved_data_space(inode, len);
7530 }
7531
7532 /*
7533 * In the case of write we need to clear and unlock the entire range,
7534 * in the case of read we need to unlock only the end area that we
7535 * aren't using if there is any left over space.
7536 */
7537 if (lockstart < lockend) {
7538 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7539 lockend, unlock_bits, 1, 0,
7540 &cached_state, GFP_NOFS);
7541 } else {
7542 free_extent_state(cached_state);
7543 }
7544
7545 free_extent_map(em);
7546
7547 return 0;
7548
7549 unlock_err:
7550 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7551 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7552 if (outstanding_extents)
7553 current->journal_info = outstanding_extents;
7554 return ret;
7555 }
7556
7557 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7558 int rw, int mirror_num)
7559 {
7560 struct btrfs_root *root = BTRFS_I(inode)->root;
7561 int ret;
7562
7563 BUG_ON(rw & REQ_WRITE);
7564
7565 bio_get(bio);
7566
7567 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7568 BTRFS_WQ_ENDIO_DIO_REPAIR);
7569 if (ret)
7570 goto err;
7571
7572 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7573 err:
7574 bio_put(bio);
7575 return ret;
7576 }
7577
7578 static int btrfs_check_dio_repairable(struct inode *inode,
7579 struct bio *failed_bio,
7580 struct io_failure_record *failrec,
7581 int failed_mirror)
7582 {
7583 int num_copies;
7584
7585 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7586 failrec->logical, failrec->len);
7587 if (num_copies == 1) {
7588 /*
7589 * we only have a single copy of the data, so don't bother with
7590 * all the retry and error correction code that follows. no
7591 * matter what the error is, it is very likely to persist.
7592 */
7593 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7594 num_copies, failrec->this_mirror, failed_mirror);
7595 return 0;
7596 }
7597
7598 failrec->failed_mirror = failed_mirror;
7599 failrec->this_mirror++;
7600 if (failrec->this_mirror == failed_mirror)
7601 failrec->this_mirror++;
7602
7603 if (failrec->this_mirror > num_copies) {
7604 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7605 num_copies, failrec->this_mirror, failed_mirror);
7606 return 0;
7607 }
7608
7609 return 1;
7610 }
7611
7612 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7613 struct page *page, u64 start, u64 end,
7614 int failed_mirror, bio_end_io_t *repair_endio,
7615 void *repair_arg)
7616 {
7617 struct io_failure_record *failrec;
7618 struct bio *bio;
7619 int isector;
7620 int read_mode;
7621 int ret;
7622
7623 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7624
7625 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7626 if (ret)
7627 return ret;
7628
7629 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7630 failed_mirror);
7631 if (!ret) {
7632 free_io_failure(inode, failrec);
7633 return -EIO;
7634 }
7635
7636 if (failed_bio->bi_vcnt > 1)
7637 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7638 else
7639 read_mode = READ_SYNC;
7640
7641 isector = start - btrfs_io_bio(failed_bio)->logical;
7642 isector >>= inode->i_sb->s_blocksize_bits;
7643 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7644 0, isector, repair_endio, repair_arg);
7645 if (!bio) {
7646 free_io_failure(inode, failrec);
7647 return -EIO;
7648 }
7649
7650 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7651 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7652 read_mode, failrec->this_mirror, failrec->in_validation);
7653
7654 ret = submit_dio_repair_bio(inode, bio, read_mode,
7655 failrec->this_mirror);
7656 if (ret) {
7657 free_io_failure(inode, failrec);
7658 bio_put(bio);
7659 }
7660
7661 return ret;
7662 }
7663
7664 struct btrfs_retry_complete {
7665 struct completion done;
7666 struct inode *inode;
7667 u64 start;
7668 int uptodate;
7669 };
7670
7671 static void btrfs_retry_endio_nocsum(struct bio *bio, int err)
7672 {
7673 struct btrfs_retry_complete *done = bio->bi_private;
7674 struct bio_vec *bvec;
7675 int i;
7676
7677 if (err)
7678 goto end;
7679
7680 done->uptodate = 1;
7681 bio_for_each_segment_all(bvec, bio, i)
7682 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7683 end:
7684 complete(&done->done);
7685 bio_put(bio);
7686 }
7687
7688 static int __btrfs_correct_data_nocsum(struct inode *inode,
7689 struct btrfs_io_bio *io_bio)
7690 {
7691 struct bio_vec *bvec;
7692 struct btrfs_retry_complete done;
7693 u64 start;
7694 int i;
7695 int ret;
7696
7697 start = io_bio->logical;
7698 done.inode = inode;
7699
7700 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7701 try_again:
7702 done.uptodate = 0;
7703 done.start = start;
7704 init_completion(&done.done);
7705
7706 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7707 start + bvec->bv_len - 1,
7708 io_bio->mirror_num,
7709 btrfs_retry_endio_nocsum, &done);
7710 if (ret)
7711 return ret;
7712
7713 wait_for_completion(&done.done);
7714
7715 if (!done.uptodate) {
7716 /* We might have another mirror, so try again */
7717 goto try_again;
7718 }
7719
7720 start += bvec->bv_len;
7721 }
7722
7723 return 0;
7724 }
7725
7726 static void btrfs_retry_endio(struct bio *bio, int err)
7727 {
7728 struct btrfs_retry_complete *done = bio->bi_private;
7729 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7730 struct bio_vec *bvec;
7731 int uptodate;
7732 int ret;
7733 int i;
7734
7735 if (err)
7736 goto end;
7737
7738 uptodate = 1;
7739 bio_for_each_segment_all(bvec, bio, i) {
7740 ret = __readpage_endio_check(done->inode, io_bio, i,
7741 bvec->bv_page, 0,
7742 done->start, bvec->bv_len);
7743 if (!ret)
7744 clean_io_failure(done->inode, done->start,
7745 bvec->bv_page, 0);
7746 else
7747 uptodate = 0;
7748 }
7749
7750 done->uptodate = uptodate;
7751 end:
7752 complete(&done->done);
7753 bio_put(bio);
7754 }
7755
7756 static int __btrfs_subio_endio_read(struct inode *inode,
7757 struct btrfs_io_bio *io_bio, int err)
7758 {
7759 struct bio_vec *bvec;
7760 struct btrfs_retry_complete done;
7761 u64 start;
7762 u64 offset = 0;
7763 int i;
7764 int ret;
7765
7766 err = 0;
7767 start = io_bio->logical;
7768 done.inode = inode;
7769
7770 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7771 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7772 0, start, bvec->bv_len);
7773 if (likely(!ret))
7774 goto next;
7775 try_again:
7776 done.uptodate = 0;
7777 done.start = start;
7778 init_completion(&done.done);
7779
7780 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7781 start + bvec->bv_len - 1,
7782 io_bio->mirror_num,
7783 btrfs_retry_endio, &done);
7784 if (ret) {
7785 err = ret;
7786 goto next;
7787 }
7788
7789 wait_for_completion(&done.done);
7790
7791 if (!done.uptodate) {
7792 /* We might have another mirror, so try again */
7793 goto try_again;
7794 }
7795 next:
7796 offset += bvec->bv_len;
7797 start += bvec->bv_len;
7798 }
7799
7800 return err;
7801 }
7802
7803 static int btrfs_subio_endio_read(struct inode *inode,
7804 struct btrfs_io_bio *io_bio, int err)
7805 {
7806 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7807
7808 if (skip_csum) {
7809 if (unlikely(err))
7810 return __btrfs_correct_data_nocsum(inode, io_bio);
7811 else
7812 return 0;
7813 } else {
7814 return __btrfs_subio_endio_read(inode, io_bio, err);
7815 }
7816 }
7817
7818 static void btrfs_endio_direct_read(struct bio *bio, int err)
7819 {
7820 struct btrfs_dio_private *dip = bio->bi_private;
7821 struct inode *inode = dip->inode;
7822 struct bio *dio_bio;
7823 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7824
7825 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
7826 err = btrfs_subio_endio_read(inode, io_bio, err);
7827
7828 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7829 dip->logical_offset + dip->bytes - 1);
7830 dio_bio = dip->dio_bio;
7831
7832 kfree(dip);
7833
7834 /* If we had a csum failure make sure to clear the uptodate flag */
7835 if (err)
7836 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7837 dio_end_io(dio_bio, err);
7838
7839 if (io_bio->end_io)
7840 io_bio->end_io(io_bio, err);
7841 bio_put(bio);
7842 }
7843
7844 static void btrfs_endio_direct_write(struct bio *bio, int err)
7845 {
7846 struct btrfs_dio_private *dip = bio->bi_private;
7847 struct inode *inode = dip->inode;
7848 struct btrfs_root *root = BTRFS_I(inode)->root;
7849 struct btrfs_ordered_extent *ordered = NULL;
7850 u64 ordered_offset = dip->logical_offset;
7851 u64 ordered_bytes = dip->bytes;
7852 struct bio *dio_bio;
7853 int ret;
7854
7855 if (err)
7856 goto out_done;
7857 again:
7858 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7859 &ordered_offset,
7860 ordered_bytes, !err);
7861 if (!ret)
7862 goto out_test;
7863
7864 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
7865 finish_ordered_fn, NULL, NULL);
7866 btrfs_queue_work(root->fs_info->endio_write_workers,
7867 &ordered->work);
7868 out_test:
7869 /*
7870 * our bio might span multiple ordered extents. If we haven't
7871 * completed the accounting for the whole dio, go back and try again
7872 */
7873 if (ordered_offset < dip->logical_offset + dip->bytes) {
7874 ordered_bytes = dip->logical_offset + dip->bytes -
7875 ordered_offset;
7876 ordered = NULL;
7877 goto again;
7878 }
7879 out_done:
7880 dio_bio = dip->dio_bio;
7881
7882 kfree(dip);
7883
7884 /* If we had an error make sure to clear the uptodate flag */
7885 if (err)
7886 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7887 dio_end_io(dio_bio, err);
7888 bio_put(bio);
7889 }
7890
7891 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7892 struct bio *bio, int mirror_num,
7893 unsigned long bio_flags, u64 offset)
7894 {
7895 int ret;
7896 struct btrfs_root *root = BTRFS_I(inode)->root;
7897 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7898 BUG_ON(ret); /* -ENOMEM */
7899 return 0;
7900 }
7901
7902 static void btrfs_end_dio_bio(struct bio *bio, int err)
7903 {
7904 struct btrfs_dio_private *dip = bio->bi_private;
7905
7906 if (err)
7907 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
7908 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7909 btrfs_ino(dip->inode), bio->bi_rw,
7910 (unsigned long long)bio->bi_iter.bi_sector,
7911 bio->bi_iter.bi_size, err);
7912
7913 if (dip->subio_endio)
7914 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
7915
7916 if (err) {
7917 dip->errors = 1;
7918
7919 /*
7920 * before atomic variable goto zero, we must make sure
7921 * dip->errors is perceived to be set.
