1 files changed, 49 insertions, 10 deletions

diff --git a/fs/mount.h b/fs/mount.h
index 179f690a0c72..ad7173037924 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -5,18 +5,33 @@
 #include <linux/ns_common.h>
 #include <linux/fs_pin.h>
 
+extern struct list_head notify_list;
+
 struct mnt_namespace {
 	struct ns_common	ns;
 	struct mount *	root;
-	struct rb_root		mounts; /* Protected by namespace_sem */
+	struct {
+		struct rb_root	mounts;		 /* Protected by namespace_sem */
+		struct rb_node	*mnt_last_node;	 /* last (rightmost) mount in the rbtree */
+		struct rb_node	*mnt_first_node; /* first (leftmost) mount in the rbtree */
+	};
 	struct user_namespace	*user_ns;
 	struct ucounts		*ucounts;
 	u64			seq;	/* Sequence number to prevent loops */
-	wait_queue_head_t poll;
+	union {
+		wait_queue_head_t	poll;
+		struct rcu_head		mnt_ns_rcu;
+	};
+	u64			seq_origin; /* Sequence number of origin mount namespace */
 	u64 event;
+#ifdef CONFIG_FSNOTIFY
+	__u32			n_fsnotify_mask;
+	struct fsnotify_mark_connector __rcu *n_fsnotify_marks;
+#endif
 	unsigned int		nr_mounts; /* # of mounts in the namespace */
 	unsigned int		pending_mounts;
 	struct rb_node		mnt_ns_tree_node; /* node in the mnt_ns_tree */
+	struct list_head	mnt_ns_list; /* entry in the sequential list of mounts namespace */
 	refcount_t		passive; /* number references not pinning @mounts */
 } __randomize_layout;
 
@@ -68,6 +83,8 @@ struct mount {
 #ifdef CONFIG_FSNOTIFY
 	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
 	__u32 mnt_fsnotify_mask;
+	struct list_head to_notify;	/* need to queue notification */
+	struct mnt_namespace *prev_ns;	/* previous namespace (NULL if none) */
 #endif
 	int mnt_id;			/* mount identifier, reused */
 	u64 mnt_id_unique;		/* mount ID unique until reboot */
@@ -148,25 +165,47 @@ static inline bool mnt_ns_attached(const struct mount *mnt)
 	return !RB_EMPTY_NODE(&mnt->mnt_node);
 }
 
+static inline bool mnt_ns_empty(const struct mnt_namespace *ns)
+{
+	return RB_EMPTY_ROOT(&ns->mounts);
+}
+
 static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
 {
+	struct mnt_namespace *ns = mnt->mnt_ns;
 	WARN_ON(!mnt_ns_attached(mnt));
-	rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts);
+	if (ns->mnt_last_node == &mnt->mnt_node)
+		ns->mnt_last_node = rb_prev(&mnt->mnt_node);
+	if (ns->mnt_first_node == &mnt->mnt_node)
+		ns->mnt_first_node = rb_next(&mnt->mnt_node);
+	rb_erase(&mnt->mnt_node, &ns->mounts);
 	RB_CLEAR_NODE(&mnt->mnt_node);
 	list_add_tail(&mnt->mnt_list, dt_list);
 }
 
 bool has_locked_children(struct mount *mnt, struct dentry *dentry);
-struct mnt_namespace *__lookup_next_mnt_ns(struct mnt_namespace *mnt_ns, bool previous);
-static inline struct mnt_namespace *lookup_next_mnt_ns(struct mnt_namespace *mntns)
+struct mnt_namespace *get_sequential_mnt_ns(struct mnt_namespace *mnt_ns,
+					    bool previous);
+
+static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
 {
-	return __lookup_next_mnt_ns(mntns, false);
+	return container_of(ns, struct mnt_namespace, ns);
 }
-static inline struct mnt_namespace *lookup_prev_mnt_ns(struct mnt_namespace *mntns)
+
+#ifdef CONFIG_FSNOTIFY
+static inline void mnt_notify_add(struct mount *m)
 {
-	return __lookup_next_mnt_ns(mntns, true);
+	/* Optimize the case where there are no watches */
+	if ((m->mnt_ns && m->mnt_ns->n_fsnotify_marks) ||
+	    (m->prev_ns && m->prev_ns->n_fsnotify_marks))
+		list_add_tail(&m->to_notify, &notify_list);
+	else
+		m->prev_ns = m->mnt_ns;
 }
-static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
+#else
+static inline void mnt_notify_add(struct mount *m)
 {
-	return container_of(ns, struct mnt_namespace, ns);
 }
+#endif
+
+struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry);