2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include <linux/slab.h>
21 #include <linux/sched.h>
22 #include <linux/writeback.h>
23 #include <linux/pagemap.h>
24 #include <linux/blkdev.h>
25 #include <linux/uuid.h>
28 #include "transaction.h"
31 #include "inode-map.h"
33 #include "dev-replace.h"
36 #define BTRFS_ROOT_TRANS_TAG 0
38 static unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
39 [TRANS_STATE_RUNNING] = 0U,
40 [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE |
42 [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE |
45 [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE |
49 [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE |
54 [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE |
61 void btrfs_put_transaction(struct btrfs_transaction *transaction)
63 WARN_ON(atomic_read(&transaction->use_count) == 0);
64 if (atomic_dec_and_test(&transaction->use_count)) {
65 BUG_ON(!list_empty(&transaction->list));
66 WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root));
67 while (!list_empty(&transaction->pending_chunks)) {
68 struct extent_map *em;
70 em = list_first_entry(&transaction->pending_chunks,
71 struct extent_map, list);
72 list_del_init(&em->list);
75 kmem_cache_free(btrfs_transaction_cachep, transaction);
79 static noinline void switch_commit_roots(struct btrfs_transaction *trans,
80 struct btrfs_fs_info *fs_info)
82 struct btrfs_root *root, *tmp;
84 down_write(&fs_info->commit_root_sem);
85 list_for_each_entry_safe(root, tmp, &trans->switch_commits,
87 list_del_init(&root->dirty_list);
88 free_extent_buffer(root->commit_root);
89 root->commit_root = btrfs_root_node(root);
90 if (is_fstree(root->objectid))
91 btrfs_unpin_free_ino(root);
93 up_write(&fs_info->commit_root_sem);
96 static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
99 if (type & TRANS_EXTWRITERS)
100 atomic_inc(&trans->num_extwriters);
103 static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
106 if (type & TRANS_EXTWRITERS)
107 atomic_dec(&trans->num_extwriters);
110 static inline void extwriter_counter_init(struct btrfs_transaction *trans,
113 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
116 static inline int extwriter_counter_read(struct btrfs_transaction *trans)
118 return atomic_read(&trans->num_extwriters);
122 * either allocate a new transaction or hop into the existing one
124 static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
126 struct btrfs_transaction *cur_trans;
127 struct btrfs_fs_info *fs_info = root->fs_info;
129 spin_lock(&fs_info->trans_lock);
131 /* The file system has been taken offline. No new transactions. */
132 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
133 spin_unlock(&fs_info->trans_lock);
137 cur_trans = fs_info->running_transaction;
139 if (cur_trans->aborted) {
140 spin_unlock(&fs_info->trans_lock);
141 return cur_trans->aborted;
143 if (btrfs_blocked_trans_types[cur_trans->state] & type) {
144 spin_unlock(&fs_info->trans_lock);
147 atomic_inc(&cur_trans->use_count);
148 atomic_inc(&cur_trans->num_writers);
149 extwriter_counter_inc(cur_trans, type);
150 spin_unlock(&fs_info->trans_lock);
153 spin_unlock(&fs_info->trans_lock);
156 * If we are ATTACH, we just want to catch the current transaction,
157 * and commit it. If there is no transaction, just return ENOENT.
159 if (type == TRANS_ATTACH)
163 * JOIN_NOLOCK only happens during the transaction commit, so
164 * it is impossible that ->running_transaction is NULL
166 BUG_ON(type == TRANS_JOIN_NOLOCK);
168 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
172 spin_lock(&fs_info->trans_lock);
173 if (fs_info->running_transaction) {
175 * someone started a transaction after we unlocked. Make sure
176 * to redo the checks above
178 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
180 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
181 spin_unlock(&fs_info->trans_lock);
182 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
186 atomic_set(&cur_trans->num_writers, 1);
187 extwriter_counter_init(cur_trans, type);
188 init_waitqueue_head(&cur_trans->writer_wait);
189 init_waitqueue_head(&cur_trans->commit_wait);
190 cur_trans->state = TRANS_STATE_RUNNING;
192 * One for this trans handle, one so it will live on until we
193 * commit the transaction.
195 atomic_set(&cur_trans->use_count, 2);
196 cur_trans->start_time = get_seconds();
198 cur_trans->delayed_refs.href_root = RB_ROOT;
199 atomic_set(&cur_trans->delayed_refs.num_entries, 0);
200 cur_trans->delayed_refs.num_heads_ready = 0;
201 cur_trans->delayed_refs.num_heads = 0;
202 cur_trans->delayed_refs.flushing = 0;
203 cur_trans->delayed_refs.run_delayed_start = 0;
206 * although the tree mod log is per file system and not per transaction,
207 * the log must never go across transaction boundaries.
210 if (!list_empty(&fs_info->tree_mod_seq_list))
211 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
212 "creating a fresh transaction\n");
213 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
214 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
215 "creating a fresh transaction\n");
216 atomic64_set(&fs_info->tree_mod_seq, 0);
218 spin_lock_init(&cur_trans->delayed_refs.lock);
220 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
221 INIT_LIST_HEAD(&cur_trans->pending_chunks);
222 INIT_LIST_HEAD(&cur_trans->switch_commits);
223 list_add_tail(&cur_trans->list, &fs_info->trans_list);
224 extent_io_tree_init(&cur_trans->dirty_pages,
225 fs_info->btree_inode->i_mapping);
226 fs_info->generation++;
227 cur_trans->transid = fs_info->generation;
228 fs_info->running_transaction = cur_trans;
229 cur_trans->aborted = 0;
230 spin_unlock(&fs_info->trans_lock);
236 * this does all the record keeping required to make sure that a reference
237 * counted root is properly recorded in a given transaction. This is required
238 * to make sure the old root from before we joined the transaction is deleted
239 * when the transaction commits
241 static int record_root_in_trans(struct btrfs_trans_handle *trans,
242 struct btrfs_root *root)
244 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
245 root->last_trans < trans->transid) {
246 WARN_ON(root == root->fs_info->extent_root);
247 WARN_ON(root->commit_root != root->node);
250 * see below for IN_TRANS_SETUP usage rules
251 * we have the reloc mutex held now, so there
252 * is only one writer in this function
254 set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
256 /* make sure readers find IN_TRANS_SETUP before
257 * they find our root->last_trans update
261 spin_lock(&root->fs_info->fs_roots_radix_lock);
262 if (root->last_trans == trans->transid) {
263 spin_unlock(&root->fs_info->fs_roots_radix_lock);
266 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
267 (unsigned long)root->root_key.objectid,
268 BTRFS_ROOT_TRANS_TAG);
269 spin_unlock(&root->fs_info->fs_roots_radix_lock);
270 root->last_trans = trans->transid;
272 /* this is pretty tricky. We don't want to
273 * take the relocation lock in btrfs_record_root_in_trans
274 * unless we're really doing the first setup for this root in
277 * Normally we'd use root->last_trans as a flag to decide
278 * if we want to take the expensive mutex.
