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fs/Makefile: Stupid typo breakage of exofs inclusion
[linux-btrfs-devel.git] / fs / btrfs / disk-io.c
blob07b3ac662e193e6b3a19180c3c3c9bfccbeb8028
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/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/crc32c.h>
30 #include <linux/slab.h>
31 #include <linux/migrate.h>
32 #include <linux/ratelimit.h>
33 #include <asm/unaligned.h>
34 #include "compat.h"
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "async-thread.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "inode-map.h"
46
47 static struct extent_io_ops btree_extent_io_ops;
48 static void end_workqueue_fn(struct btrfs_work *work);
49 static void free_fs_root(struct btrfs_root *root);
50 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
51 int read_only);
52 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
53 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
54 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
55 struct btrfs_root *root);
56 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
57 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
58 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
59 struct extent_io_tree *dirty_pages,
60 int mark);
61 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
62 struct extent_io_tree *pinned_extents);
63 static int btrfs_cleanup_transaction(struct btrfs_root *root);
64
65 /*
66 * end_io_wq structs are used to do processing in task context when an IO is
67 * complete. This is used during reads to verify checksums, and it is used
68 * by writes to insert metadata for new file extents after IO is complete.
69 */
70 struct end_io_wq {
71 struct bio *bio;
72 bio_end_io_t *end_io;
73 void *private;
74 struct btrfs_fs_info *info;
75 int error;
76 int metadata;
77 struct list_head list;
78 struct btrfs_work work;
79 };
80
81 /*
82 * async submit bios are used to offload expensive checksumming
83 * onto the worker threads. They checksum file and metadata bios
84 * just before they are sent down the IO stack.
85 */
86 struct async_submit_bio {
87 struct inode *inode;
88 struct bio *bio;
89 struct list_head list;
90 extent_submit_bio_hook_t *submit_bio_start;
91 extent_submit_bio_hook_t *submit_bio_done;
92 int rw;
93 int mirror_num;
94 unsigned long bio_flags;
95 /*
96 * bio_offset is optional, can be used if the pages in the bio
97 * can't tell us where in the file the bio should go
98 */
99 u64 bio_offset;
100 struct btrfs_work work;
101 };
102
103 /*
104 * Lockdep class keys for extent_buffer->lock's in this root. For a given
105 * eb, the lockdep key is determined by the btrfs_root it belongs to and
106 * the level the eb occupies in the tree.
107 *
108 * Different roots are used for different purposes and may nest inside each
109 * other and they require separate keysets. As lockdep keys should be
110 * static, assign keysets according to the purpose of the root as indicated
111 * by btrfs_root->objectid. This ensures that all special purpose roots
112 * have separate keysets.
113 *
114 * Lock-nesting across peer nodes is always done with the immediate parent
115 * node locked thus preventing deadlock. As lockdep doesn't know this, use
116 * subclass to avoid triggering lockdep warning in such cases.
117 *
118 * The key is set by the readpage_end_io_hook after the buffer has passed
119 * csum validation but before the pages are unlocked. It is also set by
120 * btrfs_init_new_buffer on freshly allocated blocks.
121 *
122 * We also add a check to make sure the highest level of the tree is the
123 * same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this code
124 * needs update as well.
125 */
126 #ifdef CONFIG_DEBUG_LOCK_ALLOC
127 # if BTRFS_MAX_LEVEL != 8
128 # error
129 # endif
130
131 static struct btrfs_lockdep_keyset {
132 u64 id; /* root objectid */
133 const char *name_stem; /* lock name stem */
134 char names[BTRFS_MAX_LEVEL + 1][20];
135 struct lock_class_key keys[BTRFS_MAX_LEVEL + 1];
136 } btrfs_lockdep_keysets[] = {
137 { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" },
138 { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" },
139 { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" },
140 { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" },
141 { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" },
142 { .id = BTRFS_CSUM_TREE_OBJECTID, .name_stem = "csum" },
143 { .id = BTRFS_ORPHAN_OBJECTID, .name_stem = "orphan" },
144 { .id = BTRFS_TREE_LOG_OBJECTID, .name_stem = "log" },
145 { .id = BTRFS_TREE_RELOC_OBJECTID, .name_stem = "treloc" },
146 { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc" },
147 { .id = 0, .name_stem = "tree" },
148 };
149
150 void __init btrfs_init_lockdep(void)
151 {
152 int i, j;
153
154 /* initialize lockdep class names */
155 for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
156 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
157
158 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
159 snprintf(ks->names[j], sizeof(ks->names[j]),
160 "btrfs-%s-%02d", ks->name_stem, j);
161 }
162 }
163
164 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
165 int level)
166 {
167 struct btrfs_lockdep_keyset *ks;
168
169 BUG_ON(level >= ARRAY_SIZE(ks->keys));
170
171 /* find the matching keyset, id 0 is the default entry */
172 for (ks = btrfs_lockdep_keysets; ks->id; ks++)
173 if (ks->id == objectid)
174 break;
175
176 lockdep_set_class_and_name(&eb->lock,
177 &ks->keys[level], ks->names[level]);
178 }
179
180 #endif
181
182 /*
183 * extents on the btree inode are pretty simple, there's one extent
184 * that covers the entire device
185 */
186 static struct extent_map *btree_get_extent(struct inode *inode,
187 struct page *page, size_t pg_offset, u64 start, u64 len,
188 int create)
189 {
190 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
191 struct extent_map *em;
192 int ret;
193
194 read_lock(&em_tree->lock);
195 em = lookup_extent_mapping(em_tree, start, len);
196 if (em) {
197 em->bdev =
198 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
199 read_unlock(&em_tree->lock);
200 goto out;
201 }
202 read_unlock(&em_tree->lock);
203
204 em = alloc_extent_map();
205 if (!em) {
206 em = ERR_PTR(-ENOMEM);
207 goto out;
208 }
209 em->start = 0;
210 em->len = (u64)-1;
211 em->block_len = (u64)-1;
212 em->block_start = 0;
213 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
214
215 write_lock(&em_tree->lock);
216 ret = add_extent_mapping(em_tree, em);
217 if (ret == -EEXIST) {
218 u64 failed_start = em->start;
219 u64 failed_len = em->len;
220
221 free_extent_map(em);
222 em = lookup_extent_mapping(em_tree, start, len);
223 if (em) {
224 ret = 0;
225 } else {
226 em = lookup_extent_mapping(em_tree, failed_start,
227 failed_len);
228 ret = -EIO;
229 }
230 } else if (ret) {
231 free_extent_map(em);
232 em = NULL;
233 }
234 write_unlock(&em_tree->lock);
235
236 if (ret)
237 em = ERR_PTR(ret);
238 out:
239 return em;
240 }
241
242 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
243 {
244 return crc32c(seed, data, len);
245 }
246
247 void btrfs_csum_final(u32 crc, char *result)
248 {
249 put_unaligned_le32(~crc, result);
250 }
251
252 /*
253 * compute the csum for a btree block, and either verify it or write it
254 * into the csum field of the block.
255 */
256 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
257 int verify)
258 {
259 u16 csum_size =
260 btrfs_super_csum_size(&root->fs_info->super_copy);
261 char *result = NULL;
262 unsigned long len;
263 unsigned long cur_len;
264 unsigned long offset = BTRFS_CSUM_SIZE;
265 char *kaddr;
266 unsigned long map_start;
267 unsigned long map_len;
268 int err;
269 u32 crc = ~(u32)0;
270 unsigned long inline_result;
271
272 len = buf->len - offset;
273 while (len > 0) {
274 err = map_private_extent_buffer(buf, offset, 32,
275 &kaddr, &map_start, &map_len);
276 if (err)
277 return 1;
278 cur_len = min(len, map_len - (offset - map_start));
279 crc = btrfs_csum_data(root, kaddr + offset - map_start,
280 crc, cur_len);
281 len -= cur_len;
282 offset += cur_len;
283 }
284 if (csum_size > sizeof(inline_result)) {
285 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
286 if (!result)
287 return 1;
288 } else {
289 result = (char *)&inline_result;
290 }
291
292 btrfs_csum_final(crc, result);
293
294 if (verify) {
295 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
296 u32 val;
297 u32 found = 0;
298 memcpy(&found, result, csum_size);
299
300 read_extent_buffer(buf, &val, 0, csum_size);
301 printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
302 "failed on %llu wanted %X found %X "
303 "level %d\n",
304 root->fs_info->sb->s_id,
305 (unsigned long long)buf->start, val, found,
306 btrfs_header_level(buf));
307 if (result != (char *)&inline_result)
308 kfree(result);
309 return 1;
310 }
311 } else {
312 write_extent_buffer(buf, result, 0, csum_size);
313 }
314 if (result != (char *)&inline_result)
315 kfree(result);
316 return 0;
317 }
318
319 /*
320 * we can't consider a given block up to date unless the transid of the
321 * block matches the transid in the parent node's pointer. This is how we
322 * detect blocks that either didn't get written at all or got written
323 * in the wrong place.
324 */
325 static int verify_parent_transid(struct extent_io_tree *io_tree,
326 struct extent_buffer *eb, u64 parent_transid)
327 {
328 struct extent_state *cached_state = NULL;
329 int ret;
330
331 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
332 return 0;
333
334 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
335 0, &cached_state, GFP_NOFS);
336 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
337 btrfs_header_generation(eb) == parent_transid) {
338 ret = 0;
339 goto out;
340 }
341 printk_ratelimited("parent transid verify failed on %llu wanted %llu "
342 "found %llu\n",
343 (unsigned long long)eb->start,
344 (unsigned long long)parent_transid,
345 (unsigned long long)btrfs_header_generation(eb));
346 ret = 1;
347 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
348 out:
349 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
350 &cached_state, GFP_NOFS);
351 return ret;
352 }
353
354 /*
355 * helper to read a given tree block, doing retries as required when
356 * the checksums don't match and we have alternate mirrors to try.
357 */
358 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
359 struct extent_buffer *eb,
360 u64 start, u64 parent_transid)
361 {
362 struct extent_io_tree *io_tree;
363 int ret;
364 int num_copies = 0;
365 int mirror_num = 0;
366
367 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
368 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
369 while (1) {
370 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
371 btree_get_extent, mirror_num);
372 if (!ret &&
373 !verify_parent_transid(io_tree, eb, parent_transid))
374 return ret;
375
376 /*
377 * This buffer's crc is fine, but its contents are corrupted, so
378 * there is no reason to read the other copies, they won't be
379 * any less wrong.
380 */
381 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
382 return ret;
383
384 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
385 eb->start, eb->len);
386 if (num_copies == 1)
387 return ret;
388
389 mirror_num++;
390 if (mirror_num > num_copies)
391 return ret;
392 }
393 return -EIO;
394 }
395
396 /*
397 * checksum a dirty tree block before IO. This has extra checks to make sure
398 * we only fill in the checksum field in the first page of a multi-page block
399 */
400
401 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
402 {
403 struct extent_io_tree *tree;
404 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
405 u64 found_start;
406 unsigned long len;
407 struct extent_buffer *eb;
408 int ret;
409
410 tree = &BTRFS_I(page->mapping->host)->io_tree;
411
412 if (page->private == EXTENT_PAGE_PRIVATE) {
413 WARN_ON(1);
414 goto out;
415 }
416 if (!page->private) {
417 WARN_ON(1);
418 goto out;
419 }
420 len = page->private >> 2;
421 WARN_ON(len == 0);
422
423 eb = alloc_extent_buffer(tree, start, len, page);
424 if (eb == NULL) {
425 WARN_ON(1);
426 goto out;
427 }
428 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
429 btrfs_header_generation(eb));
430 BUG_ON(ret);
431 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
432
433 found_start = btrfs_header_bytenr(eb);
434 if (found_start != start) {
435 WARN_ON(1);
436 goto err;
437 }
438 if (eb->first_page != page) {
439 WARN_ON(1);
440 goto err;
441 }
442 if (!PageUptodate(page)) {
443 WARN_ON(1);
444 goto err;
445 }
446 csum_tree_block(root, eb, 0);
447 err:
448 free_extent_buffer(eb);
449 out:
450 return 0;
451 }
452
453 static int check_tree_block_fsid(struct btrfs_root *root,
454 struct extent_buffer *eb)
455 {
456 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
457 u8 fsid[BTRFS_UUID_SIZE];
458 int ret = 1;
459
460 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
461 BTRFS_FSID_SIZE);
462 while (fs_devices) {
463 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
464 ret = 0;
465 break;
466 }
467 fs_devices = fs_devices->seed;
468 }
469 return ret;
470 }
471
472 #define CORRUPT(reason, eb, root, slot) \
473 printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
474 "root=%llu, slot=%d\n", reason, \
475 (unsigned long long)btrfs_header_bytenr(eb), \
476 (unsigned long long)root->objectid, slot)
477
478 static noinline int check_leaf(struct btrfs_root *root,
479 struct extent_buffer *leaf)
480 {
481 struct btrfs_key key;
482 struct btrfs_key leaf_key;
483 u32 nritems = btrfs_header_nritems(leaf);
484 int slot;
485
486 if (nritems == 0)
487 return 0;
488
489 /* Check the 0 item */
490 if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
491 BTRFS_LEAF_DATA_SIZE(root)) {
492 CORRUPT("invalid item offset size pair", leaf, root, 0);
493 return -EIO;
494 }
495
496 /*
497 * Check to make sure each items keys are in the correct order and their
498 * offsets make sense. We only have to loop through nritems-1 because
499 * we check the current slot against the next slot, which verifies the
500 * next slot's offset+size makes sense and that the current's slot
501 * offset is correct.
