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);
86 * Do a single barrier for the waitqueue_active check here, the state
87 * of the waitqueue should not change once clear_btree_io_tree is
91 while (!RB_EMPTY_ROOT(&tree->state)) {
93 struct extent_state *state;
95 node = rb_first(&tree->state);
96 state = rb_entry(node, struct extent_state, rb_node);
97 rb_erase(&state->rb_node, &tree->state);
98 RB_CLEAR_NODE(&state->rb_node);
100 * btree io trees aren't supposed to have tasks waiting for
101 * changes in the flags of extent states ever.
103 ASSERT(!waitqueue_active(&state->wq));
104 free_extent_state(state);
106 cond_resched_lock(&tree->lock);
108 spin_unlock(&tree->lock);
111 static noinline void switch_commit_roots(struct btrfs_transaction *trans,
112 struct btrfs_fs_info *fs_info)
114 struct btrfs_root *root, *tmp;
116 down_write(&fs_info->commit_root_sem);
117 list_for_each_entry_safe(root, tmp, &trans->switch_commits,
119 list_del_init(&root->dirty_list);
120 free_extent_buffer(root->commit_root);
121 root->commit_root = btrfs_root_node(root);
122 if (is_fstree(root->objectid))
123 btrfs_unpin_free_ino(root);
124 clear_btree_io_tree(&root->dirty_log_pages);
127 /* We can free old roots now. */
128 spin_lock(&trans->dropped_roots_lock);
129 while (!list_empty(&trans->dropped_roots)) {
130 root = list_first_entry(&trans->dropped_roots,
131 struct btrfs_root, root_list);
132 list_del_init(&root->root_list);
133 spin_unlock(&trans->dropped_roots_lock);
134 btrfs_drop_and_free_fs_root(fs_info, root);
135 spin_lock(&trans->dropped_roots_lock);
137 spin_unlock(&trans->dropped_roots_lock);
138 up_write(&fs_info->commit_root_sem);
141 static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
144 if (type & TRANS_EXTWRITERS)
145 atomic_inc(&trans->num_extwriters);
148 static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
151 if (type & TRANS_EXTWRITERS)
152 atomic_dec(&trans->num_extwriters);
155 static inline void extwriter_counter_init(struct btrfs_transaction *trans,
158 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
161 static inline int extwriter_counter_read(struct btrfs_transaction *trans)
163 return atomic_read(&trans->num_extwriters);
167 * either allocate a new transaction or hop into the existing one
169 static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
171 struct btrfs_transaction *cur_trans;
172 struct btrfs_fs_info *fs_info = root->fs_info;
174 spin_lock(&fs_info->trans_lock);
176 /* The file system has been taken offline. No new transactions. */
177 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
178 spin_unlock(&fs_info->trans_lock);
182 cur_trans = fs_info->running_transaction;
184 if (cur_trans->aborted) {
185 spin_unlock(&fs_info->trans_lock);
186 return cur_trans->aborted;
188 if (btrfs_blocked_trans_types[cur_trans->state] & type) {
189 spin_unlock(&fs_info->trans_lock);
192 atomic_inc(&cur_trans->use_count);
193 atomic_inc(&cur_trans->num_writers);
194 extwriter_counter_inc(cur_trans, type);
195 spin_unlock(&fs_info->trans_lock);
198 spin_unlock(&fs_info->trans_lock);
201 * If we are ATTACH, we just want to catch the current transaction,
202 * and commit it. If there is no transaction, just return ENOENT.
204 if (type == TRANS_ATTACH)
208 * JOIN_NOLOCK only happens during the transaction commit, so
209 * it is impossible that ->running_transaction is NULL
211 BUG_ON(type == TRANS_JOIN_NOLOCK);
213 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
217 spin_lock(&fs_info->trans_lock);
218 if (fs_info->running_transaction) {
220 * someone started a transaction after we unlocked. Make sure
221 * to redo the checks above
223 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
225 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
226 spin_unlock(&fs_info->trans_lock);
227 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
231 atomic_set(&cur_trans->num_writers, 1);
232 extwriter_counter_init(cur_trans, type);
233 init_waitqueue_head(&cur_trans->writer_wait);
234 init_waitqueue_head(&cur_trans->commit_wait);
235 cur_trans->state = TRANS_STATE_RUNNING;
237 * One for this trans handle, one so it will live on until we
238 * commit the transaction.
240 atomic_set(&cur_trans->use_count, 2);
241 cur_trans->have_free_bgs = 0;
242 cur_trans->start_time = get_seconds();
243 cur_trans->dirty_bg_run = 0;
245 cur_trans->delayed_refs.href_root = RB_ROOT;
246 cur_trans->delayed_refs.dirty_extent_root = RB_ROOT;
247 atomic_set(&cur_trans->delayed_refs.num_entries, 0);
248 cur_trans->delayed_refs.num_heads_ready = 0;
249 cur_trans->delayed_refs.pending_csums = 0;
250 cur_trans->delayed_refs.num_heads = 0;
251 cur_trans->delayed_refs.flushing = 0;
252 cur_trans->delayed_refs.run_delayed_start = 0;
253 cur_trans->delayed_refs.qgroup_to_skip = 0;
256 * although the tree mod log is per file system and not per transaction,
257 * the log must never go across transaction boundaries.
260 if (!list_empty(&fs_info->tree_mod_seq_list))
261 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
262 "creating a fresh transaction\n");
263 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
264 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
265 "creating a fresh transaction\n");
266 atomic64_set(&fs_info->tree_mod_seq, 0);
268 spin_lock_init(&cur_trans->delayed_refs.lock);
270 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
271 INIT_LIST_HEAD(&cur_trans->pending_chunks);
272 INIT_LIST_HEAD(&cur_trans->switch_commits);
273 INIT_LIST_HEAD(&cur_trans->pending_ordered);
274 INIT_LIST_HEAD(&cur_trans->dirty_bgs);
275 INIT_LIST_HEAD(&cur_trans->io_bgs);
276 INIT_LIST_HEAD(&cur_trans->dropped_roots);
277 mutex_init(&cur_trans->cache_write_mutex);
278 cur_trans->num_dirty_bgs = 0;
279 spin_lock_init(&cur_trans->dirty_bgs_lock);
280 INIT_LIST_HEAD(&cur_trans->deleted_bgs);
281 spin_lock_init(&cur_trans->deleted_bgs_lock);
282 spin_lock_init(&cur_trans->dropped_roots_lock);
283 list_add_tail(&cur_trans->list, &fs_info->trans_list);
284 extent_io_tree_init(&cur_trans->dirty_pages,
285 fs_info->btree_inode->i_mapping);
286 fs_info->generation++;
287 cur_trans->transid = fs_info->generation;
288 fs_info->running_transaction = cur_trans;
289 cur_trans->aborted = 0;
290 spin_unlock(&fs_info->trans_lock);
296 * this does all the record keeping required to make sure that a reference
297 * counted root is properly recorded in a given transaction. This is required
298 * to make sure the old root from before we joined the transaction is deleted
299 * when the transaction commits
301 static int record_root_in_trans(struct btrfs_trans_handle *trans,
302 struct btrfs_root *root)
304 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
305 root->last_trans < trans->transid) {
306 WARN_ON(root == root->fs_info->extent_root);
307 WARN_ON(root->commit_root != root->node);
310 * see below for IN_TRANS_SETUP usage rules
311 * we have the reloc mutex held now, so there
312 * is only one writer in this function
314 set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
316 /* make sure readers find IN_TRANS_SETUP before
317 * they find our root->last_trans update
321 spin_lock(&root->fs_info->fs_roots_radix_lock);
322 if (root->last_trans == trans->transid) {
323 spin_unlock(&root->fs_info->fs_roots_radix_lock);
326 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
327 (unsigned long)root->root_key.objectid,
328 BTRFS_ROOT_TRANS_TAG);
329 spin_unlock(&root->fs_info->fs_roots_radix_lock);
330 root->last_trans = trans->transid;
332 /* this is pretty tricky. We don't want to
333 * take the relocation lock in btrfs_record_root_in_trans
334 * unless we're really doing the first setup for this root in
337 * Normally we'd use root->last_trans as a flag to decide
338 * if we want to take the expensive mutex.
