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(&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, GFP_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_path.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_path.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_path.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_path.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 const 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: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 332         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 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         }
 590         mutex_unlock(&dir->i_mutex);
 591         return 0;
 592 out_bad:
 593         mutex_unlock(&dir->i_mutex);
 594         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 595                         __FILE__, __FUNCTION__, parent->d_name.name);
 596         return -ENOMEM;
 597 }
 598
 599 static int
 600 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 601 {
 602         struct inode *inode;
 603
 604         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
 605         if (!inode)
 606                 goto out_err;
 607         inode->i_ino = iunique(dir->i_sb, 100);
 608         d_instantiate(dentry, inode);
 609         inc_nlink(dir);
 610         inode_dir_notify(dir, DN_CREATE);
 611         return 0;
 612 out_err:
 613         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 614                         __FILE__, __FUNCTION__, dentry->d_name.name);
 615         return -ENOMEM;
 616 }
 617
 618 static int
 619 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 620 {
 621         int error;
 622         error = simple_rmdir(dir, dentry);
 623         if (!error)
 624                 d_delete(dentry);
 625         return error;
 626 }
 627
 628 static struct dentry *
 629 rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
 630 {
 631         struct inode *dir = parent->d_inode;
 632         struct dentry *dentry;
 633
 634         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 635         dentry = lookup_one_len(name, parent, len);
 636         if (IS_ERR(dentry))
 637                 goto out_err;
 638         if (!dentry->d_inode)
 639                 dentry->d_op = &rpc_dentry_operations;
 640         else if (exclusive) {
 641                 dput(dentry);
 642                 dentry = ERR_PTR(-EEXIST);
 643                 goto out_err;
 644         }
 645         return dentry;
 646 out_err:
 647         mutex_unlock(&dir->i_mutex);
 648         return dentry;
 649 }
 650
 651 static struct dentry *
 652 rpc_lookup_negative(char *path, struct nameidata *nd)
 653 {
 654         struct dentry *dentry;
 655         int error;
 656
 657         if ((error = rpc_lookup_parent(path, nd)) != 0)
 658                 return ERR_PTR(error);
 659         dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1);
 660         if (IS_ERR(dentry))
 661                 rpc_release_path(nd);
 662         return dentry;
 663 }
 664
 665
 666 struct dentry *
 667 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 668 {
 669         struct nameidata nd;
 670         struct dentry *dentry;
 671         struct inode *dir;
 672         int error;
 673
 674         dentry = rpc_lookup_negative(path, &nd);
 675         if (IS_ERR(dentry))
 676                 return dentry;
 677         dir = nd.dentry->d_inode;
 678         if ((error = __rpc_mkdir(dir, dentry)) != 0)
 679                 goto err_dput;
 680         RPC_I(dentry->d_inode)->private = rpc_client;
 681         error = rpc_populate(dentry, authfiles,
 682                         RPCAUTH_info, RPCAUTH_EOF);
 683         if (error)
 684                 goto err_depopulate;
 685         dget(dentry);
 686 out:
 687         mutex_unlock(&dir->i_mutex);
 688         rpc_release_path(&nd);
 689         return dentry;
 690 err_depopulate:
 691         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 692         __rpc_rmdir(dir, dentry);
 693 err_dput:
 694         dput(dentry);
 695         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
 696                         __FILE__, __FUNCTION__, path, error);
 697         dentry = ERR_PTR(error);
 698         goto out;
 699 }
 700
 701 int
 702 rpc_rmdir(struct dentry *dentry)
 703 {
 704         struct dentry *parent;
 705         struct inode *dir;
 706         int error;
 707
 708         parent = dget_parent(dentry);
 709         dir = parent->d_inode;
 710         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 711         rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
 712         error = __rpc_rmdir(dir, dentry);
 713         dput(dentry);
 714         mutex_unlock(&dir->i_mutex);
 715         dput(parent);
 716         return error;
 717 }
 718
 719 struct dentry *
 720 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
 721 {
 722         struct dentry *dentry;
 723         struct inode *dir, *inode;
 724         struct rpc_inode *rpci;
 725
 726         dentry = rpc_lookup_create(parent, name, strlen(name), 0);
 727         if (IS_ERR(dentry))
 728                 return dentry;
 729         dir = parent->d_inode;
 730         if (dentry->d_inode) {
