bcache: explicitly make cache_set only have single cache
Currently although the bcache code has a framework for multiple caches
in a cache set, but indeed the multiple caches never completed and users
use md raid1 for multiple copies of the cached data.
This patch does the following change in struct cache_set, to explicitly
make a cache_set only have single cache,
- Change pointer array "*cache[MAX_CACHES_PER_SET]" to a single pointer
"*cache".
- Remove pointer array "*cache_by_alloc[MAX_CACHES_PER_SET]".
- Remove "caches_loaded".
Now the code looks as exactly what it does in practic: only one cache is
used in the cache set.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 5ff6e95..aa112c1 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -519,9 +519,7 @@ struct cache_set {
struct cache_sb sb;
- struct cache *cache[MAX_CACHES_PER_SET];
- struct cache *cache_by_alloc[MAX_CACHES_PER_SET];
- int caches_loaded;
+ struct cache *cache;
struct bcache_device **devices;
unsigned int devices_max_used;
@@ -808,7 +806,7 @@ static inline struct cache *PTR_CACHE(struct cache_set *c,
const struct bkey *k,
unsigned int ptr)
{
- return c->cache[PTR_DEV(k, ptr)];
+ return c->cache;
}
static inline size_t PTR_BUCKET_NR(struct cache_set *c,
@@ -890,7 +888,7 @@ do { \
/* Looping macros */
#define for_each_cache(ca, cs, iter) \
- for (iter = 0; ca = cs->cache[iter], iter < (cs)->sb.nr_in_set; iter++)
+ for (iter = 0; ca = cs->cache, iter < 1; iter++)
#define for_each_bucket(b, ca) \
for (b = (ca)->buckets + (ca)->sb.first_bucket; \
