release/src-rt-6.x.4708/linux/linux-2.6.36/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 <asm/uaccess.h>
  20 #include "os.h"
  21
  22 static struct inode *get_inode(struct super_block *, struct dentry *);
  23
  24 struct hppfs_data {
  25         struct list_head list;
  26         char contents[PAGE_SIZE - sizeof(struct list_head)];
  27 };
  28
  29 struct hppfs_private {
  30         struct file *proc_file;
  31         int host_fd;
  32         loff_t len;
  33         struct hppfs_data *contents;
  34 };
  35
  36 struct hppfs_inode_info {
  37         struct dentry *proc_dentry;
  38         struct inode vfs_inode;
  39 };
  40
  41 static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
  42 {
  43         return container_of(inode, struct hppfs_inode_info, vfs_inode);
  44 }
  45
  46 #define HPPFS_SUPER_MAGIC 0xb00000ee
  47
  48 static const struct super_operations hppfs_sbops;
  49
  50 static int is_pid(struct dentry *dentry)
  51 {
  52         struct super_block *sb;
  53         int i;
  54
  55         sb = dentry->d_sb;
  56         if (dentry->d_parent != sb->s_root)
  57                 return 0;
  58
  59         for (i = 0; i < dentry->d_name.len; i++) {
  60                 if (!isdigit(dentry->d_name.name[i]))
  61                         return 0;
  62         }
  63         return 1;
  64 }
  65
  66 static char *dentry_name(struct dentry *dentry, int extra)
  67 {
  68         struct dentry *parent;
  69         char *root, *name;
  70         const char *seg_name;
  71         int len, seg_len;
  72
  73         len = 0;
  74         parent = dentry;
  75         while (parent->d_parent != parent) {
  76                 if (is_pid(parent))
  77                         len += strlen("pid") + 1;
  78                 else len += parent->d_name.len + 1;
  79                 parent = parent->d_parent;
  80         }
  81
  82         root = "proc";
  83         len += strlen(root);
  84         name = kmalloc(len + extra + 1, GFP_KERNEL);
  85         if (name == NULL)
  86                 return NULL;
  87
  88         name[len] = '\0';
  89         parent = dentry;
  90         while (parent->d_parent != parent) {
  91                 if (is_pid(parent)) {
  92                         seg_name = "pid";
  93                         seg_len = strlen("pid");
  94                 }
  95                 else {
  96                         seg_name = parent->d_name.name;
  97                         seg_len = parent->d_name.len;
  98                 }
  99
 100                 len -= seg_len + 1;
 101                 name[len] = '/';
 102                 strncpy(&name[len + 1], seg_name, seg_len);
 103                 parent = parent->d_parent;
 104         }
 105         strncpy(name, root, strlen(root));
 106         return name;
 107 }
 108
 109 static int file_removed(struct dentry *dentry, const char *file)
 110 {
 111         char *host_file;
 112         int extra, fd;
 113
 114         extra = 0;
 115         if (file != NULL)
 116                 extra += strlen(file) + 1;
 117
 118         host_file = dentry_name(dentry, extra + strlen("/remove"));
 119         if (host_file == NULL) {
 120                 printk(KERN_ERR "file_removed : allocation failed\n");
 121                 return -ENOMEM;
 122         }
 123
 124         if (file != NULL) {
 125                 strcat(host_file, "/");
 126                 strcat(host_file, file);
 127         }
 128         strcat(host_file, "/remove");
 129
 130         fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
 131         kfree(host_file);
 132         if (fd > 0) {
 133                 os_close_file(fd);
 134                 return 1;
 135         }
 136         return 0;
 137 }
 138
 139 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
 140                                    struct nameidata *nd)
 141 {
 142         struct dentry *proc_dentry, *new, *parent;
 143         struct inode *inode;
 144         int err, deleted;
 145
 146         deleted = file_removed(dentry, NULL);
 147         if (deleted < 0)
 148                 return ERR_PTR(deleted);
 149         else if (deleted)
 150                 return ERR_PTR(-ENOENT);
 151
 152         err = -ENOMEM;
 153         parent = HPPFS_I(ino)->proc_dentry;
