[PATCH 2/2] [MTD] Call bdi_init() and bdi_register()

[Paolo Minazzi]

I Jens,
I'm Paolo Minazzi and I have a problem with logfs and 2.6.34rc5.
Can I apply the patch to rc5 and make a test on my ARM board ?
Paolo



On Tue, Apr 27, 2010 at 9:52 AM, Jens Axboe <jens.axboe at oracle.com> wrote:
> On Mon, Apr 26 2010, Jörn Engel wrote:
>> On Mon, 26 April 2010 19:02:48 +0200, Jens Axboe wrote:
>> > On Mon, Apr 26 2010, Jörn Engel wrote:
>> > > Otherwise we hit a BUG_ON in bdi_queue_work().
>> > >
>> > > Signed-off-by: Joern Engel <joern at logfs.org>
>> > > ---
>> > >  drivers/mtd/mtdcore.c |   17 ++++++++++++++++-
>> > >  1 files changed, 16 insertions(+), 1 deletions(-)
>> > >
>> > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
>> > > index cb4858b..8dd3e46 100644
>> > > --- a/drivers/mtd/mtdcore.c
>> > > +++ b/drivers/mtd/mtdcore.c
>> > > @@ -322,6 +322,12 @@ int add_mtd_device(struct mtd_info *mtd)
>> > >           if (!mtd_table[i]) {
>> > >                   struct mtd_notifier *not;
>> > >
>> > > +                 err = bdi_register(mtd->backing_dev_info, NULL, "mtd%d",
>> > > +                                 i);
>> > > +                 if (err) {
>> > > +                         /* We lose the errno information :( */
>> > > +                         break;
>> > > +                 }
>> >
>> > This is not a good idea, even if it'll currently work.
>> >
>> > > @@ -692,6 +698,15 @@ static int __init init_mtd(void)
>> > >   int ret;
>> > >   ret = class_register(&mtd_class);
>> > >
>> > > + ret = bdi_init(&mtd_bdi_unmappable);
>> > > + if (ret)
>> > > +         return ret;
>> > > + ret = bdi_init(&mtd_bdi_ro_mappable);
>> > > + if (ret)
>> > > +         return ret;
>> > > + ret = bdi_init(&mtd_bdi_rw_mappable);
>> > > + if (ret)
>> > > +         return ret;
>> >
>> > Do the bdi_register() here as well.
>>
>> -ENOBRAIN
>>
>> Initially I wanted to do just than.  Then I looked at the block layer
>> and thought we could create one backing_dev_info per mtd as well.  Not
>> necessarily a bad if I would actually _create_ them and not just reuse
>> the same ones over and over again.
>
> I cooked up that patch myself, here:
>
> http://git.kernel.dk/?p=linux-2.6-block.git;a=commit;h=0661b1ac5d48eb47c8a5948c0554fea25e0895ab
>
> Care to give it a quick spin?
>
> --
> Jens Axboe
>
>