[linux-block.git] / fs / vboxsf / super.c

// SPDX-License-Identifier: MIT
/*
 * VirtualBox Guest Shared Folders support: Virtual File System.
 *
 * Module initialization/finalization
 * File system registration/deregistration
 * Superblock reading
 * Few utility functions
 *
 * Copyright (C) 2006-2018 Oracle Corporation
 */

#include <linux/idr.h>
#include <linux/fs_parser.h>
#include <linux/magic.h>
#include <linux/module.h>
#include <linux/nls.h>
#include <linux/statfs.h>
#include <linux/vbox_utils.h>
#include "vfsmod.h"

#define VBOXSF_SUPER_MAGIC 0x786f4256 /* 'VBox' little endian */

static const unsigned char VBSF_MOUNT_SIGNATURE[4] = "\000\377\376\375";

static int follow_symlinks;
module_param(follow_symlinks, int, 0444);
MODULE_PARM_DESC(follow_symlinks,
		 "Let host resolve symlinks rather than showing them");

static DEFINE_IDA(vboxsf_bdi_ida);
static DEFINE_MUTEX(vboxsf_setup_mutex);
static bool vboxsf_setup_done;
static struct super_operations vboxsf_super_ops; /* forward declaration */
static struct kmem_cache *vboxsf_inode_cachep;

static char * const vboxsf_default_nls = CONFIG_NLS_DEFAULT;

enum  { opt_nls, opt_uid, opt_gid, opt_ttl, opt_dmode, opt_fmode,
	opt_dmask, opt_fmask };

static const struct fs_parameter_spec vboxsf_fs_parameters[] = {
	fsparam_string	("nls",		opt_nls),
	fsparam_u32	("uid",		opt_uid),
	fsparam_u32	("gid",		opt_gid),
	fsparam_u32	("ttl",		opt_ttl),
	fsparam_u32oct	("dmode",	opt_dmode),
	fsparam_u32oct	("fmode",	opt_fmode),
	fsparam_u32oct	("dmask",	opt_dmask),
	fsparam_u32oct	("fmask",	opt_fmask),
	{}
};

static int vboxsf_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
	struct vboxsf_fs_context *ctx = fc->fs_private;
	struct fs_parse_result result;
	kuid_t uid;
	kgid_t gid;
	int opt;

	opt = fs_parse(fc, vboxsf_fs_parameters, param, &result);
	if (opt < 0)
		return opt;

	switch (opt) {
	case opt_nls:
		if (ctx->nls_name || fc->purpose != FS_CONTEXT_FOR_MOUNT) {
			vbg_err("vboxsf: Cannot reconfigure nls option\n");
			return -EINVAL;
		}
		ctx->nls_name = param->string;
		param->string = NULL;
		break;
	case opt_uid:
		uid = make_kuid(current_user_ns(), result.uint_32);
		if (!uid_valid(uid))
			return -EINVAL;
		ctx->o.uid = uid;
		break;
	case opt_gid:
		gid = make_kgid(current_user_ns(), result.uint_32);
		if (!gid_valid(gid))
			return -EINVAL;
		ctx->o.gid = gid;
		break;
	case opt_ttl:
		ctx->o.ttl = msecs_to_jiffies(result.uint_32);
		break;
	case opt_dmode:
		if (result.uint_32 & ~0777)
			return -EINVAL;
		ctx->o.dmode = result.uint_32;
		ctx->o.dmode_set = true;
		break;
	case opt_fmode:
		if (result.uint_32 & ~0777)
			return -EINVAL;
		ctx->o.fmode = result.uint_32;
		ctx->o.fmode_set = true;
		break;
	case opt_dmask:
		if (result.uint_32 & ~07777)
			return -EINVAL;
		ctx->o.dmask = result.uint_32;
		break;
	case opt_fmask:
		if (result.uint_32 & ~07777)
			return -EINVAL;
		ctx->o.fmask = result.uint_32;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
{
	struct vboxsf_fs_context *ctx = fc->fs_private;
	struct shfl_string *folder_name, root_path;
	struct vboxsf_sbi *sbi;
	struct dentry *droot;
	struct inode *iroot;
	char *nls_name;
	size_t size;
	int err;

	if (!fc->source)
		return -EINVAL;

