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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/fsnotify.h>
  18 #include <linux/kernel.h>
  19
  20 #include <asm/ioctls.h>
  21 #include <linux/fs.h>
  22 #include <linux/poll.h>
  23 #include <linux/wait.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/sunrpc/rpc_pipe_fs.h>
  29
  30 static struct vfsmount *rpc_mount __read_mostly;
  31 static int rpc_mount_count;
  32
  33 static struct file_system_type rpc_pipe_fs_type;
  34
  35
  36 static struct kmem_cache *rpc_inode_cachep __read_mostly;
  37
  38 #define RPC_UPCALL_TIMEOUT (30*HZ)
  39
  40 static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
  41                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  42 {
  43         struct rpc_pipe_msg *msg;
  44
  45         if (list_empty(head))
  46                 return;
  47         do {
  48                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  49                 list_del(&msg->list);
  50                 msg->errno = err;
  51                 destroy_msg(msg);
  52         } while (!list_empty(head));
  53         wake_up(&rpci->waitq);
  54 }
  55
  56 static void
  57 rpc_timeout_upcall_queue(struct work_struct *work)
  58 {
  59         LIST_HEAD(free_list);
  60         struct rpc_inode *rpci =
  61                 container_of(work, struct rpc_inode, queue_timeout.work);
  62         struct inode *inode = &rpci->vfs_inode;
  63         void (*destroy_msg)(struct rpc_pipe_msg *);
  64
  65         spin_lock(&inode->i_lock);
  66         if (rpci->ops == NULL) {
  67                 spin_unlock(&inode->i_lock);
  68                 return;
  69         }
  70         destroy_msg = rpci->ops->destroy_msg;
  71         if (rpci->nreaders == 0) {
  72                 list_splice_init(&rpci->pipe, &free_list);
  73                 rpci->pipelen = 0;
  74         }
  75         spin_unlock(&inode->i_lock);
  76         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
  77 }
  78
  79 /**
  80  * rpc_queue_upcall
  81  * @inode: inode of upcall pipe on which to queue given message
  82  * @msg: message to queue
  83  *
  84  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
  85  * A userspace process may then later read the upcall by performing a
  86  * read on an open file for this inode.  It is up to the caller to
  87  * initialize the fields of @msg (other than @msg->list) appropriately.
  88  */
  89 int
  90 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
  91 {
  92         struct rpc_inode *rpci = RPC_I(inode);
  93         int res = -EPIPE;
  94
  95         spin_lock(&inode->i_lock);
  96         if (rpci->ops == NULL)
  97                 goto out;
  98         if (rpci->nreaders) {
  99                 list_add_tail(&msg->list, &rpci->pipe);
 100                 rpci->pipelen += msg->len;
 101                 res = 0;
 102         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
 103                 if (list_empty(&rpci->pipe))
 104                         queue_delayed_work(rpciod_workqueue,
 105                                         &rpci->queue_timeout,
 106                                         RPC_UPCALL_TIMEOUT);
 107                 list_add_tail(&msg->list, &rpci->pipe);
 108                 rpci->pipelen += msg->len;
 109                 res = 0;
 110         }
 111 out:
 112         spin_unlock(&inode->i_lock);
 113         wake_up(&rpci->waitq);
 114         return res;
 115 }
 116 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 117
 118 static inline void
 119 rpc_inode_setowner(struct inode *inode, void *private)
 120 {
 121         RPC_I(inode)->private = private;
 122 }
 123
 124 static void
 125 rpc_close_pipes(struct inode *inode)
 126 {
 127         struct rpc_inode *rpci = RPC_I(inode);
 128         const struct rpc_pipe_ops *ops;
 129         int need_release;
 130
 131         mutex_lock(&inode->i_mutex);
 132         ops = rpci->ops;
 133         if (ops != NULL) {
 134                 LIST_HEAD(free_list);
 135                 spin_lock(&inode->i_lock);
 136                 need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
 137                 rpci->nreaders = 0;
 138                 list_splice_init(&rpci->in_upcall, &free_list);
 139                 list_splice_init(&rpci->pipe, &free_list);
 140                 rpci->pipelen = 0;
 141                 rpci->ops = NULL;
 142                 spin_unlock(&inode->i_lock);
 143                 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
 144                 rpci->nwriters = 0;
