From: Mikulas Patocka dm-stripe is supposed to ensure that all the space allocated to the stripes is fully used and that all stripes are the same size. This patch fixes the test. It checks that device length is divisible by the chunk size and checks that the resulting quotient is divisible by the number of stripes (which is equivalent to testing if device length is divisible by chunk_size * stripes). Previously, the code only tested that the number of sectors in the target was divisible by each of the chunk size and the number of stripes separately, which could leave entire stripes unused. (A setup that genuinely needs some stripes to be shorter than others can be created by concatenating striped targets.) Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- Documentation/device-mapper/striped.txt | 3 +-- drivers/md/dm-stripe.c | 1 - 2 files changed, 1 insertion(+), 3 deletions(-) Index: linux/Documentation/device-mapper/striped.txt =================================================================== --- linux.orig/Documentation/device-mapper/striped.txt +++ linux/Documentation/device-mapper/striped.txt @@ -16,8 +16,7 @@ Parameters: [: Starting sector within the device. One or more underlying devices can be specified. The striped device size must -be a multiple of the chunk size and a multiple of the number of underlying -devices. +be a multiple of the chunk size multiplied by the number of underlying devices. Example scripts Index: linux/drivers/md/dm-stripe.c =================================================================== --- linux.orig/drivers/md/dm-stripe.c +++ linux/drivers/md/dm-stripe.c @@ -132,7 +132,6 @@ static int stripe_ctr(struct dm_target * return -EINVAL; } - width = ti->len; if (sector_div(width, stripes)) { ti->error = "Target length not divisible by " "number of stripes";