1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
7 #include <linux/blkdev.h>
8 #include <linux/radix-tree.h>
9 #include <linux/writeback.h>
10 #include <linux/workqueue.h>
11 #include <linux/kthread.h>
12 #include <linux/slab.h>
13 #include <linux/migrate.h>
14 #include <linux/ratelimit.h>
15 #include <linux/uuid.h>
16 #include <linux/semaphore.h>
17 #include <linux/error-injection.h>
18 #include <linux/crc32c.h>
19 #include <linux/sched/mm.h>
20 #include <asm/unaligned.h>
21 #include <crypto/hash.h>
24 #include "transaction.h"
25 #include "btrfs_inode.h"
27 #include "print-tree.h"
30 #include "free-space-cache.h"
31 #include "free-space-tree.h"
32 #include "check-integrity.h"
33 #include "rcu-string.h"
34 #include "dev-replace.h"
38 #include "compression.h"
39 #include "tree-checker.h"
40 #include "ref-verify.h"
41 #include "block-group.h"
43 #include "space-info.h"
47 #define BTRFS_SUPER_FLAG_SUPP (BTRFS_HEADER_FLAG_WRITTEN |\
48 BTRFS_HEADER_FLAG_RELOC |\
49 BTRFS_SUPER_FLAG_ERROR |\
50 BTRFS_SUPER_FLAG_SEEDING |\
51 BTRFS_SUPER_FLAG_METADUMP |\
52 BTRFS_SUPER_FLAG_METADUMP_V2)
54 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
55 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
56 struct btrfs_fs_info *fs_info);
57 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
58 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
59 struct extent_io_tree *dirty_pages,
61 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
62 struct extent_io_tree *pinned_extents);
63 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
64 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
66 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
68 if (fs_info->csum_shash)
69 crypto_free_shash(fs_info->csum_shash);
73 * async submit bios are used to offload expensive checksumming
74 * onto the worker threads. They checksum file and metadata bios
75 * just before they are sent down the IO stack.
77 struct async_submit_bio {
80 extent_submit_bio_start_t *submit_bio_start;
83 /* Optional parameter for submit_bio_start used by direct io */
85 struct btrfs_work work;
90 * Lockdep class keys for extent_buffer->lock's in this root. For a given
91 * eb, the lockdep key is determined by the btrfs_root it belongs to and
92 * the level the eb occupies in the tree.
94 * Different roots are used for different purposes and may nest inside each
95 * other and they require separate keysets. As lockdep keys should be
96 * static, assign keysets according to the purpose of the root as indicated
97 * by btrfs_root->root_key.objectid. This ensures that all special purpose
98 * roots have separate keysets.
100 * Lock-nesting across peer nodes is always done with the immediate parent
101 * node locked thus preventing deadlock. As lockdep doesn't know this, use
102 * subclass to avoid triggering lockdep warning in such cases.
104 * The key is set by the readpage_end_io_hook after the buffer has passed
105 * csum validation but before the pages are unlocked. It is also set by
106 * btrfs_init_new_buffer on freshly allocated blocks.
108 * We also add a check to make sure the highest level of the tree is the
109 * same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this code
110 * needs update as well.
112 #ifdef CONFIG_DEBUG_LOCK_ALLOC
113 # if BTRFS_MAX_LEVEL != 8
117 #define DEFINE_LEVEL(stem, level) \
118 .names[level] = "btrfs-" stem "-0" #level,
120 #define DEFINE_NAME(stem) \
121 DEFINE_LEVEL(stem, 0) \
122 DEFINE_LEVEL(stem, 1) \
123 DEFINE_LEVEL(stem, 2) \
124 DEFINE_LEVEL(stem, 3) \
125 DEFINE_LEVEL(stem, 4) \
126 DEFINE_LEVEL(stem, 5) \
127 DEFINE_LEVEL(stem, 6) \
128 DEFINE_LEVEL(stem, 7)
130 static struct btrfs_lockdep_keyset {
131 u64 id; /* root objectid */
132 /* Longest entry: btrfs-free-space-00 */
133 char names[BTRFS_MAX_LEVEL][20];
134 struct lock_class_key keys[BTRFS_MAX_LEVEL];
135 } btrfs_lockdep_keysets[] = {
136 { .id = BTRFS_ROOT_TREE_OBJECTID, DEFINE_NAME("root") },
137 { .id = BTRFS_EXTENT_TREE_OBJECTID, DEFINE_NAME("extent") },
138 { .id = BTRFS_CHUNK_TREE_OBJECTID, DEFINE_NAME("chunk") },
139 { .id = BTRFS_DEV_TREE_OBJECTID, DEFINE_NAME("dev") },
140 { .id = BTRFS_CSUM_TREE_OBJECTID, DEFINE_NAME("csum") },
141 { .id = BTRFS_QUOTA_TREE_OBJECTID, DEFINE_NAME("quota") },
142 { .id = BTRFS_TREE_LOG_OBJECTID, DEFINE_NAME("log") },
143 { .id = BTRFS_TREE_RELOC_OBJECTID, DEFINE_NAME("treloc") },
144 { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, DEFINE_NAME("dreloc") },
145 { .id = BTRFS_UUID_TREE_OBJECTID, DEFINE_NAME("uuid") },
146 { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, DEFINE_NAME("free-space") },
147 { .id = 0, DEFINE_NAME("tree") },
153 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
156 struct btrfs_lockdep_keyset *ks;
158 BUG_ON(level >= ARRAY_SIZE(ks->keys));
160 /* find the matching keyset, id 0 is the default entry */
161 for (ks = btrfs_lockdep_keysets; ks->id; ks++)
162 if (ks->id == objectid)
165 lockdep_set_class_and_name(&eb->lock,
166 &ks->keys[level], ks->names[level]);
172 * Compute the csum of a btree block and store the result to provided buffer.
174 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
176 struct btrfs_fs_info *fs_info = buf->fs_info;
177 const int num_pages = num_extent_pages(buf);
178 const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
179 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
183 shash->tfm = fs_info->csum_shash;
184 crypto_shash_init(shash);
185 kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
186 crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
187 first_page_part - BTRFS_CSUM_SIZE);
189 for (i = 1; i < num_pages; i++) {
190 kaddr = page_address(buf->pages[i]);
191 crypto_shash_update(shash, kaddr, PAGE_SIZE);
193 memset(result, 0, BTRFS_CSUM_SIZE);
194 crypto_shash_final(shash, result);
198 * we can't consider a given block up to date unless the transid of the
199 * block matches the transid in the parent node's pointer. This is how we
200 * detect blocks that either didn't get written at all or got written
201 * in the wrong place.
203 static int verify_parent_transid(struct extent_io_tree *io_tree,
204 struct extent_buffer *eb, u64 parent_transid,
207 struct extent_state *cached_state = NULL;
210 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
216 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
218 if (extent_buffer_uptodate(eb) &&
219 btrfs_header_generation(eb) == parent_transid) {
223 btrfs_err_rl(eb->fs_info,
224 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
225 eb->start, eb->read_mirror,
226 parent_transid, btrfs_header_generation(eb));
228 clear_extent_buffer_uptodate(eb);
230 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
235 static bool btrfs_supported_super_csum(u16 csum_type)
238 case BTRFS_CSUM_TYPE_CRC32:
239 case BTRFS_CSUM_TYPE_XXHASH:
240 case BTRFS_CSUM_TYPE_SHA256:
241 case BTRFS_CSUM_TYPE_BLAKE2:
249 * Return 0 if the superblock checksum type matches the checksum value of that
250 * algorithm. Pass the raw disk superblock data.
252 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
255 struct btrfs_super_block *disk_sb =
256 (struct btrfs_super_block *)raw_disk_sb;
257 char result[BTRFS_CSUM_SIZE];
258 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
260 shash->tfm = fs_info->csum_shash;
263 * The super_block structure does not span the whole
264 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
265 * filled with zeros and is included in the checksum.
267 crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
268 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
270 if (memcmp(disk_sb->csum, result, fs_info->csum_size))
276 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
277 struct btrfs_key *first_key, u64 parent_transid)
279 struct btrfs_fs_info *fs_info = eb->fs_info;
281 struct btrfs_key found_key;
284 found_level = btrfs_header_level(eb);
285 if (found_level != level) {
286 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
287 KERN_ERR "BTRFS: tree level check failed\n");
289 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
290 eb->start, level, found_level);
298 * For live tree block (new tree blocks in current transaction),
299 * we need proper lock context to avoid race, which is impossible here.
300 * So we only checks tree blocks which is read from disk, whose
301 * generation <= fs_info->last_trans_committed.
303 if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
306 /* We have @first_key, so this @eb must have at least one item */
307 if (btrfs_header_nritems(eb) == 0) {
309 "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
311 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
316 btrfs_node_key_to_cpu(eb, &found_key, 0);
318 btrfs_item_key_to_cpu(eb, &found_key, 0);
319 ret = btrfs_comp_cpu_keys(first_key, &found_key);
322 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
323 KERN_ERR "BTRFS: tree first key check failed\n");
325 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
326 eb->start, parent_transid, first_key->objectid,
327 first_key->type, first_key->offset,
328 found_key.objectid, found_key.type,
335 * helper to read a given tree block, doing retries as required when
336 * the checksums don't match and we have alternate mirrors to try.
338 * @parent_transid: expected transid, skip check if 0
339 * @level: expected level, mandatory check
340 * @first_key: expected key of first slot, skip check if NULL
342 int btrfs_read_extent_buffer(struct extent_buffer *eb,
343 u64 parent_transid, int level,
344 struct btrfs_key *first_key)
346 struct btrfs_fs_info *fs_info = eb->fs_info;
347 struct extent_io_tree *io_tree;
352 int failed_mirror = 0;
354 io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
356 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
357 ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
359 if (verify_parent_transid(io_tree, eb,
362 else if (btrfs_verify_level_key(eb, level,
363 first_key, parent_transid))
369 num_copies = btrfs_num_copies(fs_info,
374 if (!failed_mirror) {
376 failed_mirror = eb->read_mirror;
380 if (mirror_num == failed_mirror)
383 if (mirror_num > num_copies)
387 if (failed && !ret && failed_mirror)
388 btrfs_repair_eb_io_failure(eb, failed_mirror);
393 static int csum_one_extent_buffer(struct extent_buffer *eb)
395 struct btrfs_fs_info *fs_info = eb->fs_info;
396 u8 result[BTRFS_CSUM_SIZE];
399 ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
400 offsetof(struct btrfs_header, fsid),
401 BTRFS_FSID_SIZE) == 0);
402 csum_tree_block(eb, result);
404 if (btrfs_header_level(eb))
405 ret = btrfs_check_node(eb);
407 ret = btrfs_check_leaf_full(eb);
413 * Also check the generation, the eb reached here must be newer than
414 * last committed. Or something seriously wrong happened.
416 if (unlikely(btrfs_header_generation(eb) <= fs_info->last_trans_committed)) {
419 "block=%llu bad generation, have %llu expect > %llu",
420 eb->start, btrfs_header_generation(eb),
421 fs_info->last_trans_committed);
424 write_extent_buffer(eb, result, 0, fs_info->csum_size);
429 btrfs_print_tree(eb, 0);
430 btrfs_err(fs_info, "block=%llu write time tree block corruption detected",
432 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
436 /* Checksum all dirty extent buffers in one bio_vec */
437 static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
438 struct bio_vec *bvec)
440 struct page *page = bvec->bv_page;
441 u64 bvec_start = page_offset(page) + bvec->bv_offset;
445 for (cur = bvec_start; cur < bvec_start + bvec->bv_len;
446 cur += fs_info->nodesize) {
447 struct extent_buffer *eb;
450 eb = find_extent_buffer(fs_info, cur);
451 uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
454 /* A dirty eb shouldn't disappear from buffer_radix */
458 if (WARN_ON(cur != btrfs_header_bytenr(eb))) {
459 free_extent_buffer(eb);
462 if (WARN_ON(!uptodate)) {
463 free_extent_buffer(eb);
467 ret = csum_one_extent_buffer(eb);
468 free_extent_buffer(eb);
476 * Checksum a dirty tree block before IO. This has extra checks to make sure
477 * we only fill in the checksum field in the first page of a multi-page block.
478 * For subpage extent buffers we need bvec to also read the offset in the page.
480 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
482 struct page *page = bvec->bv_page;
483 u64 start = page_offset(page);
485 struct extent_buffer *eb;
487 if (fs_info->nodesize < PAGE_SIZE)
488 return csum_dirty_subpage_buffers(fs_info, bvec);
490 eb = (struct extent_buffer *)page->private;
491 if (page != eb->pages[0])
494 found_start = btrfs_header_bytenr(eb);
496 if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
497 WARN_ON(found_start != 0);
502 * Please do not consolidate these warnings into a single if.
503 * It is useful to know what went wrong.
505 if (WARN_ON(found_start != start))
507 if (WARN_ON(!PageUptodate(page)))
510 return csum_one_extent_buffer(eb);
513 static int check_tree_block_fsid(struct extent_buffer *eb)
515 struct btrfs_fs_info *fs_info = eb->fs_info;
516 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
517 u8 fsid[BTRFS_FSID_SIZE];
520 read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
523 * Checking the incompat flag is only valid for the current fs. For
524 * seed devices it's forbidden to have their uuid changed so reading
525 * ->fsid in this case is fine
527 if (btrfs_fs_incompat(fs_info, METADATA_UUID))
528 metadata_uuid = fs_devices->metadata_uuid;
530 metadata_uuid = fs_devices->fsid;
532 if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
535 list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
536 if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
542 /* Do basic extent buffer checks at read time */
543 static int validate_extent_buffer(struct extent_buffer *eb)
545 struct btrfs_fs_info *fs_info = eb->fs_info;
547 const u32 csum_size = fs_info->csum_size;
549 u8 result[BTRFS_CSUM_SIZE];
550 const u8 *header_csum;
553 found_start = btrfs_header_bytenr(eb);
554 if (found_start != eb->start) {
555 btrfs_err_rl(fs_info,
556 "bad tree block start, mirror %u want %llu have %llu",
557 eb->read_mirror, eb->start, found_start);
561 if (check_tree_block_fsid(eb)) {
562 btrfs_err_rl(fs_info, "bad fsid on logical %llu mirror %u",
563 eb->start, eb->read_mirror);
567 found_level = btrfs_header_level(eb);
568 if (found_level >= BTRFS_MAX_LEVEL) {
570 "bad tree block level, mirror %u level %d on logical %llu",
571 eb->read_mirror, btrfs_header_level(eb), eb->start);
576 csum_tree_block(eb, result);
577 header_csum = page_address(eb->pages[0]) +
578 get_eb_offset_in_page(eb, offsetof(struct btrfs_header, csum));
580 if (memcmp(result, header_csum, csum_size) != 0) {
581 btrfs_warn_rl(fs_info,
582 "checksum verify failed on logical %llu mirror %u wanted " CSUM_FMT " found " CSUM_FMT " level %d",
583 eb->start, eb->read_mirror,
584 CSUM_FMT_VALUE(csum_size, header_csum),
585 CSUM_FMT_VALUE(csum_size, result),
586 btrfs_header_level(eb));
592 * If this is a leaf block and it is corrupt, set the corrupt bit so
593 * that we don't try and read the other copies of this block, just
596 if (found_level == 0 && btrfs_check_leaf_full(eb)) {
597 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
601 if (found_level > 0 && btrfs_check_node(eb))
605 set_extent_buffer_uptodate(eb);
608 "read time tree block corruption detected on logical %llu mirror %u",
609 eb->start, eb->read_mirror);
614 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
617 struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
618 struct extent_buffer *eb;
623 * We don't allow bio merge for subpage metadata read, so we should
624 * only get one eb for each endio hook.
626 ASSERT(end == start + fs_info->nodesize - 1);
627 ASSERT(PagePrivate(page));
629 eb = find_extent_buffer(fs_info, start);
631 * When we are reading one tree block, eb must have been inserted into
632 * the radix tree. If not, something is wrong.
636 reads_done = atomic_dec_and_test(&eb->io_pages);
637 /* Subpage read must finish in page read */
640 eb->read_mirror = mirror;
641 if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
645 ret = validate_extent_buffer(eb);
649 set_extent_buffer_uptodate(eb);
651 free_extent_buffer(eb);
655 * end_bio_extent_readpage decrements io_pages in case of error,
656 * make sure it has something to decrement.
