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/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 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 (!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         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                         kref_get(&clnt->cl_kref);
 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 const 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 rpc_delete_dentry(struct dentry *dentry)
 451 {
 452         return 1;
 453 }
 454
 455 static struct dentry_operations rpc_dentry_operations = {
 456         .d_delete = rpc_delete_dentry,
 457 };
 458
 459 static int
 460 rpc_lookup_parent(char *path, struct nameidata *nd)
 461 {
 462         struct vfsmount *mnt;
 463
 464         if (path[0] == '\0')
 465                 return -ENOENT;
 466
 467         mnt = rpc_get_mount();
 468         if (IS_ERR(mnt)) {
 469                 printk(KERN_WARNING "%s: %s failed to mount "
 470                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
 471                 return PTR_ERR(mnt);
 472         }
 473
 474         if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
 475                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
 476                                 __FILE__, __FUNCTION__, path);
 477                 rpc_put_mount();
 478                 return -ENOENT;
 479         }
 480         return 0;
 481 }
 482
 483 static void
 484 rpc_release_path(struct nameidata *nd)
 485 {
 486         path_release(nd);
 487         rpc_put_mount();
 488 }
 489
 490 static struct inode *
 491 rpc_get_inode(struct super_block *sb, int mode)
 492 {
 493         struct inode *inode = new_inode(sb);
 494         if (!inode)
 495                 return NULL;
 496         inode->i_mode = mode;
 497         inode->i_uid = inode->i_gid = 0;
 498         inode->i_blocks = 0;
 499         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 500         switch(mode & S_IFMT) {
 501                 case S_IFDIR:
 502                         inode->i_fop = &simple_dir_operations;
 503                         inode->i_op = &simple_dir_inode_operations;
 504                         inc_nlink(inode);
 505                 default:
 506                         break;
 507         }
 508         return inode;
 509 }
 510
 511 /*
 512  * FIXME: This probably has races.
 513  */
 514 static void
 515 rpc_depopulate(struct dentry *parent, int start, int eof)
 516 {
 517         struct inode *dir = parent->d_inode;
 518         struct list_head *pos, *next;
 519         struct dentry *dentry, *dvec[10];
 520         int n = 0;
 521
 522         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 523 repeat:
 524         spin_lock(&dcache_lock);
 525         list_for_each_safe(pos, next, &parent->d_subdirs) {
 526                 dentry = list_entry(pos, struct dentry, d_u.d_child);
 527                 if (!dentry->d_inode ||
 528                                 dentry->d_inode->i_ino < start ||
 529                                 dentry->d_inode->i_ino >= eof)
 530                         continue;
 531                 spin_lock(&dentry->d_lock);
 532                 if (!d_unhashed(dentry)) {
 533                         dget_locked(dentry);
 534                         __d_drop(dentry);
 535                         spin_unlock(&dentry->d_lock);
 536                         dvec[n++] = dentry;
 537                         if (n == ARRAY_SIZE(dvec))
 538                                 break;
 539                 } else
 540                         spin_unlock(&dentry->d_lock);
 541         }
 542         spin_unlock(&dcache_lock);
 543         if (n) {
 544                 do {
 545                         dentry = dvec[--n];
 546                         if (S_ISREG(dentry->d_inode->i_mode))
 547                                 simple_unlink(dir, dentry);
 548                         else if (S_ISDIR(dentry->d_inode->i_mode))
 549                                 simple_rmdir(dir, dentry);
 550                         d_delete(dentry);
 551                         dput(dentry);
 552                 } while (n);
 553                 goto repeat;
 554         }
 555         mutex_unlock(&dir->i_mutex);
 556 }
 557
 558 static int
 559 rpc_populate(struct dentry *parent,
 560                 struct rpc_filelist *files,
 561                 int start, int eof)
 562 {
 563         struct inode *inode, *dir = parent->d_inode;
 564         void *private = RPC_I(dir)->private;
 565         struct dentry *dentry;
 566         int mode, i;
 567
 568         mutex_lock(&dir->i_mutex);
 569         for (i = start; i < eof; i++) {
 570                 dentry = d_alloc_name(parent, files[i].name);
 571                 if (!dentry)
 572                         goto out_bad;
 573                 dentry->d_op = &rpc_dentry_operations;
 574                 mode = files[i].mode;
 575                 inode = rpc_get_inode(dir->i_sb, mode);
 576                 if (!inode) {
 577                         dput(dentry);
 578                         goto out_bad;
 579                 }
