[linux-2.6-block.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/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/time.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/seq_file.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 */
	time64_t last_update;		/* last update, CLOCK_MONOTONIC time */
	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 = ktime_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_drop(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 == ktime_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, };

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

static const struct fs_parameter_description hypfs_fs_parameters = {
	.name		= "hypfs",
	.specs		= hypfs_param_specs,
};

static int hypfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
	struct hypfs_sb_info *hypfs_info = fc->s_fs_info;
	struct fs_parse_result result;
	kuid_t uid;
	kgid_t gid;
	int opt;

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

	switch (opt) {
	case Opt_uid:
		uid = make_kuid(current_user_ns(), result.uint_32);
		if (!uid_valid(uid))
			return invalf(fc, "Unknown uid");
		hypfs_info->uid = uid;
		break;
	case Opt_gid:
		gid = make_kgid(current_user_ns(), result.uint_32);
		if (!gid_valid(gid))
			return invalf(fc, "Unknown gid");
		hypfs_info->gid = gid;
		break;
	}
	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, struct fs_context *fc)
{
	struct hypfs_sb_info *sbi = sb->s_fs_info;
	struct inode *root_inode;
	struct dentry *root_dentry, *update_file;
	int rc;

	sb->s_blocksize = PAGE_SIZE;
	sb->s_blocksize_bits = PAGE_SHIFT;
	sb->s_magic = HYPFS_MAGIC;
	sb->s_op = &hypfs_s_ops;

	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;
	update_file = hypfs_create_update_file(root_dentry);
	if (IS_ERR(update_file))
		return PTR_ERR(update_file);
	sbi->update_file = update_file;
	hypfs_update_update(sb);
	pr_info("Hypervisor filesystem mounted\n");
	return 0;
}

static int hypfs_get_tree(struct fs_context *fc)
{
	return get_tree_single(fc, hypfs_fill_super);
}

static void hypfs_free_fc(struct fs_context *fc)
{
	kfree(fc->s_fs_info);
}

static const struct fs_context_operations hypfs_context_ops = {
	.free		= hypfs_free_fc,
	.parse_param	= hypfs_parse_param,
	.get_tree	= hypfs_get_tree,
};

static int hypfs_init_fs_context(struct fs_context *fc)
{
	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();

	fc->s_fs_info = sbi;
	fc->ops = &hypfs_context_ops;
	return 0;
}

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",
	.init_fs_context = hypfs_init_fs_context,
	.parameters	= &hypfs_fs_parameters,
	.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;

	hypfs_dbfs_init();

