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 const 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 if (transaction->delayed_refs.pending_csums)
68 printk(KERN_ERR "pending csums is %llu\n",
69 transaction->delayed_refs.pending_csums);
70 while (!list_empty(&transaction->pending_chunks)) {
71 struct extent_map *em;
73 em = list_first_entry(&transaction->pending_chunks,
74 struct extent_map, list);
75 list_del_init(&em->list);
78 kmem_cache_free(btrfs_transaction_cachep, transaction);
82 static void clear_btree_io_tree(struct extent_io_tree *tree)
84 spin_lock(&tree->lock);
85 while (!RB_EMPTY_ROOT(&tree->state)) {
87 struct extent_state *state;
89 node = rb_first(&tree->state);
90 state = rb_entry(node, struct extent_state, rb_node);
91 rb_erase(&state->rb_node, &tree->state);
92 RB_CLEAR_NODE(&state->rb_node);
94 * btree io trees aren't supposed to have tasks waiting for
95 * changes in the flags of extent states ever.
97 ASSERT(!waitqueue_active(&state->wq));
98 free_extent_state(state);
100 cond_resched_lock(&tree->lock);
102 spin_unlock(&tree->lock);
105 static noinline void switch_commit_roots(struct btrfs_transaction *trans,
106 struct btrfs_fs_info *fs_info)
108 struct btrfs_root *root, *tmp;
110 down_write(&fs_info->commit_root_sem);
111 list_for_each_entry_safe(root, tmp, &trans->switch_commits,
113 list_del_init(&root->dirty_list);
114 free_extent_buffer(root->commit_root);
115 root->commit_root = btrfs_root_node(root);
116 if (is_fstree(root->objectid))
117 btrfs_unpin_free_ino(root);
118 clear_btree_io_tree(&root->dirty_log_pages);
121 /* We can free old roots now. */
122 spin_lock(&trans->dropped_roots_lock);
123 while (!list_empty(&trans->dropped_roots)) {
124 root = list_first_entry(&trans->dropped_roots,
125 struct btrfs_root, root_list);
126 list_del_init(&root->root_list);
127 spin_unlock(&trans->dropped_roots_lock);
128 btrfs_drop_and_free_fs_root(fs_info, root);
129 spin_lock(&trans->dropped_roots_lock);
131 spin_unlock(&trans->dropped_roots_lock);
132 up_write(&fs_info->commit_root_sem);
135 static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
138 if (type & TRANS_EXTWRITERS)
139 atomic_inc(&trans->num_extwriters);
142 static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
145 if (type & TRANS_EXTWRITERS)
146 atomic_dec(&trans->num_extwriters);
149 static inline void extwriter_counter_init(struct btrfs_transaction *trans,
152 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
155 static inline int extwriter_counter_read(struct btrfs_transaction *trans)
157 return atomic_read(&trans->num_extwriters);
161 * either allocate a new transaction or hop into the existing one
163 static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
165 struct btrfs_transaction *cur_trans;
166 struct btrfs_fs_info *fs_info = root->fs_info;
168 spin_lock(&fs_info->trans_lock);
170 /* The file system has been taken offline. No new transactions. */
171 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
172 spin_unlock(&fs_info->trans_lock);
176 cur_trans = fs_info->running_transaction;
178 if (cur_trans->aborted) {
179 spin_unlock(&fs_info->trans_lock);
180 return cur_trans->aborted;
182 if (btrfs_blocked_trans_types[cur_trans->state] & type) {
183 spin_unlock(&fs_info->trans_lock);
186 atomic_inc(&cur_trans->use_count);
187 atomic_inc(&cur_trans->num_writers);
188 extwriter_counter_inc(cur_trans, type);
189 spin_unlock(&fs_info->trans_lock);
192 spin_unlock(&fs_info->trans_lock);
195 * If we are ATTACH, we just want to catch the current transaction,
196 * and commit it. If there is no transaction, just return ENOENT.
198 if (type == TRANS_ATTACH)
202 * JOIN_NOLOCK only happens during the transaction commit, so
203 * it is impossible that ->running_transaction is NULL
205 BUG_ON(type == TRANS_JOIN_NOLOCK);
207 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
211 spin_lock(&fs_info->trans_lock);
212 if (fs_info->running_transaction) {
214 * someone started a transaction after we unlocked. Make sure
215 * to redo the checks above
217 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
219 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
220 spin_unlock(&fs_info->trans_lock);
221 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
225 atomic_set(&cur_trans->num_writers, 1);
226 extwriter_counter_init(cur_trans, type);
227 init_waitqueue_head(&cur_trans->writer_wait);
228 init_waitqueue_head(&cur_trans->commit_wait);
229 cur_trans->state = TRANS_STATE_RUNNING;
231 * One for this trans handle, one so it will live on until we
232 * commit the transaction.
234 atomic_set(&cur_trans->use_count, 2);
235 cur_trans->have_free_bgs = 0;
236 cur_trans->start_time = get_seconds();
237 cur_trans->dirty_bg_run = 0;
239 cur_trans->delayed_refs.href_root = RB_ROOT;
240 cur_trans->delayed_refs.dirty_extent_root = RB_ROOT;
241 atomic_set(&cur_trans->delayed_refs.num_entries, 0);
242 cur_trans->delayed_refs.num_heads_ready = 0;
243 cur_trans->delayed_refs.pending_csums = 0;
244 cur_trans->delayed_refs.num_heads = 0;
245 cur_trans->delayed_refs.flushing = 0;
246 cur_trans->delayed_refs.run_delayed_start = 0;
247 cur_trans->delayed_refs.qgroup_to_skip = 0;
250 * although the tree mod log is per file system and not per transaction,
251 * the log must never go across transaction boundaries.
254 if (!list_empty(&fs_info->tree_mod_seq_list))
255 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
256 "creating a fresh transaction\n");
257 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
258 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
259 "creating a fresh transaction\n");
260 atomic64_set(&fs_info->tree_mod_seq, 0);
262 spin_lock_init(&cur_trans->delayed_refs.lock);
264 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
265 INIT_LIST_HEAD(&cur_trans->pending_chunks);
266 INIT_LIST_HEAD(&cur_trans->switch_commits);
267 INIT_LIST_HEAD(&cur_trans->pending_ordered);
268 INIT_LIST_HEAD(&cur_trans->dirty_bgs);
269 INIT_LIST_HEAD(&cur_trans->io_bgs);
270 INIT_LIST_HEAD(&cur_trans->dropped_roots);
271 mutex_init(&cur_trans->cache_write_mutex);
272 cur_trans->num_dirty_bgs = 0;
273 spin_lock_init(&cur_trans->dirty_bgs_lock);
274 INIT_LIST_HEAD(&cur_trans->deleted_bgs);
275 spin_lock_init(&cur_trans->deleted_bgs_lock);
276 spin_lock_init(&cur_trans->dropped_roots_lock);
277 list_add_tail(&cur_trans->list, &fs_info->trans_list);
278 extent_io_tree_init(&cur_trans->dirty_pages,
279 fs_info->btree_inode->i_mapping);
280 fs_info->generation++;
281 cur_trans->transid = fs_info->generation;
282 fs_info->running_transaction = cur_trans;
283 cur_trans->aborted = 0;
284 spin_unlock(&fs_info->trans_lock);
290 * this does all the record keeping required to make sure that a reference
291 * counted root is properly recorded in a given transaction. This is required
292 * to make sure the old root from before we joined the transaction is deleted
293 * when the transaction commits
295 static int record_root_in_trans(struct btrfs_trans_handle *trans,
296 struct btrfs_root *root)
298 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
299 root->last_trans < trans->transid) {
300 WARN_ON(root == root->fs_info->extent_root);
301 WARN_ON(root->commit_root != root->node);
304 * see below for IN_TRANS_SETUP usage rules
305 * we have the reloc mutex held now, so there
306 * is only one writer in this function
308 set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
310 /* make sure readers find IN_TRANS_SETUP before
311 * they find our root->last_trans update
315 spin_lock(&root->fs_info->fs_roots_radix_lock);
316 if (root->last_trans == trans->transid) {
317 spin_unlock(&root->fs_info->fs_roots_radix_lock);
320 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
321 (unsigned long)root->root_key.objectid,
322 BTRFS_ROOT_TRANS_TAG);
323 spin_unlock(&root->fs_info->fs_roots_radix_lock);
324 root->last_trans = trans->transid;
326 /* this is pretty tricky. We don't want to
327 * take the relocation lock in btrfs_record_root_in_trans
328 * unless we're really doing the first setup for this root in
331 * Normally we'd use root->last_trans as a flag to decide
332 * if we want to take the expensive mutex.