 580                 inode->i_ino = i;
 581                 if (files[i].i_fop)
 582                         inode->i_fop = files[i].i_fop;
 583                 if (private)
 584                         rpc_inode_setowner(inode, private);
 585                 if (S_ISDIR(mode))
 586                         inc_nlink(dir);
 587                 d_add(dentry, inode);
 588         }
 589         mutex_unlock(&dir->i_mutex);
 590         return 0;
 591 out_bad:
 592         mutex_unlock(&dir->i_mutex);
 593         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 594                         __FILE__, __FUNCTION__, parent->d_name.name);
 595         return -ENOMEM;
 596 }
 597
 598 static int
 599 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 600 {
 601         struct inode *inode;
 602
 603         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
 604         if (!inode)
 605                 goto out_err;
 606         inode->i_ino = iunique(dir->i_sb, 100);
 607         d_instantiate(dentry, inode);
 608         inc_nlink(dir);
 609         inode_dir_notify(dir, DN_CREATE);
 610         return 0;
 611 out_err:
 612         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 613                         __FILE__, __FUNCTION__, dentry->d_name.name);
 614         return -ENOMEM;
 615 }
 616
 617 static int
 618 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 619 {
 620         int error;
 621         error = simple_rmdir(dir, dentry);
 622         if (!error)
 623                 d_delete(dentry);
 624         return error;
 625 }
 626
 627 static struct dentry *
 628 rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
 629 {
 630         struct inode *dir = parent->d_inode;
 631         struct dentry *dentry;
 632
 633         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 634         dentry = lookup_one_len(name, parent, len);
 635         if (IS_ERR(dentry))
 636                 goto out_err;
 637         if (!dentry->d_inode)
 638                 dentry->d_op = &rpc_dentry_operations;
 639         else if (exclusive) {
 640                 dput(dentry);
 641                 dentry = ERR_PTR(-EEXIST);
 642                 goto out_err;
 643         }
 644         return dentry;
 645 out_err:
 646         mutex_unlock(&dir->i_mutex);
 647         return dentry;
 648 }
 649
 650 static struct dentry *
 651 rpc_lookup_negative(char *path, struct nameidata *nd)
 652 {
 653         struct dentry *dentry;
 654         int error;
 655
 656         if ((error = rpc_lookup_parent(path, nd)) != 0)
 657                 return ERR_PTR(error);
 658         dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1);
 659         if (IS_ERR(dentry))
 660                 rpc_release_path(nd);
 661         return dentry;
 662 }
 663
 664
 665 struct dentry *
 666 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 667 {
 668         struct nameidata nd;
 669         struct dentry *dentry;
 670         struct inode *dir;
 671         int error;
 672
 673         dentry = rpc_lookup_negative(path, &nd);
 674         if (IS_ERR(dentry))
 675                 return dentry;
 676         dir = nd.dentry->d_inode;
 677         if ((error = __rpc_mkdir(dir, dentry)) != 0)
 678                 goto err_dput;
 679         RPC_I(dentry->d_inode)->private = rpc_client;
 680         error = rpc_populate(dentry, authfiles,
 681                         RPCAUTH_info, RPCAUTH_EOF);
 682         if (error)
 683                 goto err_depopulate;
 684         dget(dentry);
 685 out:
 686         mutex_unlock(&dir->i_mutex);
 687         rpc_release_path(&nd);
 688         return dentry;
 689 err_depopulate:
 690         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 691         __rpc_rmdir(dir, dentry);
 692 err_dput:
 693         dput(dentry);
 694         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
 695                         __FILE__, __FUNCTION__, path, error);
 696         dentry = ERR_PTR(error);
 697         goto out;
 698 }
 699
 700 int
 701 rpc_rmdir(struct dentry *dentry)
 702 {
 703         struct dentry *parent;
 704         struct inode *dir;
 705         int error;
 706
 707         parent = dget_parent(dentry);
 708         dir = parent->d_inode;
 709         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 710         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 711         error = __rpc_rmdir(dir, dentry);
 712         dput(dentry);
 713         mutex_unlock(&dir->i_mutex);
 714         dput(parent);
 715         return error;
 716 }
 717
 718 struct dentry *
 719 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
 720 {
 721         struct dentry *dentry;
 722         struct inode *dir, *inode;
 723         struct rpc_inode *rpci;
 724
 725         dentry = rpc_lookup_create(parent, name, strlen(name), 0);
 726         if (IS_ERR(dentry))
 727                 return dentry;
 728         dir = parent->d_inode;
 729         if (dentry->d_inode) {
 730                 rpci = RPC_I(dentry->d_inode);
 731                 if (rpci->private != private ||
 732                                 rpci->ops != ops ||
