1 /* 2 * net/sunrpc/rpc_pipe.c 3 * 4 * Userland/kernel interface for rpcauth_gss. 5 * Code shamelessly plagiarized from fs/nfsd/nfsctl.c 6 * and fs/sysfs/inode.c 7 * 8 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no> 9 * 10 */ 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/string.h> 14 #include <linux/pagemap.h> 15 #include <linux/mount.h> 16 #include <linux/namei.h> 17 #include <linux/dnotify.h> 18 #include <linux/kernel.h> 19 20 #include <asm/ioctls.h> 21 #include <linux/fs.h> 22 #include <linux/poll.h> 23 #include <linux/wait.h> 24 #include <linux/seq_file.h> 25 26 #include <linux/sunrpc/clnt.h> 27 #include <linux/workqueue.h> 28 #include <linux/sunrpc/rpc_pipe_fs.h> 29 30 static struct vfsmount *rpc_mount __read_mostly; 31 static int rpc_mount_count; 32 33 static struct file_system_type rpc_pipe_fs_type; 34 35 36 static struct kmem_cache *rpc_inode_cachep __read_mostly; 37 38 #define RPC_UPCALL_TIMEOUT (30*HZ) 39 40 static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head, 41 void (*destroy_msg)(struct rpc_pipe_msg *), int err) 42 { 43 struct rpc_pipe_msg *msg; 44 45 if (list_empty(head)) 46 return; 47 do { 48 msg = list_entry(head->next, struct rpc_pipe_msg, list); 49 list_del(&msg->list); 50 msg->errno = err; 51 destroy_msg(msg); 52 } while (!list_empty(head)); 53 wake_up(&rpci->waitq); 54 } 55 56 static void 57 rpc_timeout_upcall_queue(struct work_struct *work) 58 { 59 LIST_HEAD(free_list); 60 struct rpc_inode *rpci = 61 container_of(work, struct rpc_inode, queue_timeout.work); 62 struct inode *inode = &rpci->vfs_inode; 63 void (*destroy_msg)(struct rpc_pipe_msg *); 64 65 spin_lock(&inode->i_lock); 66 if (rpci->ops == NULL) { 67 spin_unlock(&inode->i_lock); 68 return; 69 } 70 destroy_msg = rpci->ops->destroy_msg; 71 if (rpci->nreaders == 0) { 72 list_splice_init(&rpci->pipe, &free_list); 73 rpci->pipelen = 0; 74 } 75 spin_unlock(&inode->i_lock); 76 rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT); 77 } 78 79 int 80 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg) 81 { 82 struct rpc_inode *rpci = RPC_I(inode); 83 int res = -EPIPE; 84 85 spin_lock(&inode->i_lock); 86 if (rpci->ops == NULL) 87 goto out; 88 if (rpci->nreaders) { 89 list_add_tail(&msg->list, &rpci->pipe); 90 rpci->pipelen += msg->len; 91 res = 0; 92 } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) { 93 if (list_empty(&rpci->pipe)) 94 queue_delayed_work(rpciod_workqueue, 95 &rpci->queue_timeout, 96 RPC_UPCALL_TIMEOUT); 97 list_add_tail(&msg->list, &rpci->pipe); 98 rpci->pipelen += msg->len; 99 res = 0; 100 } 101 out: 102 spin_unlock(&inode->i_lock); 103 wake_up(&rpci->waitq); 104 return res; 105 } 106 107 static inline void 108 rpc_inode_setowner(struct inode *inode, void *private) 109 { 110 RPC_I(inode)->private = private; 111 } 112 113 static void 114 rpc_close_pipes(struct inode *inode) 115 { 116 struct rpc_inode *rpci = RPC_I(inode); 117 struct rpc_pipe_ops *ops; 118 119 mutex_lock(&inode->i_mutex); 120 ops = rpci->ops; 121 if (ops != NULL) { 122 LIST_HEAD(free_list); 123 124 spin_lock(&inode->i_lock); 125 rpci->nreaders = 0; 126 list_splice_init(&rpci->in_upcall, &free_list); 