dm stripe: fix size test (f14fa693) · Commits · 戴 / test

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 <mpatocka@redhat.com> Signed-off-by:

Alasdair G Kergon <agk@redhat.com>

Documentation/device-mapper/striped.txt

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -16,8 +16,7 @@ Parameters: <num devs> <chunk size> [<dev path> <offset>]+
	<offset>: Starting sector within the device.		<offset>: Starting sector within the device.

	One or more underlying devices can be specified. The striped device size must		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		be a multiple of the chunk size multiplied by the number of underlying devices.
	devices.


	Example scripts		Example scripts

drivers/md/dm-stripe.c

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -132,7 +132,6 @@ static int stripe_ctr(struct dm_target ti, unsigned int argc, char *argv)
	return -EINVAL;		return -EINVAL;
	}		}

	width = ti->len;
	if (sector_div(width, stripes)) {		if (sector_div(width, stripes)) {
	ti->error = "Target length not divisible by "		ti->error = "Target length not divisible by "
	"number of stripes";		"number of stripes";

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