334 * But, we have to set root->last_trans before we
335 * init the relocation root, otherwise, we trip over warnings
336 * in ctree.c. The solution used here is to flag ourselves
337 * with root IN_TRANS_SETUP. When this is 1, we're still
338 * fixing up the reloc trees and everyone must wait.
340 * When this is zero, they can trust root->last_trans and fly
341 * through btrfs_record_root_in_trans without having to take the
342 * lock. smp_wmb() makes sure that all the writes above are
343 * done before we pop in the zero below
345 btrfs_init_reloc_root(trans, root);
346 smp_mb__before_atomic();
347 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
353 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
354 struct btrfs_root *root)
356 struct btrfs_transaction *cur_trans = trans->transaction;
358 /* Add ourselves to the transaction dropped list */
359 spin_lock(&cur_trans->dropped_roots_lock);
360 list_add_tail(&root->root_list, &cur_trans->dropped_roots);
361 spin_unlock(&cur_trans->dropped_roots_lock);
363 /* Make sure we don't try to update the root at commit time */
364 spin_lock(&root->fs_info->fs_roots_radix_lock);
365 radix_tree_tag_clear(&root->fs_info->fs_roots_radix,
366 (unsigned long)root->root_key.objectid,
367 BTRFS_ROOT_TRANS_TAG);
368 spin_unlock(&root->fs_info->fs_roots_radix_lock);
371 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
372 struct btrfs_root *root)
374 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
378 * see record_root_in_trans for comments about IN_TRANS_SETUP usage
382 if (root->last_trans == trans->transid &&
383 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state))
386 mutex_lock(&root->fs_info->reloc_mutex);
387 record_root_in_trans(trans, root);
388 mutex_unlock(&root->fs_info->reloc_mutex);
393 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
395 return (trans->state >= TRANS_STATE_BLOCKED &&
396 trans->state < TRANS_STATE_UNBLOCKED &&
400 /* wait for commit against the current transaction to become unblocked
401 * when this is done, it is safe to start a new transaction, but the current
402 * transaction might not be fully on disk.
404 static void wait_current_trans(struct btrfs_root *root)
406 struct btrfs_transaction *cur_trans;
408 spin_lock(&root->fs_info->trans_lock);
409 cur_trans = root->fs_info->running_transaction;
410 if (cur_trans && is_transaction_blocked(cur_trans)) {
411 atomic_inc(&cur_trans->use_count);
412 spin_unlock(&root->fs_info->trans_lock);
414 wait_event(root->fs_info->transaction_wait,
415 cur_trans->state >= TRANS_STATE_UNBLOCKED ||
417 btrfs_put_transaction(cur_trans);
419 spin_unlock(&root->fs_info->trans_lock);
423 static int may_wait_transaction(struct btrfs_root *root, int type)
425 if (root->fs_info->log_root_recovering)
428 if (type == TRANS_USERSPACE)
431 if (type == TRANS_START &&
432 !atomic_read(&root->fs_info->open_ioctl_trans))
438 static inline bool need_reserve_reloc_root(struct btrfs_root *root)
440 if (!root->fs_info->reloc_ctl ||
441 !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
442 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
449 static struct btrfs_trans_handle *
450 start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
451 enum btrfs_reserve_flush_enum flush)
453 struct btrfs_trans_handle *h;
454 struct btrfs_transaction *cur_trans;
456 u64 qgroup_reserved = 0;
457 bool reloc_reserved = false;
460 /* Send isn't supposed to start transactions. */
461 ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
463 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
464 return ERR_PTR(-EROFS);
466 if (current->journal_info) {
467 WARN_ON(type & TRANS_EXTWRITERS);
468 h = current->journal_info;
470 WARN_ON(h->use_count > 2);
471 h->orig_rsv = h->block_rsv;
477 * Do the reservation before we join the transaction so we can do all
478 * the appropriate flushing if need be.
480 if (num_items > 0 && root != root->fs_info->chunk_root) {
481 if (root->fs_info->quota_enabled &&
482 is_fstree(root->root_key.objectid)) {
483 qgroup_reserved = num_items * root->nodesize;
484 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
489 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
491 * Do the reservation for the relocation root creation
493 if (need_reserve_reloc_root(root)) {
494 num_bytes += root->nodesize;
495 reloc_reserved = true;
498 ret = btrfs_block_rsv_add(root,
499 &root->fs_info->trans_block_rsv,
505 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
512 * If we are JOIN_NOLOCK we're already committing a transaction and
513 * waiting on this guy, so we don't need to do the sb_start_intwrite
514 * because we're already holding a ref. We need this because we could
515 * have raced in and did an fsync() on a file which can kick a commit
516 * and then we deadlock with somebody doing a freeze.
518 * If we are ATTACH, it means we just want to catch the current
519 * transaction and commit it, so we needn't do sb_start_intwrite().
