net/sunrpc/rpc_pipe.c

   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/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/string.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/mount.h>
  16 #include <linux/namei.h>
  17 #include <linux/fsnotify.h>
  18 #include <linux/kernel.h>
  19
  20 #include <asm/ioctls.h>
  21 #include <linux/fs.h>
  22 #include <linux/poll.h>
  23 #include <linux/wait.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/sunrpc/rpc_pipe_fs.h>
  29
  30 static struct vfsmount *rpc_mount __read_mostly;
  31 static int rpc_mount_count;
  32
  33 static struct file_system_type rpc_pipe_fs_type;
  34
  35
  36 static struct kmem_cache *rpc_inode_cachep __read_mostly;
  37
  38 #define RPC_UPCALL_TIMEOUT (30*HZ)
  39
  40 static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
  41                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  42 {
  43         struct rpc_pipe_msg *msg;
  44
  45         if (list_empty(head))
  46                 return;
  47         do {
  48                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  49                 list_del(&msg->list);
  50                 msg->errno = err;
  51                 destroy_msg(msg);
  52         } while (!list_empty(head));
  53         wake_up(&rpci->waitq);
  54 }
  55
  56 static void
  57 rpc_timeout_upcall_queue(struct work_struct *work)
  58 {
  59         LIST_HEAD(free_list);
  60         struct rpc_inode *rpci =
  61                 container_of(work, struct rpc_inode, queue_timeout.work);
  62         struct inode *inode = &rpci->vfs_inode;
  63         void (*destroy_msg)(struct rpc_pipe_msg *);
  64
  65         spin_lock(&inode->i_lock);
  66         if (rpci->ops == NULL) {
  67                 spin_unlock(&inode->i_lock);
  68                 return;
  69         }
  70         destroy_msg = rpci->ops->destroy_msg;
  71         if (rpci->nreaders == 0) {
  72                 list_splice_init(&rpci->pipe, &free_list);
  73                 rpci->pipelen = 0;
  74         }
  75         spin_unlock(&inode->i_lock);
  76         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
  77 }
  78
  79 int
  80 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
  81 {
  82         struct rpc_inode *rpci = RPC_I(inode);
  83         int res = -EPIPE;
  84
  85         spin_lock(&inode->i_lock);
  86         if (rpci->ops == NULL)
  87                 goto out;
  88         if (rpci->nreaders) {
  89                 list_add_tail(&msg->list, &rpci->pipe);
  90                 rpci->pipelen += msg->len;
  91                 res = 0;
  92         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
  93                 if (list_empty(&rpci->pipe))
  94                         queue_delayed_work(rpciod_workqueue,
  95                                         &rpci->queue_timeout,
  96                                         RPC_UPCALL_TIMEOUT);
  97                 list_add_tail(&msg->list, &rpci->pipe);
  98                 rpci->pipelen += msg->len;
  99                 res = 0;
 100         }
 101 out:
 102         spin_unlock(&inode->i_lock);
 103         wake_up(&rpci->waitq);
 104         return res;
 105 }
 106
 107 static inline void
 108 rpc_inode_setowner(struct inode *inode, void *private)
 109 {
 110         RPC_I(inode)->private = private;
 111 }
 112
 113 static void
 114 rpc_close_pipes(struct inode *inode)
 115 {
 116         struct rpc_inode *rpci = RPC_I(inode);
 117         struct rpc_pipe_ops *ops;
 118
 119         mutex_lock(&inode->i_mutex);
 120         ops = rpci->ops;
 121         if (ops != NULL) {
 122                 LIST_HEAD(free_list);
 123
 124                 spin_lock(&inode->i_lock);
 125                 rpci->nreaders = 0;
 126                 list_splice_init(&rpci->in_upcall, &free_list);
 127                 list_splice_init(&rpci->pipe, &free_list);
 128                 rpci->pipelen = 0;
 129                 rpci->ops = NULL;
 130                 spin_unlock(&inode->i_lock);
 131                 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
 132                 rpci->nwriters = 0;
 133                 if (ops->release_pipe)
 134                         ops->release_pipe(inode);
 135                 cancel_delayed_work_sync(&rpci->queue_timeout);
 136         }