658 atomic_inc(&eb->io_pages);
659 clear_extent_buffer_uptodate(eb);
660 free_extent_buffer(eb);
664 int btrfs_validate_metadata_buffer(struct btrfs_bio *bbio,
665 struct page *page, u64 start, u64 end,
668 struct extent_buffer *eb;
672 ASSERT(page->private);
674 if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
675 return validate_subpage_buffer(page, start, end, mirror);
677 eb = (struct extent_buffer *)page->private;
680 * The pending IO might have been the only thing that kept this buffer
681 * in memory. Make sure we have a ref for all this other checks
683 atomic_inc(&eb->refs);
685 reads_done = atomic_dec_and_test(&eb->io_pages);
689 eb->read_mirror = mirror;
690 if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
694 ret = validate_extent_buffer(eb);
698 * our io error hook is going to dec the io pages
699 * again, we have to make sure it has something
702 atomic_inc(&eb->io_pages);
703 clear_extent_buffer_uptodate(eb);
705 free_extent_buffer(eb);
710 static void run_one_async_start(struct btrfs_work *work)
712 struct async_submit_bio *async;
715 async = container_of(work, struct async_submit_bio, work);
716 ret = async->submit_bio_start(async->inode, async->bio,
717 async->dio_file_offset);
723 * In order to insert checksums into the metadata in large chunks, we wait
724 * until bio submission time. All the pages in the bio are checksummed and
725 * sums are attached onto the ordered extent record.
727 * At IO completion time the csums attached on the ordered extent record are
728 * inserted into the tree.
730 static void run_one_async_done(struct btrfs_work *work)
732 struct async_submit_bio *async;
735 async = container_of(work, struct async_submit_bio, work);
736 inode = async->inode;
738 /* If an error occurred we just want to clean up the bio and move on */
740 async->bio->bi_status = async->status;
741 bio_endio(async->bio);
746 * All of the bios that pass through here are from async helpers.
747 * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
748 * This changes nothing when cgroups aren't in use.
750 async->bio->bi_opf |= REQ_CGROUP_PUNT;
751 btrfs_submit_bio(btrfs_sb(inode->i_sb), async->bio, async->mirror_num);
754 static void run_one_async_free(struct btrfs_work *work)
756 struct async_submit_bio *async;
758 async = container_of(work, struct async_submit_bio, work);
763 * Submit bio to an async queue.
766 * - true if the work has been succesfuly submitted
767 * - false in case of error
769 bool btrfs_wq_submit_bio(struct inode *inode, struct bio *bio, int mirror_num,
771 extent_submit_bio_start_t *submit_bio_start)
773 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
774 struct async_submit_bio *async;
776 async = kmalloc(sizeof(*async), GFP_NOFS);
780 async->inode = inode;
782 async->mirror_num = mirror_num;
783 async->submit_bio_start = submit_bio_start;
785 btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
788 async->dio_file_offset = dio_file_offset;
792 if (op_is_sync(bio->bi_opf))
793 btrfs_queue_work(fs_info->hipri_workers, &async->work);
795 btrfs_queue_work(fs_info->workers, &async->work);
799 static blk_status_t btree_csum_one_bio(struct bio *bio)
801 struct bio_vec *bvec;
802 struct btrfs_root *root;
804 struct bvec_iter_all iter_all;
806 ASSERT(!bio_flagged(bio, BIO_CLONED));
807 bio_for_each_segment_all(bvec, bio, iter_all) {
808 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
809 ret = csum_dirty_buffer(root->fs_info, bvec);
814 return errno_to_blk_status(ret);
817 static blk_status_t btree_submit_bio_start(struct inode *inode, struct bio *bio,
821 * when we're called for a write, we're already in the async
822 * submission context. Just jump into btrfs_submit_bio.
824 return btree_csum_one_bio(bio);
827 static bool should_async_write(struct btrfs_fs_info *fs_info,
828 struct btrfs_inode *bi)
830 if (btrfs_is_zoned(fs_info))
832 if (atomic_read(&bi->sync_writers))
834 if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
839 void btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio, int mirror_num)
841 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
844 bio->bi_opf |= REQ_META;
846 if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
847 btrfs_submit_bio(fs_info, bio, mirror_num);
852 * Kthread helpers are used to submit writes so that checksumming can
853 * happen in parallel across all CPUs.
855 if (should_async_write(fs_info, BTRFS_I(inode)) &&
856 btrfs_wq_submit_bio(inode, bio, mirror_num, 0, btree_submit_bio_start))
859 ret = btree_csum_one_bio(bio);
861 bio->bi_status = ret;
866 btrfs_submit_bio(fs_info, bio, mirror_num);
869 #ifdef CONFIG_MIGRATION
870 static int btree_migrate_folio(struct address_space *mapping,
871 struct folio *dst, struct folio *src, enum migrate_mode mode)
874 * we can't safely write a btree page from here,
875 * we haven't done the locking hook
877 if (folio_test_dirty(src))
880 * Buffers may be managed in a filesystem specific way.
881 * We must have no buffers or drop them.
883 if (folio_get_private(src) &&
884 !filemap_release_folio(src, GFP_KERNEL))
886 return migrate_folio(mapping, dst, src, mode);
889 #define btree_migrate_folio NULL
892 static int btree_writepages(struct address_space *mapping,
893 struct writeback_control *wbc)
895 struct btrfs_fs_info *fs_info;
898 if (wbc->sync_mode == WB_SYNC_NONE) {
900 if (wbc->for_kupdate)
903 fs_info = BTRFS_I(mapping->host)->root->fs_info;
904 /* this is a bit racy, but that's ok */
905 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
906 BTRFS_DIRTY_METADATA_THRESH,
907 fs_info->dirty_metadata_batch);
911 return btree_write_cache_pages(mapping, wbc);
914 static bool btree_release_folio(struct folio *folio, gfp_t gfp_flags)
916 if (folio_test_writeback(folio) || folio_test_dirty(folio))
919 return try_release_extent_buffer(&folio->page);
922 static void btree_invalidate_folio(struct folio *folio, size_t offset,
925 struct extent_io_tree *tree;
926 tree = &BTRFS_I(folio->mapping->host)->io_tree;
927 extent_invalidate_folio(tree, folio, offset);
928 btree_release_folio(folio, GFP_NOFS);
929 if (folio_get_private(folio)) {
930 btrfs_warn(BTRFS_I(folio->mapping->host)->root->fs_info,
931 "folio private not zero on folio %llu",
932 (unsigned long long)folio_pos(folio));
933 folio_detach_private(folio);
938 static bool btree_dirty_folio(struct address_space *mapping,
941 struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
942 struct btrfs_subpage *subpage;
943 struct extent_buffer *eb;
945 u64 page_start = folio_pos(folio);
947 if (fs_info->sectorsize == PAGE_SIZE) {
948 eb = folio_get_private(folio);
950 BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
951 BUG_ON(!atomic_read(&eb->refs));
952 btrfs_assert_tree_write_locked(eb);
953 return filemap_dirty_folio(mapping, folio);
955 subpage = folio_get_private(folio);
957 ASSERT(subpage->dirty_bitmap);
958 while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
961 u16 tmp = (1 << cur_bit);
963 spin_lock_irqsave(&subpage->lock, flags);
964 if (!(tmp & subpage->dirty_bitmap)) {
965 spin_unlock_irqrestore(&subpage->lock, flags);
969 spin_unlock_irqrestore(&subpage->lock, flags);
970 cur = page_start + cur_bit * fs_info->sectorsize;
972 eb = find_extent_buffer(fs_info, cur);
974 ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
975 ASSERT(atomic_read(&eb->refs));
976 btrfs_assert_tree_write_locked(eb);
977 free_extent_buffer(eb);
979 cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
981 return filemap_dirty_folio(mapping, folio);
984 #define btree_dirty_folio filemap_dirty_folio
987 static const struct address_space_operations btree_aops = {
988 .writepages = btree_writepages,
989 .release_folio = btree_release_folio,
990 .invalidate_folio = btree_invalidate_folio,
991 .migrate_folio = btree_migrate_folio,
992 .dirty_folio = btree_dirty_folio,
995 struct extent_buffer *btrfs_find_create_tree_block(
996 struct btrfs_fs_info *fs_info,
997 u64 bytenr, u64 owner_root,
1000 if (btrfs_is_testing(fs_info))
1001 return alloc_test_extent_buffer(fs_info, bytenr);
1002 return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
1006 * Read tree block at logical address @bytenr and do variant basic but critical
1009 * @owner_root: the objectid of the root owner for this block.
1010 * @parent_transid: expected transid of this tree block, skip check if 0
1011 * @level: expected level, mandatory check
1012 * @first_key: expected key in slot 0, skip check if NULL
1014 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1015 u64 owner_root, u64 parent_transid,
1016 int level, struct btrfs_key *first_key)
1018 struct extent_buffer *buf = NULL;
1021 buf = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
1025 ret = btrfs_read_extent_buffer(buf, parent_transid, level, first_key);
1027 free_extent_buffer_stale(buf);
1028 return ERR_PTR(ret);
1030 if (btrfs_check_eb_owner(buf, owner_root)) {
1031 free_extent_buffer_stale(buf);
1032 return ERR_PTR(-EUCLEAN);
1038 void btrfs_clean_tree_block(struct extent_buffer *buf)
1040 struct btrfs_fs_info *fs_info = buf->fs_info;
1041 if (btrfs_header_generation(buf) ==
1042 fs_info->running_transaction->transid) {
1043 btrfs_assert_tree_write_locked(buf);
1045 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1046 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1048 fs_info->dirty_metadata_batch);
1049 clear_extent_buffer_dirty(buf);
1054 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1057 bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1059 memset(&root->root_key, 0, sizeof(root->root_key));
1060 memset(&root->root_item, 0, sizeof(root->root_item));
1061 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1062 root->fs_info = fs_info;
1063 root->root_key.objectid = objectid;
1065 root->commit_root = NULL;
1067 RB_CLEAR_NODE(&root->rb_node);
1069 root->last_trans = 0;
1070 root->free_objectid = 0;
1071 root->nr_delalloc_inodes = 0;
1072 root->nr_ordered_extents = 0;
1073 root->inode_tree = RB_ROOT;
1074 INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1076 btrfs_init_root_block_rsv(root);
1078 INIT_LIST_HEAD(&root->dirty_list);
1079 INIT_LIST_HEAD(&root->root_list);
1080 INIT_LIST_HEAD(&root->delalloc_inodes);
1081 INIT_LIST_HEAD(&root->delalloc_root);
1082 INIT_LIST_HEAD(&root->ordered_extents);
1083 INIT_LIST_HEAD(&root->ordered_root);
1084 INIT_LIST_HEAD(&root->reloc_dirty_list);
1085 INIT_LIST_HEAD(&root->logged_list[0]);
1086 INIT_LIST_HEAD(&root->logged_list[1]);
1087 spin_lock_init(&root->inode_lock);
1088 spin_lock_init(&root->delalloc_lock);
1089 spin_lock_init(&root->ordered_extent_lock);
1090 spin_lock_init(&root->accounting_lock);
1091 spin_lock_init(&root->log_extents_lock[0]);
1092 spin_lock_init(&root->log_extents_lock[1]);
1093 spin_lock_init(&root->qgroup_meta_rsv_lock);
1094 mutex_init(&root->objectid_mutex);
1095 mutex_init(&root->log_mutex);
1096 mutex_init(&root->ordered_extent_mutex);
1097 mutex_init(&root->delalloc_mutex);
1098 init_waitqueue_head(&root->qgroup_flush_wait);
1099 init_waitqueue_head(&root->log_writer_wait);
1100 init_waitqueue_head(&root->log_commit_wait[0]);
1101 init_waitqueue_head(&root->log_commit_wait[1]);
1102 INIT_LIST_HEAD(&root->log_ctxs[0]);
1103 INIT_LIST_HEAD(&root->log_ctxs[1]);
1104 atomic_set(&root->log_commit[0], 0);
1105 atomic_set(&root->log_commit[1], 0);
1106 atomic_set(&root->log_writers, 0);
1107 atomic_set(&root->log_batch, 0);
1108 refcount_set(&root->refs, 1);
1109 atomic_set(&root->snapshot_force_cow, 0);
1110 atomic_set(&root->nr_swapfiles, 0);
1111 root->log_transid = 0;
1112 root->log_transid_committed = -1;
1113 root->last_log_commit = 0;
1116 extent_io_tree_init(fs_info, &root->dirty_log_pages,
1117 IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
1118 extent_io_tree_init(fs_info, &root->log_csum_range,
1119 IO_TREE_LOG_CSUM_RANGE, NULL);
1122 spin_lock_init(&root->root_item_lock);
1123 btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1124 #ifdef CONFIG_BTRFS_DEBUG
1125 INIT_LIST_HEAD(&root->leak_list);
1126 spin_lock(&fs_info->fs_roots_radix_lock);
1127 list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1128 spin_unlock(&fs_info->fs_roots_radix_lock);
1132 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1133 u64 objectid, gfp_t flags)
1135 struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1137 __setup_root(root, fs_info, objectid);
1141 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1142 /* Should only be used by the testing infrastructure */
1143 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1145 struct btrfs_root *root;
1148 return ERR_PTR(-EINVAL);
1150 root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1152 return ERR_PTR(-ENOMEM);
1154 /* We don't use the stripesize in selftest, set it as sectorsize */
1155 root->alloc_bytenr = 0;
1161 static int global_root_cmp(struct rb_node *a_node, const struct rb_node *b_node)
1163 const struct btrfs_root *a = rb_entry(a_node, struct btrfs_root, rb_node);
1164 const struct btrfs_root *b = rb_entry(b_node, struct btrfs_root, rb_node);
1166 return btrfs_comp_cpu_keys(&a->root_key, &b->root_key);
1169 static int global_root_key_cmp(const void *k, const struct rb_node *node)
1171 const struct btrfs_key *key = k;
1172 const struct btrfs_root *root = rb_entry(node, struct btrfs_root, rb_node);
1174 return btrfs_comp_cpu_keys(key, &root->root_key);
1177 int btrfs_global_root_insert(struct btrfs_root *root)
1179 struct btrfs_fs_info *fs_info = root->fs_info;
1180 struct rb_node *tmp;
1182 write_lock(&fs_info->global_root_lock);
1183 tmp = rb_find_add(&root->rb_node, &fs_info->global_root_tree, global_root_cmp);
1184 write_unlock(&fs_info->global_root_lock);
1187 return tmp ? -EEXIST : 0;
1190 void btrfs_global_root_delete(struct btrfs_root *root)
1192 struct btrfs_fs_info *fs_info = root->fs_info;
1194 write_lock(&fs_info->global_root_lock);
1195 rb_erase(&root->rb_node, &fs_info->global_root_tree);
1196 write_unlock(&fs_info->global_root_lock);
1199 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
1200 struct btrfs_key *key)
1202 struct rb_node *node;
1203 struct btrfs_root *root = NULL;
1205 read_lock(&fs_info->global_root_lock);
1206 node = rb_find(key, &fs_info->global_root_tree, global_root_key_cmp);
1208 root = container_of(node, struct btrfs_root, rb_node);
1209 read_unlock(&fs_info->global_root_lock);
1214 static u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
1216 struct btrfs_block_group *block_group;
1219 if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
1223 block_group = btrfs_lookup_block_group(fs_info, bytenr);
1225 block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
1226 ASSERT(block_group);
1229 ret = block_group->global_root_id;
1230 btrfs_put_block_group(block_group);
1235 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1237 struct btrfs_key key = {
1238 .objectid = BTRFS_CSUM_TREE_OBJECTID,
1239 .type = BTRFS_ROOT_ITEM_KEY,
1240 .offset = btrfs_global_root_id(fs_info, bytenr),
1243 return btrfs_global_root(fs_info, &key);
1246 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1248 struct btrfs_key key = {
1249 .objectid = BTRFS_EXTENT_TREE_OBJECTID,
1250 .type = BTRFS_ROOT_ITEM_KEY,
1251 .offset = btrfs_global_root_id(fs_info, bytenr),
1254 return btrfs_global_root(fs_info, &key);
1257 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1260 struct btrfs_fs_info *fs_info = trans->fs_info;
1261 struct extent_buffer *leaf;
1262 struct btrfs_root *tree_root = fs_info->tree_root;
1263 struct btrfs_root *root;
1264 struct btrfs_key key;
1265 unsigned int nofs_flag;
1269 * We're holding a transaction handle, so use a NOFS memory allocation
1270 * context to avoid deadlock if reclaim happens.
