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=-9.5 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_PASS,URIBL_BLOCKED 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 359E0C43387 for ; Fri, 4 Jan 2019 05:26:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F28972070D for ; Fri, 4 Jan 2019 05:26:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="YnICo6o1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726464AbfADF06 (ORCPT ); Fri, 4 Jan 2019 00:26:58 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:38406 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726308AbfADF05 (ORCPT ); Fri, 4 Jan 2019 00:26:57 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x045O56X096505; Fri, 4 Jan 2019 05:26:53 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : references : cc : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=jKEK0bZAFmdFcwCsYhdJ5xqsTAvTlsLWSgsJwx79uNY=; b=YnICo6o1sR9EA2LglAOYFDy+GJQAFgulNsUHHtUKgfbCj+hh1xv51SrgMbEeHZF6SECk ppUx4hDccVlXErM5jbYeSPrlZ1cg3J7x7lnxdOvudmrev8DRHOC84rSu9v9bjMINfgrW sWwBkFwj0UP9e345iqPv17Gj2bkp+iud2zZf1DYomsFhvB6yo2+U9m2uQtIAhH+tbAzd 4Ni1u9Yfx1eTp4+RLT25mdqBENYDxuAG5eHxYQ8ROYDPqRr6ulD+7L69MSWWGj/GQbS+ hkCCuOsECPv2re/O8q/EbOy1Oqe6zzQx5TP/SYo9Eer3AhfqA4gpOnDmYmEo/NGf+zQx /w== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2pp1jrabvm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 04 Jan 2019 05:26:53 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x045QrWs008740 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 4 Jan 2019 05:26:53 GMT Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x045Qqhj006849; Fri, 4 Jan 2019 05:26:53 GMT Received: from [192.168.1.145] (/116.87.143.221) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 03 Jan 2019 21:26:52 -0800 Subject: Re: [PATCH v13] btrfs: introduce feature to forget a btrfs device To: dsterba@suse.cz References: <1546502498-28070-1-git-send-email-anand.jain@oracle.com> <1546502498-28070-2-git-send-email-anand.jain@oracle.com> <20190103152426.GI23615@twin.jikos.cz> Cc: linux-btrfs@vger.kernel.org From: Anand Jain Message-ID: <1fb23edf-d63d-a060-be99-2f93ef946d06@oracle.com> Date: Fri, 4 Jan 2019 13:26:51 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190103152426.GI23615@twin.jikos.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9125 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901040047 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 01/03/2019 11:24 PM, David Sterba wrote: > On Thu, Jan 03, 2019 at 04:01:37PM +0800, Anand Jain wrote: >> Support for a new command 'btrfs dev forget [dev]' is proposed here >> to undo the effects of 'btrfs dev scan [dev]'. For this purpose >> this patch proposes to use ioctl #5 as it was empty. >> IOW(BTRFS_IOCTL_MAGIC, 5, ..) >> This patch adds new ioctl BTRFS_IOC_FORGET_DEV which can be sent from >> the /dev/btrfs-control to forget one or all devices, (devices which are >> not mounted) from the btrfs kernel. >> >> The argument it takes is struct btrfs_ioctl_vol_args, and ::name can be >> set to specify the device path. And all unmounted devices can be removed >> from the kernel if no device path is provided. >> >> Again, the devices are removed only if the relevant fsid aren't mounted. >> >> This new cli can provide.. >> . Release of unwanted btrfs_fs_devices and btrfs_devices memory if the >> device is not going to be mounted. >> . Ability to mount the device in degraded mode when one of the other >> device is corrupted like in split brain raid1. >> . Running test cases which requires btrfs.ko-reload if the rootfs >> is btrfs. >> >> Signed-off-by: Anand Jain >> Reviewed-by: Nikolay Borisov >> --- >> v12->v13: >> btrfs.ko returns error on failing to find the given device. >> For no argument (btrfs device scan --forget) if there is >> no device to forget then it shall just return success. >> v11->v12: fix coding style add spacing before after ":". >> v1->v11: Pls ref to the cover-letter. (sorry about that). >> >> fs/btrfs/super.c | 3 +++ >> fs/btrfs/volumes.c | 55 +++++++++++++++++++++++++++++++++++----------- >> fs/btrfs/volumes.h | 1 + >> include/uapi/linux/btrfs.h | 2 ++ >> 4 files changed, 48 insertions(+), 13 deletions(-) >> >> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c >> index 33cc9aba9c94..a4e8beec0fc5 100644 >> --- a/fs/btrfs/super.c >> +++ b/fs/btrfs/super.c >> @@ -2247,6 +2247,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, >> ret = PTR_ERR_OR_ZERO(device); >> mutex_unlock(&uuid_mutex); >> break; >> + case BTRFS_IOC_FORGET_DEV: >> + ret = btrfs_forget_devices(vol->name); >> + break; >> case BTRFS_IOC_DEVICES_READY: >> mutex_lock(&uuid_mutex); >> device = btrfs_scan_one_device(vol->name, FMODE_READ, >> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c >> index 2576b1a379c9..2ab42bfe5d3c 100644 >> --- a/fs/btrfs/volumes.c >> +++ b/fs/btrfs/volumes.c >> @@ -734,6 +734,19 @@ static void pending_bios_fn(struct btrfs_work *work) >> run_scheduled_bios(device); >> } >> >> +static bool device_path_matched(const char *path, struct btrfs_device *device) >> +{ >> + int found; >> + >> + rcu_read_lock(); >> + found = strcmp(rcu_str_deref(device->name), path); >> + rcu_read_unlock(); >> + >> + if (!found) >> + return true; >> + return false; >> +} >> + >> /* >> * Search and remove all stale (devices which are not mounted) devices. >> * When both inputs are NULL, it will search and release all stale devices. >> @@ -742,44 +755,47 @@ static void pending_bios_fn(struct btrfs_work *work) >> * skip_dev: Optional. Will skip this device when searching for the stale >> * devices. >> */ >> -static void btrfs_free_stale_devices(const char *path, >> +static int btrfs_free_stale_devices(const char *path, >> struct btrfs_device *skip_device) >> { >> struct btrfs_fs_devices *fs_devices, *tmp_fs_devices; >> struct btrfs_device *device, *tmp_device; >> + int ret; >> + >> + if (path) >> + ret = -ENXIO; >> + else >> + ret = 0; > > Can you please split this change to another patch? It's a preparatory > work for the new ioctl. The return value meaning should be also > documented in the function comment. > Pls find v14. I have also use -ENOENT instead of -ENXIO and documented the return value in the function header.