From d17260fd5f9cd5c112cbcbbfd3024186d34c02d7 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Mon, 11 Dec 2017 06:35:23 -0500
Subject: [PATCH 20/24] xfs: avoid setting XFS_ILOG_CORE if i_version doesn't
 need incrementing
Git-commit: d17260fd5f9cd5c112cbcbbfd3024186d34c02d7
Patch-mainline: v4.16-rc1
References: bsc#1081186

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>
Acked-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>

---
 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 5d5eccf96a17..a26799948c28 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;
-- 
2.10.0