340 * But, we have to set root->last_trans before we
341 * init the relocation root, otherwise, we trip over warnings
342 * in ctree.c. The solution used here is to flag ourselves
343 * with root IN_TRANS_SETUP. When this is 1, we're still
344 * fixing up the reloc trees and everyone must wait.
346 * When this is zero, they can trust root->last_trans and fly
347 * through btrfs_record_root_in_trans without having to take the
348 * lock. smp_wmb() makes sure that all the writes above are
349 * done before we pop in the zero below
351 btrfs_init_reloc_root(trans, root);
352 smp_mb__before_atomic();
353 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
359 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
360 struct btrfs_root *root)
362 struct btrfs_transaction *cur_trans = trans->transaction;
364 /* Add ourselves to the transaction dropped list */
365 spin_lock(&cur_trans->dropped_roots_lock);
366 list_add_tail(&root->root_list, &cur_trans->dropped_roots);
367 spin_unlock(&cur_trans->dropped_roots_lock);
369 /* Make sure we don't try to update the root at commit time */
370 spin_lock(&root->fs_info->fs_roots_radix_lock);
371 radix_tree_tag_clear(&root->fs_info->fs_roots_radix,
372 (unsigned long)root->root_key.objectid,
373 BTRFS_ROOT_TRANS_TAG);
374 spin_unlock(&root->fs_info->fs_roots_radix_lock);
377 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
378 struct btrfs_root *root)
380 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
384 * see record_root_in_trans for comments about IN_TRANS_SETUP usage
388 if (root->last_trans == trans->transid &&
389 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state))
392 mutex_lock(&root->fs_info->reloc_mutex);
393 record_root_in_trans(trans, root);
394 mutex_unlock(&root->fs_info->reloc_mutex);
399 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
401 return (trans->state >= TRANS_STATE_BLOCKED &&
402 trans->state < TRANS_STATE_UNBLOCKED &&
406 /* wait for commit against the current transaction to become unblocked
407 * when this is done, it is safe to start a new transaction, but the current
408 * transaction might not be fully on disk.
410 static void wait_current_trans(struct btrfs_root *root)
412 struct btrfs_transaction *cur_trans;
414 spin_lock(&root->fs_info->trans_lock);
415 cur_trans = root->fs_info->running_transaction;
416 if (cur_trans && is_transaction_blocked(cur_trans)) {
417 atomic_inc(&cur_trans->use_count);
418 spin_unlock(&root->fs_info->trans_lock);
420 wait_event(root->fs_info->transaction_wait,
421 cur_trans->state >= TRANS_STATE_UNBLOCKED ||
423 btrfs_put_transaction(cur_trans);
425 spin_unlock(&root->fs_info->trans_lock);
429 static int may_wait_transaction(struct btrfs_root *root, int type)
431 if (root->fs_info->log_root_recovering)
434 if (type == TRANS_USERSPACE)
437 if (type == TRANS_START &&
438 !atomic_read(&root->fs_info->open_ioctl_trans))
444 static inline bool need_reserve_reloc_root(struct btrfs_root *root)
446 if (!root->fs_info->reloc_ctl ||
447 !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
448 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
455 static struct btrfs_trans_handle *
456 start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
457 enum btrfs_reserve_flush_enum flush)
459 struct btrfs_trans_handle *h;
460 struct btrfs_transaction *cur_trans;
462 u64 qgroup_reserved = 0;
463 bool reloc_reserved = false;
466 /* Send isn't supposed to start transactions. */
467 ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
469 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
470 return ERR_PTR(-EROFS);
472 if (current->journal_info) {
473 WARN_ON(type & TRANS_EXTWRITERS);
474 h = current->journal_info;
476 WARN_ON(h->use_count > 2);
477 h->orig_rsv = h->block_rsv;
483 * Do the reservation before we join the transaction so we can do all
484 * the appropriate flushing if need be.
486 if (num_items > 0 && root != root->fs_info->chunk_root) {
487 if (root->fs_info->quota_enabled &&
488 is_fstree(root->root_key.objectid)) {
489 qgroup_reserved = num_items * root->nodesize;
490 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
495 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
497 * Do the reservation for the relocation root creation
499 if (need_reserve_reloc_root(root)) {
500 num_bytes += root->nodesize;
501 reloc_reserved = true;
504 ret = btrfs_block_rsv_add(root,
505 &root->fs_info->trans_block_rsv,
511 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
518 * If we are JOIN_NOLOCK we're already committing a transaction and
519 * waiting on this guy, so we don't need to do the sb_start_intwrite
520 * because we're already holding a ref. We need this because we could
521 * have raced in and did an fsync() on a file which can kick a commit
522 * and then we deadlock with somebody doing a freeze.
524 * If we are ATTACH, it means we just want to catch the current
525 * transaction and commit it, so we needn't do sb_start_intwrite().
527 if (type & __TRANS_FREEZABLE)
528 sb_start_intwrite(root->fs_info->sb);
530 if (may_wait_transaction(root, type))
531 wait_current_trans(root);
534 ret = join_transaction(root, type);
536 wait_current_trans(root);
537 if (unlikely(type == TRANS_ATTACH))
540 } while (ret == -EBUSY);
543 /* We must get the transaction if we are JOIN_NOLOCK. */
544 BUG_ON(type == TRANS_JOIN_NOLOCK);
548 cur_trans = root->fs_info->running_transaction;
550 h->transid = cur_trans->transid;
551 h->transaction = cur_trans;
553 h->bytes_reserved = 0;
554 h->chunk_bytes_reserved = 0;
556 h->delayed_ref_updates = 0;
562 h->qgroup_reserved = 0;
563 h->delayed_ref_elem.seq = 0;
565 h->allocating_chunk = false;
566 h->can_flush_pending_bgs = true;
567 h->reloc_reserved = false;
569 INIT_LIST_HEAD(&h->qgroup_ref_list);
570 INIT_LIST_HEAD(&h->new_bgs);
571 INIT_LIST_HEAD(&h->ordered);
574 if (cur_trans->state >= TRANS_STATE_BLOCKED &&
575 may_wait_transaction(root, type)) {
576 current->journal_info = h;
577 btrfs_commit_transaction(h, root);
582 trace_btrfs_space_reservation(root->fs_info, "transaction",
583 h->transid, num_bytes, 1);
584 h->block_rsv = &root->fs_info->trans_block_rsv;
585 h->bytes_reserved = num_bytes;
586 h->reloc_reserved = reloc_reserved;
588 h->qgroup_reserved = qgroup_reserved;
591 btrfs_record_root_in_trans(h, root);
593 if (!current->journal_info && type != TRANS_USERSPACE)
594 current->journal_info = h;
598 if (type & __TRANS_FREEZABLE)
599 sb_end_intwrite(root->fs_info->sb);
600 kmem_cache_free(btrfs_trans_handle_cachep, h);
603 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
607 btrfs_qgroup_free(root, qgroup_reserved);
611 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
614 return start_transaction(root, num_items, TRANS_START,
615 BTRFS_RESERVE_FLUSH_ALL);
618 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
619 struct btrfs_root *root, int num_items)
621 return start_transaction(root, num_items, TRANS_START,
622 BTRFS_RESERVE_FLUSH_LIMIT);
625 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
627 return start_transaction(root, 0, TRANS_JOIN, 0);
630 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
632 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
635 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
637 return start_transaction(root, 0, TRANS_USERSPACE, 0);
641 * btrfs_attach_transaction() - catch the running transaction
643 * It is used when we want to commit the current the transaction, but
644 * don't want to start a new one.