 137         rpc_inode_setowner(inode, NULL);
 138         mutex_unlock(&inode->i_mutex);
 139 }
 140
 141 static struct inode *
 142 rpc_alloc_inode(struct super_block *sb)
 143 {
 144         struct rpc_inode *rpci;
 145         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 146         if (!rpci)
 147                 return NULL;
 148         return &rpci->vfs_inode;
 149 }
 150
 151 static void
 152 rpc_destroy_inode(struct inode *inode)
 153 {
 154         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 155 }
 156
 157 static int
 158 rpc_pipe_open(struct inode *inode, struct file *filp)
 159 {
 160         struct rpc_inode *rpci = RPC_I(inode);
 161         int res = -ENXIO;
 162
 163         mutex_lock(&inode->i_mutex);
 164         if (rpci->ops != NULL) {
 165                 if (filp->f_mode & FMODE_READ)
 166                         rpci->nreaders ++;
 167                 if (filp->f_mode & FMODE_WRITE)
 168                         rpci->nwriters ++;
 169                 res = 0;
 170         }
 171         mutex_unlock(&inode->i_mutex);
 172         return res;
 173 }
 174
 175 static int
 176 rpc_pipe_release(struct inode *inode, struct file *filp)
 177 {
 178         struct rpc_inode *rpci = RPC_I(inode);
 179         struct rpc_pipe_msg *msg;
 180
 181         mutex_lock(&inode->i_mutex);
 182         if (rpci->ops == NULL)
 183                 goto out;
 184         msg = (struct rpc_pipe_msg *)filp->private_data;
 185         if (msg != NULL) {
 186                 spin_lock(&inode->i_lock);
 187                 msg->errno = -EAGAIN;
 188                 list_del(&msg->list);
 189                 spin_unlock(&inode->i_lock);
 190                 rpci->ops->destroy_msg(msg);
 191         }
 192         if (filp->f_mode & FMODE_WRITE)
 193                 rpci->nwriters --;
 194         if (filp->f_mode & FMODE_READ) {
 195                 rpci->nreaders --;
 196                 if (rpci->nreaders == 0) {
 197                         LIST_HEAD(free_list);
 198                         spin_lock(&inode->i_lock);
 199                         list_splice_init(&rpci->pipe, &free_list);
 200                         rpci->pipelen = 0;
 201                         spin_unlock(&inode->i_lock);
 202                         rpc_purge_list(rpci, &free_list,
 203                                         rpci->ops->destroy_msg, -EAGAIN);
 204                 }
 205         }
 206         if (rpci->ops->release_pipe)
 207                 rpci->ops->release_pipe(inode);
 208 out:
 209         mutex_unlock(&inode->i_mutex);
 210         return 0;
 211 }
 212
 213 static ssize_t
 214 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 215 {
 216         struct inode *inode = filp->f_path.dentry->d_inode;
 217         struct rpc_inode *rpci = RPC_I(inode);
 218         struct rpc_pipe_msg *msg;
 219         int res = 0;
 220
 221         mutex_lock(&inode->i_mutex);
 222         if (rpci->ops == NULL) {
 223                 res = -EPIPE;
 224                 goto out_unlock;
 225         }
 226         msg = filp->private_data;
 227         if (msg == NULL) {
 228                 spin_lock(&inode->i_lock);
 229                 if (!list_empty(&rpci->pipe)) {
 230                         msg = list_entry(rpci->pipe.next,
 231                                         struct rpc_pipe_msg,
 232                                         list);
 233                         list_move(&msg->list, &rpci->in_upcall);
 234                         rpci->pipelen -= msg->len;
 235                         filp->private_data = msg;
 236                         msg->copied = 0;
 237                 }
 238                 spin_unlock(&inode->i_lock);
 239                 if (msg == NULL)
 240                         goto out_unlock;
 241         }
 242         /* NOTE: it is up to the callback to update msg->copied */
 243         res = rpci->ops->upcall(filp, msg, buf, len);
 244         if (res < 0 || msg->len == msg->copied) {
 245                 filp->private_data = NULL;
 246                 spin_lock(&inode->i_lock);
 247                 list_del(&msg->list);
 248                 spin_unlock(&inode->i_lock);
 249                 rpci->ops->destroy_msg(msg);
 250         }
 251 out_unlock:
 252         mutex_unlock(&inode->i_mutex);
 253         return res;
 254 }
 255