7922 */
7923 smp_mb__before_atomic();
7924 }
7925
7926 /* if there are more bios still pending for this dio, just exit */
7927 if (!atomic_dec_and_test(&dip->pending_bios))
7928 goto out;
7929
7930 if (dip->errors) {
7931 bio_io_error(dip->orig_bio);
7932 } else {
7933 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
7934 bio_endio(dip->orig_bio, 0);
7935 }
7936 out:
7937 bio_put(bio);
7938 }
7939
7940 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7941 u64 first_sector, gfp_t gfp_flags)
7942 {
7943 int nr_vecs = bio_get_nr_vecs(bdev);
7944 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7945 }
7946
7947 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
7948 struct inode *inode,
7949 struct btrfs_dio_private *dip,
7950 struct bio *bio,
7951 u64 file_offset)
7952 {
7953 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7954 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
7955 int ret;
7956
7957 /*
7958 * We load all the csum data we need when we submit
7959 * the first bio to reduce the csum tree search and
7960 * contention.
7961 */
7962 if (dip->logical_offset == file_offset) {
7963 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
7964 file_offset);
7965 if (ret)
7966 return ret;
7967 }
7968
7969 if (bio == dip->orig_bio)
7970 return 0;
7971
7972 file_offset -= dip->logical_offset;
7973 file_offset >>= inode->i_sb->s_blocksize_bits;
7974 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
7975
7976 return 0;
7977 }
7978
7979 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7980 int rw, u64 file_offset, int skip_sum,
7981 int async_submit)
7982 {
7983 struct btrfs_dio_private *dip = bio->bi_private;
7984 int write = rw & REQ_WRITE;
7985 struct btrfs_root *root = BTRFS_I(inode)->root;
7986 int ret;
7987
7988 if (async_submit)
7989 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7990
7991 bio_get(bio);
7992
7993 if (!write) {
7994 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7995 BTRFS_WQ_ENDIO_DATA);
7996 if (ret)
7997 goto err;
7998 }
7999
8000 if (skip_sum)
8001 goto map;
8002
8003 if (write && async_submit) {
8004 ret = btrfs_wq_submit_bio(root->fs_info,
8005 inode, rw, bio, 0, 0,
8006 file_offset,
8007 __btrfs_submit_bio_start_direct_io,
8008 __btrfs_submit_bio_done);
8009 goto err;
8010 } else if (write) {
8011 /*
8012 * If we aren't doing async submit, calculate the csum of the
8013 * bio now.
8014 */
8015 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8016 if (ret)
8017 goto err;
8018 } else {
8019 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8020 file_offset);
8021 if (ret)
8022 goto err;
8023 }
8024 map:
8025 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8026 err:
8027 bio_put(bio);
8028 return ret;
8029 }
8030
8031 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8032 int skip_sum)
8033 {
8034 struct inode *inode = dip->inode;
8035 struct btrfs_root *root = BTRFS_I(inode)->root;
8036 struct bio *bio;
8037 struct bio *orig_bio = dip->orig_bio;
8038 struct bio_vec *bvec = orig_bio->bi_io_vec;
8039 u64 start_sector = orig_bio->bi_iter.bi_sector;
8040 u64 file_offset = dip->logical_offset;
8041 u64 submit_len = 0;
8042 u64 map_length;
8043 int nr_pages = 0;
8044 int ret;
8045 int async_submit = 0;
8046
8047 map_length = orig_bio->bi_iter.bi_size;
8048 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8049 &map_length, NULL, 0);
8050 if (ret)
8051 return -EIO;
8052
8053 if (map_length >= orig_bio->bi_iter.bi_size) {
8054 bio = orig_bio;
8055 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8056 goto submit;
8057 }
8058
8059 /* async crcs make it difficult to collect full stripe writes. */
8060 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8061 async_submit = 0;
8062 else
8063 async_submit = 1;
8064
8065 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8066 if (!bio)
8067 return -ENOMEM;
8068
8069 bio->bi_private = dip;
8070 bio->bi_end_io = btrfs_end_dio_bio;
8071 btrfs_io_bio(bio)->logical = file_offset;
8072 atomic_inc(&dip->pending_bios);
8073
8074 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8075 if (map_length < submit_len + bvec->bv_len ||
8076 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8077 bvec->bv_offset) < bvec->bv_len) {
8078 /*
8079 * inc the count before we submit the bio so
8080 * we know the end IO handler won't happen before
8081 * we inc the count. Otherwise, the dip might get freed
8082 * before we're done setting it up
8083 */
8084 atomic_inc(&dip->pending_bios);
8085 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8086 file_offset, skip_sum,
8087 async_submit);
8088 if (ret) {
8089 bio_put(bio);
8090 atomic_dec(&dip->pending_bios);
8091 goto out_err;
8092 }
8093
8094 start_sector += submit_len >> 9;
8095 file_offset += submit_len;
8096
8097 submit_len = 0;
8098 nr_pages = 0;
8099
8100 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8101 start_sector, GFP_NOFS);
8102 if (!bio)
8103 goto out_err;
8104 bio->bi_private = dip;
8105 bio->bi_end_io = btrfs_end_dio_bio;
8106 btrfs_io_bio(bio)->logical = file_offset;
8107
8108 map_length = orig_bio->bi_iter.bi_size;
8109 ret = btrfs_map_block(root->fs_info, rw,
8110 start_sector << 9,
8111 &map_length, NULL, 0);
8112 if (ret) {
8113 bio_put(bio);
8114 goto out_err;
8115 }
8116 } else {
8117 submit_len += bvec->bv_len;
8118 nr_pages++;
8119 bvec++;
8120 }
8121 }
8122
8123 submit:
8124 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8125 async_submit);
8126 if (!ret)
8127 return 0;
8128
8129 bio_put(bio);
8130 out_err:
8131 dip->errors = 1;
8132 /*
8133 * before atomic variable goto zero, we must
8134 * make sure dip->errors is perceived to be set.
8135 */
8136 smp_mb__before_atomic();
8137 if (atomic_dec_and_test(&dip->pending_bios))
8138 bio_io_error(dip->orig_bio);
8139
8140 /* bio_end_io() will handle error, so we needn't return it */
8141 return 0;
8142 }
8143
8144 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8145 struct inode *inode, loff_t file_offset)
8146 {
8147 struct btrfs_root *root = BTRFS_I(inode)->root;
8148 struct btrfs_dio_private *dip;
8149 struct bio *io_bio;
8150 struct btrfs_io_bio *btrfs_bio;
8151 int skip_sum;
8152 int write = rw & REQ_WRITE;
8153 int ret = 0;
8154
8155 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8156
8157 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8158 if (!io_bio) {
8159 ret = -ENOMEM;
8160 goto free_ordered;
8161 }
8162
8163 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8164 if (!dip) {
8165 ret = -ENOMEM;
8166 goto free_io_bio;
8167 }
8168
8169 dip->private = dio_bio->bi_private;
8170 dip->inode = inode;
8171 dip->logical_offset = file_offset;
8172 dip->bytes = dio_bio->bi_iter.bi_size;
8173 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8174 io_bio->bi_private = dip;
8175 dip->orig_bio = io_bio;
8176 dip->dio_bio = dio_bio;
8177 atomic_set(&dip->pending_bios, 0);
8178 btrfs_bio = btrfs_io_bio(io_bio);
8179 btrfs_bio->logical = file_offset;
8180
8181 if (write) {
8182 io_bio->bi_end_io = btrfs_endio_direct_write;
8183 } else {
8184 io_bio->bi_end_io = btrfs_endio_direct_read;
8185 dip->subio_endio = btrfs_subio_endio_read;
8186 }
8187
8188 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8189 if (!ret)
8190 return;
8191
8192 if (btrfs_bio->end_io)
8193 btrfs_bio->end_io(btrfs_bio, ret);
8194 free_io_bio:
8195 bio_put(io_bio);
8196
8197 free_ordered:
8198 /*
8199 * If this is a write, we need to clean up the reserved space and kill
8200 * the ordered extent.
8201 */
8202 if (write) {
8203 struct btrfs_ordered_extent *ordered;
8204 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
8205 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
8206 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
8207 btrfs_free_reserved_extent(root, ordered->start,
8208 ordered->disk_len, 1);
8209 btrfs_put_ordered_extent(ordered);
8210 btrfs_put_ordered_extent(ordered);
8211 }
8212 bio_endio(dio_bio, ret);
8213 }
8214
8215 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8216 const struct iov_iter *iter, loff_t offset)
8217 {
8218 int seg;
8219 int i;
8220 unsigned blocksize_mask = root->sectorsize - 1;
8221 ssize_t retval = -EINVAL;
8222
8223 if (offset & blocksize_mask)
8224 goto out;
8225
8226 if (iov_iter_alignment(iter) & blocksize_mask)
8227 goto out;
8228
8229 /* If this is a write we don't need to check anymore */
8230 if (iov_iter_rw(iter) == WRITE)
8231 return 0;
8232 /*
8233 * Check to make sure we don't have duplicate iov_base's in this
8234 * iovec, if so return EINVAL, otherwise we'll get csum errors
8235 * when reading back.
8236 */
8237 for (seg = 0; seg < iter->nr_segs; seg++) {
8238 for (i = seg + 1; i < iter->nr_segs; i++) {
8239 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8240 goto out;
8241 }
8242 }
8243 retval = 0;
8244 out:
8245 return retval;
8246 }
8247
8248 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8249 loff_t offset)
8250 {
8251 struct file *file = iocb->ki_filp;
8252 struct inode *inode = file->f_mapping->host;
8253 u64 outstanding_extents = 0;
8254 size_t count = 0;
8255 int flags = 0;
8256 bool wakeup = true;
8257 bool relock = false;
8258 ssize_t ret;
8259
8260 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8261 return 0;
8262
8263 atomic_inc(&inode->i_dio_count);
8264 smp_mb__after_atomic();
8265
8266 /*
8267 * The generic stuff only does filemap_write_and_wait_range, which
8268 * isn't enough if we've written compressed pages to this area, so
8269 * we need to flush the dirty pages again to make absolutely sure
8270 * that any outstanding dirty pages are on disk.
8271 */
8272 count = iov_iter_count(iter);
8273 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8274 &BTRFS_I(inode)->runtime_flags))
8275 filemap_fdatawrite_range(inode->i_mapping, offset,
8276 offset + count - 1);
8277
8278 if (iov_iter_rw(iter) == WRITE) {
8279 /*
8280 * If the write DIO is beyond the EOF, we need update
8281 * the isize, but it is protected by i_mutex. So we can
8282 * not unlock the i_mutex at this case.
8283 */
8284 if (offset + count <= inode->i_size) {
8285 mutex_unlock(&inode->i_mutex);
8286 relock = true;
8287 }
8288 ret = btrfs_delalloc_reserve_space(inode, count);
8289 if (ret)
8290 goto out;
8291 outstanding_extents = div64_u64(count +
8292 BTRFS_MAX_EXTENT_SIZE - 1,
8293 BTRFS_MAX_EXTENT_SIZE);
8294
8295 /*
8296 * We need to know how many extents we reserved so that we can
8297 * do the accounting properly if we go over the number we
8298 * originally calculated. Abuse current->journal_info for this.
8299 */
8300 current->journal_info = &outstanding_extents;
8301 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8302 &BTRFS_I(inode)->runtime_flags)) {
8303 inode_dio_done(inode);
8304 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8305 wakeup = false;
8306 }
8307
8308 ret = __blockdev_direct_IO(iocb, inode,
8309 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8310 iter, offset, btrfs_get_blocks_direct, NULL,
8311 btrfs_submit_direct, flags);
8312 if (iov_iter_rw(iter) == WRITE) {
8313 current->journal_info = NULL;
8314 if (ret < 0 && ret != -EIOCBQUEUED)
8315 btrfs_delalloc_release_space(inode, count);
8316 else if (ret >= 0 && (size_t)ret < count)
8317 btrfs_delalloc_release_space(inode,
8318 count - (size_t)ret);
8319 }
8320 out:
8321 if (wakeup)
8322 inode_dio_done(inode);
8323 if (relock)
8324 mutex_lock(&inode->i_mutex);
8325
8326 return ret;
8327 }
8328
8329 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8330
8331 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8332 __u64 start, __u64 len)
8333 {
8334 int ret;
8335
8336 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8337 if (ret)
8338 return ret;
8339
8340 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8341 }
8342
8343 int btrfs_readpage(struct file *file, struct page *page)
8344 {
8345 struct extent_io_tree *tree;
8346 tree = &BTRFS_I(page->mapping->host)->io_tree;
8347 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8348 }
8349
8350 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8351 {
8352 struct extent_io_tree *tree;
8353
8354
8355 if (current->flags & PF_MEMALLOC) {
8356 redirty_page_for_writepage(wbc, page);
8357 unlock_page(page);
8358 return 0;
8359 }
8360 tree = &BTRFS_I(page->mapping->host)->io_tree;
8361 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8362 }
8363
8364 static int btrfs_writepages(struct address_space *mapping,
8365 struct writeback_control *wbc)
8366 {
8367 struct extent_io_tree *tree;
8368
8369 tree = &BTRFS_I(mapping->host)->io_tree;
8370 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8371 }
8372
8373 static int
8374 btrfs_readpages(struct file *file, struct address_space *mapping,
8375 struct list_head *pages, unsigned nr_pages)
8376 {
8377 struct extent_io_tree *tree;
8378 tree = &BTRFS_I(mapping->host)->io_tree;
8379 return extent_readpages(tree, mapping, pages, nr_pages,
8380 btrfs_get_extent);
8381 }
8382 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8383 {
8384 struct extent_io_tree *tree;
8385 struct extent_map_tree *map;
8386 int ret;
8387
8388 tree = &BTRFS_I(page->mapping->host)->io_tree;
8389 map = &BTRFS_I(page->mapping->host)->extent_tree;
8390 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8391 if (ret == 1) {
8392 ClearPagePrivate(page);
8393 set_page_private(page, 0);
8394 page_cache_release(page);
8395 }
8396 return ret;
8397 }
8398
8399 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8400 {
8401 if (PageWriteback(page) || PageDirty(page))
8402 return 0;
8403 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8404 }
8405
8406 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8407 unsigned int length)
8408 {
8409 struct inode *inode = page->mapping->host;
8410 struct extent_io_tree *tree;
8411 struct btrfs_ordered_extent *ordered;
8412 struct extent_state *cached_state = NULL;
8413 u64 page_start = page_offset(page);
8414 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8415 int inode_evicting = inode->i_state & I_FREEING;
8416
8417 /*
8418 * we have the page locked, so new writeback can't start,
8419 * and the dirty bit won't be cleared while we are here.
8420 *
8421 * Wait for IO on this page so that we can safely clear
8422 * the PagePrivate2 bit and do ordered accounting
8423 */
8424 wait_on_page_writeback(page);
8425
8426 tree = &BTRFS_I(inode)->io_tree;
8427 if (offset) {
8428 btrfs_releasepage(page, GFP_NOFS);
8429 return;
8430 }
8431
8432 if (!inode_evicting)
8433 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
8434 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8435 if (ordered) {
8436 /*
8437 * IO on this page will never be started, so we need
8438 * to account for any ordered extents now
8439 */
8440 if (!inode_evicting)
8441 clear_extent_bit(tree, page_start, page_end,
8442 EXTENT_DIRTY | EXTENT_DELALLOC |
8443 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8444 EXTENT_DEFRAG, 1, 0, &cached_state,
8445 GFP_NOFS);
8446 /*
8447 * whoever cleared the private bit is responsible
8448 * for the finish_ordered_io
8449 */
8450 if (TestClearPagePrivate2(page)) {
8451 struct btrfs_ordered_inode_tree *tree;
8452 u64 new_len;
8453
8454 tree = &BTRFS_I(inode)->ordered_tree;
8455
8456 spin_lock_irq(&tree->lock);
8457 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8458 new_len = page_start - ordered->file_offset;
8459 if (new_len < ordered->truncated_len)
8460 ordered->truncated_len = new_len;
8461 spin_unlock_irq(&tree->lock);
8462
8463 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8464 page_start,
8465 PAGE_CACHE_SIZE, 1))
8466 btrfs_finish_ordered_io(ordered);
8467 }
8468 btrfs_put_ordered_extent(ordered);
8469 if (!inode_evicting) {
8470 cached_state = NULL;
8471 lock_extent_bits(tree, page_start, page_end, 0,
8472 &cached_state);
8473 }
8474 }
8475
8476 if (!inode_evicting) {
8477 clear_extent_bit(tree, page_start, page_end,
8478 EXTENT_LOCKED | EXTENT_DIRTY |
8479 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8480 EXTENT_DEFRAG, 1, 1,
8481 &cached_state, GFP_NOFS);
8482
8483 __btrfs_releasepage(page, GFP_NOFS);
8484 }
8485
8486 ClearPageChecked(page);
8487 if (PagePrivate(page)) {
8488 ClearPagePrivate(page);
8489 set_page_private(page, 0);
8490 page_cache_release(page);
8491 }
8492 }
8493
8494 /*
8495 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8496 * called from a page fault handler when a page is first dirtied. Hence we must
8497 * be careful to check for EOF conditions here. We set the page up correctly
8498 * for a written page which means we get ENOSPC checking when writing into
8499 * holes and correct delalloc and unwritten extent mapping on filesystems that
8500 * support these features.