 154         mutex_lock(&parent->d_inode->i_mutex);
 155         proc_dentry = d_lookup(parent, &dentry->d_name);
 156         if (proc_dentry == NULL) {
 157                 proc_dentry = d_alloc(parent, &dentry->d_name);
 158                 if (proc_dentry == NULL) {
 159                         mutex_unlock(&parent->d_inode->i_mutex);
 160                         goto out;
 161                 }
 162                 new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
 163                                                        proc_dentry, NULL);
 164                 if (new) {
 165                         dput(proc_dentry);
 166                         proc_dentry = new;
 167                 }
 168         }
 169         mutex_unlock(&parent->d_inode->i_mutex);
 170
 171         if (IS_ERR(proc_dentry))
 172                 return proc_dentry;
 173
 174         err = -ENOMEM;
 175         inode = get_inode(ino->i_sb, proc_dentry);
 176         if (!inode)
 177                 goto out_dput;
 178
 179         d_add(dentry, inode);
 180         return NULL;
 181
 182  out_dput:
 183         dput(proc_dentry);
 184  out:
 185         return ERR_PTR(err);
 186 }
 187
 188 static const struct inode_operations hppfs_file_iops = {
 189 };
 190
 191 static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
 192                          loff_t *ppos, int is_user)
 193 {
 194         ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
 195         ssize_t n;
 196
 197         read = file->f_path.dentry->d_inode->i_fop->read;
 198
 199         if (!is_user)
 200                 set_fs(KERNEL_DS);
 201
 202         n = (*read)(file, buf, count, &file->f_pos);
 203
 204         if (!is_user)
 205                 set_fs(USER_DS);
 206
 207         if (ppos)
 208                 *ppos = file->f_pos;
 209         return n;
 210 }
 211
 212 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
 213 {
 214         ssize_t n;
 215         int cur, err;
 216         char *new_buf;
 217
 218         n = -ENOMEM;
 219         new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 220         if (new_buf == NULL) {
 221                 printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
 222                 goto out;
 223         }
 224         n = 0;
 225         while (count > 0) {
 226                 cur = min_t(ssize_t, count, PAGE_SIZE);
 227                 err = os_read_file(fd, new_buf, cur);
 228                 if (err < 0) {
 229                         printk(KERN_ERR "hppfs_read : read failed, "
 230                                "errno = %d\n", err);
 231                         n = err;
 232                         goto out_free;
 233                 } else if (err == 0)
 234                         break;
 235
 236                 if (copy_to_user(buf, new_buf, err)) {
 237                         n = -EFAULT;
 238                         goto out_free;
 239                 }
 240                 n += err;
 241                 count -= err;
 242         }
 243  out_free:
 244         kfree(new_buf);
 245  out:
 246         return n;
 247 }
 248
 249 static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
 250                           loff_t *ppos)
 251 {
 252         struct hppfs_private *hppfs = file->private_data;
 253         struct hppfs_data *data;
 254         loff_t off;
 255         int err;
 256
 257         if (hppfs->contents != NULL) {
 258                 int rem;
 259
 260                 if (*ppos >= hppfs->len)
 261                         return 0;
 262
 263                 data = hppfs->contents;
 264                 off = *ppos;
 265                 while (off >= sizeof(data->contents)) {
 266                         data = list_entry(data->list.next, struct hppfs_data,
 267                                           list);
 268                         off -= sizeof(data->contents);
 269                 }
 270
 271                 if (off + count > hppfs->len)
 272                         count = hppfs->len - off;
 273                 rem = copy_to_user(buf, &data->contents[off], count);
 274                 *ppos += count - rem;
 275                 if (rem > 0)
 276                         return -EFAULT;
 277         } else if (hppfs->host_fd != -1) {
 278                 err = os_seek_file(hppfs->host_fd, *ppos);
