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);
79 * If any block groups are found in ->deleted_bgs then it's
80 * because the transaction was aborted and a commit did not
81 * happen (things failed before writing the new superblock
82 * and calling btrfs_finish_extent_commit()), so we can not
83 * discard the physical locations of the block groups.
85 while (!list_empty(&transaction->deleted_bgs)) {
86 struct btrfs_block_group_cache *cache;
88 cache = list_first_entry(&transaction->deleted_bgs,
89 struct btrfs_block_group_cache,
91 list_del_init(&cache->bg_list);
92 btrfs_put_block_group_trimming(cache);
93 btrfs_put_block_group(cache);
95 kmem_cache_free(btrfs_transaction_cachep, transaction);
99 static void clear_btree_io_tree(struct extent_io_tree *tree)
101 spin_lock(&tree->lock);
103 * Do a single barrier for the waitqueue_active check here, the state
104 * of the waitqueue should not change once clear_btree_io_tree is
108 while (!RB_EMPTY_ROOT(&tree->state)) {
109 struct rb_node *node;
110 struct extent_state *state;
112 node = rb_first(&tree->state);
113 state = rb_entry(node, struct extent_state, rb_node);
114 rb_erase(&state->rb_node, &tree->state);
115 RB_CLEAR_NODE(&state->rb_node);
117 * btree io trees aren't supposed to have tasks waiting for
118 * changes in the flags of extent states ever.
120 ASSERT(!waitqueue_active(&state->wq));
121 free_extent_state(state);
123 cond_resched_lock(&tree->lock);
125 spin_unlock(&tree->lock);
128 static noinline void switch_commit_roots(struct btrfs_transaction *trans,
129 struct btrfs_fs_info *fs_info)
131 struct btrfs_root *root, *tmp;
133 down_write(&fs_info->commit_root_sem);
134 list_for_each_entry_safe(root, tmp, &trans->switch_commits,
136 list_del_init(&root->dirty_list);
137 free_extent_buffer(root->commit_root);
138 root->commit_root = btrfs_root_node(root);
139 if (is_fstree(root->objectid))
140 btrfs_unpin_free_ino(root);
141 clear_btree_io_tree(&root->dirty_log_pages);
144 /* We can free old roots now. */
145 spin_lock(&trans->dropped_roots_lock);
146 while (!list_empty(&trans->dropped_roots)) {
147 root = list_first_entry(&trans->dropped_roots,
148 struct btrfs_root, root_list);
149 list_del_init(&root->root_list);
150 spin_unlock(&trans->dropped_roots_lock);
151 btrfs_drop_and_free_fs_root(fs_info, root);
152 spin_lock(&trans->dropped_roots_lock);
154 spin_unlock(&trans->dropped_roots_lock);
155 up_write(&fs_info->commit_root_sem);
158 static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
161 if (type & TRANS_EXTWRITERS)
162 atomic_inc(&trans->num_extwriters);
165 static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
168 if (type & TRANS_EXTWRITERS)
169 atomic_dec(&trans->num_extwriters);
172 static inline void extwriter_counter_init(struct btrfs_transaction *trans,
175 atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
178 static inline int extwriter_counter_read(struct btrfs_transaction *trans)
180 return atomic_read(&trans->num_extwriters);
184 * either allocate a new transaction or hop into the existing one
186 static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
188 struct btrfs_transaction *cur_trans;
189 struct btrfs_fs_info *fs_info = root->fs_info;
191 spin_lock(&fs_info->trans_lock);
193 /* The file system has been taken offline. No new transactions. */
194 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
195 spin_unlock(&fs_info->trans_lock);
199 cur_trans = fs_info->running_transaction;
201 if (cur_trans->aborted) {
202 spin_unlock(&fs_info->trans_lock);
203 return cur_trans->aborted;
205 if (btrfs_blocked_trans_types[cur_trans->state] & type) {
206 spin_unlock(&fs_info->trans_lock);
209 atomic_inc(&cur_trans->use_count);
210 atomic_inc(&cur_trans->num_writers);
211 extwriter_counter_inc(cur_trans, type);
212 spin_unlock(&fs_info->trans_lock);
215 spin_unlock(&fs_info->trans_lock);
218 * If we are ATTACH, we just want to catch the current transaction,
219 * and commit it. If there is no transaction, just return ENOENT.
221 if (type == TRANS_ATTACH)
225 * JOIN_NOLOCK only happens during the transaction commit, so
226 * it is impossible that ->running_transaction is NULL
228 BUG_ON(type == TRANS_JOIN_NOLOCK);
230 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
234 spin_lock(&fs_info->trans_lock);
235 if (fs_info->running_transaction) {
237 * someone started a transaction after we unlocked. Make sure
238 * to redo the checks above
240 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
242 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
243 spin_unlock(&fs_info->trans_lock);
244 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
248 atomic_set(&cur_trans->num_writers, 1);
249 extwriter_counter_init(cur_trans, type);
250 init_waitqueue_head(&cur_trans->writer_wait);
251 init_waitqueue_head(&cur_trans->commit_wait);
252 init_waitqueue_head(&cur_trans->pending_wait);
253 cur_trans->state = TRANS_STATE_RUNNING;
255 * One for this trans handle, one so it will live on until we
256 * commit the transaction.
258 atomic_set(&cur_trans->use_count, 2);
259 atomic_set(&cur_trans->pending_ordered, 0);
260 cur_trans->flags = 0;
261 cur_trans->start_time = get_seconds();
263 memset(&cur_trans->delayed_refs, 0, sizeof(cur_trans->delayed_refs));
265 cur_trans->delayed_refs.href_root = RB_ROOT;
266 cur_trans->delayed_refs.dirty_extent_root = RB_ROOT;
267 atomic_set(&cur_trans->delayed_refs.num_entries, 0);
270 * although the tree mod log is per file system and not per transaction,
271 * the log must never go across transaction boundaries.
274 if (!list_empty(&fs_info->tree_mod_seq_list))
275 WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
276 "creating a fresh transaction\n");
277 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
278 WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
279 "creating a fresh transaction\n");
280 atomic64_set(&fs_info->tree_mod_seq, 0);
282 spin_lock_init(&cur_trans->delayed_refs.lock);
284 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
285 INIT_LIST_HEAD(&cur_trans->pending_chunks);
286 INIT_LIST_HEAD(&cur_trans->switch_commits);
287 INIT_LIST_HEAD(&cur_trans->dirty_bgs);
288 INIT_LIST_HEAD(&cur_trans->io_bgs);
289 INIT_LIST_HEAD(&cur_trans->dropped_roots);
290 mutex_init(&cur_trans->cache_write_mutex);
291 cur_trans->num_dirty_bgs = 0;
292 spin_lock_init(&cur_trans->dirty_bgs_lock);
293 INIT_LIST_HEAD(&cur_trans->deleted_bgs);
294 spin_lock_init(&cur_trans->dropped_roots_lock);
295 list_add_tail(&cur_trans->list, &fs_info->trans_list);
296 extent_io_tree_init(&cur_trans->dirty_pages,
297 fs_info->btree_inode->i_mapping);
298 fs_info->generation++;
299 cur_trans->transid = fs_info->generation;
300 fs_info->running_transaction = cur_trans;
301 cur_trans->aborted = 0;
302 spin_unlock(&fs_info->trans_lock);
308 * this does all the record keeping required to make sure that a reference
309 * counted root is properly recorded in a given transaction. This is required
310 * to make sure the old root from before we joined the transaction is deleted
311 * when the transaction commits
313 static int record_root_in_trans(struct btrfs_trans_handle *trans,
314 struct btrfs_root *root)
316 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
317 root->last_trans < trans->transid) {
318 WARN_ON(root == root->fs_info->extent_root);
319 WARN_ON(root->commit_root != root->node);
322 * see below for IN_TRANS_SETUP usage rules
323 * we have the reloc mutex held now, so there
324 * is only one writer in this function
326 set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
328 /* make sure readers find IN_TRANS_SETUP before
329 * they find our root->last_trans update
333 spin_lock(&root->fs_info->fs_roots_radix_lock);
334 if (root->last_trans == trans->transid) {
335 spin_unlock(&root->fs_info->fs_roots_radix_lock);
338 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
339 (unsigned long)root->root_key.objectid,
340 BTRFS_ROOT_TRANS_TAG);
341 spin_unlock(&root->fs_info->fs_roots_radix_lock);
342 root->last_trans = trans->transid;
344 /* this is pretty tricky. We don't want to
345 * take the relocation lock in btrfs_record_root_in_trans
346 * unless we're really doing the first setup for this root in
349 * Normally we'd use root->last_trans as a flag to decide
350 * if we want to take the expensive mutex.
