From: Christoph Hellwig <hch@lst.de>
Date: Thu, 2 May 2024 07:33:54 +0000 (+0200)
Subject: xfs: remove a racy if_bytes check in xfs_reflink_end_cow_extent
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=86de848403abda05bf9c16dcdb6bef65a8d88c41;p=linux.git

xfs: remove a racy if_bytes check in xfs_reflink_end_cow_extent

Accessing if_bytes without the ilock is racy.  Remove the initial
if_bytes == 0 check in xfs_reflink_end_cow_extent and let
ext_iext_lookup_extent fail for this case after we've taken the ilock.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
---

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 93f775c13b664..520f5ef3743c4 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -712,12 +712,6 @@ xfs_reflink_end_cow_extent(
 	int			nmaps;
 	int			error;
 
-	/* No COW extents?  That's easy! */
-	if (ifp->if_bytes == 0) {
-		*offset_fsb = end_fsb;
-		return 0;
-	}
-
 	resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0,
 			XFS_TRANS_RESERVE, &tp);