1272 nofs_flag = memalloc_nofs_save();
1273 root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1274 memalloc_nofs_restore(nofs_flag);
1276 return ERR_PTR(-ENOMEM);
1278 root->root_key.objectid = objectid;
1279 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1280 root->root_key.offset = 0;
1282 leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1283 BTRFS_NESTING_NORMAL);
1285 ret = PTR_ERR(leaf);
1291 btrfs_mark_buffer_dirty(leaf);
1293 root->commit_root = btrfs_root_node(root);
1294 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1296 btrfs_set_root_flags(&root->root_item, 0);
1297 btrfs_set_root_limit(&root->root_item, 0);
1298 btrfs_set_root_bytenr(&root->root_item, leaf->start);
1299 btrfs_set_root_generation(&root->root_item, trans->transid);
1300 btrfs_set_root_level(&root->root_item, 0);
1301 btrfs_set_root_refs(&root->root_item, 1);
1302 btrfs_set_root_used(&root->root_item, leaf->len);
1303 btrfs_set_root_last_snapshot(&root->root_item, 0);
1304 btrfs_set_root_dirid(&root->root_item, 0);
1305 if (is_fstree(objectid))
1306 generate_random_guid(root->root_item.uuid);
1308 export_guid(root->root_item.uuid, &guid_null);
1309 btrfs_set_root_drop_level(&root->root_item, 0);
1311 btrfs_tree_unlock(leaf);
1313 key.objectid = objectid;
1314 key.type = BTRFS_ROOT_ITEM_KEY;
1316 ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1324 btrfs_tree_unlock(leaf);
1326 btrfs_put_root(root);
1328 return ERR_PTR(ret);
1331 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1332 struct btrfs_fs_info *fs_info)
1334 struct btrfs_root *root;
1336 root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1338 return ERR_PTR(-ENOMEM);
1340 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1341 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1342 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1347 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
1348 struct btrfs_root *root)
1350 struct extent_buffer *leaf;
1353 * DON'T set SHAREABLE bit for log trees.
1355 * Log trees are not exposed to user space thus can't be snapshotted,
1356 * and they go away before a real commit is actually done.
1358 * They do store pointers to file data extents, and those reference
1359 * counts still get updated (along with back refs to the log tree).
1362 leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1363 NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1365 return PTR_ERR(leaf);
1369 btrfs_mark_buffer_dirty(root->node);
1370 btrfs_tree_unlock(root->node);
1375 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1376 struct btrfs_fs_info *fs_info)
1378 struct btrfs_root *log_root;
1380 log_root = alloc_log_tree(trans, fs_info);
1381 if (IS_ERR(log_root))
1382 return PTR_ERR(log_root);
1384 if (!btrfs_is_zoned(fs_info)) {
1385 int ret = btrfs_alloc_log_tree_node(trans, log_root);
1388 btrfs_put_root(log_root);
1393 WARN_ON(fs_info->log_root_tree);
1394 fs_info->log_root_tree = log_root;
1398 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1399 struct btrfs_root *root)
1401 struct btrfs_fs_info *fs_info = root->fs_info;
1402 struct btrfs_root *log_root;
1403 struct btrfs_inode_item *inode_item;
1406 log_root = alloc_log_tree(trans, fs_info);
1407 if (IS_ERR(log_root))
1408 return PTR_ERR(log_root);
1410 ret = btrfs_alloc_log_tree_node(trans, log_root);
1412 btrfs_put_root(log_root);
1416 log_root->last_trans = trans->transid;
1417 log_root->root_key.offset = root->root_key.objectid;
1419 inode_item = &log_root->root_item.inode;
1420 btrfs_set_stack_inode_generation(inode_item, 1);
1421 btrfs_set_stack_inode_size(inode_item, 3);
1422 btrfs_set_stack_inode_nlink(inode_item, 1);
1423 btrfs_set_stack_inode_nbytes(inode_item,
1425 btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1427 btrfs_set_root_node(&log_root->root_item, log_root->node);
1429 WARN_ON(root->log_root);
1430 root->log_root = log_root;
1431 root->log_transid = 0;
1432 root->log_transid_committed = -1;
1433 root->last_log_commit = 0;
1437 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1438 struct btrfs_path *path,
1439 struct btrfs_key *key)
1441 struct btrfs_root *root;
1442 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1447 root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1449 return ERR_PTR(-ENOMEM);
1451 ret = btrfs_find_root(tree_root, key, path,
1452 &root->root_item, &root->root_key);
1459 generation = btrfs_root_generation(&root->root_item);
1460 level = btrfs_root_level(&root->root_item);
1461 root->node = read_tree_block(fs_info,
1462 btrfs_root_bytenr(&root->root_item),
1463 key->objectid, generation, level, NULL);
1464 if (IS_ERR(root->node)) {
1465 ret = PTR_ERR(root->node);
1469 if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1475 * For real fs, and not log/reloc trees, root owner must
1476 * match its root node owner
1478 if (!test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state) &&
1479 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1480 root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
1481 root->root_key.objectid != btrfs_header_owner(root->node)) {
1483 "root=%llu block=%llu, tree root owner mismatch, have %llu expect %llu",
1484 root->root_key.objectid, root->node->start,
1485 btrfs_header_owner(root->node),
1486 root->root_key.objectid);
1490 root->commit_root = btrfs_root_node(root);
1493 btrfs_put_root(root);
1494 return ERR_PTR(ret);
1497 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1498 struct btrfs_key *key)
1500 struct btrfs_root *root;
1501 struct btrfs_path *path;
1503 path = btrfs_alloc_path();
1505 return ERR_PTR(-ENOMEM);
1506 root = read_tree_root_path(tree_root, path, key);
1507 btrfs_free_path(path);
1513 * Initialize subvolume root in-memory structure
1515 * @anon_dev: anonymous device to attach to the root, if zero, allocate new
1517 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1520 unsigned int nofs_flag;
1523 * We might be called under a transaction (e.g. indirect backref
1524 * resolution) which could deadlock if it triggers memory reclaim
1526 nofs_flag = memalloc_nofs_save();
1527 ret = btrfs_drew_lock_init(&root->snapshot_lock);
1528 memalloc_nofs_restore(nofs_flag);
1532 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1533 !btrfs_is_data_reloc_root(root)) {
1534 set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1535 btrfs_check_and_init_root_item(&root->root_item);
1539 * Don't assign anonymous block device to roots that are not exposed to
1540 * userspace, the id pool is limited to 1M
1542 if (is_fstree(root->root_key.objectid) &&
1543 btrfs_root_refs(&root->root_item) > 0) {
1545 ret = get_anon_bdev(&root->anon_dev);
1549 root->anon_dev = anon_dev;
1553 mutex_lock(&root->objectid_mutex);
1554 ret = btrfs_init_root_free_objectid(root);
1556 mutex_unlock(&root->objectid_mutex);
1560 ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1562 mutex_unlock(&root->objectid_mutex);
1566 /* The caller is responsible to call btrfs_free_fs_root */
1570 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1573 struct btrfs_root *root;
1575 spin_lock(&fs_info->fs_roots_radix_lock);
1576 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1577 (unsigned long)root_id);
1579 root = btrfs_grab_root(root);
1580 spin_unlock(&fs_info->fs_roots_radix_lock);
1584 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1587 struct btrfs_key key = {
1588 .objectid = objectid,
1589 .type = BTRFS_ROOT_ITEM_KEY,
1593 if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1594 return btrfs_grab_root(fs_info->tree_root);
1595 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1596 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1597 if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1598 return btrfs_grab_root(fs_info->chunk_root);
1599 if (objectid == BTRFS_DEV_TREE_OBJECTID)
1600 return btrfs_grab_root(fs_info->dev_root);
1601 if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1602 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1603 if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1604 return btrfs_grab_root(fs_info->quota_root) ?
1605 fs_info->quota_root : ERR_PTR(-ENOENT);
1606 if (objectid == BTRFS_UUID_TREE_OBJECTID)
1607 return btrfs_grab_root(fs_info->uuid_root) ?
1608 fs_info->uuid_root : ERR_PTR(-ENOENT);
1609 if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) {
1610 struct btrfs_root *root = btrfs_global_root(fs_info, &key);
1612 return btrfs_grab_root(root) ? root : ERR_PTR(-ENOENT);
1617 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1618 struct btrfs_root *root)
1622 ret = radix_tree_preload(GFP_NOFS);
1626 spin_lock(&fs_info->fs_roots_radix_lock);
1627 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1628 (unsigned long)root->root_key.objectid,
1631 btrfs_grab_root(root);
1632 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1634 spin_unlock(&fs_info->fs_roots_radix_lock);
1635 radix_tree_preload_end();
1640 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1642 #ifdef CONFIG_BTRFS_DEBUG
1643 struct btrfs_root *root;
1645 while (!list_empty(&fs_info->allocated_roots)) {
1646 char buf[BTRFS_ROOT_NAME_BUF_LEN];
1648 root = list_first_entry(&fs_info->allocated_roots,
1649 struct btrfs_root, leak_list);
1650 btrfs_err(fs_info, "leaked root %s refcount %d",
1651 btrfs_root_name(&root->root_key, buf),
1652 refcount_read(&root->refs));
1653 while (refcount_read(&root->refs) > 1)
1654 btrfs_put_root(root);
1655 btrfs_put_root(root);
1660 static void free_global_roots(struct btrfs_fs_info *fs_info)
1662 struct btrfs_root *root;
1663 struct rb_node *node;
1665 while ((node = rb_first_postorder(&fs_info->global_root_tree)) != NULL) {
1666 root = rb_entry(node, struct btrfs_root, rb_node);
1667 rb_erase(&root->rb_node, &fs_info->global_root_tree);
1668 btrfs_put_root(root);
1672 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1674 percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1675 percpu_counter_destroy(&fs_info->delalloc_bytes);
1676 percpu_counter_destroy(&fs_info->ordered_bytes);
1677 percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1678 btrfs_free_csum_hash(fs_info);
1679 btrfs_free_stripe_hash_table(fs_info);
1680 btrfs_free_ref_cache(fs_info);
1681 kfree(fs_info->balance_ctl);
1682 kfree(fs_info->delayed_root);
1683 free_global_roots(fs_info);
1684 btrfs_put_root(fs_info->tree_root);
1685 btrfs_put_root(fs_info->chunk_root);
1686 btrfs_put_root(fs_info->dev_root);
1687 btrfs_put_root(fs_info->quota_root);
1688 btrfs_put_root(fs_info->uuid_root);
1689 btrfs_put_root(fs_info->fs_root);
1690 btrfs_put_root(fs_info->data_reloc_root);
1691 btrfs_put_root(fs_info->block_group_root);
1692 btrfs_check_leaked_roots(fs_info);
1693 btrfs_extent_buffer_leak_debug_check(fs_info);
1694 kfree(fs_info->super_copy);
1695 kfree(fs_info->super_for_commit);
1696 kfree(fs_info->subpage_info);
1702 * Get an in-memory reference of a root structure.
1704 * For essential trees like root/extent tree, we grab it from fs_info directly.
1705 * For subvolume trees, we check the cached filesystem roots first. If not
1706 * found, then read it from disk and add it to cached fs roots.
1708 * Caller should release the root by calling btrfs_put_root() after the usage.
1710 * NOTE: Reloc and log trees can't be read by this function as they share the
1711 * same root objectid.
1713 * @objectid: root id
1714 * @anon_dev: preallocated anonymous block device number for new roots,
1715 * pass 0 for new allocation.
1716 * @check_ref: whether to check root item references, If true, return -ENOENT
1719 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1720 u64 objectid, dev_t anon_dev,
1723 struct btrfs_root *root;
1724 struct btrfs_path *path;
1725 struct btrfs_key key;
1728 root = btrfs_get_global_root(fs_info, objectid);
1732 root = btrfs_lookup_fs_root(fs_info, objectid);
1734 /* Shouldn't get preallocated anon_dev for cached roots */
1736 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1737 btrfs_put_root(root);
1738 return ERR_PTR(-ENOENT);
1743 key.objectid = objectid;
1744 key.type = BTRFS_ROOT_ITEM_KEY;
1745 key.offset = (u64)-1;
1746 root = btrfs_read_tree_root(fs_info->tree_root, &key);
1750 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1755 ret = btrfs_init_fs_root(root, anon_dev);
1759 path = btrfs_alloc_path();
1764 key.objectid = BTRFS_ORPHAN_OBJECTID;
1765 key.type = BTRFS_ORPHAN_ITEM_KEY;
1766 key.offset = objectid;
1768 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1769 btrfs_free_path(path);
1773 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1775 ret = btrfs_insert_fs_root(fs_info, root);
1777 if (ret == -EEXIST) {
1778 btrfs_put_root(root);
1786 * If our caller provided us an anonymous device, then it's his
1787 * responsibility to free it in case we fail. So we have to set our
1788 * root's anon_dev to 0 to avoid a double free, once by btrfs_put_root()
1789 * and once again by our caller.
1793 btrfs_put_root(root);
1794 return ERR_PTR(ret);
1798 * Get in-memory reference of a root structure
1800 * @objectid: tree objectid
1801 * @check_ref: if set, verify that the tree exists and the item has at least
1804 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1805 u64 objectid, bool check_ref)
1807 return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
1811 * Get in-memory reference of a root structure, created as new, optionally pass
1812 * the anonymous block device id
1814 * @objectid: tree objectid
1815 * @anon_dev: if zero, allocate a new anonymous block device or use the
1818 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1819 u64 objectid, dev_t anon_dev)
1821 return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1825 * btrfs_get_fs_root_commit_root - return a root for the given objectid
1826 * @fs_info: the fs_info
1827 * @objectid: the objectid we need to lookup
1829 * This is exclusively used for backref walking, and exists specifically because
1830 * of how qgroups does lookups. Qgroups will do a backref lookup at delayed ref
1831 * creation time, which means we may have to read the tree_root in order to look
1832 * up a fs root that is not in memory. If the root is not in memory we will
1833 * read the tree root commit root and look up the fs root from there. This is a
1834 * temporary root, it will not be inserted into the radix tree as it doesn't
1835 * have the most uptodate information, it'll simply be discarded once the
1836 * backref code is finished using the root.
1838 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1839 struct btrfs_path *path,
1842 struct btrfs_root *root;
1843 struct btrfs_key key;
1845 ASSERT(path->search_commit_root && path->skip_locking);
1848 * This can return -ENOENT if we ask for a root that doesn't exist, but
1849 * since this is called via the backref walking code we won't be looking
1850 * up a root that doesn't exist, unless there's corruption. So if root
1851 * != NULL just return it.
1853 root = btrfs_get_global_root(fs_info, objectid);
1857 root = btrfs_lookup_fs_root(fs_info, objectid);
1861 key.objectid = objectid;
1862 key.type = BTRFS_ROOT_ITEM_KEY;
1863 key.offset = (u64)-1;
1864 root = read_tree_root_path(fs_info->tree_root, path, &key);
1865 btrfs_release_path(path);
1870 static int cleaner_kthread(void *arg)
1872 struct btrfs_fs_info *fs_info = arg;
1878 set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1880 /* Make the cleaner go to sleep early. */
1881 if (btrfs_need_cleaner_sleep(fs_info))
1885 * Do not do anything if we might cause open_ctree() to block
1886 * before we have finished mounting the filesystem.
1888 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1891 if (!mutex_trylock(&fs_info->cleaner_mutex))
1895 * Avoid the problem that we change the status of the fs
1896 * during the above check and trylock.
1898 if (btrfs_need_cleaner_sleep(fs_info)) {
1899 mutex_unlock(&fs_info->cleaner_mutex);
1903 btrfs_run_delayed_iputs(fs_info);
1905 again = btrfs_clean_one_deleted_snapshot(fs_info);
1906 mutex_unlock(&fs_info->cleaner_mutex);
1909 * The defragger has dealt with the R/O remount and umount,
1910 * needn't do anything special here.
1912 btrfs_run_defrag_inodes(fs_info);
1915 * Acquires fs_info->reclaim_bgs_lock to avoid racing
1916 * with relocation (btrfs_relocate_chunk) and relocation
1917 * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1918 * after acquiring fs_info->reclaim_bgs_lock. So we
1919 * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1920 * unused block groups.