521 if (type & __TRANS_FREEZABLE)
522 sb_start_intwrite(root->fs_info->sb);
524 if (may_wait_transaction(root, type))
525 wait_current_trans(root);
528 ret = join_transaction(root, type);
530 wait_current_trans(root);
531 if (unlikely(type == TRANS_ATTACH))
534 } while (ret == -EBUSY);
537 /* We must get the transaction if we are JOIN_NOLOCK. */
538 BUG_ON(type == TRANS_JOIN_NOLOCK);
542 cur_trans = root->fs_info->running_transaction;
544 h->transid = cur_trans->transid;
545 h->transaction = cur_trans;
547 h->bytes_reserved = 0;
548 h->chunk_bytes_reserved = 0;
550 h->delayed_ref_updates = 0;
556 h->qgroup_reserved = 0;
557 h->delayed_ref_elem.seq = 0;
559 h->allocating_chunk = false;
560 h->can_flush_pending_bgs = true;
561 h->reloc_reserved = false;
563 INIT_LIST_HEAD(&h->qgroup_ref_list);
564 INIT_LIST_HEAD(&h->new_bgs);
565 INIT_LIST_HEAD(&h->ordered);
568 if (cur_trans->state >= TRANS_STATE_BLOCKED &&
569 may_wait_transaction(root, type)) {
570 current->journal_info = h;
571 btrfs_commit_transaction(h, root);
576 trace_btrfs_space_reservation(root->fs_info, "transaction",
577 h->transid, num_bytes, 1);
578 h->block_rsv = &root->fs_info->trans_block_rsv;
579 h->bytes_reserved = num_bytes;
580 h->reloc_reserved = reloc_reserved;
582 h->qgroup_reserved = qgroup_reserved;
585 btrfs_record_root_in_trans(h, root);
587 if (!current->journal_info && type != TRANS_USERSPACE)
588 current->journal_info = h;
592 if (type & __TRANS_FREEZABLE)
593 sb_end_intwrite(root->fs_info->sb);
594 kmem_cache_free(btrfs_trans_handle_cachep, h);
597 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
601 btrfs_qgroup_free(root, qgroup_reserved);
605 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
608 return start_transaction(root, num_items, TRANS_START,
609 BTRFS_RESERVE_FLUSH_ALL);
612 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
613 struct btrfs_root *root, int num_items)
615 return start_transaction(root, num_items, TRANS_START,
616 BTRFS_RESERVE_FLUSH_LIMIT);
619 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
621 return start_transaction(root, 0, TRANS_JOIN, 0);
624 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
626 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
629 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
631 return start_transaction(root, 0, TRANS_USERSPACE, 0);
635 * btrfs_attach_transaction() - catch the running transaction
637 * It is used when we want to commit the current the transaction, but
638 * don't want to start a new one.
640 * Note: If this function return -ENOENT, it just means there is no
641 * running transaction. But it is possible that the inactive transaction
642 * is still in the memory, not fully on disk. If you hope there is no
643 * inactive transaction in the fs when -ENOENT is returned, you should
645 * btrfs_attach_transaction_barrier()
647 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
649 return start_transaction(root, 0, TRANS_ATTACH, 0);
653 * btrfs_attach_transaction_barrier() - catch the running transaction
655 * It is similar to the above function, the differentia is this one
656 * will wait for all the inactive transactions until they fully
659 struct btrfs_trans_handle *
660 btrfs_attach_transaction_barrier(struct btrfs_root *root)
662 struct btrfs_trans_handle *trans;
664 trans = start_transaction(root, 0, TRANS_ATTACH, 0);
665 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
666 btrfs_wait_for_commit(root, 0);
671 /* wait for a transaction commit to be fully complete */
672 static noinline void wait_for_commit(struct btrfs_root *root,
673 struct btrfs_transaction *commit)
675 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
678 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
680 struct btrfs_transaction *cur_trans = NULL, *t;
684 if (transid <= root->fs_info->last_trans_committed)
687 /* find specified transaction */
688 spin_lock(&root->fs_info->trans_lock);
689 list_for_each_entry(t, &root->fs_info->trans_list, list) {
690 if (t->transid == transid) {
692 atomic_inc(&cur_trans->use_count);
696 if (t->transid > transid) {
701 spin_unlock(&root->fs_info->trans_lock);
704 * The specified transaction doesn't exist, or we
705 * raced with btrfs_commit_transaction
708 if (transid > root->fs_info->last_trans_committed)
713 /* find newest transaction that is committing | committed */
714 spin_lock(&root->fs_info->trans_lock);
715 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
717 if (t->state >= TRANS_STATE_COMMIT_START) {
718 if (t->state == TRANS_STATE_COMPLETED)
721 atomic_inc(&cur_trans->use_count);
725 spin_unlock(&root->fs_info->trans_lock);
727 goto out; /* nothing committing|committed */
730 wait_for_commit(root, cur_trans);
731 btrfs_put_transaction(cur_trans);
736 void btrfs_throttle(struct btrfs_root *root)
738 if (!atomic_read(&root->fs_info->open_ioctl_trans))
739 wait_current_trans(root);
742 static int should_end_transaction(struct btrfs_trans_handle *trans,
743 struct btrfs_root *root)
745 if (root->fs_info->global_block_rsv.space_info->full &&
746 btrfs_check_space_for_delayed_refs(trans, root))
749 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
752 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
753 struct btrfs_root *root)
755 struct btrfs_transaction *cur_trans = trans->transaction;
760 if (cur_trans->state >= TRANS_STATE_BLOCKED ||
761 cur_trans->delayed_refs.flushing)
764 updates = trans->delayed_ref_updates;
765 trans->delayed_ref_updates = 0;
767 err = btrfs_run_delayed_refs(trans, root, updates * 2);
768 if (err) /* Error code will also eval true */
772 return should_end_transaction(trans, root);
775 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
776 struct btrfs_root *root, int throttle)
778 struct btrfs_transaction *cur_trans = trans->transaction;
779 struct btrfs_fs_info *info = root->fs_info;
780 unsigned long cur = trans->delayed_ref_updates;
781 int lock = (trans->type != TRANS_JOIN_NOLOCK);
783 int must_run_delayed_refs = 0;
785 if (trans->use_count > 1) {
787 trans->block_rsv = trans->orig_rsv;
791 btrfs_trans_release_metadata(trans, root);
792 trans->block_rsv = NULL;
794 if (!list_empty(&trans->new_bgs))
795 btrfs_create_pending_block_groups(trans, root);
797 if (!list_empty(&trans->ordered)) {
798 spin_lock(&info->trans_lock);
799 list_splice_init(&trans->ordered, &cur_trans->pending_ordered);
800 spin_unlock(&info->trans_lock);
803 trans->delayed_ref_updates = 0;
805 must_run_delayed_refs =
806 btrfs_should_throttle_delayed_refs(trans, root);
807 cur = max_t(unsigned long, cur, 32);
810 * don't make the caller wait if they are from a NOLOCK
811 * or ATTACH transaction, it will deadlock with commit
813 if (must_run_delayed_refs == 1 &&
814 (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
815 must_run_delayed_refs = 2;
818 if (trans->qgroup_reserved) {
820 * the same root has to be passed here between start_transaction
821 * and end_transaction. Subvolume quota depends on this.
