From: Jonathan Brassow Date: Mon, 24 Sep 2012 06:41:29 +0000 (+1000) Subject: DM RAID: Fix for "sync" directive ineffectiveness X-Git-Tag: next-20120926~52^2~14 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=078a67f6af4188efb2e0048cff5b4cdd3031ef00;p=karo-tx-linux.git 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 Signed-off-by: NeilBrown --- diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 89a06a361332..45d94a7e7f6d 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -1017,6 +1017,19 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) 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;