[PATCH] md: fix calculation of ->degraded for multipath and raid10

Two less-used md personalities have bugs in the calculation of ->degraded (the
extent to which the array is degraded).
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/multipath.c

@@ -501,7 +501,7 @@ static int multipath_run (mddev_t *mddev)
 			mdname(mddev));
 		goto out_free_conf;
 	}
-	mddev->degraded = conf->raid_disks = conf->working_disks;
+	mddev->degraded = conf->raid_disks - conf->working_disks;
 
 	conf->pool = mempool_create_kzalloc_pool(NR_RESERVED_BUFS,
 						 sizeof(struct multipath_bh));

drivers/md/raid10.c

@@ -2079,7 +2079,7 @@ static int run(mddev_t *mddev)
 		disk = conf->mirrors + i;
 
 		if (!disk->rdev ||
-		    !test_bit(In_sync, &rdev->flags)) {
+		    !test_bit(In_sync, &disk->rdev->flags)) {
 			disk->head_position = 0;
 			mddev->degraded++;
 		}