Re: [PATCH stable-5.4.y] btrfs: free device in btrfs_close_devices for a single device filesystem

[Greg KH <greg@kroah.com>]

On Wed, Feb 15, 2023 at 12:53:03PM +0800, Anand Jain wrote:
> commit 5f58d783fd7823b2c2d5954d1126e702f94bfc4c upstream
> 
> We have this check to make sure we don't accidentally add older devices
> that may have disappeared and re-appeared with an older generation from
> being added to an fs_devices (such as a replace source device). This
> makes sense, we don't want stale disks in our file system. However for
> single disks this doesn't really make sense.
> 
> I've seen this in testing, but I was provided a reproducer from a
> project that builds btrfs images on loopback devices. The loopback
> device gets cached with the new generation, and then if it is re-used to
> generate a new file system we'll fail to mount it because the new fs is
> "older" than what we have in cache.
> 
> Fix this by freeing the cache when closing the device for a single device
> filesystem. This will ensure that the mount command passed device path is
> scanned successfully during the next mount.
> 
> CC: stable@vger.kernel.org # 5.10+
> Reported-by: Daan De Meyer <daandemeyer@fb.com>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> Reviewed-by: David Sterba <dsterba@suse.com>
> Signed-off-by: David Sterba <dsterba@suse.com>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
> This patch has already been submitted for the LTS stable 5.10 and above.

Now queued up, thanks.

greg k-h