Re: [PATCH] sony_pi: Remove the BKL from sonypi_misc_open

From: John Kacur
Date: Wed Oct 21 2009 - 17:42:36 EST




On Wed, 21 Oct 2009, Frederic Weisbecker wrote:

> On Tue, Oct 20, 2009 at 12:08:57AM +0200, Arnd Bergmann wrote:
> > On Tuesday 20 October 2009, Arnd Bergmann wrote:
> > > On Monday 19 October 2009, John Kacur wrote:
> > > > How does this look? (Version 2 of the patch follows)
> > >
> > > Looks good now.
> > >
> >
> > A bit of background:
> >
> > Doing only one of the two conversions is a correct patch as well
> > of course, I just want to make sure you don't have to go through all
> > the same files again once someone does a blind pushdown into the ioctl
> > and llseek functions, so once you prove that a specific driver doesn't
> > need the BKL, please always make sure to remove it from all three places.
> >
> > I fear that the llseek part will get interesting as well, just because
> > we call default_llseek instead of no_ll by default currently.
> > It might be a good idea to add one of .llseek=no_llseek or
> > .llseek=generic_file_llseek in any file_operations that you prove
> > to not require the BKL.
> >
> > Arnd <><
>
>
> What about a pusdown of default_lseek attribution for these
> fops that don't have any llseek() (and rename it to
> deprecated_default_lseek() )
>
> Because we can probably fix these fops one by one but what
> about the next drivers that will have no llseek() ?
>
> We can't attribute default_llseek() by default anymore for
> further fops that are to come.
>
>

Frederic, I think it is still useful to explicity set to no_llseek,
drivers that don't use llseek.

I also have to agree with you, that we should no longer be using a
default_llseek that relies on the BKL.

That is a rather large effort though. All drivers that don't specify an
llseek function, need to either set it to no_llseek, or as you are
proposing a deprecated default_llseek that uses the bkl.

thinking of how to start this.

John
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/