[PATCH] xfs_mkfs: wipe old signatures from the device

[Eric Sandeen]

On 2/14/13 8:48 AM, Martin Steigerwald wrote:
> Am Donnerstag, 14. Februar 2013 schrieb Dave Chinner:
>>> So I
>>> think that it got to the point where users will usually use mkfs.xfs
>>> -f all the time. And even if they did not and they would use a wrong
>>> device they would probably get the same warning even for the device
>>> they wanted to use in the first place.
>>
>> I get a couple of queries a year from people saying they
>> accidentally ran mkfs.ext4 on the wrong device and want to know if
>> they can recover their XFS filesystem. The next question is usually
>> "why didn't mkfs.ext4 warn me there was an existing filesystem on
>> the device like mkfs.xfs does?".
>>
>> That is why the "don't overwrite an existing filesystem by default"
>> behaviour is important. Users like to be protected from mistakes
>> they weren't aware they made, and far too few of our filesystem
>> utilities provide that safety net.
>>
>> A couple of users a year losing data like this is a couple of users
>> too many. Especially when it would only take a couple of hours of
>> your time to implement....
>>
>>> So even thoug it might help in some cases I do not think that we
>>> should go and change all file systems to do that as well, it would
>>> not be very useful anyway.
>>
>> Tell that to the next user that trashes their data because a
>> filesystem tool simply assumed in correctly that it owned the block
>> device.
> 
> Full ACK.
> 
> I always loved that mkfs.xfs asks in that case.
> 
> IMO its just sane to do so.

I just sent a patch to do so for btrfs-progs, FWIW.  :)

-Eric