From patchwork Sat Jul 25 12:00:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 11684991 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D4A15138C for ; Sat, 25 Jul 2020 12:03:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCE9E206F6 for ; Sat, 25 Jul 2020 12:03:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727034AbgGYMDS (ORCPT ); Sat, 25 Jul 2020 08:03:18 -0400 Received: from mx2.suse.de ([195.135.220.15]:52462 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727023AbgGYMDR (ORCPT ); Sat, 25 Jul 2020 08:03:17 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 94CB2AEAF; Sat, 25 Jul 2020 12:03:25 +0000 (UTC) From: Coly Li To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, Coly Li , Hannes Reinecke Subject: [PATCH 15/25] bcache: struct cache_sb is only for in-memory super block now Date: Sat, 25 Jul 2020 20:00:29 +0800 Message-Id: <20200725120039.91071-16-colyli@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200725120039.91071-1-colyli@suse.de> References: <20200725120039.91071-1-colyli@suse.de> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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 --- 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 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; };