From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com [122.248.162.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp04.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 2051B2C032C for ; Wed, 26 Jun 2013 06:33:18 +1000 (EST) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 26 Jun 2013 01:57:02 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 17DC0394004E for ; Wed, 26 Jun 2013 02:03:14 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5PKXTV824379646 for ; Wed, 26 Jun 2013 02:03:29 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5PKXBhF021996 for ; Wed, 26 Jun 2013 06:33:13 +1000 From: "Srivatsa S. Bhat" Subject: [PATCH v2 24/45] [SCSI] fcoe: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com Date: Wed, 26 Jun 2013 01:59:57 +0530 Message-ID: <20130625202956.16593.29123.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> References: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, "James E.J. Bottomley" , nikunj@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, linux-scsi@vger.kernel.org, sbw@mit.edu, wangyun@linux.vnet.ibm.com, "Srivatsa S. Bhat" , netdev@vger.kernel.org, Robert Love , linuxppc-dev@lists.ozlabs.org, devel@open-fcoe.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Robert Love Cc: "James E.J. Bottomley" Cc: devel@open-fcoe.org Cc: linux-scsi@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- drivers/scsi/fcoe/fcoe.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 292b24f..a107d3c 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1484,6 +1484,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, * was originated, otherwise select cpu using rx exchange id * or fcoe_select_cpu(). */ + get_online_cpus_atomic(); if (ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX) cpu = ntohs(fh->fh_ox_id) & fc_cpu_mask; else { @@ -1493,8 +1494,10 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, cpu = ntohs(fh->fh_rx_id) & fc_cpu_mask; } - if (cpu >= nr_cpu_ids) + if (cpu >= nr_cpu_ids) { + put_online_cpus_atomic(); goto err; + } fps = &per_cpu(fcoe_percpu, cpu); spin_lock(&fps->fcoe_rx_list.lock); @@ -1514,6 +1517,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, spin_lock(&fps->fcoe_rx_list.lock); if (!fps->thread) { spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); goto err; } } @@ -1535,6 +1539,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, if (fps->thread->state == TASK_INTERRUPTIBLE) wake_up_process(fps->thread); spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); return 0; err: