1 /* 2 FUSE: Filesystem in Userspace 3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> 4 5 This program can be distributed under the terms of the GNU GPL. 6 See the file COPYING. 7 */ 8 9 #include "fuse_i.h" 10 11 #include <linux/init.h> 12 #include <linux/module.h> 13 #include <linux/poll.h> 14 #include <linux/uio.h> 15 #include <linux/miscdevice.h> 16 #include <linux/pagemap.h> 17 #include <linux/file.h> 18 #include <linux/slab.h> 19 #include <linux/pipe_fs_i.h> 20 #include <linux/swap.h> 21 #include <linux/splice.h> 22 23 MODULE_ALIAS_MISCDEV(FUSE_MINOR); 24 MODULE_ALIAS("devname:fuse"); 25 26 static struct kmem_cache *fuse_req_cachep; 27 28 static struct fuse_dev *fuse_get_dev(struct file *file) 29 { 30 /* 31 * Lockless access is OK, because file->private data is set 32 * once during mount and is valid until the file is released. 33 */ 34 return ACCESS_ONCE(file->private_data); 35 } 36 37 static void fuse_request_init(struct fuse_req *req, struct page **pages, 38 struct fuse_page_desc *page_descs, 39 unsigned npages) 40 { 41 memset(req, 0, sizeof(*req)); 42 memset(pages, 0, sizeof(*pages) * npages); 43 memset(page_descs, 0, sizeof(*page_descs) * npages); 44 INIT_LIST_HEAD(&req->list); 45 INIT_LIST_HEAD(&req->intr_entry); 46 init_waitqueue_head(&req->waitq); 47 atomic_set(&req->count, 1); 48 req->pages = pages; 49 req->page_descs = page_descs; 50 req->max_pages = npages; 51 __set_bit(FR_PENDING, &req->flags); 52 } 53 54 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags) 55 { 56 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags); 57 if (req) { 58 struct page **pages; 59 struct fuse_page_desc *page_descs; 60 61 if (npages <= FUSE_REQ_INLINE_PAGES) { 62 pages = req->inline_pages; 63 page_descs = req->inline_page_descs; 64 } else { 65 pages = kmalloc(sizeof(struct page *) * npages, flags); 66 page_descs = kmalloc(sizeof(struct fuse_page_desc) * 67 npages, flags); 68 } 69 70 if (!pages || !page_descs) { 71 kfree(pages); 72 kfree(page_descs); 73 kmem_cache_free(fuse_req_cachep, req); 74 return NULL; 75 } 76 77 fuse_request_init(req, pages, page_descs, npages); 78 } 79 return req; 80 } 81 82 struct fuse_req *fuse_request_alloc(unsigned npages) 83 { 84 return __fuse_request_alloc(npages, GFP_KERNEL); 85 } 86 EXPORT_SYMBOL_GPL(fuse_request_alloc); 87 88 struct fuse_req *fuse_request_alloc_nofs(unsigned npages) 89 { 90 return __fuse_request_alloc(npages, GFP_NOFS); 91 } 92 93 void fuse_request_free(struct fuse_req *req) 94 { 95 if (req->pages != req->inline_pages) { 96 kfree(req->pages); 97 kfree(req->page_descs); 98 } 99 kmem_cache_free(fuse_req_cachep, req); 100 } 101 102 static void block_sigs(sigset_t *oldset) 103 { 104 sigset_t mask; 105 106 siginitsetinv(&mask, sigmask(SIGKILL)); 107 sigprocmask(SIG_BLOCK, &mask, oldset); 108 } 109 110 static void restore_sigs(sigset_t *oldset) 111 { 112 sigprocmask(SIG_SETMASK, oldset, NULL); 113 } 114 115 void __fuse_get_request(struct fuse_req *req) 116 { 117 atomic_inc(&req->count); 118 } 119 120 /* Must be called with > 1 refcount */ 121 static void __fuse_put_request(struct fuse_req *req) 122 { 123 BUG_ON(atomic_read(&req->count) < 2); 124 atomic_dec(&req->count); 125 } 126 127 static void fuse_req_init_context(struct fuse_req *req) 128 { 129 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid()); 130 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid()); 131 req->in.h.pid = current->pid; 132 } 133 134 void fuse_set_initialized(struct fuse_conn *fc) 135 { 136 /* Make sure stores before this are seen on another CPU */ 137 smp_wmb(); 138 fc->initialized = 1; 139 } 140 141 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background) 142 { 143 return !fc->initialized || (for_background && fc->blocked); 144 } 145 146 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages, 147 bool for_background) 148 { 149 struct fuse_req *req; 150 int err; 151 atomic_inc(&fc->num_waiting); 152 153 if (fuse_block_alloc(fc, for_background)) { 154 sigset_t oldset; 155 int intr; 156 157 block_sigs(&oldset); 158 intr = wait_event_interruptible_exclusive(fc->blocked_waitq, 159 !fuse_block_alloc(fc, for_background)); 160 restore_sigs(&oldset); 161 err = -EINTR; 162 if (intr) 163 goto out; 164 } 