[linux-2.6-block.git] / fs / efivarfs / super.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Red Hat, Inc.
 * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
 */

#include <linux/ctype.h>
#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/ucs2_string.h>
#include <linux/slab.h>
#include <linux/magic.h>
#include <linux/statfs.h>

#include "internal.h"

LIST_HEAD(efivarfs_list);

static void efivarfs_evict_inode(struct inode *inode)
{
	clear_inode(inode);
}

static int efivarfs_show_options(struct seq_file *m, struct dentry *root)
{
	struct super_block *sb = root->d_sb;
	struct efivarfs_fs_info *sbi = sb->s_fs_info;
	struct efivarfs_mount_opts *opts = &sbi->mount_opts;

	if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
		seq_printf(m, ",uid=%u",
				from_kuid_munged(&init_user_ns, opts->uid));
	if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
		seq_printf(m, ",gid=%u",
				from_kgid_munged(&init_user_ns, opts->gid));
	return 0;
}

static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	const u32 attr = EFI_VARIABLE_NON_VOLATILE |
			 EFI_VARIABLE_BOOTSERVICE_ACCESS |
			 EFI_VARIABLE_RUNTIME_ACCESS;
	u64 storage_space, remaining_space, max_variable_size;
	efi_status_t status;

	status = efivar_query_variable_info(attr, &storage_space, &remaining_space,
					    &max_variable_size);
	if (status != EFI_SUCCESS)
		return efi_status_to_err(status);

	/*
	 * This is not a normal filesystem, so no point in pretending it has a block
	 * size; we declare f_bsize to 1, so that we can then report the exact value
	 * sent by EFI QueryVariableInfo in f_blocks and f_bfree
	 */
	buf->f_bsize	= 1;
	buf->f_namelen	= NAME_MAX;
	buf->f_blocks	= storage_space;
	buf->f_bfree	= remaining_space;
	buf->f_type	= dentry->d_sb->s_magic;

	/*
	 * In f_bavail we declare the free space that the kernel will allow writing
	 * when the storage_paranoia x86 quirk is active. To use more, users
	 * should boot the kernel with efi_no_storage_paranoia.
	 */
	if (remaining_space > efivar_reserved_space())
		buf->f_bavail = remaining_space - efivar_reserved_space();
	else
		buf->f_bavail = 0;

	return 0;
}
static const struct super_operations efivarfs_ops = {
	.statfs = efivarfs_statfs,
	.drop_inode = generic_delete_inode,
	.evict_inode = efivarfs_evict_inode,
	.show_options = efivarfs_show_options,
};

/*
 * Compare two efivarfs file names.
 *
 * An efivarfs filename is composed of two parts,
 *
 *	1. A case-sensitive variable name
 *	2. A case-insensitive GUID
 *
 * So we need to perform a case-sensitive match on part 1 and a
 * case-insensitive match on part 2.
 */
static int efivarfs_d_compare(const struct dentry *dentry,
			      unsigned int len, const char *str,
			      const struct qstr *name)
{
	int guid = len - EFI_VARIABLE_GUID_LEN;

	if (name->len != len)
		return 1;

	/* Case-sensitive compare for the variable name */
	if (memcmp(str, name->name, guid))
		return 1;

	/* Case-insensitive compare for the GUID */
	return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
}

static int efivarfs_d_hash(const struct dentry *dentry, struct qstr *qstr)
{
	unsigned long hash = init_name_hash(dentry);
	const unsigned char *s = qstr->name;
	unsigned int len = qstr->len;

	if (!efivarfs_valid_name(s, len))
		return -EINVAL;

	while (len-- > EFI_VARIABLE_GUID_LEN)
		hash = partial_name_hash(*s++, hash);