	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;

	sbi->o = ctx->o;
	idr_init(&sbi->ino_idr);
	spin_lock_init(&sbi->ino_idr_lock);
	sbi->next_generation = 1;
	sbi->bdi_id = -1;

	/* Load nls if not utf8 */
	nls_name = ctx->nls_name ? ctx->nls_name : vboxsf_default_nls;
	if (strcmp(nls_name, "utf8") != 0) {
		if (nls_name == vboxsf_default_nls)
			sbi->nls = load_nls_default();
		else
			sbi->nls = load_nls(nls_name);

		if (!sbi->nls) {
			vbg_err("vboxsf: Count not load '%s' nls\n", nls_name);
			err = -EINVAL;
			goto fail_free;
		}
	}

	sbi->bdi_id = ida_simple_get(&vboxsf_bdi_ida, 0, 0, GFP_KERNEL);
	if (sbi->bdi_id < 0) {
		err = sbi->bdi_id;
		goto fail_free;
	}

	err = super_setup_bdi_name(sb, "vboxsf-%d", sbi->bdi_id);
	if (err)
		goto fail_free;
	sb->s_bdi->ra_pages = 0;
	sb->s_bdi->io_pages = 0;

	/* Turn source into a shfl_string and map the folder */
	size = strlen(fc->source) + 1;
	folder_name = kmalloc(SHFLSTRING_HEADER_SIZE + size, GFP_KERNEL);
	if (!folder_name) {
		err = -ENOMEM;
		goto fail_free;
	}
	folder_name->size = size;
	folder_name->length = size - 1;
	strlcpy(folder_name->string.utf8, fc->source, size);
	err = vboxsf_map_folder(folder_name, &sbi->root);
	kfree(folder_name);
	if (err) {
		vbg_err("vboxsf: Host rejected mount of '%s' with error %d\n",
			fc->source, err);
		goto fail_free;
	}

	root_path.length = 1;
	root_path.size = 2;
	root_path.string.utf8[0] = '/';
	root_path.string.utf8[1] = 0;
	err = vboxsf_stat(sbi, &root_path, &sbi->root_info);
	if (err)
		goto fail_unmap;

	sb->s_magic = VBOXSF_SUPER_MAGIC;
	sb->s_blocksize = 1024;
	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_op = &vboxsf_super_ops;
	sb->s_d_op = &vboxsf_dentry_ops;

	iroot = iget_locked(sb, 0);
	if (!iroot) {
		err = -ENOMEM;
		goto fail_unmap;
	}
	vboxsf_init_inode(sbi, iroot, &sbi->root_info, false);
	unlock_new_inode(iroot);

	droot = d_make_root(iroot);
	if (!droot) {
		err = -ENOMEM;
		goto fail_unmap;
	}

	sb->s_root = droot;
	sb->s_fs_info = sbi;
	return 0;

fail_unmap:
	vboxsf_unmap_folder(sbi->root);
fail_free:
	if (sbi->bdi_id >= 0)
		ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
	if (sbi->nls)
		unload_nls(sbi->nls);
	idr_destroy(&sbi->ino_idr);
	kfree(sbi);
	return err;
}

static void vboxsf_inode_init_once(void *data)
{
	struct vboxsf_inode *sf_i = data;

	mutex_init(&sf_i->handle_list_mutex);
	inode_init_once(&sf_i->vfs_inode);
}

static struct inode *vboxsf_alloc_inode(struct super_block *sb)
{
	struct vboxsf_inode *sf_i;

	sf_i = alloc_inode_sb(sb, vboxsf_inode_cachep, GFP_NOFS);
	if (!sf_i)
		return NULL;

	sf_i->force_restat = 0;
	INIT_LIST_HEAD(&sf_i->handle_list);

	return &sf_i->vfs_inode;
}

static void vboxsf_free_inode(struct inode *inode)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
	unsigned long flags;

	spin_lock_irqsave(&sbi->ino_idr_lock, flags);
	idr_remove(&sbi->ino_idr, inode->i_ino);
	spin_unlock_irqrestore(&sbi->ino_idr_lock, flags);
	kmem_cache_free(vboxsf_inode_cachep, VBOXSF_I(inode));
}

static void vboxsf_put_super(struct super_block *sb)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(sb);

	vboxsf_unmap_folder(sbi->root);
	if (sbi->bdi_id >= 0)
		ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
	if (sbi->nls)
		unload_nls(sbi->nls);

