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: %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 atomic_inc(&clnt->cl_users); 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 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 451 rpc_lookup_parent(char *path, struct nameidata *nd) 452 { 453 if (path[0] == '\0') 454 return -ENOENT; 455 nd->mnt = rpc_get_mount(); 456 if (IS_ERR(nd->mnt)) { 457 printk(KERN_WARNING "%s: %s failed to mount " 458 "pseudofilesystem \n", __FILE__, __FUNCTION__); 459 return PTR_ERR(nd->mnt); 460 } 461 mntget(nd->mnt); 462 nd->dentry = dget(rpc_mount->mnt_root); 463 nd->last_type = LAST_ROOT; 464 nd->flags = LOOKUP_PARENT; 465 nd->depth = 0; 466 467 if (path_walk(path, nd)) { 468 printk(KERN_WARNING "%s: %s failed to find path %s\n", 469 __FILE__, __FUNCTION__, path); 470 rpc_put_mount(); 471 return -ENOENT; 472 } 473 return 0; 474 } 475 476 static void 477 rpc_release_path(struct nameidata *nd) 478 { 479 path_release(nd); 480 rpc_put_mount(); 481 } 482 483 static struct inode * 484 rpc_get_inode(struct super_block *sb, int mode) 485 { 486 struct inode *inode = new_inode(sb); 487 if (!inode) 488 return NULL; 489 inode->i_mode = mode; 490 inode->i_uid = inode->i_gid = 0; 491 inode->i_blksize = PAGE_CACHE_SIZE; 492 inode->i_blocks = 0; 493 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 494 switch(mode & S_IFMT) { 495 case S_IFDIR: 496 inode->i_fop = &simple_dir_operations; 497 inode->i_op = &simple_dir_inode_operations; 498 inode->i_nlink++; 499 default: 500 break; 501 } 502 return inode; 503 } 504 505 /* 506 * FIXME: This probably has races. 507 */ 508 static void 509 rpc_depopulate(struct dentry *parent) 510 { 511 struct inode *dir = parent->d_inode; 512 struct list_head *pos, *next; 513 struct dentry *dentry, *dvec[10]; 514 int n = 0; 515 516 mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); 517 repeat: 518 spin_lock(&dcache_lock); 519 list_for_each_safe(pos, next, &parent->d_subdirs) { 520 dentry = list_entry(pos, struct dentry, d_u.d_child); 521 spin_lock(&dentry->d_lock); 522 if (!d_unhashed(dentry)) { 523 dget_locked(dentry); 524 __d_drop(dentry); 525 spin_unlock(&dentry->d_lock); 526 dvec[n++] = dentry; 527 if (n == ARRAY_SIZE(dvec)) 528 break; 529 } else 530 spin_unlock(&dentry->d_lock); 531 } 532 spin_unlock(&dcache_lock); 533 if (n) { 534 do { 535 dentry = dvec[--n]; 536 if (dentry->d_inode) { 537 rpc_close_pipes(dentry->d_inode); 538 simple_unlink(dir, dentry); 539 } 540 inode_dir_notify(dir, DN_DELETE); 541 dput(dentry); 542 } while (n); 543 goto repeat; 544 } 545 mutex_unlock(&dir->i_mutex); 546 } 547 548 static int 549 rpc_populate(struct dentry *parent, 550 struct rpc_filelist *files, 551 int start, int eof) 552 { 553 struct inode *inode, *dir = parent->d_inode; 554 void *private = RPC_I(dir)->private; 555 struct dentry *dentry; 556 int mode, i; 557 558 mutex_lock(&dir->i_mutex); 559 for (i = start; i < eof; i++) { 560 dentry = d_alloc_name(parent, files[i].name); 561 if (!dentry) 562 goto out_bad; 563 mode = files[i].mode; 564 inode = rpc_get_inode(dir->i_sb, mode); 565 if (!inode) { 566 dput(dentry); 567 goto out_bad; 568 } 569 inode->i_ino = i; 570 if (files[i].i_fop) 571 inode->i_fop = files[i].i_fop; 572 if (private) 573 rpc_inode_setowner(inode, private); 574 if (S_ISDIR(mode)) 575 dir->i_nlink++; 576 d_add(dentry, inode); 577 } 578 mutex_unlock(&dir->i_mutex); 579 return 0; 580 out_bad: 581 