280 * But, we have to set root->last_trans before we
281 * init the relocation root, otherwise, we trip over warnings
282 * in ctree.c. The solution used here is to flag ourselves
283 * with root IN_TRANS_SETUP. When this is 1, we're still
284 * fixing up the reloc trees and everyone must wait.
286 * When this is zero, they can trust root->last_trans and fly
287 * through btrfs_record_root_in_trans without having to take the
288 * lock. smp_wmb() makes sure that all the writes above are
289 * done before we pop in the zero below
291 btrfs_init_reloc_root(trans, root);
292 smp_mb__before_atomic();
293 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
299 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
300 struct btrfs_root *root)
302 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
306 * see record_root_in_trans for comments about IN_TRANS_SETUP usage
310 if (root->last_trans == trans->transid &&
311 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state))
314 mutex_lock(&root->fs_info->reloc_mutex);
315 record_root_in_trans(trans, root);
316 mutex_unlock(&root->fs_info->reloc_mutex);
321 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
323 return (trans->state >= TRANS_STATE_BLOCKED &&
324 trans->state < TRANS_STATE_UNBLOCKED &&
328 /* wait for commit against the current transaction to become unblocked
329 * when this is done, it is safe to start a new transaction, but the current
330 * transaction might not be fully on disk.
332 static void wait_current_trans(struct btrfs_root *root)
334 struct btrfs_transaction *cur_trans;
336 spin_lock(&root->fs_info->trans_lock);
337 cur_trans = root->fs_info->running_transaction;
338 if (cur_trans && is_transaction_blocked(cur_trans)) {
339 atomic_inc(&cur_trans->use_count);
340 spin_unlock(&root->fs_info->trans_lock);
342 wait_event(root->fs_info->transaction_wait,
343 cur_trans->state >= TRANS_STATE_UNBLOCKED ||
345 btrfs_put_transaction(cur_trans);
347 spin_unlock(&root->fs_info->trans_lock);
351 static int may_wait_transaction(struct btrfs_root *root, int type)
353 if (root->fs_info->log_root_recovering)
356 if (type == TRANS_USERSPACE)
359 if (type == TRANS_START &&
360 !atomic_read(&root->fs_info->open_ioctl_trans))
366 static inline bool need_reserve_reloc_root(struct btrfs_root *root)
368 if (!root->fs_info->reloc_ctl ||
369 !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
370 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
377 static struct btrfs_trans_handle *
378 start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
379 enum btrfs_reserve_flush_enum flush)
381 struct btrfs_trans_handle *h;
382 struct btrfs_transaction *cur_trans;
384 u64 qgroup_reserved = 0;
385 bool reloc_reserved = false;
388 /* Send isn't supposed to start transactions. */
389 ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
391 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
392 return ERR_PTR(-EROFS);
394 if (current->journal_info) {
395 WARN_ON(type & TRANS_EXTWRITERS);
396 h = current->journal_info;
398 WARN_ON(h->use_count > 2);
399 h->orig_rsv = h->block_rsv;
405 * Do the reservation before we join the transaction so we can do all
406 * the appropriate flushing if need be.
408 if (num_items > 0 && root != root->fs_info->chunk_root) {
409 if (root->fs_info->quota_enabled &&
410 is_fstree(root->root_key.objectid)) {
411 qgroup_reserved = num_items * root->nodesize;
412 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
417 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
419 * Do the reservation for the relocation root creation
421 if (need_reserve_reloc_root(root)) {
422 num_bytes += root->nodesize;
423 reloc_reserved = true;
426 ret = btrfs_block_rsv_add(root,
427 &root->fs_info->trans_block_rsv,
433 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
440 * If we are JOIN_NOLOCK we're already committing a transaction and
441 * waiting on this guy, so we don't need to do the sb_start_intwrite
442 * because we're already holding a ref. We need this because we could
443 * have raced in and did an fsync() on a file which can kick a commit
444 * and then we deadlock with somebody doing a freeze.
446 * If we are ATTACH, it means we just want to catch the current
447 * transaction and commit it, so we needn't do sb_start_intwrite().
449 if (type & __TRANS_FREEZABLE)
450 sb_start_intwrite(root->fs_info->sb);
452 if (may_wait_transaction(root, type))
453 wait_current_trans(root);
456 ret = join_transaction(root, type);
458 wait_current_trans(root);
459 if (unlikely(type == TRANS_ATTACH))
462 } while (ret == -EBUSY);
465 /* We must get the transaction if we are JOIN_NOLOCK. */
466 BUG_ON(type == TRANS_JOIN_NOLOCK);
470 cur_trans = root->fs_info->running_transaction;
472 h->transid = cur_trans->transid;
473 h->transaction = cur_trans;
475 h->bytes_reserved = 0;
477 h->delayed_ref_updates = 0;
483 h->qgroup_reserved = 0;
484 h->delayed_ref_elem.seq = 0;
486 h->allocating_chunk = false;
487 h->reloc_reserved = false;
489 INIT_LIST_HEAD(&h->qgroup_ref_list);
490 INIT_LIST_HEAD(&h->new_bgs);
493 if (cur_trans->state >= TRANS_STATE_BLOCKED &&
494 may_wait_transaction(root, type)) {
495 current->journal_info = h;
496 btrfs_commit_transaction(h, root);
501 trace_btrfs_space_reservation(root->fs_info, "transaction",
502 h->transid, num_bytes, 1);
503 h->block_rsv = &root->fs_info->trans_block_rsv;
504 h->bytes_reserved = num_bytes;
505 h->reloc_reserved = reloc_reserved;
507 h->qgroup_reserved = qgroup_reserved;
510 btrfs_record_root_in_trans(h, root);
512 if (!current->journal_info && type != TRANS_USERSPACE)
513 current->journal_info = h;
517 if (type & __TRANS_FREEZABLE)
518 sb_end_intwrite(root->fs_info->sb);
519 kmem_cache_free(btrfs_trans_handle_cachep, h);
522 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
526 btrfs_qgroup_free(root, qgroup_reserved);
530 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
533 return start_transaction(root, num_items, TRANS_START,
534 BTRFS_RESERVE_FLUSH_ALL);
537 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
538 struct btrfs_root *root, int num_items)
540 return start_transaction(root, num_items, TRANS_START,
541 BTRFS_RESERVE_FLUSH_LIMIT);
544 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
546 return start_transaction(root, 0, TRANS_JOIN, 0);
549 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
551 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
554 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
556 return start_transaction(root, 0, TRANS_USERSPACE, 0);
560 * btrfs_attach_transaction() - catch the running transaction
562 * It is used when we want to commit the current the transaction, but
563 * don't want to start a new one.