127 list_splice_init(&rpci->pipe, &free_list); 128 rpci->pipelen = 0; 129 rpci->ops = NULL; 130 spin_unlock(&inode->i_lock); 131 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE); 132 rpci->nwriters = 0; 133 if (ops->release_pipe) 134 ops->release_pipe(inode); 135 cancel_delayed_work_sync(&rpci->queue_timeout); 136 } 137 rpc_inode_setowner(inode, NULL); 138 mutex_unlock(&inode->i_mutex); 139 } 140 141 static struct inode * 142 rpc_alloc_inode(struct super_block *sb) 143 { 144 struct rpc_inode *rpci; 145 rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL); 146 if (!rpci) 147 return NULL; 148 return &rpci->vfs_inode; 149 } 150 151 static void 152 rpc_destroy_inode(struct inode *inode) 153 { 154 kmem_cache_free(rpc_inode_cachep, RPC_I(inode)); 155 } 156 157 static int 158 rpc_pipe_open(struct inode *inode, struct file *filp) 159 { 160 struct rpc_inode *rpci = RPC_I(inode); 161 int res = -ENXIO; 162 163 mutex_lock(&inode->i_mutex); 164 if (rpci->ops != NULL) { 165 if (filp->f_mode & FMODE_READ) 166 rpci->nreaders ++; 167 if (filp->f_mode & FMODE_WRITE) 168 rpci->nwriters ++; 169 res = 0; 170 } 171 mutex_unlock(&inode->i_mutex); 172 return res; 173 } 174 175 static int 176 rpc_pipe_release(struct inode *inode, struct file *filp) 177 { 178 struct rpc_inode *rpci = RPC_I(inode); 179 struct rpc_pipe_msg *msg; 180 181 mutex_lock(&inode->i_mutex); 182 if (rpci->ops == NULL) 183 goto out; 184 msg = (struct rpc_pipe_msg *)filp->private_data; 185 if (msg != NULL) { 186 spin_lock(&inode->i_lock); 187 msg->errno = -EAGAIN; 188 list_del(&msg->list); 189 spin_unlock(&inode->i_lock); 190 rpci->ops->destroy_msg(msg); 191 } 192 if (filp->f_mode & FMODE_WRITE) 193 rpci->nwriters --; 194 if (filp->f_mode & FMODE_READ) { 195 rpci->nreaders --; 196 if (rpci->nreaders == 0) { 197 LIST_HEAD(free_list); 198 spin_lock(&inode->i_lock); 199 list_splice_init(&rpci->pipe, &free_list); 200 rpci->pipelen = 0; 201 spin_unlock(&inode->i_lock); 202 rpc_purge_list(rpci, &free_list, 203 rpci->ops->destroy_msg, -EAGAIN); 204 } 205 } 206 if (rpci->ops->release_pipe) 207 rpci->ops->release_pipe(inode); 208 out: 209 mutex_unlock(&inode->i_mutex); 210 return 0; 211 } 212 213 static ssize_t 214 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) 215 { 216 struct inode *inode = filp->f_path.dentry->d_inode; 217 struct rpc_inode *rpci = RPC_I(inode); 218 struct rpc_pipe_msg *msg; 219 int res = 0; 220 221 mutex_lock(&inode->i_mutex); 222 if (rpci->ops == NULL) { 223 res = -EPIPE; 224 goto out_unlock; 225 } 226 msg = filp->private_data; 227 if (msg == NULL) { 228 spin_lock(&inode->i_lock); 229 if (!list_empty(&rpci->pipe)) { 230 msg = list_entry(rpci->pipe.next, 231 struct rpc_pipe_msg, 232 list); 233 list_move(&msg->list, &rpci->in_upcall); 234 rpci->pipelen -= msg->len; 235 filp->private_data = msg; 236 msg->copied = 0; 237 } 238 spin_unlock(&inode->i_lock); 239 if (msg == NULL) 240 goto out_unlock; 241 } 242 /* NOTE: it is up to the callback to update msg->copied */ 243 res = rpci->ops->upcall(filp, msg, buf, len); 244 if (res < 0 || msg->len == msg->copied) { 245 filp->private_data = NULL; 246 