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[RFC 2/2] fs: Add VirtualBox guest shared folder (vboxsf) support




VirtualBox hosts can share folders with guests, this commit adds a
VFS driver implementing the Linux-guest side of this, allowing folders
exported by the host to be mounted under Linux.

This driver depends on the guest <-> host IPC functions exported by
the vboxguest driver.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
 fs/Kconfig                  |    1 +
 fs/Makefile                 |    1 +
 fs/vboxsf/Kconfig           |    9 +
 fs/vboxsf/Makefile          |    3 +
 fs/vboxsf/dirops.c          |  730 ++++++++++++++++++++++++
 fs/vboxsf/lnkops.c          |   41 ++
 fs/vboxsf/regops.c          |  557 ++++++++++++++++++
 fs/vboxsf/shfl_hostintf.h   | 1318 +++++++++++++++++++++++++++++++++++++++++++
 fs/vboxsf/utils.c           |  671 ++++++++++++++++++++++
 fs/vboxsf/vboxsf_wrappers.c |  542 ++++++++++++++++++
 fs/vboxsf/vboxsf_wrappers.h |  104 ++++
 fs/vboxsf/vbsfmount.h       |   69 +++
 fs/vboxsf/vfsmod.c          |  412 ++++++++++++++
 fs/vboxsf/vfsmod.h          |  111 ++++
 14 files changed, 4569 insertions(+)
 create mode 100644 fs/vboxsf/Kconfig
 create mode 100644 fs/vboxsf/Makefile
 create mode 100644 fs/vboxsf/dirops.c
 create mode 100644 fs/vboxsf/lnkops.c
 create mode 100644 fs/vboxsf/regops.c
 create mode 100644 fs/vboxsf/shfl_hostintf.h
 create mode 100644 fs/vboxsf/utils.c
 create mode 100644 fs/vboxsf/vboxsf_wrappers.c
 create mode 100644 fs/vboxsf/vboxsf_wrappers.h
 create mode 100644 fs/vboxsf/vbsfmount.h
 create mode 100644 fs/vboxsf/vfsmod.c
 create mode 100644 fs/vboxsf/vfsmod.h

diff --git a/fs/Kconfig b/fs/Kconfig
index 7aee6d699fd6..7f80ad1cf591 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -248,6 +248,7 @@ source "fs/pstore/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
 source "fs/exofs/Kconfig"
+source "fs/vboxsf/Kconfig"
 
 endif # MISC_FILESYSTEMS
 
diff --git a/fs/Makefile b/fs/Makefile
index 7bbaca9c67b1..6b5039e3ade5 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -128,3 +128,4 @@ obj-y				+= exofs/ # Multiple modules
 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..620e2232969c
--- /dev/null
+++ b/fs/vboxsf/Kconfig
@@ -0,0 +1,9 @@
+config VBOXSF_FS
+	tristate "VirtualBox guest shared folder (vboxsf) support"
+	depends on VBOXGUEST
+	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..f3529ea02d5c
--- /dev/null
+++ b/fs/vboxsf/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_VBOXSF_FS) += vboxsf.o
+
+vboxsf-objs := dirops.o lnkops.o regops.o utils.o vboxsf_wrappers.o vfsmod.o
diff --git a/fs/vboxsf/dirops.c b/fs/vboxsf/dirops.c
new file mode 100644
index 000000000000..e32040abca98
--- /dev/null
+++ b/fs/vboxsf/dirops.c
@@ -0,0 +1,730 @@
+/*
+ * VirtualBox Guest Shared Folders support: Directory inode and file operations
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+#include <linux/vbox_err.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+/**
+ * Open a directory. Read the complete content into a buffer.
+ *
+ * @param inode     inode
+ * @param file      file
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_dir_open(struct inode *inode, struct file *file)
+{
+	int rc;
+	int err;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_dir_info *sf_d;
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct shfl_createparms params = {};
+
+	BUG_ON(!sf_g);
+	BUG_ON(!sf_i);
+
+	if (file->private_data)
+		return 0;
+
+	sf_d = sf_dir_info_alloc();
+	if (!sf_d)
+		return -ENOMEM;
+
+	params.Handle = SHFL_HANDLE_NIL;
+	params.CreateFlags = 0
+	    | SHFL_CF_DIRECTORY
+	    | SHFL_CF_ACT_OPEN_IF_EXISTS
+	    | SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;
+
+	rc = vboxsf_create(sf_g->root, sf_i->path, &params);
+	if (rc >= 0) {
+		if (params.Result == SHFL_FILE_EXISTS) {
+			err = sf_dir_read_all(sf_g, sf_i, sf_d, params.Handle);
+			if (!err)
+				file->private_data = sf_d;
+		} else
+			err = -ENOENT;
+
+		vboxsf_close(sf_g->root, params.Handle);
+	} else
+		err = -EPERM;
+
+	if (err)
+		sf_dir_info_free(sf_d);
+
+	return err;
+}
+
+/**
+ * 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
+ *
+ * @param inode     inode
+ * @param file      file
+ * returns 0 on success, Linux error code otherwise
+ */
+static int sf_dir_release(struct inode *inode, struct file *file)
+{
+	if (file->private_data)
+		sf_dir_info_free(file->private_data);
+
+	return 0;
+}
+
+/**
+ * Translate RTFMODE into DT_xxx (in conjunction to rtDirType())
+ * @param fMode     file mode
+ * returns d_type
+ */
+static int sf_get_d_type(u32 fMode)
+{
+	int d_type;
+	switch (fMode & 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;
+}
+
+/**
+ * Extract element ([dir]->f_pos) from the directory [dir] into [d_name].
+ *
+ * @returns 0 for success, 1 for end reached, Linux error code otherwise.
+ */
+static int sf_getdent(struct file *dir, char d_name[NAME_MAX], int *d_type)
+{
+	loff_t cur;
+	struct sf_glob_info *sf_g;
+	struct sf_dir_info *sf_d;
+	struct sf_inode_info *sf_i;
+	struct inode *inode;
+	struct list_head *pos, *list;
+
+	inode = GET_F_DENTRY(dir)->d_inode;
+	sf_i = GET_INODE_INFO(inode);
+	sf_g = GET_GLOB_INFO(inode->i_sb);
+	sf_d = dir->private_data;
+
+	BUG_ON(!sf_g);
+	BUG_ON(!sf_d);
+	BUG_ON(!sf_i);
+
+	if (sf_i->force_reread) {
+		int rc;
+		int err;
+		struct shfl_createparms params = {};
+
+		params.Handle = SHFL_HANDLE_NIL;
+		params.CreateFlags = 0
+		    | SHFL_CF_DIRECTORY
+		    | SHFL_CF_ACT_OPEN_IF_EXISTS
+		    | SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;
+
+		rc = vboxsf_create(sf_g->root, sf_i->path, &params);
+		if (rc < 0)
+			return -EPERM;
+
+		if (params.Result != SHFL_FILE_EXISTS) {
+			sf_dir_info_free(sf_d);
+			return -ENOENT;
+		}
+
+		sf_dir_info_empty(sf_d);
+		err = sf_dir_read_all(sf_g, sf_i, sf_d, params.Handle);
+		vboxsf_close(sf_g->root, params.Handle);
+		if (err)
+			return err;
+
+		sf_i->force_reread = 0;
+	}
+
+	cur = 0;
+	list = &sf_d->info_list;
+	list_for_each(pos, list) {
+		struct sf_dir_buf *b;
+		SHFLDIRINFO *info;
+		loff_t i;
+
+		b = list_entry(pos, struct sf_dir_buf, head);
+		if (dir->f_pos >= cur + b->cEntries) {
+			cur += b->cEntries;
+			continue;
+		}
+
+		for (i = 0, info = b->buf; i < dir->f_pos - cur; ++i) {
+			size_t size;
+
+			size =
+			    offsetof(SHFLDIRINFO,
+				     name.String) + info->name.u16Size;
+			info = (SHFLDIRINFO *) ((uintptr_t) info + size);
+		}
+
+		*d_type = sf_get_d_type(info->Info.Attr.fMode);
+
+		return sf_nlscpy(sf_g, d_name, NAME_MAX,
+				 info->name.String.utf8, info->name.u16Length);
+	}
+
+	return 1;
+}
+
+/**
+ * This is called when vfs wants to populate internal buffers with
+ * directory [dir]s contents. [opaque] is an argument to the
+ * [filldir]. [filldir] magically modifies it's argument - [opaque]
+ * and takes following additional arguments (which i in turn get from
+ * the host via sf_getdent):
+ *
+ * name : name of the entry (i must also supply it's length huh?)
+ * type : type of the entry (FILE | DIR | etc) (i ellect to use DT_UNKNOWN)
+ * pos : position/index of the entry
+ * ino : inode number of the entry (i fake those)
+ *
+ * [dir] contains:
+ * f_pos : cursor into the directory listing
+ * private_data : mean of communication with the host side
+ *
+ * Extract elements from the directory listing (incrementing f_pos
+ * along the way) and feed them to [filldir] until:
+ *
+ * a. there are no more entries (i.e. sf_getdent set done to 1)
+ * b. failure to compute fake inode number
+ * c. filldir returns an error (see comment on that)
+ */
+static int sf_dir_iterate(struct file *dir, struct dir_context *ctx)
+{
+	for (;;) {
+		int err;
+		ino_t fake_ino;
+		loff_t sanity;
+		char d_name[NAME_MAX];
+		int d_type = DT_UNKNOWN;
+
+		err = sf_getdent(dir, d_name, &d_type);
+		switch (err) {
+		case 1:
+			return 0;
+
+		case 0:
+			break;
+
+		case -1:
+		default:
+			/* skip erroneous entry and proceed */
+			dir->f_pos += 1;
+			ctx->pos += 1;
+			continue;
+		}
+
+		/* d_name now contains a valid entry name */
+		sanity = ctx->pos + 0xbeef;
+		fake_ino = sanity;
+		/*
+		 * On 32 bit systems pos is 64 signed, while ino is 32 bit
+		 * unsigned so fake_ino may overflow, check for this.
+		 */
+		if (sanity - fake_ino) {
+			vbg_err("vboxsf: can not compute ino\n");
+			return -EINVAL;
+		}
+		if (!dir_emit(ctx, d_name, strlen(d_name), fake_ino, d_type))
+			return 0;
+
+		dir->f_pos += 1;
+		ctx->pos += 1;
+	}
+}
+
+struct file_operations sf_dir_fops = {
+	.open = sf_dir_open,
+	.iterate = sf_dir_iterate,
+	.release = sf_dir_release,
+	.read = generic_read_dir,
+	.llseek = generic_file_llseek,
+};
+
+/* iops */
+
+/**
+ * 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. NULL(or "positive" pointer) ought to be
+ * returned in case of success and "negative" pointer on error
+ */
+static struct dentry *sf_lookup(struct inode *parent, struct dentry *dentry,
+				unsigned int flags)
+{
+	int err;
+	struct sf_inode_info *sf_i, *sf_new_i;
+	struct sf_glob_info *sf_g;
+	SHFLSTRING *path;
+	struct inode *inode;
+	ino_t ino;
+	struct shfl_fsobjinfo fsinfo;
+
+	sf_g = GET_GLOB_INFO(parent->i_sb);
+	sf_i = GET_INODE_INFO(parent);
+
+	BUG_ON(!sf_g);
+	BUG_ON(!sf_i);
+
+	err = sf_path_from_dentry(__func__, sf_g, sf_i, dentry, &path);
+	if (err)
+		goto fail0;
+
+	err = sf_stat(__func__, sf_g, path, &fsinfo, 1);
+	if (err) {
+		if (err == -ENOENT) {
+			/* -ENOENT: add NULL inode to dentry so it later can be
+			   created via call to create/mkdir/open */
+			kfree(path);
+			inode = NULL;
+		} else
+			goto fail1;
+	} else {
+		sf_new_i = kmalloc(sizeof(*sf_new_i), GFP_KERNEL);
+		if (!sf_new_i) {
+			err = -ENOMEM;
+			goto fail1;
+		}
+		sf_new_i->handle = SHFL_HANDLE_NIL;
+		sf_new_i->force_reread = 0;
+
+		ino = iunique(parent->i_sb, 1);
+		inode = iget_locked(parent->i_sb, ino);
+		if (!inode) {
+			err = -ENOMEM;	/* XXX: ??? */
+			goto fail2;
+		}
+
+		SET_INODE_INFO(inode, sf_new_i);
+		sf_init_inode(sf_g, inode, &fsinfo);
+		sf_new_i->path = path;
+
+		unlock_new_inode(inode);
+	}
+
+	sf_i->force_restat = 0;
+	dentry->d_time = jiffies;
+	d_set_d_op(dentry, &sf_dentry_ops);
+	d_add(dentry, inode);
+	return NULL;
+
+fail2:
+	kfree(sf_new_i);
+
+fail1:
+	kfree(path);
+
+fail0:
+	return ERR_PTR(err);
+}
+
+/**
+ * This should allocate memory for sf_inode_info, compute a unique inode
+ * number, get an inode from vfs, initialize inode info, instantiate
+ * dentry.
+ *
+ * @param parent        inode entry of the directory
+ * @param dentry        directory cache entry
+ * @param path          path name
+ * @param info          file information
+ * @param handle        handle
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_instantiate(struct inode *parent, struct dentry *dentry,
+			  SHFLSTRING * path, struct shfl_fsobjinfo *info,
+			  SHFLHANDLE handle)
+{
+	int err;
+	ino_t ino;
+	struct inode *inode;
+	struct sf_inode_info *sf_new_i;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+
+	BUG_ON(!sf_g);
+
+	sf_new_i = kmalloc(sizeof(*sf_new_i), GFP_KERNEL);
+	if (!sf_new_i) {
+		err = -ENOMEM;
+		goto fail0;
+	}
+
+	ino = iunique(parent->i_sb, 1);
+	inode = iget_locked(parent->i_sb, ino);
+	if (!inode) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	sf_init_inode(sf_g, inode, info);
+	sf_new_i->path = path;
+	SET_INODE_INFO(inode, sf_new_i);
+	sf_new_i->force_restat = 1;
+	sf_new_i->force_reread = 0;
+
+	d_instantiate(dentry, inode);
+	unlock_new_inode(inode);
+
+	/* Store this handle if we leave the handle open. */
+	sf_new_i->handle = handle;
+	return 0;
+
+fail1:
+	kfree(sf_new_i);
+
+fail0:
+	return err;
+
+}
+
+/**
+ * Create a new regular file / directory.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @param mode          file mode
+ * @param fDirectory    true if directory, false otherwise
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_create_aux(struct inode *parent, struct dentry *dentry,
+			 umode_t mode, int fDirectory)
+{
+	int rc, err;
+	struct shfl_createparms params = {};
+	SHFLSTRING *path;
+	struct sf_inode_info *sf_i = GET_INODE_INFO(parent);
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+
+	BUG_ON(!sf_i);
+	BUG_ON(!sf_g);
+
+	err = sf_path_from_dentry(__func__, sf_g, sf_i, dentry, &path);
+	if (err)
+		goto fail0;
+
+	params.Handle = SHFL_HANDLE_NIL;
+	params.CreateFlags = 0
+	    | SHFL_CF_ACT_CREATE_IF_NEW
+	    | SHFL_CF_ACT_FAIL_IF_EXISTS
+	    | SHFL_CF_ACCESS_READWRITE | (fDirectory ? SHFL_CF_DIRECTORY : 0);
+	params.Info.Attr.fMode = 0
+	    | (fDirectory ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE)
+	    | (mode & S_IRWXUGO);
+	params.Info.Attr.enmAdditional = SHFLFSOBJATTRADD_NOTHING;
+
+	rc = vboxsf_create(sf_g->root, path, &params);
+	if (rc < 0) {
+		if (rc == VERR_WRITE_PROTECT) {
+			err = -EROFS;
+			goto fail1;
+		}
+		err = -EPROTO;
+		goto fail1;
+	}
+
+	if (params.Result != SHFL_FILE_CREATED) {
+		err = -EPERM;
+		goto fail1;
+	}
+
+	err = sf_instantiate(parent, dentry, path, &params.Info,
+			     fDirectory ? SHFL_HANDLE_NIL : params.Handle);
+	if (err)
+		goto fail2;
+
+	/*
+	 * Don't close this handle right now. We assume that the same file is
+	 * opened with sf_reg_open() and later closed with sf_reg_close(). Save
+	 * the handle in between. Does not apply to directories. True?
