dm cache: fix some issues with the new discard range support

Commit 7ae34e777 ("dm cache: improve discard support") needed to also:
- discontinue having DM core split the discard bios on cache block
  boundaries
- calculate the cache's discard_nr_blocks relative to the determined
  discard_block_size rather than using oblock_to_dblock()

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Joe Thornber 2014-11-24 14:05:16 +00:00 committed by Mike Snitzer
parent 8001e87d0e
commit 2572629a13

View File

@ -2338,8 +2338,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
ti->num_discard_bios = 1;
ti->discards_supported = true;
ti->discard_zeroes_data_unsupported = true;
/* Discard bios must be split on a block boundary */
ti->split_discard_bios = true;
ti->split_discard_bios = false;
cache->features = ca->features;
ti->per_bio_data_size = get_per_bio_data_size(cache);
@ -2440,7 +2439,8 @@ static int cache_create(struct cache_args *ca, struct cache **result)
cache->discard_block_size =
calculate_discard_block_size(cache->sectors_per_block,
cache->origin_sectors);
cache->discard_nr_blocks = oblock_to_dblock(cache, cache->origin_blocks);
cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors,
cache->discard_block_size));
cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks));
if (!cache->discard_bitset) {
*error = "could not allocate discard bitset";