352 * But, we have to set root->last_trans before we
353 * init the relocation root, otherwise, we trip over warnings
354 * in ctree.c. The solution used here is to flag ourselves
355 * with root IN_TRANS_SETUP. When this is 1, we're still
356 * fixing up the reloc trees and everyone must wait.
358 * When this is zero, they can trust root->last_trans and fly
359 * through btrfs_record_root_in_trans without having to take the
360 * lock. smp_wmb() makes sure that all the writes above are
361 * done before we pop in the zero below
363 btrfs_init_reloc_root(trans, root);
364 smp_mb__before_atomic();
365 clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
371 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
372 struct btrfs_root *root)
374 struct btrfs_transaction *cur_trans = trans->transaction;
376 /* Add ourselves to the transaction dropped list */
377 spin_lock(&cur_trans->dropped_roots_lock);
378 list_add_tail(&root->root_list, &cur_trans->dropped_roots);
379 spin_unlock(&cur_trans->dropped_roots_lock);
381 /* Make sure we don't try to update the root at commit time */
382 spin_lock(&root->fs_info->fs_roots_radix_lock);
383 radix_tree_tag_clear(&root->fs_info->fs_roots_radix,
384 (unsigned long)root->root_key.objectid,
385 BTRFS_ROOT_TRANS_TAG);
386 spin_unlock(&root->fs_info->fs_roots_radix_lock);
389 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
390 struct btrfs_root *root)
392 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
396 * see record_root_in_trans for comments about IN_TRANS_SETUP usage
400 if (root->last_trans == trans->transid &&
401 !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state))
404 mutex_lock(&root->fs_info->reloc_mutex);
405 record_root_in_trans(trans, root);
406 mutex_unlock(&root->fs_info->reloc_mutex);
411 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
413 return (trans->state >= TRANS_STATE_BLOCKED &&
414 trans->state < TRANS_STATE_UNBLOCKED &&
418 /* wait for commit against the current transaction to become unblocked
419 * when this is done, it is safe to start a new transaction, but the current
420 * transaction might not be fully on disk.
422 static void wait_current_trans(struct btrfs_root *root)
424 struct btrfs_transaction *cur_trans;
426 spin_lock(&root->fs_info->trans_lock);
427 cur_trans = root->fs_info->running_transaction;
428 if (cur_trans && is_transaction_blocked(cur_trans)) {
429 atomic_inc(&cur_trans->use_count);
430 spin_unlock(&root->fs_info->trans_lock);
432 wait_event(root->fs_info->transaction_wait,
433 cur_trans->state >= TRANS_STATE_UNBLOCKED ||
435 btrfs_put_transaction(cur_trans);
437 spin_unlock(&root->fs_info->trans_lock);
441 static int may_wait_transaction(struct btrfs_root *root, int type)
443 if (root->fs_info->log_root_recovering)
446 if (type == TRANS_USERSPACE)
449 if (type == TRANS_START &&
450 !atomic_read(&root->fs_info->open_ioctl_trans))
456 static inline bool need_reserve_reloc_root(struct btrfs_root *root)
458 if (!root->fs_info->reloc_ctl ||
459 !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
460 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
467 static struct btrfs_trans_handle *
468 start_transaction(struct btrfs_root *root, unsigned int num_items,
469 unsigned int type, enum btrfs_reserve_flush_enum flush)
471 struct btrfs_trans_handle *h;
472 struct btrfs_transaction *cur_trans;
474 u64 qgroup_reserved = 0;
475 bool reloc_reserved = false;
478 /* Send isn't supposed to start transactions. */
479 ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
481 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
482 return ERR_PTR(-EROFS);
484 if (current->journal_info) {
485 WARN_ON(type & TRANS_EXTWRITERS);
486 h = current->journal_info;
488 WARN_ON(h->use_count > 2);
489 h->orig_rsv = h->block_rsv;
495 * Do the reservation before we join the transaction so we can do all
496 * the appropriate flushing if need be.
498 if (num_items > 0 && root != root->fs_info->chunk_root) {
499 qgroup_reserved = num_items * root->nodesize;
500 ret = btrfs_qgroup_reserve_meta(root, qgroup_reserved);
504 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
506 * Do the reservation for the relocation root creation
508 if (need_reserve_reloc_root(root)) {
509 num_bytes += root->nodesize;
510 reloc_reserved = true;
513 ret = btrfs_block_rsv_add(root,
514 &root->fs_info->trans_block_rsv,
520 h = kmem_cache_zalloc(btrfs_trans_handle_cachep, GFP_NOFS);
527 * If we are JOIN_NOLOCK we're already committing a transaction and
528 * waiting on this guy, so we don't need to do the sb_start_intwrite
529 * because we're already holding a ref. We need this because we could
530 * have raced in and did an fsync() on a file which can kick a commit
531 * and then we deadlock with somebody doing a freeze.
533 * If we are ATTACH, it means we just want to catch the current
534 * transaction and commit it, so we needn't do sb_start_intwrite().