565 * Note: If this function return -ENOENT, it just means there is no
566 * running transaction. But it is possible that the inactive transaction
567 * is still in the memory, not fully on disk. If you hope there is no
568 * inactive transaction in the fs when -ENOENT is returned, you should
570 * btrfs_attach_transaction_barrier()
572 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
574 return start_transaction(root, 0, TRANS_ATTACH, 0);
578 * btrfs_attach_transaction_barrier() - catch the running transaction
580 * It is similar to the above function, the differentia is this one
581 * will wait for all the inactive transactions until they fully
584 struct btrfs_trans_handle *
585 btrfs_attach_transaction_barrier(struct btrfs_root *root)
587 struct btrfs_trans_handle *trans;
589 trans = start_transaction(root, 0, TRANS_ATTACH, 0);
590 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
591 btrfs_wait_for_commit(root, 0);
596 /* wait for a transaction commit to be fully complete */
597 static noinline void wait_for_commit(struct btrfs_root *root,
598 struct btrfs_transaction *commit)
600 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
603 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
605 struct btrfs_transaction *cur_trans = NULL, *t;
609 if (transid <= root->fs_info->last_trans_committed)
612 /* find specified transaction */
613 spin_lock(&root->fs_info->trans_lock);
614 list_for_each_entry(t, &root->fs_info->trans_list, list) {
615 if (t->transid == transid) {
617 atomic_inc(&cur_trans->use_count);
621 if (t->transid > transid) {
626 spin_unlock(&root->fs_info->trans_lock);
629 * The specified transaction doesn't exist, or we
630 * raced with btrfs_commit_transaction
633 if (transid > root->fs_info->last_trans_committed)
638 /* find newest transaction that is committing | committed */
639 spin_lock(&root->fs_info->trans_lock);
640 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
642 if (t->state >= TRANS_STATE_COMMIT_START) {
643 if (t->state == TRANS_STATE_COMPLETED)
646 atomic_inc(&cur_trans->use_count);
650 spin_unlock(&root->fs_info->trans_lock);
652 goto out; /* nothing committing|committed */
655 wait_for_commit(root, cur_trans);
656 btrfs_put_transaction(cur_trans);
661 void btrfs_throttle(struct btrfs_root *root)
663 if (!atomic_read(&root->fs_info->open_ioctl_trans))
664 wait_current_trans(root);
667 static int should_end_transaction(struct btrfs_trans_handle *trans,
668 struct btrfs_root *root)
670 if (root->fs_info->global_block_rsv.space_info->full &&
671 btrfs_check_space_for_delayed_refs(trans, root))
674 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
677 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
678 struct btrfs_root *root)
680 struct btrfs_transaction *cur_trans = trans->transaction;
685 if (cur_trans->state >= TRANS_STATE_BLOCKED ||
686 cur_trans->delayed_refs.flushing)
689 updates = trans->delayed_ref_updates;
690 trans->delayed_ref_updates = 0;
692 err = btrfs_run_delayed_refs(trans, root, updates);
693 if (err) /* Error code will also eval true */
697 return should_end_transaction(trans, root);
700 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
701 struct btrfs_root *root, int throttle)
703 struct btrfs_transaction *cur_trans = trans->transaction;
704 struct btrfs_fs_info *info = root->fs_info;
705 unsigned long cur = trans->delayed_ref_updates;
706 int lock = (trans->type != TRANS_JOIN_NOLOCK);
708 int must_run_delayed_refs = 0;
710 if (trans->use_count > 1) {
712 trans->block_rsv = trans->orig_rsv;
716 btrfs_trans_release_metadata(trans, root);
717 trans->block_rsv = NULL;
719 if (!list_empty(&trans->new_bgs))
720 btrfs_create_pending_block_groups(trans, root);
722 trans->delayed_ref_updates = 0;
724 must_run_delayed_refs =
725 btrfs_should_throttle_delayed_refs(trans, root);
726 cur = max_t(unsigned long, cur, 32);
729 * don't make the caller wait if they are from a NOLOCK
730 * or ATTACH transaction, it will deadlock with commit
732 if (must_run_delayed_refs == 1 &&
733 (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
734 must_run_delayed_refs = 2;
737 if (trans->qgroup_reserved) {
739 * the same root has to be passed here between start_transaction
740 * and end_transaction. Subvolume quota depends on this.