646 * Note: If this function return -ENOENT, it just means there is no
647 * running transaction. But it is possible that the inactive transaction
648 * is still in the memory, not fully on disk. If you hope there is no
649 * inactive transaction in the fs when -ENOENT is returned, you should
651 * btrfs_attach_transaction_barrier()
653 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
655 return start_transaction(root, 0, TRANS_ATTACH, 0);
659 * btrfs_attach_transaction_barrier() - catch the running transaction
661 * It is similar to the above function, the differentia is this one
662 * will wait for all the inactive transactions until they fully
665 struct btrfs_trans_handle *
666 btrfs_attach_transaction_barrier(struct btrfs_root *root)
668 struct btrfs_trans_handle *trans;
670 trans = start_transaction(root, 0, TRANS_ATTACH, 0);
671 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
672 btrfs_wait_for_commit(root, 0);
677 /* wait for a transaction commit to be fully complete */
678 static noinline void wait_for_commit(struct btrfs_root *root,
679 struct btrfs_transaction *commit)
681 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
684 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
686 struct btrfs_transaction *cur_trans = NULL, *t;
690 if (transid <= root->fs_info->last_trans_committed)
693 /* find specified transaction */
694 spin_lock(&root->fs_info->trans_lock);
695 list_for_each_entry(t, &root->fs_info->trans_list, list) {
696 if (t->transid == transid) {
698 atomic_inc(&cur_trans->use_count);
702 if (t->transid > transid) {
707 spin_unlock(&root->fs_info->trans_lock);
710 * The specified transaction doesn't exist, or we
711 * raced with btrfs_commit_transaction
714 if (transid > root->fs_info->last_trans_committed)
719 /* find newest transaction that is committing | committed */
720 spin_lock(&root->fs_info->trans_lock);
721 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
723 if (t->state >= TRANS_STATE_COMMIT_START) {
724 if (t->state == TRANS_STATE_COMPLETED)
727 atomic_inc(&cur_trans->use_count);
731 spin_unlock(&root->fs_info->trans_lock);
733 goto out; /* nothing committing|committed */
736 wait_for_commit(root, cur_trans);
737 btrfs_put_transaction(cur_trans);
742 void btrfs_throttle(struct btrfs_root *root)
744 if (!atomic_read(&root->fs_info->open_ioctl_trans))
745 wait_current_trans(root);
748 static int should_end_transaction(struct btrfs_trans_handle *trans,
749 struct btrfs_root *root)
751 if (root->fs_info->global_block_rsv.space_info->full &&
752 btrfs_check_space_for_delayed_refs(trans, root))
755 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
758 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
759 struct btrfs_root *root)
761 struct btrfs_transaction *cur_trans = trans->transaction;
766 if (cur_trans->state >= TRANS_STATE_BLOCKED ||
767 cur_trans->delayed_refs.flushing)
770 updates = trans->delayed_ref_updates;
771 trans->delayed_ref_updates = 0;
773 err = btrfs_run_delayed_refs(trans, root, updates * 2);
774 if (err) /* Error code will also eval true */
778 return should_end_transaction(trans, root);
781 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
782 struct btrfs_root *root, int throttle)
784 struct btrfs_transaction *cur_trans = trans->transaction;
785 struct btrfs_fs_info *info = root->fs_info;
786 unsigned long cur = trans->delayed_ref_updates;
787 int lock = (trans->type != TRANS_JOIN_NOLOCK);
789 int must_run_delayed_refs = 0;
791 if (trans->use_count > 1) {
793 trans->block_rsv = trans->orig_rsv;
797 btrfs_trans_release_metadata(trans, root);
798 trans->block_rsv = NULL;
800 if (!list_empty(&trans->new_bgs))
801 btrfs_create_pending_block_groups(trans, root);
803 if (!list_empty(&trans->ordered)) {
804 spin_lock(&info->trans_lock);
805 list_splice_init(&trans->ordered, &cur_trans->pending_ordered);
806 spin_unlock(&info->trans_lock);
809 trans->delayed_ref_updates = 0;
811 must_run_delayed_refs =
812 btrfs_should_throttle_delayed_refs(trans, root);
813 cur = max_t(unsigned long, cur, 32);
816 * don't make the caller wait if they are from a NOLOCK
817 * or ATTACH transaction, it will deadlock with commit
819 if (must_run_delayed_refs == 1 &&
820 (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
821 must_run_delayed_refs = 2;
824 if (trans->qgroup_reserved) {
826 * the same root has to be passed here between start_transaction
827 * and end_transaction. Subvolume quota depends on this.
829 btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
830 trans->qgroup_reserved = 0;
833 btrfs_trans_release_metadata(trans, root);
834 trans->block_rsv = NULL;
836 if (!list_empty(&trans->new_bgs))
837 btrfs_create_pending_block_groups(trans, root);
839 btrfs_trans_release_chunk_metadata(trans);
841 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
842 should_end_transaction(trans, root) &&
843 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
844 spin_lock(&info->trans_lock);
845 if (cur_trans->state == TRANS_STATE_RUNNING)
846 cur_trans->state = TRANS_STATE_BLOCKED;
847 spin_unlock(&info->trans_lock);
850 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
852 return btrfs_commit_transaction(trans, root);
854 wake_up_process(info->transaction_kthread);
857 if (trans->type & __TRANS_FREEZABLE)
858 sb_end_intwrite(root->fs_info->sb);
860 WARN_ON(cur_trans != info->running_transaction);
861 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
862 atomic_dec(&cur_trans->num_writers);
863 extwriter_counter_dec(cur_trans, trans->type);
866 * Make sure counter is updated before we wake up waiters.
