Commit 21e478dd authored by Coly Li's avatar Coly Li Committed by Jens Axboe
Browse files

bcache: handle c->uuids properly for bucket size > 8MB 



Bcache allocates a whole bucket to store c->uuids on cache device, and
allocates continuous pages to store it in-memory. When the bucket size
exceeds maximum allocable continuous pages, bch_cache_set_alloc() will
fail and cache device registration will fail.

This patch allocates c->uuids by alloc_meta_bucket_pages(), and uses
ilog2(meta_bucket_pages(c)) to indicate order of c->uuids pages when
free it. When writing c->uuids to cache device, its size is decided
by meta_bucket_pages(c) * PAGE_SECTORS. Now c->uuids is properly handled
for bucket size > 8MB.

Signed-off-by: default avatarColy Li <colyli@suse.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent de1fafab

drivers/md/bcache/super.c

+6 −4
Original line number Diff line number Diff line
@@ -466,6 +466,7 @@ static int __uuid_write(struct cache_set *c) 
	BKEY_PADDED(key) k;

	struct closure cl;

	struct cache *ca;

	unsigned int size;



	closure_init_stack(&cl);

	lockdep_assert_held(&bch_register_lock);
@@ -473,7 +474,8 @@ static int __uuid_write(struct cache_set *c) 
	if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true))

		return 1;



	SET_KEY_SIZE(&k.key, c->sb.bucket_size);

	size =  meta_bucket_pages(&c->sb) * PAGE_SECTORS;

	SET_KEY_SIZE(&k.key, size);

	uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl);

	closure_sync(&cl);
@@ -1664,7 +1666,7 @@ static void cache_set_free(struct closure *cl) 
		}



	bch_bset_sort_state_free(&c->sort);

	free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));

	free_pages((unsigned long) c->uuids, ilog2(meta_bucket_pages(&c->sb)));



	if (c->moving_gc_wq)

		destroy_workqueue(c->moving_gc_wq);
@@ -1870,7 +1872,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) 


	c->bucket_bits		= ilog2(sb->bucket_size);

	c->block_bits		= ilog2(sb->block_size);

	c->nr_uuids		= bucket_bytes(c) / sizeof(struct uuid_entry);

	c->nr_uuids		= meta_bucket_bytes(&c->sb) / sizeof(struct uuid_entry);

	c->devices_max_used	= 0;

	atomic_set(&c->attached_dev_nr, 0);

	c->btree_pages		= bucket_pages(c);
@@ -1921,7 +1923,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) 
			BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER))

		goto err;



	c->uuids = alloc_bucket_pages(GFP_KERNEL, c);

	c->uuids = alloc_meta_bucket_pages(GFP_KERNEL, &c->sb);

	if (!c->uuids)

		goto err;

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