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   1 /*
   2  * net/sunrpc/rpc_pipe.c
   3  *
   4  * Userland/kernel interface for rpcauth_gss.
   5  * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
   6  * and fs/sysfs/inode.c
   7  *
   8  * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
   9  *
  10  */
  11 #include <linux/config.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/string.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/dnotify.h>
  19 #include <linux/kernel.h>
  20
  21 #include <asm/ioctls.h>
  22 #include <linux/fs.h>
  23 #include <linux/poll.h>
  24 #include <linux/wait.h>
  25 #include <linux/seq_file.h>
  26
  27 #include <linux/sunrpc/clnt.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/sunrpc/rpc_pipe_fs.h>
  30
  31 static struct vfsmount *rpc_mount __read_mostly;
  32 static int rpc_mount_count;
  33
  34 static struct file_system_type rpc_pipe_fs_type;
  35
  36
  37 static kmem_cache_t *rpc_inode_cachep __read_mostly;
  38
  39 #define RPC_UPCALL_TIMEOUT (30*HZ)
  40
  41 static void
  42 __rpc_purge_upcall(struct inode *inode, int err)
  43 {
  44         struct rpc_inode *rpci = RPC_I(inode);
  45         struct rpc_pipe_msg *msg;
  46
  47         while (!list_empty(&rpci->pipe)) {
  48                 msg = list_entry(rpci->pipe.next, struct rpc_pipe_msg, list);
  49                 list_del_init(&msg->list);
  50                 msg->errno = err;
  51                 rpci->ops->destroy_msg(msg);
  52         }
  53         while (!list_empty(&rpci->in_upcall)) {
  54                 msg = list_entry(rpci->pipe.next, struct rpc_pipe_msg, list);
  55                 list_del_init(&msg->list);
  56                 msg->errno = err;
  57                 rpci->ops->destroy_msg(msg);
  58         }
  59         rpci->pipelen = 0;
  60         wake_up(&rpci->waitq);
  61 }
  62
  63 static void
  64 rpc_timeout_upcall_queue(void *data)
  65 {
  66         struct rpc_inode *rpci = (struct rpc_inode *)data;
  67         struct inode *inode = &rpci->vfs_inode;
  68
  69         down(&inode->i_sem);
  70         if (rpci->nreaders == 0 && !list_empty(&rpci->pipe))
  71                 __rpc_purge_upcall(inode, -ETIMEDOUT);
  72         up(&inode->i_sem);
  73 }
  74
  75 int
  76 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
  77 {
  78         struct rpc_inode *rpci = RPC_I(inode);
  79         int res = 0;
  80
  81         down(&inode->i_sem);
  82         if (rpci->nreaders) {
  83                 list_add_tail(&msg->list, &rpci->pipe);
  84                 rpci->pipelen += msg->len;
  85         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
  86                 if (list_empty(&rpci->pipe))
  87                         schedule_delayed_work(&rpci->queue_timeout,
  88                                         RPC_UPCALL_TIMEOUT);
  89                 list_add_tail(&msg->list, &rpci->pipe);
  90                 rpci->pipelen += msg->len;
  91         } else
  92                 res = -EPIPE;
  93         up(&inode->i_sem);
  94         wake_up(&rpci->waitq);
  95         return res;
  96 }
  97
  98 static void
  99 rpc_close_pipes(struct inode *inode)
 100 {
 101         struct rpc_inode *rpci = RPC_I(inode);
 102
 103         cancel_delayed_work(&rpci->queue_timeout);
 104         flush_scheduled_work();
 105         down(&inode->i_sem);
 106         if (rpci->ops != NULL) {
 107                 rpci->nreaders = 0;
 108                 __rpc_purge_upcall(inode, -EPIPE);
 109                 rpci->nwriters = 0;
 110                 if (rpci->ops->release_pipe)
 111                         rpci->ops->release_pipe(inode);
 112                 rpci->ops = NULL;
 113         }
 114         up(&inode->i_sem);
 115 }
 116
 117 static inline void
 118 rpc_inode_setowner(struct inode *inode, void *private)
 119 {
 120         RPC_I(inode)->private = private;
 121 }
 122
 123 static struct inode *
 124 rpc_alloc_inode(struct super_block *sb)
 125 {
 126         struct rpc_inode *rpci;
