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,URIBL_BLOCKED, 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 0F1D8C43387 for ; Wed, 2 Jan 2019 05:49:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C86702089F for ; Wed, 2 Jan 2019 05:49:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="IhAH+1mR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728183AbfABFtn (ORCPT ); Wed, 2 Jan 2019 00:49:43 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:46526 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726353AbfABFtn (ORCPT ); Wed, 2 Jan 2019 00:49:43 -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 x025n6k9168518 for ; Wed, 2 Jan 2019 05:49:42 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=n2s3ss0sZTJS2xCjzl/rk8BxV6S8dr9S/hKeQ4l1gXQ=; b=IhAH+1mRej/bWx6p7SPDAwmOROiIKQQy1qM6HePyyxb5sHzHnmmMWaw0vpU9XovdO6Xn t8ZtVYNPic5an1D3mC5+nDjakt5J+aStddYasjsbgcopYtigHSyZPH1j2p7fQa+U665F kLxgwkopSdJ5X6/RjYBZoI0IlLLGQhDwXd/3w6W5ZO/P1v3QQjwlcIbth757CXBi2Tjs PIJuSI7z1CzMB9IVVMlXEdP09AlRboqscB0lFAU4sOX3L5qHTN2+PKZvzDSrx9N8RiLD jzskCq8ry7a6vUivs3PK0JAmx6M9+agxw/DyeulB+MvTUyCzM1ceYEQPavjUgp8yjf+W QQ== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2120.oracle.com with ESMTP id 2pp1jr0egk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 02 Jan 2019 05:49:42 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x025nfL9004752 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 2 Jan 2019 05:49:41 GMT Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x025nfhL016006 for ; Wed, 2 Jan 2019 05:49:41 GMT Received: from tpasj.wifi.oracle.com (/192.188.170.109) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 01 Jan 2019 21:49:41 -0800 From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH RESEND v12] btrfs: introduce feature to forget a btrfs device Date: Wed, 2 Jan 2019 13:49:31 +0800 Message-Id: <1546408172-5193-2-git-send-email-anand.jain@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1546408172-5193-1-git-send-email-anand.jain@oracle.com> References: <1546408172-5193-1-git-send-email-anand.jain@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9123 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-1901020052 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 Reviewed-by: Nikolay Borisov --- 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 | 9 +++++++++ fs/btrfs/volumes.h | 1 + include/uapi/linux/btrfs.h | 2 ++ 4 files changed, 15 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index d3c6bbc0aa3a..eba2966913ae 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 8e36cbb355df..48415a9edd46 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1397,6 +1397,15 @@ static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr, return 0; } +int btrfs_forget_devices(const char *path) +{ + mutex_lock(&uuid_mutex); + btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL); + mutex_unlock(&uuid_mutex); + + return 0; +} + /* * 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 1d936ce282c3..a4a89d5050f5 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -414,6 +414,7 @@ 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