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>

4 files changed, 41 insertions, 21 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) {
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index db12d9de3526..180740e9ec82 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -58,7 +58,7 @@ static inline void fsnotify_link_count(struct inode *inode)
 {
         inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
 
-        fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL);
 }
 
 /*
@@ -91,8 +91,8 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
         inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name,
                                   source);
 
-        fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE);
-        fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE);
+        fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name);
+        fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name);
 
         if (target) {
                 inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
@@ -104,7 +104,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
 
         if (source) {
                 inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
-                fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE);
+                fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL);
         }
         audit_inode_child(new_name, moved, new_dir);
 }
@@ -138,7 +138,7 @@ static inline void fsnotify_inoderemove(struct inode *inode)
         inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
         inotify_inode_is_dead(inode);
 
-        fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL);
         __fsnotify_inode_delete(inode);
 }
 
@@ -151,7 +151,7 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
                                   dentry->d_inode);
         audit_inode_child(dentry->d_name.name, dentry, inode);
 
-        fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name);
 }
 
 /*
@@ -166,7 +166,7 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct
         fsnotify_link_count(inode);
         audit_inode_child(new_dentry->d_name.name, new_dentry, dir);
 
-        fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name);
 }
 
 /*
@@ -180,7 +180,7 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
         inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode);
         audit_inode_child(dentry->d_name.name, dentry, inode);
 
-        fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name);
 }
 
 /*
@@ -197,7 +197,7 @@ static inline void fsnotify_access(struct dentry *dentry)
         inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
         fsnotify_parent(dentry, mask);
-        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL);
 }
 
 /*
@@ -214,7 +214,7 @@ static inline void fsnotify_modify(struct dentry *dentry)
         inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
         fsnotify_parent(dentry, mask);
-        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL);
 }
 
 /*
@@ -231,7 +231,7 @@ static inline void fsnotify_open(struct dentry *dentry)
         inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
         fsnotify_parent(dentry, mask);
-        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL);
 }
 
 /*
@@ -250,7 +250,7 @@ static inline void fsnotify_close(struct file *file)
         inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
         fsnotify_parent(dentry, mask);
-        fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE);
+        fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL);
 }
 
 /*
@@ -267,7 +267,7 @@ static inline void fsnotify_xattr(struct dentry *dentry)
         inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
         fsnotify_parent(dentry, mask);
-        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
+        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL);
 }
 
 /*
@@ -303,7 +303,7 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
                 inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 
                 fsnotify_parent(dentry, mask);
-                fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
+                fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL);
         }
 }
 
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 15f8f82a5c57..52692f405890 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -192,6 +192,9 @@ struct fsnotify_event {
         int data_type;          /* which of the above union we have */
         atomic_t refcnt;        /* how many groups still are using/need to send this event */
         __u32 mask;             /* the type of access, bitwise OR for FS_* event types */
+
+        char *file_name;
+        size_t name_len;
 };
 
 /*
@@ -224,7 +227,7 @@ struct fsnotify_mark_entry {
 /* called from the vfs helpers */
 
 /* main fsnotify call to send events */
-extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is);
+extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *name);
 extern void __fsnotify_parent(struct dentry *dentry, __u32 mask);
 extern void __fsnotify_inode_delete(struct inode *inode);
 
@@ -319,10 +322,12 @@ extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry);
 
 /* put here because inotify does some weird stuff when destroying watches */
 extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
-                                                    void *data, int data_is);
+                                                    void *data, int data_is, const char *name);
+
 #else
 
-static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
+static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+                            const char *name);
 {}
 
 static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask)