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

fail_filesystem:
	kobject_put(s390_kobj);
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;
}

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

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
a118cfdf	31	static struct dentry hypfs_create_update_file(struct dentry dir);
24bbb1fa MH	32
24bbb1fa MH	33	struct hypfs_sb_info {
6a62a216 EB	34	kuid_t uid; /* uid used for files and dirs */
6a62a216 EB	35	kgid_t gid; /* gid used for files and dirs */
24bbb1fa MH	36	struct dentry update_file; / file to trigger update */
	37	time_t last_update; /* last update time in secs since 1970 */
	38	struct mutex lock; /* lock to protect update process */
	39	};
	40
5dfe4c96	41	static const struct file_operations hypfs_file_ops;
24bbb1fa	42	static struct file_system_type hypfs_type;
b87221de	43	static const struct super_operations hypfs_s_ops;
24bbb1fa MH	44
	45	/* start of list of all dentries, which have to be deleted on update */
	46	static struct dentry *hypfs_last_dentry;
	47
	48	static void hypfs_update_update(struct super_block *sb)
	49	{
	50	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	51	struct inode *inode = sb_info->update_file->d_inode;
	52
	53	sb_info->last_update = get_seconds();
	54	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	55	}
	56
	57	/* directory tree removal functions */
	58
	59	static void hypfs_add_dentry(struct dentry *dentry)
	60	{
	61	dentry->d_fsdata = hypfs_last_dentry;
	62	hypfs_last_dentry = dentry;
	63	}
	64
9b5a03e1 MH	65	static inline int hypfs_positive(struct dentry *dentry)
	66	{
	67	return dentry->d_inode && !d_unhashed(dentry);
	68	}
	69
24bbb1fa MH	70	static void hypfs_remove(struct dentry *dentry)
	71	{
	72	struct dentry *parent;
	73
	74	parent = dentry->d_parent;
9b5a03e1 MH	75	mutex_lock(&parent->d_inode->i_mutex);
	76	if (hypfs_positive(dentry)) {
	77	if (S_ISDIR(dentry->d_inode->i_mode))
	78	simple_rmdir(parent->d_inode, dentry);
	79	else
	80	simple_unlink(parent->d_inode, dentry);
	81	}
24bbb1fa MH	82	d_delete(dentry);
24bbb1fa MH	83	dput(dentry);
9b5a03e1	84	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	85	}
	86
	87	static void hypfs_delete_tree(struct dentry *root)
	88	{
	89	while (hypfs_last_dentry) {
	90	struct dentry *next_dentry;
	91	next_dentry = hypfs_last_dentry->d_fsdata;
	92	hypfs_remove(hypfs_last_dentry);
	93	hypfs_last_dentry = next_dentry;
	94	}
	95	}
	96
fec0ebae	97	static struct inode hypfs_make_inode(struct super_block sb, umode_t mode)
24bbb1fa MH	98	{
	99	struct inode *ret = new_inode(sb);
	100
	101	if (ret) {
	102	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
c960bec4	103	ret->i_ino = get_next_ino();
24bbb1fa MH	104	ret->i_mode = mode;
	105	ret->i_uid = hypfs_info->uid;
	106	ret->i_gid = hypfs_info->gid;
24bbb1fa	107	ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
fec0ebae	108	if (S_ISDIR(mode))
bfe86848	109	set_nlink(ret, 2);
24bbb1fa MH	110	}
	111	return ret;
	112	}
	113
b69257f2	114	static void hypfs_evict_inode(struct inode *inode)
24bbb1fa	115	{
