From: Mike Snitzer Date: Fri, 12 Oct 2012 20:02:07 +0000 (+0100) Subject: dm thin: support discard with non power of two block size X-Git-Tag: v3.7-rc1~21^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=28eed34e7662d7602da6753b0ba2563006b8e7a2;p=pandora-kernel.git dm thin: support discard with non power of two block size Support discards when the pool's block size is not a power of 2. The block layer assumes discard_granularity is a power of 2 (in blkdev_issue_discard), so we set this to the largest power of 2 that is a divides into the number of sectors in each block, but never less than DATA_DEV_BLOCK_SIZE_MIN_SECTORS. This patch eliminates the "Discard support must be disabled when the block size is not a power of 2" constraint that was imposed in commit 55f2b8b ("dm thin: support for non power of 2 pool blocksize"). That commit was incomplete: using a block size that is not a power of 2 shouldn't mean disabling discard support on the device completely. Signed-off-by: Mike Snitzer Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon --- Reading git-diff-tree failed