Re: [PATCH STABLE 5.4] btrfs: harden identification of a stale device

Greg KH
2022-09-02T09:23:29Z

On Fri, Sep 02, 2022 at 05:09:38PM +0800, Anand Jain wrote:
> commit 770c79fb65506fc7c16459855c3839429f46cb32 upstream
>
> Identifying and removing the stale device from the fs_uuids list is done
> by btrfs_free_stale_devices(). btrfs_free_stale_devices() in turn
> depends on device_path_matched() to check if the device appears in more
> than one btrfs_device structure.
>
> The matching of the device happens by its path, the device path. However,
> when device mapper is in use, the dm device paths are nothing but a link
> to the actual block device, which leads to the device_path_matched()
> failing to match.
>
> Fix this by matching the dev_t as provided by lookup_bdev() instead of
> plain string compare of the device paths.
>
> CC: stable@vger.kernel.org #5.4
> Reported-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
> fs/btrfs/volumes.c | 44 +++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 37 insertions(+), 7 deletions(-)

What about the same change for 5.10.y?

thanks,

greg k-h