diff --git a/fs/Makefile b/fs/Makefile
index 293733f61594..5563cf34f7c2 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -12,7 +12,8 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
 		pnode.o splice.o sync.o utimes.o d_path.o \
-		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
+		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
+		fs_context.o
 
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
diff --git a/fs/fs_context.c b/fs/fs_context.c
new file mode 100644
index 000000000000..4294091b689d
--- /dev/null
+++ b/fs/fs_context.c
@@ -0,0 +1,182 @@
+/* Provide a way to create a superblock configuration context within the kernel
+ * that allows a superblock to be set up prior to mounting.
+ *
+ * Copyright (C) 2017 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/fs_context.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/nsproxy.h>
+#include <linux/slab.h>
+#include <linux/magic.h>
+#include <linux/security.h>
+#include <linux/mnt_namespace.h>
+#include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
+#include <net/net_namespace.h>
+#include "mount.h"
+#include "internal.h"
+
+struct legacy_fs_context {
+	char			*legacy_data;	/* Data page for legacy filesystems */
+	size_t			data_size;
+};
+
+static int legacy_init_fs_context(struct fs_context *fc);
+
+/**
+ * alloc_fs_context - Create a filesystem context.
+ * @fs_type: The filesystem type.
+ * @reference: The dentry from which this one derives (or NULL)
+ * @sb_flags: Filesystem/superblock flags (SB_*)
+ * @sb_flags_mask: Applicable members of @sb_flags
+ * @purpose: The purpose that this configuration shall be used for.
+ *
+ * Open a filesystem and create a mount context.  The mount context is
+ * initialised with the supplied flags and, if a submount/automount from
+ * another superblock (referred to by @reference) is supplied, may have
+ * parameters such as namespaces copied across from that superblock.
+ */
+static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
+				      struct dentry *reference,
+				      unsigned int sb_flags,
+				      unsigned int sb_flags_mask,
+				      enum fs_context_purpose purpose)
+{
+	struct fs_context *fc;
+	int ret = -ENOMEM;
+
+	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
+	if (!fc)
+		return ERR_PTR(-ENOMEM);
+
+	fc->purpose	= purpose;
+	fc->sb_flags	= sb_flags;
+	fc->sb_flags_mask = sb_flags_mask;
+	fc->fs_type	= get_filesystem(fs_type);
+	fc->cred	= get_current_cred();
+	fc->net_ns	= get_net(current->nsproxy->net_ns);
+
+	switch (purpose) {
+	case FS_CONTEXT_FOR_MOUNT:
+		fc->user_ns = get_user_ns(fc->cred->user_ns);
+		break;
+	}
+
+	ret = legacy_init_fs_context(fc);
+	if (ret < 0)
+		goto err_fc;
+	fc->need_free = true;
+	return fc;
+
+err_fc:
+	put_fs_context(fc);
+	return ERR_PTR(ret);
+}
+
+struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
+					unsigned int sb_flags)
+{
+	return alloc_fs_context(fs_type, NULL, sb_flags, 0,
+					FS_CONTEXT_FOR_MOUNT);
+}
+EXPORT_SYMBOL(fs_context_for_mount);
+
+static void legacy_fs_context_free(struct fs_context *fc);
+/**
+ * put_fs_context - Dispose of a superblock configuration context.
+ * @fc: The context to dispose of.
+ */
+void put_fs_context(struct fs_context *fc)
+{
+	struct super_block *sb;
+
+	if (fc->root) {
+		sb = fc->root->d_sb;
+		dput(fc->root);
+		fc->root = NULL;
+		deactivate_super(sb);
+	}
+
+	if (fc->need_free)
+		legacy_fs_context_free(fc);
+
+	security_free_mnt_opts(&fc->security);
+	if (fc->net_ns)
+		put_net(fc->net_ns);
+	put_user_ns(fc->user_ns);
+	put_cred(fc->cred);
+	kfree(fc->subtype);
+	put_filesystem(fc->fs_type);
+	kfree(fc->source);
+	kfree(fc);
+}
+EXPORT_SYMBOL(put_fs_context);
+
+/*
+ * Free the config for a filesystem that doesn't support fs_context.
+ */
+static void legacy_fs_context_free(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+/*
+ * Add monolithic mount data.
+ */
+static int legacy_parse_monolithic(struct fs_context *fc, void *data)
+{
+	struct legacy_fs_context *ctx = fc->fs_private;
+	ctx->legacy_data = data;
+	if (!ctx->legacy_data)
+		return 0;
+	if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA)
+		return 0;
+	return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security);
+}
+
+/*
+ * Get a mountable root with the legacy mount command.
+ */
+int legacy_get_tree(struct fs_context *fc)
+{
+	struct legacy_fs_context *ctx = fc->fs_private;
+	struct super_block *sb;
+	struct dentry *root;
+
+	root = fc->fs_type->mount(fc->fs_type, fc->sb_flags,
+				      fc->source, ctx->legacy_data);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	sb = root->d_sb;
+	BUG_ON(!sb);
+
+	fc->root = root;
+	return 0;
+}
+
+/*
+ * Initialise a legacy context for a filesystem that doesn't support
+ * fs_context.
+ */
+static int legacy_init_fs_context(struct fs_context *fc)
+{
+	fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL);
+	if (!fc->fs_private)
+		return -ENOMEM;
+	return 0;
+}
+
+int parse_monolithic_mount_data(struct fs_context *fc, void *data)
+{
+	return legacy_parse_monolithic(fc, data);
+}
diff --git a/fs/internal.h b/fs/internal.h
index d410186bc369..f85c3212d25d 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -17,6 +17,7 @@ struct linux_binprm;
 struct path;
 struct mount;
 struct shrink_control;
+struct fs_context;
 
