Re: [bug?] raid1 integrity checking is broken on 2.6.18-rc4

[Justin Piszcz <jpiszcz@lucidpixels.com>]

On Sat, 12 Aug 2006, Chuck Ebbert wrote:

> Doing this on a raid1 array:
>        echo "check" >/sys/block/md0/md/sync_action
>
> On 2.6.16.27:
>        Activity lights on both mirrors show activity for a while,
>        then the array status prints on the console.
>
> On 2.6.18-rc4 + the below patch:
>        Drive activity light blinks once on one drive, then the
>        array status prints (obviously no checking takes place.)
>
>
> Applied hotfix on 2.6.18-rc4:
>
> --- .prev/drivers/md/md.c       2006-08-08 09:00:44.000000000 +1000
> +++ ./drivers/md/md.c   2006-08-08 09:04:04.000000000 +1000
> @@ -1597,6 +1597,19 @@ void md_update_sb(mddev_t * mddev)
>
> repeat:
>        spin_lock_irq(&mddev->write_lock);
> +
> +       if (mddev->degraded && mddev->sb_dirty == 3)
> +               /* If the array is degraded, then skipping spares is both
> +                * dangerous and fairly pointless.
> +                * Dangerous because a device that was removed from the array
> +                * might have a event_count that still looks up-to-date,
> +                * so it can be re-added without a resync.
> +                * Pointless because if there are any spares to skip,
> +                * then a recovery will happen and soon that array won't
> +                * be degraded any more and the spare can go back to sleep then.
> +                */
> +               mddev->sb_dirty = 1;
> +
>        sync_req = mddev->in_sync;
>        mddev->utime = get_seconds();
>        if (mddev->sb_dirty == 3)
> -- 
> Chuck
>
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Is there a doc for all of the options you can echo into the sync_action? 
I'm assuming mdadm does these as well and echo is just another way to run 
work with the array?