 733                                 rpci->flags != flags) {
 734                         dput (dentry);
 735                         dentry = ERR_PTR(-EBUSY);
 736                 }
 737                 rpci->nkern_readwriters++;
 738                 goto out;
 739         }
 740         inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
 741         if (!inode)
 742                 goto err_dput;
 743         inode->i_ino = iunique(dir->i_sb, 100);
 744         inode->i_fop = &rpc_pipe_fops;
 745         d_instantiate(dentry, inode);
 746         rpci = RPC_I(inode);
 747         rpci->private = private;
 748         rpci->flags = flags;
 749         rpci->ops = ops;
 750         rpci->nkern_readwriters = 1;
 751         inode_dir_notify(dir, DN_CREATE);
 752         dget(dentry);
 753 out:
 754         mutex_unlock(&dir->i_mutex);
 755         return dentry;
 756 err_dput:
 757         dput(dentry);
 758         dentry = ERR_PTR(-ENOMEM);
 759         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
 760                         __FILE__, __FUNCTION__, parent->d_name.name, name,
 761                         -ENOMEM);
 762         goto out;
 763 }
 764
 765 int
 766 rpc_unlink(struct dentry *dentry)
 767 {
 768         struct dentry *parent;
 769         struct inode *dir;
 770         int error = 0;
 771
 772         parent = dget_parent(dentry);
 773         dir = parent->d_inode;
 774         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 775         if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
 776                 rpc_close_pipes(dentry->d_inode);
 777                 error = simple_unlink(dir, dentry);
 778                 if (!error)
 779                         d_delete(dentry);
 780         }
 781         dput(dentry);
 782         mutex_unlock(&dir->i_mutex);
 783         dput(parent);
 784         return error;
 785 }
 786
 787 /*
 788  * populate the filesystem
 789  */
 790 static struct super_operations s_ops = {
 791         .alloc_inode    = rpc_alloc_inode,
 792         .destroy_inode  = rpc_destroy_inode,
 793         .statfs         = simple_statfs,
 794 };
 795
 796 #define RPCAUTH_GSSMAGIC 0x67596969
 797
 798 static int
 799 rpc_fill_super(struct super_block *sb, void *data, int silent)
 800 {
 801         struct inode *inode;
 802         struct dentry *root;
 803
 804         sb->s_blocksize = PAGE_CACHE_SIZE;
 805         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 806         sb->s_magic = RPCAUTH_GSSMAGIC;
 807         sb->s_op = &s_ops;
 808         sb->s_time_gran = 1;
 809
 810         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 811         if (!inode)
 812                 return -ENOMEM;
 813         root = d_alloc_root(inode);
 814         if (!root) {
 815                 iput(inode);
 816                 return -ENOMEM;
 817         }
 818         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 819                 goto out;
 820         sb->s_root = root;
 821         return 0;
 822 out:
 823         d_genocide(root);
 824         dput(root);
 825         return -ENOMEM;
 826 }
 827
 828 static int
 829 rpc_get_sb(struct file_system_type *fs_type,
 830                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 831 {
 832         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
 833 }
 834
 835 static struct file_system_type rpc_pipe_fs_type = {
 836         .owner          = THIS_MODULE,
 837         .name           = "rpc_pipefs",
 838         .get_sb         = rpc_get_sb,
 839         .kill_sb        = kill_litter_super,
 840 };
 841
 842 static void
 843 init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
 844 {
 845         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 846
 847         inode_init_once(&rpci->vfs_inode);
 848         rpci->private = NULL;
 849         rpci->nreaders = 0;
 850         rpci->nwriters = 0;
 851         INIT_LIST_HEAD(&rpci->in_upcall);
 852         INIT_LIST_HEAD(&rpci->in_downcall);
 853         INIT_LIST_HEAD(&rpci->pipe);
 854         rpci->pipelen = 0;
 855         init_waitqueue_head(&rpci->waitq);
 856         INIT_DELAYED_WORK(&rpci->queue_timeout,
 857                             rpc_timeout_upcall_queue);
 858         rpci->ops = NULL;
 859 }
 860
 861 int register_rpc_pipefs(void)
 862 {
 863         int err;
 864
 865         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 866                                 sizeof(struct rpc_inode),
 867                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
 868                                                 SLAB_MEM_SPREAD),
 869                                 init_once);
 870         if (!rpc_inode_cachep)
 871                 return -ENOMEM;
 872         err = register_filesystem(&rpc_pipe_fs_type);
 873         if (err) {
 874                 kmem_cache_destroy(rpc_inode_cachep);
 875                 return err;
 876         }
 877
 878         return 0;
 879 }
 880
 881 void unregister_rpc_pipefs(void)
 882 {
 883         kmem_cache_destroy(rpc_inode_cachep);
 884         unregister_filesystem(&rpc_pipe_fs_type);
 885 }