[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;

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_drop_inode(struct inode *inode)
{
	kfree(inode->i_private);
	generic_delete_inode(inode);
}

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 0;
}

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 int hypfs_get_super(struct file_system_type *fst, int flags,
			const char *devname, void *data, struct vfsmount *mnt)
{
	return get_sb_single(fst, flags, data, hypfs_fill_super, mnt);
}

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,
};

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

static const struct super_operations hypfs_s_ops = {
	.statfs		= simple_statfs,
	.drop_inode	= hypfs_drop_inode,
	.show_options	= hypfs_show_options,
};

static struct kobject *s390_kobj;

static int __init hypfs_init(void)
{
	int rc;

	if (MACHINE_IS_VM) {
		if (hypfs_vm_init())
			/* no diag 2fc, just exit */
			return -ENODATA;
	} else {
		if (hypfs_diag_init()) {
			rc = -ENODATA;
			goto fail_diag;
		}
	}
	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
	if (!s390_kobj) {
		rc = -ENOMEM;
		goto fail_sysfs;
	}
	rc = register_filesystem(&hypfs_type);
	if (rc)
		goto fail_filesystem;
	return 0;

fail_filesystem:
	kobject_put(s390_kobj);
fail_sysfs:
	if (!MACHINE_IS_VM)
		hypfs_diag_exit();
fail_diag:
	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
	return rc;
}