 279                 if (err) {
 280                         printk(KERN_ERR "hppfs_read : seek failed, "
 281                                "errno = %d\n", err);
 282                         return err;
 283                 }
 284                 err = hppfs_read_file(hppfs->host_fd, buf, count);
 285                 if (err < 0) {
 286                         printk(KERN_ERR "hppfs_read: read failed: %d\n", err);
 287                         return err;
 288                 }
 289                 count = err;
 290                 if (count > 0)
 291                         *ppos += count;
 292         }
 293         else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
 294
 295         return count;
 296 }
 297
 298 static ssize_t hppfs_write(struct file *file, const char __user *buf,
 299                            size_t len, loff_t *ppos)
 300 {
 301         struct hppfs_private *data = file->private_data;
 302         struct file *proc_file = data->proc_file;
 303         ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
 304
 305         write = proc_file->f_path.dentry->d_inode->i_fop->write;
 306         return (*write)(proc_file, buf, len, ppos);
 307 }
 308
 309 static int open_host_sock(char *host_file, int *filter_out)
 310 {
 311         char *end;
 312         int fd;
 313
 314         end = &host_file[strlen(host_file)];
 315         strcpy(end, "/rw");
 316         *filter_out = 1;
 317         fd = os_connect_socket(host_file);
 318         if (fd > 0)
 319                 return fd;
 320
 321         strcpy(end, "/r");
 322         *filter_out = 0;
 323         fd = os_connect_socket(host_file);
 324         return fd;
 325 }
 326
 327 static void free_contents(struct hppfs_data *head)
 328 {
 329         struct hppfs_data *data;
 330         struct list_head *ele, *next;
 331
 332         if (head == NULL)
 333                 return;
 334
 335         list_for_each_safe(ele, next, &head->list) {
 336                 data = list_entry(ele, struct hppfs_data, list);
 337                 kfree(data);
 338         }
 339         kfree(head);
 340 }
 341
 342 static struct hppfs_data *hppfs_get_data(int fd, int filter,
 343                                          struct file *proc_file,
 344                                          struct file *hppfs_file,
 345                                          loff_t *size_out)
 346 {
 347         struct hppfs_data *data, *new, *head;
 348         int n, err;
 349
 350         err = -ENOMEM;
 351         data = kmalloc(sizeof(*data), GFP_KERNEL);
 352         if (data == NULL) {
 353                 printk(KERN_ERR "hppfs_get_data : head allocation failed\n");
 354                 goto failed;
 355         }
 356
 357         INIT_LIST_HEAD(&data->list);
 358
 359         head = data;
 360         *size_out = 0;
 361
 362         if (filter) {
 363                 while ((n = read_proc(proc_file, data->contents,
 364                                       sizeof(data->contents), NULL, 0)) > 0)
 365                         os_write_file(fd, data->contents, n);
 366                 err = os_shutdown_socket(fd, 0, 1);
 367                 if (err) {
 368                         printk(KERN_ERR "hppfs_get_data : failed to shut down "
 369                                "socket\n");
 370                         goto failed_free;
 371                 }
 372         }
 373         while (1) {
 374                 n = os_read_file(fd, data->contents, sizeof(data->contents));
 375                 if (n < 0) {
 376                         err = n;
 377                         printk(KERN_ERR "hppfs_get_data : read failed, "
 378                                "errno = %d\n", err);
 379                         goto failed_free;
 380                 } else if (n == 0)
 381                         break;
 382
 383                 *size_out += n;
 384
 385                 if (n < sizeof(data->contents))
 386                         break;
 387
 388                 new = kmalloc(sizeof(*data), GFP_KERNEL);
 389                 if (new == 0) {
 390                         printk(KERN_ERR "hppfs_get_data : data allocation "
 391                                "failed\n");
 392                         err = -ENOMEM;
 393                         goto failed_free;
 394                 }
 395
 396                 INIT_LIST_HEAD(&new->list);
 397                 list_add(&new->list, &data->list);
 398                 data = new;
 399         }
 400         return head;
 401
 402  failed_free:
 403         free_contents(head);
 404  failed:
 405         return ERR_PTR(err);
 406 }
 407
 408 static struct hppfs_private *hppfs_data(void)
 409 {
 410         struct hppfs_private *data;
 411
 412         data = kmalloc(sizeof(*data), GFP_KERNEL);
 413         if (data == NULL)
 414                 return data;
 415
 416         *data = ((struct hppfs_private ) { .host_fd             = -1,
 417                                            .len                 = -1,
 418                                            .contents            = NULL } );
 419         return data;
 420 }
 421
 422 static int file_mode(int fmode)
 423 {
 424         if (fmode == (FMODE_READ | FMODE_WRITE))
 425                 return O_RDWR;
 426         if (fmode == FMODE_READ)
 427                 return O_RDONLY;
 428         if (fmode == FMODE_WRITE)
 429                 return O_WRONLY;
 430         return 0;
 431 }
 432
 433 static int hppfs_open(struct inode *inode, struct file *file)
 434 {
 435         const struct cred *cred = file->f_cred;
 436         struct hppfs_private *data;
 437         struct vfsmount *proc_mnt;
 438         struct dentry *proc_dentry;
 439         char *host_file;
 440         int err, fd, type, filter;
 441
 442         err = -ENOMEM;
 443         data = hppfs_data();
 444         if (data == NULL)
 445                 goto out;
 446
 447         host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
 448         if (host_file == NULL)
 449                 goto out_free2;
 450
 451         proc_dentry = HPPFS_I(inode)->proc_dentry;
 452         proc_mnt = inode->i_sb->s_fs_info;
 453
 454         data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
 455                                       file_mode(file->f_mode), cred);
 456         err = PTR_ERR(data->proc_file);
 457         if (IS_ERR(data->proc_file))
 458                 goto out_free1;
 459
 460         type = os_file_type(host_file);
 461         if (type == OS_TYPE_FILE) {
 462                 fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
 463                 if (fd >= 0)
 464                         data->host_fd = fd;
 465                 else
 466                         printk(KERN_ERR "hppfs_open : failed to open '%s', "
 467                                "errno = %d\n", host_file, -fd);
 468
 469                 data->contents = NULL;
 470         } else if (type == OS_TYPE_DIR) {
 471                 fd = open_host_sock(host_file, &filter);
 472                 if (fd > 0) {
 473                         data->contents = hppfs_get_data(fd, filter,
 474                                                         data->proc_file,
 475                                                         file, &data->len);
 476                         if (!IS_ERR(data->contents))
 477                                 data->host_fd = fd;
 478                 } else
 479                         printk(KERN_ERR "hppfs_open : failed to open a socket "
 480                                "in '%s', errno = %d\n", host_file, -fd);
 481         }
 482         kfree(host_file);
 483
 484         file->private_data = data;
 485         return 0;
 486
 487  out_free1:
 488         kfree(host_file);
 489  out_free2:
 490         free_contents(data->contents);
 491         kfree(data);
 492  out:
 493         return err;
 494 }
 495
 496 static int hppfs_dir_open(struct inode *inode, struct file *file)
 497 {
 498         const struct cred *cred = file->f_cred;
 499         struct hppfs_private *data;
 500         struct vfsmount *proc_mnt;
 501         struct dentry *proc_dentry;
 502         int err;
 503
 504         err = -ENOMEM;
 505         data = hppfs_data();
 506         if (data == NULL)
 507                 goto out;
 508
 509         proc_dentry = HPPFS_I(inode)->proc_dentry;
 510         proc_mnt = inode->i_sb->s_fs_info;
 511         data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
 512                                       file_mode(file->f_mode), cred);
 513         err = PTR_ERR(data->proc_file);