dbd5768f	116	clear_inode(inode);
8e18e294	117	kfree(inode->i_private);
24bbb1fa MH	118	}
	119
	120	static int hypfs_open(struct inode inode, struct file filp)
	121	{
496ad9aa	122	char *data = file_inode(filp)->i_private;
24bbb1fa MH	123	struct hypfs_sb_info *fs_info;
	124
	125	if (filp->f_mode & FMODE_WRITE) {
	126	if (!(inode->i_mode & S_IWUGO))
	127	return -EACCES;
	128	}
	129	if (filp->f_mode & FMODE_READ) {
	130	if (!(inode->i_mode & S_IRUGO))
	131	return -EACCES;
	132	}
	133
	134	fs_info = inode->i_sb->s_fs_info;
	135	if(data) {
	136	mutex_lock(&fs_info->lock);
	137	filp->private_data = kstrdup(data, GFP_KERNEL);
	138	if (!filp->private_data) {
	139	mutex_unlock(&fs_info->lock);
	140	return -ENOMEM;
	141	}
	142	mutex_unlock(&fs_info->lock);
	143	}
58ea91c0	144	return nonseekable_open(inode, filp);
24bbb1fa MH	145	}
24bbb1fa MH	146
027445c3 BP	147	static ssize_t hypfs_aio_read(struct kiocb iocb, const struct iovec iov,
027445c3 BP	148	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	149	{
24bbb1fa MH	150	char *data;
a29591c4	151	ssize_t ret;
24bbb1fa	152	struct file *filp = iocb->ki_filp;
027445c3 BP	153	/* XXX: temporary */
	154	char __user *buf = iov[0].iov_base;
	155	size_t count = iov[0].iov_len;
	156
a29591c4 AM	157	if (nr_segs != 1)
a29591c4 AM	158	return -EINVAL;
24bbb1fa MH	159
24bbb1fa MH	160	data = filp->private_data;
a29591c4 AM	161	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
	162	if (ret <= 0)
	163	return ret;
	164
	165	iocb->ki_pos += ret;
24bbb1fa	166	file_accessed(filp);
a29591c4 AM	167
a29591c4 AM	168	return ret;
24bbb1fa	169	}
027445c3 BP	170	static ssize_t hypfs_aio_write(struct kiocb iocb, const struct iovec iov,
027445c3 BP	171	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	172	{
24bbb1fa MH	173	int rc;
6131ffaa AV	174	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
6131ffaa AV	175	struct hypfs_sb_info *fs_info = sb->s_fs_info;
027445c3	176	size_t count = iov_length(iov, nr_segs);
24bbb1fa	177
24bbb1fa MH	178	/*
	179	* Currently we only allow one update per second for two reasons:
	180	* 1. diag 204 is VERY expensive
	181	* 2. If several processes do updates in parallel and then read the
	182	* hypfs data, the likelihood of collisions is reduced, if we restrict
	183	* the minimum update interval. A collision occurs, if during the
	184	* data gathering of one process another process triggers an update
	185	* If the first process wants to ensure consistent data, it has
	186	* to restart data collection in this case.
	187	*/
	188	mutex_lock(&fs_info->lock);
	189	if (fs_info->last_update == get_seconds()) {
	190	rc = -EBUSY;
	191	goto out;
	192	}
	193	hypfs_delete_tree(sb->s_root);
31cb4bd3	194	if (MACHINE_IS_VM)
f78e41e3	195	rc = hypfs_vm_create_files(sb->s_root);
31cb4bd3	196	else
e334cf4f	197	rc = hypfs_diag_create_files(sb->s_root);
24bbb1fa	198	if (rc) {
f55495ba	199	pr_err("Updating the hypfs tree failed\n");
24bbb1fa MH	200	hypfs_delete_tree(sb->s_root);
	201	goto out;
	202	}
	203	hypfs_update_update(sb);
	204	rc = count;
	205	out:
	206	mutex_unlock(&fs_info->lock);