869 if (waitqueue_active(&cur_trans->writer_wait))
870 wake_up(&cur_trans->writer_wait);
871 btrfs_put_transaction(cur_trans);
873 if (current->journal_info == trans)
874 current->journal_info = NULL;
877 btrfs_run_delayed_iputs(root);
879 if (trans->aborted ||
880 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
881 wake_up_process(info->transaction_kthread);
884 assert_qgroups_uptodate(trans);
886 kmem_cache_free(btrfs_trans_handle_cachep, trans);
887 if (must_run_delayed_refs) {
888 btrfs_async_run_delayed_refs(root, cur,
889 must_run_delayed_refs == 1);
894 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
895 struct btrfs_root *root)
897 return __btrfs_end_transaction(trans, root, 0);
900 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
901 struct btrfs_root *root)
903 return __btrfs_end_transaction(trans, root, 1);
907 * when btree blocks are allocated, they have some corresponding bits set for
908 * them in one of two extent_io trees. This is used to make sure all of
909 * those extents are sent to disk but does not wait on them
911 int btrfs_write_marked_extents(struct btrfs_root *root,
912 struct extent_io_tree *dirty_pages, int mark)
916 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
917 struct extent_state *cached_state = NULL;
921 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
922 mark, &cached_state)) {
923 bool wait_writeback = false;
925 err = convert_extent_bit(dirty_pages, start, end,
927 mark, &cached_state, GFP_NOFS);
929 * convert_extent_bit can return -ENOMEM, which is most of the
930 * time a temporary error. So when it happens, ignore the error
931 * and wait for writeback of this range to finish - because we
932 * failed to set the bit EXTENT_NEED_WAIT for the range, a call
933 * to btrfs_wait_marked_extents() would not know that writeback
934 * for this range started and therefore wouldn't wait for it to
935 * finish - we don't want to commit a superblock that points to
936 * btree nodes/leafs for which writeback hasn't finished yet
937 * (and without errors).
938 * We cleanup any entries left in the io tree when committing
939 * the transaction (through clear_btree_io_tree()).
941 if (err == -ENOMEM) {
943 wait_writeback = true;
946 err = filemap_fdatawrite_range(mapping, start, end);
949 else if (wait_writeback)
950 werr = filemap_fdatawait_range(mapping, start, end);
951 free_extent_state(cached_state);
960 * when btree blocks are allocated, they have some corresponding bits set for
961 * them in one of two extent_io trees. This is used to make sure all of
962 * those extents are on disk for transaction or log commit. We wait
963 * on all the pages and clear them from the dirty pages state tree
965 int btrfs_wait_marked_extents(struct btrfs_root *root,
966 struct extent_io_tree *dirty_pages, int mark)
970 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
971 struct extent_state *cached_state = NULL;
974 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
977 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
978 EXTENT_NEED_WAIT, &cached_state)) {
980 * Ignore -ENOMEM errors returned by clear_extent_bit().
981 * When committing the transaction, we'll remove any entries
982 * left in the io tree. For a log commit, we don't remove them
983 * after committing the log because the tree can be accessed
984 * concurrently - we do it only at transaction commit time when
985 * it's safe to do it (through clear_btree_io_tree()).
987 err = clear_extent_bit(dirty_pages, start, end,
989 0, 0, &cached_state, GFP_NOFS);
993 err = filemap_fdatawait_range(mapping, start, end);
996 free_extent_state(cached_state);
1004 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1005 if ((mark & EXTENT_DIRTY) &&
1006 test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
1007 &btree_ino->runtime_flags))
1010 if ((mark & EXTENT_NEW) &&
1011 test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
1012 &btree_ino->runtime_flags))
1015 if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
1016 &btree_ino->runtime_flags))
1020 if (errors && !werr)
1027 * when btree blocks are allocated, they have some corresponding bits set for
1028 * them in one of two extent_io trees. This is used to make sure all of
1029 * those extents are on disk for transaction or log commit
1031 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
1032 struct extent_io_tree *dirty_pages, int mark)
1036 struct blk_plug plug;
1038 blk_start_plug(&plug);
1039 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
1040 blk_finish_plug(&plug);
1041 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
1050 static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
1051 struct btrfs_root *root)
1055 ret = btrfs_write_and_wait_marked_extents(root,
1056 &trans->transaction->dirty_pages,
1058 clear_btree_io_tree(&trans->transaction->dirty_pages);
1064 * this is used to update the root pointer in the tree of tree roots.
1066 * But, in the case of the extent allocation tree, updating the root
1067 * pointer may allocate blocks which may change the root of the extent
1070 * So, this loops and repeats and makes sure the cowonly root didn't
1071 * change while the root pointer was being updated in the metadata.
1073 static int update_cowonly_root(struct btrfs_trans_handle *trans,
1074 struct btrfs_root *root)
1077 u64 old_root_bytenr;
1079 struct btrfs_root *tree_root = root->fs_info->tree_root;
1081 old_root_used = btrfs_root_used(&root->root_item);
1084 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
1085 if (old_root_bytenr == root->node->start &&
1086 old_root_used == btrfs_root_used(&root->root_item))
1089 btrfs_set_root_node(&root->root_item, root->node);
1090 ret = btrfs_update_root(trans, tree_root,
1096 old_root_used = btrfs_root_used(&root->root_item);
1103 * update all the cowonly tree roots on disk
1105 * The error handling in this function may not be obvious. Any of the
1106 * failures will cause the file system to go offline. We still need
1107 * to clean up the delayed refs.
1109 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
1110 struct btrfs_root *root)
1112 struct btrfs_fs_info *fs_info = root->fs_info;
1113 struct list_head *dirty_bgs = &trans->transaction->dirty_bgs;
1114 struct list_head *io_bgs = &trans->transaction->io_bgs;
1115 struct list_head *next;
1116 struct extent_buffer *eb;
1119 eb = btrfs_lock_root_node(fs_info->tree_root);
1120 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
1122 btrfs_tree_unlock(eb);
1123 free_extent_buffer(eb);
1128 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1132 ret = btrfs_run_dev_stats(trans, root->fs_info);
1135 ret = btrfs_run_dev_replace(trans, root->fs_info);
1138 ret = btrfs_run_qgroups(trans, root->fs_info);
1142 ret = btrfs_setup_space_cache(trans, root);
1146 /* run_qgroups might have added some more refs */
1147 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1151 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
1152 next = fs_info->dirty_cowonly_roots.next;
1153 list_del_init(next);
1154 root = list_entry(next, struct btrfs_root, dirty_list);
1155 clear_bit(BTRFS_ROOT_DIRTY, &root->state);
1157 if (root != fs_info->extent_root)
1158 list_add_tail(&root->dirty_list,
1159 &trans->transaction->switch_commits);
1160 ret = update_cowonly_root(trans, root);
1163 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1168 while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) {
1169 ret = btrfs_write_dirty_block_groups(trans, root);
1172 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1177 if (!list_empty(&fs_info->dirty_cowonly_roots))
1180 list_add_tail(&fs_info->extent_root->dirty_list,
1181 &trans->transaction->switch_commits);
1182 btrfs_after_dev_replace_commit(fs_info);
1188 * dead roots are old snapshots that need to be deleted. This allocates
1189 * a dirty root struct and adds it into the list of dead roots that need to
1192 void btrfs_add_dead_root(struct btrfs_root *root)
1194 spin_lock(&root->fs_info->trans_lock);
1195 if (list_empty(&root->root_list))
1196 list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1197 spin_unlock(&root->fs_info->trans_lock);
1201 * update all the cowonly tree roots on disk
1203 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1204 struct btrfs_root *root)
1206 struct btrfs_root *gang[8];
1207 struct btrfs_fs_info *fs_info = root->fs_info;
1212 spin_lock(&fs_info->fs_roots_radix_lock);
1214 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1217 BTRFS_ROOT_TRANS_TAG);
1220 for (i = 0; i < ret; i++) {
1222 radix_tree_tag_clear(&fs_info->fs_roots_radix,
1223 (unsigned long)root->root_key.objectid,
1224 BTRFS_ROOT_TRANS_TAG);
1225 spin_unlock(&fs_info->fs_roots_radix_lock);
1227 btrfs_free_log(trans, root);
1228 btrfs_update_reloc_root(trans, root);
1229 btrfs_orphan_commit_root(trans, root);
1231 btrfs_save_ino_cache(root, trans);
1233 /* see comments in should_cow_block() */
1234 clear_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1235 smp_mb__after_atomic();
1237 if (root->commit_root != root->node) {
1238 list_add_tail(&root->dirty_list,
1239 &trans->transaction->switch_commits);
1240 btrfs_set_root_node(&root->root_item,
1244 err = btrfs_update_root(trans, fs_info->tree_root,
1247 spin_lock(&fs_info->fs_roots_radix_lock);
1252 spin_unlock(&fs_info->fs_roots_radix_lock);
1257 * defrag a given btree.
1258 * Every leaf in the btree is read and defragged.
1260 int btrfs_defrag_root(struct btrfs_root *root)
1262 struct btrfs_fs_info *info = root->fs_info;
1263 struct btrfs_trans_handle *trans;
1266 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
1270 trans = btrfs_start_transaction(root, 0);
1272 return PTR_ERR(trans);
1274 ret = btrfs_defrag_leaves(trans, root);
1276 btrfs_end_transaction(trans, root);
1277 btrfs_btree_balance_dirty(info->tree_root);
1280 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1283 if (btrfs_defrag_cancelled(root->fs_info)) {
1284 pr_debug("BTRFS: defrag_root cancelled\n");
1289 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
1294 * new snapshots need to be created at a very specific time in the
1295 * transaction commit. This does the actual creation.
1298 * If the error which may affect the commitment of the current transaction
1299 * happens, we should return the error number. If the error which just affect
1300 * the creation of the pending snapshots, just return 0.
1302 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1303 struct btrfs_fs_info *fs_info,
1304 struct btrfs_pending_snapshot *pending)
1306 struct btrfs_key key;
1307 struct btrfs_root_item *new_root_item;
1308 struct btrfs_root *tree_root = fs_info->tree_root;
1309 struct btrfs_root *root = pending->root;
1310 struct btrfs_root *parent_root;
1311 struct btrfs_block_rsv *rsv;
1312 struct inode *parent_inode;
1313 struct btrfs_path *path;
1314 struct btrfs_dir_item *dir_item;
1315 struct dentry *dentry;
1316 struct extent_buffer *tmp;
1317 struct extent_buffer *old;
1318 struct timespec cur_time = CURRENT_TIME;
1326 path = btrfs_alloc_path();
1328 pending->error = -ENOMEM;
1332 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1333 if (!new_root_item) {
1334 pending->error = -ENOMEM;
1335 goto root_item_alloc_fail;
1338 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1340 goto no_free_objectid;
1343 * Make qgroup to skip current new snapshot's qgroupid, as it is
1344 * accounted by later btrfs_qgroup_inherit().
1346 btrfs_set_skip_qgroup(trans, objectid);
1348 btrfs_reloc_pre_snapshot(pending, &to_reserve);
1350 if (to_reserve > 0) {
1351 pending->error = btrfs_block_rsv_add(root,
1352 &pending->block_rsv,
1354 BTRFS_RESERVE_NO_FLUSH);
1356 goto clear_skip_qgroup;
1359 key.objectid = objectid;
1360 key.offset = (u64)-1;
1361 key.type = BTRFS_ROOT_ITEM_KEY;
1363 rsv = trans->block_rsv;
1364 trans->block_rsv = &pending->block_rsv;
1365 trans->bytes_reserved = trans->block_rsv->reserved;
1367 dentry = pending->dentry;
1368 parent_inode = pending->dir;
1369 parent_root = BTRFS_I(parent_inode)->root;
1370 record_root_in_trans(trans, parent_root);
1373 * insert the directory item
1375 ret = btrfs_set_inode_index(parent_inode, &index);
1376 BUG_ON(ret); /* -ENOMEM */
1378 /* check if there is a file/dir which has the same name. */
1379 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1380 btrfs_ino(parent_inode),
1381 dentry->d_name.name,
1382 dentry->d_name.len, 0);
1383 if (dir_item != NULL && !IS_ERR(dir_item)) {
1384 pending->error = -EEXIST;
1385 goto dir_item_existed;
1386 } else if (IS_ERR(dir_item)) {
1387 ret = PTR_ERR(dir_item);
1388 btrfs_abort_transaction(trans, root, ret);
1391 btrfs_release_path(path);
1394 * pull in the delayed directory update
1395 * and the delayed inode item
1396 * otherwise we corrupt the FS during
1399 ret = btrfs_run_delayed_items(trans, root);
1400 if (ret) { /* Transaction aborted */
1401 btrfs_abort_transaction(trans, root, ret);
1405 record_root_in_trans(trans, root);
1406 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1407 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1408 btrfs_check_and_init_root_item(new_root_item);
1410 root_flags = btrfs_root_flags(new_root_item);
1411 if (pending->readonly)
1412 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1414 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1415 btrfs_set_root_flags(new_root_item, root_flags);
1417 btrfs_set_root_generation_v2(new_root_item,
1419 uuid_le_gen(&new_uuid);
1420 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1421 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1423 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1424 memset(new_root_item->received_uuid, 0,
1425 sizeof(new_root_item->received_uuid));
1426 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1427 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1428 btrfs_set_root_stransid(new_root_item, 0);
1429 btrfs_set_root_rtransid(new_root_item, 0);
1431 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1432 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1433 btrfs_set_root_otransid(new_root_item, trans->transid);
1435 old = btrfs_lock_root_node(root);
1436 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1438 btrfs_tree_unlock(old);
1439 free_extent_buffer(old);
1440 btrfs_abort_transaction(trans, root, ret);
1444 btrfs_set_lock_blocking(old);
1446 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1447 /* clean up in any case */
1448 btrfs_tree_unlock(old);
1449 free_extent_buffer(old);
1451 btrfs_abort_transaction(trans, root, ret);
1454 /* see comments in should_cow_block() */
1455 set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1458 btrfs_set_root_node(new_root_item, tmp);
1459 /* record when the snapshot was created in key.offset */
1460 key.offset = trans->transid;
1461 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1462 btrfs_tree_unlock(tmp);
1463 free_extent_buffer(tmp);
1465 btrfs_abort_transaction(trans, root, ret);
1470 * insert root back/forward references
1472 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1473 parent_root->root_key.objectid,
1474 btrfs_ino(parent_inode), index,
1475 dentry->d_name.name, dentry->d_name.len);
1477 btrfs_abort_transaction(trans, root, ret);
1481 key.offset = (u64)-1;
1482 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1483 if (IS_ERR(pending->snap)) {
1484 ret = PTR_ERR(pending->snap);
1485 btrfs_abort_transaction(trans, root, ret);
1489 ret = btrfs_reloc_post_snapshot(trans, pending);
1491 btrfs_abort_transaction(trans, root, ret);
1495 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1497 btrfs_abort_transaction(trans, root, ret);