502 */
503 for (slot = 0; slot < nritems - 1; slot++) {
504 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
505 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
506
507 /* Make sure the keys are in the right order */
508 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
509 CORRUPT("bad key order", leaf, root, slot);
510 return -EIO;
511 }
512
513 /*
514 * Make sure the offset and ends are right, remember that the
515 * item data starts at the end of the leaf and grows towards the
516 * front.
517 */
518 if (btrfs_item_offset_nr(leaf, slot) !=
519 btrfs_item_end_nr(leaf, slot + 1)) {
520 CORRUPT("slot offset bad", leaf, root, slot);
521 return -EIO;
522 }
523
524 /*
525 * Check to make sure that we don't point outside of the leaf,
526 * just incase all the items are consistent to eachother, but
527 * all point outside of the leaf.
528 */
529 if (btrfs_item_end_nr(leaf, slot) >
530 BTRFS_LEAF_DATA_SIZE(root)) {
531 CORRUPT("slot end outside of leaf", leaf, root, slot);
532 return -EIO;
533 }
534 }
535
536 return 0;
537 }
538
539 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
540 struct extent_state *state)
541 {
542 struct extent_io_tree *tree;
543 u64 found_start;
544 int found_level;
545 unsigned long len;
546 struct extent_buffer *eb;
547 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
548 int ret = 0;
549
550 tree = &BTRFS_I(page->mapping->host)->io_tree;
551 if (page->private == EXTENT_PAGE_PRIVATE)
552 goto out;
553 if (!page->private)
554 goto out;
555
556 len = page->private >> 2;
557 WARN_ON(len == 0);
558
559 eb = alloc_extent_buffer(tree, start, len, page);
560 if (eb == NULL) {
561 ret = -EIO;
562 goto out;
563 }
564
565 found_start = btrfs_header_bytenr(eb);
566 if (found_start != start) {
567 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
568 "%llu %llu\n",
569 (unsigned long long)found_start,
570 (unsigned long long)eb->start);
571 ret = -EIO;
572 goto err;
573 }
574 if (eb->first_page != page) {
575 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
576 eb->first_page->index, page->index);
577 WARN_ON(1);
578 ret = -EIO;
579 goto err;
580 }
581 if (check_tree_block_fsid(root, eb)) {
582 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
583 (unsigned long long)eb->start);
584 ret = -EIO;
585 goto err;
586 }
587 found_level = btrfs_header_level(eb);
588
589 btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
590 eb, found_level);
591
592 ret = csum_tree_block(root, eb, 1);
593 if (ret) {
594 ret = -EIO;
595 goto err;
596 }
597
598 /*
599 * If this is a leaf block and it is corrupt, set the corrupt bit so
600 * that we don't try and read the other copies of this block, just
601 * return -EIO.
602 */
603 if (found_level == 0 && check_leaf(root, eb)) {
604 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
605 ret = -EIO;
606 }
607
608 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
609 end = eb->start + end - 1;
610 err:
611 free_extent_buffer(eb);
612 out:
613 return ret;
614 }
615
616 static void end_workqueue_bio(struct bio *bio, int err)
617 {
618 struct end_io_wq *end_io_wq = bio->bi_private;
619 struct btrfs_fs_info *fs_info;
620
621 fs_info = end_io_wq->info;
622 end_io_wq->error = err;
623 end_io_wq->work.func = end_workqueue_fn;
624 end_io_wq->work.flags = 0;
625
626 if (bio->bi_rw & REQ_WRITE) {
627 if (end_io_wq->metadata == 1)
628 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
629 &end_io_wq->work);
630 else if (end_io_wq->metadata == 2)
631 btrfs_queue_worker(&fs_info->endio_freespace_worker,
632 &end_io_wq->work);
633 else
634 btrfs_queue_worker(&fs_info->endio_write_workers,
635 &end_io_wq->work);
636 } else {
637 if (end_io_wq->metadata)
638 btrfs_queue_worker(&fs_info->endio_meta_workers,
639 &end_io_wq->work);
640 else
641 btrfs_queue_worker(&fs_info->endio_workers,
642 &end_io_wq->work);
643 }
644 }
645
646 /*
647 * For the metadata arg you want
648 *
649 * 0 - if data
650 * 1 - if normal metadta
651 * 2 - if writing to the free space cache area
652 */
653 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
654 int metadata)
655 {
656 struct end_io_wq *end_io_wq;
657 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
658 if (!end_io_wq)
659 return -ENOMEM;
660
661 end_io_wq->private = bio->bi_private;
662 end_io_wq->end_io = bio->bi_end_io;
663 end_io_wq->info = info;
664 end_io_wq->error = 0;
665 end_io_wq->bio = bio;
666 end_io_wq->metadata = metadata;
667
668 bio->bi_private = end_io_wq;
669 bio->bi_end_io = end_workqueue_bio;
670 return 0;
671 }
672
673 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
674 {
675 unsigned long limit = min_t(unsigned long,
676 info->workers.max_workers,
677 info->fs_devices->open_devices);
678 return 256 * limit;
679 }
680
681 static void run_one_async_start(struct btrfs_work *work)
682 {
683 struct async_submit_bio *async;
684
685 async = container_of(work, struct async_submit_bio, work);
686 async->submit_bio_start(async->inode, async->rw, async->bio,
687 async->mirror_num, async->bio_flags,
688 async->bio_offset);
689 }
690
691 static void run_one_async_done(struct btrfs_work *work)
692 {
693 struct btrfs_fs_info *fs_info;
694 struct async_submit_bio *async;
695 int limit;
696
697 async = container_of(work, struct async_submit_bio, work);
698 fs_info = BTRFS_I(async->inode)->root->fs_info;
699
700 limit = btrfs_async_submit_limit(fs_info);
701 limit = limit * 2 / 3;
702
703 atomic_dec(&fs_info->nr_async_submits);
704
705 if (atomic_read(&fs_info->nr_async_submits) < limit &&
706 waitqueue_active(&fs_info->async_submit_wait))
707 wake_up(&fs_info->async_submit_wait);
708
709 async->submit_bio_done(async->inode, async->rw, async->bio,
710 async->mirror_num, async->bio_flags,
711 async->bio_offset);
712 }
713
714 static void run_one_async_free(struct btrfs_work *work)
715 {
716 struct async_submit_bio *async;
717
718 async = container_of(work, struct async_submit_bio, work);
719 kfree(async);
720 }
721
722 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
723 int rw, struct bio *bio, int mirror_num,
724 unsigned long bio_flags,
725 u64 bio_offset,
726 extent_submit_bio_hook_t *submit_bio_start,
727 extent_submit_bio_hook_t *submit_bio_done)
728 {
729 struct async_submit_bio *async;
730
731 async = kmalloc(sizeof(*async), GFP_NOFS);
732 if (!async)
733 return -ENOMEM;
734
735 async->inode = inode;
736 async->rw = rw;
737 async->bio = bio;
738 async->mirror_num = mirror_num;
739 async->submit_bio_start = submit_bio_start;
740 async->submit_bio_done = submit_bio_done;
741
742 async->work.func = run_one_async_start;
743 async->work.ordered_func = run_one_async_done;
744 async->work.ordered_free = run_one_async_free;
745
746 async->work.flags = 0;
747 async->bio_flags = bio_flags;
748 async->bio_offset = bio_offset;
749
750 atomic_inc(&fs_info->nr_async_submits);
751
752 if (rw & REQ_SYNC)
753 btrfs_set_work_high_prio(&async->work);
754
755 btrfs_queue_worker(&fs_info->workers, &async->work);
756
757 while (atomic_read(&fs_info->async_submit_draining) &&
758 atomic_read(&fs_info->nr_async_submits)) {
759 wait_event(fs_info->async_submit_wait,
760 (atomic_read(&fs_info->nr_async_submits) == 0));
761 }
762
763 return 0;
764 }
765
766 static int btree_csum_one_bio(struct bio *bio)
767 {
768 struct bio_vec *bvec = bio->bi_io_vec;
769 int bio_index = 0;
770 struct btrfs_root *root;
771
772 WARN_ON(bio->bi_vcnt <= 0);
773 while (bio_index < bio->bi_vcnt) {
774 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
775 csum_dirty_buffer(root, bvec->bv_page);
776 bio_index++;
777 bvec++;
778 }
779 return 0;
780 }
781
782 static int __btree_submit_bio_start(struct inode *inode, int rw,
783 struct bio *bio, int mirror_num,
784 unsigned long bio_flags,
785 u64 bio_offset)
786 {
787 /*
788 * when we're called for a write, we're already in the async
789 * submission context. Just jump into btrfs_map_bio
790 */
791 btree_csum_one_bio(bio);
792 return 0;
793 }
794
795 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
796 int mirror_num, unsigned long bio_flags,
797 u64 bio_offset)
798 {
799 /*
800 * when we're called for a write, we're already in the async
801 * submission context. Just jump into btrfs_map_bio
802 */
803 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
804 }
805
806 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
807 int mirror_num, unsigned long bio_flags,
808 u64 bio_offset)
809 {
810 int ret;
811
812 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
813 bio, 1);
814 BUG_ON(ret);
815
816 if (!(rw & REQ_WRITE)) {
817 /*
818 * called for a read, do the setup so that checksum validation
819 * can happen in the async kernel threads
820 */
821 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
822 mirror_num, 0);
823 }
824
825 /*
826 * kthread helpers are used to submit writes so that checksumming
827 * can happen in parallel across all CPUs
828 */
829 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
830 inode, rw, bio, mirror_num, 0,
831 bio_offset,
832 __btree_submit_bio_start,
833 __btree_submit_bio_done);
834 }
835
836 #ifdef CONFIG_MIGRATION
837 static int btree_migratepage(struct address_space *mapping,
838 struct page *newpage, struct page *page)
839 {
840 /*
841 * we can't safely write a btree page from here,
842 * we haven't done the locking hook
843 */
844 if (PageDirty(page))
845 return -EAGAIN;
846 /*
847 * Buffers may be managed in a filesystem specific way.
848 * We must have no buffers or drop them.