	if (hypfs_diag_init()) {
		rc = -ENODATA;
		goto fail_dbfs_exit;
	}
	if (hypfs_vm_init()) {
		rc = -ENODATA;
		goto fail_hypfs_diag_exit;
	}
	hypfs_sprp_init();
	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();
	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>
8f8d8d11 DH	15	#include <linux/fs_context.h>
8f8d8d11 DH	16	#include <linux/fs_parser.h>
24bbb1fa MH	17	#include <linux/namei.h>
24bbb1fa MH	18	#include <linux/vfs.h>
5a0e3ad6	19	#include <linux/slab.h>
24bbb1fa	20	#include <linux/pagemap.h>
24bbb1fa	21	#include <linux/time.h>
24bbb1fa	22	#include <linux/sysfs.h>
cee672e1 PG	23	#include <linux/init.h>
cee672e1 PG	24	#include <linux/kobject.h>
b01af5ba	25	#include <linux/seq_file.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	38	struct dentry update_file; / file to trigger update */
6075e4ae	39	time64_t last_update; /* last update, CLOCK_MONOTONIC time */
24bbb1fa MH	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	54
6075e4ae	55	sb_info->last_update = ktime_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	}
29dfeb0b	79	d_drop(dentry);
24bbb1fa	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);
6075e4ae	182	if (fs_info->last_update == ktime_get_seconds()) {
24bbb1fa MH	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
8f8d8d11	210	enum { Opt_uid, Opt_gid, };
24bbb1fa	211
8f8d8d11 DH	212	static const struct fs_parameter_spec hypfs_param_specs[] = {
	213	fsparam_u32("gid", Opt_gid),
	214	fsparam_u32("uid", Opt_uid),
	215	{}
24bbb1fa MH	216	};
24bbb1fa MH	217
8f8d8d11 DH	218	static const struct fs_parameter_description hypfs_fs_parameters = {
	219	.name = "hypfs",
	220	.specs = hypfs_param_specs,
	221	};
	222
	223	static int hypfs_parse_param(struct fs_context fc, struct fs_parameter param)
24bbb1fa	224	{
8f8d8d11 DH	225	struct hypfs_sb_info *hypfs_info = fc->s_fs_info;
8f8d8d11 DH	226	struct fs_parse_result result;
6a62a216 EB	227	kuid_t uid;
6a62a216 EB	228	kgid_t gid;
8f8d8d11 DH	229	int opt;
	230
	231	opt = fs_parse(fc, &hypfs_fs_parameters, param, &result);
	232	if (opt < 0)
	233	return opt;
	234
	235	switch (opt) {
	236	case Opt_uid:
	237	uid = make_kuid(current_user_ns(), result.uint_32);
	238	if (!uid_valid(uid))
	239	return invalf(fc, "Unknown uid");
	240	hypfs_info->uid = uid;
	241	break;
	242	case Opt_gid:
	243	gid = make_kgid(current_user_ns(), result.uint_32);
	244	if (!gid_valid(gid))
	245	return invalf(fc, "Unknown gid");
	246	hypfs_info->gid = gid;
	247	break;
24bbb1fa MH	248	}
	249	return 0;
	250	}
	251
34c80b1d	252	static int hypfs_show_options(struct seq_file s, struct dentry root)
b01af5ba	253	{
34c80b1d	254	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
b01af5ba	255
6a62a216 EB	256	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
6a62a216 EB	257	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
b01af5ba MH	258	return 0;
	259	}
	260
8f8d8d11	261	static int hypfs_fill_super(struct super_block sb, struct fs_context fc)
24bbb1fa	262	{
8f8d8d11	263	struct hypfs_sb_info *sbi = sb->s_fs_info;
24bbb1fa	264	struct inode *root_inode;
b54c64f7	265	struct dentry root_dentry, update_file;
8f8d8d11	266	int rc;
24bbb1fa	267
09cbfeaf KS	268	sb->s_blocksize = PAGE_SIZE;
09cbfeaf KS	269	sb->s_blocksize_bits = PAGE_SHIFT;
24bbb1fa MH	270	sb->s_magic = HYPFS_MAGIC;
24bbb1fa MH	271	sb->s_op = &hypfs_s_ops;
8f8d8d11	272
24bbb1fa	273	root_inode = hypfs_make_inode(sb, S_IFDIR \| 0755);
f1771ffa AV	274	if (!root_inode)
f1771ffa AV	275	return -ENOMEM;
24bbb1fa MH	276	root_inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	277	root_inode->i_fop = &simple_dir_operations;