static void __exit hypfs_exit(void)
{
	if (!MACHINE_IS_VM)
		hypfs_diag_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	/*
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
	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	if (!parent \|\| !parent->d_inode)
	77	return;
	78	mutex_lock(&parent->d_inode->i_mutex);
	79	if (hypfs_positive(dentry)) {
	80	if (S_ISDIR(dentry->d_inode->i_mode))
	81	simple_rmdir(parent->d_inode, dentry);
	82	else
	83	simple_unlink(parent->d_inode, dentry);
	84	}
24bbb1fa MH	85	d_delete(dentry);
24bbb1fa MH	86	dput(dentry);
9b5a03e1	87	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	88	}
	89
	90	static void hypfs_delete_tree(struct dentry *root)
	91	{
	92	while (hypfs_last_dentry) {
	93	struct dentry *next_dentry;
	94	next_dentry = hypfs_last_dentry->d_fsdata;
	95	hypfs_remove(hypfs_last_dentry);
	96	hypfs_last_dentry = next_dentry;
	97	}
	98	}
	99
	100	static struct inode hypfs_make_inode(struct super_block sb, int mode)
	101	{
	102	struct inode *ret = new_inode(sb);
	103
	104	if (ret) {
	105	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	106	ret->i_mode = mode;
	107	ret->i_uid = hypfs_info->uid;
	108	ret->i_gid = hypfs_info->gid;
24bbb1fa MH	109	ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
	110	if (mode & S_IFDIR)
	111	ret->i_nlink = 2;
	112	else
	113	ret->i_nlink = 1;
	114	}
	115	return ret;
	116	}
	117
	118	static void hypfs_drop_inode(struct inode *inode)
	119	{
8e18e294	120	kfree(inode->i_private);
24bbb1fa MH	121	generic_delete_inode(inode);
	122	}
	123
	124	static int hypfs_open(struct inode inode, struct file filp)
	125	{
d20343e7	126	char *data = filp->f_path.dentry->d_inode->i_private;
24bbb1fa MH	127	struct hypfs_sb_info *fs_info;
	128
	129	if (filp->f_mode & FMODE_WRITE) {
	130	if (!(inode->i_mode & S_IWUGO))
	131	return -EACCES;
	132	}
	133	if (filp->f_mode & FMODE_READ) {
	134	if (!(inode->i_mode & S_IRUGO))
	135	return -EACCES;
	136	}
	137
	138	fs_info = inode->i_sb->s_fs_info;
	139	if(data) {
	140	mutex_lock(&fs_info->lock);
	141	filp->private_data = kstrdup(data, GFP_KERNEL);
	142	if (!filp->private_data) {
	143	mutex_unlock(&fs_info->lock);
	144	return -ENOMEM;
	145	}
	146	mutex_unlock(&fs_info->lock);
	147	}
	148	return 0;
	149	}
	150
027445c3 BP	151	static ssize_t hypfs_aio_read(struct kiocb iocb, const struct iovec iov,
027445c3 BP	152	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	153	{
24bbb1fa MH	154	char *data;
a29591c4	155	ssize_t ret;
24bbb1fa	156	struct file *filp = iocb->ki_filp;
027445c3 BP	157	/* XXX: temporary */
	158	char __user *buf = iov[0].iov_base;
	159	size_t count = iov[0].iov_len;
	160
a29591c4 AM	161	if (nr_segs != 1)
a29591c4 AM	162	return -EINVAL;
24bbb1fa MH	163
24bbb1fa MH	164	data = filp->private_data;
a29591c4 AM	165	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));
	166	if (ret <= 0)
	167	return ret;
	168
	169	iocb->ki_pos += ret;
24bbb1fa	170	file_accessed(filp);
a29591c4 AM	171
a29591c4 AM	172	return ret;
24bbb1fa	173	}
027445c3 BP	174	static ssize_t hypfs_aio_write(struct kiocb iocb, const struct iovec iov,
027445c3 BP	175	unsigned long nr_segs, loff_t offset)
24bbb1fa MH	176	{
	177	int rc;
	178	struct super_block *sb;
	179	struct hypfs_sb_info *fs_info;
027445c3	180	size_t count = iov_length(iov, nr_segs);
24bbb1fa	181
d20343e7	182	sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
24bbb1fa MH	183	fs_info = sb->s_fs_info;
	184	/*
	185	* Currently we only allow one update per second for two reasons:
	186	* 1. diag 204 is VERY expensive
	187	* 2. If several processes do updates in parallel and then read the
	188	* hypfs data, the likelihood of collisions is reduced, if we restrict
	189	* the minimum update interval. A collision occurs, if during the
	190	* data gathering of one process another process triggers an update
	191	* If the first process wants to ensure consistent data, it has
	192	* to restart data collection in this case.
	193	*/
	194	mutex_lock(&fs_info->lock);
	195	if (fs_info->last_update == get_seconds()) {
	196	rc = -EBUSY;
	197	goto out;
	198	}
	199	hypfs_delete_tree(sb->s_root);
31cb4bd3 MH	200	if (MACHINE_IS_VM)
	201	rc = hypfs_vm_create_files(sb, sb->s_root);
	202	else
	203	rc = hypfs_diag_create_files(sb, sb->s_root);
24bbb1fa	204	if (rc) {
