Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754102AbYJ1XqA (ORCPT ); Tue, 28 Oct 2008 19:46:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752892AbYJ1Xpw (ORCPT ); Tue, 28 Oct 2008 19:45:52 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:34241 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752781AbYJ1Xpv (ORCPT ); Tue, 28 Oct 2008 19:45:51 -0400 To: ncunningham@crca.org.au CC: miklos@szeredi.hu, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org In-reply-to: <1225237298.9661.55.camel@nigel-laptop> (message from Nigel Cunningham on Wed, 29 Oct 2008 10:41:38 +1100) Subject: Re: [linux-pm] Freezer: Don't count threads waiting for frozen filesystems. References: <1224886068.6478.21.camel@nigel-laptop> <1225106427.26724.5.camel@nigel-laptop> <200810271237.40049.rjw@sisk.pl> <1225107607.26724.9.camel@nigel-laptop> <1225141168.26724.23.camel@nigel-laptop> <1225145607.26724.54.camel@nigel-laptop> <1225235054.9661.37.camel@nigel-laptop> <1225235860.9661.42.camel@nigel-laptop> <1225237298.9661.55.camel@nigel-laptop> Message-Id: From: Miklos Szeredi Date: Wed, 29 Oct 2008 00:45:42 +0100 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1310 Lines: 34 On Wed, 29 Oct 2008, Nigel Cunningham wrote: > Hi. > > On Wed, 2008-10-29 at 00:24 +0100, Miklos Szeredi wrote: > > On Wed, 29 Oct 2008, Nigel Cunningham wrote: > > > Remember, though, that we're only freezing fuse at the moment, and > > > strictly one filesystem at a time. We can thus happily wait for the > > > i_mutex taken by some other process to be released. > > > > Not going to work: you need to wait for all requests to be finished, > > but those might depend on some other fuse filesystem which has already > > been frozen. > > Okay. In that case, am I right in thinking that the request waiting on > the frozen filesystem will be stuck in request_wait_answer, Yes. > and the > userspace process that was trying to satisfy the request will be stuck > in the FUSE_MIGHT_FREEZE call that was invoked for the frozen > filesystem? No, it already passed that, before the filesystem got frozen. But it doesn't matter, in either case i_mutex will already have been taken by the VFS and it won't be released until the request completely finishes. Miklos -- 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/