 514         if (IS_ERR(data->proc_file))
 515                 goto out_free;
 516
 517         file->private_data = data;
 518         return 0;
 519
 520  out_free:
 521         kfree(data);
 522  out:
 523         return err;
 524 }
 525
 526 static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
 527 {
 528         struct hppfs_private *data = file->private_data;
 529         struct file *proc_file = data->proc_file;
 530         loff_t (*llseek)(struct file *, loff_t, int);
 531         loff_t ret;
 532
 533         llseek = proc_file->f_path.dentry->d_inode->i_fop->llseek;
 534         if (llseek != NULL) {
 535                 ret = (*llseek)(proc_file, off, where);
 536                 if (ret < 0)
 537                         return ret;
 538         }
 539
 540         return default_llseek(file, off, where);
 541 }
 542
 543 static const struct file_operations hppfs_file_fops = {
 544         .owner          = NULL,
 545         .llseek         = hppfs_llseek,
 546         .read           = hppfs_read,
 547         .write          = hppfs_write,
 548         .open           = hppfs_open,
 549 };
 550
 551 struct hppfs_dirent {
 552         void *vfs_dirent;
 553         filldir_t filldir;
 554         struct dentry *dentry;
 555 };
 556
 557 static int hppfs_filldir(void *d, const char *name, int size,
 558                          loff_t offset, u64 inode, unsigned int type)
 559 {
 560         struct hppfs_dirent *dirent = d;
 561
 562         if (file_removed(dirent->dentry, name))
 563                 return 0;
 564
 565         return (*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
 566                                   inode, type);
 567 }
 568
 569 static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
 570 {
 571         struct hppfs_private *data = file->private_data;
 572         struct file *proc_file = data->proc_file;
 573         int (*readdir)(struct file *, void *, filldir_t);
 574         struct hppfs_dirent dirent = ((struct hppfs_dirent)
 575                                       { .vfs_dirent     = ent,
 576                                         .filldir        = filldir,
 577                                         .dentry         = file->f_path.dentry
 578                                       });
 579         int err;
 580
 581         readdir = proc_file->f_path.dentry->d_inode->i_fop->readdir;
 582
 583         proc_file->f_pos = file->f_pos;
 584         err = (*readdir)(proc_file, &dirent, hppfs_filldir);
 585         file->f_pos = proc_file->f_pos;
 586
 587         return err;
 588 }
 589
 590 static int hppfs_fsync(struct file *file, int datasync)
 591 {
 592         return 0;
 593 }
 594
 595 static const struct file_operations hppfs_dir_fops = {
 596         .owner          = NULL,
 597         .readdir        = hppfs_readdir,
 598         .open           = hppfs_dir_open,
 599         .fsync          = hppfs_fsync,
 600 };
 601
 602 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
 603 {
 604         sf->f_blocks = 0;
 605         sf->f_bfree = 0;
 606         sf->f_bavail = 0;
 607         sf->f_files = 0;
 608         sf->f_ffree = 0;
 609         sf->f_type = HPPFS_SUPER_MAGIC;
 610         return 0;
 611 }
 612
 613 static struct inode *hppfs_alloc_inode(struct super_block *sb)
 614 {
 615         struct hppfs_inode_info *hi;
 616
 617         hi = kmalloc(sizeof(*hi), GFP_KERNEL);
 618         if (!hi)
 619                 return NULL;
 620
 621         hi->proc_dentry = NULL;
 622         inode_init_once(&hi->vfs_inode);
 623         return &hi->vfs_inode;
 624 }
 625
 626 void hppfs_evict_inode(struct inode *ino)
 627 {
 628         end_writeback(ino);
 629         dput(HPPFS_I(ino)->proc_dentry);
 630         mntput(ino->i_sb->s_fs_info);
 631 }
 632
 633 static void hppfs_destroy_inode(struct inode *inode)
 634 {
 635         kfree(HPPFS_I(inode));
 636 }
 637
 638 static const struct super_operations hppfs_sbops = {
 639         .alloc_inode    = hppfs_alloc_inode,
 640         .destroy_inode  = hppfs_destroy_inode,
 641         .evict_inode    = hppfs_evict_inode,
 642         .statfs         = hppfs_statfs,
 643 };
 644
 645 static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
 646                           int buflen)
 647 {