 145                 if (need_release && ops->release_pipe)
 146                         ops->release_pipe(inode);
 147                 cancel_delayed_work_sync(&rpci->queue_timeout);
 148         }
 149         rpc_inode_setowner(inode, NULL);
 150         mutex_unlock(&inode->i_mutex);
 151 }
 152
 153 static struct inode *
 154 rpc_alloc_inode(struct super_block *sb)
 155 {
 156         struct rpc_inode *rpci;
 157         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 158         if (!rpci)
 159                 return NULL;
 160         return &rpci->vfs_inode;
 161 }
 162
 163 static void
 164 rpc_destroy_inode(struct inode *inode)
 165 {
 166         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 167 }
 168
 169 static int
 170 rpc_pipe_open(struct inode *inode, struct file *filp)
 171 {
 172         struct rpc_inode *rpci = RPC_I(inode);
 173         int first_open;
 174         int res = -ENXIO;
 175
 176         mutex_lock(&inode->i_mutex);
 177         if (rpci->ops == NULL)
 178                 goto out;
 179         first_open = rpci->nreaders == 0 && rpci->nwriters == 0;
 180         if (first_open && rpci->ops->open_pipe) {
 181                 res = rpci->ops->open_pipe(inode);
 182                 if (res)
 183                         goto out;
 184         }
 185         if (filp->f_mode & FMODE_READ)
 186                 rpci->nreaders++;
 187         if (filp->f_mode & FMODE_WRITE)
 188                 rpci->nwriters++;
 189         res = 0;
 190 out:
 191         mutex_unlock(&inode->i_mutex);
 192         return res;
 193 }
 194
 195 static int
 196 rpc_pipe_release(struct inode *inode, struct file *filp)
 197 {
 198         struct rpc_inode *rpci = RPC_I(inode);
 199         struct rpc_pipe_msg *msg;
 200         int last_close;
 201
 202         mutex_lock(&inode->i_mutex);
 203         if (rpci->ops == NULL)
 204                 goto out;
 205         msg = (struct rpc_pipe_msg *)filp->private_data;
 206         if (msg != NULL) {
 207                 spin_lock(&inode->i_lock);
 208                 msg->errno = -EAGAIN;
 209                 list_del(&msg->list);
 210                 spin_unlock(&inode->i_lock);
 211                 rpci->ops->destroy_msg(msg);
 212         }
 213         if (filp->f_mode & FMODE_WRITE)
 214                 rpci->nwriters --;
 215         if (filp->f_mode & FMODE_READ) {
 216                 rpci->nreaders --;
 217                 if (rpci->nreaders == 0) {
 218                         LIST_HEAD(free_list);
 219                         spin_lock(&inode->i_lock);
 220                         list_splice_init(&rpci->pipe, &free_list);
 221                         rpci->pipelen = 0;
 222                         spin_unlock(&inode->i_lock);
 223                         rpc_purge_list(rpci, &free_list,
 224                                         rpci->ops->destroy_msg, -EAGAIN);
 225                 }
 226         }
 227         last_close = rpci->nwriters == 0 && rpci->nreaders == 0;
 228         if (last_close && rpci->ops->release_pipe)
 229                 rpci->ops->release_pipe(inode);
 230 out:
 231         mutex_unlock(&inode->i_mutex);
 232         return 0;
 233 }
 234
 235 static ssize_t
 236 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 237 {
 238         struct inode *inode = filp->f_path.dentry->d_inode;
 239         struct rpc_inode *rpci = RPC_I(inode);
 240         struct rpc_pipe_msg *msg;
 241         int res = 0;
 242
 243         mutex_lock(&inode->i_mutex);
 244         if (rpci->ops == NULL) {
 245                 res = -EPIPE;
 246                 goto out_unlock;
 247         }
 248         msg = filp->private_data;
 249         if (msg == NULL) {
 250                 spin_lock(&inode->i_lock);
 251                 if (!list_empty(&rpci->pipe)) {
 252                         msg = list_entry(rpci->pipe.next,
 253                                         struct rpc_pipe_msg,
 254                                         list);
 255                         list_move(&msg->list, &rpci->in_upcall);
 256                         rpci->pipelen -= msg->len;
 257                         filp->private_data = msg;
 258                         msg->copied = 0;
 259                 }
 260                 spin_unlock(&inode->i_lock);
 261                 if (msg == NULL)
 262                         goto out_unlock;
 263         }
 264         /* NOTE: it is up to the callback to update msg->copied */
 265         res = rpci->ops->upcall(filp, msg, buf, len);
 266         if (res < 0 || msg->len == msg->copied) {
 267                 filp->private_data = NULL;