536 if (type & __TRANS_FREEZABLE)
537 sb_start_intwrite(root->fs_info->sb);
539 if (may_wait_transaction(root, type))
540 wait_current_trans(root);
543 ret = join_transaction(root, type);
545 wait_current_trans(root);
546 if (unlikely(type == TRANS_ATTACH))
549 } while (ret == -EBUSY);
552 /* We must get the transaction if we are JOIN_NOLOCK. */
553 BUG_ON(type == TRANS_JOIN_NOLOCK);
557 cur_trans = root->fs_info->running_transaction;
559 h->transid = cur_trans->transid;
560 h->transaction = cur_trans;
565 h->can_flush_pending_bgs = true;
566 INIT_LIST_HEAD(&h->qgroup_ref_list);
567 INIT_LIST_HEAD(&h->new_bgs);
570 if (cur_trans->state >= TRANS_STATE_BLOCKED &&
571 may_wait_transaction(root, type)) {
572 current->journal_info = h;
573 btrfs_commit_transaction(h, root);
578 trace_btrfs_space_reservation(root->fs_info, "transaction",
579 h->transid, num_bytes, 1);
580 h->block_rsv = &root->fs_info->trans_block_rsv;
581 h->bytes_reserved = num_bytes;
582 h->reloc_reserved = reloc_reserved;
586 btrfs_record_root_in_trans(h, root);
588 if (!current->journal_info && type != TRANS_USERSPACE)
589 current->journal_info = h;
593 if (type & __TRANS_FREEZABLE)
594 sb_end_intwrite(root->fs_info->sb);
595 kmem_cache_free(btrfs_trans_handle_cachep, h);
598 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
601 btrfs_qgroup_free_meta(root, qgroup_reserved);
605 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
606 unsigned int num_items)
608 return start_transaction(root, num_items, TRANS_START,
609 BTRFS_RESERVE_FLUSH_ALL);
611 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
612 struct btrfs_root *root,
613 unsigned int num_items,
616 struct btrfs_trans_handle *trans;
620 trans = btrfs_start_transaction(root, num_items);
621 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
624 trans = btrfs_start_transaction(root, 0);
628 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
629 ret = btrfs_cond_migrate_bytes(root->fs_info,
630 &root->fs_info->trans_block_rsv,
634 btrfs_end_transaction(trans, root);
638 trans->block_rsv = &root->fs_info->trans_block_rsv;
639 trans->bytes_reserved = num_bytes;
644 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
645 struct btrfs_root *root,
646 unsigned int num_items)
648 return start_transaction(root, num_items, TRANS_START,
649 BTRFS_RESERVE_FLUSH_LIMIT);
652 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
654 return start_transaction(root, 0, TRANS_JOIN,
655 BTRFS_RESERVE_NO_FLUSH);
658 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
660 return start_transaction(root, 0, TRANS_JOIN_NOLOCK,
661 BTRFS_RESERVE_NO_FLUSH);
664 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
666 return start_transaction(root, 0, TRANS_USERSPACE,
667 BTRFS_RESERVE_NO_FLUSH);
671 * btrfs_attach_transaction() - catch the running transaction
673 * It is used when we want to commit the current the transaction, but
674 * don't want to start a new one.
676 * Note: If this function return -ENOENT, it just means there is no
677 * running transaction. But it is possible that the inactive transaction
678 * is still in the memory, not fully on disk. If you hope there is no
679 * inactive transaction in the fs when -ENOENT is returned, you should
681 * btrfs_attach_transaction_barrier()
683 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
685 return start_transaction(root, 0, TRANS_ATTACH,
686 BTRFS_RESERVE_NO_FLUSH);
690 * btrfs_attach_transaction_barrier() - catch the running transaction
692 * It is similar to the above function, the differentia is this one
693 * will wait for all the inactive transactions until they fully
696 struct btrfs_trans_handle *
697 btrfs_attach_transaction_barrier(struct btrfs_root *root)
699 struct btrfs_trans_handle *trans;
701 trans = start_transaction(root, 0, TRANS_ATTACH,
702 BTRFS_RESERVE_NO_FLUSH);
703 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
704 btrfs_wait_for_commit(root, 0);
709 /* wait for a transaction commit to be fully complete */
710 static noinline void wait_for_commit(struct btrfs_root *root,
711 struct btrfs_transaction *commit)
713 wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
716 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
718 struct btrfs_transaction *cur_trans = NULL, *t;
722 if (transid <= root->fs_info->last_trans_committed)
725 /* find specified transaction */
726 spin_lock(&root->fs_info->trans_lock);
727 list_for_each_entry(t, &root->fs_info->trans_list, list) {
728 if (t->transid == transid) {
730 atomic_inc(&cur_trans->use_count);
734 if (t->transid > transid) {
739 spin_unlock(&root->fs_info->trans_lock);
742 * The specified transaction doesn't exist, or we
743 * raced with btrfs_commit_transaction
746 if (transid > root->fs_info->last_trans_committed)
751 /* find newest transaction that is committing | committed */
752 spin_lock(&root->fs_info->trans_lock);
753 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
755 if (t->state >= TRANS_STATE_COMMIT_START) {
756 if (t->state == TRANS_STATE_COMPLETED)
759 atomic_inc(&cur_trans->use_count);
763 spin_unlock(&root->fs_info->trans_lock);
765 goto out; /* nothing committing|committed */
768 wait_for_commit(root, cur_trans);
769 btrfs_put_transaction(cur_trans);
774 void btrfs_throttle(struct btrfs_root *root)
776 if (!atomic_read(&root->fs_info->open_ioctl_trans))
777 wait_current_trans(root);
780 static int should_end_transaction(struct btrfs_trans_handle *trans,
781 struct btrfs_root *root)
783 if (root->fs_info->global_block_rsv.space_info->full &&
784 btrfs_check_space_for_delayed_refs(trans, root))
787 return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
790 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
791 struct btrfs_root *root)
793 struct btrfs_transaction *cur_trans = trans->transaction;
798 if (cur_trans->state >= TRANS_STATE_BLOCKED ||
799 cur_trans->delayed_refs.flushing)
802 updates = trans->delayed_ref_updates;
803 trans->delayed_ref_updates = 0;
805 err = btrfs_run_delayed_refs(trans, root, updates * 2);
806 if (err) /* Error code will also eval true */
810 return should_end_transaction(trans, root);
813 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
814 struct btrfs_root *root, int throttle)
816 struct btrfs_transaction *cur_trans = trans->transaction;
817 struct btrfs_fs_info *info = root->fs_info;
818 unsigned long cur = trans->delayed_ref_updates;
819 int lock = (trans->type != TRANS_JOIN_NOLOCK);
821 int must_run_delayed_refs = 0;
823 if (trans->use_count > 1) {
825 trans->block_rsv = trans->orig_rsv;
829 btrfs_trans_release_metadata(trans, root);
830 trans->block_rsv = NULL;
832 if (!list_empty(&trans->new_bgs))
833 btrfs_create_pending_block_groups(trans, root);
835 trans->delayed_ref_updates = 0;
837 must_run_delayed_refs =
838 btrfs_should_throttle_delayed_refs(trans, root);
839 cur = max_t(unsigned long, cur, 32);
842 * don't make the caller wait if they are from a NOLOCK
843 * or ATTACH transaction, it will deadlock with commit
845 if (must_run_delayed_refs == 1 &&
846 (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
847 must_run_delayed_refs = 2;
850 btrfs_trans_release_metadata(trans, root);
851 trans->block_rsv = NULL;
853 if (!list_empty(&trans->new_bgs))
854 btrfs_create_pending_block_groups(trans, root);
856 btrfs_trans_release_chunk_metadata(trans);
858 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
859 should_end_transaction(trans, root) &&
860 ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
861 spin_lock(&info->trans_lock);
862 if (cur_trans->state == TRANS_STATE_RUNNING)
863 cur_trans->state = TRANS_STATE_BLOCKED;
864 spin_unlock(&info->trans_lock);
867 if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
869 return btrfs_commit_transaction(trans, root);
871 wake_up_process(info->transaction_kthread);
874 if (trans->type & __TRANS_FREEZABLE)
875 sb_end_intwrite(root->fs_info->sb);
877 WARN_ON(cur_trans != info->running_transaction);
878 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
879 atomic_dec(&cur_trans->num_writers);
880 extwriter_counter_dec(cur_trans, trans->type);
883 * Make sure counter is updated before we wake up waiters.
886 if (waitqueue_active(&cur_trans->writer_wait))
887 wake_up(&cur_trans->writer_wait);
888 btrfs_put_transaction(cur_trans);
890 if (current->journal_info == trans)
891 current->journal_info = NULL;
894 btrfs_run_delayed_iputs(root);
896 if (trans->aborted ||
897 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
898 wake_up_process(info->transaction_kthread);
901 assert_qgroups_uptodate(trans);
903 kmem_cache_free(btrfs_trans_handle_cachep, trans);
904 if (must_run_delayed_refs) {
905 btrfs_async_run_delayed_refs(root, cur,
906 must_run_delayed_refs == 1);
911 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
912 struct btrfs_root *root)
914 return __btrfs_end_transaction(trans, root, 0);
917 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
918 struct btrfs_root *root)
920 return __btrfs_end_transaction(trans, root, 1);
924 * when btree blocks are allocated, they have some corresponding bits set for
925 * them in one of two extent_io trees. This is used to make sure all of
926 * those extents are sent to disk but does not wait on them
928 int btrfs_write_marked_extents(struct btrfs_root *root,
929 struct extent_io_tree *dirty_pages, int mark)
933 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
934 struct extent_state *cached_state = NULL;
938 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
939 mark, &cached_state)) {
940 bool wait_writeback = false;
942 err = convert_extent_bit(dirty_pages, start, end,
944 mark, &cached_state, GFP_NOFS);
946 * convert_extent_bit can return -ENOMEM, which is most of the
947 * time a temporary error. So when it happens, ignore the error
948 * and wait for writeback of this range to finish - because we
949 * failed to set the bit EXTENT_NEED_WAIT for the range, a call
950 * to btrfs_wait_marked_extents() would not know that writeback
951 * for this range started and therefore wouldn't wait for it to
952 * finish - we don't want to commit a superblock that points to
953 * btree nodes/leafs for which writeback hasn't finished yet
954 * (and without errors).
955 * We cleanup any entries left in the io tree when committing
956 * the transaction (through clear_btree_io_tree()).
958 if (err == -ENOMEM) {
960 wait_writeback = true;
963 err = filemap_fdatawrite_range(mapping, start, end);
966 else if (wait_writeback)
967 werr = filemap_fdatawait_range(mapping, start, end);
968 free_extent_state(cached_state);
977 * when btree blocks are allocated, they have some corresponding bits set for
978 * them in one of two extent_io trees. This is used to make sure all of
979 * those extents are on disk for transaction or log commit. We wait
980 * on all the pages and clear them from the dirty pages state tree
982 int btrfs_wait_marked_extents(struct btrfs_root *root,
983 struct extent_io_tree *dirty_pages, int mark)
987 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
988 struct extent_state *cached_state = NULL;
991 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
994 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
995 EXTENT_NEED_WAIT, &cached_state)) {
997 * Ignore -ENOMEM errors returned by clear_extent_bit().
998 * When committing the transaction, we'll remove any entries
999 * left in the io tree. For a log commit, we don't remove them
1000 * after committing the log because the tree can be accessed
1001 * concurrently - we do it only at transaction commit time when
1002 * it's safe to do it (through clear_btree_io_tree()).
1004 err = clear_extent_bit(dirty_pages, start, end,
1006 0, 0, &cached_state, GFP_NOFS);
1010 err = filemap_fdatawait_range(mapping, start, end);
1013 free_extent_state(cached_state);
1014 cached_state = NULL;
1021 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1022 if ((mark & EXTENT_DIRTY) &&
1023 test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
1024 &btree_ino->runtime_flags))
1027 if ((mark & EXTENT_NEW) &&
1028 test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
1029 &btree_ino->runtime_flags))
1032 if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
1033 &btree_ino->runtime_flags))
1037 if (errors && !werr)
1044 * when btree blocks are allocated, they have some corresponding bits set for
1045 * them in one of two extent_io trees. This is used to make sure all of
1046 * those extents are on disk for transaction or log commit
1048 static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
1049 struct extent_io_tree *dirty_pages, int mark)
1053 struct blk_plug plug;
1055 blk_start_plug(&plug);
1056 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
1057 blk_finish_plug(&plug);
1058 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
1067 static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
1068 struct btrfs_root *root)
1072 ret = btrfs_write_and_wait_marked_extents(root,
1073 &trans->transaction->dirty_pages,
1075 clear_btree_io_tree(&trans->transaction->dirty_pages);
1081 * this is used to update the root pointer in the tree of tree roots.
1083 * But, in the case of the extent allocation tree, updating the root
1084 * pointer may allocate blocks which may change the root of the extent
1087 * So, this loops and repeats and makes sure the cowonly root didn't
1088 * change while the root pointer was being updated in the metadata.
1090 static int update_cowonly_root(struct btrfs_trans_handle *trans,
1091 struct btrfs_root *root)
1094 u64 old_root_bytenr;
1096 struct btrfs_root *tree_root = root->fs_info->tree_root;
1098 old_root_used = btrfs_root_used(&root->root_item);
1101 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
1102 if (old_root_bytenr == root->node->start &&
1103 old_root_used == btrfs_root_used(&root->root_item))
1106 btrfs_set_root_node(&root->root_item, root->node);
1107 ret = btrfs_update_root(trans, tree_root,
1113 old_root_used = btrfs_root_used(&root->root_item);
1120 * update all the cowonly tree roots on disk
1122 * The error handling in this function may not be obvious. Any of the
1123 * failures will cause the file system to go offline. We still need
1124 * to clean up the delayed refs.
