Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932281Ab2JZKsO (ORCPT ); Fri, 26 Oct 2012 06:48:14 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:32178 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1758269Ab2JZKsL (ORCPT ); Fri, 26 Oct 2012 06:48:11 -0400 X-IronPort-AV: E=Sophos;i="4.80,654,1344182400"; d="scan'208";a="6078656" From: wency@cn.fujitsu.com To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Cc: liuj97@gmail.com, len.brown@intel.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, rjw@sisk.pl, laijs@cn.fujitsu.com, Wen Congyang , David Rientjes , Christoph Lameter , Minchan Kim Subject: [PATCH v3 2/3] acpi,memory-hotplug: introduce a mutex lock to protect the list in acpi_memory_device Date: Fri, 26 Oct 2012 18:31:02 +0800 Message-Id: <1351247463-5653-3-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.8.0 In-Reply-To: <1351247463-5653-1-git-send-email-wency@cn.fujitsu.com> References: <1351247463-5653-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/26 18:24:49, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/26 18:24:53, Serialize complete at 2012/10/26 18:24:53 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4876 Lines: 130 From: Wen Congyang The memory device can be removed by 2 ways: 1. send eject request by SCI 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject This 2 events may happen at the same time, so we may touch acpi_memory_device.res_list at the same time. This patch introduce a lock to protect this list. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Yasuaki Ishimatsu Signed-off-by: Wen Congyang --- drivers/acpi/acpi_memhotplug.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 1e90e8f..666dac6 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -83,7 +83,8 @@ struct acpi_memory_info { struct acpi_memory_device { struct acpi_device * device; unsigned int state; /* State of the memory device */ - struct list_head res_list; + struct mutex list_lock; + struct list_head res_list; /* protected by list_lock */ }; static int acpi_hotmem_initialized; @@ -101,19 +102,23 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) (address64.resource_type != ACPI_MEMORY_RANGE)) return AE_OK; + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { /* Can we combine the resource range information? */ if ((info->caching == address64.info.mem.caching) && (info->write_protect == address64.info.mem.write_protect) && (info->start_addr + info->length == address64.minimum)) { info->length += address64.address_length; + mutex_unlock(&mem_device->list_lock); return AE_OK; } } new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); - if (!new) + if (!new) { + mutex_unlock(&mem_device->list_lock); return AE_ERROR; + } INIT_LIST_HEAD(&new->list); new->caching = address64.info.mem.caching; @@ -121,6 +126,7 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) new->start_addr = address64.minimum; new->length = address64.address_length; list_add_tail(&new->list, &mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return AE_OK; } @@ -138,9 +144,11 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); if (ACPI_FAILURE(status)) { + mutex_lock(&mem_device->list_lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) kfree(info); INIT_LIST_HEAD(&mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return -EINVAL; } @@ -236,6 +244,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) * We don't have memory-hot-add rollback function,now. * (i.e. memory-hot-remove function) */ + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { if (info->enabled) { /* just sanity check...*/ num_enabled++; @@ -256,6 +265,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) info->enabled = 1; num_enabled++; } + mutex_unlock(&mem_device->list_lock); if (!num_enabled) { printk(KERN_ERR PREFIX "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; @@ -316,6 +326,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) * Ask the VM to offline this memory range. * Note: Assume that this function returns zero on success */ + mutex_lock(&mem_device->list_lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (info->enabled) { result = remove_memory(info->start_addr, info->length); @@ -324,6 +335,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) } kfree(info); } + mutex_unlock(&mem_device->list_lock); /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); @@ -438,6 +450,7 @@ static int acpi_memory_device_add(struct acpi_device *device) mem_device->device = device; sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); + mutex_init(&mem_device->list_lock); device->driver_data = mem_device; /* Get the range from the _CRS */ -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/