	/*
	 * vboxsf_free_inode uses the idr, make sure all delayed rcu free
	 * inodes are flushed.
	 */
	rcu_barrier();
	idr_destroy(&sbi->ino_idr);
	kfree(sbi);
}

static int vboxsf_statfs(struct dentry *dentry, struct kstatfs *stat)
{
	struct super_block *sb = dentry->d_sb;
	struct shfl_volinfo shfl_volinfo;
	struct vboxsf_sbi *sbi;
	u32 buf_len;
	int err;

	sbi = VBOXSF_SBI(sb);
	buf_len = sizeof(shfl_volinfo);
	err = vboxsf_fsinfo(sbi->root, 0, SHFL_INFO_GET | SHFL_INFO_VOLUME,
			    &buf_len, &shfl_volinfo);
	if (err)
		return err;

	stat->f_type = VBOXSF_SUPER_MAGIC;
	stat->f_bsize = shfl_volinfo.bytes_per_allocation_unit;

	do_div(shfl_volinfo.total_allocation_bytes,
	       shfl_volinfo.bytes_per_allocation_unit);
	stat->f_blocks = shfl_volinfo.total_allocation_bytes;

	do_div(shfl_volinfo.available_allocation_bytes,
	       shfl_volinfo.bytes_per_allocation_unit);
	stat->f_bfree  = shfl_volinfo.available_allocation_bytes;
	stat->f_bavail = shfl_volinfo.available_allocation_bytes;

	stat->f_files = 1000;
	/*
	 * Don't return 0 here since the guest may then think that it is not
	 * possible to create any more files.
	 */
	stat->f_ffree = 1000000;
	stat->f_fsid.val[0] = 0;
	stat->f_fsid.val[1] = 0;
	stat->f_namelen = 255;
	return 0;
}

static struct super_operations vboxsf_super_ops = {
	.alloc_inode	= vboxsf_alloc_inode,
	.free_inode	= vboxsf_free_inode,
	.put_super	= vboxsf_put_super,
	.statfs		= vboxsf_statfs,
};

static int vboxsf_setup(void)
{
	int err;

	mutex_lock(&vboxsf_setup_mutex);

	if (vboxsf_setup_done)
		goto success;

	vboxsf_inode_cachep =
		kmem_cache_create("vboxsf_inode_cache",
				  sizeof(struct vboxsf_inode), 0,
				  (SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD |
				   SLAB_ACCOUNT),
				  vboxsf_inode_init_once);
	if (!vboxsf_inode_cachep) {
		err = -ENOMEM;
		goto fail_nomem;
	}

	err = vboxsf_connect();
	if (err) {
		vbg_err("vboxsf: err %d connecting to guest PCI-device\n", err);
		vbg_err("vboxsf: make sure you are inside a VirtualBox VM\n");
		vbg_err("vboxsf: and check dmesg for vboxguest errors\n");
		goto fail_free_cache;
	}

	err = vboxsf_set_utf8();
	if (err) {
		vbg_err("vboxsf_setutf8 error %d\n", err);
		goto fail_disconnect;
	}

	if (!follow_symlinks) {
		err = vboxsf_set_symlinks();
		if (err)
			vbg_warn("vboxsf: Unable to show symlinks: %d\n", err);
	}

	vboxsf_setup_done = true;
success:
	mutex_unlock(&vboxsf_setup_mutex);
	return 0;

fail_disconnect:
	vboxsf_disconnect();
fail_free_cache:
	kmem_cache_destroy(vboxsf_inode_cachep);
fail_nomem:
	mutex_unlock(&vboxsf_setup_mutex);
	return err;
}

static int vboxsf_parse_monolithic(struct fs_context *fc, void *data)
{
	if (data && !memcmp(data, VBSF_MOUNT_SIGNATURE, 4)) {
		vbg_err("vboxsf: Old binary mount data not supported, remove obsolete mount.vboxsf and/or update your VBoxService.\n");
		return -EINVAL;
	}

	return generic_parse_monolithic(fc, data);
}

static int vboxsf_get_tree(struct fs_context *fc)
{
	int err;

	err = vboxsf_setup();
	if (err)
		return err;

	return get_tree_nodev(fc, vboxsf_fill_super);
}

static int vboxsf_reconfigure(struct fs_context *fc)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(fc->root->d_sb);
	struct vboxsf_fs_context *ctx = fc->fs_private;
	struct inode *iroot = fc->root->d_sb->s_root->d_inode;