165 /* Matches smp_wmb() in fuse_set_initialized() */ 166 smp_rmb(); 167 168 err = -ENOTCONN; 169 if (!fc->connected) 170 goto out; 171 172 err = -ECONNREFUSED; 173 if (fc->conn_error) 174 goto out; 175 176 req = fuse_request_alloc(npages); 177 err = -ENOMEM; 178 if (!req) { 179 if (for_background) 180 wake_up(&fc->blocked_waitq); 181 goto out; 182 } 183 184 fuse_req_init_context(req); 185 __set_bit(FR_WAITING, &req->flags); 186 if (for_background) 187 __set_bit(FR_BACKGROUND, &req->flags); 188 189 return req; 190 191 out: 192 atomic_dec(&fc->num_waiting); 193 return ERR_PTR(err); 194 } 195 196 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages) 197 { 198 return __fuse_get_req(fc, npages, false); 199 } 200 EXPORT_SYMBOL_GPL(fuse_get_req); 201 202 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc, 203 unsigned npages) 204 { 205 return __fuse_get_req(fc, npages, true); 206 } 207 EXPORT_SYMBOL_GPL(fuse_get_req_for_background); 208 209 /* 210 * Return request in fuse_file->reserved_req. However that may 211 * currently be in use. If that is the case, wait for it to become 212 * available. 213 */ 214 static struct fuse_req *get_reserved_req(struct fuse_conn *fc, 215 struct file *file) 216 { 217 struct fuse_req *req = NULL; 218 struct fuse_file *ff = file->private_data; 219 220 do { 221 wait_event(fc->reserved_req_waitq, ff->reserved_req); 222 spin_lock(&fc->lock); 223 if (ff->reserved_req) { 224 req = ff->reserved_req; 225 ff->reserved_req = NULL; 226 req->stolen_file = get_file(file); 227 } 228 spin_unlock(&fc->lock); 229 } while (!req); 230 231 return req; 232 } 233 234 /* 235 * Put stolen request back into fuse_file->reserved_req 236 */ 237 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req) 238 { 239 struct file *file = req->stolen_file; 240 struct fuse_file *ff = file->private_data; 241 242 spin_lock(&fc->lock); 243 fuse_request_init(req, req->pages, req->page_descs, req->max_pages); 244 BUG_ON(ff->reserved_req); 245 ff->reserved_req = req; 246 wake_up_all(&fc->reserved_req_waitq); 247 spin_unlock(&fc->lock); 248 fput(file); 249 } 250 251 /* 252 * Gets a requests for a file operation, always succeeds 253 * 254 * This is used for sending the FLUSH request, which must get to 255 * userspace, due to POSIX locks which may need to be unlocked. 256 * 257 * If allocation fails due to OOM, use the reserved request in 258 * fuse_file. 259 * 260 * This is very unlikely to deadlock accidentally, since the 261 * filesystem should not have it's own file open. If deadlock is 262 * intentional, it can still be broken by "aborting" the filesystem. 263 */ 264 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, 265 struct file *file) 266 { 267 struct fuse_req *req; 268 269 atomic_inc(&fc->num_waiting); 270 wait_event(fc->blocked_waitq, fc->initialized); 271 /* Matches smp_wmb() in fuse_set_initialized() */ 272 smp_rmb(); 273 req = fuse_request_alloc(0); 274 if (!req) 275 req = get_reserved_req(fc, file); 276 277 fuse_req_init_context(req); 278 __set_bit(FR_WAITING, &req->flags); 279 __clear_bit(FR_BACKGROUND, &req->flags); 280 return req; 281 } 282 283 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) 284 { 285 if (atomic_dec_and_test(&req->count)) { 286 if (test_bit(FR_BACKGROUND, &req->flags)) { 287 /* 288 * We get here in the unlikely case that a background 289 * request was allocated but not sent 290 */ 291 spin_lock(&fc->lock); 292 if (!fc->blocked) 293 wake_up(&fc->blocked_waitq); 294 spin_unlock(&fc->lock); 295 } 296 297 if (test_bit(FR_WAITING, &req->flags)) { 298 __clear_bit(FR_WAITING, &req->flags); 299 atomic_dec(&fc->num_waiting); 300 } 301 302 if (req->stolen_file) 303 put_reserved_req(fc, req); 304 else 305 fuse_request_free(req); 306 } 307 } 308 EXPORT_SYMBOL_GPL(fuse_put_request); 309 310 static unsigned len_args(unsigned numargs, struct fuse_arg *args) 311 { 312 unsigned nbytes = 0; 313 unsigned i; 314 315 for (i = 0; i < numargs; i++) 316 nbytes += args[i].size; 317 318 return nbytes; 319 } 320 321 static u64 fuse_get_unique(struct fuse_iqueue *fiq) 322 { 323 return ++fiq->reqctr; 324 } 325 326 static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req) 327 { 328 req->in.h.len = sizeof(struct fuse_in_header) + 