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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 rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
  42                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  43 {
  44         struct rpc_pipe_msg *msg;
  45
  46         if (list_empty(head))
  47                 return;
  48         do {
  49                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  50                 list_del(&msg->list);
  51                 msg->errno = err;
  52                 destroy_msg(msg);
  53         } while (!list_empty(head));
  54         wake_up(&rpci->waitq);
  55 }
  56
  57 static void
  58 rpc_timeout_upcall_queue(void *data)
  59 {
  60         LIST_HEAD(free_list);
  61         struct rpc_inode *rpci = (struct rpc_inode *)data;
  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(&rpci->queue_timeout);
 136                 flush_workqueue(rpciod_workqueue);
 137         }
 138         rpc_inode_setowner(inode, NULL);
 139         mutex_unlock(&inode->i_mutex);
 140 }
 141
 142 static struct inode *
 143 rpc_alloc_inode(struct super_block *sb)
 144 {
 145         struct rpc_inode *rpci;
 146         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, SLAB_KERNEL);
 147         if (!rpci)
 148                 return NULL;
 149         return &rpci->vfs_inode;
 150 }
 151
 152 static void
 153 rpc_destroy_inode(struct inode *inode)
 154 {
 155         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 156 }
 157
 158 static int
 159 rpc_pipe_open(struct inode *inode, struct file *filp)
 160 {
 161         struct rpc_inode *rpci = RPC_I(inode);
 162         int res = -ENXIO;
 163
 164         mutex_lock(&inode->i_mutex);
 165         if (rpci->ops != NULL) {
 166                 if (filp->f_mode & FMODE_READ)
 167                         rpci->nreaders ++;
 168                 if (filp->f_mode & FMODE_WRITE)
 169                         rpci->nwriters ++;
 170                 res = 0;
 171         }
 172         mutex_unlock(&inode->i_mutex);
 173         return res;
 174 }
 175
 176 static int
 177 rpc_pipe_release(struct inode *inode, struct file *filp)
 178 {
 179         struct rpc_inode *rpci = RPC_I(inode);
 180         struct rpc_pipe_msg *msg;
 181
 182         mutex_lock(&inode->i_mutex);
 183         if (rpci->ops == NULL)
 184                 goto out;
 185         msg = (struct rpc_pipe_msg *)filp->private_data;
 186         if (msg != NULL) {
 187                 spin_lock(&inode->i_lock);
 188                 msg->errno = -EAGAIN;
 189                 list_del(&msg->list);
 190                 spin_unlock(&inode->i_lock);
 191                 rpci->ops->destroy_msg(msg);
 192         }
 193         if (filp->f_mode & FMODE_WRITE)
 194                 rpci->nwriters --;
 195         if (filp->f_mode & FMODE_READ) {
 196                 rpci->nreaders --;
 197                 if (rpci->nreaders == 0) {
 198                         LIST_HEAD(free_list);
 199                         spin_lock(&inode->i_lock);
 200                         list_splice_init(&rpci->pipe, &free_list);
 201                         rpci->pipelen = 0;
 202                         spin_unlock(&inode->i_lock);
 203                         rpc_purge_list(rpci, &free_list,
 204                                         rpci->ops->destroy_msg, -EAGAIN);
 205                 }
 206         }
 207         if (rpci->ops->release_pipe)
 208                 rpci->ops->release_pipe(inode);
 209 out:
 210         mutex_unlock(&inode->i_mutex);
 211         return 0;
 212 }
 213
 214 static ssize_t
 215 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 216 {
 217         struct inode *inode = filp->f_dentry->d_inode;
 218         struct rpc_inode *rpci = RPC_I(inode);
 219         struct rpc_pipe_msg *msg;
 220         int res = 0;
 221
 222         mutex_lock(&inode->i_mutex);
 223         if (rpci->ops == NULL) {
 224                 res = -EPIPE;
 225                 goto out_unlock;
 226         }
 227         msg = filp->private_data;
 228         if (msg == NULL) {
 229                 spin_lock(&inode->i_lock);
 230                 if (!list_empty(&rpci->pipe)) {
 231                         msg = list_entry(rpci->pipe.next,
 232                                         struct rpc_pipe_msg,
 233                                         list);
 234                         list_move(&msg->list, &rpci->in_upcall);
 235                         rpci->pipelen -= msg->len;
 236                         filp->private_data = msg;
 237                         msg->copied = 0;
 238                 }
 239                 spin_unlock(&inode->i_lock);
 240                 if (msg == NULL)
 241                         goto out_unlock;
 242         }
 243         /* NOTE: it is up to the callback to update msg->copied */
