[PATCH -next 2/5] md: fix data corruption for raid456 when reshape restart while grow up
From: Yu Kuai <hidden>
Date: 2023-05-12 01:59:17
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
From: Yu Kuai <redacted> 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> --- 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 e1bc223d58b3..cf60d4b5356d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c@@ -4827,11 +4827,21 @@ 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); }
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2.39.2