[mirror_ubuntu-bionic-kernel.git] / arch / s390 / hypfs / inode.c

// SPDX-License-Identifier: GPL-1.0+
/*
 *    Hypervisor filesystem for Linux on s390.
 *
 *    Copyright IBM Corp. 2006, 2008
 *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
 */

#define KMSG_COMPONENT "hypfs"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/time.h>
#include <linux/parser.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/uio.h>
#include <asm/ebcdic.h>
#include "hypfs.h"

#define HYPFS_MAGIC 0x687970	/* ASCII 'hyp' */
#define TMP_SIZE 64		/* size of temporary buffers */

static struct dentry *hypfs_create_update_file(struct dentry *dir);

struct hypfs_sb_info {
	kuid_t uid;			/* uid used for files and dirs */
	kgid_t gid;			/* gid used for files and dirs */
	struct dentry *update_file;	/* file to trigger update */
	time_t last_update;		/* last update time in secs since 1970 */
	struct mutex lock;		/* lock to protect update process */
};

static const struct file_operations hypfs_file_ops;
static struct file_system_type hypfs_type;
static const struct super_operations hypfs_s_ops;

/* start of list of all dentries, which have to be deleted on update */
static struct dentry *hypfs_last_dentry;

static void hypfs_update_update(struct super_block *sb)
{
	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	struct inode *inode = d_inode(sb_info->update_file);

	sb_info->last_update = get_seconds();
	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
}

/* directory tree removal functions */

static void hypfs_add_dentry(struct dentry *dentry)
{
	dentry->d_fsdata = hypfs_last_dentry;
	hypfs_last_dentry = dentry;
}

static void hypfs_remove(struct dentry *dentry)
{
	struct dentry *parent;

	parent = dentry->d_parent;
	inode_lock(d_inode(parent));
	if (simple_positive(dentry)) {
		if (d_is_dir(dentry))
			simple_rmdir(d_inode(parent), dentry);
		else
			simple_unlink(d_inode(parent), dentry);
	}
	d_delete(dentry);
	dput(dentry);
	inode_unlock(d_inode(parent));
}

static void hypfs_delete_tree(struct dentry *root)
{
	while (hypfs_last_dentry) {
		struct dentry *next_dentry;
		next_dentry = hypfs_last_dentry->d_fsdata;
		hypfs_remove(hypfs_last_dentry);
		hypfs_last_dentry = next_dentry;
	}
}

static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
{
	struct inode *ret = new_inode(sb);

	if (ret) {
		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
		ret->i_ino = get_next_ino();
		ret->i_mode = mode;
		ret->i_uid = hypfs_info->uid;
		ret->i_gid = hypfs_info->gid;
		ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
		if (S_ISDIR(mode))
			set_nlink(ret, 2);
	}
	return ret;
}

static void hypfs_evict_inode(struct inode *inode)
{
	clear_inode(inode);
	kfree(inode->i_private);
}

static int hypfs_open(struct inode *inode, struct file *filp)
{
	char *data = file_inode(filp)->i_private;
	struct hypfs_sb_info *fs_info;

	if (filp->f_mode & FMODE_WRITE) {
		if (!(inode->i_mode & S_IWUGO))
			return -EACCES;
	}
	if (filp->f_mode & FMODE_READ) {
		if (!(inode->i_mode & S_IRUGO))
			return -EACCES;
	}

	fs_info = inode->i_sb->s_fs_info;
	if(data) {
		mutex_lock(&fs_info->lock);
		filp->private_data = kstrdup(data, GFP_KERNEL);
		if (!filp->private_data) {
			mutex_unlock(&fs_info->lock);
			return -ENOMEM;
		}
		mutex_unlock(&fs_info->lock);
	}
	return nonseekable_open(inode, filp);
}

static ssize_t hypfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *file = iocb->ki_filp;
	char *data = file->private_data;
	size_t available = strlen(data);
	loff_t pos = iocb->ki_pos;
	size_t count;

	if (pos < 0)
		return -EINVAL;
	if (pos >= available || !iov_iter_count(to))
		return 0;
	count = copy_to_iter(data + pos, available - pos, to);
	if (!count)
		return -EFAULT;
	iocb->ki_pos = pos + count;
	file_accessed(file);
	return count;
}

static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	int rc;
	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
	struct hypfs_sb_info *fs_info = sb->s_fs_info;
	size_t count = iov_iter_count(from);

	/*
	 * Currently we only allow one update per second for two reasons:
	 * 1. diag 204 is VERY expensive
	 * 2. If several processes do updates in parallel and then read the
	 *    hypfs data, the likelihood of collisions is reduced, if we restrict
	 *    the minimum update interval. A collision occurs, if during the
	 *    data gathering of one process another process triggers an update
	 *    If the first process wants to ensure consistent data, it has
	 *    to restart data collection in this case.
	 */
	mutex_lock(&fs_info->lock);
	if (fs_info->last_update == get_seconds()) {
		rc = -EBUSY;
		goto out;
	}
	hypfs_delete_tree(sb->s_root);
	if (MACHINE_IS_VM)
		rc = hypfs_vm_create_files(sb->s_root);
	else
		rc = hypfs_diag_create_files(sb->s_root);
	if (rc) {
		pr_err("Updating the hypfs tree failed\n");
		hypfs_delete_tree(sb->s_root);
		goto out;
	}
	hypfs_update_update(sb);
	rc = count;
	iov_iter_advance(from, count);
out:
	mutex_unlock(&fs_info->lock);
	return rc;
}

static int hypfs_release(struct inode *inode, struct file *filp)
{
	kfree(filp->private_data);
	return 0;
}

enum { opt_uid, opt_gid, opt_err };

static const match_table_t hypfs_tokens = {
	{opt_uid, "uid=%u"},
	{opt_gid, "gid=%u"},
	{opt_err, NULL}
};

static int hypfs_parse_options(char *options, struct super_block *sb)
{
	char *str;
	substring_t args[MAX_OPT_ARGS];
	kuid_t uid;
	kgid_t gid;

	if (!options)
		return 0;
	while ((str = strsep(&options, ",")) != NULL) {
		int token, option;
		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;

		if (!*str)
			continue;
		token = match_token(str, hypfs_tokens, args);
		switch (token) {
		case opt_uid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			uid = make_kuid(current_user_ns(), option);
			if (!uid_valid(uid))
				return -EINVAL;
			hypfs_info->uid = uid;
			break;
		case opt_gid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			gid = make_kgid(current_user_ns(), option);
			if (!gid_valid(gid))
				return -EINVAL;
			hypfs_info->gid = gid;
			break;
		case opt_err:
		default:
			pr_err("%s is not a valid mount option\n", str);
			return -EINVAL;
		}
	}
	return 0;
}

static int hypfs_show_options(struct seq_file *s, struct dentry *root)
{
	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;

	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
	return 0;
}

static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct inode *root_inode;
	struct dentry *root_dentry;
	int rc = 0;
	struct hypfs_sb_info *sbi;

	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;
	mutex_init(&sbi->lock);
	sbi->uid = current_uid();
	sbi->gid = current_gid();
	sb->s_fs_info = sbi;
	sb->s_blocksize = PAGE_SIZE;
	sb->s_blocksize_bits = PAGE_SHIFT;
	sb->s_magic = HYPFS_MAGIC;
	sb->s_op = &hypfs_s_ops;
	if (hypfs_parse_options(data, sb))
		return -EINVAL;
	root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
	if (!root_inode)
		return -ENOMEM;
	root_inode->i_op = &simple_dir_inode_operations;
	root_inode->i_fop = &simple_dir_operations;
	sb->s_root = root_dentry = d_make_root(root_inode);
	if (!root_dentry)
		return -ENOMEM;
	if (MACHINE_IS_VM)
		rc = hypfs_vm_create_files(root_dentry);
	else
		rc = hypfs_diag_create_files(root_dentry);
	if (rc)
		return rc;
	sbi->update_file = hypfs_create_update_file(root_dentry);
	if (IS_ERR(sbi->update_file))
		return PTR_ERR(sbi->update_file);
	hypfs_update_update(sb);
	pr_info("Hypervisor filesystem mounted\n");
	return 0;
}

static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
			const char *devname, void *data)
{
	return mount_single(fst, flags, data, hypfs_fill_super);
}

static void hypfs_kill_super(struct super_block *sb)
{
	struct hypfs_sb_info *sb_info = sb->s_fs_info;

	if (sb->s_root)
		hypfs_delete_tree(sb->s_root);
	if (sb_info && sb_info->update_file)
		hypfs_remove(sb_info->update_file);
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
	kill_litter_super(sb);
}

