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

/*
 *    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/module.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/aio.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 super_block *sb,
					       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 = sb_info->update_file->d_inode;

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

/* directory tree removal functions */

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

static inline int hypfs_positive(struct dentry *dentry)
{
	return dentry->d_inode && !d_unhashed(dentry);
}

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

	parent = dentry->d_parent;
	mutex_lock(&parent->d_inode->i_mutex);
	if (hypfs_positive(dentry)) {
		if (S_ISDIR(dentry->d_inode->i_mode))
			simple_rmdir(parent->d_inode, dentry);
		else
			simple_unlink(parent->d_inode, dentry);
	}
	d_delete(dentry);
	dput(dentry);
	mutex_unlock(&parent->d_inode->i_mutex);
}

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;
		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_aio_read(struct kiocb *iocb, const struct iovec *iov,
			      unsigned long nr_segs, loff_t offset)
{
	char *data;
	ssize_t ret;
	struct file *filp = iocb->ki_filp;
	/* XXX: temporary */
	char __user *buf = iov[0].iov_base;
	size_t count = iov[0].iov_len;

	if (nr_segs != 1)
		return -EINVAL;

	data = filp->private_data;
	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
	if (ret <= 0)
		return ret;

	iocb->ki_pos += ret;
	file_accessed(filp);

	return ret;
}
static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
			      unsigned long nr_segs, loff_t offset)
{
	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_length(iov, nr_segs);

	/*
	 * 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;
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_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_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(sb, 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->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 super_block *sb,
					struct dentry *parent, const char *name,
					char *data, umode_t mode)
{
	struct dentry *dentry;
	struct inode *inode;

	mutex_lock(&parent->d_inode->i_mutex);
	dentry = lookup_one_len(name, parent, strlen(name));
	if (IS_ERR(dentry)) {
		dentry = ERR_PTR(-ENOMEM);
		goto fail;
	}
	inode = hypfs_make_inode(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(parent->d_inode);
	} else
		BUG();
	inode->i_private = data;
	d_instantiate(dentry, inode);
	dget(dentry);
fail:
	mutex_unlock(&parent->d_inode->i_mutex);
	return dentry;
}

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

	dentry = hypfs_create_file(sb, 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 super_block *sb,
					       struct dentry *dir)
{
	struct dentry *dentry;

	dentry = hypfs_create_file(sb, 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 super_block *sb, 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(sb, 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 super_block *sb, 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(sb, 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		= do_sync_read,
	.write		= do_sync_write,
	.aio_read	= hypfs_aio_read,
	.aio_write	= hypfs_aio_write,
	.llseek		= no_llseek,
};

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

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

static struct kobject *s390_kobj;

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;
	}
	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
	if (!s390_kobj) {
		rc = -ENOMEM;
		goto fail_hypfs_vm_exit;
	}
	rc = register_filesystem(&hypfs_type);
	if (rc)
		goto fail_filesystem;
	return 0;

fail_filesystem:
	kobject_put(s390_kobj);
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;
}

static void __exit hypfs_exit(void)
{
	hypfs_diag_exit();
	hypfs_vm_exit();
	hypfs_dbfs_exit();
	unregister_filesystem(&hypfs_type);
	kobject_put(s390_kobj);
}