f55495ba	205	pr_err("Updating the hypfs tree failed\n");
24bbb1fa MH	206	hypfs_delete_tree(sb->s_root);
	207	goto out;
	208	}
	209	hypfs_update_update(sb);
	210	rc = count;
	211	out:
	212	mutex_unlock(&fs_info->lock);
	213	return rc;
	214	}
	215
	216	static int hypfs_release(struct inode inode, struct file filp)
	217	{
	218	kfree(filp->private_data);
	219	return 0;
	220	}
	221
	222	enum { opt_uid, opt_gid, opt_err };
	223
a447c093	224	static const match_table_t hypfs_tokens = {
24bbb1fa MH	225	{opt_uid, "uid=%u"},
	226	{opt_gid, "gid=%u"},
	227	{opt_err, NULL}
	228	};
	229
	230	static int hypfs_parse_options(char options, struct super_block sb)
	231	{
	232	char *str;
	233	substring_t args[MAX_OPT_ARGS];
	234
	235	if (!options)
	236	return 0;
	237	while ((str = strsep(&options, ",")) != NULL) {
	238	int token, option;
	239	struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
	240
	241	if (!*str)
	242	continue;
	243	token = match_token(str, hypfs_tokens, args);
	244	switch (token) {
	245	case opt_uid:
	246	if (match_int(&args[0], &option))
	247	return -EINVAL;
	248	hypfs_info->uid = option;
	249	break;
	250	case opt_gid:
	251	if (match_int(&args[0], &option))
	252	return -EINVAL;
	253	hypfs_info->gid = option;
	254	break;
	255	case opt_err:
	256	default:
f55495ba	257	pr_err("%s is not a valid mount option\n", str);
24bbb1fa MH	258	return -EINVAL;
	259	}
	260	}
	261	return 0;
	262	}
	263
b01af5ba MH	264	static int hypfs_show_options(struct seq_file s, struct vfsmount mnt)
	265	{
	266	struct hypfs_sb_info *hypfs_info = mnt->mnt_sb->s_fs_info;
	267
	268	seq_printf(s, ",uid=%u", hypfs_info->uid);
	269	seq_printf(s, ",gid=%u", hypfs_info->gid);
	270	return 0;
	271	}
	272
24bbb1fa MH	273	static int hypfs_fill_super(struct super_block sb, void data, int silent)
	274	{
	275	struct inode *root_inode;
	276	struct dentry *root_dentry;
	277	int rc = 0;
	278	struct hypfs_sb_info *sbi;
	279
	280	sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
	281	if (!sbi)
	282	return -ENOMEM;
	283	mutex_init(&sbi->lock);
e5423705 DH	284	sbi->uid = current_uid();
e5423705 DH	285	sbi->gid = current_gid();
24bbb1fa MH	286	sb->s_fs_info = sbi;
	287	sb->s_blocksize = PAGE_CACHE_SIZE;
	288	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	289	sb->s_magic = HYPFS_MAGIC;
	290	sb->s_op = &hypfs_s_ops;
f1771ffa AV	291	if (hypfs_parse_options(data, sb))
f1771ffa AV	292	return -EINVAL;
24bbb1fa	293	root_inode = hypfs_make_inode(sb, S_IFDIR \| 0755);
f1771ffa AV	294	if (!root_inode)
f1771ffa AV	295	return -ENOMEM;
24bbb1fa MH	296	root_inode->i_op = &simple_dir_inode_operations;
24bbb1fa MH	297	root_inode->i_fop = &simple_dir_operations;
f1771ffa	298	sb->s_root = root_dentry = d_alloc_root(root_inode);
24bbb1fa MH	299	if (!root_dentry) {
24bbb1fa MH	300	iput(root_inode);
f1771ffa	301	return -ENOMEM;
24bbb1fa	302	}
31cb4bd3 MH	303	if (MACHINE_IS_VM)
	304	rc = hypfs_vm_create_files(sb, root_dentry);
	305	else
	306	rc = hypfs_diag_create_files(sb, root_dentry);
24bbb1fa	307	if (rc)
f1771ffa	308	return rc;
24bbb1fa	309	sbi->update_file = hypfs_create_update_file(sb, 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
a5cf4b9a AM	317	static int hypfs_get_super(struct file_system_type *fst, int flags,
a5cf4b9a AM	318	const char devname, void data, struct vfsmount *mnt)
24bbb1fa	319	{
a5cf4b9a	320	return get_sb_single(fst, flags, data, hypfs_fill_super, mnt);
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
	336	static struct dentry hypfs_create_file(struct super_block sb,
	337	struct dentry parent, const char name,
	338	char *data, mode_t mode)
	339	{
	340	struct dentry *dentry;
	341	struct inode *inode;
24bbb1fa	342
9b5a03e1	343	mutex_lock(&parent->d_inode->i_mutex);
24bbb1fa	344	dentry = lookup_one_len(name, parent, strlen(name));
9b5a03e1 MH	345	if (IS_ERR(dentry)) {
	346	dentry = ERR_PTR(-ENOMEM);
	347	goto fail;
	348	}
24bbb1fa MH	349	inode = hypfs_make_inode(sb, mode);
	350	if (!inode) {
	351	dput(dentry);
9b5a03e1 MH	352	dentry = ERR_PTR(-ENOMEM);
9b5a03e1 MH	353	goto fail;
24bbb1fa MH	354	}
	355	if (mode & S_IFREG) {
	356	inode->i_fop = &hypfs_file_ops;
	357	if (data)
	358	inode->i_size = strlen(data);
	359	else
	360	inode->i_size = 0;
	361	} else if (mode & S_IFDIR) {
	362	inode->i_op = &simple_dir_inode_operations;
	363	inode->i_fop = &simple_dir_operations;