329 len_args(req->in.numargs, (struct fuse_arg *) req->in.args); 330 list_add_tail(&req->list, &fiq->pending); 331 wake_up_locked(&fiq->waitq); 332 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 333 } 334 335 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, 336 u64 nodeid, u64 nlookup) 337 { 338 struct fuse_iqueue *fiq = &fc->iq; 339 340 forget->forget_one.nodeid = nodeid; 341 forget->forget_one.nlookup = nlookup; 342 343 spin_lock(&fiq->waitq.lock); 344 if (fiq->connected) { 345 fiq->forget_list_tail->next = forget; 346 fiq->forget_list_tail = forget; 347 wake_up_locked(&fiq->waitq); 348 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 349 } else { 350 kfree(forget); 351 } 352 spin_unlock(&fiq->waitq.lock); 353 } 354 355 static void flush_bg_queue(struct fuse_conn *fc) 356 { 357 while (fc->active_background < fc->max_background && 358 !list_empty(&fc->bg_queue)) { 359 struct fuse_req *req; 360 struct fuse_iqueue *fiq = &fc->iq; 361 362 req = list_entry(fc->bg_queue.next, struct fuse_req, list); 363 list_del(&req->list); 364 fc->active_background++; 365 spin_lock(&fiq->waitq.lock); 366 req->in.h.unique = fuse_get_unique(fiq); 367 queue_request(fiq, req); 368 spin_unlock(&fiq->waitq.lock); 369 } 370 } 371 372 /* 373 * This function is called when a request is finished. Either a reply 374 * has arrived or it was aborted (and not yet sent) or some error 375 * occurred during communication with userspace, or the device file 376 * was closed. The requester thread is woken up (if still waiting), 377 * the 'end' callback is called if given, else the reference to the 378 * request is released 379 */ 380 static void request_end(struct fuse_conn *fc, struct fuse_req *req) 381 { 382 struct fuse_iqueue *fiq = &fc->iq; 383 384 if (test_and_set_bit(FR_FINISHED, &req->flags)) 385 return; 386 387 spin_lock(&fiq->waitq.lock); 388 list_del_init(&req->intr_entry); 389 spin_unlock(&fiq->waitq.lock); 390 WARN_ON(test_bit(FR_PENDING, &req->flags)); 391 WARN_ON(test_bit(FR_SENT, &req->flags)); 392 if (test_bit(FR_BACKGROUND, &req->flags)) { 393 spin_lock(&fc->lock); 394 clear_bit(FR_BACKGROUND, &req->flags); 395 if (fc->num_background == fc->max_background) 396 fc->blocked = 0; 397 398 /* Wake up next waiter, if any */ 399 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq)) 400 wake_up(&fc->blocked_waitq); 401 402 if (fc->num_background == fc->congestion_threshold && 403 fc->connected && fc->bdi_initialized) { 404 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC); 405 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC); 406 } 407 fc->num_background--; 408 fc->active_background--; 409 flush_bg_queue(fc); 410 spin_unlock(&fc->lock); 411 } 412 wake_up(&req->waitq); 413 if (req->end) 414 req->end(fc, req); 415 fuse_put_request(fc, req); 416 } 417 418 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req) 419 { 420 spin_lock(&fiq->waitq.lock); 421 if (list_empty(&req->intr_entry)) { 422 list_add_tail(&req->intr_entry, &fiq->interrupts); 423 wake_up_locked(&fiq->waitq); 424 } 425 spin_unlock(&fiq->waitq.lock); 426 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 427 } 428 429 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req) 430 { 431 struct fuse_iqueue *fiq = &fc->iq; 432 int err; 433 434 if (!fc->no_interrupt) { 435 /* Any signal may interrupt this */ 436 err = wait_event_interruptible(req->waitq, 437 test_bit(FR_FINISHED, &req->flags)); 438 if (!err) 439 return; 440 441 set_bit(FR_INTERRUPTED, &req->flags); 442 /* matches barrier in fuse_dev_do_read() */ 443 smp_mb__after_atomic(); 444 if (test_bit(FR_SENT, &req->flags)) 445 queue_interrupt(fiq, req); 446 } 447 448 if (!test_bit(FR_FORCE, &req->flags)) { 449 sigset_t oldset; 450 451 /* Only fatal signals may interrupt this */ 452 block_sigs(&oldset); 453 err = wait_event_interruptible(req->waitq, 454 test_bit(FR_FINISHED, &req->flags)); 455 restore_sigs(&oldset); 456 457 if (!err) 458 return; 459 460 spin_lock(&fiq->waitq.lock); 461 /* Request is not yet in userspace, bail out */ 462 if (test_bit(FR_PENDING, &req->flags)) { 463 list_del(&req->list); 464 spin_unlock(&fiq->waitq.lock); 465 __fuse_put_request(req); 466 req->out.h.error = -EINTR; 467 return; 468 } 469 spin_unlock(&fiq->waitq.lock); 470 } 471 472 /* 473 * Either request is already in userspace, or it was forced. 