1126 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
1127 struct btrfs_root *root)
1129 struct btrfs_fs_info *fs_info = root->fs_info;
1130 struct list_head *dirty_bgs = &trans->transaction->dirty_bgs;
1131 struct list_head *io_bgs = &trans->transaction->io_bgs;
1132 struct list_head *next;
1133 struct extent_buffer *eb;
1136 eb = btrfs_lock_root_node(fs_info->tree_root);
1137 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
1139 btrfs_tree_unlock(eb);
1140 free_extent_buffer(eb);
1145 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1149 ret = btrfs_run_dev_stats(trans, root->fs_info);
1152 ret = btrfs_run_dev_replace(trans, root->fs_info);
1155 ret = btrfs_run_qgroups(trans, root->fs_info);
1159 ret = btrfs_setup_space_cache(trans, root);
1163 /* run_qgroups might have added some more refs */
1164 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1168 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
1169 next = fs_info->dirty_cowonly_roots.next;
1170 list_del_init(next);
1171 root = list_entry(next, struct btrfs_root, dirty_list);
1172 clear_bit(BTRFS_ROOT_DIRTY, &root->state);
1174 if (root != fs_info->extent_root)
1175 list_add_tail(&root->dirty_list,
1176 &trans->transaction->switch_commits);
1177 ret = update_cowonly_root(trans, root);
1180 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1185 while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) {
1186 ret = btrfs_write_dirty_block_groups(trans, root);
1189 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1194 if (!list_empty(&fs_info->dirty_cowonly_roots))
1197 list_add_tail(&fs_info->extent_root->dirty_list,
1198 &trans->transaction->switch_commits);
1199 btrfs_after_dev_replace_commit(fs_info);
1205 * dead roots are old snapshots that need to be deleted. This allocates
1206 * a dirty root struct and adds it into the list of dead roots that need to
1209 void btrfs_add_dead_root(struct btrfs_root *root)
1211 spin_lock(&root->fs_info->trans_lock);
1212 if (list_empty(&root->root_list))
1213 list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1214 spin_unlock(&root->fs_info->trans_lock);
1218 * update all the cowonly tree roots on disk
1220 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1221 struct btrfs_root *root)
1223 struct btrfs_root *gang[8];
1224 struct btrfs_fs_info *fs_info = root->fs_info;
1229 spin_lock(&fs_info->fs_roots_radix_lock);
1231 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1234 BTRFS_ROOT_TRANS_TAG);
1237 for (i = 0; i < ret; i++) {
1239 radix_tree_tag_clear(&fs_info->fs_roots_radix,
1240 (unsigned long)root->root_key.objectid,
1241 BTRFS_ROOT_TRANS_TAG);
1242 spin_unlock(&fs_info->fs_roots_radix_lock);
1244 btrfs_free_log(trans, root);
1245 btrfs_update_reloc_root(trans, root);
1246 btrfs_orphan_commit_root(trans, root);
1248 btrfs_save_ino_cache(root, trans);
1250 /* see comments in should_cow_block() */
1251 clear_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1252 smp_mb__after_atomic();
1254 if (root->commit_root != root->node) {
1255 list_add_tail(&root->dirty_list,
1256 &trans->transaction->switch_commits);
1257 btrfs_set_root_node(&root->root_item,
1261 err = btrfs_update_root(trans, fs_info->tree_root,
1264 spin_lock(&fs_info->fs_roots_radix_lock);
1267 btrfs_qgroup_free_meta_all(root);
1270 spin_unlock(&fs_info->fs_roots_radix_lock);
1275 * defrag a given btree.
1276 * Every leaf in the btree is read and defragged.
1278 int btrfs_defrag_root(struct btrfs_root *root)
1280 struct btrfs_fs_info *info = root->fs_info;
1281 struct btrfs_trans_handle *trans;
1284 if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
1288 trans = btrfs_start_transaction(root, 0);
1290 return PTR_ERR(trans);
1292 ret = btrfs_defrag_leaves(trans, root);
1294 btrfs_end_transaction(trans, root);
1295 btrfs_btree_balance_dirty(info->tree_root);
1298 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1301 if (btrfs_defrag_cancelled(root->fs_info)) {
1302 pr_debug("BTRFS: defrag_root cancelled\n");
1307 clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
1312 * new snapshots need to be created at a very specific time in the
1313 * transaction commit. This does the actual creation.
1316 * If the error which may affect the commitment of the current transaction
1317 * happens, we should return the error number. If the error which just affect
1318 * the creation of the pending snapshots, just return 0.
1320 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1321 struct btrfs_fs_info *fs_info,
1322 struct btrfs_pending_snapshot *pending)
1324 struct btrfs_key key;
1325 struct btrfs_root_item *new_root_item;
1326 struct btrfs_root *tree_root = fs_info->tree_root;
1327 struct btrfs_root *root = pending->root;
1328 struct btrfs_root *parent_root;
1329 struct btrfs_block_rsv *rsv;
1330 struct inode *parent_inode;
1331 struct btrfs_path *path;
1332 struct btrfs_dir_item *dir_item;
1333 struct dentry *dentry;
1334 struct extent_buffer *tmp;
1335 struct extent_buffer *old;
1336 struct timespec cur_time = CURRENT_TIME;
1344 ASSERT(pending->path);
1345 path = pending->path;
1347 ASSERT(pending->root_item);
1348 new_root_item = pending->root_item;
1350 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1352 goto no_free_objectid;
1355 * Make qgroup to skip current new snapshot's qgroupid, as it is
1356 * accounted by later btrfs_qgroup_inherit().
1358 btrfs_set_skip_qgroup(trans, objectid);
1360 btrfs_reloc_pre_snapshot(pending, &to_reserve);
1362 if (to_reserve > 0) {
1363 pending->error = btrfs_block_rsv_add(root,
1364 &pending->block_rsv,
1366 BTRFS_RESERVE_NO_FLUSH);
1368 goto clear_skip_qgroup;
1371 key.objectid = objectid;
1372 key.offset = (u64)-1;
1373 key.type = BTRFS_ROOT_ITEM_KEY;
1375 rsv = trans->block_rsv;
1376 trans->block_rsv = &pending->block_rsv;
1377 trans->bytes_reserved = trans->block_rsv->reserved;
1379 dentry = pending->dentry;
1380 parent_inode = pending->dir;
1381 parent_root = BTRFS_I(parent_inode)->root;
1382 record_root_in_trans(trans, parent_root);
1385 * insert the directory item
1387 ret = btrfs_set_inode_index(parent_inode, &index);
1388 BUG_ON(ret); /* -ENOMEM */
1390 /* check if there is a file/dir which has the same name. */
1391 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1392 btrfs_ino(parent_inode),
1393 dentry->d_name.name,
1394 dentry->d_name.len, 0);
1395 if (dir_item != NULL && !IS_ERR(dir_item)) {
1396 pending->error = -EEXIST;
1397 goto dir_item_existed;
1398 } else if (IS_ERR(dir_item)) {
1399 ret = PTR_ERR(dir_item);
1400 btrfs_abort_transaction(trans, root, ret);
1403 btrfs_release_path(path);
1406 * pull in the delayed directory update
1407 * and the delayed inode item
1408 * otherwise we corrupt the FS during
1411 ret = btrfs_run_delayed_items(trans, root);
1412 if (ret) { /* Transaction aborted */
1413 btrfs_abort_transaction(trans, root, ret);
1417 record_root_in_trans(trans, root);
1418 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1419 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1420 btrfs_check_and_init_root_item(new_root_item);
1422 root_flags = btrfs_root_flags(new_root_item);
1423 if (pending->readonly)
1424 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1426 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1427 btrfs_set_root_flags(new_root_item, root_flags);
1429 btrfs_set_root_generation_v2(new_root_item,
1431 uuid_le_gen(&new_uuid);
1432 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1433 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1435 if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1436 memset(new_root_item->received_uuid, 0,
1437 sizeof(new_root_item->received_uuid));
1438 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1439 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1440 btrfs_set_root_stransid(new_root_item, 0);
1441 btrfs_set_root_rtransid(new_root_item, 0);
