[PATCH v5 17/19] xfs: avoid setting XFS_ILOG_CORE if i_version doesn't need incrementing

Jeff Layton
2018-01-09T14:11:52Z

If XFS_ILOG_CORE is already set then go ahead and increment it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/xfs_trans_inode.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_trans_inode.c b/fs/xfs/xfs_trans_inode.c
index 225544327c4f..4a89da4b6fe7 100644
--- a/fs/xfs/xfs_trans_inode.c
+++ b/fs/xfs/xfs_trans_inode.c
@@ -112,15 +112,17 @@ xfs_trans_log_inode(

/*
* First time we log the inode in a transaction, bump the inode change
- * counter if it is configured for this to occur. We don't use
- * inode_inc_version() because there is no need for extra locking around
- * i_version as we already hold the inode locked exclusively for
- * metadata modification.
+ * counter if it is configured for this to occur. While we have the
+ * inode locked exclusively for metadata modification, we can usually
+ * avoid setting XFS_ILOG_CORE if no one has queried the value since
+ * the last time it was incremented. If we have XFS_ILOG_CORE already
+ * set however, then go ahead and bump the i_version counter
+ * unconditionally.
*/
if (!(ip->i_itemp->ili_item.li_desc->lid_flags & XFS_LID_DIRTY) &&
IS_I_VERSION(VFS_I(ip))) {
- inode_inc_iversion(VFS_I(ip));
- flags |= XFS_ILOG_CORE;
+ if (inode_maybe_inc_iversion(VFS_I(ip), flags & XFS_ILOG_CORE))
+ flags |= XFS_ILOG_CORE;
}

tp->t_flags |= XFS_TRANS_DIRTY;
--
2.14.3