4 files changed, 112 insertions, 26 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 23b5cfbeed50..a61aaa710825 100644
--- a/fs/notify/fsnotify.c
+++ b/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
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 5bd22412017f..2ba59158969f 100644
--- a/fs/notify/fsnotify.h
+++ b/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);
 
diff --git a/fs/notify/group.c b/fs/notify/group.c
index 34fccbd2809c..aa4654fe6ec2 100644
--- a/fs/notify/group.c
+++ b/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);
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index a3230c485531..beffebb64627 100644
--- a/fs/notify/inode_mark.c
+++ b/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!!!!