Re: ioctl32 (was Re: filefrag abort)

[Eric Sandeen <sandeen@redhat.com>]

Andreas Dilger wrote:
> On Jul 21, 2009  19:57 -0500, Eric Sandeen wrote:
>> Ron Johnson wrote:
>>> On 2009-07-20 21:03, Theodore Tso wrote:
>>>> On Mon, Jul 20, 2009 at 04:49:04PM -0500, Ron Johnson wrote:
>>>>> Hi,
>>>>>
>>>>> (Is this OT?  http://sourceforge.net/forum/forum.php?forum_id=7052  
>>>>> doesn't show much activity...)
>>>>>
>>>>> Debian Sid, e2fsprogs 1.41.8-1
>>>>> Home-rolled 64-bit 2.6.30 with 32-bit userland
>>>> Should be fixed in e2fsprogs 1.41.8-2
>>> ff seems to work now, but I still get this in dmesg:
>>>
>>> [188883.274547] ioctl32(filefrag:7086): Unknown cmd fd(3) 
>>> cmd(c020660b){t:'f';sz:32} arg(ffacb808) on /some/large/file
>> Huh, did we miss a compat ioctl for fiemap.... looks like so.  I'll look
>> into that tomorrow, thanks.
> 
> Sigh, I wish there was some sort of automatic ioctl parser tool that
> would report if the ioctl will need compat handling or not.  I thought
> the fiemap structs didn't need any compat handling because they are
> properly sized/aligned and w/o pointers...

They are properly sized yep but I think they still have to be flagged:

/* pointer to compatible structure or no argument */
#define COMPATIBLE_IOCTL(cmd) \
        { (cmd), do_ioctl32_pointer },

I have to remind myself how this all works, despite doing a bunch of
ioctl32 work for xfs last year :)

I think adding COMPATIBLE_IOCTL(FS_IOC_FIEMAP); to fs/compat_ioctl.c
should be enough, I'll try to get it tested tomorrow.

-Eric

-Eric