From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:36624 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbbCTKEi (ORCPT ); Fri, 20 Mar 2015 06:04:38 -0400 From: Anand Jain To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz Subject: [PATCH 24/27] Btrfs: free the stale device Date: Fri, 20 Mar 2015 18:01:39 +0800 Message-Id: <1426845702-6298-25-git-send-email-anand.jain@oracle.com> In-Reply-To: <1426845702-6298-1-git-send-email-anand.jain@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: References: <1426845702-6298-1-git-send-email-anand.jain@oracle.com> From: Anand Jain When the btrfs on a device is overwritten with a new btrfs (mkfs), the old btrfs instance in the kernel becomes stale. So with this patch if kernel finds device is overwritten then delete the stale fsid/uuid. Signed-off-by: Anand Jain --- fs/btrfs/volumes.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 58232bc..452abb3 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -446,6 +446,55 @@ static void pending_bios_fn(struct btrfs_work *work) run_scheduled_bios(device); } + +void btrfs_free_stale_device(struct btrfs_device *cur_dev) +{ + int del = 0; + struct btrfs_fs_devices *fs_devs; + struct btrfs_device *dev; + + list_for_each_entry(fs_devs, &fs_uuids, list) { + if (fs_devs->opened) + continue; + if (fs_devs->seeding) + continue; + list_for_each_entry(dev, &fs_devs->devices, dev_list) { + if (dev == cur_dev) + continue; + + /* + * Todo: This won't be enough. What if same device + * comes back with new uuid and with its mapper path? + * But for now, this does helps as mostly an admin will + * use either mapper or non mapper path throughout. + */ + + if (!strcmp(rcu_str_deref(dev->name), + rcu_str_deref(cur_dev->name))) { + del = 1; + break; + } + } + if (del) { + /* delete the stale */ + if (fs_devs->num_devices == 1) { + btrfs_kobj_rm_device(fs_devs, dev); + btrfs_sysfs_remove_fsid(fs_devs); + list_del(&fs_devs->list); + free_fs_devices(fs_devs); + } else { + fs_devs->num_devices--; + btrfs_kobj_rm_device(fs_devs, dev); + list_del(&dev->dev_list); + rcu_string_free(dev->name); + kfree(dev); + } + break; + } + } + return; +} + /* * Add new device to list of registered devices * @@ -561,6 +610,8 @@ static noinline int device_list_add(const char *path, if (!fs_devices->opened) device->generation = found_transid; + btrfs_free_stale_device(device); + *fs_devices_ret = fs_devices; return ret; -- 2.0.0.153.g79dcccc