 731                 rpci = RPC_I(dentry->d_inode);
 732                 if (rpci->private != private ||
 733                                 rpci->ops != ops ||
 734                                 rpci->flags != flags) {
 735                         dput (dentry);
 736                         dentry = ERR_PTR(-EBUSY);
 737                 }
 738                 rpci->nkern_readwriters++;
 739                 goto out;
 740         }
 741         inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
 742         if (!inode)
 743                 goto err_dput;
 744         inode->i_ino = iunique(dir->i_sb, 100);
 745         inode->i_fop = &rpc_pipe_fops;
 746         d_instantiate(dentry, inode);
 747         rpci = RPC_I(inode);
 748         rpci->private = private;
 749         rpci->flags = flags;
 750         rpci->ops = ops;
 751         rpci->nkern_readwriters = 1;
 752         inode_dir_notify(dir, DN_CREATE);
 753         dget(dentry);
 754 out:
 755         mutex_unlock(&dir->i_mutex);
 756         return dentry;
 757 err_dput:
 758         dput(dentry);
 759         dentry = ERR_PTR(-ENOMEM);
 760         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
 761                         __FILE__, __FUNCTION__, parent->d_name.name, name,
 762                         -ENOMEM);
 763         goto out;
 764 }
 765
 766 int
 767 rpc_unlink(struct dentry *dentry)
 768 {
 769         struct dentry *parent;
 770         struct inode *dir;
 771         int error = 0;
 772
 773         parent = dget_parent(dentry);
 774         dir = parent->d_inode;
 775         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 776         if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
 777                 rpc_close_pipes(dentry->d_inode);
 778                 error = simple_unlink(dir, dentry);
 779                 if (!error)
 780                         d_delete(dentry);
 781         }
 782         dput(dentry);
 783         mutex_unlock(&dir->i_mutex);
 784         dput(parent);
 785         return error;
 786 }
 787
 788 /*
 789  * populate the filesystem
 790  */
 791 static struct super_operations s_ops = {
 792         .alloc_inode    = rpc_alloc_inode,
 793         .destroy_inode  = rpc_destroy_inode,
 794         .statfs         = simple_statfs,
 795 };
 796
 797 #define RPCAUTH_GSSMAGIC 0x67596969
 798
 799 static int
 800 rpc_fill_super(struct super_block *sb, void *data, int silent)
 801 {
 802         struct inode *inode;
 803         struct dentry *root;
 804
 805         sb->s_blocksize = PAGE_CACHE_SIZE;
 806         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 807         sb->s_magic = RPCAUTH_GSSMAGIC;
 808         sb->s_op = &s_ops;
 809         sb->s_time_gran = 1;
 810
 811         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 812         if (!inode)
 813                 return -ENOMEM;
 814         root = d_alloc_root(inode);
 815         if (!root) {
 816                 iput(inode);
 817                 return -ENOMEM;
 818         }
 819         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
 820                 goto out;
 821         sb->s_root = root;
 822         return 0;
 823 out:
 824         d_genocide(root);
 825         dput(root);
 826         return -ENOMEM;
 827 }
 828
 829 static int
 830 rpc_get_sb(struct file_system_type *fs_type,
 831                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 832 {
 833         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
 834 }
 835
 836 static struct file_system_type rpc_pipe_fs_type = {
 837         .owner          = THIS_MODULE,
 838         .name           = "rpc_pipefs",
 839         .get_sb         = rpc_get_sb,
 840         .kill_sb        = kill_litter_super,
 841 };
 842
 843 static void
 844 init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
 845 {
 846         struct rpc_inode *rpci = (struct rpc_inode *) foo;
 847
 848         inode_init_once(&rpci->vfs_inode);
 849         rpci->private = NULL;
 850         rpci->nreaders = 0;
 851         rpci->nwriters = 0;
 852         INIT_LIST_HEAD(&rpci->in_upcall);
 853         INIT_LIST_HEAD(&rpci->in_downcall);
 854         INIT_LIST_HEAD(&rpci->pipe);
 855         rpci->pipelen = 0;
 856         init_waitqueue_head(&rpci->waitq);
 857         INIT_DELAYED_WORK(&rpci->queue_timeout,
 858                             rpc_timeout_upcall_queue);
 859         rpci->ops = NULL;
 860 }
 861
 862 int register_rpc_pipefs(void)
 863 {
 864         int err;
 865
 866         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
 867                                 sizeof(struct rpc_inode),
 868                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
 869                                                 SLAB_MEM_SPREAD),
 870                                 init_once, NULL);
 871         if (!rpc_inode_cachep)
 872                 return -ENOMEM;
 873         err = register_filesystem(&rpc_pipe_fs_type);
 874         if (err) {
 875                 kmem_cache_destroy(rpc_inode_cachep);
 876                 return err;
 877         }
 878
 879         return 0;
 880 }
 881
 882 void unregister_rpc_pipefs(void)
 883 {
 884         kmem_cache_destroy(rpc_inode_cachep);
 885         unregister_filesystem(&rpc_pipe_fs_type);
 886 }