Re: Ideas to do custom operation just after mount?

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

Qu Wenruo wrote on 2015/12/21 10:25 +0800:
>
>
> Dave Chinner wrote on 2015/12/21 11:16 +1100:
>> On Thu, Dec 17, 2015 at 09:55:14AM +0800, Qu Wenruo wrote:
>>> Hi,
>>>
>>> Will xfstests provides some API to do some operation just after
>>> mounting a filesystem?
>>>
>>> Some filesystem(OK, btrfs again) has some function(now qgroup only)
>>> which needed to be enabled by ioctl instead of mount option.
>>
>> Irk.
>>
>> Seriously, I need ot find some time to split all the fs specific
>> stuff in common/rc into separate files and have each different
>> filesystem implement it's own version of the relevant functions
>> like _scratch_mkfs, _scratch_mount, etc.
>>
>> That will enable btrfs to do truly hideous stuff like this that
>> admins will hate you for requiring, and the rest of us won't have to
>> care about it.

BTW, any good idea for btrfs to do such operation like 
enabling/disabling some minor features? Especially when it can be set on 
individual file/dirs.

Features like incoming write time deduplication, is designed to be 
enabled/disabled for individual file/dirs, so it's not a quite good idea 
to use mount option to do it.

Although some feature, like btrfs quota(qgroup), should be implemented 
by mount option though.
I don't understand why qgroup is enabled/disabled by ioctl. :(

Thanks,
Qu

>>
>>> So is there any good idea to do some operation just after mounting
>>> in xfstests?
>>
>> You're just going to have to wait a bit - the first piece of this
>> is in the overlayfs support patches, and the rest of it is in my
>> local work area in an incomplete state.
>
> Glad to hear that, I'll just wait for the formal implement.
>
> Thanks,
> Qu
>
>>
>> Cheers,
>>
>> Dave.
>>
>
>
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