From: Coly Li Date: Sat, 25 Jul 2020 12:00:29 +0000 (+0800) Subject: bcache: struct cache_sb is only for in-memory super block now X-Git-Tag: Ubuntu-5.13.0-19.19~5386^2~13 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=4c1ccd0896d6a45f2159280d957afd441a7aeaba;p=mirror_ubuntu-jammy-kernel.git bcache: struct cache_sb is only for in-memory super block now We have struct cache_sb_disk for on-disk super block already, it is unnecessary to keep the in-memory super block format exactly mapping to the on-disk struct layout. This patch adds code comments to notice that struct cache_sb is not exactly mapping to cache_sb_disk, and removes the useless member csum and pad[5]. Although struct cache_sb does not belong to uapi, but there are still some on-disk format related macros reference it and it is unncessary to get rid of such dependency now. So struct cache_sb will continue to stay in include/uapi/linux/bache.h for now. Signed-off-by: Coly Li Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h index 47df2db2e727..0ef984ea515a 100644 --- a/include/uapi/linux/bcache.h +++ b/include/uapi/linux/bcache.h @@ -215,8 +215,13 @@ struct cache_sb_disk { __le64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */ }; +/* + * This is for in-memory bcache super block. + * NOTE: cache_sb is NOT exactly mapping to cache_sb_disk, the member + * size, ordering and even whole struct size may be different + * from cache_sb_disk. + */ struct cache_sb { - __u64 csum; __u64 offset; /* sector where this sb was written */ __u64 version; @@ -236,8 +241,6 @@ struct cache_sb { __u64 feature_incompat; __u64 feature_ro_compat; - __u64 pad[5]; - union { struct { /* Cache devices */ @@ -245,7 +248,6 @@ struct cache_sb { __u16 block_size; /* sectors */ __u16 bucket_size; /* sectors */ - __u16 nr_in_set; __u16 nr_this_dev; };