9 files changed, 58 insertions, 14 deletions

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index 0b9ff4395e6a..abc8cbcfe90e 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -86,7 +86,7 @@ static int dnotify_handle_event(struct fsnotify_group *group,
                                 struct fsnotify_mark *inode_mark,
                                 struct fsnotify_mark *vfsmount_mark,
                                 u32 mask, void *data, int data_type,
-                                const unsigned char *file_name)
+                                const unsigned char *file_name, u32 cookie)
 {
         struct dnotify_mark *dn_mark;
         struct dnotify_struct *dn;
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 0e792f5e3147..dc638f786d5c 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -147,7 +147,7 @@ static int fanotify_handle_event(struct fsnotify_group *group,
                                  struct fsnotify_mark *inode_mark,
                                  struct fsnotify_mark *fanotify_mark,
                                  u32 mask, void *data, int data_type,
-                                 const unsigned char *file_name)
+                                 const unsigned char *file_name, u32 cookie)
 {
         int ret = 0;
         struct fanotify_event_info *event;
@@ -192,10 +192,12 @@ static int fanotify_handle_event(struct fsnotify_group *group,
 
         ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge);
         if (ret) {
-                BUG_ON(mask & FAN_ALL_PERM_EVENTS);
+                /* Permission events shouldn't be merged */
+                BUG_ON(ret == 1 && mask & FAN_ALL_PERM_EVENTS);
                 /* Our event wasn't used in the end. Free it. */
                 fsnotify_destroy_event(group, fsn_event);
-                ret = 0;
+
+                return 0;
         }
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index b6175fa11bf8..287a22c04149 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -698,6 +698,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         struct fsnotify_group *group;
         int f_flags, fd;
         struct user_struct *user;
+        struct fanotify_event_info *oevent;
 
         pr_debug("%s: flags=%d event_f_flags=%d\n",
                 __func__, flags, event_f_flags);
@@ -730,8 +731,20 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         group->fanotify_data.user = user;
         atomic_inc(&user->fanotify_listeners);
 
+        oevent = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL);
+        if (unlikely(!oevent)) {
+                fd = -ENOMEM;
+                goto out_destroy_group;
+        }
+        group->overflow_event = &oevent->fse;
+        fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW);
+        oevent->tgid = get_pid(task_tgid(current));
+        oevent->path.mnt = NULL;
+        oevent->path.dentry = NULL;
+
         group->fanotify_data.f_flags = event_f_flags;
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+        oevent->response = 0;
         mutex_init(&group->fanotify_data.access_mutex);
         init_waitqueue_head(&group->fanotify_data.access_waitq);
         INIT_LIST_HEAD(&group->fanotify_data.access_list);
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 1d4e1ea2f37c..9d3e9c50066a 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -179,7 +179,7 @@ static int send_to_group(struct inode *to_tell,
 
         return group->ops->handle_event(group, to_tell, inode_mark,
                                         vfsmount_mark, mask, data, data_is,
-                                        file_name);
+                                        file_name, cookie);
 }
 
 /*
diff --git a/fs/notify/group.c b/fs/notify/group.c
index ee674fe2cec7..ad1995980456 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -55,6 +55,13 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
         /* clear the notification queue of all events */
         fsnotify_flush_notify(group);
 
+        /*
+         * Destroy overflow event (we cannot use fsnotify_destroy_event() as
+         * that deliberately ignores overflow events.
+         */
+        if (group->overflow_event)
+                group->ops->free_event(group->overflow_event);
+
         fsnotify_put_group(group);
 }
 
