From patchwork Sun Nov 21 23:55:42 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 554 Return-Path: Received: from mail.gmx.net (mailout-de.gmx.net [213.165.64.23]) by open-mesh.org (Postfix) with SMTP id 92FF8154582 for ; Mon, 22 Nov 2010 00:55:56 +0100 (CET) Received: (qmail invoked by alias); 21 Nov 2010 23:55:55 -0000 Received: from vpnclient-194-112.hrz.tu-chemnitz.de (EHLO sven-desktop.lazhur.ath.cx) [134.109.194.112] by mail.gmx.net (mp041) with SMTP; 22 Nov 2010 00:55:55 +0100 X-Authenticated: #15668376 X-Provags-ID: V01U2FsdGVkX19/57EBJsN/1+t1EIvlp6F+VnBzETw1SGFaIy2C9V Vob4NAANUWVWNP From: Sven Eckelmann To: greg@kroah.com Date: Mon, 22 Nov 2010 00:55:42 +0100 Message-Id: <1290383767-32602-5-git-send-email-sven.eckelmann@gmx.de> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1290383767-32602-1-git-send-email-sven.eckelmann@gmx.de> References: <1290383767-32602-1-git-send-email-sven.eckelmann@gmx.de> X-Y-GMX-Trusted: 0 Cc: b.a.t.m.a.n@lists.open-mesh.org Subject: [B.A.T.M.A.N.] [PATCH 04/29] Staging: batman-adv: Don't remove interface with spinlock held X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Nov 2010 23:55:57 -0000 We call a lot of the netdevice code when holding if_list_lock which will spin the whole time. This is not necessary because we only want to protect the access to the list to be serialized. An extra queue can be used which hold all interfaces which should be removed and then use that queue without any locks for netdevice cleanup. Reported-by: Rafal Lesniak Signed-off-by: Sven Eckelmann --- drivers/staging/batman-adv/hard-interface.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c index b68a7e5..d85de82 100644 --- a/drivers/staging/batman-adv/hard-interface.c +++ b/drivers/staging/batman-adv/hard-interface.c @@ -463,9 +463,6 @@ static void hardif_remove_interface(struct batman_if *batman_if) return; batman_if->if_status = IF_TO_BE_REMOVED; - - /* caller must take if_list_lock */ - list_del_rcu(&batman_if->list); synchronize_rcu(); sysfs_del_hardif(&batman_if->hardif_obj); hardif_put(batman_if); @@ -474,13 +471,21 @@ static void hardif_remove_interface(struct batman_if *batman_if) void hardif_remove_interfaces(void) { struct batman_if *batman_if, *batman_if_tmp; + struct list_head if_queue; + + INIT_LIST_HEAD(&if_queue); - rtnl_lock(); spin_lock(&if_list_lock); list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) { - hardif_remove_interface(batman_if); + list_del_rcu(&batman_if->list); + list_add_tail(&batman_if->list, &if_queue); } spin_unlock(&if_list_lock); + + rtnl_lock(); + list_for_each_entry_safe(batman_if, batman_if_tmp, &if_queue, list) { + hardif_remove_interface(batman_if); + } rtnl_unlock(); } @@ -507,8 +512,10 @@ static int hard_if_event(struct notifier_block *this, break; case NETDEV_UNREGISTER: spin_lock(&if_list_lock); - hardif_remove_interface(batman_if); + list_del_rcu(&batman_if->list); spin_unlock(&if_list_lock); + + hardif_remove_interface(batman_if); break; case NETDEV_CHANGEMTU: if (batman_if->soft_iface)