1443 btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1444 btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1445 btrfs_set_root_otransid(new_root_item, trans->transid);
1447 old = btrfs_lock_root_node(root);
1448 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1450 btrfs_tree_unlock(old);
1451 free_extent_buffer(old);
1452 btrfs_abort_transaction(trans, root, ret);
1456 btrfs_set_lock_blocking(old);
1458 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1459 /* clean up in any case */
1460 btrfs_tree_unlock(old);
1461 free_extent_buffer(old);
1463 btrfs_abort_transaction(trans, root, ret);
1466 /* see comments in should_cow_block() */
1467 set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1470 btrfs_set_root_node(new_root_item, tmp);
1471 /* record when the snapshot was created in key.offset */
1472 key.offset = trans->transid;
1473 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1474 btrfs_tree_unlock(tmp);
1475 free_extent_buffer(tmp);
1477 btrfs_abort_transaction(trans, root, ret);
1482 * insert root back/forward references
1484 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1485 parent_root->root_key.objectid,
1486 btrfs_ino(parent_inode), index,
1487 dentry->d_name.name, dentry->d_name.len);
1489 btrfs_abort_transaction(trans, root, ret);
1493 key.offset = (u64)-1;
1494 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1495 if (IS_ERR(pending->snap)) {
1496 ret = PTR_ERR(pending->snap);
1497 btrfs_abort_transaction(trans, root, ret);
1501 ret = btrfs_reloc_post_snapshot(trans, pending);
1503 btrfs_abort_transaction(trans, root, ret);
1507 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1509 btrfs_abort_transaction(trans, root, ret);
1513 ret = btrfs_insert_dir_item(trans, parent_root,
1514 dentry->d_name.name, dentry->d_name.len,
1516 BTRFS_FT_DIR, index);
1517 /* We have check then name at the beginning, so it is impossible. */
1518 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1520 btrfs_abort_transaction(trans, root, ret);
1524 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1525 dentry->d_name.len * 2);
1526 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1527 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1529 btrfs_abort_transaction(trans, root, ret);
1532 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1533 BTRFS_UUID_KEY_SUBVOL, objectid);
1535 btrfs_abort_transaction(trans, root, ret);
1538 if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1539 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1540 new_root_item->received_uuid,
1541 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1543 if (ret && ret != -EEXIST) {
1544 btrfs_abort_transaction(trans, root, ret);
1549 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1551 btrfs_abort_transaction(trans, root, ret);
1556 * account qgroup counters before qgroup_inherit()
1558 ret = btrfs_qgroup_prepare_account_extents(trans, fs_info);
1561 ret = btrfs_qgroup_account_extents(trans, fs_info);
1564 ret = btrfs_qgroup_inherit(trans, fs_info,
1565 root->root_key.objectid,
1566 objectid, pending->inherit);
1568 btrfs_abort_transaction(trans, root, ret);
1573 pending->error = ret;
1575 trans->block_rsv = rsv;
1576 trans->bytes_reserved = 0;
1578 btrfs_clear_skip_qgroup(trans);
1580 kfree(new_root_item);
1581 pending->root_item = NULL;
1582 btrfs_free_path(path);
1583 pending->path = NULL;
1589 * create all the snapshots we've scheduled for creation
1591 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1592 struct btrfs_fs_info *fs_info)
1594 struct btrfs_pending_snapshot *pending, *next;
1595 struct list_head *head = &trans->transaction->pending_snapshots;
1598 list_for_each_entry_safe(pending, next, head, list) {
1599 list_del(&pending->list);
1600 ret = create_pending_snapshot(trans, fs_info, pending);
1607 static void update_super_roots(struct btrfs_root *root)
1609 struct btrfs_root_item *root_item;
1610 struct btrfs_super_block *super;
1612 super = root->fs_info->super_copy;
1614 root_item = &root->fs_info->chunk_root->root_item;
1615 super->chunk_root = root_item->bytenr;
1616 super->chunk_root_generation = root_item->generation;
1617 super->chunk_root_level = root_item->level;
1619 root_item = &root->fs_info->tree_root->root_item;
1620 super->root = root_item->bytenr;
1621 super->generation = root_item->generation;
1622 super->root_level = root_item->level;
1623 if (btrfs_test_opt(root, SPACE_CACHE))
1624 super->cache_generation = root_item->generation;
1625 if (root->fs_info->update_uuid_tree_gen)
1626 super->uuid_tree_generation = root_item->generation;
1629 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1631 struct btrfs_transaction *trans;
1634 spin_lock(&info->trans_lock);
1635 trans = info->running_transaction;
1637 ret = (trans->state >= TRANS_STATE_COMMIT_START);
1638 spin_unlock(&info->trans_lock);
1642 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1644 struct btrfs_transaction *trans;
1647 spin_lock(&info->trans_lock);
1648 trans = info->running_transaction;
1650 ret = is_transaction_blocked(trans);
1651 spin_unlock(&info->trans_lock);
1656 * wait for the current transaction commit to start and block subsequent
1659 static void wait_current_trans_commit_start(struct btrfs_root *root,
1660 struct btrfs_transaction *trans)
1662 wait_event(root->fs_info->transaction_blocked_wait,
1663 trans->state >= TRANS_STATE_COMMIT_START ||
1668 * wait for the current transaction to start and then become unblocked.
1671 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1672 struct btrfs_transaction *trans)
1674 wait_event(root->fs_info->transaction_wait,
1675 trans->state >= TRANS_STATE_UNBLOCKED ||
1680 * commit transactions asynchronously. once btrfs_commit_transaction_async
1681 * returns, any subsequent transaction will not be allowed to join.
1683 struct btrfs_async_commit {
1684 struct btrfs_trans_handle *newtrans;
1685 struct btrfs_root *root;
1686 struct work_struct work;
1689 static void do_async_commit(struct work_struct *work)
1691 struct btrfs_async_commit *ac =
1692 container_of(work, struct btrfs_async_commit, work);
1695 * We've got freeze protection passed with the transaction.
1696 * Tell lockdep about it.
1698 if (ac->newtrans->type & __TRANS_FREEZABLE)
1699 __sb_writers_acquired(ac->root->fs_info->sb, SB_FREEZE_FS);
1701 current->journal_info = ac->newtrans;
1703 btrfs_commit_transaction(ac->newtrans, ac->root);
1707 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1708 struct btrfs_root *root,
1709 int wait_for_unblock)
1711 struct btrfs_async_commit *ac;
1712 struct btrfs_transaction *cur_trans;
1714 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1718 INIT_WORK(&ac->work, do_async_commit);
1720 ac->newtrans = btrfs_join_transaction(root);
1721 if (IS_ERR(ac->newtrans)) {
1722 int err = PTR_ERR(ac->newtrans);
1727 /* take transaction reference */
1728 cur_trans = trans->transaction;
1729 atomic_inc(&cur_trans->use_count);
1731 btrfs_end_transaction(trans, root);
1734 * Tell lockdep we've released the freeze rwsem, since the
1735 * async commit thread will be the one to unlock it.
1737 if (ac->newtrans->type & __TRANS_FREEZABLE)
1738 __sb_writers_release(root->fs_info->sb, SB_FREEZE_FS);
1740 schedule_work(&ac->work);
1742 /* wait for transaction to start and unblock */
1743 if (wait_for_unblock)
1744 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1746 wait_current_trans_commit_start(root, cur_trans);
1748 if (current->journal_info == trans)
1749 current->journal_info = NULL;
1751 btrfs_put_transaction(cur_trans);
1756 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1757 struct btrfs_root *root, int err)
1759 struct btrfs_transaction *cur_trans = trans->transaction;
1762 WARN_ON(trans->use_count > 1);
1764 btrfs_abort_transaction(trans, root, err);
1766 spin_lock(&root->fs_info->trans_lock);
1769 * If the transaction is removed from the list, it means this
1770 * transaction has been committed successfully, so it is impossible
1771 * to call the cleanup function.