 244         res = rpci->ops->upcall(filp, msg, buf, len);
 245         if (res < 0 || msg->len == msg->copied) {
 246                 filp->private_data = NULL;
 247                 spin_lock(&inode->i_lock);
 248                 list_del(&msg->list);
 249                 spin_unlock(&inode->i_lock);
 250                 rpci->ops->destroy_msg(msg);
 251         }
 252 out_unlock:
 253         mutex_unlock(&inode->i_mutex);
 254         return res;
 255 }
 256
 257 static ssize_t
 258 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 259 {
 260         struct inode *inode = filp->f_dentry->d_inode;
 261         struct rpc_inode *rpci = RPC_I(inode);
 262         int res;
 263
 264         mutex_lock(&inode->i_mutex);
 265         res = -EPIPE;
 266         if (rpci->ops != NULL)
 267                 res = rpci->ops->downcall(filp, buf, len);
 268         mutex_unlock(&inode->i_mutex);
 269         return res;
 270 }
 271
 272 static unsigned int
 273 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 274 {
 275         struct rpc_inode *rpci;
 276         unsigned int mask = 0;
 277
 278         rpci = RPC_I(filp->f_dentry->d_inode);
 279         poll_wait(filp, &rpci->waitq, wait);
 280
 281         mask = POLLOUT | POLLWRNORM;
 282         if (rpci->ops == NULL)
 283                 mask |= POLLERR | POLLHUP;
 284         if (!list_empty(&rpci->pipe))
 285                 mask |= POLLIN | POLLRDNORM;
 286         return mask;
 287 }
 288
 289 static int
 290 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
 291                 unsigned int cmd, unsigned long arg)
 292 {
 293         struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
 294         int len;
 295
 296         switch (cmd) {
 297         case FIONREAD:
 298                 if (rpci->ops == NULL)
 299                         return -EPIPE;
 300                 len = rpci->pipelen;
 301                 if (filp->private_data) {
 302                         struct rpc_pipe_msg *msg;
 303                         msg = (struct rpc_pipe_msg *)filp->private_data;
 304                         len += msg->len - msg->copied;
 305                 }
 306                 return put_user(len, (int __user *)arg);
 307         default:
 308                 return -EINVAL;
 309         }
 310 }
 311
 312 static struct file_operations rpc_pipe_fops = {
 313         .owner          = THIS_MODULE,
 314         .llseek         = no_llseek,
 315         .read           = rpc_pipe_read,
 316         .write          = rpc_pipe_write,
 317         .poll           = rpc_pipe_poll,
 318         .ioctl          = rpc_pipe_ioctl,
 319         .open           = rpc_pipe_open,
 320         .release        = rpc_pipe_release,
 321 };
 322
 323 static int
 324 rpc_show_info(struct seq_file *m, void *v)
 325 {
 326         struct rpc_clnt *clnt = m->private;
 327
 328         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
 329         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
 330                         clnt->cl_prog, clnt->cl_vers);
 331         seq_printf(m, "address: %u.%u.%u.%u\n",
 332                         NIPQUAD(clnt->cl_xprt->addr.sin_addr.s_addr));
 333         seq_printf(m, "protocol: %s\n",
 334                         clnt->cl_xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
 335         return 0;
 336 }
 337
 338 static int
 339 rpc_info_open(struct inode *inode, struct file *file)
 340 {
 341         struct rpc_clnt *clnt;
 342         int ret = single_open(file, rpc_show_info, NULL);
 343
 344         if (!ret) {
 345                 struct seq_file *m = file->private_data;
 346                 mutex_lock(&inode->i_mutex);
 347                 clnt = RPC_I(inode)->private;
 348                 if (clnt) {
 349                         atomic_inc(&clnt->cl_users);
 350                         m->private = clnt;
 351                 } else {
 352                         single_release(inode, file);
 353                         ret = -EINVAL;
 354                 }
 355                 mutex_unlock(&inode->i_mutex);
 356         }
 357         return ret;
 358 }
 359
 360 static int
 361 rpc_info_release(struct inode *inode, struct file *file)
 362 {
 363         struct seq_file *m = file->private_data;
 364         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 365
 366         if (clnt)
 367                 rpc_release_client(clnt);
 368         return single_release(inode, file);
 369 }
 370
 371 static struct file_operations rpc_info_operations = {
 372         .owner          = THIS_MODULE,
 373         .open           = rpc_info_open,
 374         .read           = seq_read,
 375         .llseek         = seq_lseek,
 376         .release        = rpc_info_release,
 377 };
 378
 379
 380 /*
 381  * We have a single directory with 1 node in it.
