Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756967Ab3CGXDU (ORCPT ); Thu, 7 Mar 2013 18:03:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:25625 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752547Ab3CGXDT (ORCPT ); Thu, 7 Mar 2013 18:03:19 -0500 Date: Thu, 7 Mar 2013 18:03:02 -0500 From: Dave Jones To: Linus Torvalds Cc: Linux Kernel , Al Viro Subject: Re: BUG_ON(nd->inode->i_op->follow_link); Message-ID: <20130307230302.GA4495@redhat.com> Mail-Followup-To: Dave Jones , Linus Torvalds , Linux Kernel , Al Viro References: <20130307021645.GA10173@redhat.com> <20130307153052.GA18246@redhat.com> <20130307193501.GA2802@redhat.com> <20130307221800.GA572@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1627 Lines: 42 On Thu, Mar 07, 2013 at 02:50:55PM -0800, Linus Torvalds wrote: > Yes, I can reproduce this, and I know what's going on. I don't have a > patch, though, and I think it's in Al's court on what we should do. > Al? > > Anyway, so the "old=fd" thing implies that it's one of the symlinks in > /proc/xyz/fd/, so that's something. It could have been the > cwd/exe/mmap ones. But that was kind of the expectation to begin with. > > The "new=1:9" is the path that the file descriptor contained, and > since you're playing games with /proc, /sys and /dev, *and* since you > hit the "it shouldn't be a symlink" test, I'm *guessing* that it might > be something like > > /sys/dev/char/1:9 Strange, I told it to *only* use /proc on that run, so it shouldn't have sucked in anything from /dev unless something in /proc symlinks there and nftw() ended up chasing it. > which is a symlink to ../../devices/virtual/mem/urandom/. > > And here is how you reproduce this: But this at least is one step towards restoring my belief that I'm not going crazy here. > Al, I think the BUG_ON() is simply bogus. Should we just remove it? Or > is there some conceptual reason why we can't handle a symlink there? For the time being, I'll remove that just so I can stop seeing it, as it seems there's plenty of others to be chasing and you've got a handle on this one. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/