	/* Apply changed options to the root inode */
	sbi->o = ctx->o;
	vboxsf_init_inode(sbi, iroot, &sbi->root_info, true);

	return 0;
}

static void vboxsf_free_fc(struct fs_context *fc)
{
	struct vboxsf_fs_context *ctx = fc->fs_private;

	kfree(ctx->nls_name);
	kfree(ctx);
}

static const struct fs_context_operations vboxsf_context_ops = {
	.free			= vboxsf_free_fc,
	.parse_param		= vboxsf_parse_param,
	.parse_monolithic	= vboxsf_parse_monolithic,
	.get_tree		= vboxsf_get_tree,
	.reconfigure		= vboxsf_reconfigure,
};

static int vboxsf_init_fs_context(struct fs_context *fc)
{
	struct vboxsf_fs_context *ctx;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	current_uid_gid(&ctx->o.uid, &ctx->o.gid);

	fc->fs_private = ctx;
	fc->ops = &vboxsf_context_ops;
	return 0;
}

static struct file_system_type vboxsf_fs_type = {
	.owner			= THIS_MODULE,
	.name			= "vboxsf",
	.init_fs_context	= vboxsf_init_fs_context,
	.kill_sb		= kill_anon_super
};

/* Module initialization/finalization handlers */
static int __init vboxsf_init(void)
{
	return register_filesystem(&vboxsf_fs_type);
}

static void __exit vboxsf_fini(void)
{
	unregister_filesystem(&vboxsf_fs_type);

	mutex_lock(&vboxsf_setup_mutex);
	if (vboxsf_setup_done) {
		vboxsf_disconnect();
		/*
		 * Make sure all delayed rcu free inodes are flushed
		 * before we destroy the cache.
		 */
		rcu_barrier();
		kmem_cache_destroy(vboxsf_inode_cachep);
	}
	mutex_unlock(&vboxsf_setup_mutex);
}

module_init(vboxsf_init);
module_exit(vboxsf_fini);