@@ -99,7 +106,6 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
         INIT_LIST_HEAD(&group->marks_list);
 
         group->ops = ops;
-        fsnotify_init_event(&group->overflow_event, NULL, FS_Q_OVERFLOW);
 
         return group;
 }
diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index 485eef3f4407..ed855ef6f077 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -27,6 +27,6 @@ extern int inotify_handle_event(struct fsnotify_group *group,
                                 struct fsnotify_mark *inode_mark,
                                 struct fsnotify_mark *vfsmount_mark,
                                 u32 mask, void *data, int data_type,
-                                const unsigned char *file_name);
+                                const unsigned char *file_name, u32 cookie);
 
 extern const struct fsnotify_ops inotify_fsnotify_ops;
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index d5ee56348bb8..43ab1e1a07a2 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -67,7 +67,7 @@ int inotify_handle_event(struct fsnotify_group *group,
                          struct fsnotify_mark *inode_mark,
                          struct fsnotify_mark *vfsmount_mark,
                          u32 mask, void *data, int data_type,
-                         const unsigned char *file_name)
+                         const unsigned char *file_name, u32 cookie)
 {
         struct inotify_inode_mark *i_mark;
         struct inotify_event_info *event;
@@ -103,6 +103,7 @@ int inotify_handle_event(struct fsnotify_group *group,
         fsn_event = &event->fse;
         fsnotify_init_event(fsn_event, inode, mask);
         event->wd = i_mark->wd;
+        event->sync_cookie = cookie;
         event->name_len = len;
         if (len)
                 strcpy(event->name, file_name);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 497395c8274b..78a2ca3966c3 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -495,7 +495,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
 
         /* Queue ignore event for the watch */
         inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED,
-                             NULL, FSNOTIFY_EVENT_NONE, NULL);
+                             NULL, FSNOTIFY_EVENT_NONE, NULL, 0);
 
         i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
         /* remove this mark from the idr */
@@ -633,11 +633,23 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod
 static struct fsnotify_group *inotify_new_group(unsigned int max_events)
 {
         struct fsnotify_group *group;
+        struct inotify_event_info *oevent;
 
         group = fsnotify_alloc_group(&inotify_fsnotify_ops);
         if (IS_ERR(group))
                 return group;
 
+        oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL);
+        if (unlikely(!oevent)) {
+                fsnotify_destroy_group(group);
+                return ERR_PTR(-ENOMEM);
+        }
+        group->overflow_event = &oevent->fse;
+        fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW);
+        oevent->wd = -1;
+        oevent->sync_cookie = 0;
+        oevent->name_len = 0;
+
         group->max_events = max_events;
 
         spin_lock_init(&group->inotify_data.idr_lock);
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 18b3c4427dca..1e58402171a5 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -80,7 +80,8 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
 /*
  * Add an event to the group notification queue.  The group can later pull this
  * event off the queue to deal with.  The function returns 0 if the event was
- * added to the queue, 1 if the event was merged with some other queued event.
+ * added to the queue, 1 if the event was merged with some other queued event,
+ * 2 if the queue of events has overflown.
  */
 int fsnotify_add_notify_event(struct fsnotify_group *group,
                               struct fsnotify_event *event,
@@ -95,10 +96,14 @@ int fsnotify_add_notify_event(struct fsnotify_group *group,
         mutex_lock(&group->notification_mutex);
 
         if (group->q_len >= group->max_events) {
+                ret = 2;
                 /* Queue overflow event only if it isn't already queued */
-                if (list_empty(&group->overflow_event.list))
-                        event = &group->overflow_event;
-                ret = 1;
+                if (!list_empty(&group->overflow_event->list)) {
+                        mutex_unlock(&group->notification_mutex);
+                        return ret;
+                }
+                event = group->overflow_event;
+                goto queue;
         }
 
         if (!list_empty(list) && merge) {
@@ -109,6 +114,7 @@ int fsnotify_add_notify_event(struct fsnotify_group *group,
                 }
         }
 
+queue:
         group->q_len++;
         list_add_tail(&event->list, list);
         mutex_unlock(&group->notification_mutex);
@@ -132,7 +138,11 @@ struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group
 
         event = list_first_entry(&group->notification_list,
                                  struct fsnotify_event, list);
-        list_del(&event->list);
+        /*
+         * We need to init list head for the case of overflow event so that
+         * check in fsnotify_add_notify_events() works
+         */
+        list_del_init(&event->list);
         group->q_len--;
 
         return event;