 382  */
 383 enum {
 384         RPCAUTH_Root = 1,
 385         RPCAUTH_lockd,
 386         RPCAUTH_mount,
 387         RPCAUTH_nfs,
 388         RPCAUTH_portmap,
 389         RPCAUTH_statd,
 390         RPCAUTH_RootEOF
 391 };
 392
 393 /*
 394  * Description of fs contents.
 395  */
 396 struct rpc_filelist {
 397         char *name;
 398         struct file_operations *i_fop;
 399         int mode;
 400 };
 401
 402 static struct rpc_filelist files[] = {
 403         [RPCAUTH_lockd] = {
 404                 .name = "lockd",
 405                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 406         },
 407         [RPCAUTH_mount] = {
 408                 .name = "mount",
 409                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 410         },
 411         [RPCAUTH_nfs] = {
 412                 .name = "nfs",
 413                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 414         },
 415         [RPCAUTH_portmap] = {
 416                 .name = "portmap",
 417                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 418         },
 419         [RPCAUTH_statd] = {
 420                 .name = "statd",
 421                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 422         },
 423 };
 424
 425 enum {
 426         RPCAUTH_info = 2,
 427         RPCAUTH_EOF
 428 };
 429
 430 static struct rpc_filelist authfiles[] = {
 431         [RPCAUTH_info] = {
 432                 .name = "info",
 433                 .i_fop = &rpc_info_operations,
 434                 .mode = S_IFREG | S_IRUSR,
 435         },
 436 };
 437
 438 static int
 439 rpc_get_mount(void)
 440 {
 441         return simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
 442 }
 443
 444 static void
 445 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         if (rpc_get_mount()) {
 456                 printk(KERN_WARNING "%s: %s failed to mount "
 457                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
 458                 return -ENODEV;
 459         }
 460         nd->mnt = mntget(rpc_mount);
 461         nd->dentry = dget(rpc_mount->mnt_root);
 462         nd->last_type = LAST_ROOT;
 463         nd->flags = LOOKUP_PARENT;
 464         nd->depth = 0;
 465
 466         if (path_walk(path, nd)) {
 467                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
 468                                 __FILE__, __FUNCTION__, path);
 469                 rpc_put_mount();
 470                 return -ENOENT;
 471         }
 472         return 0;
 473 }
 474
 475 static void
 476 rpc_release_path(struct nameidata *nd)
 477 {
 478         path_release(nd);
 479         rpc_put_mount();
 480 }
 481
 482 static struct inode *
 483 rpc_get_inode(struct super_block *sb, int mode)
 484 {
 485         struct inode *inode = new_inode(sb);
 486         if (!inode)
 487                 return NULL;
 488         inode->i_mode = mode;
 489         inode->i_uid = inode->i_gid = 0;
 490         inode->i_blksize = PAGE_CACHE_SIZE;
 491         inode->i_blocks = 0;
 492         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 493         switch(mode & S_IFMT) {
 494                 case S_IFDIR:
 495                         inode->i_fop = &simple_dir_operations;
 496                         inode->i_op = &simple_dir_inode_operations;
 497                         inode->i_nlink++;
 498                 default:
 499                         break;
 500         }
 501         return inode;
 502 }
 503
 504 /*
 505  * FIXME: This probably has races.