849 */
850 if (page_has_private(page) &&
851 !try_to_release_page(page, GFP_KERNEL))
852 return -EAGAIN;
853 return migrate_page(mapping, newpage, page);
854 }
855 #endif
856
857 static int btree_writepage(struct page *page, struct writeback_control *wbc)
858 {
859 struct extent_io_tree *tree;
860 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
861 struct extent_buffer *eb;
862 int was_dirty;
863
864 tree = &BTRFS_I(page->mapping->host)->io_tree;
865 if (!(current->flags & PF_MEMALLOC)) {
866 return extent_write_full_page(tree, page,
867 btree_get_extent, wbc);
868 }
869
870 redirty_page_for_writepage(wbc, page);
871 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
872 WARN_ON(!eb);
873
874 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
875 if (!was_dirty) {
876 spin_lock(&root->fs_info->delalloc_lock);
877 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
878 spin_unlock(&root->fs_info->delalloc_lock);
879 }
880 free_extent_buffer(eb);
881
882 unlock_page(page);
883 return 0;
884 }
885
886 static int btree_writepages(struct address_space *mapping,
887 struct writeback_control *wbc)
888 {
889 struct extent_io_tree *tree;
890 tree = &BTRFS_I(mapping->host)->io_tree;
891 if (wbc->sync_mode == WB_SYNC_NONE) {
892 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
893 u64 num_dirty;
894 unsigned long thresh = 32 * 1024 * 1024;
895
896 if (wbc->for_kupdate)
897 return 0;
898
899 /* this is a bit racy, but that's ok */
900 num_dirty = root->fs_info->dirty_metadata_bytes;
901 if (num_dirty < thresh)
902 return 0;
903 }
904 return extent_writepages(tree, mapping, btree_get_extent, wbc);
905 }
906
907 static int btree_readpage(struct file *file, struct page *page)
908 {
909 struct extent_io_tree *tree;
910 tree = &BTRFS_I(page->mapping->host)->io_tree;
911 return extent_read_full_page(tree, page, btree_get_extent);
912 }
913
914 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
915 {
916 struct extent_io_tree *tree;
917 struct extent_map_tree *map;
918 int ret;
919
920 if (PageWriteback(page) || PageDirty(page))
921 return 0;
922
923 tree = &BTRFS_I(page->mapping->host)->io_tree;
924 map = &BTRFS_I(page->mapping->host)->extent_tree;
925
926 ret = try_release_extent_state(map, tree, page, gfp_flags);
927 if (!ret)
928 return 0;
929
930 ret = try_release_extent_buffer(tree, page);
931 if (ret == 1) {
932 ClearPagePrivate(page);
933 set_page_private(page, 0);
934 page_cache_release(page);
935 }
936
937 return ret;
938 }
939
940 static void btree_invalidatepage(struct page *page, unsigned long offset)
941 {
942 struct extent_io_tree *tree;
943 tree = &BTRFS_I(page->mapping->host)->io_tree;
944 extent_invalidatepage(tree, page, offset);
945 btree_releasepage(page, GFP_NOFS);
946 if (PagePrivate(page)) {
947 printk(KERN_WARNING "btrfs warning page private not zero "
948 "on page %llu\n", (unsigned long long)page_offset(page));
949 ClearPagePrivate(page);
950 set_page_private(page, 0);
951 page_cache_release(page);
952 }
953 }
954
955 static const struct address_space_operations btree_aops = {
956 .readpage = btree_readpage,
957 .writepage = btree_writepage,
958 .writepages = btree_writepages,
959 .releasepage = btree_releasepage,
960 .invalidatepage = btree_invalidatepage,
961 #ifdef CONFIG_MIGRATION
962 .migratepage = btree_migratepage,
963 #endif
964 };
965
966 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
967 u64 parent_transid)
968 {
969 struct extent_buffer *buf = NULL;
970 struct inode *btree_inode = root->fs_info->btree_inode;
971 int ret = 0;
972
973 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
974 if (!buf)
975 return 0;
976 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
977 buf, 0, 0, btree_get_extent, 0);
978 free_extent_buffer(buf);
979 return ret;
980 }
981
982 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
983 u64 bytenr, u32 blocksize)
984 {
985 struct inode *btree_inode = root->fs_info->btree_inode;
986 struct extent_buffer *eb;
987 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
988 bytenr, blocksize);
989 return eb;
990 }
991
992 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
993 u64 bytenr, u32 blocksize)
994 {
995 struct inode *btree_inode = root->fs_info->btree_inode;
996 struct extent_buffer *eb;
997
998 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
999 bytenr, blocksize, NULL);
1000 return eb;
1001 }
1002
1003
1004 int btrfs_write_tree_block(struct extent_buffer *buf)
1005 {
1006 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1007 buf->start + buf->len - 1);
1008 }
1009
1010 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1011 {
1012 return filemap_fdatawait_range(buf->first_page->mapping,
1013 buf->start, buf->start + buf->len - 1);
1014 }
1015
1016 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1017 u32 blocksize, u64 parent_transid)
1018 {
1019 struct extent_buffer *buf = NULL;
1020 int ret;
1021
1022 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1023 if (!buf)
1024 return NULL;
1025
1026 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1027
1028 if (ret == 0)
1029 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1030 return buf;
1031
1032 }
1033
1034 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1035 struct extent_buffer *buf)
1036 {
1037 struct inode *btree_inode = root->fs_info->btree_inode;
1038 if (btrfs_header_generation(buf) ==
1039 root->fs_info->running_transaction->transid) {
1040 btrfs_assert_tree_locked(buf);
1041
1042 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1043 spin_lock(&root->fs_info->delalloc_lock);
1044 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1045 root->fs_info->dirty_metadata_bytes -= buf->len;
1046 else
1047 WARN_ON(1);
1048 spin_unlock(&root->fs_info->delalloc_lock);
1049 }
1050
1051 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1052 btrfs_set_lock_blocking(buf);
1053 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1054 buf);
1055 }
1056 return 0;
1057 }
1058
1059 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1060 u32 stripesize, struct btrfs_root *root,
1061 struct btrfs_fs_info *fs_info,
1062 u64 objectid)
1063 {
1064 root->node = NULL;
1065 root->commit_root = NULL;
1066 root->sectorsize = sectorsize;
1067 root->nodesize = nodesize;
1068 root->leafsize = leafsize;
1069 root->stripesize = stripesize;
1070 root->ref_cows = 0;
1071 root->track_dirty = 0;
1072 root->in_radix = 0;
1073 root->orphan_item_inserted = 0;
1074 root->orphan_cleanup_state = 0;
1075
1076 root->fs_info = fs_info;
1077 root->objectid = objectid;
1078 root->last_trans = 0;
1079 root->highest_objectid = 0;
1080 root->name = NULL;
1081 root->inode_tree = RB_ROOT;
1082 INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1083 root->block_rsv = NULL;
1084 root->orphan_block_rsv = NULL;
1085
1086 INIT_LIST_HEAD(&root->dirty_list);
1087 INIT_LIST_HEAD(&root->orphan_list);
1088 INIT_LIST_HEAD(&root->root_list);
1089 spin_lock_init(&root->orphan_lock);
1090 spin_lock_init(&root->inode_lock);
1091 spin_lock_init(&root->accounting_lock);
1092 mutex_init(&root->objectid_mutex);
1093 mutex_init(&root->log_mutex);
1094 init_waitqueue_head(&root->log_writer_wait);
1095 init_waitqueue_head(&root->log_commit_wait[0]);
1096 init_waitqueue_head(&root->log_commit_wait[1]);
1097 atomic_set(&root->log_commit[0], 0);
1098 atomic_set(&root->log_commit[1], 0);
1099 atomic_set(&root->log_writers, 0);
1100 root->log_batch = 0;
1101 root->log_transid = 0;
1102 root->last_log_commit = 0;
1103 extent_io_tree_init(&root->dirty_log_pages,
1104 fs_info->btree_inode->i_mapping);
1105
1106 memset(&root->root_key, 0, sizeof(root->root_key));
1107 memset(&root->root_item, 0, sizeof(root->root_item));
1108 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1109 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1110 root->defrag_trans_start = fs_info->generation;
1111 init_completion(&root->kobj_unregister);
1112 root->defrag_running = 0;
1113 root->root_key.objectid = objectid;
1114 root->anon_dev = 0;
1115 return 0;
1116 }
1117
1118 static int find_and_setup_root(struct btrfs_root *tree_root,
1119 struct btrfs_fs_info *fs_info,
1120 u64 objectid,
1121 struct btrfs_root *root)
1122 {
1123 int ret;
1124 u32 blocksize;
1125 u64 generation;
1126
1127 __setup_root(tree_root->nodesize, tree_root->leafsize,
1128 tree_root->sectorsize, tree_root->stripesize,
1129 root, fs_info, objectid);
1130 ret = btrfs_find_last_root(tree_root, objectid,
1131 &root->root_item, &root->root_key);
1132 if (ret > 0)
1133 return -ENOENT;
1134 BUG_ON(ret);
1135
1136 generation = btrfs_root_generation(&root->root_item);
1137 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1138 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1139 blocksize, generation);
1140 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1141 free_extent_buffer(root->node);
1142 return -EIO;
1143 }
1144 root->commit_root = btrfs_root_node(root);
1145 return 0;
1146 }
1147
1148 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1149 struct btrfs_fs_info *fs_info)
1150 {
1151 struct btrfs_root *root;
1152 struct btrfs_root *tree_root = fs_info->tree_root;
1153 struct extent_buffer *leaf;
1154
1155 root = kzalloc(sizeof(*root), GFP_NOFS);
1156 if (!root)
1157 return ERR_PTR(-ENOMEM);
1158
1159 __setup_root(tree_root->nodesize, tree_root->leafsize,
1160 tree_root->sectorsize, tree_root->stripesize,
1161 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1162
1163 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1164 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1165 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1166 /*
1167 * log trees do not get reference counted because they go away
1168 * before a real commit is actually done. They do store pointers
1169 * to file data extents, and those reference counts still get
1170 * updated (along with back refs to the log tree).