823 btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
824 trans->qgroup_reserved = 0;
827 btrfs_trans_release_metadata(trans, root);
828 trans->block_rsv = NULL;
830 if (!list_empty(&trans->new_bgs))
831 btrfs_create_pending_block_groups(trans, root);
833 btrfs_trans_release_chunk_metadata(trans);
835 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
836 should_end_transaction(trans, root) &&
837 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
838 spin_lock(&info->trans_lock);
839 if (cur_trans->state == TRANS_STATE_RUNNING)
840 cur_trans->state = TRANS_STATE_BLOCKED;
841 spin_unlock(&info->trans_lock);
844 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
846 return btrfs_commit_transaction(trans, root);
848 wake_up_process(info->transaction_kthread);
851 if (trans->type & __TRANS_FREEZABLE)
852 sb_end_intwrite(root->fs_info->sb);
854 WARN_ON(cur_trans != info->running_transaction);
855 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
856 atomic_dec(&cur_trans->num_writers);
857 extwriter_counter_dec(cur_trans, trans->type);
860 if (waitqueue_active(&cur_trans->writer_wait))
861 wake_up(&cur_trans->writer_wait);
862 btrfs_put_transaction(cur_trans);
864 if (current->journal_info == trans)
865 current->journal_info = NULL;
868 btrfs_run_delayed_iputs(root);
870 if (trans->aborted ||
871 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
872 wake_up_process(info->transaction_kthread);
875 assert_qgroups_uptodate(trans);
877 kmem_cache_free(btrfs_trans_handle_cachep, trans);
878 if (must_run_delayed_refs) {
879 btrfs_async_run_delayed_refs(root, cur,
880 must_run_delayed_refs == 1);
885 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
886 struct btrfs_root *root)
888 return __btrfs_end_transaction(trans, root, 0);
891 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
892 struct btrfs_root *root)
894 return __btrfs_end_transaction(trans, root, 1);
898 * when btree blocks are allocated, they have some corresponding bits set for
899 * them in one of two extent_io trees. This is used to make sure all of
900 * those extents are sent to disk but does not wait on them
902 int btrfs_write_marked_extents(struct btrfs_root *root,
903 struct extent_io_tree *dirty_pages, int mark)
907 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
908 struct extent_state *cached_state = NULL;
912 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
913 mark, &cached_state)) {
914 bool wait_writeback = false;
916 err = convert_extent_bit(dirty_pages, start, end,
918 mark, &cached_state, GFP_NOFS);
920 * convert_extent_bit can return -ENOMEM, which is most of the
921 * time a temporary error. So when it happens, ignore the error
922 * and wait for writeback of this range to finish - because we
923 * failed to set the bit EXTENT_NEED_WAIT for the range, a call
924 * to btrfs_wait_marked_extents() would not know that writeback
925 * for this range started and therefore wouldn't wait for it to
926 * finish - we don't want to commit a superblock that points to
927 * btree nodes/leafs for which writeback hasn't finished yet
928 * (and without errors).
929 * We cleanup any entries left in the io tree when committing
930 * the transaction (through clear_btree_io_tree()).
932 if (err == -ENOMEM) {
934 wait_writeback = true;
937 err = filemap_fdatawrite_range(mapping, start, end);
940 else if (wait_writeback)
941 werr = filemap_fdatawait_range(mapping, start, end);
942 free_extent_state(cached_state);
951 * when btree blocks are allocated, they have some corresponding bits set for
952 * them in one of two extent_io trees. This is used to make sure all of
953 * those extents are on disk for transaction or log commit. We wait
954 * on all the pages and clear them from the dirty pages state tree
956 int btrfs_wait_marked_extents(struct btrfs_root *root,
957 struct extent_io_tree *dirty_pages, int mark)
961 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
962 struct extent_state *cached_state = NULL;
965 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
968 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
969 EXTENT_NEED_WAIT, &cached_state)) {
971 * Ignore -ENOMEM errors returned by clear_extent_bit().
972 * When committing the transaction, we'll remove any entries
973 * left in the io tree. For a log commit, we don't remove them
974 * after committing the log because the tree can be accessed
975 * concurrently - we do it only at transaction commit time when
976 * it's safe to do it (through clear_btree_io_tree()).
978 err = clear_extent_bit(dirty_pages, start, end,
980 0, 0, &cached_state, GFP_NOFS);
984 err = filemap_fdatawait_range(mapping, start, end);
987 free_extent_state(cached_state);
995 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
996 if ((mark & EXTENT_DIRTY) &&
997 test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
998 &btree_ino->runtime_flags))
1001 if ((mark & EXTENT_NEW) &&
1002 test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
1003 &btree_ino->runtime_flags))
1006 if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
1007 &btree_ino->runtime_flags))
1011 if (errors && !werr)
1018 * when btree blocks are allocated, they have some corresponding bits set for
1019 * them in one of two extent_io trees. This is used to make sure all of
1020 * those extents are on disk for transaction or log commit
1022 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
1023 struct extent_io_tree *dirty_pages, int mark)
1027 struct blk_plug plug;
1029 blk_start_plug(&plug);
1030 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
1031 blk_finish_plug(&plug);
1032 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
1041 static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
1042 struct btrfs_root *root)
1046 ret = btrfs_write_and_wait_marked_extents(root,
1047 &trans->transaction->dirty_pages,
1049 clear_btree_io_tree(&trans->transaction->dirty_pages);
1055 * this is used to update the root pointer in the tree of tree roots.
1057 * But, in the case of the extent allocation tree, updating the root
1058 * pointer may allocate blocks which may change the root of the extent
1061 * So, this loops and repeats and makes sure the cowonly root didn't
1062 * change while the root pointer was being updated in the metadata.
1064 static int update_cowonly_root(struct btrfs_trans_handle *trans,
1065 struct btrfs_root *root)
1068 u64 old_root_bytenr;
1070 struct btrfs_root *tree_root = root->fs_info->tree_root;
1072 old_root_used = btrfs_root_used(&root->root_item);
1075 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
1076 if (old_root_bytenr == root->node->start &&
1077 old_root_used == btrfs_root_used(&root->root_item))
1080 btrfs_set_root_node(&root->root_item, root->node);
1081 ret = btrfs_update_root(trans, tree_root,
1087 old_root_used = btrfs_root_used(&root->root_item);
1094 * update all the cowonly tree roots on disk
1096 * The error handling in this function may not be obvious. Any of the
1097 * failures will cause the file system to go offline. We still need
1098 * to clean up the delayed refs.
1100 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
1101 struct btrfs_root *root)
1103 struct btrfs_fs_info *fs_info = root->fs_info;
1104 struct list_head *dirty_bgs = &trans->transaction->dirty_bgs;
1105 struct list_head *io_bgs = &trans->transaction->io_bgs;
1106 struct list_head *next;
1107 struct extent_buffer *eb;
1110 eb = btrfs_lock_root_node(fs_info->tree_root);
1111 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
1113 btrfs_tree_unlock(eb);
1114 free_extent_buffer(eb);
1119 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1123 ret = btrfs_run_dev_stats(trans, root->fs_info);
1126 ret = btrfs_run_dev_replace(trans, root->fs_info);
1129 ret = btrfs_run_qgroups(trans, root->fs_info);
1133 ret = btrfs_setup_space_cache(trans, root);
1137 /* run_qgroups might have added some more refs */
1138 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1142 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
1143 next = fs_info->dirty_cowonly_roots.next;
1144 list_del_init(next);
1145 root = list_entry(next, struct btrfs_root, dirty_list);
1146 clear_bit(BTRFS_ROOT_DIRTY, &root->state);
1148 if (root != fs_info->extent_root)
1149 list_add_tail(&root->dirty_list,
1150 &trans->transaction->switch_commits);
1151 ret = update_cowonly_root(trans, root);
1154 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1159 while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) {
1160 ret = btrfs_write_dirty_block_groups(trans, root);
1163 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1168 if (!list_empty(&fs_info->dirty_cowonly_roots))
1171 list_add_tail(&fs_info->extent_root->dirty_list,
1172 &trans->transaction->switch_commits);
1173 btrfs_after_dev_replace_commit(fs_info);
1179 * dead roots are old snapshots that need to be deleted. This allocates
1180 * a dirty root struct and adds it into the list of dead roots that need to
1183 void btrfs_add_dead_root(struct btrfs_root *root)
1185 spin_lock(&root->fs_info->trans_lock);
1186 if (list_empty(&root->root_list))
1187 list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1188 spin_unlock(&root->fs_info->trans_lock);
1192 * update all the cowonly tree roots on disk
1194 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1195 struct btrfs_root *root)
1197 struct btrfs_root *gang[8];
1198 struct btrfs_fs_info *fs_info = root->fs_info;
1203 spin_lock(&fs_info->fs_roots_radix_lock);
1205 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1208 BTRFS_ROOT_TRANS_TAG);
1211 for (i = 0; i < ret; i++) {
1213 radix_tree_tag_clear(&fs_info->fs_roots_radix,
1214 (unsigned long)root->root_key.objectid,
1215 BTRFS_ROOT_TRANS_TAG);
1216 spin_unlock(&fs_info->fs_roots_radix_lock);
1218 btrfs_free_log(trans, root);
1219 btrfs_update_reloc_root(trans, root);
1220 btrfs_orphan_commit_root(trans, root);
1222 btrfs_save_ino_cache(root, trans);
1224 /* see comments in should_cow_block() */
1225 clear_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1226 smp_mb__after_atomic();
1228 if (root->commit_root != root->node) {
1229 list_add_tail(&root->dirty_list,
1230 &trans->transaction->switch_commits);
1231 btrfs_set_root_node(&root->root_item,
1235 err = btrfs_update_root(trans, fs_info->tree_root,
1238 spin_lock(&fs_info->fs_roots_radix_lock);
1243 spin_unlock(&fs_info->fs_roots_radix_lock);
1248 * defrag a given btree.