 /*
  * block_dev.c
@@ -51,6 +52,12 @@ int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
  */
 extern void __init chrdev_init(void);
 
+/*
+ * fs_context.c
+ */
+extern int legacy_get_tree(struct fs_context *fc);
+extern int parse_monolithic_mount_data(struct fs_context *, void *);
+
 /*
  * namei.c
  */
@@ -101,8 +108,6 @@ extern struct file *alloc_empty_file_noaccount(int, const struct cred *);
  */
 extern int do_remount_sb(struct super_block *, int, void *, int);
 extern bool trylock_super(struct super_block *sb);
-extern struct dentry *mount_fs(struct file_system_type *,
-			       int, const char *, void *);
 extern struct super_block *user_get_super(dev_t);
 
 /*
diff --git a/fs/namespace.c b/fs/namespace.c
index f0b8a8ca08df..3f2fd7a34733 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -27,6 +27,7 @@
 #include <linux/task_work.h>
 #include <linux/sched/task.h>
 #include <uapi/linux/mount.h>
+#include <linux/fs_context.h>
 
 #include "pnode.h"
 #include "internal.h"
@@ -940,36 +941,53 @@ static struct mount *skip_mnt_tree(struct mount *p)
 	return p;
 }
 
-struct vfsmount *
-vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
+struct vfsmount *vfs_kern_mount(struct file_system_type *type,
+				int flags, const char *name,
+				void *data)
 {
+	struct fs_context *fc;
 	struct mount *mnt;
-	struct dentry *root;
+	int ret = 0;
 
 	if (!type)
 		return ERR_PTR(-ENODEV);
 
+	fc = fs_context_for_mount(type, flags);
+	if (IS_ERR(fc))
+		return ERR_CAST(fc);
+
+	if (name) {
+		fc->source = kstrdup(name, GFP_KERNEL);
+		if (!fc->source)
+			ret = -ENOMEM;
+	}
+	if (!ret)
+		ret = parse_monolithic_mount_data(fc, data);
+	if (!ret)
+		ret = vfs_get_tree(fc);
+	if (ret) {
+		put_fs_context(fc);
+		return ERR_PTR(ret);
+	}
+	up_write(&fc->root->d_sb->s_umount);
 	mnt = alloc_vfsmnt(name);
-	if (!mnt)
+	if (!mnt) {
+		put_fs_context(fc);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	if (flags & SB_KERNMOUNT)
 		mnt->mnt.mnt_flags = MNT_INTERNAL;
 
-	root = mount_fs(type, flags, name, data);
-	if (IS_ERR(root)) {
-		mnt_free_id(mnt);
-		free_vfsmnt(mnt);
-		return ERR_CAST(root);
-	}
-
-	mnt->mnt.mnt_root = root;
-	mnt->mnt.mnt_sb = root->d_sb;
+	atomic_inc(&fc->root->d_sb->s_active);
+	mnt->mnt.mnt_root = dget(fc->root);
+	mnt->mnt.mnt_sb = fc->root->d_sb;
 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
 	mnt->mnt_parent = mnt;
 	lock_mount_hash();
-	list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
+	list_add_tail(&mnt->mnt_instance, &fc->root->d_sb->s_mounts);
 	unlock_mount_hash();
+	put_fs_context(fc);
 	return &mnt->mnt;
 }
 EXPORT_SYMBOL_GPL(vfs_kern_mount);
diff --git a/fs/super.c b/fs/super.c
index 48e25eba8465..fc3887277ad1 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -35,6 +35,7 @@
 #include <linux/fsnotify.h>
 #include <linux/lockdep.h>
 #include <linux/user_namespace.h>
+#include <linux/fs_context.h>
 #include <uapi/linux/mount.h>
 #include "internal.h"
 