1501 ret = btrfs_insert_dir_item(trans, parent_root,
1502 dentry->d_name.name, dentry->d_name.len,
1504 BTRFS_FT_DIR, index);
1505 /* We have check then name at the beginning, so it is impossible. */
1506 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1508 btrfs_abort_transaction(trans, root, ret);
1512 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1513 dentry->d_name.len * 2);
1514 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1515 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1517 btrfs_abort_transaction(trans, root, ret);
1520 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1521 BTRFS_UUID_KEY_SUBVOL, objectid);
1523 btrfs_abort_transaction(trans, root, ret);
1526 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1527 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1528 new_root_item->received_uuid,
1529 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1531 if (ret && ret != -EEXIST) {
1532 btrfs_abort_transaction(trans, root, ret);
1537 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1539 btrfs_abort_transaction(trans, root, ret);
1544 * account qgroup counters before qgroup_inherit()
1546 ret = btrfs_qgroup_prepare_account_extents(trans, fs_info);
1549 ret = btrfs_qgroup_account_extents(trans, fs_info);
1552 ret = btrfs_qgroup_inherit(trans, fs_info,
1553 root->root_key.objectid,
1554 objectid, pending->inherit);
1556 btrfs_abort_transaction(trans, root, ret);
1561 pending->error = ret;
1563 trans->block_rsv = rsv;
1564 trans->bytes_reserved = 0;
1566 btrfs_clear_skip_qgroup(trans);
1568 kfree(new_root_item);
1569 root_item_alloc_fail:
1570 btrfs_free_path(path);
1575 * create all the snapshots we've scheduled for creation
1577 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1578 struct btrfs_fs_info *fs_info)
1580 struct btrfs_pending_snapshot *pending, *next;
1581 struct list_head *head = &trans->transaction->pending_snapshots;
1584 list_for_each_entry_safe(pending, next, head, list) {
1585 list_del(&pending->list);
1586 ret = create_pending_snapshot(trans, fs_info, pending);
1593 static void update_super_roots(struct btrfs_root *root)
1595 struct btrfs_root_item *root_item;
1596 struct btrfs_super_block *super;
1598 super = root->fs_info->super_copy;
1600 root_item = &root->fs_info->chunk_root->root_item;
1601 super->chunk_root = root_item->bytenr;
1602 super->chunk_root_generation = root_item->generation;
1603 super->chunk_root_level = root_item->level;
1605 root_item = &root->fs_info->tree_root->root_item;
1606 super->root = root_item->bytenr;
1607 super->generation = root_item->generation;
1608 super->root_level = root_item->level;
1609 if (btrfs_test_opt(root, SPACE_CACHE))
1610 super->cache_generation = root_item->generation;
1611 if (root->fs_info->update_uuid_tree_gen)
1612 super->uuid_tree_generation = root_item->generation;
1615 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1617 struct btrfs_transaction *trans;
1620 spin_lock(&info->trans_lock);
1621 trans = info->running_transaction;
1623 ret = (trans->state >= TRANS_STATE_COMMIT_START);
1624 spin_unlock(&info->trans_lock);
1628 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1630 struct btrfs_transaction *trans;
1633 spin_lock(&info->trans_lock);
1634 trans = info->running_transaction;
1636 ret = is_transaction_blocked(trans);
1637 spin_unlock(&info->trans_lock);
1642 * wait for the current transaction commit to start and block subsequent
1645 static void wait_current_trans_commit_start(struct btrfs_root *root,
1646 struct btrfs_transaction *trans)
1648 wait_event(root->fs_info->transaction_blocked_wait,
1649 trans->state >= TRANS_STATE_COMMIT_START ||
1654 * wait for the current transaction to start and then become unblocked.
1657 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1658 struct btrfs_transaction *trans)
1660 wait_event(root->fs_info->transaction_wait,
1661 trans->state >= TRANS_STATE_UNBLOCKED ||
1666 * commit transactions asynchronously. once btrfs_commit_transaction_async
1667 * returns, any subsequent transaction will not be allowed to join.
1669 struct btrfs_async_commit {
1670 struct btrfs_trans_handle *newtrans;
1671 struct btrfs_root *root;
1672 struct work_struct work;
1675 static void do_async_commit(struct work_struct *work)
1677 struct btrfs_async_commit *ac =
1678 container_of(work, struct btrfs_async_commit, work);
1681 * We've got freeze protection passed with the transaction.
1682 * Tell lockdep about it.
1684 if (ac->newtrans->type & __TRANS_FREEZABLE)
1685 __sb_writers_acquired(ac->root->fs_info->sb, SB_FREEZE_FS);
1687 current->journal_info = ac->newtrans;
1689 btrfs_commit_transaction(ac->newtrans, ac->root);
1693 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1694 struct btrfs_root *root,
1695 int wait_for_unblock)
1697 struct btrfs_async_commit *ac;
1698 struct btrfs_transaction *cur_trans;
1700 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1704 INIT_WORK(&ac->work, do_async_commit);
1706 ac->newtrans = btrfs_join_transaction(root);
1707 if (IS_ERR(ac->newtrans)) {
1708 int err = PTR_ERR(ac->newtrans);
1713 /* take transaction reference */
1714 cur_trans = trans->transaction;
1715 atomic_inc(&cur_trans->use_count);
1717 btrfs_end_transaction(trans, root);
1720 * Tell lockdep we've released the freeze rwsem, since the
1721 * async commit thread will be the one to unlock it.
1723 if (ac->newtrans->type & __TRANS_FREEZABLE)
1724 __sb_writers_release(root->fs_info->sb, SB_FREEZE_FS);
1726 schedule_work(&ac->work);
1728 /* wait for transaction to start and unblock */
1729 if (wait_for_unblock)
1730 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1732 wait_current_trans_commit_start(root, cur_trans);
1734 if (current->journal_info == trans)
1735 current->journal_info = NULL;
1737 btrfs_put_transaction(cur_trans);
1742 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1743 struct btrfs_root *root, int err)
1745 struct btrfs_transaction *cur_trans = trans->transaction;
1748 WARN_ON(trans->use_count > 1);
1750 btrfs_abort_transaction(trans, root, err);
1752 spin_lock(&root->fs_info->trans_lock);
1755 * If the transaction is removed from the list, it means this
1756 * transaction has been committed successfully, so it is impossible
1757 * to call the cleanup function.