 268                 spin_lock(&inode->i_lock);
 269                 list_del(&msg->list);
 270                 spin_unlock(&inode->i_lock);
 271                 rpci->ops->destroy_msg(msg);
 272         }
 273 out_unlock:
 274         mutex_unlock(&inode->i_mutex);
 275         return res;
 276 }
 277
 278 static ssize_t
 279 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 280 {
 281         struct inode *inode = filp->f_path.dentry->d_inode;
 282         struct rpc_inode *rpci = RPC_I(inode);
 283         int res;
 284
 285         mutex_lock(&inode->i_mutex);
 286         res = -EPIPE;
 287         if (rpci->ops != NULL)
 288                 res = rpci->ops->downcall(filp, buf, len);
 289         mutex_unlock(&inode->i_mutex);
 290         return res;
 291 }
 292
 293 static unsigned int
 294 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 295 {
 296         struct rpc_inode *rpci;
 297         unsigned int mask = 0;
 298
 299         rpci = RPC_I(filp->f_path.dentry->d_inode);
 300         poll_wait(filp, &rpci->waitq, wait);
 301
 302         mask = POLLOUT | POLLWRNORM;
 303         if (rpci->ops == NULL)
 304                 mask |= POLLERR | POLLHUP;
 305         if (filp->private_data || !list_empty(&rpci->pipe))
 306                 mask |= POLLIN | POLLRDNORM;
 307         return mask;
 308 }
 309
 310 static int
 311 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
 312                 unsigned int cmd, unsigned long arg)
 313 {
 314         struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 315         int len;
 316
 317         switch (cmd) {
 318         case FIONREAD:
 319                 if (rpci->ops == NULL)
 320                         return -EPIPE;
 321                 len = rpci->pipelen;
 322                 if (filp->private_data) {
 323                         struct rpc_pipe_msg *msg;
 324                         msg = (struct rpc_pipe_msg *)filp->private_data;
 325                         len += msg->len - msg->copied;
 326                 }
 327                 return put_user(len, (int __user *)arg);
 328         default:
 329                 return -EINVAL;
 330         }
 331 }
 332
 333 static const struct file_operations rpc_pipe_fops = {
 334         .owner          = THIS_MODULE,
 335         .llseek         = no_llseek,
 336         .read           = rpc_pipe_read,
 337         .write          = rpc_pipe_write,
 338         .poll           = rpc_pipe_poll,
 339         .ioctl          = rpc_pipe_ioctl,
 340         .open           = rpc_pipe_open,
 341         .release        = rpc_pipe_release,
 342 };
 343
 344 static int
 345 rpc_show_info(struct seq_file *m, void *v)
 346 {
 347         struct rpc_clnt *clnt = m->private;
 348
 349         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
 350         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
 351                         clnt->cl_prog, clnt->cl_vers);
 352         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 353         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 354         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 355         return 0;
 356 }
 357
 358 static int
 359 rpc_info_open(struct inode *inode, struct file *file)
 360 {
 361         struct rpc_clnt *clnt;
 362         int ret = single_open(file, rpc_show_info, NULL);
 363
 364         if (!ret) {
 365                 struct seq_file *m = file->private_data;
 366                 mutex_lock(&inode->i_mutex);
 367                 clnt = RPC_I(inode)->private;
 368                 if (clnt) {
 369                         kref_get(&clnt->cl_kref);
 370                         m->private = clnt;
 371                 } else {
 372                         single_release(inode, file);
 373                         ret = -EINVAL;
 374                 }
 375                 mutex_unlock(&inode->i_mutex);
 376         }
 377         return ret;
 378 }
 379
 380 static int
 381 rpc_info_release(struct inode *inode, struct file *file)
 382 {
 383         struct seq_file *m = file->private_data;
 384         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 385
 386         if (clnt)
 387                 rpc_release_client(clnt);
 388         return single_release(inode, file);
 389 }
 390
 391 static const struct file_operations rpc_info_operations = {
 392         .owner          = THIS_MODULE,
 393         .open           = rpc_info_open,
 394         .read           = seq_read,
 395         .llseek         = seq_lseek,
 396         .release        = rpc_info_release,
 397 };
 398
 399
 400 /*
 401  * Description of fs contents.