8501 *
8502 * We are not allowed to take the i_mutex here so we have to play games to
8503 * protect against truncate races as the page could now be beyond EOF. Because
8504 * vmtruncate() writes the inode size before removing pages, once we have the
8505 * page lock we can determine safely if the page is beyond EOF. If it is not
8506 * beyond EOF, then the page is guaranteed safe against truncation until we
8507 * unlock the page.
8508 */
8509 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8510 {
8511 struct page *page = vmf->page;
8512 struct inode *inode = file_inode(vma->vm_file);
8513 struct btrfs_root *root = BTRFS_I(inode)->root;
8514 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8515 struct btrfs_ordered_extent *ordered;
8516 struct extent_state *cached_state = NULL;
8517 char *kaddr;
8518 unsigned long zero_start;
8519 loff_t size;
8520 int ret;
8521 int reserved = 0;
8522 u64 page_start;
8523 u64 page_end;
8524
8525 sb_start_pagefault(inode->i_sb);
8526 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
8527 if (!ret) {
8528 ret = file_update_time(vma->vm_file);
8529 reserved = 1;
8530 }
8531 if (ret) {
8532 if (ret == -ENOMEM)
8533 ret = VM_FAULT_OOM;
8534 else /* -ENOSPC, -EIO, etc */
8535 ret = VM_FAULT_SIGBUS;
8536 if (reserved)
8537 goto out;
8538 goto out_noreserve;
8539 }
8540
8541 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8542 again:
8543 lock_page(page);
8544 size = i_size_read(inode);
8545 page_start = page_offset(page);
8546 page_end = page_start + PAGE_CACHE_SIZE - 1;
8547
8548 if ((page->mapping != inode->i_mapping) ||
8549 (page_start >= size)) {
8550 /* page got truncated out from underneath us */
8551 goto out_unlock;
8552 }
8553 wait_on_page_writeback(page);
8554
8555 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
8556 set_page_extent_mapped(page);
8557
8558 /*
8559 * we can't set the delalloc bits if there are pending ordered
8560 * extents. Drop our locks and wait for them to finish
8561 */
8562 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8563 if (ordered) {
8564 unlock_extent_cached(io_tree, page_start, page_end,
8565 &cached_state, GFP_NOFS);
8566 unlock_page(page);
8567 btrfs_start_ordered_extent(inode, ordered, 1);
8568 btrfs_put_ordered_extent(ordered);
8569 goto again;
8570 }
8571
8572 /*
8573 * XXX - page_mkwrite gets called every time the page is dirtied, even
8574 * if it was already dirty, so for space accounting reasons we need to
8575 * clear any delalloc bits for the range we are fixing to save. There
8576 * is probably a better way to do this, but for now keep consistent with
8577 * prepare_pages in the normal write path.
8578 */
8579 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8580 EXTENT_DIRTY | EXTENT_DELALLOC |
8581 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8582 0, 0, &cached_state, GFP_NOFS);
8583
8584 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8585 &cached_state);
8586 if (ret) {
8587 unlock_extent_cached(io_tree, page_start, page_end,
8588 &cached_state, GFP_NOFS);
8589 ret = VM_FAULT_SIGBUS;
8590 goto out_unlock;
8591 }
8592 ret = 0;
8593
8594 /* page is wholly or partially inside EOF */
8595 if (page_start + PAGE_CACHE_SIZE > size)
8596 zero_start = size & ~PAGE_CACHE_MASK;
8597 else
8598 zero_start = PAGE_CACHE_SIZE;
8599
8600 if (zero_start != PAGE_CACHE_SIZE) {
8601 kaddr = kmap(page);
8602 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8603 flush_dcache_page(page);
8604 kunmap(page);
8605 }
8606 ClearPageChecked(page);
8607 set_page_dirty(page);
8608 SetPageUptodate(page);
8609
8610 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8611 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8612 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8613
8614 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8615
8616 out_unlock:
8617 if (!ret) {
8618 sb_end_pagefault(inode->i_sb);
8619 return VM_FAULT_LOCKED;
8620 }
8621 unlock_page(page);
8622 out:
8623 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
8624 out_noreserve:
8625 sb_end_pagefault(inode->i_sb);
8626 return ret;
8627 }
8628
8629 static int btrfs_truncate(struct inode *inode)
8630 {
8631 struct btrfs_root *root = BTRFS_I(inode)->root;
8632 struct btrfs_block_rsv *rsv;
8633 int ret = 0;
8634 int err = 0;
8635 struct btrfs_trans_handle *trans;
8636 u64 mask = root->sectorsize - 1;
8637 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8638
8639 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8640 (u64)-1);
8641 if (ret)
8642 return ret;
8643
8644 /*
8645 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8646 * 3 things going on here
8647 *
8648 * 1) We need to reserve space for our orphan item and the space to
8649 * delete our orphan item. Lord knows we don't want to have a dangling
8650 * orphan item because we didn't reserve space to remove it.
8651 *
8652 * 2) We need to reserve space to update our inode.
8653 *
8654 * 3) We need to have something to cache all the space that is going to
8655 * be free'd up by the truncate operation, but also have some slack
8656 * space reserved in case it uses space during the truncate (thank you
8657 * very much snapshotting).
8658 *
8659 * And we need these to all be seperate. The fact is we can use alot of
8660 * space doing the truncate, and we have no earthly idea how much space
8661 * we will use, so we need the truncate reservation to be seperate so it
8662 * doesn't end up using space reserved for updating the inode or
8663 * removing the orphan item. We also need to be able to stop the
8664 * transaction and start a new one, which means we need to be able to
8665 * update the inode several times, and we have no idea of knowing how
8666 * many times that will be, so we can't just reserve 1 item for the
8667 * entirety of the opration, so that has to be done seperately as well.
8668 * Then there is the orphan item, which does indeed need to be held on
8669 * to for the whole operation, and we need nobody to touch this reserved
8670 * space except the orphan code.
8671 *
8672 * So that leaves us with
8673 *
8674 * 1) root->orphan_block_rsv - for the orphan deletion.
8675 * 2) rsv - for the truncate reservation, which we will steal from the
8676 * transaction reservation.
8677 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8678 * updating the inode.
8679 */
8680 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8681 if (!rsv)
8682 return -ENOMEM;
8683 rsv->size = min_size;
8684 rsv->failfast = 1;
8685
8686 /*
8687 * 1 for the truncate slack space
8688 * 1 for updating the inode.
8689 */
8690 trans = btrfs_start_transaction(root, 2);
8691 if (IS_ERR(trans)) {
8692 err = PTR_ERR(trans);
8693 goto out;
8694 }
8695
8696 /* Migrate the slack space for the truncate to our reserve */
8697 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8698 min_size);
8699 BUG_ON(ret);
8700
8701 /*
8702 * So if we truncate and then write and fsync we normally would just
8703 * write the extents that changed, which is a problem if we need to
8704 * first truncate that entire inode. So set this flag so we write out
8705 * all of the extents in the inode to the sync log so we're completely
8706 * safe.
8707 */
8708 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8709 trans->block_rsv = rsv;
8710
8711 while (1) {
8712 ret = btrfs_truncate_inode_items(trans, root, inode,
8713 inode->i_size,
8714 BTRFS_EXTENT_DATA_KEY);
8715 if (ret != -ENOSPC && ret != -EAGAIN) {
8716 err = ret;
8717 break;
8718 }
8719
8720 trans->block_rsv = &root->fs_info->trans_block_rsv;
8721 ret = btrfs_update_inode(trans, root, inode);
8722 if (ret) {
8723 err = ret;
8724 break;
8725 }
8726
8727 btrfs_end_transaction(trans, root);
8728 btrfs_btree_balance_dirty(root);
8729
8730 trans = btrfs_start_transaction(root, 2);
8731 if (IS_ERR(trans)) {
8732 ret = err = PTR_ERR(trans);
8733 trans = NULL;
8734 break;
8735 }
8736
8737 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8738 rsv, min_size);
8739 BUG_ON(ret); /* shouldn't happen */
8740 trans->block_rsv = rsv;
8741 }
8742
8743 if (ret == 0 && inode->i_nlink > 0) {
8744 trans->block_rsv = root->orphan_block_rsv;
8745 ret = btrfs_orphan_del(trans, inode);
8746 if (ret)
8747 err = ret;
8748 }
8749
8750 if (trans) {
8751 trans->block_rsv = &root->fs_info->trans_block_rsv;
8752 ret = btrfs_update_inode(trans, root, inode);
8753 if (ret && !err)
8754 err = ret;
8755
8756 ret = btrfs_end_transaction(trans, root);
8757 btrfs_btree_balance_dirty(root);
8758 }
8759
8760 out:
8761 btrfs_free_block_rsv(root, rsv);
8762
8763 if (ret && !err)
8764 err = ret;
8765
8766 return err;
8767 }
8768
8769 /*
8770 * create a new subvolume directory/inode (helper for the ioctl).
