From: bingjingc <bingjingc@xxxxxxxxxxxx> [ Upstream commit aff69d89bdebc39235cddb4445371eb979b49685 ] When disk failure occurs on new disks for reshape, mddev->degraded is not calculated correctly. Faulty bit of the failure device is not set before raid5_calc_degraded(conf). mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/loop[012] mdadm /dev/md0 -a /dev/loop3 mdadm /dev/md0 --grow -n4 mdadm /dev/md0 -f /dev/loop3 # simulating disk failure cat /sys/block/md0/md/degraded # it outputs 0, but it should be 1. However, mdadm -D /dev/md0 will show that it is degraded. It's a bug. It can be fixed by moving the resources raid5_calc_degraded() depends on before it. Reported-by: Roy Chung <roychung@xxxxxxxxxxxx> Reviewed-by: Alex Wu <alexwu@xxxxxxxxxxxx> Signed-off-by: BingJing Chang <bingjingc@xxxxxxxxxxxx> Signed-off-by: Shaohua Li <shli@xxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- 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 c406f16f5295..7ec822ced80b 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2678,13 +2678,13 @@ static void raid5_error(struct mddev *mddev, struct md_rdev *rdev) pr_debug("raid456: error called\n"); spin_lock_irqsave(&conf->device_lock, flags); + set_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); mddev->degraded = raid5_calc_degraded(conf); spin_unlock_irqrestore(&conf->device_lock, flags); set_bit(MD_RECOVERY_INTR, &mddev->recovery); set_bit(Blocked, &rdev->flags); - set_bit(Faulty, &rdev->flags); set_mask_bits(&mddev->sb_flags, 0, BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); pr_crit("md/raid:%s: Disk failure on %s, disabling device.\n" -- 2.11.0