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 kmem_cache_t *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(void *data) 58 { 59 LIST_HEAD(free_list); 60 struct rpc_inode *rpci = (struct rpc_inode *)data; 61 struct inode *inode = &rpci->vfs_inode; 62 void (*destroy_msg)(struct rpc_pipe_msg *); 63 64 spin_lock(&inode->i_lock); 65 if (rpci->ops == NULL) { 66 spin_unlock(&inode->i_lock); 67 return; 68 } 69 destroy_msg = rpci->ops->destroy_msg; 70 if (rpci->nreaders == 0) { 71 list_splice_init(&rpci->pipe, &free_list); 72 rpci->pipelen = 0; 73 } 74 spin_unlock(&inode->i_lock); 75 rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT); 76 } 77 78 int 79 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg) 80 { 81 struct rpc_inode *rpci = RPC_I(inode); 82 int res = -EPIPE; 83 84 spin_lock(&inode->i_lock); 85 if (rpci->ops == NULL) 86 goto out; 87 if (rpci->nreaders) { 88 list_add_tail(&msg->list, &rpci->pipe); 89 rpci->pipelen += msg->len; 90 res = 0; 91 } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) { 92 if (list_empty(&rpci->pipe)) 93 queue_delayed_work(rpciod_workqueue, 94 &rpci->queue_timeout, 95 RPC_UPCALL_TIMEOUT); 96 list_add_tail(&msg->list, &rpci->pipe); 97 rpci->pipelen += msg->len; 98 res = 0; 99 } 100 out: 101 spin_unlock(&inode->i_lock); 102 wake_up(&rpci->waitq); 103 return res; 104 } 105 106 static inline void 107 rpc_inode_setowner(struct inode *inode, void *private) 108 { 109 RPC_I(inode)->private = private; 110 } 111 112 static void 113 rpc_close_pipes(struct inode *inode) 114 { 115 struct rpc_inode *rpci = RPC_I(inode); 116 struct rpc_pipe_ops *ops; 117 118 mutex_lock(&inode->i_mutex); 119 ops = rpci->ops; 120 if (ops != NULL) { 121 LIST_HEAD(free_list); 122 123 spin_lock(&inode->i_lock); 124 rpci->nreaders = 0; 125 list_splice_init(&rpci->in_upcall, &free_list); 126 list_splice_init(&rpci->pipe, &free_list); 127 rpci->pipelen = 0; 128 rpci->ops = NULL; 129 spin_unlock(&inode->i_lock); 130 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE); 131 rpci->nwriters = 0; 132 if (ops->release_pipe) 133 ops->release_pipe(inode); 134 cancel_delayed_work(&rpci->queue_timeout); 135 flush_workqueue(rpciod_workqueue); 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, SLAB_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_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_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_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_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 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: %u.%u.%u.%u\n", 331 NIPQUAD(clnt->cl_xprt->addr.sin_addr.s_addr)); 332 seq_printf(m, "protocol: %s\n", 333 clnt->cl_xprt->prot == IPPROTO_UDP ? "udp" : "tcp"); 334 return 0; 335 } 336 337 static int 338 rpc_info_open(struct inode *inode, struct file *file) 339 { 340 struct rpc_clnt *clnt; 341 int ret = single_open(file, rpc_show_info, NULL); 342 343 if (!ret) { 344 struct seq_file *m = file->private_data; 345 mutex_lock(&inode->i_mutex); 346 clnt = RPC_I(inode)->private; 347 if (clnt) { 348 atomic_inc(&clnt->cl_users); 349 m->private = clnt; 350 } else { 351 single_release(inode, file); 352 ret = -EINVAL; 353 } 354 mutex_unlock(&inode->i_mutex); 355 } 356 return ret; 357 } 358 359 static int 360 rpc_info_release(struct inode *inode, struct file *file) 361 { 362 struct seq_file *m = file->private_data; 363 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private; 364 365 if (clnt) 366 rpc_release_client(clnt); 367 return single_release(inode, file); 368 } 369 370 static struct file_operations rpc_info_operations = { 371 .owner = THIS_MODULE, 372 .open = rpc_info_open, 373 .read = seq_read, 374 .llseek = seq_lseek, 375 .release = rpc_info_release, 376 }; 377 378 379 /* 380 * We have a single directory with 1 node in it. 381 */ 382 enum { 383 RPCAUTH_Root = 1, 384 RPCAUTH_lockd, 385 RPCAUTH_mount, 386 RPCAUTH_nfs, 387 RPCAUTH_portmap, 388 RPCAUTH_statd, 389 RPCAUTH_RootEOF 390 }; 391 392 /* 393 * Description of fs contents. 394 */ 395 struct rpc_filelist { 396 char *name; 397 const struct file_operations *i_fop; 398 int mode; 399 }; 400 401 static struct rpc_filelist files[] = { 402 [RPCAUTH_lockd] = { 403 .name = "lockd", 404 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 405 }, 406 [RPCAUTH_mount] = { 407 .name = "mount", 408 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 409 }, 410 [RPCAUTH_nfs] = { 411 .name = "nfs", 412 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 413 }, 414 [RPCAUTH_portmap] = { 415 .name = "portmap", 416 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 417 }, 418 [RPCAUTH_statd] = { 419 .name = "statd", 420 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 421 }, 422 }; 423 424 enum { 425 RPCAUTH_info = 2, 426 RPCAUTH_EOF 427 }; 428 429 static struct rpc_filelist authfiles[] = { 430 [RPCAUTH_info] = { 431 .name = "info", 432 .i_fop = &rpc_info_operations, 433 .mode = S_IFREG | S_IRUSR, 434 }, 435 }; 436 437 struct vfsmount *rpc_get_mount(void) 438 { 439 int err; 440 441 err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count); 442 if (err != 0) 443 return ERR_PTR(err); 444 return rpc_mount; 445 } 446 447 void rpc_put_mount(void) 448 { 449 simple_release_fs(&rpc_mount, &rpc_mount_count); 450 } 451 452 static int 453 rpc_lookup_parent(char *path, struct nameidata *nd) 454 { 455 if (path[0] == '\0') 456 return -ENOENT; 457 nd->mnt = rpc_get_mount(); 458 if (IS_ERR(nd->mnt)) { 459 printk(KERN_WARNING "%s: %s failed to mount " 460 "pseudofilesystem \n", __FILE__, __FUNCTION__); 461 return PTR_ERR(nd->mnt); 462 } 463 mntget(nd->mnt); 464 nd->dentry = dget(rpc_mount->mnt_root); 465 nd->last_type = LAST_ROOT; 466 nd->flags = LOOKUP_PARENT; 467 nd->depth = 0; 468 469 if (path_walk(path, nd)) { 470 printk(KERN_WARNING "%s: %s failed to find path %s\n", 471 __FILE__, __FUNCTION__, path); 472 rpc_put_mount(); 473 return -ENOENT; 474 } 475 return 0; 476 } 477 478 static void 479 rpc_release_path(struct nameidata *nd) 480 { 481 path_release(nd); 482 rpc_put_mount(); 483 } 484 485 static struct inode * 486 rpc_get_inode(struct super_block *sb, int mode) 487 { 488 struct inode *inode = new_inode(sb); 489 if (!inode) 490 return NULL; 491 inode->i_mode = mode; 492 inode->i_uid = inode->i_gid = 0; 493 inode->i_blksize = PAGE_CACHE_SIZE; 494 inode->i_blocks = 0; 495 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 496 switch(mode & S_IFMT) { 497 case S_IFDIR: 498 inode->i_fop = &simple_dir_operations; 499 inode->i_op = &simple_dir_inode_operations; 500 inode->i_nlink++; 501 default: 502 break; 503 } 504 return inode; 505 } 506 507 /* 508 * FIXME: This probably has races. 509 */ 510 static void 511 rpc_depopulate(struct dentry *parent) 512 { 513 struct inode *dir = parent->d_inode; 514 struct list_head *pos, *next; 515 struct dentry *dentry, *dvec[10]; 516 int n = 0; 517 518 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); 519 repeat: 520 spin_lock(&dcache_lock); 521 list_for_each_safe(pos, next, &parent->d_subdirs) { 522 dentry = list_entry(pos, struct dentry, d_u.d_child); 523 spin_lock(&dentry->d_lock); 524 if (!d_unhashed(dentry)) { 525 dget_locked(dentry); 526 __d_drop(dentry); 527 spin_unlock(&dentry->d_lock); 528 dvec[n++] = dentry; 529 if (n == ARRAY_SIZE(dvec)) 530 break; 531 } else 532 spin_unlock(&dentry->d_lock); 533 } 534 spin_unlock(&dcache_lock); 535 if (n) { 536 do { 537 dentry = dvec[--n]; 538 if (dentry->d_inode) { 539 rpc_close_pipes(dentry->d_inode); 540 simple_unlink(dir, dentry); 541 } 542 dput(dentry); 543 } while (n); 544 goto repeat; 545 } 546 mutex_unlock(&dir->i_mutex); 547 } 548 549 static int 550 rpc_populate(struct dentry *parent, 551 struct rpc_filelist *files, 552 int start, int eof) 553 { 554 struct inode *inode, *dir = parent->d_inode; 555 void *private = RPC_I(dir)->private; 556 struct dentry *dentry; 557 int mode, i; 558 559 mutex_lock(&dir->i_mutex); 560 