dm raid: stop using BUG() in __rdev_sectors()

Return 0 rather than BUG() if __rdev_sectors() fails and catch invalid
rdev size in the constructor.

Reported-by: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 7d893228c40f..67b3eb23e771 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1571,7 +1571,7 @@ static sector_t __rdev_sectors(struct raid_set *rs)
                         return rdev->sectors;
         }
 
-        BUG(); /* Constructor ensures we got some. */
+        return 0;
 }
 
 /* Calculate the sectors per device and per array used for @rs */
@@ -2930,7 +2930,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         bool resize;
         struct raid_type *rt;
         unsigned int num_raid_params, num_raid_devs;
-        sector_t calculated_dev_sectors;
+        sector_t calculated_dev_sectors, rdev_sectors;
         struct raid_set *rs = NULL;
         const char *arg;
         struct rs_layout rs_layout;
@@ -3006,7 +3006,14 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         if (r)
                 goto bad;
 
-        resize = calculated_dev_sectors != __rdev_sectors(rs);
+        rdev_sectors = __rdev_sectors(rs);
+        if (!rdev_sectors) {
+                ti->error = "Invalid rdev size";
+                r = -EINVAL;
+                goto bad;
+        }
+
+        resize = calculated_dev_sectors != rdev_sectors;
 
         INIT_WORK(&rs->md.event_work, do_table_event);
         ti->private = rs;