1171 */
1172 root->ref_cows = 0;
1173
1174 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1175 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1176 if (IS_ERR(leaf)) {
1177 kfree(root);
1178 return ERR_CAST(leaf);
1179 }
1180
1181 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1182 btrfs_set_header_bytenr(leaf, leaf->start);
1183 btrfs_set_header_generation(leaf, trans->transid);
1184 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1185 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1186 root->node = leaf;
1187
1188 write_extent_buffer(root->node, root->fs_info->fsid,
1189 (unsigned long)btrfs_header_fsid(root->node),
1190 BTRFS_FSID_SIZE);
1191 btrfs_mark_buffer_dirty(root->node);
1192 btrfs_tree_unlock(root->node);
1193 return root;
1194 }
1195
1196 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1197 struct btrfs_fs_info *fs_info)
1198 {
1199 struct btrfs_root *log_root;
1200
1201 log_root = alloc_log_tree(trans, fs_info);
1202 if (IS_ERR(log_root))
1203 return PTR_ERR(log_root);
1204 WARN_ON(fs_info->log_root_tree);
1205 fs_info->log_root_tree = log_root;
1206 return 0;
1207 }
1208
1209 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1210 struct btrfs_root *root)
1211 {
1212 struct btrfs_root *log_root;
1213 struct btrfs_inode_item *inode_item;
1214
1215 log_root = alloc_log_tree(trans, root->fs_info);
1216 if (IS_ERR(log_root))
1217 return PTR_ERR(log_root);
1218
1219 log_root->last_trans = trans->transid;
1220 log_root->root_key.offset = root->root_key.objectid;
1221
1222 inode_item = &log_root->root_item.inode;
1223 inode_item->generation = cpu_to_le64(1);
1224 inode_item->size = cpu_to_le64(3);
1225 inode_item->nlink = cpu_to_le32(1);
1226 inode_item->nbytes = cpu_to_le64(root->leafsize);
1227 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1228
1229 btrfs_set_root_node(&log_root->root_item, log_root->node);
1230
1231 WARN_ON(root->log_root);
1232 root->log_root = log_root;
1233 root->log_transid = 0;
1234 root->last_log_commit = 0;
1235 return 0;
1236 }
1237
1238 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1239 struct btrfs_key *location)
1240 {
1241 struct btrfs_root *root;
1242 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1243 struct btrfs_path *path;
1244 struct extent_buffer *l;
1245 u64 generation;
1246 u32 blocksize;
1247 int ret = 0;
1248
1249 root = kzalloc(sizeof(*root), GFP_NOFS);
1250 if (!root)
1251 return ERR_PTR(-ENOMEM);
1252 if (location->offset == (u64)-1) {
1253 ret = find_and_setup_root(tree_root, fs_info,
1254 location->objectid, root);
1255 if (ret) {
1256 kfree(root);
1257 return ERR_PTR(ret);
1258 }
1259 goto out;
1260 }
1261
1262 __setup_root(tree_root->nodesize, tree_root->leafsize,
1263 tree_root->sectorsize, tree_root->stripesize,
1264 root, fs_info, location->objectid);
1265
1266 path = btrfs_alloc_path();
1267 if (!path) {
1268 kfree(root);
1269 return ERR_PTR(-ENOMEM);
1270 }
1271 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1272 if (ret == 0) {
1273 l = path->nodes[0];
1274 read_extent_buffer(l, &root->root_item,
1275 btrfs_item_ptr_offset(l, path->slots[0]),
1276 sizeof(root->root_item));
1277 memcpy(&root->root_key, location, sizeof(*location));
1278 }
1279 btrfs_free_path(path);
1280 if (ret) {
1281 kfree(root);
1282 if (ret > 0)
1283 ret = -ENOENT;
1284 return ERR_PTR(ret);
1285 }
1286
1287 generation = btrfs_root_generation(&root->root_item);
1288 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1289 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1290 blocksize, generation);
1291 root->commit_root = btrfs_root_node(root);
1292 BUG_ON(!root->node);
1293 out:
1294 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1295 root->ref_cows = 1;
1296 btrfs_check_and_init_root_item(&root->root_item);
1297 }
1298
1299 return root;
1300 }
1301
1302 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1303 struct btrfs_key *location)
1304 {
1305 struct btrfs_root *root;
1306 int ret;
1307
1308 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1309 return fs_info->tree_root;
1310 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1311 return fs_info->extent_root;
1312 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1313 return fs_info->chunk_root;
1314 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1315 return fs_info->dev_root;
1316 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1317 return fs_info->csum_root;
1318 again:
1319 spin_lock(&fs_info->fs_roots_radix_lock);
1320 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1321 (unsigned long)location->objectid);
1322 spin_unlock(&fs_info->fs_roots_radix_lock);
1323 if (root)
1324 return root;
1325
1326 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1327 if (IS_ERR(root))
1328 return root;
1329
1330 root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1331 root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1332 GFP_NOFS);
1333 if (!root->free_ino_pinned || !root->free_ino_ctl) {
1334 ret = -ENOMEM;
1335 goto fail;
1336 }
1337
1338 btrfs_init_free_ino_ctl(root);
1339 mutex_init(&root->fs_commit_mutex);
1340 spin_lock_init(&root->cache_lock);
1341 init_waitqueue_head(&root->cache_wait);
1342
1343 ret = get_anon_bdev(&root->anon_dev);
1344 if (ret)
1345 goto fail;
1346
1347 if (btrfs_root_refs(&root->root_item) == 0) {
1348 ret = -ENOENT;
1349 goto fail;
1350 }
1351
1352 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1353 if (ret < 0)
1354 goto fail;
1355 if (ret == 0)
1356 root->orphan_item_inserted = 1;
1357
1358 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1359 if (ret)
1360 goto fail;
1361
1362 spin_lock(&fs_info->fs_roots_radix_lock);
1363 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1364 (unsigned long)root->root_key.objectid,
1365 root);
1366 if (ret == 0)
1367 root->in_radix = 1;
1368
1369 spin_unlock(&fs_info->fs_roots_radix_lock);
1370 radix_tree_preload_end();
1371 if (ret) {
1372 if (ret == -EEXIST) {
1373 free_fs_root(root);
1374 goto again;
1375 }
1376 goto fail;
1377 }
1378
1379 ret = btrfs_find_dead_roots(fs_info->tree_root,
1380 root->root_key.objectid);
1381 WARN_ON(ret);
1382 return root;
1383 fail:
1384 free_fs_root(root);
1385 return ERR_PTR(ret);
1386 }
1387
1388 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1389 {
1390 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1391 int ret = 0;
1392 struct btrfs_device *device;
1393 struct backing_dev_info *bdi;
1394
1395 rcu_read_lock();
1396 list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1397 if (!device->bdev)
1398 continue;
1399 bdi = blk_get_backing_dev_info(device->bdev);
1400 if (bdi && bdi_congested(bdi, bdi_bits)) {
1401 ret = 1;
1402 break;
1403 }
1404 }
1405 rcu_read_unlock();
1406 return ret;
1407 }
1408
1409 /*
1410 * If this fails, caller must call bdi_destroy() to get rid of the
1411 * bdi again.
1412 */
1413 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1414 {
1415 int err;
1416
1417 bdi->capabilities = BDI_CAP_MAP_COPY;
1418 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1419 if (err)
1420 return err;
1421
1422 bdi->ra_pages = default_backing_dev_info.ra_pages;
1423 bdi->congested_fn = btrfs_congested_fn;
1424 bdi->congested_data = info;
1425 return 0;
1426 }
1427
1428 static int bio_ready_for_csum(struct bio *bio)
1429 {
1430 u64 length = 0;
1431 u64 buf_len = 0;
1432 u64 start = 0;
1433 struct page *page;
1434 struct extent_io_tree *io_tree = NULL;
1435 struct bio_vec *bvec;
1436 int i;
1437 int ret;
1438
1439 bio_for_each_segment(bvec, bio, i) {
1440 page = bvec->bv_page;
1441 if (page->private == EXTENT_PAGE_PRIVATE) {
1442 length += bvec->bv_len;
1443 continue;
1444 }
1445 if (!page->private) {
1446 length += bvec->bv_len;
1447 continue;
1448 }
1449 length = bvec->bv_len;
1450 buf_len = page->private >> 2;
1451 start = page_offset(page) + bvec->bv_offset;
1452 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1453 }
1454 /* are we fully contained in this bio? */
1455 if (buf_len <= length)
1456 return 1;
1457
1458 ret = extent_range_uptodate(io_tree, start + length,
1459 start + buf_len - 1);
1460 return ret;
1461 }
1462
1463 /*
1464 * called by the kthread helper functions to finally call the bio end_io
1465 * functions. This is where read checksum verification actually happens
1466 */
1467 static void end_workqueue_fn(struct btrfs_work *work)
1468 {
1469 struct bio *bio;
1470 struct end_io_wq *end_io_wq;
1471 struct btrfs_fs_info *fs_info;
1472 int error;
1473
1474 end_io_wq = container_of(work, struct end_io_wq, work);
1475 bio = end_io_wq->bio;
1476 fs_info = end_io_wq->info;
1477
1478 /* metadata bio reads are special because the whole tree block must
1479 * be checksummed at once. This makes sure the entire block is in
1480 * ram and up to date before trying to verify things. For
1481 * blocksize <= pagesize, it is basically a noop
1482 */
1483 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1484 !bio_ready_for_csum(bio)) {
1485 btrfs_queue_worker(&fs_info->endio_meta_workers,
1486 &end_io_wq->work);
1487 return;
1488 }
1489 error = end_io_wq->error;
1490 bio->bi_private = end_io_wq->private;
1491 bio->bi_end_io = end_io_wq->end_io;
1492 kfree(end_io_wq);
1493 bio_endio(bio, error);
1494 }
1495
1496 static int cleaner_kthread(void *arg)
1497 {
1498 struct btrfs_root *root = arg;
1499
1500 do {
1501 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1502
1503 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1504 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1505 btrfs_run_delayed_iputs(root);
1506 btrfs_clean_old_snapshots(root);
1507 mutex_unlock(&root->fs_info->cleaner_mutex);
1508 btrfs_run_defrag_inodes(root->fs_info);
1509 }
1510
1511 if (freezing(current)) {
1512 refrigerator();
1513 } else {
1514 set_current_state(TASK_INTERRUPTIBLE);
1515 if (!kthread_should_stop())
1516 schedule();
1517 __set_current_state(TASK_RUNNING);
1518 }
1519 } while (!kthread_should_stop());
1520 return 0;
1521 }
1522
1523 static int transaction_kthread(void *arg)
1524 {
1525 struct btrfs_root *root = arg;
1526 struct btrfs_trans_handle *trans;
1527 struct btrfs_transaction *cur;
1528 u64 transid;
1529 unsigned long now;
1530 unsigned long delay;
1531 int ret;
1532
1533 do {
1534 delay = HZ * 30;
1535 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1536 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1537
1538 spin_lock(&root->fs_info->trans_lock);
1539 cur = root->fs_info->running_transaction;
1540 if (!cur) {
1541 spin_unlock(&root->fs_info->trans_lock);
1542 goto sleep;
1543 }
1544
1545 now = get_seconds();
1546 if (!cur->blocked &&
1547 (now < cur->start_time || now - cur->start_time < 30)) {
1548 spin_unlock(&root->fs_info->trans_lock);
1549 delay = HZ * 5;
1550 goto sleep;
1551 }
1552 transid = cur->transid;
1553 spin_unlock(&root->fs_info->trans_lock);
1554
1555 trans = btrfs_join_transaction(root);
1556 BUG_ON(IS_ERR(trans));
1557 if (transid == trans->transid) {
1558 ret = btrfs_commit_transaction(trans, root);
1559 BUG_ON(ret);
1560 } else {
1561 btrfs_end_transaction(trans, root);
1562 }
1563 sleep:
1564 wake_up_process(root->fs_info->cleaner_kthread);
1565 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1566
1567 if (freezing(current)) {
1568 refrigerator();
1569 } else {
1570 set_current_state(TASK_INTERRUPTIBLE);
1571 if (!kthread_should_stop() &&
1572 !btrfs_transaction_blocked(root->fs_info))
1573 schedule_timeout(delay);
1574 __set_current_state(TASK_RUNNING);
1575 }
1576 } while (!kthread_should_stop());
1577 return 0;
1578 }
1579
1580 struct btrfs_root *open_ctree(struct super_block *sb,
1581 struct btrfs_fs_devices *fs_devices,
1582 char *options)
1583 {
1584 u32 sectorsize;
1585 u32 nodesize;
1586 u32 leafsize;
1587 u32 blocksize;
1588 u32 stripesize;
1589 u64 generation;
1590 u64 features;
1591 struct btrfs_key location;
1592 struct buffer_head *bh;
1593 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1594 GFP_NOFS);
1595 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1596 GFP_NOFS);
1597 struct btrfs_root *tree_root = btrfs_sb(sb);
1598 struct btrfs_fs_info *fs_info = NULL;
1599 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1600 GFP_NOFS);
1601 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1602 GFP_NOFS);
1603 struct btrfs_root *log_tree_root;
1604
1605 int ret;
1606 int err = -EINVAL;
1607
1608 struct btrfs_super_block *disk_super;
1609
1610 if (!extent_root || !tree_root || !tree_root->fs_info ||
1611 !chunk_root || !dev_root || !csum_root) {
1612 err = -ENOMEM;
1613 goto fail;
1614 }
1615 fs_info = tree_root->fs_info;
1616
1617 ret = init_srcu_struct(&fs_info->subvol_srcu);
1618 if (ret) {
1619 err = ret;
1620 goto fail;
1621 }
1622
1623 ret = setup_bdi(fs_info, &fs_info->bdi);
1624 if (ret) {
1625 err = ret;
1626 goto fail_srcu;
1627 }
1628
1629 fs_info->btree_inode = new_inode(sb);
1630 if (!fs_info->btree_inode) {
1631 err = -ENOMEM;
1632 goto fail_bdi;
1633 }
1634
1635 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1636
1637 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1638 INIT_LIST_HEAD(&fs_info->trans_list);
1639 INIT_LIST_HEAD(&fs_info->dead_roots);
1640 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1641 INIT_LIST_HEAD(&fs_info->hashers);
1642 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1643 INIT_LIST_HEAD(&fs_info->ordered_operations);
1644 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1645 spin_lock_init(&fs_info->delalloc_lock);
1646 spin_lock_init(&fs_info->trans_lock);
1647 spin_lock_init(&fs_info->ref_cache_lock);
1648 spin_lock_init(&fs_info->fs_roots_radix_lock);
1649 spin_lock_init(&fs_info->delayed_iput_lock);
1650 spin_lock_init(&fs_info->defrag_inodes_lock);
1651 mutex_init(&fs_info->reloc_mutex);
1652
1653 init_completion(&fs_info->kobj_unregister);
1654 fs_info->tree_root = tree_root;
1655 fs_info->extent_root = extent_root;
1656 fs_info->csum_root = csum_root;
1657 fs_info->chunk_root = chunk_root;
1658 fs_info->dev_root = dev_root;
1659 fs_info->fs_devices = fs_devices;
1660 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1661 INIT_LIST_HEAD(&fs_info->space_info);
1662 btrfs_mapping_init(&fs_info->mapping_tree);
1663 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1664 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1665 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1666 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1667 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1668 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1669 mutex_init(&fs_info->durable_block_rsv_mutex);
1670 atomic_set(&fs_info->nr_async_submits, 0);
1671 atomic_set(&fs_info->async_delalloc_pages, 0);
1672 atomic_set(&fs_info->async_submit_draining, 0);
1673 atomic_set(&fs_info->nr_async_bios, 0);
1674 atomic_set(&fs_info->defrag_running, 0);
1675 fs_info->sb = sb;
1676 fs_info->max_inline = 8192 * 1024;
1677 fs_info->metadata_ratio = 0;
1678 fs_info->defrag_inodes = RB_ROOT;
1679 fs_info->trans_no_join = 0;
1680
1681 fs_info->thread_pool_size = min_t(unsigned long,
1682 num_online_cpus() + 2, 8);
1683
1684 INIT_LIST_HEAD(&fs_info->ordered_extents);
1685 spin_lock_init(&fs_info->ordered_extent_lock);
1686 fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1687 GFP_NOFS);
1688 if (!fs_info->delayed_root) {
1689 err = -ENOMEM;
1690 goto fail_iput;
1691 }
1692 btrfs_init_delayed_root(fs_info->delayed_root);
1693
1694 mutex_init(&fs_info->scrub_lock);
1695 atomic_set(&fs_info->scrubs_running, 0);
1696 atomic_set(&fs_info->scrub_pause_req, 0);
1697 atomic_set(&fs_info->scrubs_paused, 0);
1698 atomic_set(&fs_info->scrub_cancel_req, 0);
1699 init_waitqueue_head(&fs_info->scrub_pause_wait);
1700 init_rwsem(&fs_info->scrub_super_lock);
1701 fs_info->scrub_workers_refcnt = 0;
1702
1703 sb->s_blocksize = 4096;
1704 sb->s_blocksize_bits = blksize_bits(4096);
1705 sb->s_bdi = &fs_info->bdi;
1706
1707 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1708 fs_info->btree_inode->i_nlink = 1;
1709 /*
1710 * we set the i_size on the btree inode to the max possible int.
