[PATCH 5.19 440/717] md/raid5: Ensure stripe_fill happens on non-read IO with journal

Greg Kroah-Hartman
2022-10-22T09:18:21Z

From: Logan Gunthorpe <logang@deltatee.com>

[ Upstream commit e2eed85bc75138a9eeb63863d20f8904ac42a577 ]

When doing degrade/recover tests using the journal a kernel BUG
is hit at drivers/md/raid5.c:4381 in handle_parity_checks5():

BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));

This was found to occur because handle_stripe_fill() was skipped
for stripes in the journal due to a condition in that function.
Thus blocks were not fetched and R5_UPTODATE was not set when
the code reached handle_parity_checks5().

To fix this, don't skip handle_stripe_fill() unless the stripe is
for read.

Fixes: 07e83364845e ("md/r5cache: shift complex rmw from read path to write path")
Link: https://lore.kernel.org/linux-raid/e05c4239-41a9-d2f7-3cfa-4aa9d2cea8c1@deltatee.com/
Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/raid5.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 1c1310d539f2..d6cad962669a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3951,7 +3951,7 @@ static void handle_stripe_fill(struct stripe_head *sh,
* back cache (prexor with orig_page, and then xor with
* page) in the read path
*/
- if (s->injournal && s->failed) {
+ if (s->to_read && s->injournal && s->failed) {
if (test_bit(STRIPE_R5C_CACHING, &sh->state))
r5c_make_stripe_write_out(sh);
goto out;
--
2.35.1