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Commit 58f77a21 authored by Mike Snitzer's avatar Mike Snitzer Committed by Alasdair G Kergon
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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: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 3daec3b4

drivers/md/dm-thin.c

+13 −12
Original line number Diff line number Diff line
@@ -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;