742 btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
743 trans->qgroup_reserved = 0;
746 btrfs_trans_release_metadata(trans, root);
747 trans->block_rsv = NULL;
749 if (!list_empty(&trans->new_bgs))
750 btrfs_create_pending_block_groups(trans, root);
752 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
753 should_end_transaction(trans, root) &&
754 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
755 spin_lock(&info->trans_lock);
756 if (cur_trans->state == TRANS_STATE_RUNNING)
757 cur_trans->state = TRANS_STATE_BLOCKED;
758 spin_unlock(&info->trans_lock);
761 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
763 return btrfs_commit_transaction(trans, root);
765 wake_up_process(info->transaction_kthread);
768 if (trans->type & __TRANS_FREEZABLE)
769 sb_end_intwrite(root->fs_info->sb);
771 WARN_ON(cur_trans != info->running_transaction);
772 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
773 atomic_dec(&cur_trans->num_writers);
774 extwriter_counter_dec(cur_trans, trans->type);
777 if (waitqueue_active(&cur_trans->writer_wait))
778 wake_up(&cur_trans->writer_wait);
779 btrfs_put_transaction(cur_trans);
781 if (current->journal_info == trans)
782 current->journal_info = NULL;
785 btrfs_run_delayed_iputs(root);
787 if (trans->aborted ||
788 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
789 wake_up_process(info->transaction_kthread);
792 assert_qgroups_uptodate(trans);
794 kmem_cache_free(btrfs_trans_handle_cachep, trans);
795 if (must_run_delayed_refs) {
796 btrfs_async_run_delayed_refs(root, cur,
797 must_run_delayed_refs == 1);
802 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
803 struct btrfs_root *root)
805 return __btrfs_end_transaction(trans, root, 0);
808 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
809 struct btrfs_root *root)
811 return __btrfs_end_transaction(trans, root, 1);
815 * when btree blocks are allocated, they have some corresponding bits set for
816 * them in one of two extent_io trees. This is used to make sure all of
817 * those extents are sent to disk but does not wait on them
819 int btrfs_write_marked_extents(struct btrfs_root *root,
820 struct extent_io_tree *dirty_pages, int mark)
824 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
825 struct extent_state *cached_state = NULL;
829 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
830 mark, &cached_state)) {
831 convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
832 mark, &cached_state, GFP_NOFS);
834 err = filemap_fdatawrite_range(mapping, start, end);
846 * when btree blocks are allocated, they have some corresponding bits set for
847 * them in one of two extent_io trees. This is used to make sure all of
848 * those extents are on disk for transaction or log commit. We wait
849 * on all the pages and clear them from the dirty pages state tree
851 int btrfs_wait_marked_extents(struct btrfs_root *root,
852 struct extent_io_tree *dirty_pages, int mark)
856 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
857 struct extent_state *cached_state = NULL;
860 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
863 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
864 EXTENT_NEED_WAIT, &cached_state)) {
865 clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
866 0, 0, &cached_state, GFP_NOFS);
867 err = filemap_fdatawait_range(mapping, start, end);
876 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
877 if ((mark & EXTENT_DIRTY) &&
878 test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
879 &btree_ino->runtime_flags))
882 if ((mark & EXTENT_NEW) &&
883 test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
884 &btree_ino->runtime_flags))
887 if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
888 &btree_ino->runtime_flags))
899 * when btree blocks are allocated, they have some corresponding bits set for
900 * them in one of two extent_io trees. This is used to make sure all of
901 * those extents are on disk for transaction or log commit
903 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
904 struct extent_io_tree *dirty_pages, int mark)
908 struct blk_plug plug;
910 blk_start_plug(&plug);
911 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
912 blk_finish_plug(&plug);
913 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
922 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
923 struct btrfs_root *root)
925 if (!trans || !trans->transaction) {
926 struct inode *btree_inode;
927 btree_inode = root->fs_info->btree_inode;
928 return filemap_write_and_wait(btree_inode->i_mapping);
930 return btrfs_write_and_wait_marked_extents(root,
931 &trans->transaction->dirty_pages,
936 * this is used to update the root pointer in the tree of tree roots.
938 * But, in the case of the extent allocation tree, updating the root
939 * pointer may allocate blocks which may change the root of the extent
942 * So, this loops and repeats and makes sure the cowonly root didn't
943 * change while the root pointer was being updated in the metadata.
945 static int update_cowonly_root(struct btrfs_trans_handle *trans,
946 struct btrfs_root *root)
951 struct btrfs_root *tree_root = root->fs_info->tree_root;
953 old_root_used = btrfs_root_used(&root->root_item);
954 btrfs_write_dirty_block_groups(trans, root);
957 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
958 if (old_root_bytenr == root->node->start &&
959 old_root_used == btrfs_root_used(&root->root_item))
962 btrfs_set_root_node(&root->root_item, root->node);
963 ret = btrfs_update_root(trans, tree_root,
969 old_root_used = btrfs_root_used(&root->root_item);
970 ret = btrfs_write_dirty_block_groups(trans, root);
979 * update all the cowonly tree roots on disk
981 * The error handling in this function may not be obvious. Any of the
982 * failures will cause the file system to go offline. We still need
983 * to clean up the delayed refs.
985 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
986 struct btrfs_root *root)
988 struct btrfs_fs_info *fs_info = root->fs_info;
989 struct list_head *next;
990 struct extent_buffer *eb;
993 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
997 eb = btrfs_lock_root_node(fs_info->tree_root);
998 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
1000 btrfs_tree_unlock(eb);
1001 free_extent_buffer(eb);
1006 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1010 ret = btrfs_run_dev_stats(trans, root->fs_info);
1013 ret = btrfs_run_dev_replace(trans, root->fs_info);
1016 ret = btrfs_run_qgroups(trans, root->fs_info);
1020 /* run_qgroups might have added some more refs */
1021 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1025 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
1026 next = fs_info->dirty_cowonly_roots.next;
1027 list_del_init(next);
1028 root = list_entry(next, struct btrfs_root, dirty_list);
1030 if (root != fs_info->extent_root)
1031 list_add_tail(&root->dirty_list,
1032 &trans->transaction->switch_commits);
1033 ret = update_cowonly_root(trans, root);
1038 list_add_tail(&fs_info->extent_root->dirty_list,
1039 &trans->transaction->switch_commits);
1040 btrfs_after_dev_replace_commit(fs_info);
1046 * dead roots are old snapshots that need to be deleted. This allocates
1047 * a dirty root struct and adds it into the list of dead roots that need to
1050 void btrfs_add_dead_root(struct btrfs_root *root)
1052 spin_lock(&root->fs_info->trans_lock);
1053 if (list_empty(&root->root_list))
1054 list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1055 spin_unlock(&root->fs_info->trans_lock);
1059 * update all the cowonly tree roots on disk
1061 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1062 struct btrfs_root *root)
1064 struct btrfs_root *gang[8];
1065 struct btrfs_fs_info *fs_info = root->fs_info;
1070 spin_lock(&fs_info->fs_roots_radix_lock);
1072 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1075 BTRFS_ROOT_TRANS_TAG);
1078 for (i = 0; i < ret; i++) {
1080 radix_tree_tag_clear(&fs_info->fs_roots_radix,
1081 (unsigned long)root->root_key.objectid,
1082 BTRFS_ROOT_TRANS_TAG);
1083 spin_unlock(&fs_info->fs_roots_radix_lock);
1085 btrfs_free_log(trans, root);
1086 btrfs_update_reloc_root(trans, root);
1087 btrfs_orphan_commit_root(trans, root);
1089 btrfs_save_ino_cache(root, trans);
1091 /* see comments in should_cow_block() */
1092 clear_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1093 smp_mb__after_atomic();
1095 if (root->commit_root != root->node) {
1096 list_add_tail(&root->dirty_list,
1097 &trans->transaction->switch_commits);
1098 btrfs_set_root_node(&root->root_item,
1102 err = btrfs_update_root(trans, fs_info->tree_root,
1105 spin_lock(&fs_info->fs_roots_radix_lock);
1110 spin_unlock(&fs_info->fs_roots_radix_lock);
1115 * defrag a given btree.
1116 * Every leaf in the btree is read and defragged.
1118 int btrfs_defrag_root(struct btrfs_root *root)
1120 struct btrfs_fs_info *info = root->fs_info;
1121 struct btrfs_trans_handle *trans;
1124 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
1128 trans = btrfs_start_transaction(root, 0);
1130 return PTR_ERR(trans);
1132 ret = btrfs_defrag_leaves(trans, root);
1134 btrfs_end_transaction(trans, root);
1135 btrfs_btree_balance_dirty(info->tree_root);
1138 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1141 if (btrfs_defrag_cancelled(root->fs_info)) {
1142 pr_debug("BTRFS: defrag_root cancelled\n");
1147 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
1152 * new snapshots need to be created at a very specific time in the
1153 * transaction commit. This does the actual creation.
1156 * If the error which may affect the commitment of the current transaction
1157 * happens, we should return the error number. If the error which just affect
1158 * the creation of the pending snapshots, just return 0.
1160 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1161 struct btrfs_fs_info *fs_info,
1162 struct btrfs_pending_snapshot *pending)
1164 struct btrfs_key key;
1165 struct btrfs_root_item *new_root_item;
1166 struct btrfs_root *tree_root = fs_info->tree_root;
1167 struct btrfs_root *root = pending->root;
1168 struct btrfs_root *parent_root;
1169 struct btrfs_block_rsv *rsv;
1170 struct inode *parent_inode;
1171 struct btrfs_path *path;
1172 struct btrfs_dir_item *dir_item;
1173 struct dentry *dentry;
1174 struct extent_buffer *tmp;
1175 struct extent_buffer *old;
1176 struct timespec cur_time = CURRENT_TIME;
1184 path = btrfs_alloc_path();
1186 pending->error = -ENOMEM;
1190 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1191 if (!new_root_item) {
1192 pending->error = -ENOMEM;
1193 goto root_item_alloc_fail;
1196 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1198 goto no_free_objectid;
1200 btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
1202 if (to_reserve > 0) {
1203 pending->error = btrfs_block_rsv_add(root,
1204 &pending->block_rsv,
1206 BTRFS_RESERVE_NO_FLUSH);
1208 goto no_free_objectid;
1211 key.objectid = objectid;
1212 key.offset = (u64)-1;
1213 key.type = BTRFS_ROOT_ITEM_KEY;
1215 rsv = trans->block_rsv;
1216 trans->block_rsv = &pending->block_rsv;
1217 trans->bytes_reserved = trans->block_rsv->reserved;
1219 dentry = pending->dentry;
1220 parent_inode = pending->dir;
1221 parent_root = BTRFS_I(parent_inode)->root;
1222 record_root_in_trans(trans, parent_root);
1225 * insert the directory item
1227 ret = btrfs_set_inode_index(parent_inode, &index);
1228 BUG_ON(ret); /* -ENOMEM */
1230 /* check if there is a file/dir which has the same name. */
1231 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1232 btrfs_ino(parent_inode),
1233 dentry->d_name.name,
1234 dentry->d_name.len, 0);
1235 if (dir_item != NULL && !IS_ERR(dir_item)) {
1236 pending->error = -EEXIST;
1237 goto dir_item_existed;
1238 } else if (IS_ERR(dir_item)) {
1239 ret = PTR_ERR(dir_item);
1240 btrfs_abort_transaction(trans, root, ret);
1243 btrfs_release_path(path);
1246 * pull in the delayed directory update
1247 * and the delayed inode item
1248 * otherwise we corrupt the FS during
1251 ret = btrfs_run_delayed_items(trans, root);
1252 if (ret) { /* Transaction aborted */
1253 btrfs_abort_transaction(trans, root, ret);
1257 record_root_in_trans(trans, root);
1258 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1259 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1260 btrfs_check_and_init_root_item(new_root_item);
1262 root_flags = btrfs_root_flags(new_root_item);
1263 if (pending->readonly)
1264 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1266 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1267 btrfs_set_root_flags(new_root_item, root_flags);
1269 btrfs_set_root_generation_v2(new_root_item,
1271 uuid_le_gen(&new_uuid);
1272 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1273 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1275 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1276 memset(new_root_item->received_uuid, 0,
1277 sizeof(new_root_item->received_uuid));
1278 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1279 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1280 btrfs_set_root_stransid(new_root_item, 0);
1281 btrfs_set_root_rtransid(new_root_item, 0);
1283 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1284 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1285 btrfs_set_root_otransid(new_root_item, trans->transid);
1287 old = btrfs_lock_root_node(root);
1288 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1290 btrfs_tree_unlock(old);
1291 free_extent_buffer(old);
1292 btrfs_abort_transaction(trans, root, ret);
1296 btrfs_set_lock_blocking(old);
1298 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1299 /* clean up in any case */
1300 btrfs_tree_unlock(old);
1301 free_extent_buffer(old);
1303 btrfs_abort_transaction(trans, root, ret);
1308 * We need to flush delayed refs in order to make sure all of our quota
1309 * operations have been done before we call btrfs_qgroup_inherit.
