[PATCH 5.10.y] xfs: jump out of xchk_bmap_check_rmap if fatal signals

[Sasha Levin <sashal@kernel.org>]

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

[ Upstream commit 49d300a51442bd64b627645b7b0b1cd66e492905 ]

LOLLM observes that we never check for fatal signals inside the loop
that checks file fork mappings against the rmapbt.  This can lead to
lengthy delays in responding to a ^C, so add some bailout checks.

Cc: stable@vger.kernel.org # v4.17
Fixes: 5e777b62b0bcb6 ("xfs: bmap scrubber should do rmap xref with bmap for sparse files")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
[ sashal: Adjusted loop context to preserve direct updates to rec instead of using a check_rec copy. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/scrub/bmap.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
index fed56d213a3f9..5748545afb5be 100644
--- a/fs/xfs/scrub/bmap.c
+++ b/fs/xfs/scrub/bmap.c
@@ -487,6 +487,10 @@ xchk_bmap_check_rmap(
 	struct xfs_ifork		*ifp;
 	struct xfs_scrub		*sc = sbcri->sc;
 	bool				have_map;
+	int				error = 0;
+
+	if (xchk_should_terminate(sc, &error))
+		return error;
 
 	/* Is this even the right fork? */
 	if (rec->rm_owner != sc->ip->i_ino)
@@ -517,6 +521,9 @@ xchk_bmap_check_rmap(
 	 * entire rmap is covered by bmbt records.
 	 */
 	while (have_map) {
+		if (xchk_should_terminate(sc, &error))
+			return error;
+
 		if (irec.br_startoff != rec->rm_offset)
 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 					rec->rm_offset);
-- 
2.53.0