1711 * the real end of the address space is determined by all of
1712 * the devices in the system
1713 */
1714 fs_info->btree_inode->i_size = OFFSET_MAX;
1715 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1716 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1717
1718 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1719 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1720 fs_info->btree_inode->i_mapping);
1721 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
1722
1723 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1724
1725 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1726 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1727 sizeof(struct btrfs_key));
1728 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1729 insert_inode_hash(fs_info->btree_inode);
1730
1731 spin_lock_init(&fs_info->block_group_cache_lock);
1732 fs_info->block_group_cache_tree = RB_ROOT;
1733
1734 extent_io_tree_init(&fs_info->freed_extents[0],
1735 fs_info->btree_inode->i_mapping);
1736 extent_io_tree_init(&fs_info->freed_extents[1],
1737 fs_info->btree_inode->i_mapping);
1738 fs_info->pinned_extents = &fs_info->freed_extents[0];
1739 fs_info->do_barriers = 1;
1740
1741
1742 mutex_init(&fs_info->ordered_operations_mutex);
1743 mutex_init(&fs_info->tree_log_mutex);
1744 mutex_init(&fs_info->chunk_mutex);
1745 mutex_init(&fs_info->transaction_kthread_mutex);
1746 mutex_init(&fs_info->cleaner_mutex);
1747 mutex_init(&fs_info->volume_mutex);
1748 init_rwsem(&fs_info->extent_commit_sem);
1749 init_rwsem(&fs_info->cleanup_work_sem);
1750 init_rwsem(&fs_info->subvol_sem);
1751
1752 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1753 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1754
1755 init_waitqueue_head(&fs_info->transaction_throttle);
1756 init_waitqueue_head(&fs_info->transaction_wait);
1757 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1758 init_waitqueue_head(&fs_info->async_submit_wait);
1759
1760 __setup_root(4096, 4096, 4096, 4096, tree_root,
1761 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1762
1763 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1764 if (!bh) {
1765 err = -EINVAL;
1766 goto fail_alloc;
1767 }
1768
1769 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1770 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1771 sizeof(fs_info->super_for_commit));
1772 brelse(bh);
1773
1774 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1775
1776 disk_super = &fs_info->super_copy;
1777 if (!btrfs_super_root(disk_super))
1778 goto fail_alloc;
1779
1780 /* check FS state, whether FS is broken. */
1781 fs_info->fs_state |= btrfs_super_flags(disk_super);
1782
1783 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1784
1785 /*
1786 * In the long term, we'll store the compression type in the super
1787 * block, and it'll be used for per file compression control.
1788 */
1789 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1790
1791 ret = btrfs_parse_options(tree_root, options);
1792 if (ret) {
1793 err = ret;
1794 goto fail_alloc;
1795 }
1796
1797 features = btrfs_super_incompat_flags(disk_super) &
1798 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1799 if (features) {
1800 printk(KERN_ERR "BTRFS: couldn't mount because of "
1801 "unsupported optional features (%Lx).\n",
1802 (unsigned long long)features);
1803 err = -EINVAL;
1804 goto fail_alloc;
1805 }
1806
1807 features = btrfs_super_incompat_flags(disk_super);
1808 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1809 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1810 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1811 btrfs_set_super_incompat_flags(disk_super, features);
1812
1813 features = btrfs_super_compat_ro_flags(disk_super) &
1814 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1815 if (!(sb->s_flags & MS_RDONLY) && features) {
1816 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1817 "unsupported option features (%Lx).\n",
1818 (unsigned long long)features);
1819 err = -EINVAL;
1820 goto fail_alloc;
1821 }
1822
1823 btrfs_init_workers(&fs_info->generic_worker,
1824 "genwork", 1, NULL);
1825
1826 btrfs_init_workers(&fs_info->workers, "worker",
1827 fs_info->thread_pool_size,
1828 &fs_info->generic_worker);
1829
1830 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1831 fs_info->thread_pool_size,
1832 &fs_info->generic_worker);
1833
1834 btrfs_init_workers(&fs_info->submit_workers, "submit",
1835 min_t(u64, fs_devices->num_devices,
1836 fs_info->thread_pool_size),
1837 &fs_info->generic_worker);
1838
1839 btrfs_init_workers(&fs_info->caching_workers, "cache",
1840 2, &fs_info->generic_worker);
1841
1842 /* a higher idle thresh on the submit workers makes it much more
1843 * likely that bios will be send down in a sane order to the
1844 * devices
1845 */
1846 fs_info->submit_workers.idle_thresh = 64;
1847
1848 fs_info->workers.idle_thresh = 16;
1849 fs_info->workers.ordered = 1;
1850
1851 fs_info->delalloc_workers.idle_thresh = 2;
1852 fs_info->delalloc_workers.ordered = 1;
1853
1854 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1855 &fs_info->generic_worker);
1856 btrfs_init_workers(&fs_info->endio_workers, "endio",
1857 fs_info->thread_pool_size,
1858 &fs_info->generic_worker);
1859 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1860 fs_info->thread_pool_size,
1861 &fs_info->generic_worker);
1862 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1863 "endio-meta-write", fs_info->thread_pool_size,
1864 &fs_info->generic_worker);
1865 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1866 fs_info->thread_pool_size,
1867 &fs_info->generic_worker);
1868 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1869 1, &fs_info->generic_worker);
1870 btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
1871 fs_info->thread_pool_size,
1872 &fs_info->generic_worker);
1873
1874 /*
1875 * endios are largely parallel and should have a very
1876 * low idle thresh
1877 */
1878 fs_info->endio_workers.idle_thresh = 4;
1879 fs_info->endio_meta_workers.idle_thresh = 4;
1880
1881 fs_info->endio_write_workers.idle_thresh = 2;
1882 fs_info->endio_meta_write_workers.idle_thresh = 2;
1883
1884 btrfs_start_workers(&fs_info->workers, 1);
1885 btrfs_start_workers(&fs_info->generic_worker, 1);
1886 btrfs_start_workers(&fs_info->submit_workers, 1);
1887 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1888 btrfs_start_workers(&fs_info->fixup_workers, 1);
1889 btrfs_start_workers(&fs_info->endio_workers, 1);
1890 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1891 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1892 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1893 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1894 btrfs_start_workers(&fs_info->delayed_workers, 1);
1895 btrfs_start_workers(&fs_info->caching_workers, 1);
1896
1897 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1898 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1899 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1900
1901 nodesize = btrfs_super_nodesize(disk_super);
1902 leafsize = btrfs_super_leafsize(disk_super);
1903 sectorsize = btrfs_super_sectorsize(disk_super);
1904 stripesize = btrfs_super_stripesize(disk_super);
1905 tree_root->nodesize = nodesize;
1906 tree_root->leafsize = leafsize;
1907 tree_root->sectorsize = sectorsize;
1908 tree_root->stripesize = stripesize;
1909
1910 sb->s_blocksize = sectorsize;
1911 sb->s_blocksize_bits = blksize_bits(sectorsize);
1912
1913 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1914 sizeof(disk_super->magic))) {
1915 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1916 goto fail_sb_buffer;
1917 }
1918
1919 mutex_lock(&fs_info->chunk_mutex);
1920 ret = btrfs_read_sys_array(tree_root);
1921 mutex_unlock(&fs_info->chunk_mutex);
1922 if (ret) {
1923 printk(KERN_WARNING "btrfs: failed to read the system "
1924 "array on %s\n", sb->s_id);
1925 goto fail_sb_buffer;
1926 }
1927
1928 blocksize = btrfs_level_size(tree_root,
1929 btrfs_super_chunk_root_level(disk_super));
1930 generation = btrfs_super_chunk_root_generation(disk_super);
1931
1932 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1933 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1934
1935 chunk_root->node = read_tree_block(chunk_root,
1936 btrfs_super_chunk_root(disk_super),
1937 blocksize, generation);
1938 BUG_ON(!chunk_root->node);
1939 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1940 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1941 sb->s_id);
1942 goto fail_chunk_root;
1943 }
1944 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1945 chunk_root->commit_root = btrfs_root_node(chunk_root);
1946
1947 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1948 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1949 BTRFS_UUID_SIZE);
1950
1951 mutex_lock(&fs_info->chunk_mutex);
1952 ret = btrfs_read_chunk_tree(chunk_root);
1953 mutex_unlock(&fs_info->chunk_mutex);
