From: Jonathan Brassow If the user does not supply a bitmap region_size to the dm raid target, a reasonable size is computed automatically. If this is not a power of 2, the md code will report an error later. This patch catches the problem early and rounds the region_size to the next power of two. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon --- drivers/md/dm-raid.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Index: linux/drivers/md/dm-raid.c =================================================================== --- linux.orig/drivers/md/dm-raid.c +++ linux/drivers/md/dm-raid.c @@ -295,9 +295,11 @@ static int validate_region_size(struct r * Choose a reasonable default. All figures in sectors. */ 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); DMINFO("Choosing default region size of %lu sectors", region_size); - region_size = min_region_size; } else { DMINFO("Choosing default region size of 4MiB"); region_size = 1 << 13; /* sectors */