diff --git a/MAINTAINERS b/MAINTAINERS
index bd186c616b8b..1262a06d2358 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16823,6 +16823,12 @@ F:	include/linux/vbox_utils.h
 F:	include/uapi/linux/vbox*.h
 F:	drivers/virt/vboxguest/
 
+VIRTUAL BOX SHARED FOLDER VFS DRIVER:
+M:	Hans de Goede <hdegoede@redhat.com>
+L:	linux-fsdevel@vger.kernel.org
+S:	Maintained
+F:	fs/vboxsf/*
+
 VIRTUAL SERIO DEVICE DRIVER
 M:	Stephen Chandler Paul <thatslyude@gmail.com>
 S:	Maintained
diff --git a/fs/Kconfig b/fs/Kconfig
index f1046cf6ad85..b05dafd4db0f 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -262,6 +262,7 @@ source "fs/romfs/Kconfig"
 source "fs/pstore/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
+source "fs/vboxsf/Kconfig"
 
 endif # MISC_FILESYSTEMS
 
diff --git a/fs/Makefile b/fs/Makefile
index c9aea23aba56..76bcde11a689 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -130,3 +130,4 @@ obj-$(CONFIG_F2FS_FS)		+= f2fs/
 obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
 obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/
+obj-$(CONFIG_VBOXSF_FS)		+= vboxsf/
diff --git a/fs/vboxsf/Kconfig b/fs/vboxsf/Kconfig
new file mode 100644
index 000000000000..b84586ae08b3
--- /dev/null
+++ b/fs/vboxsf/Kconfig
@@ -0,0 +1,10 @@
+config VBOXSF_FS
+	tristate "VirtualBox guest shared folder (vboxsf) support"
+	depends on X86 && VBOXGUEST
+	select NLS
+	help
+	  VirtualBox hosts can share folders with guests, this driver
+	  implements the Linux-guest side of this allowing folders exported
+	  by the host to be mounted under Linux.
+
+	  If you want to use shared folders in VirtualBox guests, answer Y or M.
diff --git a/fs/vboxsf/Makefile b/fs/vboxsf/Makefile
new file mode 100644
index 000000000000..fcbd488f9eec
--- /dev/null
+++ b/fs/vboxsf/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_VBOXSF_FS) += vboxsf.o
+
+vboxsf-objs := dir.o file.o utils.o vboxsf_wrappers.o super.o
diff --git a/fs/vboxsf/dir.c b/fs/vboxsf/dir.c
new file mode 100644
index 000000000000..83aae6a06958
--- /dev/null
+++ b/fs/vboxsf/dir.c
@@ -0,0 +1,562 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Directory inode and file operations
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/namei.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+/**
+ * sf_dir_open - Open a directory
+ * @inode:	inode
+ * @file:	file
+ *
+ * Open a directory. Read the complete content into a buffer.
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_dir_open(struct inode *inode, struct file *file)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct shfl_createparms params = {};
+	struct sf_dir_info *sf_d;
+	int err;
+
+	sf_d = vboxsf_dir_info_alloc();
+	if (!sf_d)
+		return -ENOMEM;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_DIRECTORY | SHFL_CF_ACT_OPEN_IF_EXISTS |
+			      SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;
+
+	err = vboxsf_create_at_dentry(file_dentry(file), &params);
+	if (err == 0) {
+		if (params.result == SHFL_FILE_EXISTS) {
+			err = vboxsf_dir_read_all(sf_g, sf_d, params.handle);
+			if (!err)
+				file->private_data = sf_d;
+		} else
+			err = -ENOENT;
+
+		vboxsf_close(sf_g->root, params.handle);
+	}
+
+	if (err)
+		vboxsf_dir_info_free(sf_d);
+
+	return err;
+}
+
+/**
+ * sf_dir_release - Directory file release method
+ * @inode:	inode
+ * @file:	file
+ *
+ * This is called when reference count of [file] goes to zero. Notify
+ * the host that it can free whatever is associated with this directory
+ * and deallocate our own internal buffers
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_dir_release(struct inode *inode, struct file *file)
+{
+	if (file->private_data)
+		vboxsf_dir_info_free(file->private_data);
+
+	return 0;
+}
+
+/**
+ * sf_get_d_type - Translate RTFMODE into DT_xxx
+ * @mode:	file mode
+ *
+ * Returns:
+ * d_type
+ */
+static unsigned int sf_get_d_type(u32 mode)
+{
+	unsigned int d_type;
+
+	switch (mode & SHFL_TYPE_MASK) {
+	case SHFL_TYPE_FIFO:
+		d_type = DT_FIFO;
+		break;
+	case SHFL_TYPE_DEV_CHAR:
+		d_type = DT_CHR;
+		break;
+	case SHFL_TYPE_DIRECTORY:
+		d_type = DT_DIR;
+		break;
+	case SHFL_TYPE_DEV_BLOCK:
+		d_type = DT_BLK;
+		break;
+	case SHFL_TYPE_FILE:
+		d_type = DT_REG;
+		break;
+	case SHFL_TYPE_SYMLINK:
+		d_type = DT_LNK;
+		break;
+	case SHFL_TYPE_SOCKET:
+		d_type = DT_SOCK;
+		break;
+	case SHFL_TYPE_WHITEOUT:
+		d_type = DT_WHT;
+		break;
+	default:
+		d_type = DT_UNKNOWN;
+		break;
+	}
+	return d_type;
+}
+
+/**
+ * sf_getdent - Get name and type of directory-entry
+ * @dir:	Directory to get element at f_pos from
+ * @d_name:	Buffer in which to return element name
+ * @d_type:	Buffer in which to return element file-type
+ *
+ * Extract element (@dir->f_pos) from the directory @dir into @d_name
+ * and @d_type.
+ *
+ * Returns:
+ * 0 on success, 1 when the end of the dir is reached, or a negative errno
+ * value on error.
+ */
+static int sf_getdent(struct file *dir, loff_t pos,
+		      char d_name[NAME_MAX], unsigned int *d_type)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(file_inode(dir)->i_sb);
+	struct sf_dir_info *sf_d = dir->private_data;
+	struct shfl_dirinfo *info;
+	struct sf_dir_buf *b;
+	loff_t i, cur = 0;
+
+	list_for_each_entry(b, &sf_d->info_list, head) {
+		if (pos >= cur + b->entries) {
+			cur += b->entries;
+			continue;
+		}
+
+		/*
+		 * Note the sf_dir_info objects we are iterating over here
+		 * are variable sized, so the info pointer may end up being
+		 * unaligned. This is how we get the data from the host.
+		 * Since vboxsf is only supported on x86 machines this is not
+		 * a problem.
+		 */
+		for (i = 0, info = b->buf; i < pos - cur; ++i) {
+			size_t size;
+
+			size = offsetof(struct shfl_dirinfo, name.string) +
+			       info->name.size;
+			info = (struct shfl_dirinfo *)((uintptr_t) info + size);
+		}
+
+		*d_type = sf_get_d_type(info->info.attr.mode);
+
+		return vboxsf_nlscpy(sf_g, d_name, NAME_MAX,
+				     info->name.string.utf8, info->name.length);
+	}
+
+	return 1;
+}
+
+/**
+ * sf_dir_iterate - Iterate over directory entries
+ * @dir:	Directory to read
+ * @ctx:	Directory context in which to store read elements
+ *
+ * This is called when vfs wants to populate internal buffers with
+ * the directory's contents.
+ *
+ * Extract elements from the directory listing (incrementing @ctx->pos
+ * along the way) and emit them using dir_emit until:
+ *
+ * a. there are no more entries (sf_getdent returns 1)
+ * b. failure to compute fake inode number
+ * c. dir_emit() returns false
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_dir_iterate(struct file *dir, struct dir_context *ctx)
+{
+	char d_name[NAME_MAX];
+	unsigned int d_type;
+	ino_t fake_ino;
+	int err;
+
+	for (;;) {
+		err = sf_getdent(dir, ctx->pos, d_name, &d_type);
+		if (unlikely(err)) { /* EOF or an error */
+			if (err == 1)
+				return 0;
+			/* skip erroneous entry and proceed */
+			ctx->pos += 1;
+			continue;
+		}
+
+		/*
+		 * On 32 bit systems pos is 64 signed, while ino is 32 bit
+		 * unsigned so fake_ino may overflow, check for this.
+		 */
+		if ((ino_t)(ctx->pos + 1) != (u64)(ctx->pos + 1)) {
+			vbg_err("vboxsf: can not compute ino\n");
+			return -EINVAL;
+		}
+		fake_ino = ctx->pos + 1;
+
+		if (!dir_emit(ctx, d_name, strlen(d_name), fake_ino, d_type))
+			return 0;
+
+		ctx->pos += 1;
+	}
+}
+
+const struct file_operations vboxsf_dir_fops = {
+	.open = sf_dir_open,
+	.iterate = sf_dir_iterate,
+	.release = sf_dir_release,
+	.read = generic_read_dir,
+	.llseek = generic_file_llseek,
+};
+
+/*
+ * This is called during name resolution/lookup to check if the @dentry in
+ * the cache is still valid. the job is handled by vboxsf_inode_revalidate.
+ */
+static int sf_dentry_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	if (d_really_is_positive(dentry))
+		return vboxsf_inode_revalidate(dentry) == 0;
+	else
+		return vboxsf_stat_dentry(dentry, NULL) == -ENOENT;
+}
+
+const struct dentry_operations vboxsf_dentry_ops = {
+	.d_revalidate = sf_dentry_revalidate
+};
+
+/* iops */
+
+/**
+ * sf_lookup - lookup a directory entry
+ * @parent:	inode of the parent directory
+ * @dentry:	dentry to populate
+ * @flags:	flags
+ *
+ * This is called when vfs failed to locate dentry in the cache. The
+ * job of this function is to allocate inode and link it to dentry.
+ * [dentry] contains the name to be looked in the [parent] directory.
+ * Failure to locate the name is not a "hard" error, in this case NULL
+ * inode is added to [dentry] and vfs should proceed trying to create
+ * the entry via other means.
+ *
+ * Returns:
+ * NULL on success, ERR_PTR on failure.
+ */
+static struct dentry *sf_lookup(struct inode *parent, struct dentry *dentry,
+				unsigned int flags)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	struct shfl_fsobjinfo fsinfo;
+	struct inode *inode;
+	int err;
+
+	dentry->d_time = jiffies;
+
+	err = vboxsf_stat_dentry(dentry, &fsinfo);
+	if (err) {
+		inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
+	} else {
+		inode = vboxsf_new_inode(parent->i_sb);
+		if (!IS_ERR(inode))
+			vboxsf_init_inode(sf_g, inode, &fsinfo);
+	}
+
+	return d_splice_alias(inode, dentry);
+}
+
+/**
+ * sf_instantiate - Instantiate inode for dentry
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ * @info:	file information
+ *
+ * Create a new inode, initialize it with info from @info and instantiate.
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_instantiate(struct inode *parent, struct dentry *dentry,
+			  struct shfl_fsobjinfo *info)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	struct sf_inode_info *sf_i;
+	struct inode *inode;
+
+	inode = vboxsf_new_inode(parent->i_sb);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	sf_i = GET_INODE_INFO(inode);
+	/* The host may have given us different attr then requested */
+	sf_i->force_restat = 1;
+	vboxsf_init_inode(sf_g, inode, info);
+
+	d_instantiate(dentry, inode);
+
+	return 0;
+}
+
+/**
+ * sf_create_aux - Create a new regular file / directory
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ * @mode:	file mode
+ * @is_dir:	true if directory, false otherwise
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_create_aux(struct inode *parent, struct dentry *dentry,
+			 umode_t mode, int is_dir)
+{
+	struct sf_inode_info *sf_parent_i = GET_INODE_INFO(parent);
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	struct shfl_createparms params = {};
+	int err;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW |
+			      SHFL_CF_ACT_FAIL_IF_EXISTS |
+			      SHFL_CF_ACCESS_READWRITE |
+			      (is_dir ? SHFL_CF_DIRECTORY : 0);
+	params.info.attr.mode = (mode & 0777) |
+				(is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE);
+	params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING;
+
+	err = vboxsf_create_at_dentry(dentry, &params);
+	if (err)
+		return err;
+
+	if (params.result != SHFL_FILE_CREATED)
+		return -EPERM;
+
+	vboxsf_close(sf_g->root, params.handle);
+
+	err = sf_instantiate(parent, dentry, &params.info);
+	if (err)
+		return err;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+
+	return 0;
+}
+
+/**
+ * sf_create - Create a new regular file
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ * @mode:	file mode
+ * @excl:	Possible O_EXCL...
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_create(struct inode *parent, struct dentry *dentry, umode_t mode,
+		     bool excl)
+{
+	return sf_create_aux(parent, dentry, mode, 0);
+}
+
+/**
+ * sf_mkdir - Create a new regular directory
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ * @mode:	file mode
+ * @excl:	Possible O_EXCL...
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_mkdir(struct inode *parent, struct dentry *dentry, umode_t mode)
+{
+	return sf_create_aux(parent, dentry, mode, 1);
+}
+
+/**
+ * sf_unlink_aux - Remove a regular file / directory.
