From 47f1441b281decde6954a2fa82b4131637d685ac Mon Sep 17 00:00:00 2001 From: Yunye Zhao Date: Thu, 23 Jul 2026 21:55:33 +0800 Subject: [PATCH] md/raid10: fix still_degraded being inverted in raid10_sync_request() Commit fe6a19d40ceb ("md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations") converted still_degraded from int to bool, but inverted the assignment in the loop that checks whether the array will still be degraded after the current device is recovered: "still_degraded = 1" became "still_degraded = false". As a result, recovering a device while another mirror is still missing calls md_bitmap_start_sync() with degraded == false, which clears bitmap bits that the still-missing device needs. When that device is re-added, its bitmap-based recovery finds the bits already cleared and skips every region written while the array was degraded, so it is marked In_sync while holding stale data: silent corruption. Reproducer (raid10 near=2, 4 disks, internal bitmap): - fail and remove one disk of each mirror pair - write to the degraded array - re-add both disks and let recovery finish - "check" reports mismatch_cnt=262272 after 256 MiB of degraded writes and file contents differ; the second disk's "recovery" completes in milliseconds because everything is skipped The same conversion in raid1 got it right (still_degraded = true). Restore the correct value. Fixes: fe6a19d40ceb ("md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations") Cc: stable@vger.kernel.org Signed-off-by: Yunye Zhao Reviewed-by: Mykola Marzhan Reviewed-by: Paul Menzel Reviewed-by: Yu Kuai Link: https://patch.msgid.link/20260723135535.101995-2-yunye.zhao@linux.alibaba.com Signed-off-by: Yu Kuai --- drivers/md/raid10.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 562a325a7195..1093c798d9dd 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -3337,7 +3337,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, struct md_rdev *rdev = conf->mirrors[j].rdev; if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { - still_degraded = false; + still_degraded = true; break; } }