1759 BUG_ON(list_empty(&cur_trans->list));
1761 list_del_init(&cur_trans->list);
1762 if (cur_trans == root->fs_info->running_transaction) {
1763 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1764 spin_unlock(&root->fs_info->trans_lock);
1765 wait_event(cur_trans->writer_wait,
1766 atomic_read(&cur_trans->num_writers) == 1);
1768 spin_lock(&root->fs_info->trans_lock);
1770 spin_unlock(&root->fs_info->trans_lock);
1772 btrfs_cleanup_one_transaction(trans->transaction, root);
1774 spin_lock(&root->fs_info->trans_lock);
1775 if (cur_trans == root->fs_info->running_transaction)
1776 root->fs_info->running_transaction = NULL;
1777 spin_unlock(&root->fs_info->trans_lock);
1779 if (trans->type & __TRANS_FREEZABLE)
1780 sb_end_intwrite(root->fs_info->sb);
1781 btrfs_put_transaction(cur_trans);
1782 btrfs_put_transaction(cur_trans);
1784 trace_btrfs_transaction_commit(root);
1786 if (current->journal_info == trans)
1787 current->journal_info = NULL;
1788 btrfs_scrub_cancel(root->fs_info);
1790 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1793 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1795 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1796 return btrfs_start_delalloc_roots(fs_info, 1, -1);
1800 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1802 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1803 btrfs_wait_ordered_roots(fs_info, -1);
1807 btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans,
1808 struct btrfs_fs_info *fs_info)
1810 struct btrfs_ordered_extent *ordered;
1812 spin_lock(&fs_info->trans_lock);
1813 while (!list_empty(&cur_trans->pending_ordered)) {
1814 ordered = list_first_entry(&cur_trans->pending_ordered,
1815 struct btrfs_ordered_extent,
1817 list_del_init(&ordered->trans_list);
1818 spin_unlock(&fs_info->trans_lock);
1820 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_COMPLETE,
1822 btrfs_put_ordered_extent(ordered);
1823 spin_lock(&fs_info->trans_lock);
1825 spin_unlock(&fs_info->trans_lock);
1828 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1829 struct btrfs_root *root)
1831 struct btrfs_transaction *cur_trans = trans->transaction;
1832 struct btrfs_transaction *prev_trans = NULL;
1833 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
1836 /* Stop the commit early if ->aborted is set */
1837 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1838 ret = cur_trans->aborted;
1839 btrfs_end_transaction(trans, root);
1843 /* make a pass through all the delayed refs we have so far
1844 * any runnings procs may add more while we are here
1846 ret = btrfs_run_delayed_refs(trans, root, 0);
1848 btrfs_end_transaction(trans, root);
1852 btrfs_trans_release_metadata(trans, root);
1853 trans->block_rsv = NULL;
1854 if (trans->qgroup_reserved) {
1855 btrfs_qgroup_free(root, trans->qgroup_reserved);
1856 trans->qgroup_reserved = 0;
1859 cur_trans = trans->transaction;
1862 * set the flushing flag so procs in this transaction have to
1863 * start sending their work down.
1865 cur_trans->delayed_refs.flushing = 1;
1868 if (!list_empty(&trans->new_bgs))
1869 btrfs_create_pending_block_groups(trans, root);
1871 ret = btrfs_run_delayed_refs(trans, root, 0);
1873 btrfs_end_transaction(trans, root);
1877 if (!cur_trans->dirty_bg_run) {
1880 /* this mutex is also taken before trying to set
1881 * block groups readonly. We need to make sure
1882 * that nobody has set a block group readonly
1883 * after a extents from that block group have been
1884 * allocated for cache files. btrfs_set_block_group_ro
1885 * will wait for the transaction to commit if it
1886 * finds dirty_bg_run = 1
1888 * The dirty_bg_run flag is also used to make sure only
1889 * one process starts all the block group IO. It wouldn't
1890 * hurt to have more than one go through, but there's no
1891 * real advantage to it either.
1893 mutex_lock(&root->fs_info->ro_block_group_mutex);
1894 if (!cur_trans->dirty_bg_run) {
1896 cur_trans->dirty_bg_run = 1;
1898 mutex_unlock(&root->fs_info->ro_block_group_mutex);
1901 ret = btrfs_start_dirty_block_groups(trans, root);
1904 btrfs_end_transaction(trans, root);
1908 spin_lock(&root->fs_info->trans_lock);
1909 list_splice_init(&trans->ordered, &cur_trans->pending_ordered);
1910 if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1911 spin_unlock(&root->fs_info->trans_lock);
1912 atomic_inc(&cur_trans->use_count);
1913 ret = btrfs_end_transaction(trans, root);
1915 wait_for_commit(root, cur_trans);
1917 if (unlikely(cur_trans->aborted))
1918 ret = cur_trans->aborted;
1920 btrfs_put_transaction(cur_trans);
1925 cur_trans->state = TRANS_STATE_COMMIT_START;
1926 wake_up(&root->fs_info->transaction_blocked_wait);
1928 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1929 prev_trans = list_entry(cur_trans->list.prev,
1930 struct btrfs_transaction, list);
1931 if (prev_trans->state != TRANS_STATE_COMPLETED) {
1932 atomic_inc(&prev_trans->use_count);
1933 spin_unlock(&root->fs_info->trans_lock);
1935 wait_for_commit(root, prev_trans);
1936 ret = prev_trans->aborted;
1938 btrfs_put_transaction(prev_trans);
1940 goto cleanup_transaction;
1942 spin_unlock(&root->fs_info->trans_lock);
1945 spin_unlock(&root->fs_info->trans_lock);
1948 extwriter_counter_dec(cur_trans, trans->type);
1950 ret = btrfs_start_delalloc_flush(root->fs_info);
1952 goto cleanup_transaction;
1954 ret = btrfs_run_delayed_items(trans, root);
1956 goto cleanup_transaction;
1958 wait_event(cur_trans->writer_wait,
1959 extwriter_counter_read(cur_trans) == 0);
1961 /* some pending stuffs might be added after the previous flush. */
1962 ret = btrfs_run_delayed_items(trans, root);
1964 goto cleanup_transaction;
1966 btrfs_wait_delalloc_flush(root->fs_info);
1968 btrfs_wait_pending_ordered(cur_trans, root->fs_info);
1970 btrfs_scrub_pause(root);
1972 * Ok now we need to make sure to block out any other joins while we
1973 * commit the transaction. We could have started a join before setting
1974 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1976 spin_lock(&root->fs_info->trans_lock);
1977 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1978 spin_unlock(&root->fs_info->trans_lock);
1979 wait_event(cur_trans->writer_wait,
1980 atomic_read(&cur_trans->num_writers) == 1);
1982 /* ->aborted might be set after the previous check, so check it */
1983 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1984 ret = cur_trans->aborted;
1985 goto scrub_continue;
1988 * the reloc mutex makes sure that we stop
1989 * the balancing code from coming in and moving
1990 * extents around in the middle of the commit
1992 mutex_lock(&root->fs_info->reloc_mutex);
1995 * We needn't worry about the delayed items because we will
1996 * deal with them in create_pending_snapshot(), which is the
1997 * core function of the snapshot creation.
1999 ret = create_pending_snapshots(trans, root->fs_info);
2001 mutex_unlock(&root->fs_info->reloc_mutex);
2002 goto scrub_continue;
2006 * We insert the dir indexes of the snapshots and update the inode
2007 * of the snapshots' parents after the snapshot creation, so there
2008 * are some delayed items which are not dealt with. Now deal with
2011 * We needn't worry that this operation will corrupt the snapshots,
2012 * because all the tree which are snapshoted will be forced to COW
2013 * the nodes and leaves.
2015 ret = btrfs_run_delayed_items(trans, root);
2017 mutex_unlock(&root->fs_info->reloc_mutex);
2018 goto scrub_continue;
2021 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
2023 mutex_unlock(&root->fs_info->reloc_mutex);
2024 goto scrub_continue;
2027 /* Reocrd old roots for later qgroup accounting */
2028 ret = btrfs_qgroup_prepare_account_extents(trans, root->fs_info);
2030 mutex_unlock(&root->fs_info->reloc_mutex);
2031 goto scrub_continue;
2035 * make sure none of the code above managed to slip in a
2038 btrfs_assert_delayed_root_empty(root);
2040 WARN_ON(cur_trans != trans->transaction);
2042 /* btrfs_commit_tree_roots is responsible for getting the
2043 * various roots consistent with each other. Every pointer
2044 * in the tree of tree roots has to point to the most up to date
2045 * root for every subvolume and other tree. So, we have to keep
2046 * the tree logging code from jumping in and changing any
2049 * At this point in the commit, there can't be any tree-log
2050 * writers, but a little lower down we drop the trans mutex
2051 * and let new people in. By holding the tree_log_mutex
2052 * from now until after the super is written, we avoid races
2053 * with the tree-log code.
