From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933421Ab3GWQDF (ORCPT ); Tue, 23 Jul 2013 12:03:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54617 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932595Ab3GWQDD (ORCPT ); Tue, 23 Jul 2013 12:03:03 -0400 Date: Tue, 23 Jul 2013 12:02:58 -0400 From: Jeff Layton To: David Howells Cc: torvalds@linux-foundation.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-cachefs@redhat.com, Milosz Tanski , Yacine Belkadi Subject: Re: [PATCH] Fix __wait_on_atomic_t() to call the action func if the counter != 0 Message-ID: <20130723120258.01024e81@tlielax.poochiereds.net> In-Reply-To: <20130723154924.24306.42326.stgit@warthog.procyon.org.uk> References: <20130723154924.24306.42326.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Jul 2013 16:49:24 +0100 David Howells wrote: > Fix __wait_on_atomic_t() so that it calls the action func if the counter != 0 > rather than if the counter is 0 so as to be analogous to __wait_on_bit(). > > Thanks to Yacine who found this by visual inspection. > > This will affect FS-Cache in that it will could fail to sleep correctly when > trying to clean up after a netfs cookie is withdrawn. > > Reported-by: Yacine Belkadi > Signed-off-by: David Howells > cc: Yacine Belkadi > cc: Milosz Tanski > cc: Jeff Layton > --- > > kernel/wait.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/wait.c b/kernel/wait.c > index ce0daa3..dec68bd 100644 > --- a/kernel/wait.c > +++ b/kernel/wait.c > @@ -333,7 +333,8 @@ int __wait_on_atomic_t(wait_queue_head_t *wq, struct wait_bit_queue *q, > prepare_to_wait(wq, &q->wait, mode); > val = q->key.flags; > if (atomic_read(val) == 0) > - ret = (*action)(val); > + break; > + ret = (*action)(val); > } while (!ret && atomic_read(val) != 0); nit: can you now eliminate the check for "val" in the while condition? It doesn't look like it harms anything, but eliminating it would probably simplify the code slightly... > finish_wait(wq, &q->wait); > return ret; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jeff Layton