1773 BUG_ON(list_empty(&cur_trans->list));
1775 list_del_init(&cur_trans->list);
1776 if (cur_trans == root->fs_info->running_transaction) {
1777 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1778 spin_unlock(&root->fs_info->trans_lock);
1779 wait_event(cur_trans->writer_wait,
1780 atomic_read(&cur_trans->num_writers) == 1);
1782 spin_lock(&root->fs_info->trans_lock);
1784 spin_unlock(&root->fs_info->trans_lock);
1786 btrfs_cleanup_one_transaction(trans->transaction, root);
1788 spin_lock(&root->fs_info->trans_lock);
1789 if (cur_trans == root->fs_info->running_transaction)
1790 root->fs_info->running_transaction = NULL;
1791 spin_unlock(&root->fs_info->trans_lock);
1793 if (trans->type & __TRANS_FREEZABLE)
1794 sb_end_intwrite(root->fs_info->sb);
1795 btrfs_put_transaction(cur_trans);
1796 btrfs_put_transaction(cur_trans);
1798 trace_btrfs_transaction_commit(root);
1800 if (current->journal_info == trans)
1801 current->journal_info = NULL;
1802 btrfs_scrub_cancel(root->fs_info);
1804 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1807 static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1809 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1810 return btrfs_start_delalloc_roots(fs_info, 1, -1);
1814 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1816 if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1817 btrfs_wait_ordered_roots(fs_info, -1);
1821 btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans)
1823 wait_event(cur_trans->pending_wait,
1824 atomic_read(&cur_trans->pending_ordered) == 0);
1827 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1828 struct btrfs_root *root)
1830 struct btrfs_transaction *cur_trans = trans->transaction;
1831 struct btrfs_transaction *prev_trans = NULL;
1832 struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
1835 /* Stop the commit early if ->aborted is set */
1836 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1837 ret = cur_trans->aborted;
1838 btrfs_end_transaction(trans, root);
1842 /* make a pass through all the delayed refs we have so far
1843 * any runnings procs may add more while we are here
1845 ret = btrfs_run_delayed_refs(trans, root, 0);
1847 btrfs_end_transaction(trans, root);
1851 btrfs_trans_release_metadata(trans, root);
1852 trans->block_rsv = NULL;
1854 cur_trans = trans->transaction;
1857 * set the flushing flag so procs in this transaction have to
1858 * start sending their work down.
1860 cur_trans->delayed_refs.flushing = 1;
1863 if (!list_empty(&trans->new_bgs))
1864 btrfs_create_pending_block_groups(trans, root);
1866 ret = btrfs_run_delayed_refs(trans, root, 0);
1868 btrfs_end_transaction(trans, root);
1872 if (!test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &cur_trans->flags)) {
1875 /* this mutex is also taken before trying to set
1876 * block groups readonly. We need to make sure
1877 * that nobody has set a block group readonly
1878 * after a extents from that block group have been
1879 * allocated for cache files. btrfs_set_block_group_ro
1880 * will wait for the transaction to commit if it
1881 * finds BTRFS_TRANS_DIRTY_BG_RUN set.
1883 * The BTRFS_TRANS_DIRTY_BG_RUN flag is also used to make sure
1884 * only one process starts all the block group IO. It wouldn't
1885 * hurt to have more than one go through, but there's no
1886 * real advantage to it either.
1888 mutex_lock(&root->fs_info->ro_block_group_mutex);
1889 if (!test_and_set_bit(BTRFS_TRANS_DIRTY_BG_RUN,
1892 mutex_unlock(&root->fs_info->ro_block_group_mutex);
1895 ret = btrfs_start_dirty_block_groups(trans, root);
1898 btrfs_end_transaction(trans, root);
1902 spin_lock(&root->fs_info->trans_lock);
1903 if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1904 spin_unlock(&root->fs_info->trans_lock);
1905 atomic_inc(&cur_trans->use_count);
1906 ret = btrfs_end_transaction(trans, root);
1908 wait_for_commit(root, cur_trans);
1910 if (unlikely(cur_trans->aborted))
1911 ret = cur_trans->aborted;
1913 btrfs_put_transaction(cur_trans);
1918 cur_trans->state = TRANS_STATE_COMMIT_START;
1919 wake_up(&root->fs_info->transaction_blocked_wait);
1921 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1922 prev_trans = list_entry(cur_trans->list.prev,
1923 struct btrfs_transaction, list);
1924 if (prev_trans->state != TRANS_STATE_COMPLETED) {
1925 atomic_inc(&prev_trans->use_count);
1926 spin_unlock(&root->fs_info->trans_lock);
1928 wait_for_commit(root, prev_trans);
1929 ret = prev_trans->aborted;
1931 btrfs_put_transaction(prev_trans);
1933 goto cleanup_transaction;
1935 spin_unlock(&root->fs_info->trans_lock);
1938 spin_unlock(&root->fs_info->trans_lock);
1941 extwriter_counter_dec(cur_trans, trans->type);
1943 ret = btrfs_start_delalloc_flush(root->fs_info);
1945 goto cleanup_transaction;
1947 ret = btrfs_run_delayed_items(trans, root);
1949 goto cleanup_transaction;
1951 wait_event(cur_trans->writer_wait,
1952 extwriter_counter_read(cur_trans) == 0);
1954 /* some pending stuffs might be added after the previous flush. */
1955 ret = btrfs_run_delayed_items(trans, root);
1957 goto cleanup_transaction;
1959 btrfs_wait_delalloc_flush(root->fs_info);
1961 btrfs_wait_pending_ordered(cur_trans);
1963 btrfs_scrub_pause(root);
1965 * Ok now we need to make sure to block out any other joins while we
1966 * commit the transaction. We could have started a join before setting
1967 * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1969 spin_lock(&root->fs_info->trans_lock);
1970 cur_trans->state = TRANS_STATE_COMMIT_DOING;
1971 spin_unlock(&root->fs_info->trans_lock);
1972 wait_event(cur_trans->writer_wait,
1973 atomic_read(&cur_trans->num_writers) == 1);
1975 /* ->aborted might be set after the previous check, so check it */
1976 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1977 ret = cur_trans->aborted;
1978 goto scrub_continue;
1981 * the reloc mutex makes sure that we stop
1982 * the balancing code from coming in and moving
1983 * extents around in the middle of the commit
1985 mutex_lock(&root->fs_info->reloc_mutex);
1988 * We needn't worry about the delayed items because we will
1989 * deal with them in create_pending_snapshot(), which is the
1990 * core function of the snapshot creation.
1992 ret = create_pending_snapshots(trans, root->fs_info);
1994 mutex_unlock(&root->fs_info->reloc_mutex);
1995 goto scrub_continue;
1999 * We insert the dir indexes of the snapshots and update the inode
2000 * of the snapshots' parents after the snapshot creation, so there
2001 * are some delayed items which are not dealt with. Now deal with
2004 * We needn't worry that this operation will corrupt the snapshots,
2005 * because all the tree which are snapshoted will be forced to COW
2006 * the nodes and leaves.
2008 ret = btrfs_run_delayed_items(trans, root);
2010 mutex_unlock(&root->fs_info->reloc_mutex);
2011 goto scrub_continue;
2014 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
2016 mutex_unlock(&root->fs_info->reloc_mutex);
2017 goto scrub_continue;
2020 /* Reocrd old roots for later qgroup accounting */
2021 ret = btrfs_qgroup_prepare_account_extents(trans, root->fs_info);
2023 mutex_unlock(&root->fs_info->reloc_mutex);
2024 goto scrub_continue;
2028 * make sure none of the code above managed to slip in a
2031 btrfs_assert_delayed_root_empty(root);
2033 WARN_ON(cur_trans != trans->transaction);
2035 /* btrfs_commit_tree_roots is responsible for getting the
2036 * various roots consistent with each other. Every pointer
2037 * in the tree of tree roots has to point to the most up to date
2038 * root for every subvolume and other tree. So, we have to keep
2039 * the tree logging code from jumping in and changing any
2042 * At this point in the commit, there can't be any tree-log
2043 * writers, but a little lower down we drop the trans mutex
2044 * and let new people in. By holding the tree_log_mutex
2045 * from now until after the super is written, we avoid races
2046 * with the tree-log code.
2048 mutex_lock(&root->fs_info->tree_log_mutex);
2050 ret = commit_fs_roots(trans, root);
2052 mutex_unlock(&root->fs_info->tree_log_mutex);
2053 mutex_unlock(&root->fs_info->reloc_mutex);
2054 goto scrub_continue;
2058 * Since the transaction is done, we can apply the pending changes
2059 * before the next transaction.
2061 btrfs_apply_pending_changes(root->fs_info);
2063 /* commit_fs_roots gets rid of all the tree log roots, it is now
2064 * safe to free the root of tree log roots
2066 btrfs_free_log_root_tree(trans, root->fs_info);
2069 * Since fs roots are all committed, we can get a quite accurate
2070 * new_roots. So let's do quota accounting.
2072 ret = btrfs_qgroup_account_extents(trans, root->fs_info);
2074 mutex_unlock(&root->fs_info->tree_log_mutex);
2075 mutex_unlock(&root->fs_info->reloc_mutex);
2076 goto scrub_continue;
2079 ret = commit_cowonly_roots(trans, root);
2081 mutex_unlock(&root->fs_info->tree_log_mutex);
2082 mutex_unlock(&root->fs_info->reloc_mutex);
2083 goto scrub_continue;
2087 * The tasks which save the space cache and inode cache may also
2088 * update ->aborted, check it.
2090 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
2091 ret = cur_trans->aborted;
2092 mutex_unlock(&root->fs_info->tree_log_mutex);
2093 mutex_unlock(&root->fs_info->reloc_mutex);
2094 goto scrub_continue;
2097 btrfs_prepare_extent_commit(trans, root);
2099 cur_trans = root->fs_info->running_transaction;
2101 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
2102 root->fs_info->tree_root->node);
2103 list_add_tail(&root->fs_info->tree_root->dirty_list,
2104 &cur_trans->switch_commits);
2106 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
2107 root->fs_info->chunk_root->node);
2108 list_add_tail(&root->fs_info->chunk_root->dirty_list,
2109 &cur_trans->switch_commits);
2111 switch_commit_roots(cur_trans, root->fs_info);
2113 assert_qgroups_uptodate(trans);
2114 ASSERT(list_empty(&cur_trans->dirty_bgs));
2115 ASSERT(list_empty(&cur_trans->io_bgs));
2116 update_super_roots(root);
2118 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
2119 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
2120 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
2121 sizeof(*root->fs_info->super_copy));
2123 btrfs_update_commit_device_size(root->fs_info);
2124 btrfs_update_commit_device_bytes_used(root, cur_trans);
2126 clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
2127 clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
2129 btrfs_trans_release_chunk_metadata(trans);
2131 spin_lock(&root->fs_info->trans_lock);
2132 cur_trans->state = TRANS_STATE_UNBLOCKED;
2133 root->fs_info->running_transaction = NULL;
2134 spin_unlock(&root->fs_info->trans_lock);
2135 mutex_unlock(&root->fs_info->reloc_mutex);
2137 wake_up(&root->fs_info->transaction_wait);
2139 ret = btrfs_write_and_wait_transaction(trans, root);
2141 btrfs_std_error(root->fs_info, ret,
2142 "Error while writing out transaction");
2143 mutex_unlock(&root->fs_info->tree_log_mutex);
2144 goto scrub_continue;
2147 ret = write_ctree_super(trans, root, 0);
2149 mutex_unlock(&root->fs_info->tree_log_mutex);
2150 goto scrub_continue;
2154 * the super is written, we can safely allow the tree-loggers
2155 * to go about their business
2157 mutex_unlock(&root->fs_info->tree_log_mutex);
2159 btrfs_finish_extent_commit(trans, root);
2161 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &cur_trans->flags))
2162 btrfs_clear_space_info_full(root->fs_info);
2164 root->fs_info->last_trans_committed = cur_trans->transid;
2166 * We needn't acquire the lock here because there is no other task
2167 * which can change it.
2169 cur_trans->state = TRANS_STATE_COMPLETED;
2170 wake_up(&cur_trans->commit_wait);
2172 spin_lock(&root->fs_info->trans_lock);
2173 list_del_init(&cur_trans->list);
2174 spin_unlock(&root->fs_info->trans_lock);
2176 btrfs_put_transaction(cur_trans);
2177 btrfs_put_transaction(cur_trans);
2179 if (trans->type & __TRANS_FREEZABLE)
2180 sb_end_intwrite(root->fs_info->sb);
2182 trace_btrfs_transaction_commit(root);
2184 btrfs_scrub_continue(root);
2186 if (current->journal_info == trans)
2187 current->journal_info = NULL;
2189 kmem_cache_free(btrfs_trans_handle_cachep, trans);
2191 if (current != root->fs_info->transaction_kthread &&
2192 current != root->fs_info->cleaner_kthread)
2193 btrfs_run_delayed_iputs(root);
2198 btrfs_scrub_continue(root);
2199 cleanup_transaction:
2200 btrfs_trans_release_metadata(trans, root);
2201 btrfs_trans_release_chunk_metadata(trans);
2202 trans->block_rsv = NULL;
2203 btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
2204 if (current->journal_info == trans)
2205 current->journal_info = NULL;
2206 cleanup_transaction(trans, root, ret);
2212 * return < 0 if error
2213 * 0 if there are no more dead_roots at the time of call
2214 * 1 there are more to be processed, call me again
2216 * The return value indicates there are certainly more snapshots to delete, but
2217 * if there comes a new one during processing, it may return 0. We don't mind,
2218 * because btrfs_commit_super will poke cleaner thread and it will process it a
2219 * few seconds later.
2221 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
2224 struct btrfs_fs_info *fs_info = root->fs_info;
2226 spin_lock(&fs_info->trans_lock);
2227 if (list_empty(&fs_info->dead_roots)) {
2228 spin_unlock(&fs_info->trans_lock);
2231 root = list_first_entry(&fs_info->dead_roots,
2232 struct btrfs_root, root_list);
2233 list_del_init(&root->root_list);
2234 spin_unlock(&fs_info->trans_lock);
2236 pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
2238 btrfs_kill_all_delayed_nodes(root);
2240 if (btrfs_header_backref_rev(root->node) <
2241 BTRFS_MIXED_BACKREF_REV)
2242 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
2244 ret = btrfs_drop_snapshot(root, NULL, 1, 0);
2246 return (ret < 0) ? 0 : 1;
2249 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info)
2254 prev = xchg(&fs_info->pending_changes, 0);
2258 bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE;
2260 btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2263 bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE;
2265 btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE);
2268 bit = 1 << BTRFS_PENDING_COMMIT;
2270 btrfs_debug(fs_info, "pending commit done");
2275 "unknown pending changes left 0x%lx, ignoring", prev);