diff options
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-cache-target.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 6e36a075310..abdd45d07bf 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2301,6 +2301,19 @@ static sector_t calculate_discard_block_size(sector_t cache_block_size, return discard_block_size; } +static void set_cache_size(struct cache *cache, dm_cblock_t size) +{ + dm_block_t nr_blocks = from_cblock(size); + + if (nr_blocks > (1 << 20) && cache->cache_size != size) + DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" + "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" + "Please consider increasing the cache block size to reduce the overall cache block count.", + (unsigned long long) nr_blocks); + + cache->cache_size = size; +} + #define DEFAULT_MIGRATION_THRESHOLD 2048 static int cache_create(struct cache_args *ca, struct cache **result) @@ -2356,10 +2369,10 @@ static int cache_create(struct cache_args *ca, struct cache **result) cache->sectors_per_block_shift = -1; cache_size = block_div(cache_size, ca->block_size); - cache->cache_size = to_cblock(cache_size); + set_cache_size(cache, to_cblock(cache_size)); } else { cache->sectors_per_block_shift = __ffs(ca->block_size); - cache->cache_size = to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift); + set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); } r = create_cache_policy(cache, ca, error); @@ -2856,7 +2869,7 @@ static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) return r; } - cache->cache_size = new_size; + set_cache_size(cache, new_size); return 0; } |