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>
diff --git a/drivers/md/dm-unstripe.c b/drivers/md/dm-unstripe.c
index 061b4f1..65f838f 100644
--- a/drivers/md/dm-unstripe.c
+++ b/drivers/md/dm-unstripe.c
@@ -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;
