[PATCH 5.12 318/384] md/raid1: properly indicate failure when ending a failed write request

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 08:50:09 EST


From: Paul Clements <paul.clements@xxxxxxxxxxx>

commit 2417b9869b81882ab90fd5ed1081a1cb2d4db1dd upstream.

This patch addresses a data corruption bug in raid1 arrays using bitmaps.
Without this fix, the bitmap bits for the failed I/O end up being cleared.

Since we are in the failure leg of raid1_end_write_request, the request
either needs to be retried (R1BIO_WriteError) or failed (R1BIO_Degraded).

Fixes: eeba6809d8d5 ("md/raid1: end bio when the device faulty")
Cc: stable@xxxxxxxxxxxxxxx # v5.2+
Signed-off-by: Paul Clements <paul.clements@xxxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid1.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -478,6 +478,8 @@ static void raid1_end_write_request(stru
if (!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_WriteError, &r1_bio->state);
else {
+ /* Fail the request */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
/* Finished with this branch */
r1_bio->bios[mirror] = NULL;
to_put = bio;