8771 */
8772 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
8773 struct btrfs_root *new_root,
8774 struct btrfs_root *parent_root,
8775 u64 new_dirid)
8776 {
8777 struct inode *inode;
8778 int err;
8779 u64 index = 0;
8780
8781 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
8782 new_dirid, new_dirid,
8783 S_IFDIR | (~current_umask() & S_IRWXUGO),
8784 &index);
8785 if (IS_ERR(inode))
8786 return PTR_ERR(inode);
8787 inode->i_op = &btrfs_dir_inode_operations;
8788 inode->i_fop = &btrfs_dir_file_operations;
8789
8790 set_nlink(inode, 1);
8791 btrfs_i_size_write(inode, 0);
8792 unlock_new_inode(inode);
8793
8794 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
8795 if (err)
8796 btrfs_err(new_root->fs_info,
8797 "error inheriting subvolume %llu properties: %d",
8798 new_root->root_key.objectid, err);
8799
8800 err = btrfs_update_inode(trans, new_root, inode);
8801
8802 iput(inode);
8803 return err;
8804 }
8805
8806 struct inode *btrfs_alloc_inode(struct super_block *sb)
8807 {
8808 struct btrfs_inode *ei;
8809 struct inode *inode;
8810
8811 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
8812 if (!ei)
8813 return NULL;
8814
8815 ei->root = NULL;
8816 ei->generation = 0;
8817 ei->last_trans = 0;
8818 ei->last_sub_trans = 0;
8819 ei->logged_trans = 0;
8820 ei->delalloc_bytes = 0;
8821 ei->defrag_bytes = 0;
8822 ei->disk_i_size = 0;
8823 ei->flags = 0;
8824 ei->csum_bytes = 0;
8825 ei->index_cnt = (u64)-1;
8826 ei->dir_index = 0;
8827 ei->last_unlink_trans = 0;
8828 ei->last_log_commit = 0;
8829
8830 spin_lock_init(&ei->lock);
8831 ei->outstanding_extents = 0;
8832 ei->reserved_extents = 0;
8833
8834 ei->runtime_flags = 0;
8835 ei->force_compress = BTRFS_COMPRESS_NONE;
8836
8837 ei->delayed_node = NULL;
8838
8839 ei->i_otime.tv_sec = 0;
8840 ei->i_otime.tv_nsec = 0;
8841
8842 inode = &ei->vfs_inode;
8843 extent_map_tree_init(&ei->extent_tree);
8844 extent_io_tree_init(&ei->io_tree, &inode->i_data);
8845 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
8846 ei->io_tree.track_uptodate = 1;
8847 ei->io_failure_tree.track_uptodate = 1;
8848 atomic_set(&ei->sync_writers, 0);
8849 mutex_init(&ei->log_mutex);
8850 mutex_init(&ei->delalloc_mutex);
8851 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8852 INIT_LIST_HEAD(&ei->delalloc_inodes);
8853 RB_CLEAR_NODE(&ei->rb_node);
8854
8855 return inode;
8856 }
8857
8858 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8859 void btrfs_test_destroy_inode(struct inode *inode)
8860 {
8861 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8862 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8863 }
8864 #endif
8865
8866 static void btrfs_i_callback(struct rcu_head *head)
8867 {
8868 struct inode *inode = container_of(head, struct inode, i_rcu);
8869 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8870 }
8871
8872 void btrfs_destroy_inode(struct inode *inode)
8873 {
8874 struct btrfs_ordered_extent *ordered;
8875 struct btrfs_root *root = BTRFS_I(inode)->root;
8876
8877 WARN_ON(!hlist_empty(&inode->i_dentry));
8878 WARN_ON(inode->i_data.nrpages);
8879 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8880 WARN_ON(BTRFS_I(inode)->reserved_extents);
8881 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8882 WARN_ON(BTRFS_I(inode)->csum_bytes);
8883 WARN_ON(BTRFS_I(inode)->defrag_bytes);
8884
8885 /*
8886 * This can happen where we create an inode, but somebody else also
8887 * created the same inode and we need to destroy the one we already
8888 * created.
8889 */
8890 if (!root)
8891 goto free;
8892
8893 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8894 &BTRFS_I(inode)->runtime_flags)) {
8895 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8896 btrfs_ino(inode));
8897 atomic_dec(&root->orphan_inodes);
8898 }
8899
8900 while (1) {
8901 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8902 if (!ordered)
8903 break;
8904 else {
8905 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8906 ordered->file_offset, ordered->len);
8907 btrfs_remove_ordered_extent(inode, ordered);
8908 btrfs_put_ordered_extent(ordered);
8909 btrfs_put_ordered_extent(ordered);
8910 }
8911 }
8912 inode_tree_del(inode);
8913 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8914 free:
8915 call_rcu(&inode->i_rcu, btrfs_i_callback);
8916 }
8917
8918 int btrfs_drop_inode(struct inode *inode)
8919 {
8920 struct btrfs_root *root = BTRFS_I(inode)->root;
8921
8922 if (root == NULL)
8923 return 1;
8924
8925 /* the snap/subvol tree is on deleting */
8926 if (btrfs_root_refs(&root->root_item) == 0)
8927 return 1;
8928 else
8929 return generic_drop_inode(inode);
8930 }
8931
8932 static void init_once(void *foo)
8933 {
8934 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8935
8936 inode_init_once(&ei->vfs_inode);
8937 }
8938
8939 void btrfs_destroy_cachep(void)
8940 {
8941 /*
8942 * Make sure all delayed rcu free inodes are flushed before we
8943 * destroy cache.
8944 */
8945 rcu_barrier();
8946 if (btrfs_inode_cachep)
8947 kmem_cache_destroy(btrfs_inode_cachep);
8948 if (btrfs_trans_handle_cachep)
8949 kmem_cache_destroy(btrfs_trans_handle_cachep);
8950 if (btrfs_transaction_cachep)
8951 kmem_cache_destroy(btrfs_transaction_cachep);
8952 if (btrfs_path_cachep)
8953 kmem_cache_destroy(btrfs_path_cachep);
8954 if (btrfs_free_space_cachep)
8955 kmem_cache_destroy(btrfs_free_space_cachep);
8956 if (btrfs_delalloc_work_cachep)
8957 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8958 }
8959
8960 int btrfs_init_cachep(void)
8961 {
8962 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8963 sizeof(struct btrfs_inode), 0,
8964 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8965 if (!btrfs_inode_cachep)
8966 goto fail;
8967
8968 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8969 sizeof(struct btrfs_trans_handle), 0,
8970 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8971 if (!btrfs_trans_handle_cachep)
8972 goto fail;
8973
8974 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8975 sizeof(struct btrfs_transaction), 0,
8976 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8977 if (!btrfs_transaction_cachep)
8978 goto fail;
8979
8980 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8981 sizeof(struct btrfs_path), 0,
8982 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8983 if (!btrfs_path_cachep)
8984 goto fail;
8985
8986 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8987 sizeof(struct btrfs_free_space), 0,
8988 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8989 if (!btrfs_free_space_cachep)
8990 goto fail;
8991
8992 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8993 sizeof(struct btrfs_delalloc_work), 0,
8994 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8995 NULL);
8996 if (!btrfs_delalloc_work_cachep)
8997 goto fail;
8998
8999 return 0;
9000 fail:
9001 btrfs_destroy_cachep();
9002 return -ENOMEM;
9003 }
9004
9005 static int btrfs_getattr(struct vfsmount *mnt,
9006 struct dentry *dentry, struct kstat *stat)
9007 {
9008 u64 delalloc_bytes;
9009 struct inode *inode = dentry->d_inode;
9010 u32 blocksize = inode->i_sb->s_blocksize;
9011
9012 generic_fillattr(inode, stat);
9013 stat->dev = BTRFS_I(inode)->root->anon_dev;
9014 stat->blksize = PAGE_CACHE_SIZE;
9015
9016 spin_lock(&BTRFS_I(inode)->lock);
9017 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9018 spin_unlock(&BTRFS_I(inode)->lock);
9019 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9020 ALIGN(delalloc_bytes, blocksize)) >> 9;
9021 return 0;
9022 }
9023
9024 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9025 struct inode *new_dir, struct dentry *new_dentry)
9026 {
9027 struct btrfs_trans_handle *trans;
9028 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9029 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9030 struct inode *new_inode = new_dentry->d_inode;
9031 struct inode *old_inode = old_dentry->d_inode;
9032 struct timespec ctime = CURRENT_TIME;
9033 u64 index = 0;
9034 u64 root_objectid;
9035 int ret;
9036 u64 old_ino = btrfs_ino(old_inode);
9037
9038 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9039 return -EPERM;
9040
9041 /* we only allow rename subvolume link between subvolumes */
9042 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9043 return -EXDEV;
9044
9045 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9046 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9047 return -ENOTEMPTY;
9048
9049 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9050 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9051 return -ENOTEMPTY;
9052
9053
9054 /* check for collisions, even if the name isn't there */
9055 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9056 new_dentry->d_name.name,
9057 new_dentry->d_name.len);
9058
9059 if (ret) {
9060 if (ret == -EEXIST) {
9061 /* we shouldn't get
9062 * eexist without a new_inode */
9063 if (WARN_ON(!new_inode)) {
9064 return ret;
9065 }
9066 } else {
9067 /* maybe -EOVERFLOW */
9068 return ret;
9069 }
9070 }
9071 ret = 0;
9072
9073 /*
9074 * we're using rename to replace one file with another. Start IO on it
9075 * now so we don't add too much work to the end of the transaction
9076 */
9077 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9078 filemap_flush(old_inode->i_mapping);
9079
9080 /* close the racy window with snapshot create/destroy ioctl */
9081 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9082 down_read(&root->fs_info->subvol_sem);
9083 /*
9084 * We want to reserve the absolute worst case amount of items. So if
9085 * both inodes are subvols and we need to unlink them then that would
9086 * require 4 item modifications, but if they are both normal inodes it
9087 * would require 5 item modifications, so we'll assume their normal
9088 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9089 * should cover the worst case number of items we'll modify.
