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

[Franck Jullien]

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)) ....