 256 static ssize_t
 257 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 258 {
 259         struct inode *inode = filp->f_path.dentry->d_inode;
 260         struct rpc_inode *rpci = RPC_I(inode);
 261         int res;
 262
 263         mutex_lock(&inode->i_mutex);
 264         res = -EPIPE;
 265         if (rpci->ops != NULL)
 266                 res = rpci->ops->downcall(filp, buf, len);
 267         mutex_unlock(&inode->i_mutex);
 268         return res;
 269 }
 270
 271 static unsigned int
 272 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 273 {
 274         struct rpc_inode *rpci;
 275         unsigned int mask = 0;
 276
 277         rpci = RPC_I(filp->f_path.dentry->d_inode);
 278         poll_wait(filp, &rpci->waitq, wait);
 279
 280         mask = POLLOUT | POLLWRNORM;
 281         if (rpci->ops == NULL)
 282                 mask |= POLLERR | POLLHUP;
 283         if (filp->private_data || !list_empty(&rpci->pipe))
 284                 mask |= POLLIN | POLLRDNORM;
 285         return mask;
 286 }
 287
 288 static int
 289 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
 290                 unsigned int cmd, unsigned long arg)
 291 {
 292         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 293         int len;
 294
 295         switch (cmd) {
 296         case FIONREAD:
 297                 if (rpci->ops == NULL)
 298                         return -EPIPE;
 299                 len = rpci->pipelen;
 300                 if (filp->private_data) {
 301                         struct rpc_pipe_msg *msg;
 302                         msg = (struct rpc_pipe_msg *)filp->private_data;
 303                         len += msg->len - msg->copied;
 304                 }
 305                 return put_user(len, (int __user *)arg);
 306         default:
 307                 return -EINVAL;
 308         }
 309 }
 310
 311 static const struct file_operations rpc_pipe_fops = {
 312         .owner          = THIS_MODULE,
 313         .llseek         = no_llseek,
 314         .read           = rpc_pipe_read,
 315         .write          = rpc_pipe_write,
 316         .poll           = rpc_pipe_poll,
 317         .ioctl          = rpc_pipe_ioctl,
 318         .open           = rpc_pipe_open,
 319         .release        = rpc_pipe_release,
 320 };
 321
 322 static int
 323 rpc_show_info(struct seq_file *m, void *v)
 324 {
 325         struct rpc_clnt *clnt = m->private;
 326
 327         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
 328         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
 329                         clnt->cl_prog, clnt->cl_vers);
 330         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 331         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 332         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 333         return 0;
 334 }
 335
 336 static int
 337 rpc_info_open(struct inode *inode, struct file *file)
 338 {
 339         struct rpc_clnt *clnt;
 340         int ret = single_open(file, rpc_show_info, NULL);
 341
 342         if (!ret) {
 343                 struct seq_file *m = file->private_data;
 344                 mutex_lock(&inode->i_mutex);
 345                 clnt = RPC_I(inode)->private;
 346                 if (clnt) {
 347                         kref_get(&clnt->cl_kref);
 348                         m->private = clnt;
 349                 } else {
 350                         single_release(inode, file);
 351                         ret = -EINVAL;
 352                 }
 353                 mutex_unlock(&inode->i_mutex);
 354         }
 355         return ret;
 356 }
 357
 358 static int
 359 rpc_info_release(struct inode *inode, struct file *file)
 360 {
 361         struct seq_file *m = file->private_data;
 362         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 363
 364         if (clnt)
 365                 rpc_release_client(clnt);
 366         return single_release(inode, file);
 367 }
 368
 369 static const struct file_operations rpc_info_operations = {
 370         .owner          = THIS_MODULE,
 371         .open           = rpc_info_open,
 372         .read           = seq_read,
 373         .llseek         = seq_lseek,
 374         .release        = rpc_info_release,
 375 };
 376
 377
 378 /*
 379  * We have a single directory with 1 node in it.
