dm cache: remove remainder of distinct discard block size
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>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index bccb7ae..8534679 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -237,9 +237,8 @@
/*
* 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 @@
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 @@
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 @@
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 @@
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_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 @@
}
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 @@
{
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_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 @@
/*
* 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)