From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ursula Braun Subject: [patch 2/7] [PATCH] iucv: fix iucv_buffer_cpumask check when calling IUCV functions Date: Wed, 16 Sep 2009 16:37:23 +0200 Message-ID: <20090916144304.269646000@linux.vnet.ibm.com> References: <20090916143721.863799000@linux.vnet.ibm.com> Cc: schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, Hendrik Brueckner , Ursula Braun To: davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org Return-path: Received: from mtagate6.de.ibm.com ([195.212.17.166]:57641 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751653AbZIPOnC (ORCPT ); Wed, 16 Sep 2009 10:43:02 -0400 Content-Disposition: inline; filename=601-iucv-cpumask.diff Sender: netdev-owner@vger.kernel.org List-ID: From: Hendrik Brueckner Prior to calling IUCV functions, the DECLARE BUFFER function must have been called for at least one CPU to receive IUCV interrupts. With commit "iucv: establish reboot notifier" (6c005961), a check has been introduced to avoid calling IUCV functions if the current CPU does not have an interrupt buffer declared. Because one interrupt buffer is sufficient, change the condition to ensure that one interrupt buffer is available. In addition, checking the buffer on the current CPU creates a race with CPU up/down notifications: before checking the buffer, the IUCV function might be interrupted by an smp_call_function() that retrieves the interrupt buffer for the current CPU. When the IUCV function continues, the check fails and -EIO is returned. If a buffer is available on any other CPU, the IUCV function call must be invoked (instead of failing with -EIO). Signed-off-by: Hendrik Brueckner Signed-off-by: Ursula Braun --- net/iucv/iucv.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff -urpN linux-2.6/net/iucv/iucv.c linux-2.6-patched/net/iucv/iucv.c --- linux-2.6/net/iucv/iucv.c 2009-09-15 12:25:32.000000000 +0200 +++ linux-2.6-patched/net/iucv/iucv.c 2009-09-15 12:25:32.000000000 +0200 @@ -864,7 +864,7 @@ int iucv_path_accept(struct iucv_path *p int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -913,7 +913,7 @@ int iucv_path_connect(struct iucv_path * spin_lock_bh(&iucv_table_lock); iucv_cleanup_queue(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -973,7 +973,7 @@ int iucv_path_quiesce(struct iucv_path * int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1005,7 +1005,7 @@ int iucv_path_resume(struct iucv_path *p int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1034,7 +1034,7 @@ int iucv_path_sever(struct iucv_path *pa int rc; preempt_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1068,7 +1068,7 @@ int iucv_message_purge(struct iucv_path int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1160,7 +1160,7 @@ int __iucv_message_receive(struct iucv_p if (msg->flags & IUCV_IPRMDATA) return iucv_message_receive_iprmdata(path, msg, flags, buffer, size, residual); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1233,7 +1233,7 @@ int iucv_message_reject(struct iucv_path int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1272,7 +1272,7 @@ int iucv_message_reply(struct iucv_path int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1322,7 +1322,7 @@ int __iucv_message_send(struct iucv_path union iucv_param *parm; int rc; - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; } @@ -1409,7 +1409,7 @@ int iucv_message_send2way(struct iucv_pa int rc; local_bh_disable(); - if (!cpu_isset(smp_processor_id(), iucv_buffer_cpumask)) { + if (cpus_empty(iucv_buffer_cpumask)) { rc = -EIO; goto out; }