	/* GUID is case-insensitive. */
	while (len--)
		hash = partial_name_hash(tolower(*s++), hash);

	qstr->hash = end_name_hash(hash);
	return 0;
}

static const struct dentry_operations efivarfs_d_ops = {
	.d_compare = efivarfs_d_compare,
	.d_hash = efivarfs_d_hash,
	.d_delete = always_delete_dentry,
};

static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
{
	struct dentry *d;
	struct qstr q;
	int err;

	q.name = name;
	q.len = strlen(name);

	err = efivarfs_d_hash(parent, &q);
	if (err)
		return ERR_PTR(err);

	d = d_alloc(parent, &q);
	if (d)
		return d;

	return ERR_PTR(-ENOMEM);
}

static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
			     unsigned long name_size, void *data)
{
	struct super_block *sb = (struct super_block *)data;
	struct efivar_entry *entry;
	struct inode *inode = NULL;
	struct dentry *dentry, *root = sb->s_root;
	unsigned long size = 0;
	char *name;
	int len;
	int err = -ENOMEM;
	bool is_removable = false;

	if (guid_equal(&vendor, &LINUX_EFI_RANDOM_SEED_TABLE_GUID))
		return 0;

	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
	if (!entry)
		return err;

	memcpy(entry->var.VariableName, name16, name_size);
	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));

	len = ucs2_utf8size(entry->var.VariableName);

	/* name, plus '-', plus GUID, plus NUL*/
	name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
	if (!name)
		goto fail;

	ucs2_as_utf8(name, entry->var.VariableName, len);

	if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))
		is_removable = true;

	name[len] = '-';

	efi_guid_to_str(&entry->var.VendorGuid, name + len + 1);

	name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';

	/* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
	strreplace(name, '/', '!');

	inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
				   is_removable);
	if (!inode)
		goto fail_name;

	dentry = efivarfs_alloc_dentry(root, name);
	if (IS_ERR(dentry)) {
		err = PTR_ERR(dentry);
		goto fail_inode;
	}

	__efivar_entry_get(entry, NULL, &size, NULL);
	__efivar_entry_add(entry, &efivarfs_list);

	/* copied by the above to local storage in the dentry. */
	kfree(name);

	inode_lock(inode);
	inode->i_private = entry;
	i_size_write(inode, size + sizeof(entry->var.Attributes));
	inode_unlock(inode);
	d_add(dentry, inode);

	return 0;

fail_inode:
	iput(inode);
fail_name:
	kfree(name);
fail:
	kfree(entry);
	return err;
}

static int efivarfs_destroy(struct efivar_entry *entry, void *data)
{
	efivar_entry_remove(entry);
	kfree(entry);
	return 0;
}

enum {
	Opt_uid, Opt_gid,
};

static const struct fs_parameter_spec efivarfs_parameters[] = {
	fsparam_u32("uid", Opt_uid),
	fsparam_u32("gid", Opt_gid),
	{},
};

static int efivarfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
	struct efivarfs_fs_info *sbi = fc->s_fs_info;
	struct efivarfs_mount_opts *opts = &sbi->mount_opts;
	struct fs_parse_result result;
	int opt;

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

	switch (opt) {
	case Opt_uid:
		opts->uid = make_kuid(current_user_ns(), result.uint_32);
		if (!uid_valid(opts->uid))
			return -EINVAL;
		break;
	case Opt_gid:
		opts->gid = make_kgid(current_user_ns(), result.uint_32);
		if (!gid_valid(opts->gid))
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
	struct inode *inode = NULL;
	struct dentry *root;
	int err;

	if (!efivar_is_available())
		return -EOPNOTSUPP;

	sb->s_maxbytes          = MAX_LFS_FILESIZE;
	sb->s_blocksize         = PAGE_SIZE;
	sb->s_blocksize_bits    = PAGE_SHIFT;
	sb->s_magic             = EFIVARFS_MAGIC;
	sb->s_op                = &efivarfs_ops;
	sb->s_d_op		= &efivarfs_d_ops;
	sb->s_time_gran         = 1;

	if (!efivar_supports_writes())
		sb->s_flags |= SB_RDONLY;

	inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0, true);
	if (!inode)
		return -ENOMEM;
	inode->i_op = &efivarfs_dir_inode_operations;

	root = d_make_root(inode);
	sb->s_root = root;
	if (!root)
		return -ENOMEM;

