Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759906AbbFCNAK (ORCPT ); Wed, 3 Jun 2015 09:00:10 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57779 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244AbbFCMRF (ORCPT ); Wed, 3 Jun 2015 08:17:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Eric W. Biederman" Subject: [PATCH 4.0 002/148] fs_pin: Allow for the possibility that m_list or s_list go unused. Date: Wed, 3 Jun 2015 21:07:52 +0900 Message-Id: <20150603114205.435888161@linuxfoundation.org> X-Mailer: git-send-email 2.4.2 In-Reply-To: <20150603114205.337615117@linuxfoundation.org> References: <20150603114205.337615117@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 59 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit 820f9f147dcce2602eefd9b575bbbd9ea14f0953 upstream. This is needed to support lazily umounting locked mounts. Because the entire unmounted subtree needs to stay together until there are no users with references to any part of the subtree. To support this guarantee that the fs_pin m_list and s_list nodes are initialized by initializing them in init_fs_pin allowing for the possibility that pin_insert_group does not touch them. Further use hlist_del_init in pin_remove so that there is a hlist_unhashed test before the list we attempt to update the previous list item. Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/fs_pin.c | 4 ++-- include/linux/fs_pin.h | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-) --- a/fs/fs_pin.c +++ b/fs/fs_pin.c @@ -9,8 +9,8 @@ static DEFINE_SPINLOCK(pin_lock); void pin_remove(struct fs_pin *pin) { spin_lock(&pin_lock); - hlist_del(&pin->m_list); - hlist_del(&pin->s_list); + hlist_del_init(&pin->m_list); + hlist_del_init(&pin->s_list); spin_unlock(&pin_lock); spin_lock_irq(&pin->wait.lock); pin->done = 1; --- a/include/linux/fs_pin.h +++ b/include/linux/fs_pin.h @@ -13,6 +13,8 @@ struct vfsmount; static inline void init_fs_pin(struct fs_pin *p, void (*kill)(struct fs_pin *)) { init_waitqueue_head(&p->wait); + INIT_HLIST_NODE(&p->s_list); + INIT_HLIST_NODE(&p->m_list); p->kill = kill; } -- 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/