 127         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, SLAB_KERNEL);
 128         if (!rpci)
 129                 return NULL;
 130         return &rpci->vfs_inode;
 131 }
 132
 133 static void
 134 rpc_destroy_inode(struct inode *inode)
 135 {
 136         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 137 }
 138
 139 static int
 140 rpc_pipe_open(struct inode *inode, struct file *filp)
 141 {
 142         struct rpc_inode *rpci = RPC_I(inode);
 143         int res = -ENXIO;
 144
 145         down(&inode->i_sem);
 146         if (rpci->ops != NULL) {
 147                 if (filp->f_mode & FMODE_READ)
 148                         rpci->nreaders ++;
 149                 if (filp->f_mode & FMODE_WRITE)
 150                         rpci->nwriters ++;
 151                 res = 0;
 152         }
 153         up(&inode->i_sem);
 154         return res;
 155 }
 156
 157 static int
 158 rpc_pipe_release(struct inode *inode, struct file *filp)
 159 {
 160         struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
 161         struct rpc_pipe_msg *msg;
 162
 163         down(&inode->i_sem);
 164         if (rpci->ops == NULL)
 165                 goto out;
 166         msg = (struct rpc_pipe_msg *)filp->private_data;
 167         if (msg != NULL) {
 168                 msg->errno = -EPIPE;
 169                 list_del_init(&msg->list);
 170                 rpci->ops->destroy_msg(msg);
 171         }
 172         if (filp->f_mode & FMODE_WRITE)
 173                 rpci->nwriters --;
 174         if (filp->f_mode & FMODE_READ)
 175                 rpci->nreaders --;
 176         if (!rpci->nreaders)
 177                 __rpc_purge_upcall(inode, -EPIPE);
 178         if (rpci->ops->release_pipe)
 179                 rpci->ops->release_pipe(inode);
 180 out:
 181         up(&inode->i_sem);
 182         return 0;
 183 }
 184
 185 static ssize_t
 186 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 187 {
 188         struct inode *inode = filp->f_dentry->d_inode;
 189         struct rpc_inode *rpci = RPC_I(inode);
 190         struct rpc_pipe_msg *msg;
 191         int res = 0;
 192
 193         down(&inode->i_sem);
 194         if (rpci->ops == NULL) {
 195                 res = -EPIPE;
 196                 goto out_unlock;
 197         }
 198         msg = filp->private_data;
 199         if (msg == NULL) {
 200                 if (!list_empty(&rpci->pipe)) {
 201                         msg = list_entry(rpci->pipe.next,
 202                                         struct rpc_pipe_msg,
 203                                         list);
 204                         list_move(&msg->list, &rpci->in_upcall);
 205                         rpci->pipelen -= msg->len;
 206                         filp->private_data = msg;
 207                         msg->copied = 0;
 208                 }
 209                 if (msg == NULL)
 210                         goto out_unlock;
 211         }
 212         /* NOTE: it is up to the callback to update msg->copied */
 213         res = rpci->ops->upcall(filp, msg, buf, len);
 214         if (res < 0 || msg->len == msg->copied) {
 215                 filp->private_data = NULL;
 216                 list_del_init(&msg->list);
 217                 rpci->ops->destroy_msg(msg);
 218         }
 219 out_unlock:
 220         up(&inode->i_sem);
 221         return res;
 222 }
 223
 224 static ssize_t
 225 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 226 {
 227         struct inode *inode = filp->f_dentry->d_inode;
 228         struct rpc_inode *rpci = RPC_I(inode);
 229         int res;
 230
 231         down(&inode->i_sem);
 232         res = -EPIPE;
 233         if (rpci->ops != NULL)
 234                 res = rpci->ops->downcall(filp, buf, len);
 235         up(&inode->i_sem);
 236         return res;
 237 }
 238
 239 static unsigned int
 240 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 241 {
 242         struct rpc_inode *rpci;
 243         unsigned int mask = 0;
