[PATCH 4/4] fsnotify: make MOVED_FROM a dentry event

[Amir Goldstein <amir73il@gmail.com>]

Propagate old/new parent dentries to fsnotify_move()
and pass old parent dentry as FSNOTIFY_DENTRY info of
MOVED_FROM event.

This change has no effect on current backends. Soon, this will
allow fanotify backend to get MOVED_FROM events.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/debugfs/inode.c       |  2 +-
 fs/namei.c               |  7 +++++--
 include/linux/fsnotify.h | 18 ++++++++++--------
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index c83336f..a6fb6ae 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -754,7 +754,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 		goto exit;
 	}
 	d_move(old_dentry, dentry);
-	fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name,
+	fsnotify_move(old_dir, new_dir, old_name,
 		d_is_dir(old_dentry),
 		NULL, old_dentry);
 	fsnotify_oldname_free(old_name);
diff --git a/fs/namei.c b/fs/namei.c
index 706b685..f951680 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4300,6 +4300,8 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int error;
 	bool is_dir = d_is_dir(old_dentry);
 	const unsigned char *old_name;
+	struct dentry *old_parent = old_dentry->d_parent;
+	struct dentry *new_parent = new_dentry->d_parent;
 	struct inode *source = old_dentry->d_inode;
 	struct inode *target = new_dentry->d_inode;
 	bool new_is_dir = false;
@@ -4405,10 +4407,11 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		inode_unlock(target);
 	dput(new_dentry);
 	if (!error) {
-		fsnotify_move(old_dir, new_dir, old_name, is_dir,
+		fsnotify_move(old_parent, new_parent, old_name, is_dir,
 			      !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
 		if (flags & RENAME_EXCHANGE) {
-			fsnotify_move(new_dir, old_dir, old_dentry->d_name.name,
+			fsnotify_move(new_parent, old_parent,
+				      old_dentry->d_name.name,
 				      new_is_dir, NULL, new_dentry);
 		}
 	}
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 93efa8c..7a98370 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -94,17 +94,19 @@ static inline void fsnotify_link_count(struct inode *inode)
 /*
  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  */
-static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
+static inline void fsnotify_move(struct dentry *old_dir,
+				 struct dentry *new_dir,
 				 const unsigned char *old_name,
-				 int isdir, struct inode *target, struct dentry *moved)
+				 int isdir, struct inode *target,
+				 struct dentry *moved)
 {
-	struct inode *source = moved->d_inode;
+	struct inode *source = d_inode(moved);
 	u32 fs_cookie = fsnotify_get_cookie();
 	__u32 old_dir_mask = FS_MOVED_FROM;
 	__u32 new_dir_mask = FS_MOVED_TO;
 	const unsigned char *new_name = moved->d_name.name;
 
-	if (old_dir == new_dir)
+	if (d_inode(old_dir) == d_inode(new_dir))
 		old_dir_mask |= FS_DN_RENAME;
 
 	if (isdir) {
@@ -112,15 +114,15 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
 		new_dir_mask |= FS_ISDIR;
 	}
 
-	fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
-		 fs_cookie);
-	fsnotify_filename(moved->d_parent, new_dir_mask, new_name, fs_cookie);
+	fsnotify_filename(old_dir, old_dir_mask, old_name, fs_cookie);
+	fsnotify_filename(new_dir, new_dir_mask, new_name, fs_cookie);
 
 	if (target)
 		fsnotify_link_count(target);
 
 	if (source)
-		fsnotify(source, FS_MOVE_SELF, moved, FSNOTIFY_EVENT_DENTRY, NULL, 0);
+		fsnotify(source, FS_MOVE_SELF, moved, FSNOTIFY_EVENT_DENTRY,
+			 NULL, 0);
 	audit_dentry_child(moved, AUDIT_TYPE_CHILD_CREATE);
 }
 
-- 
2.7.4