From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f42.google.com (mail-ee0-f42.google.com [74.125.83.42]) by kanga.kvack.org (Postfix) with ESMTP id 758D46B0069 for ; Wed, 16 Apr 2014 00:19:31 -0400 (EDT) Received: by mail-ee0-f42.google.com with SMTP id d17so8354695eek.1 for ; Tue, 15 Apr 2014 21:19:30 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r9si28121540eew.228.2014.04.15.21.19.29 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 15 Apr 2014 21:19:30 -0700 (PDT) From: NeilBrown Date: Wed, 16 Apr 2014 14:03:36 +1000 Subject: [PATCH 14/19] driver core: set PF_FSTRANS while holding gdp_mutex Message-ID: <20140416040336.10604.223.stgit@notabene.brown> In-Reply-To: <20140416033623.10604.69237.stgit@notabene.brown> References: <20140416033623.10604.69237.stgit@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Cc: xfs@oss.sgi.com lockdep reports a locking chain: sk_lock-AF_INET --> rtnl_mutex --> gdp_mutex As sk_lock can be needed for memory reclaim (when loop-back NFS is in use at least), any memory allocation under gdp_mutex needs to be protected by PF_FSTRANS. The path frome rtnl_mutex to gdp_mutex is [] get_device_parent+0x4c/0x1f0 [] device_add+0xe6/0x610 [] netdev_register_kobject+0x7a/0x130 [] register_netdevice+0x354/0x550 [] register_netdev+0x15/0x30 Signed-off-by: NeilBrown --- drivers/base/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 2b567177ef78..1a2735237650 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -750,6 +750,7 @@ static struct kobject *get_device_parent(struct device *dev, struct kobject *kobj = NULL; struct kobject *parent_kobj; struct kobject *k; + unsigned int pflags; #ifdef CONFIG_BLOCK /* block disks show up in /sys/block */ @@ -788,7 +789,9 @@ static struct kobject *get_device_parent(struct device *dev, } /* or create a new class-directory at the parent device */ + current_set_flags_nested(&pflags, PF_FSTRANS); k = class_dir_create_and_add(dev->class, parent_kobj); + current_restore_flags_nested(&pflags, PF_FSTRANS); /* do not emit an uevent for this simple "glue" directory */ mutex_unlock(&gdp_mutex); return k; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org