From: Rob Gardner <rob.gardner@hp.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "tmtalpey@gmail.com" <tmtalpey@gmail.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: Huge race in lockd for async lock requests?
Date: Thu, 28 May 2009 20:59:02 -0600 [thread overview]
Message-ID: <4A1F4F76.70108@hp.com> (raw)
In-Reply-To: <20090529002636.GA19184@fieldses.org>
J. Bruce Fields wrote:
>
> Looking at the code.... This is all under the BKL, and as far as I can
> tell there aren't any blocking operations anywhere there, so I don't
> think this should happen if the filesystem is careful. Have you seen it
> happen?
Aha, I just figured it out and you were right. The filesystem in this
case was not careful. It broke the rules and actually made the fl_grant
call *before* even returning to nlmsvc_lock's call to vfs_lock_file, and
it did it in the lockd thread! So the BKL was of no use, and I saw
nlmsvc_grant_deferred print "grant for unknown block". So I think
everything is ok, no huge race in lockd for async lock requests. Thank
you for clearing this up.
Rob Gardner
next prev parent reply other threads:[~2009-05-29 2:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-15 14:48 Virtual IPs and blocking locks Sachin S. Prabhu
2009-05-15 16:50 ` Rob Gardner
2009-05-18 13:41 ` Sachin S. Prabhu
2009-05-18 13:46 ` Trond Myklebust
2009-05-18 13:55 ` Rob Gardner
2009-05-19 20:43 ` Huge race in lockd for async lock requests? Rob Gardner
2009-05-19 21:33 ` Tom Talpey
2009-05-20 6:55 ` Rob Gardner
2009-05-20 14:00 ` Tom Talpey
[not found] ` <4a140d0a.85c2f10a.53bc.0979-ATjtLOhZ0NVl57MIdRCFDg@public.gmane.org>
2009-05-20 14:14 ` Tom Talpey
[not found] ` <4a14106e.48c3f10a.7ce3.0e55-ATjtLOhZ0NVl57MIdRCFDg@public.gmane.org>
2009-05-20 23:20 ` Rob Gardner
2009-05-20 16:37 ` Rob Gardner
2009-05-28 20:05 ` J. Bruce Fields
2009-05-28 21:34 ` Rob Gardner
2009-05-29 0:26 ` J. Bruce Fields
2009-05-29 2:59 ` Rob Gardner [this message]
2009-05-29 13:22 ` Tom Talpey
[not found] ` <4a1fe1c0.06045a0a.165b.5fbc-ATjtLOhZ0NVl57MIdRCFDg@public.gmane.org>
2009-05-29 15:24 ` Rob Gardner
2009-05-29 19:14 ` J. Bruce Fields
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