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"
35 #define BTRFS_ROOT_TRANS_TAG 0
37 static unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
38 [TRANS_STATE_RUNNING] = 0U,
39 [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE |
41 [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE |
44 [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE |
48 [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE |
53 [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE |
60 void btrfs_put_transaction(struct btrfs_transaction *transaction)
62 WARN_ON(atomic_read(&transaction->use_count) == 0);
63 if (atomic_dec_and_test(&transaction->use_count)) {
64 BUG_ON(!list_empty(&transaction->list));
65 WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.root));
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_root(struct btrfs_root *root)
81 free_extent_buffer(root->commit_root);
82 root->commit_root = btrfs_root_node(root);
85 static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
88 if (type & TRANS_EXTWRITERS)
89 atomic_inc(&trans->num_extwriters);
92 static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
95 if (type & TRANS_EXTWRITERS)
96 atomic_dec(&trans->num_extwriters);
99 static inline void extwriter_counter_init(struct btrfs_transaction *trans,
102 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
105 static inline int extwriter_counter_read(struct btrfs_transaction *trans)
107 return atomic_read(&trans->num_extwriters);
111 * either allocate a new transaction or hop into the existing one
113 static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
115 struct btrfs_transaction *cur_trans;
116 struct btrfs_fs_info *fs_info = root->fs_info;
118 spin_lock(&fs_info->trans_lock);
120 /* The file system has been taken offline. No new transactions. */
121 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
122 spin_unlock(&fs_info->trans_lock);
126 cur_trans = fs_info->running_transaction;
128 if (cur_trans->aborted) {
129 spin_unlock(&fs_info->trans_lock);
130 return cur_trans->aborted;
132 if (btrfs_blocked_trans_types[cur_trans->state] & type) {
133 spin_unlock(&fs_info->trans_lock);
136 atomic_inc(&cur_trans->use_count);
137 atomic_inc(&cur_trans->num_writers);
138 extwriter_counter_inc(cur_trans, type);
139 spin_unlock(&fs_info->trans_lock);
142 spin_unlock(&fs_info->trans_lock);
145 * If we are ATTACH, we just want to catch the current transaction,
146 * and commit it. If there is no transaction, just return ENOENT.
148 if (type == TRANS_ATTACH)
152 * JOIN_NOLOCK only happens during the transaction commit, so
153 * it is impossible that ->running_transaction is NULL
155 BUG_ON(type == TRANS_JOIN_NOLOCK);
157 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
161 spin_lock(&fs_info->trans_lock);
162 if (fs_info->running_transaction) {
164 * someone started a transaction after we unlocked. Make sure
165 * to redo the checks above
167 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
169 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
170 spin_unlock(&fs_info->trans_lock);
171 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
175 atomic_set(&cur_trans->num_writers, 1);
176 extwriter_counter_init(cur_trans, type);
177 init_waitqueue_head(&cur_trans->writer_wait);
178 init_waitqueue_head(&cur_trans->commit_wait);
179 cur_trans->state = TRANS_STATE_RUNNING;
181 * One for this trans handle, one so it will live on until we
182 * commit the transaction.
184 atomic_set(&cur_trans->use_count, 2);
185 cur_trans->start_time = get_seconds();
187 cur_trans->delayed_refs.root = RB_ROOT;
188 cur_trans->delayed_refs.href_root = RB_ROOT;
189 cur_trans->delayed_refs.num_entries = 0;
190 cur_trans->delayed_refs.num_heads_ready = 0;
191 cur_trans->delayed_refs.num_heads = 0;
192 cur_trans->delayed_refs.flushing = 0;
193 cur_trans->delayed_refs.run_delayed_start = 0;
196 * although the tree mod log is per file system and not per transaction,
197 * the log must never go across transaction boundaries.
200 if (!list_empty(&fs_info->tree_mod_seq_list))
201 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
202 "creating a fresh transaction\n");
203 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
204 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
205 "creating a fresh transaction\n");
206 atomic64_set(&fs_info->tree_mod_seq, 0);
208 spin_lock_init(&cur_trans->delayed_refs.lock);
209 atomic_set(&cur_trans->delayed_refs.procs_running_refs, 0);
210 atomic_set(&cur_trans->delayed_refs.ref_seq, 0);
211 init_waitqueue_head(&cur_trans->delayed_refs.wait);
213 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
214 INIT_LIST_HEAD(&cur_trans->ordered_operations);
215 INIT_LIST_HEAD(&cur_trans->pending_chunks);
216 list_add_tail(&cur_trans->list, &fs_info->trans_list);
217 extent_io_tree_init(&cur_trans->dirty_pages,
218 fs_info->btree_inode->i_mapping);
219 fs_info->generation++;
220 cur_trans->transid = fs_info->generation;
221 fs_info->running_transaction = cur_trans;
222 cur_trans->aborted = 0;
223 spin_unlock(&fs_info->trans_lock);
229 * this does all the record keeping required to make sure that a reference
230 * counted root is properly recorded in a given transaction. This is required
231 * to make sure the old root from before we joined the transaction is deleted
232 * when the transaction commits
234 static int record_root_in_trans(struct btrfs_trans_handle *trans,
235 struct btrfs_root *root)
237 if (root->ref_cows && root->last_trans < trans->transid) {
238 WARN_ON(root == root->fs_info->extent_root);
239 WARN_ON(root->commit_root != root->node);
242 * see below for in_trans_setup usage rules
243 * we have the reloc mutex held now, so there
244 * is only one writer in this function
246 root->in_trans_setup = 1;
248 /* make sure readers find in_trans_setup before
249 * they find our root->last_trans update
253 spin_lock(&root->fs_info->fs_roots_radix_lock);
254 if (root->last_trans == trans->transid) {
255 spin_unlock(&root->fs_info->fs_roots_radix_lock);
258 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
259 (unsigned long)root->root_key.objectid,
260 BTRFS_ROOT_TRANS_TAG);
261 spin_unlock(&root->fs_info->fs_roots_radix_lock);
262 root->last_trans = trans->transid;
264 /* this is pretty tricky. We don't want to
265 * take the relocation lock in btrfs_record_root_in_trans
266 * unless we're really doing the first setup for this root in
269 * Normally we'd use root->last_trans as a flag to decide
270 * if we want to take the expensive mutex.