1954 if (ret) {
1955 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1956 sb->s_id);
1957 goto fail_chunk_root;
1958 }
1959
1960 btrfs_close_extra_devices(fs_devices);
1961
1962 blocksize = btrfs_level_size(tree_root,
1963 btrfs_super_root_level(disk_super));
1964 generation = btrfs_super_generation(disk_super);
1965
1966 tree_root->node = read_tree_block(tree_root,
1967 btrfs_super_root(disk_super),
1968 blocksize, generation);
1969 if (!tree_root->node)
1970 goto fail_chunk_root;
1971 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1972 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1973 sb->s_id);
1974 goto fail_tree_root;
1975 }
1976 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1977 tree_root->commit_root = btrfs_root_node(tree_root);
1978
1979 ret = find_and_setup_root(tree_root, fs_info,
1980 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1981 if (ret)
1982 goto fail_tree_root;
1983 extent_root->track_dirty = 1;
1984
1985 ret = find_and_setup_root(tree_root, fs_info,
1986 BTRFS_DEV_TREE_OBJECTID, dev_root);
1987 if (ret)
1988 goto fail_extent_root;
1989 dev_root->track_dirty = 1;
1990
1991 ret = find_and_setup_root(tree_root, fs_info,
1992 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1993 if (ret)
1994 goto fail_dev_root;
1995
1996 csum_root->track_dirty = 1;
1997
1998 fs_info->generation = generation;
1999 fs_info->last_trans_committed = generation;
2000 fs_info->data_alloc_profile = (u64)-1;
2001 fs_info->metadata_alloc_profile = (u64)-1;
2002 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
2003
2004 ret = btrfs_init_space_info(fs_info);
2005 if (ret) {
2006 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2007 goto fail_block_groups;
2008 }
2009
2010 ret = btrfs_read_block_groups(extent_root);
2011 if (ret) {
2012 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2013 goto fail_block_groups;
2014 }
2015
2016 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2017 "btrfs-cleaner");
2018 if (IS_ERR(fs_info->cleaner_kthread))
2019 goto fail_block_groups;
2020
2021 fs_info->transaction_kthread = kthread_run(transaction_kthread,
2022 tree_root,
2023 "btrfs-transaction");
2024 if (IS_ERR(fs_info->transaction_kthread))
2025 goto fail_cleaner;
2026
2027 if (!btrfs_test_opt(tree_root, SSD) &&
2028 !btrfs_test_opt(tree_root, NOSSD) &&
2029 !fs_info->fs_devices->rotating) {
2030 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2031 "mode\n");
2032 btrfs_set_opt(fs_info->mount_opt, SSD);
2033 }
2034
2035 /* do not make disk changes in broken FS */
2036 if (btrfs_super_log_root(disk_super) != 0 &&
2037 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2038 u64 bytenr = btrfs_super_log_root(disk_super);
2039
2040 if (fs_devices->rw_devices == 0) {
2041 printk(KERN_WARNING "Btrfs log replay required "
2042 "on RO media\n");
2043 err = -EIO;
2044 goto fail_trans_kthread;
2045 }
2046 blocksize =
2047 btrfs_level_size(tree_root,
2048 btrfs_super_log_root_level(disk_super));
2049
2050 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2051 if (!log_tree_root) {
2052 err = -ENOMEM;
2053 goto fail_trans_kthread;
2054 }
2055
2056 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2057 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2058
2059 log_tree_root->node = read_tree_block(tree_root, bytenr,
2060 blocksize,
2061 generation + 1);
2062 ret = btrfs_recover_log_trees(log_tree_root);
2063 BUG_ON(ret);
2064
2065 if (sb->s_flags & MS_RDONLY) {
2066 ret = btrfs_commit_super(tree_root);
2067 BUG_ON(ret);
2068 }
2069 }
2070
2071 ret = btrfs_find_orphan_roots(tree_root);
2072 BUG_ON(ret);
2073
2074 if (!(sb->s_flags & MS_RDONLY)) {
2075 ret = btrfs_cleanup_fs_roots(fs_info);
2076 BUG_ON(ret);
2077
2078 ret = btrfs_recover_relocation(tree_root);
2079 if (ret < 0) {
2080 printk(KERN_WARNING
2081 "btrfs: failed to recover relocation\n");
2082 err = -EINVAL;
2083 goto fail_trans_kthread;
2084 }
2085 }
2086
2087 location.objectid = BTRFS_FS_TREE_OBJECTID;
2088 location.type = BTRFS_ROOT_ITEM_KEY;
2089 location.offset = (u64)-1;
2090
2091 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2092 if (!fs_info->fs_root)
2093 goto fail_trans_kthread;
2094 if (IS_ERR(fs_info->fs_root)) {
2095 err = PTR_ERR(fs_info->fs_root);
2096 goto fail_trans_kthread;
2097 }
2098
2099 if (!(sb->s_flags & MS_RDONLY)) {
2100 down_read(&fs_info->cleanup_work_sem);
2101 err = btrfs_orphan_cleanup(fs_info->fs_root);
2102 if (!err)
2103 err = btrfs_orphan_cleanup(fs_info->tree_root);
2104 up_read(&fs_info->cleanup_work_sem);
2105 if (err) {
2106 close_ctree(tree_root);
2107 return ERR_PTR(err);
2108 }
2109 }
2110
2111 return tree_root;
2112
2113 fail_trans_kthread:
2114 kthread_stop(fs_info->transaction_kthread);
2115 fail_cleaner:
2116 kthread_stop(fs_info->cleaner_kthread);
2117
2118 /*
2119 * make sure we're done with the btree inode before we stop our
2120 * kthreads
2121 */
2122 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2123 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2124
2125 fail_block_groups:
2126 btrfs_free_block_groups(fs_info);
2127 free_extent_buffer(csum_root->node);
2128 free_extent_buffer(csum_root->commit_root);
2129 fail_dev_root:
2130 free_extent_buffer(dev_root->node);
2131 free_extent_buffer(dev_root->commit_root);
2132 fail_extent_root:
2133 free_extent_buffer(extent_root->node);
2134 free_extent_buffer(extent_root->commit_root);
2135 fail_tree_root:
2136 free_extent_buffer(tree_root->node);
2137 free_extent_buffer(tree_root->commit_root);
2138 fail_chunk_root:
2139 free_extent_buffer(chunk_root->node);
2140 free_extent_buffer(chunk_root->commit_root);
2141 fail_sb_buffer:
2142 btrfs_stop_workers(&fs_info->generic_worker);
2143 btrfs_stop_workers(&fs_info->fixup_workers);
2144 btrfs_stop_workers(&fs_info->delalloc_workers);
2145 btrfs_stop_workers(&fs_info->workers);
2146 btrfs_stop_workers(&fs_info->endio_workers);
2147 btrfs_stop_workers(&fs_info->endio_meta_workers);
2148 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2149 btrfs_stop_workers(&fs_info->endio_write_workers);
2150 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2151 btrfs_stop_workers(&fs_info->submit_workers);
2152 btrfs_stop_workers(&fs_info->delayed_workers);
2153 btrfs_stop_workers(&fs_info->caching_workers);
2154 fail_alloc:
2155 kfree(fs_info->delayed_root);
2156 fail_iput:
2157 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2158 iput(fs_info->btree_inode);
2159
2160 btrfs_close_devices(fs_info->fs_devices);
2161 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2162 fail_bdi:
2163 bdi_destroy(&fs_info->bdi);
2164 fail_srcu:
2165 cleanup_srcu_struct(&fs_info->subvol_srcu);
2166 fail:
2167 kfree(extent_root);
2168 kfree(tree_root);
2169 kfree(fs_info);
2170 kfree(chunk_root);
2171 kfree(dev_root);
2172 kfree(csum_root);
2173 return ERR_PTR(err);
2174 }
2175
2176 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2177 {
2178 char b[BDEVNAME_SIZE];
2179
2180 if (uptodate) {
2181 set_buffer_uptodate(bh);
2182 } else {
2183 printk_ratelimited(KERN_WARNING "lost page write due to "
2184 "I/O error on %s\n",
2185 bdevname(bh->b_bdev, b));
2186 /* note, we dont' set_buffer_write_io_error because we have
2187 * our own ways of dealing with the IO errors
2188 */
2189 clear_buffer_uptodate(bh);
2190 }
2191 unlock_buffer(bh);
2192 put_bh(bh);
2193 }
2194
2195 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2196 {
2197 struct buffer_head *bh;
2198 struct buffer_head *latest = NULL;
2199 struct btrfs_super_block *super;
2200 int i;
2201 u64 transid = 0;
2202 u64 bytenr;
2203
2204 /* we would like to check all the supers, but that would make
2205 * a btrfs mount succeed after a mkfs from a different FS.
2206 * So, we need to add a special mount option to scan for
2207 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2208 */
2209 for (i = 0; i < 1; i++) {
2210 bytenr = btrfs_sb_offset(i);
2211 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2212 break;
2213 bh = __bread(bdev, bytenr / 4096, 4096);
2214 if (!bh)
2215 continue;
2216
2217 super = (struct btrfs_super_block *)bh->b_data;
2218 if (btrfs_super_bytenr(super) != bytenr ||
2219 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2220 sizeof(super->magic))) {
2221 brelse(bh);
2222 continue;
2223 }
2224
2225 if (!latest || btrfs_super_generation(super) > transid) {
2226 brelse(latest);
2227 latest = bh;
2228 transid = btrfs_super_generation(super);
2229 } else {
2230 brelse(bh);
2231 }
2232 }
2233 return latest;
2234 }
2235
2236 /*
2237 * this should be called twice, once with wait == 0 and
2238 * once with wait == 1. When wait == 0 is done, all the buffer heads
2239 * we write are pinned.
2240 *
2241 * They are released when wait == 1 is done.
2242 * max_mirrors must be the same for both runs, and it indicates how
2243 * many supers on this one device should be written.
2244 *
2245 * max_mirrors == 0 means to write them all.