spin_lock(&inode->i_lock); 247 list_del(&msg->list); 248 spin_unlock(&inode->i_lock); 249 rpci->ops->destroy_msg(msg); 250 } 251 out_unlock: 252 mutex_unlock(&inode->i_mutex); 253 return res; 254 } 255 256 static ssize_t 257 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset) 258 { 259 struct inode *inode = filp->f_path.dentry->d_inode; 260 struct rpc_inode *rpci = RPC_I(inode); 261 int res; 262 263 mutex_lock(&inode->i_mutex); 264 res = -EPIPE; 265 if (rpci->ops != NULL) 266 res = rpci->ops->downcall(filp, buf, len); 267 mutex_unlock(&inode->i_mutex); 268 return res; 269 } 270 271 static unsigned int 272 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait) 273 { 274 struct rpc_inode *rpci; 275 unsigned int mask = 0; 276 277 rpci = RPC_I(filp->f_path.dentry->d_inode); 278 poll_wait(filp, &rpci->waitq, wait); 279 280 mask = POLLOUT | POLLWRNORM; 281 if (rpci->ops == NULL) 282 mask |= POLLERR | POLLHUP; 283 if (!list_empty(&rpci->pipe)) 284 mask |= POLLIN | POLLRDNORM; 285 return mask; 286 } 287 288 static int 289 rpc_pipe_ioctl(struct inode *ino, struct file *filp, 290 unsigned int cmd, unsigned long arg) 291 { 292 struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode); 293 int len; 294 295 switch (cmd) { 296 case FIONREAD: 297 if (rpci->ops == NULL) 298 return -EPIPE; 299 len = rpci->pipelen; 300 if (filp->private_data) { 301 struct rpc_pipe_msg *msg; 302 msg = (struct rpc_pipe_msg *)filp->private_data; 303 len += msg->len - msg->copied; 304 } 305 return put_user(len, (int __user *)arg); 306 default: 307 return -EINVAL; 308 } 309 } 310 311 static const struct file_operations rpc_pipe_fops = { 312 .owner = THIS_MODULE, 313 .llseek = no_llseek, 314 .read = rpc_pipe_read, 315 .write = rpc_pipe_write, 316 .poll = rpc_pipe_poll, 317 .ioctl = rpc_pipe_ioctl, 318 .open = rpc_pipe_open, 319 .release = rpc_pipe_release, 320 }; 321 322 static int 323 rpc_show_info(struct seq_file *m, void *v) 324 { 325 struct rpc_clnt *clnt = m->private; 326 327 seq_printf(m, "RPC server: %s\n", clnt->cl_server); 328 seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname, 329 clnt->cl_prog, clnt->cl_vers); 330 seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR)); 331 seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO)); 332 return 0; 333 } 334 335 static int 336 rpc_info_open(struct inode *inode, struct file *file) 337 { 338 struct rpc_clnt *clnt; 339 int ret = single_open(file, rpc_show_info, NULL); 340 341 if (!ret) { 342 struct seq_file *m = file->private_data; 343 mutex_lock(&inode->i_mutex); 344 clnt = RPC_I(inode)->private; 345 if (clnt) { 346 kref_get(&clnt->cl_kref); 347 m->private = clnt; 348 } else { 349 single_release(inode, file); 350 ret = -EINVAL; 351 } 352 mutex_unlock(&inode->i_mutex); 353 } 354 return ret; 355 } 356 357 static int 358 rpc_info_release(struct inode *inode, struct file *file) 359 { 360 struct seq_file *m = file->private_data; 361 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private; 362 363 if (clnt) 364 rpc_release_client(clnt); 365 return single_release(inode, file); 366 } 367 368 static const struct file_operations rpc_info_operations = { 369 .owner = THIS_MODULE, 370 .open = rpc_info_open, 371 .read = seq_read, 372 .llseek = seq_lseek, 373 .release = rpc_info_release, 374 }; 375 376 377 /* 378 * We have a single directory with 1 node in it. 379 */ 380 enum { 381 RPCAUTH_Root = 1, 382 RPCAUTH_lockd, 383 RPCAUTH_mount, 384 RPCAUTH_nfs, 385 RPCAUTH_portmap, 386 RPCAUTH_statd, 387 RPCAUTH_RootEOF 388 }; 389 390 /* 391 * Description of fs contents. 392 */ 393 struct rpc_filelist { 394 char *name; 395 const struct file_operations *i_fop; 396 int mode; 397 }; 398 399 static struct rpc_filelist files[] = { 400 [RPCAUTH_lockd] = { 401 .name = "lockd", 402 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 403 }, 404 [RPCAUTH_mount] = { 405 .name = "mount", 406 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 407 }, 408 [RPCAUTH_nfs] = { 409 .name = "nfs", 410 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 411 }, 412 [RPCAUTH_portmap] = { 413 .name = "portmap", 414 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 415 }, 416 [RPCAUTH_statd] = { 417 .name = "statd", 418 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 419 }, 420 }; 421 422 enum { 423 RPCAUTH_info = 2, 424 RPCAUTH_EOF 425 }; 426 427 static struct rpc_filelist authfiles[] = { 428 [RPCAUTH_info] = { 429 .name = "info", 430 .i_fop = &rpc_info_operations, 431 .mode = S_IFREG | S_IRUSR, 432 }, 433 }; 434 435 struct vfsmount *rpc_get_mount(void) 436 { 437 int err; 438 439 err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count); 440 if (err != 0) 441 return ERR_PTR(err); 442 return rpc_mount; 443 } 444 445 void rpc_put_mount(void) 446 { 447 simple_release_fs(&rpc_mount, &rpc_mount_count); 448 } 449 450 static int rpc_delete_dentry(struct dentry *dentry) 451 { 452 return 1; 453 } 454 455 static struct dentry_operations rpc_dentry_operations = { 456 .d_delete = rpc_delete_dentry, 457 }; 458 459 static int 460 rpc_lookup_parent(char *path, struct nameidata *nd) 461 { 462 struct vfsmount *mnt; 463 464 if (path[0] == '\0') 465 return -ENOENT; 466 467 mnt = rpc_get_mount(); 468 if (IS_ERR(mnt)) { 469 printk(KERN_WARNING "%s: %s failed to mount " 470 "pseudofilesystem \n", __FILE__, __FUNCTION__); 471 return PTR_ERR(mnt); 472 } 473 474 if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) { 475 printk(KERN_WARNING "%s: %s failed to find path %s\n", 476 __FILE__, __FUNCTION__, path); 477 rpc_put_mount(); 478 return -ENOENT; 479 } 480 return 0; 481 } 482 483 static void 484 rpc_release_path(struct nameidata *nd) 485 { 486 path_release(nd); 487 rpc_put_mount(); 488 } 489 490 static struct inode * 491 rpc_get_inode(struct super_block *sb, int mode) 492 { 493 struct inode *inode = new_inode(sb); 494 if (!inode) 495 return NULL; 496 inode->i_mode = mode; 497 inode->i_uid = inode->i_gid = 0; 498 inode->i_blocks = 0; 499 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 500 switch(mode & S_IFMT) { 501 case S_IFDIR: 502 inode->i_fop = &simple_dir_operations; 503 inode->i_op = &simple_dir_inode_operations; 504 inc_nlink(inode); 505 default: 506 break; 507 } 508 return inode; 509 } 510 511 /* 512 * FIXME: This probably has races. 