ocfs2: Introduce dir lookup helper struct

Many directory manipulation calls pass around a tuple of dirent, and it's
containing buffer_head. Dir indexing has a bit more state, but instead of
adding yet more arguments to functions, we introduce 'struct
ocfs2_dir_lookup_result'. In this patch, it simply holds the same tuple, but
future patches will add more state.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/dir.h

@@ -26,44 +26,48 @@
 #ifndef OCFS2_DIR_H
 #define OCFS2_DIR_H
 
-struct buffer_head *ocfs2_find_entry(const char *name,
-				     int namelen,
-				     struct inode *dir,
-				     struct ocfs2_dir_entry **res_dir);
+struct ocfs2_dir_lookup_result {
+	struct buffer_head		*dl_leaf_bh;
+	struct ocfs2_dir_entry		*dl_entry;
+};
+void ocfs2_free_dir_lookup_result(struct ocfs2_dir_lookup_result *res);
+
+int ocfs2_find_entry(const char *name, int namelen,
+		     struct inode *dir,
+		     struct ocfs2_dir_lookup_result *lookup);
 int ocfs2_delete_entry(handle_t *handle,
 		       struct inode *dir,
-		       struct ocfs2_dir_entry *de_del,
-		       struct buffer_head *bh);
+		       struct ocfs2_dir_lookup_result *res);
 int __ocfs2_add_entry(handle_t *handle,
 		      struct inode *dir,
 		      const char *name, int namelen,
 		      struct inode *inode, u64 blkno,
 		      struct buffer_head *parent_fe_bh,
-		      struct buffer_head *insert_bh);
+		      struct ocfs2_dir_lookup_result *lookup);
 static inline int ocfs2_add_entry(handle_t *handle,
 				  struct dentry *dentry,
 				  struct inode *inode, u64 blkno,
 				  struct buffer_head *parent_fe_bh,
-				  struct buffer_head *insert_bh)
+				  struct ocfs2_dir_lookup_result *lookup)
 {
 	return __ocfs2_add_entry(handle, dentry->d_parent->d_inode,
 				 dentry->d_name.name, dentry->d_name.len,
-				 inode, blkno, parent_fe_bh, insert_bh);
+				 inode, blkno, parent_fe_bh, lookup);
 }
 int ocfs2_update_entry(struct inode *dir, handle_t *handle,
-		       struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
+		       struct ocfs2_dir_lookup_result *res,
 		       struct inode *new_entry_inode);
 
 int ocfs2_check_dir_for_entry(struct inode *dir,
 			      const char *name,
 			      int namelen);
 int ocfs2_empty_dir(struct inode *inode);
+
 int ocfs2_find_files_on_disk(const char *name,
 			     int namelen,
 			     u64 *blkno,
 			     struct inode *inode,
-			     struct buffer_head **dirent_bh,
-			     struct ocfs2_dir_entry **dirent);
+			     struct ocfs2_dir_lookup_result *res);
 int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
 			       int namelen, u64 *blkno);
 int ocfs2_readdir(struct file *filp, void *dirent, filldir_t filldir);
@@ -74,7 +78,7 @@ int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
 				 struct buffer_head *parent_fe_bh,
 				 const char *name,
 				 int namelen,
-				 struct buffer_head **ret_de_bh);
+				 struct ocfs2_dir_lookup_result *lookup);
 struct ocfs2_alloc_context;
 int ocfs2_fill_new_dir(struct ocfs2_super *osb,
 		       handle_t *handle,