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ * @is_dir:	true if directory, false otherwise
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_unlink_aux(struct inode *parent, struct dentry *dentry,
+			 int is_dir)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	struct sf_inode_info *sf_parent_i = GET_INODE_INFO(parent);
+	struct inode *inode = d_inode(dentry);
+	struct shfl_string *path;
+	uint32_t flags;
+	int err;
+
+	flags = is_dir ? SHFL_REMOVE_DIR : SHFL_REMOVE_FILE;
+	if ((inode->i_mode & S_IFLNK) == S_IFLNK)
+		flags |= SHFL_REMOVE_SYMLINK;
+
+	path = vboxsf_path_from_dentry(sf_g, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	err = vboxsf_remove(sf_g->root, path, flags);
+	__putname(path);
+	if (err)
+		return err;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+
+	return 0;
+}
+
+/**
+ * sf_unlink_aux - Remove a regular file
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_unlink(struct inode *parent, struct dentry *dentry)
+{
+	return sf_unlink_aux(parent, dentry, 0);
+}
+
+/**
+ * sf_rmdir - Remove a directory
+ * @parent:	inode of the parent directory
+ * @dentry:	directory entry
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_rmdir(struct inode *parent, struct dentry *dentry)
+{
+	return sf_unlink_aux(parent, dentry, 1);
+}
+
+/**
+ * sf_rename - Rename a regular file or directory
+ * @old_parent:  inode of the old parent directory
+ * @old_dentry:  old directory entry
+ * @new_parent:  inode of the new parent directory
+ * @new_dentry:  new directory entry
+ * @flags:       flags
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+static int sf_rename(struct inode *old_parent, struct dentry *old_dentry,
+		     struct inode *new_parent, struct dentry *new_dentry,
+		     unsigned int flags)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(old_parent->i_sb);
+	struct sf_inode_info *sf_old_parent_i = GET_INODE_INFO(old_parent);
+	struct sf_inode_info *sf_new_parent_i = GET_INODE_INFO(new_parent);
+	u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS;
+	struct shfl_string *old_path, *new_path;
+	int err;
+
+	if (flags)
+		return -EINVAL;
+
+	old_path = vboxsf_path_from_dentry(sf_g, old_dentry);
+	if (IS_ERR(old_path))
+		return PTR_ERR(old_path);
+
+	new_path = vboxsf_path_from_dentry(sf_g, new_dentry);
+	if (IS_ERR(new_path)) {
+		__putname(old_path);
+		return PTR_ERR(new_path);
+	}
+
+	if (d_inode(old_dentry)->i_mode & S_IFDIR)
+		shfl_flags = 0;
+
+	err = vboxsf_rename(sf_g->root, old_path, new_path, shfl_flags);
+	if (err == 0) {
+		/* parent directories access/change time changed */
+		sf_new_parent_i->force_restat = 1;
+		sf_old_parent_i->force_restat = 1;
+	}
+
+	__putname(new_path);
+	__putname(old_path);
+	return err;
+}
+
+static int sf_symlink(struct inode *parent, struct dentry *dentry,
+		      const char *symname)
+{
+	struct sf_inode_info *sf_parent_i = GET_INODE_INFO(parent);
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	int symname_size = strlen(symname) + 1;
+	struct shfl_string *path, *ssymname;
+	struct shfl_fsobjinfo info;
+	int err;
+
+	path = vboxsf_path_from_dentry(sf_g, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	ssymname = kmalloc(SHFLSTRING_HEADER_SIZE + symname_size, GFP_KERNEL);
+	if (!ssymname) {
+		__putname(path);
+		return -ENOMEM;
+	}
+	ssymname->length = symname_size - 1;
+	ssymname->size = symname_size;
+	memcpy(ssymname->string.utf8, symname, symname_size);
+
+	err = vboxsf_symlink(sf_g->root, path, ssymname, &info);
+	kfree(ssymname);
+	__putname(path);
+	if (err) {
+		/* -EROFS means symlinks are note support -> -EPERM */
+		return (err == -EROFS) ? -EPERM : err;
+	}
+
+	err = sf_instantiate(parent, dentry, &info);
+	if (err)
+		return err;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+	return 0;
+}
+
+const struct inode_operations vboxsf_dir_iops = {
+	.lookup = sf_lookup,
+	.create = sf_create,
+	.mkdir = sf_mkdir,
+	.rmdir = sf_rmdir,
+	.unlink = sf_unlink,
+	.rename = sf_rename,
+	.getattr = vboxsf_getattr,
+	.setattr = vboxsf_setattr,
+	.symlink = sf_symlink
+};
diff --git a/fs/vboxsf/file.c b/fs/vboxsf/file.c
new file mode 100644
index 000000000000..60fa7ef6d797
--- /dev/null
+++ b/fs/vboxsf/file.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Regular file inode and file ops.
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/sizes.h>
+#include "vfsmod.h"
+
+struct sf_handle {
+	u64 handle;
+	u32 root;
+	u32 access_flags;
+	struct kref refcount;
+	struct list_head head;
+};
+
+/**
+ * Read from a regular file.
+ * Return: The number of bytes read on success, negative errno value otherwise
+ * @file	the file
+ * @buf		the buffer
+ * @size	length of the buffer
+ * @off		offset within the file
+ */
+static ssize_t sf_reg_read(struct file *file, char __user *buf, size_t size,
+			   loff_t *off)
+{
+	struct sf_handle *sf_handle = file->private_data;
+	u64 pos = *off;
+	u32 nread;
+	int err;
+
+	if (!size)
+		return 0;
+
+	if (size > SHFL_MAX_RW_COUNT)
+		nread = SHFL_MAX_RW_COUNT;
+	else
+		nread = size;
+
+	err = vboxsf_read(sf_handle->root, sf_handle->handle, pos, &nread,
+			  (uintptr_t)buf, true);
+	if (err)
+		return err;
+
+	*off += nread;
+	return nread;
+}
+
+/**
+ * Write to a regular file.
+ * Return: The number of bytes written on success, negative errno val otherwise
+ * @file	the file
+ * @buf		the buffer
+ * @size	length of the buffer
+ * @off		offset within the file
+ */
+static ssize_t sf_reg_write(struct file *file, const char __user *buf,
+			    size_t size, loff_t *off)
+{
+	struct inode *inode = file_inode(file);
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct sf_handle *sf_handle = file->private_data;
+	u32 nwritten;
+	u64 pos;
+	int err;
+
+	if (file->f_flags & O_APPEND)
+		pos = i_size_read(inode);
+	else
+		pos = *off;
+
+	if (!size)
+		return 0;
+
+	if (size > SHFL_MAX_RW_COUNT)
+		nwritten = SHFL_MAX_RW_COUNT;
+	else
+		nwritten = size;
+
+	/* Make sure any pending writes done through mmap are flushed */
+	err = filemap_fdatawait_range(inode->i_mapping, pos, pos + nwritten);
+	if (err)
+		return err;
+
+	err = vboxsf_write(sf_handle->root, sf_handle->handle, pos, &nwritten,
+			   (uintptr_t)buf, true);
+	if (err)
+		return err;
+
+	if (pos + nwritten > i_size_read(inode))
+		i_size_write(inode, pos + nwritten);
+
+	/* Invalidate page-cache so that mmap using apps see the changes too */
+	invalidate_mapping_pages(inode->i_mapping, pos >> PAGE_SHIFT,
+				 (pos + nwritten) >> PAGE_SHIFT);
+
+	/* mtime changed */
+	sf_i->force_restat = 1;
+
+	*off = pos + nwritten;
+	return nwritten;
+}
+
+/**
+ * Open a regular file.
+ * Return: 0 or negative errno value.
+ * @inode	inode
+ * @file	file
+ */
+static int sf_reg_open(struct inode *inode, struct file *file)
+{
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct shfl_createparms params = {};
+	struct sf_handle *sf_handle;
+	u32 access_flags = 0;
+	int err;
+
+	sf_handle = kmalloc(sizeof(*sf_handle), GFP_KERNEL);
+	if (!sf_handle)
+		return -ENOMEM;
+
+	/*
+	 * We check the value of params.handle afterwards to find out if
+	 * the call succeeded or failed, as the API does not seem to cleanly
+	 * distinguish error and informational messages.
+	 *
+	 * Furthermore, we must set params.handle to SHFL_HANDLE_NIL to
+	 * make the shared folders host service use our mode parameter.
+	 */
+	params.handle = SHFL_HANDLE_NIL;
+	if (file->f_flags & O_CREAT) {
+		params.create_flags |= SHFL_CF_ACT_CREATE_IF_NEW;
+		/*
+		 * We ignore O_EXCL, as the Linux kernel seems to call create
+		 * beforehand itself, so O_EXCL should always fail.
+		 */
+		if (file->f_flags & O_TRUNC)
+			params.create_flags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
+		else
+			params.create_flags |= SHFL_CF_ACT_OPEN_IF_EXISTS;
+	} else {
+		params.create_flags |= SHFL_CF_ACT_FAIL_IF_NEW;
+		if (file->f_flags & O_TRUNC)
+			params.create_flags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
+	}
+
+	switch (file->f_flags & O_ACCMODE) {
+	case O_RDONLY:
+		access_flags |= SHFL_CF_ACCESS_READ;
+		break;
+
+	case O_WRONLY:
+		access_flags |= SHFL_CF_ACCESS_WRITE;
+		break;
+
+	case O_RDWR:
+		access_flags |= SHFL_CF_ACCESS_READWRITE;
+		break;
+
+	default:
+		WARN_ON(1);
+	}
+
+	if (file->f_flags & O_APPEND)
+		access_flags |= SHFL_CF_ACCESS_APPEND;
+
+	params.create_flags |= access_flags;
+	params.info.attr.mode = inode->i_mode;
+
+	err = vboxsf_create_at_dentry(file_dentry(file), &params);
+	if (err == 0 && params.handle == SHFL_HANDLE_NIL)
+		err = (params.result == SHFL_FILE_EXISTS) ? -EEXIST : -ENOENT;
+	if (err) {
+		kfree(sf_handle);
+		return err;
+	}
+
+	/* the host may have given us different attr then requested */
+	sf_i->force_restat = 1;
+
+	/* init our handle struct and add it to the inode's handles list */
+	sf_handle->handle = params.handle;
+	sf_handle->root = GET_GLOB_INFO(inode->i_sb)->root;
+	sf_handle->access_flags = access_flags;
+	kref_init(&sf_handle->refcount);
+
+	mutex_lock(&sf_i->handle_list_mutex);
+	list_add(&sf_handle->head, &sf_i->handle_list);
+	mutex_unlock(&sf_i->handle_list_mutex);
+
+	file->private_data = sf_handle;
+	return 0;
+}
+
+static void sf_handle_release(struct kref *refcount)
+{
+	struct sf_handle *sf_handle = container_of(refcount, struct sf_handle,
+						   refcount);
+
+	vboxsf_close(sf_handle->root, sf_handle->handle);
+	kfree(sf_handle);
+}
+
+/**
+ * Close a regular file.
+ * Return: 0 or negative errno value.