2246 */
2247 static int write_dev_supers(struct btrfs_device *device,
2248 struct btrfs_super_block *sb,
2249 int do_barriers, int wait, int max_mirrors)
2250 {
2251 struct buffer_head *bh;
2252 int i;
2253 int ret;
2254 int errors = 0;
2255 u32 crc;
2256 u64 bytenr;
2257 int last_barrier = 0;
2258
2259 if (max_mirrors == 0)
2260 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2261
2262 /* make sure only the last submit_bh does a barrier */
2263 if (do_barriers) {
2264 for (i = 0; i < max_mirrors; i++) {
2265 bytenr = btrfs_sb_offset(i);
2266 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2267 device->total_bytes)
2268 break;
2269 last_barrier = i;
2270 }
2271 }
2272
2273 for (i = 0; i < max_mirrors; i++) {
2274 bytenr = btrfs_sb_offset(i);
2275 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2276 break;
2277
2278 if (wait) {
2279 bh = __find_get_block(device->bdev, bytenr / 4096,
2280 BTRFS_SUPER_INFO_SIZE);
2281 BUG_ON(!bh);
2282 wait_on_buffer(bh);
2283 if (!buffer_uptodate(bh))
2284 errors++;
2285
2286 /* drop our reference */
2287 brelse(bh);
2288
2289 /* drop the reference from the wait == 0 run */
2290 brelse(bh);
2291 continue;
2292 } else {
2293 btrfs_set_super_bytenr(sb, bytenr);
2294
2295 crc = ~(u32)0;
2296 crc = btrfs_csum_data(NULL, (char *)sb +
2297 BTRFS_CSUM_SIZE, crc,
2298 BTRFS_SUPER_INFO_SIZE -
2299 BTRFS_CSUM_SIZE);
2300 btrfs_csum_final(crc, sb->csum);
2301
2302 /*
2303 * one reference for us, and we leave it for the
2304 * caller
2305 */
2306 bh = __getblk(device->bdev, bytenr / 4096,
2307 BTRFS_SUPER_INFO_SIZE);
2308 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2309
2310 /* one reference for submit_bh */
2311 get_bh(bh);
2312
2313 set_buffer_uptodate(bh);
2314 lock_buffer(bh);
2315 bh->b_end_io = btrfs_end_buffer_write_sync;
2316 }
2317
2318 if (i == last_barrier && do_barriers)
2319 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2320 else
2321 ret = submit_bh(WRITE_SYNC, bh);
2322
2323 if (ret)
2324 errors++;
2325 }
2326 return errors < i ? 0 : -1;
2327 }
2328
2329 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2330 {
2331 struct list_head *head;
2332 struct btrfs_device *dev;
2333 struct btrfs_super_block *sb;
2334 struct btrfs_dev_item *dev_item;
2335 int ret;
2336 int do_barriers;
2337 int max_errors;
2338 int total_errors = 0;
2339 u64 flags;
2340
2341 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2342 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2343
2344 sb = &root->fs_info->super_for_commit;
2345 dev_item = &sb->dev_item;
2346
2347 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2348 head = &root->fs_info->fs_devices->devices;
2349 list_for_each_entry_rcu(dev, head, dev_list) {
2350 if (!dev->bdev) {
2351 total_errors++;
2352 continue;
2353 }
2354 if (!dev->in_fs_metadata || !dev->writeable)
2355 continue;
2356
2357 btrfs_set_stack_device_generation(dev_item, 0);
2358 btrfs_set_stack_device_type(dev_item, dev->type);
2359 btrfs_set_stack_device_id(dev_item, dev->devid);
2360 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2361 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2362 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2363 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2364 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2365 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2366 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2367
2368 flags = btrfs_super_flags(sb);
2369 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2370
2371 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2372 if (ret)
2373 total_errors++;
2374 }
2375 if (total_errors > max_errors) {
2376 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2377 total_errors);
2378 BUG();
2379 }
2380
2381 total_errors = 0;
2382 list_for_each_entry_rcu(dev, head, dev_list) {
2383 if (!dev->bdev)
2384 continue;
2385 if (!dev->in_fs_metadata || !dev->writeable)
2386 continue;
2387
2388 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2389 if (ret)
2390 total_errors++;
2391 }
2392 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2393 if (total_errors > max_errors) {
2394 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2395 total_errors);
2396 BUG();
2397 }
2398 return 0;
2399 }
2400
2401 int write_ctree_super(struct btrfs_trans_handle *trans,
2402 struct btrfs_root *root, int max_mirrors)
2403 {
2404 int ret;
2405
2406 ret = write_all_supers(root, max_mirrors);
2407 return ret;
2408 }
2409
2410 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2411 {
2412 spin_lock(&fs_info->fs_roots_radix_lock);
2413 radix_tree_delete(&fs_info->fs_roots_radix,
2414 (unsigned long)root->root_key.objectid);
2415 spin_unlock(&fs_info->fs_roots_radix_lock);
2416
2417 if (btrfs_root_refs(&root->root_item) == 0)
2418 synchronize_srcu(&fs_info->subvol_srcu);
2419
2420 __btrfs_remove_free_space_cache(root->free_ino_pinned);
2421 __btrfs_remove_free_space_cache(root->free_ino_ctl);
2422 free_fs_root(root);
2423 return 0;
2424 }
2425
2426 static void free_fs_root(struct btrfs_root *root)
2427 {
2428 iput(root->cache_inode);
2429 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2430 if (root->anon_dev)
2431 free_anon_bdev(root->anon_dev);
2432 free_extent_buffer(root->node);
2433 free_extent_buffer(root->commit_root);
2434 kfree(root->free_ino_ctl);
2435 kfree(root->free_ino_pinned);
2436 kfree(root->name);
2437 kfree(root);
2438 }
2439
2440 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2441 {
2442 int ret;
2443 struct btrfs_root *gang[8];
2444 int i;
2445
2446 while (!list_empty(&fs_info->dead_roots)) {
2447 gang[0] = list_entry(fs_info->dead_roots.next,
2448 struct btrfs_root, root_list);
2449 list_del(&gang[0]->root_list);
2450
2451 if (gang[0]->in_radix) {
2452 btrfs_free_fs_root(fs_info, gang[0]);
2453 } else {
2454 free_extent_buffer(gang[0]->node);
2455 free_extent_buffer(gang[0]->commit_root);
2456 kfree(gang[0]);
2457 }
2458 }
2459
2460 while (1) {
2461 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2462 (void **)gang, 0,
2463 ARRAY_SIZE(gang));
2464 if (!ret)
2465 break;
2466 for (i = 0; i < ret; i++)
2467 btrfs_free_fs_root(fs_info, gang[i]);
2468 }
2469 return 0;
2470 }
2471
2472 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2473 {
2474 u64 root_objectid = 0;
2475 struct btrfs_root *gang[8];
2476 int i;
2477 int ret;
2478
2479 while (1) {
2480 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2481 (void **)gang, root_objectid,
2482 ARRAY_SIZE(gang));
2483 if (!ret)
2484 break;
2485
2486 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2487 for (i = 0; i < ret; i++) {
2488 int err;
2489
2490 root_objectid = gang[i]->root_key.objectid;
2491 err = btrfs_orphan_cleanup(gang[i]);
2492 if (err)
2493 return err;
2494 }
2495 root_objectid++;
2496 }
2497 return 0;
2498 }
2499
2500 int btrfs_commit_super(struct btrfs_root *root)
2501 {
2502 struct btrfs_trans_handle *trans;
2503 int ret;
2504
2505 mutex_lock(&root->fs_info->cleaner_mutex);
2506 btrfs_run_delayed_iputs(root);
2507 btrfs_clean_old_snapshots(root);
2508 mutex_unlock(&root->fs_info->cleaner_mutex);
2509
2510 /* wait until ongoing cleanup work done */
2511 down_write(&root->fs_info->cleanup_work_sem);
2512 up_write(&root->fs_info->cleanup_work_sem);
2513
2514 trans = btrfs_join_transaction(root);
2515 if (IS_ERR(trans))
2516 return PTR_ERR(trans);
2517 ret = btrfs_commit_transaction(trans, root);
2518 BUG_ON(ret);
2519 /* run commit again to drop the original snapshot */
2520 trans = btrfs_join_transaction(root);
2521 if (IS_ERR(trans))
2522 return PTR_ERR(trans);
2523 btrfs_commit_transaction(trans, root);
2524 ret = btrfs_write_and_wait_transaction(NULL, root);
2525 BUG_ON(ret);
2526
2527 ret = write_ctree_super(NULL, root, 0);
2528 return ret;
2529 }
2530
2531 int close_ctree(struct btrfs_root *root)
2532 {
2533 struct btrfs_fs_info *fs_info = root->fs_info;
2534 int ret;
2535
2536 fs_info->closing = 1;
2537 smp_mb();
2538
2539 btrfs_scrub_cancel(root);
2540
2541 /* wait for any defraggers to finish */
2542 wait_event(fs_info->transaction_wait,
2543 (atomic_read(&fs_info->defrag_running) == 0));
2544
2545 /* clear out the rbtree of defraggable inodes */
2546 btrfs_run_defrag_inodes(root->fs_info);
2547
2548 btrfs_put_block_group_cache(fs_info);
2549
2550 /*
2551 * Here come 2 situations when btrfs is broken to flip readonly:
2552 *
2553 * 1. when btrfs flips readonly somewhere else before
2554 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2555 * and btrfs will skip to write sb directly to keep
2556 * ERROR state on disk.
2557 *
2558 * 2. when btrfs flips readonly just in btrfs_commit_super,
2559 * and in such case, btrfs cannot write sb via btrfs_commit_super,
2560 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2561 * btrfs will cleanup all FS resources first and write sb then.
2562 */
2563 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2564 ret = btrfs_commit_super(root);
2565 if (ret)
2566 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2567 }
2568
2569 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2570 ret = btrfs_error_commit_super(root);
2571 if (ret)
2572 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2573 }
2574
2575 kthread_stop(root->fs_info->transaction_kthread);
2576 kthread_stop(root->fs_info->cleaner_kthread);
2577
2578 fs_info->closing = 2;
2579 smp_mb();
2580
2581 if (fs_info->delalloc_bytes) {
2582 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2583 (unsigned long long)fs_info->delalloc_bytes);
2584 }
2585 if (fs_info->total_ref_cache_size) {
2586 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2587 (unsigned long long)fs_info->total_ref_cache_size);
2588 }
2589
2590 free_extent_buffer(fs_info->extent_root->node);
2591 free_extent_buffer(fs_info->extent_root->commit_root);
2592 free_extent_buffer(fs_info->tree_root->node);
2593 free_extent_buffer(fs_info->tree_root->commit_root);
2594 free_extent_buffer(root->fs_info->chunk_root->node);
2595 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2596 free_extent_buffer(root->fs_info->dev_root->node);
2597 free_extent_buffer(root->fs_info->dev_root->commit_root);
2598 free_extent_buffer(root->fs_info->csum_root->node);
2599 free_extent_buffer(root->fs_info->csum_root->commit_root);
2600
2601 btrfs_free_block_groups(root->fs_info);
2602
2603 del_fs_roots(fs_info);
2604
2605 iput(fs_info->btree_inode);
2606 kfree(fs_info->delayed_root);
2607
2608 btrfs_stop_workers(&fs_info->generic_worker);
2609 btrfs_stop_workers(&fs_info->fixup_workers);
2610 btrfs_stop_workers(&fs_info->delalloc_workers);
2611 btrfs_stop_workers(&fs_info->workers);
2612 btrfs_stop_workers(&fs_info->endio_workers);
2613 btrfs_stop_workers(&fs_info->endio_meta_workers);
2614 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2615 btrfs_stop_workers(&fs_info->endio_write_workers);
2616 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2617 btrfs_stop_workers(&fs_info->submit_workers);
2618 btrfs_stop_workers(&fs_info->delayed_workers);
2619 btrfs_stop_workers(&fs_info->caching_workers);
2620
2621 btrfs_close_devices(fs_info->fs_devices);
2622 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2623
2624 bdi_destroy(&fs_info->bdi);
2625 cleanup_srcu_struct(&fs_info->subvol_srcu);
2626
2627 kfree(fs_info->extent_root);
2628 kfree(fs_info->tree_root);
2629 kfree(fs_info->chunk_root);
2630 kfree(fs_info->dev_root);
2631 kfree(fs_info->csum_root);
2632 kfree(fs_info);
2633
2634 return 0;
2635 }
2636
2637 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2638 {
2639 int ret;
2640 struct inode *btree_inode = buf->first_page->mapping->host;
2641
2642 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2643 NULL);
2644 if (!ret)
2645 return ret;
2646
2647 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2648 parent_transid);
2649 return !ret;
2650 }
2651
2652 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2653 {
2654 struct inode *btree_inode = buf->first_page->mapping->host;
2655 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2656 buf);
2657 }
2658
2659 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2660 {
2661 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2662 u64 transid = btrfs_header_generation(buf);
2663 struct inode *btree_inode = root->fs_info->btree_inode;
2664 int was_dirty;
2665
2666 btrfs_assert_tree_locked(buf);
2667 if (transid != root->fs_info->generation) {
2668 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2669 "found %llu running %llu\n",
