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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 74AA8C433FF for ; Tue, 30 Jul 2019 06:21:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 30DC420882 for ; Tue, 30 Jul 2019 06:21:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="42eqip90" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727627AbfG3GVC (ORCPT ); Tue, 30 Jul 2019 02:21:02 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:59680 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbfG3GVC (ORCPT ); Tue, 30 Jul 2019 02:21:02 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6U6J3Xv053912; Tue, 30 Jul 2019 06:20:39 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=5n8OzrZ77RhnGg+5veAoaGbh8/tBKL2m5epcFu44MYY=; b=42eqip90AAbtzB6ZvgXhwkI8XAN/OPvcHZWvZpDlRDSyQ3Eo0whNMYnPKK+EVZXdKFqI Vp7VJpukJfhi00uVfoT3yYoxbdrCNyA17f71tQmkObzsmYMOC7XydFZRk+4dBCqleqED vilZteBonMT8gK0iiIXUmmz8+5GXnrDvKN0d2/J49xSCFqT0TLC9Iai7LQ9LJ690S3TN +TbTDBtpAF6xTWMKMns+MMPz3dORLffCZh4/PDkWAdm/rJwF7UfnKHEJjvdW+Csb5m3c T17T80i7nmSsp+ZUP7Auo9RV8QzLTs28eITV1UAqMq44Ag+ogSJOKAEMOrD0fImEl9Li LA== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2u0e1tmap5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Jul 2019 06:20:39 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6U67pDb073545; Tue, 30 Jul 2019 06:20:39 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2u0ee4u69w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Jul 2019 06:20:38 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x6U6KbGR031036; Tue, 30 Jul 2019 06:20:37 GMT Received: from [192.168.1.24] (/180.169.93.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 29 Jul 2019 23:20:37 -0700 Subject: Re: [PATCH 1/2] md/raid0: Introduce new array state 'broken' for raid0 To: "Guilherme G. Piccoli" , linux-raid@vger.kernel.org Cc: linux-block@vger.kernel.org, dm-devel@redhat.com, jay.vosburgh@canonical.com, neilb@suse.com, songliubraving@fb.com References: <20190729203135.12934-1-gpiccoli@canonical.com> <20190729203135.12934-2-gpiccoli@canonical.com> From: Bob Liu Message-ID: Date: Tue, 30 Jul 2019 14:20:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190729203135.12934-2-gpiccoli@canonical.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9333 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907300065 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9333 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907300066 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7/30/19 4:31 AM, Guilherme G. Piccoli wrote: > Currently if a md/raid0 array gets one or more members removed while > being mounted, kernel keeps showing state 'clean' in the 'array_state' > sysfs attribute. Despite udev signaling the member device is gone, 'mdadm' > cannot issue the STOP_ARRAY ioctl successfully, given the array is mounted. > > Nothing else hints that something is wrong (except that the removed devices > don't show properly in the output of 'mdadm detail' command). There is no > other property to be checked, and if user is not performing reads/writes > to the array, even kernel log is quiet and doesn't give a clue about the > missing member. > > This patch changes this behavior; when 'array_state' is read we introduce > a non-expensive check (only for raid0) that relies in the comparison of > the total number of disks when array was assembled with gendisk flags of> those devices to validate if all members are available and functional. > A new array state 'broken' was added: it mimics the state 'clean' in every > aspect, being useful only to distinguish if such array has some member > missing. Also, we show a rate-limited warning in kernel log in such case. > > This patch has no proper functional change other than adding a 'clean'-like > state; it was tested with ext4 and xfs filesystems. It requires a 'mdadm' > counterpart to handle the 'broken' state. > > Cc: NeilBrown > Cc: Song Liu > Signed-off-by: Guilherme G. Piccoli > --- > drivers/md/md.c | 23 +++++++++++++++++++---- > drivers/md/md.h | 2 ++ > drivers/md/raid0.c | 26 ++++++++++++++++++++++++++ > 3 files changed, 47 insertions(+), 4 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index fba49918d591..b80f36084ec1 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -4160,12 +4160,18 @@ __ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR, > * active-idle > * like active, but no writes have been seen for a while (100msec). > * > + * broken > + * RAID0-only: same as clean, but array is missing a member. > + * It's useful because RAID0 mounted-arrays aren't stopped > + * when a member is gone, so this state will at least alert > + * the user that something is wrong. Curious why only raid0 has this issue? Thanks, -Bob > + * > */ > enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active, > - write_pending, active_idle, bad_word}; > + write_pending, active_idle, broken, bad_word}; > static char *array_states[] = { > "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active", > - "write-pending", "active-idle", NULL }; > + "write-pending", "active-idle", "broken", NULL }; > > static int match_word(const char *word, char **list) > { > @@ -4181,7 +4187,7 @@ array_state_show(struct mddev *mddev, char *page) > { > enum array_state st = inactive; > > - if (mddev->pers) > + if (mddev->pers) { > switch(mddev->ro) { > case 1: > st = readonly; > @@ -4201,7 +4207,15 @@ array_state_show(struct mddev *mddev, char *page) > st = active; > spin_unlock(&mddev->lock); > } > - else { > + > + if ((mddev->pers->level == 0) && > + ((st == clean) || (st == broken))) { > + if (mddev->pers->is_missing_dev(mddev)) > + st = broken; > + else > + st = clean; > + } > + } else { > if (list_empty(&mddev->disks) && > mddev->raid_disks == 0 && > mddev->dev_sectors == 0) > @@ -4315,6 +4329,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len) > break; > case write_pending: > case active_idle: > + case broken: > /* these cannot be set */ > break; > } > diff --git a/drivers/md/md.h b/drivers/md/md.h > index 41552e615c4c..e7b42b75701a 100644 > --- a/drivers/md/md.h > +++ b/drivers/md/md.h > @@ -590,6 +590,8 @@ struct md_personality > int (*congested)(struct mddev *mddev, int bits); > /* Changes the consistency policy of an active array. */ > int (*change_consistency_policy)(struct mddev *mddev, const char *buf); > + /* Check if there is any missing/failed members - RAID0 only for now. */ > + bool (*is_missing_dev)(struct mddev *mddev); > }; > > struct md_sysfs_entry { > diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c > index 58a9cc5193bf..79618a6ae31a 100644 > --- a/drivers/md/raid0.c > +++ b/drivers/md/raid0.c > @@ -455,6 +455,31 @@ static inline int is_io_in_chunk_boundary(struct mddev *mddev, > } > } > > +bool raid0_is_missing_dev(struct mddev *mddev) > +{ > + struct md_rdev *rdev; > + static int already_missing; > + int def_disks, work_disks = 0; > + struct r0conf *conf = mddev->private; > + > + def_disks = conf->strip_zone[0].nb_dev; > + rdev_for_each(rdev, mddev) > + if (rdev->bdev->bd_disk->flags & GENHD_FL_UP) > + work_disks++; > + > + if (unlikely(def_disks - work_disks)) { > + if (!already_missing) { > + already_missing = 1; > + pr_warn("md: %s: raid0 array has %d missing/failed members\n", > + mdname(mddev), (def_disks - work_disks)); > + } > + return true; > + } > + > + already_missing = 0; > + return false; > +} > + > static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) > { > struct r0conf *conf = mddev->private; > @@ -789,6 +814,7 @@ static struct md_personality raid0_personality= > .takeover = raid0_takeover, > .quiesce = raid0_quiesce, > .congested = raid0_congested, > + .is_missing_dev = raid0_is_missing_dev, > }; > > static int __init raid0_init (void) >