+ * @inode	inode
+ * @file	file
+ */
+static int sf_reg_release(struct inode *inode, struct file *file)
+{
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct sf_handle *sf_handle = file->private_data;
+
+	filemap_write_and_wait(inode->i_mapping);
+
+	mutex_lock(&sf_i->handle_list_mutex);
+	list_del(&sf_handle->head);
+	mutex_unlock(&sf_i->handle_list_mutex);
+
+	kref_put(&sf_handle->refcount, sf_handle_release);
+	file->private_data = NULL;
+	return 0;
+}
+
+/*
+ * Write back dirty pages now, because there may not be any suitable
+ * open files later
+ */
+static void sf_vma_close(struct vm_area_struct *vma)
+{
+	filemap_write_and_wait(vma->vm_file->f_mapping);
+}
+
+static vm_fault_t sf_page_mkwrite(struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	struct inode *inode = file_inode(vmf->vma->vm_file);
+
+	lock_page(page);
+	if (page->mapping != inode->i_mapping) {
+		unlock_page(page);
+		return VM_FAULT_NOPAGE;
+	}
+
+	return VM_FAULT_LOCKED;
+}
+
+static const struct vm_operations_struct sf_file_vm_ops = {
+	.close		= sf_vma_close,
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= sf_page_mkwrite,
+};
+
+static int sf_reg_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	int err;
+
+	err = generic_file_mmap(file, vma);
+	if (!err)
+		vma->vm_ops = &sf_file_vm_ops;
+
+	return err;
+}
+
+const struct file_operations vboxsf_reg_fops = {
+	.read = sf_reg_read,
+	.open = sf_reg_open,
+	.write = sf_reg_write,
+	.release = sf_reg_release,
+	.mmap = sf_reg_mmap,
+	.splice_read = generic_file_splice_read,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
+	.fsync = noop_fsync,
+	.llseek = generic_file_llseek,
+};
+
+const struct inode_operations vboxsf_reg_iops = {
+	.getattr = vboxsf_getattr,
+	.setattr = vboxsf_setattr
+};
+
+static int sf_readpage(struct file *file, struct page *page)
+{
+	struct sf_handle *sf_handle = file->private_data;
+	loff_t off = page_offset(page);
+	u32 nread = PAGE_SIZE;
+	u8 *buf;
+	int err;
+
+	buf = kmap(page);
+
+	err = vboxsf_read(sf_handle->root, sf_handle->handle, off, &nread,
+			  (uintptr_t)buf, false);
+	if (err == 0) {
+		memset(&buf[nread], 0, PAGE_SIZE - nread);
+		flush_dcache_page(page);
+		SetPageUptodate(page);
+	} else {
+		SetPageError(page);
+	}
+
+	kunmap(page);
+	unlock_page(page);
+	return err;
+}
+
+static struct sf_handle *sf_get_writeable_handle(struct sf_inode_info *sf_i)
+{
+	struct sf_handle *h, *sf_handle = NULL;
+
+	mutex_lock(&sf_i->handle_list_mutex);
+	list_for_each_entry(h, &sf_i->handle_list, head) {
+		if (h->access_flags == SHFL_CF_ACCESS_WRITE ||
+		    h->access_flags == SHFL_CF_ACCESS_READWRITE) {
+			kref_get(&h->refcount);
+			sf_handle = h;
+			break;
+		}
+	}
+	mutex_unlock(&sf_i->handle_list_mutex);
+
+	return sf_handle;
+}
+
+static int sf_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct sf_handle *sf_handle;
+	loff_t off = page_offset(page);
+	loff_t size = i_size_read(inode);
+	u32 nwrite = PAGE_SIZE;
+	u8 *buf;
+	int err;
+
+	if (off + PAGE_SIZE > size)
+		nwrite = size & ~PAGE_MASK;
+
+	sf_handle = sf_get_writeable_handle(sf_i);
+	if (!sf_handle)
+		return -EBADF;
+
+	buf = kmap(page);
+	err = vboxsf_write(sf_handle->root, sf_handle->handle, off, &nwrite,
+			   (uintptr_t)buf, false);
+	kunmap(page);
+
+	kref_put(&sf_handle->refcount, sf_handle_release);
+
+	if (err == 0) {
+		ClearPageError(page);
+		/* mtime changed */
+		sf_i->force_restat = 1;
+	} else {
+		ClearPageUptodate(page);
+	}
+
+	unlock_page(page);
+	return err;
+}
+
+static int sf_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned int len, unsigned int copied,
+			struct page *page, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct sf_handle *sf_handle = file->private_data;
+	unsigned int from = pos & ~PAGE_MASK;
+	u32 nwritten = len;
+	u8 *buf;
+	int err;
+
+	buf = kmap(page);
+	err = vboxsf_write(sf_handle->root, sf_handle->handle, pos, &nwritten,
+			   (uintptr_t)buf + from, false);
+	kunmap(page);
+
+	if (err) {
+		nwritten = 0;
+		goto out;
+	}
+
+	/* mtime changed */
+	GET_INODE_INFO(inode)->force_restat = 1;
+
+	if (!PageUptodate(page) && nwritten == PAGE_SIZE)
+		SetPageUptodate(page);
+
+	pos += nwritten;
+	if (pos > inode->i_size)
+		i_size_write(inode, pos);
+
+out:
+	unlock_page(page);
+	put_page(page);
+
+	return nwritten;
+}
+
+const struct address_space_operations vboxsf_reg_aops = {
+	.readpage = sf_readpage,
+	.writepage = sf_writepage,
+	.set_page_dirty = __set_page_dirty_nobuffers,
+	.write_begin = simple_write_begin,
+	.write_end = sf_write_end,
+};
+
+static const char *sf_get_link(struct dentry *dentry, struct inode *inode,
+			       struct delayed_call *done)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct shfl_string *path;
+	char *link;
+	int err;
+
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
+	path = vboxsf_path_from_dentry(sf_g, dentry);
+	if (IS_ERR(path))
+		return (char *)path;
+
+	link = kzalloc(PATH_MAX, GFP_KERNEL);
+	if (!link) {
+		__putname(path);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	err = vboxsf_readlink(sf_g->root, path, PATH_MAX, link);
+	__putname(path);
+	if (err) {
+		kfree(link);
+		return ERR_PTR(err);
+	}
+
+	set_delayed_call(done, kfree_link, link);
+	return link;
+}
+
+const struct inode_operations vboxsf_lnk_iops = {
+	.get_link = sf_get_link
+};
diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h
new file mode 100644
index 000000000000..09531260a5f1
--- /dev/null
+++ b/fs/vboxsf/shfl_hostintf.h
@@ -0,0 +1,901 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * VirtualBox Shared Folders: host interface definition.
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#ifndef SHFL_HOSTINTF_H
+#define SHFL_HOSTINTF_H
+
+#include <linux/vbox_vmmdev_types.h>
+
+/* The max in/out buffer size for a FN_READ or FN_WRITE call */
+#define SHFL_MAX_RW_COUNT           (16 * SZ_1M)
+
+/*
+ * Structures shared between guest and the service
+ * can be relocated and use offsets to point to variable
+ * length parts.
+ *
+ * Shared folders protocol works with handles.
+ * Before doing any action on a file system object,
+ * one have to obtain the object handle via a SHFL_FN_CREATE
+ * request. A handle must be closed with SHFL_FN_CLOSE.
+ */
+
+enum {
+	SHFL_FN_QUERY_MAPPINGS = 1,	/* Query mappings changes. */
+	SHFL_FN_QUERY_MAP_NAME,		/* Query map name. */
+	SHFL_FN_CREATE,			/* Open/create object. */
+	SHFL_FN_CLOSE,			/* Close object handle. */
+	SHFL_FN_READ,			/* Read object content. */
+	SHFL_FN_WRITE,			/* Write new object content. */
+	SHFL_FN_LOCK,			/* Lock/unlock a range in the object. */
+	SHFL_FN_LIST,			/* List object content. */
+	SHFL_FN_INFORMATION,		/* Query/set object information. */
+	/* Note function number 10 is not used! */
+	SHFL_FN_REMOVE = 11,		/* Remove object */
+	SHFL_FN_MAP_FOLDER_OLD,		/* Map folder (legacy) */
+	SHFL_FN_UNMAP_FOLDER,		/* Unmap folder */
+	SHFL_FN_RENAME,			/* Rename object */
+	SHFL_FN_FLUSH,			/* Flush file */
+	SHFL_FN_SET_UTF8,		/* Select UTF8 filename encoding */
+	SHFL_FN_MAP_FOLDER,		/* Map folder */
+	SHFL_FN_READLINK,		/* Read symlink dest (as of VBox 4.0) */
+	SHFL_FN_SYMLINK,		/* Create symlink (as of VBox 4.0) */
+	SHFL_FN_SET_SYMLINKS,		/* Ask host to show symlinks (as of 4.0) */
+};
+
+/* Root handles for a mapping are of type u32, Root handles are unique. */
+#define SHFL_ROOT_NIL		UINT_MAX
+
+/* Shared folders handle for an opened object are of type u64. */
+#define SHFL_HANDLE_NIL		ULLONG_MAX
+
+/* Hardcoded maximum length (in chars) of a shared folder name. */
+#define SHFL_MAX_LEN         (256)
+/* Hardcoded maximum number of shared folder mapping available to the guest. */
+#define SHFL_MAX_MAPPINGS    (64)
+
+/** Shared folder string buffer structure. */
+struct shfl_string {
+	/** Allocated size of the string member in bytes. */
+	u16 size;
+
+	/** Length of string without trailing nul in bytes. */
+	u16 length;
+
+	/** UTF-8 or UTF-16 string. Nul terminated. */
+	union {
+		u8 utf8[2];
+		u16 utf16[1];
+		u16 ucs2[1]; /* misnomer, use utf16. */
+	} string;
+};
+VMMDEV_ASSERT_SIZE(shfl_string, 6);
+
+/* The size of shfl_string w/o the string part. */
+#define SHFLSTRING_HEADER_SIZE  4
+
+/* Calculate size of the string. */
+static inline u32 shfl_string_buf_size(const struct shfl_string *string)
+{
+	return string ? SHFLSTRING_HEADER_SIZE + string->size : 0;
+}
+
+/* Set user id on execution (S_ISUID). */
+#define SHFL_UNIX_ISUID             0004000U
+/* Set group id on execution (S_ISGID). */
+#define SHFL_UNIX_ISGID             0002000U
+/* Sticky bit (S_ISVTX / S_ISTXT). */
+#define SHFL_UNIX_ISTXT             0001000U
+
+/* Owner readable (S_IRUSR). */
+#define SHFL_UNIX_IRUSR             0000400U
+/* Owner writable (S_IWUSR). */
+#define SHFL_UNIX_IWUSR             0000200U
+/* Owner executable (S_IXUSR). */
+#define SHFL_UNIX_IXUSR             0000100U
+
+/* Group readable (S_IRGRP). */
+#define SHFL_UNIX_IRGRP             0000040U
+/* Group writable (S_IWGRP). */
+#define SHFL_UNIX_IWGRP             0000020U
+/* Group executable (S_IXGRP). */
+#define SHFL_UNIX_IXGRP             0000010U
+
+/* Other readable (S_IROTH). */
+#define SHFL_UNIX_IROTH             0000004U
+/* Other writable (S_IWOTH). */
+#define SHFL_UNIX_IWOTH             0000002U
+/* Other executable (S_IXOTH). */
+#define SHFL_UNIX_IXOTH             0000001U
+
+/* Named pipe (fifo) (S_IFIFO). */
+#define SHFL_TYPE_FIFO              0010000U
+/* Character device (S_IFCHR). */
+#define SHFL_TYPE_DEV_CHAR          0020000U
+/* Directory (S_IFDIR). */
+#define SHFL_TYPE_DIRECTORY         0040000U
+/* Block device (S_IFBLK). */
+#define SHFL_TYPE_DEV_BLOCK         0060000U
+/* Regular file (S_IFREG). */
+#define SHFL_TYPE_FILE              0100000U
+/* Symbolic link (S_IFLNK). */
+#define SHFL_TYPE_SYMLINK           0120000U
+/* Socket (S_IFSOCK). */
+#define SHFL_TYPE_SOCKET            0140000U
+/* Whiteout (S_IFWHT). */
+#define SHFL_TYPE_WHITEOUT          0160000U
+/* Type mask (S_IFMT). */
+#define SHFL_TYPE_MASK              0170000U
+
+/* Checks the mode flags indicate a directory (S_ISDIR). */
+#define SHFL_IS_DIRECTORY(m)   (((m) & SHFL_TYPE_MASK) == SHFL_TYPE_DIRECTORY)
+/* Checks the mode flags indicate a symbolic link (S_ISLNK). */
+#define SHFL_IS_SYMLINK(m)     (((m) & SHFL_TYPE_MASK) == SHFL_TYPE_SYMLINK)
+
+/** The available additional information in a shfl_fsobjattr object. */
+enum shfl_fsobjattr_add {
+	/** No additional information is available / requested. */
+	SHFLFSOBJATTRADD_NOTHING = 1,
+	/**
+	 * The additional unix attributes (shfl_fsobjattr::u::unix_attr) are
+	 *  available / requested.
+	 */
+	SHFLFSOBJATTRADD_UNIX,
+	/**
+	 * The additional extended attribute size (shfl_fsobjattr::u::size) is
+	 *  available / requested.
+	 */
+	SHFLFSOBJATTRADD_EASIZE,
+	/**
+	 * The last valid item (inclusive).
+	 * The valid range is SHFLFSOBJATTRADD_NOTHING thru
+	 * SHFLFSOBJATTRADD_LAST.
+	 */
+	SHFLFSOBJATTRADD_LAST = SHFLFSOBJATTRADD_EASIZE,
+
+	/** The usual 32-bit hack. */
+	SHFLFSOBJATTRADD_32BIT_SIZE_HACK = 0x7fffffff
+};
+
+/**
+ * Additional unix Attributes, these are available when
+ * shfl_fsobjattr.additional == SHFLFSOBJATTRADD_UNIX.
+ */
+struct shfl_fsobjattr_unix {
+	/**
+	 * The user owning the filesystem object (st_uid).
+	 * This field is ~0U if not supported.
+	 */
+	u32 uid;
+
+	/**
+	 * The group the filesystem object is assigned (st_gid).
+	 * This field is ~0U if not supported.
+	 */
+	u32 gid;
+
+	/**
+	 * Number of hard links to this filesystem object (st_nlink).
+	 * This field is 1 if the filesystem doesn't support hardlinking or
+	 * the information isn't available.
+	 */
+	u32 hardlinks;
+
+	/**
+	 * The device number of the device which this filesystem object resides
+	 * on (st_dev). This field is 0 if this information is not available.
+	 */
+	u32 inode_id_device;
+
+	/**
+	 * The unique identifier (within the filesystem) of this filesystem
+	 * object (st_ino). Together with inode_id_device, this field can be
+	 * used as a OS wide unique id, when both their values are not 0.
+	 * This field is 0 if the information is not available.
+	 */
+	u64 inode_id;
+
+	/**
+	 * User flags (st_flags).
+	 * This field is 0 if this information is not available.
+	 */
+	u32 flags;
+
+	/**
+	 * The current generation number (st_gen).
+	 * This field is 0 if this information is not available.
+	 */
+	u32 generation_id;
+
+	/**
+	 * The device number of a char. or block device type object (st_rdev).
+	 * This field is 0 if the file isn't a char. or block device or when
+	 * the OS doesn't use the major+minor device idenfication scheme.
+	 */
+	u32 device;
+} __packed;
+
+/** Extended attribute size. */
+struct shfl_fsobjattr_easize {
+	/** Size of EAs. */
+	s64 cb;
+} __packed;
+
+/** Shared folder filesystem object attributes. */
+struct shfl_fsobjattr {
+	/** Mode flags (st_mode). SHFL_UNIX_*, SHFL_TYPE_*, and SHFL_DOS_*. */
+	u32 mode;
+
+	/** The additional attributes available. */
+	enum shfl_fsobjattr_add additional;
+
+	/**
+	 * Additional attributes.
+	 *
+	 * Unless explicitly specified to an API, the API can provide additional
+	 * data as it is provided by the underlying OS.
