48fde701af
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
515 lines
12 KiB
C
515 lines
12 KiB
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, umode_t 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 (S_ISDIR(mode))
|
|
set_nlink(ret, 2);
|
|
}
|
|
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 dentry *root)
|
|
{
|
|
struct hypfs_sb_info *hypfs_info = root->d_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_make_root(root_inode);
|
|
if (!root_dentry)
|
|
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, 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
|
|
};
|
|
|
|
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");
|