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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/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/dnotify.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 kmem_cache_t *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(void *data)
  58 {
  59         LIST_HEAD(free_list);
  60         struct rpc_inode *rpci = (struct rpc_inode *)data;
  61         struct inode *inode = &rpci->vfs_inode;
  62         void (*destroy_msg)(struct rpc_pipe_msg *);
  63
  64         spin_lock(&inode->i_lock);
  65         if (rpci->ops == NULL) {
  66                 spin_unlock(&inode->i_lock);
  67                 return;
  68         }
  69         destroy_msg = rpci->ops->destroy_msg;
  70         if (rpci->nreaders == 0) {
  71                 list_splice_init(&rpci->pipe, &free_list);
  72                 rpci->pipelen = 0;
  73         }
  74         spin_unlock(&inode->i_lock);
  75         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
  76 }
  77
  78 int
  79 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
  80 {
  81         struct rpc_inode *rpci = RPC_I(inode);
  82         int res = -EPIPE;
  83
  84         spin_lock(&inode->i_lock);
  85         if (rpci->ops == NULL)
  86                 goto out;
  87         if (rpci->nreaders) {
  88                 list_add_tail(&msg->list, &rpci->pipe);
  89                 rpci->pipelen += msg->len;
  90                 res = 0;
  91         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
  92                 if (list_empty(&rpci->pipe))
  93                         queue_delayed_work(rpciod_workqueue,
  94                                         &rpci->queue_timeout,
  95                                         RPC_UPCALL_TIMEOUT);
  96                 list_add_tail(&msg->list, &rpci->pipe);
  97                 rpci->pipelen += msg->len;
  98                 res = 0;
  99         }
 100 out:
 101         spin_unlock(&inode->i_lock);
 102         wake_up(&rpci->waitq);
 103         return res;
 104 }
 105
 106 static inline void
 107 rpc_inode_setowner(struct inode *inode, void *private)
 108 {
 109         RPC_I(inode)->private = private;
 110 }
 111
 112 static void
 113 rpc_close_pipes(struct inode *inode)
 114 {
 115         struct rpc_inode *rpci = RPC_I(inode);
 116         struct rpc_pipe_ops *ops;
 117
 118         mutex_lock(&inode->i_mutex);
 119         ops = rpci->ops;
 120         if (ops != NULL) {
 121                 LIST_HEAD(free_list);
 122
 123                 spin_lock(&inode->i_lock);
 124                 rpci->nreaders = 0;
 125                 list_splice_init(&rpci->in_upcall, &free_list);
 126                 list_splice_init(&rpci->pipe, &free_list);
 127                 rpci->pipelen = 0;
 128                 rpci->ops = NULL;
 129                 spin_unlock(&inode->i_lock);
 130                 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
 131                 rpci->nwriters = 0;
 132                 if (ops->release_pipe)
 133                         ops->release_pipe(inode);
 134                 cancel_delayed_work(&rpci->queue_timeout);
 135                 flush_workqueue(rpciod_workqueue);
 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, SLAB_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_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_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_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 (!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_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 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         return 0;
 333 }
 334
 335 static int
 336 rpc_info_open(struct inode *inode, struct file *file)
 337 {
 338         struct rpc_clnt *clnt;
 339         int ret = single_open(file, rpc_show_info, NULL);
 340
 341         if (!ret) {
 342                 struct seq_file *m = file->private_data;
 343                 mutex_lock(&inode->i_mutex);
 344                 clnt = RPC_I(inode)->private;
 345                 if (clnt) {
 346                         atomic_inc(&clnt->cl_users);
 347                         m->private = clnt;
 348                 } else {
 349                         single_release(inode, file);
 350                         ret = -EINVAL;
 351                 }
 352                 mutex_unlock(&inode->i_mutex);
 353         }
 354         return ret;
 355 }
 356
 357 static int
 358 rpc_info_release(struct inode *inode, struct file *file)
 359 {
 360         struct seq_file *m = file->private_data;
 361         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 362
 363         if (clnt)
 364                 rpc_release_client(clnt);
 365         return single_release(inode, file);
 366 }
 367
 368 static struct file_operations rpc_info_operations = {
 369         .owner          = THIS_MODULE,
 370         .open           = rpc_info_open,
 371         .read           = seq_read,
 372         .llseek         = seq_lseek,
 373         .release        = rpc_info_release,
 374 };
 375
 376
 377 /*
 378  * We have a single directory with 1 node in it.
 379  */
 380 enum {
 381         RPCAUTH_Root = 1,
 382         RPCAUTH_lockd,
 383         RPCAUTH_mount,
 384         RPCAUTH_nfs,
 385         RPCAUTH_portmap,
 386         RPCAUTH_statd,
 387         RPCAUTH_RootEOF
 388 };
 389
 390 /*
 391  * Description of fs contents.
 392  */
 393 struct rpc_filelist {
 394         char *name;
 395         const struct file_operations *i_fop;
 396         int mode;
 397 };
 398
 399 static struct rpc_filelist files[] = {
 400         [RPCAUTH_lockd] = {
 401                 .name = "lockd",
 402                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 403         },
 404         [RPCAUTH_mount] = {
 405                 .name = "mount",
 406                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 407         },
 408         [RPCAUTH_nfs] = {
 409                 .name = "nfs",
 410                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 411         },
 412         [RPCAUTH_portmap] = {
 413                 .name = "portmap",
 414                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 415         },
 416         [RPCAUTH_statd] = {
 417                 .name = "statd",
 418                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 419         },
 420 };
 421
 422 enum {
 423         RPCAUTH_info = 2,
 424         RPCAUTH_EOF
 425 };
 426
 427 static struct rpc_filelist authfiles[] = {
 428         [RPCAUTH_info] = {
 429                 .name = "info",
 430                 .i_fop = &rpc_info_operations,
 431                 .mode = S_IFREG | S_IRUSR,
 432         },
 433 };
 434
 435 struct vfsmount *rpc_get_mount(void)
 436 {
 437         int err;
 438
 439         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
 440         if (err != 0)
 441                 return ERR_PTR(err);
 442         return rpc_mount;
 443 }
 444
 445 void rpc_put_mount(void)
 446 {
 447         simple_release_fs(&rpc_mount, &rpc_mount_count);
 448 }
 449
 450 static int
 451 rpc_lookup_parent(char *path, struct nameidata *nd)
 452 {
 453         if (path[0] == '\0')
 454                 return -ENOENT;
 455         nd->mnt = rpc_get_mount();
 456         if (IS_ERR(nd->mnt)) {
 457                 printk(KERN_WARNING "%s: %s failed to mount "
 458                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
 459                 return PTR_ERR(nd->mnt);
 460         }
 461         mntget(nd->mnt);
 462         nd->dentry = dget(rpc_mount->mnt_root);
 463         nd->last_type = LAST_ROOT;
 464         nd->flags = LOOKUP_PARENT;
 465         nd->depth = 0;
 466
 467         if (path_walk(path, nd)) {
 468                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
 469                                 __FILE__, __FUNCTION__, path);
 470                 rpc_put_mount();
 471                 return -ENOENT;
 472         }
 473         return 0;
 474 }
 475
 476 static void
 477 rpc_release_path(struct nameidata *nd)
 478 {
 479         path_release(nd);
 480         rpc_put_mount();
 481 }
 482
 483 static struct inode *
 484 rpc_get_inode(struct super_block *sb, int mode)
 485 {
 486         struct inode *inode = new_inode(sb);
 487         if (!inode)
 488                 return NULL;
 489         inode->i_mode = mode;
 490         inode->i_uid = inode->i_gid = 0;
 491         inode->i_blksize = PAGE_CACHE_SIZE;
 492         inode->i_blocks = 0;
 493         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 494         switch(mode & S_IFMT) {
 495                 case S_IFDIR:
 496                         inode->i_fop = &simple_dir_operations;
 497                         inode->i_op = &simple_dir_inode_operations;
 498                         inode->i_nlink++;
 499                 default:
 500                         break;
 501         }
 502         return inode;
 503 }
 504
 505 /*
 506  * FIXME: This probably has races.
