ext4: create a new function search_dir

search_dirblock is used to search a dir block, but the code is almost
the same for searching an inline dir.

So create a new fuction search_dir and let search_dirblock call it.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ext4.h

@@ -2122,6 +2122,13 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 				__u32 start_minor_hash, __u32 *next_hash);
+extern int search_dir(struct buffer_head *bh,
+		      char *search_buf,
+		      int buf_size,
+		      struct inode *dir,
+		      const struct qstr *d_name,
+		      unsigned int offset,
+		      struct ext4_dir_entry_2 **res_dir);
 
 /* resize.c */
 extern int ext4_group_add(struct super_block *sb,

fs/ext4/namei.c

@@ -1005,6 +1005,16 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 	return (err);
 }
 
+static inline int search_dirblock(struct buffer_head *bh,
+				  struct inode *dir,
+				  const struct qstr *d_name,
+				  unsigned int offset,
+				  struct ext4_dir_entry_2 **res_dir)
+{
+	return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
+			  d_name, offset, res_dir);
+}
+
 
 /*
  * Directory block splitting, compacting
@@ -1098,11 +1108,13 @@ static inline int ext4_match (int len, const char * const name,
 /*
  * Returns 0 if not found, -1 on failure, and 1 on success
  */
-static inline int search_dirblock(struct buffer_head *bh,
-				  struct inode *dir,
-				  const struct qstr *d_name,
-				  unsigned int offset,
-				  struct ext4_dir_entry_2 ** res_dir)
+int search_dir(struct buffer_head *bh,
+	       char *search_buf,
+	       int buf_size,
+	       struct inode *dir,
+	       const struct qstr *d_name,
+	       unsigned int offset,
+	       struct ext4_dir_entry_2 **res_dir)
 {
 	struct ext4_dir_entry_2 * de;
 	char * dlimit;
@@ -1110,8 +1122,8 @@ static inline int search_dirblock(struct buffer_head *bh,
 	const char *name = d_name->name;
 	int namelen = d_name->len;
 
-	de = (struct ext4_dir_entry_2 *) bh->b_data;
-	dlimit = bh->b_data + dir->i_sb->s_blocksize;
+	de = (struct ext4_dir_entry_2 *)search_buf;
+	dlimit = search_buf + buf_size;
 	while ((char *) de < dlimit) {
 		/* this code is executed quadratically often */
 		/* do minimal checking `by hand' */