272 * But, we have to set root->last_trans before we
273 * init the relocation root, otherwise, we trip over warnings
274 * in ctree.c. The solution used here is to flag ourselves
275 * with root->in_trans_setup. When this is 1, we're still
276 * fixing up the reloc trees and everyone must wait.
278 * When this is zero, they can trust root->last_trans and fly
279 * through btrfs_record_root_in_trans without having to take the
280 * lock. smp_wmb() makes sure that all the writes above are
281 * done before we pop in the zero below
283 btrfs_init_reloc_root(trans, root);
285 root->in_trans_setup = 0;
291 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
292 struct btrfs_root *root)
298 * see record_root_in_trans for comments about in_trans_setup usage
302 if (root->last_trans == trans->transid &&
303 !root->in_trans_setup)
306 mutex_lock(&root->fs_info->reloc_mutex);
307 record_root_in_trans(trans, root);
308 mutex_unlock(&root->fs_info->reloc_mutex);
313 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
315 return (trans->state >= TRANS_STATE_BLOCKED &&
316 trans->state < TRANS_STATE_UNBLOCKED &&
320 /* wait for commit against the current transaction to become unblocked
321 * when this is done, it is safe to start a new transaction, but the current
322 * transaction might not be fully on disk.
324 static void wait_current_trans(struct btrfs_root *root)
326 struct btrfs_transaction *cur_trans;
328 spin_lock(&root->fs_info->trans_lock);
329 cur_trans = root->fs_info->running_transaction;
330 if (cur_trans && is_transaction_blocked(cur_trans)) {
331 atomic_inc(&cur_trans->use_count);
332 spin_unlock(&root->fs_info->trans_lock);
334 wait_event(root->fs_info->transaction_wait,
335 cur_trans->state >= TRANS_STATE_UNBLOCKED ||
337 btrfs_put_transaction(cur_trans);
339 spin_unlock(&root->fs_info->trans_lock);
343 static int may_wait_transaction(struct btrfs_root *root, int type)
345 if (root->fs_info->log_root_recovering)
348 if (type == TRANS_USERSPACE)
351 if (type == TRANS_START &&
352 !atomic_read(&root->fs_info->open_ioctl_trans))
358 static inline bool need_reserve_reloc_root(struct btrfs_root *root)
360 if (!root->fs_info->reloc_ctl ||
362 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
369 static struct btrfs_trans_handle *
370 start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
371 enum btrfs_reserve_flush_enum flush)
373 struct btrfs_trans_handle *h;
374 struct btrfs_transaction *cur_trans;
376 u64 qgroup_reserved = 0;
377 bool reloc_reserved = false;
380 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
381 return ERR_PTR(-EROFS);
383 if (current->journal_info) {
384 WARN_ON(type & TRANS_EXTWRITERS);
385 h = current->journal_info;
387 WARN_ON(h->use_count > 2);
388 h->orig_rsv = h->block_rsv;
394 * Do the reservation before we join the transaction so we can do all
395 * the appropriate flushing if need be.
397 if (num_items > 0 && root != root->fs_info->chunk_root) {
398 if (root->fs_info->quota_enabled &&
399 is_fstree(root->root_key.objectid)) {
400 qgroup_reserved = num_items * root->leafsize;
401 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
406 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
408 * Do the reservation for the relocation root creation
410 if (unlikely(need_reserve_reloc_root(root))) {
411 num_bytes += root->nodesize;
412 reloc_reserved = true;
415 ret = btrfs_block_rsv_add(root,
416 &root->fs_info->trans_block_rsv,
422 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
429 * If we are JOIN_NOLOCK we're already committing a transaction and
430 * waiting on this guy, so we don't need to do the sb_start_intwrite
431 * because we're already holding a ref. We need this because we could
432 * have raced in and did an fsync() on a file which can kick a commit
433 * and then we deadlock with somebody doing a freeze.
435 * If we are ATTACH, it means we just want to catch the current
436 * transaction and commit it, so we needn't do sb_start_intwrite().
438 if (type & __TRANS_FREEZABLE)
439 sb_start_intwrite(root->fs_info->sb);
441 if (may_wait_transaction(root, type))
442 wait_current_trans(root);
445 ret = join_transaction(root, type);
447 wait_current_trans(root);
448 if (unlikely(type == TRANS_ATTACH))
451 } while (ret == -EBUSY);
454 /* We must get the transaction if we are JOIN_NOLOCK. */
455 BUG_ON(type == TRANS_JOIN_NOLOCK);
459 cur_trans = root->fs_info->running_transaction;
461 h->transid = cur_trans->transid;
462 h->transaction = cur_trans;
464 h->bytes_reserved = 0;
466 h->delayed_ref_updates = 0;
472 h->qgroup_reserved = 0;
473 h->delayed_ref_elem.seq = 0;
475 h->allocating_chunk = false;
476 h->reloc_reserved = false;
477 INIT_LIST_HEAD(&h->qgroup_ref_list);
478 INIT_LIST_HEAD(&h->new_bgs);
481 if (cur_trans->state >= TRANS_STATE_BLOCKED &&
482 may_wait_transaction(root, type)) {
483 btrfs_commit_transaction(h, root);
488 trace_btrfs_space_reservation(root->fs_info, "transaction",
489 h->transid, num_bytes, 1);
490 h->block_rsv = &root->fs_info->trans_block_rsv;
491 h->bytes_reserved = num_bytes;
492 h->reloc_reserved = reloc_reserved;
494 h->qgroup_reserved = qgroup_reserved;
497 btrfs_record_root_in_trans(h, root);
499 if (!current->journal_info && type != TRANS_USERSPACE)
500 current->journal_info = h;
504 if (type & __TRANS_FREEZABLE)
505 sb_end_intwrite(root->fs_info->sb);
506 kmem_cache_free(btrfs_trans_handle_cachep, h);
509 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
513 btrfs_qgroup_free(root, qgroup_reserved);
517 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
520 return start_transaction(root, num_items, TRANS_START,
521 BTRFS_RESERVE_FLUSH_ALL);
524 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
525 struct btrfs_root *root, int num_items)
527 return start_transaction(root, num_items, TRANS_START,
528 BTRFS_RESERVE_FLUSH_LIMIT);
531 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
533 return start_transaction(root, 0, TRANS_JOIN, 0);
536 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
538 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
541 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
543 return start_transaction(root, 0, TRANS_USERSPACE, 0);
547 * btrfs_attach_transaction() - catch the running transaction
549 * It is used when we want to commit the current the transaction, but
550 * don't want to start a new one.
552 * Note: If this function return -ENOENT, it just means there is no
553 * running transaction. But it is possible that the inactive transaction
554 * is still in the memory, not fully on disk. If you hope there is no
555 * inactive transaction in the fs when -ENOENT is returned, you should
557 * btrfs_attach_transaction_barrier()
559 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
561 return start_transaction(root, 0, TRANS_ATTACH, 0);
565 * btrfs_attach_transaction_barrier() - catch the running transaction
567 * It is similar to the above function, the differentia is this one
568 * will wait for all the inactive transactions until they fully
571 struct btrfs_trans_handle *
572 btrfs_attach_transaction_barrier(struct btrfs_root *root)
574 struct btrfs_trans_handle *trans;
576 trans = start_transaction(root, 0, TRANS_ATTACH, 0);
577 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
578 btrfs_wait_for_commit(root, 0);
583 /* wait for a transaction commit to be fully complete */
584 static noinline void wait_for_commit(struct btrfs_root *root,
585 struct btrfs_transaction *commit)
587 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
590 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
592 struct btrfs_transaction *cur_trans = NULL, *t;
596 if (transid <= root->fs_info->last_trans_committed)
600 /* find specified transaction */
601 spin_lock(&root->fs_info->trans_lock);
602 list_for_each_entry(t, &root->fs_info->trans_list, list) {
603 if (t->transid == transid) {
605 atomic_inc(&cur_trans->use_count);
609 if (t->transid > transid) {
614 spin_unlock(&root->fs_info->trans_lock);
615 /* The specified transaction doesn't exist */
619 /* find newest transaction that is committing | committed */
620 spin_lock(&root->fs_info->trans_lock);
621 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
623 if (t->state >= TRANS_STATE_COMMIT_START) {
624 if (t->state == TRANS_STATE_COMPLETED)
627 atomic_inc(&cur_trans->use_count);
631 spin_unlock(&root->fs_info->trans_lock);
633 goto out; /* nothing committing|committed */
636 wait_for_commit(root, cur_trans);
637 btrfs_put_transaction(cur_trans);
642 void btrfs_throttle(struct btrfs_root *root)
644 if (!atomic_read(&root->fs_info->open_ioctl_trans))
645 wait_current_trans(root);
648 static int should_end_transaction(struct btrfs_trans_handle *trans,
649 struct btrfs_root *root)
651 if (root->fs_info->global_block_rsv.space_info->full &&
652 btrfs_should_throttle_delayed_refs(trans, root))
655 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
658 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
659 struct btrfs_root *root)
661 struct btrfs_transaction *cur_trans = trans->transaction;
666 if (cur_trans->state >= TRANS_STATE_BLOCKED ||
667 cur_trans->delayed_refs.flushing)
670 updates = trans->delayed_ref_updates;
671 trans->delayed_ref_updates = 0;
673 err = btrfs_run_delayed_refs(trans, root, updates);
674 if (err) /* Error code will also eval true */
678 return should_end_transaction(trans, root);
681 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
682 struct btrfs_root *root, int throttle)
684 struct btrfs_transaction *cur_trans = trans->transaction;
685 struct btrfs_fs_info *info = root->fs_info;
686 unsigned long cur = trans->delayed_ref_updates;
687 int lock = (trans->type != TRANS_JOIN_NOLOCK);
690 if (--trans->use_count) {
691 trans->block_rsv = trans->orig_rsv;
696 * do the qgroup accounting as early as possible
698 err = btrfs_delayed_refs_qgroup_accounting(trans, info);
700 btrfs_trans_release_metadata(trans, root);
701 trans->block_rsv = NULL;
703 if (trans->qgroup_reserved) {
705 * the same root has to be passed here between start_transaction
706 * and end_transaction. Subvolume quota depends on this.
708 btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
709 trans->qgroup_reserved = 0;
712 if (!list_empty(&trans->new_bgs))
713 btrfs_create_pending_block_groups(trans, root);
715 trans->delayed_ref_updates = 0;
716 if (btrfs_should_throttle_delayed_refs(trans, root)) {
717 cur = max_t(unsigned long, cur, 1);
718 trans->delayed_ref_updates = 0;
719 btrfs_run_delayed_refs(trans, root, cur);
722 btrfs_trans_release_metadata(trans, root);
723 trans->block_rsv = NULL;
725 if (!list_empty(&trans->new_bgs))
726 btrfs_create_pending_block_groups(trans, root);
728 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
729 should_end_transaction(trans, root) &&
730 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
731 spin_lock(&info->trans_lock);
732 if (cur_trans->state == TRANS_STATE_RUNNING)
733 cur_trans->state = TRANS_STATE_BLOCKED;
734 spin_unlock(&info->trans_lock);
737 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
740 * We may race with somebody else here so end up having
741 * to call end_transaction on ourselves again, so inc
745 return btrfs_commit_transaction(trans, root);
747 wake_up_process(info->transaction_kthread);
751 if (trans->type & __TRANS_FREEZABLE)
752 sb_end_intwrite(root->fs_info->sb);
754 WARN_ON(cur_trans != info->running_transaction);
755 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
756 atomic_dec(&cur_trans->num_writers);
757 extwriter_counter_dec(cur_trans, trans->type);
760 if (waitqueue_active(&cur_trans->writer_wait))
761 wake_up(&cur_trans->writer_wait);
762 btrfs_put_transaction(cur_trans);
764 if (current->journal_info == trans)
765 current->journal_info = NULL;
768 btrfs_run_delayed_iputs(root);
770 if (trans->aborted ||
771 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
772 wake_up_process(info->transaction_kthread);
775 assert_qgroups_uptodate(trans);
777 kmem_cache_free(btrfs_trans_handle_cachep, trans);
781 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
782 struct btrfs_root *root)
784 return __btrfs_end_transaction(trans, root, 0);
787 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
788 struct btrfs_root *root)
790 return __btrfs_end_transaction(trans, root, 1);
794 * when btree blocks are allocated, they have some corresponding bits set for
795 * them in one of two extent_io trees. This is used to make sure all of
796 * those extents are sent to disk but does not wait on them
798 int btrfs_write_marked_extents(struct btrfs_root *root,
799 struct extent_io_tree *dirty_pages, int mark)
803 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
804 struct extent_state *cached_state = NULL;
808 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
809 mark, &cached_state)) {
810 convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
811 mark, &cached_state, GFP_NOFS);
813 err = filemap_fdatawrite_range(mapping, start, end);
825 * when btree blocks are allocated, they have some corresponding bits set for
826 * them in one of two extent_io trees. This is used to make sure all of
827 * those extents are on disk for transaction or log commit. We wait
828 * on all the pages and clear them from the dirty pages state tree
830 int btrfs_wait_marked_extents(struct btrfs_root *root,
831 struct extent_io_tree *dirty_pages, int mark)
835 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
836 struct extent_state *cached_state = NULL;
840 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
841 EXTENT_NEED_WAIT, &cached_state)) {
842 clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
843 0, 0, &cached_state, GFP_NOFS);
844 err = filemap_fdatawait_range(mapping, start, end);
856 * when btree blocks are allocated, they have some corresponding bits set for
857 * them in one of two extent_io trees. This is used to make sure all of
858 * those extents are on disk for transaction or log commit
860 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
861 struct extent_io_tree *dirty_pages, int mark)
865 struct blk_plug plug;
867 blk_start_plug(&plug);
868 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
869 blk_finish_plug(&plug);
870 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
879 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
880 struct btrfs_root *root)
882 if (!trans || !trans->transaction) {
883 struct inode *btree_inode;
884 btree_inode = root->fs_info->btree_inode;
885 return filemap_write_and_wait(btree_inode->i_mapping);
887 return btrfs_write_and_wait_marked_extents(root,
888 &trans->transaction->dirty_pages,
893 * this is used to update the root pointer in the tree of tree roots.
895 * But, in the case of the extent allocation tree, updating the root
896 * pointer may allocate blocks which may change the root of the extent
899 * So, this loops and repeats and makes sure the cowonly root didn't
900 * change while the root pointer was being updated in the metadata.
902 static int update_cowonly_root(struct btrfs_trans_handle *trans,
903 struct btrfs_root *root)
908 struct btrfs_root *tree_root = root->fs_info->tree_root;
910 old_root_used = btrfs_root_used(&root->root_item);
911 btrfs_write_dirty_block_groups(trans, root);
914 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
915 if (old_root_bytenr == root->node->start &&
916 old_root_used == btrfs_root_used(&root->root_item))
919 btrfs_set_root_node(&root->root_item, root->node);
920 ret = btrfs_update_root(trans, tree_root,
926 old_root_used = btrfs_root_used(&root->root_item);
927 ret = btrfs_write_dirty_block_groups(trans, root);
932 if (root != root->fs_info->extent_root)
933 switch_commit_root(root);
939 * update all the cowonly tree roots on disk
941 * The error handling in this function may not be obvious. Any of the
942 * failures will cause the file system to go offline. We still need
943 * to clean up the delayed refs.
945 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
946 struct btrfs_root *root)
948 struct btrfs_fs_info *fs_info = root->fs_info;
949 struct list_head *next;
950 struct extent_buffer *eb;
953 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
957 eb = btrfs_lock_root_node(fs_info->tree_root);
958 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
960 btrfs_tree_unlock(eb);
961 free_extent_buffer(eb);
966 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
970 ret = btrfs_run_dev_stats(trans, root->fs_info);
973 ret = btrfs_run_dev_replace(trans, root->fs_info);
976 ret = btrfs_run_qgroups(trans, root->fs_info);
980 /* run_qgroups might have added some more refs */
981 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
985 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
986 next = fs_info->dirty_cowonly_roots.next;
988 root = list_entry(next, struct btrfs_root, dirty_list);
990 ret = update_cowonly_root(trans, root);
995 down_write(&fs_info->extent_commit_sem);
996 switch_commit_root(fs_info->extent_root);
997 up_write(&fs_info->extent_commit_sem);
999 btrfs_after_dev_replace_commit(fs_info);
1005 * dead roots are old snapshots that need to be deleted. This allocates
1006 * a dirty root struct and adds it into the list of dead roots that need to
1009 void btrfs_add_dead_root(struct btrfs_root *root)
1011 spin_lock(&root->fs_info->trans_lock);
1012 if (list_empty(&root->root_list))
1013 list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1014 spin_unlock(&root->fs_info->trans_lock);
1018 * update all the cowonly tree roots on disk
1020 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1021 struct btrfs_root *root)
1023 struct btrfs_root *gang[8];
1024 struct btrfs_fs_info *fs_info = root->fs_info;
1029 spin_lock(&fs_info->fs_roots_radix_lock);
1031 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1034 BTRFS_ROOT_TRANS_TAG);
1037 for (i = 0; i < ret; i++) {
1039 radix_tree_tag_clear(&fs_info->fs_roots_radix,
1040 (unsigned long)root->root_key.objectid,
1041 BTRFS_ROOT_TRANS_TAG);
1042 spin_unlock(&fs_info->fs_roots_radix_lock);
1044 btrfs_free_log(trans, root);
1045 btrfs_update_reloc_root(trans, root);
1046 btrfs_orphan_commit_root(trans, root);
1048 btrfs_save_ino_cache(root, trans);
1050 /* see comments in should_cow_block() */
1051 root->force_cow = 0;
1054 if (root->commit_root != root->node) {
1055 mutex_lock(&root->fs_commit_mutex);
1056 switch_commit_root(root);
1057 btrfs_unpin_free_ino(root);
1058 mutex_unlock(&root->fs_commit_mutex);
1060 btrfs_set_root_node(&root->root_item,
1064 err = btrfs_update_root(trans, fs_info->tree_root,
1067 spin_lock(&fs_info->fs_roots_radix_lock);
1072 spin_unlock(&fs_info->fs_roots_radix_lock);
1077 * defrag a given btree.
1078 * Every leaf in the btree is read and defragged.
1080 int btrfs_defrag_root(struct btrfs_root *root)
1082 struct btrfs_fs_info *info = root->fs_info;
1083 struct btrfs_trans_handle *trans;
1086 if (xchg(&root->defrag_running, 1))
1090 trans = btrfs_start_transaction(root, 0);
1092 return PTR_ERR(trans);
1094 ret = btrfs_defrag_leaves(trans, root);
1096 btrfs_end_transaction(trans, root);
1097 btrfs_btree_balance_dirty(info->tree_root);
1100 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1103 if (btrfs_defrag_cancelled(root->fs_info)) {
1104 pr_debug("BTRFS: defrag_root cancelled\n");
1109 root->defrag_running = 0;
1114 * new snapshots need to be created at a very specific time in the
1115 * transaction commit. This does the actual creation.
1118 * If the error which may affect the commitment of the current transaction
1119 * happens, we should return the error number. If the error which just affect
1120 * the creation of the pending snapshots, just return 0.
1122 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1123 struct btrfs_fs_info *fs_info,
1124 struct btrfs_pending_snapshot *pending)
1126 struct btrfs_key key;
1127 struct btrfs_root_item *new_root_item;
1128 struct btrfs_root *tree_root = fs_info->tree_root;
1129 struct btrfs_root *root = pending->root;
1130 struct btrfs_root *parent_root;
1131 struct btrfs_block_rsv *rsv;
1132 struct inode *parent_inode;
1133 struct btrfs_path *path;
1134 struct btrfs_dir_item *dir_item;
1135 struct dentry *dentry;
1136 struct extent_buffer *tmp;
1137 struct extent_buffer *old;
1138 struct timespec cur_time = CURRENT_TIME;
1146 path = btrfs_alloc_path();
1148 pending->error = -ENOMEM;
1152 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1153 if (!new_root_item) {
1154 pending->error = -ENOMEM;
1155 goto root_item_alloc_fail;
1158 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1160 goto no_free_objectid;
1162 btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
1164 if (to_reserve > 0) {
1165 pending->error = btrfs_block_rsv_add(root,
1166 &pending->block_rsv,
1168 BTRFS_RESERVE_NO_FLUSH);
1170 goto no_free_objectid;
1173 pending->error = btrfs_qgroup_inherit(trans, fs_info,
1174 root->root_key.objectid,
1175 objectid, pending->inherit);
1177 goto no_free_objectid;
1179 key.objectid = objectid;
1180 key.offset = (u64)-1;
1181 key.type = BTRFS_ROOT_ITEM_KEY;
1183 rsv = trans->block_rsv;
1184 trans->block_rsv = &pending->block_rsv;
1185 trans->bytes_reserved = trans->block_rsv->reserved;
1187 dentry = pending->dentry;
1188 parent_inode = pending->dir;
1189 parent_root = BTRFS_I(parent_inode)->root;
1190 record_root_in_trans(trans, parent_root);
1193 * insert the directory item
1195 ret = btrfs_set_inode_index(parent_inode, &index);
1196 BUG_ON(ret); /* -ENOMEM */
1198 /* check if there is a file/dir which has the same name. */
1199 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1200 btrfs_ino(parent_inode),
1201 dentry->d_name.name,
1202 dentry->d_name.len, 0);
1203 if (dir_item != NULL && !IS_ERR(dir_item)) {
1204 pending->error = -EEXIST;
1205 goto dir_item_existed;
1206 } else if (IS_ERR(dir_item)) {
1207 ret = PTR_ERR(dir_item);
1208 btrfs_abort_transaction(trans, root, ret);
1211 btrfs_release_path(path);
1214 * pull in the delayed directory update
1215 * and the delayed inode item
1216 * otherwise we corrupt the FS during
1219 ret = btrfs_run_delayed_items(trans, root);
1220 if (ret) { /* Transaction aborted */
1221 btrfs_abort_transaction(trans, root, ret);
1225 record_root_in_trans(trans, root);
1226 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1227 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1228 btrfs_check_and_init_root_item(new_root_item);
1230 root_flags = btrfs_root_flags(new_root_item);
1231 if (pending->readonly)
1232 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1234 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1235 btrfs_set_root_flags(new_root_item, root_flags);
1237 btrfs_set_root_generation_v2(new_root_item,
1239 uuid_le_gen(&new_uuid);
1240 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1241 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1243 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1244 memset(new_root_item->received_uuid, 0,
1245 sizeof(new_root_item->received_uuid));
1246 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1247 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1248 btrfs_set_root_stransid(new_root_item, 0);
1249 btrfs_set_root_rtransid(new_root_item, 0);
1251 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1252 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1253 btrfs_set_root_otransid(new_root_item, trans->transid);
1255 old = btrfs_lock_root_node(root);
1256 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1258 btrfs_tree_unlock(old);
1259 free_extent_buffer(old);
1260 btrfs_abort_transaction(trans, root, ret);
1264 btrfs_set_lock_blocking(old);
1266 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1267 /* clean up in any case */
1268 btrfs_tree_unlock(old);
1269 free_extent_buffer(old);
1271 btrfs_abort_transaction(trans, root, ret);
1275 /* see comments in should_cow_block() */
1276 root->force_cow = 1;
1279 btrfs_set_root_node(new_root_item, tmp);
1280 /* record when the snapshot was created in key.offset */
1281 key.offset = trans->transid;
1282 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1283 btrfs_tree_unlock(tmp);
1284 free_extent_buffer(tmp);
1286 btrfs_abort_transaction(trans, root, ret);
1291 * insert root back/forward references
1293 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1294 parent_root->root_key.objectid,
1295 btrfs_ino(parent_inode), index,
1296 dentry->d_name.name, dentry->d_name.len);
1298 btrfs_abort_transaction(trans, root, ret);
1302 key.offset = (u64)-1;
1303 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1304 if (IS_ERR(pending->snap)) {
1305 ret = PTR_ERR(pending->snap);
1306 btrfs_abort_transaction(trans, root, ret);
