Re: [PATCH RESUBMIT 0/2] fs/seq_file: Add seq_open_init()

[Rob Jones]

On 25/09/14 17:09, Kees Cook wrote:
> On Thu, Sep 25, 2014 at 1:57 AM, Rob Jones <rob.jones@xxxxxxxxxxxxxxx> wrote:
> > On 24/09/14 19:06, Kees Cook wrote:
> > > On Wed, Sep 24, 2014 at 4:15 AM, Rob Jones <rob.jones@xxxxxxxxxxxxxxx>
> > > wrote:
> > > > Series resubmitted due to a typo in an email address.
> > > >
> > > > This patch series implements and documents a new interface function for
> > > > seq_file.
> > > >
> > > > The existing set of open functions: seq_open(), seq_open_private() and
> > > > __seq_open_private() satisfy the majority of use cases however there is
> > > > one more use case that is also very common that this new function
> > > > addresses.
> > > >
> > > > This case is where the iterator needs information that is available only
> > > > at
> > > > the time the seq_file is opened but does not need any space allocated,
> > > > e.g.
> > > > access to the inode structure. This type of open occurs, by my best
> > > > estimate,
> > > > in well over 40 places.
> > > >
> > > > Using the new function saves at least two lines of boilerplate code per
> > > > instance as well as making the code easier to follow. The additional code
> > > > in seq_file.c to implement the function is minimal as the first place
> > > > that
> > > > code can be removed is within seq_file.c itself.
> > > >
> > > > Once this patch is accepted, the instances of boilerplate code can be
> > > > addressed.
> > >
> > >
> > > Would it be possible to write a coccinelle patch for the replacements?
> >
> >
> > I'm afraid I don't know what that means.
>
> It's a very flexible tool that should be able to find all the places
> where this pattern is being used, and you can replace it with the new
> function call:
>
> http://lwn.net/Articles/315686/

I suspect that the learning curve would exceed the utility but I'll have
a look at it. Unless there's a coccinelle expert available to do it, in
which case I could point them in the right direction.

My gut reaction would be that by the time I had analysed enough cases
to come up with a viable set of SmPL scripts I would have done most of
the work required, especially if I had to learn a new syntax and tool
to do it.

But first impressions aren't always right.

> -Kees

--
Rob Jones
Codethink Ltd
mailto:rob.jones@xxxxxxxxxxxxxxx
tel:+44 161 236 5575
--
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/