 244
 245         rpci = RPC_I(filp->f_dentry->d_inode);
 246         poll_wait(filp, &rpci->waitq, wait);
 247
 248         mask = POLLOUT | POLLWRNORM;
 249         if (rpci->ops == NULL)
 250                 mask |= POLLERR | POLLHUP;
 251         if (!list_empty(&rpci->pipe))
 252                 mask |= POLLIN | POLLRDNORM;
 253         return mask;
 254 }
 255
 256 static int
 257 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
 258                 unsigned int cmd, unsigned long arg)
 259 {
 260         struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
 261         int len;
 262
 263         switch (cmd) {
 264         case FIONREAD:
 265                 if (rpci->ops == NULL)
 266                         return -EPIPE;
 267                 len = rpci->pipelen;
 268                 if (filp->private_data) {
 269                         struct rpc_pipe_msg *msg;
 270                         msg = (struct rpc_pipe_msg *)filp->private_data;
 271                         len += msg->len - msg->copied;
 272                 }
 273                 return put_user(len, (int __user *)arg);
 274         default:
 275                 return -EINVAL;
 276         }
 277 }
 278
 279 static struct file_operations rpc_pipe_fops = {
 280         .owner          = THIS_MODULE,
 281         .llseek         = no_llseek,
 282         .read           = rpc_pipe_read,
 283         .write          = rpc_pipe_write,
 284         .poll           = rpc_pipe_poll,
 285         .ioctl          = rpc_pipe_ioctl,
 286         .open           = rpc_pipe_open,
 287         .release        = rpc_pipe_release,
 288 };
 289
 290 static int
 291 rpc_show_info(struct seq_file *m, void *v)
 292 {
 293         struct rpc_clnt *clnt = m->private;
 294
 295         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
 296         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
 297                         clnt->cl_prog, clnt->cl_vers);
 298         seq_printf(m, "address: %u.%u.%u.%u\n",
 299                         NIPQUAD(clnt->cl_xprt->addr.sin_addr.s_addr));
 300         seq_printf(m, "protocol: %s\n",
 301                         clnt->cl_xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
 302         return 0;
 303 }
 304
 305 static int
 306 rpc_info_open(struct inode *inode, struct file *file)
 307 {
 308         struct rpc_clnt *clnt;
 309         int ret = single_open(file, rpc_show_info, NULL);
 310
 311         if (!ret) {
 312                 struct seq_file *m = file->private_data;
 313                 down(&inode->i_sem);
 314                 clnt = RPC_I(inode)->private;
 315                 if (clnt) {
 316                         atomic_inc(&clnt->cl_users);
 317                         m->private = clnt;
 318                 } else {
 319                         single_release(inode, file);
 320                         ret = -EINVAL;
 321                 }
 322                 up(&inode->i_sem);
 323         }
 324         return ret;
 325 }
 326
 327 static int
 328 rpc_info_release(struct inode *inode, struct file *file)
 329 {
 330         struct seq_file *m = file->private_data;
 331         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 332
 333         if (clnt)
 334                 rpc_release_client(clnt);
 335         return single_release(inode, file);
 336 }
 337
 338 static struct file_operations rpc_info_operations = {
 339         .owner          = THIS_MODULE,
 340         .open           = rpc_info_open,
 341         .read           = seq_read,
 342         .llseek         = seq_lseek,
 343         .release        = rpc_info_release,
 344 };
 345
 346
 347 /*
 348  * We have a single directory with 1 node in it.
 349  */
 350 enum {
 351         RPCAUTH_Root = 1,
 352         RPCAUTH_lockd,
 353         RPCAUTH_mount,
 354         RPCAUTH_nfs,
 355         RPCAUTH_portmap,
 356         RPCAUTH_statd,
 357         RPCAUTH_RootEOF
 358 };
 359
 360 /*
 361  * Description of fs contents.
 362  */
 363 struct rpc_filelist {
 364         char *name;
 365         struct file_operations *i_fop;
 366         int mode;
 367 };
 368
 369 static struct rpc_filelist files[] = {
 370         [RPCAUTH_lockd] = {
 371                 .name = "lockd",
 372                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 373         },
 374         [RPCAUTH_mount] = {
 375                 .name = "mount",
 376                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 377         },
 378         [RPCAUTH_nfs] = {
 379                 .name = "nfs",
 380                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 381         },
 382         [RPCAUTH_portmap] = {
 383                 .name = "portmap",
 384                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 385         },
 386         [RPCAUTH_statd] = {
 387                 .name = "statd",
 388                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 389         },
 390 };
 391
 392 enum {
 393         RPCAUTH_info = 2,
 394         RPCAUTH_EOF
 395 };
 396
 397 static struct rpc_filelist authfiles[] = {
 398         [RPCAUTH_info] = {
 399                 .name = "info",
 400                 .i_fop = &rpc_info_operations,
 401                 .mode = S_IFREG | S_IRUSR,
 402         },
 403 };
 404
 405 static int
 406 rpc_get_mount(void)
 407 {
 408         return simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
 409 }
 410
 411 static void
 412 rpc_put_mount(void)
 413 {
 414         simple_release_fs(&rpc_mount, &rpc_mount_count);
 415 }
 416
 417 static struct inode *
 418 rpc_get_inode(struct super_block *sb, int mode)
 419 {
 420         struct inode *inode = new_inode(sb);
 421         if (!inode)
 422                 return NULL;
 423         inode->i_mode = mode;
 424         inode->i_uid = inode->i_gid = 0;
 425         inode->i_blksize = PAGE_CACHE_SIZE;
 426         inode->i_blocks = 0;
 427         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 428         switch(mode & S_IFMT) {
 429                 case S_IFDIR:
 430                         inode->i_fop = &simple_dir_operations;
 431                         inode->i_op = &simple_dir_inode_operations;
 432                         inode->i_nlink++;
 433                 default:
 434                         break;
 435         }
 436         return inode;
 437 }
 438
 439 /*
 440  * FIXME: This probably has races.
 441  */
 442 static void
 443 rpc_depopulate(struct dentry *parent)
 444 {
 445         struct inode *dir = parent->d_inode;
 446         struct list_head *pos, *next;
 447         struct dentry *dentry, *dvec[10];
 448         int n = 0;
 449
 450         down(&dir->i_sem);
 451 repeat:
 452         spin_lock(&dcache_lock);
 453         list_for_each_safe(pos, next, &parent->d_subdirs) {
 454                 dentry = list_entry(pos, struct dentry, d_child);
 455                 spin_lock(&dentry->d_lock);
 456                 if (!d_unhashed(dentry)) {
 457                         dget_locked(dentry);
 458                         __d_drop(dentry);
 459                         spin_unlock(&dentry->d_lock);
 460                         dvec[n++] = dentry;
 461                         if (n == ARRAY_SIZE(dvec))
 462                                 break;
 463                 } else
 464                         spin_unlock(&dentry->d_lock);
 465         }
 466         spin_unlock(&dcache_lock);
 467         if (n) {
 468                 do {
 469                         dentry = dvec[--n];
 470                         if (dentry->d_inode) {
 471                                 rpc_close_pipes(dentry->d_inode);
 472                                 rpc_inode_setowner(dentry->d_inode, NULL);
 473                                 simple_unlink(dir, dentry);
 474                         }
 475                         dput(dentry);
 476                 } while (n);
 477                 goto repeat;
 478         }
 479         up(&dir->i_sem);
 480 }
 481
 482 static int
 483 rpc_populate(struct dentry *parent,
 484                 struct rpc_filelist *files,
 485                 int start, int eof)
 486 {
 487         struct inode *inode, *dir = parent->d_inode;
 488         void *private = RPC_I(dir)->private;
 489         struct dentry *dentry;
 490         int mode, i;
 491
 492         down(&dir->i_sem);