48fde701 AV	278	sb->s_root = root_dentry = d_make_root(root_inode);
48fde701 AV	279	if (!root_dentry)
f1771ffa	280	return -ENOMEM;
31cb4bd3	281	if (MACHINE_IS_VM)
f78e41e3	282	rc = hypfs_vm_create_files(root_dentry);
31cb4bd3	283	else
e334cf4f	284	rc = hypfs_diag_create_files(root_dentry);
24bbb1fa	285	if (rc)
f1771ffa	286	return rc;
b54c64f7 DH	287	update_file = hypfs_create_update_file(root_dentry);
	288	if (IS_ERR(update_file))
	289	return PTR_ERR(update_file);
	290	sbi->update_file = update_file;
24bbb1fa	291	hypfs_update_update(sb);
f55495ba	292	pr_info("Hypervisor filesystem mounted\n");
24bbb1fa	293	return 0;
24bbb1fa MH	294	}
24bbb1fa MH	295
8f8d8d11 DH	296	static int hypfs_get_tree(struct fs_context *fc)
	297	{
	298	return get_tree_single(fc, hypfs_fill_super);
	299	}
	300
	301	static void hypfs_free_fc(struct fs_context *fc)
24bbb1fa	302	{
8f8d8d11 DH	303	kfree(fc->s_fs_info);
	304	}
	305
	306	static const struct fs_context_operations hypfs_context_ops = {
	307	.free = hypfs_free_fc,
	308	.parse_param = hypfs_parse_param,
	309	.get_tree = hypfs_get_tree,
	310	};
	311
	312	static int hypfs_init_fs_context(struct fs_context *fc)
	313	{
	314	struct hypfs_sb_info *sbi;
	315
	316	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	317	if (!sbi)
	318	return -ENOMEM;
	319
	320	mutex_init(&sbi->lock);
	321	sbi->uid = current_uid();
	322	sbi->gid = current_gid();
	323
	324	fc->s_fs_info = sbi;
	325	fc->ops = &hypfs_context_ops;
	326	return 0;
24bbb1fa MH	327	}
	328
	329	static void hypfs_kill_super(struct super_block *sb)
	330	{
	331	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	332
f1771ffa	333	if (sb->s_root)
388c571c	334	hypfs_delete_tree(sb->s_root);
a24cd490	335	if (sb_info && sb_info->update_file)
388c571c	336	hypfs_remove(sb_info->update_file);
f1771ffa AV	337	kfree(sb->s_fs_info);
f1771ffa AV	338	sb->s_fs_info = NULL;
24bbb1fa MH	339	kill_litter_super(sb);
	340	}
	341
a118cfdf	342	static struct dentry hypfs_create_file(struct dentry parent, const char *name,
fec0ebae	343	char *data, umode_t mode)
24bbb1fa MH	344	{
	345	struct dentry *dentry;
	346	struct inode *inode;
24bbb1fa	347
5955102c	348	inode_lock(d_inode(parent));
24bbb1fa	349	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	350	if (IS_ERR(dentry)) {
	351	dentry = ERR_PTR(-ENOMEM);
	352	goto fail;
	353	}
a118cfdf	354	inode = hypfs_make_inode(parent->d_sb, mode);
24bbb1fa MH	355	if (!inode) {
24bbb1fa MH	356	dput(dentry);
9b5a03e1 MH	357	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	358	goto fail;
24bbb1fa	359	}
fec0ebae	360	if (S_ISREG(mode)) {
24bbb1fa MH	361	inode->i_fop = &hypfs_file_ops;
	362	if (data)
	363	inode->i_size = strlen(data);
	364	else
	365	inode->i_size = 0;
fec0ebae	366	} else if (S_ISDIR(mode)) {
24bbb1fa MH	367	inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	368	inode->i_fop = &simple_dir_operations;
75c3cfa8	369	inc_nlink(d_inode(parent));
24bbb1fa MH	370	} else
24bbb1fa MH	371	BUG();
8e18e294	372	inode->i_private = data;
24bbb1fa MH	373	d_instantiate(dentry, inode);
24bbb1fa MH	374	dget(dentry);
9b5a03e1	375	fail:
5955102c	376	inode_unlock(d_inode(parent));
24bbb1fa MH	377	return dentry;
	378	}
	379
a118cfdf	380	struct dentry hypfs_mkdir(struct dentry parent, const char *name)
24bbb1fa MH	381	{
	382	struct dentry *dentry;
	383
a118cfdf	384	dentry = hypfs_create_file(parent, name, NULL, S_IFDIR \| DIR_MODE);
24bbb1fa MH	385	if (IS_ERR(dentry))
	386	return dentry;
	387	hypfs_add_dentry(dentry);
24bbb1fa MH	388	return dentry;
	389	}
	390
a118cfdf	391	static struct dentry hypfs_create_update_file(struct dentry dir)
