[RFC][FAT] Handle MBR on the first sector

[Franck Jullien]

2012/9/14 Franck Jullien <franck.jullien at gmail.com>:
> 2012/9/14 Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>:
>>
>> On 10:47 Fri 14 Sep     , Franck Jullien wrote:
>>>
>>> 2012/9/14 Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>:
>>> >
>>> > On 09:25 Fri 14 Sep     , Sascha Hauer wrote:
>>> >>
>>> >> On Fri, Sep 14, 2012 at 09:22:07AM +0200, Franck Jullien wrote:
>>> >> > 2012/9/14 Sascha Hauer <s.hauer at pengutronix.de>:
>>> >> > > Hi Franck,
>>> >> > >
>>> >> > > On Thu, Sep 13, 2012 at 02:13:29PM +0200, Franck Jullien wrote:
>>> >> > >> *** Did not send this email with git because it's no working where I am **
>>> >> > >>
>>> >> > >> We may have some disk with MBR as a first sector. In this case, the
>>> >> > >> current FAT check returns an error. However, the FAT sector exist and
>>> >> > >> the MBR can tell us where it is.
>>> >> > >>
>>> >> > >> This patch make the FAT fs try to find the FAT boot sector on the first
>>> >> > >> sector of the first partition in case it is not on sector 0.
>>> >> > >
>>> >> > > The patch looks good. Not applying it because it's RFC, but I would if
>>> >> > > you give your ok.
>>> >> > >
>>> >> >
>>> >> > You have it.
>>> >>
>>> >> Thanks, applied
>>> >
>>> > Does this work with the fat autodetection
>>> >
>>> > Best Regards,
>>> > J.
>>>
>>> What do you mean ?
>>>
>>> It works when you mount your device as FAT. The FAT fs check is the
>>> first sector is FAT boot sector. If not, it suppose it is an MBR and
>>> the FAT boot sector is in the first partition.
>> check the the next branch
>>
>> I add the fs detection to do not specify the filesystem type anymore in mount
>>
>> Best Regards,
>> J.
>
> It won't. We need to check if it is an MBR here too (static int
> is_fat(u8 *buf)) ....

We should factorise the fat type detection code in ff.c than use it in
filetype.c