	207	return rc;
	208	}
	209
	210	static int hypfs_release(struct inode inode, struct file filp)
	211	{
	212	kfree(filp->private_data);
	213	return 0;
	214	}
	215
	216	enum { opt_uid, opt_gid, opt_err };
	217
a447c093	218	static const match_table_t hypfs_tokens = {
24bbb1fa MH	219	{opt_uid, "uid=%u"},
	220	{opt_gid, "gid=%u"},
	221	{opt_err, NULL}
	222	};
	223
	224	static int hypfs_parse_options(char options, struct super_block sb)
	225	{
	226	char *str;
	227	substring_t args[MAX_OPT_ARGS];
6a62a216 EB	228	kuid_t uid;
6a62a216 EB	229	kgid_t gid;
24bbb1fa MH	230
	231	if (!options)
	232	return 0;
	233	while ((str = strsep(&options, ",")) != NULL) {
	234	int token, option;
	235	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	236
	237	if (!*str)
	238	continue;
	239	token = match_token(str, hypfs_tokens, args);
	240	switch (token) {
	241	case opt_uid:
	242	if (match_int(&args[0], &option))
	243	return -EINVAL;
6a62a216 EB	244	uid = make_kuid(current_user_ns(), option);
	245	if (!uid_valid(uid))
	246	return -EINVAL;
	247	hypfs_info->uid = uid;
24bbb1fa MH	248	break;
	249	case opt_gid:
	250	if (match_int(&args[0], &option))
	251	return -EINVAL;
6a62a216 EB	252	gid = make_kgid(current_user_ns(), option);
	253	if (!gid_valid(gid))
	254	return -EINVAL;
	255	hypfs_info->gid = gid;
24bbb1fa MH	256	break;
	257	case opt_err:
	258	default:
f55495ba	259	pr_err("%s is not a valid mount option\n", str);
24bbb1fa MH	260	return -EINVAL;
	261	}
	262	}
	263	return 0;
	264	}
	265
34c80b1d	266	static int hypfs_show_options(struct seq_file s, struct dentry root)
b01af5ba	267	{
34c80b1d	268	struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
b01af5ba	269
6a62a216 EB	270	seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
6a62a216 EB	271	seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
b01af5ba MH	272	return 0;
	273	}
	274
24bbb1fa MH	275	static int hypfs_fill_super(struct super_block sb, void data, int silent)
	276	{
	277	struct inode *root_inode;
	278	struct dentry *root_dentry;
	279	int rc = 0;
	280	struct hypfs_sb_info *sbi;
	281
	282	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	283	if (!sbi)
	284	return -ENOMEM;
	285	mutex_init(&sbi->lock);
e5423705 DH	286	sbi->uid = current_uid();
e5423705 DH	287	sbi->gid = current_gid();
24bbb1fa MH	288	sb->s_fs_info = sbi;
	289	sb->s_blocksize = PAGE_CACHE_SIZE;
	290	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	291	sb->s_magic = HYPFS_MAGIC;
	292	sb->s_op = &hypfs_s_ops;
f1771ffa AV	293	if (hypfs_parse_options(data, sb))
f1771ffa AV	294	return -EINVAL;
24bbb1fa	295	root_inode = hypfs_make_inode(sb, S_IFDIR \| 0755);
f1771ffa AV	296	if (!root_inode)
f1771ffa AV	297	return -ENOMEM;
24bbb1fa MH	298	root_inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	299	root_inode->i_fop = &simple_dir_operations;
48fde701 AV	300	sb->s_root = root_dentry = d_make_root(root_inode);
48fde701 AV	301	if (!root_dentry)
f1771ffa	302	return -ENOMEM;
31cb4bd3	303	if (MACHINE_IS_VM)
f78e41e3	304	rc = hypfs_vm_create_files(root_dentry);
31cb4bd3	305	else
e334cf4f	306	rc = hypfs_diag_create_files(root_dentry);