+	 */
+	union {
+		struct shfl_fsobjattr_unix unix_attr;
+		struct shfl_fsobjattr_easize size;
+	} __packed u;
+} __packed;
+VMMDEV_ASSERT_SIZE(shfl_fsobjattr, 44);
+
+struct shfl_timespec {
+	s64 ns_relative_to_unix_epoch;
+};
+
+/** Filesystem object information structure. */
+struct shfl_fsobjinfo {
+	/**
+	 * Logical size (st_size).
+	 * For normal files this is the size of the file.
+	 * For symbolic links, this is the length of the path name contained
+	 * in the symbolic link.
+	 * For other objects this fields needs to be specified.
+	 */
+	s64 size;
+
+	/** Disk allocation size (st_blocks * DEV_BSIZE). */
+	s64 allocated;
+
+	/** Time of last access (st_atime). */
+	struct shfl_timespec access_time;
+
+	/** Time of last data modification (st_mtime). */
+	struct shfl_timespec modification_time;
+
+	/**
+	 * Time of last status change (st_ctime).
+	 * If not available this is set to modification_time.
+	 */
+	struct shfl_timespec change_time;
+
+	/**
+	 * Time of file birth (st_birthtime).
+	 * If not available this is set to change_time.
+	 */
+	struct shfl_timespec birth_time;
+
+	/** Attributes. */
+	struct shfl_fsobjattr attr;
+
+} __packed;
+VMMDEV_ASSERT_SIZE(shfl_fsobjinfo, 92);
+
+/**
+ * result of an open/create request.
+ * Along with handle value the result code
+ * identifies what has happened while
+ * trying to open the object.
+ */
+enum shfl_create_result {
+	SHFL_NO_RESULT,
+	/** Specified path does not exist. */
+	SHFL_PATH_NOT_FOUND,
+	/** Path to file exists, but the last component does not. */
+	SHFL_FILE_NOT_FOUND,
+	/** File already exists and either has been opened or not. */
+	SHFL_FILE_EXISTS,
+	/** New file was created. */
+	SHFL_FILE_CREATED,
+	/** Existing file was replaced or overwritten. */
+	SHFL_FILE_REPLACED
+};
+
+/* No flags. Initialization value. */
+#define SHFL_CF_NONE                  (0x00000000)
+
+/*
+ * Only lookup the object, do not return a handle. When this is set all other
+ * flags are ignored.
+ */
+#define SHFL_CF_LOOKUP                (0x00000001)
+
+/*
+ * Open parent directory of specified object.
+ * Useful for the corresponding Windows FSD flag
+ * and for opening paths like \\dir\\*.* to search the 'dir'.
+ */
+#define SHFL_CF_OPEN_TARGET_DIRECTORY (0x00000002)
+
+/* Create/open a directory. */
+#define SHFL_CF_DIRECTORY             (0x00000004)
+
+/*
+ *  Open/create action to do if object exists
+ *  and if the object does not exists.
+ *  REPLACE file means atomically DELETE and CREATE.
+ *  OVERWRITE file means truncating the file to 0 and
+ *  setting new size.
+ *  When opening an existing directory REPLACE and OVERWRITE
+ *  actions are considered invalid, and cause returning
+ *  FILE_EXISTS with NIL handle.
+ */
+#define SHFL_CF_ACT_MASK_IF_EXISTS      (0x000000f0)
+#define SHFL_CF_ACT_MASK_IF_NEW         (0x00000f00)
+
+/* What to do if object exists. */
+#define SHFL_CF_ACT_OPEN_IF_EXISTS      (0x00000000)
+#define SHFL_CF_ACT_FAIL_IF_EXISTS      (0x00000010)
+#define SHFL_CF_ACT_REPLACE_IF_EXISTS   (0x00000020)
+#define SHFL_CF_ACT_OVERWRITE_IF_EXISTS (0x00000030)
+
+/* What to do if object does not exist. */
+#define SHFL_CF_ACT_CREATE_IF_NEW       (0x00000000)
+#define SHFL_CF_ACT_FAIL_IF_NEW         (0x00000100)
+
+/* Read/write requested access for the object. */
+#define SHFL_CF_ACCESS_MASK_RW          (0x00003000)
+
+/* No access requested. */
+#define SHFL_CF_ACCESS_NONE             (0x00000000)
+/* Read access requested. */
+#define SHFL_CF_ACCESS_READ             (0x00001000)
+/* Write access requested. */
+#define SHFL_CF_ACCESS_WRITE            (0x00002000)
+/* Read/Write access requested. */
+#define SHFL_CF_ACCESS_READWRITE	(0x00003000)
+
+/* Requested share access for the object. */
+#define SHFL_CF_ACCESS_MASK_DENY        (0x0000c000)
+
+/* Allow any access. */
+#define SHFL_CF_ACCESS_DENYNONE         (0x00000000)
+/* Do not allow read. */
+#define SHFL_CF_ACCESS_DENYREAD         (0x00004000)
+/* Do not allow write. */
+#define SHFL_CF_ACCESS_DENYWRITE        (0x00008000)
+/* Do not allow access. */
+#define SHFL_CF_ACCESS_DENYALL          (0x0000c000)
+
+/* Requested access to attributes of the object. */
+#define SHFL_CF_ACCESS_MASK_ATTR        (0x00030000)
+
+/* No access requested. */
+#define SHFL_CF_ACCESS_ATTR_NONE        (0x00000000)
+/* Read access requested. */
+#define SHFL_CF_ACCESS_ATTR_READ        (0x00010000)
+/* Write access requested. */
+#define SHFL_CF_ACCESS_ATTR_WRITE       (0x00020000)
+/* Read/Write access requested. */
+#define SHFL_CF_ACCESS_ATTR_READWRITE   (0x00030000)
+
+/*
+ * The file is opened in append mode.
+ * Ignored if SHFL_CF_ACCESS_WRITE is not set.
+ */
+#define SHFL_CF_ACCESS_APPEND           (0x00040000)
+
+/** Create parameters buffer struct for SHFL_FN_CREATE call */
+struct shfl_createparms {
+	/** Returned handle of opened object. */
+	u64 handle;
+
+	/** Returned result of the operation */
+	enum shfl_create_result result;
+
+	/** SHFL_CF_* */
+	u32 create_flags;
+
+	/**
+	 * Attributes of object to create and
+	 * returned actual attributes of opened/created object.
+	 */
+	struct shfl_fsobjinfo info;
+} __packed;
+
+/** Shared Folder directory information */
+struct shfl_dirinfo {
+	/** Full information about the object. */
+	struct shfl_fsobjinfo info;
+	/**
+	 * The length of the short field (number of UTF16 chars).
+	 * It is 16-bit for reasons of alignment.
+	 */
+	u16 short_name_len;
+	/**
+	 * The short name for 8.3 compatibility.
+	 * Empty string if not available.
+	 */
+	u16 short_name[14];
+	struct shfl_string name;
+};
+
+/** Shared folder filesystem properties. */
+struct shfl_fsproperties {
+	/**
+	 * The maximum size of a filesystem object name.
+	 * This does not include the '\\0'.
+	 */
+	u32 max_component_len;
+
+	/**
+	 * True if the filesystem is remote.
+	 * False if the filesystem is local.
+	 */
+	bool remote;
+
+	/**
+	 * True if the filesystem is case sensitive.
+	 * False if the filesystem is case insensitive.
+	 */
+	bool case_sensitive;
+
+	/**
+	 * True if the filesystem is mounted read only.
+	 * False if the filesystem is mounted read write.
+	 */
+	bool read_only;
+
+	/**
+	 * True if the filesystem can encode unicode object names.
+	 * False if it can't.
+	 */
+	bool supports_unicode;
+
+	/**
+	 * True if the filesystem is compresses.
+	 * False if it isn't or we don't know.
+	 */
+	bool compressed;
+
+	/**
+	 * True if the filesystem compresses of individual files.
+	 * False if it doesn't or we don't know.
+	 */
+	bool file_compression;
+};
+VMMDEV_ASSERT_SIZE(shfl_fsproperties, 12);
+
+struct shfl_volinfo {
+	s64 total_allocation_bytes;
+	s64 available_allocation_bytes;
+	u32 bytes_per_allocation_unit;
+	u32 bytes_per_sector;
+	u32 serial;
+	struct shfl_fsproperties properties;
+};
+
+
+/** SHFL_FN_MAP_FOLDER Parameters structure. */
+struct shfl_map_folder {
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string buffer.
+	 */
+	struct vmmdev_hgcm_function_parameter path;
+
+	/**
+	 * pointer, out: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in: UTF16
+	 * Path delimiter
+	 */
+	struct vmmdev_hgcm_function_parameter delimiter;
+
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Case senstive flag
+	 */
+	struct vmmdev_hgcm_function_parameter case_sensitive;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_MAP_FOLDER (4)
+
+
+/** SHFL_FN_UNMAP_FOLDER Parameters structure. */
+struct shfl_unmap_folder {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_UNMAP_FOLDER (1)
+
+
+/** SHFL_FN_CREATE Parameters structure. */
+struct shfl_create {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string buffer.
+	 */
+	struct vmmdev_hgcm_function_parameter path;
+
+	/**
+	 * pointer, in/out:
+	 * Points to struct shfl_createparms buffer.
+	 */
+	struct vmmdev_hgcm_function_parameter parms;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_CREATE (3)
+
+
+/** SHFL_FN_CLOSE Parameters structure. */
+struct shfl_close {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE (u64) of object to close.
+	 */
+	struct vmmdev_hgcm_function_parameter handle;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_CLOSE (2)
+
+
+/** SHFL_FN_READ Parameters structure. */
+struct shfl_read {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE (u64) of object to read from.
+	 */
+	struct vmmdev_hgcm_function_parameter handle;
+
+	/**
+	 * value64, in:
+	 * Offset to read from.
+	 */
+	struct vmmdev_hgcm_function_parameter offset;
+
+	/**
+	 * value64, in/out:
+	 * Bytes to read/How many were read.
+	 */
+	struct vmmdev_hgcm_function_parameter cb;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place data to.
+	 */
+	struct vmmdev_hgcm_function_parameter buffer;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_READ (5)
+
+
+/** SHFL_FN_WRITE Parameters structure. */
+struct shfl_write {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE (u64) of object to write to.
+	 */
+	struct vmmdev_hgcm_function_parameter handle;
+
+	/**
+	 * value64, in:
+	 * Offset to write to.
+	 */
+	struct vmmdev_hgcm_function_parameter offset;
+
+	/**
+	 * value64, in/out:
+	 * Bytes to write/How many were written.
+	 */
+	struct vmmdev_hgcm_function_parameter cb;
+
+	/**
+	 * pointer, in:
+	 * Data to write.
+	 */
+	struct vmmdev_hgcm_function_parameter buffer;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_WRITE (5)
+
+
+/*
+ * SHFL_FN_LIST
+ * Listing information includes variable length RTDIRENTRY[EX] structures.
+ */
+
+#define SHFL_LIST_NONE			0
+#define SHFL_LIST_RETURN_ONE		1
+
+/** SHFL_FN_LIST Parameters structure. */
+struct shfl_list {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE (u64) of object to be listed.
+	 */
+	struct vmmdev_hgcm_function_parameter handle;
+
+	/**
+	 * value32, in:
+	 * List flags SHFL_LIST_*.
+	 */
+	struct vmmdev_hgcm_function_parameter flags;
+
+	/**
+	 * value32, in/out:
+	 * Bytes to be used for listing information/How many bytes were used.
+	 */
+	struct vmmdev_hgcm_function_parameter cb;
+
+	/**
+	 * pointer, in/optional
+	 * Points to struct shfl_string buffer that specifies a search path.
+	 */
+	struct vmmdev_hgcm_function_parameter path;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place listing information to. (struct shfl_dirinfo)
+	 */
+	struct vmmdev_hgcm_function_parameter buffer;
+
+	/**
+	 * value32, in/out:
+	 * Indicates a key where the listing must be resumed.
+	 * in: 0 means start from begin of object.
+	 * out: 0 means listing completed.
+	 */
+	struct vmmdev_hgcm_function_parameter resume_point;
+
+	/**
+	 * pointer, out:
+	 * Number of files returned
+	 */
+	struct vmmdev_hgcm_function_parameter file_count;
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_LIST (8)
+
+
+/** SHFL_FN_READLINK Parameters structure. */
+struct shfl_readLink {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string buffer.
+	 */
+	struct vmmdev_hgcm_function_parameter path;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place data to.
+	 */
+	struct vmmdev_hgcm_function_parameter buffer;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_READLINK (3)
+
+
+/* SHFL_FN_INFORMATION */
+
+/* Mask of Set/Get bit. */
+#define SHFL_INFO_MODE_MASK    (0x1)
+/* Get information */
+#define SHFL_INFO_GET          (0x0)
+/* Set information */
+#define SHFL_INFO_SET          (0x1)
+
+/* Get name of the object. */
+#define SHFL_INFO_NAME         (0x2)
+/* Set size of object (extend/trucate); only applies to file objects */
+#define SHFL_INFO_SIZE         (0x4)
+/* Get/Set file object info. */
+#define SHFL_INFO_FILE         (0x8)
+/* Get volume information. */
+#define SHFL_INFO_VOLUME       (0x10)
+
+/** SHFL_FN_INFORMATION Parameters structure. */
+struct shfl_information {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE (u64) of object to be listed.