1922 btrfs_delete_unused_bgs(fs_info);
1925 * Reclaim block groups in the reclaim_bgs list after we deleted
1926 * all unused block_groups. This possibly gives us some more free
1929 btrfs_reclaim_bgs(fs_info);
1931 clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1932 if (kthread_should_park())
1934 if (kthread_should_stop())
1937 set_current_state(TASK_INTERRUPTIBLE);
1939 __set_current_state(TASK_RUNNING);
1944 static int transaction_kthread(void *arg)
1946 struct btrfs_root *root = arg;
1947 struct btrfs_fs_info *fs_info = root->fs_info;
1948 struct btrfs_trans_handle *trans;
1949 struct btrfs_transaction *cur;
1952 unsigned long delay;
1956 cannot_commit = false;
1957 delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1958 mutex_lock(&fs_info->transaction_kthread_mutex);
1960 spin_lock(&fs_info->trans_lock);
1961 cur = fs_info->running_transaction;
1963 spin_unlock(&fs_info->trans_lock);
1967 delta = ktime_get_seconds() - cur->start_time;
1968 if (!test_and_clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags) &&
1969 cur->state < TRANS_STATE_COMMIT_START &&
1970 delta < fs_info->commit_interval) {
1971 spin_unlock(&fs_info->trans_lock);
1972 delay -= msecs_to_jiffies((delta - 1) * 1000);
1974 msecs_to_jiffies(fs_info->commit_interval * 1000));
1977 transid = cur->transid;
1978 spin_unlock(&fs_info->trans_lock);
1980 /* If the file system is aborted, this will always fail. */
1981 trans = btrfs_attach_transaction(root);
1982 if (IS_ERR(trans)) {
1983 if (PTR_ERR(trans) != -ENOENT)
1984 cannot_commit = true;
1987 if (transid == trans->transid) {
1988 btrfs_commit_transaction(trans);
1990 btrfs_end_transaction(trans);
1993 wake_up_process(fs_info->cleaner_kthread);
1994 mutex_unlock(&fs_info->transaction_kthread_mutex);
1996 if (BTRFS_FS_ERROR(fs_info))
1997 btrfs_cleanup_transaction(fs_info);
1998 if (!kthread_should_stop() &&
1999 (!btrfs_transaction_blocked(fs_info) ||
2001 schedule_timeout_interruptible(delay);
2002 } while (!kthread_should_stop());
2007 * This will find the highest generation in the array of root backups. The
2008 * index of the highest array is returned, or -EINVAL if we can't find
2011 * We check to make sure the array is valid by comparing the
2012 * generation of the latest root in the array with the generation
2013 * in the super block. If they don't match we pitch it.
2015 static int find_newest_super_backup(struct btrfs_fs_info *info)
2017 const u64 newest_gen = btrfs_super_generation(info->super_copy);
2019 struct btrfs_root_backup *root_backup;
2022 for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2023 root_backup = info->super_copy->super_roots + i;
2024 cur = btrfs_backup_tree_root_gen(root_backup);
2025 if (cur == newest_gen)
2033 * copy all the root pointers into the super backup array.
2034 * this will bump the backup pointer by one when it is
2037 static void backup_super_roots(struct btrfs_fs_info *info)
2039 const int next_backup = info->backup_root_index;
2040 struct btrfs_root_backup *root_backup;
2042 root_backup = info->super_for_commit->super_roots + next_backup;
2045 * make sure all of our padding and empty slots get zero filled
2046 * regardless of which ones we use today
2048 memset(root_backup, 0, sizeof(*root_backup));
2050 info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2052 btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2053 btrfs_set_backup_tree_root_gen(root_backup,
2054 btrfs_header_generation(info->tree_root->node));
2056 btrfs_set_backup_tree_root_level(root_backup,
2057 btrfs_header_level(info->tree_root->node));
2059 btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2060 btrfs_set_backup_chunk_root_gen(root_backup,
2061 btrfs_header_generation(info->chunk_root->node));
2062 btrfs_set_backup_chunk_root_level(root_backup,
2063 btrfs_header_level(info->chunk_root->node));
2065 if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
2066 btrfs_set_backup_block_group_root(root_backup,
2067 info->block_group_root->node->start);
2068 btrfs_set_backup_block_group_root_gen(root_backup,
2069 btrfs_header_generation(info->block_group_root->node));
2070 btrfs_set_backup_block_group_root_level(root_backup,
2071 btrfs_header_level(info->block_group_root->node));
2073 struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
2074 struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
2076 btrfs_set_backup_extent_root(root_backup,
2077 extent_root->node->start);
2078 btrfs_set_backup_extent_root_gen(root_backup,
2079 btrfs_header_generation(extent_root->node));
2080 btrfs_set_backup_extent_root_level(root_backup,
2081 btrfs_header_level(extent_root->node));
2083 btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
2084 btrfs_set_backup_csum_root_gen(root_backup,
2085 btrfs_header_generation(csum_root->node));
2086 btrfs_set_backup_csum_root_level(root_backup,
2087 btrfs_header_level(csum_root->node));
2091 * we might commit during log recovery, which happens before we set
2092 * the fs_root. Make sure it is valid before we fill it in.
2094 if (info->fs_root && info->fs_root->node) {
2095 btrfs_set_backup_fs_root(root_backup,
2096 info->fs_root->node->start);
2097 btrfs_set_backup_fs_root_gen(root_backup,
2098 btrfs_header_generation(info->fs_root->node));
2099 btrfs_set_backup_fs_root_level(root_backup,
2100 btrfs_header_level(info->fs_root->node));
2103 btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2104 btrfs_set_backup_dev_root_gen(root_backup,
2105 btrfs_header_generation(info->dev_root->node));
2106 btrfs_set_backup_dev_root_level(root_backup,
2107 btrfs_header_level(info->dev_root->node));
2109 btrfs_set_backup_total_bytes(root_backup,
2110 btrfs_super_total_bytes(info->super_copy));
2111 btrfs_set_backup_bytes_used(root_backup,
2112 btrfs_super_bytes_used(info->super_copy));
2113 btrfs_set_backup_num_devices(root_backup,
2114 btrfs_super_num_devices(info->super_copy));
2117 * if we don't copy this out to the super_copy, it won't get remembered
2118 * for the next commit
2120 memcpy(&info->super_copy->super_roots,
2121 &info->super_for_commit->super_roots,
2122 sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2126 * read_backup_root - Reads a backup root based on the passed priority. Prio 0
2127 * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
2129 * fs_info - filesystem whose backup roots need to be read
2130 * priority - priority of backup root required
2132 * Returns backup root index on success and -EINVAL otherwise.
2134 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
2136 int backup_index = find_newest_super_backup(fs_info);
2137 struct btrfs_super_block *super = fs_info->super_copy;
2138 struct btrfs_root_backup *root_backup;
2140 if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
2142 return backup_index;
2144 backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
2145 backup_index %= BTRFS_NUM_BACKUP_ROOTS;
2150 root_backup = super->super_roots + backup_index;
2152 btrfs_set_super_generation(super,
2153 btrfs_backup_tree_root_gen(root_backup));
2154 btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2155 btrfs_set_super_root_level(super,
2156 btrfs_backup_tree_root_level(root_backup));
2157 btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2160 * Fixme: the total bytes and num_devices need to match or we should
2163 btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2164 btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2166 return backup_index;
2169 /* helper to cleanup workers */
2170 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2172 btrfs_destroy_workqueue(fs_info->fixup_workers);
2173 btrfs_destroy_workqueue(fs_info->delalloc_workers);
2174 btrfs_destroy_workqueue(fs_info->hipri_workers);
2175 btrfs_destroy_workqueue(fs_info->workers);
2176 if (fs_info->endio_workers)
2177 destroy_workqueue(fs_info->endio_workers);
2178 if (fs_info->endio_raid56_workers)
2179 destroy_workqueue(fs_info->endio_raid56_workers);
2180 if (fs_info->rmw_workers)
2181 destroy_workqueue(fs_info->rmw_workers);
2182 if (fs_info->compressed_write_workers)
2183 destroy_workqueue(fs_info->compressed_write_workers);
2184 btrfs_destroy_workqueue(fs_info->endio_write_workers);
2185 btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2186 btrfs_destroy_workqueue(fs_info->delayed_workers);
2187 btrfs_destroy_workqueue(fs_info->caching_workers);
2188 btrfs_destroy_workqueue(fs_info->flush_workers);
2189 btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2190 if (fs_info->discard_ctl.discard_workers)
2191 destroy_workqueue(fs_info->discard_ctl.discard_workers);
2193 * Now that all other work queues are destroyed, we can safely destroy
2194 * the queues used for metadata I/O, since tasks from those other work
2195 * queues can do metadata I/O operations.
2197 if (fs_info->endio_meta_workers)
2198 destroy_workqueue(fs_info->endio_meta_workers);
2201 static void free_root_extent_buffers(struct btrfs_root *root)
2204 free_extent_buffer(root->node);
2205 free_extent_buffer(root->commit_root);
2207 root->commit_root = NULL;
2211 static void free_global_root_pointers(struct btrfs_fs_info *fs_info)
2213 struct btrfs_root *root, *tmp;
2215 rbtree_postorder_for_each_entry_safe(root, tmp,
2216 &fs_info->global_root_tree,
2218 free_root_extent_buffers(root);
2221 /* helper to cleanup tree roots */
2222 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2224 free_root_extent_buffers(info->tree_root);
2226 free_global_root_pointers(info);
2227 free_root_extent_buffers(info->dev_root);
2228 free_root_extent_buffers(info->quota_root);
2229 free_root_extent_buffers(info->uuid_root);
2230 free_root_extent_buffers(info->fs_root);
2231 free_root_extent_buffers(info->data_reloc_root);
2232 free_root_extent_buffers(info->block_group_root);
2233 if (free_chunk_root)
2234 free_root_extent_buffers(info->chunk_root);
2237 void btrfs_put_root(struct btrfs_root *root)
2242 if (refcount_dec_and_test(&root->refs)) {
2243 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2244 WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2246 free_anon_bdev(root->anon_dev);
2247 btrfs_drew_lock_destroy(&root->snapshot_lock);
2248 free_root_extent_buffers(root);
2249 #ifdef CONFIG_BTRFS_DEBUG
2250 spin_lock(&root->fs_info->fs_roots_radix_lock);
2251 list_del_init(&root->leak_list);
2252 spin_unlock(&root->fs_info->fs_roots_radix_lock);
2258 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2261 struct btrfs_root *gang[8];
2264 while (!list_empty(&fs_info->dead_roots)) {
2265 gang[0] = list_entry(fs_info->dead_roots.next,
2266 struct btrfs_root, root_list);
2267 list_del(&gang[0]->root_list);
2269 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2270 btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2271 btrfs_put_root(gang[0]);
2275 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2280 for (i = 0; i < ret; i++)
2281 btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2285 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2287 mutex_init(&fs_info->scrub_lock);
2288 atomic_set(&fs_info->scrubs_running, 0);
2289 atomic_set(&fs_info->scrub_pause_req, 0);
2290 atomic_set(&fs_info->scrubs_paused, 0);
2291 atomic_set(&fs_info->scrub_cancel_req, 0);
2292 init_waitqueue_head(&fs_info->scrub_pause_wait);
2293 refcount_set(&fs_info->scrub_workers_refcnt, 0);
2296 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2298 spin_lock_init(&fs_info->balance_lock);
2299 mutex_init(&fs_info->balance_mutex);
2300 atomic_set(&fs_info->balance_pause_req, 0);
2301 atomic_set(&fs_info->balance_cancel_req, 0);
2302 fs_info->balance_ctl = NULL;
2303 init_waitqueue_head(&fs_info->balance_wait_q);
2304 atomic_set(&fs_info->reloc_cancel_req, 0);
2307 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2309 struct inode *inode = fs_info->btree_inode;
2311 inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2312 set_nlink(inode, 1);
2314 * we set the i_size on the btree inode to the max possible int.
2315 * the real end of the address space is determined by all of
2316 * the devices in the system
2318 inode->i_size = OFFSET_MAX;
2319 inode->i_mapping->a_ops = &btree_aops;
2321 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2322 extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2323 IO_TREE_BTREE_INODE_IO, inode);
2324 BTRFS_I(inode)->io_tree.track_uptodate = false;
2325 extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2327 BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2328 BTRFS_I(inode)->location.objectid = BTRFS_BTREE_INODE_OBJECTID;
2329 BTRFS_I(inode)->location.type = 0;
2330 BTRFS_I(inode)->location.offset = 0;
2331 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2332 btrfs_insert_inode_hash(inode);
2335 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2337 mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2338 init_rwsem(&fs_info->dev_replace.rwsem);
2339 init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2342 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2344 spin_lock_init(&fs_info->qgroup_lock);
2345 mutex_init(&fs_info->qgroup_ioctl_lock);
2346 fs_info->qgroup_tree = RB_ROOT;
2347 INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2348 fs_info->qgroup_seq = 1;
2349 fs_info->qgroup_ulist = NULL;
2350 fs_info->qgroup_rescan_running = false;
2351 mutex_init(&fs_info->qgroup_rescan_lock);
2354 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
2356 u32 max_active = fs_info->thread_pool_size;
2357 unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2360 btrfs_alloc_workqueue(fs_info, "worker", flags, max_active, 16);
2361 fs_info->hipri_workers =
2362 btrfs_alloc_workqueue(fs_info, "worker-high",
2363 flags | WQ_HIGHPRI, max_active, 16);
2365 fs_info->delalloc_workers =
2366 btrfs_alloc_workqueue(fs_info, "delalloc",
2367 flags, max_active, 2);
2369 fs_info->flush_workers =
2370 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2371 flags, max_active, 0);
2373 fs_info->caching_workers =
2374 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2376 fs_info->fixup_workers =
2377 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2379 fs_info->endio_workers =
2380 alloc_workqueue("btrfs-endio", flags, max_active);
2381 fs_info->endio_meta_workers =
2382 alloc_workqueue("btrfs-endio-meta", flags, max_active);
2383 fs_info->endio_raid56_workers =
2384 alloc_workqueue("btrfs-endio-raid56", flags, max_active);
2385 fs_info->rmw_workers = alloc_workqueue("btrfs-rmw", flags, max_active);
2386 fs_info->endio_write_workers =
2387 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2389 fs_info->compressed_write_workers =
2390 alloc_workqueue("btrfs-compressed-write", flags, max_active);
2391 fs_info->endio_freespace_worker =
2392 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2394 fs_info->delayed_workers =
2395 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2397 fs_info->qgroup_rescan_workers =
2398 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2399 fs_info->discard_ctl.discard_workers =
2400 alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2402 if (!(fs_info->workers && fs_info->hipri_workers &&
2403 fs_info->delalloc_workers && fs_info->flush_workers &&
2404 fs_info->endio_workers && fs_info->endio_meta_workers &&
2405 fs_info->compressed_write_workers &&
2406 fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2407 fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2408 fs_info->caching_workers && fs_info->fixup_workers &&
2409 fs_info->delayed_workers && fs_info->qgroup_rescan_workers &&
2410 fs_info->discard_ctl.discard_workers)) {
2417 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2419 struct crypto_shash *csum_shash;
2420 const char *csum_driver = btrfs_super_csum_driver(csum_type);
2422 csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2424 if (IS_ERR(csum_shash)) {
2425 btrfs_err(fs_info, "error allocating %s hash for checksum",
2427 return PTR_ERR(csum_shash);
2430 fs_info->csum_shash = csum_shash;
2432 btrfs_info(fs_info, "using %s (%s) checksum algorithm",
2433 btrfs_super_csum_name(csum_type),
2434 crypto_shash_driver_name(csum_shash));
2438 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2439 struct btrfs_fs_devices *fs_devices)
2442 struct btrfs_root *log_tree_root;
2443 struct btrfs_super_block *disk_super = fs_info->super_copy;
2444 u64 bytenr = btrfs_super_log_root(disk_super);
2445 int level = btrfs_super_log_root_level(disk_super);
2447 if (fs_devices->rw_devices == 0) {
2448 btrfs_warn(fs_info, "log replay required on RO media");
2452 log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2457 log_tree_root->node = read_tree_block(fs_info, bytenr,
2458 BTRFS_TREE_LOG_OBJECTID,
2459 fs_info->generation + 1, level,
2461 if (IS_ERR(log_tree_root->node)) {
2462 btrfs_warn(fs_info, "failed to read log tree");
2463 ret = PTR_ERR(log_tree_root->node);
2464 log_tree_root->node = NULL;
2465 btrfs_put_root(log_tree_root);
2468 if (!extent_buffer_uptodate(log_tree_root->node)) {
2469 btrfs_err(fs_info, "failed to read log tree");
2470 btrfs_put_root(log_tree_root);
2474 /* returns with log_tree_root freed on success */
2475 ret = btrfs_recover_log_trees(log_tree_root);
2477 btrfs_handle_fs_error(fs_info, ret,
2478 "Failed to recover log tree");
2479 btrfs_put_root(log_tree_root);
2483 if (sb_rdonly(fs_info->sb)) {
2484 ret = btrfs_commit_super(fs_info);
2492 static int load_global_roots_objectid(struct btrfs_root *tree_root,
2493 struct btrfs_path *path, u64 objectid,
2496 struct btrfs_fs_info *fs_info = tree_root->fs_info;
2497 struct btrfs_root *root;
2498 u64 max_global_id = 0;
2500 struct btrfs_key key = {
2501 .objectid = objectid,
2502 .type = BTRFS_ROOT_ITEM_KEY,
2507 /* If we have IGNOREDATACSUMS skip loading these roots. */
2508 if (objectid == BTRFS_CSUM_TREE_OBJECTID &&
2509 btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2510 set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2515 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2519 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2520 ret = btrfs_next_leaf(tree_root, path);
2529 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2530 if (key.objectid != objectid)
2532 btrfs_release_path(path);
2535 * Just worry about this for extent tree, it'll be the same for
2538 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2539 max_global_id = max(max_global_id, key.offset);
2542 root = read_tree_root_path(tree_root, path, &key);
2544 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2545 ret = PTR_ERR(root);
2548 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2549 ret = btrfs_global_root_insert(root);
2551 btrfs_put_root(root);
2556 btrfs_release_path(path);
2558 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2559 fs_info->nr_global_roots = max_global_id + 1;
2561 if (!found || ret) {
2562 if (objectid == BTRFS_CSUM_TREE_OBJECTID)
2563 set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2565 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2566 ret = ret ? ret : -ENOENT;
2569 btrfs_err(fs_info, "failed to load root %s", name);
2574 static int load_global_roots(struct btrfs_root *tree_root)
2576 struct btrfs_path *path;
2579 path = btrfs_alloc_path();
2583 ret = load_global_roots_objectid(tree_root, path,
2584 BTRFS_EXTENT_TREE_OBJECTID, "extent");
2587 ret = load_global_roots_objectid(tree_root, path,
2588 BTRFS_CSUM_TREE_OBJECTID, "csum");
2591 if (!btrfs_fs_compat_ro(tree_root->fs_info, FREE_SPACE_TREE))
2593 ret = load_global_roots_objectid(tree_root, path,
2594 BTRFS_FREE_SPACE_TREE_OBJECTID,
2597 btrfs_free_path(path);
2601 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2603 struct btrfs_root *tree_root = fs_info->tree_root;
2604 struct btrfs_root *root;
2605 struct btrfs_key location;
2608 BUG_ON(!fs_info->tree_root);
2610 ret = load_global_roots(tree_root);
2614 location.objectid = BTRFS_DEV_TREE_OBJECTID;
2615 location.type = BTRFS_ROOT_ITEM_KEY;
2616 location.offset = 0;
2618 root = btrfs_read_tree_root(tree_root, &location);
2620 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2621 ret = PTR_ERR(root);
2625 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2626 fs_info->dev_root = root;
2628 /* Initialize fs_info for all devices in any case */
2629 btrfs_init_devices_late(fs_info);
2632 * This tree can share blocks with some other fs tree during relocation
2633 * and we need a proper setup by btrfs_get_fs_root
2635 root = btrfs_get_fs_root(tree_root->fs_info,
2636 BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2638 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2639 ret = PTR_ERR(root);
2643 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2644 fs_info->data_reloc_root = root;
2647 location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2648 root = btrfs_read_tree_root(tree_root, &location);
2649 if (!IS_ERR(root)) {
2650 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2651 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2652 fs_info->quota_root = root;
2655 location.objectid = BTRFS_UUID_TREE_OBJECTID;
2656 root = btrfs_read_tree_root(tree_root, &location);
2658 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2659 ret = PTR_ERR(root);
2664 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2665 fs_info->uuid_root = root;
2670 btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2671 location.objectid, ret);
2676 * Real super block validation
2677 * NOTE: super csum type and incompat features will not be checked here.