24bbb1fa	307	if (rc)
f1771ffa	308	return rc;
a118cfdf	309	sbi->update_file = hypfs_create_update_file(root_dentry);
f1771ffa AV	310	if (IS_ERR(sbi->update_file))
f1771ffa AV	311	return PTR_ERR(sbi->update_file);
24bbb1fa	312	hypfs_update_update(sb);
f55495ba	313	pr_info("Hypervisor filesystem mounted\n");
24bbb1fa	314	return 0;
24bbb1fa MH	315	}
24bbb1fa MH	316
fc14f2fe AV	317	static struct dentry hypfs_mount(struct file_system_type fst, int flags,
fc14f2fe AV	318	const char devname, void data)
24bbb1fa	319	{
fc14f2fe	320	return mount_single(fst, flags, data, hypfs_fill_super);
24bbb1fa MH	321	}
	322
	323	static void hypfs_kill_super(struct super_block *sb)
	324	{
	325	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	326
f1771ffa	327	if (sb->s_root)
388c571c	328	hypfs_delete_tree(sb->s_root);
f1771ffa	329	if (sb_info->update_file)
388c571c	330	hypfs_remove(sb_info->update_file);
f1771ffa AV	331	kfree(sb->s_fs_info);
f1771ffa AV	332	sb->s_fs_info = NULL;
24bbb1fa MH	333	kill_litter_super(sb);
	334	}
	335
a118cfdf	336	static struct dentry hypfs_create_file(struct dentry parent, const char *name,
fec0ebae	337	char *data, umode_t mode)
24bbb1fa MH	338	{
	339	struct dentry *dentry;
	340	struct inode *inode;
24bbb1fa	341
9b5a03e1	342	mutex_lock(&parent->d_inode->i_mutex);
24bbb1fa	343	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	344	if (IS_ERR(dentry)) {
	345	dentry = ERR_PTR(-ENOMEM);
	346	goto fail;
	347	}
a118cfdf	348	inode = hypfs_make_inode(parent->d_sb, mode);
24bbb1fa MH	349	if (!inode) {
24bbb1fa MH	350	dput(dentry);
9b5a03e1 MH	351	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	352	goto fail;
24bbb1fa	353	}
fec0ebae	354	if (S_ISREG(mode)) {
24bbb1fa MH	355	inode->i_fop = &hypfs_file_ops;
	356	if (data)
	357	inode->i_size = strlen(data);
	358	else
	359	inode->i_size = 0;
fec0ebae	360	} else if (S_ISDIR(mode)) {
24bbb1fa MH	361	inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	362	inode->i_fop = &simple_dir_operations;
6d6b77f1	363	inc_nlink(parent->d_inode);
24bbb1fa MH	364	} else
24bbb1fa MH	365	BUG();
8e18e294	366	inode->i_private = data;
24bbb1fa MH	367	d_instantiate(dentry, inode);
24bbb1fa MH	368	dget(dentry);
9b5a03e1 MH	369	fail:
9b5a03e1 MH	370	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	371	return dentry;
	372	}
	373
a118cfdf	374	struct dentry hypfs_mkdir(struct dentry parent, const char *name)
24bbb1fa MH	375	{
	376	struct dentry *dentry;
	377
a118cfdf	378	dentry = hypfs_create_file(parent, name, NULL, S_IFDIR \| DIR_MODE);
24bbb1fa MH	379	if (IS_ERR(dentry))
	380	return dentry;
	381	hypfs_add_dentry(dentry);
24bbb1fa MH	382	return dentry;
	383	}
	384
a118cfdf	385	static struct dentry hypfs_create_update_file(struct dentry dir)
24bbb1fa MH	386	{
	387	struct dentry *dentry;
	388
a118cfdf	389	dentry = hypfs_create_file(dir, "update", NULL,
24bbb1fa MH	390	S_IFREG \| UPDATE_FILE_MODE);
	391	/*
	392	* We do not put the update file on the 'delete' list with
	393	* hypfs_add_dentry(), since it should not be removed when the tree
	394	* is updated.