+	 */
+	struct vmmdev_hgcm_function_parameter handle;
+
+	/**
+	 * value32, in:
+	 * SHFL_INFO_*
+	 */
+	struct vmmdev_hgcm_function_parameter flags;
+
+	/**
+	 * value32, in/out:
+	 * Bytes to be used for information/How many bytes were used.
+	 */
+	struct vmmdev_hgcm_function_parameter cb;
+
+	/**
+	 * pointer, in/out:
+	 * Information to be set/get (shfl_fsobjinfo or shfl_string). Do not
+	 * forget to set the shfl_fsobjinfo::attr::additional for a get
+	 * operation as well.
+	 */
+	struct vmmdev_hgcm_function_parameter info;
+
+};
+
+/* Number of parameters */
+#define SHFL_CPARMS_INFORMATION (5)
+
+
+/* SHFL_FN_REMOVE */
+
+#define SHFL_REMOVE_FILE        (0x1)
+#define SHFL_REMOVE_DIR         (0x2)
+#define SHFL_REMOVE_SYMLINK     (0x4)
+
+/** SHFL_FN_REMOVE Parameters structure. */
+struct shfl_remove {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string buffer.
+	 */
+	struct vmmdev_hgcm_function_parameter path;
+
+	/**
+	 * value32, in:
+	 * remove flags (file/directory)
+	 */
+	struct vmmdev_hgcm_function_parameter flags;
+
+};
+
+#define SHFL_CPARMS_REMOVE  (3)
+
+
+/* SHFL_FN_RENAME */
+
+#define SHFL_RENAME_FILE                (0x1)
+#define SHFL_RENAME_DIR                 (0x2)
+#define SHFL_RENAME_REPLACE_IF_EXISTS   (0x4)
+
+/** SHFL_FN_RENAME Parameters structure. */
+struct shfl_rename {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string src.
+	 */
+	struct vmmdev_hgcm_function_parameter src;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string dest.
+	 */
+	struct vmmdev_hgcm_function_parameter dest;
+
+	/**
+	 * value32, in:
+	 * rename flags (file/directory)
+	 */
+	struct vmmdev_hgcm_function_parameter flags;
+
+};
+
+#define SHFL_CPARMS_RENAME  (4)
+
+
+/** SHFL_FN_SYMLINK Parameters structure. */
+struct shfl_symlink {
+	/**
+	 * pointer, in: SHFLROOT (u32)
+	 * Root handle of the mapping which name is queried.
+	 */
+	struct vmmdev_hgcm_function_parameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string of path for the new symlink.
+	 */
+	struct vmmdev_hgcm_function_parameter new_path;
+
+	/**
+	 * pointer, in:
+	 * Points to struct shfl_string of destination for symlink.
+	 */
+	struct vmmdev_hgcm_function_parameter old_path;
+
+	/**
+	 * pointer, out:
+	 * Information about created symlink.
+	 */
+	struct vmmdev_hgcm_function_parameter info;
+
+};
+
+#define SHFL_CPARMS_SYMLINK  (4)
+
+#endif
diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c
new file mode 100644
index 000000000000..76d1a2184077
--- /dev/null
+++ b/fs/vboxsf/super.c
@@ -0,0 +1,482 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Virtual File System.
+ *
+ * Module initialization/finalization
+ * File system registration/deregistration
+ * Superblock reading
+ * Few utility functions
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/idr.h>
+#include <linux/fs_parser.h>
+#include <linux/magic.h>
+#include <linux/module.h>
+#include <linux/nls.h>
+#include <linux/statfs.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+#define VBOXSF_SUPER_MAGIC 0x786f4256 /* 'VBox' little endian */
+
+#define VBSF_MOUNT_SIGNATURE_BYTE_0 ('\000')
+#define VBSF_MOUNT_SIGNATURE_BYTE_1 ('\377')
+#define VBSF_MOUNT_SIGNATURE_BYTE_2 ('\376')
+#define VBSF_MOUNT_SIGNATURE_BYTE_3 ('\375')
+
+static int follow_symlinks;
+module_param(follow_symlinks, int, 0444);
+MODULE_PARM_DESC(follow_symlinks,
+		 "Let host resolve symlinks rather than showing them");
+
+static DEFINE_IDA(vboxsf_bdi_ida);
+static DEFINE_MUTEX(vboxsf_setup_mutex);
+static bool vboxsf_setup_done;
+static struct super_operations vboxsf_super_ops; /* forward declaration */
+static struct kmem_cache *sf_inode_cachep;
+
+static char * const vboxsf_default_nls = CONFIG_NLS_DEFAULT;
+
+enum  { opt_nls, opt_uid, opt_gid, opt_ttl, opt_dmode, opt_fmode,
+	opt_dmask, opt_fmask };
+
+static const struct fs_parameter_spec vboxsf_param_specs[] = {
+	fsparam_string("nls", opt_nls),
+	fsparam_u32("uid", opt_uid),
+	fsparam_u32("gid", opt_gid),
+	fsparam_u32("ttl", opt_ttl),
+	fsparam_u32oct("dmode", opt_dmode),
+	fsparam_u32oct("fmode", opt_fmode),
+	fsparam_u32oct("dmask", opt_dmask),
+	fsparam_u32oct("fmask", opt_fmask),
+	{}
+};
+
+static const struct fs_parameter_description vboxsf_fs_parameters = {
+	.name  = "vboxsf",
+	.specs  = vboxsf_param_specs,
+};
+
+static int vboxsf_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, &vboxsf_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_nls:
+		if (fc->purpose != FS_CONTEXT_FOR_MOUNT) {
+			vbg_err("vboxsf: Cannot reconfigure nls option\n");
+			return -EINVAL;
+		}
+		ctx->nls_name = param->string;
+		param->string = NULL;
+		break;
+	case opt_uid:
+		ctx->o.uid = result.uint_32;
+		break;
+	case opt_gid:
+		ctx->o.gid = result.uint_32;
+		break;
+	case opt_ttl:
+		ctx->o.ttl = msecs_to_jiffies(result.uint_32);
+		break;
+	case opt_dmode:
+		ctx->o.dmode = result.uint_32;
+		break;
+	case opt_fmode:
+		ctx->o.fmode = result.uint_32;
+		break;
+	case opt_dmask:
+		ctx->o.dmask = result.uint_32;
+		break;
+	case opt_fmask:
+		ctx->o.fmask = result.uint_32;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct shfl_string *folder_name, root_path;
+	struct sf_glob_info *sf_g;
+	struct dentry *droot;
+	struct inode *iroot;
+	char *nls_name;
+	size_t size;
+	int err;
+
+	if (!fc->source)
+		return -EINVAL;
+
+	sf_g = kzalloc(sizeof(*sf_g), GFP_KERNEL);
+	if (!sf_g)
+		return -ENOMEM;
+
+	sf_g->o = ctx->o;
+	idr_init(&sf_g->ino_idr);
+	spin_lock_init(&sf_g->ino_idr_lock);
+	sf_g->next_generation = 1;
+	sf_g->bdi_id = -1;
+
+ 	/* Load nls if not utf8 */
+	nls_name = ctx->nls_name ? ctx->nls_name : vboxsf_default_nls;
+	if (strcmp(nls_name, "utf8") != 0) {
+		if (nls_name == vboxsf_default_nls)
+			sf_g->nls = load_nls_default();
+		else
+			sf_g->nls = load_nls(nls_name);
+
+		if (!sf_g->nls) {
+			vbg_err("vboxsf: Count not load '%s' nls\n", nls_name);
+			err = -EINVAL;
+			goto fail_free;
+		}
+	}
+
+	sf_g->bdi_id = ida_simple_get(&vboxsf_bdi_ida, 0, 0, GFP_KERNEL);
+	if (sf_g->bdi_id < 0) {
+		err = sf_g->bdi_id;
+		goto fail_free;
+	}
+
+	err = super_setup_bdi_name(sb, "vboxsf-%s.%d", fc->source,
+				   sf_g->bdi_id);
+	if (err)
+		goto fail_free;
+
+	/* Turn source into a shfl_string and map the folder */
+	size = strlen(fc->source) + 1;
+	folder_name = kmalloc(SHFLSTRING_HEADER_SIZE + size, GFP_KERNEL);
+	if (!folder_name)
+		goto fail_free;
+	folder_name->size = size;
+	folder_name->length = size - 1;
+	strlcpy(folder_name->string.utf8, fc->source, size);
+	err = vboxsf_map_folder(folder_name, &sf_g->root);
+	kfree(folder_name);
+	if (err) {
+		vbg_err("vboxsf: Host rejected mount of '%s' with error %d\n",
+			fc->source, err);
+		goto fail_free;
+	}
+
+	root_path.length = 1;
+	root_path.size = 2;
+	root_path.string.utf8[0] = '/';
+	root_path.string.utf8[1] = 0;
+	err = vboxsf_stat(sf_g, &root_path, &sf_g->root_info);
+	if (err)
+		goto fail_unmap;
+
+	sb->s_magic = VBOXSF_SUPER_MAGIC;
+	sb->s_blocksize = 1024;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_op = &vboxsf_super_ops;
+	sb->s_d_op = &vboxsf_dentry_ops;
+
+	iroot = iget_locked(sb, 0);
+	if (!iroot) {
+		err = -ENOMEM;
+		goto fail_unmap;
+	}
+	vboxsf_init_inode(sf_g, iroot, &sf_g->root_info);
+	unlock_new_inode(iroot);
+
+	droot = d_make_root(iroot);
+	if (!droot) {
+		err = -ENOMEM;
+		goto fail_unmap;
+	}
+
+	sb->s_root = droot;
+	SET_GLOB_INFO(sb, sf_g);
+	return 0;
+
+fail_unmap:
+	vboxsf_unmap_folder(sf_g->root);
+fail_free:
+	if (sf_g->bdi_id >= 0)
+		ida_simple_remove(&vboxsf_bdi_ida, sf_g->bdi_id);
+	if (sf_g->nls)
+		unload_nls(sf_g->nls);
+	idr_destroy(&sf_g->ino_idr);
+	kfree(sf_g);
+	return err;
+}
+
+static void sf_inode_init_once(void *data)
+{
+	struct sf_inode_info *sf_i = (struct sf_inode_info *)data;
+
+	mutex_init(&sf_i->handle_list_mutex);
+	inode_init_once(&sf_i->vfs_inode);
+}
+
+static struct inode *sf_alloc_inode(struct super_block *sb)
+{
+	struct sf_inode_info *sf_i;
+
+	sf_i = kmem_cache_alloc(sf_inode_cachep, GFP_NOFS);
+	if (!sf_i)
+		return NULL;
+
+	sf_i->force_restat = 0;
+	INIT_LIST_HEAD(&sf_i->handle_list);
+
+	return &sf_i->vfs_inode;
+}
+
+static void sf_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+
+	spin_lock(&sf_g->ino_idr_lock);
+	idr_remove(&sf_g->ino_idr, inode->i_ino);
+	spin_unlock(&sf_g->ino_idr_lock);
+	kmem_cache_free(sf_inode_cachep, GET_INODE_INFO(inode));
+}
+
+static void sf_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, sf_i_callback);
+}
+
+static void sf_put_super(struct super_block *sb)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(sb);
+
+	vboxsf_unmap_folder(sf_g->root);
+	if (sf_g->bdi_id >= 0)
+		ida_simple_remove(&vboxsf_bdi_ida, sf_g->bdi_id);
+	if (sf_g->nls)
+		unload_nls(sf_g->nls);
+	idr_destroy(&sf_g->ino_idr);
+	kfree(sf_g);
+}
+
+static int sf_statfs(struct dentry *dentry, struct kstatfs *stat)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct shfl_volinfo SHFLVolumeInfo;
+	struct sf_glob_info *sf_g;
+	u32 buf_len;
+	int err;
+
+	sf_g = GET_GLOB_INFO(sb);
+	buf_len = sizeof(SHFLVolumeInfo);
+	err = vboxsf_fsinfo(sf_g->root, 0, SHFL_INFO_GET | SHFL_INFO_VOLUME,
+			    &buf_len, &SHFLVolumeInfo);
+	if (err)
+		return err;
+
+	stat->f_type = VBOXSF_SUPER_MAGIC;
+	stat->f_bsize = SHFLVolumeInfo.bytes_per_allocation_unit;
+
+	do_div(SHFLVolumeInfo.total_allocation_bytes,
+	       SHFLVolumeInfo.bytes_per_allocation_unit);
+	stat->f_blocks = SHFLVolumeInfo.total_allocation_bytes;
+
+	do_div(SHFLVolumeInfo.available_allocation_bytes,
+	       SHFLVolumeInfo.bytes_per_allocation_unit);
+	stat->f_bfree  = SHFLVolumeInfo.available_allocation_bytes;
+	stat->f_bavail = SHFLVolumeInfo.available_allocation_bytes;
+
+	stat->f_files = 1000;
+	/*
+	 * Don't return 0 here since the guest may then think that it is not
+	 * possible to create any more files.