@@ -1241,27 +1242,24 @@ struct dentry *mount_single(struct file_system_type *fs_type,
 }
 EXPORT_SYMBOL(mount_single);
 
-struct dentry *
-mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
+/**
+ * vfs_get_tree - Get the mountable root
+ * @fc: The superblock configuration context.
+ *
+ * The filesystem is invoked to get or create a superblock which can then later
+ * be used for mounting.  The filesystem places a pointer to the root to be
+ * used for mounting in @fc->root.
+ */
+int vfs_get_tree(struct fs_context *fc)
 {
-	struct dentry *root;
 	struct super_block *sb;
-	int error = -ENOMEM;
-	void *sec_opts = NULL;
+	int error;
 
-	if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
-		error = security_sb_eat_lsm_opts(data, &sec_opts);
-		if (error)
-			return ERR_PTR(error);
-	}
+	error = legacy_get_tree(fc);
+	if (error < 0)
+		return error;
 
-	root = type->mount(type, flags, name, data);
-	if (IS_ERR(root)) {
-		error = PTR_ERR(root);
-		goto out_free_secdata;
-	}
-	sb = root->d_sb;
-	BUG_ON(!sb);
+	sb = fc->root->d_sb;
 	WARN_ON(!sb->s_bdi);
 
 	/*
@@ -1273,11 +1271,11 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	smp_wmb();
 	sb->s_flags |= SB_BORN;
 
-	error = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
+	error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
 	if (error)
 		goto out_sb;
 
-	if (!(flags & (MS_KERNMOUNT|MS_SUBMOUNT))) {
+	if (!(fc->sb_flags & (MS_KERNMOUNT|MS_SUBMOUNT))) {
 		error = security_sb_kern_mount(sb);
 		if (error)
 			goto out_sb;
@@ -1290,18 +1288,16 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	 * violate this rule.
 	 */
 	WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to "
-		"negative value (%lld)\n", type->name, sb->s_maxbytes);
+		"negative value (%lld)\n", fc->fs_type->name, sb->s_maxbytes);
 
-	up_write(&sb->s_umount);
-	security_free_mnt_opts(&sec_opts);
-	return root;
+	return 0;
 out_sb:
-	dput(root);
+	dput(fc->root);
+	fc->root = NULL;
 	deactivate_locked_super(sb);
-out_free_secdata:
-	security_free_mnt_opts(&sec_opts);
-	return ERR_PTR(error);
+	return error;
 }
+EXPORT_SYMBOL(vfs_get_tree);
 
 /*
  * Setup private BDI for given superblock. It gets automatically cleaned up
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
new file mode 100644
index 000000000000..9805514444c9
--- /dev/null
+++ b/include/linux/fs_context.h
@@ -0,0 +1,64 @@
+/* Filesystem superblock creation and reconfiguration context.
+ *
+ * Copyright (C) 2018 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_FS_CONTEXT_H
+#define _LINUX_FS_CONTEXT_H
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/security.h>
+
+struct cred;
+struct dentry;
+struct file_operations;
+struct file_system_type;
+struct net;
+struct user_namespace;
+
+enum fs_context_purpose {
+	FS_CONTEXT_FOR_MOUNT,		/* New superblock for explicit mount */
+};
+
+/*
+ * Filesystem context for holding the parameters used in the creation or
+ * reconfiguration of a superblock.
+ *
+ * Superblock creation fills in ->root whereas reconfiguration begins with this
+ * already set.
+ *
+ * See Documentation/filesystems/mounting.txt
+ */
+struct fs_context {
+	struct file_system_type	*fs_type;
+	void			*fs_private;	/* The filesystem's context */
+	struct dentry		*root;		/* The root and superblock */
+	struct user_namespace	*user_ns;	/* The user namespace for this mount */
+	struct net		*net_ns;	/* The network namespace for this mount */
+	const struct cred	*cred;		/* The mounter's credentials */
+	const char		*source;	/* The source name (eg. dev path) */
+	const char		*subtype;	/* The subtype to set on the superblock */
+	void			*security;	/* Linux S&M options */
+	unsigned int		sb_flags;	/* Proposed superblock flags (SB_*) */
+	unsigned int		sb_flags_mask;	/* Superblock flags that were changed */
+	enum fs_context_purpose	purpose:8;
+	bool			need_free:1;	/* Need to call ops->free() */
+};
+
+/*
+ * fs_context manipulation functions.
+ */
+extern struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
+						unsigned int sb_flags);
+
+extern int vfs_get_tree(struct fs_context *fc);
+extern void put_fs_context(struct fs_context *fc);
+
+#endif /* _LINUX_FS_CONTEXT_H */