vfs: add vfs_select_inode() helper

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.2+
diff --git a/fs/open.c b/fs/open.c
index 17cb6b1..081d3d6 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -840,16 +840,12 @@
 int vfs_open(const struct path *path, struct file *file,
 	     const struct cred *cred)
 {
-	struct dentry *dentry = path->dentry;
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode = vfs_select_inode(path->dentry, file->f_flags);
+
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
 
 	file->f_path = *path;
-	if (dentry->d_flags & DCACHE_OP_SELECT_INODE) {
-		inode = dentry->d_op->d_select_inode(dentry, file->f_flags);
-		if (IS_ERR(inode))
-			return PTR_ERR(inode);
-	}
-
 	return do_dentry_open(file, inode, NULL, cred);
 }