	364	parent->d_inode->i_nlink++;
	365	} else
	366	BUG();
8e18e294	367	inode->i_private = data;
24bbb1fa MH	368	d_instantiate(dentry, inode);
24bbb1fa MH	369	dget(dentry);
9b5a03e1 MH	370	fail:
9b5a03e1 MH	371	mutex_unlock(&parent->d_inode->i_mutex);
24bbb1fa MH	372	return dentry;
	373	}
	374
	375	struct dentry hypfs_mkdir(struct super_block sb, struct dentry *parent,
	376	const char *name)
	377	{
	378	struct dentry *dentry;
	379
	380	dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR \| DIR_MODE);
	381	if (IS_ERR(dentry))
	382	return dentry;
	383	hypfs_add_dentry(dentry);
24bbb1fa MH	384	return dentry;
	385	}
	386
	387	static struct dentry hypfs_create_update_file(struct super_block sb,
	388	struct dentry *dir)
	389	{
	390	struct dentry *dentry;
	391
	392	dentry = hypfs_create_file(sb, dir, "update", NULL,
	393	S_IFREG \| UPDATE_FILE_MODE);
	394	/*
	395	* We do not put the update file on the 'delete' list with
	396	* hypfs_add_dentry(), since it should not be removed when the tree
	397	* is updated.
	398	*/
	399	return dentry;
	400	}
	401
	402	struct dentry hypfs_create_u64(struct super_block sb, struct dentry *dir,
	403	const char *name, __u64 value)
	404	{
	405	char *buffer;
	406	char tmp[TMP_SIZE];
	407	struct dentry *dentry;
	408
ad2a5d8e	409	snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
24bbb1fa MH	410	buffer = kstrdup(tmp, GFP_KERNEL);
	411	if (!buffer)
	412	return ERR_PTR(-ENOMEM);
	413	dentry =
	414	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	415	if (IS_ERR(dentry)) {
	416	kfree(buffer);
	417	return ERR_PTR(-ENOMEM);
	418	}
	419	hypfs_add_dentry(dentry);
	420	return dentry;
	421	}
	422
	423	struct dentry hypfs_create_str(struct super_block sb, struct dentry *dir,
	424	const char name, char string)
	425	{
	426	char *buffer;
	427	struct dentry *dentry;
	428
	429	buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
	430	if (!buffer)
	431	return ERR_PTR(-ENOMEM);
	432	sprintf(buffer, "%s\n", string);
	433	dentry =
	434	hypfs_create_file(sb, dir, name, buffer, S_IFREG \| REG_FILE_MODE);
	435	if (IS_ERR(dentry)) {
	436	kfree(buffer);
	437	return ERR_PTR(-ENOMEM);
	438	}
	439	hypfs_add_dentry(dentry);
	440	return dentry;
	441	}
	442
5dfe4c96	443	static const struct file_operations hypfs_file_ops = {
24bbb1fa MH	444	.open = hypfs_open,
	445	.release = hypfs_release,
	446	.read = do_sync_read,
	447	.write = do_sync_write,
	448	.aio_read = hypfs_aio_read,
	449	.aio_write = hypfs_aio_write,
	450	};
	451
	452	static struct file_system_type hypfs_type = {
	453	.owner = THIS_MODULE,
	454	.name = "s390_hypfs",
	455	.get_sb = hypfs_get_super,
	456	.kill_sb = hypfs_kill_super
	457	};
	458
b87221de	459	static const struct super_operations hypfs_s_ops = {
24bbb1fa MH	460	.statfs = simple_statfs,
24bbb1fa MH	461	.drop_inode = hypfs_drop_inode,
b01af5ba	462	.show_options = hypfs_show_options,
24bbb1fa MH	463	};
24bbb1fa MH	464
9b477705	465	static struct kobject *s390_kobj;
24bbb1fa MH	466
	467	static int __init hypfs_init(void)
	468	{
	469	int rc;
	470
31cb4bd3 MH	471	if (MACHINE_IS_VM) {
	472	if (hypfs_vm_init())
	473	/* no diag 2fc, just exit */
	474	return -ENODATA;
	475	} else {
	476	if (hypfs_diag_init()) {
	477	rc = -ENODATA;
	478	goto fail_diag;
	479	}
24bbb1fa	480	}
9b477705 GKH	481	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
9b477705 GKH	482	if (!s390_kobj) {
a419aef8	483	rc = -ENOMEM;
24bbb1fa	484	goto fail_sysfs;
9b477705	485	}
24bbb1fa MH	486	rc = register_filesystem(&hypfs_type);
	487	if (rc)
	488	goto fail_filesystem;
	489	return 0;
	490
	491	fail_filesystem:
38a382ae	492	kobject_put(s390_kobj);
24bbb1fa	493	fail_sysfs:
31cb4bd3 MH	494	if (!MACHINE_IS_VM)
31cb4bd3 MH	495	hypfs_diag_exit();
24bbb1fa	496	fail_diag:
f55495ba	497	pr_err("Initialization of hypfs failed with rc=%i\n", rc);
24bbb1fa MH	498	return rc;
	499	}
	500
	501	static void __exit hypfs_exit(void)
	502	{
31cb4bd3 MH	503	if (!MACHINE_IS_VM)
31cb4bd3 MH	504	hypfs_diag_exit();
24bbb1fa	505	unregister_filesystem(&hypfs_type);
38a382ae	506	kobject_put(s390_kobj);
24bbb1fa MH	507	}
	508
	509	module_init(hypfs_init)
	510	module_exit(hypfs_exit)
	511
	512	MODULE_LICENSE("GPL");
	513	MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>");
	514	MODULE_DESCRIPTION("s390 Hypervisor Filesystem");