1310 ret = btrfs_reloc_post_snapshot(trans, pending);
1312 btrfs_abort_transaction(trans, root, ret);
1316 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1318 btrfs_abort_transaction(trans, root, ret);
1322 ret = btrfs_insert_dir_item(trans, parent_root,
1323 dentry->d_name.name, dentry->d_name.len,
1325 BTRFS_FT_DIR, index);
1326 /* We have check then name at the beginning, so it is impossible. */
1327 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1329 btrfs_abort_transaction(trans, root, ret);
1333 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1334 dentry->d_name.len * 2);
1335 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1336 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1338 btrfs_abort_transaction(trans, root, ret);
1341 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1342 BTRFS_UUID_KEY_SUBVOL, objectid);
1344 btrfs_abort_transaction(trans, root, ret);
1347 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1348 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1349 new_root_item->received_uuid,
1350 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1352 if (ret && ret != -EEXIST) {
1353 btrfs_abort_transaction(trans, root, ret);
1358 pending->error = ret;
1360 trans->block_rsv = rsv;
1361 trans->bytes_reserved = 0;
1363 kfree(new_root_item);
1364 root_item_alloc_fail:
1365 btrfs_free_path(path);
1370 * create all the snapshots we've scheduled for creation
1372 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1373 struct btrfs_fs_info *fs_info)
1375 struct btrfs_pending_snapshot *pending, *next;
1376 struct list_head *head = &trans->transaction->pending_snapshots;
1379 list_for_each_entry_safe(pending, next, head, list) {
1380 list_del(&pending->list);
1381 ret = create_pending_snapshot(trans, fs_info, pending);
1388 static void update_super_roots(struct btrfs_root *root)
1390 struct btrfs_root_item *root_item;
1391 struct btrfs_super_block *super;
1393 super = root->fs_info->super_copy;
1395 root_item = &root->fs_info->chunk_root->root_item;
1396 super->chunk_root = root_item->bytenr;
1397 super->chunk_root_generation = root_item->generation;
1398 super->chunk_root_level = root_item->level;
1400 root_item = &root->fs_info->tree_root->root_item;
1401 super->root = root_item->bytenr;
1402 super->generation = root_item->generation;
1403 super->root_level = root_item->level;
1404 if (btrfs_test_opt(root, SPACE_CACHE))
1405 super->cache_generation = root_item->generation;
1406 if (root->fs_info->update_uuid_tree_gen)
1407 super->uuid_tree_generation = root_item->generation;
1410 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1412 struct btrfs_transaction *trans;
1415 spin_lock(&info->trans_lock);
1416 trans = info->running_transaction;
1418 ret = (trans->state >= TRANS_STATE_COMMIT_START);
1419 spin_unlock(&info->trans_lock);
1423 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1425 struct btrfs_transaction *trans;
1428 spin_lock(&info->trans_lock);
1429 trans = info->running_transaction;
1431 ret = is_transaction_blocked(trans);
1432 spin_unlock(&info->trans_lock);
1437 * wait for the current transaction commit to start and block subsequent
1440 static void wait_current_trans_commit_start(struct btrfs_root *root,
1441 struct btrfs_transaction *trans)
1443 wait_event(root->fs_info->transaction_blocked_wait,
1444 trans->state >= TRANS_STATE_COMMIT_START ||
1449 * wait for the current transaction to start and then become unblocked.
1452 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1453 struct btrfs_transaction *trans)
1455 wait_event(root->fs_info->transaction_wait,
1456 trans->state >= TRANS_STATE_UNBLOCKED ||
1461 * commit transactions asynchronously. once btrfs_commit_transaction_async
1462 * returns, any subsequent transaction will not be allowed to join.
1464 struct btrfs_async_commit {
1465 struct btrfs_trans_handle *newtrans;
1466 struct btrfs_root *root;
1467 struct work_struct work;
1470 static void do_async_commit(struct work_struct *work)
1472 struct btrfs_async_commit *ac =
1473 container_of(work, struct btrfs_async_commit, work);
1476 * We've got freeze protection passed with the transaction.
1477 * Tell lockdep about it.
1479 if (ac->newtrans->type & __TRANS_FREEZABLE)
1481 &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1484 current->journal_info = ac->newtrans;
1486 btrfs_commit_transaction(ac->newtrans, ac->root);
1490 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1491 struct btrfs_root *root,
1492 int wait_for_unblock)
1494 struct btrfs_async_commit *ac;
1495 struct btrfs_transaction *cur_trans;
1497 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1501 INIT_WORK(&ac->work, do_async_commit);
1503 ac->newtrans = btrfs_join_transaction(root);
1504 if (IS_ERR(ac->newtrans)) {
1505 int err = PTR_ERR(ac->newtrans);
1510 /* take transaction reference */
1511 cur_trans = trans->transaction;
1512 atomic_inc(&cur_trans->use_count);
1514 btrfs_end_transaction(trans, root);
1517 * Tell lockdep we've released the freeze rwsem, since the
1518 * async commit thread will be the one to unlock it.
1520 if (ac->newtrans->type & __TRANS_FREEZABLE)
1522 &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1525 schedule_work(&ac->work);
1527 /* wait for transaction to start and unblock */
1528 if (wait_for_unblock)
1529 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1531 wait_current_trans_commit_start(root, cur_trans);
1533 if (current->journal_info == trans)
1534 current->journal_info = NULL;
1536 btrfs_put_transaction(cur_trans);
1541 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1542 struct btrfs_root *root, int err)
1544 struct btrfs_transaction *cur_trans = trans->transaction;
1547 WARN_ON(trans->use_count > 1);
1549 btrfs_abort_transaction(trans, root, err);
1551 spin_lock(&root->fs_info->trans_lock);
1554 * If the transaction is removed from the list, it means this
1555 * transaction has been committed successfully, so it is impossible
1556 * to call the cleanup function.
1558 BUG_ON(list_empty(&cur_trans->list));
1560 list_del_init(&cur_trans->list);
1561 if (cur_trans == root->fs_info->running_transaction) {
1562 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1563 spin_unlock(&root->fs_info->trans_lock);
1564 wait_event(cur_trans->writer_wait,
1565 atomic_read(&cur_trans->num_writers) == 1);
1567 spin_lock(&root->fs_info->trans_lock);
1569 spin_unlock(&root->fs_info->trans_lock);
1571 btrfs_cleanup_one_transaction(trans->transaction, root);
1573 spin_lock(&root->fs_info->trans_lock);
1574 if (cur_trans == root->fs_info->running_transaction)
1575 root->fs_info->running_transaction = NULL;
1576 spin_unlock(&root->fs_info->trans_lock);
1578 if (trans->type & __TRANS_FREEZABLE)
1579 sb_end_intwrite(root->fs_info->sb);
1580 btrfs_put_transaction(cur_trans);
1581 btrfs_put_transaction(cur_trans);
1583 trace_btrfs_transaction_commit(root);
1585 btrfs_scrub_continue(root);
1587 if (current->journal_info == trans)
1588 current->journal_info = NULL;
1590 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1593 static int btrfs_flush_all_pending_stuffs(struct btrfs_trans_handle *trans,
1594 struct btrfs_root *root)
1598 ret = btrfs_run_delayed_items(trans, root);
1600 * running the delayed items may have added new refs. account
1601 * them now so that they hinder processing of more delayed refs
1602 * as little as possible.
1605 btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
1609 ret = btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
1614 * rename don't use btrfs_join_transaction, so, once we
1615 * set the transaction to blocked above, we aren't going
1616 * to get any new ordered operations. We can safely run
1617 * it here and no for sure that nothing new will be added
1620 ret = btrfs_run_ordered_operations(trans, root, 1);
1625 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1627 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1628 return btrfs_start_delalloc_roots(fs_info, 1);
1632 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1634 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1635 btrfs_wait_ordered_roots(fs_info, -1);
1638 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1639 struct btrfs_root *root)
1641 struct btrfs_transaction *cur_trans = trans->transaction;
1642 struct btrfs_transaction *prev_trans = NULL;
1645 ret = btrfs_run_ordered_operations(trans, root, 0);
1647 btrfs_abort_transaction(trans, root, ret);
1648 btrfs_end_transaction(trans, root);
1652 /* Stop the commit early if ->aborted is set */
1653 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1654 ret = cur_trans->aborted;
1655 btrfs_end_transaction(trans, root);
1659 /* make a pass through all the delayed refs we have so far
1660 * any runnings procs may add more while we are here
1662 ret = btrfs_run_delayed_refs(trans, root, 0);
1664 btrfs_end_transaction(trans, root);
1668 btrfs_trans_release_metadata(trans, root);
1669 trans->block_rsv = NULL;
1670 if (trans->qgroup_reserved) {
1671 btrfs_qgroup_free(root, trans->qgroup_reserved);
1672 trans->qgroup_reserved = 0;
1675 cur_trans = trans->transaction;
1678 * set the flushing flag so procs in this transaction have to
1679 * start sending their work down.
1681 cur_trans->delayed_refs.flushing = 1;
1684 if (!list_empty(&trans->new_bgs))
1685 btrfs_create_pending_block_groups(trans, root);
1687 ret = btrfs_run_delayed_refs(trans, root, 0);
1689 btrfs_end_transaction(trans, root);
1693 spin_lock(&root->fs_info->trans_lock);
1694 if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1695 spin_unlock(&root->fs_info->trans_lock);
1696 atomic_inc(&cur_trans->use_count);
1697 ret = btrfs_end_transaction(trans, root);
1699 wait_for_commit(root, cur_trans);
1701 btrfs_put_transaction(cur_trans);
1706 cur_trans->state = TRANS_STATE_COMMIT_START;
1707 wake_up(&root->fs_info->transaction_blocked_wait);
1709 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1710 prev_trans = list_entry(cur_trans->list.prev,
1711 struct btrfs_transaction, list);
1712 if (prev_trans->state != TRANS_STATE_COMPLETED) {
1713 atomic_inc(&prev_trans->use_count);
1714 spin_unlock(&root->fs_info->trans_lock);
1716 wait_for_commit(root, prev_trans);
1718 btrfs_put_transaction(prev_trans);
1720 spin_unlock(&root->fs_info->trans_lock);
1723 spin_unlock(&root->fs_info->trans_lock);
1726 extwriter_counter_dec(cur_trans, trans->type);
1728 ret = btrfs_start_delalloc_flush(root->fs_info);
1730 goto cleanup_transaction;
1732 ret = btrfs_flush_all_pending_stuffs(trans, root);
1734 goto cleanup_transaction;
1736 wait_event(cur_trans->writer_wait,
1737 extwriter_counter_read(cur_trans) == 0);
1739 /* some pending stuffs might be added after the previous flush. */
1740 ret = btrfs_flush_all_pending_stuffs(trans, root);
1742 goto cleanup_transaction;
1744 btrfs_wait_delalloc_flush(root->fs_info);
1746 btrfs_scrub_pause(root);
1748 * Ok now we need to make sure to block out any other joins while we
1749 * commit the transaction. We could have started a join before setting
1750 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1752 spin_lock(&root->fs_info->trans_lock);
1753 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1754 spin_unlock(&root->fs_info->trans_lock);
1755 wait_event(cur_trans->writer_wait,
1756 atomic_read(&cur_trans->num_writers) == 1);
1758 /* ->aborted might be set after the previous check, so check it */
1759 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1760 ret = cur_trans->aborted;
1761 goto cleanup_transaction;
1764 * the reloc mutex makes sure that we stop
1765 * the balancing code from coming in and moving
1766 * extents around in the middle of the commit
1768 mutex_lock(&root->fs_info->reloc_mutex);
1771 * We needn't worry about the delayed items because we will
1772 * deal with them in create_pending_snapshot(), which is the
1773 * core function of the snapshot creation.
1775 ret = create_pending_snapshots(trans, root->fs_info);
1777 mutex_unlock(&root->fs_info->reloc_mutex);
1778 goto cleanup_transaction;
1782 * We insert the dir indexes of the snapshots and update the inode
1783 * of the snapshots' parents after the snapshot creation, so there
1784 * are some delayed items which are not dealt with. Now deal with
1787 * We needn't worry that this operation will corrupt the snapshots,
1788 * because all the tree which are snapshoted will be forced to COW
1789 * the nodes and leaves.
