From patchwork Wed Sep 6 14:59:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tuomas Tynkkynen X-Patchwork-Id: 810664 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xnRqQ0D2Rz9t2R for ; Thu, 7 Sep 2017 01:10:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932870AbdIFPKl (ORCPT ); Wed, 6 Sep 2017 11:10:41 -0400 Received: from mx1.mpynet.fi ([82.197.21.84]:42703 "EHLO mx1.mpynet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932263AbdIFPKe (ORCPT ); Wed, 6 Sep 2017 11:10:34 -0400 X-Greylist: delayed 501 seconds by postgrey-1.27 at vger.kernel.org; Wed, 06 Sep 2017 11:10:32 EDT From: Tuomas Tynkkynen To: Al Viro CC: , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , "David S. Miller" , , , , Tuomas Tynkkynen , Subject: [PATCH 2/2] net/9p: Switch to wait_event_killable() Date: Wed, 6 Sep 2017 17:59:08 +0300 Message-ID: <20170906145908.8082-3-tuomas@tuxera.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170906145908.8082-1-tuomas@tuxera.com> References: <20170906145908.8082-1-tuomas@tuxera.com> MIME-Version: 1.0 X-ClientProxiedBy: tuxera-exch.ad.tuxera.com (10.20.48.11) To tuxera-exch.ad.tuxera.com (10.20.48.11) Received-SPF: none Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Because userspace gets Very Unhappy when calls like stat() and execve() return -EINTR on 9p filesystem mounts. For instance, when bash is looking in PATH for things to execute and some SIGCHLD interrupts stat(), bash can throw a spurious 'command not found' since it doesn't retry the stat(). In practice, hitting the problem is rare and needs a really slow/bogged down 9p server. Cc: stable@vger.kernel.org Signed-off-by: Tuomas Tynkkynen --- net/9p/client.c | 3 +-- net/9p/trans_virtio.c | 13 ++++++------- net/9p/trans_xen.c | 4 ++-- 3 files changed, 9 insertions(+), 11 deletions(-) diff --git a/net/9p/client.c b/net/9p/client.c index 4674235b0d9b..1beb131dd3e1 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -773,8 +773,7 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...) } again: /* Wait for the response */ - err = wait_event_interruptible(*req->wq, - req->status >= REQ_STATUS_RCVD); + err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD); /* * Make sure our req is coherent with regard to updates in other diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index f24b25c25106..f3a4efcf1456 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -286,8 +286,8 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) if (err == -ENOSPC) { chan->ring_bufs_avail = 0; spin_unlock_irqrestore(&chan->lock, flags); - err = wait_event_interruptible(*chan->vc_wq, - chan->ring_bufs_avail); + err = wait_event_killable(*chan->vc_wq, + chan->ring_bufs_avail); if (err == -ERESTARTSYS) return err; @@ -327,7 +327,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, * Other zc request to finish here */ if (atomic_read(&vp_pinned) >= chan->p9_max_pages) { - err = wait_event_interruptible(vp_wq, + err = wait_event_killable(vp_wq, (atomic_read(&vp_pinned) < chan->p9_max_pages)); if (err == -ERESTARTSYS) return err; @@ -471,8 +471,8 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req, if (err == -ENOSPC) { chan->ring_bufs_avail = 0; spin_unlock_irqrestore(&chan->lock, flags); - err = wait_event_interruptible(*chan->vc_wq, - chan->ring_bufs_avail); + err = wait_event_killable(*chan->vc_wq, + chan->ring_bufs_avail); if (err == -ERESTARTSYS) goto err_out; @@ -489,8 +489,7 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req, virtqueue_kick(chan->vq); spin_unlock_irqrestore(&chan->lock, flags); p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); - err = wait_event_interruptible(*req->wq, - req->status >= REQ_STATUS_RCVD); + err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD); /* * Non kernel buffers are pinned, unpin them */ diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index 6ad3e043c617..325c56043007 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -156,8 +156,8 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req) ring = &priv->rings[num]; again: - while (wait_event_interruptible(ring->wq, - p9_xen_write_todo(ring, size)) != 0) + while (wait_event_killable(ring->wq, + p9_xen_write_todo(ring, size)) != 0) ; spin_lock_irqsave(&ring->lock, flags);