From: Coly Li <colyli@suse.de>
To: Hannes Reinecke <hare@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 17:03:05 +0800 [thread overview]
Message-ID: <f48d11e2-bd17-ba6e-1bc1-b496929e5e59@suse.de> (raw)
In-Reply-To: <668b8126-6a34-7029-dea4-2ad0ecc3915e@suse.de>
On 2020/7/15 14:02, Hannes Reinecke wrote:
> 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.
Hi Hannes,
When I try to move the offset comment to the line end, I find it
conflicts with normal code comment, e.g.
__le64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
I have to add the offset comment to the line start. I guess this is why
ocfs2 code adds the offset comment at the line start.
So finally I have to keep the offset comment on line start still...
Coly Li
next prev parent reply other threads:[~2020-07-15 9:03 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
2020-07-15 9:03 ` Coly Li [this message]
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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