From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99A77ECDFD0 for ; Fri, 14 Sep 2018 10:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D92C20881 for ; Fri, 14 Sep 2018 10:00:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D92C20881 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728133AbeINPOZ (ORCPT ); Fri, 14 Sep 2018 11:14:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:39670 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726868AbeINPOY (ORCPT ); Fri, 14 Sep 2018 11:14:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C22F2AE66; Fri, 14 Sep 2018 10:00:37 +0000 (UTC) Subject: Re: [PATCH] add label interface for cache device in sysfs To: Dongbo Cao Cc: kent.overstreet@gmail.com, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180914095120.2699-1-cdbdyx@163.com> From: Coly Li Message-ID: Date: Fri, 14 Sep 2018 18:00:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20180914095120.2699-1-cdbdyx@163.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/14/18 5:51 PM, Dongbo Cao wrote: > label interface will be called by bcache tools in user space. > > Signed-off-by: Dongbo Cao Hi Dongbo, In your change I see you set superblock label to cache set. What is the use case for doing this ? Thanks. Coly Li > --- > drivers/md/bcache/sysfs.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c > index 225b15aa..e64c718f 100644 > --- a/drivers/md/bcache/sysfs.c > +++ b/drivers/md/bcache/sysfs.c > @@ -950,6 +950,13 @@ SHOW(__bch_cache) > return ret; > } > > + if (attr == &sysfs_label) { > + memcpy(buf, ca->sb.label, SB_LABEL_SIZE); > + buf[SB_LABEL_SIZE + 1] = '\0'; > + strcat(buf, "\n"); > + return strlen(buf); > + } > + > return 0; > } > SHOW_LOCKED(bch_cache) > @@ -993,6 +1000,17 @@ STORE(__bch_cache) > atomic_set(&ca->io_errors, 0); > } > > + if (attr == &sysfs_label) { > + if (size > SB_LABEL_SIZE) > + return -EINVAL; > + memcpy(ca->sb.label, buf, size); > + if (size < SB_LABEL_SIZE) > + ca->sb.label[size] = '\0'; > + if (size && ca->sb.label[size - 1] == '\n') > + ca->sb.label[size - 1] = '\0'; > + bcache_write_super(ca->set); > + } > + > return size; > } > STORE_LOCKED(bch_cache) > @@ -1009,6 +1027,7 @@ static struct attribute *bch_cache_files[] = { > &sysfs_io_errors, > &sysfs_clear_stats, > &sysfs_cache_replacement_policy, > + &sysfs_label, > NULL > }; > KTYPE(bch_cache);