Commit 414dd67d authored by Joe Thornber's avatar Joe Thornber Committed by Alasdair G Kergon
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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: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 3b6b7813

drivers/md/dm-cache-target.c

+14 −7
Original line number Original line Diff line number Diff line
@@ -158,7 +158,7 @@ struct cache { 
	/*

	/*

	 * origin_blocks entries, discarded if set.

	 * 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;

	dm_dblock_t discard_nr_blocks;

	unsigned long *discard_bitset;

	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;

	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)

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);

	dm_block_t b = from_oblock(oblock);





	if (!block_size_is_power_of_two(cache))

	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

	else

		discard_blocks >>= cache->sectors_per_block_shift;

		discard_blocks >>= cache->sectors_per_block_shift;





	(void) sector_div(b, discard_blocks);

	b = block_div(b, discard_blocks);





	return to_dblock(b);

	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 end_block = bio->bi_sector + bio_sectors(bio);

	dm_block_t b;

	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++)

	for (b = start_block; b < end_block; b++)

		set_discard(cache, to_dblock(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 */

	/* FIXME: factor out this whole section */

	origin_blocks = cache->origin_sectors = ca->origin_sectors;

	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->origin_blocks = to_oblock(origin_blocks);





	cache->sectors_per_block = ca->block_size;

	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;

		dm_block_t cache_size = ca->cache_sectors;





		cache->sectors_per_block_shift = -1;

		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);

		cache->cache_size = to_cblock(cache_size);

	} else {

	} else {

		cache->sectors_per_block_shift = __ffs(ca->block_size);

		cache->sectors_per_block_shift = __ffs(ca->block_size);