From 36c00a3073e1c64aa0cef472827429939e4ec998 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Fri, 15 Nov 2019 17:16:22 -0500
Subject: [PATCH] xfs: reinitialize rm_flags when unpacking an offset into an
 rmap irec

Source kernel commit: ffb5696f7555e44c04b7c1212fcd83ddedc43498

In xfs_rmap_irec_offset_unpack, we should always clear the contents of
rm_flags before we begin unpacking the encoded (ondisk) offset into the
incore rm_offset and incore rm_flags fields.  Remove the open-coded
field zeroing as this encourages api misuse.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net
---
 libxfs/xfs_rmap.c | 1 -
 libxfs/xfs_rmap.h | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/libxfs/xfs_rmap.c b/libxfs/xfs_rmap.c
index d9b19c671..34739ff2f 100644
--- a/libxfs/xfs_rmap.c
+++ b/libxfs/xfs_rmap.c
@@ -166,7 +166,6 @@ xfs_rmap_btrec_to_irec(
 	union xfs_btree_rec	*rec,
 	struct xfs_rmap_irec	*irec)
 {
-	irec->rm_flags = 0;
 	irec->rm_startblock = be32_to_cpu(rec->rmap.rm_startblock);
 	irec->rm_blockcount = be32_to_cpu(rec->rmap.rm_blockcount);
 	irec->rm_owner = be64_to_cpu(rec->rmap.rm_owner);
diff --git a/libxfs/xfs_rmap.h b/libxfs/xfs_rmap.h
index 0c2c3cb73..abe633403 100644
--- a/libxfs/xfs_rmap.h
+++ b/libxfs/xfs_rmap.h
@@ -68,6 +68,7 @@ xfs_rmap_irec_offset_unpack(
 	if (offset & ~(XFS_RMAP_OFF_MASK | XFS_RMAP_OFF_FLAGS))
 		return -EFSCORRUPTED;
 	irec->rm_offset = XFS_RMAP_OFF(offset);
+	irec->rm_flags = 0;
 	if (offset & XFS_RMAP_OFF_ATTR_FORK)
 		irec->rm_flags |= XFS_RMAP_ATTR_FORK;
 	if (offset & XFS_RMAP_OFF_BMBT_BLOCK)
-- 
2.47.2