Re: [PATCH, RFC] btrfs-progs: require mkfs -f force option to overwrite filesystem or partition table

[Tsutomu Itoh <t-itoh@jp.fujitsu.com>]

On 2013/02/26 13:06, Eric Sandeen wrote:
> On 2/25/13 9:55 PM, Tsutomu Itoh wrote:
>> On 2013/02/26 9:07, Eric Sandeen wrote:
>>> On 2/25/13 5:39 PM, Tsutomu Itoh wrote:
>>>> On 2013/02/21 0:37, Stefan Behrens wrote:
>>>>> On Thu, 14 Feb 2013 12:30:03 -0600, Eric Sandeen wrote:
>>>>>> The core of this is shamelessly stolen from xfsprogs.
>>>>>>
>>>>>> Use blkid to detect an existing filesystem or partition
>>>>>> table on any of the target devices.  If something is found,
>>>>>> require the '-f' option to overwrite it, hopefully avoiding
>>>>>> disaster due to mistyped devicenames, etc.
>>>>>>
>>>>>> # mkfs.btrfs /dev/sda1
>>>>>>
>>>>>> WARNING! - Btrfs v0.20-rc1-59-gd00279c-dirty IS EXPERIMENTAL
>>>>>> WARNING! - see http://btrfs.wiki.kernel.org before using
>>>>>>
>>>>>> /dev/sda1 appears to contain an existing filesystem (xfs).
>>>>>> Use the -f option to force overwrite.
>>>>>> #
>>>>>>
>>>>>> This does introduce a requirement on libblkid.
>>>>>>
>>>>>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>>>>>
>>>>> This means that it is now required to change all occurrences of
>>>>> "mkfs.btrfs" to "mkfs.btrfs -f" everywhere. Can't we first establish a
>>>>
>>>> I also think so.
>>>> It means -f is not significant to me, I think.
>>>> (Most of my test scripts fails without -f. So I'll always type "mkfs.btrfs -f")
>>>>
>>>> Therefore I want you to revert commit:2a2d8e1962e8b6cda7b0a7584f6d2fb95d442cb6.
>>>>     btrfs-progs: require mkfs -f force option to overwrite filesystem or partition table
>>>>
>>>> How do you think about it?
>>>
>>> What if you submit a patch to look at an environment variable,
>>> BTRFS_CLOBBERS_ALL=1 which causes it to not require -f to overwrite?
>>> Then you can just set it once at the top of your test environment,
>>> and not change every instance?
>>
>> Yes. But,
>>>> (Most of my test scripts fails without -f. So I'll always type "mkfs.btrfs -f")
>> is one example.
>>
>> Almost everyone types "mkfs.btrfs -f" (or BTRFS_CLOBBERS_ALL=1 :)
>> unconditionally, I think.
>> So, I think -f option is almost meaningless.
>>
>>> Otherwise, I guess I think:
>>>
>>> WARNING! - Btrfs v0.20-rc1-212-gf6ef8b5 IS EXPERIMENTAL
>>>
>>> and we need to expect that things might change ...
>>
>> EXPERIMENTAL... It's certainly so.
>> However, I think that we should not add the option that it troubles
>> a lot of people.
>
> Well, I sent it as an RFC.  Chris merged it; I'll defer to his judgement.

Agreed. So, I sent revert request to Chris :)

Thanks,
Tsutomu

>
> Thanks,
> -Eric
>
>> Thanks,
>> Tsutomu
>>
>>>
>>> -Eric
>>>
>>>> Thanks,
>>>> Tsutomu
>>>>
>>>>> time period of 100 years where the -f option is tolerated and ignored,
>>>>> and then in 2113 we require that the users add the -f option?
>>>>>
>>>>> (Just had to do this string replacement everywhere, and had to add -f to
>>>>> xfstest's _scratch_mkfs in common.rc as well). Sigh.
>>>>>