513 */ 514 static void 515 rpc_depopulate(struct dentry *parent, int start, int eof) 516 { 517 struct inode *dir = parent->d_inode; 518 struct list_head *pos, *next; 519 struct dentry *dentry, *dvec[10]; 520 int n = 0; 521 522 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); 523 repeat: 524 spin_lock(&dcache_lock); 525 list_for_each_safe(pos, next, &parent->d_subdirs) { 526 dentry = list_entry(pos, struct dentry, d_u.d_child); 527 if (!dentry->d_inode || 528 dentry->d_inode->i_ino < start || 529 dentry->d_inode->i_ino >= eof) 530 continue; 531 spin_lock(&dentry->d_lock); 532 if (!d_unhashed(dentry)) { 533 dget_locked(dentry); 534 __d_drop(dentry); 535 spin_unlock(&dentry->d_lock); 536 dvec[n++] = dentry; 537 if (n == ARRAY_SIZE(dvec)) 538 break; 539 } else 540 spin_unlock(&dentry->d_lock); 541 } 542 spin_unlock(&dcache_lock); 543 if (n) { 544 do { 545 dentry = dvec[--n]; 546 if (S_ISREG(dentry->d_inode->i_mode)) 547 simple_unlink(dir, dentry); 548 else if (S_ISDIR(dentry->d_inode->i_mode)) 549 simple_rmdir(dir, dentry); 550 d_delete(dentry); 551 dput(dentry); 552 } while (n); 553 goto repeat; 554 } 555 mutex_unlock(&dir->i_mutex); 556 } 557 558 static int 559 rpc_populate(struct dentry *parent, 560 struct rpc_filelist *files, 561 int start, int eof) 562 { 563 struct inode *inode, *dir = parent->d_inode; 564 void *private = RPC_I(dir)->private; 565 struct dentry *dentry; 566 int mode, i; 567 568 mutex_lock(&dir->i_mutex); 569 for (i = start; i < eof; i++) { 570 dentry = d_alloc_name(parent, files[i].name); 571 if (!dentry) 572 goto out_bad; 573 dentry->d_op = &rpc_dentry_operations; 574 mode = files[i].mode; 575 inode = rpc_get_inode(dir->i_sb, mode); 576 if (!inode) { 577 dput(dentry); 578 goto out_bad; 579 } 580 inode->i_ino = i; 581 if (files[i].i_fop) 582 inode->i_fop = files[i].i_fop; 583 if (private) 584 rpc_inode_setowner(inode, private); 585 if (S_ISDIR(mode)) 586 inc_nlink(dir); 587 d_add(dentry, inode); 588 } 589 mutex_unlock(&dir->i_mutex); 590 return 0; 591 out_bad: 592 mutex_unlock(&dir->i_mutex); 593 printk(KERN_WARNING "%s: %s failed to populate directory %s\n", 594 __FILE__, __FUNCTION__, parent->d_name.name); 595 return -ENOMEM; 596 } 597 598 static int 599 __rpc_mkdir(struct inode *dir, struct dentry *dentry) 600 { 601 struct inode *inode; 602 603 inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO); 604 if (!inode) 605 goto out_err; 606 inode->i_ino = iunique(dir->i_sb, 100); 607 d_instantiate(dentry, inode); 608 inc_nlink(dir); 609 inode_dir_notify(dir, DN_CREATE); 610 return 0; 611 out_err: 612 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", 613 __FILE__, __FUNCTION__, dentry->d_name.name); 614 return -ENOMEM; 615 } 616 617 static int 618 __rpc_rmdir(struct inode *dir, struct dentry *dentry) 619 { 620 int error; 621 error = simple_rmdir(dir, dentry); 622 if (!error) 623 d_delete(dentry); 624 return error; 625 } 626 627 static struct dentry * 628 rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive) 629 { 630 struct inode *dir = parent->d_inode; 631 struct dentry *dentry; 632 633 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 634 dentry = lookup_one_len(name, parent, len); 