From 9f0346dcbea363787186c94ef94dd01aaa215afa Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 5 Sep 2026 11:59:05 -0700
Subject: Merge tag 'driver-core-7.3-rc2' of
 git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core fixes from Danilo Krummrich:

 - Fix kernfs listxattr() not returning security xattr names (e.g.
   SELinux labels) when the kernfs node has no allocated kernfs_iattrs

 - Fix silent truncation of IRQ vector indices in the Rust PCI
   abstractions

 - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is
   disabled instead of silently enabling extra kernel functionality

 - Russ Weight is retiring from kernel development; update the Firmware
   Loader sysfs contact to the driver-core mailing list, add a CREDITS
   entry for Firmware Upload, and update MAINTAINERS accordingly

* tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  MAINTAINERS: Remove Russ Weight from Firmware Loader
  CREDITS: Add CREDITS entry for Firmware Upload
  firmware_loader: Change contact for sysfs nodes
  rust: pci: reject IRQ vector indices that do not fit in u32
  kernfs: preserve security xattrs without allocating iattrs
  drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF
---
 fs/nullfs.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 fs/nullfs.c

(limited to 'fs/nullfs.c')

diff --git a/fs/nullfs.c b/fs/nullfs.c
new file mode 100644
index 000000000..e06352c7b
--- /dev/null
+++ b/fs/nullfs.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2026 Christian Brauner <brauner@kernel.org> */
+#include <linux/fs/super_types.h>
+#include <linux/fs_context.h>
+#include <linux/magic.h>
+
+#include "mount.h"
+
+static const struct super_operations nullfs_super_operations = {
+	.statfs	= simple_statfs,
+};
+
+static int nullfs_fs_fill_super(struct super_block *s, struct fs_context *fc)
+{
+	struct inode *inode;
+
+	s->s_maxbytes		= MAX_LFS_FILESIZE;
+	s->s_blocksize		= PAGE_SIZE;
+	s->s_blocksize_bits	= PAGE_SHIFT;
+	s->s_magic		= NULL_FS_MAGIC;
+	s->s_op			= &nullfs_super_operations;
+	s->s_export_op		= NULL;
+	s->s_xattr		= NULL;
+	s->s_time_gran		= 1;
+	s->s_d_flags		= 0;
+
+	inode = new_inode(s);
+	if (!inode)
+		return -ENOMEM;
+
+	/* nullfs is permanently empty... */
+	make_empty_dir_inode(inode);
+	simple_inode_init_ts(inode);
+	inode->i_ino	= 1;
+	/* ... and immutable. */
+	inode->i_flags |= S_IMMUTABLE;
+
+	s->s_root = d_make_root(inode);
+	if (!s->s_root)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int nullfs_fs_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, nullfs_fs_fill_super);
+}
+
+static const struct fs_context_operations nullfs_fs_context_ops = {
+	.get_tree	= nullfs_fs_get_tree,
+};
+
+static int nullfs_init_fs_context(struct fs_context *fc)
+{
+	fc->ops		= &nullfs_fs_context_ops;
+	fc->sb_flags	|= SB_NOUSER;
+	fc->s_iflags	|= SB_I_NOEXEC | SB_I_NODEV;
+	return 0;
+}
+
+struct file_system_type nullfs_fs_type = {
+	.name			= "nullfs",
+	.init_fs_context	= nullfs_init_fs_context,
+	.kill_sb		= kill_anon_super,
+};
-- 
cgit v1.3.1