+	 */
+	stat->f_ffree = 1000000;
+	stat->f_fsid.val[0] = 0;
+	stat->f_fsid.val[1] = 0;
+	stat->f_namelen = 255;
+	return 0;
+}
+
+static struct super_operations vboxsf_super_ops = {
+	.alloc_inode	= sf_alloc_inode,
+	.destroy_inode	= sf_destroy_inode,
+	.put_super	= sf_put_super,
+	.statfs		= sf_statfs,
+};
+
+static int vboxsf_setup(void)
+{
+	int err;
+
+	mutex_lock(&vboxsf_setup_mutex);
+
+	if (vboxsf_setup_done)
+		goto success;
+
+	sf_inode_cachep = kmem_cache_create("vboxsf_inode_cache",
+					     sizeof(struct sf_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+					     sf_inode_init_once);
+	if (sf_inode_cachep == NULL) {
+		err = -ENOMEM;
+		goto fail_nomem;
+	}
+
+	err = vboxsf_connect();
+	if (err) {
+		vbg_err("vboxsf: err %d connecting to guest PCI-device\n", err);
+		vbg_err("vboxsf: make sure you are inside a VirtualBox VM\n");
+		vbg_err("vboxsf: and check dmesg for vboxguest errors\n");
+		goto fail_free_cache;
+	}
+
+	err = vboxsf_set_utf8();
+	if (err) {
+		vbg_err("vboxsf_setutf8 error %d\n", err);
+		goto fail_disconnect;
+	}
+
+	if (!follow_symlinks) {
+		err = vboxsf_set_symlinks();
+		if (err)
+			vbg_warn("vboxsf: Unable to show symlinks: %d\n", err);
+	}
+
+	vboxsf_setup_done = true;
+success:
+	mutex_unlock(&vboxsf_setup_mutex);
+	return 0;
+
+fail_disconnect:
+	vboxsf_disconnect();
+fail_free_cache:
+	kmem_cache_destroy(sf_inode_cachep);
+fail_nomem:
+	mutex_unlock(&vboxsf_setup_mutex);
+	return err;
+}
+
+int vboxsf_parse_monolithic(struct fs_context *fc, void *data)
+{
+	char *options = data;
+
+	if (options && options[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 &&
+		       options[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 &&
+		       options[2] == VBSF_MOUNT_SIGNATURE_BYTE_2 &&
+		       options[3] == VBSF_MOUNT_SIGNATURE_BYTE_3) {
+		vbg_err("vboxsf: Old binary mount data not supported, remove obsolete mount.vboxsf and/or update your VBoxService.\n");
+		return -EINVAL;
+	}
+
+	return generic_parse_monolithic(fc, data);
+}
+
+static int vboxsf_get_tree(struct fs_context *fc)
+{
+	int err;
+
+	err = vboxsf_setup();
+	if (err)
+		return err;
+
+	return vfs_get_super(fc, vfs_get_independent_super, vboxsf_fill_super);
+}
+
+static int vboxsf_reconfigure(struct fs_context *fc)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(fc->root->d_sb);
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+	struct inode *iroot;
+
+	iroot = ilookup(fc->root->d_sb, 0);
+	if (!iroot)
+		return -ENOENT;
+
+	/* Apply changed options to the root inode */
+	sf_g->o = ctx->o;
+	vboxsf_init_inode(sf_g, iroot, &sf_g->root_info);
+
+	return 0;
+}
+
+static void vboxsf_free_fc(struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx = fc->fs_private;
+
+	kfree(ctx->nls_name);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations vboxsf_context_ops = {
+	.free			= vboxsf_free_fc,
+	.parse_param		= vboxsf_parse_param,
+	.parse_monolithic	= vboxsf_parse_monolithic,
+	.get_tree		= vboxsf_get_tree,
+	.reconfigure		= vboxsf_reconfigure,
+};
+
+static int vboxsf_init_fs_context(struct fs_context *fc)
+{
+	struct vboxsf_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	/* ~0 means use whatever the host gives as mode info */
+	ctx->o.dmode = ~0;
+	ctx->o.fmode = ~0;
+
+	fc->fs_private = ctx;
+	fc->ops = &vboxsf_context_ops;
+	return 0;
+}
+
+static struct file_system_type vboxsf_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= "vboxsf",
+	.init_fs_context	= vboxsf_init_fs_context,
+	.parameters		= &vboxsf_fs_parameters,
+	.kill_sb		= kill_anon_super
+};
+
+/* Module initialization/finalization handlers */
+static int __init vboxsf_init(void)
+{
+	return register_filesystem(&vboxsf_fs_type);
+}
+
+static void __exit vboxsf_fini(void)
+{
+	unregister_filesystem(&vboxsf_fs_type);
+
+	mutex_lock(&vboxsf_setup_mutex);
+	if (vboxsf_setup_done) {
+		vboxsf_disconnect();
+		/*
+		 * Make sure all delayed rcu free inodes are flushed
+		 * before we destroy the cache.
+		 */
+		rcu_barrier();
+		kmem_cache_destroy(sf_inode_cachep);
+	}
+	mutex_unlock(&vboxsf_setup_mutex);
+}
+
+module_init(vboxsf_init);
+module_exit(vboxsf_fini);
+
+MODULE_DESCRIPTION("Oracle VM VirtualBox Module for Host File System Access");
+MODULE_AUTHOR("Oracle Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_FS("vboxsf");
diff --git a/fs/vboxsf/utils.c b/fs/vboxsf/utils.c
new file mode 100644
index 000000000000..2d42b5836fa9
--- /dev/null
+++ b/fs/vboxsf/utils.c
@@ -0,0 +1,568 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Utility functions.
+ * Mainly conversion from/to VirtualBox/Linux data structures.
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/namei.h>
+#include <linux/nls.h>
+#include <linux/sizes.h>
+#include <linux/vfs.h>
+#include "vfsmod.h"
+
+struct inode *vboxsf_new_inode(struct super_block *sb)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(sb);
+	struct inode *inode;
+	int cursor, ret;
+	u32 gen;
+
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&sf_g->ino_idr_lock);
+	cursor = idr_get_cursor(&sf_g->ino_idr);
+	ret = idr_alloc_cyclic(&sf_g->ino_idr, inode, 1, 0, GFP_ATOMIC);
+	if (ret >= 0 && ret < cursor)
+		sf_g->next_generation++;
+	gen = sf_g->next_generation;
+	spin_unlock(&sf_g->ino_idr_lock);
+	idr_preload_end();
+
+	if (ret < 0) {
+		iput(inode);
+		return ERR_PTR(ret);
+	}
+
+	inode->i_ino = ret;
+	inode->i_generation = gen;
+	return inode;
+}
+
+/* set [inode] attributes based on [info], uid/gid based on [sf_g] */
+void vboxsf_init_inode(struct sf_glob_info *sf_g, struct inode *inode,
+		       const struct shfl_fsobjinfo *info)
+{
+	const struct shfl_fsobjattr *attr;
+	s64 allocated;
+	int mode;
+
+	attr = &info->attr;
+
+#define mode_set(r) ((attr->mode & (SHFL_UNIX_##r)) ? (S_##r) : 0)
+
+	mode = mode_set(IRUSR);
+	mode |= mode_set(IWUSR);
+	mode |= mode_set(IXUSR);
+
+	mode |= mode_set(IRGRP);
+	mode |= mode_set(IWGRP);
+	mode |= mode_set(IXGRP);
+
+	mode |= mode_set(IROTH);
+	mode |= mode_set(IWOTH);
+	mode |= mode_set(IXOTH);
+
+#undef mode_set
+
+	/* We use the host-side values for these */
+	inode->i_flags |= S_NOATIME | S_NOCMTIME;
+	inode->i_mapping->a_ops = &vboxsf_reg_aops;
+
+	if (SHFL_IS_DIRECTORY(attr->mode)) {
+		inode->i_mode =
+			sf_g->o.dmode != ~0 ? (sf_g->o.dmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->o.dmask;
+		inode->i_mode |= S_IFDIR;
+		inode->i_op = &vboxsf_dir_iops;
+		inode->i_fop = &vboxsf_dir_fops;
+		/*
+		 * XXX: this probably should be set to the number of entries
+		 * in the directory plus two (. ..)
+		 */
+		set_nlink(inode, 1);
+	} else if (SHFL_IS_SYMLINK(attr->mode)) {
+		inode->i_mode =
+			sf_g->o.fmode != ~0 ? (sf_g->o.fmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->o.fmask;
+		inode->i_mode |= S_IFLNK;
+		inode->i_op = &vboxsf_lnk_iops;
+		set_nlink(inode, 1);
+	} else {
+		inode->i_mode =
+			sf_g->o.fmode != ~0 ? (sf_g->o.fmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->o.fmask;
+		inode->i_mode |= S_IFREG;
+		inode->i_op = &vboxsf_reg_iops;
+		inode->i_fop = &vboxsf_reg_fops;
+		set_nlink(inode, 1);
+	}
+
+	inode->i_uid = make_kuid(current_user_ns(), sf_g->o.uid);
+	inode->i_gid = make_kgid(current_user_ns(), sf_g->o.gid);
+
+	inode->i_size = info->size;
+	inode->i_blkbits = 12;
+	/* i_blocks always in units of 512 bytes! */
+	allocated = info->allocated + 511;
+	do_div(allocated, 512);
+	inode->i_blocks = allocated;
+
+	inode->i_atime = ns_to_timespec64(
+				 info->access_time.ns_relative_to_unix_epoch);
+	inode->i_ctime = ns_to_timespec64(
+				 info->change_time.ns_relative_to_unix_epoch);
+	inode->i_mtime = ns_to_timespec64(
+			   info->modification_time.ns_relative_to_unix_epoch);
+}
+
+int vboxsf_create_at_dentry(struct dentry *dentry,
+			    struct shfl_createparms *params)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(dentry->d_sb);
+	struct shfl_string *path;
+	int err;
+
+	path = vboxsf_path_from_dentry(sf_g, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	err = vboxsf_create(sf_g->root, path, params);
+	__putname(path);
+
+	return err;
+}
+
+int vboxsf_stat(struct sf_glob_info *sf_g, struct shfl_string *path,
+		struct shfl_fsobjinfo *info)
+{
+	struct shfl_createparms params = {};
+	int err;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW;
+
+	err = vboxsf_create(sf_g->root, path, &params);
+	if (err)
+		return err;
+
+	if (params.result != SHFL_FILE_EXISTS)
+		return -ENOENT;
+
+	if (info)
+		*info = params.info;
+
+	return 0;
+}
+
+int vboxsf_stat_dentry(struct dentry *dentry, struct shfl_fsobjinfo *info)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(dentry->d_sb);
+	struct shfl_string *path;
+	int err;
+
+	path = vboxsf_path_from_dentry(sf_g, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	err = vboxsf_stat(sf_g, path, info);
+	__putname(path);
+	return err;
+}
+
+int vboxsf_inode_revalidate(struct dentry *dentry)
+{
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(dentry->d_sb);
+	struct sf_inode_info *sf_i;
+	struct shfl_fsobjinfo info;
+	struct timespec64 prev_mtime;
+	struct inode *inode;
+	int err;
+
+	if (!dentry || !d_really_is_positive(dentry))
+		return -EINVAL;
+
+	inode = d_inode(dentry);
+	prev_mtime = inode->i_mtime;
+	sf_i = GET_INODE_INFO(inode);
+	if (!sf_i->force_restat) {
+		if (time_before(jiffies, dentry->d_time + sf_g->o.ttl))
+			return 0;
+	}
+
+	err = vboxsf_stat_dentry(dentry, &info);
+	if (err)
+		return err;
+
+	dentry->d_time = jiffies;
+	sf_i->force_restat = 0;
+	vboxsf_init_inode(sf_g, inode, &info);
+
+	/*
+	 * mmap()-ed files use the page-cache, if the file was changed on the
+	 * host side we need to invalidate the page-cache for it.  Note this
+	 * also gets triggered by our own writes, this is unavoidable.
+	 */
+	if (timespec64_compare(&inode->i_mtime, &prev_mtime) > 0)
+		invalidate_mapping_pages(inode->i_mapping, 0, -1);
+
+	return 0;
+}
+
+int vboxsf_getattr(const struct path *path, struct kstat *kstat,
+		   u32 request_mask, unsigned int flags)
+{
+	int err;
+	struct dentry *dentry = path->dentry;
+	struct inode *inode = d_inode(dentry);
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+
+	switch (flags & AT_STATX_SYNC_TYPE) {
+	case AT_STATX_DONT_SYNC:
+		err = 0;
+		break;
+	case AT_STATX_FORCE_SYNC:
+		sf_i->force_restat = 1;
+		/* fall-through */
+	default:
+		err = vboxsf_inode_revalidate(dentry);
+	}
+	if (err)
+		return err;
+
+	generic_fillattr(d_inode(dentry), kstat);
+	return 0;
+}
+
+int vboxsf_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	struct sf_inode_info *sf_i = GET_INODE_INFO(d_inode(dentry));
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(dentry->d_sb);
+	struct shfl_createparms params = {};
+	struct shfl_fsobjinfo info = {};
+	uint32_t buf_len;
+	int err;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_ACT_OPEN_IF_EXISTS |
+			      SHFL_CF_ACT_FAIL_IF_NEW |
+			      SHFL_CF_ACCESS_ATTR_WRITE;
+
+	/* this is at least required for Posix hosts */
+	if (iattr->ia_valid & ATTR_SIZE)
+		params.create_flags |= SHFL_CF_ACCESS_WRITE;
+
+	err = vboxsf_create_at_dentry(dentry, &params);
+	if (err || params.result != SHFL_FILE_EXISTS)
+		return err ? err : -ENOENT;
+
+#define mode_set(r) ((iattr->ia_mode & (S_##r)) ? SHFL_UNIX_##r : 0)
+
+	/*
+	 * Setting the file size and setting the other attributes has to
+	 * be handled separately.
