dm thin: use block_size_is_power_of_two

Use block_size_is_power_of_two() rather than checking
sectors_per_block_shift directly.  Also introduce local pool variable in
get_bio_block() to eliminate redundant tc->pool dereferences.

No functional change.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mike Snitzer 2013-03-01 22:45:45 +00:00 committed by Alasdair G Kergon
parent 3daec3b447
commit 58f77a2196

View file

@ -330,14 +330,20 @@ static void requeue_io(struct thin_c *tc)
* target.
*/
static bool block_size_is_power_of_two(struct pool *pool)
{
return pool->sectors_per_block_shift >= 0;
}
static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
sector_t block_nr = bio->bi_sector;
if (tc->pool->sectors_per_block_shift < 0)
(void) sector_div(block_nr, tc->pool->sectors_per_block);
if (block_size_is_power_of_two(pool))
block_nr >>= pool->sectors_per_block_shift;
else
block_nr >>= tc->pool->sectors_per_block_shift;
(void) sector_div(block_nr, pool->sectors_per_block);
return block_nr;
}
@ -348,12 +354,12 @@ static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
sector_t bi_sector = bio->bi_sector;
bio->bi_bdev = tc->pool_dev->bdev;
if (tc->pool->sectors_per_block_shift < 0)
bio->bi_sector = (block * pool->sectors_per_block) +
sector_div(bi_sector, pool->sectors_per_block);
else
if (block_size_is_power_of_two(pool))
bio->bi_sector = (block << pool->sectors_per_block_shift) |
(bi_sector & (pool->sectors_per_block - 1));
else
bio->bi_sector = (block * pool->sectors_per_block) +
sector_div(bi_sector, pool->sectors_per_block);
}
static void remap_to_origin(struct thin_c *tc, struct bio *bio)
@ -2425,11 +2431,6 @@ static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
static bool block_size_is_power_of_two(struct pool *pool)
{
return pool->sectors_per_block_shift >= 0;
}
static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
{
struct pool *pool = pt->pool;