Re: [PATCH 2/4] btrfs: detect uninitialized btrfs_root::anon_dev for user visible subvolumes

Josef Bacik
2020-06-16T23:32:45Z

On 6/16/20 6:49 PM, Qu Wenruo wrote:
>
>
> On 2020/6/17 上午3:25, Josef Bacik wrote:
>> On 6/15/20 10:17 PM, Qu Wenruo wrote:
>>> btrfs_root::anon_dev is an indicator for different subvolume namespaces.
>>> Thus it should always be initialized to an anonymous block device.
>>>
>>> Add a safe net to catch such uninitialized values.
>>>
>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>
>> Can we handle stat->dev not having a device set?  Or will this blow up
>> in other ways?  Thanks,
>
> We can handle it without any problem, just users get confused.
>
> As a common practice, we use different bdev as a namespace for different
> subvolumes.
> Without a valid bdev, some user space tools may not be able to
> distinguish inodes in different subvolumes.
>

Alright that's fine then. But I feel like stat is one of those things that'll
flood the console, can we put this somewhere else that's going to be hit less?
Thanks,

Josef