for (i = start; i < eof; i++) { 561 dentry = d_alloc_name(parent, files[i].name); 562 if (!dentry) 563 goto out_bad; 564 mode = files[i].mode; 565 inode = rpc_get_inode(dir->i_sb, mode); 566 if (!inode) { 567 dput(dentry); 568 goto out_bad; 569 } 570 inode->i_ino = i; 571 if (files[i].i_fop) 572 inode->i_fop = files[i].i_fop; 573 if (private) 574 rpc_inode_setowner(inode, private); 575 if (S_ISDIR(mode)) 576 dir->i_nlink++; 577 d_add(dentry, inode); 578 } 579 mutex_unlock(&dir->i_mutex); 580 return 0; 581 out_bad: 582 mutex_unlock(&dir->i_mutex); 583 printk(KERN_WARNING "%s: %s failed to populate directory %s\n", 584 __FILE__, __FUNCTION__, parent->d_name.name); 585 return -ENOMEM; 586 } 587 588 static int 589 __rpc_mkdir(struct inode *dir, struct dentry *dentry) 590 { 591 struct inode *inode; 592 593 inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR); 594 if (!inode) 595 goto out_err; 596 inode->i_ino = iunique(dir->i_sb, 100); 597 d_instantiate(dentry, inode); 598 dir->i_nlink++; 599 inode_dir_notify(dir, DN_CREATE); 600 return 0; 601 out_err: 602 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", 603 __FILE__, __FUNCTION__, dentry->d_name.name); 604 return -ENOMEM; 605 } 606 607 static int 608 __rpc_rmdir(struct inode *dir, struct dentry *dentry) 609 { 610 int error; 611 612 shrink_dcache_parent(dentry); 613 if (dentry->d_inode) 614 rpc_close_pipes(dentry->d_inode); 615 if ((error = simple_rmdir(dir, dentry)) != 0) 616 return error; 617 if (!error) { 618 inode_dir_notify(dir, DN_DELETE); 619 d_drop(dentry); 620 } 621 return 0; 622 } 623 624 static struct dentry * 625 rpc_lookup_negative(char *path, struct nameidata *nd) 626 { 627 struct dentry *dentry; 628 struct inode *dir; 629 int error; 630 631 if ((error = rpc_lookup_parent(path, nd)) != 0) 632 return ERR_PTR(error); 633 dir = nd->dentry->d_inode; 634 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 635 dentry = lookup_one_len(nd->last.name, nd->dentry, nd->last.len); 636 if (IS_ERR(dentry)) 637 goto out_err; 638 if (dentry->d_inode) { 639 dput(dentry); 640 dentry = ERR_PTR(-EEXIST); 641 goto out_err; 642 } 643 return dentry; 644 out_err: 645 mutex_unlock(&dir->i_mutex); 646 rpc_release_path(nd); 647 return dentry; 648 } 649 650 651 struct dentry * 652 rpc_mkdir(char *path, struct rpc_clnt *rpc_client) 653 { 654 struct nameidata nd; 655 struct dentry *dentry; 656 struct inode *dir; 657 int error; 658 659 dentry = rpc_lookup_negative(path, &nd); 660 if (IS_ERR(dentry)) 661 return dentry; 662 dir = nd.dentry->d_inode; 663 if ((error = __rpc_mkdir(dir, dentry)) != 0) 664 goto err_dput; 665 RPC_I(dentry->d_inode)->private = rpc_client; 666 error = rpc_populate(dentry, authfiles, 667 RPCAUTH_info, RPCAUTH_EOF); 668 if (error) 669 goto err_depopulate; 670 out: 671 mutex_unlock(&dir->i_mutex); 672 rpc_release_path(&nd); 673 return dget(dentry); 674 err_depopulate: 675 rpc_depopulate(dentry); 676 __rpc_rmdir(dir, dentry); 677 err_dput: 678 dput(dentry); 679 printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n", 680 __FILE__, __FUNCTION__, path, error); 681 dentry = ERR_PTR(error); 682 goto out; 683 } 684 685 int 686 rpc_rmdir(char *path) 687 { 688 struct nameidata nd; 689 struct dentry *dentry; 690 struct inode *dir; 691 int error; 692 693 if ((error = rpc_lookup_parent(path, &nd)) != 0) 694 return error; 695 dir = nd.dentry->d_inode; 696 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 697 dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len); 698 if (IS_ERR(dentry)) { 699 error = PTR_ERR(dentry); 700 goto out_release; 701 } 702 rpc_depopulate(dentry); 703 error = __rpc_rmdir(dir, dentry); 704 dput(dentry); 705 out_release: 706 mutex_unlock(&dir->i_mutex); 707 rpc_release_path(&nd); 708 return error; 709 } 710 711 struct dentry * 712 rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags) 713 { 714 struct nameidata nd; 715 struct dentry *dentry; 716 struct inode *dir, *inode; 717 struct rpc_inode *rpci; 718 719 dentry = rpc_lookup_negative(path, &nd); 720 if (IS_ERR(dentry)) 721 return dentry; 722 dir = nd.dentry->d_inode; 723 inode = rpc_get_inode(dir->i_sb, S_IFSOCK | S_IRUSR | S_IWUSR); 724 if (!inode) 725 goto err_dput; 726 inode->i_ino = iunique(dir->i_sb, 100); 727 inode->i_fop = &rpc_pipe_fops; 728 d_instantiate(dentry, inode); 729 rpci = RPC_I(inode); 730 rpci->private = private; 731 rpci->flags = flags; 732 rpci->ops = ops; 733 inode_dir_notify(dir, DN_CREATE); 734 out: 735 mutex_unlock(&dir->i_mutex); 736 rpc_release_path(&nd); 737 return dget(dentry); 738 err_dput: 739 dput(dentry); 740 dentry = ERR_PTR(-ENOMEM); 741 printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n", 742 __FILE__, __FUNCTION__, path, -ENOMEM); 743 goto out; 744 } 745 746 int 747 rpc_unlink(char *path) 748 { 749 struct nameidata nd; 750 struct dentry *dentry; 751 struct inode *dir; 752 int error; 753 754 if ((error = rpc_lookup_parent(path, &nd)) != 0) 755 return error; 756 dir = nd.dentry->d_inode; 757 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 758 dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len); 759 if (IS_ERR(dentry)) { 760 error = PTR_ERR(dentry); 761 goto out_release; 762 } 763 d_drop(dentry); 764 if (dentry->d_inode) { 765 rpc_close_pipes(dentry->d_inode); 766 error = simple_unlink(dir, dentry); 767 } 768 dput(dentry); 769 inode_dir_notify(dir, DN_DELETE); 770 out_release: 771 mutex_unlock(&dir->i_mutex); 772 rpc_release_path(&nd); 773 return error; 774 } 775 776 /* 777 * populate the filesystem 778 */ 779 static struct super_operations s_ops = { 780 .alloc_inode = rpc_alloc_inode, 781 .destroy_inode = rpc_destroy_inode, 782 .statfs = simple_statfs, 783 }; 784 785 #define RPCAUTH_GSSMAGIC 0x67596969 786 787 static int 788 rpc_fill_super(struct super_block *sb, void *data, int silent) 789 { 790 struct inode *inode; 791 struct dentry *root; 792 793 sb->s_blocksize = PAGE_CACHE_SIZE; 794 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 795 sb->s_magic = RPCAUTH_GSSMAGIC; 796 sb->s_op = &s_ops; 797 sb->s_time_gran = 1; 798 799 inode = rpc_get_inode(sb, S_IFDIR | 0755); 800 if (!inode) 801 return -ENOMEM; 802 root = d_alloc_root(inode); 803 if (!root) { 804 iput(inode); 805 return -ENOMEM; 806 } 807 if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF)) 808 goto out; 809 sb->s_root = root; 810 return 0; 811 out: 812 d_genocide(root); 813 dput(root); 814 return -ENOMEM; 815 } 816 817 static int 818 rpc_get_sb(struct file_system_type *fs_type, 819 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 820 { 821 return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt); 822 } 823 824 static struct file_system_type rpc_pipe_fs_type = { 825 .owner = THIS_MODULE, 826 .name = "rpc_pipefs", 827 .get_sb = rpc_get_sb, 828 .kill_sb = kill_litter_super, 829 }; 830 831 static void 832 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 833 { 834 struct rpc_inode *rpci = (struct rpc_inode *) foo; 835 836 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 837 SLAB_CTOR_CONSTRUCTOR) { 838 inode_init_once(&rpci->vfs_inode); 839 rpci->private = NULL; 840 rpci->nreaders = 0; 841 rpci->nwriters = 0; 842 INIT_LIST_HEAD(&rpci->in_upcall); 843 INIT_LIST_HEAD(&rpci->pipe); 844 rpci->pipelen = 0; 845 init_waitqueue_head(&rpci->waitq); 846 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci); 847 rpci->ops = NULL; 848 } 849 } 850 851 int register_rpc_pipefs(void) 852 { 853 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", 854 sizeof(struct rpc_inode), 855 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 856 SLAB_MEM_SPREAD), 857 init_once, NULL); 858 if (!rpc_inode_cachep) 859 return -ENOMEM; 860 register_filesystem(&rpc_pipe_fs_type); 861 return 0; 862 } 863 864 void unregister_rpc_pipefs(void) 865 { 866 if (kmem_cache_destroy(rpc_inode_cachep)) 867 printk(KERN_WARNING "RPC: unable to free inode cache\n"); 868 unregister_filesystem(&rpc_pipe_fs_type); 869 } 870