 380  */
 381 enum {
 382         RPCAUTH_Root = 1,
 383         RPCAUTH_lockd,
 384         RPCAUTH_mount,
 385         RPCAUTH_nfs,
 386         RPCAUTH_portmap,
 387         RPCAUTH_statd,
 388         RPCAUTH_RootEOF
 389 };
 390
 391 /*
 392  * Description of fs contents.
 393  */
 394 struct rpc_filelist {
 395         char *name;
 396         const struct file_operations *i_fop;
 397         int mode;
 398 };
 399
 400 static struct rpc_filelist files[] = {
 401         [RPCAUTH_lockd] = {
 402                 .name = "lockd",
 403                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 404         },
 405         [RPCAUTH_mount] = {
 406                 .name = "mount",
 407                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 408         },
 409         [RPCAUTH_nfs] = {
 410                 .name = "nfs",
 411                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 412         },
 413         [RPCAUTH_portmap] = {
 414                 .name = "portmap",
 415                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 416         },
 417         [RPCAUTH_statd] = {
 418                 .name = "statd",
 419                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 420         },
 421 };
 422
 423 enum {
 424         RPCAUTH_info = 2,
 425         RPCAUTH_EOF
 426 };
 427
 428 static struct rpc_filelist authfiles[] = {
 429         [RPCAUTH_info] = {
 430                 .name = "info",
 431                 .i_fop = &rpc_info_operations,
 432                 .mode = S_IFREG | S_IRUSR,
 433         },
 434 };
 435
 436 struct vfsmount *rpc_get_mount(void)
 437 {
 438         int err;
 439
 440         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
 441         if (err != 0)
 442                 return ERR_PTR(err);
 443         return rpc_mount;
 444 }
 445
 446 void rpc_put_mount(void)
 447 {
 448         simple_release_fs(&rpc_mount, &rpc_mount_count);
 449 }
 450
 451 static int rpc_delete_dentry(struct dentry *dentry)
 452 {
 453         return 1;
 454 }
 455
 456 static struct dentry_operations rpc_dentry_operations = {
 457         .d_delete = rpc_delete_dentry,
 458 };
 459
 460 static int
 461 rpc_lookup_parent(char *path, struct nameidata *nd)
 462 {
 463         struct vfsmount *mnt;
 464
 465         if (path[0] == '\0')
 466                 return -ENOENT;
 467
 468         mnt = rpc_get_mount();
 469         if (IS_ERR(mnt)) {
 470                 printk(KERN_WARNING "%s: %s failed to mount "
 471                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
 472                 return PTR_ERR(mnt);
 473         }
 474
 475         if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
 476                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
 477                                 __FILE__, __FUNCTION__, path);
 478                 rpc_put_mount();
 479                 return -ENOENT;
 480         }
 481         return 0;
 482 }
 483
 484 static void
 485 rpc_release_path(struct nameidata *nd)
 486 {
 487         path_release(nd);
 488         rpc_put_mount();
 489 }
 490
 491 static struct inode *
 492 rpc_get_inode(struct super_block *sb, int mode)
 493 {
 494         struct inode *inode = new_inode(sb);
 495         if (!inode)
 496                 return NULL;
 497         inode->i_mode = mode;
 498         inode->i_uid = inode->i_gid = 0;
 499         inode->i_blocks = 0;
 500         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 501         switch(mode & S_IFMT) {
 502                 case S_IFDIR:
 503                         inode->i_fop = &simple_dir_operations;
 504                         inode->i_op = &simple_dir_inode_operations;
 505                         inc_nlink(inode);
 506                 default:
 507                         break;
 508         }
 509         return inode;
 510 }
 511
 512 /*
 513  * FIXME: This probably has races.
