bcache: use read_cache_page_gfp to read the superblock

Avoid a pointless dependency on buffer heads in bcache by simply open
coding reading a single page.  Also add a SB_OFFSET define for the
byte offset of the superblock instead of using magic numbers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2020-01-24 01:01:34 +08:00 committed by Jens Axboe
parent 475389ae5c
commit 6321bef028
2 changed files with 8 additions and 9 deletions

View file

@ -148,6 +148,7 @@ static inline struct bkey *bkey_idx(const struct bkey *k, unsigned int nr_keys)
#define BCACHE_SB_MAX_VERSION 4
#define SB_SECTOR 8
#define SB_OFFSET (SB_SECTOR << SECTOR_SHIFT)
#define SB_SIZE 4096
#define SB_LABEL_SIZE 32
#define SB_JOURNAL_BUCKETS 256U