 493         for (i = start; i < eof; i++) {
 494                 dentry = d_alloc_name(parent, files[i].name);
 495                 if (!dentry)
 496                         goto out_bad;
 497                 mode = files[i].mode;
 498                 inode = rpc_get_inode(dir->i_sb, mode);
 499                 if (!inode) {
 500                         dput(dentry);
 501                         goto out_bad;
 502                 }
 503                 inode->i_ino = i;
 504                 if (files[i].i_fop)
 505                         inode->i_fop = files[i].i_fop;
 506                 if (private)
 507                         rpc_inode_setowner(inode, private);
 508                 if (S_ISDIR(mode))
 509                         dir->i_nlink++;
 510                 d_add(dentry, inode);
 511         }
 512         up(&dir->i_sem);
 513         return 0;
 514 out_bad:
 515         up(&dir->i_sem);
 516         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 517                         __FILE__, __FUNCTION__, parent->d_name.name);
 518         return -ENOMEM;
 519 }
 520
 521 struct dentry *
 522 rpc_mkdir(struct dentry *parent, char *name, struct rpc_clnt *rpc_client)
 523 {
 524         struct inode *dir;
 525         struct dentry *dentry;
 526         struct inode *inode;
 527         int error;
 528
 529         if (!parent)
 530                 parent = rpc_mount->mnt_root;
 531
 532         dir = parent->d_inode;
 533
 534         error = rpc_get_mount();
 535         if (error)
 536                 return ERR_PTR(error);
 537
 538         down(&dir->i_sem);
 539         dentry = lookup_one_len(name, parent, strlen(name));
 540         if (IS_ERR(dentry))
 541                 goto out_unlock;
 542         if (dentry->d_inode) {
 543                 dentry = ERR_PTR(-EEXIST);
 544                 goto out_dput;
 545         }
 546
 547         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
 548         if (!inode)
 549                 goto out_dput;
 550         inode->i_ino = iunique(dir->i_sb, 100);
 551         dir->i_nlink++;
 552         RPC_I(dentry->d_inode)->private = rpc_client;
 553
 554         d_instantiate(dentry, inode);
 555         dget(dentry);
 556         up(&dir->i_sem);
 557
 558         inode_dir_notify(dir, DN_CREATE);
 559
 560         error = rpc_populate(dentry, authfiles,
 561                         RPCAUTH_info, RPCAUTH_EOF);
 562         if (error)
 563                 goto out_depopulate;
 564
 565         return dentry;
 566
 567  out_depopulate:
 568         rpc_rmdir(dentry);
 569  out_dput:
 570         dput(dentry);
 571  out_unlock:
 572         up(&dir->i_sem);
 573         rpc_put_mount();
 574         return dentry;
 575 }
 576
 577 void
 578 rpc_rmdir(struct dentry *dentry)
 579 {
 580         struct dentry *parent = dentry->d_parent;
 581
 582         rpc_depopulate(dentry);
 583
 584         down(&parent->d_inode->i_sem);
 585         if (dentry->d_inode) {
 586                 rpc_close_pipes(dentry->d_inode);
 587                 rpc_inode_setowner(dentry->d_inode, NULL);
 588                 simple_rmdir(parent->d_inode, dentry);
 589         }
 590         up(&parent->d_inode->i_sem);
 591
 592         inode_dir_notify(parent->d_inode, DN_DELETE);
 593         rpc_put_mount();
 594 }
 595
 596 struct dentry *
 597 rpc_mkpipe(struct dentry *parent, char *name, void *private,
 598            struct rpc_pipe_ops *ops, int flags)
 599 {
 600         struct inode *dir = parent->d_inode;
 601         struct dentry *dentry;
 602         struct inode *inode;
 603         struct rpc_inode *rpci;
 604         int error;
 605
 606         error = rpc_get_mount();
 607         if (error)
 608                 return ERR_PTR(error);
 609
 610         down(&parent->d_inode->i_sem);
 611         dentry = lookup_one_len(name, parent, strlen(name));
 612         if (IS_ERR(dentry))
 613                 goto out_unlock;
 614         if (dentry->d_inode) {
 615                 dentry = ERR_PTR(-EEXIST);
 616                 goto out_dput;
 617         }
 618
 619         inode = rpc_get_inode(parent->d_inode->i_sb,
 620                         S_IFSOCK | S_IRUSR | S_IWUSR);
 621         if (!inode) {
 622                 dentry = ERR_PTR(-ENOMEM);
 623                 goto out_dput;
 624         }
 625
 626         inode->i_ino = iunique(dir->i_sb, 100);
