[net-next-2.6.git] / arch / s390 / hypfs / inode.c

/*
 *  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 <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 {
	uid_t uid;			/* uid used for files and dirs */
	gid_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;

struct dentry *hypfs_dbfs_dir;

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;
	if (!parent || !parent->d_inode)
		return;
	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, int mode)
{
	struct inode *ret = new_inode(sb);

	if (ret) {
		struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
		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 (mode & S_IFDIR)
			ret->i_nlink = 2;
		else
			ret->i_nlink = 1;
	}
	return ret;
}

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

static int hypfs_open(struct inode *inode, struct file *filp)
{
	char *data = filp->f_path.dentry->d_inode->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;
	struct hypfs_sb_info *fs_info;
	size_t count = iov_length(iov, nr_segs);

	sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
	fs_info = sb->s_fs_info;
	/*
	 * 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, sb->s_root);
	else
		rc = hypfs_diag_create_files(sb, 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];

	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;
			hypfs_info->uid = option;
			break;
		case opt_gid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			hypfs_info->gid = option;
			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 vfsmount *mnt)
{
	struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info;

	seq_printf(s, ",uid=%u", hypfs_info->uid);
	seq_printf(s, ",gid=%u", 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_alloc_root(root_inode);
	if (!root_dentry) {
		iput(root_inode);
		return -ENOMEM;
	}
	if (MACHINE_IS_VM)
		rc = hypfs_vm_create_files(sb, root_dentry);
	else
		rc = hypfs_diag_create_files(sb, 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, mode_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 (mode & S_IFREG) {
		inode->i_fop = &hypfs_file_ops;
		if (data)
			inode->i_size = strlen(data);
		else
			inode->i_size = 0;
	} else if (mode & S_IFDIR) {
		inode->i_op = &simple_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
		parent->d_inode->i_nlink++;
	} 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
};

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;

	hypfs_dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
	if (IS_ERR(hypfs_dbfs_dir))
		return PTR_ERR(hypfs_dbfs_dir);

	if (hypfs_diag_init()) {
		rc = -ENODATA;
		goto fail_debugfs_remove;
	}
	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_debugfs_remove:
	debugfs_remove(hypfs_dbfs_dir);

	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();
	debugfs_remove(hypfs_dbfs_dir);
	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	/*
f19bfb2c	2	* arch/s390/hypfs/inode.c
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>
	22	#include <linux/module.h>
b01af5ba MH	23	#include <linux/seq_file.h>
b01af5ba MH	24	#include <linux/mount.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 {
	35	uid_t uid; /* uid used for files and dirs */
	36	gid_t gid; /* gid used for files and dirs */
	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
57b28f66 MH	49	struct dentry *hypfs_dbfs_dir;
57b28f66 MH	50
24bbb1fa MH	51	static void hypfs_update_update(struct super_block *sb)
	52	{
	53	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	54	struct inode *inode = sb_info->update_file->d_inode;
	55
	56	sb_info->last_update = get_seconds();
	57	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	58	}
	59
	60	/* directory tree removal functions */
	61
	62	static void hypfs_add_dentry(struct dentry *dentry)
	63	{
	64	dentry->d_fsdata = hypfs_last_dentry;
	65	hypfs_last_dentry = dentry;
	66	}
	67
9b5a03e1 MH	68	static inline int hypfs_positive(struct dentry *dentry)
	69	{
	70	return dentry->d_inode && !d_unhashed(dentry);
	71	}
	72
24bbb1fa MH	73	static void hypfs_remove(struct dentry *dentry)
	74	{
	75	struct dentry *parent;
	76
	77	parent = dentry->d_parent;
9b5a03e1 MH	78	if (!parent \|\| !parent->d_inode)
	79	return;
	80	mutex_lock(&parent->d_inode->i_mutex);
	81	if (hypfs_positive(dentry)) {
	82	if (S_ISDIR(dentry->d_inode->i_mode))
	83	simple_rmdir(parent->d_inode, dentry);
	84	else
	85	simple_unlink(parent->d_inode, dentry);
	86	}
24bbb1fa MH	87	d_delete(dentry);
24bbb1fa MH	88	dput(dentry);
9b5a03e1	89	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	90	}
	91
	92	static void hypfs_delete_tree(struct dentry *root)
	93	{
	94	while (hypfs_last_dentry) {
	95	struct dentry *next_dentry;
	96	next_dentry = hypfs_last_dentry->d_fsdata;
	97	hypfs_remove(hypfs_last_dentry);
	98	hypfs_last_dentry = next_dentry;
	99	}
	100	}
	101
	102	static struct inode hypfs_make_inode(struct super_block sb, int mode)
	103	{
	104	struct inode *ret = new_inode(sb);
	105
	106	if (ret) {
	107	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	108	ret->i_mode = mode;
	109	ret->i_uid = hypfs_info->uid;
	110	ret->i_gid = hypfs_info->gid;
24bbb1fa MH	111	ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
	112	if (mode & S_IFDIR)
	113	ret->i_nlink = 2;
	114	else
	115	ret->i_nlink = 1;
	116	}
	117	return ret;
	118	}
	119
b69257f2	120	static void hypfs_evict_inode(struct inode *inode)
24bbb1fa	121	{
b69257f2	122	end_writeback(inode);
8e18e294	123	kfree(inode->i_private);
24bbb1fa MH	124	}
	125
	126	static int hypfs_open(struct inode inode, struct file filp)
	127	{
d20343e7	128	char *data = filp->f_path.dentry->d_inode->i_private;
24bbb1fa MH	129	struct hypfs_sb_info *fs_info;
	130
	131	if (filp->f_mode & FMODE_WRITE) {
	132	if (!(inode->i_mode & S_IWUGO))
	133	return -EACCES;
	134	}
	135	if (filp->f_mode & FMODE_READ) {
	136	if (!(inode->i_mode & S_IRUGO))
	137	return -EACCES;
	138	}
	139
	140	fs_info = inode->i_sb->s_fs_info;
	141	if(data) {
	142	mutex_lock(&fs_info->lock);
	143	filp->private_data = kstrdup(data, GFP_KERNEL);
	144	if (!filp->private_data) {
	145	mutex_unlock(&fs_info->lock);
	146	return -ENOMEM;
	147	}
	148	mutex_unlock(&fs_info->lock);
	149	}
58ea91c0	150	return nonseekable_open(inode, filp);
24bbb1fa MH	151	}
24bbb1fa MH	152
027445c3 BP	153	static ssize_t hypfs_aio_read(struct kiocb iocb, const struct iovec iov,
027445c3 BP	154	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	155	{
24bbb1fa MH	156	char *data;
a29591c4	157	ssize_t ret;
24bbb1fa	158	struct file *filp = iocb->ki_filp;
027445c3 BP	159	/* XXX: temporary */
	160	char __user *buf = iov[0].iov_base;
	161	size_t count = iov[0].iov_len;
	162
a29591c4 AM	163	if (nr_segs != 1)
a29591c4 AM	164	return -EINVAL;
24bbb1fa MH	165
24bbb1fa MH	166	data = filp->private_data;
a29591c4 AM	167	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
	168	if (ret <= 0)
	169	return ret;
	170
	171	iocb->ki_pos += ret;
24bbb1fa	172	file_accessed(filp);
a29591c4 AM	173
a29591c4 AM	174	return ret;
24bbb1fa	175	}
027445c3 BP	176	static ssize_t hypfs_aio_write(struct kiocb iocb, const struct iovec iov,
027445c3 BP	177	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	178	{
	179	int rc;
	180	struct super_block *sb;
	181	struct hypfs_sb_info *fs_info;
027445c3	182	size_t count = iov_length(iov, nr_segs);
24bbb1fa	183
d20343e7	184	sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
24bbb1fa MH	185	fs_info = sb->s_fs_info;
	186	/*
	187	* Currently we only allow one update per second for two reasons:
	188	* 1. diag 204 is VERY expensive
	189	* 2. If several processes do updates in parallel and then read the
	190	* hypfs data, the likelihood of collisions is reduced, if we restrict
	191	* the minimum update interval. A collision occurs, if during the
	192	* data gathering of one process another process triggers an update
	193	* If the first process wants to ensure consistent data, it has
	194	* to restart data collection in this case.
	195	*/
	196	mutex_lock(&fs_info->lock);
	197	if (fs_info->last_update == get_seconds()) {
	198	rc = -EBUSY;
	199	goto out;
	200	}
	201	hypfs_delete_tree(sb->s_root);
31cb4bd3 MH	202	if (MACHINE_IS_VM)
	203	rc = hypfs_vm_create_files(sb, sb->s_root);
	204	else
	205	rc = hypfs_diag_create_files(sb, sb->s_root);
24bbb1fa	206	if (rc) {
f55495ba	207	pr_err("Updating the hypfs tree failed\n");
24bbb1fa MH	208	hypfs_delete_tree(sb->s_root);
	209	goto out;
	210	}
	211	hypfs_update_update(sb);
	212	rc = count;
	213	out:
	214	mutex_unlock(&fs_info->lock);
	215	return rc;
	216	}
	217
	218	static int hypfs_release(struct inode inode, struct file filp)
	219	{
	220	kfree(filp->private_data);
	221	return 0;
	222	}
	223
	224	enum { opt_uid, opt_gid, opt_err };
	225
a447c093	226	static const match_table_t hypfs_tokens = {
24bbb1fa MH	227	{opt_uid, "uid=%u"},
	228	{opt_gid, "gid=%u"},
	229	{opt_err, NULL}
	230	};
	231
	232	static int hypfs_parse_options(char options, struct super_block sb)
	233	{
	234	char *str;
	235	substring_t args[MAX_OPT_ARGS];
	236
	237	if (!options)
	238	return 0;
	239	while ((str = strsep(&options, ",")) != NULL) {
	240	int token, option;
	241	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	242
	243	if (!*str)
	244	continue;
	245	token = match_token(str, hypfs_tokens, args);
	246	switch (token) {
	247	case opt_uid:
	248	if (match_int(&args[0], &option))
	249	return -EINVAL;
	250	hypfs_info->uid = option;
	251	break;
	252	case opt_gid:
	253	if (match_int(&args[0], &option))
	254	return -EINVAL;
	255	hypfs_info->gid = option;
	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
b01af5ba MH	266	static int hypfs_show_options(struct seq_file s, struct vfsmount mnt)
	267	{
	268	struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info;
	269
	270	seq_printf(s, ",uid=%u", hypfs_info->uid);
	271	seq_printf(s, ",gid=%u", hypfs_info->gid);
	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;
f1771ffa	300	sb->s_root = root_dentry = d_alloc_root(root_inode);
24bbb1fa MH	301	if (!root_dentry) {
24bbb1fa MH	302	iput(root_inode);
f1771ffa	303	return -ENOMEM;
24bbb1fa	304	}
31cb4bd3 MH	305	if (MACHINE_IS_VM)
	306	rc = hypfs_vm_create_files(sb, root_dentry);
	307	else
	308	rc = hypfs_diag_create_files(sb, root_dentry);
24bbb1fa	309	if (rc)
f1771ffa	310	return rc;
24bbb1fa	311	sbi->update_file = hypfs_create_update_file(sb, root_dentry);
f1771ffa AV	312	if (IS_ERR(sbi->update_file))
f1771ffa AV	313	return PTR_ERR(sbi->update_file);
24bbb1fa	314	hypfs_update_update(sb);
f55495ba	315	pr_info("Hypervisor filesystem mounted\n");
24bbb1fa	316	return 0;
24bbb1fa MH	317	}
24bbb1fa MH	318
fc14f2fe AV	319	static struct dentry hypfs_mount(struct file_system_type fst, int flags,
fc14f2fe AV	320	const char devname, void data)
24bbb1fa	321	{
fc14f2fe	322	return mount_single(fst, flags, data, hypfs_fill_super);
24bbb1fa MH	323	}
	324
	325	static void hypfs_kill_super(struct super_block *sb)
	326	{
	327	struct hypfs_sb_info *sb_info = sb->s_fs_info;
	328
f1771ffa	329	if (sb->s_root)
388c571c	330	hypfs_delete_tree(sb->s_root);
f1771ffa	331	if (sb_info->update_file)
388c571c	332	hypfs_remove(sb_info->update_file);
f1771ffa AV	333	kfree(sb->s_fs_info);
f1771ffa AV	334	sb->s_fs_info = NULL;
24bbb1fa MH	335	kill_litter_super(sb);
	336	}
	337
	338	static struct dentry hypfs_create_file(struct super_block sb,
	339	struct dentry parent, const char name,
	340	char *data, mode_t mode)
	341	{
	342	struct dentry *dentry;
	343	struct inode *inode;
24bbb1fa	344
9b5a03e1	345	mutex_lock(&parent->d_inode->i_mutex);
24bbb1fa	346	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	347	if (IS_ERR(dentry)) {
	348	dentry = ERR_PTR(-ENOMEM);
	349	goto fail;
	350	}
24bbb1fa MH	351	inode = hypfs_make_inode(sb, mode);
	352	if (!inode) {
	353	dput(dentry);