2670 (unsigned long long)buf->start,
2671 (unsigned long long)transid,
2672 (unsigned long long)root->fs_info->generation);
2673 WARN_ON(1);
2674 }
2675 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2676 buf);
2677 if (!was_dirty) {
2678 spin_lock(&root->fs_info->delalloc_lock);
2679 root->fs_info->dirty_metadata_bytes += buf->len;
2680 spin_unlock(&root->fs_info->delalloc_lock);
2681 }
2682 }
2683
2684 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2685 {
2686 /*
2687 * looks as though older kernels can get into trouble with
2688 * this code, they end up stuck in balance_dirty_pages forever
2689 */
2690 u64 num_dirty;
2691 unsigned long thresh = 32 * 1024 * 1024;
2692
2693 if (current->flags & PF_MEMALLOC)
2694 return;
2695
2696 btrfs_balance_delayed_items(root);
2697
2698 num_dirty = root->fs_info->dirty_metadata_bytes;
2699
2700 if (num_dirty > thresh) {
2701 balance_dirty_pages_ratelimited_nr(
2702 root->fs_info->btree_inode->i_mapping, 1);
2703 }
2704 return;
2705 }
2706
2707 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2708 {
2709 /*
2710 * looks as though older kernels can get into trouble with
2711 * this code, they end up stuck in balance_dirty_pages forever
2712 */
2713 u64 num_dirty;
2714 unsigned long thresh = 32 * 1024 * 1024;
2715
2716 if (current->flags & PF_MEMALLOC)
2717 return;
2718
2719 num_dirty = root->fs_info->dirty_metadata_bytes;
2720
2721 if (num_dirty > thresh) {
2722 balance_dirty_pages_ratelimited_nr(
2723 root->fs_info->btree_inode->i_mapping, 1);
2724 }
2725 return;
2726 }
2727
2728 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2729 {
2730 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2731 int ret;
2732 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2733 if (ret == 0)
2734 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2735 return ret;
2736 }
2737
2738 int btree_lock_page_hook(struct page *page)
2739 {
2740 struct inode *inode = page->mapping->host;
2741 struct btrfs_root *root = BTRFS_I(inode)->root;
2742 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2743 struct extent_buffer *eb;
2744 unsigned long len;
2745 u64 bytenr = page_offset(page);
2746
2747 if (page->private == EXTENT_PAGE_PRIVATE)
2748 goto out;
2749
2750 len = page->private >> 2;
2751 eb = find_extent_buffer(io_tree, bytenr, len);
2752 if (!eb)
2753 goto out;
2754
2755 btrfs_tree_lock(eb);
2756 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2757
2758 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2759 spin_lock(&root->fs_info->delalloc_lock);
2760 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2761 root->fs_info->dirty_metadata_bytes -= eb->len;
2762 else
2763 WARN_ON(1);
2764 spin_unlock(&root->fs_info->delalloc_lock);
2765 }
2766
2767 btrfs_tree_unlock(eb);
2768 free_extent_buffer(eb);
2769 out:
2770 lock_page(page);
2771 return 0;
2772 }
2773
2774 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2775 int read_only)
2776 {
2777 if (read_only)
2778 return;
2779
2780 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2781 printk(KERN_WARNING "warning: mount fs with errors, "
2782 "running btrfsck is recommended\n");
2783 }
2784
2785 int btrfs_error_commit_super(struct btrfs_root *root)
2786 {
2787 int ret;
2788
2789 mutex_lock(&root->fs_info->cleaner_mutex);
2790 btrfs_run_delayed_iputs(root);
2791 mutex_unlock(&root->fs_info->cleaner_mutex);
2792
2793 down_write(&root->fs_info->cleanup_work_sem);
2794 up_write(&root->fs_info->cleanup_work_sem);
2795
2796 /* cleanup FS via transaction */
2797 btrfs_cleanup_transaction(root);
2798
2799 ret = write_ctree_super(NULL, root, 0);
2800
2801 return ret;
2802 }
2803
2804 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2805 {
2806 struct btrfs_inode *btrfs_inode;
2807 struct list_head splice;
2808
2809 INIT_LIST_HEAD(&splice);
2810
2811 mutex_lock(&root->fs_info->ordered_operations_mutex);
2812 spin_lock(&root->fs_info->ordered_extent_lock);
2813
2814 list_splice_init(&root->fs_info->ordered_operations, &splice);
2815 while (!list_empty(&splice)) {
2816 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2817 ordered_operations);
2818
2819 list_del_init(&btrfs_inode->ordered_operations);
2820
2821 btrfs_invalidate_inodes(btrfs_inode->root);
2822 }
2823
2824 spin_unlock(&root->fs_info->ordered_extent_lock);
2825 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2826
2827 return 0;
2828 }
2829
2830 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2831 {
2832 struct list_head splice;
2833 struct btrfs_ordered_extent *ordered;
2834 struct inode *inode;
2835
2836 INIT_LIST_HEAD(&splice);
2837
2838 spin_lock(&root->fs_info->ordered_extent_lock);
2839
2840 list_splice_init(&root->fs_info->ordered_extents, &splice);
2841 while (!list_empty(&splice)) {
2842 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2843 root_extent_list);
2844
2845 list_del_init(&ordered->root_extent_list);
2846 atomic_inc(&ordered->refs);
2847
2848 /* the inode may be getting freed (in sys_unlink path). */
2849 inode = igrab(ordered->inode);
2850
2851 spin_unlock(&root->fs_info->ordered_extent_lock);
2852 if (inode)
2853 iput(inode);
2854
2855 atomic_set(&ordered->refs, 1);
2856 btrfs_put_ordered_extent(ordered);
2857
2858 spin_lock(&root->fs_info->ordered_extent_lock);
2859 }
2860
2861 spin_unlock(&root->fs_info->ordered_extent_lock);
2862
2863 return 0;
2864 }
2865
2866 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2867 struct btrfs_root *root)
2868 {
2869 struct rb_node *node;
2870 struct btrfs_delayed_ref_root *delayed_refs;
2871 struct btrfs_delayed_ref_node *ref;
2872 int ret = 0;
2873
2874 delayed_refs = &trans->delayed_refs;
2875
2876 spin_lock(&delayed_refs->lock);
2877 if (delayed_refs->num_entries == 0) {
2878 spin_unlock(&delayed_refs->lock);
2879 printk(KERN_INFO "delayed_refs has NO entry\n");
2880 return ret;
2881 }
2882
2883 node = rb_first(&delayed_refs->root);
2884 while (node) {
2885 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2886 node = rb_next(node);
2887
2888 ref->in_tree = 0;
2889 rb_erase(&ref->rb_node, &delayed_refs->root);
2890 delayed_refs->num_entries--;
2891
2892 atomic_set(&ref->refs, 1);
2893 if (btrfs_delayed_ref_is_head(ref)) {
2894 struct btrfs_delayed_ref_head *head;
2895
2896 head = btrfs_delayed_node_to_head(ref);
2897 mutex_lock(&head->mutex);
2898 kfree(head->extent_op);
2899 delayed_refs->num_heads--;
2900 if (list_empty(&head->cluster))
2901 delayed_refs->num_heads_ready--;
2902 list_del_init(&head->cluster);
2903 mutex_unlock(&head->mutex);
2904 }
2905
2906 spin_unlock(&delayed_refs->lock);
2907 btrfs_put_delayed_ref(ref);
2908
2909 cond_resched();
2910 spin_lock(&delayed_refs->lock);
2911 }
2912
2913 spin_unlock(&delayed_refs->lock);
2914
2915 return ret;
2916 }
2917
2918 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2919 {
2920 struct btrfs_pending_snapshot *snapshot;
2921 struct list_head splice;
2922
2923 INIT_LIST_HEAD(&splice);
2924
2925 list_splice_init(&t->pending_snapshots, &splice);
2926
2927 while (!list_empty(&splice)) {
2928 snapshot = list_entry(splice.next,
2929 struct btrfs_pending_snapshot,
2930 list);
2931
2932 list_del_init(&snapshot->list);
2933
2934 kfree(snapshot);
2935 }
2936
2937 return 0;
2938 }
2939
2940 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2941 {
2942 struct btrfs_inode *btrfs_inode;
2943 struct list_head splice;
2944
2945 INIT_LIST_HEAD(&splice);
2946
2947 spin_lock(&root->fs_info->delalloc_lock);
2948 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2949
2950 while (!list_empty(&splice)) {
2951 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2952 delalloc_inodes);
2953
2954 list_del_init(&btrfs_inode->delalloc_inodes);
2955
2956 btrfs_invalidate_inodes(btrfs_inode->root);
2957 }
2958
2959 spin_unlock(&root->fs_info->delalloc_lock);
2960
2961 return 0;
2962 }
2963
2964 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2965 struct extent_io_tree *dirty_pages,
2966 int mark)
2967 {
2968 int ret;
2969 struct page *page;
2970 struct inode *btree_inode = root->fs_info->btree_inode;
2971 struct extent_buffer *eb;
2972 u64 start = 0;
2973 u64 end;
2974 u64 offset;
2975 unsigned long index;
2976
2977 while (1) {
2978 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2979 mark);
2980 if (ret)
2981 break;
2982
2983 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2984 while (start <= end) {
2985 index = start >> PAGE_CACHE_SHIFT;
2986 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2987 page = find_get_page(btree_inode->i_mapping, index);
2988 if (!page)
2989 continue;
2990 offset = page_offset(page);
2991
2992 spin_lock(&dirty_pages->buffer_lock);
2993 eb = radix_tree_lookup(
2994 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2995 offset >> PAGE_CACHE_SHIFT);
2996 spin_unlock(&dirty_pages->buffer_lock);
2997 if (eb) {
2998 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2999 &eb->bflags);
3000 atomic_set(&eb->refs, 1);
3001 }
3002 if (PageWriteback(page))
3003 end_page_writeback(page);
3004
3005 lock_page(page);
3006 if (PageDirty(page)) {
3007 clear_page_dirty_for_io(page);
3008 spin_lock_irq(&page->mapping->tree_lock);
3009 radix_tree_tag_clear(&page->mapping->page_tree,
3010 page_index(page),
3011 PAGECACHE_TAG_DIRTY);
3012 spin_unlock_irq(&page->mapping->tree_lock);
3013 }
3014
3015 page->mapping->a_ops->invalidatepage(page, 0);
3016 unlock_page(page);
3017 }
3018 }
3019
3020 return ret;
3021 }
3022
3023 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3024 struct extent_io_tree *pinned_extents)
3025 {
3026 struct extent_io_tree *unpin;
3027 u64 start;
3028 u64 end;
3029 int ret;
3030
3031 unpin = pinned_extents;
3032 while (1) {
3033 ret = find_first_extent_bit(unpin, 0, &start, &end,
3034 EXTENT_DIRTY);
3035 if (ret)
3036 break;
3037
3038 /* opt_discard */
3039 if (btrfs_test_opt(root, DISCARD))
3040 ret = btrfs_error_discard_extent(root, start,
3041 end + 1 - start,
3042 NULL);
3043
3044 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3045 btrfs_error_unpin_extent_range(root, start, end);
3046 cond_resched();
3047 }
3048
3049 return 0;
3050 }
3051
3052 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3053 {
3054 struct btrfs_transaction *t;
3055 LIST_HEAD(list);
3056
3057 WARN_ON(1);
3058
3059 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3060
3061 spin_lock(&root->fs_info->trans_lock);
3062 list_splice_init(&root->fs_info->trans_list, &list);
3063 root->fs_info->trans_no_join = 1;
3064 spin_unlock(&root->fs_info->trans_lock);
3065
3066 while (!list_empty(&list)) {
3067 t = list_entry(list.next, struct btrfs_transaction, list);
3068 if (!t)
3069 break;
3070
3071 btrfs_destroy_ordered_operations(root);
3072
3073 btrfs_destroy_ordered_extents(root);
3074
3075 btrfs_destroy_delayed_refs(t, root);
3076
3077 btrfs_block_rsv_release(root,
3078 &root->fs_info->trans_block_rsv,
3079 t->dirty_pages.dirty_bytes);
3080
3081 /* FIXME: cleanup wait for commit */
3082 t->in_commit = 1;
3083 t->blocked = 1;
3084 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3085 wake_up(&root->fs_info->transaction_blocked_wait);
3086
3087 t->blocked = 0;
3088 if (waitqueue_active(&root->fs_info->transaction_wait))
3089 wake_up(&root->fs_info->transaction_wait);
3090
3091 t->commit_done = 1;
3092 if (waitqueue_active(&t->commit_wait))
3093 wake_up(&t->commit_wait);
3094
3095 btrfs_destroy_pending_snapshots(t);
3096
3097 btrfs_destroy_delalloc_inodes(root);
3098
3099 spin_lock(&root->fs_info->trans_lock);
3100 root->fs_info->running_transaction = NULL;
3101 spin_unlock(&root->fs_info->trans_lock);
3102
3103 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3104 EXTENT_DIRTY);
3105
3106 btrfs_destroy_pinned_extent(root,
3107 root->fs_info->pinned_extents);
3108
3109 atomic_set(&t->use_count, 0);
3110 list_del_init(&t->list);
3111 memset(t, 0, sizeof(*t));
3112 kmem_cache_free(btrfs_transaction_cachep, t);
3113 }
3114
3115 spin_lock(&root->fs_info->trans_lock);
3116 root->fs_info->trans_no_join = 0;
3117 spin_unlock(&root->fs_info->trans_lock);
3118 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3119
3120 return 0;
3121 }
3122
3123 static struct extent_io_ops btree_extent_io_ops = {
3124 .write_cache_pages_lock_hook = btree_lock_page_hook,
3125 .readpage_end_io_hook = btree_readpage_end_io_hook,
3126 .submit_bio_hook = btree_submit_bio_hook,
3127 /* note we're sharing with inode.c for the merge bio hook */
3128 .merge_bio_hook = btrfs_merge_bio_hook,
3129 };
Linux Btrfs Development