+	 */
+	if (fDirectory)
+		vboxsf_close(sf_g->root, params.Handle);
+
+	sf_i->force_restat = 1;
+	return 0;
+
+fail2:
+	vboxsf_close(sf_g->root, params.Handle);
+
+fail1:
+	kfree(path);
+
+fail0:
+	return err;
+}
+
+/**
+ * Create a new regular file.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @param mode          file mode
+ * @param excl          Possible O_EXCL...
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_create(struct inode *parent, struct dentry *dentry, umode_t mode,
+		     bool excl)
+{
+	return sf_create_aux(parent, dentry, mode, 0);
+}
+
+/**
+ * Create a new directory.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @param mode          file mode
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_mkdir(struct inode *parent, struct dentry *dentry, umode_t mode)
+{
+	return sf_create_aux(parent, dentry, mode, 1);
+}
+
+/**
+ * Remove a regular file / directory.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @param fDirectory    true if directory, false otherwise
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_unlink_aux(struct inode *parent, struct dentry *dentry,
+			 int fDirectory)
+{
+	int rc, err;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(parent->i_sb);
+	struct sf_inode_info *sf_i = GET_INODE_INFO(parent);
+	SHFLSTRING *path;
+	uint32_t fFlags;
+
+	BUG_ON(!sf_g);
+
+	err = sf_path_from_dentry(__func__, sf_g, sf_i, dentry, &path);
+	if (err)
+		goto fail0;
+
+	fFlags = fDirectory ? SHFL_REMOVE_DIR : SHFL_REMOVE_FILE;
+	if (dentry
+	    && dentry->d_inode
+	    && ((dentry->d_inode->i_mode & S_IFLNK) == S_IFLNK))
+		fFlags |= SHFL_REMOVE_SYMLINK;
+	rc = vboxsf_remove(sf_g->root, path, fFlags);
+	if (rc < 0) {
+		err = -vbg_status_code_to_errno(rc);
+		goto fail1;
+	}
+
+	/* directory access/change time changed */
+	sf_i->force_restat = 1;
+	/* directory content changed */
+	sf_i->force_reread = 1;
+
+	err = 0;
+
+fail1:
+	kfree(path);
+
+fail0:
+	return err;
+}
+
+/**
+ * Remove a regular file.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_unlink(struct inode *parent, struct dentry *dentry)
+{
+	return sf_unlink_aux(parent, dentry, 0);
+}
+
+/**
+ * Remove a directory.
+ *
+ * @param parent        inode of the directory
+ * @param dentry        directory cache entry
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_rmdir(struct inode *parent, struct dentry *dentry)
+{
+	return sf_unlink_aux(parent, dentry, 1);
+}
+
+/**
+ * Rename a regular file / directory.
+ *
+ * @param old_parent    inode of the old parent directory
+ * @param old_dentry    old directory cache entry
+ * @param new_parent    inode of the new parent directory
+ * @param new_dentry    new directory cache entry
+ * @param flags         flags
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_rename(struct inode *old_parent, struct dentry *old_dentry,
+		     struct inode *new_parent, struct dentry *new_dentry,
+		     unsigned int flags)
+{
+	int err = 0, rc = VINF_SUCCESS;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(old_parent->i_sb);
+	u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS;
+
+	if (flags)
+		return -EINVAL;
+
+	if (sf_g != GET_GLOB_INFO(new_parent->i_sb)) {
+		err = -EINVAL;
+	} else {
+		struct sf_inode_info *sf_old_i = GET_INODE_INFO(old_parent);
+		struct sf_inode_info *sf_new_i = GET_INODE_INFO(new_parent);
+		/*
+		 * As we save the relative path inside the inode structure,
+		 * we need to change this if the rename is successful.
+		 */
+		struct sf_inode_info *sf_file_i =
+		    GET_INODE_INFO(old_dentry->d_inode);
+		SHFLSTRING *old_path;
+		SHFLSTRING *new_path;
+
+		BUG_ON(!sf_old_i);
+		BUG_ON(!sf_new_i);
+		BUG_ON(!sf_file_i);
+
+		old_path = sf_file_i->path;
+		err = sf_path_from_dentry(__func__, sf_g, sf_new_i,
+					  new_dentry, &new_path);
+		if (err == 0) {
+			if (old_dentry->d_inode->i_mode & S_IFDIR)
+				shfl_flags = 0;
+
+			rc = vboxsf_rename(sf_g->root, old_path, new_path,
+					   shfl_flags);
+			if (rc >= 0) {
+				kfree(old_path);
+				sf_new_i->force_restat = 1;
+				sf_old_i->force_restat = 1;	/* XXX: needed? */
+				/* Set the new relative path in the inode. */
+				sf_file_i->path = new_path;
+			} else {
+				err = -vbg_status_code_to_errno(rc);
+				kfree(new_path);
+			}
+		}
+	}
+	return err;
+}
+
+static int sf_symlink(struct inode *parent, struct dentry *dentry,
+		      const char *symname)
+{
+	int err;
+	int rc;
+	struct sf_inode_info *sf_i;
+	struct sf_glob_info *sf_g;
+	SHFLSTRING *path, *ssymname;
+	struct shfl_fsobjinfo info;
+	int symname_len = strlen(symname) + 1;
+
+	sf_g = GET_GLOB_INFO(parent->i_sb);
+	sf_i = GET_INODE_INFO(parent);
+
+	BUG_ON(!sf_g);
+	BUG_ON(!sf_i);
+
+	err = sf_path_from_dentry(__func__, sf_g, sf_i, dentry, &path);
+	if (err)
+		goto fail0;
+
+	ssymname =
+	    kmalloc(offsetof(SHFLSTRING, String.utf8) + symname_len,
+		    GFP_KERNEL);
+	if (!ssymname) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	ssymname->u16Length = symname_len - 1;
+	ssymname->u16Size = symname_len;
+	memcpy(ssymname->String.utf8, symname, symname_len);
+
+	rc = vboxsf_symlink(sf_g->root, path, ssymname, &info);
+	kfree(ssymname);
+
+	if (rc < 0) {
+		if (rc == VERR_WRITE_PROTECT) {
+			err = -EROFS;
+			goto fail1;
+		}
+		err = -EPROTO;
+		goto fail1;
+	}
+
+	err = sf_instantiate(parent, dentry, path, &info, SHFL_HANDLE_NIL);
+	if (err)
+		goto fail1;
+
+	sf_i->force_restat = 1;
+	return 0;
+
+fail1:
+	kfree(path);
+fail0:
+	return err;
+}
+
+struct inode_operations sf_dir_iops = {
+	.lookup = sf_lookup,
+	.create = sf_create,
+	.mkdir = sf_mkdir,
+	.rmdir = sf_rmdir,
+	.unlink = sf_unlink,
+	.rename = sf_rename,
+	.getattr = sf_getattr,
+	.setattr = sf_setattr,
+	.symlink = sf_symlink
+};
diff --git a/fs/vboxsf/lnkops.c b/fs/vboxsf/lnkops.c
new file mode 100644
index 000000000000..546b2a83166a
--- /dev/null
+++ b/fs/vboxsf/lnkops.c
@@ -0,0 +1,41 @@
+/*
+ * VirtualBox Guest Shared Folders: Operations for symbolic links.
+ *
+ * Copyright (C) 2010-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+#include "vfsmod.h"
+
+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 sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	char *path;
+	int rc;
+
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+	path = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!path)
+		return ERR_PTR(-ENOMEM);
+	rc = vboxsf_readlink(sf_g->root, sf_i->path, PATH_MAX, path);
+	if (rc < 0) {
+		kfree(path);
+		return ERR_PTR(-EPROTO);
+	}
+	set_delayed_call(done, kfree_link, path);
+	return path;
+}
+
+struct inode_operations sf_lnk_iops = {
+	.get_link = sf_get_link
+};
diff --git a/fs/vboxsf/regops.c b/fs/vboxsf/regops.c
new file mode 100644
index 000000000000..c3ee582df2a2
--- /dev/null
+++ b/fs/vboxsf/regops.c
@@ -0,0 +1,557 @@
+/*
+ * VirtualBox Guest Shared Folders support: Regular file inode and file ops.
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*
+ * Limitations: only COW memory mapping is supported
+ */
+
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+static void *alloc_bounce_buffer(size_t * tmp_sizep, u64 * physp, size_t
+				 xfer_size, const char *caller)
+{
+	size_t tmp_size;
+	void *tmp;
+
+	/* try for big first. */
+	tmp_size = PAGE_ALIGN(xfer_size);
+	if (tmp_size > SZ_16K)
+		tmp_size = SZ_16K;
+	tmp = kmalloc(tmp_size, GFP_KERNEL);
+	if (!tmp) {
+		/* fall back on a page sized buffer. */
+		tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!tmp)
+			return NULL;
+		tmp_size = PAGE_SIZE;
+	}
+
+	*tmp_sizep = tmp_size;
+	*physp = virt_to_phys(tmp);
+	return tmp;
+}
+
+static void free_bounce_buffer(void *tmp)
+{
+	kfree(tmp);
+}
+
+/* fops */
+static int sf_reg_read_aux(const char *caller, struct sf_glob_info *sf_g,
+			   struct sf_reg_info *sf_r, void *buf,
+			   uint32_t * nread, uint64_t pos)
+{
+	/**
+	 * @todo bird: yes, kmap() and kmalloc() input only. Since the buffer is
+	 * contiguous in physical memory (kmalloc or single page), we should
+	 * use a physical address here to speed things up.
+	 */
+	int rc = vboxsf_read(sf_g->root, sf_r->handle, pos, nread, buf);
+	if (rc < 0)
+		return -EPROTO;
+
+	return 0;
+}
+
+static int sf_reg_write_aux(const char *caller, struct sf_glob_info *sf_g,
+			    struct sf_reg_info *sf_r, void *buf,
+			    uint32_t * nwritten, uint64_t pos)
+{
+	/**
+	 * @todo bird: yes, kmap() and kmalloc() input only. Since the buffer
+	 * is contiguous in physical memory (kmalloc or single page), we should
+	 * use a physical address here to speed things up.
+	 */
+	int rc = vboxsf_write(sf_g->root, sf_r->handle, pos, nwritten, buf);
+	if (rc < 0)
+		return -EPROTO;
+
+	return 0;
+}
+
+/**
+ * Read from a regular file.
+ *
+ * @param file          the file
+ * @param buf           the buffer
+ * @param size          length of the buffer
+ * @param off           offset within the file
+ * @returns the number of read bytes on success, Linux error code otherwise
+ */
+static ssize_t sf_reg_read(struct file *file, char *buf, size_t size,
+			   loff_t * off)
+{
+	int err;
+	void *tmp;
+	u64 tmp_phys;
+	size_t tmp_size;
+	size_t left = size;
+	ssize_t total_bytes_read = 0;
+	struct inode *inode = GET_F_DENTRY(file)->d_inode;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_reg_info *sf_r = file->private_data;
+	loff_t pos = *off;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+    /** XXX Check read permission according to inode->i_mode! */
+
+	if (!size)
+		return 0;
+
+	tmp =
+	    alloc_bounce_buffer(&tmp_size, &tmp_phys, size,
+				__PRETTY_FUNCTION__);
+	if (!tmp)
+		return -ENOMEM;
+
+	while (left) {
+		uint32_t to_read, nread;
+
+		to_read = tmp_size;
+		if (to_read > left)
+			to_read = (uint32_t) left;
+
+		nread = to_read;
+
+		err = sf_reg_read_aux(__func__, sf_g, sf_r, tmp, &nread, pos);
+		if (err)
+			goto fail;
+
+		if (copy_to_user(buf, tmp, nread)) {
+			err = -EFAULT;
+			goto fail;
+		}
+
+		pos += nread;
+		left -= nread;
+		buf += nread;
+		total_bytes_read += nread;
+		if (nread != to_read)
+			break;
+	}
+
+	*off += total_bytes_read;
+	free_bounce_buffer(tmp);
+	return total_bytes_read;
+
+fail:
+	free_bounce_buffer(tmp);
+	return err;
+}
+
+/**
+ * Write to a regular file.
+ *
+ * @param file          the file
+ * @param buf           the buffer
+ * @param size          length of the buffer
+ * @param off           offset within the file
+ * @returns the number of written bytes on success, Linux error code otherwise
+ */
+static ssize_t sf_reg_write(struct file *file, const char *buf, size_t size,
+			    loff_t * off)
+{
+	int err;
+	void *tmp;
+	u64 tmp_phys;
+	size_t tmp_size;
+	size_t left = size;
+	ssize_t total_bytes_written = 0;
+	struct inode *inode = GET_F_DENTRY(file)->d_inode;
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_reg_info *sf_r = file->private_data;
+	loff_t pos;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	pos = *off;
+	if (file->f_flags & O_APPEND) {
+		pos = inode->i_size;
+		*off = pos;
+	}
+
+    /** XXX Check write permission according to inode->i_mode! */
+
+	if (!size)
+		return 0;
+
+	tmp =
+	    alloc_bounce_buffer(&tmp_size, &tmp_phys, size,
+				__PRETTY_FUNCTION__);
+	if (!tmp)
+		return -ENOMEM;
+
+	while (left) {
+		uint32_t to_write, nwritten;
+
+		to_write = tmp_size;
+		if (to_write > left)
+			to_write = (uint32_t) left;
+
+		nwritten = to_write;
+
+		if (copy_from_user(tmp, buf, to_write)) {
+			err = -EFAULT;
+			goto fail;
+		}
+
+		err = vboxsf_write_physcont(sf_g->root, sf_r->handle, pos,
+					    &nwritten, tmp_phys);
+		if (err < 0) {
+			err = -EPROTO;
+			goto fail;
+		}
+
+		pos += nwritten;
+		left -= nwritten;
+		buf += nwritten;
+		total_bytes_written += nwritten;
+		if (nwritten != to_write)
+			break;
+	}
+
+	*off += total_bytes_written;
+	if (*off > inode->i_size)
+		inode->i_size = *off;
+
+	sf_i->force_restat = 1;
+	free_bounce_buffer(tmp);
+	return total_bytes_written;
+
+fail:
+	free_bounce_buffer(tmp);
+	return err;
+}
+
+/**
+ * Open a regular file.
