From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <green@linuxhacker.ru>,
"<linux-kernel@vger.kernel.org> Mailing List"
<linux-kernel@vger.kernel.org>,
"<linux-fsdevel@vger.kernel.org>" <linux-fsdevel@vger.kernel.org>
Subject: Re: Dcache oops
Date: Fri, 3 Jun 2016 23:23:55 +0100 [thread overview]
Message-ID: <20160603222355.GW14480@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFyYkbXqoJ3PqfrnxWDEXJM_BH6Q_OdKf+UVJYEUF4gdQA@mail.gmail.com>
On Fri, Jun 03, 2016 at 03:00:02PM -0700, Linus Torvalds wrote:
> Is perhaps the "delayed_call" logic broken, and the symlink is free'd too early?
>
> That whole set_delayed_call/do_delayed_call thing came in 4.5. Maybe
> something broke that logic, and we've executed the delayed freeing
> before we should have.
>
> Normally it's done at terminate_walk() time. But I note that in
> walk_component(), we do put_link(nd) which does a do_delayed_call(),
> but does *not* do a clear_delayed_call(), so now I think a subsequent
> terminate_walk() might drop it *again*.
Nope - put_link() also decrements nd->depth. No double calls there...
> I'm probably missing something, but I have to say that the old
> explicit "put_link()" callback logic was more obvious than the new
> delayed calls are.
It's not that. It's explicit put_link() in do_last(), followed by
ESTALEOPEN and subsequent misbegotten "retry the last step on ESTALEOPEN"
looking at now-freed nd->last.name. IOW, the bug predates delayed_call
stuff.
next prev parent reply other threads:[~2016-06-03 22:23 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-02 22:46 NFS/d_splice_alias breakage Oleg Drokin
2016-06-02 23:59 ` [PATCH] Allow d_splice_alias to accept hashed dentries green
2016-06-03 0:25 ` Oleg Drokin
2016-06-03 0:44 ` NFS/d_splice_alias breakage Trond Myklebust
2016-06-03 0:54 ` Oleg Drokin
2016-06-03 3:26 ` Al Viro
2016-06-03 3:38 ` Al Viro
2016-06-03 3:28 ` Al Viro
2016-06-03 3:37 ` Al Viro
2016-06-03 3:43 ` Oleg Drokin
2016-06-03 4:26 ` Al Viro
2016-06-03 4:42 ` Al Viro
2016-06-03 4:53 ` Al Viro
2016-06-03 4:58 ` Oleg Drokin
2016-06-03 5:56 ` Al Viro
2016-06-06 23:36 ` Oleg Drokin
2016-06-10 1:33 ` Oleg Drokin
2016-06-10 16:49 ` Oleg Drokin
2016-06-20 13:25 ` Oleg Drokin
2016-06-20 14:08 ` Al Viro
2016-06-20 14:54 ` Trond Myklebust
2016-06-20 15:28 ` Al Viro
2016-06-20 15:43 ` Anna Schumaker
2016-06-20 15:45 ` Oleg Drokin
2016-06-20 15:47 ` Trond Myklebust
2016-06-03 16:38 ` Dcache oops Oleg Drokin
2016-06-03 18:22 ` Al Viro
2016-06-03 18:35 ` Oleg Drokin
2016-06-03 20:07 ` Al Viro
2016-06-03 21:17 ` Oleg Drokin
2016-06-03 21:46 ` Al Viro
2016-06-03 22:17 ` Al Viro
2016-06-03 21:18 ` Linus Torvalds
2016-06-03 21:26 ` Al Viro
2016-06-03 22:00 ` Linus Torvalds
2016-06-03 22:23 ` Al Viro [this message]
2016-06-03 22:29 ` Al Viro
2016-06-03 22:36 ` Linus Torvalds
2016-06-03 22:42 ` Oleg Drokin
2016-06-03 22:43 ` Al Viro
2016-06-03 22:37 ` Al Viro
2016-06-03 22:49 ` Oleg Drokin
2016-06-03 23:58 ` Oleg Drokin
2016-06-04 0:56 ` Al Viro
2016-06-04 12:25 ` Jeff Layton
2016-06-04 16:12 ` Oleg Drokin
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