+	 */
+	if (iattr->ia_valid & (ATTR_MODE | ATTR_ATIME | ATTR_MTIME)) {
+		if (iattr->ia_valid & ATTR_MODE) {
+			info.attr.mode = mode_set(IRUSR);
+			info.attr.mode |= mode_set(IWUSR);
+			info.attr.mode |= mode_set(IXUSR);
+			info.attr.mode |= mode_set(IRGRP);
+			info.attr.mode |= mode_set(IWGRP);
+			info.attr.mode |= mode_set(IXGRP);
+			info.attr.mode |= mode_set(IROTH);
+			info.attr.mode |= mode_set(IWOTH);
+			info.attr.mode |= mode_set(IXOTH);
+
+			if (iattr->ia_mode & S_IFDIR)
+				info.attr.mode |= SHFL_TYPE_DIRECTORY;
+			else
+				info.attr.mode |= SHFL_TYPE_FILE;
+		}
+
+		if (iattr->ia_valid & ATTR_ATIME)
+			info.access_time.ns_relative_to_unix_epoch =
+					    timespec64_to_ns(&iattr->ia_atime);
+
+		if (iattr->ia_valid & ATTR_MTIME)
+			info.modification_time.ns_relative_to_unix_epoch =
+					    timespec64_to_ns(&iattr->ia_mtime);
+
+		/*
+		 * Ignore ctime (inode change time) as it can't be set
+		 * from userland anyway.
+		 */
+
+		buf_len = sizeof(info);
+		err = vboxsf_fsinfo(sf_g->root, params.handle,
+				   SHFL_INFO_SET | SHFL_INFO_FILE, &buf_len,
+				   &info);
+		if (err) {
+			vboxsf_close(sf_g->root, params.handle);
+			return err;
+		}
+
+		/* the host may have given us different attr then requested */
+		sf_i->force_restat = 1;
+	}
+
+#undef mode_set
+
+	if (iattr->ia_valid & ATTR_SIZE) {
+		memset(&info, 0, sizeof(info));
+		info.size = iattr->ia_size;
+		buf_len = sizeof(info);
+		err = vboxsf_fsinfo(sf_g->root, params.handle,
+				   SHFL_INFO_SET | SHFL_INFO_SIZE, &buf_len,
+				   &info);
+		if (err) {
+			vboxsf_close(sf_g->root, params.handle);
+			return err;
+		}
+
+		/* the host may have given us different attr then requested */
+		sf_i->force_restat = 1;
+	}
+
+	vboxsf_close(sf_g->root, params.handle);
+
+	/* Update the inode with what the host has actually given us. */
+	if (sf_i->force_restat)
+		vboxsf_inode_revalidate(dentry);
+
+	return 0;
+}
+
+/*
+ * [dentry] contains string encoded in coding system that corresponds
+ * to [sf_g]->nls, we must convert it to UTF8 here.
+ * Returns a shfl_string allocated through __getname (must be freed using
+ * __putname), or an ERR_PTR on error.
+ */
+struct shfl_string *vboxsf_path_from_dentry(struct sf_glob_info *sf_g,
+					    struct dentry *dentry)
+{
+	struct shfl_string *shfl_path;
+	int path_len, out_len, nb;
+	char *buf, *path;
+	wchar_t uni;
+	u8 *out;
+
+	buf = __getname();
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	path = dentry_path_raw(dentry, buf, PATH_MAX);
+	if (IS_ERR(path)) {
+		__putname(buf);
+		return (struct shfl_string *)path;
+	}
+	path_len = strlen(path);
+
+	if (sf_g->nls) {
+		shfl_path = __getname();
+		if (!shfl_path) {
+			__putname(buf);
+			return ERR_PTR(-ENOMEM);
+		}
+
+		out = shfl_path->string.utf8;
+		out_len = PATH_MAX - SHFLSTRING_HEADER_SIZE - 1;
+
+		while (path_len) {
+			nb = sf_g->nls->char2uni(path, path_len, &uni);
+			if (nb < 0) {
+				__putname(shfl_path);
+				__putname(buf);
+				return ERR_PTR(-EINVAL);
+			}
+			path += nb;
+			path_len -= nb;
+
+			nb = utf32_to_utf8(uni, out, out_len);
+			if (nb < 0) {
+				__putname(shfl_path);
+				__putname(buf);
+				return ERR_PTR(-ENAMETOOLONG);
+			}
+			out += nb;
+			out_len -= nb;
+		}
+		*out = 0;
+		shfl_path->length = out - shfl_path->string.utf8;
+		shfl_path->size = shfl_path->length + 1;
+		__putname(buf);
+	} else {
+		if ((SHFLSTRING_HEADER_SIZE + path_len + 1) > PATH_MAX) {
+			__putname(buf);
+			return ERR_PTR(-ENAMETOOLONG);
+		}
+		/*
+		 * dentry_path stores the name at the end of buf, but the
+		 * shfl_string string we return must be properly aligned.
+		 */
+		shfl_path = (struct shfl_string *)buf;
+		memmove(shfl_path->string.utf8, path, path_len);
+		shfl_path->string.utf8[path_len] = 0;
+		shfl_path->length = path_len;
+		shfl_path->size = path_len + 1;
+	}
+
+	return shfl_path;
+}
+
+int vboxsf_nlscpy(struct sf_glob_info *sf_g, char *name, size_t name_bound_len,
+		  const unsigned char *utf8_name, size_t utf8_len)
+{
+	if (sf_g->nls) {
+		const char *in;
+		char *out;
+		size_t out_len;
+		size_t out_bound_len;
+		size_t in_bound_len;
+
+		in = utf8_name;
+		in_bound_len = utf8_len;
+
+		out = name;
+		out_len = 0;
+		/* Reserve space for terminating 0 */
+		out_bound_len = name_bound_len - 1;
+
+		while (in_bound_len) {
+			int nb;
+			unicode_t uni;
+
+			nb = utf8_to_utf32(in, in_bound_len, &uni);
+			if (nb < 0)
+				return -EINVAL;
+
+			in += nb;
+			in_bound_len -= nb;
+
+			nb = sf_g->nls->uni2char(uni, out, out_bound_len);
+			if (nb < 0)
+				return nb;
+
+			out += nb;
+			out_bound_len -= nb;
+			out_len += nb;
+		}
+
+		*out = 0;
+	} else {
+		if (utf8_len + 1 > name_bound_len)
+			return -ENAMETOOLONG;
+
+		memcpy(name, utf8_name, utf8_len + 1);
+	}
+	return 0;
+}
+
+static struct sf_dir_buf *sf_dir_buf_alloc(struct list_head *list)
+{
+	struct sf_dir_buf *b;
+
+	b = kmalloc(sizeof(*b), GFP_KERNEL);
+	if (!b)
+		return NULL;
+
+	b->buf = kmalloc(DIR_BUFFER_SIZE, GFP_KERNEL);
+	if (!b->buf) {
+		kfree(b);
+		return NULL;
+	}
+
+	b->entries = 0;
+	b->used = 0;
+	b->free = DIR_BUFFER_SIZE;
+	list_add(&b->head, list);
+
+	return b;
+}
+
+static void sf_dir_buf_free(struct sf_dir_buf *b)
+{
+	list_del(&b->head);
+	kfree(b->buf);
+	kfree(b);
+}
+
+/**
+ * vboxsf_dir_info_alloc - Create a new directory buffer descriptor
+ *
+ * Returns:
+ * Created sf_dir_info buffer, or NULL when malloc fails
+ */
+struct sf_dir_info *vboxsf_dir_info_alloc(void)
+{
+	struct sf_dir_info *p;
+
+	p = kmalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return NULL;
+
+	INIT_LIST_HEAD(&p->info_list);
+	return p;
+}
+
+/**
+ * vboxsf_dir_info_free - Free the directory buffer
+ * @p:		sf_dir_info buffer to free
+ */
+void vboxsf_dir_info_free(struct sf_dir_info *p)
+{
+	struct list_head *list, *pos, *tmp;
+
+	list = &p->info_list;
+	list_for_each_safe(pos, tmp, list) {
+		struct sf_dir_buf *b;
+
+		b = list_entry(pos, struct sf_dir_buf, head);
+		sf_dir_buf_free(b);
+	}
+	kfree(p);
+}
+
+int vboxsf_dir_read_all(struct sf_glob_info *sf_g, struct sf_dir_info *sf_d,
+			u64 handle)
+{
+	struct sf_dir_buf *b;
+	u32 entries, size;
+	int err = 0;
+	void *buf;
+
+	/* vboxsf_dirinfo returns 1 on end of dir */
+	while (err == 0) {
+		b = sf_dir_buf_alloc(&sf_d->info_list);
+		if (!b) {
+			err = -ENOMEM;
+			break;
+		}
+
+		buf = b->buf;
+		size = b->free;
+
+		err = vboxsf_dirinfo(sf_g->root, handle, NULL, 0, 0,
+				     &size, buf, &entries);
+		if (err < 0)
+			break;
+
+		b->entries += entries;
+		b->free -= size;
+		b->used += size;
+	}
+
+	if (b && b->used == 0)
+		sf_dir_buf_free(b);
+
+	/* -EILSEQ means the host could not translate a filename, ignore */
+	if (err > 0 || err == -EILSEQ)
+		err = 0;
+
+	return err;
+}
diff --git a/fs/vboxsf/vboxsf_wrappers.c b/fs/vboxsf/vboxsf_wrappers.c
new file mode 100644
index 000000000000..fb13b894c8b4
--- /dev/null
+++ b/fs/vboxsf/vboxsf_wrappers.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Wrapper functions for the shfl host calls.
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vbox_err.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+#define SHFL_REQUEST \
+	(VMMDEV_REQUESTOR_KERNEL | VMMDEV_REQUESTOR_USR_DRV_OTHER | \
+	 VMMDEV_REQUESTOR_CON_DONT_KNOW | VMMDEV_REQUESTOR_TRUST_NOT_GIVEN)
+
+static u32 vboxsf_client_id;
+
+int vboxsf_connect(void)
+{
+	struct vbg_dev *gdev;
+	struct vmmdev_hgcm_service_location loc;
+	int err, vbox_status;
+
+	loc.type = VMMDEV_HGCM_LOC_LOCALHOST_EXISTING;
+	strcpy(loc.u.localhost.service_name, "VBoxSharedFolders");
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return -ENODEV;	/* No guest-device */
+
+	err = vbg_hgcm_connect(gdev, SHFL_REQUEST, &loc,
+			       &vboxsf_client_id, &vbox_status);
+	vbg_put_gdev(gdev);
+
+	return err ? err : vbg_status_code_to_errno(vbox_status);
+}
+
+void vboxsf_disconnect(void)
+{
+	struct vbg_dev *gdev;
+	int vbox_status;
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return;   /* guest-device is gone, already disconnected */
+
+	vbg_hgcm_disconnect(gdev, SHFL_REQUEST, vboxsf_client_id, &vbox_status);
+	vbg_put_gdev(gdev);
+}
+
+static int vboxsf_call(u32 function, void *parms, u32 parm_count, int *status)
+{
+	struct vbg_dev *gdev;
+	int err, vbox_status;
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return -ESHUTDOWN; /* guest-dev removed underneath us */
+
+	err = vbg_hgcm_call(gdev, SHFL_REQUEST, vboxsf_client_id, function,
+			    U32_MAX, parms, parm_count, &vbox_status);
+	vbg_put_gdev(gdev);
+
+	if (err < 0)
+		return err;
+
+	if (status)
+		*status = vbox_status;
+
+	return vbg_status_code_to_errno(vbox_status);
+}
+
+int vboxsf_map_folder(struct shfl_string *folder_name, u32 *root)
+{
+	struct shfl_map_folder parms;
+	int err, status;
+
+	parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL;
+	parms.path.u.pointer.size = shfl_string_buf_size(folder_name);
+	parms.path.u.pointer.u.linear_addr = (uintptr_t)folder_name;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = 0;
+
+	parms.delimiter.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.delimiter.u.value32 = '/';
+
+	parms.case_sensitive.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.case_sensitive.u.value32 = 1;
+
+	err = vboxsf_call(SHFL_FN_MAP_FOLDER, &parms, SHFL_CPARMS_MAP_FOLDER,
+			  &status);
+	if (err == -ENOSYS && status == VERR_NOT_IMPLEMENTED)
+		vbg_err("%s: Error host is too old\n", __func__);
+
+	*root = parms.root.u.value32;
+	return err;
+}
+
+int vboxsf_unmap_folder(u32 root)
+{
+	struct shfl_unmap_folder parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	return vboxsf_call(SHFL_FN_UNMAP_FOLDER, &parms,
+			   SHFL_CPARMS_UNMAP_FOLDER, NULL);
+}
+
+/**
+ * vboxsf_create - Create a new file or folder
+ * @root:         Root of the shared folder in which to create the file
+ * @parsed_path:  The path of the file or folder relative to the shared folder
+ * @param:        create_parms Parameters for file/folder creation.
+ *
+ * Create a new file or folder or open an existing one in a shared folder.
+ * Note this function always returns 0 / success unless an exceptional condition
+ * occurs - out of memory, invalid arguments, etc. If the file or folder could
+ * not be opened or created, create_parms->handle will be set to
+ * SHFL_HANDLE_NIL on return.  In this case the value in create_parms->result
+ * provides information as to why (e.g. SHFL_FILE_EXISTS), create_parms->result
+ * is also set on success as additional information.
+ *
+ * Returns:
+ * 0 or negative errno value.
