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From: Hannes Reinecke <hare@suse.de>
To: Coly Li <colyli@suse.de>, linux-bcache@vger.kernel.org
Cc: linux-block@vger.kernel.org
Subject: Re: [PATCH v2 01/17] bcache: add comments to mark member offset of struct cache_sb_disk
Date: Wed, 15 Jul 2020 08:02:53 +0200	[thread overview]
Message-ID: <668b8126-6a34-7029-dea4-2ad0ecc3915e@suse.de> (raw)
In-Reply-To: <20200715054612.6349-2-colyli@suse.de>

On 7/15/20 7:45 AM, Coly Li wrote:
> This patch adds comments to mark each member of struct cache_sb_disk,
> it is helpful to understand the bcache superblock on-disk layout.
> 
> Signed-off-by: Coly Li <colyli@suse.de>
> ---
>   include/uapi/linux/bcache.h | 39 +++++++++++++++++++------------------
>   1 file changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h
> index 9a1965c6c3d0..afbd1b56a661 100644
> --- a/include/uapi/linux/bcache.h
> +++ b/include/uapi/linux/bcache.h
> @@ -158,33 +158,33 @@ static inline struct bkey *bkey_idx(const struct bkey *k, unsigned int nr_keys)
>   #define BDEV_DATA_START_DEFAULT		16	/* sectors */
>   
>   struct cache_sb_disk {
> -	__le64			csum;
> -	__le64			offset;	/* sector where this sb was written */
> -	__le64			version;
> +/*000*/	__le64			csum;
> +/*008*/	__le64			offset;	/* sector where this sb was written */
> +/*010*/	__le64			version;
>   
> -	__u8			magic[16];
> +/*018*/	__u8			magic[16];
>   
> -	__u8			uuid[16];
> +/*028*/	__u8			uuid[16];
>   	union {
> -		__u8		set_uuid[16];
> +/*038*/		__u8		set_uuid[16];
>   		__le64		set_magic;
>   	};
> -	__u8			label[SB_LABEL_SIZE];
> +/*048*/	__u8			label[SB_LABEL_SIZE];
>   
> -	__le64			flags;
> -	__le64			seq;
> -	__le64			pad[8];
> +/*068*/	__le64			flags;
> +/*070*/	__le64			seq;
> +/*078*/	__le64			pad[8];
>   
>   	union {
>   	struct {
>   		/* Cache devices */
> -		__le64		nbuckets;	/* device size */
> +/*0b8*/		__le64		nbuckets;	/* device size */
>   
> -		__le16		block_size;	/* sectors */
> -		__le16		bucket_size;	/* sectors */
> +/*0c0*/		__le16		block_size;	/* sectors */
> +/*0c2*/		__le16		bucket_size;	/* sectors */
>   
> -		__le16		nr_in_set;
> -		__le16		nr_this_dev;
> +/*0c4*/		__le16		nr_in_set;
> +/*0c6*/		__le16		nr_this_dev;
>   	};
>   	struct {
>   		/* Backing devices */
> @@ -198,14 +198,15 @@ struct cache_sb_disk {
>   	};
>   	};
>   
> -	__le32			last_mount;	/* time overflow in y2106 */
> +/*0c8*/	__le32			last_mount;	/* time overflow in y2106 */
>   
> -	__le16			first_bucket;
> +/*0cc*/	__le16			first_bucket;
>   	union {
> -		__le16		njournal_buckets;
> +/*0ce*/		__le16		njournal_buckets;
>   		__le16		keys;
>   	};
> -	__le64			d[SB_JOURNAL_BUCKETS];	/* journal buckets */
> +/*0d0*/	__le64			d[SB_JOURNAL_BUCKETS];	/* journal buckets */
> +/*8d0*/
>   };
>   
>   struct cache_sb {
> 
Common practice is to place comments at the end; please don't use the 
start of the line here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

  reply	other threads:[~2020-07-15  6:02 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-15  5:45 [PATCH v2 00/17] bcache: extend bucket size to 32bit width Coly Li
2020-07-15  5:45 ` [PATCH v2 01/17] bcache: add comments to mark member offset of struct cache_sb_disk Coly Li
2020-07-15  6:02   ` Hannes Reinecke [this message]
2020-07-15  9:03     ` Coly Li
2020-07-15  9:08       ` Johannes Thumshirn
2020-07-15 10:35         ` Coly Li
2020-07-15  5:45 ` [PATCH v2 02/17] bcache: add read_super_basic() to read major part of super block Coly Li
2020-07-15  6:03   ` Hannes Reinecke
2020-07-15  5:45 ` [PATCH v2 03/17] bcache: add more accurate error information in read_super_basic() Coly Li
2020-07-15  6:04   ` Hannes Reinecke
2020-07-15  5:45 ` [PATCH v2 04/17] bcache: disassemble the big if() checks in bch_cache_set_alloc() Coly Li
2020-07-15  6:08   ` Hannes Reinecke
2020-07-15  5:46 ` [PATCH v2 05/17] bcache: fix super block seq numbers comparision in register_cache_set() Coly Li
2020-07-15  6:10   ` Hannes Reinecke
2020-07-15  5:46 ` [PATCH v2 06/17] bcache: increase super block version for cache device and backing device Coly Li
2020-07-15  6:11   ` Hannes Reinecke
2020-07-15  5:46 ` [PATCH v2 07/17] bcache: move bucket related code into read_super_basic() Coly Li
2020-07-15  6:44   ` Hannes Reinecke
2020-07-15  5:46 ` [PATCH v2 08/17] bcache: struct cache_sb is only for in-memory super block now Coly Li
2020-07-15  6:45   ` Hannes Reinecke
2020-07-15  5:46 ` [PATCH v2 09/17] bcache: introduce meta_bucket_pages() related helper routines Coly Li
2020-07-15  5:46 ` [PATCH v2 10/17] bcache: handle c->uuids properly for bucket size > 8MB Coly Li
2020-07-15  5:46 ` [PATCH v2 11/17] bcache: handle cache prio_buckets and disk_buckets " Coly Li
2020-07-15  5:46 ` [PATCH v2 12/17] bcache: handle cache set verify_ondisk " Coly Li
2020-07-15  5:46 ` [PATCH v2 13/17] bcache: handle btree node memory allocation " Coly Li
2020-07-15  5:46 ` [PATCH v2 14/17] bcache: add bucket_size_hi into struct cache_sb_disk for large bucket Coly Li
2020-07-15  5:46 ` [PATCH v2 15/17] bcache: add sysfs file to display feature sets information of cache set Coly Li
2020-07-15  5:46 ` [PATCH v2 16/17] bcache: avoid extra memory allocation from mempool c->fill_iter Coly Li
2020-07-15  5:46 ` [PATCH v2 17/17] bcache: avoid extra memory consumption in struct bbio for large bucket size Coly Li

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