1249 * Every leaf in the btree is read and defragged.
1251 int btrfs_defrag_root(struct btrfs_root *root)
1253 struct btrfs_fs_info *info = root->fs_info;
1254 struct btrfs_trans_handle *trans;
1257 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
1261 trans = btrfs_start_transaction(root, 0);
1263 return PTR_ERR(trans);
1265 ret = btrfs_defrag_leaves(trans, root);
1267 btrfs_end_transaction(trans, root);
1268 btrfs_btree_balance_dirty(info->tree_root);
1271 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1274 if (btrfs_defrag_cancelled(root->fs_info)) {
1275 pr_debug("BTRFS: defrag_root cancelled\n");
1280 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
1285 * new snapshots need to be created at a very specific time in the
1286 * transaction commit. This does the actual creation.
1289 * If the error which may affect the commitment of the current transaction
1290 * happens, we should return the error number. If the error which just affect
1291 * the creation of the pending snapshots, just return 0.
1293 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1294 struct btrfs_fs_info *fs_info,
1295 struct btrfs_pending_snapshot *pending)
1297 struct btrfs_key key;
1298 struct btrfs_root_item *new_root_item;
1299 struct btrfs_root *tree_root = fs_info->tree_root;
1300 struct btrfs_root *root = pending->root;
1301 struct btrfs_root *parent_root;
1302 struct btrfs_block_rsv *rsv;
1303 struct inode *parent_inode;
1304 struct btrfs_path *path;
1305 struct btrfs_dir_item *dir_item;
1306 struct dentry *dentry;
1307 struct extent_buffer *tmp;
1308 struct extent_buffer *old;
1309 struct timespec cur_time = CURRENT_TIME;
1317 path = btrfs_alloc_path();
1319 pending->error = -ENOMEM;
1323 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1324 if (!new_root_item) {
1325 pending->error = -ENOMEM;
1326 goto root_item_alloc_fail;
1329 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1331 goto no_free_objectid;
1334 * Make qgroup to skip current new snapshot's qgroupid, as it is
1335 * accounted by later btrfs_qgroup_inherit().
1337 btrfs_set_skip_qgroup(trans, objectid);
1339 btrfs_reloc_pre_snapshot(pending, &to_reserve);
1341 if (to_reserve > 0) {
1342 pending->error = btrfs_block_rsv_add(root,
1343 &pending->block_rsv,
1345 BTRFS_RESERVE_NO_FLUSH);
1347 goto clear_skip_qgroup;
1350 key.objectid = objectid;
1351 key.offset = (u64)-1;
1352 key.type = BTRFS_ROOT_ITEM_KEY;
1354 rsv = trans->block_rsv;
1355 trans->block_rsv = &pending->block_rsv;
1356 trans->bytes_reserved = trans->block_rsv->reserved;
1358 dentry = pending->dentry;
1359 parent_inode = pending->dir;
1360 parent_root = BTRFS_I(parent_inode)->root;
1361 record_root_in_trans(trans, parent_root);
1364 * insert the directory item
1366 ret = btrfs_set_inode_index(parent_inode, &index);
1367 BUG_ON(ret); /* -ENOMEM */
1369 /* check if there is a file/dir which has the same name. */
1370 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1371 btrfs_ino(parent_inode),
1372 dentry->d_name.name,
1373 dentry->d_name.len, 0);
1374 if (dir_item != NULL && !IS_ERR(dir_item)) {
1375 pending->error = -EEXIST;
1376 goto dir_item_existed;
1377 } else if (IS_ERR(dir_item)) {
1378 ret = PTR_ERR(dir_item);
1379 btrfs_abort_transaction(trans, root, ret);
1382 btrfs_release_path(path);
1385 * pull in the delayed directory update
1386 * and the delayed inode item
1387 * otherwise we corrupt the FS during
1390 ret = btrfs_run_delayed_items(trans, root);
1391 if (ret) { /* Transaction aborted */
1392 btrfs_abort_transaction(trans, root, ret);
1396 record_root_in_trans(trans, root);
1397 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1398 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1399 btrfs_check_and_init_root_item(new_root_item);
1401 root_flags = btrfs_root_flags(new_root_item);
1402 if (pending->readonly)
1403 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1405 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1406 btrfs_set_root_flags(new_root_item, root_flags);
1408 btrfs_set_root_generation_v2(new_root_item,
1410 uuid_le_gen(&new_uuid);
1411 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1412 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1414 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1415 memset(new_root_item->received_uuid, 0,
1416 sizeof(new_root_item->received_uuid));
1417 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1418 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1419 btrfs_set_root_stransid(new_root_item, 0);
1420 btrfs_set_root_rtransid(new_root_item, 0);
1422 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1423 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1424 btrfs_set_root_otransid(new_root_item, trans->transid);
1426 old = btrfs_lock_root_node(root);
1427 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1429 btrfs_tree_unlock(old);
1430 free_extent_buffer(old);
1431 btrfs_abort_transaction(trans, root, ret);
1435 btrfs_set_lock_blocking(old);
1437 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1438 /* clean up in any case */
1439 btrfs_tree_unlock(old);
1440 free_extent_buffer(old);
1442 btrfs_abort_transaction(trans, root, ret);
1445 /* see comments in should_cow_block() */
1446 set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1449 btrfs_set_root_node(new_root_item, tmp);
1450 /* record when the snapshot was created in key.offset */
1451 key.offset = trans->transid;
1452 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1453 btrfs_tree_unlock(tmp);
1454 free_extent_buffer(tmp);
1456 btrfs_abort_transaction(trans, root, ret);
1461 * insert root back/forward references
1463 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1464 parent_root->root_key.objectid,
1465 btrfs_ino(parent_inode), index,
1466 dentry->d_name.name, dentry->d_name.len);
1468 btrfs_abort_transaction(trans, root, ret);
1472 key.offset = (u64)-1;
1473 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1474 if (IS_ERR(pending->snap)) {
1475 ret = PTR_ERR(pending->snap);
1476 btrfs_abort_transaction(trans, root, ret);
1480 ret = btrfs_reloc_post_snapshot(trans, pending);
1482 btrfs_abort_transaction(trans, root, ret);
1486 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1488 btrfs_abort_transaction(trans, root, ret);
