xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dm cache: remove remainder of distinct discard block size

Browse Source 
Discard block size not being equal to cache block size causes data
corruption by erroneously avoiding migrations in issue_copy() because
the discard state is being cleared for a group of cache blocks when it
should not.

Completely remove all code that enabled a distinction between the
cache block size and discard block size.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Heinz Mauelshagen
2014-03-27 15:14:10 -04:00
committed by Mike Snitzer
parent d132cc6d9e
commit 64ab346a36
4 changed files with 46 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
drivers/md/dm-cache-target.c
View File

@@ -237,9 +237,8 @@ struct cache {
/*
* origin_blocks entries, discarded if set.
*/
dm_dblock_t discard_nr_blocks;
dm_oblock_t discard_nr_blocks;
unsigned long *discard_bitset;
uint32_t discard_block_size;
/*
* Rather than reconstructing the table line for the status we just
@@ -526,48 +525,33 @@ static dm_block_t block_div(dm_block_t b, uint32_t n)
return b;
}
static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock)
{
uint32_t discard_blocks = cache->discard_block_size;
dm_block_t b = from_oblock(oblock);
if (!block_size_is_power_of_two(cache))
discard_blocks = discard_blocks / cache->sectors_per_block;
else
discard_blocks >>= cache->sectors_per_block_shift;
b = block_div(b, discard_blocks);
return to_dblock(b);
}
static void set_discard(struct cache *cache, dm_dblock_t b)
static void set_discard(struct cache *cache, dm_oblock_t b)
{
unsigned long flags;
atomic_inc(&cache->stats.discard_count);
spin_lock_irqsave(&cache->lock, flags);
set_bit(from_dblock(b), cache->discard_bitset);
set_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
}
static void clear_discard(struct cache *cache, dm_dblock_t b)
static void clear_discard(struct cache *cache, dm_oblock_t b)
{
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
clear_bit(from_dblock(b), cache->discard_bitset);
clear_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
}
static bool is_discarded(struct cache *cache, dm_dblock_t b)
static bool is_discarded(struct cache *cache, dm_oblock_t b)
{
int r;
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
r = test_bit(from_dblock(b), cache->discard_bitset);
r = test_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
return r;
@@ -579,8 +563,7 @@ static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b)
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
r = test_bit(from_dblock(oblock_to_dblock(cache, b)),
cache->discard_bitset);
r = test_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
return r;
@@ -705,7 +688,7 @@ static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio,
check_if_tick_bio_needed(cache, bio);
remap_to_origin(cache, bio);
if (bio_data_dir(bio) == WRITE)
clear_discard(cache, oblock_to_dblock(cache, oblock));
clear_discard(cache, oblock);
}
static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
@@ -715,7 +698,7 @@ static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
remap_to_cache(cache, bio, cblock);
if (bio_data_dir(bio) == WRITE) {
set_dirty(cache, oblock, cblock);
clear_discard(cache, oblock_to_dblock(cache, oblock));
clear_discard(cache, oblock);
}
}
@@ -1288,14 +1271,14 @@ static void process_flush_bio(struct cache *cache, struct bio *bio)
static void process_discard_bio(struct cache *cache, struct bio *bio)
{
dm_block_t start_block = dm_sector_div_up(bio->bi_iter.bi_sector,
cache->discard_block_size);
cache->sectors_per_block);
dm_block_t end_block = bio_end_sector(bio);
dm_block_t b;
end_block = block_div(end_block, cache->discard_block_size);
end_block = block_div(end_block, cache->sectors_per_block);
for (b = start_block; b < end_block; b++)
set_discard(cache, to_dblock(b));
set_discard(cache, to_oblock(b));
bio_endio(bio, 0);
}
@@ -2292,14 +2275,13 @@ static int cache_create(struct cache_args *ca, struct cache **result)
}
clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size));
cache->discard_block_size = cache->sectors_per_block;
cache->discard_nr_blocks = oblock_to_dblock(cache, cache->origin_blocks);
cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks));
cache->discard_nr_blocks = cache->origin_blocks;
cache->discard_bitset = alloc_bitset(from_oblock(cache->discard_nr_blocks));
if (!cache->discard_bitset) {
*error = "could not allocate discard bitset";
goto bad;
}
clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks));
clear_bitset(cache->discard_bitset, from_oblock(cache->discard_nr_blocks));
cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(cache->copier)) {
@@ -2583,16 +2565,16 @@ static int write_discard_bitset(struct cache *cache)
{
unsigned i, r;
r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size,
cache->discard_nr_blocks);
r = dm_cache_discard_bitset_resize(cache->cmd, cache->sectors_per_block,
cache->origin_blocks);
if (r) {
DMERR("could not resize on-disk discard bitset");
return r;
}
for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_dblock(i),
is_discarded(cache, to_dblock(i)));
for (i = 0; i < from_oblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_oblock(i),
is_discarded(cache, to_oblock(i)));
if (r)
return r;
}
@@ -2689,16 +2671,14 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
}
static int load_discard(void *context, sector_t discard_block_size,
dm_dblock_t dblock, bool discard)
dm_oblock_t oblock, bool discard)
{
struct cache *cache = context;
/* FIXME: handle mis-matched block size */
if (discard)
set_discard(cache, dblock);
set_discard(cache, oblock);
else
clear_discard(cache, dblock);
clear_discard(cache, oblock);
return 0;
}
@@ -3089,8 +3069,8 @@ static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
/*
* FIXME: these limits may be incompatible with the cache device
*/
limits->max_discard_sectors = cache->discard_block_size;
limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT;
limits->max_discard_sectors = cache->sectors_per_block;
limits->discard_granularity = cache->sectors_per_block << SECTOR_SHIFT;
}
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)