 402  */
 403 struct rpc_filelist {
 404         const char *name;
 405         const struct file_operations *i_fop;
 406         umode_t mode;
 407 };
 408
 409 enum {
 410         RPCAUTH_info,
 411         RPCAUTH_EOF
 412 };
 413
 414 static const struct rpc_filelist authfiles[] = {
 415         [RPCAUTH_info] = {
 416                 .name = "info",
 417                 .i_fop = &rpc_info_operations,
 418                 .mode = S_IFREG | S_IRUSR,
 419         },
 420 };
 421
 422 struct vfsmount *rpc_get_mount(void)
 423 {
 424         int err;
 425
 426         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
 427         if (err != 0)
 428                 return ERR_PTR(err);
 429         return rpc_mount;
 430 }
 431
 432 void rpc_put_mount(void)
 433 {
 434         simple_release_fs(&rpc_mount, &rpc_mount_count);
 435 }
 436
 437 static int rpc_delete_dentry(struct dentry *dentry)
 438 {
 439         return 1;
 440 }
 441
 442 static const struct dentry_operations rpc_dentry_operations = {
 443         .d_delete = rpc_delete_dentry,
 444 };
 445
 446 static int __rpc_lookup_path(const char *pathname, unsigned flags,
 447                              struct nameidata *nd)
 448 {
 449         struct vfsmount *mnt;
 450
 451         if (pathname[0] == '\0')
 452                 return -ENOENT;
 453
 454         mnt = rpc_get_mount();
 455         if (IS_ERR(mnt)) {
 456                 printk(KERN_WARNING "%s: %s failed to mount "
 457                                "pseudofilesystem \n", __FILE__, __func__);
 458                 return PTR_ERR(mnt);
 459         }
 460
 461         if (vfs_path_lookup(mnt->mnt_root, mnt, pathname, flags, nd)) {
 462                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
 463                                 __FILE__, __func__, pathname);
 464                 rpc_put_mount();
 465                 return -ENOENT;
 466         }
 467         return 0;
 468 }
 469
 470 static int rpc_lookup_parent(const char *pathname, struct nameidata *nd)
 471 {
 472         return __rpc_lookup_path(pathname, LOOKUP_PARENT, nd);
 473 }
 474
 475 static void
 476 rpc_release_path(struct nameidata *nd)
 477 {
 478         path_put(&nd->path);
 479         rpc_put_mount();
 480 }
 481
 482 static struct inode *
 483 rpc_get_inode(struct super_block *sb, umode_t mode)
 484 {
 485         struct inode *inode = new_inode(sb);
 486         if (!inode)
 487                 return NULL;
 488         inode->i_mode = mode;
 489         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 490         switch(mode & S_IFMT) {
 491                 case S_IFDIR:
 492                         inode->i_fop = &simple_dir_operations;
 493                         inode->i_op = &simple_dir_inode_operations;
 494                         inc_nlink(inode);
 495                 default:
 496                         break;
 497         }
 498         return inode;
 499 }
 500
 501 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
 502                                umode_t mode,
 503                                const struct file_operations *i_fop,
 504                                void *private)
 505 {
 506         struct inode *inode;
 507
 508         BUG_ON(!d_unhashed(dentry));
 509         inode = rpc_get_inode(dir->i_sb, mode);
 510         if (!inode)
 511                 goto out_err;
 512         inode->i_ino = iunique(dir->i_sb, 100);
 513         if (i_fop)
 514                 inode->i_fop = i_fop;
 515         if (private)
 516                 rpc_inode_setowner(inode, private);
 517         d_add(dentry, inode);
 518         return 0;
 519 out_err:
 520         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 521                         __FILE__, __func__, dentry->d_name.name);
 522         dput(dentry);
 523         return -ENOMEM;
 524 }
 525
 526 static int __rpc_create(struct inode *dir, struct dentry *dentry,
 527                         umode_t mode,
 528                         const struct file_operations *i_fop,
 529                         void *private)
 530 {
 531         int err;
 532
 533         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
 534         if (err)
 535                 return err;
 536         fsnotify_create(dir, dentry);
 537         return 0;
 538 }
 539
 540 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
 541                        umode_t mode,
 542                        const struct file_operations *i_fop,
 543                        void *private)
 544 {
 545         int err;
 546
 547         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
 548         if (err)
 549                 return err;
 550         inc_nlink(dir);
 551         fsnotify_mkdir(dir, dentry);
 552         return 0;
 553 }
 554
 555 static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry,
 556                         umode_t mode,
 557                         const struct file_operations *i_fop,
 558                         void *private,
 559                         const struct rpc_pipe_ops *ops,
 560                         int flags)
 561 {
 562         struct rpc_inode *rpci;
 563         int err;
 564
 565         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
 566         if (err)
 567                 return err;
 568         rpci = RPC_I(dentry->d_inode);
 569         rpci->nkern_readwriters = 1;
 570         rpci->private = private;
 571         rpci->flags = flags;
 572         rpci->ops = ops;
 573         fsnotify_create(dir, dentry);
 574         return 0;
 575 }
 576
 577 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 578 {
 579         int ret;
 580
 581         dget(dentry);
 582         ret = simple_rmdir(dir, dentry);
 583         d_delete(dentry);
 584         dput(dentry);
 585         return ret;
 586 }
 587
 588 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 589 {
 590         int ret;
 591
 592         dget(dentry);
 593         ret = simple_unlink(dir, dentry);
 594         d_delete(dentry);
 595         dput(dentry);
 596         return ret;
 597 }
 598
 599 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 600 {
 601         struct inode *inode = dentry->d_inode;
 602         struct rpc_inode *rpci = RPC_I(inode);
 603
 604         rpci->nkern_readwriters--;
 605         if (rpci->nkern_readwriters != 0)
 606                 return 0;
 607         rpc_close_pipes(inode);
 608         return __rpc_unlink(dir, dentry);
 609 }
 610
 611 static struct dentry *__rpc_lookup_create(struct dentry *parent,
 612                                           struct qstr *name)
 613 {
 614         struct dentry *dentry;
 615
 616         dentry = d_lookup(parent, name);
 617         if (!dentry) {
 618                 dentry = d_alloc(parent, name);
 619                 if (!dentry) {
 620                         dentry = ERR_PTR(-ENOMEM);
 621                         goto out_err;
 622                 }
 623         }
 624         if (!dentry->d_inode)
 625                 dentry->d_op = &rpc_dentry_operations;
 626 out_err:
 627         return dentry;
 628 }
 629
 630 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 631                                           struct qstr *name)
 632 {
 633         struct dentry *dentry;
 634
 635         dentry = __rpc_lookup_create(parent, name);
 636         if (dentry->d_inode == NULL)
 637                 return dentry;
 638         dput(dentry);
 639         return ERR_PTR(-EEXIST);
 640 }
 641
 642 /*
 643  * FIXME: This probably has races.