474 * Wait it out. 475 */ 476 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags)); 477 } 478 479 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) 480 { 481 struct fuse_iqueue *fiq = &fc->iq; 482 483 BUG_ON(test_bit(FR_BACKGROUND, &req->flags)); 484 spin_lock(&fiq->waitq.lock); 485 if (!fiq->connected) { 486 spin_unlock(&fiq->waitq.lock); 487 req->out.h.error = -ENOTCONN; 488 } else { 489 req->in.h.unique = fuse_get_unique(fiq); 490 queue_request(fiq, req); 491 /* acquire extra reference, since request is still needed 492 after request_end() */ 493 __fuse_get_request(req); 494 spin_unlock(&fiq->waitq.lock); 495 496 request_wait_answer(fc, req); 497 /* Pairs with smp_wmb() in request_end() */ 498 smp_rmb(); 499 } 500 } 501 502 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) 503 { 504 __set_bit(FR_ISREPLY, &req->flags); 505 if (!test_bit(FR_WAITING, &req->flags)) { 506 __set_bit(FR_WAITING, &req->flags); 507 atomic_inc(&fc->num_waiting); 508 } 509 __fuse_request_send(fc, req); 510 } 511 EXPORT_SYMBOL_GPL(fuse_request_send); 512 513 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) 514 { 515 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS) 516 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE; 517 518 if (fc->minor < 9) { 519 switch (args->in.h.opcode) { 520 case FUSE_LOOKUP: 521 case FUSE_CREATE: 522 case FUSE_MKNOD: 523 case FUSE_MKDIR: 524 case FUSE_SYMLINK: 525 case FUSE_LINK: 526 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 527 break; 528 case FUSE_GETATTR: 529 case FUSE_SETATTR: 530 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 531 break; 532 } 533 } 534 if (fc->minor < 12) { 535 switch (args->in.h.opcode) { 536 case FUSE_CREATE: 537 args->in.args[0].size = sizeof(struct fuse_open_in); 538 break; 539 case FUSE_MKNOD: 540 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE; 541 break; 542 } 543 } 544 } 545 546 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args) 547 { 548 struct fuse_req *req; 549 ssize_t ret; 550 551 req = fuse_get_req(fc, 0); 552 if (IS_ERR(req)) 553 return PTR_ERR(req); 554 555 /* Needs to be done after fuse_get_req() so that fc->minor is valid */ 556 fuse_adjust_compat(fc, args); 557 558 req->in.h.opcode = args->in.h.opcode; 559 req->in.h.nodeid = args->in.h.nodeid; 560 req->in.numargs = args->in.numargs; 561 memcpy(req->in.args, args->in.args, 562 args->in.numargs * sizeof(struct fuse_in_arg)); 563 req->out.argvar = args->out.argvar; 564 req->out.numargs = args->out.numargs; 565 memcpy(req->out.args, args->out.args, 566 args->out.numargs * sizeof(struct fuse_arg)); 567 fuse_request_send(fc, req); 568 ret = req->out.h.error; 569 if (!ret && args->out.argvar) { 570 BUG_ON(args->out.numargs != 1); 571 ret = req->out.args[0].size; 572 } 573 fuse_put_request(fc, req); 574 575 return ret; 576 } 577 578 /* 579 * Called under fc->lock 580 * 581 * fc->connected must have been checked previously 582 */ 583 void fuse_request_send_background_locked(struct fuse_conn *fc, 584 struct fuse_req *req) 585 { 586 BUG_ON(!test_bit(FR_BACKGROUND, &req->flags)); 587 if (!test_bit(FR_WAITING, &req->flags)) { 588 __set_bit(FR_WAITING, &req->flags); 589 atomic_inc(&fc->num_waiting); 590 } 591 __set_bit(FR_ISREPLY, &req->flags); 592 fc->num_background++; 593 if (fc->num_background == fc->max_background) 594 fc->blocked = 1; 595 if (fc->num_background == fc->congestion_threshold && 596 fc->bdi_initialized) { 597 set_bdi_congested(&fc->bdi, BLK_RW_SYNC); 598 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC); 599 } 600 list_add_tail(&req->list, &fc->bg_queue); 601 flush_bg_queue(fc); 602 } 603 604 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req) 605 { 606 BUG_ON(!req->end); 607 spin_lock(&fc->lock); 608 if (fc->connected) { 609 fuse_request_send_background_locked(fc, req); 610 spin_unlock(&fc->lock); 611 } else { 612 spin_unlock(&fc->lock); 613 req->out.h.error = -ENOTCONN; 614 req->end(fc, req); 615 fuse_put_request(fc, req); 616 } 617 } 618 EXPORT_SYMBOL_GPL(fuse_request_send_background); 619 620 static int fuse_request_send_notify_reply(struct fuse_conn *fc, 621 