From mboxrd@z Thu Jan 1 00:00:00 1970 From: Coly Li Subject: [RFC PATCH 01/16] bcache: add comments to mark member offset of struct cache_sb_disk Date: Sun, 5 Jul 2020 23:55:46 +0800 Message-ID: <20200705155601.5404-2-colyli@suse.de> References: <20200705155601.5404-1-colyli@suse.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mx2.suse.de ([195.135.220.15]:38012 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726996AbgGEP4M (ORCPT ); Sun, 5 Jul 2020 11:56:12 -0400 In-Reply-To: <20200705155601.5404-1-colyli@suse.de> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: linux-bcache@vger.kernel.org Cc: linux-block@vger.kernel.org, Coly Li 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 --- 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 { -- 2.26.2