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=-11.5 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,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 985AAC43613 for ; Fri, 4 Jan 2019 05:33:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A26121872 for ; Fri, 4 Jan 2019 05:33:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="olaJpfxZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726607AbfADFcJ (ORCPT ); Fri, 4 Jan 2019 00:32:09 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:57904 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726508AbfADFcI (ORCPT ); Fri, 4 Jan 2019 00:32:08 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x045SbKR140401 for ; Fri, 4 Jan 2019 05:32:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=CsUE/xq2aY4bpZpLthODmWbBIvIknX3j4ql0mtwzHtg=; b=olaJpfxZYKLMXhFY82SNVmkY60ImVPraHeH9M31q/N9B8fWkBm2DhaA7bqzGPqhTcEpb Zv1vaTeOzHrbxh5JcD1VxJMc2VuZoNiyXGlMseIe4DWeV6Q6pcIqeXldGo37qHVkIklv Q2fDuQ/Z6gi0TxswLRyozL+lWvtY10dRzgSFP3oXZejvLwlcG+a4W8UA+jeNa9G9IGoO 7pBcYRHY0SqmuyjCY5iBbmFydrVH0CaOAIP9y5SiixCqGUFyxpWEZYO9pedfKVy7uEwU yRfLqTIbDF0ZlDeu+bDg5WbrTme6PTmgXqxe/5YDSX2XLZcKxraZrELwkLOgyjnj8lUg Qw== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2130.oracle.com with ESMTP id 2pp0bu2fqt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 04 Jan 2019 05:32:06 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x045W1b4000701 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 4 Jan 2019 05:32:01 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x045W1Oj004345 for ; Fri, 4 Jan 2019 05:32:01 GMT Received: from tpasj.localdomain (/116.87.143.221) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 03 Jan 2019 21:32:00 -0800 From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH 2/2 v14] btrfs: introduce feature to forget a btrfs device Date: Fri, 4 Jan 2019 13:31:54 +0800 Message-Id: <1546579914-14971-4-git-send-email-anand.jain@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1546579914-14971-1-git-send-email-anand.jain@oracle.com> References: <1546579914-14971-1-git-send-email-anand.jain@oracle.com> 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-1901040048 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org 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 --- v13->v14: Now the changes related to refactor of btrfs_free_stale_devices() is moved to a new patch. 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 | 11 +++++++++++ fs/btrfs/volumes.h | 1 + include/uapi/linux/btrfs.h | 2 ++ 4 files changed, 17 insertions(+) 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 d8ac63e3666d..cec329f64ac0 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1473,6 +1473,17 @@ static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr, return 0; } +int btrfs_forget_devices(const char *path) +{ + int ret; + + mutex_lock(&uuid_mutex); + ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL); + mutex_unlock(&uuid_mutex); + + return ret; +} + /* * Look for a btrfs signature on a device. This may be called out of the mount path * and we are not allowed to call set_blocksize during the scan. The superblock diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index ed806649a473..1e73257e55fb 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -416,6 +416,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fmode_t flags, void *holder); struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags, void *holder); +int btrfs_forget_devices(const char *path); int btrfs_close_devices(struct btrfs_fs_devices *fs_devices); void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step); void btrfs_assign_next_active_device(struct btrfs_device *device, diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index e0763bc4158e..c195896d478f 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -837,6 +837,8 @@ enum btrfs_err_code { struct btrfs_ioctl_vol_args) #define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \ struct btrfs_ioctl_vol_args) +#define BTRFS_IOC_FORGET_DEV _IOW(BTRFS_IOCTL_MAGIC, 5, \ + struct btrfs_ioctl_vol_args) /* trans start and trans end are dangerous, and only for * use by applications that know how to avoid the * resulting deadlocks -- 1.8.3.1