Re: [PATCH] Missing usb_find_device symbol from usb.c

[Oliver Neukum <oliver@neukum.org>]

Am Donnerstag, 24. Januar 2008 13:34:00 schrieb Pekka Enberg:
> Hi Oliver,
> 
> On Jan 24, 2008 2:24 PM, Oliver Neukum <oliver@neukum.org> wrote:
> > > Sure but the filesystems in fs/ are general purpose and they can be
> > > mounted on top of any block device (except for the in-memory ones like
> >
> > nfs, cifs, jffs, ...
> 
> But none of them mess around with *hardware*. Sure, you can split it
> in two: driver and filesystem but yet again, the latter is not general
> purpose at all. I think this is somewhat similar to spufs which is
> really hardware specific and thus not eligible for fs/.

So we put it into drivers/usb/misc
Does that change the code?

> On Jan 24, 2008 2:24 PM, Oliver Neukum <oliver@neukum.org> wrote:
> > > sysfs). Furthermore, the problem with iriverfs is that it assumes that
> > > there can be only one device plugged to the host. What we want is
> > > something like
> > >
> > >   $ mount -t iriverfs /dev/iriver0 /mnt/media
> > >
> > > Which can be accomplished with an USB driver in driver/usb/ that
> > > registers the special iriverfs.
> >
> > And what happens if you do
> > mount -t vfat /dev/iriver0 /mnt/media ?
> 
> If /dev/iriver0 is registered as a block device, we read the
> superblock but don't find a vfat filesystem and the mount fails as
> expected. As for
> 
>    mount -t iriverfs /dev/sd1 /mnt/media
> 
> we need to make sure file_system_type->get_sb() does something like
> what drivers/mtd/mtdsuper.c::get_sb_mtd() does to make sure we only
> let it mount if the block device is indeed an iriver player.

How do you make a block device on top of this device? It has no notion
of reading/writing arbitrary blocks. It operates on files.

	Regards
		Oliver