	INIT_LIST_HEAD(&efivarfs_list);

	err = efivar_init(efivarfs_callback, (void *)sb, true, &efivarfs_list);
	if (err)
		efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);

	return err;
}

static int efivarfs_get_tree(struct fs_context *fc)
{
	return get_tree_single(fc, efivarfs_fill_super);
}

static const struct fs_context_operations efivarfs_context_ops = {
	.get_tree	= efivarfs_get_tree,
	.parse_param	= efivarfs_parse_param,
};

static int efivarfs_init_fs_context(struct fs_context *fc)
{
	struct efivarfs_fs_info *sfi;

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

	sfi->mount_opts.uid = GLOBAL_ROOT_UID;
	sfi->mount_opts.gid = GLOBAL_ROOT_GID;

	fc->s_fs_info = sfi;
	fc->ops = &efivarfs_context_ops;
	return 0;
}

static void efivarfs_kill_sb(struct super_block *sb)
{
	kill_litter_super(sb);

	if (!efivar_is_available())
		return;

	/* Remove all entries and destroy */
	efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
}

static struct file_system_type efivarfs_type = {
	.owner   = THIS_MODULE,
	.name    = "efivarfs",
	.init_fs_context = efivarfs_init_fs_context,
	.kill_sb = efivarfs_kill_sb,
	.parameters = efivarfs_parameters,
};

static __init int efivarfs_init(void)
{
	return register_filesystem(&efivarfs_type);
}

static __exit void efivarfs_exit(void)
{
	unregister_filesystem(&efivarfs_type);
}

MODULE_AUTHOR("Matthew Garrett, Jeremy Kerr");
MODULE_DESCRIPTION("EFI Variable Filesystem");
MODULE_LICENSE("GPL");
MODULE_ALIAS_FS("efivarfs");