1791 ret = btrfs_run_delayed_items(trans, root);
1793 mutex_unlock(&root->fs_info->reloc_mutex);
1794 goto cleanup_transaction;
1797 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1799 mutex_unlock(&root->fs_info->reloc_mutex);
1800 goto cleanup_transaction;
1804 * make sure none of the code above managed to slip in a
1807 btrfs_assert_delayed_root_empty(root);
1809 WARN_ON(cur_trans != trans->transaction);
1811 /* btrfs_commit_tree_roots is responsible for getting the
1812 * various roots consistent with each other. Every pointer
1813 * in the tree of tree roots has to point to the most up to date
1814 * root for every subvolume and other tree. So, we have to keep
1815 * the tree logging code from jumping in and changing any
1818 * At this point in the commit, there can't be any tree-log
1819 * writers, but a little lower down we drop the trans mutex
1820 * and let new people in. By holding the tree_log_mutex
1821 * from now until after the super is written, we avoid races
1822 * with the tree-log code.
1824 mutex_lock(&root->fs_info->tree_log_mutex);
1826 ret = commit_fs_roots(trans, root);
1828 mutex_unlock(&root->fs_info->tree_log_mutex);
1829 mutex_unlock(&root->fs_info->reloc_mutex);
1830 goto cleanup_transaction;
1833 /* commit_fs_roots gets rid of all the tree log roots, it is now
1834 * safe to free the root of tree log roots
1836 btrfs_free_log_root_tree(trans, root->fs_info);
1838 ret = commit_cowonly_roots(trans, root);
1840 mutex_unlock(&root->fs_info->tree_log_mutex);
1841 mutex_unlock(&root->fs_info->reloc_mutex);
1842 goto cleanup_transaction;
1846 * The tasks which save the space cache and inode cache may also
1847 * update ->aborted, check it.
1849 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1850 ret = cur_trans->aborted;
1851 mutex_unlock(&root->fs_info->tree_log_mutex);
1852 mutex_unlock(&root->fs_info->reloc_mutex);
1853 goto cleanup_transaction;
1856 btrfs_prepare_extent_commit(trans, root);
1858 cur_trans = root->fs_info->running_transaction;
1860 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1861 root->fs_info->tree_root->node);
1862 switch_commit_root(root->fs_info->tree_root);
1864 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1865 root->fs_info->chunk_root->node);
1866 switch_commit_root(root->fs_info->chunk_root);
1868 assert_qgroups_uptodate(trans);
1869 update_super_roots(root);
1871 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
1872 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
1873 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
1874 sizeof(*root->fs_info->super_copy));
1876 spin_lock(&root->fs_info->trans_lock);
1877 cur_trans->state = TRANS_STATE_UNBLOCKED;
1878 root->fs_info->running_transaction = NULL;
1879 spin_unlock(&root->fs_info->trans_lock);
1880 mutex_unlock(&root->fs_info->reloc_mutex);
1882 wake_up(&root->fs_info->transaction_wait);
1884 ret = btrfs_write_and_wait_transaction(trans, root);
1886 btrfs_error(root->fs_info, ret,
1887 "Error while writing out transaction");
1888 mutex_unlock(&root->fs_info->tree_log_mutex);
1889 goto cleanup_transaction;
1892 ret = write_ctree_super(trans, root, 0);
1894 mutex_unlock(&root->fs_info->tree_log_mutex);
1895 goto cleanup_transaction;
1899 * the super is written, we can safely allow the tree-loggers
1900 * to go about their business
1902 mutex_unlock(&root->fs_info->tree_log_mutex);
1904 btrfs_finish_extent_commit(trans, root);
1906 root->fs_info->last_trans_committed = cur_trans->transid;
1908 * We needn't acquire the lock here because there is no other task
1909 * which can change it.
1911 cur_trans->state = TRANS_STATE_COMPLETED;
1912 wake_up(&cur_trans->commit_wait);
1914 spin_lock(&root->fs_info->trans_lock);
1915 list_del_init(&cur_trans->list);
1916 spin_unlock(&root->fs_info->trans_lock);
1918 btrfs_put_transaction(cur_trans);
1919 btrfs_put_transaction(cur_trans);
1921 if (trans->type & __TRANS_FREEZABLE)
1922 sb_end_intwrite(root->fs_info->sb);
1924 trace_btrfs_transaction_commit(root);
1926 btrfs_scrub_continue(root);
1928 if (current->journal_info == trans)
1929 current->journal_info = NULL;
1931 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1933 if (current != root->fs_info->transaction_kthread)
1934 btrfs_run_delayed_iputs(root);
1938 cleanup_transaction:
1939 btrfs_trans_release_metadata(trans, root);
1940 trans->block_rsv = NULL;
1941 if (trans->qgroup_reserved) {
1942 btrfs_qgroup_free(root, trans->qgroup_reserved);
1943 trans->qgroup_reserved = 0;
1945 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
1946 if (current->journal_info == trans)
1947 current->journal_info = NULL;
1948 cleanup_transaction(trans, root, ret);
1954 * return < 0 if error
1955 * 0 if there are no more dead_roots at the time of call
1956 * 1 there are more to be processed, call me again
1958 * The return value indicates there are certainly more snapshots to delete, but
1959 * if there comes a new one during processing, it may return 0. We don't mind,
1960 * because btrfs_commit_super will poke cleaner thread and it will process it a
1961 * few seconds later.
1963 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
1966 struct btrfs_fs_info *fs_info = root->fs_info;
1968 spin_lock(&fs_info->trans_lock);
1969 if (list_empty(&fs_info->dead_roots)) {
1970 spin_unlock(&fs_info->trans_lock);
1973 root = list_first_entry(&fs_info->dead_roots,
1974 struct btrfs_root, root_list);
1975 list_del_init(&root->root_list);
1976 spin_unlock(&fs_info->trans_lock);
1978 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
1980 btrfs_kill_all_delayed_nodes(root);
1982 if (btrfs_header_backref_rev(root->node) <
1983 BTRFS_MIXED_BACKREF_REV)
1984 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
1986 ret = btrfs_drop_snapshot(root, NULL, 1, 0);
1988 * If we encounter a transaction abort during snapshot cleaning, we
1989 * don't want to crash here
1991 return (ret < 0) ? 0 : 1;