MODULE_DESCRIPTION("Oracle VM VirtualBox Module for Host File System Access");
MODULE_AUTHOR("Oracle Corporation");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_FS("vboxsf");
Commit	Line	Data
0fd16957 HG	1	// SPDX-License-Identifier: MIT
	2	/*
	3	* VirtualBox Guest Shared Folders support: Virtual File System.
	4	*
	5	* Module initialization/finalization
	6	* File system registration/deregistration
	7	* Superblock reading
	8	* Few utility functions
	9	*
	10	* Copyright (C) 2006-2018 Oracle Corporation
	11	*/
	12
	13	#include <linux/idr.h>
	14	#include <linux/fs_parser.h>
	15	#include <linux/magic.h>
	16	#include <linux/module.h>
	17	#include <linux/nls.h>
	18	#include <linux/statfs.h>
	19	#include <linux/vbox_utils.h>
	20	#include "vfsmod.h"
	21
	22	#define VBOXSF_SUPER_MAGIC 0x786f4256 /* 'VBox' little endian */
	23
9b3b353e	24	static const unsigned char VBSF_MOUNT_SIGNATURE[4] = "\000\377\376\375";
0fd16957 HG	25
	26	static int follow_symlinks;
	27	module_param(follow_symlinks, int, 0444);
	28	MODULE_PARM_DESC(follow_symlinks,
	29	"Let host resolve symlinks rather than showing them");
	30
	31	static DEFINE_IDA(vboxsf_bdi_ida);
	32	static DEFINE_MUTEX(vboxsf_setup_mutex);
	33	static bool vboxsf_setup_done;
	34	static struct super_operations vboxsf_super_ops; /* forward declaration */
	35	static struct kmem_cache *vboxsf_inode_cachep;
	36
	37	static char * const vboxsf_default_nls = CONFIG_NLS_DEFAULT;
	38
	39	enum { opt_nls, opt_uid, opt_gid, opt_ttl, opt_dmode, opt_fmode,
	40	opt_dmask, opt_fmask };
	41
	42	static const struct fs_parameter_spec vboxsf_fs_parameters[] = {
	43	fsparam_string ("nls", opt_nls),
	44	fsparam_u32 ("uid", opt_uid),
	45	fsparam_u32 ("gid", opt_gid),
	46	fsparam_u32 ("ttl", opt_ttl),
	47	fsparam_u32oct ("dmode", opt_dmode),
	48	fsparam_u32oct ("fmode", opt_fmode),
	49	fsparam_u32oct ("dmask", opt_dmask),
	50	fsparam_u32oct ("fmask", opt_fmask),
	51	{}
	52	};
	53
	54	static int vboxsf_parse_param(struct fs_context fc, struct fs_parameter param)
	55	{
	56	struct vboxsf_fs_context *ctx = fc->fs_private;
	57	struct fs_parse_result result;
	58	kuid_t uid;
	59	kgid_t gid;
	60	int opt;
	61
	62	opt = fs_parse(fc, vboxsf_fs_parameters, param, &result);
	63	if (opt < 0)
	64	return opt;
	65
	66	switch (opt) {
	67	case opt_nls:
	68	if (ctx->nls_name \|\| fc->purpose != FS_CONTEXT_FOR_MOUNT) {
	69	vbg_err("vboxsf: Cannot reconfigure nls option\n");
	70	return -EINVAL;
	71	}
	72	ctx->nls_name = param->string;
	73	param->string = NULL;
	74	break;
	75	case opt_uid:
	76	uid = make_kuid(current_user_ns(), result.uint_32);
	77	if (!uid_valid(uid))
	78	return -EINVAL;
	79	ctx->o.uid = uid;
	80	break;
	81	case opt_gid:
	82	gid = make_kgid(current_user_ns(), result.uint_32);
	83	if (!gid_valid(gid))
	84	return -EINVAL;
	85	ctx->o.gid = gid;
	86	break;
	87	case opt_ttl:
	88	ctx->o.ttl = msecs_to_jiffies(result.uint_32);
89	break;
90	case opt_dmode:
91	if (result.uint_32 & ~0777)
92	return -EINVAL;
93	ctx->o.dmode = result.uint_32;
94	ctx->o.dmode_set = true;
95	break;
96	case opt_fmode:
97	if (result.uint_32 & ~0777)
98	return -EINVAL;
99	ctx->o.fmode = result.uint_32;
100	ctx->o.fmode_set = true;
101	break;
102	case opt_dmask:
103	if (result.uint_32 & ~07777)
104	return -EINVAL;
105	ctx->o.dmask = result.uint_32;
106	break;
107	case opt_fmask:
108	if (result.uint_32 & ~07777)
109	return -EINVAL;