1311 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1313 btrfs_abort_transaction(trans, root, ret);
1317 ret = btrfs_qgroup_inherit(trans, fs_info,
1318 root->root_key.objectid,
1319 objectid, pending->inherit);
1321 btrfs_abort_transaction(trans, root, ret);
1325 /* see comments in should_cow_block() */
1326 set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1329 btrfs_set_root_node(new_root_item, tmp);
1330 /* record when the snapshot was created in key.offset */
1331 key.offset = trans->transid;
1332 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1333 btrfs_tree_unlock(tmp);
1334 free_extent_buffer(tmp);
1336 btrfs_abort_transaction(trans, root, ret);
1341 * insert root back/forward references
1343 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1344 parent_root->root_key.objectid,
1345 btrfs_ino(parent_inode), index,
1346 dentry->d_name.name, dentry->d_name.len);
1348 btrfs_abort_transaction(trans, root, ret);
1352 key.offset = (u64)-1;
1353 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1354 if (IS_ERR(pending->snap)) {
1355 ret = PTR_ERR(pending->snap);
1356 btrfs_abort_transaction(trans, root, ret);
1360 ret = btrfs_reloc_post_snapshot(trans, pending);
1362 btrfs_abort_transaction(trans, root, ret);
1366 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1368 btrfs_abort_transaction(trans, root, ret);
1372 ret = btrfs_insert_dir_item(trans, parent_root,
1373 dentry->d_name.name, dentry->d_name.len,
1375 BTRFS_FT_DIR, index);
1376 /* We have check then name at the beginning, so it is impossible. */
1377 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1379 btrfs_abort_transaction(trans, root, ret);
1383 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1384 dentry->d_name.len * 2);
1385 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1386 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1388 btrfs_abort_transaction(trans, root, ret);
1391 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1392 BTRFS_UUID_KEY_SUBVOL, objectid);
1394 btrfs_abort_transaction(trans, root, ret);
1397 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1398 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1399 new_root_item->received_uuid,
1400 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1402 if (ret && ret != -EEXIST) {
1403 btrfs_abort_transaction(trans, root, ret);
1408 pending->error = ret;
1410 trans->block_rsv = rsv;
1411 trans->bytes_reserved = 0;
1413 kfree(new_root_item);
1414 root_item_alloc_fail:
1415 btrfs_free_path(path);
1420 * create all the snapshots we've scheduled for creation
1422 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1423 struct btrfs_fs_info *fs_info)
1425 struct btrfs_pending_snapshot *pending, *next;
1426 struct list_head *head = &trans->transaction->pending_snapshots;
1429 list_for_each_entry_safe(pending, next, head, list) {
1430 list_del(&pending->list);
1431 ret = create_pending_snapshot(trans, fs_info, pending);
1438 static void update_super_roots(struct btrfs_root *root)
1440 struct btrfs_root_item *root_item;
1441 struct btrfs_super_block *super;
1443 super = root->fs_info->super_copy;
1445 root_item = &root->fs_info->chunk_root->root_item;
1446 super->chunk_root = root_item->bytenr;
1447 super->chunk_root_generation = root_item->generation;
1448 super->chunk_root_level = root_item->level;
1450 root_item = &root->fs_info->tree_root->root_item;
1451 super->root = root_item->bytenr;
1452 super->generation = root_item->generation;
1453 super->root_level = root_item->level;
1454 if (btrfs_test_opt(root, SPACE_CACHE))
1455 super->cache_generation = root_item->generation;
1456 if (root->fs_info->update_uuid_tree_gen)
1457 super->uuid_tree_generation = root_item->generation;
1460 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1462 struct btrfs_transaction *trans;
1465 spin_lock(&info->trans_lock);
1466 trans = info->running_transaction;
1468 ret = (trans->state >= TRANS_STATE_COMMIT_START);
1469 spin_unlock(&info->trans_lock);
1473 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1475 struct btrfs_transaction *trans;
1478 spin_lock(&info->trans_lock);
1479 trans = info->running_transaction;
1481 ret = is_transaction_blocked(trans);
1482 spin_unlock(&info->trans_lock);
1487 * wait for the current transaction commit to start and block subsequent
1490 static void wait_current_trans_commit_start(struct btrfs_root *root,
1491 struct btrfs_transaction *trans)
1493 wait_event(root->fs_info->transaction_blocked_wait,
1494 trans->state >= TRANS_STATE_COMMIT_START ||
1499 * wait for the current transaction to start and then become unblocked.
1502 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1503 struct btrfs_transaction *trans)
1505 wait_event(root->fs_info->transaction_wait,
1506 trans->state >= TRANS_STATE_UNBLOCKED ||
1511 * commit transactions asynchronously. once btrfs_commit_transaction_async
1512 * returns, any subsequent transaction will not be allowed to join.
1514 struct btrfs_async_commit {
1515 struct btrfs_trans_handle *newtrans;
1516 struct btrfs_root *root;
1517 struct work_struct work;
1520 static void do_async_commit(struct work_struct *work)
1522 struct btrfs_async_commit *ac =
1523 container_of(work, struct btrfs_async_commit, work);
1526 * We've got freeze protection passed with the transaction.
1527 * Tell lockdep about it.
1529 if (ac->newtrans->type & __TRANS_FREEZABLE)
1531 &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1534 current->journal_info = ac->newtrans;
1536 btrfs_commit_transaction(ac->newtrans, ac->root);
1540 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1541 struct btrfs_root *root,
1542 int wait_for_unblock)
1544 struct btrfs_async_commit *ac;
1545 struct btrfs_transaction *cur_trans;
1547 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1551 INIT_WORK(&ac->work, do_async_commit);
1553 ac->newtrans = btrfs_join_transaction(root);
1554 if (IS_ERR(ac->newtrans)) {
1555 int err = PTR_ERR(ac->newtrans);
1560 /* take transaction reference */
1561 cur_trans = trans->transaction;
1562 atomic_inc(&cur_trans->use_count);
1564 btrfs_end_transaction(trans, root);
1567 * Tell lockdep we've released the freeze rwsem, since the
1568 * async commit thread will be the one to unlock it.
1570 if (ac->newtrans->type & __TRANS_FREEZABLE)
1572 &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1575 schedule_work(&ac->work);
1577 /* wait for transaction to start and unblock */
1578 if (wait_for_unblock)
1579 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1581 wait_current_trans_commit_start(root, cur_trans);
1583 if (current->journal_info == trans)
1584 current->journal_info = NULL;
1586 btrfs_put_transaction(cur_trans);
1591 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1592 struct btrfs_root *root, int err)
1594 struct btrfs_transaction *cur_trans = trans->transaction;
1597 WARN_ON(trans->use_count > 1);
1599 btrfs_abort_transaction(trans, root, err);
1601 spin_lock(&root->fs_info->trans_lock);
1604 * If the transaction is removed from the list, it means this
1605 * transaction has been committed successfully, so it is impossible
1606 * to call the cleanup function.
