---

yaml
---
r: 207637
b: refs/heads/master
c: 7131485
h: refs/heads/master
i:
  207635: 80e003a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4ca763523e040dc61191d4866a82981a5d30a4e9
+refs/heads/master: 7131485a93679ff9a543b74df280cfd119eb03ca

trunk/fs/notify/fsnotify.c

@@ -21,6 +21,7 @@
 #include <linux/gfp.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/mount.h>
 #include <linux/srcu.h>
 
 #include <linux/fsnotify_backend.h>
@@ -134,6 +135,45 @@ void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
 }
 EXPORT_SYMBOL_GPL(__fsnotify_parent);
 
+static void send_to_group(__u32 mask,
+			  struct fsnotify_group *group,
+			  void *data, int data_is, const char *file_name,
+			  u32 cookie, struct fsnotify_event **event,
+			  struct inode *to_tell)
+{
+	if (!group->ops->should_send_event(group, to_tell, mask,
+					   data, data_is))
+		return;
+	if (!*event) {
+		*event = fsnotify_create_event(to_tell, mask, data,
+						data_is, file_name,
+						cookie, GFP_KERNEL);
+		/*
+		 * shit, we OOM'd and now we can't tell, maybe
+		 * someday someone else will want to do something
+		 * here
+		 */
+		if (!*event)
+			return;
+	}
+	group->ops->handle_event(group, *event);
+}
+
+static bool needed_by_vfsmount(__u32 test_mask, void *data, int data_is)
+{
+	struct path *path;
+
+	if (data_is == FSNOTIFY_EVENT_PATH)
+		path = (struct path *)data;
+	else if (data_is == FSNOTIFY_EVENT_FILE)
+		path = &((struct file *)data)->f_path;
+	else
+		return false;
+
+	/* hook in this when mnt->mnt_fsnotify_mask is defined */
+	/* return (test_mask & path->mnt->mnt_fsnotify_mask); */
+	return false;
+}
 /*
  * This is the main call to fsnotify.  The VFS calls into hook specific functions
  * in linux/fsnotify.h.  Those functions then in turn call here.  Here will call
@@ -148,38 +188,46 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const
 	/* global tests shouldn't care about events on child only the specific event */
 	__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
 
-	if (list_empty(&fsnotify_inode_groups))
-		return;
+	/* if no fsnotify listeners, nothing to do */
+	if (list_empty(&fsnotify_inode_groups) &&
+	    list_empty(&fsnotify_vfsmount_groups))
+                return;
+
+	/* if none of the directed listeners or vfsmount listeners care */
+	if (!(test_mask & fsnotify_inode_mask) &&
+	    !(test_mask & fsnotify_vfsmount_mask))
+                return;
+
+	/* if this inode's directed listeners don't care and nothing on the vfsmount
+	 * listeners list cares, nothing to do */
+	if (!(test_mask & to_tell->i_fsnotify_mask) &&
+	    !needed_by_vfsmount(test_mask, data, data_is))
+                return;
 
-	if (!(test_mask & fsnotify_inode_mask))
-		return;
-
-	if (!(test_mask & to_tell->i_fsnotify_mask))
-		return;
 	/*
 	 * SRCU!!  the groups list is very very much read only and the path is
 	 * very hot.  The VAST majority of events are not going to need to do
 	 * anything other than walk the list so it's crazy to pre-allocate.
 	 */
 	idx = srcu_read_lock(&fsnotify_grp_srcu);
-	list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list) {
-		if (test_mask & group->mask) {
-			if (!group->ops->should_send_event(group, to_tell, mask,
-							   data, data_is))
-				continue;
-			if (!event) {
-				event = fsnotify_create_event(to_tell, mask, data,
-							      data_is, file_name, cookie,
-							      GFP_KERNEL);
-				/* shit, we OOM'd and now we can't tell, maybe
-				 * someday someone else will want to do something
-				 * here */
-				if (!event)
-					break;
+
+	if (test_mask & to_tell->i_fsnotify_mask) {
+		list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list) {
+			if (test_mask & group->mask) {
+				send_to_group(mask, group, data, data_is,
+					      file_name, cookie, &event, to_tell);
 			}
-			group->ops->handle_event(group, event);
 		}
 	}
+	if (needed_by_vfsmount(test_mask, data, data_is)) {
+		list_for_each_entry_rcu(group, &fsnotify_vfsmount_groups, vfsmount_group_list) {
+			if (test_mask & group->mask) {
+				send_to_group(mask, group, data, data_is,
+					      file_name, cookie, &event, to_tell);
+			}
+		}
+	}
+
 	srcu_read_unlock(&fsnotify_grp_srcu, idx);
 	/*
 	 * fsnotify_create_event() took a reference so the event can't be cleaned

trunk/fs/notify/fsnotify.h

@@ -10,14 +10,20 @@
 extern struct srcu_struct fsnotify_grp_srcu;
 /* all groups which receive inode fsnotify events */
 extern struct list_head fsnotify_inode_groups;
+/* all groups which receive vfsmount fsnotify events */
+extern struct list_head fsnotify_vfsmount_groups;
 /* all bitwise OR of all event types (FS_*) for all fsnotify_inode_groups */
 extern __u32 fsnotify_inode_mask;
+/* all bitwise OR of all event types (FS_*) for all fsnotify_vfsmount_groups */
+extern __u32 fsnotify_vfsmount_mask;
 
