From 414dd67d50a6b9a11af23bbb68e8fae13d726c8b Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Wed, 20 Mar 2013 17:21:25 +0000 Subject: [PATCH] dm cache: avoid 64 bit division on 32 bit Squash various 32bit link errors. >> on i386: >> drivers/built-in.o: In function `is_discarded_oblock': >> dm-cache-target.c:(.text+0x1ea28e): undefined reference to `__udivdi3' ... Reported-by: Randy Dunlap Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon --- drivers/md/dm-cache-target.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 0f4e84b15c30..5ad227f0cea3 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -158,7 +158,7 @@ struct cache { /* * origin_blocks entries, discarded if set. */ - sector_t discard_block_size; /* a power of 2 times sectors per block */ + uint32_t discard_block_size; /* a power of 2 times sectors per block */ dm_dblock_t discard_nr_blocks; unsigned long *discard_bitset; @@ -412,17 +412,24 @@ static bool block_size_is_power_of_two(struct cache *cache) return cache->sectors_per_block_shift >= 0; } +static dm_block_t block_div(dm_block_t b, uint32_t n) +{ + do_div(b, n); + + return b; +} + static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) { - sector_t discard_blocks = cache->discard_block_size; + uint32_t discard_blocks = cache->discard_block_size; dm_block_t b = from_oblock(oblock); if (!block_size_is_power_of_two(cache)) - (void) sector_div(discard_blocks, cache->sectors_per_block); + discard_blocks = discard_blocks / cache->sectors_per_block; else discard_blocks >>= cache->sectors_per_block_shift; - (void) sector_div(b, discard_blocks); + b = block_div(b, discard_blocks); return to_dblock(b); } @@ -1002,7 +1009,7 @@ static void process_discard_bio(struct cache *cache, struct bio *bio) dm_block_t end_block = bio->bi_sector + bio_sectors(bio); dm_block_t b; - (void) sector_div(end_block, cache->discard_block_size); + end_block = block_div(end_block, cache->discard_block_size); for (b = start_block; b < end_block; b++) set_discard(cache, to_dblock(b)); @@ -1835,7 +1842,7 @@ static int cache_create(struct cache_args *ca, struct cache **result) /* FIXME: factor out this whole section */ origin_blocks = cache->origin_sectors = ca->origin_sectors; - (void) sector_div(origin_blocks, ca->block_size); + origin_blocks = block_div(origin_blocks, ca->block_size); cache->origin_blocks = to_oblock(origin_blocks); cache->sectors_per_block = ca->block_size; @@ -1848,7 +1855,7 @@ static int cache_create(struct cache_args *ca, struct cache **result) dm_block_t cache_size = ca->cache_sectors; cache->sectors_per_block_shift = -1; - (void) sector_div(cache_size, ca->block_size); + cache_size = block_div(cache_size, ca->block_size); cache->cache_size = to_cblock(cache_size); } else { cache->sectors_per_block_shift = __ffs(ca->block_size);