module_init(hypfs_init)
module_exit(hypfs_exit)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
MODULE_DESCRIPTION("s390 Hypervisor Filesystem");
Commit	Line	Data
24bbb1fa	1	/*
24bbb1fa MH	2	* Hypervisor filesystem for Linux on s390.
24bbb1fa MH	3	*
f55495ba	4	* Copyright IBM Corp. 2006, 2008
24bbb1fa MH	5	* Author(s): Michael Holzheu <holzheu@de.ibm.com>
	6	*/
	7
f55495ba MH	8	#define KMSG_COMPONENT "hypfs"
	9	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	10
24bbb1fa MH	11	#include <linux/types.h>
	12	#include <linux/errno.h>
	13	#include <linux/fs.h>
	14	#include <linux/namei.h>
	15	#include <linux/vfs.h>
5a0e3ad6	16	#include <linux/slab.h>
24bbb1fa	17	#include <linux/pagemap.h>
24bbb1fa MH	18	#include <linux/time.h>
	19	#include <linux/parser.h>
	20	#include <linux/sysfs.h>
	21	#include <linux/module.h>
b01af5ba MH	22	#include <linux/seq_file.h>
b01af5ba MH	23	#include <linux/mount.h>
a27bb332	24	#include <linux/aio.h>
24bbb1fa MH	25	#include <asm/ebcdic.h>
24bbb1fa MH	26	#include "hypfs.h"
24bbb1fa MH	27
	28	#define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */
	29	#define TMP_SIZE 64 /* size of temporary buffers */
	30
	31	static struct dentry hypfs_create_update_file(struct super_block sb,
	32	struct dentry *dir);
	33
	34	struct hypfs_sb_info {
6a62a216 EB	35	kuid_t uid; /* uid used for files and dirs */
6a62a216 EB	36	kgid_t gid; /* gid used for files and dirs */
24bbb1fa MH	37	struct dentry update_file; / file to trigger update */
	38	time_t last_update; /* last update time in secs since 1970 */
	39	struct mutex lock; /* lock to protect update process */
	40	};
	41
5dfe4c96	42	static const struct file_operations hypfs_file_ops;
24bbb1fa	43	static struct file_system_type hypfs_type;
b87221de	44	static const struct super_operations hypfs_s_ops;
24bbb1fa MH	45
	46	/* start of list of all dentries, which have to be deleted on update */
	47	static struct dentry *hypfs_last_dentry;
	48
	49	static void hypfs_update_update(struct super_block *sb)
	50	{
	51	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	52	struct inode *inode = sb_info->update_file->d_inode;
	53
	54	sb_info->last_update = get_seconds();
	55	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	56	}
	57
	58	/* directory tree removal functions */
	59
	60	static void hypfs_add_dentry(struct dentry *dentry)
	61	{
	62	dentry->d_fsdata = hypfs_last_dentry;
	63	hypfs_last_dentry = dentry;
	64	}
	65
9b5a03e1 MH	66	static inline int hypfs_positive(struct dentry *dentry)
	67	{
	68	return dentry->d_inode && !d_unhashed(dentry);
	69	}
	70
24bbb1fa MH	71	static void hypfs_remove(struct dentry *dentry)
	72	{
	73	struct dentry *parent;
	74
	75	parent = dentry->d_parent;
9b5a03e1 MH	76	mutex_lock(&parent->d_inode->i_mutex);
	77	if (hypfs_positive(dentry)) {
	78	if (S_ISDIR(dentry->d_inode->i_mode))
	79	simple_rmdir(parent->d_inode, dentry);
	80	else
	81	simple_unlink(parent->d_inode, dentry);
	82	}
24bbb1fa MH	83	d_delete(dentry);
24bbb1fa MH	84	dput(dentry);
9b5a03e1	85	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	86	}
	87
	88	static void hypfs_delete_tree(struct dentry *root)
	89	{
	90	while (hypfs_last_dentry) {
	91	struct dentry *next_dentry;
	92	next_dentry = hypfs_last_dentry->d_fsdata;
	93	hypfs_remove(hypfs_last_dentry);
