bcache: remove embedded struct cache_sb from struct cache_set

Since bcache code was merged into mainline kerrnel, each cache set only
as one single cache in it. The multiple caches framework is here but the
code is far from completed. Considering the multiple copies of cached
data can also be stored on e.g. md raid1 devices, it is unnecessary to
support multiple caches in one cache set indeed.

The previous preparation patches fix the dependencies of explicitly
making a cache set only have single cache. Now we don't have to maintain
an embedded partial super block in struct cache_set, the in-memory super
block can be directly referenced from struct cache.

This patch removes the embedded struct cache_sb from struct cache_set,
and fixes all locations where the superb lock was referenced from this
removed super block by referencing the in-memory super block of struct
cache.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index cd46f33db507..aefbdb7e003b 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -666,7 +666,7 @@ static void journal_reclaim(struct cache_set *c)
 
 	bkey_init(k);
 	SET_KEY_PTRS(k, 1);
-	c->journal.blocks_free = c->sb.bucket_size >> c->block_bits;
+	c->journal.blocks_free = ca->sb.bucket_size >> c->block_bits;
 
 out:
 	if (!journal_full(&c->journal))
@@ -735,7 +735,7 @@ static void journal_write_unlocked(struct closure *cl)
 	struct journal_write *w = c->journal.cur;
 	struct bkey *k = &c->journal.key;
 	unsigned int i, sectors = set_blocks(w->data, block_bytes(ca)) *
-		c->sb.block_size;
+		ca->sb.block_size;
 
 	struct bio *bio;
 	struct bio_list list;
@@ -762,7 +762,7 @@ static void journal_write_unlocked(struct closure *cl)
 	bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
 
 	w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
-	w->data->magic		= jset_magic(&c->sb);
+	w->data->magic		= jset_magic(&ca->sb);
 	w->data->version	= BCACHE_JSET_VERSION;
 	w->data->last_seq	= last_seq(&c->journal);
 	w->data->csum		= csum_set(w->data);
@@ -838,6 +838,7 @@ static struct journal_write *journal_wait_for_write(struct cache_set *c,
 	size_t sectors;
 	struct closure cl;
 	bool wait = false;
+	struct cache *ca = c->cache;
 
 	closure_init_stack(&cl);
 
@@ -847,10 +848,10 @@ static struct journal_write *journal_wait_for_write(struct cache_set *c,
 		struct journal_write *w = c->journal.cur;
 
 		sectors = __set_blocks(w->data, w->data->keys + nkeys,
-				       block_bytes(c->cache)) * c->sb.block_size;
+				       block_bytes(ca)) * ca->sb.block_size;
 
 		if (sectors <= min_t(size_t,
-				     c->journal.blocks_free * c->sb.block_size,
+				     c->journal.blocks_free * ca->sb.block_size,
 				     PAGE_SECTORS << JSET_BITS))
 			return w;