xfs: optimize log flushing in xfs_fsync
If we have a pinned inode it must have a log item attached to it.
Usually that log item will have ili_last_lsn already set, in which
case we only need to flush the log up to that LSN instead of doing a
full log force. This gives speedups of about 5% in some fsync heavy
workloads.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 43241e2..ddd2c5d 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -629,8 +629,14 @@
*/
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (xfs_ipincount(ip)) {
- error = _xfs_log_force(ip->i_mount, XFS_LOG_SYNC,
- &log_flushed);
+ if (ip->i_itemp->ili_last_lsn) {
+ error = _xfs_log_force_lsn(ip->i_mount,
+ ip->i_itemp->ili_last_lsn,
+ XFS_LOG_SYNC, &log_flushed);
+ } else {
+ error = _xfs_log_force(ip->i_mount,
+ XFS_LOG_SYNC, &log_flushed);
+ }
}
} else {
/*