struct fuse_req *req, u64 unique) 622 { 623 int err = -ENODEV; 624 struct fuse_iqueue *fiq = &fc->iq; 625 626 __clear_bit(FR_ISREPLY, &req->flags); 627 req->in.h.unique = unique; 628 spin_lock(&fiq->waitq.lock); 629 if (fiq->connected) { 630 queue_request(fiq, req); 631 err = 0; 632 } 633 spin_unlock(&fiq->waitq.lock); 634 635 return err; 636 } 637 638 void fuse_force_forget(struct file *file, u64 nodeid) 639 { 640 struct inode *inode = file_inode(file); 641 struct fuse_conn *fc = get_fuse_conn(inode); 642 struct fuse_req *req; 643 struct fuse_forget_in inarg; 644 645 memset(&inarg, 0, sizeof(inarg)); 646 inarg.nlookup = 1; 647 req = fuse_get_req_nofail_nopages(fc, file); 648 req->in.h.opcode = FUSE_FORGET; 649 req->in.h.nodeid = nodeid; 650 req->in.numargs = 1; 651 req->in.args[0].size = sizeof(inarg); 652 req->in.args[0].value = &inarg; 653 __clear_bit(FR_ISREPLY, &req->flags); 654 __fuse_request_send(fc, req); 655 /* ignore errors */ 656 fuse_put_request(fc, req); 657 } 658 659 /* 660 * Lock the request. Up to the next unlock_request() there mustn't be 661 * anything that could cause a page-fault. If the request was already 662 * aborted bail out. 663 */ 664 static int lock_request(struct fuse_req *req) 665 { 666 int err = 0; 667 if (req) { 668 spin_lock(&req->waitq.lock); 669 if (test_bit(FR_ABORTED, &req->flags)) 670 err = -ENOENT; 671 else 672 set_bit(FR_LOCKED, &req->flags); 673 spin_unlock(&req->waitq.lock); 674 } 675 return err; 676 } 677 678 /* 679 * Unlock request. If it was aborted while locked, caller is responsible 680 * for unlocking and ending the request. 681 */ 682 static int unlock_request(struct fuse_req *req) 683 { 684 int err = 0; 685 if (req) { 686 spin_lock(&req->waitq.lock); 687 if (test_bit(FR_ABORTED, &req->flags)) 688 err = -ENOENT; 689 else 690 clear_bit(FR_LOCKED, &req->flags); 691 spin_unlock(&req->waitq.lock); 692 } 693 return err; 694 } 695 696 struct fuse_copy_state { 697 int write; 698 struct fuse_req *req; 699 struct iov_iter *iter; 700 struct pipe_buffer *pipebufs; 701 struct pipe_buffer *currbuf; 702 struct pipe_inode_info *pipe; 703 unsigned long nr_segs; 704 struct page *pg; 705 unsigned len; 706 unsigned offset; 707 unsigned move_pages:1; 708 }; 709 710 static void fuse_copy_init(struct fuse_copy_state *cs, int write, 711 struct iov_iter *iter) 712 { 713 memset(cs, 0, sizeof(*cs)); 714 cs->write = write; 715 cs->iter = iter; 716 } 717 718 /* Unmap and put previous page of userspace buffer */ 719 static void fuse_copy_finish(struct fuse_copy_state *cs) 720 { 721 if (cs->currbuf) { 722 struct pipe_buffer *buf = cs->currbuf; 723 724 if (cs->write) 725 buf->len = PAGE_SIZE - cs->len; 726 cs->currbuf = NULL; 727 } else if (cs->pg) { 728 if (cs->write) { 729 flush_dcache_page(cs->pg); 730 set_page_dirty_lock(cs->pg); 731 } 732 put_page(cs->pg); 733 } 734 cs->pg = NULL; 735 } 736 737 /* 738 * Get another pagefull of userspace buffer, and map it to kernel 739 * address space, and lock request 740 */ 741 static int fuse_copy_fill(struct fuse_copy_state *cs) 742 { 743 struct page *page; 744 int err; 745 746 err = unlock_request(cs->req); 747 if (err) 748 return err; 749 750 fuse_copy_finish(cs); 751 if (cs->pipebufs) { 752 struct pipe_buffer *buf = cs->pipebufs; 753 754 if (!cs->write) { 755 err = buf->ops->confirm(cs->pipe, buf); 756 if (err) 757 return err; 758 759 BUG_ON(!cs->nr_segs); 760 cs->currbuf = buf; 761 cs->pg = buf->page; 762 cs->offset = buf->offset; 763 cs->len = buf->len; 764 cs->pipebufs++; 765 cs->nr_segs--; 766 } else { 767 if (cs->nr_segs == cs->pipe->buffers) 768 return -EIO; 769 770 page = alloc_page(GFP_HIGHUSER); 771 if (!page) 772 return -ENOMEM; 773 774 buf->page = page; 775 buf->offset = 0; 776 buf->len = 0; 777 778 cs->currbuf = buf; 779 cs->pg = page; 780 cs->offset = 0; 781 cs->len = PAGE_SIZE; 782 cs->pipebufs++; 783 cs->nr_segs++; 784 } 785 } else { 786 size_t off; 787 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off); 788 if (err < 0) 789 return err; 790 BUG_ON(!err); 791 cs->len = err; 792 cs->offset = off; 793 cs->pg = page; 794 cs->offset = off; 795 iov_iter_advance(cs->iter, err); 796 } 797 798 return lock_request(cs->req); 799 } 800 801 /* Do as much copy to/from