module_init(efivarfs_init);
module_exit(efivarfs_exit);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
d68772b7 MF	2	/*
	3	* Copyright (C) 2012 Red Hat, Inc.
	4	* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
d68772b7 MF	5	*/
	6
	7	#include <linux/ctype.h>
	8	#include <linux/efi.h>
	9	#include <linux/fs.h>
47999745	10	#include <linux/fs_context.h>
5329aa51	11	#include <linux/fs_parser.h>
d68772b7 MF	12	#include <linux/module.h>
d68772b7 MF	13	#include <linux/pagemap.h>
a614e192	14	#include <linux/ucs2_string.h>
20b4fb48 LT	15	#include <linux/slab.h>
20b4fb48 LT	16	#include <linux/magic.h>
d86ff333	17	#include <linux/statfs.h>
d68772b7 MF	18
	19	#include "internal.h"
	20
	21	LIST_HEAD(efivarfs_list);
	22
	23	static void efivarfs_evict_inode(struct inode *inode)
	24	{
	25	clear_inode(inode);
	26	}
	27
5329aa51 JZ	28	static int efivarfs_show_options(struct seq_file m, struct dentry root)
	29	{
	30	struct super_block *sb = root->d_sb;
	31	struct efivarfs_fs_info *sbi = sb->s_fs_info;
	32	struct efivarfs_mount_opts *opts = &sbi->mount_opts;
	33
	34	if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
	35	seq_printf(m, ",uid=%u",
	36	from_kuid_munged(&init_user_ns, opts->uid));
	37	if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
	38	seq_printf(m, ",gid=%u",
	39	from_kgid_munged(&init_user_ns, opts->gid));
	40	return 0;
	41	}
	42
d86ff333 AA	43	static int efivarfs_statfs(struct dentry dentry, struct kstatfs buf)
	44	{
	45	const u32 attr = EFI_VARIABLE_NON_VOLATILE \|
	46	EFI_VARIABLE_BOOTSERVICE_ACCESS \|
	47	EFI_VARIABLE_RUNTIME_ACCESS;
	48	u64 storage_space, remaining_space, max_variable_size;
	49	efi_status_t status;
	50
	51	status = efivar_query_variable_info(attr, &storage_space, &remaining_space,
	52	&max_variable_size);
	53	if (status != EFI_SUCCESS)
	54	return efi_status_to_err(status);
	55
	56	/*
	57	* This is not a normal filesystem, so no point in pretending it has a block
	58	* size; we declare f_bsize to 1, so that we can then report the exact value
	59	* sent by EFI QueryVariableInfo in f_blocks and f_bfree
	60	*/
	61	buf->f_bsize = 1;
	62	buf->f_namelen = NAME_MAX;
	63	buf->f_blocks = storage_space;
	64	buf->f_bfree = remaining_space;
	65	buf->f_type = dentry->d_sb->s_magic;
	66
	67	/*
	68	* In f_bavail we declare the free space that the kernel will allow writing
	69	* when the storage_paranoia x86 quirk is active. To use more, users
	70	* should boot the kernel with efi_no_storage_paranoia.
	71	*/
	72	if (remaining_space > efivar_reserved_space())
	73	buf->f_bavail = remaining_space - efivar_reserved_space();
	74	else
	75	buf->f_bavail = 0;
	76
	77	return 0;
	78	}
d68772b7	79	static const struct super_operations efivarfs_ops = {
d86ff333	80	.statfs = efivarfs_statfs,
d68772b7 MF	81	.drop_inode = generic_delete_inode,
d68772b7 MF	82	.evict_inode = efivarfs_evict_inode,
5329aa51	83	.show_options = efivarfs_show_options,
d68772b7 MF	84	};
d68772b7 MF	85
d68772b7 MF	86	/*
	87	* Compare two efivarfs file names.
	88	*
	89	* An efivarfs filename is composed of two parts,
	90	*
	91	* 1. A case-sensitive variable name
	92	* 2. A case-insensitive GUID
	93	*
	94	* So we need to perform a case-sensitive match on part 1 and a
	95	* case-insensitive match on part 2.
	96	*/
6fa67e70	97	static int efivarfs_d_compare(const struct dentry *dentry,
d68772b7 MF	98	unsigned int len, const char *str,
	99	const struct qstr *name)
	100	{
	101	int guid = len - EFI_VARIABLE_GUID_LEN;
	102
	103	if (name->len != len)
	104	return 1;
	105
	106	/* Case-sensitive compare for the variable name */
	107	if (memcmp(str, name->name, guid))
	108	return 1;
	109
	110	/* Case-insensitive compare for the GUID */
	111	return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
	112	}
	113
da53be12	114	static int efivarfs_d_hash(const struct dentry dentry, struct qstr qstr)
d68772b7	115	{
