fs/hppfs/hppfs.c

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/ctype.h>
   7 #include <linux/dcache.h>
   8 #include <linux/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/list.h>
  13 #include <linux/module.h>
  14 #include <linux/mount.h>
  15 #include <linux/slab.h>
  16 #include <linux/statfs.h>
  17 #include <linux/types.h>
  18 #include <linux/pid_namespace.h>
  19 #include <linux/namei.h>
  20 #include <asm/uaccess.h>
  21 #include <os.h>
  22
  23 static struct inode *get_inode(struct super_block *, struct dentry *);
  24
  25 struct hppfs_data {
  26         struct list_head list;
  27         char contents[PAGE_SIZE - sizeof(struct list_head)];
  28 };
  29
  30 struct hppfs_private {
  31         struct file *proc_file;
  32         int host_fd;
  33         loff_t len;
  34         struct hppfs_data *contents;
  35 };
  36
  37 struct hppfs_inode_info {
  38         struct dentry *proc_dentry;
  39         struct inode vfs_inode;
  40 };
  41
  42 static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
  43 {
  44         return container_of(inode, struct hppfs_inode_info, vfs_inode);
  45 }
  46
  47 #define HPPFS_SUPER_MAGIC 0xb00000ee
  48
  49 static const struct super_operations hppfs_sbops;
  50
  51 static int is_pid(struct dentry *dentry)
  52 {
  53         struct super_block *sb;
  54         int i;
  55
  56         sb = dentry->d_sb;
  57         if (dentry->d_parent != sb->s_root)
  58                 return 0;
  59
  60         for (i = 0; i < dentry->d_name.len; i++) {
  61                 if (!isdigit(dentry->d_name.name[i]))
  62                         return 0;
  63         }
  64         return 1;
  65 }
  66
  67 static char *dentry_name(struct dentry *dentry, int extra)
  68 {
  69         struct dentry *parent;
  70         char *root, *name;
  71         const char *seg_name;
  72         int len, seg_len, root_len;
  73
  74         len = 0;
  75         parent = dentry;
  76         while (parent->d_parent != parent) {
  77                 if (is_pid(parent))
  78                         len += strlen("pid") + 1;
  79                 else len += parent->d_name.len + 1;
  80                 parent = parent->d_parent;
  81         }
  82
  83         root = "proc";
  84         root_len = strlen(root);
  85         len += root_len;
  86         name = kmalloc(len + extra + 1, GFP_KERNEL);
  87         if (name == NULL)
  88                 return NULL;
  89
  90         name[len] = '\0';
  91         parent = dentry;
  92         while (parent->d_parent != parent) {
  93                 if (is_pid(parent)) {
  94                         seg_name = "pid";
  95                         seg_len = strlen(seg_name);
  96                 }
  97                 else {
  98                         seg_name = parent->d_name.name;
  99                         seg_len = parent->d_name.len;
 100                 }
 101
 102                 len -= seg_len + 1;
 103                 name[len] = '/';
 104                 memcpy(&name[len + 1], seg_name, seg_len);
 105                 parent = parent->d_parent;
 106         }
 107         memcpy(name, root, root_len);
 108         return name;
 109 }
 110
 111 static int file_removed(struct dentry *dentry, const char *file)
 112 {
 113         char *host_file;
 114         int extra, fd;
 115
 116         extra = 0;
 117         if (file != NULL)
 118                 extra += strlen(file) + 1;
 119
 120         host_file = dentry_name(dentry, extra + strlen("/remove"));
 121         if (host_file == NULL) {
 122                 printk(KERN_ERR "file_removed : allocation failed\n");
 123                 return -ENOMEM;
 124         }
 125
 126         if (file != NULL) {
 127                 strcat(host_file, "/");
 128                 strcat(host_file, file);
 129         }
 130         strcat(host_file, "/remove");
 131
 132         fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
 133         kfree(host_file);
 134         if (fd > 0) {
 135                 os_close_file(fd);
 136                 return 1;
 137         }
 138         return 0;
 139 }
 140
 141 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
 142                                    unsigned int flags)