1608 BUG_ON(list_empty(&cur_trans->list));
1610 list_del_init(&cur_trans->list);
1611 if (cur_trans == root->fs_info->running_transaction) {
1612 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1613 spin_unlock(&root->fs_info->trans_lock);
1614 wait_event(cur_trans->writer_wait,
1615 atomic_read(&cur_trans->num_writers) == 1);
1617 spin_lock(&root->fs_info->trans_lock);
1619 spin_unlock(&root->fs_info->trans_lock);
1621 btrfs_cleanup_one_transaction(trans->transaction, root);
1623 spin_lock(&root->fs_info->trans_lock);
1624 if (cur_trans == root->fs_info->running_transaction)
1625 root->fs_info->running_transaction = NULL;
1626 spin_unlock(&root->fs_info->trans_lock);
1628 if (trans->type & __TRANS_FREEZABLE)
1629 sb_end_intwrite(root->fs_info->sb);
1630 btrfs_put_transaction(cur_trans);
1631 btrfs_put_transaction(cur_trans);
1633 trace_btrfs_transaction_commit(root);
1635 if (current->journal_info == trans)
1636 current->journal_info = NULL;
1637 btrfs_scrub_cancel(root->fs_info);
1639 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1642 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1644 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1645 return btrfs_start_delalloc_roots(fs_info, 1, -1);
1649 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1651 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1652 btrfs_wait_ordered_roots(fs_info, -1);
1655 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1656 struct btrfs_root *root)
1658 struct btrfs_transaction *cur_trans = trans->transaction;
1659 struct btrfs_transaction *prev_trans = NULL;
1660 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
1663 /* Stop the commit early if ->aborted is set */
1664 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1665 ret = cur_trans->aborted;
1666 btrfs_end_transaction(trans, root);
1670 /* make a pass through all the delayed refs we have so far
1671 * any runnings procs may add more while we are here
1673 ret = btrfs_run_delayed_refs(trans, root, 0);
1675 btrfs_end_transaction(trans, root);
1679 btrfs_trans_release_metadata(trans, root);
1680 trans->block_rsv = NULL;
1681 if (trans->qgroup_reserved) {
1682 btrfs_qgroup_free(root, trans->qgroup_reserved);
1683 trans->qgroup_reserved = 0;
1686 cur_trans = trans->transaction;
1689 * set the flushing flag so procs in this transaction have to
1690 * start sending their work down.
1692 cur_trans->delayed_refs.flushing = 1;
1695 if (!list_empty(&trans->new_bgs))
1696 btrfs_create_pending_block_groups(trans, root);
1698 ret = btrfs_run_delayed_refs(trans, root, 0);
1700 btrfs_end_transaction(trans, root);
1704 spin_lock(&root->fs_info->trans_lock);
1705 if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1706 spin_unlock(&root->fs_info->trans_lock);
1707 atomic_inc(&cur_trans->use_count);
1708 ret = btrfs_end_transaction(trans, root);
1710 wait_for_commit(root, cur_trans);
1712 btrfs_put_transaction(cur_trans);
1717 cur_trans->state = TRANS_STATE_COMMIT_START;
1718 wake_up(&root->fs_info->transaction_blocked_wait);
1720 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1721 prev_trans = list_entry(cur_trans->list.prev,
1722 struct btrfs_transaction, list);
1723 if (prev_trans->state != TRANS_STATE_COMPLETED) {
1724 atomic_inc(&prev_trans->use_count);
1725 spin_unlock(&root->fs_info->trans_lock);
1727 wait_for_commit(root, prev_trans);
1729 btrfs_put_transaction(prev_trans);
1731 spin_unlock(&root->fs_info->trans_lock);
1734 spin_unlock(&root->fs_info->trans_lock);
1737 extwriter_counter_dec(cur_trans, trans->type);
1739 ret = btrfs_start_delalloc_flush(root->fs_info);
1741 goto cleanup_transaction;
1743 ret = btrfs_run_delayed_items(trans, root);
1745 goto cleanup_transaction;
1747 wait_event(cur_trans->writer_wait,
1748 extwriter_counter_read(cur_trans) == 0);
1750 /* some pending stuffs might be added after the previous flush. */
1751 ret = btrfs_run_delayed_items(trans, root);
1753 goto cleanup_transaction;
1755 btrfs_wait_delalloc_flush(root->fs_info);
1757 btrfs_scrub_pause(root);
1759 * Ok now we need to make sure to block out any other joins while we
1760 * commit the transaction. We could have started a join before setting
1761 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1763 spin_lock(&root->fs_info->trans_lock);
1764 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1765 spin_unlock(&root->fs_info->trans_lock);
1766 wait_event(cur_trans->writer_wait,
1767 atomic_read(&cur_trans->num_writers) == 1);
1769 /* ->aborted might be set after the previous check, so check it */
1770 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1771 ret = cur_trans->aborted;
1772 goto scrub_continue;
1775 * the reloc mutex makes sure that we stop
1776 * the balancing code from coming in and moving
1777 * extents around in the middle of the commit
1779 mutex_lock(&root->fs_info->reloc_mutex);
1782 * We needn't worry about the delayed items because we will
1783 * deal with them in create_pending_snapshot(), which is the
1784 * core function of the snapshot creation.
1786 ret = create_pending_snapshots(trans, root->fs_info);
1788 mutex_unlock(&root->fs_info->reloc_mutex);
1789 goto scrub_continue;
1793 * We insert the dir indexes of the snapshots and update the inode
1794 * of the snapshots' parents after the snapshot creation, so there
1795 * are some delayed items which are not dealt with. Now deal with
1798 * We needn't worry that this operation will corrupt the snapshots,
1799 * because all the tree which are snapshoted will be forced to COW
1800 * the nodes and leaves.
1802 ret = btrfs_run_delayed_items(trans, root);
1804 mutex_unlock(&root->fs_info->reloc_mutex);
1805 goto scrub_continue;
1808 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1810 mutex_unlock(&root->fs_info->reloc_mutex);
1811 goto scrub_continue;
1815 * make sure none of the code above managed to slip in a
1818 btrfs_assert_delayed_root_empty(root);
1820 WARN_ON(cur_trans != trans->transaction);
1822 /* btrfs_commit_tree_roots is responsible for getting the
1823 * various roots consistent with each other. Every pointer
1824 * in the tree of tree roots has to point to the most up to date
1825 * root for every subvolume and other tree. So, we have to keep
1826 * the tree logging code from jumping in and changing any
1829 * At this point in the commit, there can't be any tree-log
1830 * writers, but a little lower down we drop the trans mutex
1831 * and let new people in. By holding the tree_log_mutex
1832 * from now until after the super is written, we avoid races
1833 * with the tree-log code.