8387ff25	116	unsigned long hash = init_name_hash(dentry);
d68772b7 MF	117	const unsigned char *s = qstr->name;
	118	unsigned int len = qstr->len;
	119
	120	if (!efivarfs_valid_name(s, len))
	121	return -EINVAL;
	122
	123	while (len-- > EFI_VARIABLE_GUID_LEN)
	124	hash = partial_name_hash(*s++, hash);
	125
	126	/* GUID is case-insensitive. */
	127	while (len--)
	128	hash = partial_name_hash(tolower(*s++), hash);
	129
	130	qstr->hash = end_name_hash(hash);
	131	return 0;
	132	}
	133
e37dcbfb	134	static const struct dentry_operations efivarfs_d_ops = {
d68772b7 MF	135	.d_compare = efivarfs_d_compare,
d68772b7 MF	136	.d_hash = efivarfs_d_hash,
b26d4cd3	137	.d_delete = always_delete_dentry,
d68772b7 MF	138	};
	139
	140	static struct dentry efivarfs_alloc_dentry(struct dentry parent, char *name)
	141	{
	142	struct dentry *d;
	143	struct qstr q;
	144	int err;
	145
	146	q.name = name;
	147	q.len = strlen(name);
	148
8387ff25	149	err = efivarfs_d_hash(parent, &q);
d68772b7 MF	150	if (err)
	151	return ERR_PTR(err);
	152
	153	d = d_alloc(parent, &q);
	154	if (d)
	155	return d;
	156
	157	return ERR_PTR(-ENOMEM);
	158	}
	159
	160	static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
	161	unsigned long name_size, void *data)
	162	{
	163	struct super_block sb = (struct super_block )data;
	164	struct efivar_entry *entry;
	165	struct inode *inode = NULL;
	166	struct dentry dentry, root = sb->s_root;
	167	unsigned long size = 0;
	168	char *name;
e0d64e6a	169	int len;
d68772b7	170	int err = -ENOMEM;
ed8b0de5	171	bool is_removable = false;
d68772b7	172
63ffb573 JD	173	if (guid_equal(&vendor, &LINUX_EFI_RANDOM_SEED_TABLE_GUID))
	174	return 0;
	175
c57dcb56	176	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
d68772b7 MF	177	if (!entry)
	178	return err;
	179
	180	memcpy(entry->var.VariableName, name16, name_size);
	181	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
	182
e0d64e6a	183	len = ucs2_utf8size(entry->var.VariableName);
d68772b7 MF	184
	185	/* name, plus '-', plus GUID, plus NUL*/
	186	name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
	187	if (!name)
	188	goto fail;
	189
e0d64e6a	190	ucs2_as_utf8(name, entry->var.VariableName, len);
d68772b7	191
ed8b0de5 PJ	192	if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))
	193	is_removable = true;
	194
d68772b7 MF	195	name[len] = '-';
d68772b7 MF	196
26e02272	197	efi_guid_to_str(&entry->var.VendorGuid, name + len + 1);
d68772b7 MF	198
	199	name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
	200
336af6a4 MS	201	/* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
	202	strreplace(name, '/', '!');
	203
ed8b0de5 PJ	204	inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG \| 0644, 0,
ed8b0de5 PJ	205	is_removable);
d68772b7 MF	206	if (!inode)
	207	goto fail_name;
	208
	209	dentry = efivarfs_alloc_dentry(root, name);
	210	if (IS_ERR(dentry)) {
	211	err = PTR_ERR(dentry);
	212	goto fail_inode;
	213	}
	214
ec3507b2 AB	215	__efivar_entry_get(entry, NULL, &size, NULL);
ec3507b2 AB	216	__efivar_entry_add(entry, &efivarfs_list);
d68772b7	217
22c2b77f MF	218	/* copied by the above to local storage in the dentry. */
	219	kfree(name);
	220
5955102c	221	inode_lock(inode);
d68772b7 MF	222	inode->i_private = entry;
d68772b7 MF	223	i_size_write(inode, size + sizeof(entry->var.Attributes));
5955102c	224	inode_unlock(inode);
d68772b7 MF	225	d_add(dentry, inode);
	226
	227	return 0;
	228
	229	fail_inode:
	230	iput(inode);
	231	fail_name:
	232	kfree(name);
	233	fail:
	234	kfree(entry);
	235	return err;
	236	}
	237
	238	static int efivarfs_destroy(struct efivar_entry entry, void data)
	239	{
3a75f9f2	240	efivar_entry_remove(entry);
d68772b7 MF	241	kfree(entry);
	242	return 0;
	243	}
	244
5329aa51 JZ	245	enum {
	246	Opt_uid, Opt_gid,
	247	};
	248
	249	static const struct fs_parameter_spec efivarfs_parameters[] = {
	250	fsparam_u32("uid", Opt_uid),