1492 ret = btrfs_insert_dir_item(trans, parent_root,
1493 dentry->d_name.name, dentry->d_name.len,
1495 BTRFS_FT_DIR, index);
1496 /* We have check then name at the beginning, so it is impossible. */
1497 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1499 btrfs_abort_transaction(trans, root, ret);
1503 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1504 dentry->d_name.len * 2);
1505 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1506 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1508 btrfs_abort_transaction(trans, root, ret);
1511 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1512 BTRFS_UUID_KEY_SUBVOL, objectid);
1514 btrfs_abort_transaction(trans, root, ret);
1517 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1518 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1519 new_root_item->received_uuid,
1520 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1522 if (ret && ret != -EEXIST) {
1523 btrfs_abort_transaction(trans, root, ret);
1528 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1530 btrfs_abort_transaction(trans, root, ret);
1535 * account qgroup counters before qgroup_inherit()
1537 ret = btrfs_qgroup_prepare_account_extents(trans, fs_info);
1540 ret = btrfs_qgroup_account_extents(trans, fs_info);
1543 ret = btrfs_qgroup_inherit(trans, fs_info,
1544 root->root_key.objectid,
1545 objectid, pending->inherit);
1547 btrfs_abort_transaction(trans, root, ret);
1552 pending->error = ret;
1554 trans->block_rsv = rsv;
1555 trans->bytes_reserved = 0;
1557 btrfs_clear_skip_qgroup(trans);
1559 kfree(new_root_item);
1560 root_item_alloc_fail:
1561 btrfs_free_path(path);
1566 * create all the snapshots we've scheduled for creation
1568 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1569 struct btrfs_fs_info *fs_info)
1571 struct btrfs_pending_snapshot *pending, *next;
1572 struct list_head *head = &trans->transaction->pending_snapshots;
1575 list_for_each_entry_safe(pending, next, head, list) {
1576 list_del(&pending->list);
1577 ret = create_pending_snapshot(trans, fs_info, pending);
1584 static void update_super_roots(struct btrfs_root *root)
1586 struct btrfs_root_item *root_item;
1587 struct btrfs_super_block *super;
1589 super = root->fs_info->super_copy;
1591 root_item = &root->fs_info->chunk_root->root_item;
1592 super->chunk_root = root_item->bytenr;
1593 super->chunk_root_generation = root_item->generation;
1594 super->chunk_root_level = root_item->level;
1596 root_item = &root->fs_info->tree_root->root_item;
1597 super->root = root_item->bytenr;
1598 super->generation = root_item->generation;
1599 super->root_level = root_item->level;
1600 if (btrfs_test_opt(root, SPACE_CACHE))
1601 super->cache_generation = root_item->generation;
1602 if (root->fs_info->update_uuid_tree_gen)
1603 super->uuid_tree_generation = root_item->generation;
1606 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1608 struct btrfs_transaction *trans;
1611 spin_lock(&info->trans_lock);
1612 trans = info->running_transaction;
1614 ret = (trans->state >= TRANS_STATE_COMMIT_START);
1615 spin_unlock(&info->trans_lock);
1619 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1621 struct btrfs_transaction *trans;
1624 spin_lock(&info->trans_lock);
1625 trans = info->running_transaction;
1627 ret = is_transaction_blocked(trans);
1628 spin_unlock(&info->trans_lock);
1633 * wait for the current transaction commit to start and block subsequent
1636 static void wait_current_trans_commit_start(struct btrfs_root *root,
1637 struct btrfs_transaction *trans)
1639 wait_event(root->fs_info->transaction_blocked_wait,
1640 trans->state >= TRANS_STATE_COMMIT_START ||
1645 * wait for the current transaction to start and then become unblocked.
1648 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1649 struct btrfs_transaction *trans)
1651 wait_event(root->fs_info->transaction_wait,
1652 trans->state >= TRANS_STATE_UNBLOCKED ||
1657 * commit transactions asynchronously. once btrfs_commit_transaction_async
1658 * returns, any subsequent transaction will not be allowed to join.
1660 struct btrfs_async_commit {
1661 struct btrfs_trans_handle *newtrans;
1662 struct btrfs_root *root;
1663 struct work_struct work;
1666 static void do_async_commit(struct work_struct *work)
1668 struct btrfs_async_commit *ac =
1669 container_of(work, struct btrfs_async_commit, work);
1672 * We've got freeze protection passed with the transaction.
1673 * Tell lockdep about it.
1675 if (ac->newtrans->type & __TRANS_FREEZABLE)
1676 __sb_writers_acquired(ac->root->fs_info->sb, SB_FREEZE_FS);
1678 current->journal_info = ac->newtrans;
1680 btrfs_commit_transaction(ac->newtrans, ac->root);
1684 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1685 struct btrfs_root *root,
1686 int wait_for_unblock)
1688 struct btrfs_async_commit *ac;
1689 struct btrfs_transaction *cur_trans;
1691 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1695 INIT_WORK(&ac->work, do_async_commit);
1697 ac->newtrans = btrfs_join_transaction(root);
1698 if (IS_ERR(ac->newtrans)) {
1699 int err = PTR_ERR(ac->newtrans);
1704 /* take transaction reference */
1705 cur_trans = trans->transaction;
1706 atomic_inc(&cur_trans->use_count);
1708 btrfs_end_transaction(trans, root);
1711 * Tell lockdep we've released the freeze rwsem, since the
1712 * async commit thread will be the one to unlock it.
1714 if (ac->newtrans->type & __TRANS_FREEZABLE)
1715 __sb_writers_release(root->fs_info->sb, SB_FREEZE_FS);
1717 schedule_work(&ac->work);
1719 /* wait for transaction to start and unblock */
1720 if (wait_for_unblock)
1721 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1723 wait_current_trans_commit_start(root, cur_trans);
1725 if (current->journal_info == trans)
1726 current->journal_info = NULL;
1728 btrfs_put_transaction(cur_trans);
1733 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1734 struct btrfs_root *root, int err)
1736 struct btrfs_transaction *cur_trans = trans->transaction;
1739 WARN_ON(trans->use_count > 1);
1741 btrfs_abort_transaction(trans, root, err);
1743 spin_lock(&root->fs_info->trans_lock);
1746 * If the transaction is removed from the list, it means this
1747 * transaction has been committed successfully, so it is impossible
1748 * to call the cleanup function.