+ *
+ * @param inode         the inode
+ * @param file          the file
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_reg_open(struct inode *inode, struct file *file)
+{
+	int rc, rc_linux = 0;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct sf_reg_info *sf_r;
+	struct shfl_createparms params = {};
+
+	sf_r = kmalloc(sizeof(*sf_r), GFP_KERNEL);
+	if (!sf_r)
+		return -ENOMEM;
+
+	/* Already open? */
+	if (sf_i->handle != SHFL_HANDLE_NIL) {
+		/*
+		 * This inode was created with sf_create_aux(). Check the CreateFlags:
+		 * O_CREAT, O_TRUNC: inherent true (file was just created). Not sure
+		 * about the access flags (SHFL_CF_ACCESS_*).
+		 */
+		sf_i->force_restat = 1;
+		sf_r->handle = sf_i->handle;
+		sf_i->handle = SHFL_HANDLE_NIL;
+		sf_i->file = file;
+		file->private_data = sf_r;
+		return 0;
+	}
+
+	params.Handle = SHFL_HANDLE_NIL;
+	/* 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 fMode parameter */
+
+	if (file->f_flags & O_CREAT) {
+		params.CreateFlags |= 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.CreateFlags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
+		else
+			params.CreateFlags |= SHFL_CF_ACT_OPEN_IF_EXISTS;
+	} else {
+		params.CreateFlags |= SHFL_CF_ACT_FAIL_IF_NEW;
+		if (file->f_flags & O_TRUNC)
+			params.CreateFlags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
+	}
+
+	switch (file->f_flags & O_ACCMODE) {
+	case O_RDONLY:
+		params.CreateFlags |= SHFL_CF_ACCESS_READ;
+		break;
+
+	case O_WRONLY:
+		params.CreateFlags |= SHFL_CF_ACCESS_WRITE;
+		break;
+
+	case O_RDWR:
+		params.CreateFlags |= SHFL_CF_ACCESS_READWRITE;
+		break;
+
+	default:
+		BUG();
+	}
+
+	if (file->f_flags & O_APPEND)
+		params.CreateFlags |= SHFL_CF_ACCESS_APPEND;
+
+	params.Info.Attr.fMode = inode->i_mode;
+	rc = vboxsf_create(sf_g->root, sf_i->path, &params);
+	if (rc < 0) {
+		kfree(sf_r);
+		return -vbg_status_code_to_errno(rc);
+	}
+
+	if (SHFL_HANDLE_NIL == params.Handle) {
+		switch (params.Result) {
+		case SHFL_PATH_NOT_FOUND:
+		case SHFL_FILE_NOT_FOUND:
+			rc_linux = -ENOENT;
+			break;
+		case SHFL_FILE_EXISTS:
+			rc_linux = -EEXIST;
+			break;
+		default:
+			break;
+		}
+	}
+
+	sf_i->force_restat = 1;
+	sf_r->handle = params.Handle;
+	sf_i->file = file;
+	file->private_data = sf_r;
+	return rc_linux;
+}
+
+/**
+ * Close a regular file.
+ *
+ * @param inode         the inode
+ * @param file          the file
+ * @returns 0 on success, Linux error code otherwise
+ */
+static int sf_reg_release(struct inode *inode, struct file *file)
+{
+	struct sf_reg_info *sf_r;
+	struct sf_glob_info *sf_g;
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+
+	sf_g = GET_GLOB_INFO(inode->i_sb);
+	sf_r = file->private_data;
+
+	filemap_write_and_wait(inode->i_mapping);
+
+	vboxsf_close(sf_g->root, sf_r->handle);
+
+	kfree(sf_r);
+	sf_i->file = NULL;
+	sf_i->handle = SHFL_HANDLE_NIL;
+	file->private_data = NULL;
+	return 0;
+}
+
+static int sf_reg_fault(struct vm_fault *vmf)
+{
+	struct page *page;
+	char *buf;
+	loff_t off;
+	uint32_t nread = PAGE_SIZE;
+	int err;
+	struct vm_area_struct *vma = vmf->vma;
+	struct file *file = vma->vm_file;
+	struct inode *inode = GET_F_DENTRY(file)->d_inode;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_reg_info *sf_r = file->private_data;
+
+	if (vmf->pgoff > vma->vm_end)
+		return VM_FAULT_SIGBUS;
+
+	/*
+	 * Don't use GFP_HIGHUSER as long as sf_reg_read_aux() calls
+	 * vboxsf_read() which works on virtual addresses.
+	 */
+	page = alloc_page(GFP_USER);
+	if (!page)
+		return VM_FAULT_OOM;
+
+	buf = kmap(page);
+	off = (vmf->pgoff << PAGE_SHIFT);
+	err = sf_reg_read_aux(__func__, sf_g, sf_r, buf, &nread, off);
+	if (err) {
+		kunmap(page);
+		put_page(page);
+		return VM_FAULT_SIGBUS;
+	}
+
+	if (!nread)
+		clear_user_page(page_address(page), vmf->pgoff, page);
+	else
+		memset(buf + nread, 0, PAGE_SIZE - nread);
+
+	flush_dcache_page(page);
+	kunmap(page);
+	vmf->page = page;
+	return 0;
+}
+
+static struct vm_operations_struct sf_vma_ops = {
+	.fault = sf_reg_fault
+};
+
+static int sf_reg_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (vma->vm_flags & VM_SHARED)
+		return -EINVAL;
+
+	vma->vm_ops = &sf_vma_ops;
+	return 0;
+}
+
+struct file_operations sf_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,
+};
+
+struct inode_operations sf_reg_iops = {
+	.getattr = sf_getattr,
+	.setattr = sf_setattr
+};
+
+static int sf_readpage(struct file *file, struct page *page)
+{
+	struct inode *inode = GET_F_DENTRY(file)->d_inode;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_reg_info *sf_r = file->private_data;
+	uint32_t nread = PAGE_SIZE;
+	char *buf;
+	loff_t off = ((loff_t) page->index) << PAGE_SHIFT;
+	int err;
+
+	buf = kmap(page);
+	err = sf_reg_read_aux(__func__, sf_g, sf_r, buf, &nread, off);
+	if (err) {
+		kunmap(page);
+		if (PageLocked(page))
+			unlock_page(page);
+		return err;
+	}
+	memset(&buf[nread], 0, PAGE_SIZE - nread);
+	flush_dcache_page(page);
+	kunmap(page);
+	SetPageUptodate(page);
+	unlock_page(page);
+	return 0;
+}
+
+static int sf_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_inode_info *sf_i = GET_INODE_INFO(inode);
+	struct file *file = sf_i->file;
+	struct sf_reg_info *sf_r = file->private_data;
+	char *buf;
+	uint32_t nwritten = PAGE_SIZE;
+	int end_index = inode->i_size >> PAGE_SHIFT;
+	loff_t off = ((loff_t) page->index) << PAGE_SHIFT;
+	int err;
+
+	if (page->index >= end_index)
+		nwritten = inode->i_size & (PAGE_SIZE - 1);
+
+	buf = kmap(page);
+
+	err = sf_reg_write_aux(__func__, sf_g, sf_r, buf, &nwritten, off);
+	if (err < 0) {
+		ClearPageUptodate(page);
+		goto out;
+	}
+
+	if (off > inode->i_size)
+		inode->i_size = off;
+
+	if (PageError(page))
+		ClearPageError(page);
+	err = 0;
+
+out:
+	kunmap(page);
+
+	unlock_page(page);
+	return err;
+}
+
+int sf_write_begin(struct file *file, struct address_space *mapping, loff_t pos,
+		   unsigned len, unsigned flags, struct page **pagep,
+		   void **fsdata)
+{
+	return simple_write_begin(file, mapping, pos, len, flags, pagep,
+				  fsdata);
+}
+
+int sf_write_end(struct file *file, struct address_space *mapping, loff_t pos,
+		 unsigned len, unsigned copied, struct page *page, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct sf_glob_info *sf_g = GET_GLOB_INFO(inode->i_sb);
+	struct sf_reg_info *sf_r = file->private_data;
+	void *buf;
+	unsigned from = pos & (PAGE_SIZE - 1);
+	uint32_t nwritten = len;
+	int err;
+
+	buf = kmap(page);
+	err =
+	    sf_reg_write_aux(__func__, sf_g, sf_r, buf + from, &nwritten, pos);
+	kunmap(page);
+
+	if (!PageUptodate(page) && err == PAGE_SIZE)
+		SetPageUptodate(page);
+
+	if (err >= 0) {
+		pos += nwritten;
+		if (pos > inode->i_size)
+			inode->i_size = pos;
+	}
+
+	unlock_page(page);
+	put_page(page);
+
+	return nwritten;
+}
+
+struct address_space_operations sf_reg_aops = {
+	.readpage = sf_readpage,
+	.writepage = sf_writepage,
+	.write_begin = sf_write_begin,
+	.write_end = sf_write_end,
+};
diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h
new file mode 100644
index 000000000000..071f72cfbb86
--- /dev/null
+++ b/fs/vboxsf/shfl_hostintf.h
@@ -0,0 +1,1318 @@
+/*
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * VirtualBox Shared Folders: host interface definition.
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#ifndef SHFL_HOSTINTF_H
+#define SHFL_HOSTINTF_H
+
+#include <linux/vbox_vmmdev.h>
+
+/*
+ * We cannot use linux' compiletime_assert here because it expects to be used
+ * inside a function only. Use a typedef to a char array with a negative size.
+ */
+#define VBOXSF_ASSERT_SIZE(type, size) \
+    typedef char type ## _assert_size[1 - 2*!!(sizeof(struct type) != (size))]
+
+/**
+ * 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.
+ */
+
+/** Shared Folders service functions. (guest)
+ *  @{
+ */
+
+/** Query mappings changes. */
+#define SHFL_FN_QUERY_MAPPINGS      (1)
+/** Query mappings changes. */
+#define SHFL_FN_QUERY_MAP_NAME      (2)
+/** Open/create object. */
+#define SHFL_FN_CREATE              (3)
+/** Close object handle. */
+#define SHFL_FN_CLOSE               (4)
+/** Read object content. */
+#define SHFL_FN_READ                (5)
+/** Write new object content. */
+#define SHFL_FN_WRITE               (6)
+/** Lock/unlock a range in the object. */
+#define SHFL_FN_LOCK                (7)
+/** List object content. */
+#define SHFL_FN_LIST                (8)
+/** Query/set object information. */
+#define SHFL_FN_INFORMATION         (9)
+/** Remove object */
+#define SHFL_FN_REMOVE              (11)
+/** Map folder (legacy) */
+#define SHFL_FN_MAP_FOLDER_OLD      (12)
+/** Unmap folder */
+#define SHFL_FN_UNMAP_FOLDER        (13)
+/** Rename object (possibly moving it to another directory) */
+#define SHFL_FN_RENAME              (14)
+/** Flush file */
+#define SHFL_FN_FLUSH               (15)
+/** @todo macl, a description, please. */
+#define SHFL_FN_SET_UTF8            (16)
+#define SHFL_CPARMS_SET_UTF8        0
+/** Map folder */
+#define SHFL_FN_MAP_FOLDER          (17)
+/** Read symlink destination (as of VBox 4.0) */
+#define SHFL_FN_READLINK            (18)
+/** Create symlink (as of VBox 4.0) */
+#define SHFL_FN_SYMLINK             (19)
+/** Ask host to show symlinks (as of VBox 4.0) */
+#define SHFL_FN_SET_SYMLINKS        (20)
+#define SHFL_CPARMS_SET_SYMLINKS    0
+
+/** @} */
+
+/** Shared Folders service functions. (host)
+ *  @{
+ */
+
+/** Add shared folder mapping. */
+#define SHFL_FN_ADD_MAPPING         (1)
+/** Remove shared folder mapping. */
+#define SHFL_FN_REMOVE_MAPPING      (2)
+/** Set the led status light address. */
+#define SHFL_FN_SET_STATUS_LED      (3)
+/** Allow the guest to create symbolic links (as of VBox 4.0) */
+#define SHFL_FN_ALLOW_SYMLINKS_CREATE (4)
+/** @} */
+
+/** Root handle for a mapping. Root handles are unique.
+ *  @note
+ *  Function parameters structures consider
+ *  the root handle as 32 bit value. If the typedef
+ *  will be changed, then function parameters must be
+ *  changed accordingly. All those parameters are marked
+ *  with SHFLROOT in comments.
+ */
+typedef uint32_t SHFLROOT;
+
+#define SHFL_ROOT_NIL ((SHFLROOT)~0)
+
+/** A shared folders handle for an opened object. */
+typedef uint64_t SHFLHANDLE;
+
+#define SHFL_HANDLE_NIL  ((SHFLHANDLE)~0LL)
+#define SHFL_HANDLE_ROOT ((SHFLHANDLE)0LL)
+
+/** 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)
+
+/** @name Shared Folders strings. They can be either UTF-8 or UTF-16.
+ * @{
+ */
+
+/**
+ * Shared folder string buffer structure.
+ */
+typedef struct SHFLSTRING {
+	/** Allocated size of the String member in bytes. */
+	uint16_t u16Size;
+
+	/** Length of string without trailing nul in bytes. */
+	uint16_t u16Length;
+
+	/** UTF-8 or UTF-16 string. Nul terminated. */
+	union {
+		u8 utf8[1];
+		u16 utf16[1];
+		u16 ucs2[1];  /**< misnomer, use utf16. */
+	} String;
+} SHFLSTRING;
+VMMDEV_ASSERT_SIZE(SHFLSTRING, 6);
+VMMDEV_ASSERT_MEMBER_OFFSET(SHFLSTRING, String, 4);
+/** The size of SHFLSTRING w/o the string part. */
+#define SHFLSTRING_HEADER_SIZE  4
+VMMDEV_ASSERT_MEMBER_OFFSET(SHFLSTRING, String, SHFLSTRING_HEADER_SIZE);
+
+/** Pointer to a shared folder string buffer. */
+typedef SHFLSTRING *PSHFLSTRING;
+/** Pointer to a const shared folder string buffer. */
+typedef const SHFLSTRING *PCSHFLSTRING;
+
+/** Calculate size of the string. */
+static inline u32 ShflStringSizeOfBuffer(const struct SHFLSTRING *string)
+{
+	return string ? (uint32_t) (SHFLSTRING_HEADER_SIZE +
+				    string->u16Size) : 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) are
+	 *  available / requested.
+	 */
+	SHFLFSOBJATTRADD_UNIX,
+	/**
+	 * The additional extended attribute size (shfl_fsobjattr::u::EASize) 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.enmAdditional == 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 cHardlinks;
+
+	/**
+	 * 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 INodeIdDevice;
+
+	/**
+	 * The unique identifier (within the filesystem) of this filesystem object (st_ino).
+	 * Together with INodeIdDevice, 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 INodeId;
+
+	/**
+	 * User flags (st_flags).
+	 * This field is 0 if this information is not available.
+	 */
+	u32 fFlags;
+
+	/**
+	 * The current generation number (st_gen).
+	 * This field is 0 if this information is not available.
+	 */
+	u32 GenerationId;
+
+	/**
+	 * The device number of a character or block device type object (st_rdev).
+	 * This field is 0 if the file isn't of a character or block device type and
+	 * when the OS doesn't subscribe to the major+minor device idenfication scheme.