9090 */
9091 trans = btrfs_start_transaction(root, 11);
9092 if (IS_ERR(trans)) {
9093 ret = PTR_ERR(trans);
9094 goto out_notrans;
9095 }
9096
9097 if (dest != root)
9098 btrfs_record_root_in_trans(trans, dest);
9099
9100 ret = btrfs_set_inode_index(new_dir, &index);
9101 if (ret)
9102 goto out_fail;
9103
9104 BTRFS_I(old_inode)->dir_index = 0ULL;
9105 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9106 /* force full log commit if subvolume involved. */
9107 btrfs_set_log_full_commit(root->fs_info, trans);
9108 } else {
9109 ret = btrfs_insert_inode_ref(trans, dest,
9110 new_dentry->d_name.name,
9111 new_dentry->d_name.len,
9112 old_ino,
9113 btrfs_ino(new_dir), index);
9114 if (ret)
9115 goto out_fail;
9116 /*
9117 * this is an ugly little race, but the rename is required
9118 * to make sure that if we crash, the inode is either at the
9119 * old name or the new one. pinning the log transaction lets
9120 * us make sure we don't allow a log commit to come in after
9121 * we unlink the name but before we add the new name back in.
9122 */
9123 btrfs_pin_log_trans(root);
9124 }
9125
9126 inode_inc_iversion(old_dir);
9127 inode_inc_iversion(new_dir);
9128 inode_inc_iversion(old_inode);
9129 old_dir->i_ctime = old_dir->i_mtime = ctime;
9130 new_dir->i_ctime = new_dir->i_mtime = ctime;
9131 old_inode->i_ctime = ctime;
9132
9133 if (old_dentry->d_parent != new_dentry->d_parent)
9134 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9135
9136 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9137 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9138 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9139 old_dentry->d_name.name,
9140 old_dentry->d_name.len);
9141 } else {
9142 ret = __btrfs_unlink_inode(trans, root, old_dir,
9143 old_dentry->d_inode,
9144 old_dentry->d_name.name,
9145 old_dentry->d_name.len);
9146 if (!ret)
9147 ret = btrfs_update_inode(trans, root, old_inode);
9148 }
9149 if (ret) {
9150 btrfs_abort_transaction(trans, root, ret);
9151 goto out_fail;
9152 }
9153
9154 if (new_inode) {
9155 inode_inc_iversion(new_inode);
9156 new_inode->i_ctime = CURRENT_TIME;
9157 if (unlikely(btrfs_ino(new_inode) ==
9158 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9159 root_objectid = BTRFS_I(new_inode)->location.objectid;
9160 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9161 root_objectid,
9162 new_dentry->d_name.name,
9163 new_dentry->d_name.len);
9164 BUG_ON(new_inode->i_nlink == 0);
9165 } else {
9166 ret = btrfs_unlink_inode(trans, dest, new_dir,
9167 new_dentry->d_inode,
9168 new_dentry->d_name.name,
9169 new_dentry->d_name.len);
9170 }
9171 if (!ret && new_inode->i_nlink == 0)
9172 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
9173 if (ret) {
9174 btrfs_abort_transaction(trans, root, ret);
9175 goto out_fail;
9176 }
9177 }
9178
9179 ret = btrfs_add_link(trans, new_dir, old_inode,
9180 new_dentry->d_name.name,
9181 new_dentry->d_name.len, 0, index);
9182 if (ret) {
9183 btrfs_abort_transaction(trans, root, ret);
9184 goto out_fail;
9185 }
9186
9187 if (old_inode->i_nlink == 1)
9188 BTRFS_I(old_inode)->dir_index = index;
9189
9190 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9191 struct dentry *parent = new_dentry->d_parent;
9192 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9193 btrfs_end_log_trans(root);
9194 }
9195 out_fail:
9196 btrfs_end_transaction(trans, root);
9197 out_notrans:
9198 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9199 up_read(&root->fs_info->subvol_sem);
9200
9201 return ret;
9202 }
9203
9204 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9205 struct inode *new_dir, struct dentry *new_dentry,
9206 unsigned int flags)
9207 {
9208 if (flags & ~RENAME_NOREPLACE)
9209 return -EINVAL;
9210
9211 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9212 }
9213
9214 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9215 {
9216 struct btrfs_delalloc_work *delalloc_work;
9217 struct inode *inode;
9218
9219 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9220 work);
9221 inode = delalloc_work->inode;
9222 if (delalloc_work->wait) {
9223 btrfs_wait_ordered_range(inode, 0, (u64)-1);
9224 } else {
9225 filemap_flush(inode->i_mapping);
9226 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9227 &BTRFS_I(inode)->runtime_flags))
9228 filemap_flush(inode->i_mapping);
9229 }
9230
9231 if (delalloc_work->delay_iput)
9232 btrfs_add_delayed_iput(inode);
9233 else
9234 iput(inode);
9235 complete(&delalloc_work->completion);
9236 }
9237
9238 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9239 int wait, int delay_iput)
9240 {
9241 struct btrfs_delalloc_work *work;
9242
9243 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
9244 if (!work)
9245 return NULL;
9246
9247 init_completion(&work->completion);
9248 INIT_LIST_HEAD(&work->list);
9249 work->inode = inode;
9250 work->wait = wait;
9251 work->delay_iput = delay_iput;
9252 WARN_ON_ONCE(!inode);
9253 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9254 btrfs_run_delalloc_work, NULL, NULL);
9255
9256 return work;
9257 }
9258
9259 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9260 {
9261 wait_for_completion(&work->completion);
9262 kmem_cache_free(btrfs_delalloc_work_cachep, work);
9263 }
9264
9265 /*
9266 * some fairly slow code that needs optimization. This walks the list
9267 * of all the inodes with pending delalloc and forces them to disk.
9268 */
9269 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9270 int nr)
9271 {
9272 struct btrfs_inode *binode;
9273 struct inode *inode;
9274 struct btrfs_delalloc_work *work, *next;
9275 struct list_head works;
9276 struct list_head splice;
9277 int ret = 0;
9278
9279 INIT_LIST_HEAD(&works);
9280 INIT_LIST_HEAD(&splice);
9281
9282 mutex_lock(&root->delalloc_mutex);
9283 spin_lock(&root->delalloc_lock);
9284 list_splice_init(&root->delalloc_inodes, &splice);
9285 while (!list_empty(&splice)) {
9286 binode = list_entry(splice.next, struct btrfs_inode,
9287 delalloc_inodes);
9288
9289 list_move_tail(&binode->delalloc_inodes,
9290 &root->delalloc_inodes);
9291 inode = igrab(&binode->vfs_inode);
9292 if (!inode) {
9293 cond_resched_lock(&root->delalloc_lock);
9294 continue;
9295 }
9296 spin_unlock(&root->delalloc_lock);
9297
9298 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
9299 if (!work) {
9300 if (delay_iput)
9301 btrfs_add_delayed_iput(inode);
9302 else
9303 iput(inode);
9304 ret = -ENOMEM;
9305 goto out;
9306 }
9307 list_add_tail(&work->list, &works);
9308 btrfs_queue_work(root->fs_info->flush_workers,
9309 &work->work);
9310 ret++;
9311 if (nr != -1 && ret >= nr)
9312 goto out;
9313 cond_resched();
9314 spin_lock(&root->delalloc_lock);
9315 }
9316 spin_unlock(&root->delalloc_lock);
9317
9318 out:
9319 list_for_each_entry_safe(work, next, &works, list) {
9320 list_del_init(&work->list);
9321 btrfs_wait_and_free_delalloc_work(work);
9322 }
9323
9324 if (!list_empty_careful(&splice)) {
9325 spin_lock(&root->delalloc_lock);
9326 list_splice_tail(&splice, &root->delalloc_inodes);
9327 spin_unlock(&root->delalloc_lock);
9328 }
9329 mutex_unlock(&root->delalloc_mutex);
9330 return ret;
9331 }
9332
9333 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9334 {
9335 int ret;
9336
9337 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9338 return -EROFS;
9339
9340 ret = __start_delalloc_inodes(root, delay_iput, -1);
9341 if (ret > 0)
9342 ret = 0;
9343 /*
9344 * the filemap_flush will queue IO into the worker threads, but
9345 * we have to make sure the IO is actually started and that
9346 * ordered extents get created before we return
9347 */
9348 atomic_inc(&root->fs_info->async_submit_draining);
9349 while (atomic_read(&root->fs_info->nr_async_submits) ||
9350 atomic_read(&root->fs_info->async_delalloc_pages)) {
9351 wait_event(root->fs_info->async_submit_wait,
9352 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9353 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9354 }
9355 atomic_dec(&root->fs_info->async_submit_draining);
9356 return ret;
9357 }
9358
9359 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9360 int nr)
9361 {
9362 struct btrfs_root *root;
9363 struct list_head splice;
9364 int ret;
9365
