[PATCH 2/6] xfs: cleanup xfs_ilock_iocb_for_write

[Christoph Hellwig <hch@lst.de>]

Move the relock path out of the straight line and add a comment
explaining why it exists.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/xfs_file.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b240ea5241dc9d..74c2c8d253e69b 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -213,14 +213,18 @@ xfs_ilock_iocb_for_write(
 	if (ret)
 		return ret;
 
-	if (*lock_mode == XFS_IOLOCK_EXCL)
-		return 0;
-	if (!xfs_iflags_test(ip, XFS_IREMAPPING))
-		return 0;
+	/*
+	 * If a reflink remap is in progress we always need to take the iolock
+	 * exclusively to wait for it to finish.
+	 */
+	if (*lock_mode == XFS_IOLOCK_SHARED &&
+	    xfs_iflags_test(ip, XFS_IREMAPPING)) {
+		xfs_iunlock(ip, *lock_mode);
+		*lock_mode = XFS_IOLOCK_EXCL;
+		return xfs_ilock_iocb(iocb, *lock_mode);
+	}
 
-	xfs_iunlock(ip, *lock_mode);
-	*lock_mode = XFS_IOLOCK_EXCL;
-	return xfs_ilock_iocb(iocb, *lock_mode);
+	return 0;
 }
 
 static unsigned int
-- 
2.43.0