Re: [V9fs-developer] [Patch] Dead code in fs/9p/vfs_inode.c

["David Leimbach" <leimy2k@gmail.com>]

On 6/28/06, Eric Sesterhenn / Snakebyte <snakebyte@gmx.de> wrote:
> * Russ Cox (rsc@swtch.com) wrote:
> > >coverity (id #971) found some dead code. In all error
> > >cases ret is NULL, so we can remove the if statement.
> > >
> > >Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
> > >
> > >--- linux-2.6.17-git11/fs/9p/vfs_inode.c.orig   2006-06-29
> > >00:50:53.000000000 +0200
> > >+++ linux-2.6.17-git11/fs/9p/vfs_inode.c        2006-06-29
> > >00:51:11.000000000 +0200
> > >@@ -386,9 +386,6 @@ v9fs_inode_from_fid(struct v9fs_session_
> > >
> > > error:
> > >        kfree(fcall);
> > >-       if (ret)
> > >-               iput(ret);
> > >-
> > >        return ERR_PTR(err);
> > > }
> >
> > What about when someone changes the code and does have ret != NULL here?
> > This seems like reasonable defensive programming to me.
> >
> > Is the official LK policy that we can't have code that trips coverity
> > checks like this?
>
> If this is whats agreed upon I will no longer send patches for
> such bugs, and mark them as ignore in the coverity system.
> But I guess it makes also sense to remove unused code, because I
> am not sure if gcc can figure out to remove it. In this case
> the generated object file is 10 bytes smaller.
>
> Eric
>

I wonder if anyone cares about those 10 bytes more than the fact that
the code that generates them is written in a defensive manner. :-)

I'd be willing to give up 10 bytes to know that if things changed in
the future that check is still there :-)

Seems like a fairly meaningless optimization to me.  No offense
intended toward Eric/Snakebyte, just that sometimes things that seem
like they are optimizations and fixes end up not being either.