24bbb1fa MH	392	{
	393	struct dentry *dentry;
	394
a118cfdf	395	dentry = hypfs_create_file(dir, "update", NULL,
24bbb1fa MH	396	S_IFREG \| UPDATE_FILE_MODE);
	397	/*
	398	* We do not put the update file on the 'delete' list with
	399	* hypfs_add_dentry(), since it should not be removed when the tree
	400	* is updated.
	401	*/
	402	return dentry;
	403	}
	404
a118cfdf	405	struct dentry hypfs_create_u64(struct dentry dir,
24bbb1fa MH	406	const char *name, __u64 value)
	407	{
	408	char *buffer;
	409	char tmp[TMP_SIZE];
	410	struct dentry *dentry;
	411
ad2a5d8e	412	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	413	buffer = kstrdup(tmp, GFP_KERNEL);
	414	if (!buffer)
	415	return ERR_PTR(-ENOMEM);
	416	dentry =
a118cfdf	417	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	418	if (IS_ERR(dentry)) {
	419	kfree(buffer);
	420	return ERR_PTR(-ENOMEM);
	421	}
	422	hypfs_add_dentry(dentry);
	423	return dentry;
	424	}
	425
a118cfdf	426	struct dentry hypfs_create_str(struct dentry dir,
24bbb1fa MH	427	const char name, char string)
	428	{
	429	char *buffer;
	430	struct dentry *dentry;
	431
	432	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	433	if (!buffer)
	434	return ERR_PTR(-ENOMEM);
	435	sprintf(buffer, "%s\n", string);
	436	dentry =
a118cfdf	437	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	438	if (IS_ERR(dentry)) {
	439	kfree(buffer);
	440	return ERR_PTR(-ENOMEM);
	441	}
	442	hypfs_add_dentry(dentry);
	443	return dentry;
	444	}
	445
5dfe4c96	446	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	447	.open = hypfs_open,
24bbb1fa MH	448	.release = hypfs_release,
a457ac28 AV	449	.read_iter = hypfs_read_iter,
a457ac28 AV	450	.write_iter = hypfs_write_iter,
6038f373	451	.llseek = no_llseek,
24bbb1fa MH	452	};
	453
	454	static struct file_system_type hypfs_type = {
	455	.owner = THIS_MODULE,
	456	.name = "s390_hypfs",
8f8d8d11 DH	457	.init_fs_context = hypfs_init_fs_context,
8f8d8d11 DH	458	.parameters = &hypfs_fs_parameters,
24bbb1fa MH	459	.kill_sb = hypfs_kill_super
	460	};
	461
b87221de	462	static const struct super_operations hypfs_s_ops = {
24bbb1fa	463	.statfs = simple_statfs,
b69257f2	464	.evict_inode = hypfs_evict_inode,
b01af5ba	465	.show_options = hypfs_show_options,
24bbb1fa MH	466	};
24bbb1fa MH	467
24bbb1fa MH	468	static int __init hypfs_init(void)
	469	{
	470	int rc;
	471
f36108c4 GKH	472	hypfs_dbfs_init();
f36108c4 GKH	473
57b28f66 MH	474	if (hypfs_diag_init()) {
57b28f66 MH	475	rc = -ENODATA;
2fcb3686	476	goto fail_dbfs_exit;
57b28f66 MH	477	}
	478	if (hypfs_vm_init()) {
	479	rc = -ENODATA;
	480	goto fail_hypfs_diag_exit;
24bbb1fa	481	}
f36108c4	482	hypfs_sprp_init();
34c0dad7 MH	483	if (hypfs_diag0c_init()) {
	484	rc = -ENODATA;
	485	goto fail_hypfs_sprp_exit;
	486	}
f9bb4882 EB	487	rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
f9bb4882 EB	488	if (rc)
34c0dad7	489	goto fail_hypfs_diag0c_exit;
24bbb1fa MH	490	rc = register_filesystem(&hypfs_type);
	491	if (rc)
	492	goto fail_filesystem;
	493	return 0;
	494
	495	fail_filesystem:
f9bb4882	496	sysfs_remove_mount_point(hypervisor_kobj, "s390");
34c0dad7 MH	497	fail_hypfs_diag0c_exit:
34c0dad7 MH	498	hypfs_diag0c_exit();
07be0382 MS	499	fail_hypfs_sprp_exit:
07be0382 MS	500	hypfs_sprp_exit();
57b28f66 MH	501	hypfs_vm_exit();
	502	fail_hypfs_diag_exit:
	503	hypfs_diag_exit();
2fcb3686 MH	504	fail_dbfs_exit:
2fcb3686 MH	505	hypfs_dbfs_exit();
f55495ba	506	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
24bbb1fa MH	507	return rc;
24bbb1fa MH	508	}
cee672e1	509	device_initcall(hypfs_init)