From 3a0f9aaee02857609d79b20c809c02a8b7c39d06 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Fri, 21 Dec 2012 20:23:33 +0000 Subject: [PATCH] dm raid: round region_size to power of two 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(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 45d94a7e7f6d..4a20bf8c72da 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -295,9 +295,11 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size) * 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 */