1835 mutex_lock(&root->fs_info->tree_log_mutex);
1837 ret = commit_fs_roots(trans, root);
1839 mutex_unlock(&root->fs_info->tree_log_mutex);
1840 mutex_unlock(&root->fs_info->reloc_mutex);
1841 goto scrub_continue;
1845 * Since the transaction is done, we should set the inode map cache flag
1846 * before any other comming transaction.
1848 if (btrfs_test_opt(root, CHANGE_INODE_CACHE))
1849 btrfs_set_opt(root->fs_info->mount_opt, INODE_MAP_CACHE);
1851 btrfs_clear_opt(root->fs_info->mount_opt, INODE_MAP_CACHE);
1853 /* commit_fs_roots gets rid of all the tree log roots, it is now
1854 * safe to free the root of tree log roots
1856 btrfs_free_log_root_tree(trans, root->fs_info);
1858 ret = commit_cowonly_roots(trans, root);
1860 mutex_unlock(&root->fs_info->tree_log_mutex);
1861 mutex_unlock(&root->fs_info->reloc_mutex);
1862 goto scrub_continue;
1866 * The tasks which save the space cache and inode cache may also
1867 * update ->aborted, check it.
1869 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1870 ret = cur_trans->aborted;
1871 mutex_unlock(&root->fs_info->tree_log_mutex);
1872 mutex_unlock(&root->fs_info->reloc_mutex);
1873 goto scrub_continue;
1876 btrfs_prepare_extent_commit(trans, root);
1878 cur_trans = root->fs_info->running_transaction;
1880 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1881 root->fs_info->tree_root->node);
1882 list_add_tail(&root->fs_info->tree_root->dirty_list,
1883 &cur_trans->switch_commits);
1885 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1886 root->fs_info->chunk_root->node);
1887 list_add_tail(&root->fs_info->chunk_root->dirty_list,
1888 &cur_trans->switch_commits);
1890 switch_commit_roots(cur_trans, root->fs_info);
1892 assert_qgroups_uptodate(trans);
1893 update_super_roots(root);
1895 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
1896 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
1897 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
1898 sizeof(*root->fs_info->super_copy));
1900 btrfs_update_commit_device_size(root->fs_info);
1901 btrfs_update_commit_device_bytes_used(root, cur_trans);
1903 clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
1904 clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
1906 spin_lock(&root->fs_info->trans_lock);
1907 cur_trans->state = TRANS_STATE_UNBLOCKED;
1908 root->fs_info->running_transaction = NULL;
1909 spin_unlock(&root->fs_info->trans_lock);
1910 mutex_unlock(&root->fs_info->reloc_mutex);
1912 wake_up(&root->fs_info->transaction_wait);
1914 ret = btrfs_write_and_wait_transaction(trans, root);
1916 btrfs_error(root->fs_info, ret,
1917 "Error while writing out transaction");
1918 mutex_unlock(&root->fs_info->tree_log_mutex);
1919 goto scrub_continue;
1922 ret = write_ctree_super(trans, root, 0);
1924 mutex_unlock(&root->fs_info->tree_log_mutex);
1925 goto scrub_continue;
1929 * the super is written, we can safely allow the tree-loggers
1930 * to go about their business
1932 mutex_unlock(&root->fs_info->tree_log_mutex);
1934 btrfs_finish_extent_commit(trans, root);
1936 root->fs_info->last_trans_committed = cur_trans->transid;
1938 * We needn't acquire the lock here because there is no other task
1939 * which can change it.
1941 cur_trans->state = TRANS_STATE_COMPLETED;
1942 wake_up(&cur_trans->commit_wait);
1944 spin_lock(&root->fs_info->trans_lock);
1945 list_del_init(&cur_trans->list);
1946 spin_unlock(&root->fs_info->trans_lock);
1948 btrfs_put_transaction(cur_trans);
1949 btrfs_put_transaction(cur_trans);
1951 if (trans->type & __TRANS_FREEZABLE)
1952 sb_end_intwrite(root->fs_info->sb);
1954 trace_btrfs_transaction_commit(root);
1956 btrfs_scrub_continue(root);
1958 if (current->journal_info == trans)
1959 current->journal_info = NULL;
1961 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1963 if (current != root->fs_info->transaction_kthread)
1964 btrfs_run_delayed_iputs(root);
1969 btrfs_scrub_continue(root);
1970 cleanup_transaction:
1971 btrfs_trans_release_metadata(trans, root);
1972 trans->block_rsv = NULL;
1973 if (trans->qgroup_reserved) {
1974 btrfs_qgroup_free(root, trans->qgroup_reserved);
1975 trans->qgroup_reserved = 0;
1977 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
1978 if (current->journal_info == trans)
1979 current->journal_info = NULL;
1980 cleanup_transaction(trans, root, ret);
1986 * return < 0 if error
1987 * 0 if there are no more dead_roots at the time of call
1988 * 1 there are more to be processed, call me again
1990 * The return value indicates there are certainly more snapshots to delete, but
1991 * if there comes a new one during processing, it may return 0. We don't mind,
1992 * because btrfs_commit_super will poke cleaner thread and it will process it a
1993 * few seconds later.
1995 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
1998 struct btrfs_fs_info *fs_info = root->fs_info;
2000 spin_lock(&fs_info->trans_lock);
2001 if (list_empty(&fs_info->dead_roots)) {
2002 spin_unlock(&fs_info->trans_lock);
2005 root = list_first_entry(&fs_info->dead_roots,
2006 struct btrfs_root, root_list);
2007 list_del_init(&root->root_list);
2008 spin_unlock(&fs_info->trans_lock);
2010 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
2012 btrfs_kill_all_delayed_nodes(root);
2014 if (btrfs_header_backref_rev(root->node) <
2015 BTRFS_MIXED_BACKREF_REV)
2016 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
2018 ret = btrfs_drop_snapshot(root, NULL, 1, 0);
2020 return (ret < 0) ? 0 : 1;