static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
					char *data, umode_t mode)
{
	struct dentry *dentry;
	struct inode *inode;

	inode_lock(d_inode(parent));
	dentry = lookup_one_len(name, parent, strlen(name));
	if (IS_ERR(dentry)) {
		dentry = ERR_PTR(-ENOMEM);
		goto fail;
	}
	inode = hypfs_make_inode(parent->d_sb, mode);
	if (!inode) {
		dput(dentry);
		dentry = ERR_PTR(-ENOMEM);
		goto fail;
	}
	if (S_ISREG(mode)) {
		inode->i_fop = &hypfs_file_ops;
		if (data)
			inode->i_size = strlen(data);
		else
			inode->i_size = 0;
	} else if (S_ISDIR(mode)) {
		inode->i_op = &simple_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
		inc_nlink(d_inode(parent));
	} else
		BUG();
	inode->i_private = data;
	d_instantiate(dentry, inode);
	dget(dentry);
fail:
	inode_unlock(d_inode(parent));
	return dentry;
}

struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
{
	struct dentry *dentry;

	dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
	if (IS_ERR(dentry))
		return dentry;
	hypfs_add_dentry(dentry);
	return dentry;
}

static struct dentry *hypfs_create_update_file(struct dentry *dir)
{
	struct dentry *dentry;

	dentry = hypfs_create_file(dir, "update", NULL,
				   S_IFREG | UPDATE_FILE_MODE);
	/*
	 * We do not put the update file on the 'delete' list with
	 * hypfs_add_dentry(), since it should not be removed when the tree
	 * is updated.
	 */
	return dentry;
}

struct dentry *hypfs_create_u64(struct dentry *dir,
				const char *name, __u64 value)
{
	char *buffer;
	char tmp[TMP_SIZE];
	struct dentry *dentry;

	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
	buffer = kstrdup(tmp, GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);
	dentry =
	    hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
	if (IS_ERR(dentry)) {
		kfree(buffer);
		return ERR_PTR(-ENOMEM);
	}
	hypfs_add_dentry(dentry);
	return dentry;
}

struct dentry *hypfs_create_str(struct dentry *dir,
				const char *name, char *string)
{
	char *buffer;
	struct dentry *dentry;

	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);
	sprintf(buffer, "%s\n", string);
	dentry =
	    hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
	if (IS_ERR(dentry)) {
		kfree(buffer);
		return ERR_PTR(-ENOMEM);
	}
	hypfs_add_dentry(dentry);
	return dentry;
}

static const struct file_operations hypfs_file_ops = {
	.open		= hypfs_open,
	.release	= hypfs_release,
	.read_iter	= hypfs_read_iter,
	.write_iter	= hypfs_write_iter,
	.llseek		= no_llseek,
};

static struct file_system_type hypfs_type = {
	.owner		= THIS_MODULE,
	.name		= "s390_hypfs",
	.mount		= hypfs_mount,
	.kill_sb	= hypfs_kill_super
};

static const struct super_operations hypfs_s_ops = {
	.statfs		= simple_statfs,
	.evict_inode	= hypfs_evict_inode,
	.show_options	= hypfs_show_options,
};

static int __init hypfs_init(void)
{
	int rc;

	rc = hypfs_dbfs_init();
	if (rc)
		return rc;
	if (hypfs_diag_init()) {
		rc = -ENODATA;
		goto fail_dbfs_exit;
	}
	if (hypfs_vm_init()) {
		rc = -ENODATA;
		goto fail_hypfs_diag_exit;
	}
	if (hypfs_sprp_init()) {
		rc = -ENODATA;
		goto fail_hypfs_vm_exit;
	}
	if (hypfs_diag0c_init()) {
		rc = -ENODATA;
		goto fail_hypfs_sprp_exit;
	}
	rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
	if (rc)
		goto fail_hypfs_diag0c_exit;
	rc = register_filesystem(&hypfs_type);
	if (rc)
		goto fail_filesystem;
	return 0;