+	 */
+	u32 Device;
+} __packed;
+
+/** Extended attribute size. */
+struct SHFLFSOBJATTREASIZE {
+	s64 cb; /**< Size of EAs. */
+} __packed;
+
+/** Shared folder filesystem object attributes. */
+struct shfl_fsobjattr {
+	/**
+	 * Mode flags (st_mode). SHFL_UNIX_*, SHFL_TYPE_*, and SHFL_DOS_*.
+	 * @remarks We depend on a number of SHFL_ defines to remain unchanged.
+	 *          Fortuntately, these are depending on windows, dos and unix
+	 *          standard values, so this shouldn't be much of a pain.
+	 */
+	u32 fMode;
+
+	/** The additional attributes available. */
+	enum shfl_fsobjattr_add enmAdditional;
+
+	/**
+	 * 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;
+		struct shfl_fsobjattr_unix EASize;
+	} __packed u;
+} __packed;
+VBOXSF_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 cbObject;
+
+	/** Disk allocation size (st_blocks * DEV_BSIZE). */
+	s64 cbAllocated;
+
+	/**
+	 * Time of last access (st_atime).
+	 * @remarks  Here (and other places) we depend on the IPRT timespec to
+	 *           remain unchanged.
+	 */
+	struct shfl_timespec AccessTime;
+
+	/** Time of last data modification (st_mtime). */
+	struct shfl_timespec ModificationTime;
+
+	/**
+	 * Time of last status change (st_ctime).
+	 * If not available this is set to ModificationTime.
+	 */
+	struct shfl_timespec ChangeTime;
+
+	/**
+	 * Time of file birth (st_birthtime).
+	 * If not available this is set to ChangeTime.
+	 */
+	struct shfl_timespec BirthTime;
+
+	/** Attributes. */
+	struct shfl_fsobjattr Attr;
+
+} __packed;
+VBOXSF_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.
+ */
+typedef enum _SHFLCREATERESULT {
+	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
+} SHFLCREATERESULT;
+
+/** Open/create flags.
+ *  @{
+ */
+
+/** No flags. Initialization value. */
+#define SHFL_CF_NONE                  (0x00000000)
+
+/** Lookup only the object, do not return a handle. 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'.
+ *  @todo possibly not needed???
+ */
+#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        (SHFL_CF_ACCESS_READ | SHFL_CF_ACCESS_WRITE)
+
+/** 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          (SHFL_CF_ACCESS_DENYREAD | SHFL_CF_ACCESS_DENYWRITE)
+
+/** 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   (SHFL_CF_ACCESS_ATTR_READ | SHFL_CF_ACCESS_ATTR_WRITE)
+
+/** The file is opened in append mode. Ignored if SHFL_CF_ACCESS_WRITE is not set. */
+#define SHFL_CF_ACCESS_APPEND           (0x00040000)
+
+/** @} */
+
+struct shfl_createparms {
+	/* Returned handle of opened object. */
+	SHFLHANDLE Handle;
+
+	/* Returned result of the operation */
+	SHFLCREATERESULT Result;
+
+	/* SHFL_CF_* */
+	uint32_t CreateFlags;
+
+	/*
+	 * Attributes of object to create and
+	 * returned actual attributes of opened/created object.
+	 */
+	struct shfl_fsobjinfo Info;
+} __packed;
+
+/** Shared Folders mappings.
+ *  @{
+ */
+
+/** The mapping has been added since last query. */
+#define SHFL_MS_NEW        (1)
+/** The mapping has been deleted since last query. */
+#define SHFL_MS_DELETED    (2)
+
+typedef struct _SHFLMAPPING {
+	/** Mapping status. */
+	uint32_t u32Status;
+	/** Root handle. */
+	SHFLROOT root;
+} SHFLMAPPING;
+/** Pointer to a SHFLMAPPING structure. */
+typedef SHFLMAPPING *PSHFLMAPPING;
+
+/** @} */
+
+/** Shared Folder directory information
+ *  @{
+ */
+
+typedef struct _SHFLDIRINFO {
+	/** 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.
+	 */
+	uint16_t cucShortName;
+	/**
+	 * The short name for 8.3 compatibility.
+	 * Empty string if not available.
+	 */
+	u16 uszShortName[14];
+	/** @todo malc, a description, please. */
+	SHFLSTRING name;
+} SHFLDIRINFO, *PSHFLDIRINFO;
+
+/**
+ * Shared folder filesystem properties.
+ */
+typedef struct SHFLFSPROPERTIES {
+	/**
+	 * The maximum size of a filesystem object name.
+	 * This does not include the '\\0'.
+	 */
+	uint32_t cbMaxComponent;
+
+	/**
+	 * True if the filesystem is remote.
+	 * False if the filesystem is local.
+	 */
+	bool fRemote;
+
+	/**
+	 * True if the filesystem is case sensitive.
+	 * False if the filesystem is case insensitive.
+	 */
+	bool fCaseSensitive;
+
+	/**
+	 * True if the filesystem is mounted read only.
+	 * False if the filesystem is mounted read write.
+	 */
+	bool fReadOnly;
+
+	/**
+	 * True if the filesystem can encode unicode object names.
+	 * False if it can't.
+	 */
+	bool fSupportsUnicode;
+
+	/**
+	 * True if the filesystem is compresses.
+	 * False if it isn't or we don't know.
+	 */
+	bool fCompressed;
+
+	/**
+	 * True if the filesystem compresses of individual files.
+	 * False if it doesn't or we don't know.
+	 */
+	bool fFileCompression;
+
+	/** @todo more? */
+} SHFLFSPROPERTIES;
+VMMDEV_ASSERT_SIZE(SHFLFSPROPERTIES, 12);
+/** Pointer to a shared folder filesystem properties structure. */
+typedef SHFLFSPROPERTIES *PSHFLFSPROPERTIES;
+/** Pointer to a const shared folder filesystem properties structure. */
+typedef SHFLFSPROPERTIES const *PCSHFLFSPROPERTIES;
+
+typedef struct _SHFLVOLINFO {
+	s64 ullTotalAllocationBytes;
+	s64 ullAvailableAllocationBytes;
+	uint32_t ulBytesPerAllocationUnit;
+	uint32_t ulBytesPerSector;
+	uint32_t ulSerial;
+	SHFLFSPROPERTIES fsProperties;
+} SHFLVOLINFO, *PSHFLVOLINFO;
+
+/** @} */
+
+/**
+ * Function parameter structures.
+ * @{
+ */
+
+/** SHFL_FN_QUERY_MAPPINGS */
+
+/**
+  * Validation mask.  Needs to be adjusted
+  * whenever a new SHFL_MF_ flag is added.
+  */
+#define SHFL_MF_MASK       (0x00000011)
+/** UC2 enconded strings. */
+#define SHFL_MF_UCS2       (0x00000000)
+/** Guest uses UTF8 strings, if not set then the strings are unicode (UCS2). */
+#define SHFL_MF_UTF8       (0x00000001)
+/** Just handle the auto-mounted folders. */
+#define SHFL_MF_AUTOMOUNT  (0x00000010)
+
+/** Type of guest system. For future system dependent features. */
+#define SHFL_MF_SYSTEM_MASK    (0x0000FF00)
+#define SHFL_MF_SYSTEM_NONE    (0x00000000)
+#define SHFL_MF_SYSTEM_WINDOWS (0x00000100)
+#define SHFL_MF_SYSTEM_LINUX   (0x00000200)
+
+/** Parameters structure. */
+typedef struct _VBoxSFQueryMappings {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * 32bit, in:
+	 * Flags describing various client needs.
+	 */
+	HGCMFunctionParameter flags;
+
+	/**
+	 * 32bit, in/out:
+	 * Number of mappings the client expects.
+	 * This is the number of elements in the
+	 * mappings array.
+	 */
+	HGCMFunctionParameter numberOfMappings;
+
+	/**
+	 * pointer, in/out:
+	 * Points to array of SHFLMAPPING structures.
+	 */
+	HGCMFunctionParameter mappings;
+
+} VBoxSFQueryMappings;
+
+/** Number of parameters */
+#define SHFL_CPARMS_QUERY_MAPPINGS (3)
+
+/**
+ * SHFL_FN_QUERY_MAP_NAME
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFQueryMapName {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * 32bit, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in/out:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter name;
+
+} VBoxSFQueryMapName;
+
+/** Number of parameters */
+#define SHFL_CPARMS_QUERY_MAP_NAME (2)
+
+/**
+ * SHFL_FN_MAP_FOLDER_OLD
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFMapFolder_Old {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * pointer, out: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in: UTF16
+	 * Path delimiter
+	 */
+	HGCMFunctionParameter delimiter;
+
+} VBoxSFMapFolder_Old;
+
+/** Number of parameters */
+#define SHFL_CPARMS_MAP_FOLDER_OLD (3)
+
+/**
+ * SHFL_FN_MAP_FOLDER
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFMapFolder {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * pointer, out: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in: UTF16
+	 * Path delimiter
+	 */
+	HGCMFunctionParameter delimiter;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Case senstive flag
+	 */
+	HGCMFunctionParameter fCaseSensitive;
+
+} VBoxSFMapFolder;
+
+/** Number of parameters */
+#define SHFL_CPARMS_MAP_FOLDER (4)
+
+/**
+ * SHFL_FN_UNMAP_FOLDER
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFUnmapFolder {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+} VBoxSFUnmapFolder;
+
+/** Number of parameters */
+#define SHFL_CPARMS_UNMAP_FOLDER (1)
+
+/**
+ * SHFL_FN_CREATE
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFCreate {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * pointer, in/out:
+	 * Points to SHFLCREATEPARMS buffer.
+	 */
+	HGCMFunctionParameter parms;
+
+} VBoxSFCreate;
+
+/** Number of parameters */
+#define SHFL_CPARMS_CREATE (3)
+
+/**
+ * SHFL_FN_CLOSE
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFClose {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to close.
+	 */
+	HGCMFunctionParameter handle;
+
+} VBoxSFClose;
+
+/** Number of parameters */
+#define SHFL_CPARMS_CLOSE (2)
+
+/**
+ * SHFL_FN_READ
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFRead {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to read from.
+	 */
+	HGCMFunctionParameter handle;
+
+	/**
+	 * value64, in:
+	 * Offset to read from.
+	 */
+	HGCMFunctionParameter offset;
+
+	/**
+	 * value64, in/out:
+	 * Bytes to read/How many were read.
+	 */
+	HGCMFunctionParameter cb;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place data to.
+	 */
+	HGCMFunctionParameter buffer;
+
+} VBoxSFRead;
+
+/** Number of parameters */
+#define SHFL_CPARMS_READ (5)
+
+/**
+ * SHFL_FN_WRITE
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFWrite {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to write to.
+	 */
+	HGCMFunctionParameter handle;
+
+	/**
+	 * value64, in:
+	 * Offset to write to.
+	 */
+	HGCMFunctionParameter offset;
+
+	/**
+	 * value64, in/out:
+	 * Bytes to write/How many were written.
+	 */
+	HGCMFunctionParameter cb;
+
+	/**
+	 * pointer, in:
+	 * Data to write.
+	 */
+	HGCMFunctionParameter buffer;
+
+} VBoxSFWrite;
+
+/** Number of parameters */
+#define SHFL_CPARMS_WRITE (5)
+
+/**
+ * SHFL_FN_LOCK
+ */
+
+/** Lock owner is the HGCM client. */
+
+/** Lock mode bit mask. */
+#define SHFL_LOCK_MODE_MASK  (0x3)
+/** Cancel lock on the given range. */
+#define SHFL_LOCK_CANCEL     (0x0)
+/** Acquire read only lock. Prevent write to the range. */
+#define SHFL_LOCK_SHARED     (0x1)
+/** Acquire write lock. Prevent both write and read to the range. */
+#define SHFL_LOCK_EXCLUSIVE  (0x2)
+
+/** Do not wait for lock if it can not be acquired at the time. */
+#define SHFL_LOCK_NOWAIT     (0x0)
+/** Wait and acquire lock. */
+#define SHFL_LOCK_WAIT       (0x4)
+
+/** Lock the specified range. */
+#define SHFL_LOCK_PARTIAL    (0x0)
+/** Lock entire object. */
+#define SHFL_LOCK_ENTIRE     (0x8)
+
+/** Parameters structure. */
+typedef struct _VBoxSFLock {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to be locked.
+	 */
+	HGCMFunctionParameter handle;
+
+	/**
+	 * value64, in:
+	 * Starting offset of lock range.
+	 */
+	HGCMFunctionParameter offset;
+
+	/**
+	 * value64, in:
+	 * Length of range.
+	 */
+	HGCMFunctionParameter length;
+
+	/**
+	 * value32, in:
+	 * Lock flags SHFL_LOCK_*.
+	 */
+	HGCMFunctionParameter flags;
+
+} VBoxSFLock;
+
+/** Number of parameters */
+#define SHFL_CPARMS_LOCK (5)
+
+/**
+ * SHFL_FN_FLUSH
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFFlush {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to be locked.
+	 */
+	HGCMFunctionParameter handle;
+
+} VBoxSFFlush;
+
+/** Number of parameters */
+#define SHFL_CPARMS_FLUSH (2)
+
+/**
+ * SHFL_FN_LIST
+ */
+
+/** Listing information includes variable length RTDIRENTRY[EX] structures. */
+
+/** @todo might be necessary for future. */
+#define SHFL_LIST_NONE          0
+#define SHFL_LIST_RETURN_ONE        1
+
+/** Parameters structure. */
+typedef struct _VBoxSFList {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to be listed.
+	 */
+	HGCMFunctionParameter handle;
+
+	/**
+	 * value32, in:
+	 * List flags SHFL_LIST_*.
+	 */
+	HGCMFunctionParameter flags;
+
+	/**
+	 * value32, in/out:
+	 * Bytes to be used for listing information/How many bytes were used.
+	 */
+	HGCMFunctionParameter cb;
+
+	/**
+	 * pointer, in/optional
+	 * Points to SHFLSTRING buffer that specifies a search path.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place listing information to. (SHFLDIRINFO)
+	 */
+	HGCMFunctionParameter 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.
+	 */
+	HGCMFunctionParameter resumePoint;
+
+	/**
+	 * pointer, out:
+	 * Number of files returned
+	 */
+	HGCMFunctionParameter cFiles;
+
+} VBoxSFList;
+
+/** Number of parameters */
+#define SHFL_CPARMS_LIST (8)
+
+/**
+ * SHFL_FN_READLINK
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFReadLink {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * pointer, out:
+	 * Buffer to place data to.
+	 */
+	HGCMFunctionParameter buffer;
+
+} VBoxSFReadLink;
+
+/** 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)
+
+/** @todo different file info structures */
+
+/** Parameters structure. */
+typedef struct _VBoxSFInformation {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * value64, in:
+	 * SHFLHANDLE of object to be listed.
+	 */
+	HGCMFunctionParameter handle;
+
+	/**
+	 * value32, in:
+	 * SHFL_INFO_*
+	 */
+	HGCMFunctionParameter flags;
+
+	/**
+	 * value32, in/out:
+	 * Bytes to be used for information/How many bytes were used.