2679 * @sb: super block to check
2680 * @mirror_num: the super block number to check its bytenr:
2681 * 0 the primary (1st) sb
2682 * 1, 2 2nd and 3rd backup copy
2683 * -1 skip bytenr check
2685 static int validate_super(struct btrfs_fs_info *fs_info,
2686 struct btrfs_super_block *sb, int mirror_num)
2688 u64 nodesize = btrfs_super_nodesize(sb);
2689 u64 sectorsize = btrfs_super_sectorsize(sb);
2692 if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2693 btrfs_err(fs_info, "no valid FS found");
2696 if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2697 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2698 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2701 if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2702 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2703 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2706 if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2707 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2708 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2711 if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2712 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2713 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2718 * Check sectorsize and nodesize first, other check will need it.
2719 * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2721 if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2722 sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2723 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2728 * We only support at most two sectorsizes: 4K and PAGE_SIZE.
2730 * We can support 16K sectorsize with 64K page size without problem,
2731 * but such sectorsize/pagesize combination doesn't make much sense.
2732 * 4K will be our future standard, PAGE_SIZE is supported from the very
2735 if (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K && sectorsize != PAGE_SIZE)) {
2737 "sectorsize %llu not yet supported for page size %lu",
2738 sectorsize, PAGE_SIZE);
2742 if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2743 nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2744 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2747 if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2748 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2749 le32_to_cpu(sb->__unused_leafsize), nodesize);
2753 /* Root alignment check */
2754 if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2755 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2756 btrfs_super_root(sb));
2759 if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2760 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2761 btrfs_super_chunk_root(sb));
2764 if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2765 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2766 btrfs_super_log_root(sb));
2770 if (memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
2773 "superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2774 fs_info->super_copy->fsid, fs_info->fs_devices->fsid);
2778 if (btrfs_fs_incompat(fs_info, METADATA_UUID) &&
2779 memcmp(fs_info->fs_devices->metadata_uuid,
2780 fs_info->super_copy->metadata_uuid, BTRFS_FSID_SIZE)) {
2782 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2783 fs_info->super_copy->metadata_uuid,
2784 fs_info->fs_devices->metadata_uuid);
2788 if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2789 BTRFS_FSID_SIZE) != 0) {
2791 "dev_item UUID does not match metadata fsid: %pU != %pU",
2792 fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2797 * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2800 if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2801 btrfs_err(fs_info, "bytes_used is too small %llu",
2802 btrfs_super_bytes_used(sb));
2805 if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2806 btrfs_err(fs_info, "invalid stripesize %u",
2807 btrfs_super_stripesize(sb));
2810 if (btrfs_super_num_devices(sb) > (1UL << 31))
2811 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2812 btrfs_super_num_devices(sb));
2813 if (btrfs_super_num_devices(sb) == 0) {
2814 btrfs_err(fs_info, "number of devices is 0");
2818 if (mirror_num >= 0 &&
2819 btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2820 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2821 btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2826 * Obvious sys_chunk_array corruptions, it must hold at least one key
2829 if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2830 btrfs_err(fs_info, "system chunk array too big %u > %u",
2831 btrfs_super_sys_array_size(sb),
2832 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2835 if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2836 + sizeof(struct btrfs_chunk)) {
2837 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2838 btrfs_super_sys_array_size(sb),
2839 sizeof(struct btrfs_disk_key)
2840 + sizeof(struct btrfs_chunk));
2845 * The generation is a global counter, we'll trust it more than the others
2846 * but it's still possible that it's the one that's wrong.
2848 if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2850 "suspicious: generation < chunk_root_generation: %llu < %llu",
2851 btrfs_super_generation(sb),
2852 btrfs_super_chunk_root_generation(sb));
2853 if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2854 && btrfs_super_cache_generation(sb) != (u64)-1)
2856 "suspicious: generation < cache_generation: %llu < %llu",
2857 btrfs_super_generation(sb),
2858 btrfs_super_cache_generation(sb));
2864 * Validation of super block at mount time.
2865 * Some checks already done early at mount time, like csum type and incompat
2866 * flags will be skipped.
2868 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2870 return validate_super(fs_info, fs_info->super_copy, 0);
2874 * Validation of super block at write time.
2875 * Some checks like bytenr check will be skipped as their values will be
2877 * Extra checks like csum type and incompat flags will be done here.
2879 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2880 struct btrfs_super_block *sb)
2884 ret = validate_super(fs_info, sb, -1);
2887 if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2889 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2890 btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2893 if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2896 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2897 btrfs_super_incompat_flags(sb),
2898 (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2904 "super block corruption detected before writing it to disk");
2908 static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int level)
2912 root->node = read_tree_block(root->fs_info, bytenr,
2913 root->root_key.objectid, gen, level, NULL);
2914 if (IS_ERR(root->node)) {
2915 ret = PTR_ERR(root->node);
2919 if (!extent_buffer_uptodate(root->node)) {
2920 free_extent_buffer(root->node);
2925 btrfs_set_root_node(&root->root_item, root->node);
2926 root->commit_root = btrfs_root_node(root);
2927 btrfs_set_root_refs(&root->root_item, 1);
2931 static int load_important_roots(struct btrfs_fs_info *fs_info)
2933 struct btrfs_super_block *sb = fs_info->super_copy;
2937 bytenr = btrfs_super_root(sb);
2938 gen = btrfs_super_generation(sb);
2939 level = btrfs_super_root_level(sb);
2940 ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
2942 btrfs_warn(fs_info, "couldn't read tree root");
2946 if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
2949 bytenr = btrfs_super_block_group_root(sb);
2950 gen = btrfs_super_block_group_root_generation(sb);
2951 level = btrfs_super_block_group_root_level(sb);
2952 ret = load_super_root(fs_info->block_group_root, bytenr, gen, level);
2954 btrfs_warn(fs_info, "couldn't read block group root");
2958 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2960 int backup_index = find_newest_super_backup(fs_info);
2961 struct btrfs_super_block *sb = fs_info->super_copy;
2962 struct btrfs_root *tree_root = fs_info->tree_root;
2963 bool handle_error = false;
2967 if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2968 struct btrfs_root *root;
2970 root = btrfs_alloc_root(fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID,
2974 fs_info->block_group_root = root;
2977 for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2979 if (!IS_ERR(tree_root->node))
2980 free_extent_buffer(tree_root->node);
2981 tree_root->node = NULL;
2983 if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2986 free_root_pointers(fs_info, 0);
2989 * Don't use the log in recovery mode, it won't be
2992 btrfs_set_super_log_root(sb, 0);
2994 /* We can't trust the free space cache either */
2995 btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2997 ret = read_backup_root(fs_info, i);
3003 ret = load_important_roots(fs_info);
3005 handle_error = true;
3010 * No need to hold btrfs_root::objectid_mutex since the fs
3011 * hasn't been fully initialised and we are the only user
3013 ret = btrfs_init_root_free_objectid(tree_root);
3015 handle_error = true;
3019 ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
3021 ret = btrfs_read_roots(fs_info);
3023 handle_error = true;
3027 /* All successful */
3028 fs_info->generation = btrfs_header_generation(tree_root->node);
3029 fs_info->last_trans_committed = fs_info->generation;
3030 fs_info->last_reloc_trans = 0;
3032 /* Always begin writing backup roots after the one being used */
3033 if (backup_index < 0) {
3034 fs_info->backup_root_index = 0;
3036 fs_info->backup_root_index = backup_index + 1;
3037 fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
3045 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
3047 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
3048 INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
3049 INIT_LIST_HEAD(&fs_info->trans_list);
3050 INIT_LIST_HEAD(&fs_info->dead_roots);
3051 INIT_LIST_HEAD(&fs_info->delayed_iputs);
3052 INIT_LIST_HEAD(&fs_info->delalloc_roots);
3053 INIT_LIST_HEAD(&fs_info->caching_block_groups);
3054 spin_lock_init(&fs_info->delalloc_root_lock);
3055 spin_lock_init(&fs_info->trans_lock);
3056 spin_lock_init(&fs_info->fs_roots_radix_lock);
3057 spin_lock_init(&fs_info->delayed_iput_lock);
3058 spin_lock_init(&fs_info->defrag_inodes_lock);
3059 spin_lock_init(&fs_info->super_lock);
3060 spin_lock_init(&fs_info->buffer_lock);
3061 spin_lock_init(&fs_info->unused_bgs_lock);
3062 spin_lock_init(&fs_info->treelog_bg_lock);
3063 spin_lock_init(&fs_info->zone_active_bgs_lock);
3064 spin_lock_init(&fs_info->relocation_bg_lock);
3065 rwlock_init(&fs_info->tree_mod_log_lock);
3066 rwlock_init(&fs_info->global_root_lock);
3067 mutex_init(&fs_info->unused_bg_unpin_mutex);
3068 mutex_init(&fs_info->reclaim_bgs_lock);
3069 mutex_init(&fs_info->reloc_mutex);
3070 mutex_init(&fs_info->delalloc_root_mutex);
3071 mutex_init(&fs_info->zoned_meta_io_lock);
3072 mutex_init(&fs_info->zoned_data_reloc_io_lock);
3073 seqlock_init(&fs_info->profiles_lock);
3075 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
3076 INIT_LIST_HEAD(&fs_info->space_info);
3077 INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
3078 INIT_LIST_HEAD(&fs_info->unused_bgs);
3079 INIT_LIST_HEAD(&fs_info->reclaim_bgs);
3080 INIT_LIST_HEAD(&fs_info->zone_active_bgs);
3081 #ifdef CONFIG_BTRFS_DEBUG
3082 INIT_LIST_HEAD(&fs_info->allocated_roots);
3083 INIT_LIST_HEAD(&fs_info->allocated_ebs);
3084 spin_lock_init(&fs_info->eb_leak_lock);
3086 extent_map_tree_init(&fs_info->mapping_tree);
3087 btrfs_init_block_rsv(&fs_info->global_block_rsv,
3088 BTRFS_BLOCK_RSV_GLOBAL);
3089 btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
3090 btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
3091 btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
3092 btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
3093 BTRFS_BLOCK_RSV_DELOPS);
3094 btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
3095 BTRFS_BLOCK_RSV_DELREFS);
3097 atomic_set(&fs_info->async_delalloc_pages, 0);
3098 atomic_set(&fs_info->defrag_running, 0);
3099 atomic_set(&fs_info->nr_delayed_iputs, 0);
3100 atomic64_set(&fs_info->tree_mod_seq, 0);
3101 fs_info->global_root_tree = RB_ROOT;
3102 fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
3103 fs_info->metadata_ratio = 0;
3104 fs_info->defrag_inodes = RB_ROOT;
3105 atomic64_set(&fs_info->free_chunk_space, 0);
3106 fs_info->tree_mod_log = RB_ROOT;
3107 fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
3108 fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
3109 btrfs_init_ref_verify(fs_info);
3111 fs_info->thread_pool_size = min_t(unsigned long,
3112 num_online_cpus() + 2, 8);
3114 INIT_LIST_HEAD(&fs_info->ordered_roots);
3115 spin_lock_init(&fs_info->ordered_root_lock);
3117 btrfs_init_scrub(fs_info);
3118 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3119 fs_info->check_integrity_print_mask = 0;
3121 btrfs_init_balance(fs_info);
3122 btrfs_init_async_reclaim_work(fs_info);
3124 rwlock_init(&fs_info->block_group_cache_lock);
3125 fs_info->block_group_cache_tree = RB_ROOT_CACHED;
3127 extent_io_tree_init(fs_info, &fs_info->excluded_extents,
3128 IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
3130 mutex_init(&fs_info->ordered_operations_mutex);
3131 mutex_init(&fs_info->tree_log_mutex);
3132 mutex_init(&fs_info->chunk_mutex);
3133 mutex_init(&fs_info->transaction_kthread_mutex);
3134 mutex_init(&fs_info->cleaner_mutex);
3135 mutex_init(&fs_info->ro_block_group_mutex);
3136 init_rwsem(&fs_info->commit_root_sem);
3137 init_rwsem(&fs_info->cleanup_work_sem);
3138 init_rwsem(&fs_info->subvol_sem);
3139 sema_init(&fs_info->uuid_tree_rescan_sem, 1);
3141 btrfs_init_dev_replace_locks(fs_info);
3142 btrfs_init_qgroup(fs_info);
3143 btrfs_discard_init(fs_info);
3145 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
3146 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
3148 init_waitqueue_head(&fs_info->transaction_throttle);
3149 init_waitqueue_head(&fs_info->transaction_wait);
3150 init_waitqueue_head(&fs_info->transaction_blocked_wait);
3151 init_waitqueue_head(&fs_info->async_submit_wait);
3152 init_waitqueue_head(&fs_info->delayed_iputs_wait);
3153 init_waitqueue_head(&fs_info->zone_finish_wait);
3155 /* Usable values until the real ones are cached from the superblock */
3156 fs_info->nodesize = 4096;
3157 fs_info->sectorsize = 4096;
3158 fs_info->sectorsize_bits = ilog2(4096);
3159 fs_info->stripesize = 4096;
3161 fs_info->max_extent_size = BTRFS_MAX_EXTENT_SIZE;
3163 spin_lock_init(&fs_info->swapfile_pins_lock);
3164 fs_info->swapfile_pins = RB_ROOT;
3166 fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
3167 INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
3170 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
3175 sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
3176 sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
3178 ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
3182 ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
3186 fs_info->dirty_metadata_batch = PAGE_SIZE *
3187 (1 + ilog2(nr_cpu_ids));
3189 ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
3193 ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
3198 fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
3200 if (!fs_info->delayed_root)
3202 btrfs_init_delayed_root(fs_info->delayed_root);
3205 set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
3207 return btrfs_alloc_stripe_hash_table(fs_info);
3210 static int btrfs_uuid_rescan_kthread(void *data)
3212 struct btrfs_fs_info *fs_info = data;
3216 * 1st step is to iterate through the existing UUID tree and
3217 * to delete all entries that contain outdated data.
