dm thin: fix non power of two discard granularity calc
authorJoe Thornber <ejt@redhat.com>
Wed, 20 Mar 2013 17:21:25 +0000 (17:21 +0000)
committerAlasdair G Kergon <agk@redhat.com>
Wed, 20 Mar 2013 17:21:25 +0000 (17:21 +0000)
commit58051b94e05a59c4d34f9f1a441af40894817c59
tree4a4e33cac9a808805e42f0c816a4b8e5b434f28f
parentf046f89a99ccfd9408b94c653374ff3065c7edb3
dm thin: fix non power of two discard granularity calc

Fix a discard granularity calculation to work for non power of 2 block sizes.

In order for thinp to passdown discard bios to the underlying data
device, the data device must have a discard granularity that is a
factor of the thinp block size.  Originally this check was done by
using bitops since the block_size was known to be a power of two.

Introduced by commit f13945d75730081830b6f3360266950e2b7c9067
("dm thin: support a non power of 2 discard_granularity").

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-thin.c