fail_filesystem:
	sysfs_remove_mount_point(hypervisor_kobj, "s390");
fail_hypfs_diag0c_exit:
	hypfs_diag0c_exit();
fail_hypfs_sprp_exit:
	hypfs_sprp_exit();
fail_hypfs_vm_exit:
	hypfs_vm_exit();
fail_hypfs_diag_exit:
	hypfs_diag_exit();
fail_dbfs_exit:
	hypfs_dbfs_exit();
	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
	return rc;
}
device_initcall(hypfs_init)
Commit	Line	Data
0b73214f	1	// SPDX-License-Identifier: GPL-1.0+
24bbb1fa	2	/*
24bbb1fa MH	3	* Hypervisor filesystem for Linux on s390.
24bbb1fa MH	4	*
f55495ba	5	* Copyright IBM Corp. 2006, 2008
24bbb1fa MH	6	* Author(s): Michael Holzheu <holzheu@de.ibm.com>
	7	*/
	8
f55495ba MH	9	#define KMSG_COMPONENT "hypfs"
	10	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	11
24bbb1fa MH	12	#include <linux/types.h>
	13	#include <linux/errno.h>
	14	#include <linux/fs.h>
	15	#include <linux/namei.h>
	16	#include <linux/vfs.h>
5a0e3ad6	17	#include <linux/slab.h>
24bbb1fa	18	#include <linux/pagemap.h>
24bbb1fa MH	19	#include <linux/time.h>
	20	#include <linux/parser.h>
	21	#include <linux/sysfs.h>
cee672e1 PG	22	#include <linux/init.h>
cee672e1 PG	23	#include <linux/kobject.h>
b01af5ba MH	24	#include <linux/seq_file.h>
b01af5ba MH	25	#include <linux/mount.h>
e2e40f2c	26	#include <linux/uio.h>
24bbb1fa MH	27	#include <asm/ebcdic.h>
24bbb1fa MH	28	#include "hypfs.h"
24bbb1fa MH	29
	30	#define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */
	31	#define TMP_SIZE 64 /* size of temporary buffers */
	32
a118cfdf	33	static struct dentry hypfs_create_update_file(struct dentry dir);
24bbb1fa MH	34
24bbb1fa MH	35	struct hypfs_sb_info {
6a62a216 EB	36	kuid_t uid; /* uid used for files and dirs */
6a62a216 EB	37	kgid_t gid; /* gid used for files and dirs */
24bbb1fa MH	38	struct dentry update_file; / file to trigger update */
	39	time_t last_update; /* last update time in secs since 1970 */
	40	struct mutex lock; /* lock to protect update process */
	41	};
	42
5dfe4c96	43	static const struct file_operations hypfs_file_ops;
24bbb1fa	44	static struct file_system_type hypfs_type;
b87221de	45	static const struct super_operations hypfs_s_ops;
24bbb1fa MH	46
	47	/* start of list of all dentries, which have to be deleted on update */
	48	static struct dentry *hypfs_last_dentry;
	49
	50	static void hypfs_update_update(struct super_block *sb)
	51	{
	52	struct hypfs_sb_info *sb_info = sb->s_fs_info;
75c3cfa8	53	struct inode *inode = d_inode(sb_info->update_file);
24bbb1fa MH	54
24bbb1fa MH	55	sb_info->last_update = get_seconds();
078cd827	56	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
24bbb1fa MH	57	}
	58
	59	/* directory tree removal functions */
	60
	61	static void hypfs_add_dentry(struct dentry *dentry)
	62	{
	63	dentry->d_fsdata = hypfs_last_dentry;
	64	hypfs_last_dentry = dentry;
	65	}
	66
	67	static void hypfs_remove(struct dentry *dentry)
	68	{
	69	struct dentry *parent;
	70
	71	parent = dentry->d_parent;
5955102c	72	inode_lock(d_inode(parent));
dc3f4198	73	if (simple_positive(dentry)) {
e36cb0b8	74	if (d_is_dir(dentry))
75c3cfa8	75	simple_rmdir(d_inode(parent), dentry);
9b5a03e1	76	else
75c3cfa8	77	simple_unlink(d_inode(parent), dentry);
9b5a03e1	78	}
24bbb1fa MH	79	d_delete(dentry);
24bbb1fa MH	80	dput(dentry);
5955102c	81	inode_unlock(d_inode(parent));
24bbb1fa MH	82	}
	83
	84	static void hypfs_delete_tree(struct dentry *root)
	85	{
	86	while (hypfs_last_dentry) {
	87	struct dentry *next_dentry;
	88	next_dentry = hypfs_last_dentry->d_fsdata;
	89	hypfs_remove(hypfs_last_dentry);
	90	hypfs_last_dentry = next_dentry;
	91	}
	92	}
	93
fec0ebae	94	static struct inode hypfs_make_inode(struct super_block sb, umode_t mode)
24bbb1fa MH	95	{
	96	struct inode *ret = new_inode(sb);
	97
	98	if (ret) {
	99	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
c960bec4	100	ret->i_ino = get_next_ino();
24bbb1fa MH	101	ret->i_mode = mode;
	102	ret->i_uid = hypfs_info->uid;
	103	ret->i_gid = hypfs_info->gid;
078cd827	104	ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
fec0ebae	105	if (S_ISDIR(mode))
bfe86848	106	set_nlink(ret, 2);
24bbb1fa MH	107	}
	108	return ret;
	109	}
	110
b69257f2	111	static void hypfs_evict_inode(struct inode *inode)
24bbb1fa	112	{
dbd5768f	113	clear_inode(inode);
8e18e294	114	kfree(inode->i_private);
24bbb1fa MH	115	}
	116
	117	static int hypfs_open(struct inode inode, struct file filp)
	118	{
496ad9aa	119	char *data = file_inode(filp)->i_private;
24bbb1fa MH	120	struct hypfs_sb_info *fs_info;
	121
	122	if (filp->f_mode & FMODE_WRITE) {
	123	if (!(inode->i_mode & S_IWUGO))
	124	return -EACCES;
	125	}
	126	if (filp->f_mode & FMODE_READ) {
	127	if (!(inode->i_mode & S_IRUGO))
	128	return -EACCES;
	129	}
	130
	131	fs_info = inode->i_sb->s_fs_info;
	132	if(data) {
	133	mutex_lock(&fs_info->lock);
	134	filp->private_data = kstrdup(data, GFP_KERNEL);
	135	if (!filp->private_data) {
	136	mutex_unlock(&fs_info->lock);
	137	return -ENOMEM;
	138	}
	139	mutex_unlock(&fs_info->lock);
	140	}
58ea91c0	141	return nonseekable_open(inode, filp);
24bbb1fa MH	142	}
24bbb1fa MH	143
a457ac28	144	static ssize_t hypfs_read_iter(struct kiocb iocb, struct iov_iter to)
24bbb1fa	145	{
a457ac28 AV	146	struct file *file = iocb->ki_filp;
	147	char *data = file->private_data;
	148	size_t available = strlen(data);
	149	loff_t pos = iocb->ki_pos;
	150	size_t count;
a29591c4	151
a457ac28 AV	152	if (pos < 0)
	153	return -EINVAL;
	154	if (pos >= available \|\| !iov_iter_count(to))
	155	return 0;
	156	count = copy_to_iter(data + pos, available - pos, to);
	157	if (!count)
	158	return -EFAULT;
	159	iocb->ki_pos = pos + count;
	160	file_accessed(file);
	161	return count;
24bbb1fa	162	}
a457ac28 AV	163
a457ac28 AV	164	static ssize_t hypfs_write_iter(struct kiocb iocb, struct iov_iter from)
24bbb1fa MH	165	{
24bbb1fa MH	166	int rc;
6131ffaa AV	167	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
6131ffaa AV	168	struct hypfs_sb_info *fs_info = sb->s_fs_info;
a457ac28	169	size_t count = iov_iter_count(from);
24bbb1fa	170
24bbb1fa MH	171	/*
	172	* Currently we only allow one update per second for two reasons:
	173	* 1. diag 204 is VERY expensive
	174	* 2. If several processes do updates in parallel and then read the
	175	* hypfs data, the likelihood of collisions is reduced, if we restrict
	176	* the minimum update interval. A collision occurs, if during the
	177	* data gathering of one process another process triggers an update
	178	* If the first process wants to ensure consistent data, it has
	179	* to restart data collection in this case.
	180	*/
	181	mutex_lock(&fs_info->lock);
	182	if (fs_info->last_update == get_seconds()) {
	183	rc = -EBUSY;
	184	goto out;
	185	}
	186	hypfs_delete_tree(sb->s_root);
31cb4bd3	187	if (MACHINE_IS_VM)
f78e41e3	188	rc = hypfs_vm_create_files(sb->s_root);
31cb4bd3	189	else
e334cf4f	190	rc = hypfs_diag_create_files(sb->s_root);
24bbb1fa	191	if (rc) {
f55495ba	192	pr_err("Updating the hypfs tree failed\n");
24bbb1fa MH	193	hypfs_delete_tree(sb->s_root);
	194	goto out;
	195	}
	196	hypfs_update_update(sb);
	197	rc = count;
a457ac28	198	iov_iter_advance(from, count);
24bbb1fa MH	199	out:
	200	mutex_unlock(&fs_info->lock);
	201	return rc;
	202	}
	203
	204	static int hypfs_release(struct inode inode, struct file filp)
	205	{
	206	kfree(filp->private_data);
	207	return 0;
	208	}
	209
	210	enum { opt_uid, opt_gid, opt_err };
	211
a447c093	212	static const match_table_t hypfs_tokens = {
24bbb1fa MH	213	{opt_uid, "uid=%u"},
	214	{opt_gid, "gid=%u"},
	215	{opt_err, NULL}
	216	};
	217
	218	static int hypfs_parse_options(char options, struct super_block sb)
	219	{
	220	char *str;
	221	substring_t args[MAX_OPT_ARGS];
6a62a216 EB	222	kuid_t uid;
6a62a216 EB	223	kgid_t gid;
24bbb1fa MH	224
	225	if (!options)
	226	return 0;
	227	while ((str = strsep(&options, ",")) != NULL) {
	228	int token, option;
	229	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	230
	231	if (!*str)
	232	continue;
	233	token = match_token(str, hypfs_tokens, args);
	234	switch (token) {
	235	case opt_uid:
	236	if (match_int(&args[0], &option))
	237	return -EINVAL;
6a62a216 EB	238	uid = make_kuid(current_user_ns(), option);
	239	if (!uid_valid(uid))
	240	return -EINVAL;
	241	hypfs_info->uid = uid;
24bbb1fa MH	242	break;
	243	case opt_gid:
	244	if (match_int(&args[0], &option))
	245	return -EINVAL;
6a62a216 EB	246	gid = make_kgid(current_user_ns(), option);
	247	if (!gid_valid(gid))
	248	return -EINVAL;
	249	hypfs_info->gid = gid;
24bbb1fa MH	250	break;
	251	case opt_err:
	252	default:
f55495ba	253	pr_err("%s is not a valid mount option\n", str);
24bbb1fa MH	254	return -EINVAL;
	255	}
	256	}
	257	return 0;
	258	}
	259
34c80b1d	260	static int hypfs_show_options(struct seq_file s, struct dentry root)
b01af5ba	261	{
34c80b1d	262	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
b01af5ba	263
6a62a216 EB	264	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
6a62a216 EB	265	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
b01af5ba MH	266	return 0;
	267	}
	268
24bbb1fa MH	269	static int hypfs_fill_super(struct super_block sb, void data, int silent)
	270	{
	271	struct inode *root_inode;
	272	struct dentry *root_dentry;
	273	int rc = 0;
	274	struct hypfs_sb_info *sbi;
	275
	276	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	277	if (!sbi)
	278	return -ENOMEM;
	279	mutex_init(&sbi->lock);
e5423705 DH	280	sbi->uid = current_uid();
e5423705 DH	281	sbi->gid = current_gid();
24bbb1fa	282	sb->s_fs_info = sbi;
09cbfeaf KS	283	sb->s_blocksize = PAGE_SIZE;
09cbfeaf KS	284	sb->s_blocksize_bits = PAGE_SHIFT;
24bbb1fa MH	285	sb->s_magic = HYPFS_MAGIC;
24bbb1fa MH	286	sb->s_op = &hypfs_s_ops;
f1771ffa AV	287	if (hypfs_parse_options(data, sb))
f1771ffa AV	288	return -EINVAL;
24bbb1fa	289	root_inode = hypfs_make_inode(sb, S_IFDIR \| 0755);
f1771ffa AV	290	if (!root_inode)
f1771ffa AV	291	return -ENOMEM;
24bbb1fa MH	292	root_inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	293	root_inode->i_fop = &simple_dir_operations;
48fde701 AV	294	sb->s_root = root_dentry = d_make_root(root_inode);
48fde701 AV	295	if (!root_dentry)
f1771ffa	296	return -ENOMEM;
31cb4bd3	297	if (MACHINE_IS_VM)
f78e41e3	298	rc = hypfs_vm_create_files(root_dentry);
31cb4bd3	299	else
e334cf4f	300	rc = hypfs_diag_create_files(root_dentry);
24bbb1fa	301	if (rc)
f1771ffa	302	return rc;
a118cfdf	303	sbi->update_file = hypfs_create_update_file(root_dentry);
f1771ffa AV	304	if (IS_ERR(sbi->update_file))
f1771ffa AV	305	return PTR_ERR(sbi->update_file);
24bbb1fa	306	hypfs_update_update(sb);
f55495ba	307	pr_info("Hypervisor filesystem mounted\n");
24bbb1fa	308	return 0;
24bbb1fa MH	309	}
24bbb1fa MH	310
fc14f2fe AV	311	static struct dentry hypfs_mount(struct file_system_type fst, int flags,
fc14f2fe AV	312	const char devname, void data)
24bbb1fa	313	{
fc14f2fe	314	return mount_single(fst, flags, data, hypfs_fill_super);
24bbb1fa MH	315	}
	316
	317	static void hypfs_kill_super(struct super_block *sb)
	318	{
	319	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	320
f1771ffa	321	if (sb->s_root)
388c571c	322	hypfs_delete_tree(sb->s_root);
15ebb10e	323	if (sb_info && sb_info->update_file)
388c571c	324	hypfs_remove(sb_info->update_file);
f1771ffa AV	325	kfree(sb->s_fs_info);
f1771ffa AV	326	sb->s_fs_info = NULL;
24bbb1fa MH	327	kill_litter_super(sb);
	328	}
	329
a118cfdf	330	static struct dentry hypfs_create_file(struct dentry parent, const char *name,
fec0ebae	331	char *data, umode_t mode)
24bbb1fa MH	332	{
	333	struct dentry *dentry;
	334	struct inode *inode;
24bbb1fa	335
5955102c	336	inode_lock(d_inode(parent));
24bbb1fa	337	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	338	if (IS_ERR(dentry)) {
	339	dentry = ERR_PTR(-ENOMEM);
	340	goto fail;
	341	}
a118cfdf	342	inode = hypfs_make_inode(parent->d_sb, mode);
24bbb1fa MH	343	if (!inode) {
24bbb1fa MH	344	dput(dentry);
9b5a03e1 MH	345	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	346	goto fail;
24bbb1fa	347	}
fec0ebae	348	if (S_ISREG(mode)) {
24bbb1fa MH	349	inode->i_fop = &hypfs_file_ops;
	350	if (data)
	351	inode->i_size = strlen(data);
	352	else
	353	inode->i_size = 0;
fec0ebae	354	} else if (S_ISDIR(mode)) {
24bbb1fa MH	355	inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	356	inode->i_fop = &simple_dir_operations;
75c3cfa8	357	inc_nlink(d_inode(parent));
24bbb1fa MH	358	} else
24bbb1fa MH	359	BUG();
8e18e294	360	inode->i_private = data;
24bbb1fa MH	361	d_instantiate(dentry, inode);
24bbb1fa MH	362	dget(dentry);
9b5a03e1	363	fail:
5955102c	364	inode_unlock(d_inode(parent));
24bbb1fa MH	365	return dentry;
	366	}
	367
a118cfdf	368	struct dentry hypfs_mkdir(struct dentry parent, const char *name)
24bbb1fa MH	369	{
	370	struct dentry *dentry;
	371
a118cfdf	372	dentry = hypfs_create_file(parent, name, NULL, S_IFDIR \| DIR_MODE);
24bbb1fa MH	373	if (IS_ERR(dentry))
	374	return dentry;
	375	hypfs_add_dentry(dentry);
24bbb1fa MH	376	return dentry;
	377	}
	378
a118cfdf	379	static struct dentry hypfs_create_update_file(struct dentry dir)
24bbb1fa MH	380	{
	381	struct dentry *dentry;
	382
a118cfdf	383	dentry = hypfs_create_file(dir, "update", NULL,
24bbb1fa MH	384	S_IFREG \| UPDATE_FILE_MODE);
	385	/*
	386	* We do not put the update file on the 'delete' list with
	387	* hypfs_add_dentry(), since it should not be removed when the tree