3218 * 2nd step is to add all missing entries to the UUID tree.
3220 ret = btrfs_uuid_tree_iterate(fs_info);
3223 btrfs_warn(fs_info, "iterating uuid_tree failed %d",
3225 up(&fs_info->uuid_tree_rescan_sem);
3228 return btrfs_uuid_scan_kthread(data);
3231 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3233 struct task_struct *task;
3235 down(&fs_info->uuid_tree_rescan_sem);
3236 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3238 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3239 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3240 up(&fs_info->uuid_tree_rescan_sem);
3241 return PTR_ERR(task);
3248 * Some options only have meaning at mount time and shouldn't persist across
3249 * remounts, or be displayed. Clear these at the end of mount and remount
3252 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
3254 btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3255 btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
3259 * Mounting logic specific to read-write file systems. Shared by open_ctree
3260 * and btrfs_remount when remounting from read-only to read-write.
3262 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
3265 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
3266 bool clear_free_space_tree = false;
3268 if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3269 btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3270 clear_free_space_tree = true;
3271 } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3272 !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3273 btrfs_warn(fs_info, "free space tree is invalid");
3274 clear_free_space_tree = true;
3277 if (clear_free_space_tree) {
3278 btrfs_info(fs_info, "clearing free space tree");
3279 ret = btrfs_clear_free_space_tree(fs_info);
3282 "failed to clear free space tree: %d", ret);
3288 * btrfs_find_orphan_roots() is responsible for finding all the dead
3289 * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3290 * them into the fs_info->fs_roots_radix tree. This must be done before
3291 * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3292 * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3293 * item before the root's tree is deleted - this means that if we unmount
3294 * or crash before the deletion completes, on the next mount we will not
3295 * delete what remains of the tree because the orphan item does not
3296 * exists anymore, which is what tells us we have a pending deletion.
3298 ret = btrfs_find_orphan_roots(fs_info);
3302 ret = btrfs_cleanup_fs_roots(fs_info);
3306 down_read(&fs_info->cleanup_work_sem);
3307 if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3308 (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3309 up_read(&fs_info->cleanup_work_sem);
3312 up_read(&fs_info->cleanup_work_sem);
3314 mutex_lock(&fs_info->cleaner_mutex);
3315 ret = btrfs_recover_relocation(fs_info);
3316 mutex_unlock(&fs_info->cleaner_mutex);
3318 btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3322 if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3323 !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3324 btrfs_info(fs_info, "creating free space tree");
3325 ret = btrfs_create_free_space_tree(fs_info);
3328 "failed to create free space tree: %d", ret);
3333 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3334 ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3339 ret = btrfs_resume_balance_async(fs_info);
3343 ret = btrfs_resume_dev_replace_async(fs_info);
3345 btrfs_warn(fs_info, "failed to resume dev_replace");
3349 btrfs_qgroup_rescan_resume(fs_info);
3351 if (!fs_info->uuid_root) {
3352 btrfs_info(fs_info, "creating UUID tree");
3353 ret = btrfs_create_uuid_tree(fs_info);
3356 "failed to create the UUID tree %d", ret);
3365 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3374 struct btrfs_super_block *disk_super;
3375 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3376 struct btrfs_root *tree_root;
3377 struct btrfs_root *chunk_root;
3382 ret = init_mount_fs_info(fs_info, sb);
3388 /* These need to be init'ed before we start creating inodes and such. */
3389 tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3391 fs_info->tree_root = tree_root;
3392 chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3394 fs_info->chunk_root = chunk_root;
3395 if (!tree_root || !chunk_root) {
3400 fs_info->btree_inode = new_inode(sb);
3401 if (!fs_info->btree_inode) {
3405 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3406 btrfs_init_btree_inode(fs_info);
3408 invalidate_bdev(fs_devices->latest_dev->bdev);
3411 * Read super block and check the signature bytes only
3413 disk_super = btrfs_read_dev_super(fs_devices->latest_dev->bdev);
3414 if (IS_ERR(disk_super)) {
3415 err = PTR_ERR(disk_super);
3420 * Verify the type first, if that or the checksum value are
3421 * corrupted, we'll find out
3423 csum_type = btrfs_super_csum_type(disk_super);
3424 if (!btrfs_supported_super_csum(csum_type)) {
3425 btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3428 btrfs_release_disk_super(disk_super);
3432 fs_info->csum_size = btrfs_super_csum_size(disk_super);
3434 ret = btrfs_init_csum_hash(fs_info, csum_type);
3437 btrfs_release_disk_super(disk_super);
3442 * We want to check superblock checksum, the type is stored inside.
3443 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3445 if (btrfs_check_super_csum(fs_info, (u8 *)disk_super)) {
3446 btrfs_err(fs_info, "superblock checksum mismatch");
3448 btrfs_release_disk_super(disk_super);
3453 * super_copy is zeroed at allocation time and we never touch the
3454 * following bytes up to INFO_SIZE, the checksum is calculated from
3455 * the whole block of INFO_SIZE
3457 memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3458 btrfs_release_disk_super(disk_super);
3460 disk_super = fs_info->super_copy;
3463 features = btrfs_super_flags(disk_super);
3464 if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3465 features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3466 btrfs_set_super_flags(disk_super, features);
3468 "found metadata UUID change in progress flag, clearing");
3471 memcpy(fs_info->super_for_commit, fs_info->super_copy,
3472 sizeof(*fs_info->super_for_commit));
3474 ret = btrfs_validate_mount_super(fs_info);
3476 btrfs_err(fs_info, "superblock contains fatal errors");
3481 if (!btrfs_super_root(disk_super))
3484 /* check FS state, whether FS is broken. */
3485 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3486 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3489 * In the long term, we'll store the compression type in the super
3490 * block, and it'll be used for per file compression control.
3492 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3495 /* Set up fs_info before parsing mount options */
3496 nodesize = btrfs_super_nodesize(disk_super);
3497 sectorsize = btrfs_super_sectorsize(disk_super);
3498 stripesize = sectorsize;
3499 fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3500 fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3502 fs_info->nodesize = nodesize;
3503 fs_info->sectorsize = sectorsize;
3504 fs_info->sectorsize_bits = ilog2(sectorsize);
3505 fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3506 fs_info->stripesize = stripesize;
3508 ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3514 features = btrfs_super_incompat_flags(disk_super) &
3515 ~BTRFS_FEATURE_INCOMPAT_SUPP;
3518 "cannot mount because of unsupported optional features (0x%llx)",
3524 features = btrfs_super_incompat_flags(disk_super);
3525 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3526 if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3527 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3528 else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3529 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3532 * Flag our filesystem as having big metadata blocks if they are bigger
3533 * than the page size.
3535 if (btrfs_super_nodesize(disk_super) > PAGE_SIZE)
3536 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3539 * mixed block groups end up with duplicate but slightly offset
3540 * extent buffers for the same range. It leads to corruptions
3542 if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3543 (sectorsize != nodesize)) {
3545 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3546 nodesize, sectorsize);
3551 * Needn't use the lock because there is no other task which will
3554 btrfs_set_super_incompat_flags(disk_super, features);
3556 features = btrfs_super_compat_ro_flags(disk_super) &
3557 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
3558 if (!sb_rdonly(sb) && features) {
3560 "cannot mount read-write because of unsupported optional features (0x%llx)",
3566 * We have unsupported RO compat features, although RO mounted, we
3567 * should not cause any metadata write, including log replay.
3568 * Or we could screw up whatever the new feature requires.
3570 if (unlikely(features && btrfs_super_log_root(disk_super) &&
3571 !btrfs_test_opt(fs_info, NOLOGREPLAY))) {
3573 "cannot replay dirty log with unsupported compat_ro features (0x%llx), try rescue=nologreplay",
3580 if (sectorsize < PAGE_SIZE) {
3581 struct btrfs_subpage_info *subpage_info;
3584 * V1 space cache has some hardcoded PAGE_SIZE usage, and is
3585 * going to be deprecated.
3587 * Force to use v2 cache for subpage case.
3589 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
3590 btrfs_set_and_info(fs_info, FREE_SPACE_TREE,
3591 "forcing free space tree for sector size %u with page size %lu",
3592 sectorsize, PAGE_SIZE);
3595 "read-write for sector size %u with page size %lu is experimental",
3596 sectorsize, PAGE_SIZE);
3597 subpage_info = kzalloc(sizeof(*subpage_info), GFP_KERNEL);
3600 btrfs_init_subpage_info(subpage_info, sectorsize);
3601 fs_info->subpage_info = subpage_info;
3604 ret = btrfs_init_workqueues(fs_info);
3607 goto fail_sb_buffer;
3610 sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3611 sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3613 sb->s_blocksize = sectorsize;
3614 sb->s_blocksize_bits = blksize_bits(sectorsize);
3615 memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3617 mutex_lock(&fs_info->chunk_mutex);
3618 ret = btrfs_read_sys_array(fs_info);
3619 mutex_unlock(&fs_info->chunk_mutex);
3621 btrfs_err(fs_info, "failed to read the system array: %d", ret);
3622 goto fail_sb_buffer;
3625 generation = btrfs_super_chunk_root_generation(disk_super);
3626 level = btrfs_super_chunk_root_level(disk_super);
3627 ret = load_super_root(chunk_root, btrfs_super_chunk_root(disk_super),
3630 btrfs_err(fs_info, "failed to read chunk root");
3631 goto fail_tree_roots;
3634 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3635 offsetof(struct btrfs_header, chunk_tree_uuid),
3638 ret = btrfs_read_chunk_tree(fs_info);
3640 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3641 goto fail_tree_roots;
3645 * At this point we know all the devices that make this filesystem,
3646 * including the seed devices but we don't know yet if the replace
3647 * target is required. So free devices that are not part of this
3648 * filesystem but skip the replace target device which is checked
3649 * below in btrfs_init_dev_replace().
3651 btrfs_free_extra_devids(fs_devices);
3652 if (!fs_devices->latest_dev->bdev) {
3653 btrfs_err(fs_info, "failed to read devices");
3654 goto fail_tree_roots;
3657 ret = init_tree_roots(fs_info);
3659 goto fail_tree_roots;
3662 * Get zone type information of zoned block devices. This will also
3663 * handle emulation of a zoned filesystem if a regular device has the
3664 * zoned incompat feature flag set.
3666 ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3669 "zoned: failed to read device zone info: %d",
3671 goto fail_block_groups;
3675 * If we have a uuid root and we're not being told to rescan we need to
3676 * check the generation here so we can set the
3677 * BTRFS_FS_UPDATE_UUID_TREE_GEN bit. Otherwise we could commit the
3678 * transaction during a balance or the log replay without updating the
3679 * uuid generation, and then if we crash we would rescan the uuid tree,
3680 * even though it was perfectly fine.
3682 if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3683 fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3684 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3686 ret = btrfs_verify_dev_extents(fs_info);
3689 "failed to verify dev extents against chunks: %d",
3691 goto fail_block_groups;
3693 ret = btrfs_recover_balance(fs_info);
3695 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3696 goto fail_block_groups;
3699 ret = btrfs_init_dev_stats(fs_info);
3701 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3702 goto fail_block_groups;
3705 ret = btrfs_init_dev_replace(fs_info);
3707 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3708 goto fail_block_groups;
3711 ret = btrfs_check_zoned_mode(fs_info);
3713 btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3715 goto fail_block_groups;
3718 ret = btrfs_sysfs_add_fsid(fs_devices);
3720 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3722 goto fail_block_groups;
3725 ret = btrfs_sysfs_add_mounted(fs_info);
3727 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3728 goto fail_fsdev_sysfs;
3731 ret = btrfs_init_space_info(fs_info);
3733 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3737 ret = btrfs_read_block_groups(fs_info);
3739 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3743 btrfs_free_zone_cache(fs_info);
3745 if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices &&
3746 !btrfs_check_rw_degradable(fs_info, NULL)) {
3748 "writable mount is not allowed due to too many missing devices");
3752 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, fs_info,
3754 if (IS_ERR(fs_info->cleaner_kthread))
3757 fs_info->transaction_kthread = kthread_run(transaction_kthread,
3759 "btrfs-transaction");
3760 if (IS_ERR(fs_info->transaction_kthread))
3763 if (!btrfs_test_opt(fs_info, NOSSD) &&
3764 !fs_info->fs_devices->rotating) {
3765 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3769 * Mount does not set all options immediately, we can do it now and do
3770 * not have to wait for transaction commit
3772 btrfs_apply_pending_changes(fs_info);
3774 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3775 if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3776 ret = btrfsic_mount(fs_info, fs_devices,
3777 btrfs_test_opt(fs_info,
3778 CHECK_INTEGRITY_DATA) ? 1 : 0,
3779 fs_info->check_integrity_print_mask);
3782 "failed to initialize integrity check module: %d",
3786 ret = btrfs_read_qgroup_config(fs_info);
3788 goto fail_trans_kthread;
3790 if (btrfs_build_ref_tree(fs_info))
3791 btrfs_err(fs_info, "couldn't build ref tree");
3793 /* do not make disk changes in broken FS or nologreplay is given */
3794 if (btrfs_super_log_root(disk_super) != 0 &&
3795 !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3796 btrfs_info(fs_info, "start tree-log replay");
3797 ret = btrfs_replay_log(fs_info, fs_devices);
3804 fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3805 if (IS_ERR(fs_info->fs_root)) {
3806 err = PTR_ERR(fs_info->fs_root);
3807 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3808 fs_info->fs_root = NULL;
3815 ret = btrfs_start_pre_rw_mount(fs_info);
3817 close_ctree(fs_info);
3820 btrfs_discard_resume(fs_info);
3822 if (fs_info->uuid_root &&
3823 (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3824 fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3825 btrfs_info(fs_info, "checking UUID tree");
3826 ret = btrfs_check_uuid_tree(fs_info);
3829 "failed to check the UUID tree: %d", ret);
3830 close_ctree(fs_info);
3835 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3837 /* Kick the cleaner thread so it'll start deleting snapshots. */
3838 if (test_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags))
3839 wake_up_process(fs_info->cleaner_kthread);
3842 btrfs_clear_oneshot_options(fs_info);
3846 btrfs_free_qgroup_config(fs_info);
3848 kthread_stop(fs_info->transaction_kthread);
3849 btrfs_cleanup_transaction(fs_info);
3850 btrfs_free_fs_roots(fs_info);
3852 kthread_stop(fs_info->cleaner_kthread);
3855 * make sure we're done with the btree inode before we stop our
3858 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3861 btrfs_sysfs_remove_mounted(fs_info);
3864 btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3867 btrfs_put_block_group_cache(fs_info);
3870 if (fs_info->data_reloc_root)
3871 btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3872 free_root_pointers(fs_info, true);
3873 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3876 btrfs_stop_all_workers(fs_info);
3877 btrfs_free_block_groups(fs_info);
3879 btrfs_mapping_tree_free(&fs_info->mapping_tree);
3881 iput(fs_info->btree_inode);
3883 btrfs_close_devices(fs_info->fs_devices);
3886 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3888 static void btrfs_end_super_write(struct bio *bio)
3890 struct btrfs_device *device = bio->bi_private;
3891 struct bio_vec *bvec;
3892 struct bvec_iter_all iter_all;
3895 bio_for_each_segment_all(bvec, bio, iter_all) {
3896 page = bvec->bv_page;
3898 if (bio->bi_status) {
3899 btrfs_warn_rl_in_rcu(device->fs_info,
3900 "lost page write due to IO error on %s (%d)",
3901 rcu_str_deref(device->name),
3902 blk_status_to_errno(bio->bi_status));
3903 ClearPageUptodate(page);
3905 btrfs_dev_stat_inc_and_print(device,
3906 BTRFS_DEV_STAT_WRITE_ERRS);
3908 SetPageUptodate(page);
3918 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3921 struct btrfs_super_block *super;
3923 u64 bytenr, bytenr_orig;
3924 struct address_space *mapping = bdev->bd_inode->i_mapping;
3927 bytenr_orig = btrfs_sb_offset(copy_num);
3928 ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3930 return ERR_PTR(-EINVAL);
3932 return ERR_PTR(ret);
3934 if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev))
3935 return ERR_PTR(-EINVAL);
3937 page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3939 return ERR_CAST(page);
3941 super = page_address(page);
3942 if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3943 btrfs_release_disk_super(super);
3944 return ERR_PTR(-ENODATA);
3947 if (btrfs_super_bytenr(super) != bytenr_orig) {
3948 btrfs_release_disk_super(super);
3949 return ERR_PTR(-EINVAL);
3956 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3958 struct btrfs_super_block *super, *latest = NULL;
3962 /* we would like to check all the supers, but that would make
3963 * a btrfs mount succeed after a mkfs from a different FS.
