From a166f5987df8d7bf89fd934602dd12a6e872916e Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 14 Feb 2013 09:42:36 +1100 Subject: [PATCH] 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 Signed-off-by: Alasdair G Kergon --- drivers/md/dm-thin.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index a4c9dea686f7..8f4944e4f8e7 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -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) @@ -2414,11 +2420,6 @@ 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; -- 2.39.5