+	 */
+	HGCMFunctionParameter cb;
+
+	/**
+	 * pointer, in/out:
+	 * Information to be set/get (shfl_fsobjinfo or SHFLSTRING). Do not forget
+	 * to set the shfl_fsobjinfo::Attr::enmAdditional for Get operation as well.
+	 */
+	HGCMFunctionParameter info;
+
+} VBoxSFInformation;
+
+/** 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)
+
+/** Parameters structure. */
+typedef struct _VBoxSFRemove {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING buffer.
+	 */
+	HGCMFunctionParameter path;
+
+	/**
+	 * value32, in:
+	 * remove flags (file/directory)
+	 */
+	HGCMFunctionParameter flags;
+
+} VBoxSFRemove;
+
+#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)
+
+/** Parameters structure. */
+typedef struct _VBoxSFRename {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING src.
+	 */
+	HGCMFunctionParameter src;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING dest.
+	 */
+	HGCMFunctionParameter dest;
+
+	/**
+	 * value32, in:
+	 * rename flags (file/directory)
+	 */
+	HGCMFunctionParameter flags;
+
+} VBoxSFRename;
+
+#define SHFL_CPARMS_RENAME  (4)
+
+/**
+ * SHFL_FN_SYMLINK
+ */
+
+/** Parameters structure. */
+typedef struct _VBoxSFSymlink {
+	VBoxGuestHGCMCallInfo callInfo;
+
+	/**
+	 * pointer, in: SHFLROOT
+	 * Root handle of the mapping which name is queried.
+	 */
+	HGCMFunctionParameter root;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING of path for the new symlink.
+	 */
+	HGCMFunctionParameter newPath;
+
+	/**
+	 * pointer, in:
+	 * Points to SHFLSTRING of destination for symlink.
+	 */
+	HGCMFunctionParameter oldPath;
+
+	/**
+	 * pointer, out:
+	 * Information about created symlink.
+	 */
+	HGCMFunctionParameter info;
+
+} VBoxSFSymlink;
+
+#define SHFL_CPARMS_SYMLINK  (4)
+
+/**
+ * SHFL_FN_ADD_MAPPING
+ * Host call, no guest structure is used.
+ */
+
+/** mapping is writable */
+#define SHFL_ADD_MAPPING_F_WRITABLE         (RT_BIT_32(0))
+/** mapping is automounted by the guest */
+#define SHFL_ADD_MAPPING_F_AUTOMOUNT        (RT_BIT_32(1))
+/** allow the guest to create symlinks */
+#define SHFL_ADD_MAPPING_F_CREATE_SYMLINKS  (RT_BIT_32(2))
+/** mapping is actually missing on the host */
+#define SHFL_ADD_MAPPING_F_MISSING          (RT_BIT_32(3))
+
+#define SHFL_CPARMS_ADD_MAPPING  (3)
+
+/**
+ * SHFL_FN_REMOVE_MAPPING
+ * Host call, no guest structure is used.
+ */
+
+#define SHFL_CPARMS_REMOVE_MAPPING (1)
+
+/**
+ * SHFL_FN_SET_STATUS_LED
+ * Host call, no guest structure is used.
+ */
+
+#define SHFL_CPARMS_SET_STATUS_LED (1)
+
+/** @} */
+
+#endif
diff --git a/fs/vboxsf/utils.c b/fs/vboxsf/utils.c
new file mode 100644
index 000000000000..533dd539a480
--- /dev/null
+++ b/fs/vboxsf/utils.c
@@ -0,0 +1,671 @@
+/*
+ * VirtualBox Guest Shared Folders support: Utility functions.
+ * Mainly conversion from/to VirtualBox/Linux data structures.
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+#include <linux/namei.h>
+#include <linux/nfs_fs.h>
+#include <linux/nls.h>
+#include <linux/vfs.h>
+#include <linux/vbox_err.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+/*
+ * sf_reg_aops and sf_backing_dev_info are just quick implementations to make
+ * sendfile work. For more information have a look at
+ *
+ *   http://us1.samba.org/samba/ftp/cifs-cvs/ols2006-fs-tutorial-smf.odp
+ *
+ * and the sample implementation
+ *
+ *   http://pserver.samba.org/samba/ftp/cifs-cvs/samplefs.tar.gz
+ */
+
+static void sf_timespec_from_vbox(struct timespec *tv,
+				  const struct shfl_timespec *ts)
+{
+	s64 nsec, t = ts->ns_relative_to_unix_epoch;
+
+	nsec = do_div(t, 1000000000);
+	tv->tv_sec = t;
+	tv->tv_nsec = nsec;
+}
+
+static void sf_timespec_to_vbox(struct shfl_timespec *ts,
+				const struct timespec *tv)
+{
+	s64 t = (s64) tv->tv_nsec + (s64) tv->tv_sec * 1000000000;
+
+	ts->ns_relative_to_unix_epoch = t;
+}
+
+/* set [inode] attributes based on [info], uid/gid based on [sf_g] */
+void sf_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->fMode & (SHFL_UNIX_##r) ? (S_##r) : 0;
+
+	mode = mode_set(ISUID);
+	mode |= mode_set(ISGID);
+
+	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
+
+	inode->i_mapping->a_ops = &sf_reg_aops;
+
+	if (SHFL_IS_DIRECTORY(attr->fMode)) {
+		inode->i_mode = sf_g->dmode != ~0 ? (sf_g->dmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->dmask;
+		inode->i_mode |= S_IFDIR;
+		inode->i_op = &sf_dir_iops;
+		inode->i_fop = &sf_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->fMode)) {
+		inode->i_mode = sf_g->fmode != ~0 ? (sf_g->fmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->fmask;
+		inode->i_mode |= S_IFLNK;
+		inode->i_op = &sf_lnk_iops;
+		set_nlink(inode, 1);
+	} else {
+		inode->i_mode = sf_g->fmode != ~0 ? (sf_g->fmode & 0777) : mode;
+		inode->i_mode &= ~sf_g->fmask;
+		inode->i_mode |= S_IFREG;
+		inode->i_op = &sf_reg_iops;
+		inode->i_fop = &sf_reg_fops;
+		set_nlink(inode, 1);
+	}
+
+	inode->i_uid = make_kuid(current_user_ns(), sf_g->uid);
+	inode->i_gid = make_kgid(current_user_ns(), sf_g->gid);
+
+	inode->i_size = info->cbObject;
+	inode->i_blkbits = 12;
+	/* i_blocks always in units of 512 bytes! */
+	allocated = info->cbAllocated + 511;
+	do_div(allocated, 512);
+	inode->i_blocks = allocated;
+
+	sf_timespec_from_vbox(&inode->i_atime, &info->AccessTime);
+	sf_timespec_from_vbox(&inode->i_ctime, &info->ChangeTime);
+	sf_timespec_from_vbox(&inode->i_mtime, &info->ModificationTime);
+}
+
+int sf_stat(const char *caller, struct sf_glob_info *sf_g,
+	    SHFLSTRING * path, struct shfl_fsobjinfo *result, int ok_to_fail)
+{
+	struct shfl_createparms params = {};
+	int rc;
+
+	params.Handle = SHFL_HANDLE_NIL;
+	params.CreateFlags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW;
+	rc = vboxsf_create(sf_g->root, path, &params);
+	if (rc == VERR_INVALID_NAME) {
+		/* this can happen for names like 'foo*' on a Windows host */
+		return -ENOENT;
+	}
+	if (rc < 0)
+		return -EPROTO;
+
+	if (params.Result != SHFL_FILE_EXISTS)
+		return -ENOENT;
+
+	*result = params.Info;
+	return 0;
+}
+
+/* this is called directly as iop on 2.4, indirectly as dop
+   [sf_dentry_revalidate] on 2.4/2.6, indirectly as iop through
+   [sf_getattr] on 2.6. the job is to find out whether dentry/inode is
+   still valid. the test is failed if [dentry] does not have an inode
+   or [sf_stat] is unsuccessful, otherwise we return success and
+   update inode attributes */
+int sf_inode_revalidate(struct dentry *dentry)
+{
+	int err;
+	struct sf_glob_info *sf_g;
+	struct sf_inode_info *sf_i;
+	struct shfl_fsobjinfo info;
+
+	if (!dentry || !dentry->d_inode)
+		return -EINVAL;
+
+	sf_g = GET_GLOB_INFO(dentry->d_inode->i_sb);
+	sf_i = GET_INODE_INFO(dentry->d_inode);
+
+	BUG_ON(!sf_g);
+	BUG_ON(!sf_i);
+
+	if (!sf_i->force_restat) {
+		if (jiffies - dentry->d_time < sf_g->ttl)
+			return 0;
+	}
+
+	err = sf_stat(__func__, sf_g, sf_i->path, &info, 1);
+	if (err)
+		return err;
+
+	dentry->d_time = jiffies;
+	sf_init_inode(sf_g, dentry->d_inode, &info);
+	return 0;
+}
+
+/* this is called during name resolution/lookup to check if the
+   [dentry] in the cache is still valid. the job is handled by
+   [sf_inode_revalidate] */
+static int sf_dentry_revalidate(struct dentry *dentry, unsigned flags)
+{
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	if (sf_inode_revalidate(dentry))
+		return 0;
+
+	return 1;
+}
+
+int sf_getattr(const struct path *path, struct kstat *kstat, u32 request_mask,
+	       unsigned int flags)
+{
+	int err;
+	struct dentry *dentry = path->dentry;
+
+	err = sf_inode_revalidate(dentry);
+	if (err)
+		return err;
+
+	generic_fillattr(dentry->d_inode, kstat);
+	return 0;
+}
+
+int sf_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	struct sf_glob_info *sf_g;
+	struct sf_inode_info *sf_i;
+	struct shfl_createparms params = {};
+	struct shfl_fsobjinfo info = {};
+	uint32_t cbBuffer;
+	int rc, err;
+
+	sf_g = GET_GLOB_INFO(dentry->d_inode->i_sb);
+	sf_i = GET_INODE_INFO(dentry->d_inode);
+	err = 0;
+
+	params.Handle = SHFL_HANDLE_NIL;
+	params.CreateFlags = 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.CreateFlags |= SHFL_CF_ACCESS_WRITE;
+
+	rc = vboxsf_create(sf_g->root, sf_i->path, &params);
+	if (rc < 0) {
+		err = -vbg_status_code_to_errno(rc);
+		goto fail2;
+	}
+	if (params.Result != SHFL_FILE_EXISTS) {
+		err = -ENOENT;
+		goto fail1;
+	}
+#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.fMode = mode_set(ISUID);
+			info.Attr.fMode |= mode_set(ISGID);
+			info.Attr.fMode |= mode_set(IRUSR);
+			info.Attr.fMode |= mode_set(IWUSR);
+			info.Attr.fMode |= mode_set(IXUSR);
+			info.Attr.fMode |= mode_set(IRGRP);
+			info.Attr.fMode |= mode_set(IWGRP);
+			info.Attr.fMode |= mode_set(IXGRP);
+			info.Attr.fMode |= mode_set(IROTH);
+			info.Attr.fMode |= mode_set(IWOTH);
+			info.Attr.fMode |= mode_set(IXOTH);
+
+			if (iattr->ia_mode & S_IFDIR)
+				info.Attr.fMode |= SHFL_TYPE_DIRECTORY;
+			else
+				info.Attr.fMode |= SHFL_TYPE_FILE;
+		}
+
+		if (iattr->ia_valid & ATTR_ATIME)
+			sf_timespec_to_vbox(&info.AccessTime, &iattr->ia_atime);
+		if (iattr->ia_valid & ATTR_MTIME)
+			sf_timespec_to_vbox(&info.ModificationTime,
+					    &iattr->ia_mtime);
+		/* ignore ctime (inode change time) as it can't be set from userland anyway */
+
+		cbBuffer = sizeof(info);
+		rc = vboxsf_fsinfo(sf_g->root, params.Handle,
+				   SHFL_INFO_SET | SHFL_INFO_FILE, &cbBuffer,
+				   (PSHFLDIRINFO) & info);
+		if (rc < 0) {
+			err = -vbg_status_code_to_errno(rc);
+			goto fail1;
+		}
+	}
+#undef mode_set
+
+	if (iattr->ia_valid & ATTR_SIZE) {
+		memset(&info, 0, sizeof(info));
+		info.cbObject = iattr->ia_size;
+		cbBuffer = sizeof(info);
+		rc = vboxsf_fsinfo(sf_g->root, params.Handle,
+				   SHFL_INFO_SET | SHFL_INFO_SIZE, &cbBuffer,
+				   (PSHFLDIRINFO) & info);
+		if (rc < 0) {
+			err = -vbg_status_code_to_errno(rc);
+			goto fail1;
+		}
+	}
+
+	vboxsf_close(sf_g->root, params.Handle);
+
+	return sf_inode_revalidate(dentry);
+
+fail1:
+	vboxsf_close(sf_g->root, params.Handle);
+fail2:
+	return err;
+}
+
+static int sf_make_path(const char *caller, struct sf_inode_info *sf_i,
+			const char *d_name, size_t d_len, SHFLSTRING ** result)
+{
+	size_t path_len, shflstring_len;
+	SHFLSTRING *tmp;
+	uint16_t p_len;
+	uint8_t *p_name;
+	int fRoot = 0;
+
+	p_len = sf_i->path->u16Length;
+	p_name = sf_i->path->String.utf8;
+
+	if (p_len == 1 && *p_name == '/') {
+		path_len = d_len + 1;
+		fRoot = 1;
+	} else {
+		/* lengths of constituents plus terminating zero plus slash  */
+		path_len = p_len + d_len + 2;
+		if (path_len > 0xffff)
+			return -ENAMETOOLONG;
+	}
+
+	shflstring_len = offsetof(SHFLSTRING, String.utf8) + path_len;
+	tmp = kmalloc(shflstring_len, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	tmp->u16Length = path_len - 1;
+	tmp->u16Size = path_len;
+
+	if (fRoot)
+		memcpy(&tmp->String.utf8[0], d_name, d_len + 1);
+	else {
+		memcpy(&tmp->String.utf8[0], p_name, p_len);
+		tmp->String.utf8[p_len] = '/';
+		memcpy(&tmp->String.utf8[p_len + 1], d_name, d_len);
+		tmp->String.utf8[p_len + 1 + d_len] = '\0';
+	}
+
+	*result = tmp;
+	return 0;
+}
+
+/**
+ * [dentry] contains string encoded in coding system that corresponds
+ * to [sf_g]->nls, we must convert it to UTF8 here and pass down to
+ * [sf_make_path] which will allocate SHFLSTRING and fill it in
+ */
+int sf_path_from_dentry(const char *caller, struct sf_glob_info *sf_g,
+			struct sf_inode_info *sf_i, struct dentry *dentry,
+			SHFLSTRING ** result)
+{
+	int err;
+	const char *d_name;
+	size_t d_len;
+	const char *name;
+	size_t len = 0;
+
+	d_name = dentry->d_name.name;
+	d_len = dentry->d_name.len;
+
+	if (sf_g->nls) {
+		size_t in_len, i, out_bound_len;
+		const char *in;
+		char *out;
+
+		in = d_name;
+		in_len = d_len;
+
+		out_bound_len = PATH_MAX;
+		out = kmalloc(out_bound_len, GFP_KERNEL);
+		name = out;
+
+		for (i = 0; i < d_len; ++i) {
+			wchar_t uni;
+			int nb;
+
+			nb = sf_g->nls->char2uni(in, in_len, &uni);
+			if (nb < 0) {
+				err = -EINVAL;
+				goto fail1;
+			}
+			in_len -= nb;
+			in += nb;
+
+			nb = utf32_to_utf8(uni, out, out_bound_len);
+			if (nb < 0) {
+				err = -EINVAL;
+				goto fail1;
+			}
+			out_bound_len -= nb;
+			out += nb;
+			len += nb;
+		}
+		if (len >= PATH_MAX - 1) {
+			err = -ENAMETOOLONG;
+			goto fail1;
+		}
+
+		*out = 0;
+	} else {
+		name = d_name;
+		len = d_len;
+	}
+
+	err = sf_make_path(caller, sf_i, name, len, result);
+	if (name != d_name)
+		kfree(name);
+
+	return err;
+
+fail1:
+	kfree(name);
+	return err;
+}
+
+int sf_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;
+		out_bound_len = name_bound_len;
+
+		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(void)
+{
+	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;
+	}
+
+	INIT_LIST_HEAD(&b->head);
+	b->cEntries = 0;
+	b->cbUsed = 0;
+	b->cbFree = DIR_BUFFER_SIZE;
+	return b;
+}
+
+static void sf_dir_buf_free(struct sf_dir_buf *b)
+{
+	BUG_ON(!b || !b->buf);
+
+	list_del(&b->head);
+	kfree(b->buf);
+	kfree(b);
+}
+
+/**
+ * Free the directory buffer.
+ */
+void sf_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);
+}
+
+/**
+ * Empty (but not free) the directory buffer.
+ */
+void sf_dir_info_empty(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);
+		b->cEntries = 0;
+		b->cbUsed = 0;
+		b->cbFree = DIR_BUFFER_SIZE;
+	}
+}
+
+/**
+ * Create a new directory buffer descriptor.
+ */
+struct sf_dir_info *sf_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;
+}
+
+/**
+ * Search for an empty directory content buffer.
+ */
+static struct sf_dir_buf *sf_get_empty_dir_buf(struct sf_dir_info *sf_d)
+{
+	struct list_head *list, *pos;
+
+	list = &sf_d->info_list;
+	list_for_each(pos, list) {
+		struct sf_dir_buf *b;
+
+		b = list_entry(pos, struct sf_dir_buf, head);
+		if (!b)
+			return NULL;
+		else {
+			if (b->cbUsed == 0)
+				return b;
+		}
+	}
+
+	return NULL;
+}
+
+int sf_dir_read_all(struct sf_glob_info *sf_g, struct sf_inode_info *sf_i,
+		    struct sf_dir_info *sf_d, SHFLHANDLE handle)
+{
+	int err;
+	SHFLSTRING *mask;
+	struct sf_dir_buf *b;
+
+	err = sf_make_path(__func__, sf_i, "*", 1, &mask);
+	if (err)
+		goto fail0;
+
+	for (;;) {
+		int rc;
+		void *buf;
+		uint32_t cbSize;
+		uint32_t cEntries;
+
+		b = sf_get_empty_dir_buf(sf_d);
+		if (!b) {
+			b = sf_dir_buf_alloc();
+			if (!b) {
+				err = -ENOMEM;
+				goto fail1;
+			}
+			list_add(&b->head, &sf_d->info_list);
+		}
+
+		buf = b->buf;
+		cbSize = b->cbFree;
+
+		rc = vboxsf_dirinfo(sf_g->root, handle, mask, 0, 0,
+				    &cbSize, buf, &cEntries);
+		switch (rc) {
+		case VINF_SUCCESS:
+			/* fallthrough */
+		case VERR_NO_MORE_FILES:
+			break;
+		case VERR_NO_TRANSLATION:
+			/* XXX */
+			break;
+		default:
+			err = -vbg_status_code_to_errno(rc);
+			goto fail1;
+		}
+
+		b->cEntries += cEntries;
+		b->cbFree -= cbSize;
+		b->cbUsed += cbSize;
+
+		if (rc < 0)
+			break;
+	}
+	err = 0;
+
+fail1:
+	kfree(mask);
+
+fail0:
+	return err;
+}
+
+int sf_get_volume_info(struct super_block *sb, struct kstatfs *stat)
+{
+	struct sf_glob_info *sf_g;
+	SHFLVOLINFO SHFLVolumeInfo;
+	u32 cbBuffer;
+	int rc;
+
+	sf_g = GET_GLOB_INFO(sb);
+	cbBuffer = sizeof(SHFLVolumeInfo);
+	rc = vboxsf_fsinfo(sf_g->root, 0,
+			   SHFL_INFO_GET | SHFL_INFO_VOLUME, &cbBuffer,
+			   (PSHFLDIRINFO)&SHFLVolumeInfo);
+	if (rc < 0)
+		return -vbg_status_code_to_errno(rc);
+
+	stat->f_type = NFS_SUPER_MAGIC;	/* XXX vboxsf type? */
+	stat->f_bsize = SHFLVolumeInfo.ulBytesPerAllocationUnit;
+
+	do_div(SHFLVolumeInfo.ullTotalAllocationBytes,
+	       SHFLVolumeInfo.ulBytesPerAllocationUnit);
+	stat->f_blocks = SHFLVolumeInfo.ullTotalAllocationBytes;
+
+	do_div(SHFLVolumeInfo.ullAvailableAllocationBytes,
+	       SHFLVolumeInfo.ulBytesPerAllocationUnit);
+	stat->f_bfree  = SHFLVolumeInfo.ullAvailableAllocationBytes;
+	stat->f_bavail = SHFLVolumeInfo.ullAvailableAllocationBytes;
+
+	stat->f_files = 1000;
+	stat->f_ffree = 1000;	/* don't return 0 here since the guest may think
+				 * that it is not possible to create any more files */
+	stat->f_fsid.val[0] = 0;
+	stat->f_fsid.val[1] = 0;
+	stat->f_namelen = 255;
+	return 0;
+}
+
+struct dentry_operations sf_dentry_ops = {
+	.d_revalidate = sf_dentry_revalidate
+};
diff --git a/fs/vboxsf/vboxsf_wrappers.c b/fs/vboxsf/vboxsf_wrappers.c
new file mode 100644
index 000000000000..620b6c9b2829
--- /dev/null
+++ b/fs/vboxsf/vboxsf_wrappers.c
@@ -0,0 +1,542 @@
+/*
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * Wrapper functions for the shfl host calls.
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vbox_err.h>
+#include <linux/vbox_utils.h>
+#include "vboxsf_wrappers.h"
+
+#define VBOX_INIT_CALL(a, b, c) \
+do { \
+	(a)->result      = VINF_SUCCESS;     \
+	(a)->u32ClientID = vboxsf_client_id; \
+	(a)->u32Function = SHFL_FN_##b;      \
+	(a)->cParms      = SHFL_CPARMS_##b;  \
+} while (0)
+
+/* globals */
+static u32 vboxsf_client_id;
+
+int vboxsf_connect(void)
+{
+	struct VBOXGUESTDEVEXT *gdev;
+	HGCMServiceLocation loc;
+	int rc;
+
+	loc.type = VMMDevHGCMLoc_LocalHost_Existing;
+	strcpy(loc.u.host.achName, "VBoxSharedFolders");
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return VERR_NOT_SUPPORTED;	/* No guest-device */
+
+	rc = vbg_hgcm_connect(gdev, &loc, &vboxsf_client_id);
+	vbg_put_gdev(gdev);
+
+	return rc;
+}
+
+void vboxsf_disconnect(void)
+{
+	struct VBOXGUESTDEVEXT *gdev;
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return;   /* guest-device is gone, already disconnected */
+
+	vbg_hgcm_disconnect(gdev, vboxsf_client_id);
+	vbg_put_gdev(gdev);
+}
+
+static int vboxsf_hgcm_call(void *data, u32 len)
+{
+	VBoxGuestHGCMCallInfo *info = data;
+	struct VBOXGUESTDEVEXT *gdev;
+	int rc;
+
+	gdev = vbg_get_gdev();
+	if (IS_ERR(gdev))
+		return VERR_DEV_IO_ERROR; /* guest-dev removed underneath us */
+
+	rc = vbg_hgcm_call(gdev, info, len, U32_MAX, false);
+	vbg_put_gdev(gdev);
+
+	if (rc >= 0)
+		rc = info->result;
+
+	return rc;
+}
+
+int vboxsf_query_mappings(SHFLMAPPING paMappings[], u32 *pcMappings)
+{
+	int rc;
+	VBoxSFQueryMappings data;
+
+	VBOX_INIT_CALL(&data.callInfo, QUERY_MAPPINGS, pClient);
+
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = SHFL_MF_UCS2;
+
+	data.numberOfMappings.type = VMMDevHGCMParmType_32bit;
+	data.numberOfMappings.u.value32 = *pcMappings;
+
+	data.mappings.type = VMMDevHGCMParmType_LinAddr;
+	data.mappings.u.Pointer.size = sizeof(SHFLMAPPING) * *pcMappings;
+	data.mappings.u.Pointer.u.linearAddr = (uintptr_t)&paMappings[0];
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+	if (rc >= 0)
+		*pcMappings = data.numberOfMappings.u.value32;
+
+	return rc;
+}
+
+int vboxsf_query_mapname(SHFLROOT root, SHFLSTRING *pString, u32 size)
+{
+	VBoxSFQueryMapName data;
+
+	VBOX_INIT_CALL(&data.callInfo, QUERY_MAP_NAME, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.name.type = VMMDevHGCMParmType_LinAddr;
+	data.name.u.Pointer.size = size;
+	data.name.u.Pointer.u.linearAddr = (uintptr_t)pString;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_map_folder(PSHFLSTRING szFolderName, SHFLROOT *root)
+{
+	int rc;
+	VBoxSFMapFolder data;
+
+	VBOX_INIT_CALL(&data.callInfo, MAP_FOLDER, pClient);
+
+	data.path.type = VMMDevHGCMParmType_LinAddr;
+	data.path.u.Pointer.size = ShflStringSizeOfBuffer(szFolderName);
+	data.path.u.Pointer.u.linearAddr = (uintptr_t)szFolderName;
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = 0;
+
+	data.delimiter.type = VMMDevHGCMParmType_32bit;
+	data.delimiter.u.value32 = '/';
+
+	data.fCaseSensitive.type = VMMDevHGCMParmType_32bit;
+	data.fCaseSensitive.u.value32 = 1;
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+	if (rc >= 0) {
+		*root = data.root.u.value32;
+	} else if (rc == VERR_NOT_IMPLEMENTED) {
+		/* try the legacy interface too; temporary to assure backwards compatibility */
+		VBoxSFMapFolder_Old OldData;
+
+		VBOX_INIT_CALL(&OldData.callInfo, MAP_FOLDER_OLD, pClient);
+
+		OldData.path.type = VMMDevHGCMParmType_LinAddr;
+		OldData.path.u.Pointer.size =
+		    ShflStringSizeOfBuffer(szFolderName);
+		OldData.path.u.Pointer.u.linearAddr = (uintptr_t)szFolderName;
+
+		OldData.root.type = VMMDevHGCMParmType_32bit;
+		OldData.root.u.value32 = 0;
+
+		OldData.delimiter.type = VMMDevHGCMParmType_32bit;
+		OldData.delimiter.u.value32 = '/';
+
+		rc = vboxsf_hgcm_call(&OldData, sizeof(OldData));
+		if (rc >= 0)
+			*root = OldData.root.u.value32;
+	}
+	return rc;
+}
+
+int vboxsf_unmap_folder(SHFLROOT root)
+{
+	VBoxSFUnmapFolder data;
+
+	VBOX_INIT_CALL(&data.callInfo, UNMAP_FOLDER, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_create(SHFLROOT root, PSHFLSTRING pParsedPath,
+		  struct shfl_createparms *pCreateParms)
+{
+	/** @todo copy buffers to physical or mapped memory. */
+	VBoxSFCreate data;
+
+	VBOX_INIT_CALL(&data.callInfo, CREATE, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.path.type = VMMDevHGCMParmType_LinAddr;
+	data.path.u.Pointer.size = ShflStringSizeOfBuffer(pParsedPath);
+	data.path.u.Pointer.u.linearAddr = (uintptr_t)pParsedPath;
+
+	data.parms.type = VMMDevHGCMParmType_LinAddr;
+	data.parms.u.Pointer.size = sizeof(struct shfl_createparms);
+	data.parms.u.Pointer.u.linearAddr = (uintptr_t)pCreateParms;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_close(SHFLROOT root, SHFLHANDLE Handle)
+{
+	VBoxSFClose data;
+
+	VBOX_INIT_CALL(&data.callInfo, CLOSE, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = Handle;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_remove(SHFLROOT root, PSHFLSTRING pParsedPath, u32 flags)
+{
+	VBoxSFRemove data;
+
+	VBOX_INIT_CALL(&data.callInfo, REMOVE, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.path.type = VMMDevHGCMParmType_LinAddr_In;
+	data.path.u.Pointer.size = ShflStringSizeOfBuffer(pParsedPath);
+	data.path.u.Pointer.u.linearAddr = (uintptr_t)pParsedPath;
+
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = flags;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_rename(SHFLROOT root, PSHFLSTRING pSrcPath, PSHFLSTRING pDestPath,
+		  u32 flags)
+{
+	VBoxSFRename data;
+
+	VBOX_INIT_CALL(&data.callInfo, RENAME, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.src.type = VMMDevHGCMParmType_LinAddr_In;
+	data.src.u.Pointer.size = ShflStringSizeOfBuffer(pSrcPath);
+	data.src.u.Pointer.u.linearAddr = (uintptr_t)pSrcPath;
+
+	data.dest.type = VMMDevHGCMParmType_LinAddr_In;
+	data.dest.u.Pointer.size = ShflStringSizeOfBuffer(pDestPath);
+	data.dest.u.Pointer.u.linearAddr = (uintptr_t)pDestPath;
+
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = flags;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_read(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		u32 *pcbBuffer, u8 *pBuffer)
+{
+	int rc;
+	VBoxSFRead data;
+
+	VBOX_INIT_CALL(&data.callInfo, READ, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+	data.offset.type = VMMDevHGCMParmType_64bit;
+	data.offset.u.value64 = offset;
+	data.cb.type = VMMDevHGCMParmType_32bit;
+	data.cb.u.value32 = *pcbBuffer;
+	data.buffer.type = VMMDevHGCMParmType_LinAddr_Out;
+	data.buffer.u.Pointer.size = *pcbBuffer;
+	data.buffer.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+	if (rc >= 0)
+		*pcbBuffer = data.cb.u.value32;
+
+	return rc;
+}
+
+int vboxsf_write(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		 u32 *pcbBuffer, u8 *pBuffer)
+{
+	int rc;
+	VBoxSFWrite data;
+
+	VBOX_INIT_CALL(&data.callInfo, WRITE, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+	data.offset.type = VMMDevHGCMParmType_64bit;
+	data.offset.u.value64 = offset;
+	data.cb.type = VMMDevHGCMParmType_32bit;
+	data.cb.u.value32 = *pcbBuffer;
+	data.buffer.type = VMMDevHGCMParmType_LinAddr_In;
+	data.buffer.u.Pointer.size = *pcbBuffer;
+	data.buffer.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+	if (rc >= 0)
+		*pcbBuffer = data.cb.u.value32;
+
+	return rc;
+}
+
+int vboxsf_write_physcont(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+			  u32 *pcbBuffer, u64 PhysBuffer)
+{
+	u32 cPages, cbData, cbToWrite = *pcbBuffer;
+	HGCMPageListInfo *pPgLst;
+	VBoxSFWrite *pData;
+	u32 iPage;
+	int rc;
+
+	cPages =
+	    PAGE_ALIGN((PhysBuffer & ~PAGE_MASK) + cbToWrite) >> PAGE_SHIFT;
+	cbData =
+	    sizeof(VBoxSFWrite) + offsetof(HGCMPageListInfo, aPages[cPages]);
+	pData = kmalloc(cbData, GFP_KERNEL);
+	if (!pData)