 644  */
 645 static void __rpc_depopulate(struct dentry *parent,
 646                              const struct rpc_filelist *files,
 647                              int start, int eof)
 648 {
 649         struct inode *dir = parent->d_inode;
 650         struct dentry *dentry;
 651         struct qstr name;
 652         int i;
 653
 654         for (i = start; i < eof; i++) {
 655                 name.name = files[i].name;
 656                 name.len = strlen(files[i].name);
 657                 name.hash = full_name_hash(name.name, name.len);
 658                 dentry = d_lookup(parent, &name);
 659
 660                 if (dentry == NULL)
 661                         continue;
 662                 if (dentry->d_inode == NULL)
 663                         goto next;
 664                 switch (dentry->d_inode->i_mode & S_IFMT) {
 665                         default:
 666                                 BUG();
 667                         case S_IFREG:
 668                                 __rpc_unlink(dir, dentry);
 669                                 break;
 670                         case S_IFDIR:
 671                                 __rpc_rmdir(dir, dentry);
 672                 }
 673 next:
 674                 dput(dentry);
 675         }
 676 }
 677
 678 static void rpc_depopulate(struct dentry *parent,
 679                            const struct rpc_filelist *files,
 680                            int start, int eof)
 681 {
 682         struct inode *dir = parent->d_inode;
 683
 684         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 685         __rpc_depopulate(parent, files, start, eof);
 686         mutex_unlock(&dir->i_mutex);
 687 }
 688
 689 static int rpc_populate(struct dentry *parent,
 690                         const struct rpc_filelist *files,
 691                         int start, int eof,
 692                         void *private)
 693 {
 694         struct inode *dir = parent->d_inode;
 695         struct dentry *dentry;
 696         int i, err;
 697
 698         mutex_lock(&dir->i_mutex);
 699         for (i = start; i < eof; i++) {
 700                 struct qstr q;
 701
 702                 q.name = files[i].name;
 703                 q.len = strlen(files[i].name);
 704                 q.hash = full_name_hash(q.name, q.len);
 705                 dentry = __rpc_lookup_create_exclusive(parent, &q);
 706                 err = PTR_ERR(dentry);
 707                 if (IS_ERR(dentry))
 708                         goto out_bad;
 709                 switch (files[i].mode & S_IFMT) {
 710                         default:
 711                                 BUG();
 712                         case S_IFREG:
 713                                 err = __rpc_create(dir, dentry,
 714                                                 files[i].mode,
 715                                                 files[i].i_fop,
 716                                                 private);
 717                                 break;
 718                         case S_IFDIR:
 719                                 err = __rpc_mkdir(dir, dentry,
 720                                                 files[i].mode,
 721                                                 NULL,
 722                                                 private);
 723                 }
 724                 if (err != 0)
 725                         goto out_bad;
 726         }
 727         mutex_unlock(&dir->i_mutex);
 728         return 0;
 729 out_bad:
 730         __rpc_depopulate(parent, files, start, eof);
 731         mutex_unlock(&dir->i_mutex);
 732         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 733                         __FILE__, __func__, parent->d_name.name);
 734         return err;
 735 }
 736
 737 struct dentry *rpc_mkdir_populate(struct dentry *parent,
 738                 struct qstr *name, umode_t mode, void *private)
 739 {
 740         struct dentry *dentry;
 741         struct inode *dir = parent->d_inode;
 742         int error;
 743
 744         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 745         dentry = __rpc_lookup_create_exclusive(parent, name);
 746         if (IS_ERR(dentry))
 747                 goto out;
 748         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
 749         if (error != 0)
 750                 goto out_err;
 751         error = rpc_populate(dentry, authfiles,
 752                         RPCAUTH_info, RPCAUTH_EOF, private);
 753         if (error)
 754                 goto err_rmdir;
 755 out:
 756         mutex_unlock(&dir->i_mutex);
 757         return dentry;
 758 err_rmdir:
 759         __rpc_rmdir(dir, dentry);
 760 out_err:
 761         dentry = ERR_PTR(error);
 762         goto out;
 763 }
 764
 765 /**
 766  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
 767  * @dentry: directory to remove
 768  */
 769 int rpc_remove_client_dir(struct dentry *dentry)
 770 {
 771         struct dentry *parent;
 772         struct inode *dir;
 773         int error;
 774
 775         parent = dget_parent(dentry);
 776         dir = parent->d_inode;
 777         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 778         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
 779         error = __rpc_rmdir(dir, dentry);
 780         mutex_unlock(&dir->i_mutex);
 781         dput(parent);
 782         return error;
 783 }
 784
 785 /**
 786  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 787  * @parent: dentry of directory to create new "pipe" in
 788  * @name: name of pipe
 789  * @private: private data to associate with the pipe, for the caller's use
 790  * @ops: operations defining the behavior of the pipe: upcall, downcall,
 791  *      release_pipe, open_pipe, and destroy_msg.
