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

Anand Jain
2022-09-03T12:25:41Z

On 9/2/22 17:23, Greg KH wrote:
> 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 for reminding me.
I have sent a separate patch for 5.10 as this patch won't apply to 5.10.

- Anand

> thanks,
>
> greg k-h