userspace buffer as we can */ 802 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size) 803 { 804 unsigned ncpy = min(*size, cs->len); 805 if (val) { 806 void *pgaddr = kmap_atomic(cs->pg); 807 void *buf = pgaddr + cs->offset; 808 809 if (cs->write) 810 memcpy(buf, *val, ncpy); 811 else 812 memcpy(*val, buf, ncpy); 813 814 kunmap_atomic(pgaddr); 815 *val += ncpy; 816 } 817 *size -= ncpy; 818 cs->len -= ncpy; 819 cs->offset += ncpy; 820 return ncpy; 821 } 822 823 static int fuse_check_page(struct page *page) 824 { 825 if (page_mapcount(page) || 826 page->mapping != NULL || 827 page_count(page) != 1 || 828 (page->flags & PAGE_FLAGS_CHECK_AT_PREP & 829 ~(1 << PG_locked | 830 1 << PG_referenced | 831 1 << PG_uptodate | 832 1 << PG_lru | 833 1 << PG_active | 834 1 << PG_reclaim))) { 835 printk(KERN_WARNING "fuse: trying to steal weird page\n"); 836 printk(KERN_WARNING " page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping); 837 return 1; 838 } 839 return 0; 840 } 841 842 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 843 { 844 int err; 845 struct page *oldpage = *pagep; 846 struct page *newpage; 847 struct pipe_buffer *buf = cs->pipebufs; 848 849 err = unlock_request(cs->req); 850 if (err) 851 return err; 852 853 fuse_copy_finish(cs); 854 855 err = buf->ops->confirm(cs->pipe, buf); 856 if (err) 857 return err; 858 859 BUG_ON(!cs->nr_segs); 860 cs->currbuf = buf; 861 cs->len = buf->len; 862 cs->pipebufs++; 863 cs->nr_segs--; 864 865 if (cs->len != PAGE_SIZE) 866 goto out_fallback; 867 868 if (buf->ops->steal(cs->pipe, buf) != 0) 869 goto out_fallback; 870 871 newpage = buf->page; 872 873 if (!PageUptodate(newpage)) 874 SetPageUptodate(newpage); 875 876 ClearPageMappedToDisk(newpage); 877 878 if (fuse_check_page(newpage) != 0) 879 goto out_fallback_unlock; 880 881 /* 882 * This is a new and locked page, it shouldn't be mapped or 883 * have any special flags on it 884 */ 885 if (WARN_ON(page_mapped(oldpage))) 886 goto out_fallback_unlock; 887 if (WARN_ON(page_has_private(oldpage))) 888 goto out_fallback_unlock; 889 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage))) 890 goto out_fallback_unlock; 891 if (WARN_ON(PageMlocked(oldpage))) 892 goto out_fallback_unlock; 893 894 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL); 895 if (err) { 896 unlock_page(newpage); 897 return err; 898 } 899 900 page_cache_get(newpage); 901 902 if (!(buf->flags & PIPE_BUF_FLAG_LRU)) 903 lru_cache_add_file(newpage); 904 905 err = 0; 906 spin_lock(&cs->req->waitq.lock); 907 if (test_bit(FR_ABORTED, &cs->req->flags)) 908 err = -ENOENT; 909 else 910 *pagep = newpage; 911 spin_unlock(&cs->req->waitq.lock); 912 913 if (err) { 914 unlock_page(newpage); 915 page_cache_release(newpage); 916 return err; 917 } 918 919 unlock_page(oldpage); 920 page_cache_release(oldpage); 921 cs->len = 0; 922 923 return 0; 924 925 out_fallback_unlock: 926 unlock_page(newpage); 927 out_fallback: 928 cs->pg = buf->page; 929 cs->offset = buf->offset; 930 931 err = lock_request(cs->req); 932 if (err) 933 return err; 934 935 return 1; 936 } 937 938 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page, 939 unsigned offset, unsigned count) 940 { 941 struct pipe_buffer *buf; 942 int err; 943 944 if (cs->nr_segs == cs->pipe->buffers) 945 return -EIO; 946 947 err = unlock_request(cs->req); 948 if (err) 949 return err; 950 951 fuse_copy_finish(cs); 952 953 buf = cs->pipebufs; 954 page_cache_get(page); 955 buf->page = page; 956 buf->offset = offset; 957 buf->len = count; 958 959 cs->pipebufs++; 960 cs->nr_segs++; 961 cs->len = 0; 962 963 return 0; 964 } 965 966 /* 967 * Copy a page in the request to/from the userspace buffer. Must be 968 * done atomically 969 */ 970 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep, 971 unsigned offset, unsigned count, int zeroing) 972 { 973 int err; 974 struct page *page = *pagep; 975 976 if (page && zeroing && count < PAGE_SIZE) 977 clear_highpage(page); 978 979 while (count) { 980 if (cs->write && cs->pipebufs && page) { 981 return fuse_ref_page(cs, page, offset, count); 982 } else if (!cs->len) { 983 if (cs->move_pages && page && 984 offset == 0 && count == PAGE_SIZE) { 985 err = fuse_try_move_page(cs, pagep); 986 if (err <= 