 792  * @flags: rpc_inode flags
 793  *
 794  * Data is made available for userspace to read by calls to
 795  * rpc_queue_upcall().  The actual reads will result in calls to
 796  * @ops->upcall, which will be called with the file pointer,
 797  * message, and userspace buffer to copy to.
 798  *
 799  * Writes can come at any time, and do not necessarily have to be
 800  * responses to upcalls.  They will result in calls to @msg->downcall.
 801  *
 802  * The @private argument passed here will be available to all these methods
 803  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
 804  */
 805 struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
 806                           void *private, const struct rpc_pipe_ops *ops,
 807                           int flags)
 808 {
 809         struct dentry *dentry;
 810         struct inode *dir = parent->d_inode;
 811         umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
 812         struct qstr q;
 813         int err;
 814
 815         if (ops->upcall == NULL)
 816                 umode &= ~S_IRUGO;
 817         if (ops->downcall == NULL)
 818                 umode &= ~S_IWUGO;
 819
 820         q.name = name;
 821         q.len = strlen(name);
 822         q.hash = full_name_hash(q.name, q.len),
 823
 824         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 825         dentry = __rpc_lookup_create(parent, &q);
 826         if (IS_ERR(dentry))
 827                 goto out;
 828         if (dentry->d_inode) {
 829                 struct rpc_inode *rpci = RPC_I(dentry->d_inode);
 830                 if (rpci->private != private ||
 831                                 rpci->ops != ops ||
 832                                 rpci->flags != flags) {
 833                         dput (dentry);
 834                         err = -EBUSY;
 835                         goto out_err;
 836                 }
 837                 rpci->nkern_readwriters++;
 838                 goto out;
 839         }
 840
 841         err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops,
 842                            private, ops, flags);
 843         if (err)
 844                 goto out_err;
 845 out:
 846         mutex_unlock(&dir->i_mutex);
 847         return dentry;
 848 out_err:
 849         dentry = ERR_PTR(err);
 850         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
 851                         __FILE__, __func__, parent->d_name.name, name,
 852                         err);
 853         goto out;
 854 }
 855 EXPORT_SYMBOL_GPL(rpc_mkpipe);
 856
 857 /**
 858  * rpc_unlink - remove a pipe
 859  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 860  *
 861  * After this call, lookups will no longer find the pipe, and any
 862  * attempts to read or write using preexisting opens of the pipe will
 863  * return -EPIPE.
 864  */
 865 int
 866 rpc_unlink(struct dentry *dentry)
 867 {
 868         struct dentry *parent;
 869         struct inode *dir;
 870         int error = 0;
 871
 872         parent = dget_parent(dentry);
 873         dir = parent->d_inode;
 874         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 875         error = __rpc_rmpipe(dir, dentry);
 876         mutex_unlock(&dir->i_mutex);
 877         dput(parent);
 878         return error;
 879 }
 880 EXPORT_SYMBOL_GPL(rpc_unlink);
 881
 882 /**
 883  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
 884  * @path: path from the rpc_pipefs root to the new directory
 885  * @rpc_client: rpc client to associate with this directory
 886  *
 887  * This creates a directory at the given @path associated with
 888  * @rpc_clnt, which will contain a file named "info" with some basic
 889  * information about the client, together with any "pipes" that may
 890  * later be created using rpc_mkpipe().
 891  */
 892 struct dentry *rpc_create_client_dir(const char *path,
 893                                      struct rpc_clnt *rpc_client)
 894 {
 895         struct nameidata nd;
 896         struct dentry *ret;
 897         struct inode *dir;
 898
 899         ret = ERR_PTR(rpc_lookup_parent(path, &nd));
 900         if (IS_ERR(ret))
 901                 goto out_err;
 902         dir = nd.path.dentry->d_inode;
 903
 904         ret = rpc_mkdir_populate(nd.path.dentry, &nd.last,
 905                         S_IRUGO | S_IXUGO, rpc_client);
 906         rpc_release_path(&nd);
 907         if (!IS_ERR(ret))
 908                 return ret;
 909 out_err:
 910         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %ld)\n",
 911                         __FILE__, __func__, path, PTR_ERR(ret));
 912         return ret;
 913 }
 914
 915 /*
 916  * populate the filesystem
 917  */
 918 static struct super_operations s_ops = {
 919         .alloc_inode    = rpc_alloc_inode,
 920         .destroy_inode  = rpc_destroy_inode,
 921         .statfs         = simple_statfs,
 922 };
 923
 924 #define RPCAUTH_GSSMAGIC 0x67596969
 925
 926 /*
 927  * We have a single directory with 1 node in it.
