[PATCH 5.10 CANDIDATE 6/6] xfs: only bother with sync_filesystem during readonly remount

[Amir Goldstein <amir73il@gmail.com>]

From: "Darrick J. Wong" <djwong@kernel.org>

commit b97cca3ba9098522e5a1c3388764ead42640c1a5 upstream.

In commit 02b9984d6408, we pushed a sync_filesystem() call from the VFS
into xfs_fs_remount.  The only time that we ever need to push dirty file
data or metadata to disk for a remount is if we're remounting the
filesystem read only, so this really could be moved to xfs_remount_ro.

Once we've moved the call site, actually check the return value from
sync_filesystem.

Fixes: 02b9984d6408 ("fs: push sync_filesystem() down to the file system's remount_fs()")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/xfs/xfs_super.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ff686cb16c7b..434c87cc9fbf 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1720,6 +1720,11 @@ xfs_remount_ro(
 	};
 	int			error;
 
+	/* Flush all the dirty data to disk. */
+	error = sync_filesystem(mp->m_super);
+	if (error)
+		return error;
+
 	/*
 	 * Cancel background eofb scanning so it cannot race with the final
 	 * log force+buftarg wait and deadlock the remount.
@@ -1790,8 +1795,6 @@ xfs_fc_reconfigure(
 	if (error)
 		return error;
 
-	sync_filesystem(mp->m_super);
-
 	/* inode32 -> inode64 */
 	if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) &&
 	    !(new_mp->m_flags & XFS_MOUNT_SMALL_INUMS)) {
-- 
2.25.1