 627         inode->i_fop = &rpc_pipe_fops;
 628
 629         rpci = RPC_I(inode);
 630         rpci->private = private;
 631         rpci->flags = flags;
 632         rpci->ops = ops;
 633
 634         d_instantiate(dentry, inode);
 635         dget(dentry);
 636         up(&parent->d_inode->i_sem);
 637
 638         inode_dir_notify(dir, DN_CREATE);
 639         return dentry;
 640
 641  out_dput:
 642         dput(dentry);
 643  out_unlock:
 644         up(&parent->d_inode->i_sem);
 645         rpc_put_mount();
 646         return dentry;
 647 }
 648
 649 void
 650 rpc_unlink(struct dentry *dentry)
 651 {
 652         struct dentry *parent = dentry->d_parent;
 653
 654         down(&parent->d_inode->i_sem);
 655         if (dentry->d_inode) {
 656                 rpc_close_pipes(dentry->d_inode);
 657                 rpc_inode_setowner(dentry->d_inode, NULL);
 658                 simple_unlink(parent->d_inode, dentry);
 659         }
 660         up(&parent->d_inode->i_sem);
 661
 662         inode_dir_notify(parent->d_inode, DN_DELETE);
 663         rpc_put_mount();
 664 }
 665
 666 /*
 667  * populate the filesystem
 668  */
 669 static struct super_operations s_ops = {
 670         .alloc_inode    = rpc_alloc_inode,
 671         .destroy_inode  = rpc_destroy_inode,
 672         .statfs         = simple_statfs,
 673 };
 674
 675 #define RPCAUTH_GSSMAGIC 0x67596969
 676
 677 static int
 678 rpc_fill_super(struct super_block *sb, void *data, int silent)
 679 {
 680         struct inode *inode;
 681         struct dentry *root;
 682
 683         sb->s_blocksize = PAGE_CACHE_SIZE;
 684         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 685         sb->s_magic = RPCAUTH_GSSMAGIC;
 686         sb->s_op = &s_ops;
 687         sb->s_time_gran = 1;
 688
 689         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 690         if (!inode)
 691                 return -ENOMEM;
 692         root = d_alloc_root(inode);
 693         if (!root) {
 694                 iput(inode);
 695                 return -ENOMEM;
 696         }
 697         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 698                 goto out;
 699         sb->s_root = root;
 700         return 0;
 701 out:
 702         d_genocide(root);
 703         dput(root);
 704         return -ENOMEM;
 705 }
 706
 707 static struct super_block *
 708 rpc_get_sb(struct file_system_type *fs_type,
 709                 int flags, const char *dev_name, void *data)
 710 {
 711         return get_sb_single(fs_type, flags, data, rpc_fill_super);
 712 }
 713
 714 static struct file_system_type rpc_pipe_fs_type = {
 715         .owner          = THIS_MODULE,
 716         .name           = "rpc_pipefs",
 717         .get_sb         = rpc_get_sb,
 718         .kill_sb        = kill_litter_super,
 719 };
 720
 721 static void
 722 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 723 {
 724         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 725
 726         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 727             SLAB_CTOR_CONSTRUCTOR) {
 728                 inode_init_once(&rpci->vfs_inode);
 729                 rpci->private = NULL;
 730                 rpci->nreaders = 0;
 731                 rpci->nwriters = 0;
 732                 INIT_LIST_HEAD(&rpci->in_upcall);
 733                 INIT_LIST_HEAD(&rpci->pipe);
 734                 rpci->pipelen = 0;
 735                 init_waitqueue_head(&rpci->waitq);
 736                 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
 737                 rpci->ops = NULL;
 738         }
 739 }
 740
 741 int register_rpc_pipefs(void)
 742 {
 743         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 744                                              sizeof(struct rpc_inode),
 745                                              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
 746                                              init_once, NULL);
 747         if (!rpc_inode_cachep)
 748                 return -ENOMEM;
 749         register_filesystem(&rpc_pipe_fs_type);
 750         return 0;
 751 }
 752
 753 void unregister_rpc_pipefs(void)
 754 {
 755         if (kmem_cache_destroy(rpc_inode_cachep))
 756                 printk(KERN_WARNING "RPC: unable to free inode cache\n");
 757         unregister_filesystem(&rpc_pipe_fs_type);
 758 }