110	ctx->o.fmask = result.uint_32;
111	break;
112	default:
113	return -EINVAL;
114	}
115
116	return 0;
117	}
118
119	static int vboxsf_fill_super(struct super_block sb, struct fs_context fc)
120	{
121	struct vboxsf_fs_context *ctx = fc->fs_private;
122	struct shfl_string *folder_name, root_path;
123	struct vboxsf_sbi *sbi;
124	struct dentry *droot;
125	struct inode *iroot;
126	char *nls_name;
127	size_t size;
128	int err;
129
130	if (!fc->source)
131	return -EINVAL;
132
133	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
134	if (!sbi)
135	return -ENOMEM;
136
137	sbi->o = ctx->o;
138	idr_init(&sbi->ino_idr);
139	spin_lock_init(&sbi->ino_idr_lock);
140	sbi->next_generation = 1;
141	sbi->bdi_id = -1;
142
143	/* Load nls if not utf8 */
144	nls_name = ctx->nls_name ? ctx->nls_name : vboxsf_default_nls;
145	if (strcmp(nls_name, "utf8") != 0) {
146	if (nls_name == vboxsf_default_nls)
147	sbi->nls = load_nls_default();
148	else
149	sbi->nls = load_nls(nls_name);
150
151	if (!sbi->nls) {
152	vbg_err("vboxsf: Count not load '%s' nls\n", nls_name);
153	err = -EINVAL;
154	goto fail_free;
155	}
156	}
157
158	sbi->bdi_id = ida_simple_get(&vboxsf_bdi_ida, 0, 0, GFP_KERNEL);
159	if (sbi->bdi_id < 0) {
160	err = sbi->bdi_id;
161	goto fail_free;
162	}
163
156c7573	164	err = super_setup_bdi_name(sb, "vboxsf-%d", sbi->bdi_id);
0fd16957 HG	165	if (err)
0fd16957 HG	166	goto fail_free;
55b2598e CH	167	sb->s_bdi->ra_pages = 0;
55b2598e CH	168	sb->s_bdi->io_pages = 0;
0fd16957 HG	169
	170	/* Turn source into a shfl_string and map the folder */
	171	size = strlen(fc->source) + 1;
	172	folder_name = kmalloc(SHFLSTRING_HEADER_SIZE + size, GFP_KERNEL);
	173	if (!folder_name) {
	174	err = -ENOMEM;
	175	goto fail_free;
	176	}
	177	folder_name->size = size;
	178	folder_name->length = size - 1;
	179	strlcpy(folder_name->string.utf8, fc->source, size);
	180	err = vboxsf_map_folder(folder_name, &sbi->root);
	181	kfree(folder_name);
	182	if (err) {
	183	vbg_err("vboxsf: Host rejected mount of '%s' with error %d\n",
	184	fc->source, err);
	185	goto fail_free;
	186	}
	187
	188	root_path.length = 1;
	189	root_path.size = 2;
	190	root_path.string.utf8[0] = '/';
	191	root_path.string.utf8[1] = 0;
	192	err = vboxsf_stat(sbi, &root_path, &sbi->root_info);
	193	if (err)
	194	goto fail_unmap;
	195
	196	sb->s_magic = VBOXSF_SUPER_MAGIC;
	197	sb->s_blocksize = 1024;
	198	sb->s_maxbytes = MAX_LFS_FILESIZE;
	199	sb->s_op = &vboxsf_super_ops;
	200	sb->s_d_op = &vboxsf_dentry_ops;
	201
	202	iroot = iget_locked(sb, 0);
	203	if (!iroot) {
	204	err = -ENOMEM;
	205	goto fail_unmap;
	206	}
e98f93e7	207	vboxsf_init_inode(sbi, iroot, &sbi->root_info, false);
0fd16957 HG	208	unlock_new_inode(iroot);
	209
	210	droot = d_make_root(iroot);
	211	if (!droot) {
	212	err = -ENOMEM;
	213	goto fail_unmap;
	214	}
	215
	216	sb->s_root = droot;
	217	sb->s_fs_info = sbi;
	218	return 0;
	219
	220	fail_unmap:
	221	vboxsf_unmap_folder(sbi->root);
	222	fail_free:
	223	if (sbi->bdi_id >= 0)
	224	ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
	225	if (sbi->nls)
	226	unload_nls(sbi->nls);
	227	idr_destroy(&sbi->ino_idr);
	228	kfree(sbi);
	229	return err;
	230	}
	231
	232	static void vboxsf_inode_init_once(void *data)
	233	{
	234	struct vboxsf_inode *sf_i = data;
	235
	236	mutex_init(&sf_i->handle_list_mutex);
	237	inode_init_once(&sf_i->vfs_inode);
	238	}
	239
	240	static struct inode vboxsf_alloc_inode(struct super_block sb)
	241	{
	242	struct vboxsf_inode *sf_i;
	243
fd60b288	244	sf_i = alloc_inode_sb(sb, vboxsf_inode_cachep, GFP_NOFS);
0fd16957 HG	245	if (!sf_i)
	246	return NULL;
	247
	248	sf_i->force_restat = 0;
	249	INIT_LIST_HEAD(&sf_i->handle_list);
	250
	251	return &sf_i->vfs_inode;
	252	}
	253
	254	static void vboxsf_free_inode(struct inode *inode)
	255	{
	256	struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
	257	unsigned long flags;
	258
	259	spin_lock_irqsave(&sbi->ino_idr_lock, flags);
	260	idr_remove(&sbi->ino_idr, inode->i_ino);
	261	spin_unlock_irqrestore(&sbi->ino_idr_lock, flags);
	262	kmem_cache_free(vboxsf_inode_cachep, VBOXSF_I(inode));
	263	}
	264
	265	static void vboxsf_put_super(struct super_block *sb)
	266	{
	267	struct vboxsf_sbi *sbi = VBOXSF_SBI(sb);
	268
	269	vboxsf_unmap_folder(sbi->root);
	270	if (sbi->bdi_id >= 0)
	271	ida_simple_remove(&vboxsf_bdi_ida, sbi->bdi_id);
	272	if (sbi->nls)
	273	unload_nls(sbi->nls);
	274
	275	/*
	276	* vboxsf_free_inode uses the idr, make sure all delayed rcu free
	277	* inodes are flushed.
	278	*/
	279	rcu_barrier();
	280	idr_destroy(&sbi->ino_idr);
	281	kfree(sbi);
	282	}
	283
	284	static int vboxsf_statfs(struct dentry dentry, struct kstatfs stat)
	285	{
	286	struct super_block *sb = dentry->d_sb;
	287	struct shfl_volinfo shfl_volinfo;
	288	struct vboxsf_sbi *sbi;
	289	u32 buf_len;
	290	int err;
	291
	292	sbi = VBOXSF_SBI(sb);
	293	buf_len = sizeof(shfl_volinfo);
	294	err = vboxsf_fsinfo(sbi->root, 0, SHFL_INFO_GET \| SHFL_INFO_VOLUME,
	295	&buf_len, &shfl_volinfo);
	296	if (err)
	297	return err;
	298
	299	stat->f_type = VBOXSF_SUPER_MAGIC;
	300	stat->f_bsize = shfl_volinfo.bytes_per_allocation_unit;
	301
	302	do_div(shfl_volinfo.total_allocation_bytes,
	303	shfl_volinfo.bytes_per_allocation_unit);
	304	stat->f_blocks = shfl_volinfo.total_allocation_bytes;
	305
	306	do_div(shfl_volinfo.available_allocation_bytes,
	307	shfl_volinfo.bytes_per_allocation_unit);
	308	stat->f_bfree = shfl_volinfo.available_allocation_bytes;
309	stat->f_bavail = shfl_volinfo.available_allocation_bytes;
310
311	stat->f_files = 1000;
312	/*
313	* Don't return 0 here since the guest may then think that it is not
314	* possible to create any more files.
315	*/
316	stat->f_ffree = 1000000;
317	stat->f_fsid.val[0] = 0;
318	stat->f_fsid.val[1] = 0;
319	stat->f_namelen = 255;
320	return 0;
321	}
322
323	static struct super_operations vboxsf_super_ops = {
324	.alloc_inode = vboxsf_alloc_inode,
325	.free_inode = vboxsf_free_inode,
326	.put_super = vboxsf_put_super,
327	.statfs = vboxsf_statfs,
328	};
329
330	static int vboxsf_setup(void)
331	{
332	int err;
333
334	mutex_lock(&vboxsf_setup_mutex);
335
336	if (vboxsf_setup_done)
337	goto success;
338
339	vboxsf_inode_cachep =
340	kmem_cache_create("vboxsf_inode_cache",
341	sizeof(struct vboxsf_inode), 0,
342	(SLAB_RECLAIM_ACCOUNT \| SLAB_MEM_SPREAD \|
343	SLAB_ACCOUNT),
344	vboxsf_inode_init_once);
345	if (!vboxsf_inode_cachep) {
346	err = -ENOMEM;
347	goto fail_nomem;
348	}
349
350	err = vboxsf_connect();
351	if (err) {
352	vbg_err("vboxsf: err %d connecting to guest PCI-device\n", err);
353	vbg_err("vboxsf: make sure you are inside a VirtualBox VM\n");
354	vbg_err("vboxsf: and check dmesg for vboxguest errors\n");
355	goto fail_free_cache;
356	}
357
358	err = vboxsf_set_utf8();
359	if (err) {
