Re: VFS deadlock ?
[Posted April 2, 2013 by mkerrisk]
| From: |
| Al Viro <viro-AT-ZenIV.linux.org.uk> |
| To: |
| Linus Torvalds <torvalds-AT-linux-foundation.org> |
| Subject: |
| Re: VFS deadlock ? |
| Date: |
| Thu, 21 Mar 2013 21:26:17 +0000 |
| Message-ID: |
| <20130321212617.GA21522@ZenIV.linux.org.uk> |
| Cc: |
| Dave Jones <davej-AT-redhat.com>,
Linux Kernel <linux-kernel-AT-vger.kernel.org> |
| Archive‑link: | |
Article |
On Thu, Mar 21, 2013 at 02:18:15PM -0700, Linus Torvalds wrote:
> On Thu, Mar 21, 2013 at 2:02 PM, Dave Jones <davej@redhat.com> wrote:
> >
> > here we go...
> >
> > WARNING: at fs/namei.c:2335 lock_rename+0x156/0x160()
> > p1=irda p2=irda
>
> Ok, good. I ssupect it's /proc or /sys, we do have that entry there.
>
> But in fact I suspect we do want the parent name after all, because I
> think we have multiple "irda" directories. There's the one in
> /proc/net/ (added by net/irda/irproc.c), and there's a sysctl CTL_DIR
> "irda" directory (kernel/sysctl_binary.c). And there might even be a
> few other ones in /sys too, thanks to the ldisc called "irda" etc.
>
> I don't see where the shared inode comes from, but I suspect that
> would be easier to guess if we actually see which particular case it
> ends up being..
Well, something like
static char path[4096];
d_absolute_path(p1, path, 4096);
printk(KERN_ERR "%s %s %d %d"
path, p1->d_sb->s_type->name, d_unlinked(p1), d_unlinked(p2));
might be useful - pathname within fs, fs type and which of those suckers are
unlinked...