	94	hypfs_last_dentry = next_dentry;
	95	}
	96	}
	97
fec0ebae	98	static struct inode hypfs_make_inode(struct super_block sb, umode_t mode)
24bbb1fa MH	99	{
	100	struct inode *ret = new_inode(sb);
	101
	102	if (ret) {
	103	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
c960bec4	104	ret->i_ino = get_next_ino();
24bbb1fa MH	105	ret->i_mode = mode;
	106	ret->i_uid = hypfs_info->uid;
	107	ret->i_gid = hypfs_info->gid;
24bbb1fa	108	ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
fec0ebae	109	if (S_ISDIR(mode))
bfe86848	110	set_nlink(ret, 2);
24bbb1fa MH	111	}
	112	return ret;
	113	}
	114
b69257f2	115	static void hypfs_evict_inode(struct inode *inode)
24bbb1fa	116	{
dbd5768f	117	clear_inode(inode);
8e18e294	118	kfree(inode->i_private);
24bbb1fa MH	119	}
	120
	121	static int hypfs_open(struct inode inode, struct file filp)
	122	{
496ad9aa	123	char *data = file_inode(filp)->i_private;
24bbb1fa MH	124	struct hypfs_sb_info *fs_info;
	125
	126	if (filp->f_mode & FMODE_WRITE) {
	127	if (!(inode->i_mode & S_IWUGO))
	128	return -EACCES;
	129	}
	130	if (filp->f_mode & FMODE_READ) {
	131	if (!(inode->i_mode & S_IRUGO))
	132	return -EACCES;
	133	}
	134
	135	fs_info = inode->i_sb->s_fs_info;
	136	if(data) {
	137	mutex_lock(&fs_info->lock);
	138	filp->private_data = kstrdup(data, GFP_KERNEL);
	139	if (!filp->private_data) {
	140	mutex_unlock(&fs_info->lock);
	141	return -ENOMEM;
	142	}
	143	mutex_unlock(&fs_info->lock);
	144	}
58ea91c0	145	return nonseekable_open(inode, filp);
24bbb1fa MH	146	}
24bbb1fa MH	147
027445c3 BP	148	static ssize_t hypfs_aio_read(struct kiocb iocb, const struct iovec iov,
027445c3 BP	149	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	150	{
24bbb1fa MH	151	char *data;
a29591c4	152	ssize_t ret;
24bbb1fa	153	struct file *filp = iocb->ki_filp;
027445c3 BP	154	/* XXX: temporary */
	155	char __user *buf = iov[0].iov_base;
	156	size_t count = iov[0].iov_len;
	157
a29591c4 AM	158	if (nr_segs != 1)
a29591c4 AM	159	return -EINVAL;
24bbb1fa MH	160
24bbb1fa MH	161	data = filp->private_data;
a29591c4 AM	162	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
	163	if (ret <= 0)
	164	return ret;
	165
	166	iocb->ki_pos += ret;
24bbb1fa	167	file_accessed(filp);
a29591c4 AM	168
a29591c4 AM	169	return ret;
24bbb1fa	170	}
027445c3 BP	171	static ssize_t hypfs_aio_write(struct kiocb iocb, const struct iovec iov,
027445c3 BP	172	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	173	{
24bbb1fa MH	174	int rc;
6131ffaa AV	175	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
6131ffaa AV	176	struct hypfs_sb_info *fs_info = sb->s_fs_info;
027445c3	177	size_t count = iov_length(iov, nr_segs);
24bbb1fa	178
24bbb1fa MH	179	/*
	180	* Currently we only allow one update per second for two reasons:
	181	* 1. diag 204 is VERY expensive
	182	* 2. If several processes do updates in parallel and then read the
	183	* hypfs data, the likelihood of collisions is reduced, if we restrict
	184	* the minimum update interval. A collision occurs, if during the
	185	* data gathering of one process another process triggers an update
	186	* If the first process wants to ensure consistent data, it has
	187	* to restart data collection in this case.
	188	*/
	189	mutex_lock(&fs_info->lock);
