Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947903AbbEBVOo (ORCPT ); Sat, 2 May 2015 17:14:44 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44734 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754231AbbEBTPw (ORCPT ); Sat, 2 May 2015 15:15:52 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Eric W. Biederman" Subject: [PATCH 4.0 109/220] mnt: In umount_tree reuse mnt_list instead of mnt_hash Date: Sat, 2 May 2015 21:00:24 +0200 Message-Id: <20150502185859.043169545@linuxfoundation.org> X-Mailer: git-send-email 2.3.7 In-Reply-To: <20150502185854.333748961@linuxfoundation.org> References: <20150502185854.333748961@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: 3443 Lines: 105 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit c003b26ff98ca04a180ff34c38c007a3998d62f9 upstream. umount_tree builds a list of mounts that need to be unmounted. Utilize mnt_list for this purpose instead of mnt_hash. This begins to allow keeping a mount on the mnt_hash after it is unmounted, which is necessary for a properly functioning MNT_LOCKED implementation. The fact that mnt_list is an ordinary list makding available list_move is nice bonus. Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/namespace.c | 20 +++++++++++--------- fs/pnode.c | 6 +++--- fs/pnode.h | 2 +- 3 files changed, 15 insertions(+), 13 deletions(-) --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1329,23 +1329,25 @@ enum umount_tree_flags { */ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) { - HLIST_HEAD(tmp_list); + LIST_HEAD(tmp_list); struct mount *p; - for (p = mnt; p; p = next_mnt(p, mnt)) { - hlist_del_init_rcu(&p->mnt_hash); - hlist_add_head(&p->mnt_hash, &tmp_list); - } + /* Gather the mounts to umount */ + for (p = mnt; p; p = next_mnt(p, mnt)) + list_move(&p->mnt_list, &tmp_list); - hlist_for_each_entry(p, &tmp_list, mnt_hash) + /* Hide the mounts from lookup_mnt and mnt_mounts */ + list_for_each_entry(p, &tmp_list, mnt_list) { + hlist_del_init_rcu(&p->mnt_hash); list_del_init(&p->mnt_child); + } + /* Add propogated mounts to the tmp_list */ if (how & UMOUNT_PROPAGATE) propagate_umount(&tmp_list); - while (!hlist_empty(&tmp_list)) { - p = hlist_entry(tmp_list.first, struct mount, mnt_hash); - hlist_del_init_rcu(&p->mnt_hash); + while (!list_empty(&tmp_list)) { + p = list_first_entry(&tmp_list, struct mount, mnt_list); list_del_init(&p->mnt_expire); list_del_init(&p->mnt_list); __touch_mnt_namespace(p->mnt_ns); --- a/fs/pnode.c +++ b/fs/pnode.c @@ -384,7 +384,7 @@ static void __propagate_umount(struct mo if (child && list_empty(&child->mnt_mounts)) { list_del_init(&child->mnt_child); hlist_del_init_rcu(&child->mnt_hash); - hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash); + list_move_tail(&child->mnt_list, &mnt->mnt_list); } } } @@ -396,11 +396,11 @@ static void __propagate_umount(struct mo * * vfsmount lock must be held for write */ -int propagate_umount(struct hlist_head *list) +int propagate_umount(struct list_head *list) { struct mount *mnt; - hlist_for_each_entry(mnt, list, mnt_hash) + list_for_each_entry(mnt, list, mnt_list) __propagate_umount(mnt); return 0; } --- a/fs/pnode.h +++ b/fs/pnode.h @@ -40,7 +40,7 @@ static inline void set_mnt_shared(struct void change_mnt_propagation(struct mount *, int); int propagate_mnt(struct mount *, struct mountpoint *, struct mount *, struct hlist_head *); -int propagate_umount(struct hlist_head *); +int propagate_umount(struct list_head *); int propagate_mount_busy(struct mount *, int); void mnt_release_group_id(struct mount *); int get_dominating_id(struct mount *mnt, const struct path *root); -- 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/