+ */
+int vboxsf_create(u32 root, struct shfl_string *parsed_path,
+		  struct shfl_createparms *create_parms)
+{
+	struct shfl_create parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL;
+	parms.path.u.pointer.size = shfl_string_buf_size(parsed_path);
+	parms.path.u.pointer.u.linear_addr = (uintptr_t)parsed_path;
+
+	parms.parms.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL;
+	parms.parms.u.pointer.size = sizeof(struct shfl_createparms);
+	parms.parms.u.pointer.u.linear_addr = (uintptr_t)create_parms;
+
+	return vboxsf_call(SHFL_FN_CREATE, &parms, SHFL_CPARMS_CREATE, NULL);
+}
+
+int vboxsf_close(u32 root, u64 handle)
+{
+	struct shfl_close parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.handle.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.handle.u.value64 = handle;
+
+	return vboxsf_call(SHFL_FN_CLOSE, &parms, SHFL_CPARMS_CLOSE, NULL);
+}
+
+int vboxsf_remove(u32 root, struct shfl_string *parsed_path, u32 flags)
+{
+	struct shfl_remove parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.path.u.pointer.size = shfl_string_buf_size(parsed_path);
+	parms.path.u.pointer.u.linear_addr = (uintptr_t)parsed_path;
+
+	parms.flags.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.flags.u.value32 = flags;
+
+	return vboxsf_call(SHFL_FN_REMOVE, &parms, SHFL_CPARMS_REMOVE, NULL);
+}
+
+int vboxsf_rename(u32 root, struct shfl_string *src_path,
+		  struct shfl_string *dest_path, u32 flags)
+{
+	struct shfl_rename parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.src.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.src.u.pointer.size = shfl_string_buf_size(src_path);
+	parms.src.u.pointer.u.linear_addr = (uintptr_t)src_path;
+
+	parms.dest.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.dest.u.pointer.size = shfl_string_buf_size(dest_path);
+	parms.dest.u.pointer.u.linear_addr = (uintptr_t)dest_path;
+
+	parms.flags.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.flags.u.value32 = flags;
+
+	return vboxsf_call(SHFL_FN_RENAME, &parms, SHFL_CPARMS_RENAME, NULL);
+}
+
+int vboxsf_read(u32 root, u64 handle, u64 offset,
+		u32 *buf_len, uintptr_t buf, bool user)
+{
+	struct shfl_read parms;
+	int err;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.handle.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.handle.u.value64 = handle;
+	parms.offset.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.offset.u.value64 = offset;
+	parms.cb.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.cb.u.value32 = *buf_len;
+	if (user)
+		parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT;
+	else
+		parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT;
+	parms.buffer.u.pointer.size = *buf_len;
+	parms.buffer.u.pointer.u.linear_addr = buf;
+
+	err = vboxsf_call(SHFL_FN_READ, &parms, SHFL_CPARMS_READ, NULL);
+
+	*buf_len = parms.cb.u.value32;
+	return err;
+}
+
+int vboxsf_write(u32 root, u64 handle, u64 offset,
+		 u32 *buf_len, uintptr_t buf, bool user)
+{
+	struct shfl_write parms;
+	int err;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.handle.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.handle.u.value64 = handle;
+	parms.offset.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.offset.u.value64 = offset;
+	parms.cb.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.cb.u.value32 = *buf_len;
+	if (user)
+		parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_IN;
+	else
+		parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.buffer.u.pointer.size = *buf_len;
+	parms.buffer.u.pointer.u.linear_addr = buf;
+
+	err = vboxsf_call(SHFL_FN_WRITE, &parms, SHFL_CPARMS_WRITE, NULL);
+
+	*buf_len = parms.cb.u.value32;
+	return err;
+}
+
+/* Returns 0 on success, 1 on end-of-dir, negative errno otherwise */
+int vboxsf_dirinfo(u32 root, u64 handle,
+		   struct shfl_string *parsed_path, u32 flags, u32 index,
+		   u32 *buf_len, struct shfl_dirinfo *buf, u32 *file_count)
+{
+	struct shfl_list parms;
+	int err, status;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.handle.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.handle.u.value64 = handle;
+	parms.flags.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.flags.u.value32 = flags;
+	parms.cb.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.cb.u.value32 = *buf_len;
+	if (parsed_path) {
+		parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+		parms.path.u.pointer.size = shfl_string_buf_size(parsed_path);
+		parms.path.u.pointer.u.linear_addr = (uintptr_t)parsed_path;
+	} else {
+		parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_IN;
+		parms.path.u.pointer.size = 0;
+		parms.path.u.pointer.u.linear_addr = 0;
+	}
+
+	parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT;
+	parms.buffer.u.pointer.size = *buf_len;
+	parms.buffer.u.pointer.u.linear_addr = (uintptr_t)buf;
+
+	parms.resume_point.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.resume_point.u.value32 = index;
+	parms.file_count.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.file_count.u.value32 = 0;	/* out parameter only */
+
+	err = vboxsf_call(SHFL_FN_LIST, &parms, SHFL_CPARMS_LIST, &status);
+	if (err == -ENODATA && status == VERR_NO_MORE_FILES)
+		err = 1;
+
+	*buf_len = parms.cb.u.value32;
+	*file_count = parms.file_count.u.value32;
+	return err;
+}
+
+int vboxsf_fsinfo(u32 root, u64 handle, u32 flags,
+		  u32 *buf_len, void *buf)
+{
+	struct shfl_information parms;
+	int err;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.handle.type = VMMDEV_HGCM_PARM_TYPE_64BIT;
+	parms.handle.u.value64 = handle;
+	parms.flags.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.flags.u.value32 = flags;
+	parms.cb.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.cb.u.value32 = *buf_len;
+	parms.info.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL;
+	parms.info.u.pointer.size = *buf_len;
+	parms.info.u.pointer.u.linear_addr = (uintptr_t)buf;
+
+	err = vboxsf_call(SHFL_FN_INFORMATION, &parms, SHFL_CPARMS_INFORMATION,
+			  NULL);
+
+	*buf_len = parms.cb.u.value32;
+	return err;
+}
+
+int vboxsf_readlink(u32 root, struct shfl_string *parsed_path,
+		    u32 buf_len, u8 *buf)
+{
+	struct shfl_readLink parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.path.u.pointer.size = shfl_string_buf_size(parsed_path);
+	parms.path.u.pointer.u.linear_addr = (uintptr_t)parsed_path;
+
+	parms.buffer.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT;
+	parms.buffer.u.pointer.size = buf_len;
+	parms.buffer.u.pointer.u.linear_addr = (uintptr_t)buf;
+
+	return vboxsf_call(SHFL_FN_READLINK, &parms, SHFL_CPARMS_READLINK,
+			   NULL);
+}
+
+int vboxsf_symlink(u32 root, struct shfl_string *new_path,
+		   struct shfl_string *old_path, struct shfl_fsobjinfo *buf)
+{
+	struct shfl_symlink parms;
+
+	parms.root.type = VMMDEV_HGCM_PARM_TYPE_32BIT;
+	parms.root.u.value32 = root;
+
+	parms.new_path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.new_path.u.pointer.size = shfl_string_buf_size(new_path);
+	parms.new_path.u.pointer.u.linear_addr = (uintptr_t)new_path;
+
+	parms.old_path.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN;
+	parms.old_path.u.pointer.size = shfl_string_buf_size(old_path);
+	parms.old_path.u.pointer.u.linear_addr = (uintptr_t)old_path;
+
+	parms.info.type = VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT;
+	parms.info.u.pointer.size = sizeof(struct shfl_fsobjinfo);
+	parms.info.u.pointer.u.linear_addr = (uintptr_t)buf;
+
+	return vboxsf_call(SHFL_FN_SYMLINK, &parms, SHFL_CPARMS_SYMLINK, NULL);
+}
+
+int vboxsf_set_utf8(void)
+{
+	return vboxsf_call(SHFL_FN_SET_UTF8, NULL, 0, NULL);
+}
+
+int vboxsf_set_symlinks(void)
+{
+	return vboxsf_call(SHFL_FN_SET_SYMLINKS, NULL, 0, NULL);
+}
diff --git a/fs/vboxsf/vfsmod.h b/fs/vboxsf/vfsmod.h
new file mode 100644
index 000000000000..23a6e5deac4c
--- /dev/null
+++ b/fs/vboxsf/vfsmod.h
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * VirtualBox Guest Shared Folders support: module header.
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#ifndef VFSMOD_H
+#define VFSMOD_H
+
+#include <linux/backing-dev.h>
+#include <linux/idr.h>
+#include <linux/version.h>
+#include "shfl_hostintf.h"
+
+#define DIR_BUFFER_SIZE SZ_16K
+
+/* The cast is to prevent assignment of void * to pointers of arbitrary type */
+#define GET_GLOB_INFO(sb)       ((struct sf_glob_info *)(sb)->s_fs_info)
+#define SET_GLOB_INFO(sb, sf_g) ((sb)->s_fs_info = (sf_g))
+#define GET_INODE_INFO(i)       container_of(i, struct sf_inode_info, vfs_inode)
+
+struct vboxsf_options {
+	int ttl;
+	int uid;
+	int gid;
+	int dmode;
+	int fmode;
+	int dmask;
+	int fmask;
+};
+
+struct vboxsf_fs_context {
+	struct vboxsf_options o;
+	char *nls_name;
+};
+
+/* per-shared folder information */
+struct sf_glob_info {
+	struct vboxsf_options o;
+	struct shfl_fsobjinfo root_info;
+	struct idr ino_idr;
+	spinlock_t ino_idr_lock;
+	struct nls_table *nls;
+	u32 next_generation;
+	u32 root;
+	int bdi_id;
+};
+
+/* per-inode information */
+struct sf_inode_info {
+	/* some information was changed, update data on next revalidate */
+	int force_restat;
+	/* list of open handles for this inode + lock protecting it */
+	struct list_head handle_list;
+	struct mutex handle_list_mutex;
+	/* The VFS inode struct */
+	struct inode vfs_inode;
+};
+
+struct sf_dir_info {
+	struct list_head info_list;
+};
+
+struct sf_dir_buf {
+	size_t entries;
+	size_t free;
+	size_t used;
+	void *buf;
+	struct list_head head;
+};
+
+/* globals */
+extern const struct inode_operations vboxsf_dir_iops;
+extern const struct inode_operations vboxsf_lnk_iops;
+extern const struct inode_operations vboxsf_reg_iops;
+extern const struct file_operations vboxsf_dir_fops;
+extern const struct file_operations vboxsf_reg_fops;
+extern const struct address_space_operations vboxsf_reg_aops;
+extern const struct dentry_operations vboxsf_dentry_ops;
+
+/* from utils.c */
+struct inode *vboxsf_new_inode(struct super_block *sb);
+void vboxsf_init_inode(struct sf_glob_info *sf_g, struct inode *inode,
+		       const struct shfl_fsobjinfo *info);
+int vboxsf_create_at_dentry(struct dentry *dentry,
+			    struct shfl_createparms *params);
+int vboxsf_stat(struct sf_glob_info *sf_g, struct shfl_string *path,
+		struct shfl_fsobjinfo *info);
+int vboxsf_stat_dentry(struct dentry *dentry, struct shfl_fsobjinfo *info);
+int vboxsf_inode_revalidate(struct dentry *dentry);
+int vboxsf_getattr(const struct path *path, struct kstat *kstat,
+		   u32 request_mask, unsigned int query_flags);
+int vboxsf_setattr(struct dentry *dentry, struct iattr *iattr);
+struct shfl_string *vboxsf_path_from_dentry(struct sf_glob_info *sf_g,
+					    struct dentry *dentry);
+int vboxsf_nlscpy(struct sf_glob_info *sf_g, char *name, size_t name_bound_len,
+		  const unsigned char *utf8_name, size_t utf8_len);
+struct sf_dir_info *vboxsf_dir_info_alloc(void);
+void vboxsf_dir_info_free(struct sf_dir_info *p);
+int vboxsf_dir_read_all(struct sf_glob_info *sf_g, struct sf_dir_info *sf_d,
+			u64 handle);
+
+/* from vboxsf_wrappers.c */
+int vboxsf_connect(void);
+void vboxsf_disconnect(void);
+
+int vboxsf_create(u32 root, struct shfl_string *parsed_path,
+		  struct shfl_createparms *create_parms);
+
+int vboxsf_close(u32 root, u64 handle);
+int vboxsf_remove(u32 root, struct shfl_string *parsed_path, u32 flags);
+int vboxsf_rename(u32 root, struct shfl_string *src_path,
+		  struct shfl_string *dest_path, u32 flags);
+
+int vboxsf_read(u32 root, u64 handle, u64 offset,
+		u32 *buf_len, uintptr_t buf, bool user);
+int vboxsf_write(u32 root, u64 handle, u64 offset,
+		 u32 *buf_len, uintptr_t buf, bool user);
+
+int vboxsf_dirinfo(u32 root, u64 handle,
+		   struct shfl_string *parsed_path, u32 flags, u32 index,
+		   u32 *buf_len, struct shfl_dirinfo *buf, u32 *file_count);
+int vboxsf_fsinfo(u32 root, u64 handle, u32 flags,
+		  u32 *buf_len, void *buf);
+
+int vboxsf_map_folder(struct shfl_string *folder_name, u32 *root);
+int vboxsf_unmap_folder(u32 root);
+
+int vboxsf_readlink(u32 root, struct shfl_string *parsed_path,
+		    u32 buf_len, u8 *buf);
+int vboxsf_symlink(u32 root, struct shfl_string *new_path,
+		   struct shfl_string *old_path, struct shfl_fsobjinfo *buf);
+
+int vboxsf_set_utf8(void);
+int vboxsf_set_symlinks(void);
+
+#endif
