From patchwork Wed Apr 21 09:11:31 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Klein X-Patchwork-Id: 50644 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EA312B7CF7 for ; Wed, 21 Apr 2010 19:12:00 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753392Ab0DUJLe (ORCPT ); Wed, 21 Apr 2010 05:11:34 -0400 Received: from mtagate4.de.ibm.com ([195.212.17.164]:60692 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752686Ab0DUJLd (ORCPT ); Wed, 21 Apr 2010 05:11:33 -0400 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate4.de.ibm.com (8.13.1/8.13.1) with ESMTP id o3L9BW2T010748; Wed, 21 Apr 2010 09:11:32 GMT Received: from d12av04.megacenter.de.ibm.com (d12av04.megacenter.de.ibm.com [9.149.165.229]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o3L9BWJd1540276; Wed, 21 Apr 2010 11:11:32 +0200 Received: from d12av04.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av04.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id o3L9BVD5028900; Wed, 21 Apr 2010 11:11:31 +0200 Received: from dyn-9-152-241-108.boeblingen.de.ibm.com (dyn-9-152-241-108.boeblingen.de.ibm.com [9.152.241.108]) by d12av04.megacenter.de.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id o3L9BVOG028894; Wed, 21 Apr 2010 11:11:31 +0200 From: Thomas Klein To: davem@davemloft.net Subject: [PATCH 2/2][RESEND] ehea: fix possible DLPAR/mem deadlock Date: Wed, 21 Apr 2010 11:11:31 +0200 User-Agent: KMail/1.9.9 Cc: netdev@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, themann@de.ibm.com MIME-Version: 1.0 Content-Disposition: inline Message-Id: <201004211111.31298.tklein@de.ibm.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Force serialization of userspace-triggered DLPAR/mem operations Signed-off-by: Thomas Klein --- Patch created against net-2.6 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff -Nurp net-2.6.orig/drivers/net/ehea/ehea.h net-2.6/drivers/net/ehea/ehea.h --- net-2.6.orig/drivers/net/ehea/ehea.h 2010-04-21 10:23:21.000000000 +0200 +++ net-2.6/drivers/net/ehea/ehea.h 2010-04-21 10:42:14.000000000 +0200 @@ -40,7 +40,7 @@ #include #define DRV_NAME "ehea" -#define DRV_VERSION "EHEA_0102" +#define DRV_VERSION "EHEA_0103" /* eHEA capability flags */ #define DLPAR_PORT_ADD_REM 1 diff -Nurp net-2.6.orig/drivers/net/ehea/ehea_main.c net-2.6/drivers/net/ehea/ehea_main.c --- net-2.6.orig/drivers/net/ehea/ehea_main.c 2010-04-21 10:43:14.000000000 +0200 +++ net-2.6/drivers/net/ehea/ehea_main.c 2010-04-21 10:42:14.000000000 +0200 @@ -2889,7 +2889,6 @@ static void ehea_rereg_mrs(struct work_s int ret, i; struct ehea_adapter *adapter; - mutex_lock(&dlpar_mem_lock); ehea_info("LPAR memory changed - re-initializing driver"); list_for_each_entry(adapter, &adapter_list, list) @@ -2959,7 +2958,6 @@ static void ehea_rereg_mrs(struct work_s } ehea_info("re-initializing driver complete"); out: - mutex_unlock(&dlpar_mem_lock); return; } @@ -3542,7 +3540,14 @@ void ehea_crash_handler(void) static int ehea_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) { + int ret = NOTIFY_BAD; struct memory_notify *arg = data; + + if (!mutex_trylock(&dlpar_mem_lock)) { + ehea_info("ehea_mem_notifier must not be called parallelized"); + goto out; + } + switch (action) { case MEM_CANCEL_OFFLINE: ehea_info("memory offlining canceled"); @@ -3551,14 +3556,14 @@ static int ehea_mem_notifier(struct noti ehea_info("memory is going online"); set_bit(__EHEA_STOP_XFER, &ehea_driver_flags); if (ehea_add_sect_bmap(arg->start_pfn, arg->nr_pages)) - return NOTIFY_BAD; + goto out_unlock; ehea_rereg_mrs(NULL); break; case MEM_GOING_OFFLINE: ehea_info("memory is going offline"); set_bit(__EHEA_STOP_XFER, &ehea_driver_flags); if (ehea_rem_sect_bmap(arg->start_pfn, arg->nr_pages)) - return NOTIFY_BAD; + goto out_unlock; ehea_rereg_mrs(NULL); break; default: @@ -3566,8 +3571,12 @@ static int ehea_mem_notifier(struct noti } ehea_update_firmware_handles(); + ret = NOTIFY_OK; - return NOTIFY_OK; +out_unlock: + mutex_unlock(&dlpar_mem_lock); +out: + return ret; } static struct notifier_block ehea_mem_nb = {