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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 DDFB0C43387 for ; Thu, 3 Jan 2019 15:24:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B253B2070D for ; Thu, 3 Jan 2019 15:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731179AbfACPY5 (ORCPT ); Thu, 3 Jan 2019 10:24:57 -0500 Received: from mx2.suse.de ([195.135.220.15]:36284 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728208AbfACPY5 (ORCPT ); Thu, 3 Jan 2019 10:24:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 17264AD05; Thu, 3 Jan 2019 15:24:55 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 31806DA781; Thu, 3 Jan 2019 16:24:26 +0100 (CET) Date: Thu, 3 Jan 2019 16:24:26 +0100 From: David Sterba To: Anand Jain Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v13] btrfs: introduce feature to forget a btrfs device Message-ID: <20190103152426.GI23615@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Anand Jain , linux-btrfs@vger.kernel.org References: <1546502498-28070-1-git-send-email-anand.jain@oracle.com> <1546502498-28070-2-git-send-email-anand.jain@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1546502498-28070-2-git-send-email-anand.jain@oracle.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org 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.