From patchwork Thu Jul 26 11:32:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anand Jain X-Patchwork-Id: 10545617 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 018381805 for ; Thu, 26 Jul 2018 11:29:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E2D6528852 for ; Thu, 26 Jul 2018 11:29:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D733E28F4F; Thu, 26 Jul 2018 11:29:08 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,T_DKIM_INVALID,UNPARSEABLE_RELAY 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 6E27328852 for ; Thu, 26 Jul 2018 11:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729421AbeGZMpb (ORCPT ); Thu, 26 Jul 2018 08:45:31 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:45024 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729273AbeGZMpa (ORCPT ); Thu, 26 Jul 2018 08:45:30 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w6QBT5Xr175823 for ; Thu, 26 Jul 2018 11:29:05 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=d99fBKzLoArjacrJzJQk+v6rtE/qTVBd3RCjk0loaQI=; b=oBwBOWJ4d1Dn+K4AmOrd0CI8Dzg+sg0sT3Bzg/OcJ6tI+9rTTPhsBf41WKdmYWkYWqni 4A2pL8gUsZBCMLi0dNZrPNfCArUqlJZX+j1OWfruIiAP3RqBBfYF/stp2z73QcC3Rk9H VkJpICSiene1XW+Gc6YKRh17UhmtTlDjpewY/ao/7N3/rGkeKyQ2DjkOf/VOnjak6df2 qG8QJS0dEUa52kJNuSvx9fGl49Zi4deBnaWi9jZku5ZCOLFS273XJ5lTZLlY2e4iEfM2 55VrlR/pDnIvSWHD8nUaZrYBJA+pZoFuhSI1+8r+FnLc/S07CKP6CP6G189mbTCyz1nJ hg== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp2120.oracle.com with ESMTP id 2kbvsp2n81-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 26 Jul 2018 11:29:05 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w6QBT4IT012801 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 26 Jul 2018 11:29:04 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w6QBT4qu018916 for ; Thu, 26 Jul 2018 11:29:04 GMT Received: from localhost.localdomain (/183.90.37.189) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 26 Jul 2018 04:29:04 -0700 From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: introduce feature to forget a btrfs device Date: Thu, 26 Jul 2018 19:32:24 +0800 Message-Id: <20180726113225.1745-2-anand.jain@oracle.com> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20180726113225.1745-1-anand.jain@oracle.com> References: <20180726113225.1745-1-anand.jain@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8965 signatures=668706 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=8.0.1-1806210000 definitions=main-1807260121 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. Signed-off-by: Anand Jain --- 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 67de3c0fc85b..470a32af474e 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2244,6 +2244,9 @@ 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 8844904f9009..cd54a926141a 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1208,6 +1208,15 @@ 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 049619176831..1602b5faa7e7 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -405,6 +405,7 @@ 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 5ca1d21fc4a7..b1be7f828cb4 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -836,6 +836,8 @@ 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