From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH 2/3] pty: Lock the devpts bits privately Date: Tue, 8 May 2012 21:43:09 +0100 Message-ID: <20120508214309.2d50e5f0@pyramind.ukuu.org.uk> References: <20120503212151.568.91854.stgit@bob.linux.org.uk> <20120503212205.568.25804.stgit@bob.linux.org.uk> <4FA9637B.1060609@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:35214 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752458Ab2EHUkQ (ORCPT ); Tue, 8 May 2012 16:40:16 -0400 In-Reply-To: <4FA9637B.1060609@zytor.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org On Tue, 08 May 2012 11:18:35 -0700 "H. Peter Anvin" wrote: > On 05/03/2012 02:22 PM, Alan Cox wrote: > > From: Alan Cox > > > > This is a private pty affair, we don't want to tangle it with the tty_lock > > any more as we know all the other non tty locking is now handled by the vfs > > so we too can move. > > > > Signed-off-by: Alan Cox > > > + mutex_lock(&devpts_mutex); > > devpts_pty_kill(tty->link); > > + mutex_unlock(&devpts_mutex); > > > + mutex_lock(&devpts_mutex); > > + tty = devpts_get_tty(pts_inode, idx); > > + mutex_unlock(&devpts_mutex); > > > + mutex_lock(&devpts_mutex); > > tty = tty_init_dev(ptm_driver, index); > > + mutex_unlock(&devpts_mutex); > > Conceptually this seems fine, but it would seem cleaner to me to push > this mutex into the called functions in devpts; I suspect the lock could > be eliminated or at least be made per instance there (which would make > massive-container people happy...) One step at a time. I agree entirely that the ideal case is that devpts_foo is internally locked and coherent. That is an exercise for someone who likes devpts 8) Alan