 143 {
 144         struct dentry *proc_dentry, *parent;
 145         struct qstr *name = &dentry->d_name;
 146         struct inode *inode;
 147         int err, deleted;
 148
 149         deleted = file_removed(dentry, NULL);
 150         if (deleted < 0)
 151                 return ERR_PTR(deleted);
 152         else if (deleted)
 153                 return ERR_PTR(-ENOENT);
 154
 155         parent = HPPFS_I(ino)->proc_dentry;
 156         mutex_lock(&parent->d_inode->i_mutex);
 157         proc_dentry = lookup_one_len(name->name, parent, name->len);
 158         mutex_unlock(&parent->d_inode->i_mutex);
 159
 160         if (IS_ERR(proc_dentry))
 161                 return proc_dentry;
 162
 163         err = -ENOMEM;
 164         inode = get_inode(ino->i_sb, proc_dentry);
 165         if (!inode)
 166                 goto out;
 167
 168         d_add(dentry, inode);
 169         return NULL;
 170
 171  out:
 172         return ERR_PTR(err);
 173 }
 174
 175 static const struct inode_operations hppfs_file_iops = {
 176 };
 177
 178 static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
 179                          loff_t *ppos, int is_user)
 180 {
 181         ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
 182         ssize_t n;
 183
 184         read = file_inode(file)->i_fop->read;
 185
 186         if (!is_user)
 187                 set_fs(KERNEL_DS);
 188
 189         n = (*read)(file, buf, count, &file->f_pos);
 190
 191         if (!is_user)
 192                 set_fs(USER_DS);
 193
 194         if (ppos)
 195                 *ppos = file->f_pos;
 196         return n;
 197 }
 198
 199 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
 200 {
 201         ssize_t n;
 202         int cur, err;
 203         char *new_buf;
 204
 205         n = -ENOMEM;
 206         new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 207         if (new_buf == NULL) {
 208                 printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
 209                 goto out;
 210         }
 211         n = 0;
 212         while (count > 0) {
 213                 cur = min_t(ssize_t, count, PAGE_SIZE);
 214                 err = os_read_file(fd, new_buf, cur);
 215                 if (err < 0) {
 216                         printk(KERN_ERR "hppfs_read : read failed, "
 217                                "errno = %d\n", err);
 218                         n = err;
 219                         goto out_free;
 220                 } else if (err == 0)
 221                         break;
 222
 223                 if (copy_to_user(buf, new_buf, err)) {
 224                         n = -EFAULT;
 225                         goto out_free;
 226                 }
 227                 n += err;
 228                 count -= err;
 229         }
 230  out_free:
 231         kfree(new_buf);
 232  out:
 233         return n;
 234 }
 235
 236 static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
 237                           loff_t *ppos)
 238 {
 239         struct hppfs_private *hppfs = file->private_data;
 240         struct hppfs_data *data;
 241         loff_t off;
 242         int err;
 243
 244         if (hppfs->contents != NULL) {
 245                 int rem;
 246
 247                 if (*ppos >= hppfs->len)
 248                         return 0;
 249
 250                 data = hppfs->contents;
 251                 off = *ppos;
 252                 while (off >= sizeof(data->contents)) {
 253                         data = list_entry(data->list.next, struct hppfs_data,
 254                                           list);
 255                         off -= sizeof(data->contents);
 256                 }
 257
 258                 if (off + count > hppfs->len)
 259                         count = hppfs->len - off;
 260                 rem = copy_to_user(buf, &data->contents[off], count);
 261                 *ppos += count - rem;
 262                 if (rem > 0)
 263                         return -EFAULT;
 264         } else if (hppfs->host_fd != -1) {
 265                 err = os_seek_file(hppfs->host_fd, *ppos);
 266                 if (err) {
 267                         printk(KERN_ERR "hppfs_read : seek failed, "
