fsnotify: include pathnames with entries when possible

When inotify wants to send events to a directory about a child it includes
the name of the original file.  This patch collects that filename and makes
it available for notification.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>

2 files changed, 19 insertions, 4 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 7fc7600..675129f 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -114,7 +114,8 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
 		 * specifies these are events which came from a child. */
 		mask |= FS_EVENT_ON_CHILD;
 
-		fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE);
+		fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
+			 dentry->d_name.name);
 		dput(parent);
 	}
 
@@ -131,7 +132,7 @@ EXPORT_SYMBOL_GPL(__fsnotify_parent);
  * out to all of the registered fsnotify_group.  Those groups can then use the
  * notification event in whatever means they feel necessary.
  */
-void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
+void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name)
 {
 	struct fsnotify_group *group;
 	struct fsnotify_event *event = NULL;
@@ -156,7 +157,7 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
 			if (!group->ops->should_send_event(group, to_tell, mask))
 				continue;
 			if (!event) {
-				event = fsnotify_create_event(to_tell, mask, data, data_is);
+				event = fsnotify_create_event(to_tell, mask, data, data_is, file_name);
 				/* shit, we OOM'd and now we can't tell, maybe
 				 * someday someone else will want to do something
 				 * here */
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index dddecc7..c69b18b 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -78,6 +78,7 @@ void fsnotify_put_event(struct fsnotify_event *event)
 		if (event->data_type == FSNOTIFY_EVENT_PATH)
 			path_put(&event->path);
 
+		kfree(event->file_name);
 		kmem_cache_free(fsnotify_event_cachep, event);
 	}
 }
@@ -262,6 +263,9 @@ static void initialize_event(struct fsnotify_event *event)
 	event->data_type = FSNOTIFY_EVENT_NONE;
 
 	event->to_tell = NULL;
+
+	event->file_name = NULL;
+	event->name_len = 0;
 }
 
 /*
@@ -274,9 +278,10 @@ static void initialize_event(struct fsnotify_event *event)
  * @mask what actually happened.
  * @data pointer to the object which was actually affected
  * @data_type flag indication if the data is a file, path, inode, nothing...
+ * @name the filename, if available
  */
 struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
-					     void *data, int data_type)
+					     void *data, int data_type, const char *name)
 {
 	struct fsnotify_event *event;
 
@@ -285,6 +290,15 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
 		return NULL;
 
 	initialize_event(event);
+
+	if (name) {
+		event->file_name = kstrdup(name, GFP_KERNEL);
+		if (!event->file_name) {
+			kmem_cache_free(fsnotify_event_cachep, event);
+			return NULL;
+		}
+		event->name_len = strlen(event->file_name);
+	}
 	event->to_tell = to_tell;
 
 	switch (data_type) {