Re: [Bug 9483] circular locking dependency detected

From: Andrew Morton
Date: Tue Dec 04 2007 - 16:41:40 EST


On Tue, 4 Dec 2007 22:25:18 +0100
Ingo Molnar <mingo@xxxxxxx> wrote:

>
> * Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> wrote:
>
> > =======================================================
> > [ INFO: possible circular locking dependency detected ]
> > 2.6.24-rc3 #6
> > -------------------------------------------------------
> > bash/2294 is trying to acquire lock:
> > (&journal->j_list_lock){--..}, at: [<c01eee2f>] journal_try_to_free_buffers+0x76/0x10c
> >
> > but task is already holding lock:
> > (inode_lock){--..}, at: [<c01864b6>] drop_pagecache+0x48/0xd8
> >
> > which lock already depends on the new lock.
>
> Andrew, drop_pagecache() is root-only and it has some known deadlock,
> right?
>

yup. It takes inode_lock at too high a level so it can walk the per-sb inode
lists.
--
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/