 648         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 649         return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer,
 650                                                     buflen);
 651 }
 652
 653 static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 654 {
 655         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 656
 657         return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
 658 }
 659
 660 static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
 661                            void *cookie)
 662 {
 663         struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
 664
 665         if (proc_dentry->d_inode->i_op->put_link)
 666                 proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie);
 667 }
 668
 669 static const struct inode_operations hppfs_dir_iops = {
 670         .lookup         = hppfs_lookup,
 671 };
 672
 673 static const struct inode_operations hppfs_link_iops = {
 674         .readlink       = hppfs_readlink,
 675         .follow_link    = hppfs_follow_link,
 676         .put_link       = hppfs_put_link,
 677 };
 678
 679 static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
 680 {
 681         struct inode *proc_ino = dentry->d_inode;
 682         struct inode *inode = new_inode(sb);
 683
 684         if (!inode)
 685                 return ERR_PTR(-ENOMEM);
 686
 687         if (S_ISDIR(dentry->d_inode->i_mode)) {
 688                 inode->i_op = &hppfs_dir_iops;
 689                 inode->i_fop = &hppfs_dir_fops;
 690         } else if (S_ISLNK(dentry->d_inode->i_mode)) {
 691                 inode->i_op = &hppfs_link_iops;
 692                 inode->i_fop = &hppfs_file_fops;
 693         } else {
 694                 inode->i_op = &hppfs_file_iops;
 695                 inode->i_fop = &hppfs_file_fops;
 696         }
 697
 698         HPPFS_I(inode)->proc_dentry = dget(dentry);
 699
 700         inode->i_uid = proc_ino->i_uid;
 701         inode->i_gid = proc_ino->i_gid;
 702         inode->i_atime = proc_ino->i_atime;
 703         inode->i_mtime = proc_ino->i_mtime;
 704         inode->i_ctime = proc_ino->i_ctime;
 705         inode->i_ino = proc_ino->i_ino;
 706         inode->i_mode = proc_ino->i_mode;
 707         inode->i_nlink = proc_ino->i_nlink;
 708         inode->i_size = proc_ino->i_size;
 709         inode->i_blocks = proc_ino->i_blocks;
 710
 711         return inode;
 712 }
 713
 714 static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
 715 {
 716         struct inode *root_inode;
 717         struct vfsmount *proc_mnt;
 718         int err = -ENOENT;
 719
 720         proc_mnt = mntget(current->nsproxy->pid_ns->proc_mnt);
 721         if (IS_ERR(proc_mnt))
 722                 goto out;
 723
 724         sb->s_blocksize = 1024;
 725         sb->s_blocksize_bits = 10;
 726         sb->s_magic = HPPFS_SUPER_MAGIC;
 727         sb->s_op = &hppfs_sbops;
 728         sb->s_fs_info = proc_mnt;
 729
 730         err = -ENOMEM;
 731         root_inode = get_inode(sb, proc_mnt->mnt_sb->s_root);
 732         if (!root_inode)
 733                 goto out_mntput;
 734
 735         sb->s_root = d_alloc_root(root_inode);
 736         if (!sb->s_root)
 737                 goto out_iput;
 738
 739         return 0;
 740
 741  out_iput:
 742         iput(root_inode);
 743  out_mntput:
 744         mntput(proc_mnt);
 745  out:
 746         return(err);
 747 }
 748
 749 static int hppfs_read_super(struct file_system_type *type,
 750                             int flags, const char *dev_name,
 751                             void *data, struct vfsmount *mnt)
 752 {
 753         return get_sb_nodev(type, flags, data, hppfs_fill_super, mnt);
 754 }
 755
 756 static struct file_system_type hppfs_type = {
 757         .owner          = THIS_MODULE,
 758         .name           = "hppfs",
 759         .get_sb         = hppfs_read_super,
 760         .kill_sb        = kill_anon_super,
 761         .fs_flags       = 0,
 762 };
 763
 764 static int __init init_hppfs(void)
 765 {
 766         return register_filesystem(&hppfs_type);
 767 }
 768
 769 static void __exit exit_hppfs(void)
 770 {
 771         unregister_filesystem(&hppfs_type);
 772 }
 773
 774 module_init(init_hppfs)
 775 module_exit(exit_hppfs)
 776 MODULE_LICENSE("GPL");