360	vbg_err("vboxsf_setutf8 error %d\n", err);
361	goto fail_disconnect;
362	}
363
364	if (!follow_symlinks) {
365	err = vboxsf_set_symlinks();
366	if (err)
367	vbg_warn("vboxsf: Unable to show symlinks: %d\n", err);
368	}
369
370	vboxsf_setup_done = true;
371	success:
372	mutex_unlock(&vboxsf_setup_mutex);
373	return 0;
374
375	fail_disconnect:
376	vboxsf_disconnect();
377	fail_free_cache:
378	kmem_cache_destroy(vboxsf_inode_cachep);
379	fail_nomem:
380	mutex_unlock(&vboxsf_setup_mutex);
381	return err;
382	}
383
384	static int vboxsf_parse_monolithic(struct fs_context fc, void data)
385	{
9b3b353e	386	if (data && !memcmp(data, VBSF_MOUNT_SIGNATURE, 4)) {
0fd16957 HG	387	vbg_err("vboxsf: Old binary mount data not supported, remove obsolete mount.vboxsf and/or update your VBoxService.\n");
	388	return -EINVAL;
	389	}
	390
	391	return generic_parse_monolithic(fc, data);
	392	}
	393
	394	static int vboxsf_get_tree(struct fs_context *fc)
	395	{
	396	int err;
	397
	398	err = vboxsf_setup();
	399	if (err)
	400	return err;
	401
	402	return get_tree_nodev(fc, vboxsf_fill_super);
	403	}
	404
	405	static int vboxsf_reconfigure(struct fs_context *fc)
	406	{
	407	struct vboxsf_sbi *sbi = VBOXSF_SBI(fc->root->d_sb);
	408	struct vboxsf_fs_context *ctx = fc->fs_private;
	409	struct inode *iroot = fc->root->d_sb->s_root->d_inode;
	410
	411	/* Apply changed options to the root inode */
	412	sbi->o = ctx->o;
e98f93e7	413	vboxsf_init_inode(sbi, iroot, &sbi->root_info, true);
0fd16957 HG	414
	415	return 0;
	416	}
	417
	418	static void vboxsf_free_fc(struct fs_context *fc)
	419	{
	420	struct vboxsf_fs_context *ctx = fc->fs_private;
	421
	422	kfree(ctx->nls_name);
	423	kfree(ctx);
	424	}
	425
	426	static const struct fs_context_operations vboxsf_context_ops = {
	427	.free = vboxsf_free_fc,
	428	.parse_param = vboxsf_parse_param,
	429	.parse_monolithic = vboxsf_parse_monolithic,
	430	.get_tree = vboxsf_get_tree,
	431	.reconfigure = vboxsf_reconfigure,
	432	};
	433
	434	static int vboxsf_init_fs_context(struct fs_context *fc)
	435	{
	436	struct vboxsf_fs_context *ctx;
	437
	438	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	439	if (!ctx)
	440	return -ENOMEM;
	441
	442	current_uid_gid(&ctx->o.uid, &ctx->o.gid);
	443
	444	fc->fs_private = ctx;
	445	fc->ops = &vboxsf_context_ops;
	446	return 0;
	447	}
	448
	449	static struct file_system_type vboxsf_fs_type = {
	450	.owner = THIS_MODULE,
	451	.name = "vboxsf",
	452	.init_fs_context = vboxsf_init_fs_context,
	453	.kill_sb = kill_anon_super
	454	};
	455
	456	/* Module initialization/finalization handlers */
	457	static int __init vboxsf_init(void)
	458	{
	459	return register_filesystem(&vboxsf_fs_type);
	460	}
	461
	462	static void __exit vboxsf_fini(void)
	463	{
	464	unregister_filesystem(&vboxsf_fs_type);
	465
	466	mutex_lock(&vboxsf_setup_mutex);
	467	if (vboxsf_setup_done) {
	468	vboxsf_disconnect();
	469	/*
	470	* Make sure all delayed rcu free inodes are flushed
	471	* before we destroy the cache.
	472	*/
	473	rcu_barrier();
	474	kmem_cache_destroy(vboxsf_inode_cachep);
	475	}
	476	mutex_unlock(&vboxsf_setup_mutex);
	477	}
478
479	module_init(vboxsf_init);
480	module_exit(vboxsf_fini);
481
482	MODULE_DESCRIPTION("Oracle VM VirtualBox Module for Host File System Access");
483	MODULE_AUTHOR("Oracle Corporation");
484	MODULE_LICENSE("GPL v2");
485	MODULE_ALIAS_FS("vboxsf");