On Fri, 14 Sep 2012 13:48:03 -0500 Jonathan Brassow <jbrassow@xxxxxxxxxx>
wrote:
> Neil,
>
> I've taken your suggestion to not muck around with the BITMAP_STALE, and
> instead simply clear the superblocks as a whole when the "sync"
> directive is given.
>
> brassow
>
> DM RAID: Fix for "sync" directive ineffectiveness
>
> There are two table arguments that can be given to a DM RAID target that
> control whether the array is forced to (re)synchronize or skip initialization:
> "sync" and "nosync". When "sync" is given, we set mddev->recovery_cp to 0
> in order to cause the device to resynchronize. This is insufficient if there
> is a bitmap in use, because the array will simply look at the bitmap and see
> that there is no recovery necessary.
>
> The fix is to skip over the loading of the superblocks when "sync" is given,
> causing new superblocks to be written that will force the array to go through
> initialization (i.e. synchronization).
>
> Signed-off-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
>
> Index: linux-upstream/drivers/md/dm-raid.c
> ===================================================================
> --- linux-upstream.orig/drivers/md/dm-raid.c
> +++ linux-upstream/drivers/md/dm-raid.c
> @@ -960,6 +960,19 @@ static int analyse_superblocks(struct dm
>
> freshest = NULL;
> rdev_for_each_safe(rdev, tmp, mddev) {
> + /*
> + * Skipping super_load due to DMPF_SYNC will cause
> + * the array to undergo initialization again as
> + * though it were new. This is the intended effect
> + * of the "sync" directive.
> + *
> + * When reshaping capability is added, we must ensure
> + * that the "sync" directive is disallowed during the
> + * reshape.
> + */
> + if (rs->print_flags & DMPF_SYNC)
> + continue;
> +
> if (!rdev->meta_bdev)
> continue;
>
>
OK, applied.
Thanks.
NeilBrown
Attachment:
signature.asc
Description: PGP signature
