From: "bfields@fieldses.org" <bfields@fieldses.org>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "olivier@bm-services.com" <olivier@bm-services.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"carnil@debian.org" <carnil@debian.org>,
"chuck.lever@oracle.com" <chuck.lever@oracle.com>
Subject: Re: Kernel panic / list_add corruption when in nfsd4_run_cb_work
Date: Wed, 24 Nov 2021 17:06:41 -0500 [thread overview]
Message-ID: <20211124220640.GE30602@fieldses.org> (raw)
In-Reply-To: <e17bbb0a22b154c77c6ec82aad63424f70bfda94.camel@hammerspace.com>
On Wed, Nov 24, 2021 at 05:14:53PM +0000, Trond Myklebust wrote:
> It is a little nasty that we hide the list_del() calls in several
> levels of function call, so they probably do deserve a comment.
>
> That said, if, as in the case here, the delegation was unhashed, we
> still end up not calling list_del_init() in unhash_delegation_locked(),
> and since the list_add() is not conditional on it being successful, the
> global list is again corrupted.
>
> Yes, it is an unlikely race, but it is possible despite your change.
Thanks, good point.
Probably not something anyone's actually hitting, but another sign this
logic need rethinking.
--b.
next prev parent reply other threads:[~2021-11-24 22:06 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-11 7:59 Kernel panic / list_add corruption when in nfsd4_run_cb_work Salvatore Bonaccorso
2020-10-12 14:26 ` J. Bruce Fields
2020-10-12 15:41 ` Salvatore Bonaccorso
2020-10-12 16:33 ` J. Bruce Fields
2020-10-18 9:39 ` Salvatore Bonaccorso
2021-10-06 18:46 ` Salvatore Bonaccorso
2021-11-22 9:15 ` Olivier Monaco
2021-11-22 15:17 ` Chuck Lever III
2021-11-24 15:29 ` Bruce Fields
2021-11-24 15:59 ` Trond Myklebust
2021-11-24 16:10 ` Trond Myklebust
2021-11-24 16:10 ` bfields
2021-11-24 17:14 ` Trond Myklebust
2021-11-24 22:06 ` bfields [this message]
2021-11-24 22:17 ` Trond Myklebust
2021-12-01 22:33 ` bfields
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