 506  */
 507 static void
 508 rpc_depopulate(struct dentry *parent)
 509 {
 510         struct inode *dir = parent->d_inode;
 511         struct list_head *pos, *next;
 512         struct dentry *dentry, *dvec[10];
 513         int n = 0;
 514
 515         mutex_lock(&dir->i_mutex);
 516 repeat:
 517         spin_lock(&dcache_lock);
 518         list_for_each_safe(pos, next, &parent->d_subdirs) {
 519                 dentry = list_entry(pos, struct dentry, d_u.d_child);
 520                 spin_lock(&dentry->d_lock);
 521                 if (!d_unhashed(dentry)) {
 522                         dget_locked(dentry);
 523                         __d_drop(dentry);
 524                         spin_unlock(&dentry->d_lock);
 525                         dvec[n++] = dentry;
 526                         if (n == ARRAY_SIZE(dvec))
 527                                 break;
 528                 } else
 529                         spin_unlock(&dentry->d_lock);
 530         }
 531         spin_unlock(&dcache_lock);
 532         if (n) {
 533                 do {
 534                         dentry = dvec[--n];
 535                         if (dentry->d_inode) {
 536                                 rpc_close_pipes(dentry->d_inode);
 537                                 simple_unlink(dir, dentry);
 538                         }
 539                         dput(dentry);
 540                 } while (n);
 541                 goto repeat;
 542         }
 543         mutex_unlock(&dir->i_mutex);
 544 }
 545
 546 static int
 547 rpc_populate(struct dentry *parent,
 548                 struct rpc_filelist *files,
 549                 int start, int eof)
 550 {
 551         struct inode *inode, *dir = parent->d_inode;
 552         void *private = RPC_I(dir)->private;
 553         struct dentry *dentry;
 554         int mode, i;
 555
 556         mutex_lock(&dir->i_mutex);
 557         for (i = start; i < eof; i++) {
 558                 dentry = d_alloc_name(parent, files[i].name);
 559                 if (!dentry)
 560                         goto out_bad;
 561                 mode = files[i].mode;
 562                 inode = rpc_get_inode(dir->i_sb, mode);
 563                 if (!inode) {
 564                         dput(dentry);
 565                         goto out_bad;
 566                 }
 567                 inode->i_ino = i;
 568                 if (files[i].i_fop)
 569                         inode->i_fop = files[i].i_fop;
 570                 if (private)
 571                         rpc_inode_setowner(inode, private);
 572                 if (S_ISDIR(mode))
 573                         dir->i_nlink++;
 574                 d_add(dentry, inode);
 575         }
 576         mutex_unlock(&dir->i_mutex);
 577         return 0;
 578 out_bad:
 579         mutex_unlock(&dir->i_mutex);
 580         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 581                         __FILE__, __FUNCTION__, parent->d_name.name);
 582         return -ENOMEM;
 583 }
 584
 585 static int
 586 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 587 {
 588         struct inode *inode;
 589
 590         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
 591         if (!inode)
 592                 goto out_err;
 593         inode->i_ino = iunique(dir->i_sb, 100);
 594         d_instantiate(dentry, inode);
 595         dir->i_nlink++;
 596         inode_dir_notify(dir, DN_CREATE);
 597         rpc_get_mount();
 598         return 0;
 599 out_err:
 600         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 601                         __FILE__, __FUNCTION__, dentry->d_name.name);
 602         return -ENOMEM;
 603 }
 604
 605 static int
 606 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 607 {
 608         int error;
 609
 610         shrink_dcache_parent(dentry);
 611         if (dentry->d_inode)
 612                 rpc_close_pipes(dentry->d_inode);
 613         if ((error = simple_rmdir(dir, dentry)) != 0)
 614                 return error;
 615         if (!error) {
 616                 inode_dir_notify(dir, DN_DELETE);
 617                 d_drop(dentry);
 618                 rpc_put_mount();
 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(&dir->i_mutex);
 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 out:
 670         mutex_unlock(&dir->i_mutex);
 671         rpc_release_path(&nd);
 672         return dget(dentry);
 673 err_depopulate:
 674         rpc_depopulate(dentry);
 675         __rpc_rmdir(dir, dentry);
 676 err_dput:
 677         dput(dentry);
 678         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
 679                         __FILE__, __FUNCTION__, path, error);
 680         dentry = ERR_PTR(error);
 681         goto out;
 682 }
 683
 684 int
 685 rpc_rmdir(char *path)
 686 {
 687         struct nameidata nd;
 688         struct dentry *dentry;
 689         struct inode *dir;
 690         int error;
 691
 692         if ((error = rpc_lookup_parent(path, &nd)) != 0)
 693                 return error;
 694         dir = nd.dentry->d_inode;
 695         mutex_lock(&dir->i_mutex);
 696         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
 697         if (IS_ERR(dentry)) {
 698                 error = PTR_ERR(dentry);
 699                 goto out_release;
 700         }
 701         rpc_depopulate(dentry);
 702         error = __rpc_rmdir(dir, dentry);
 703         dput(dentry);
 704 out_release:
 705         mutex_unlock(&dir->i_mutex);
 706         rpc_release_path(&nd);
