diff options
Diffstat (limited to 'fs/btrfs/transaction.c')
-rw-r--r-- | fs/btrfs/transaction.c | 120 |
1 files changed, 114 insertions, 6 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 03de89b45f27..b008c5110958 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -854,7 +854,37 @@ btrfs_attach_transaction_barrier(struct btrfs_root *root) static noinline void wait_for_commit(struct btrfs_transaction *commit, const enum btrfs_trans_state min_state) { - wait_event(commit->commit_wait, commit->state >= min_state); + struct btrfs_fs_info *fs_info = commit->fs_info; + u64 transid = commit->transid; + bool put = false; + + while (1) { + wait_event(commit->commit_wait, commit->state >= min_state); + if (put) + btrfs_put_transaction(commit); + + if (min_state < TRANS_STATE_COMPLETED) + break; + + /* + * A transaction isn't really completed until all of the + * previous transactions are completed, but with fsync we can + * end up with SUPER_COMMITTED transactions before a COMPLETED + * transaction. Wait for those. + */ + + spin_lock(&fs_info->trans_lock); + commit = list_first_entry_or_null(&fs_info->trans_list, + struct btrfs_transaction, + list); + if (!commit || commit->transid > transid) { + spin_unlock(&fs_info->trans_lock); + break; + } + refcount_inc(&commit->use_count); + put = true; + spin_unlock(&fs_info->trans_lock); + } } int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) @@ -1320,6 +1350,32 @@ again: } /* + * If we had a pending drop we need to see if there are any others left in our + * dead roots list, and if not clear our bit and wake any waiters. + */ +void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info) +{ + /* + * We put the drop in progress roots at the front of the list, so if the + * first entry doesn't have UNFINISHED_DROP set we can wake everybody + * up. + */ + spin_lock(&fs_info->trans_lock); + if (!list_empty(&fs_info->dead_roots)) { + struct btrfs_root *root = list_first_entry(&fs_info->dead_roots, + struct btrfs_root, + root_list); + if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) { + spin_unlock(&fs_info->trans_lock); + return; + } + } + spin_unlock(&fs_info->trans_lock); + + btrfs_wake_unfinished_drop(fs_info); +} + +/* * dead roots are old snapshots that need to be deleted. This allocates * a dirty root struct and adds it into the list of dead roots that need to * be deleted @@ -1331,7 +1387,12 @@ void btrfs_add_dead_root(struct btrfs_root *root) spin_lock(&fs_info->trans_lock); if (list_empty(&root->root_list)) { btrfs_grab_root(root); - list_add_tail(&root->root_list, &fs_info->dead_roots); + + /* We want to process the partially complete drops first. */ + if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) + list_add(&root->root_list, &fs_info->dead_roots); + else + list_add_tail(&root->root_list, &fs_info->dead_roots); } spin_unlock(&fs_info->trans_lock); } @@ -1850,6 +1911,14 @@ static void update_super_roots(struct btrfs_fs_info *fs_info) super->cache_generation = 0; if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) super->uuid_tree_generation = root_item->generation; + + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + root_item = &fs_info->block_group_root->root_item; + + super->block_group_root = root_item->bytenr; + super->block_group_root_generation = root_item->generation; + super->block_group_root_level = root_item->level; + } } int btrfs_transaction_in_commit(struct btrfs_fs_info *info) @@ -1981,16 +2050,24 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); return 0; } @@ -2000,6 +2077,27 @@ static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); } +/* + * Add a pending snapshot associated with the given transaction handle to the + * respective handle. This must be called after the transaction commit started + * and while holding fs_info->trans_lock. + * This serves to guarantee a caller of btrfs_commit_transaction() that it can + * safely free the pending snapshot pointer in case btrfs_commit_transaction() + * returns an error. + */ +static void add_pending_snapshot(struct btrfs_trans_handle *trans) +{ + struct btrfs_transaction *cur_trans = trans->transaction; + + if (!trans->pending_snapshot) + return; + + lockdep_assert_held(&trans->fs_info->trans_lock); + ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START); + + list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots); +} + int btrfs_commit_transaction(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; @@ -2073,6 +2171,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (cur_trans->state >= TRANS_STATE_COMMIT_START) { enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED; + add_pending_snapshot(trans); + spin_unlock(&fs_info->trans_lock); refcount_inc(&cur_trans->use_count); @@ -2163,6 +2263,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * COMMIT_DOING so make sure to wait for num_writers to == 1 again. */ spin_lock(&fs_info->trans_lock); + add_pending_snapshot(trans); cur_trans->state = TRANS_STATE_COMMIT_DOING; spin_unlock(&fs_info->trans_lock); wait_event(cur_trans->writer_wait, @@ -2269,6 +2370,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) list_add_tail(&fs_info->chunk_root->dirty_list, &cur_trans->switch_commits); + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + btrfs_set_root_node(&fs_info->block_group_root->root_item, + fs_info->block_group_root->node); + list_add_tail(&fs_info->block_group_root->dirty_list, + &cur_trans->switch_commits); + } + switch_commit_roots(trans); ASSERT(list_empty(&cur_trans->dirty_bgs)); @@ -2397,10 +2505,10 @@ cleanup_transaction: * because btrfs_commit_super will poke cleaner thread and it will process it a * few seconds later. */ -int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) +int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info) { + struct btrfs_root *root; int ret; - struct btrfs_fs_info *fs_info = root->fs_info; spin_lock(&fs_info->trans_lock); if (list_empty(&fs_info->dead_roots)) { |