 514  */
 515 static void
 516 rpc_depopulate(struct dentry *parent, int start, int eof)
 517 {
 518         struct inode *dir = parent->d_inode;
 519         struct list_head *pos, *next;
 520         struct dentry *dentry, *dvec[10];
 521         int n = 0;
 522
 523         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 524 repeat:
 525         spin_lock(&dcache_lock);
 526         list_for_each_safe(pos, next, &parent->d_subdirs) {
 527                 dentry = list_entry(pos, struct dentry, d_u.d_child);
 528                 if (!dentry->d_inode ||
 529                                 dentry->d_inode->i_ino < start ||
 530                                 dentry->d_inode->i_ino >= eof)
 531                         continue;
 532                 spin_lock(&dentry->d_lock);
 533                 if (!d_unhashed(dentry)) {
 534                         dget_locked(dentry);
 535                         __d_drop(dentry);
 536                         spin_unlock(&dentry->d_lock);
 537                         dvec[n++] = dentry;
 538                         if (n == ARRAY_SIZE(dvec))
 539                                 break;
 540                 } else
 541                         spin_unlock(&dentry->d_lock);
 542         }
 543         spin_unlock(&dcache_lock);
 544         if (n) {
 545                 do {
 546                         dentry = dvec[--n];
 547                         if (S_ISREG(dentry->d_inode->i_mode))
 548                                 simple_unlink(dir, dentry);
 549                         else if (S_ISDIR(dentry->d_inode->i_mode))
 550                                 simple_rmdir(dir, dentry);
 551                         d_delete(dentry);
 552                         dput(dentry);
 553                 } while (n);
 554                 goto repeat;
 555         }
 556         mutex_unlock(&dir->i_mutex);
 557 }
 558
 559 static int
 560 rpc_populate(struct dentry *parent,
 561                 struct rpc_filelist *files,
 562                 int start, int eof)
 563 {
 564         struct inode *inode, *dir = parent->d_inode;
 565         void *private = RPC_I(dir)->private;
 566         struct dentry *dentry;
 567         int mode, i;
 568
 569         mutex_lock(&dir->i_mutex);
 570         for (i = start; i < eof; i++) {
 571                 dentry = d_alloc_name(parent, files[i].name);
 572                 if (!dentry)
 573                         goto out_bad;
 574                 dentry->d_op = &rpc_dentry_operations;
 575                 mode = files[i].mode;
 576                 inode = rpc_get_inode(dir->i_sb, mode);
 577                 if (!inode) {
 578                         dput(dentry);
 579                         goto out_bad;
 580                 }
 581                 inode->i_ino = i;
 582                 if (files[i].i_fop)
 583                         inode->i_fop = files[i].i_fop;
 584                 if (private)
 585                         rpc_inode_setowner(inode, private);
 586                 if (S_ISDIR(mode))
 587                         inc_nlink(dir);
 588                 d_add(dentry, inode);
 589                 fsnotify_create(dir, dentry);
 590         }
 591         mutex_unlock(&dir->i_mutex);
 592         return 0;
 593 out_bad:
 594         mutex_unlock(&dir->i_mutex);
 595         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 596                         __FILE__, __FUNCTION__, parent->d_name.name);
 597         return -ENOMEM;
 598 }
 599
 600 static int
 601 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 602 {
 603         struct inode *inode;
 604
 605         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
 606         if (!inode)
 607                 goto out_err;
 608         inode->i_ino = iunique(dir->i_sb, 100);
 609         d_instantiate(dentry, inode);
 610         inc_nlink(dir);
 611         fsnotify_mkdir(dir, dentry);
 612         return 0;
 613 out_err:
 614         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 615                         __FILE__, __FUNCTION__, dentry->d_name.name);
 616         return -ENOMEM;
 617 }
 618
 619 static int
 620 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 621 {
 622         int error;
 623         error = simple_rmdir(dir, dentry);
 624         if (!error)
 625                 d_delete(dentry);
 626         return error;