1750 BUG_ON(list_empty(&cur_trans->list));
1752 list_del_init(&cur_trans->list);
1753 if (cur_trans == root->fs_info->running_transaction) {
1754 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1755 spin_unlock(&root->fs_info->trans_lock);
1756 wait_event(cur_trans->writer_wait,
1757 atomic_read(&cur_trans->num_writers) == 1);
1759 spin_lock(&root->fs_info->trans_lock);
1761 spin_unlock(&root->fs_info->trans_lock);
1763 btrfs_cleanup_one_transaction(trans->transaction, root);
1765 spin_lock(&root->fs_info->trans_lock);
1766 if (cur_trans == root->fs_info->running_transaction)
1767 root->fs_info->running_transaction = NULL;
1768 spin_unlock(&root->fs_info->trans_lock);
1770 if (trans->type & __TRANS_FREEZABLE)
1771 sb_end_intwrite(root->fs_info->sb);
1772 btrfs_put_transaction(cur_trans);
1773 btrfs_put_transaction(cur_trans);
1775 trace_btrfs_transaction_commit(root);
1777 if (current->journal_info == trans)
1778 current->journal_info = NULL;
1779 btrfs_scrub_cancel(root->fs_info);
1781 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1784 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1786 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1787 return btrfs_start_delalloc_roots(fs_info, 1, -1);
1791 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1793 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1794 btrfs_wait_ordered_roots(fs_info, -1);
1798 btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans,
1799 struct btrfs_fs_info *fs_info)
1801 struct btrfs_ordered_extent *ordered;
1803 spin_lock(&fs_info->trans_lock);
1804 while (!list_empty(&cur_trans->pending_ordered)) {
1805 ordered = list_first_entry(&cur_trans->pending_ordered,
1806 struct btrfs_ordered_extent,
1808 list_del_init(&ordered->trans_list);
1809 spin_unlock(&fs_info->trans_lock);
1811 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_COMPLETE,
1813 btrfs_put_ordered_extent(ordered);
1814 spin_lock(&fs_info->trans_lock);
1816 spin_unlock(&fs_info->trans_lock);
1819 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1820 struct btrfs_root *root)
1822 struct btrfs_transaction *cur_trans = trans->transaction;
1823 struct btrfs_transaction *prev_trans = NULL;
1824 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
1827 /* Stop the commit early if ->aborted is set */
1828 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1829 ret = cur_trans->aborted;
1830 btrfs_end_transaction(trans, root);
1834 /* make a pass through all the delayed refs we have so far
1835 * any runnings procs may add more while we are here
1837 ret = btrfs_run_delayed_refs(trans, root, 0);
1839 btrfs_end_transaction(trans, root);
1843 btrfs_trans_release_metadata(trans, root);
1844 trans->block_rsv = NULL;
1845 if (trans->qgroup_reserved) {
1846 btrfs_qgroup_free(root, trans->qgroup_reserved);
1847 trans->qgroup_reserved = 0;
1850 cur_trans = trans->transaction;
1853 * set the flushing flag so procs in this transaction have to
1854 * start sending their work down.
1856 cur_trans->delayed_refs.flushing = 1;
1859 if (!list_empty(&trans->new_bgs))
1860 btrfs_create_pending_block_groups(trans, root);
1862 ret = btrfs_run_delayed_refs(trans, root, 0);
1864 btrfs_end_transaction(trans, root);
1868 if (!cur_trans->dirty_bg_run) {
1871 /* this mutex is also taken before trying to set
1872 * block groups readonly. We need to make sure
1873 * that nobody has set a block group readonly
1874 * after a extents from that block group have been
1875 * allocated for cache files. btrfs_set_block_group_ro
1876 * will wait for the transaction to commit if it
1877 * finds dirty_bg_run = 1
1879 * The dirty_bg_run flag is also used to make sure only
1880 * one process starts all the block group IO. It wouldn't
1881 * hurt to have more than one go through, but there's no
1882 * real advantage to it either.
1884 mutex_lock(&root->fs_info->ro_block_group_mutex);
1885 if (!cur_trans->dirty_bg_run) {
1887 cur_trans->dirty_bg_run = 1;
1889 mutex_unlock(&root->fs_info->ro_block_group_mutex);
1892 ret = btrfs_start_dirty_block_groups(trans, root);
1895 btrfs_end_transaction(trans, root);
1899 spin_lock(&root->fs_info->trans_lock);
1900 list_splice_init(&trans->ordered, &cur_trans->pending_ordered);
1901 if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1902 spin_unlock(&root->fs_info->trans_lock);
1903 atomic_inc(&cur_trans->use_count);
1904 ret = btrfs_end_transaction(trans, root);
1906 wait_for_commit(root, cur_trans);
1908 if (unlikely(cur_trans->aborted))
1909 ret = cur_trans->aborted;
1911 btrfs_put_transaction(cur_trans);
1916 cur_trans->state = TRANS_STATE_COMMIT_START;
1917 wake_up(&root->fs_info->transaction_blocked_wait);
1919 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1920 prev_trans = list_entry(cur_trans->list.prev,
1921 struct btrfs_transaction, list);
1922 if (prev_trans->state != TRANS_STATE_COMPLETED) {
1923 atomic_inc(&prev_trans->use_count);
1924 spin_unlock(&root->fs_info->trans_lock);
1926 wait_for_commit(root, prev_trans);
1927 ret = prev_trans->aborted;
1929 btrfs_put_transaction(prev_trans);
1931 goto cleanup_transaction;
1933 spin_unlock(&root->fs_info->trans_lock);
1936 spin_unlock(&root->fs_info->trans_lock);
1939 extwriter_counter_dec(cur_trans, trans->type);
1941 ret = btrfs_start_delalloc_flush(root->fs_info);
1943 goto cleanup_transaction;
1945 ret = btrfs_run_delayed_items(trans, root);
1947 goto cleanup_transaction;
1949 wait_event(cur_trans->writer_wait,
1950 extwriter_counter_read(cur_trans) == 0);
1952 /* some pending stuffs might be added after the previous flush. */
1953 ret = btrfs_run_delayed_items(trans, root);
1955 goto cleanup_transaction;
1957 btrfs_wait_delalloc_flush(root->fs_info);
1959 btrfs_wait_pending_ordered(cur_trans, root->fs_info);
1961 btrfs_scrub_pause(root);
1963 * Ok now we need to make sure to block out any other joins while we
1964 * commit the transaction. We could have started a join before setting
1965 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1967 spin_lock(&root->fs_info->trans_lock);
1968 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1969 spin_unlock(&root->fs_info->trans_lock);
1970 wait_event(cur_trans->writer_wait,
1971 atomic_read(&cur_trans->num_writers) == 1);
1973 /* ->aborted might be set after the previous check, so check it */
1974 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1975 ret = cur_trans->aborted;
1976 goto scrub_continue;
1979 * the reloc mutex makes sure that we stop
1980 * the balancing code from coming in and moving
1981 * extents around in the middle of the commit
1983 mutex_lock(&root->fs_info->reloc_mutex);
1986 * We needn't worry about the delayed items because we will
1987 * deal with them in create_pending_snapshot(), which is the
1988 * core function of the snapshot creation.
1990 ret = create_pending_snapshots(trans, root->fs_info);
1992 mutex_unlock(&root->fs_info->reloc_mutex);
1993 goto scrub_continue;
1997 * We insert the dir indexes of the snapshots and update the inode
1998 * of the snapshots' parents after the snapshot creation, so there
1999 * are some delayed items which are not dealt with. Now deal with
2002 * We needn't worry that this operation will corrupt the snapshots,
2003 * because all the tree which are snapshoted will be forced to COW
2004 * the nodes and leaves.
2006 ret = btrfs_run_delayed_items(trans, root);
2008 mutex_unlock(&root->fs_info->reloc_mutex);
2009 goto scrub_continue;
2012 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
2014 mutex_unlock(&root->fs_info->reloc_mutex);
2015 goto scrub_continue;
2018 /* Reocrd old roots for later qgroup accounting */
2019 ret = btrfs_qgroup_prepare_account_extents(trans, root->fs_info);
2021 mutex_unlock(&root->fs_info->reloc_mutex);
2022 goto scrub_continue;
2026 * make sure none of the code above managed to slip in a
2029 btrfs_assert_delayed_root_empty(root);
2031 WARN_ON(cur_trans != trans->transaction);
2033 /* btrfs_commit_tree_roots is responsible for getting the
2034 * various roots consistent with each other. Every pointer
2035 * in the tree of tree roots has to point to the most up to date
2036 * root for every subvolume and other tree. So, we have to keep
2037 * the tree logging code from jumping in and changing any
2040 * At this point in the commit, there can't be any tree-log
2041 * writers, but a little lower down we drop the trans mutex
2042 * and let new people in. By holding the tree_log_mutex
2043 * from now until after the super is written, we avoid races
2044 * with the tree-log code.