 928  */
 929 enum {
 930         RPCAUTH_lockd,
 931         RPCAUTH_mount,
 932         RPCAUTH_nfs,
 933         RPCAUTH_portmap,
 934         RPCAUTH_statd,
 935         RPCAUTH_nfsd4_cb,
 936         RPCAUTH_RootEOF
 937 };
 938
 939 static const struct rpc_filelist files[] = {
 940         [RPCAUTH_lockd] = {
 941                 .name = "lockd",
 942                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 943         },
 944         [RPCAUTH_mount] = {
 945                 .name = "mount",
 946                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 947         },
 948         [RPCAUTH_nfs] = {
 949                 .name = "nfs",
 950                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 951         },
 952         [RPCAUTH_portmap] = {
 953                 .name = "portmap",
 954                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 955         },
 956         [RPCAUTH_statd] = {
 957                 .name = "statd",
 958                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 959         },
 960         [RPCAUTH_nfsd4_cb] = {
 961                 .name = "nfsd4_cb",
 962                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
 963         },
 964 };
 965
 966 static int
 967 rpc_fill_super(struct super_block *sb, void *data, int silent)
 968 {
 969         struct inode *inode;
 970         struct dentry *root;
 971
 972         sb->s_blocksize = PAGE_CACHE_SIZE;
 973         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 974         sb->s_magic = RPCAUTH_GSSMAGIC;
 975         sb->s_op = &s_ops;
 976         sb->s_time_gran = 1;
 977
 978         inode = rpc_get_inode(sb, S_IFDIR | 0755);
 979         if (!inode)
 980                 return -ENOMEM;
 981         root = d_alloc_root(inode);
 982         if (!root) {
 983                 iput(inode);
 984                 return -ENOMEM;
 985         }
 986         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
 987                 goto out;
 988         sb->s_root = root;
 989         return 0;
 990 out:
 991         d_genocide(root);
 992         dput(root);
 993         return -ENOMEM;
 994 }
 995
 996 static int
 997 rpc_get_sb(struct file_system_type *fs_type,
 998                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 999 {
1000         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
1001 }
1002
1003 static struct file_system_type rpc_pipe_fs_type = {
1004         .owner          = THIS_MODULE,
1005         .name           = "rpc_pipefs",
1006         .get_sb         = rpc_get_sb,
1007         .kill_sb        = kill_litter_super,
1008 };
1009
1010 static void
1011 init_once(void *foo)
1012 {
1013         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1014
1015         inode_init_once(&rpci->vfs_inode);
1016         rpci->private = NULL;
1017         rpci->nreaders = 0;
1018         rpci->nwriters = 0;
1019         INIT_LIST_HEAD(&rpci->in_upcall);
1020         INIT_LIST_HEAD(&rpci->in_downcall);
1021         INIT_LIST_HEAD(&rpci->pipe);
1022         rpci->pipelen = 0;
1023         init_waitqueue_head(&rpci->waitq);
1024         INIT_DELAYED_WORK(&rpci->queue_timeout,
1025                             rpc_timeout_upcall_queue);
1026         rpci->ops = NULL;
1027 }
1028
1029 int register_rpc_pipefs(void)
1030 {
1031         int err;
1032
1033         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1034                                 sizeof(struct rpc_inode),
1035                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1036                                                 SLAB_MEM_SPREAD),
1037                                 init_once);
1038         if (!rpc_inode_cachep)
1039                 return -ENOMEM;
1040         err = register_filesystem(&rpc_pipe_fs_type);
1041         if (err) {
1042                 kmem_cache_destroy(rpc_inode_cachep);
1043                 return err;
1044         }
1045
1046         return 0;
1047 }
1048
1049 void unregister_rpc_pipefs(void)
1050 {
1051         kmem_cache_destroy(rpc_inode_cachep);
1052         unregister_filesystem(&rpc_pipe_fs_type);
1053 }