 627 }
 628
 629 static struct dentry *
 630 rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
 631 {
 632         struct inode *dir = parent->d_inode;
 633         struct dentry *dentry;
 634
 635         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 636         dentry = lookup_one_len(name, parent, len);
 637         if (IS_ERR(dentry))
 638                 goto out_err;
 639         if (!dentry->d_inode)
 640                 dentry->d_op = &rpc_dentry_operations;
 641         else if (exclusive) {
 642                 dput(dentry);
 643                 dentry = ERR_PTR(-EEXIST);
 644                 goto out_err;
 645         }
 646         return dentry;
 647 out_err:
 648         mutex_unlock(&dir->i_mutex);
 649         return dentry;
 650 }
 651
 652 static struct dentry *
 653 rpc_lookup_negative(char *path, struct nameidata *nd)
 654 {
 655         struct dentry *dentry;
 656         int error;
 657
 658         if ((error = rpc_lookup_parent(path, nd)) != 0)
 659                 return ERR_PTR(error);
 660         dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1);
 661         if (IS_ERR(dentry))
 662                 rpc_release_path(nd);
 663         return dentry;
 664 }
 665
 666
 667 struct dentry *
 668 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 669 {
 670         struct nameidata nd;
 671         struct dentry *dentry;
 672         struct inode *dir;
 673         int error;
 674
 675         dentry = rpc_lookup_negative(path, &nd);
 676         if (IS_ERR(dentry))
 677                 return dentry;
 678         dir = nd.dentry->d_inode;
 679         if ((error = __rpc_mkdir(dir, dentry)) != 0)
 680                 goto err_dput;
 681         RPC_I(dentry->d_inode)->private = rpc_client;
 682         error = rpc_populate(dentry, authfiles,
 683                         RPCAUTH_info, RPCAUTH_EOF);
 684         if (error)
 685                 goto err_depopulate;
 686         dget(dentry);
 687 out:
 688         mutex_unlock(&dir->i_mutex);
 689         rpc_release_path(&nd);
 690         return dentry;
 691 err_depopulate:
 692         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 693         __rpc_rmdir(dir, dentry);
 694 err_dput:
 695         dput(dentry);
 696         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
 697                         __FILE__, __FUNCTION__, path, error);
 698         dentry = ERR_PTR(error);
 699         goto out;
 700 }
 701
 702 int
 703 rpc_rmdir(struct dentry *dentry)
 704 {
 705         struct dentry *parent;
 706         struct inode *dir;
 707         int error;
 708
 709         parent = dget_parent(dentry);
 710         dir = parent->d_inode;
 711         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 712         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 713         error = __rpc_rmdir(dir, dentry);
 714         dput(dentry);
 715         mutex_unlock(&dir->i_mutex);
 716         dput(parent);
 717         return error;
 718 }
 719
 720 struct dentry *
 721 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
 722 {
 723         struct dentry *dentry;
 724         struct inode *dir, *inode;
 725         struct rpc_inode *rpci;
 726
 727         dentry = rpc_lookup_create(parent, name, strlen(name), 0);
 728         if (IS_ERR(dentry))
 729                 return dentry;
 730         dir = parent->d_inode;
 731         if (dentry->d_inode) {
 732                 rpci = RPC_I(dentry->d_inode);
 733                 if (rpci->private != private ||
 734                                 rpci->ops != ops ||
 735                                 rpci->flags != flags) {
 736                         dput (dentry);
 737                         dentry = ERR_PTR(-EBUSY);
 738                 }
 739                 rpci->nkern_readwriters++;
 740                 goto out;
 741         }
 742         inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
 743         if (!inode)
 744                 goto err_dput;
 745         inode->i_ino = iunique(dir->i_sb, 100);
 746         inode->i_fop = &rpc_pipe_fops;
 747         d_instantiate(dentry, inode);
 748         rpci = RPC_I(inode);
 749         rpci->private = private;
 750         rpci->flags = flags;
 751         rpci->ops = ops;
 752         rpci->nkern_readwriters = 1;
 753         fsnotify_create(dir, dentry);
