On Tue, Sep 04, 2018 at 03:08:30PM +0200, Mariusz Tkaczyk wrote:
> Currently there is an inconsistency for failing the member drives
> for arrays with different RAID levels. For RAID456 - there is a possibility
> to fail all of the devices. However - for other RAID levels - kernel blocks
> removing the member drive, if the operation results in array's FAIL state
> (EBUSY is returned). For example - removing last drive from RAID1 is not
> possible.
> This kind of blocker was never implemented for raid456 and we cannot see
> the reason why.
>
> We had tested following patch and did not observe any regression, so do you
> have any comments/reasons for current approach, or we can send the proper
> patch for this?
I didn't see why we shouldn't do this, so I'll queue this.
Thanks,
Shaohua
> Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@xxxxxxxxx>
> ---
> drivers/md/raid5.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 81eaa22..b3bdd80 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -2681,6 +2681,18 @@ static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
> pr_debug("raid456: error called\n");
>
> spin_lock_irqsave(&conf->device_lock, flags);
> +
> + if (test_bit(In_sync, &rdev->flags) &&
> + mddev->degraded == conf->max_degraded) {
> + /*
> + * Don't allow to achieve failed state
> + * Don't try to recover this device
> + */
> + conf->recovery_disabled = mddev->recovery_disabled;
> + spin_unlock_irqrestore(&conf->device_lock, flags);
> + return;
> + }
> +
> set_bit(Faulty, &rdev->flags);
> clear_bit(In_sync, &rdev->flags);
> mddev->degraded = raid5_calc_degraded(conf);
> --
> 1.8.3.1
>