635 if (IS_ERR(dentry)) 636 goto out_err; 637 if (!dentry->d_inode) 638 dentry->d_op = &rpc_dentry_operations; 639 else if (exclusive) { 640 dput(dentry); 641 dentry = ERR_PTR(-EEXIST); 642 goto out_err; 643 } 644 return dentry; 645 out_err: 646 mutex_unlock(&dir->i_mutex); 647 return dentry; 648 } 649 650 static struct dentry * 651 rpc_lookup_negative(char *path, struct nameidata *nd) 652 { 653 struct dentry *dentry; 654 int error; 655 656 if ((error = rpc_lookup_parent(path, nd)) != 0) 657 return ERR_PTR(error); 658 dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1); 659 if (IS_ERR(dentry)) 660 rpc_release_path(nd); 661 return dentry; 662 } 663 664 665 struct dentry * 666 rpc_mkdir(char *path, struct rpc_clnt *rpc_client) 667 { 668 struct nameidata nd; 669 struct dentry *dentry; 670 struct inode *dir; 671 int error; 672 673 dentry = rpc_lookup_negative(path, &nd); 674 if (IS_ERR(dentry)) 675 return dentry; 676 dir = nd.dentry->d_inode; 677 if ((error = __rpc_mkdir(dir, dentry)) != 0) 678 goto err_dput; 679 RPC_I(dentry->d_inode)->private = rpc_client; 680 error = rpc_populate(dentry, authfiles, 681 RPCAUTH_info, RPCAUTH_EOF); 682 if (error) 683 goto err_depopulate; 684 dget(dentry); 685 out: 686 mutex_unlock(&dir->i_mutex); 687 rpc_release_path(&nd); 688 return dentry; 689 err_depopulate: 690 rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF); 691 __rpc_rmdir(dir, dentry); 692 err_dput: 693 dput(dentry); 694 printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n", 695 __FILE__, __FUNCTION__, path, error); 696 dentry = ERR_PTR(error); 697 goto out; 698 } 699 700 int 701 rpc_rmdir(struct dentry *dentry) 702 { 703 struct dentry *parent; 704 struct inode *dir; 705 int error; 706 707 parent = dget_parent(dentry); 708 dir = parent->d_inode; 709 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 710 rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF); 711 error = __rpc_rmdir(dir, dentry); 712 dput(dentry); 713 mutex_unlock(&dir->i_mutex); 714 dput(parent); 715 return error; 716 } 717 718 struct dentry * 719 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags) 720 { 721 struct dentry *dentry; 722 struct inode *dir, *inode; 723 struct rpc_inode *rpci; 724 725 dentry = rpc_lookup_create(parent, name, strlen(name), 0); 726 if (IS_ERR(dentry)) 727 return dentry; 728 dir = parent->d_inode; 729 if (dentry->d_inode) { 730 rpci = RPC_I(dentry->d_inode); 731 if (rpci->private != private || 732 rpci->ops != ops || 733 rpci->flags != flags) { 734 dput (dentry); 735 dentry = ERR_PTR(-EBUSY); 736 } 737 rpci->nkern_readwriters++; 738 goto out; 739 } 740 inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR); 741 if (!inode) 742 goto err_dput; 743 inode->i_ino = iunique(dir->i_sb, 100); 744 inode->i_fop = &rpc_pipe_fops; 745 d_instantiate(dentry, inode); 746 rpci = RPC_I(inode); 747 rpci->private = private; 748 rpci->flags = flags; 749 rpci->ops = ops; 750 rpci->nkern_readwriters = 1; 751 inode_dir_notify(dir, DN_CREATE); 752 dget(dentry); 753 out: 754 mutex_unlock(&dir->i_mutex); 755 return dentry; 756 err_dput: 757 dput(dentry); 758 dentry = ERR_PTR(-ENOMEM); 