| Message ID | 20200715054612.6349-9-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bcache: extend bucket size to 32bit width | expand |
On 7/15/20 7:46 AM, Coly Li wrote: > 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 anymore, and removes the useless member > csum and pad[5]. > > Although struct cache_sb does not belong to uapi anymore, 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 <colyli@suse.de> > --- > include/uapi/linux/bcache.h | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h > index 3c0aebb4a878..f5106c5939b0 100644 > --- a/include/uapi/linux/bcache.h > +++ b/include/uapi/linux/bcache.h > @@ -216,8 +216,13 @@ struct cache_sb_disk { > /*8d0*/ > }; > > +/* > + * This is for in-memory bcache super block. > + * NOTE: cache_sb is NOT exactly mapping to cache_sb_disk anymore, > + * the member size, ordering and even whole struct size may be > + * different from cache_sb_disk now. > + */ > struct cache_sb { > - __u64 csum; > __u64 offset; /* sector where this sb was written */ > __u64 version; > > @@ -237,8 +242,6 @@ struct cache_sb { > __u64 feature_incompat; > __u64 feature_ro_compat; > > - __u64 pad[5]; > - > union { > struct { > /* Cache devices */ > @@ -246,7 +249,6 @@ struct cache_sb { > > __u16 block_size; /* sectors */ > __u16 bucket_size; /* sectors */ > - > __u16 nr_in_set; > __u16 nr_this_dev; > }; > I would drop the 'anymore' from the description, as this implies it changed recently. But otherwise: Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h index 3c0aebb4a878..f5106c5939b0 100644 --- a/include/uapi/linux/bcache.h +++ b/include/uapi/linux/bcache.h @@ -216,8 +216,13 @@ struct cache_sb_disk { /*8d0*/ }; +/* + * This is for in-memory bcache super block. + * NOTE: cache_sb is NOT exactly mapping to cache_sb_disk anymore, + * the member size, ordering and even whole struct size may be + * different from cache_sb_disk now. + */ struct cache_sb { - __u64 csum; __u64 offset; /* sector where this sb was written */ __u64 version; @@ -237,8 +242,6 @@ struct cache_sb { __u64 feature_incompat; __u64 feature_ro_compat; - __u64 pad[5]; - union { struct { /* Cache devices */ @@ -246,7 +249,6 @@ struct cache_sb { __u16 block_size; /* sectors */ __u16 bucket_size; /* sectors */ - __u16 nr_in_set; __u16 nr_this_dev; };
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 anymore, and removes the useless member csum and pad[5]. Although struct cache_sb does not belong to uapi anymore, 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 <colyli@suse.de> --- include/uapi/linux/bcache.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)