 268                                "errno = %d\n", err);
 269                         return err;
 270                 }
 271                 err = hppfs_read_file(hppfs->host_fd, buf, count);
 272                 if (err < 0) {
 273                         printk(KERN_ERR "hppfs_read: read failed: %d\n", err);
 274                         return err;
 275                 }
 276                 count = err;
 277                 if (count > 0)
 278                         *ppos += count;
 279         }
 280         else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
 281
 282         return count;
 283 }
 284
 285 static ssize_t hppfs_write(struct file *file, const char __user *buf,
 286                            size_t len, loff_t *ppos)
 287 {
 288         struct hppfs_private *data = file->private_data;
 289         struct file *proc_file = data->proc_file;
 290         ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
 291
 292         write = file_inode(proc_file)->i_fop->write;
 293         return (*write)(proc_file, buf, len, ppos);
 294 }
 295
 296 static int open_host_sock(char *host_file, int *filter_out)
 297 {
 298         char *end;
 299         int fd;
 300
 301         end = &host_file[strlen(host_file)];
 302         strcpy(end, "/rw");
 303         *filter_out = 1;
 304         fd = os_connect_socket(host_file);
 305         if (fd > 0)
 306                 return fd;
 307
 308         strcpy(end, "/r");
 309         *filter_out = 0;
 310         fd = os_connect_socket(host_file);
 311         return fd;
 312 }
 313
 314 static void free_contents(struct hppfs_data *head)
 315 {
 316         struct hppfs_data *data;
 317         struct list_head *ele, *next;
 318
 319         if (head == NULL)
 320                 return;
 321
 322         list_for_each_safe(ele, next, &head->list) {
 323                 data = list_entry(ele, struct hppfs_data, list);
 324                 kfree(data);
 325         }
 326         kfree(head);
 327 }
 328
 329 static struct hppfs_data *hppfs_get_data(int fd, int filter,
 330                                          struct file *proc_file,
 331                                          struct file *hppfs_file,
 332                                          loff_t *size_out)
 333 {
 334         struct hppfs_data *data, *new, *head;
 335         int n, err;
 336
 337         err = -ENOMEM;
 338         data = kmalloc(sizeof(*data), GFP_KERNEL);
 339         if (data == NULL) {
 340                 printk(KERN_ERR "hppfs_get_data : head allocation failed\n");
 341                 goto failed;
 342         }
 343
 344         INIT_LIST_HEAD(&data->list);
 345
 346         head = data;
 347         *size_out = 0;
 348
 349         if (filter) {
 350                 while ((n = read_proc(proc_file, data->contents,
 351                                       sizeof(data->contents), NULL, 0)) > 0)
 352                         os_write_file(fd, data->contents, n);
 353                 err = os_shutdown_socket(fd, 0, 1);
 354                 if (err) {
 355                         printk(KERN_ERR "hppfs_get_data : failed to shut down "
 356                                "socket\n");
 357                         goto failed_free;
 358                 }
 359         }
 360         while (1) {
 361                 n = os_read_file(fd, data->contents, sizeof(data->contents));
 362                 if (n < 0) {
 363                         err = n;
 364                         printk(KERN_ERR "hppfs_get_data : read failed, "
 365                                "errno = %d\n", err);
 366                         goto failed_free;
 367                 } else if (n == 0)
 368                         break;
 369
 370                 *size_out += n;
 371
 372                 if (n < sizeof(data->contents))
 373                         break;
 374
 375                 new = kmalloc(sizeof(*data), GFP_KERNEL);
 376                 if (new == 0) {
 377                         printk(KERN_ERR "hppfs_get_data : data allocation "
 378                                "failed\n");
 379                         err = -ENOMEM;
 380                         goto failed_free;
 381                 }
 382
 383                 INIT_LIST_HEAD(&new->list);
