tree 64f89f9a0270134c1895ddfe230bc6e862213ab0
parent 90cf195d9bcb4bf70e8b6df5073b05164b279ba0
author NeilBrown <neilb@suse.de> 1343693134 +1000
committer NeilBrown <neilb@suse.de> 1343693134 +1000

md/raid1: don't abort a resync on the first badblock.

If a resync of a RAID1 array with 2 devices finds a known bad block
one device it will neither read from, or write to, that device for
this block offset.
So there will be one read_target (The other device) and zero write
targets.
This condition causes md/raid1 to abort the resync assuming that it
has finished - without known bad blocks this would be true.

When there are no write targets because of the presence of bad blocks
we should only skip over the area covered by the bad block.
RAID10 already gets this right, raid1 doesn't.  Or didn't.

As this can cause a 'sync' to abort early and appear to have succeeded
it could lead to some data corruption, so it suitable for -stable.

Cc: stable@vger.kernel.org
Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>