[RFC PATCH 20/35] vfs: don't open real

From: Miklos Szeredi
Date: Thu Apr 12 2018 - 11:19:09 EST


Let overlayfs do its thing when opening a file.

This enables stacking and fixes the corner case when a file is opened for
read, modified through a writable open, and data is read from the read-only
file. After this patch the read-only open will not return stale data even
in this case.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/open.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index d509705d5740..1d1a52908b0f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -857,13 +857,8 @@ EXPORT_SYMBOL(file_path);
int vfs_open(const struct path *path, struct file *file,
const struct cred *cred)
{
- struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags, 0);
-
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
-
file->f_path = *path;
- return do_dentry_open(file, d_backing_inode(dentry), NULL, cred);
+ return do_dentry_open(file, d_backing_inode(path->dentry), NULL, cred);
}

struct file *path_open(const struct path *path, int flags, struct inode *inode,
--
2.14.3