Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/ramfs/Makefile b/fs/ramfs/Makefile
index c71e65d..d1198ad 100644
--- a/fs/ramfs/Makefile
+++ b/fs/ramfs/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for the linux ramfs routines.
 #
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 3ac1f23..4146954 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* file-nommu.c: no-MMU version of ramfs
  *
  * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #include <linux/module.h>
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 11201b2..d82636e 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -36,6 +36,8 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include "internal.h"
 
 struct ramfs_mount_opts {
@@ -175,62 +177,52 @@
 	.show_options	= ramfs_show_options,
 };
 
-enum {
+enum ramfs_param {
 	Opt_mode,
-	Opt_err
 };
 
-static const match_table_t tokens = {
-	{Opt_mode, "mode=%o"},
-	{Opt_err, NULL}
+static const struct fs_parameter_spec ramfs_param_specs[] = {
+	fsparam_u32oct("mode",	Opt_mode),
+	{}
 };
 
-static int ramfs_parse_options(char *data, struct ramfs_mount_opts *opts)
+const struct fs_parameter_description ramfs_fs_parameters = {
+	.name		= "ramfs",
+	.specs		= ramfs_param_specs,
+};
+
+static int ramfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
-	substring_t args[MAX_OPT_ARGS];
-	int option;
-	int token;
-	char *p;
+	struct fs_parse_result result;
+	struct ramfs_fs_info *fsi = fc->s_fs_info;
+	int opt;
 
-	opts->mode = RAMFS_DEFAULT_MODE;
-
-	while ((p = strsep(&data, ",")) != NULL) {
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_mode:
-			if (match_octal(&args[0], &option))
-				return -EINVAL;
-			opts->mode = option & S_IALLUGO;
-			break;
+	opt = fs_parse(fc, &ramfs_fs_parameters, param, &result);
+	if (opt < 0) {
 		/*
 		 * We might like to report bad mount options here;
 		 * but traditionally ramfs has ignored all mount options,
 		 * and as it is used as a !CONFIG_SHMEM simple substitute
 		 * for tmpfs, better continue to ignore other mount options.
 		 */
-		}
+		if (opt == -ENOPARAM)
+			opt = 0;
+		return opt;
+	}
+
+	switch (opt) {
+	case Opt_mode:
+		fsi->mount_opts.mode = result.uint_32 & S_IALLUGO;
+		break;
 	}
 
 	return 0;
 }
 
-int ramfs_fill_super(struct super_block *sb, void *data, int silent)
+static int ramfs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
-	struct ramfs_fs_info *fsi;
+	struct ramfs_fs_info *fsi = sb->s_fs_info;
 	struct inode *inode;
-	int err;
-
-	fsi = kzalloc(sizeof(struct ramfs_fs_info), GFP_KERNEL);
-	sb->s_fs_info = fsi;
-	if (!fsi)
-		return -ENOMEM;
-
-	err = ramfs_parse_options(data, &fsi->mount_opts);
-	if (err)
-		return err;
 
 	sb->s_maxbytes		= MAX_LFS_FILESIZE;
 	sb->s_blocksize		= PAGE_SIZE;
@@ -247,10 +239,34 @@
 	return 0;
 }
 
-struct dentry *ramfs_mount(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int ramfs_get_tree(struct fs_context *fc)
 {
-	return mount_nodev(fs_type, flags, data, ramfs_fill_super);
+	return get_tree_nodev(fc, ramfs_fill_super);
+}
+
+static void ramfs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations ramfs_context_ops = {
+	.free		= ramfs_free_fc,
+	.parse_param	= ramfs_parse_param,
+	.get_tree	= ramfs_get_tree,
+};
+
+int ramfs_init_fs_context(struct fs_context *fc)
+{
+	struct ramfs_fs_info *fsi;
+
+	fsi = kzalloc(sizeof(*fsi), GFP_KERNEL);
+	if (!fsi)
+		return -ENOMEM;
+
+	fsi->mount_opts.mode = RAMFS_DEFAULT_MODE;
+	fc->s_fs_info = fsi;
+	fc->ops = &ramfs_context_ops;
+	return 0;
 }
 
 static void ramfs_kill_sb(struct super_block *sb)
@@ -261,17 +277,14 @@
 
 static struct file_system_type ramfs_fs_type = {
 	.name		= "ramfs",
-	.mount		= ramfs_mount,
+	.init_fs_context = ramfs_init_fs_context,
+	.parameters	= &ramfs_fs_parameters,
 	.kill_sb	= ramfs_kill_sb,
 	.fs_flags	= FS_USERNS_MOUNT,
 };
 
-int __init init_ramfs_fs(void)
+static int __init init_ramfs_fs(void)
 {
-	static unsigned long once;
-
-	if (test_and_set_bit(0, &once))
-		return 0;
 	return register_filesystem(&ramfs_fs_type);
 }
 fs_initcall(init_ramfs_fs);
diff --git a/fs/ramfs/internal.h b/fs/ramfs/internal.h
index a9d8ae8..3257fc1 100644
--- a/fs/ramfs/internal.h
+++ b/fs/ramfs/internal.h
@@ -1,12 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /* internal.h: ramfs internal definitions
  *
  * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */