From patchwork Sun Aug 3 17:03:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 4666021 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 29579C0338 for ; Sun, 3 Aug 2014 17:03:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 608D9201BF for ; Sun, 3 Aug 2014 17:03:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66243201CD for ; Sun, 3 Aug 2014 17:03:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752629AbaHCRD1 (ORCPT ); Sun, 3 Aug 2014 13:03:27 -0400 Received: from mail-qg0-f44.google.com ([209.85.192.44]:33039 "EHLO mail-qg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752622AbaHCRD0 (ORCPT ); Sun, 3 Aug 2014 13:03:26 -0400 Received: by mail-qg0-f44.google.com with SMTP id e89so7931332qgf.17 for ; Sun, 03 Aug 2014 10:03:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=PtMGwAHTP3wDZ6xM6SniRbrTCsUtxWCSieCRnALR2kU=; b=FajM/ZJVKeOthlM1h4ATkmybHjllguvEF5q25W4hfucMEkjnZ/XiQZra/y4RQ/wTTl uNeOuDZ6kzGk4I6lNEp6inoyCwENG9KR3W/Qayve/2JzoriR69npguakxuWfeTp+U2gf BDF7GH/7kVN1A/Xpwo9bcTwLHVBhTWnkhbYWNjkkzSVjq51t+E3rpJnQ+whLA74dz4cM LlQuJxgtcoNS9vlEIBoVPWdDkvOP9rWvXdp6KHsd2ZGw3F6UnyT5NVh1bDvVXNQ2za51 5dZQOedNY58jX54oZQMkL2oCK8cI1oBGgHZlX9ROOfHSPZS0BliJqwdKb0IOaWScoleA 0F1w== X-Gm-Message-State: ALoCoQnpGaIWednMYL5fbFPf/Ep6QbYhwH6njWiKAvqYxYskMCRUhkX3QZ5o9McZHgDXhnfxKKjx X-Received: by 10.224.47.130 with SMTP id n2mr30173414qaf.87.1407085406054; Sun, 03 Aug 2014 10:03:26 -0700 (PDT) Received: from leira.trondhjem.org.localdomain (50-33-225-239.drr02.mskg.mi.frontiernet.net. [50.33.225.239]) by mx.google.com with ESMTPSA id a17sm6670702qac.1.2014.08.03.10.03.25 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 03 Aug 2014 10:03:25 -0700 (PDT) From: Trond Myklebust To: Bruce Fields Cc: linux-nfs@vger.kernel.org Subject: [PATCH 09/11] SUNRPC: Fix broken kthread_should_stop test in svc_get_next_xprt Date: Sun, 3 Aug 2014 13:03:11 -0400 Message-Id: <1407085393-3175-10-git-send-email-trond.myklebust@primarydata.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1407085393-3175-9-git-send-email-trond.myklebust@primarydata.com> References: <1407085393-3175-1-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-2-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-3-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-4-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-5-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-6-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-7-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-8-git-send-email-trond.myklebust@primarydata.com> <1407085393-3175-9-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We should definitely not be exiting svc_get_next_xprt() with the thread enqueued. Fix this by ensuring that we fall through to the dequeue. Also move the test itself outside the spin lock protected section. Signed-off-by: Trond Myklebust --- net/sunrpc/svc_xprt.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 438e91c12851..b334cf71be3a 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -632,7 +632,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) { struct svc_xprt *xprt; struct svc_pool *pool = rqstp->rq_pool; - long time_left; + long time_left = 0; /* Normally we will wait up to 5 seconds for any required * cache information to be provided. @@ -665,30 +665,19 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) /* No data pending. Go to sleep */ svc_thread_enqueue(pool, rqstp); - - /* - * checking kthread_should_stop() here allows us to avoid - * locking and signalling when stopping kthreads that call - * svc_recv. If the thread has already been woken up, then - * we can exit here without sleeping. If not, then it - * it'll be woken up quickly during the schedule_timeout - */ - if (kthread_should_stop()) { - set_current_state(TASK_RUNNING); - xprt = ERR_PTR(-EINTR); - goto out; - } - spin_unlock_bh(&pool->sp_lock); - time_left = schedule_timeout(timeout); - __set_current_state(TASK_RUNNING); + if (!(signalled() || kthread_should_stop())) { + time_left = schedule_timeout(timeout); + __set_current_state(TASK_RUNNING); - try_to_freeze(); + try_to_freeze(); - xprt = rqstp->rq_xprt; - if (xprt != NULL) - return xprt; + xprt = rqstp->rq_xprt; + if (xprt != NULL) + return xprt; + } else + __set_current_state(TASK_RUNNING); spin_lock_bh(&pool->sp_lock); if (!time_left)