759 printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n", 760 __FILE__, __FUNCTION__, parent->d_name.name, name, 761 -ENOMEM); 762 goto out; 763 } 764 765 int 766 rpc_unlink(struct dentry *dentry) 767 { 768 struct dentry *parent; 769 struct inode *dir; 770 int error = 0; 771 772 parent = dget_parent(dentry); 773 dir = parent->d_inode; 774 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 775 if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) { 776 rpc_close_pipes(dentry->d_inode); 777 error = simple_unlink(dir, dentry); 778 if (!error) 779 d_delete(dentry); 780 } 781 dput(dentry); 782 mutex_unlock(&dir->i_mutex); 783 dput(parent); 784 return error; 785 } 786 787 /* 788 * populate the filesystem 789 */ 790 static struct super_operations s_ops = { 791 .alloc_inode = rpc_alloc_inode, 792 .destroy_inode = rpc_destroy_inode, 793 .statfs = simple_statfs, 794 }; 795 796 #define RPCAUTH_GSSMAGIC 0x67596969 797 798 static int 799 rpc_fill_super(struct super_block *sb, void *data, int silent) 800 { 801 struct inode *inode; 802 struct dentry *root; 803 804 sb->s_blocksize = PAGE_CACHE_SIZE; 805 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 806 sb->s_magic = RPCAUTH_GSSMAGIC; 807 sb->s_op = &s_ops; 808 sb->s_time_gran = 1; 809 810 inode = rpc_get_inode(sb, S_IFDIR | 0755); 811 if (!inode) 812 return -ENOMEM; 813 root = d_alloc_root(inode); 814 if (!root) { 815 iput(inode); 816 return -ENOMEM; 817 } 818 if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF)) 819 goto out; 820 sb->s_root = root; 821 return 0; 822 out: 823 d_genocide(root); 824 dput(root); 825 return -ENOMEM; 826 } 827 828 static int 829 rpc_get_sb(struct file_system_type *fs_type, 830 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 831 { 832 return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt); 833 } 834 835 static struct file_system_type rpc_pipe_fs_type = { 836 .owner = THIS_MODULE, 837 .name = "rpc_pipefs", 838 .get_sb = rpc_get_sb, 839 .kill_sb = kill_litter_super, 840 }; 841 842 static void 843 init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 844 { 845 struct rpc_inode *rpci = (struct rpc_inode *) foo; 846 847 inode_init_once(&rpci->vfs_inode); 848 rpci->private = NULL; 849 rpci->nreaders = 0; 850 rpci->nwriters = 0; 851 INIT_LIST_HEAD(&rpci->in_upcall); 852 INIT_LIST_HEAD(&rpci->in_downcall); 853 INIT_LIST_HEAD(&rpci->pipe); 854 rpci->pipelen = 0; 855 init_waitqueue_head(&rpci->waitq); 856 INIT_DELAYED_WORK(&rpci->queue_timeout, 857 rpc_timeout_upcall_queue); 858 rpci->ops = NULL; 859 } 860 861 int register_rpc_pipefs(void) 862 { 863 int err; 864 865 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", 866 sizeof(struct rpc_inode), 867 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 868 SLAB_MEM_SPREAD), 869 init_once); 870 if (!rpc_inode_cachep) 871 return -ENOMEM; 872 err = register_filesystem(&rpc_pipe_fs_type); 873 if (err) { 874 kmem_cache_destroy(rpc_inode_cachep); 875 return err; 876 } 877 878 return 0; 879 } 880 881 void unregister_rpc_pipefs(void) 882 { 883 kmem_cache_destroy(rpc_inode_cachep); 884 unregister_filesystem(&rpc_pipe_fs_type); 885 } 886