 384                 list_add(&new->list, &data->list);
 385                 data = new;
 386         }
 387         return head;
 388
 389  failed_free:
 390         free_contents(head);
 391  failed:
 392         return ERR_PTR(err);
 393 }
 394
 395 static struct hppfs_private *hppfs_data(void)
 396 {
 397         struct hppfs_private *data;
 398
 399         data = kmalloc(sizeof(*data), GFP_KERNEL);
 400         if (data == NULL)
 401                 return data;
 402
 403         *data = ((struct hppfs_private ) { .host_fd             = -1,
 404                                            .len                 = -1,
 405                                            .contents            = NULL } );
 406         return data;
 407 }
 408
 409 static int file_mode(int fmode)
 410 {
 411         if (fmode == (FMODE_READ | FMODE_WRITE))
 412                 return O_RDWR;
 413         if (fmode == FMODE_READ)
 414                 return O_RDONLY;
 415         if (fmode == FMODE_WRITE)
 416                 return O_WRONLY;
 417         return 0;
 418 }
 419
 420 static int hppfs_open(struct inode *inode, struct file *file)
 421 {
 422         const struct cred *cred = file->f_cred;
 423         struct hppfs_private *data;
 424         struct path path;
 425         char *host_file;
 426         int err, fd, type, filter;
 427
 428         err = -ENOMEM;
 429         data = hppfs_data();
 430         if (data == NULL)
 431                 goto out;
 432
 433         host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
 434         if (host_file == NULL)
 435                 goto out_free2;
 436
 437         path.mnt = inode->i_sb->s_fs_info;
 438         path.dentry = HPPFS_I(inode)->proc_dentry;
 439
 440         data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
 441         err = PTR_ERR(data->proc_file);
 442         if (IS_ERR(data->proc_file))
 443                 goto out_free1;
 444
 445         type = os_file_type(host_file);
 446         if (type == OS_TYPE_FILE) {
 447                 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
 448                 if (fd >= 0)
 449                         data->host_fd = fd;
 450                 else
 451                         printk(KERN_ERR "hppfs_open : failed to open '%s', "
 452                                "errno = %d\n", host_file, -fd);
 453
 454                 data->contents = NULL;
 455         } else if (type == OS_TYPE_DIR) {
 456                 fd = open_host_sock(host_file, &filter);
 457                 if (fd > 0) {
 458                         data->contents = hppfs_get_data(fd, filter,
 459                                                         data->proc_file,
 460                                                         file, &data->len);
 461                         if (!IS_ERR(data->contents))
 462                                 data->host_fd = fd;
 463                 } else
 464                         printk(KERN_ERR "hppfs_open : failed to open a socket "
 465                                "in '%s', errno = %d\n", host_file, -fd);
 466         }
 467         kfree(host_file);
 468
 469         file->private_data = data;
 470         return 0;
 471
 472  out_free1:
 473         kfree(host_file);
 474  out_free2:
 475         free_contents(data->contents);
 476         kfree(data);
 477  out:
 478         return err;
 479 }
 480
 481 static int hppfs_dir_open(struct inode *inode, struct file *file)
 482 {
 483         const struct cred *cred = file->f_cred;
 484         struct hppfs_private *data;
 485         struct path path;
 486         int err;
 487
 488         err = -ENOMEM;
 489         data = hppfs_data();
 490         if (data == NULL)
 491                 goto out;
 492
 493         path.mnt = inode->i_sb->s_fs_info;
 494         path.dentry = HPPFS_I(inode)->proc_dentry;
 495         data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
 496         err = PTR_ERR(data->proc_file);
 497         if (IS_ERR(data->proc_file))
 498                 goto out_free;
 499
 500         file->private_data = data;
 501         return 0;
 502
 503  out_free:
 504         kfree(data);
 505  out:
 506         return err;
 507 }
 508
 509 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
