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From: "J. Bruce Fields" <bfields@fieldses.org>
To: Pavel Emelyanov <xemul@openvz.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>,
	Andrew Morton <akpm@osdl.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	devel@openvz.org
Subject: Re: [PATCH] Memory shortage can result in inconsistent flocks state
Date: Wed, 12 Sep 2007 15:06:53 -0400	[thread overview]
Message-ID: <20070912190653.GA13792@fieldses.org> (raw)
In-Reply-To: <46E68C35.7040001@openvz.org>

On Tue, Sep 11, 2007 at 04:38:13PM +0400, Pavel Emelyanov wrote:
> This is a known feature that such "re-locking" is not atomic,
> but in the racy case the file should stay locked (although by
> some other process), but in this case the file will be unlocked.

That's a little subtle (I assume you've never seen this actually
happen?), but it makes sense to me.

> The proposal is to prepare the lock in advance keeping no chance
> to fail in the future code.

And the patch certainly looks correct.

I can add it to my (trivial) lock patches, if that's helpful--it'll
get folded into the branch -mm pulls from and I can pass it along to
Linus for 2.6.24.

What I don't have that I wish I did is good regression tests for the
flock or lease code (for posix locks I've been using connectathon,
though that misses some important things too).

--b.

  reply	other threads:[~2007-09-12 19:07 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-11 12:38 [PATCH] Memory shortage can result in inconsistent flocks state Pavel Emelyanov
2007-09-12 19:06 ` J. Bruce Fields [this message]
2007-09-13  6:04   ` Pavel Emelyanov
2007-09-13  7:16     ` Balbir Singh
2007-09-13 19:27 ` Chuck Ebbert
2007-09-13 19:34   ` J. Bruce Fields
2007-09-13 19:45     ` Chuck Ebbert

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