+		return VERR_NO_TMP_MEMORY;
+
+	VBOX_INIT_CALL(&pData->callInfo, WRITE, pClient);
+
+	pData->root.type = VMMDevHGCMParmType_32bit;
+	pData->root.u.value32 = root;
+
+	pData->handle.type = VMMDevHGCMParmType_64bit;
+	pData->handle.u.value64 = hFile;
+	pData->offset.type = VMMDevHGCMParmType_64bit;
+	pData->offset.u.value64 = offset;
+	pData->cb.type = VMMDevHGCMParmType_32bit;
+	pData->cb.u.value32 = cbToWrite;
+	pData->buffer.type = VMMDevHGCMParmType_PageList;
+	pData->buffer.u.PageList.size = cbToWrite;
+	pData->buffer.u.PageList.offset = sizeof(VBoxSFWrite);
+
+	pPgLst = (HGCMPageListInfo *) (pData + 1);
+	pPgLst->flags = VBOX_HGCM_F_PARM_DIRECTION_TO_HOST;
+	pPgLst->offFirstPage = (u16)(PhysBuffer & ~PAGE_MASK);
+	pPgLst->cPages = cPages;
+	PhysBuffer &= ~(u64) ~ PAGE_MASK;
+	for (iPage = 0; iPage < cPages; iPage++, PhysBuffer += PAGE_SIZE)
+		pPgLst->aPages[iPage] = PhysBuffer;
+
+	rc = vboxsf_hgcm_call(pData, cbData);
+	if (rc >= 0)
+		*pcbBuffer = pData->cb.u.value32;
+
+	kfree(pData);
+	return rc;
+}
+
+int vboxsf_flush(SHFLROOT root, SHFLHANDLE hFile)
+{
+	VBoxSFFlush data;
+
+	VBOX_INIT_CALL(&data.callInfo, FLUSH, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_dirinfo(SHFLROOT root, SHFLHANDLE hFile, PSHFLSTRING ParsedPath,
+		   u32 flags, u32 index, u32 *pcbBuffer,
+		   PSHFLDIRINFO pBuffer, u32 *pcFiles)
+{
+	int rc;
+	VBoxSFList data;
+
+	VBOX_INIT_CALL(&data.callInfo, LIST, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = flags;
+	data.cb.type = VMMDevHGCMParmType_32bit;
+	data.cb.u.value32 = *pcbBuffer;
+	data.path.type = VMMDevHGCMParmType_LinAddr_In;
+	data.path.u.Pointer.size =
+	    ParsedPath ? ShflStringSizeOfBuffer(ParsedPath) : 0;
+	data.path.u.Pointer.u.linearAddr = (uintptr_t)ParsedPath;
+
+	data.buffer.type = VMMDevHGCMParmType_LinAddr_Out;
+	data.buffer.u.Pointer.size = *pcbBuffer;
+	data.buffer.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	data.resumePoint.type = VMMDevHGCMParmType_32bit;
+	data.resumePoint.u.value32 = index;
+	data.cFiles.type = VMMDevHGCMParmType_32bit;
+	data.cFiles.u.value32 = 0;	/* out parameters only */
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+
+	*pcbBuffer = data.cb.u.value32;
+	*pcFiles = data.cFiles.u.value32;
+
+	return rc;
+}
+
+int vboxsf_fsinfo(SHFLROOT root, SHFLHANDLE hFile, u32 flags,
+		  u32 *pcbBuffer, PSHFLDIRINFO pBuffer)
+{
+	int rc;
+	VBoxSFInformation data;
+
+	VBOX_INIT_CALL(&data.callInfo, INFORMATION, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = flags;
+	data.cb.type = VMMDevHGCMParmType_32bit;
+	data.cb.u.value32 = *pcbBuffer;
+	data.info.type = VMMDevHGCMParmType_LinAddr;
+	data.info.u.Pointer.size = *pcbBuffer;
+	data.info.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	rc = vboxsf_hgcm_call(&data, sizeof(data));
+	if (rc >= 0)
+		*pcbBuffer = data.cb.u.value32;
+
+	return rc;
+}
+
+int vboxsf_lock(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		u64 cbSize, u32 fLock)
+{
+	VBoxSFLock data;
+
+	VBOX_INIT_CALL(&data.callInfo, LOCK, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.handle.type = VMMDevHGCMParmType_64bit;
+	data.handle.u.value64 = hFile;
+	data.offset.type = VMMDevHGCMParmType_64bit;
+	data.offset.u.value64 = offset;
+	data.length.type = VMMDevHGCMParmType_64bit;
+	data.length.u.value64 = cbSize;
+
+	data.flags.type = VMMDevHGCMParmType_32bit;
+	data.flags.u.value32 = fLock;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_set_utf8(void)
+{
+	VBoxGuestHGCMCallInfo callInfo;
+
+	VBOX_INIT_CALL(&callInfo, SET_UTF8, pClient);
+
+	return vboxsf_hgcm_call(&callInfo, sizeof(callInfo));
+}
+
+int vboxsf_readlink(SHFLROOT root, PSHFLSTRING pParsedPath, u32 cbBuffer,
+		    u8 *pBuffer)
+{
+	VBoxSFReadLink data;
+
+	VBOX_INIT_CALL(&data.callInfo, READLINK, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.path.type = VMMDevHGCMParmType_LinAddr_In;
+	data.path.u.Pointer.size = ShflStringSizeOfBuffer(pParsedPath);
+	data.path.u.Pointer.u.linearAddr = (uintptr_t)pParsedPath;
+
+	data.buffer.type = VMMDevHGCMParmType_LinAddr_Out;
+	data.buffer.u.Pointer.size = cbBuffer;
+	data.buffer.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_symlink(SHFLROOT root, PSHFLSTRING pNewPath, PSHFLSTRING pOldPath,
+		   struct shfl_fsobjinfo *pBuffer)
+{
+	VBoxSFSymlink data;
+
+	VBOX_INIT_CALL(&data.callInfo, SYMLINK, pClient);
+
+	data.root.type = VMMDevHGCMParmType_32bit;
+	data.root.u.value32 = root;
+
+	data.newPath.type = VMMDevHGCMParmType_LinAddr_In;
+	data.newPath.u.Pointer.size = ShflStringSizeOfBuffer(pNewPath);
+	data.newPath.u.Pointer.u.linearAddr = (uintptr_t)pNewPath;
+
+	data.oldPath.type = VMMDevHGCMParmType_LinAddr_In;
+	data.oldPath.u.Pointer.size = ShflStringSizeOfBuffer(pOldPath);
+	data.oldPath.u.Pointer.u.linearAddr = (uintptr_t)pOldPath;
+
+	data.info.type = VMMDevHGCMParmType_LinAddr_Out;
+	data.info.u.Pointer.size = sizeof(struct shfl_fsobjinfo);
+	data.info.u.Pointer.u.linearAddr = (uintptr_t)pBuffer;
+
+	return vboxsf_hgcm_call(&data, sizeof(data));
+}
+
+int vboxsf_set_symlinks(void)
+{
+	VBoxGuestHGCMCallInfo callInfo;
+
+	VBOX_INIT_CALL(&callInfo, SET_SYMLINKS, pClient);
+
+	return vboxsf_hgcm_call(&callInfo, sizeof(callInfo));
+}
diff --git a/fs/vboxsf/vboxsf_wrappers.h b/fs/vboxsf/vboxsf_wrappers.h
new file mode 100644
index 000000000000..987b924a2c28
--- /dev/null
+++ b/fs/vboxsf/vboxsf_wrappers.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * Protype declarations for the wrapper functions for the shfl host calls.
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#ifndef VBOXSF_WRAPPERS_H
+#define VBOXSF_WRAPPERS_H
+
+#include <linux/vboxguest.h>	/* For VBoxGuestHGCMCallInfo */
+#include "shfl_hostintf.h"
+
+/**
+ * @addtogroup grp_vboxguest_lib_r0
+ *
+ * Note all these functions (all functions prefixed with vboxsf_)
+ * return a vbox status code rather then a negative errno on error.
+ * @{
+ */
+
+int vboxsf_connect(void);
+void vboxsf_disconnect(void);
+
+int vboxsf_query_mappings(SHFLMAPPING paMappings[], u32 *pcMappings);
+int vboxsf_query_mapname(SHFLROOT root, SHFLSTRING *pString, u32 size);
+
+/**
+ * Create a new file or folder or open an existing one in a shared folder.  Proxies
+ * to vbsfCreate in the host shared folder service.
+ *
+ * @returns IPRT status code, but see note below
+ * @param   pClient      Host-guest communication connection
+ * @param   root         Root of the shared folder in which to create the file
+ * @param   pParsedPath  The path of the file or folder relative to the shared
+ *                       folder
+ * @param   pCreateParms Parameters for file/folder creation.  See the
+ *                       structure description in shflsvc.h
+ * @retval  pCreateParms See the structure description in shflsvc.h
+ *
+ * @note This function reports errors as follows.  The return value is always
+ *       VINF_SUCCESS unless an exceptional condition occurs - out of
+ *       memory, invalid arguments, etc.  If the file or folder could not be
+ *       opened or created, pCreateParms->Handle will be set to
+ *       SHFL_HANDLE_NIL on return.  In this case the value in
+ *       pCreateParms->Result provides information as to why (e.g.
+ *       SHFL_FILE_EXISTS).  pCreateParms->Result is also set on success
+ *       as additional information.
+ */
+int vboxsf_create(SHFLROOT root, PSHFLSTRING pParsedPath,
+		  struct shfl_createparms *pCreateParms);
+
+int vboxsf_close(SHFLROOT root, SHFLHANDLE Handle);
+int vboxsf_remove(SHFLROOT root, PSHFLSTRING pParsedPath, u32 flags);
+int vboxsf_rename(SHFLROOT root, PSHFLSTRING pSrcPath, PSHFLSTRING pDestPath,
+		  u32 flags);
+int vboxsf_flush(SHFLROOT root, SHFLHANDLE hFile);
+
+int vboxsf_read(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		u32 *pcbBuffer, u8 *pBuffer);
+int vboxsf_write(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		 u32 *pcbBuffer, u8 *pBuffer);
+int vboxsf_write_physcont(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+			  u32 *pcbBuffer, u64 PhysBuffer);
+
+int vboxsf_lock(SHFLROOT root, SHFLHANDLE hFile, u64 offset,
+		u64 cbSize, u32 fLock);
+
+int vboxsf_dirinfo(SHFLROOT root, SHFLHANDLE hFile, PSHFLSTRING ParsedPath,
+		   u32 flags, u32 index, u32 *pcbBuffer,
+		   PSHFLDIRINFO pBuffer, u32 *pcFiles);
+int vboxsf_fsinfo(SHFLROOT root, SHFLHANDLE hFile, u32 flags,
+		  u32 *pcbBuffer, PSHFLDIRINFO pBuffer);
+
+int vboxsf_map_folder(PSHFLSTRING szFolderName, SHFLROOT *root);
+int vboxsf_unmap_folder(SHFLROOT root);
+
+int vboxsf_readlink(SHFLROOT root, PSHFLSTRING pParsedPath, u32 cbBuffer,
+		    u8 *pBuffer);
+int vboxsf_symlink(SHFLROOT root, PSHFLSTRING pNewPath, PSHFLSTRING pOldPath,
+		   struct shfl_fsobjinfo *pBuffer);
+
+int vboxsf_set_utf8(void);
+int vboxsf_set_symlinks(void);
+
+/** @} */
+
+#endif
diff --git a/fs/vboxsf/vbsfmount.h b/fs/vboxsf/vbsfmount.h
new file mode 100644
index 000000000000..1d5d12bc9166
--- /dev/null
+++ b/fs/vboxsf/vbsfmount.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * VirtualBox Guest Shared Folders: mount(2) parameter structure.
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+#ifndef VBFS_MOUNT_H
+#define VBFS_MOUNT_H
+
+#define MAX_HOST_NAME  256
+#define MAX_NLS_NAME    32
+
+/* Linux constraints the size of data mount argument to PAGE_SIZE - 1. */
+struct vbsf_mount_info_old {
+	char name[MAX_HOST_NAME];
+	char nls_name[MAX_NLS_NAME];
+	int uid;
+	int gid;
+	int ttl;
+};
+
+#define VBSF_MOUNT_SIGNATURE_BYTE_0 '\377'
+#define VBSF_MOUNT_SIGNATURE_BYTE_1 '\376'
+#define VBSF_MOUNT_SIGNATURE_BYTE_2 '\375'
+
+struct vbsf_mount_info_new {
+	char nullchar;		/* name cannot be '\0' -- we use this field
+				   to distinguish between the old structure
+				   and the new structure */
+	char signature[3];	/* signature */
+	int length;		/* length of the whole structure */
+	char name[MAX_HOST_NAME];	/* share name */
+	char nls_name[MAX_NLS_NAME];	/* name of an I/O charset */
+	int uid;		/* user ID for all entries, default 0=root */
+	int gid;		/* group ID for all entries, default 0=root */
+	int ttl;		/* time to live */
+	int dmode;		/* mode for directories if != 0xffffffff */
+	int fmode;		/* mode for regular files if != 0xffffffff */
+	int dmask;		/* umask applied to directories */
+	int fmask;		/* umask applied to regular files */
+};
+
+struct vbsf_mount_opts {
+	int uid;
+	int gid;
+	int ttl;
+	int dmode;
+	int fmode;
+	int dmask;
+	int fmask;
+	int ronly;
+	int sloppy;
+	int noexec;
+	int nodev;
+	int nosuid;
+	int remount;
+	char nls_name[MAX_NLS_NAME];
+	char *convertcp;
+};
+
+#endif /* vbsfmount.h */
diff --git a/fs/vboxsf/vfsmod.c b/fs/vboxsf/vfsmod.c
new file mode 100644
index 000000000000..49a77e44debe
--- /dev/null
+++ b/fs/vboxsf/vfsmod.c
@@ -0,0 +1,412 @@
+/*
+ * VirtualBox Guest Shared Folders support: Virtual File System.
+ *
+ * Module initialization/finalization
+ * File system registration/deregistration
+ * Superblock reading
+ * Few utility functions
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/**
+ * @note Anyone wishing to make changes here might wish to take a look at
+ *  http://www.atnf.csiro.au/people/rgooch/linux/vfs.txt
+ * which seems to be the closest there is to official documentation on
+ * writing filesystem drivers for Linux.