 507  */
 508 static void
 509 rpc_depopulate(struct dentry *parent)
 510 {
 511         struct inode *dir = parent->d_inode;
 512         struct list_head *pos, *next;
 513         struct dentry *dentry, *dvec[10];
 514         int n = 0;
 515
 516         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 517 repeat:
 518         spin_lock(&dcache_lock);
 519         list_for_each_safe(pos, next, &parent->d_subdirs) {
 520                 dentry = list_entry(pos, struct dentry, d_u.d_child);
 521                 spin_lock(&dentry->d_lock);
 522                 if (!d_unhashed(dentry)) {
 523                         dget_locked(dentry);
 524                         __d_drop(dentry);
 525                         spin_unlock(&dentry->d_lock);
 526                         dvec[n++] = dentry;
 527                         if (n == ARRAY_SIZE(dvec))
 528                                 break;
 529                 } else
 530                         spin_unlock(&dentry->d_lock);
 531         }
 532         spin_unlock(&dcache_lock);
 533         if (n) {
 534                 do {
 535                         dentry = dvec[--n];
 536                         if (dentry->d_inode) {
 537                                 rpc_close_pipes(dentry->d_inode);
 538                                 simple_unlink(dir, dentry);
 539                         }
 540                         inode_dir_notify(dir, DN_DELETE);
 541                         dput(dentry);
 542                 } while (n);
 543                 goto repeat;
 544         }
 545         mutex_unlock(&dir->i_mutex);
 546 }
 547
 548 static int
 549 rpc_populate(struct dentry *parent,
 550                 struct rpc_filelist *files,
 551                 int start, int eof)
 552 {
 553         struct inode *inode, *dir = parent->d_inode;
 554         void *private = RPC_I(dir)->private;
 555         struct dentry *dentry;
 556         int mode, i;
 557
 558         mutex_lock(&dir->i_mutex);
 559         for (i = start; i < eof; i++) {
 560                 dentry = d_alloc_name(parent, files[i].name);
 561                 if (!dentry)
 562                         goto out_bad;
 563                 mode = files[i].mode;
 564                 inode = rpc_get_inode(dir->i_sb, mode);
 565                 if (!inode) {
 566                         dput(dentry);
 567                         goto out_bad;
 568                 }
 569                 inode->i_ino = i;
 570                 if (files[i].i_fop)
 571                         inode->i_fop = files[i].i_fop;
 572                 if (private)
 573                         rpc_inode_setowner(inode, private);
 574                 if (S_ISDIR(mode))
 575                         dir->i_nlink++;
 576                 d_add(dentry, inode);
 577         }
 578         mutex_unlock(&dir->i_mutex);
 579         return 0;
 580 out_bad:
 581         mutex_unlock(&dir->i_mutex);
 582         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 583                         __FILE__, __FUNCTION__, parent->d_name.name);
 584         return -ENOMEM;
 585 }
 586
 587 static int
 588 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 589 {
 590         struct inode *inode;
 591
 592         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
 593         if (!inode)
 594                 goto out_err;
 595         inode->i_ino = iunique(dir->i_sb, 100);
 596         d_instantiate(dentry, inode);
 597         dir->i_nlink++;
 598         inode_dir_notify(dir, DN_CREATE);
 599         return 0;
 600 out_err:
 601         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 602                         __FILE__, __FUNCTION__, dentry->d_name.name);
 603         return -ENOMEM;
 604 }
 605
 606 static int
 607 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 608 {
 609         int error;
 610
 611         shrink_dcache_parent(dentry);
 612         if (d_unhashed(dentry))
 613                 return 0;
 614         if ((error = simple_rmdir(dir, dentry)) != 0)
 615                 return error;
 616         if (!error) {
 617                 inode_dir_notify(dir, DN_DELETE);
 618                 d_drop(dentry);
 619         }
 620         return 0;
 621 }
 622
 623 static struct dentry *
 624 rpc_lookup_negative(char *path, struct nameidata *nd)
 625 {
 626         struct dentry *dentry;
 627         struct inode *dir;
 628         int error;
 629
 630         if ((error = rpc_lookup_parent(path, nd)) != 0)
 631                 return ERR_PTR(error);
 632         dir = nd->dentry->d_inode;
 633         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 634         dentry = lookup_one_len(nd->last.name, nd->dentry, nd->last.len);
 635         if (IS_ERR(dentry))
 636                 goto out_err;
 637         if (dentry->d_inode) {
 638                 dput(dentry);
 639                 dentry = ERR_PTR(-EEXIST);
 640                 goto out_err;
 641         }
 642         return dentry;
 643 out_err:
 644         mutex_unlock(&dir->i_mutex);
 645         rpc_release_path(nd);
 646         return dentry;
 647 }
 648
 649
 650 struct dentry *
 651 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 652 {
 653         struct nameidata nd;
 654         struct dentry *dentry;
 655         struct inode *dir;
 656         int error;
 657
 658         dentry = rpc_lookup_negative(path, &nd);
 659         if (IS_ERR(dentry))
 660                 return dentry;
 661         dir = nd.dentry->d_inode;
 662         if ((error = __rpc_mkdir(dir, dentry)) != 0)
 663                 goto err_dput;
 664         RPC_I(dentry->d_inode)->private = rpc_client;
 665         error = rpc_populate(dentry, authfiles,
 666                         RPCAUTH_info, RPCAUTH_EOF);
 667         if (error)
 668                 goto err_depopulate;
 669         dget(dentry);
 670 out:
 671         mutex_unlock(&dir->i_mutex);
 672         rpc_release_path(&nd);
 673         return dentry;
 674 err_depopulate:
 675         rpc_depopulate(dentry);
 676         __rpc_rmdir(dir, dentry);
 677 err_dput:
 678         dput(dentry);
 679         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
 680                         __FILE__, __FUNCTION__, path, error);
 681         dentry = ERR_PTR(error);
 682         goto out;
 683 }
 684
 685 int
 686 rpc_rmdir(struct dentry *dentry)
 687 {
 688         struct dentry *parent;
 689         struct inode *dir;
 690         int error;
 691
 692         parent = dget_parent(dentry);
 693         dir = parent->d_inode;
 694         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 695         rpc_depopulate(dentry);
 696         error = __rpc_rmdir(dir, dentry);
 697         dput(dentry);
 698         mutex_unlock(&dir->i_mutex);
 699         dput(parent);
 700         return error;
 701 }
 702
 703 struct dentry *
 704 rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
 705 {
 706         struct nameidata nd;
 707         struct dentry *dentry;
 708         struct inode *dir, *inode;
 709         struct rpc_inode *rpci;
 710
 711         dentry = rpc_lookup_negative(path, &nd);
 712         if (IS_ERR(dentry))
 713                 return dentry;
 714         dir = nd.dentry->d_inode;
 715         inode = rpc_get_inode(dir->i_sb, S_IFSOCK | S_IRUSR | S_IWUSR);
 716         if (!inode)
 717                 goto err_dput;
 718         inode->i_ino = iunique(dir->i_sb, 100);
 719         inode->i_fop = &rpc_pipe_fops;
 720         d_instantiate(dentry, inode);
 721         rpci = RPC_I(inode);
 722         rpci->private = private;
 723         rpci->flags = flags;
 724         rpci->ops = ops;
 725         inode_dir_notify(dir, DN_CREATE);
 726         dget(dentry);
 727 out:
 728         mutex_unlock(&dir->i_mutex);
 729         rpc_release_path(&nd);
 730         return dentry;
 731 err_dput:
 732         dput(dentry);
 733         dentry = ERR_PTR(-ENOMEM);
 734         printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n",
 735                         __FILE__, __FUNCTION__, path, -ENOMEM);
 736         goto out;
 737 }
 738
 739 int
 740 rpc_unlink(struct dentry *dentry)
 741 {
 742         struct dentry *parent;
 743         struct inode *dir;
 744         int error = 0;
 745
 746         parent = dget_parent(dentry);
 747         dir = parent->d_inode;
 748         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 749         if (!d_unhashed(dentry)) {
 750                 d_drop(dentry);
 751                 if (dentry->d_inode) {
 752                         rpc_close_pipes(dentry->d_inode);
 753                         error = simple_unlink(dir, dentry);
 754                 }
 755                 inode_dir_notify(dir, DN_DELETE);
 756         }
 757         dput(dentry);
 758         mutex_unlock(&dir->i_mutex);
 759         dput(parent);
 760         return error;
 761 }
 762
 763 /*
 764  * populate the filesystem
 765  */
 766 static struct super_operations s_ops = {
 767         .alloc_inode    = rpc_alloc_inode,
 768         .destroy_inode  = rpc_destroy_inode,
 769         .statfs         = simple_statfs,
 770 };
 771
 772 #define RPCAUTH_GSSMAGIC 0x67596969
 773
 774 static int
 775 rpc_fill_super(struct super_block *sb, void *data, int silent)
 776 {
 777         struct inode *inode;
 778         struct dentry *root;
 779
 780         sb->s_blocksize = PAGE_CACHE_SIZE;
 781         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 782         sb->s_magic = RPCAUTH_GSSMAGIC;
 783         sb->s_op = &s_ops;
 784         sb->s_time_gran = 1;
 785
 786         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 787         if (!inode)
 788                 return -ENOMEM;
 789         root = d_alloc_root(inode);
 790         if (!root) {
 791                 iput(inode);
 792                 return -ENOMEM;
 793         }
 794         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 795                 goto out;
 796         sb->s_root = root;
 797         return 0;
 798 out:
 799         d_genocide(root);
 800         dput(root);
 801         return -ENOMEM;
 802 }
 803
 804 static int
 805 rpc_get_sb(struct file_system_type *fs_type,
 806                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 807 {
 808         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
 809 }
 810
 811 static struct file_system_type rpc_pipe_fs_type = {
 812         .owner          = THIS_MODULE,
 813         .name           = "rpc_pipefs",
 814         .get_sb         = rpc_get_sb,
 815         .kill_sb        = kill_litter_super,
 816 };
 817
 818 static void
 819 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 820 {
 821         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 822
 823         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 824             SLAB_CTOR_CONSTRUCTOR) {
 825                 inode_init_once(&rpci->vfs_inode);
 826                 rpci->private = NULL;
 827                 rpci->nreaders = 0;
 828                 rpci->nwriters = 0;
 829                 INIT_LIST_HEAD(&rpci->in_upcall);
 830                 INIT_LIST_HEAD(&rpci->pipe);
 831                 rpci->pipelen = 0;
 832                 init_waitqueue_head(&rpci->waitq);
 833                 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
 834                 rpci->ops = NULL;
 835         }
 836 }
 837
 838 int register_rpc_pipefs(void)
 839 {
 840         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 841                                 sizeof(struct rpc_inode),
 842                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
 843                                                 SLAB_MEM_SPREAD),
 844                                 init_once, NULL);
 845         if (!rpc_inode_cachep)
 846                 return -ENOMEM;
 847         register_filesystem(&rpc_pipe_fs_type);
 848         return 0;
 849 }
 850
 851 void unregister_rpc_pipefs(void)
 852 {
 853         if (kmem_cache_destroy(rpc_inode_cachep))
 854                 printk(KERN_WARNING "RPC: unable to free inode cache\n");
 855         unregister_filesystem(&rpc_pipe_fs_type);
 856 }