dm raid: fix round up of default region size

Commit 3a0f9aaee028 ("dm raid: round region_size to power of two")
intended to make sure that the default region size is a power of two.
However, the logic in that commit is incorrect and sets the variable
region_size to 0 or 1, depending on whether min_region_size is a power
of two.

Fix this logic, using roundup_pow_of_two(), so that region_size is
properly rounded up to the next power of two.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 3a0f9aaee028 ("dm raid: round region_size to power of two")
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 97e1651..a090121 100644 (file)
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -329,8 +329,7 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
                 */
                if (min_region_size > (1 << 13)) {
                        /* If not a power of 2, make it the next power of 2 */
-                       if (min_region_size & (min_region_size - 1))
-                               region_size = 1 << fls(region_size);
+                       region_size = roundup_pow_of_two(min_region_size);
                        DMINFO("Choosing default region size of %lu sectors",
                               region_size);
                } else {