+ */
+
+#include <linux/module.h>
+#include <linux/nls.h>
+#include <linux/vbox_utils.h>
+#include "vbsfmount.h"
+#include "vfsmod.h"
+
+MODULE_DESCRIPTION("Oracle VM VirtualBox Module for Host File System Access");
+MODULE_AUTHOR("Oracle Corporation");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_FS("vboxsf");
+
+/* forward declarations */
+static struct super_operations sf_super_ops;
+
+/* allocate global info, try to map host share */
+static int sf_glob_alloc(struct vbsf_mount_info_new *info,
+			 struct sf_glob_info **sf_gp)
+{
+	int err, rc;
+	SHFLSTRING *str_name;
+	size_t name_len, str_len;
+	struct sf_glob_info *sf_g;
+#ifdef CONFIG_NLS_DEFAULT
+	const char *nls_name = CONFIG_NLS_DEFAULT;
+#else
+	const char *nls_name = "";
+#endif
+
+	sf_g = kzalloc(sizeof(*sf_g), GFP_KERNEL);
+	if (!sf_g) {
+		err = -ENOMEM;
+		goto fail0;
+	}
+
+	if (info->nullchar != '\0'
+	    || info->signature[0] != VBSF_MOUNT_SIGNATURE_BYTE_0
+	    || info->signature[1] != VBSF_MOUNT_SIGNATURE_BYTE_1
+	    || info->signature[2] != VBSF_MOUNT_SIGNATURE_BYTE_2) {
+		/* An old version of mount.vboxsf made the syscall. Translate the
+		 * old parameters to the new structure. */
+		struct vbsf_mount_info_old *info_old =
+		    (struct vbsf_mount_info_old *)info;
+		static struct vbsf_mount_info_new info_compat;
+
+		info = &info_compat;
+		memset(info, 0, sizeof(*info));
+		memcpy(&info->name, &info_old->name, MAX_HOST_NAME);
+		memcpy(&info->nls_name, &info_old->nls_name, MAX_NLS_NAME);
+		info->length = offsetof(struct vbsf_mount_info_new, dmode);
+		info->uid = info_old->uid;
+		info->gid = info_old->gid;
+		info->ttl = info_old->ttl;
+	}
+
+	info->name[sizeof(info->name) - 1] = 0;
+	info->nls_name[sizeof(info->nls_name) - 1] = 0;
+
+	name_len = strlen(info->name);
+	if (name_len > 0xfffe) {
+		err = -ENAMETOOLONG;
+		goto fail1;
+	}
+
+	str_len = offsetof(SHFLSTRING, String.utf8) + name_len + 1;
+	str_name = kmalloc(str_len, GFP_KERNEL);
+	if (!str_name) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	str_name->u16Length = name_len;
+	str_name->u16Size = name_len + 1;
+	memcpy(str_name->String.utf8, info->name, name_len + 1);
+
+	if (info->nls_name[0])
+		nls_name = info->nls_name;
+
+	/* Load nls if not utf8 */
+	if (nls_name[0] && strcmp(nls_name, "utf8") != 0) {
+		sf_g->nls = load_nls(info->nls_name);
+		if (!sf_g->nls) {
+			err = -EINVAL;
+			goto fail1;
+		}
+	} else {
+		sf_g->nls = NULL;
+	}
+
+	rc = vboxsf_map_folder(str_name, &sf_g->root);
+	kfree(str_name);
+
+	if (rc < 0) {
+		err = -EPROTO;
+		goto fail2;
+	}
+
+	sf_g->ttl = info->ttl;
+	sf_g->uid = info->uid;
+	sf_g->gid = info->gid;
+
+	if ((unsigned)info->length >= sizeof(struct vbsf_mount_info_new)) {
+		/* new fields */
+		sf_g->dmode = info->dmode;
+		sf_g->fmode = info->fmode;
+		sf_g->dmask = info->dmask;
+		sf_g->fmask = info->fmask;
+	} else {
+		sf_g->dmode = ~0;
+		sf_g->fmode = ~0;
+	}
+
+	*sf_gp = sf_g;
+	return 0;
+
+fail2:
+	if (sf_g->nls)
+		unload_nls(sf_g->nls);
+
+fail1:
+	kfree(sf_g);
+
+fail0:
+	return err;
+}
+
+/* unmap the share and free global info [sf_g] */
+static void sf_glob_free(struct sf_glob_info *sf_g)
+{
+	vboxsf_unmap_folder(sf_g->root);
+
+	if (sf_g->nls)
+		unload_nls(sf_g->nls);
+
+	kfree(sf_g);
+}
+
+/**
+ * This is called when vfs mounts the fs and wants to read the super_block.
+ *
+ * calls [sf_glob_alloc] to map the folder and allocate global
+ * information structure.
+ *
+ * initializes [sb], initializes root inode and dentry.
+ *
+ * should respect [flags]
+ */
+static int sf_read_super(struct super_block *sb, void *data, int flags)
+{
+	int err;
+	struct dentry *droot;
+	struct inode *iroot;
+	struct sf_inode_info *sf_i;
+	struct sf_glob_info *sf_g;
+	struct shfl_fsobjinfo fsinfo;
+	struct vbsf_mount_info_new *info;
+
+	if (!data)
+		return -EINVAL;
+
+	info = data;
+
+	if (flags & MS_REMOUNT)
+		return -ENOSYS;
+
+	err = sf_glob_alloc(info, &sf_g);
+	if (err)
+		goto fail0;
+
+	sf_i = kmalloc(sizeof(*sf_i), GFP_KERNEL);
+	if (!sf_i) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	sf_i->handle = SHFL_HANDLE_NIL;
+	sf_i->path = kmalloc(sizeof(SHFLSTRING) + 1, GFP_KERNEL);
+	if (!sf_i->path) {
+		err = -ENOMEM;
+		goto fail2;
+	}
+
+	sf_i->path->u16Length = 1;
+	sf_i->path->u16Size = 2;
+	sf_i->path->String.utf8[0] = '/';
+	sf_i->path->String.utf8[1] = 0;
+	sf_i->force_reread = 0;
+
+	err = sf_stat(__func__, sf_g, sf_i->path, &fsinfo, 0);
+	if (err)
+		goto fail3;
+
+	sb->s_magic = 0xface;
+	sb->s_blocksize = 1024;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_op = &sf_super_ops;
+
+	iroot = iget_locked(sb, 0);
+	if (!iroot) {
+		err = -ENOMEM;	/* XXX */
+		goto fail3;
+	}
+
+	sf_init_inode(sf_g, iroot, &fsinfo);
+	SET_INODE_INFO(iroot, sf_i);
+
+	unlock_new_inode(iroot);
+
+	droot = d_make_root(iroot);
+	if (!droot) {
+		err = -ENOMEM;
+		goto fail3;
+	}
+
+	sb->s_root = droot;
+	SET_GLOB_INFO(sb, sf_g);
+	return 0;
+
+fail3:
+	kfree(sf_i->path);
+
+fail2:
+	kfree(sf_i);
+
+fail1:
+	sf_glob_free(sf_g);
+
+fail0:
+	return err;
+}
+
+/*
+ * This is called when vfs is about to destroy the [inode]. all
+ * resources associated with this [inode] must be cleared here.
+ */
+static void sf_evict_inode(struct inode *inode)
+{
+	struct sf_inode_info *sf_i;
+
+	truncate_inode_pages(&inode->i_data, 0);
+	clear_inode(inode);
+
+	sf_i = GET_INODE_INFO(inode);
+	if (!sf_i)
+		return;
+
+	kfree(sf_i->path);
+	kfree(sf_i);
+	SET_INODE_INFO(inode, NULL);
+}
+
+/*
+ * vfs is done with [sb] (umount called) call [sf_glob_free] to unmap
+ * the folder and free [sf_g]
+ */
+static void sf_put_super(struct super_block *sb)
+{
+	struct sf_glob_info *sf_g;
+
+	sf_g = GET_GLOB_INFO(sb);
+	sf_glob_free(sf_g);
+}
+
+static int sf_statfs(struct dentry *dentry, struct kstatfs* stat)
+{
+	struct super_block *sb = dentry->d_inode->i_sb;
+
+	return sf_get_volume_info(sb, stat);
+}
+
+static int sf_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+	struct sf_glob_info *sf_g;
+	struct sf_inode_info *sf_i;
+	struct inode *iroot;
+	struct shfl_fsobjinfo fsinfo;
+	int err;
+
+	sf_g = GET_GLOB_INFO(sb);
+	if (data && data[0] != 0) {
+		struct vbsf_mount_info_new *info =
+		    (struct vbsf_mount_info_new *)data;
+		if (info->signature[0] == VBSF_MOUNT_SIGNATURE_BYTE_0
+		    && info->signature[1] == VBSF_MOUNT_SIGNATURE_BYTE_1
+		    && info->signature[2] == VBSF_MOUNT_SIGNATURE_BYTE_2) {
+			sf_g->uid = info->uid;
+			sf_g->gid = info->gid;
+			sf_g->ttl = info->ttl;
+			sf_g->dmode = info->dmode;
+			sf_g->fmode = info->fmode;
+			sf_g->dmask = info->dmask;
+			sf_g->fmask = info->fmask;
+		}
+	}
+
+	iroot = ilookup(sb, 0);
+	if (!iroot)
+		return -ENOSYS;
+
+	sf_i = GET_INODE_INFO(iroot);
+	err = sf_stat(__func__, sf_g, sf_i->path, &fsinfo, 0);
+	sf_init_inode(sf_g, iroot, &fsinfo);
+
+	return 0;
+}
+
+static struct super_operations sf_super_ops = {
+	.evict_inode = sf_evict_inode,
+	.put_super = sf_put_super,
+	.statfs = sf_statfs,
+	.remount_fs = sf_remount_fs
+};
+
+static struct dentry *sf_mount(struct file_system_type *fs_type, int flags,
+			       const char *dev_name, void *data)
+{
+	return mount_nodev(fs_type, flags, data, sf_read_super);
+}
+
+static struct file_system_type vboxsf_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "vboxsf",
+	.mount = sf_mount,
+	.kill_sb = kill_anon_super
+};
+
+static int follow_symlinks = 0;
+module_param(follow_symlinks, int, 0);
+MODULE_PARM_DESC(follow_symlinks,
+		 "Let host resolve symlinks rather than showing them");
+
+/* Module initialization/finalization handlers */
+static int __init init(void)
+{
+	int rc, err;
+
+	if (sizeof(struct vbsf_mount_info_new) > PAGE_SIZE) {
+		vbg_err
+		    ("vboxsf: Mount information structure is too large %zd; Must be less than or equal to %ld\n",
+		     sizeof(struct vbsf_mount_info_new), PAGE_SIZE);
+		return -EINVAL;
+	}
+
+	err = register_filesystem(&vboxsf_fs_type);
+	if (err)
+		return err;
+
+	rc = vboxsf_connect();
+	if (rc < 0) {
+		vbg_err("vboxsf_Connect failed, rc=%d\n", rc);
+		err = -EPROTO;
+		goto fail1;
+	}
+
+	rc = vboxsf_set_utf8();
+	if (rc < 0) {
+		vbg_err("vboxsf_setutf8 failed, rc=%d\n", rc);
+		err = -EPROTO;
+		goto fail2;
+	}
+
+	if (!follow_symlinks) {
+		rc = vboxsf_set_symlinks();
+		if (rc < 0) {
+			vbg_warn("vboxsf: Host unable to show symlinks, rc=%d\n",
+				 rc);
+		}
+	}
+
+	return 0;
+
+fail2:
+	vboxsf_disconnect();
+
+fail1:
+	unregister_filesystem(&vboxsf_fs_type);
+	return err;
+}
+
+static void __exit fini(void)
+{
+	vboxsf_disconnect();
+	unregister_filesystem(&vboxsf_fs_type);
+}
+
+module_init(init);
+module_exit(fini);
diff --git a/fs/vboxsf/vfsmod.h b/fs/vboxsf/vfsmod.h
new file mode 100644
index 000000000000..ebfdaffb46d4
--- /dev/null
+++ b/fs/vboxsf/vfsmod.h
@@ -0,0 +1,111 @@
+/*
+ * VirtualBox Guest Shared Folders support: module header.
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+#ifndef VFSMOD_H
+#define VFSMOD_H
+
+#include <linux/backing-dev.h>
+#include <linux/version.h>
+#include "vboxsf_wrappers.h"
+
+#define DIR_BUFFER_SIZE SZ_16K
+
+/* per-shared folder information */
+struct sf_glob_info {
+	SHFLROOT root;
+	struct nls_table *nls;
+	int ttl;
+	int uid;
+	int gid;
+	int dmode;
+	int fmode;
+	int dmask;
+	int fmask;
+};
+
+/* per-inode information */
+struct sf_inode_info {
+	/* which file */
+	SHFLSTRING *path;
+	/* some information was changed, update data on next revalidate */
+	int force_restat;
+	/* directory content changed, update the whole directory on next sf_getdent */
+	int force_reread;
+	/* file structure, only valid between open() and release() */
+	struct file *file;
+	/* handle valid if a file was created with sf_create_aux until it will
+	 * be opened with sf_reg_open() */
+	SHFLHANDLE handle;
+};
+
+struct sf_dir_info {
+	struct list_head info_list;
+};
+
+struct sf_dir_buf {
+	size_t cEntries;
+	size_t cbFree;
+	size_t cbUsed;
+	void *buf;
+	struct list_head head;
+};
+
+struct sf_reg_info {
+	SHFLHANDLE handle;
+};
+
+/* globals */
+extern struct inode_operations sf_dir_iops;
+extern struct inode_operations sf_lnk_iops;
+extern struct inode_operations sf_reg_iops;
+extern struct file_operations sf_dir_fops;
+extern struct file_operations sf_reg_fops;
+extern struct dentry_operations sf_dentry_ops;
+extern struct address_space_operations sf_reg_aops;
+
+void sf_init_inode(struct sf_glob_info *sf_g, struct inode *inode,
+		   const struct shfl_fsobjinfo *info);
+int sf_stat(const char *caller, struct sf_glob_info *sf_g,
+	    SHFLSTRING * path, struct shfl_fsobjinfo *result, int ok_to_fail);
+int sf_inode_revalidate(struct dentry *dentry);
+int sf_getattr(const struct path *path, struct kstat *kstat,
+	       u32 request_mask, unsigned int query_flags);
+int sf_setattr(struct dentry *dentry, struct iattr *iattr);
+int sf_path_from_dentry(const char *caller, struct sf_glob_info *sf_g,
+		        struct sf_inode_info *sf_i,
+		        struct dentry *dentry, SHFLSTRING ** result);
+int sf_nlscpy(struct sf_glob_info *sf_g, char *name,
+	      size_t name_bound_len, const unsigned char *utf8_name,
+	      size_t utf8_len);
+void sf_dir_info_free(struct sf_dir_info *p);
+void sf_dir_info_empty(struct sf_dir_info *p);
+struct sf_dir_info *sf_dir_info_alloc(void);
+int sf_dir_read_all(struct sf_glob_info *sf_g,
+		    struct sf_inode_info *sf_i, struct sf_dir_info *sf_d,
+		    SHFLHANDLE handle);
+int sf_get_volume_info(struct super_block *sb, struct kstatfs *stat);
+
+/*
+ * Following casts are here 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)       ((struct sf_inode_info *) (i)->i_private)
+#define SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
+
+#define GET_F_DENTRY(f)         (f->f_path.dentry)
+
+#endif
-- 
2.13.3