[Ocfs2-devel] [PATCH 1/1] Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

[tristan <tristan.ye@oracle.com>]

Joel Becker wrote:
> On Mon, Apr 26, 2010 at 08:17:23PM +0800, Tristan Ye wrote:
>> The reason why we need this ioctl is to offer the none-privileged
>> end-user a possibility to get filesys info gathering.
>>
>> We use OCFS2_IOC_INFO to manipulate the new ioctl, userspace passes a
>> structure to kernel containing an array of request pointers and request
>> count, such as,
>
> 	You're going to hate us, but Sunil and I decided that the
> complex error reporting was just too much for what should be a simple
> query interface.  We think we should go back to the original, where any
> error is returned, and the caller cannot trust any of the results unless
> the call returns 0.  This means you don't need the ir_error field.  I
> suppose you can keep the ERROR flag, as this can tell the caller which
> request caused the error.

Yes, returning the real err_code from ioctl(2) make the ir_error 
meaningless.


Common users always give up all requests when they get an error from 
ioctl(2), while our existing scheme also guarantees advanced users' 
attempt to pick up some sane requests if they wish.

So we've reached a consensus here:-)


Tristan.

>
> Joel
>