9b5a03e1 MH	354	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	355	goto fail;
24bbb1fa MH	356	}
	357	if (mode & S_IFREG) {
	358	inode->i_fop = &hypfs_file_ops;
	359	if (data)
	360	inode->i_size = strlen(data);
	361	else
	362	inode->i_size = 0;
	363	} else if (mode & S_IFDIR) {
	364	inode->i_op = &simple_dir_inode_operations;
	365	inode->i_fop = &simple_dir_operations;
	366	parent->d_inode->i_nlink++;
	367	} else
	368	BUG();
8e18e294	369	inode->i_private = data;
24bbb1fa MH	370	d_instantiate(dentry, inode);
24bbb1fa MH	371	dget(dentry);
9b5a03e1 MH	372	fail:
9b5a03e1 MH	373	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	374	return dentry;
	375	}
	376
	377	struct dentry hypfs_mkdir(struct super_block sb, struct dentry *parent,
	378	const char *name)
	379	{
	380	struct dentry *dentry;
	381
	382	dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR \| DIR_MODE);
	383	if (IS_ERR(dentry))
	384	return dentry;
	385	hypfs_add_dentry(dentry);
24bbb1fa MH	386	return dentry;
	387	}
	388
	389	static struct dentry hypfs_create_update_file(struct super_block sb,
	390	struct dentry *dir)
	391	{
	392	struct dentry *dentry;
	393
	394	dentry = hypfs_create_file(sb, dir, "update", NULL,
	395	S_IFREG \| UPDATE_FILE_MODE);
	396	/*
	397	* We do not put the update file on the 'delete' list with
	398	* hypfs_add_dentry(), since it should not be removed when the tree
	399	* is updated.
	400	*/
	401	return dentry;
	402	}
	403
	404	struct dentry hypfs_create_u64(struct super_block sb, struct dentry *dir,
	405	const char *name, __u64 value)
	406	{
	407	char *buffer;
	408	char tmp[TMP_SIZE];
	409	struct dentry *dentry;
	410
ad2a5d8e	411	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	412	buffer = kstrdup(tmp, GFP_KERNEL);
	413	if (!buffer)
	414	return ERR_PTR(-ENOMEM);
	415	dentry =
	416	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	417	if (IS_ERR(dentry)) {
	418	kfree(buffer);
	419	return ERR_PTR(-ENOMEM);
	420	}
	421	hypfs_add_dentry(dentry);
	422	return dentry;
	423	}
	424
	425	struct dentry hypfs_create_str(struct super_block sb, struct dentry *dir,
	426	const char name, char string)
	427	{
	428	char *buffer;
	429	struct dentry *dentry;
	430
	431	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	432	if (!buffer)
	433	return ERR_PTR(-ENOMEM);
	434	sprintf(buffer, "%s\n", string);
	435	dentry =
	436	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	437	if (IS_ERR(dentry)) {
	438	kfree(buffer);
	439	return ERR_PTR(-ENOMEM);
	440	}
	441	hypfs_add_dentry(dentry);
	442	return dentry;
	443	}
	444
5dfe4c96	445	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	446	.open = hypfs_open,
	447	.release = hypfs_release,
	448	.read = do_sync_read,
	449	.write = do_sync_write,
	450	.aio_read = hypfs_aio_read,
	451	.aio_write = hypfs_aio_write,
6038f373	452	.llseek = no_llseek,
24bbb1fa MH	453	};
	454
	455	static struct file_system_type hypfs_type = {
	456	.owner = THIS_MODULE,
	457	.name = "s390_hypfs",
fc14f2fe	458	.mount = hypfs_mount,
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
9b477705	468	static struct kobject *s390_kobj;
24bbb1fa MH	469
	470	static int __init hypfs_init(void)
	471	{
	472	int rc;
	473
57b28f66 MH	474	hypfs_dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
	475	if (IS_ERR(hypfs_dbfs_dir))
	476	return PTR_ERR(hypfs_dbfs_dir);
	477
	478	if (hypfs_diag_init()) {
	479	rc = -ENODATA;
	480	goto fail_debugfs_remove;
	481	}
	482	if (hypfs_vm_init()) {
	483	rc = -ENODATA;
	484	goto fail_hypfs_diag_exit;
24bbb1fa	485	}
9b477705 GKH	486	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
9b477705 GKH	487	if (!s390_kobj) {
a419aef8	488	rc = -ENOMEM;
57b28f66	489	goto fail_hypfs_vm_exit;
9b477705	490	}
24bbb1fa MH	491	rc = register_filesystem(&hypfs_type);
	492	if (rc)
	493	goto fail_filesystem;
	494	return 0;
	495
	496	fail_filesystem:
38a382ae	497	kobject_put(s390_kobj);
57b28f66 MH	498	fail_hypfs_vm_exit:
	499	hypfs_vm_exit();
	500	fail_hypfs_diag_exit:
	501	hypfs_diag_exit();
	502	fail_debugfs_remove:
	503	debugfs_remove(hypfs_dbfs_dir);
	504
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	{
57b28f66 MH	511	hypfs_diag_exit();
	512	hypfs_vm_exit();
	513	debugfs_remove(hypfs_dbfs_dir);
24bbb1fa	514	unregister_filesystem(&hypfs_type);
38a382ae	515	kobject_put(s390_kobj);
24bbb1fa MH	516	}
	517
	518	module_init(hypfs_init)
	519	module_exit(hypfs_exit)
	520
	521	MODULE_LICENSE("GPL");
	522	MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
	523	MODULE_DESCRIPTION("s390 Hypervisor Filesystem");