 707         return error;
 708 }
 709
 710 struct dentry *
 711 rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
 712 {
 713         struct nameidata nd;
 714         struct dentry *dentry;
 715         struct inode *dir, *inode;
 716         struct rpc_inode *rpci;
 717
 718         dentry = rpc_lookup_negative(path, &nd);
 719         if (IS_ERR(dentry))
 720                 return dentry;
 721         dir = nd.dentry->d_inode;
 722         inode = rpc_get_inode(dir->i_sb, S_IFSOCK | S_IRUSR | S_IWUSR);
 723         if (!inode)
 724                 goto err_dput;
 725         inode->i_ino = iunique(dir->i_sb, 100);
 726         inode->i_fop = &rpc_pipe_fops;
 727         d_instantiate(dentry, inode);
 728         rpci = RPC_I(inode);
 729         rpci->private = private;
 730         rpci->flags = flags;
 731         rpci->ops = ops;
 732         inode_dir_notify(dir, DN_CREATE);
 733 out:
 734         mutex_unlock(&dir->i_mutex);
 735         rpc_release_path(&nd);
 736         return dget(dentry);
 737 err_dput:
 738         dput(dentry);
 739         dentry = ERR_PTR(-ENOMEM);
 740         printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n",
 741                         __FILE__, __FUNCTION__, path, -ENOMEM);
 742         goto out;
 743 }
 744
 745 int
 746 rpc_unlink(char *path)
 747 {
 748         struct nameidata nd;
 749         struct dentry *dentry;
 750         struct inode *dir;
 751         int error;
 752
 753         if ((error = rpc_lookup_parent(path, &nd)) != 0)
 754                 return error;
 755         dir = nd.dentry->d_inode;
 756         mutex_lock(&dir->i_mutex);
 757         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
 758         if (IS_ERR(dentry)) {
 759                 error = PTR_ERR(dentry);
 760                 goto out_release;
 761         }
 762         d_drop(dentry);
 763         if (dentry->d_inode) {
 764                 rpc_close_pipes(dentry->d_inode);
 765                 error = simple_unlink(dir, dentry);
 766         }
 767         dput(dentry);
 768         inode_dir_notify(dir, DN_DELETE);
 769 out_release:
 770         mutex_unlock(&dir->i_mutex);
 771         rpc_release_path(&nd);
 772         return error;
 773 }
 774
 775 /*
 776  * populate the filesystem
 777  */
 778 static struct super_operations s_ops = {
 779         .alloc_inode    = rpc_alloc_inode,
 780         .destroy_inode  = rpc_destroy_inode,
 781         .statfs         = simple_statfs,
 782 };
 783
 784 #define RPCAUTH_GSSMAGIC 0x67596969
 785
 786 static int
 787 rpc_fill_super(struct super_block *sb, void *data, int silent)
 788 {
 789         struct inode *inode;
 790         struct dentry *root;
 791
 792         sb->s_blocksize = PAGE_CACHE_SIZE;
 793         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 794         sb->s_magic = RPCAUTH_GSSMAGIC;
 795         sb->s_op = &s_ops;
 796         sb->s_time_gran = 1;
 797
 798         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 799         if (!inode)
 800                 return -ENOMEM;
 801         root = d_alloc_root(inode);
 802         if (!root) {
 803                 iput(inode);
 804                 return -ENOMEM;
 805         }
 806         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 807                 goto out;
 808         sb->s_root = root;
 809         return 0;
 810 out:
 811         d_genocide(root);
 812         dput(root);
 813         return -ENOMEM;
 814 }
 815
 816 static struct super_block *
 817 rpc_get_sb(struct file_system_type *fs_type,
 818                 int flags, const char *dev_name, void *data)
 819 {
 820         return get_sb_single(fs_type, flags, data, rpc_fill_super);
 821 }
 822
 823 static struct file_system_type rpc_pipe_fs_type = {
 824         .owner          = THIS_MODULE,
 825         .name           = "rpc_pipefs",
 826         .get_sb         = rpc_get_sb,
 827         .kill_sb        = kill_litter_super,
 828 };
 829
 830 static void
 831 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 832 {
 833         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 834
 835         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 836             SLAB_CTOR_CONSTRUCTOR) {
 837                 inode_init_once(&rpci->vfs_inode);
 838                 rpci->private = NULL;
 839                 rpci->nreaders = 0;
 840                 rpci->nwriters = 0;
 841                 INIT_LIST_HEAD(&rpci->in_upcall);
 842                 INIT_LIST_HEAD(&rpci->pipe);
 843                 rpci->pipelen = 0;
 844                 init_waitqueue_head(&rpci->waitq);
 845                 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
 846                 rpci->ops = NULL;
 847         }
 848 }
 849
 850 int register_rpc_pipefs(void)
 851 {
 852         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 853                                              sizeof(struct rpc_inode),
 854                                              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
 855                                              init_once, NULL);
 856         if (!rpc_inode_cachep)
 857                 return -ENOMEM;
 858         register_filesystem(&rpc_pipe_fs_type);
 859         return 0;
 860 }
 861
 862 void unregister_rpc_pipefs(void)
 863 {
 864         if (kmem_cache_destroy(rpc_inode_cachep))
 865                 printk(KERN_WARNING "RPC: unable to free inode cache\n");
 866         unregister_filesystem(&rpc_pipe_fs_type);
 867 }