 754         dget(dentry);
 755 out:
 756         mutex_unlock(&dir->i_mutex);
 757         return dentry;
 758 err_dput:
 759         dput(dentry);
 760         dentry = ERR_PTR(-ENOMEM);
 761         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
 762                         __FILE__, __FUNCTION__, parent->d_name.name, name,
 763                         -ENOMEM);
 764         goto out;
 765 }
 766
 767 int
 768 rpc_unlink(struct dentry *dentry)
 769 {
 770         struct dentry *parent;
 771         struct inode *dir;
 772         int error = 0;
 773
 774         parent = dget_parent(dentry);
 775         dir = parent->d_inode;
 776         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 777         if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
 778                 rpc_close_pipes(dentry->d_inode);
 779                 error = simple_unlink(dir, dentry);
 780                 if (!error)
 781                         d_delete(dentry);
 782         }
 783         dput(dentry);
 784         mutex_unlock(&dir->i_mutex);
 785         dput(parent);
 786         return error;
 787 }
 788
 789 /*
 790  * populate the filesystem
 791  */
 792 static struct super_operations s_ops = {
 793         .alloc_inode    = rpc_alloc_inode,
 794         .destroy_inode  = rpc_destroy_inode,
 795         .statfs         = simple_statfs,
 796 };
 797
 798 #define RPCAUTH_GSSMAGIC 0x67596969
 799
 800 static int
 801 rpc_fill_super(struct super_block *sb, void *data, int silent)
 802 {
 803         struct inode *inode;
 804         struct dentry *root;
 805
 806         sb->s_blocksize = PAGE_CACHE_SIZE;
 807         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 808         sb->s_magic = RPCAUTH_GSSMAGIC;
 809         sb->s_op = &s_ops;
 810         sb->s_time_gran = 1;
 811
 812         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 813         if (!inode)
 814                 return -ENOMEM;
 815         root = d_alloc_root(inode);
 816         if (!root) {
 817                 iput(inode);
 818                 return -ENOMEM;
 819         }
 820         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 821                 goto out;
 822         sb->s_root = root;
 823         return 0;
 824 out:
 825         d_genocide(root);
 826         dput(root);
 827         return -ENOMEM;
 828 }
 829
 830 static int
 831 rpc_get_sb(struct file_system_type *fs_type,
 832                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 833 {
 834         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
 835 }
 836
 837 static struct file_system_type rpc_pipe_fs_type = {
 838         .owner          = THIS_MODULE,
 839         .name           = "rpc_pipefs",
 840         .get_sb         = rpc_get_sb,
 841         .kill_sb        = kill_litter_super,
 842 };
 843
 844 static void
 845 init_once(struct kmem_cache * cachep, void *foo)
 846 {
 847         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 848
 849         inode_init_once(&rpci->vfs_inode);
 850         rpci->private = NULL;
 851         rpci->nreaders = 0;
 852         rpci->nwriters = 0;
 853         INIT_LIST_HEAD(&rpci->in_upcall);
 854         INIT_LIST_HEAD(&rpci->in_downcall);
 855         INIT_LIST_HEAD(&rpci->pipe);
 856         rpci->pipelen = 0;
 857         init_waitqueue_head(&rpci->waitq);
 858         INIT_DELAYED_WORK(&rpci->queue_timeout,
 859                             rpc_timeout_upcall_queue);
 860         rpci->ops = NULL;
 861 }
 862
 863 int register_rpc_pipefs(void)
 864 {
 865         int err;
 866
 867         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 868                                 sizeof(struct rpc_inode),
 869                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
 870                                                 SLAB_MEM_SPREAD),
 871                                 init_once);
 872         if (!rpc_inode_cachep)
 873                 return -ENOMEM;
 874         err = register_filesystem(&rpc_pipe_fs_type);
 875         if (err) {
 876                 kmem_cache_destroy(rpc_inode_cachep);
 877                 return err;
 878         }
 879
 880         return 0;
 881 }
 882
 883 void unregister_rpc_pipefs(void)
 884 {
 885         kmem_cache_destroy(rpc_inode_cachep);
 886         unregister_filesystem(&rpc_pipe_fs_type);
 887 }