diff options
| author | Chris Mason <chris.mason@oracle.com> | 2009-10-13 13:21:08 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2009-10-13 13:35:12 -0400 |
| commit | 257c62e1bce03e5b9f3f069fd52ad73a56de71fd (patch) | |
| tree | ad047fe5796156aa88e3f3600111bf2b8d12759f /fs/btrfs/transaction.h | |
| parent | 4722607db6a78bd7748c51fa4c8d7371da797254 (diff) | |
| download | lwn-257c62e1bce03e5b9f3f069fd52ad73a56de71fd.tar.gz lwn-257c62e1bce03e5b9f3f069fd52ad73a56de71fd.zip | |
Btrfs: avoid tree log commit when there are no changes
rpm has a habit of running fdatasync when the file hasn't
changed. We already detect if a file hasn't been changed
in the current transaction but it might have been sent to
the tree-log in this transaction and not changed since
the last call to fsync.
In this case, we want to avoid a tree log sync, which includes
a number of synchronous writes and barriers. This commit
extends the existing tracking of the last transaction to change
a file to also track the last sub-transaction.
The end result is that rpm -ivh and -Uvh are roughly twice as fast,
and on par with ext3.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/transaction.h')
| -rw-r--r-- | fs/btrfs/transaction.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 663c67404918..f68cbbe61e56 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -79,6 +79,7 @@ static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, struct inode *inode) { BTRFS_I(inode)->last_trans = trans->transaction->transid; + BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; } int btrfs_end_transaction(struct btrfs_trans_handle *trans, |