3964 * So, we need to add a special mount option to scan for
3965 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3967 for (i = 0; i < 1; i++) {
3968 super = btrfs_read_dev_one_super(bdev, i);
3972 if (!latest || btrfs_super_generation(super) > transid) {
3974 btrfs_release_disk_super(super);
3977 transid = btrfs_super_generation(super);
3985 * Write superblock @sb to the @device. Do not wait for completion, all the
3986 * pages we use for writing are locked.
3988 * Write @max_mirrors copies of the superblock, where 0 means default that fit
3989 * the expected device size at commit time. Note that max_mirrors must be
3990 * same for write and wait phases.
3992 * Return number of errors when page is not found or submission fails.
3994 static int write_dev_supers(struct btrfs_device *device,
3995 struct btrfs_super_block *sb, int max_mirrors)
3997 struct btrfs_fs_info *fs_info = device->fs_info;
3998 struct address_space *mapping = device->bdev->bd_inode->i_mapping;
3999 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
4003 u64 bytenr, bytenr_orig;
4005 if (max_mirrors == 0)
4006 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4008 shash->tfm = fs_info->csum_shash;
4010 for (i = 0; i < max_mirrors; i++) {
4013 struct btrfs_super_block *disk_super;
4015 bytenr_orig = btrfs_sb_offset(i);
4016 ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
4017 if (ret == -ENOENT) {
4019 } else if (ret < 0) {
4020 btrfs_err(device->fs_info,
4021 "couldn't get super block location for mirror %d",
4026 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4027 device->commit_total_bytes)
4030 btrfs_set_super_bytenr(sb, bytenr_orig);
4032 crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
4033 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
4036 page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
4039 btrfs_err(device->fs_info,
4040 "couldn't get super block page for bytenr %llu",
4046 /* Bump the refcount for wait_dev_supers() */
4049 disk_super = page_address(page);
4050 memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
4053 * Directly use bios here instead of relying on the page cache
4054 * to do I/O, so we don't lose the ability to do integrity
4057 bio = bio_alloc(device->bdev, 1,
4058 REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO,
4060 bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
4061 bio->bi_private = device;
4062 bio->bi_end_io = btrfs_end_super_write;
4063 __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
4064 offset_in_page(bytenr));
4067 * We FUA only the first super block. The others we allow to
4068 * go down lazy and there's a short window where the on-disk
4069 * copies might still contain the older version.
4071 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
4072 bio->bi_opf |= REQ_FUA;
4074 btrfsic_check_bio(bio);
4077 if (btrfs_advance_sb_log(device, i))
4080 return errors < i ? 0 : -1;
4084 * Wait for write completion of superblocks done by write_dev_supers,
4085 * @max_mirrors same for write and wait phases.
4087 * Return number of errors when page is not found or not marked up to
4090 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
4094 bool primary_failed = false;
4098 if (max_mirrors == 0)
4099 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4101 for (i = 0; i < max_mirrors; i++) {
4104 ret = btrfs_sb_log_location(device, i, READ, &bytenr);
4105 if (ret == -ENOENT) {
4107 } else if (ret < 0) {
4110 primary_failed = true;
4113 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4114 device->commit_total_bytes)
4117 page = find_get_page(device->bdev->bd_inode->i_mapping,
4118 bytenr >> PAGE_SHIFT);
4122 primary_failed = true;
4125 /* Page is submitted locked and unlocked once the IO completes */
4126 wait_on_page_locked(page);
4127 if (PageError(page)) {
4130 primary_failed = true;
4133 /* Drop our reference */
4136 /* Drop the reference from the writing run */
4140 /* log error, force error return */
4141 if (primary_failed) {
4142 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
4147 return errors < i ? 0 : -1;
4151 * endio for the write_dev_flush, this will wake anyone waiting
4152 * for the barrier when it is done
4154 static void btrfs_end_empty_barrier(struct bio *bio)
4157 complete(bio->bi_private);
4161 * Submit a flush request to the device if it supports it. Error handling is
4162 * done in the waiting counterpart.
4164 static void write_dev_flush(struct btrfs_device *device)
4166 struct bio *bio = &device->flush_bio;
4168 #ifndef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4170 * When a disk has write caching disabled, we skip submission of a bio
4171 * with flush and sync requests before writing the superblock, since
4172 * it's not needed. However when the integrity checker is enabled, this
4173 * results in reports that there are metadata blocks referred by a
4174 * superblock that were not properly flushed. So don't skip the bio
4175 * submission only when the integrity checker is enabled for the sake
4176 * of simplicity, since this is a debug tool and not meant for use in
4179 if (!bdev_write_cache(device->bdev))
4183 bio_init(bio, device->bdev, NULL, 0,
4184 REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH);
4185 bio->bi_end_io = btrfs_end_empty_barrier;
4186 init_completion(&device->flush_wait);
4187 bio->bi_private = &device->flush_wait;
4189 btrfsic_check_bio(bio);
4191 set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4195 * If the flush bio has been submitted by write_dev_flush, wait for it.
4197 static blk_status_t wait_dev_flush(struct btrfs_device *device)
4199 struct bio *bio = &device->flush_bio;
4201 if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
4204 clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4205 wait_for_completion_io(&device->flush_wait);
4207 return bio->bi_status;
4210 static int check_barrier_error(struct btrfs_fs_info *fs_info)
4212 if (!btrfs_check_rw_degradable(fs_info, NULL))
4218 * send an empty flush down to each device in parallel,
4219 * then wait for them
4221 static int barrier_all_devices(struct btrfs_fs_info *info)
4223 struct list_head *head;
4224 struct btrfs_device *dev;
4225 int errors_wait = 0;
4228 lockdep_assert_held(&info->fs_devices->device_list_mutex);
4229 /* send down all the barriers */
4230 head = &info->fs_devices->devices;
4231 list_for_each_entry(dev, head, dev_list) {
4232 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4236 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4237 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4240 write_dev_flush(dev);
4241 dev->last_flush_error = BLK_STS_OK;
4244 /* wait for all the barriers */
4245 list_for_each_entry(dev, head, dev_list) {
4246 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4252 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4253 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4256 ret = wait_dev_flush(dev);
4258 dev->last_flush_error = ret;
4259 btrfs_dev_stat_inc_and_print(dev,
4260 BTRFS_DEV_STAT_FLUSH_ERRS);
4267 * At some point we need the status of all disks
4268 * to arrive at the volume status. So error checking
4269 * is being pushed to a separate loop.
4271 return check_barrier_error(info);
4276 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
4279 int min_tolerated = INT_MAX;
4281 if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
4282 (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
4283 min_tolerated = min_t(int, min_tolerated,
4284 btrfs_raid_array[BTRFS_RAID_SINGLE].
4285 tolerated_failures);
4287 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4288 if (raid_type == BTRFS_RAID_SINGLE)
4290 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
4292 min_tolerated = min_t(int, min_tolerated,
4293 btrfs_raid_array[raid_type].
4294 tolerated_failures);
4297 if (min_tolerated == INT_MAX) {
4298 pr_warn("BTRFS: unknown raid flag: %llu", flags);
4302 return min_tolerated;
4305 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4307 struct list_head *head;
4308 struct btrfs_device *dev;
4309 struct btrfs_super_block *sb;
4310 struct btrfs_dev_item *dev_item;
4314 int total_errors = 0;
4317 do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4320 * max_mirrors == 0 indicates we're from commit_transaction,
4321 * not from fsync where the tree roots in fs_info have not
4322 * been consistent on disk.
4324 if (max_mirrors == 0)
4325 backup_super_roots(fs_info);
4327 sb = fs_info->super_for_commit;
4328 dev_item = &sb->dev_item;
4330 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4331 head = &fs_info->fs_devices->devices;
4332 max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4335 ret = barrier_all_devices(fs_info);
4338 &fs_info->fs_devices->device_list_mutex);
4339 btrfs_handle_fs_error(fs_info, ret,
4340 "errors while submitting device barriers.");
4345 list_for_each_entry(dev, head, dev_list) {
4350 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4351 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4354 btrfs_set_stack_device_generation(dev_item, 0);
4355 btrfs_set_stack_device_type(dev_item, dev->type);
4356 btrfs_set_stack_device_id(dev_item, dev->devid);
4357 btrfs_set_stack_device_total_bytes(dev_item,
4358 dev->commit_total_bytes);
4359 btrfs_set_stack_device_bytes_used(dev_item,
4360 dev->commit_bytes_used);
4361 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4362 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4363 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4364 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4365 memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4368 flags = btrfs_super_flags(sb);
4369 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4371 ret = btrfs_validate_write_super(fs_info, sb);
4373 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4374 btrfs_handle_fs_error(fs_info, -EUCLEAN,
4375 "unexpected superblock corruption detected");
4379 ret = write_dev_supers(dev, sb, max_mirrors);
4383 if (total_errors > max_errors) {
4384 btrfs_err(fs_info, "%d errors while writing supers",
4386 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4388 /* FUA is masked off if unsupported and can't be the reason */
4389 btrfs_handle_fs_error(fs_info, -EIO,
4390 "%d errors while writing supers",
4396 list_for_each_entry(dev, head, dev_list) {
4399 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4400 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4403 ret = wait_dev_supers(dev, max_mirrors);
4407 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4408 if (total_errors > max_errors) {
4409 btrfs_handle_fs_error(fs_info, -EIO,
4410 "%d errors while writing supers",
4417 /* Drop a fs root from the radix tree and free it. */
4418 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4419 struct btrfs_root *root)
4421 bool drop_ref = false;
4423 spin_lock(&fs_info->fs_roots_radix_lock);
4424 radix_tree_delete(&fs_info->fs_roots_radix,
4425 (unsigned long)root->root_key.objectid);
4426 if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4428 spin_unlock(&fs_info->fs_roots_radix_lock);
4430 if (BTRFS_FS_ERROR(fs_info)) {
4431 ASSERT(root->log_root == NULL);
4432 if (root->reloc_root) {
4433 btrfs_put_root(root->reloc_root);
4434 root->reloc_root = NULL;
4439 btrfs_put_root(root);
4442 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4444 u64 root_objectid = 0;
4445 struct btrfs_root *gang[8];
4448 unsigned int ret = 0;
4451 spin_lock(&fs_info->fs_roots_radix_lock);
4452 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4453 (void **)gang, root_objectid,
4456 spin_unlock(&fs_info->fs_roots_radix_lock);
4459 root_objectid = gang[ret - 1]->root_key.objectid + 1;
4461 for (i = 0; i < ret; i++) {
4462 /* Avoid to grab roots in dead_roots */
4463 if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4467 /* grab all the search result for later use */
4468 gang[i] = btrfs_grab_root(gang[i]);
4470 spin_unlock(&fs_info->fs_roots_radix_lock);
4472 for (i = 0; i < ret; i++) {
4475 root_objectid = gang[i]->root_key.objectid;
4476 err = btrfs_orphan_cleanup(gang[i]);
4479 btrfs_put_root(gang[i]);
4484 /* release the uncleaned roots due to error */
4485 for (; i < ret; i++) {
4487 btrfs_put_root(gang[i]);
4492 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4494 struct btrfs_root *root = fs_info->tree_root;
4495 struct btrfs_trans_handle *trans;
4497 mutex_lock(&fs_info->cleaner_mutex);
4498 btrfs_run_delayed_iputs(fs_info);
4499 mutex_unlock(&fs_info->cleaner_mutex);
4500 wake_up_process(fs_info->cleaner_kthread);
4502 /* wait until ongoing cleanup work done */
4503 down_write(&fs_info->cleanup_work_sem);
4504 up_write(&fs_info->cleanup_work_sem);
4506 trans = btrfs_join_transaction(root);
4508 return PTR_ERR(trans);
4509 return btrfs_commit_transaction(trans);
4512 static void warn_about_uncommitted_trans(struct btrfs_fs_info *fs_info)
4514 struct btrfs_transaction *trans;
4515 struct btrfs_transaction *tmp;
4518 if (list_empty(&fs_info->trans_list))
4522 * This function is only called at the very end of close_ctree(),
4523 * thus no other running transaction, no need to take trans_lock.
4525 ASSERT(test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags));
4526 list_for_each_entry_safe(trans, tmp, &fs_info->trans_list, list) {
4527 struct extent_state *cached = NULL;
4528 u64 dirty_bytes = 0;
4534 while (!find_first_extent_bit(&trans->dirty_pages, cur,
4535 &found_start, &found_end, EXTENT_DIRTY, &cached)) {
4536 dirty_bytes += found_end + 1 - found_start;
4537 cur = found_end + 1;
4540 "transaction %llu (with %llu dirty metadata bytes) is not committed",
4541 trans->transid, dirty_bytes);
4542 btrfs_cleanup_one_transaction(trans, fs_info);
4544 if (trans == fs_info->running_transaction)
4545 fs_info->running_transaction = NULL;
4546 list_del_init(&trans->list);
4548 btrfs_put_transaction(trans);
4549 trace_btrfs_transaction_commit(fs_info);
4554 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4558 set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4561 * We may have the reclaim task running and relocating a data block group,
4562 * in which case it may create delayed iputs. So stop it before we park
4563 * the cleaner kthread otherwise we can get new delayed iputs after
4564 * parking the cleaner, and that can make the async reclaim task to hang
4565 * if it's waiting for delayed iputs to complete, since the cleaner is
4566 * parked and can not run delayed iputs - this will make us hang when
4567 * trying to stop the async reclaim task.
4569 cancel_work_sync(&fs_info->reclaim_bgs_work);
4571 * We don't want the cleaner to start new transactions, add more delayed
4572 * iputs, etc. while we're closing. We can't use kthread_stop() yet
4573 * because that frees the task_struct, and the transaction kthread might
4574 * still try to wake up the cleaner.
4576 kthread_park(fs_info->cleaner_kthread);
4579 * If we had UNFINISHED_DROPS we could still be processing them, so
4580 * clear that bit and wake up relocation so it can stop.
4582 btrfs_wake_unfinished_drop(fs_info);
4584 /* wait for the qgroup rescan worker to stop */
4585 btrfs_qgroup_wait_for_completion(fs_info, false);
4587 /* wait for the uuid_scan task to finish */
4588 down(&fs_info->uuid_tree_rescan_sem);
4589 /* avoid complains from lockdep et al., set sem back to initial state */
4590 up(&fs_info->uuid_tree_rescan_sem);
4592 /* pause restriper - we want to resume on mount */
4593 btrfs_pause_balance(fs_info);
4595 btrfs_dev_replace_suspend_for_unmount(fs_info);
4597 btrfs_scrub_cancel(fs_info);
4599 /* wait for any defraggers to finish */
4600 wait_event(fs_info->transaction_wait,
4601 (atomic_read(&fs_info->defrag_running) == 0));
4603 /* clear out the rbtree of defraggable inodes */
4604 btrfs_cleanup_defrag_inodes(fs_info);
4606 cancel_work_sync(&fs_info->async_reclaim_work);
4607 cancel_work_sync(&fs_info->async_data_reclaim_work);
4608 cancel_work_sync(&fs_info->preempt_reclaim_work);
4610 /* Cancel or finish ongoing discard work */
4611 btrfs_discard_cleanup(fs_info);
4613 if (!sb_rdonly(fs_info->sb)) {
4615 * The cleaner kthread is stopped, so do one final pass over
4616 * unused block groups.
4618 btrfs_delete_unused_bgs(fs_info);
4621 * There might be existing delayed inode workers still running
4622 * and holding an empty delayed inode item. We must wait for
4623 * them to complete first because they can create a transaction.
4624 * This happens when someone calls btrfs_balance_delayed_items()
4625 * and then a transaction commit runs the same delayed nodes
4626 * before any delayed worker has done something with the nodes.
4627 * We must wait for any worker here and not at transaction
4628 * commit time since that could cause a deadlock.
4629 * This is a very rare case.
4631 btrfs_flush_workqueue(fs_info->delayed_workers);
4633 ret = btrfs_commit_super(fs_info);
4635 btrfs_err(fs_info, "commit super ret %d", ret);
4638 if (BTRFS_FS_ERROR(fs_info))
4639 btrfs_error_commit_super(fs_info);
4641 kthread_stop(fs_info->transaction_kthread);
4642 kthread_stop(fs_info->cleaner_kthread);
4644 ASSERT(list_empty(&fs_info->delayed_iputs));
4645 set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4647 if (btrfs_check_quota_leak(fs_info)) {
4648 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4649 btrfs_err(fs_info, "qgroup reserved space leaked");
4652 btrfs_free_qgroup_config(fs_info);
4653 ASSERT(list_empty(&fs_info->delalloc_roots));
4655 if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4656 btrfs_info(fs_info, "at unmount delalloc count %lld",
4657 percpu_counter_sum(&fs_info->delalloc_bytes));
4660 if (percpu_counter_sum(&fs_info->ordered_bytes))
4661 btrfs_info(fs_info, "at unmount dio bytes count %lld",
4662 percpu_counter_sum(&fs_info->ordered_bytes));
4664 btrfs_sysfs_remove_mounted(fs_info);
4665 btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4667 btrfs_put_block_group_cache(fs_info);
4670 * we must make sure there is not any read request to
4671 * submit after we stopping all workers.
