Re: [PATCH 2/4] btrfs: forget stray device on failed open

[Anand Jain <anand.jain@oracle.com>]

On 3/14/24 22:35, Boris Burkov wrote:
> On Sat, Mar 09, 2024 at 07:14:29PM +0530, Anand Jain wrote:
>> If the physical device of a flakey dm device is tried mounting it fails
>> to open the device with handle, and leaves behind a stray single device
>> in the device list.
>>
>> Remove it if the open fails and if it is a single device. As we don't
>> register a single device in the device list unless it is mounted.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>>   fs/btrfs/super.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
>> index 29fab56c8152..4b73c3a2d7ab 100644
>> --- a/fs/btrfs/super.c
>> +++ b/fs/btrfs/super.c
>> @@ -1820,6 +1820,9 @@ static int btrfs_get_tree_super(struct fs_context *fc)
>>   	fs_info->fs_devices = fs_devices;
>>   
>>   	ret = btrfs_open_devices(fs_devices, mode, &btrfs_fs_type);
>> +	if (ret && fs_devices->total_devices == 1)
>> +		btrfs_free_stale_devices(device->devt, NULL);
>> +
> 
> It feels like we need to do this free no matter what the mount error is
> after this point, not just in this one place.
> 

Indeed. At goto error, btrfs_close_devices() is called, in turn
calls free_fs_devices() for single-device filesystems.

Thanks, Anand


>>   	mutex_unlock(&uuid_mutex);
>>   	if (ret)
>>   		return ret;
>> -- 
>> 2.38.1
>>