 /* destroy all events sitting in this groups notification queue */
 extern void fsnotify_flush_notify(struct fsnotify_group *group);
 
 /* add a group to the inode group list */
 extern void fsnotify_add_inode_group(struct fsnotify_group *group);
+/* add a group to the vfsmount group list */
+extern void fsnotify_add_vfsmount_group(struct fsnotify_group *group);
 /* final kfree of a group */
 extern void fsnotify_final_destroy_group(struct fsnotify_group *group);
 

trunk/fs/notify/group.c

@@ -32,10 +32,14 @@
 static DEFINE_MUTEX(fsnotify_grp_mutex);
 /* protects reads while running the fsnotify_groups list */
 struct srcu_struct fsnotify_grp_srcu;
-/* all groups registered to receive filesystem notifications */
+/* all groups registered to receive inode filesystem notifications */
 LIST_HEAD(fsnotify_inode_groups);
+/* all groups registered to receive mount point filesystem notifications */
+LIST_HEAD(fsnotify_vfsmount_groups);
 /* bitwise OR of all events (FS_*) interesting to some group on this system */
 __u32 fsnotify_inode_mask;
+/* bitwise OR of all events (FS_*) interesting to some group on this system */
+__u32 fsnotify_vfsmount_mask;
 
 /*
  * When a new group registers or changes it's set of interesting events
@@ -44,14 +48,20 @@ __u32 fsnotify_inode_mask;
 void fsnotify_recalc_global_mask(void)
 {
 	struct fsnotify_group *group;
-	__u32 mask = 0;
+	__u32 inode_mask = 0;
+	__u32 vfsmount_mask = 0;
 	int idx;
 
 	idx = srcu_read_lock(&fsnotify_grp_srcu);
 	list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list)
-		mask |= group->mask;
+		inode_mask |= group->mask;
+	list_for_each_entry_rcu(group, &fsnotify_vfsmount_groups, vfsmount_group_list)
+		vfsmount_mask |= group->mask;
+
 	srcu_read_unlock(&fsnotify_grp_srcu, idx);
-	fsnotify_inode_mask = mask;
+
+	fsnotify_inode_mask = inode_mask;
+	fsnotify_vfsmount_mask = vfsmount_mask;
 }
 
 /*
@@ -77,6 +87,17 @@ void fsnotify_recalc_group_mask(struct fsnotify_group *group)
 		fsnotify_recalc_global_mask();
 }
 
+void fsnotify_add_vfsmount_group(struct fsnotify_group *group)
+{
+	mutex_lock(&fsnotify_grp_mutex);
+
+	if (!group->on_vfsmount_group_list)
+		list_add_tail_rcu(&group->vfsmount_group_list, &fsnotify_vfsmount_groups);
+	group->on_vfsmount_group_list = 1;
+
+	mutex_unlock(&fsnotify_grp_mutex);
+}
+
 void fsnotify_add_inode_group(struct fsnotify_group *group)
 {
 	mutex_lock(&fsnotify_grp_mutex);
@@ -132,6 +153,9 @@ static void __fsnotify_evict_group(struct fsnotify_group *group)
 	if (group->on_inode_group_list)
 		list_del_rcu(&group->inode_group_list);
 	group->on_inode_group_list = 0;
+	if (group->on_vfsmount_group_list)
+		list_del_rcu(&group->vfsmount_group_list);
+	group->on_vfsmount_group_list = 0;
 }
 
 /*
@@ -197,6 +221,7 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
 	group->max_events = UINT_MAX;
 
 	INIT_LIST_HEAD(&group->inode_group_list);
+	INIT_LIST_HEAD(&group->vfsmount_group_list);
 
 	spin_lock_init(&group->mark_lock);
 	INIT_LIST_HEAD(&group->mark_entries);

trunk/fs/notify/inode_mark.c

@@ -328,6 +328,13 @@ int fsnotify_add_mark(struct fsnotify_mark_entry *entry,
 	 */
 	if (unlikely(list_empty(&group->inode_group_list)))
 		fsnotify_add_inode_group(group);
+	/*
+	 * XXX This is where we could also do the fsnotify_add_vfsmount_group
+	 * if we are setting and vfsmount mark....
+
+	if (unlikely(list_empty(&group->vfsmount_group_list)))
+		fsnotify_add_vfsmount_group(group);
+	 */
 
 	/*
 	 * LOCKING ORDER!!!!

trunk/include/linux/fsnotify_backend.h

@@ -99,6 +99,10 @@ struct fsnotify_group {
 	 * or fsnotify_grp_srcu depending on write vs read.
 	 */
 	struct list_head inode_group_list;
+	/*
+	 * same as above except anchored by fsnotify_vfsmount_groups
+	 */
+	struct list_head vfsmount_group_list;
 
 	/*
 	 * Defines all of the event types in which this group is interested.
@@ -137,6 +141,7 @@ struct fsnotify_group {
 
 	/* prevents double list_del of group_list.  protected by global fsnotify_grp_mutex */
 	bool on_inode_group_list;
+	bool on_vfsmount_group_list;
 
 	/* groups can define private fields here or use the void *private */
 	union {