	190	if (fs_info->last_update == get_seconds()) {
	191	rc = -EBUSY;
	192	goto out;
	193	}
	194	hypfs_delete_tree(sb->s_root);
31cb4bd3	195	if (MACHINE_IS_VM)
f78e41e3	196	rc = hypfs_vm_create_files(sb->s_root);
31cb4bd3	197	else
e334cf4f	198	rc = hypfs_diag_create_files(sb->s_root);
24bbb1fa	199	if (rc) {
f55495ba	200	pr_err("Updating the hypfs tree failed\n");
24bbb1fa MH	201	hypfs_delete_tree(sb->s_root);
	202	goto out;
	203	}
	204	hypfs_update_update(sb);
	205	rc = count;
	206	out:
	207	mutex_unlock(&fs_info->lock);
	208	return rc;
	209	}
	210
	211	static int hypfs_release(struct inode inode, struct file filp)
	212	{
	213	kfree(filp->private_data);
	214	return 0;
	215	}
	216
	217	enum { opt_uid, opt_gid, opt_err };
	218
a447c093	219	static const match_table_t hypfs_tokens = {
24bbb1fa MH	220	{opt_uid, "uid=%u"},
	221	{opt_gid, "gid=%u"},
	222	{opt_err, NULL}
	223	};
	224
	225	static int hypfs_parse_options(char options, struct super_block sb)
	226	{
	227	char *str;
	228	substring_t args[MAX_OPT_ARGS];
6a62a216 EB	229	kuid_t uid;
6a62a216 EB	230	kgid_t gid;
24bbb1fa MH	231
	232	if (!options)
	233	return 0;
	234	while ((str = strsep(&options, ",")) != NULL) {
	235	int token, option;
	236	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	237
	238	if (!*str)
	239	continue;
	240	token = match_token(str, hypfs_tokens, args);
	241	switch (token) {
	242	case opt_uid:
	243	if (match_int(&args[0], &option))
	244	return -EINVAL;
6a62a216 EB	245	uid = make_kuid(current_user_ns(), option);
	246	if (!uid_valid(uid))
	247	return -EINVAL;
	248	hypfs_info->uid = uid;
24bbb1fa MH	249	break;
	250	case opt_gid:
	251	if (match_int(&args[0], &option))
	252	return -EINVAL;
6a62a216 EB	253	gid = make_kgid(current_user_ns(), option);
	254	if (!gid_valid(gid))
	255	return -EINVAL;
	256	hypfs_info->gid = gid;
24bbb1fa MH	257	break;
	258	case opt_err:
	259	default:
f55495ba	260	pr_err("%s is not a valid mount option\n", str);
24bbb1fa MH	261	return -EINVAL;
	262	}
	263	}
	264	return 0;
	265	}
	266
34c80b1d	267	static int hypfs_show_options(struct seq_file s, struct dentry root)
b01af5ba	268	{
34c80b1d	269	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
b01af5ba	270
6a62a216 EB	271	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
6a62a216 EB	272	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
b01af5ba MH	273	return 0;
	274	}
	275
24bbb1fa MH	276	static int hypfs_fill_super(struct super_block sb, void data, int silent)
	277	{
	278	struct inode *root_inode;
	279	struct dentry *root_dentry;
	280	int rc = 0;
	281	struct hypfs_sb_info *sbi;
	282
	283	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	284	if (!sbi)
	285	return -ENOMEM;
	286	mutex_init(&sbi->lock);
e5423705 DH	287	sbi->uid = current_uid();
e5423705 DH	288	sbi->gid = current_gid();
24bbb1fa MH	289	sb->s_fs_info = sbi;
	290	sb->s_blocksize = PAGE_CACHE_SIZE;
	291	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	292	sb->s_magic = HYPFS_MAGIC;
	293	sb->s_op = &hypfs_s_ops;
f1771ffa AV	294	if (hypfs_parse_options(data, sb))
f1771ffa AV	295	return -EINVAL;
24bbb1fa	296	root_inode = hypfs_make_inode(sb, S_IFDIR \| 0755);
f1771ffa AV	297	if (!root_inode)
f1771ffa AV	298	return -ENOMEM;
24bbb1fa MH	299	root_inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	300	root_inode->i_fop = &simple_dir_operations;
48fde701 AV	301	sb->s_root = root_dentry = d_make_root(root_inode);
48fde701 AV	302	if (!root_dentry)
f1771ffa	303	return -ENOMEM;
31cb4bd3	304	if (MACHINE_IS_VM)
f78e41e3	305	rc = hypfs_vm_create_files(root_dentry);
31cb4bd3	306	else
e334cf4f	307	rc = hypfs_diag_create_files(root_dentry);
24bbb1fa	308	if (rc)
f1771ffa	309	return rc;
24bbb1fa	310	sbi->update_file = hypfs_create_update_file(sb, root_dentry);
f1771ffa AV	311	if (IS_ERR(sbi->update_file))
f1771ffa AV	312	return PTR_ERR(sbi->update_file);
24bbb1fa	313	hypfs_update_update(sb);
f55495ba	314	pr_info("Hypervisor filesystem mounted\n");
24bbb1fa	315	return 0;
24bbb1fa MH	316	}
24bbb1fa MH	317
fc14f2fe AV	318	static struct dentry hypfs_mount(struct file_system_type fst, int flags,
fc14f2fe AV	319	const char devname, void data)
24bbb1fa	320	{
fc14f2fe	321	return mount_single(fst, flags, data, hypfs_fill_super);
24bbb1fa MH	322	}
	323
	324	static void hypfs_kill_super(struct super_block *sb)
	325	{
	326	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	327
f1771ffa	328	if (sb->s_root)
388c571c	329	hypfs_delete_tree(sb->s_root);
f1771ffa	330	if (sb_info->update_file)
388c571c	331	hypfs_remove(sb_info->update_file);
f1771ffa AV	332	kfree(sb->s_fs_info);
f1771ffa AV	333	sb->s_fs_info = NULL;
24bbb1fa MH	334	kill_litter_super(sb);
	335	}
	336
	337	static struct dentry hypfs_create_file(struct super_block sb,
	338	struct dentry parent, const char name,
fec0ebae	339	char *data, umode_t mode)
24bbb1fa MH	340	{
	341	struct dentry *dentry;
	342	struct inode *inode;
24bbb1fa	343
9b5a03e1	344	mutex_lock(&parent->d_inode->i_mutex);
24bbb1fa	345	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	346	if (IS_ERR(dentry)) {
	347	dentry = ERR_PTR(-ENOMEM);
	348	goto fail;
	349	}
24bbb1fa MH	350	inode = hypfs_make_inode(sb, mode);
	351	if (!inode) {
	352	dput(dentry);
9b5a03e1 MH	353	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	354	goto fail;
24bbb1fa	355	}
fec0ebae	356	if (S_ISREG(mode)) {
24bbb1fa MH	357	inode->i_fop = &hypfs_file_ops;
	358	if (data)
	359	inode->i_size = strlen(data);
	360	else
	361	inode->i_size = 0;
fec0ebae	362	} else if (S_ISDIR(mode)) {
24bbb1fa MH	363	inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	364	inode->i_fop = &simple_dir_operations;
6d6b77f1	365	inc_nlink(parent->d_inode);
24bbb1fa MH	366	} else
24bbb1fa MH	367	BUG();
8e18e294	368	inode->i_private = data;
24bbb1fa MH	369	d_instantiate(dentry, inode);
24bbb1fa MH	370	dget(dentry);
9b5a03e1 MH	371	fail:
9b5a03e1 MH	372	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	373	return dentry;
	374	}
	375
	376	struct dentry hypfs_mkdir(struct super_block sb, struct dentry *parent,
	377	const char *name)
	378	{
	379	struct dentry *dentry;
	380
	381	dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR \| DIR_MODE);
	382	if (IS_ERR(dentry))
	383	return dentry;
	384	hypfs_add_dentry(dentry);
24bbb1fa MH	385	return dentry;
	386	}
	387
	388	static struct dentry hypfs_create_update_file(struct super_block sb,
	389	struct dentry *dir)
	390	{
	391	struct dentry *dentry;
	392
	393	dentry = hypfs_create_file(sb, dir, "update", NULL,
	394	S_IFREG \| UPDATE_FILE_MODE);
	395	/*
	396	* We do not put the update file on the 'delete' list with
