From patchwork Tue Dec 18 14:32:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 10735757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 970446C2 for ; Tue, 18 Dec 2018 14:33:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 83F1127F98 for ; Tue, 18 Dec 2018 14:33:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7480228479; Tue, 18 Dec 2018 14:33:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2412F29497 for ; Tue, 18 Dec 2018 14:33:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726546AbeLROdh (ORCPT ); Tue, 18 Dec 2018 09:33:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:55564 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726426AbeLROdh (ORCPT ); Tue, 18 Dec 2018 09:33:37 -0500 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 AAD7AB121; Tue, 18 Dec 2018 14:33:35 +0000 (UTC) From: Coly Li To: linux-bcache@vger.kernel.org Cc: linux-block@vger.kernel.org, Coly Li Subject: [PATCH 1/2] bcache: export backing_dev_name via sysfs Date: Tue, 18 Dec 2018 22:32:49 +0800 Message-Id: <20181218143250.81793-1-colyli@suse.de> X-Mailer: git-send-email 2.16.4 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch export dc->backing_dev_name to sysfs file /sys/block/bcache/bcache/backing_dev_name, then people or user space tools may know the backing device name of this bcache device. Of cause it can be done by parsing sysfs links, but this method can be much simpler to find the link between bcache device and backing device. Signed-off-by: Coly Li --- drivers/md/bcache/sysfs.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index 26f035a0c5b9..8f7674d199fb 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -67,6 +67,7 @@ read_attribute(written); read_attribute(btree_written); read_attribute(metadata_written); read_attribute(active_journal_entries); +read_attribute(backing_dev_name); sysfs_time_stats_attribute(btree_gc, sec, ms); sysfs_time_stats_attribute(btree_split, sec, us); @@ -240,6 +241,12 @@ SHOW(__bch_cached_dev) return strlen(buf); } + if (attr == &sysfs_backing_dev_name) { + snprintf(buf, BDEVNAME_SIZE + 1, "%s", dc->backing_dev_name); + strcat(buf, "\n"); + return strlen(buf); + } + #undef var return 0; } @@ -431,6 +438,7 @@ static struct attribute *bch_cached_dev_files[] = { &sysfs_verify, &sysfs_bypass_torture_test, #endif + &sysfs_backing_dev_name, NULL }; KTYPE(bch_cached_dev);