4673 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4674 btrfs_stop_all_workers(fs_info);
4676 /* We shouldn't have any transaction open at this point */
4677 warn_about_uncommitted_trans(fs_info);
4679 clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4680 free_root_pointers(fs_info, true);
4681 btrfs_free_fs_roots(fs_info);
4684 * We must free the block groups after dropping the fs_roots as we could
4685 * have had an IO error and have left over tree log blocks that aren't
4686 * cleaned up until the fs roots are freed. This makes the block group
4687 * accounting appear to be wrong because there's pending reserved bytes,
4688 * so make sure we do the block group cleanup afterwards.
4690 btrfs_free_block_groups(fs_info);
4692 iput(fs_info->btree_inode);
4694 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4695 if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4696 btrfsic_unmount(fs_info->fs_devices);
4699 btrfs_mapping_tree_free(&fs_info->mapping_tree);
4700 btrfs_close_devices(fs_info->fs_devices);
4703 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4707 struct inode *btree_inode = buf->pages[0]->mapping->host;
4709 ret = extent_buffer_uptodate(buf);
4713 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4714 parent_transid, atomic);
4720 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4722 struct btrfs_fs_info *fs_info = buf->fs_info;
4723 u64 transid = btrfs_header_generation(buf);
4726 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4728 * This is a fast path so only do this check if we have sanity tests
4729 * enabled. Normal people shouldn't be using unmapped buffers as dirty
4730 * outside of the sanity tests.
4732 if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4735 btrfs_assert_tree_write_locked(buf);
4736 if (transid != fs_info->generation)
4737 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4738 buf->start, transid, fs_info->generation);
4739 was_dirty = set_extent_buffer_dirty(buf);
4741 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4743 fs_info->dirty_metadata_batch);
4744 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4746 * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4747 * but item data not updated.
4748 * So here we should only check item pointers, not item data.
4750 if (btrfs_header_level(buf) == 0 &&
4751 btrfs_check_leaf_relaxed(buf)) {
4752 btrfs_print_leaf(buf);
4758 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4762 * looks as though older kernels can get into trouble with
4763 * this code, they end up stuck in balance_dirty_pages forever
4767 if (current->flags & PF_MEMALLOC)
4771 btrfs_balance_delayed_items(fs_info);
4773 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4774 BTRFS_DIRTY_METADATA_THRESH,
4775 fs_info->dirty_metadata_batch);
4777 balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4781 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4783 __btrfs_btree_balance_dirty(fs_info, 1);
4786 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4788 __btrfs_btree_balance_dirty(fs_info, 0);
4791 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4793 /* cleanup FS via transaction */
4794 btrfs_cleanup_transaction(fs_info);
4796 mutex_lock(&fs_info->cleaner_mutex);
4797 btrfs_run_delayed_iputs(fs_info);
4798 mutex_unlock(&fs_info->cleaner_mutex);
4800 down_write(&fs_info->cleanup_work_sem);
4801 up_write(&fs_info->cleanup_work_sem);
4804 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4806 struct btrfs_root *gang[8];
4807 u64 root_objectid = 0;
4810 spin_lock(&fs_info->fs_roots_radix_lock);
4811 while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4812 (void **)gang, root_objectid,
4813 ARRAY_SIZE(gang))) != 0) {
4816 for (i = 0; i < ret; i++)
4817 gang[i] = btrfs_grab_root(gang[i]);
4818 spin_unlock(&fs_info->fs_roots_radix_lock);
4820 for (i = 0; i < ret; i++) {
4823 root_objectid = gang[i]->root_key.objectid;
4824 btrfs_free_log(NULL, gang[i]);
4825 btrfs_put_root(gang[i]);
4828 spin_lock(&fs_info->fs_roots_radix_lock);
4830 spin_unlock(&fs_info->fs_roots_radix_lock);
4831 btrfs_free_log_root_tree(NULL, fs_info);
4834 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4836 struct btrfs_ordered_extent *ordered;
4838 spin_lock(&root->ordered_extent_lock);
4840 * This will just short circuit the ordered completion stuff which will
4841 * make sure the ordered extent gets properly cleaned up.
4843 list_for_each_entry(ordered, &root->ordered_extents,
4845 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4846 spin_unlock(&root->ordered_extent_lock);
4849 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4851 struct btrfs_root *root;
4852 struct list_head splice;
4854 INIT_LIST_HEAD(&splice);
4856 spin_lock(&fs_info->ordered_root_lock);
4857 list_splice_init(&fs_info->ordered_roots, &splice);
4858 while (!list_empty(&splice)) {
4859 root = list_first_entry(&splice, struct btrfs_root,
4861 list_move_tail(&root->ordered_root,
4862 &fs_info->ordered_roots);
4864 spin_unlock(&fs_info->ordered_root_lock);
4865 btrfs_destroy_ordered_extents(root);
4868 spin_lock(&fs_info->ordered_root_lock);
4870 spin_unlock(&fs_info->ordered_root_lock);
4873 * We need this here because if we've been flipped read-only we won't
4874 * get sync() from the umount, so we need to make sure any ordered
4875 * extents that haven't had their dirty pages IO start writeout yet
4876 * actually get run and error out properly.
4878 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4881 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4882 struct btrfs_fs_info *fs_info)
4884 struct rb_node *node;
4885 struct btrfs_delayed_ref_root *delayed_refs;
4886 struct btrfs_delayed_ref_node *ref;
4889 delayed_refs = &trans->delayed_refs;
4891 spin_lock(&delayed_refs->lock);
4892 if (atomic_read(&delayed_refs->num_entries) == 0) {
4893 spin_unlock(&delayed_refs->lock);
4894 btrfs_debug(fs_info, "delayed_refs has NO entry");
4898 while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
4899 struct btrfs_delayed_ref_head *head;
4901 bool pin_bytes = false;
4903 head = rb_entry(node, struct btrfs_delayed_ref_head,
4905 if (btrfs_delayed_ref_lock(delayed_refs, head))
4908 spin_lock(&head->lock);
4909 while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
4910 ref = rb_entry(n, struct btrfs_delayed_ref_node,
4913 rb_erase_cached(&ref->ref_node, &head->ref_tree);
4914 RB_CLEAR_NODE(&ref->ref_node);
4915 if (!list_empty(&ref->add_list))
4916 list_del(&ref->add_list);
4917 atomic_dec(&delayed_refs->num_entries);
4918 btrfs_put_delayed_ref(ref);
4920 if (head->must_insert_reserved)
4922 btrfs_free_delayed_extent_op(head->extent_op);
4923 btrfs_delete_ref_head(delayed_refs, head);
4924 spin_unlock(&head->lock);
4925 spin_unlock(&delayed_refs->lock);
4926 mutex_unlock(&head->mutex);
4929 struct btrfs_block_group *cache;
4931 cache = btrfs_lookup_block_group(fs_info, head->bytenr);
4934 spin_lock(&cache->space_info->lock);
4935 spin_lock(&cache->lock);
4936 cache->pinned += head->num_bytes;
4937 btrfs_space_info_update_bytes_pinned(fs_info,
4938 cache->space_info, head->num_bytes);
4939 cache->reserved -= head->num_bytes;
4940 cache->space_info->bytes_reserved -= head->num_bytes;
4941 spin_unlock(&cache->lock);
4942 spin_unlock(&cache->space_info->lock);
4944 btrfs_put_block_group(cache);
4946 btrfs_error_unpin_extent_range(fs_info, head->bytenr,
4947 head->bytenr + head->num_bytes - 1);
4949 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
4950 btrfs_put_delayed_ref_head(head);
4952 spin_lock(&delayed_refs->lock);
4954 btrfs_qgroup_destroy_extent_records(trans);
4956 spin_unlock(&delayed_refs->lock);
4961 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4963 struct btrfs_inode *btrfs_inode;
4964 struct list_head splice;
4966 INIT_LIST_HEAD(&splice);
4968 spin_lock(&root->delalloc_lock);
4969 list_splice_init(&root->delalloc_inodes, &splice);
4971 while (!list_empty(&splice)) {
4972 struct inode *inode = NULL;
4973 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4975 __btrfs_del_delalloc_inode(root, btrfs_inode);
4976 spin_unlock(&root->delalloc_lock);
4979 * Make sure we get a live inode and that it'll not disappear
4982 inode = igrab(&btrfs_inode->vfs_inode);
4984 invalidate_inode_pages2(inode->i_mapping);
4987 spin_lock(&root->delalloc_lock);
4989 spin_unlock(&root->delalloc_lock);
4992 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4994 struct btrfs_root *root;
4995 struct list_head splice;
4997 INIT_LIST_HEAD(&splice);
4999 spin_lock(&fs_info->delalloc_root_lock);
5000 list_splice_init(&fs_info->delalloc_roots, &splice);
5001 while (!list_empty(&splice)) {
5002 root = list_first_entry(&splice, struct btrfs_root,
5004 root = btrfs_grab_root(root);
5006 spin_unlock(&fs_info->delalloc_root_lock);
5008 btrfs_destroy_delalloc_inodes(root);
5009 btrfs_put_root(root);
5011 spin_lock(&fs_info->delalloc_root_lock);
5013 spin_unlock(&fs_info->delalloc_root_lock);
5016 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
5017 struct extent_io_tree *dirty_pages,
5021 struct extent_buffer *eb;
5026 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
5031 clear_extent_bits(dirty_pages, start, end, mark);
5032 while (start <= end) {
5033 eb = find_extent_buffer(fs_info, start);
5034 start += fs_info->nodesize;
5037 wait_on_extent_buffer_writeback(eb);
5039 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
5041 clear_extent_buffer_dirty(eb);
5042 free_extent_buffer_stale(eb);
5049 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
5050 struct extent_io_tree *unpin)
5057 struct extent_state *cached_state = NULL;
5060 * The btrfs_finish_extent_commit() may get the same range as
5061 * ours between find_first_extent_bit and clear_extent_dirty.
5062 * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
5063 * the same extent range.
5065 mutex_lock(&fs_info->unused_bg_unpin_mutex);
5066 ret = find_first_extent_bit(unpin, 0, &start, &end,
5067 EXTENT_DIRTY, &cached_state);
5069 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5073 clear_extent_dirty(unpin, start, end, &cached_state);
5074 free_extent_state(cached_state);
5075 btrfs_error_unpin_extent_range(fs_info, start, end);
5076 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5083 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
5085 struct inode *inode;
5087 inode = cache->io_ctl.inode;
5089 invalidate_inode_pages2(inode->i_mapping);
5090 BTRFS_I(inode)->generation = 0;
5091 cache->io_ctl.inode = NULL;
5094 ASSERT(cache->io_ctl.pages == NULL);
5095 btrfs_put_block_group(cache);
5098 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
5099 struct btrfs_fs_info *fs_info)
5101 struct btrfs_block_group *cache;
5103 spin_lock(&cur_trans->dirty_bgs_lock);
5104 while (!list_empty(&cur_trans->dirty_bgs)) {
5105 cache = list_first_entry(&cur_trans->dirty_bgs,
5106 struct btrfs_block_group,
5109 if (!list_empty(&cache->io_list)) {
5110 spin_unlock(&cur_trans->dirty_bgs_lock);
5111 list_del_init(&cache->io_list);
5112 btrfs_cleanup_bg_io(cache);
5113 spin_lock(&cur_trans->dirty_bgs_lock);
5116 list_del_init(&cache->dirty_list);
5117 spin_lock(&cache->lock);
5118 cache->disk_cache_state = BTRFS_DC_ERROR;
5119 spin_unlock(&cache->lock);
5121 spin_unlock(&cur_trans->dirty_bgs_lock);
5122 btrfs_put_block_group(cache);
5123 btrfs_delayed_refs_rsv_release(fs_info, 1);
5124 spin_lock(&cur_trans->dirty_bgs_lock);
5126 spin_unlock(&cur_trans->dirty_bgs_lock);
5129 * Refer to the definition of io_bgs member for details why it's safe
5130 * to use it without any locking
5132 while (!list_empty(&cur_trans->io_bgs)) {
5133 cache = list_first_entry(&cur_trans->io_bgs,
5134 struct btrfs_block_group,
5137 list_del_init(&cache->io_list);
5138 spin_lock(&cache->lock);
5139 cache->disk_cache_state = BTRFS_DC_ERROR;
5140 spin_unlock(&cache->lock);
5141 btrfs_cleanup_bg_io(cache);
5145 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
5146 struct btrfs_fs_info *fs_info)
5148 struct btrfs_device *dev, *tmp;
5150 btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
5151 ASSERT(list_empty(&cur_trans->dirty_bgs));
5152 ASSERT(list_empty(&cur_trans->io_bgs));
5154 list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
5156 list_del_init(&dev->post_commit_list);
5159 btrfs_destroy_delayed_refs(cur_trans, fs_info);
5161 cur_trans->state = TRANS_STATE_COMMIT_START;
5162 wake_up(&fs_info->transaction_blocked_wait);
5164 cur_trans->state = TRANS_STATE_UNBLOCKED;
5165 wake_up(&fs_info->transaction_wait);
5167 btrfs_destroy_delayed_inodes(fs_info);
5169 btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
5171 btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
5173 btrfs_free_redirty_list(cur_trans);
5175 cur_trans->state =TRANS_STATE_COMPLETED;
5176 wake_up(&cur_trans->commit_wait);
5179 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
5181 struct btrfs_transaction *t;
5183 mutex_lock(&fs_info->transaction_kthread_mutex);
5185 spin_lock(&fs_info->trans_lock);
5186 while (!list_empty(&fs_info->trans_list)) {
5187 t = list_first_entry(&fs_info->trans_list,
5188 struct btrfs_transaction, list);
5189 if (t->state >= TRANS_STATE_COMMIT_START) {
5190 refcount_inc(&t->use_count);
5191 spin_unlock(&fs_info->trans_lock);
5192 btrfs_wait_for_commit(fs_info, t->transid);
5193 btrfs_put_transaction(t);
5194 spin_lock(&fs_info->trans_lock);
5197 if (t == fs_info->running_transaction) {
5198 t->state = TRANS_STATE_COMMIT_DOING;
5199 spin_unlock(&fs_info->trans_lock);
5201 * We wait for 0 num_writers since we don't hold a trans
5202 * handle open currently for this transaction.
5204 wait_event(t->writer_wait,
5205 atomic_read(&t->num_writers) == 0);
5207 spin_unlock(&fs_info->trans_lock);
5209 btrfs_cleanup_one_transaction(t, fs_info);
5211 spin_lock(&fs_info->trans_lock);
5212 if (t == fs_info->running_transaction)
5213 fs_info->running_transaction = NULL;
5214 list_del_init(&t->list);
5215 spin_unlock(&fs_info->trans_lock);
5217 btrfs_put_transaction(t);
5218 trace_btrfs_transaction_commit(fs_info);
5219 spin_lock(&fs_info->trans_lock);
5221 spin_unlock(&fs_info->trans_lock);
5222 btrfs_destroy_all_ordered_extents(fs_info);
5223 btrfs_destroy_delayed_inodes(fs_info);
5224 btrfs_assert_delayed_root_empty(fs_info);
5225 btrfs_destroy_all_delalloc_inodes(fs_info);
5226 btrfs_drop_all_logs(fs_info);
5227 mutex_unlock(&fs_info->transaction_kthread_mutex);
5232 int btrfs_init_root_free_objectid(struct btrfs_root *root)
5234 struct btrfs_path *path;
5236 struct extent_buffer *l;
5237 struct btrfs_key search_key;
5238 struct btrfs_key found_key;
5241 path = btrfs_alloc_path();
5245 search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
5246 search_key.type = -1;
5247 search_key.offset = (u64)-1;
5248 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5251 BUG_ON(ret == 0); /* Corruption */
5252 if (path->slots[0] > 0) {
5253 slot = path->slots[0] - 1;
5255 btrfs_item_key_to_cpu(l, &found_key, slot);
5256 root->free_objectid = max_t(u64, found_key.objectid + 1,
5257 BTRFS_FIRST_FREE_OBJECTID);
5259 root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
5263 btrfs_free_path(path);
5267 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
5270 mutex_lock(&root->objectid_mutex);
5272 if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
5273 btrfs_warn(root->fs_info,
5274 "the objectid of root %llu reaches its highest value",
5275 root->root_key.objectid);
5280 *objectid = root->free_objectid++;
5283 mutex_unlock(&root->objectid_mutex);