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 7fc760067a62..675129fa9fdd 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 dddecc74e63d..c69b18b9aba5 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) {