Thread (1 message) 1 message, 1 author, 2023-07-02

[PATCH AUTOSEL 6.4 07/15] md: fix data corruption for raid456 when reshape restart while grow up

flat view
STALE1195d

From: Sasha Levin <sashal@kernel.org>
Date: 2023-07-02 19:42:41
Also in: lkml, stable
Subsystem: software raid (multiple disks) support, the rest · Maintainers: Song Liu, Yu Kuai, Linus Torvalds

From: Yu Kuai <redacted>

[ Upstream commit 873f50ece41aad5c4f788a340960c53774b5526e ]

Currently, if reshape is interrupted, echo "reshape" to sync_action will
restart reshape from scratch, for example:

echo frozen > sync_action
echo reshape > sync_action

This will corrupt data before reshape_position if the array is growing,
fix the problem by continue reshape from reshape_position.

Reported-by: Peter Neuwirth <redacted>
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/ (local)
Signed-off-by: Yu Kuai <redacted>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com (local)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/md.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8e344b4b34446..544ccb4461a9e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4804,11 +4804,21 @@ action_store(struct mddev *mddev, const char *page, size_t len)
 			return -EINVAL;
 		err = mddev_lock(mddev);
 		if (!err) {
-			if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+			if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
 				err =  -EBUSY;
-			else {
+			} else if (mddev->reshape_position == MaxSector ||
+				   mddev->pers->check_reshape == NULL ||
+				   mddev->pers->check_reshape(mddev)) {
 				clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 				err = mddev->pers->start_reshape(mddev);
+			} else {
+				/*
+				 * If reshape is still in progress, and
+				 * md_check_recovery() can continue to reshape,
+				 * don't restart reshape because data can be
+				 * corrupted for raid456.
+				 */
+				clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 			}
 			mddev_unlock(mddev);
 		}
-- 
2.39.2
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help