From 954c736f865d6c0c68ae4263a2f3502ee7c447a3 Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il@gmail.com>
Date: Mon, 18 Sep 2017 22:53:43 +0300
Subject: [PATCH] ovl: fix may_write_real() for overlayfs directories
Overlayfs directory file_inode() is the overlay inode whether the real
inode is upper or lower.
This fixes a regression in xfstest generic/158.
Fixes: 7c6893e3c9ab ("ovl: don't allow writing ioctl on lower layer")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/namespace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index 54059b142d6b..3b601f115b6c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -468,7 +468,9 @@ static inline int may_write_real(struct file *file)
/* File refers to upper, writable layer? */
upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER);
- if (upperdentry && file_inode(file) == d_inode(upperdentry))
+ if (upperdentry &&
+ (file_inode(file) == d_inode(upperdentry) ||
+ file_inode(file) == d_inode(dentry)))
return 0;
/* Lower layer: can't write to real file, sorry... */