	251	fsparam_u32("gid", Opt_gid),
	252	{},
	253	};
	254
	255	static int efivarfs_parse_param(struct fs_context fc, struct fs_parameter param)
	256	{
	257	struct efivarfs_fs_info *sbi = fc->s_fs_info;
	258	struct efivarfs_mount_opts *opts = &sbi->mount_opts;
	259	struct fs_parse_result result;
	260	int opt;
	261
	262	opt = fs_parse(fc, efivarfs_parameters, param, &result);
	263	if (opt < 0)
	264	return opt;
	265
	266	switch (opt) {
	267	case Opt_uid:
	268	opts->uid = make_kuid(current_user_ns(), result.uint_32);
	269	if (!uid_valid(opts->uid))
	270	return -EINVAL;
	271	break;
	272	case Opt_gid:
	273	opts->gid = make_kgid(current_user_ns(), result.uint_32);
	274	if (!gid_valid(opts->gid))
	275	return -EINVAL;
	276	break;
	277	default:
	278	return -EINVAL;
	279	}
	280
	281	return 0;
	282	}
	283
47999745	284	static int efivarfs_fill_super(struct super_block sb, struct fs_context fc)
d68772b7 MF	285	{
	286	struct inode *inode = NULL;
	287	struct dentry *root;
	288	int err;
	289
301de9a2 JH	290	if (!efivar_is_available())
	291	return -EOPNOTSUPP;
	292
d68772b7	293	sb->s_maxbytes = MAX_LFS_FILESIZE;
09cbfeaf KS	294	sb->s_blocksize = PAGE_SIZE;
09cbfeaf KS	295	sb->s_blocksize_bits = PAGE_SHIFT;
d68772b7 MF	296	sb->s_magic = EFIVARFS_MAGIC;
	297	sb->s_op = &efivarfs_ops;
	298	sb->s_d_op = &efivarfs_d_ops;
	299	sb->s_time_gran = 1;
	300
f88814cc AB	301	if (!efivar_supports_writes())
	302	sb->s_flags \|= SB_RDONLY;
	303
ed8b0de5	304	inode = efivarfs_get_inode(sb, NULL, S_IFDIR \| 0755, 0, true);
d68772b7 MF	305	if (!inode)
	306	return -ENOMEM;
	307	inode->i_op = &efivarfs_dir_inode_operations;
	308
	309	root = d_make_root(inode);
	310	sb->s_root = root;
	311	if (!root)
	312	return -ENOMEM;
	313
	314	INIT_LIST_HEAD(&efivarfs_list);
	315
1cfd6316	316	err = efivar_init(efivarfs_callback, (void *)sb, true, &efivarfs_list);
d68772b7	317	if (err)
3a75f9f2	318	efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
d68772b7 MF	319
	320	return err;
	321	}
	322
47999745 DH	323	static int efivarfs_get_tree(struct fs_context *fc)
	324	{
	325	return get_tree_single(fc, efivarfs_fill_super);
	326	}
	327
	328	static const struct fs_context_operations efivarfs_context_ops = {
	329	.get_tree = efivarfs_get_tree,
5329aa51	330	.parse_param = efivarfs_parse_param,
47999745 DH	331	};
	332
	333	static int efivarfs_init_fs_context(struct fs_context *fc)
d68772b7	334	{
5329aa51 JZ	335	struct efivarfs_fs_info *sfi;
	336
	337	sfi = kzalloc(sizeof(*sfi), GFP_KERNEL);
	338	if (!sfi)
	339	return -ENOMEM;
	340
	341	sfi->mount_opts.uid = GLOBAL_ROOT_UID;
	342	sfi->mount_opts.gid = GLOBAL_ROOT_GID;
	343
	344	fc->s_fs_info = sfi;
47999745 DH	345	fc->ops = &efivarfs_context_ops;
47999745 DH	346	return 0;
d68772b7 MF	347	}
	348
	349	static void efivarfs_kill_sb(struct super_block *sb)
	350	{
	351	kill_litter_super(sb);
d68772b7	352
301de9a2 JH	353	if (!efivar_is_available())
	354	return;
	355
d68772b7	356	/* Remove all entries and destroy */
3a75f9f2	357	efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
d68772b7 MF	358	}
	359
	360	static struct file_system_type efivarfs_type = {
af5a29ae	361	.owner = THIS_MODULE,
d68772b7	362	.name = "efivarfs",
47999745	363	.init_fs_context = efivarfs_init_fs_context,
d68772b7	364	.kill_sb = efivarfs_kill_sb,
5329aa51	365	.parameters = efivarfs_parameters,
d68772b7 MF	366	};
	367
	368	static __init int efivarfs_init(void)
	369	{
d68772b7 MF	370	return register_filesystem(&efivarfs_type);
	371	}
	372
af5a29ae MK	373	static __exit void efivarfs_exit(void)
	374	{
	375	unregister_filesystem(&efivarfs_type);
	376	}
	377
d68772b7 MF	378	MODULE_AUTHOR("Matthew Garrett, Jeremy Kerr");
	379	MODULE_DESCRIPTION("EFI Variable Filesystem");
	380	MODULE_LICENSE("GPL");
	381	MODULE_ALIAS_FS("efivarfs");
	382
	383	module_init(efivarfs_init);
af5a29ae	384	module_exit(efivarfs_exit);