	395	*/
	396	return dentry;
	397	}
	398
a118cfdf	399	struct dentry hypfs_create_u64(struct dentry dir,
24bbb1fa MH	400	const char *name, __u64 value)
	401	{
	402	char *buffer;
	403	char tmp[TMP_SIZE];
	404	struct dentry *dentry;
	405
ad2a5d8e	406	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	407	buffer = kstrdup(tmp, GFP_KERNEL);
	408	if (!buffer)
	409	return ERR_PTR(-ENOMEM);
	410	dentry =
a118cfdf	411	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	412	if (IS_ERR(dentry)) {
	413	kfree(buffer);
	414	return ERR_PTR(-ENOMEM);
	415	}
	416	hypfs_add_dentry(dentry);
	417	return dentry;
	418	}
	419
a118cfdf	420	struct dentry hypfs_create_str(struct dentry dir,
24bbb1fa MH	421	const char name, char string)
	422	{
	423	char *buffer;
	424	struct dentry *dentry;
	425
	426	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	427	if (!buffer)
	428	return ERR_PTR(-ENOMEM);
	429	sprintf(buffer, "%s\n", string);
	430	dentry =
a118cfdf	431	hypfs_create_file(dir, name, buffer, S_IFREG \| REG_FILE_MODE);
24bbb1fa MH	432	if (IS_ERR(dentry)) {
	433	kfree(buffer);
	434	return ERR_PTR(-ENOMEM);
	435	}
	436	hypfs_add_dentry(dentry);
	437	return dentry;
	438	}
	439
5dfe4c96	440	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	441	.open = hypfs_open,
	442	.release = hypfs_release,
	443	.read = do_sync_read,
	444	.write = do_sync_write,
	445	.aio_read = hypfs_aio_read,
	446	.aio_write = hypfs_aio_write,
6038f373	447	.llseek = no_llseek,
24bbb1fa MH	448	};
	449
	450	static struct file_system_type hypfs_type = {
	451	.owner = THIS_MODULE,
	452	.name = "s390_hypfs",
fc14f2fe	453	.mount = hypfs_mount,
24bbb1fa MH	454	.kill_sb = hypfs_kill_super
24bbb1fa MH	455	};
7f78e035	456	MODULE_ALIAS_FS("s390_hypfs");
24bbb1fa	457
b87221de	458	static const struct super_operations hypfs_s_ops = {
24bbb1fa	459	.statfs = simple_statfs,
b69257f2	460	.evict_inode = hypfs_evict_inode,
b01af5ba	461	.show_options = hypfs_show_options,
24bbb1fa MH	462	};
24bbb1fa MH	463
9b477705	464	static struct kobject *s390_kobj;
24bbb1fa MH	465
	466	static int __init hypfs_init(void)
	467	{
	468	int rc;
	469
2fcb3686 MH	470	rc = hypfs_dbfs_init();
	471	if (rc)
	472	return rc;
57b28f66 MH	473	if (hypfs_diag_init()) {
57b28f66 MH	474	rc = -ENODATA;
2fcb3686	475	goto fail_dbfs_exit;
57b28f66 MH	476	}
	477	if (hypfs_vm_init()) {
	478	rc = -ENODATA;
	479	goto fail_hypfs_diag_exit;
24bbb1fa	480	}
07be0382 MS	481	if (hypfs_sprp_init()) {
	482	rc = -ENODATA;
	483	goto fail_hypfs_vm_exit;
	484	}
9b477705 GKH	485	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
9b477705 GKH	486	if (!s390_kobj) {
a419aef8	487	rc = -ENOMEM;
07be0382	488	goto fail_hypfs_sprp_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);
07be0382 MS	497	fail_hypfs_sprp_exit:
07be0382 MS	498	hypfs_sprp_exit();
57b28f66 MH	499	fail_hypfs_vm_exit:
	500	hypfs_vm_exit();
	501	fail_hypfs_diag_exit:
	502	hypfs_diag_exit();
2fcb3686 MH	503	fail_dbfs_exit:
2fcb3686 MH	504	hypfs_dbfs_exit();
f55495ba	505	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
24bbb1fa MH	506	return rc;
	507	}
	508
	509	static void __exit hypfs_exit(void)
	510	{
24bbb1fa	511	unregister_filesystem(&hypfs_type);
38a382ae	512	kobject_put(s390_kobj);
07be0382 MS	513	hypfs_sprp_exit();
	514	hypfs_vm_exit();
	515	hypfs_diag_exit();
	516	hypfs_dbfs_exit();
24bbb1fa MH	517	}
	518
	519	module_init(hypfs_init)
	520	module_exit(hypfs_exit)
	521
	522	MODULE_LICENSE("GPL");
	523	MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
	524	MODULE_DESCRIPTION("s390 Hypervisor Filesystem");