2046 mutex_lock(&root->fs_info->tree_log_mutex);
2048 ret = commit_fs_roots(trans, root);
2050 mutex_unlock(&root->fs_info->tree_log_mutex);
2051 mutex_unlock(&root->fs_info->reloc_mutex);
2052 goto scrub_continue;
2056 * Since the transaction is done, we can apply the pending changes
2057 * before the next transaction.
2059 btrfs_apply_pending_changes(root->fs_info);
2061 /* commit_fs_roots gets rid of all the tree log roots, it is now
2062 * safe to free the root of tree log roots
2064 btrfs_free_log_root_tree(trans, root->fs_info);
2067 * Since fs roots are all committed, we can get a quite accurate
2068 * new_roots. So let's do quota accounting.
2070 ret = btrfs_qgroup_account_extents(trans, root->fs_info);
2072 mutex_unlock(&root->fs_info->tree_log_mutex);
2073 mutex_unlock(&root->fs_info->reloc_mutex);
2074 goto scrub_continue;
2077 ret = commit_cowonly_roots(trans, root);
2079 mutex_unlock(&root->fs_info->tree_log_mutex);
2080 mutex_unlock(&root->fs_info->reloc_mutex);
2081 goto scrub_continue;
2085 * The tasks which save the space cache and inode cache may also
2086 * update ->aborted, check it.
2088 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
2089 ret = cur_trans->aborted;
2090 mutex_unlock(&root->fs_info->tree_log_mutex);
2091 mutex_unlock(&root->fs_info->reloc_mutex);
2092 goto scrub_continue;
2095 btrfs_prepare_extent_commit(trans, root);
2097 cur_trans = root->fs_info->running_transaction;
2099 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
2100 root->fs_info->tree_root->node);
2101 list_add_tail(&root->fs_info->tree_root->dirty_list,
2102 &cur_trans->switch_commits);
2104 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
2105 root->fs_info->chunk_root->node);
2106 list_add_tail(&root->fs_info->chunk_root->dirty_list,
2107 &cur_trans->switch_commits);
2109 switch_commit_roots(cur_trans, root->fs_info);
2111 assert_qgroups_uptodate(trans);
2112 ASSERT(list_empty(&cur_trans->dirty_bgs));
2113 ASSERT(list_empty(&cur_trans->io_bgs));
2114 update_super_roots(root);
2116 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
2117 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
2118 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
2119 sizeof(*root->fs_info->super_copy));
2121 btrfs_update_commit_device_size(root->fs_info);
2122 btrfs_update_commit_device_bytes_used(root, cur_trans);
2124 clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
2125 clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
2127 btrfs_trans_release_chunk_metadata(trans);
2129 spin_lock(&root->fs_info->trans_lock);
2130 cur_trans->state = TRANS_STATE_UNBLOCKED;
2131 root->fs_info->running_transaction = NULL;
2132 spin_unlock(&root->fs_info->trans_lock);
2133 mutex_unlock(&root->fs_info->reloc_mutex);
2135 wake_up(&root->fs_info->transaction_wait);
2137 ret = btrfs_write_and_wait_transaction(trans, root);
2139 btrfs_error(root->fs_info, ret,
2140 "Error while writing out transaction");
2141 mutex_unlock(&root->fs_info->tree_log_mutex);
2142 goto scrub_continue;
2145 ret = write_ctree_super(trans, root, 0);
2147 mutex_unlock(&root->fs_info->tree_log_mutex);
2148 goto scrub_continue;
2152 * the super is written, we can safely allow the tree-loggers
2153 * to go about their business
2155 mutex_unlock(&root->fs_info->tree_log_mutex);
2157 btrfs_finish_extent_commit(trans, root);
2159 if (cur_trans->have_free_bgs)
2160 btrfs_clear_space_info_full(root->fs_info);
2162 root->fs_info->last_trans_committed = cur_trans->transid;
2164 * We needn't acquire the lock here because there is no other task
2165 * which can change it.
2167 cur_trans->state = TRANS_STATE_COMPLETED;
2168 wake_up(&cur_trans->commit_wait);
2170 spin_lock(&root->fs_info->trans_lock);
2171 list_del_init(&cur_trans->list);
2172 spin_unlock(&root->fs_info->trans_lock);
2174 btrfs_put_transaction(cur_trans);
2175 btrfs_put_transaction(cur_trans);
2177 if (trans->type & __TRANS_FREEZABLE)
2178 sb_end_intwrite(root->fs_info->sb);
2180 trace_btrfs_transaction_commit(root);
2182 btrfs_scrub_continue(root);
2184 if (current->journal_info == trans)
2185 current->journal_info = NULL;
2187 kmem_cache_free(btrfs_trans_handle_cachep, trans);
2189 if (current != root->fs_info->transaction_kthread &&
2190 current != root->fs_info->cleaner_kthread)
2191 btrfs_run_delayed_iputs(root);
2196 btrfs_scrub_continue(root);
2197 cleanup_transaction:
2198 btrfs_trans_release_metadata(trans, root);
2199 btrfs_trans_release_chunk_metadata(trans);
2200 trans->block_rsv = NULL;
2201 if (trans->qgroup_reserved) {
2202 btrfs_qgroup_free(root, trans->qgroup_reserved);
2203 trans->qgroup_reserved = 0;
2205 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
2206 if (current->journal_info == trans)
2207 current->journal_info = NULL;
2208 cleanup_transaction(trans, root, ret);
2214 * return < 0 if error
2215 * 0 if there are no more dead_roots at the time of call
2216 * 1 there are more to be processed, call me again
2218 * The return value indicates there are certainly more snapshots to delete, but
2219 * if there comes a new one during processing, it may return 0. We don't mind,
2220 * because btrfs_commit_super will poke cleaner thread and it will process it a
2221 * few seconds later.
2223 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
2226 struct btrfs_fs_info *fs_info = root->fs_info;
2228 spin_lock(&fs_info->trans_lock);
2229 if (list_empty(&fs_info->dead_roots)) {
2230 spin_unlock(&fs_info->trans_lock);
2233 root = list_first_entry(&fs_info->dead_roots,
2234 struct btrfs_root, root_list);
2235 list_del_init(&root->root_list);
2236 spin_unlock(&fs_info->trans_lock);
2238 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
2240 btrfs_kill_all_delayed_nodes(root);
2242 if (btrfs_header_backref_rev(root->node) <
2243 BTRFS_MIXED_BACKREF_REV)
2244 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
2246 ret = btrfs_drop_snapshot(root, NULL, 1, 0);
2248 return (ret < 0) ? 0 : 1;
2251 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info)
2256 prev = xchg(&fs_info->pending_changes, 0);
2260 bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE;
2262 btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2265 bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE;
2267 btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2270 bit = 1 << BTRFS_PENDING_COMMIT;
2272 btrfs_debug(fs_info, "pending commit done");
2277 "unknown pending changes left 0x%lx, ignoring", prev);