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); 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 } 887