2055 mutex_lock(&root->fs_info->tree_log_mutex);
2057 ret = commit_fs_roots(trans, root);
2059 mutex_unlock(&root->fs_info->tree_log_mutex);
2060 mutex_unlock(&root->fs_info->reloc_mutex);
2061 goto scrub_continue;
2065 * Since the transaction is done, we can apply the pending changes
2066 * before the next transaction.
2068 btrfs_apply_pending_changes(root->fs_info);
2070 /* commit_fs_roots gets rid of all the tree log roots, it is now
2071 * safe to free the root of tree log roots
2073 btrfs_free_log_root_tree(trans, root->fs_info);
2076 * Since fs roots are all committed, we can get a quite accurate
2077 * new_roots. So let's do quota accounting.
2079 ret = btrfs_qgroup_account_extents(trans, root->fs_info);
2081 mutex_unlock(&root->fs_info->tree_log_mutex);
2082 mutex_unlock(&root->fs_info->reloc_mutex);
2083 goto scrub_continue;
2086 ret = commit_cowonly_roots(trans, root);
2088 mutex_unlock(&root->fs_info->tree_log_mutex);
2089 mutex_unlock(&root->fs_info->reloc_mutex);
2090 goto scrub_continue;
2094 * The tasks which save the space cache and inode cache may also
2095 * update ->aborted, check it.
2097 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
2098 ret = cur_trans->aborted;
2099 mutex_unlock(&root->fs_info->tree_log_mutex);
2100 mutex_unlock(&root->fs_info->reloc_mutex);
2101 goto scrub_continue;
2104 btrfs_prepare_extent_commit(trans, root);
2106 cur_trans = root->fs_info->running_transaction;
2108 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
2109 root->fs_info->tree_root->node);
2110 list_add_tail(&root->fs_info->tree_root->dirty_list,
2111 &cur_trans->switch_commits);
2113 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
2114 root->fs_info->chunk_root->node);
2115 list_add_tail(&root->fs_info->chunk_root->dirty_list,
2116 &cur_trans->switch_commits);
2118 switch_commit_roots(cur_trans, root->fs_info);
2120 assert_qgroups_uptodate(trans);
2121 ASSERT(list_empty(&cur_trans->dirty_bgs));
2122 ASSERT(list_empty(&cur_trans->io_bgs));
2123 update_super_roots(root);
2125 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
2126 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
2127 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
2128 sizeof(*root->fs_info->super_copy));
2130 btrfs_update_commit_device_size(root->fs_info);
2131 btrfs_update_commit_device_bytes_used(root, cur_trans);
2133 clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
2134 clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
2136 btrfs_trans_release_chunk_metadata(trans);
2138 spin_lock(&root->fs_info->trans_lock);
2139 cur_trans->state = TRANS_STATE_UNBLOCKED;
2140 root->fs_info->running_transaction = NULL;
2141 spin_unlock(&root->fs_info->trans_lock);
2142 mutex_unlock(&root->fs_info->reloc_mutex);
2144 wake_up(&root->fs_info->transaction_wait);
2146 ret = btrfs_write_and_wait_transaction(trans, root);
2148 btrfs_std_error(root->fs_info, ret,
2149 "Error while writing out transaction");
2150 mutex_unlock(&root->fs_info->tree_log_mutex);
2151 goto scrub_continue;
2154 ret = write_ctree_super(trans, root, 0);
2156 mutex_unlock(&root->fs_info->tree_log_mutex);
2157 goto scrub_continue;
2161 * the super is written, we can safely allow the tree-loggers
2162 * to go about their business
2164 mutex_unlock(&root->fs_info->tree_log_mutex);
2166 btrfs_finish_extent_commit(trans, root);
2168 if (cur_trans->have_free_bgs)
2169 btrfs_clear_space_info_full(root->fs_info);
2171 root->fs_info->last_trans_committed = cur_trans->transid;
2173 * We needn't acquire the lock here because there is no other task
2174 * which can change it.
2176 cur_trans->state = TRANS_STATE_COMPLETED;
2177 wake_up(&cur_trans->commit_wait);
2179 spin_lock(&root->fs_info->trans_lock);
2180 list_del_init(&cur_trans->list);
2181 spin_unlock(&root->fs_info->trans_lock);
2183 btrfs_put_transaction(cur_trans);
2184 btrfs_put_transaction(cur_trans);
2186 if (trans->type & __TRANS_FREEZABLE)
2187 sb_end_intwrite(root->fs_info->sb);
2189 trace_btrfs_transaction_commit(root);
2191 btrfs_scrub_continue(root);
2193 if (current->journal_info == trans)
2194 current->journal_info = NULL;
2196 kmem_cache_free(btrfs_trans_handle_cachep, trans);
2198 if (current != root->fs_info->transaction_kthread &&
2199 current != root->fs_info->cleaner_kthread)
2200 btrfs_run_delayed_iputs(root);
2205 btrfs_scrub_continue(root);
2206 cleanup_transaction:
2207 btrfs_trans_release_metadata(trans, root);
2208 btrfs_trans_release_chunk_metadata(trans);
2209 trans->block_rsv = NULL;
2210 if (trans->qgroup_reserved) {
2211 btrfs_qgroup_free(root, trans->qgroup_reserved);
2212 trans->qgroup_reserved = 0;
2214 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
2215 if (current->journal_info == trans)
2216 current->journal_info = NULL;
2217 cleanup_transaction(trans, root, ret);
2223 * return < 0 if error
2224 * 0 if there are no more dead_roots at the time of call
2225 * 1 there are more to be processed, call me again
2227 * The return value indicates there are certainly more snapshots to delete, but
2228 * if there comes a new one during processing, it may return 0. We don't mind,
2229 * because btrfs_commit_super will poke cleaner thread and it will process it a
2230 * few seconds later.
2232 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
2235 struct btrfs_fs_info *fs_info = root->fs_info;
2237 spin_lock(&fs_info->trans_lock);
2238 if (list_empty(&fs_info->dead_roots)) {
2239 spin_unlock(&fs_info->trans_lock);
2242 root = list_first_entry(&fs_info->dead_roots,
2243 struct btrfs_root, root_list);
2244 list_del_init(&root->root_list);
2245 spin_unlock(&fs_info->trans_lock);
2247 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
2249 btrfs_kill_all_delayed_nodes(root);
2251 if (btrfs_header_backref_rev(root->node) <
2252 BTRFS_MIXED_BACKREF_REV)
2253 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
2255 ret = btrfs_drop_snapshot(root, NULL, 1, 0);
2257 return (ret < 0) ? 0 : 1;
2260 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info)
2265 prev = xchg(&fs_info->pending_changes, 0);
2269 bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE;
2271 btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2274 bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE;
2276 btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2279 bit = 1 << BTRFS_PENDING_COMMIT;
2281 btrfs_debug(fs_info, "pending commit done");
2286 "unknown pending changes left 0x%lx, ignoring", prev);