Commit cc656619 authored Jan 23, 2018 by Scott Bauer Committed by Mike Snitzer Jan 29, 2018

dm unstripe: fix target length versus number of stripes size check



Since the unstripe target takes a target length which is the
size of *one* striped member we're trying to expose, not the
total size of *all* the striped members, the check does not
make sense and fails for some striped setups.

For example, say we have a 4TB striped device:
or 3907018496 sectors per underlying device:

if (sector_div(width, uc->stripes)) :
   3907018496 / 2(num stripes)  == 1953509248

tmp_len = width;
if (sector_div(tmp_len, uc->chunk_size)) :
   1953509248 / 256(chunk size) == 7630895.5
   (fails)

Fix this by removing the first check which isn't valid for unstriping.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

parent bd6d1e0a

drivers/md/dm-unstripe.c

+2 −8

Original line number	Diff line number	Diff line
		@@ -44,7 +44,7 @@ static void cleanup_unstripe(struct unstripe_c uc, struct dm_target ti)
		static int unstripe_ctr(struct dm_target ti, unsigned int argc, char *argv)
		{
		struct unstripe_c *uc;
		sector_t width, tmp_len;
		sector_t tmp_len;
		unsigned long long start;
		char dummy;

		@@ -100,13 +100,7 @@ static int unstripe_ctr(struct dm_target ti, unsigned int argc, char *argv)
		uc->unstripe_width = (uc->stripes - 1) * uc->chunk_size;
		uc->chunk_shift = fls(uc->chunk_size) - 1;

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

		tmp_len = width;
		tmp_len = ti->len;
		if (sector_div(tmp_len, uc->chunk_size)) {
		ti->error = "Target length not divisible by chunk size";
		goto err;