From b02465308f13f3266480275fd143747bfd441a2f Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Sat, 19 Jul 2014 13:25:46 -0400 Subject: [PATCH] dm cache: set minimum_io_size to cache's data block size Before, if the block layer's limit stacking didn't establish an optimal_io_size that was compatible with the cache's data block size we'd set optimal_io_size to the data block size and minimum_io_size to 0 (which the block layer adjusts to be physical_block_size). Update cache_io_hints() to set both minimum_io_size and optimal_io_size to the cache's data block size. This fixes an issue where mkfs.xfs would create more XFS Allocation Groups on cache volumes than on a normal linear LV of comparable size. Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index a54108e..1af40ee 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -3094,7 +3094,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) */ if (io_opt_sectors < cache->sectors_per_block || do_div(io_opt_sectors, cache->sectors_per_block)) { - blk_limits_io_min(limits, 0); + blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); } set_discard_limits(cache, limits); -- 2.7.4