	397	* hypfs_add_dentry(), since it should not be removed when the tree
	398	* is updated.
	399	*/
	400	return dentry;
	401	}
	402
	403	struct dentry hypfs_create_u64(struct super_block sb, struct dentry *dir,
	404	const char *name, __u64 value)
	405	{
	406	char *buffer;
	407	char tmp[TMP_SIZE];
	408	struct dentry *dentry;
	409
ad2a5d8e	410	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	411	buffer = kstrdup(tmp, GFP_KERNEL);
	412	if (!buffer)
	413	return ERR_PTR(-ENOMEM);
	414	dentry =
	415	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	416	if (IS_ERR(dentry)) {
	417	kfree(buffer);
	418	return ERR_PTR(-ENOMEM);
	419	}
	420	hypfs_add_dentry(dentry);
	421	return dentry;
	422	}
	423
	424	struct dentry hypfs_create_str(struct super_block sb, struct dentry *dir,
	425	const char name, char string)
	426	{
	427	char *buffer;
	428	struct dentry *dentry;
	429
	430	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	431	if (!buffer)
	432	return ERR_PTR(-ENOMEM);
	433	sprintf(buffer, "%s\n", string);
	434	dentry =
	435	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	436	if (IS_ERR(dentry)) {
	437	kfree(buffer);
	438	return ERR_PTR(-ENOMEM);
	439	}
	440	hypfs_add_dentry(dentry);
	441	return dentry;
	442	}
	443
5dfe4c96	444	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	445	.open = hypfs_open,
	446	.release = hypfs_release,
	447	.read = do_sync_read,
	448	.write = do_sync_write,
	449	.aio_read = hypfs_aio_read,
	450	.aio_write = hypfs_aio_write,
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",
fc14f2fe	457	.mount = hypfs_mount,
24bbb1fa MH	458	.kill_sb = hypfs_kill_super
24bbb1fa MH	459	};
7f78e035	460	MODULE_ALIAS_FS("s390_hypfs");
24bbb1fa	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
9b477705	468	static struct kobject *s390_kobj;
24bbb1fa MH	469
	470	static int __init hypfs_init(void)
	471	{
	472	int rc;
	473
2fcb3686 MH	474	rc = hypfs_dbfs_init();
	475	if (rc)
	476	return rc;
57b28f66 MH	477	if (hypfs_diag_init()) {
57b28f66 MH	478	rc = -ENODATA;
2fcb3686	479	goto fail_dbfs_exit;
57b28f66 MH	480	}
	481	if (hypfs_vm_init()) {
	482	rc = -ENODATA;
	483	goto fail_hypfs_diag_exit;
24bbb1fa	484	}
9b477705 GKH	485	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
9b477705 GKH	486	if (!s390_kobj) {
a419aef8	487	rc = -ENOMEM;
57b28f66	488	goto fail_hypfs_vm_exit;
9b477705	489	}
24bbb1fa MH	490	rc = register_filesystem(&hypfs_type);
	491	if (rc)
	492	goto fail_filesystem;
	493	return 0;
	494
	495	fail_filesystem:
38a382ae	496	kobject_put(s390_kobj);
57b28f66 MH	497	fail_hypfs_vm_exit:
	498	hypfs_vm_exit();
	499	fail_hypfs_diag_exit:
	500	hypfs_diag_exit();
2fcb3686 MH	501	fail_dbfs_exit:
2fcb3686 MH	502	hypfs_dbfs_exit();
f55495ba	503	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
24bbb1fa MH	504	return rc;
	505	}
	506
	507	static void __exit hypfs_exit(void)
	508	{
57b28f66 MH	509	hypfs_diag_exit();
57b28f66 MH	510	hypfs_vm_exit();
2fcb3686	511	hypfs_dbfs_exit();
24bbb1fa	512	unregister_filesystem(&hypfs_type);
38a382ae	513	kobject_put(s390_kobj);
24bbb1fa MH	514	}
	515
	516	module_init(hypfs_init)
	517	module_exit(hypfs_exit)
	518
	519	MODULE_LICENSE("GPL");
	520	MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
	521	MODULE_DESCRIPTION("s390 Hypervisor Filesystem");