 510 {
 511         struct hppfs_private *data = file->private_data;
 512         struct file *proc_file = data->proc_file;
 513         loff_t (*llseek)(struct file *, loff_t, int);
 514         loff_t ret;
 515
 516         llseek = file_inode(proc_file)->i_fop->llseek;
 517         if (llseek != NULL) {
 518                 ret = (*llseek)(proc_file, off, where);
 519                 if (ret < 0)
 520                         return ret;
 521         }
 522
 523         return default_llseek(file, off, where);
 524 }
 525
 526 static int hppfs_release(struct inode *inode, struct file *file)
 527 {
 528         struct hppfs_private *data = file->private_data;
 529         struct file *proc_file = data->proc_file;
 530         if (proc_file)
 531                 fput(proc_file);
 532         kfree(data);
 533         return 0;
 534 }
 535
 536 static const struct file_operations hppfs_file_fops = {
 537         .owner          = NULL,
 538         .llseek         = hppfs_llseek,
 539         .read           = hppfs_read,
 540         .write          = hppfs_write,
 541         .open           = hppfs_open,
 542         .release        = hppfs_release,
 543 };
 544
 545 struct hppfs_dirent {
 546         struct dir_context ctx;
 547         struct dir_context *caller;
 548         struct dentry *dentry;
 549 };
 550
 551 static int hppfs_filldir(void *d, const char *name, int size,
 552                          loff_t offset, u64 inode, unsigned int type)
 553 {
 554         struct hppfs_dirent *dirent = d;
 555
 556         if (file_removed(dirent->dentry, name))
 557                 return 0;
 558
 559         dirent->caller->pos = dirent->ctx.pos;
 560         return !dir_emit(dirent->caller, name, size, inode, type);
 561 }
 562
 563 static int hppfs_readdir(struct file *file, struct dir_context *ctx)
 564 {
 565         struct hppfs_private *data = file->private_data;
 566         struct file *proc_file = data->proc_file;
 567         struct hppfs_dirent d = {
 568                 .ctx.actor      = hppfs_filldir,
 569                 .caller         = ctx,
 570                 .dentry         = file->f_path.dentry
 571         };
 572         int err;
 573         proc_file->f_pos = ctx->pos;
 574         err = iterate_dir(proc_file, &d.ctx);
 575         ctx->pos = d.ctx.pos;
 576         return err;
 577 }
 578
 579 static const struct file_operations hppfs_dir_fops = {
 580         .owner          = NULL,
 581         .iterate        = hppfs_readdir,
 582         .open           = hppfs_dir_open,
 583         .llseek         = default_llseek,
 584         .release        = hppfs_release,
 585 };
 586
 587 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
 588 {
 589         sf->f_blocks = 0;
 590         sf->f_bfree = 0;
 591         sf->f_bavail = 0;
 592         sf->f_files = 0;
 593         sf->f_ffree = 0;
 594         sf->f_type = HPPFS_SUPER_MAGIC;
 595         return 0;
 596 }
 597
 598 static struct inode *hppfs_alloc_inode(struct super_block *sb)
 599 {
 600         struct hppfs_inode_info *hi;
 601
 602         hi = kmalloc(sizeof(*hi), GFP_KERNEL);
 603         if (!hi)
 604                 return NULL;
 605
 606         hi->proc_dentry = NULL;
 607         inode_init_once(&hi->vfs_inode);
 608         return &hi->vfs_inode;
 609 }
 610
 611 void hppfs_evict_inode(struct inode *ino)
 612 {
 613         clear_inode(ino);
 614         dput(HPPFS_I(ino)->proc_dentry);
 615         mntput(ino->i_sb->s_fs_info);
 616 }
 617
 618 static void hppfs_i_callback(struct rcu_head *head)
 619 {
 620         struct inode *inode = container_of(head, struct inode, i_rcu);
 621         kfree(HPPFS_I(inode));
 622 }
 623
 624 static void hppfs_destroy_inode(struct inode *inode)
 625 {
 626         call_rcu(&inode->i_rcu, hppfs_i_callback);
 627 }
 628
 629 static const struct super_operations hppfs_sbops = {
 630         .alloc_inode    = hppfs_alloc_inode,
 631         .destroy_inode  = hppfs_destroy_inode,
 632         .evict_inode    = hppfs_evict_inode,
 633         .statfs         = hppfs_statfs,
 634 };
 635
 636 static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
 637                           int buflen)
 638 {
