From patchwork Mon Feb 2 17:14:01 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sosnowski, Maciej" X-Patchwork-Id: 21578 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 [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 35488DDF08 for ; Tue, 3 Feb 2009 04:23:48 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757893AbZBBRXV (ORCPT ); Mon, 2 Feb 2009 12:23:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757914AbZBBRXU (ORCPT ); Mon, 2 Feb 2009 12:23:20 -0500 Received: from mga02.intel.com ([134.134.136.20]:42659 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757893AbZBBRXS (ORCPT ); Mon, 2 Feb 2009 12:23:18 -0500 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 02 Feb 2009 09:19:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.37,366,1231142400"; d="scan'208";a="486496215" Received: from gklab-190-232.igk.intel.com (HELO linux.site) ([172.28.190.232]) by orsmga001.jf.intel.com with ESMTP; 02 Feb 2009 09:23:05 -0800 From: Maciej Sosnowski Subject: [PATCH] dca: redesign locks To: dan.j.williams@intel.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Date: Mon, 02 Feb 2009 18:14:01 +0100 Message-ID: <20090202171312.1559.65827.stgit@linux.site> User-Agent: StGIT/0.13 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Change spin_locks to irqsave to prevent dead-locks. Protect adding and deleting to/from dca_providers list. Drop the lock during dca_sysfs_add_req() and dca_sysfs_remove_req() calls as they might sleep (use GFP_KERNEL allocation). Signed-off-by: Maciej Sosnowski Acked-by: Jeff Kirsher --- drivers/dca/dca-core.c | 51 +++++++++++++++++++++++++++++++----------------- 1 files changed, 33 insertions(+), 18 deletions(-) -- 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 --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c index 5543384..33bd753 100644 --- a/drivers/dca/dca-core.c +++ b/drivers/dca/dca-core.c @@ -28,7 +28,7 @@ #include #include #include -#define DCA_VERSION "1.4" +#define DCA_VERSION "1.8" MODULE_VERSION(DCA_VERSION); MODULE_LICENSE("GPL"); @@ -60,16 +60,17 @@ int dca_add_requester(struct device *dev { struct dca_provider *dca; int err, slot = -ENODEV; + unsigned long flags; if (!dev) return -EFAULT; - spin_lock(&dca_lock); + spin_lock_irqsave(&dca_lock, flags); /* check if the requester has not been added already */ dca = dca_find_provider_by_dev(dev); if (dca) { - spin_unlock(&dca_lock); + spin_unlock_irqrestore(&dca_lock, flags); return -EEXIST; } @@ -78,19 +79,21 @@ int dca_add_requester(struct device *dev if (slot >= 0) break; } - if (slot < 0) { - spin_unlock(&dca_lock); + + spin_unlock_irqrestore(&dca_lock, flags); + + if (slot < 0) return slot; - } err = dca_sysfs_add_req(dca, dev, slot); if (err) { - dca->ops->remove_requester(dca, dev); - spin_unlock(&dca_lock); + spin_lock_irqsave(&dca_lock, flags); + if (dca == dca_find_provider_by_dev(dev)) + dca->ops->remove_requester(dca, dev); + spin_unlock_irqrestore(&dca_lock, flags); return err; } - spin_unlock(&dca_lock); return 0; } EXPORT_SYMBOL_GPL(dca_add_requester); @@ -103,25 +106,25 @@ int dca_remove_requester(struct device * { struct dca_provider *dca; int slot; + unsigned long flags; if (!dev) return -EFAULT; - spin_lock(&dca_lock); + spin_lock_irqsave(&dca_lock, flags); dca = dca_find_provider_by_dev(dev); if (!dca) { - spin_unlock(&dca_lock); + spin_unlock_irqrestore(&dca_lock, flags); return -ENODEV; } slot = dca->ops->remove_requester(dca, dev); - if (slot < 0) { - spin_unlock(&dca_lock); + spin_unlock_irqrestore(&dca_lock, flags); + + if (slot < 0) return slot; - } dca_sysfs_remove_req(dca, slot); - spin_unlock(&dca_lock); return 0; } EXPORT_SYMBOL_GPL(dca_remove_requester); @@ -135,17 +138,18 @@ u8 dca_common_get_tag(struct device *dev { struct dca_provider *dca; u8 tag; + unsigned long flags; - spin_lock(&dca_lock); + spin_lock_irqsave(&dca_lock, flags); dca = dca_find_provider_by_dev(dev); if (!dca) { - spin_unlock(&dca_lock); + spin_unlock_irqrestore(&dca_lock, flags); return -ENODEV; } tag = dca->ops->get_tag(dca, dev, cpu); - spin_unlock(&dca_lock); + spin_unlock_irqrestore(&dca_lock, flags); return tag; } @@ -217,11 +221,16 @@ static BLOCKING_NOTIFIER_HEAD(dca_provid int register_dca_provider(struct dca_provider *dca, struct device *dev) { int err; + unsigned long flags; err = dca_sysfs_add_provider(dca, dev); if (err) return err; + + spin_lock_irqsave(&dca_lock, flags); list_add(&dca->node, &dca_providers); + spin_unlock_irqrestore(&dca_lock, flags); + blocking_notifier_call_chain(&dca_provider_chain, DCA_PROVIDER_ADD, NULL); return 0; @@ -234,9 +243,15 @@ EXPORT_SYMBOL_GPL(register_dca_provider) */ void unregister_dca_provider(struct dca_provider *dca) { + unsigned long flags; + blocking_notifier_call_chain(&dca_provider_chain, DCA_PROVIDER_REMOVE, NULL); + + spin_lock_irqsave(&dca_lock, flags); list_del(&dca->node); + spin_unlock_irqrestore(&dca_lock, flags); + dca_sysfs_remove_provider(dca); } EXPORT_SYMBOL_GPL(unregister_dca_provider);