From 46d8bc34248f3a94dea910137d1ddf5fb1e3a1cc Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Wed, 29 Aug 2012 01:07:55 -0600 Subject: [PATCH] Btrfs: fix a bug in checking whether a inode is already in log This is based on Josef's "Btrfs: turbo charge fsync". The current btrfs checks if an inode is in log by comparing root's last_log_commit to inode's last_sub_trans[2]. But the problem is that this root->last_log_commit is shared among inodes. Say we have N inodes to be logged, after the first inode, root's last_log_commit is updated and the N-1 remained files will be skipped. This fixes the bug by keeping a local copy of root's last_log_commit inside each inode and this local copy will be maintained itself. [1]: we regard each log transaction as a subset of btrfs's transaction, i.e. sub_trans Signed-off-by: Liu Bo --- fs/btrfs/btrfs_inode.h | 14 ++++++-------- fs/btrfs/inode.c | 2 ++ fs/btrfs/transaction.h | 1 + fs/btrfs/tree-log.c | 1 + 4 files changed, 10 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 7c7bf818f3c1..ed8ca7ca5eff 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -144,6 +144,9 @@ struct btrfs_inode { /* flags field from the on disk inode */ u32 flags; + /* a local copy of root's last_log_commit */ + unsigned long last_log_commit; + /* * Counters to keep track of the number of extent item's we may use due * to delalloc and such. outstanding_extents is the number of extent @@ -203,15 +206,10 @@ static inline bool btrfs_is_free_space_inode(struct inode *inode) static inline int btrfs_inode_in_log(struct inode *inode, u64 generation) { - struct btrfs_root *root = BTRFS_I(inode)->root; - int ret = 0; - - mutex_lock(&root->log_mutex); if (BTRFS_I(inode)->logged_trans == generation && - BTRFS_I(inode)->last_sub_trans <= root->last_log_commit) - ret = 1; - mutex_unlock(&root->log_mutex); - return ret; + BTRFS_I(inode)->last_sub_trans <= BTRFS_I(inode)->last_log_commit) + return 1; + return 0; } #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a6824bd04493..24745b8f2745 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6774,6 +6774,7 @@ again: BTRFS_I(inode)->last_trans = root->fs_info->generation; BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; + BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); @@ -7018,6 +7019,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->csum_bytes = 0; ei->index_cnt = (u64)-1; ei->last_unlink_trans = 0; + ei->last_log_commit = 0; spin_lock_init(&ei->lock); ei->outstanding_extents = 0; diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index e8b8416c688b..1a138bfb8f13 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -88,6 +88,7 @@ static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, { BTRFS_I(inode)->last_trans = trans->transaction->transid; BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; + BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; } int btrfs_end_transaction(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 71e71539ffb7..fc0df95c2862 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3185,6 +3185,7 @@ next_slot: } } BTRFS_I(inode)->logged_trans = trans->transid; + BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans; out_unlock: mutex_unlock(&BTRFS_I(inode)->log_mutex); -- 2.30.2