 639         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 640         return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer,
 641                                                     buflen);
 642 }
 643
 644 static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 645 {
 646         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 647
 648         return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
 649 }
 650
 651 static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
 652                            void *cookie)
 653 {
 654         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 655
 656         if (proc_dentry->d_inode->i_op->put_link)
 657                 proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie);
 658 }
 659
 660 static const struct inode_operations hppfs_dir_iops = {
 661         .lookup         = hppfs_lookup,
 662 };
 663
 664 static const struct inode_operations hppfs_link_iops = {
 665         .readlink       = hppfs_readlink,
 666         .follow_link    = hppfs_follow_link,
 667         .put_link       = hppfs_put_link,
 668 };
 669
 670 static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
 671 {
 672         struct inode *proc_ino = dentry->d_inode;
 673         struct inode *inode = new_inode(sb);
 674
 675         if (!inode) {
 676                 dput(dentry);
 677                 return NULL;
 678         }
 679
 680         if (S_ISDIR(dentry->d_inode->i_mode)) {
 681                 inode->i_op = &hppfs_dir_iops;
 682                 inode->i_fop = &hppfs_dir_fops;
 683         } else if (S_ISLNK(dentry->d_inode->i_mode)) {
 684                 inode->i_op = &hppfs_link_iops;
 685                 inode->i_fop = &hppfs_file_fops;
 686         } else {
 687                 inode->i_op = &hppfs_file_iops;
 688                 inode->i_fop = &hppfs_file_fops;
 689         }
 690
 691         HPPFS_I(inode)->proc_dentry = dentry;
 692
 693         inode->i_uid = proc_ino->i_uid;
 694         inode->i_gid = proc_ino->i_gid;
 695         inode->i_atime = proc_ino->i_atime;
 696         inode->i_mtime = proc_ino->i_mtime;
 697         inode->i_ctime = proc_ino->i_ctime;
 698         inode->i_ino = proc_ino->i_ino;
 699         inode->i_mode = proc_ino->i_mode;
 700         set_nlink(inode, proc_ino->i_nlink);
 701         inode->i_size = proc_ino->i_size;
 702         inode->i_blocks = proc_ino->i_blocks;
 703
 704         return inode;
 705 }
 706
 707 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
 708 {
 709         struct inode *root_inode;
 710         struct vfsmount *proc_mnt;
 711         int err = -ENOENT;
 712
 713         proc_mnt = mntget(task_active_pid_ns(current)->proc_mnt);
 714         if (IS_ERR(proc_mnt))
 715                 goto out;
 716
 717         sb->s_blocksize = 1024;
 718         sb->s_blocksize_bits = 10;
 719         sb->s_magic = HPPFS_SUPER_MAGIC;
 720         sb->s_op = &hppfs_sbops;
 721         sb->s_fs_info = proc_mnt;
 722
 723         err = -ENOMEM;
 724         root_inode = get_inode(sb, dget(proc_mnt->mnt_root));
 725         sb->s_root = d_make_root(root_inode);
 726         if (!sb->s_root)
 727                 goto out_mntput;
 728
 729         return 0;
 730
 731  out_mntput:
 732         mntput(proc_mnt);
 733  out:
 734         return(err);
 735 }
 736
 737 static struct dentry *hppfs_read_super(struct file_system_type *type,
 738                             int flags, const char *dev_name,
 739                             void *data)
 740 {
 741         return mount_nodev(type, flags, data, hppfs_fill_super);
 742 }
 743
 744 static struct file_system_type hppfs_type = {
 745         .owner          = THIS_MODULE,
 746         .name           = "hppfs",
 747         .mount          = hppfs_read_super,
 748         .kill_sb        = kill_anon_super,
 749         .fs_flags       = 0,
 750 };
 751 MODULE_ALIAS_FS("hppfs");
 752
 753 static int __init init_hppfs(void)
 754 {
 755         return register_filesystem(&hppfs_type);
 756 }
 757
 758 static void __exit exit_hppfs(void)
 759 {
 760         unregister_filesystem(&hppfs_type);
 761 }
 762
 763 module_init(init_hppfs)
 764 module_exit(exit_hppfs)
 765 MODULE_LICENSE("GPL");