Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:17177 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751617Ab2F1Mup (ORCPT ); Thu, 28 Jun 2012 08:50:45 -0400 Date: Thu, 28 Jun 2012 08:49:52 -0400 From: Jeff Layton To: Mel Gorman Cc: Andrew Morton , Linux-MM , Linux-Netdev , Linux-NFS , LKML , David Miller , Trond Myklebust , Neil Brown , Christoph Hellwig , Peter Zijlstra , Mike Christie , Eric B Munson Subject: Re: [PATCH 10/12] nfs: enable swap on NFS Message-ID: <20120628084952.6526f801@corrin.poochiereds.net> In-Reply-To: <20120628123734.GH8271@suse.de> References: <1340375468-22509-1-git-send-email-mgorman@suse.de> <1340375468-22509-11-git-send-email-mgorman@suse.de> <20120628082725.33b71097@corrin.poochiereds.net> <20120628123734.GH8271@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 28 Jun 2012 13:37:34 +0100 Mel Gorman wrote: > On Thu, Jun 28, 2012 at 08:27:25AM -0400, Jeff Layton wrote: > > > > > > @@ -2108,11 +2156,15 @@ static void xs_tcp_setup_socket(struct work_struct *work) > > > container_of(work, struct sock_xprt, connect_worker.work); > > > struct socket *sock = transport->sock; > > > struct rpc_xprt *xprt = &transport->xprt; > > > + unsigned long pflags = current->flags; > > > int status = -EIO; > > > > > > if (xprt->shutdown) > > > goto out; > > > > > > + if (xprt->swapper) > > > + current->flags |= PF_MEMALLOC; > > > + > > > if (!sock) { > > > clear_bit(XPRT_CONNECTION_ABORT, &xprt->state); > > > sock = xs_create_sock(xprt, transport, > > > @@ -2174,6 +2226,7 @@ out_eagain: > > > out: > > > xprt_clear_connecting(xprt); > > > xprt_wake_pending_tasks(xprt, status); > > > + tsk_restore_flags(current, pflags, PF_MEMALLOC); > > > } > > > > > > /** > > > > Apologies if this is fixed in another patch and I didn't see it... > > > > No apologies necessary. Even if it was fixed in another patch, it would > still be wrong for bisection reasons and for being rude to reviewers. > > > There's a place in the above function that returns without going > > through "out:". I think you also want to tsk_restore_flags() in that > > spot too. > > > > You're right. The case that it would trigger would be some corner case > but very nicely spotted. > > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index b84df34..3d58b92 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c > @@ -2214,6 +2214,7 @@ static void xs_tcp_setup_socket(struct work_struct *work) > case -EINPROGRESS: > case -EALREADY: > xprt_clear_connecting(xprt); > + tsk_restore_flags(current, pflags, PF_MEMALLOC); > return; > case -EINVAL: > /* Happens, for instance, if the user specified a link That looks correct. Actually it's not obvious in this function, but it turns out that this is the common case. xs_tcp_finish_connecting calls kernel_connect with O_NONBLOCK set, and that almost always immediately returns with -EINPROGRESS. Cheers, -- Jeff Layton