exfat: remove unnecessary read entry in __exfat_rename()

To determine whether it is a directory, there is no need to read its
directory entry, just use S_ISDIR(inode->i_mode).

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

Author: YuezhangMo

fs/exfat/namei.c

@@ -1131,17 +1131,12 @@ static int __exfat_rename(struct inode *old_parent_inode,
 	int ret;
 	int dentry;
 	struct exfat_chain olddir, newdir;
-	struct exfat_chain *p_dir = NULL;
 	struct exfat_uni_name uni_name;
-	struct exfat_dentry *ep;
 	struct super_block *sb = old_parent_inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	const unsigned char *new_path = new_dentry->d_name.name;
 	struct inode *new_inode = new_dentry->d_inode;
 	struct exfat_inode_info *new_ei = NULL;
-	unsigned int new_entry_type = TYPE_UNUSED;
-	int new_entry = 0;
-	struct buffer_head *new_bh = NULL;
 
 	/* check the validity of pointer parameters */
 	if (new_path == NULL || strlen(new_path) == 0)
@@ -1167,17 +1162,8 @@ static int __exfat_rename(struct inode *old_parent_inode,
 			goto out;
 		}
 
-		p_dir = &(new_ei->dir);
-		new_entry = new_ei->entry;
-		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh);
-		if (!ep)
-			goto out;
-
-		new_entry_type = exfat_get_entry_type(ep);
-		brelse(new_bh);
-
 		/* if new_inode exists, update ei */
-		if (new_entry_type == TYPE_DIR) {
+		if (S_ISDIR(new_inode->i_mode)) {
 			struct exfat_chain new_clu;
 
 			new_clu.dir = new_ei->start_clu;
@@ -1209,6 +1195,8 @@ static int __exfat_rename(struct inode *old_parent_inode,
 
 	if (!ret && new_inode) {
 		struct exfat_entry_set_cache es;
+		struct exfat_chain *p_dir = &(new_ei->dir);
+		int new_entry = new_ei->entry;
 
 		/* delete entries of new_dir */
 		ret = exfat_get_dentry_set(&es, sb, p_dir, new_entry,
@@ -1225,7 +1213,7 @@ static int __exfat_rename(struct inode *old_parent_inode,
 			goto del_out;
 
 		/* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
-		if (new_entry_type == TYPE_DIR &&
+		if (S_ISDIR(new_inode->i_mode) &&
 		    new_ei->start_clu != EXFAT_EOF_CLUSTER) {
 			/* new_ei, new_clu_to_free */
 			struct exfat_chain new_clu_to_free;