1 files changed, 33 insertions, 6 deletions

diff --git a/fs/namei.c b/fs/namei.c
index b4589922c0de..30145f8f21ed 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2267,6 +2267,33 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 EXPORT_SYMBOL(vfs_path_lookup);
 
 /**
+ * lookup_hash - lookup single pathname component on already hashed name
+ * @name:	name and hash to lookup
+ * @base:	base directory to lookup from
+ *
+ * The name must have been verified and hashed (see lookup_one_len()).  Using
+ * this after just full_name_hash() is unsafe.
+ *
+ * This function also doesn't check for search permission on base directory.
+ *
+ * Use lookup_one_len_unlocked() instead, unless you really know what you are
+ * doing.
+ *
+ * Do not hold i_mutex; this helper takes i_mutex if necessary.
+ */
+struct dentry *lookup_hash(const struct qstr *name, struct dentry *base)
+{
+	struct dentry *ret;
+
+	ret = lookup_dcache(name, base, 0);
+	if (!ret)
+		ret = lookup_slow(name, base, 0);
+
+	return ret;
+}
+EXPORT_SYMBOL(lookup_hash);
+
+/**
  * lookup_one_len - filesystem helper to lookup single pathname component
  * @name:	pathname component to lookup
  * @base:	base directory to lookup from
@@ -2337,7 +2364,6 @@ struct dentry *lookup_one_len_unlocked(const char *name,
 	struct qstr this;
 	unsigned int c;
 	int err;
-	struct dentry *ret;
 
 	this.name = name;
 	this.len = len;
@@ -2369,10 +2395,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
 	if (err)
 		return ERR_PTR(err);
 
-	ret = lookup_dcache(&this, base, 0);
-	if (!ret)
-		ret = lookup_slow(&this, base, 0);
-	return ret;
+	return lookup_hash(&this, base);
 }
 EXPORT_SYMBOL(lookup_one_len_unlocked);
 
@@ -4201,7 +4224,11 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	bool new_is_dir = false;
 	unsigned max_links = new_dir->i_sb->s_max_links;
 
-	if (source == target)
+	/*
+	 * Check source == target.
+	 * On overlayfs need to look at underlying inodes.
+	 */
+	if (vfs_select_inode(old_dentry, 0) == vfs_select_inode(new_dentry, 0))
 		return 0;
 
 	error = may_delete(old_dir, old_dentry, is_dir);