9366 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9367 return -EROFS;
9368
9369 INIT_LIST_HEAD(&splice);
9370
9371 mutex_lock(&fs_info->delalloc_root_mutex);
9372 spin_lock(&fs_info->delalloc_root_lock);
9373 list_splice_init(&fs_info->delalloc_roots, &splice);
9374 while (!list_empty(&splice) && nr) {
9375 root = list_first_entry(&splice, struct btrfs_root,
9376 delalloc_root);
9377 root = btrfs_grab_fs_root(root);
9378 BUG_ON(!root);
9379 list_move_tail(&root->delalloc_root,
9380 &fs_info->delalloc_roots);
9381 spin_unlock(&fs_info->delalloc_root_lock);
9382
9383 ret = __start_delalloc_inodes(root, delay_iput, nr);
9384 btrfs_put_fs_root(root);
9385 if (ret < 0)
9386 goto out;
9387
9388 if (nr != -1) {
9389 nr -= ret;
9390 WARN_ON(nr < 0);
9391 }
9392 spin_lock(&fs_info->delalloc_root_lock);
9393 }
9394 spin_unlock(&fs_info->delalloc_root_lock);
9395
9396 ret = 0;
9397 atomic_inc(&fs_info->async_submit_draining);
9398 while (atomic_read(&fs_info->nr_async_submits) ||
9399 atomic_read(&fs_info->async_delalloc_pages)) {
9400 wait_event(fs_info->async_submit_wait,
9401 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9402 atomic_read(&fs_info->async_delalloc_pages) == 0));
9403 }
9404 atomic_dec(&fs_info->async_submit_draining);
9405 out:
9406 if (!list_empty_careful(&splice)) {
9407 spin_lock(&fs_info->delalloc_root_lock);
9408 list_splice_tail(&splice, &fs_info->delalloc_roots);
9409 spin_unlock(&fs_info->delalloc_root_lock);
9410 }
9411 mutex_unlock(&fs_info->delalloc_root_mutex);
9412 return ret;
9413 }
9414
9415 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9416 const char *symname)
9417 {
9418 struct btrfs_trans_handle *trans;
9419 struct btrfs_root *root = BTRFS_I(dir)->root;
9420 struct btrfs_path *path;
9421 struct btrfs_key key;
9422 struct inode *inode = NULL;
9423 int err;
9424 int drop_inode = 0;
9425 u64 objectid;
9426 u64 index = 0;
9427 int name_len;
9428 int datasize;
9429 unsigned long ptr;
9430 struct btrfs_file_extent_item *ei;
9431 struct extent_buffer *leaf;
9432
9433 name_len = strlen(symname);
9434 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9435 return -ENAMETOOLONG;
9436
9437 /*
9438 * 2 items for inode item and ref
9439 * 2 items for dir items
9440 * 1 item for xattr if selinux is on
9441 */
9442 trans = btrfs_start_transaction(root, 5);
9443 if (IS_ERR(trans))
9444 return PTR_ERR(trans);
9445
9446 err = btrfs_find_free_ino(root, &objectid);
9447 if (err)
9448 goto out_unlock;
9449
9450 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9451 dentry->d_name.len, btrfs_ino(dir), objectid,
9452 S_IFLNK|S_IRWXUGO, &index);
9453 if (IS_ERR(inode)) {
9454 err = PTR_ERR(inode);
9455 goto out_unlock;
9456 }
9457
9458 /*
9459 * If the active LSM wants to access the inode during
9460 * d_instantiate it needs these. Smack checks to see
9461 * if the filesystem supports xattrs by looking at the
9462 * ops vector.
9463 */
9464 inode->i_fop = &btrfs_file_operations;
9465 inode->i_op = &btrfs_file_inode_operations;
9466 inode->i_mapping->a_ops = &btrfs_aops;
9467 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9468
9469 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9470 if (err)
9471 goto out_unlock_inode;
9472
9473 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9474 if (err)
9475 goto out_unlock_inode;
9476
9477 path = btrfs_alloc_path();
9478 if (!path) {
9479 err = -ENOMEM;
9480 goto out_unlock_inode;
9481 }
9482 key.objectid = btrfs_ino(inode);
9483 key.offset = 0;
9484 key.type = BTRFS_EXTENT_DATA_KEY;
9485 datasize = btrfs_file_extent_calc_inline_size(name_len);
9486 err = btrfs_insert_empty_item(trans, root, path, &key,
9487 datasize);
9488 if (err) {
9489 btrfs_free_path(path);
9490 goto out_unlock_inode;
9491 }
9492 leaf = path->nodes[0];
9493 ei = btrfs_item_ptr(leaf, path->slots[0],
9494 struct btrfs_file_extent_item);
9495 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9496 btrfs_set_file_extent_type(leaf, ei,
9497 BTRFS_FILE_EXTENT_INLINE);
9498 btrfs_set_file_extent_encryption(leaf, ei, 0);
9499 btrfs_set_file_extent_compression(leaf, ei, 0);
9500 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9501 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9502
9503 ptr = btrfs_file_extent_inline_start(ei);
9504 write_extent_buffer(leaf, symname, ptr, name_len);
9505 btrfs_mark_buffer_dirty(leaf);
9506 btrfs_free_path(path);
9507
9508 inode->i_op = &btrfs_symlink_inode_operations;
9509 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9510 inode_set_bytes(inode, name_len);
9511 btrfs_i_size_write(inode, name_len);
9512 err = btrfs_update_inode(trans, root, inode);
9513 if (err) {
9514 drop_inode = 1;
9515 goto out_unlock_inode;
9516 }
9517
9518 unlock_new_inode(inode);
9519 d_instantiate(dentry, inode);
9520
9521 out_unlock:
9522 btrfs_end_transaction(trans, root);
9523 if (drop_inode) {
9524 inode_dec_link_count(inode);
9525 iput(inode);
9526 }
9527 btrfs_btree_balance_dirty(root);
9528 return err;
9529
9530 out_unlock_inode:
9531 drop_inode = 1;
9532 unlock_new_inode(inode);
9533 goto out_unlock;
9534 }
9535
9536 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9537 u64 start, u64 num_bytes, u64 min_size,
9538 loff_t actual_len, u64 *alloc_hint,
9539 struct btrfs_trans_handle *trans)
9540 {
9541 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9542 struct extent_map *em;
9543 struct btrfs_root *root = BTRFS_I(inode)->root;
9544 struct btrfs_key ins;
9545 u64 cur_offset = start;
9546 u64 i_size;
9547 u64 cur_bytes;
9548 int ret = 0;
9549 bool own_trans = true;
9550
9551 if (trans)
9552 own_trans = false;
9553 while (num_bytes > 0) {
9554 if (own_trans) {
9555 trans = btrfs_start_transaction(root, 3);
9556 if (IS_ERR(trans)) {
9557 ret = PTR_ERR(trans);
9558 break;
9559 }
9560 }
9561
9562 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
9563 cur_bytes = max(cur_bytes, min_size);
9564 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9565 *alloc_hint, &ins, 1, 0);
9566 if (ret) {
9567 if (own_trans)
9568 btrfs_end_transaction(trans, root);
9569 break;
9570 }
9571
9572 ret = insert_reserved_file_extent(trans, inode,
9573 cur_offset, ins.objectid,
9574 ins.offset, ins.offset,
9575 ins.offset, 0, 0, 0,
9576 BTRFS_FILE_EXTENT_PREALLOC);
9577 if (ret) {
9578 btrfs_free_reserved_extent(root, ins.objectid,
9579 ins.offset, 0);
9580 btrfs_abort_transaction(trans, root, ret);
9581 if (own_trans)
9582 btrfs_end_transaction(trans, root);
9583 break;
9584 }
9585
9586 btrfs_drop_extent_cache(inode, cur_offset,
9587 cur_offset + ins.offset -1, 0);
9588
9589 em = alloc_extent_map();
9590 if (!em) {
9591 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9592 &BTRFS_I(inode)->runtime_flags);
9593 goto next;
9594 }
9595
9596 em->start = cur_offset;
9597 em->orig_start = cur_offset;
9598 em->len = ins.offset;
9599 em->block_start = ins.objectid;
9600 em->block_len = ins.offset;
9601 em->orig_block_len = ins.offset;
9602 em->ram_bytes = ins.offset;
9603 em->bdev = root->fs_info->fs_devices->latest_bdev;
9604 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9605 em->generation = trans->transid;
9606
9607 while (1) {
9608 write_lock(&em_tree->lock);
9609 ret = add_extent_mapping(em_tree, em, 1);
9610 write_unlock(&em_tree->lock);
9611 if (ret != -EEXIST)
9612 break;
9613 btrfs_drop_extent_cache(inode, cur_offset,
9614 cur_offset + ins.offset - 1,
9615 0);
9616 }
9617 free_extent_map(em);
9618 next:
9619 num_bytes -= ins.offset;
9620 cur_offset += ins.offset;
9621 *alloc_hint = ins.objectid + ins.offset;
9622
9623 inode_inc_iversion(inode);
9624 inode->i_ctime = CURRENT_TIME;
9625 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9626 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9627 (actual_len > inode->i_size) &&
9628 (cur_offset > inode->i_size)) {
9629 if (cur_offset > actual_len)
9630 i_size = actual_len;
9631 else
9632 i_size = cur_offset;
9633 i_size_write(inode, i_size);
9634 btrfs_ordered_update_i_size(inode, i_size, NULL);
9635 }
9636
9637 ret = btrfs_update_inode(trans, root, inode);
9638
9639 if (ret) {
9640 btrfs_abort_transaction(trans, root, ret);
9641 if (own_trans)
9642 btrfs_end_transaction(trans, root);
9643 break;
9644 }
9645
9646 if (own_trans)
9647 btrfs_end_transaction(trans, root);
9648 }
9649 return ret;
9650 }
9651
9652 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9653 u64 start, u64 num_bytes, u64 min_size,
9654 loff_t actual_len, u64 *alloc_hint)
9655 {
9656 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9657 min_size, actual_len, alloc_hint,
9658 NULL);
9659 }
9660
9661 int btrfs_prealloc_file_range_trans(struct inode *inode,
9662 struct btrfs_trans_handle *trans, int mode,
9663 u64 start, u64 num_bytes, u64 min_size,
9664 loff_t actual_len, u64 *alloc_hint)
9665 {
9666 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9667 min_size, actual_len, alloc_hint, trans);
9668 }
9669
9670 static int btrfs_set_page_dirty(struct page *page)
9671 {
9672 return __set_page_dirty_nobuffers(page);
9673 }
9674
9675 static int btrfs_permission(struct inode *inode, int mask)
9676 {
9677 struct btrfs_root *root = BTRFS_I(inode)->root;
9678 umode_t mode = inode->i_mode;
9679
9680 if (mask & MAY_WRITE &&
9681 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9682 if (btrfs_root_readonly(root))
9683 return -EROFS;
9684 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9685 return -EACCES;
9686 }
9687 return generic_permission(inode, mask);
9688 }
9689
9690 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9691 {
9692 struct btrfs_trans_handle *trans;
9693 struct btrfs_root *root = BTRFS_I(dir)->root;
9694 struct inode *inode = NULL;
9695 u64 objectid;
9696 u64 index;
9697 int ret = 0;
9698
9699 /*
9700 * 5 units required for adding orphan entry
9701 */
9702 trans = btrfs_start_transaction(root, 5);
9703 if (IS_ERR(trans))
9704 return PTR_ERR(trans);
9705
9706 ret = btrfs_find_free_ino(root, &objectid);
9707 if (ret)
9708 goto out;
9709
9710 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9711 btrfs_ino(dir), objectid, mode, &index);
9712 if (IS_ERR(inode)) {
9713 ret = PTR_ERR(inode);
9714 inode = NULL;
9715 goto out;
9716 }
9717
9718 inode->i_fop = &btrfs_file_operations;
9719 inode->i_op = &btrfs_file_inode_operations;
9720
9721 inode->i_mapping->a_ops = &btrfs_aops;
9722 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9723
9724 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9725 if (ret)
9726 goto out_inode;
9727
9728 ret = btrfs_update_inode(trans, root, inode);
9729 if (ret)
9730 goto out_inode;
9731 ret = btrfs_orphan_add(trans, inode);
9732 if (ret)
9733 goto out_inode;
9734
9735 /*
9736 * We set number of links to 0 in btrfs_new_inode(), and here we set
9737 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9738 * through:
9739 *
9740 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9741 */
9742 set_nlink(inode, 1);
9743 unlock_new_inode(inode);
9744 d_tmpfile(dentry, inode);
9745 mark_inode_dirty(inode);
9746
9747 out:
9748 btrfs_end_transaction(trans, root);
9749 if (ret)
9750 iput(inode);
9751 btrfs_balance_delayed_items(root);
9752 btrfs_btree_balance_dirty(root);
9753 return ret;
9754
9755 out_inode:
9756 unlock_new_inode(inode);
9757 goto out;
9758
9759 }
9760
9761 /* Inspired by filemap_check_errors() */
9762 int btrfs_inode_check_errors(struct inode *inode)
9763 {
9764 int ret = 0;
9765
9766 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
9767 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
9768 ret = -ENOSPC;
9769 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
9770 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
9771 ret = -EIO;
9772
9773 return ret;
9774 }
9775
9776 static const struct inode_operations btrfs_dir_inode_operations = {
9777 .getattr = btrfs_getattr,
9778 .lookup = btrfs_lookup,
9779 .create = btrfs_create,
9780 .unlink = btrfs_unlink,
9781 .link = btrfs_link,
9782 .mkdir = btrfs_mkdir,
9783 .rmdir = btrfs_rmdir,
9784 .rename2 = btrfs_rename2,
9785 .symlink = btrfs_symlink,
9786 .setattr = btrfs_setattr,
9787 .mknod = btrfs_mknod,
9788 .setxattr = btrfs_setxattr,
9789 .getxattr = btrfs_getxattr,
9790 .listxattr = btrfs_listxattr,
9791 .removexattr = btrfs_removexattr,
9792 .permission = btrfs_permission,
9793 .get_acl = btrfs_get_acl,
9794 .set_acl = btrfs_set_acl,
9795 .update_time = btrfs_update_time,
9796 .tmpfile = btrfs_tmpfile,
9797 };
9798 static const struct inode_operations btrfs_dir_ro_inode_operations = {
9799 .lookup = btrfs_lookup,
9800 .permission = btrfs_permission,
9801 .get_acl = btrfs_get_acl,
9802 .set_acl = btrfs_set_acl,
9803 .update_time = btrfs_update_time,
9804 };
9805
9806 static const struct file_operations btrfs_dir_file_operations = {
9807 .llseek = generic_file_llseek,
9808 .read = generic_read_dir,
9809 .iterate = btrfs_real_readdir,
9810 .unlocked_ioctl = btrfs_ioctl,
9811 #ifdef CONFIG_COMPAT
9812 .compat_ioctl = btrfs_ioctl,
9813 #endif
9814 .release = btrfs_release_file,
9815 .fsync = btrfs_sync_file,
9816 };
9817
9818 static struct extent_io_ops btrfs_extent_io_ops = {
9819 .fill_delalloc = run_delalloc_range,
9820 .submit_bio_hook = btrfs_submit_bio_hook,
9821 .merge_bio_hook = btrfs_merge_bio_hook,
9822 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
9823 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
9824 .writepage_start_hook = btrfs_writepage_start_hook,
9825 .set_bit_hook = btrfs_set_bit_hook,
9826 .clear_bit_hook = btrfs_clear_bit_hook,
9827 .merge_extent_hook = btrfs_merge_extent_hook,
9828 .split_extent_hook = btrfs_split_extent_hook,
9829 };
9830
9831 /*
9832 * btrfs doesn't support the bmap operation because swapfiles
9833 * use bmap to make a mapping of extents in the file. They assume
9834 * these extents won't change over the life of the file and they
9835 * use the bmap result to do IO directly to the drive.
9836 *
9837 * the btrfs bmap call would return logical addresses that aren't
9838 * suitable for IO and they also will change frequently as COW
9839 * operations happen. So, swapfile + btrfs == corruption.
9840 *
9841 * For now we're avoiding this by dropping bmap.
9842 */
9843 static const struct address_space_operations btrfs_aops = {
9844 .readpage = btrfs_readpage,
9845 .writepage = btrfs_writepage,
9846 .writepages = btrfs_writepages,
9847 .readpages = btrfs_readpages,
9848 .direct_IO = btrfs_direct_IO,
9849 .invalidatepage = btrfs_invalidatepage,
9850 .releasepage = btrfs_releasepage,
9851 .set_page_dirty = btrfs_set_page_dirty,
9852 .error_remove_page = generic_error_remove_page,
9853 };
9854
9855 static const struct address_space_operations btrfs_symlink_aops = {
9856 .readpage = btrfs_readpage,
9857 .writepage = btrfs_writepage,
9858 .invalidatepage = btrfs_invalidatepage,
9859 .releasepage = btrfs_releasepage,
9860 };
9861
9862 static const struct inode_operations btrfs_file_inode_operations = {
9863 .getattr = btrfs_getattr,
9864 .setattr = btrfs_setattr,
9865 .setxattr = btrfs_setxattr,
9866 .getxattr = btrfs_getxattr,
9867 .listxattr = btrfs_listxattr,
9868 .removexattr = btrfs_removexattr,
9869 .permission = btrfs_permission,
9870 .fiemap = btrfs_fiemap,
9871 .get_acl = btrfs_get_acl,
9872 .set_acl = btrfs_set_acl,
9873 .update_time = btrfs_update_time,
9874 };
9875 static const struct inode_operations btrfs_special_inode_operations = {
9876 .getattr = btrfs_getattr,
9877 .setattr = btrfs_setattr,
9878 .permission = btrfs_permission,
9879 .setxattr = btrfs_setxattr,
9880 .getxattr = btrfs_getxattr,
9881 .listxattr = btrfs_listxattr,
9882 .removexattr = btrfs_removexattr,
9883 .get_acl = btrfs_get_acl,
9884 .set_acl = btrfs_set_acl,
9885 .update_time = btrfs_update_time,
9886 };
9887 static const struct inode_operations btrfs_symlink_inode_operations = {
9888 .readlink = generic_readlink,
9889 .follow_link = page_follow_link_light,
9890 .put_link = page_put_link,
9891 .getattr = btrfs_getattr,
9892 .setattr = btrfs_setattr,
9893 .permission = btrfs_permission,
9894 .setxattr = btrfs_setxattr,
9895 .getxattr = btrfs_getxattr,
9896 .listxattr = btrfs_listxattr,
9897 .removexattr = btrfs_removexattr,
9898 .update_time = btrfs_update_time,
9899 };
9900
9901 const struct dentry_operations btrfs_dentry_operations = {
9902 .d_delete = btrfs_dentry_delete,
9903 .d_release = btrfs_dentry_release,
9904 };
Linux kernel - Deliverables
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