	388	* is updated.
	389	*/
	390	return dentry;
	391	}
	392
a118cfdf	393	struct dentry hypfs_create_u64(struct dentry dir,
24bbb1fa MH	394	const char *name, __u64 value)
	395	{
	396	char *buffer;
	397	char tmp[TMP_SIZE];
	398	struct dentry *dentry;
	399
ad2a5d8e	400	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	401	buffer = kstrdup(tmp, GFP_KERNEL);
	402	if (!buffer)
	403	return ERR_PTR(-ENOMEM);
	404	dentry =
a118cfdf	405	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	406	if (IS_ERR(dentry)) {
	407	kfree(buffer);
	408	return ERR_PTR(-ENOMEM);
	409	}
	410	hypfs_add_dentry(dentry);
	411	return dentry;
	412	}
	413
a118cfdf	414	struct dentry hypfs_create_str(struct dentry dir,
24bbb1fa MH	415	const char name, char string)
	416	{
	417	char *buffer;
	418	struct dentry *dentry;
	419
	420	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	421	if (!buffer)
	422	return ERR_PTR(-ENOMEM);
	423	sprintf(buffer, "%s\n", string);
	424	dentry =
a118cfdf	425	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	426	if (IS_ERR(dentry)) {
	427	kfree(buffer);
	428	return ERR_PTR(-ENOMEM);
	429	}
	430	hypfs_add_dentry(dentry);
	431	return dentry;
	432	}
	433
5dfe4c96	434	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	435	.open = hypfs_open,
24bbb1fa MH	436	.release = hypfs_release,
a457ac28 AV	437	.read_iter = hypfs_read_iter,
a457ac28 AV	438	.write_iter = hypfs_write_iter,
6038f373	439	.llseek = no_llseek,
24bbb1fa MH	440	};
	441
	442	static struct file_system_type hypfs_type = {
	443	.owner = THIS_MODULE,
	444	.name = "s390_hypfs",
fc14f2fe	445	.mount = hypfs_mount,
24bbb1fa MH	446	.kill_sb = hypfs_kill_super
	447	};
	448
b87221de	449	static const struct super_operations hypfs_s_ops = {
24bbb1fa	450	.statfs = simple_statfs,
b69257f2	451	.evict_inode = hypfs_evict_inode,
b01af5ba	452	.show_options = hypfs_show_options,
24bbb1fa MH	453	};
24bbb1fa MH	454
24bbb1fa MH	455	static int __init hypfs_init(void)
	456	{
	457	int rc;
	458
2fcb3686 MH	459	rc = hypfs_dbfs_init();
	460	if (rc)
	461	return rc;
57b28f66 MH	462	if (hypfs_diag_init()) {
57b28f66 MH	463	rc = -ENODATA;
2fcb3686	464	goto fail_dbfs_exit;
57b28f66 MH	465	}
	466	if (hypfs_vm_init()) {
	467	rc = -ENODATA;
	468	goto fail_hypfs_diag_exit;
24bbb1fa	469	}
07be0382 MS	470	if (hypfs_sprp_init()) {
	471	rc = -ENODATA;
	472	goto fail_hypfs_vm_exit;
	473	}
34c0dad7 MH	474	if (hypfs_diag0c_init()) {
	475	rc = -ENODATA;
	476	goto fail_hypfs_sprp_exit;
	477	}
f9bb4882 EB	478	rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
f9bb4882 EB	479	if (rc)
34c0dad7	480	goto fail_hypfs_diag0c_exit;
24bbb1fa MH	481	rc = register_filesystem(&hypfs_type);
	482	if (rc)
	483	goto fail_filesystem;
	484	return 0;
	485
	486	fail_filesystem:
f9bb4882	487	sysfs_remove_mount_point(hypervisor_kobj, "s390");
34c0dad7 MH	488	fail_hypfs_diag0c_exit:
34c0dad7 MH	489	hypfs_diag0c_exit();
07be0382 MS	490	fail_hypfs_sprp_exit:
07be0382 MS	491	hypfs_sprp_exit();
57b28f66 MH	492	fail_hypfs_vm_exit:
	493	hypfs_vm_exit();
	494	fail_hypfs_diag_exit:
	495	hypfs_diag_exit();
2fcb3686 MH	496	fail_dbfs_exit:
2fcb3686 MH	497	hypfs_dbfs_exit();
f55495ba	498	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
24bbb1fa MH	499	return rc;
24bbb1fa MH	500	}
cee672e1	501	device_initcall(hypfs_init)