mutex_unlock(&dir->i_mutex); 582 printk(KERN_WARNING "%s: %s failed to populate directory %s\n", 583 __FILE__, __FUNCTION__, parent->d_name.name); 584 return -ENOMEM; 585 } 586 587 static int 588 __rpc_mkdir(struct inode *dir, struct dentry *dentry) 589 { 590 struct inode *inode; 591 592 inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR); 593 if (!inode) 594 goto out_err; 595 inode->i_ino = iunique(dir->i_sb, 100); 596 d_instantiate(dentry, inode); 597 dir->i_nlink++; 598 inode_dir_notify(dir, DN_CREATE); 599 return 0; 600 out_err: 601 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", 602 __FILE__, __FUNCTION__, dentry->d_name.name); 603 return -ENOMEM; 604 } 605 606 static int 607 __rpc_rmdir(struct inode *dir, struct dentry *dentry) 608 { 609 int error; 610 611 shrink_dcache_parent(dentry); 612 if (d_unhashed(dentry)) 613 return 0; 614 if ((error = simple_rmdir(dir, dentry)) != 0) 615 return error; 616 if (!error) { 617 inode_dir_notify(dir, DN_DELETE); 618 d_drop(dentry); 619 } 620 return 0; 621 } 622 623 static struct dentry * 624 rpc_lookup_create(struct dentry *parent, const char *name, int len) 625 { 626 struct inode *dir = parent->d_inode; 627 struct dentry *dentry; 628 629 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 630 dentry = lookup_one_len(name, parent, len); 631 if (IS_ERR(dentry)) 632 goto out_err; 633 if (dentry->d_inode) { 634 dput(dentry); 635 dentry = ERR_PTR(-EEXIST); 636 goto out_err; 637 } 638 return dentry; 639 out_err: 640 mutex_unlock(&dir->i_mutex); 641 return dentry; 642 } 643 644 static struct dentry * 645 rpc_lookup_negative(char *path, struct nameidata *nd) 646 { 647 struct dentry *dentry; 648 int error; 649 650 if ((error = rpc_lookup_parent(path, nd)) != 0) 651 return ERR_PTR(error); 652 dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len); 653 if (IS_ERR(dentry)) 654 rpc_release_path(nd); 655 return dentry; 656 } 657 658 659 struct dentry * 660 rpc_mkdir(char *path, struct rpc_clnt *rpc_client) 661 { 662 struct nameidata nd; 663 struct dentry *dentry; 664 struct inode *dir; 665 int error; 666 667 dentry = rpc_lookup_negative(path, &nd); 668 if (IS_ERR(dentry)) 669 return dentry; 670 dir = nd.dentry->d_inode; 671 if ((error = __rpc_mkdir(dir, dentry)) != 0) 672 goto err_dput; 673 RPC_I(dentry->d_inode)->private = rpc_client; 674 error = rpc_populate(dentry, authfiles, 675 RPCAUTH_info, RPCAUTH_EOF); 676 if (error) 677 goto err_depopulate; 678 dget(dentry); 679 out: 680 mutex_unlock(&dir->i_mutex); 681 rpc_release_path(&nd); 682 return dentry; 683 err_depopulate: 684 rpc_depopulate(dentry); 685 __rpc_rmdir(dir, dentry); 686 err_dput: 687 dput(dentry); 688 printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n", 689 __FILE__, __FUNCTION__, path, error); 690 dentry = ERR_PTR(error); 691 goto out; 692 } 693 694 int 695 rpc_rmdir(struct dentry *dentry) 696 { 697 struct dentry *parent; 698 struct inode *dir; 699 int error; 700 701 parent = dget_parent(dentry); 702 dir = parent->d_inode; 703 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 704 rpc_depopulate(dentry); 705 error = __rpc_rmdir(dir, dentry); 706 dput(dentry); 707 mutex_unlock(&dir->i_mutex); 708 dput(parent); 709 return error; 710 } 711 712 struct dentry * 713 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags) 714 { 715 struct dentry *dentry; 716 struct inode *dir, *inode; 717 struct rpc_inode *rpci; 718 719 dentry = rpc_lookup_create(parent, name, strlen(name)); 720 if (IS_ERR(dentry)) 721 return dentry; 722 dir = parent->d_inode; 723 inode = rpc_get_inode(dir->i_sb, S_IFIFO | 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 dget(dentry); 735 out: 736 mutex_unlock(&dir->i_mutex); 737 return dentry; 738 err_dput: 739 dput(dentry); 740 dentry = ERR_PTR(-ENOMEM); 741 printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n", 742 __FILE__, __FUNCTION__, parent->d_name.name, name, 743 -ENOMEM); 744 goto out; 745 } 746 747 int 748 rpc_unlink(struct dentry *dentry) 749 { 750 struct dentry *parent; 751 struct inode *dir; 752 int error = 0; 753 754 parent = dget_parent(dentry); 755 dir = parent->d_inode; 756 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 757 if (!d_unhashed(dentry)) { 758 d_drop(dentry); 759 if (dentry->d_inode) { 760 rpc_close_pipes(dentry->d_inode); 761 error = simple_unlink(dir, dentry); 762 } 763 inode_dir_notify(dir, DN_DELETE); 764 } 765 dput(dentry); 766 mutex_unlock(&dir->i_mutex); 767 dput(parent); 768 return error; 769 } 770 771 /* 772 * populate the filesystem 773 */ 774 static struct super_operations s_ops = { 775 .alloc_inode = rpc_alloc_inode, 776 .destroy_inode = rpc_destroy_inode, 777 .statfs = simple_statfs, 778 }; 779 780 #define RPCAUTH_GSSMAGIC 0x67596969 781 782 static int 783 rpc_fill_super(struct super_block *sb, void *data, int silent) 784 { 785 struct inode *inode; 786 struct dentry *root; 787 788 sb->s_blocksize = PAGE_CACHE_SIZE; 789 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 790 sb->s_magic = RPCAUTH_GSSMAGIC; 791 sb->s_op = &s_ops; 792 sb->s_time_gran = 1; 793 794 inode = rpc_get_inode(sb, S_IFDIR | 0755); 795 if (!inode) 796 return -ENOMEM; 797 root = d_alloc_root(inode); 798 if (!root) { 799 iput(inode); 800 return -ENOMEM; 801 } 802 if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF)) 803 goto out; 804 sb->s_root = root; 805 return 0; 806 out: 807 d_genocide(root); 808 dput(root); 809 return -ENOMEM; 810 } 811 812 static int 813 rpc_get_sb(struct file_system_type *fs_type, 814 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 815 { 816 return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt); 817 } 818 819 static struct file_system_type rpc_pipe_fs_type = { 820 .owner = THIS_MODULE, 821 .name = "rpc_pipefs", 822 .get_sb = rpc_get_sb, 823 .kill_sb = kill_litter_super, 824 }; 825 826 static void 827 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 828 { 829 struct rpc_inode *rpci = (struct rpc_inode *) foo; 830 831 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 832 SLAB_CTOR_CONSTRUCTOR) { 833 inode_init_once(&rpci->vfs_inode); 834 rpci->private = NULL; 835 rpci->nreaders = 0; 836 rpci->nwriters = 0; 837 INIT_LIST_HEAD(&rpci->in_upcall); 838 INIT_LIST_HEAD(&rpci->pipe); 839 rpci->pipelen = 0; 840 init_waitqueue_head(&rpci->waitq); 841 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci); 842 rpci->ops = NULL; 843 } 844 } 845 846 int register_rpc_pipefs(void) 847 { 848 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", 849 sizeof(struct rpc_inode), 850 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 851 SLAB_MEM_SPREAD), 852 init_once, NULL); 853 if (!rpc_inode_cachep) 854 return -ENOMEM; 855 register_filesystem(&rpc_pipe_fs_type); 856 return 0; 857 } 858 859 void unregister_rpc_pipefs(void) 860 { 861 kmem_cache_destroy(rpc_inode_cachep); 862 unregister_filesystem(&rpc_pipe_fs_type); 863 } 864