From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 01/10] locks: close potential race in lease_get_mtime Date: Sun, 24 Aug 2014 08:48:17 -0700 Message-ID: <20140824154817.GA15908@infradead.org> References: <1408804878-1331-1-git-send-email-jlayton@primarydata.com> <1408804878-1331-2-git-send-email-jlayton@primarydata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, cluster-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jeff Layton Return-path: Content-Disposition: inline In-Reply-To: <1408804878-1331-2-git-send-email-jlayton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Sat, Aug 23, 2014 at 10:41:09AM -0400, Jeff Layton wrote: > lease_get_mtime is called without the i_lock held, so there's no > guarantee about the stability of the list. Between the time when we > assign "flock" and then dereference it to check whether it's a lease > and for write, the lease could be freed. > > Ensure that that doesn't occur by taking the i_lock before trying > to check the lease. Looks good. Also looks way cleaner than before by being just a tad more verbose.. Reviewed-by: Christoph Hellwig