ext4: use search_dirblock() in ext4_dx_find_entry()

Use the search_dirblock() in ext4_dx_find_entry().  It makes the code
easier to read, and it takes advantage of common code.  It also saves
100 bytes or so of text space.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Brad Spengler <spender@grsecurity.net>

fs/ext4/namei.c

@@ -974,39 +974,30 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
 	struct super_block * sb = dir->i_sb;
 	struct dx_hash_info	hinfo;
 	struct dx_frame frames[2], *frame;
-	struct ext4_dir_entry_2 *de, *top;
 	struct buffer_head *bh;
 	ext4_lblk_t block;
 	int retval;
-	int namelen = d_name->len;
-	const u8 *name = d_name->name;
 
 	if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
 		return NULL;
 	do {
 		block = dx_get_block(frame->at);
-		if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
+		if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
 			goto errout;
-		de = (struct ext4_dir_entry_2 *) bh->b_data;
-		top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
-				       EXT4_DIR_REC_LEN(0));
-		for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
-			int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
-				  + ((char *) de - bh->b_data);
 
-			if (!ext4_check_dir_entry(dir, de, bh, off)) {
+		retval = search_dirblock(bh, dir, d_name,
+					 block << EXT4_BLOCK_SIZE_BITS(sb),
+					 res_dir);
+		if (retval == 1) { 	/* Success! */
+			dx_release(frames);
+			return bh;
+		}
 		brelse(bh);
+		if (retval == -1) {
 			*err = ERR_BAD_DX_DIR;
 			goto errout;
 		}
 
-			if (ext4_match(namelen, name, de)) {
-				*res_dir = de;
-				dx_release(frames);
-				return bh;
-			}
-		}
-		brelse(bh);
 		/* Check to see if we should continue to search */
 		retval = ext4_htree_next_block(dir, hinfo.hash, frame,
 					       frames, NULL);