From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp09.in.ibm.com (e28smtp09.in.ibm.com [122.248.162.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp09.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id BD7C02C05B4 for ; Tue, 22 Jan 2013 18:41:16 +1100 (EST) Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 22 Jan 2013 13:10:02 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 4E14BE0050 for ; Tue, 22 Jan 2013 13:11:37 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r0M7f8xR39583822 for ; Tue, 22 Jan 2013 13:11:08 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r0M7f7uB011796 for ; Tue, 22 Jan 2013 18:41:09 +1100 From: "Srivatsa S. Bhat" Subject: [PATCH v5 23/45] [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 Date: Tue, 22 Jan 2013 13:09:22 +0530 Message-ID: <20130122073919.13822.73176.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.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 preempt_disable() or local_irq_disable() 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 666b7ac..c971a17 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1475,6 +1475,7 @@ 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 { @@ -1484,8 +1485,10 @@ 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); @@ -1505,6 +1508,7 @@ 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; } } @@ -1526,6 +1530,7 @@ 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: