Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935888Ab3DHWqn (ORCPT ); Mon, 8 Apr 2013 18:46:43 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:32992 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935227Ab3DHWql (ORCPT ); Mon, 8 Apr 2013 18:46:41 -0400 Date: Mon, 8 Apr 2013 23:46:37 +0100 From: Al Viro To: Stephen Warren Cc: Nathan Zimmer , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Eric W. Biederman" , David Woodhouse , stable@vger.kernel.org, "linux-next@vger.kernel.org" Subject: Re: hangs on boot in 9984d7394618df9 Message-ID: <20130408224637.GW4068@ZenIV.linux.org.uk> References: <515F0456.9040803@sgi.com> <20130405173623.GE4068@ZenIV.linux.org.uk> <515F3A71.9080008@sgi.com> <20130405210042.GH4068@ZenIV.linux.org.uk> <5162E36F.5020305@sgi.com> <20130408155847.GS4068@ZenIV.linux.org.uk> <51632DF8.2080402@sgi.com> <20130408212327.GU4068@ZenIV.linux.org.uk> <20130408214834.GV4068@ZenIV.linux.org.uk> <516341ED.5060803@wwwdotorg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <516341ED.5060803@wwwdotorg.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1715 Lines: 44 On Mon, Apr 08, 2013 at 04:17:17PM -0600, Stephen Warren wrote: > On 04/08/2013 03:48 PM, Al Viro wrote: > > On Mon, Apr 08, 2013 at 10:23:27PM +0100, Al Viro wrote: > >> On Mon, Apr 08, 2013 at 03:52:08PM -0500, Nathan Zimmer wrote: > >> > >>> Further digging seems to indicate 9984d7394618df9, the one right > >>> after the commit I previously identified. > >>> Not sure what I did wrong with my bisect to put it off by one. > >> > >> Ugh... Can't reproduce here ;-/ Could you give more details on your > >> setup? > > > > Anyway, I've just pushed a splitup of that commit (carved in 3 pieces) > > into vfs.git#pipe-splitup; could you check which part triggers that > > hang? Should propagate in a few... > > It looks like "pipe: unify ->release() and ->open()" introduces the > problem. Note that I had to add a prototype for fifo_open() before the > structs that reference it for that commit to compile. Very interesting... Just in case, could you try this on top of that branch and see if it triggers? diff --git a/fs/pipe.c b/fs/pipe.c index 8ce279b..b6cd51b 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1022,6 +1022,11 @@ static int fifo_open(struct inode *inode, struct file *filp) /* We can only do regular read/write on fifos */ filp->f_mode &= (FMODE_READ | FMODE_WRITE); + if (inode->i_sb->s_magic == PIPEFS_MAGIC) { + WARN_ON(filp->f_flags & O_NONBLOCK); + filp->f_flags &= ~O_NONBLOCK; + } + switch (filp->f_mode) { case FMODE_READ: /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/