exfat_d_revalidate(): use stable parent inode passed by caller

... no need to bother with ->d_lock and ->d_parent->d_inode.

Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>

Author: Al Viro

fs/exfat/namei.c

@@ -34,8 +34,6 @@ static inline void exfat_d_version_set(struct dentry *dentry,
 static int exfat_d_revalidate(struct inode *dir, const struct qstr *name,
 			      struct dentry *dentry, unsigned int flags)
 {
-	int ret;
-
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
 
@@ -59,11 +57,7 @@ static int exfat_d_revalidate(struct inode *dir, const struct qstr *name,
 	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 		return 0;
 
-	spin_lock(&dentry->d_lock);
-	ret = inode_eq_iversion(d_inode(dentry->d_parent),
-			exfat_d_version(dentry));
-	spin_unlock(&dentry->d_lock);
-	return ret;
+	return inode_eq_iversion(dir, exfat_d_version(dentry));
 }
 
 /* returns the length of a struct qstr, ignoring trailing dots if necessary */