0) 987 return err; 988 } else { 989 err = fuse_copy_fill(cs); 990 if (err) 991 return err; 992 } 993 } 994 if (page) { 995 void *mapaddr = kmap_atomic(page); 996 void *buf = mapaddr + offset; 997 offset += fuse_copy_do(cs, &buf, &count); 998 kunmap_atomic(mapaddr); 999 } else 1000 offset += fuse_copy_do(cs, NULL, &count); 1001 } 1002 if (page && !cs->write) 1003 flush_dcache_page(page); 1004 return 0; 1005 } 1006 1007 /* Copy pages in the request to/from userspace buffer */ 1008 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, 1009 int zeroing) 1010 { 1011 unsigned i; 1012 struct fuse_req *req = cs->req; 1013 1014 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) { 1015 int err; 1016 unsigned offset = req->page_descs[i].offset; 1017 unsigned count = min(nbytes, req->page_descs[i].length); 1018 1019 err = fuse_copy_page(cs, &req->pages[i], offset, count, 1020 zeroing); 1021 if (err) 1022 return err; 1023 1024 nbytes -= count; 1025 } 1026 return 0; 1027 } 1028 1029 /* Copy a single argument in the request to/from userspace buffer */ 1030 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size) 1031 { 1032 while (size) { 1033 if (!cs->len) { 1034 int err = fuse_copy_fill(cs); 1035 if (err) 1036 return err; 1037 } 1038 fuse_copy_do(cs, &val, &size); 1039 } 1040 return 0; 1041 } 1042 1043 /* Copy request arguments to/from userspace buffer */ 1044 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs, 1045 unsigned argpages, struct fuse_arg *args, 1046 int zeroing) 1047 { 1048 int err = 0; 1049 unsigned i; 1050 1051 for (i = 0; !err && i < numargs; i++) { 1052 struct fuse_arg *arg = &args[i]; 1053 if (i == numargs - 1 && argpages) 1054 err = fuse_copy_pages(cs, arg->size, zeroing); 1055 else 1056 err = fuse_copy_one(cs, arg->value, arg->size); 1057 } 1058 return err; 1059 } 1060 1061 static int forget_pending(struct fuse_iqueue *fiq) 1062 { 1063 return fiq->forget_list_head.next != NULL; 1064 } 1065 1066 static int request_pending(struct fuse_iqueue *fiq) 1067 { 1068 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) || 1069 forget_pending(fiq); 1070 } 1071 1072 /* 1073 * Transfer an interrupt request to userspace 1074 * 1075 * Unlike other requests this is assembled on demand, without a need 1076 * to allocate a separate fuse_req structure. 1077 * 1078 * Called with fiq->waitq.lock held, releases it 1079 */ 1080 static int fuse_read_interrupt(struct fuse_iqueue *fiq, 1081 struct fuse_copy_state *cs, 1082 size_t nbytes, struct fuse_req *req) 1083 __releases(fiq->waitq.lock) 1084 { 1085 struct fuse_in_header ih; 1086 struct fuse_interrupt_in arg; 1087 unsigned reqsize = sizeof(ih) + sizeof(arg); 1088 int err; 1089 1090 list_del_init(&req->intr_entry); 1091 req->intr_unique = fuse_get_unique(fiq); 1092 memset(&ih, 0, sizeof(ih)); 1093 memset(&arg, 0, sizeof(arg)); 1094 ih.len = reqsize; 1095 ih.opcode = FUSE_INTERRUPT; 1096 ih.unique = req->intr_unique; 1097 arg.unique = req->in.h.unique; 1098 1099 spin_unlock(&fiq->waitq.lock); 1100 if (nbytes < reqsize) 1101 return -EINVAL; 1102 1103 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1104 if (!err) 1105 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1106 fuse_copy_finish(cs); 1107 1108 return err ? err : reqsize; 1109 } 1110 1111 static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq, 1112 unsigned max, 1113 unsigned *countp) 1114 { 1115 struct fuse_forget_link *head = fiq->forget_list_head.next; 1116 struct fuse_forget_link **newhead = &head; 1117 unsigned count; 1118 1119 for (count = 0; *newhead != NULL && count < max; count++) 1120 newhead = &(*newhead)->next; 1121 1122 fiq->forget_list_head.next = *newhead; 1123 *newhead = NULL; 1124 if (fiq->forget_list_head.next == NULL) 1125 fiq->forget_list_tail = &fiq->forget_list_head; 1126 1127 if (countp != NULL) 1128 *countp = count; 1129 1130 return head; 1131 } 1132 1133 static int fuse_read_single_forget(struct fuse_iqueue *fiq, 1134 struct fuse_copy_state *cs, 1135 size_t nbytes) 1136 __releases(fiq->waitq.lock) 1137 { 1138 int err; 1139 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL); 1140 struct fuse_forget_in arg = { 1141 .nlookup = forget->forget_one.nlookup, 1142 }; 1143 struct fuse_in_header ih = { 1144 .opcode = FUSE_FORGET, 1145 .nodeid = forget->forget_one.nodeid, 1146 .unique = fuse_get_unique(fiq), 1147 .len = sizeof(ih) + sizeof(arg), 1148 }; 1149 1150 spin_unlock(&fiq->waitq.lock); 1151 kfree(forget); 1152 if (nbytes < ih.len) 1153 return -EINVAL; 1154 1155 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1156 if (!err) 1157 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1158 fuse_copy_finish(cs); 1159 1160 if (err) 1161 return err; 1162 1163 return ih.len; 1164 } 1165 1166 static int fuse_read_batch_forget(struct fuse_iqueue *fiq, 1167 struct fuse_copy_state *cs, size_t nbytes) 1168 __releases(fiq->waitq.lock) 1169 { 1170 int err; 1171 unsigned max_forgets; 1172 unsigned count; 1173 struct fuse_forget_link *head; 1174 struct fuse_batch_forget_in arg = { .count = 0 }; 1175 struct fuse_in_header ih = { 1176 .opcode = FUSE_BATCH_FORGET, 1177 .unique = fuse_get_unique(fiq), 1178 .len = sizeof(ih) + sizeof(arg), 1179 }; 1180 1181 if (nbytes < ih.len) { 1182 spin_unlock(&fiq->waitq.lock); 1183 return -EINVAL; 1184 } 1185 1186 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one); 1187 head = dequeue_forget(fiq, max_forgets, &count); 1188 spin_unlock(&fiq->waitq.lock); 1189 1190 arg.count = count; 1191 ih.len += count * sizeof(struct fuse_forget_one); 1192 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1193 if (!err) 1194 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1195 1196 while (head) { 1197 struct fuse_forget_link *forget = head; 1198 1199 if (!err) { 1200 err = fuse_copy_one(cs, &forget->forget_one, 1201 sizeof(forget->forget_one)); 1202 } 1203 head = forget->next; 1204 kfree(forget); 1205 } 1206 1207 fuse_copy_finish(cs); 1208 1209 if (err) 1210 return err; 1211 1212 return ih.len; 1213 } 1214 1215 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq, 1216 struct fuse_copy_state *cs, 1217 size_t nbytes) 1218 __releases(fiq->waitq.lock) 1219 { 1220 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL) 1221 return fuse_read_single_forget(fiq, cs, nbytes); 1222 else 1223 return fuse_read_batch_forget(fiq, cs, nbytes); 1224 } 1225 1226 /* 1227 * Read a single request into the userspace filesystem's buffer. This 1228 * function waits until a request is available, then removes it from 1229 * the pending list and copies request data to userspace buffer. If 1230 * no reply is needed (FORGET) or request has been aborted or there 1231 * was an error during the copying then it's finished by calling 1232 * request_end(). Otherwise add it to the processing list, and set 1233 * the 'sent' flag. 1234 */ 1235 static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, 1236 struct fuse_copy_state *cs, size_t nbytes) 1237 { 1238 ssize_t err; 1239 struct fuse_conn *fc = fud->fc; 1240 struct fuse_iqueue *fiq = &fc->iq; 1241 struct fuse_pqueue *fpq = &fud->pq; 1242 struct fuse_req *req; 1243 struct fuse_in *in; 1244 unsigned reqsize; 1245 1246 restart: 1247 spin_lock(&fiq->waitq.lock); 1248 err = -EAGAIN; 1249 if ((file->f_flags & O_NONBLOCK) && fiq->connected && 1250 !request_pending(fiq)) 1251 goto err_unlock; 1252 1253 err = wait_event_interruptible_exclusive_locked(fiq->waitq, 1254 !fiq->connected || request_pending(fiq)); 1255 if (err) 1256 goto err_unlock; 1257 1258 err = -ENODEV; 1259 if (!fiq->connected) 1260 goto err_unlock; 1261 1262 if (!list_empty(&fiq->interrupts)) { 1263 req = list_entry(fiq->interrupts.next, struct fuse_req, 1264 intr_entry); 1265 return fuse_read_interrupt(fiq, cs, nbytes, req); 1266 } 1267 1268 if (forget_pending(fiq)) { 1269 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0) 1270 return fuse_read_forget(fc, fiq, cs, nbytes); 1271 1272 if (fiq->forget_batch <= -8) 1273 fiq->forget_batch = 16; 1274 } 1275 1276 req = list_entry(fiq->pending.next, struct fuse_req, list); 1277 clear_bit(FR_PENDING, &req->flags); 1278 list_del_init(&req->list); 1279 spin_unlock(&fiq->waitq.lock); 1280 1281 in = &req->in; 1282 reqsize = in->h.len; 1283 /* If request is too large, reply with an error and restart the read */ 1284 if (nbytes < reqsize) { 1285 req->out.h.error = -EIO; 1286 /* SETXATTR is special, since it may contain too large data */ 1287 if (in->h.opcode == FUSE_SETXATTR) 1288 req->out.h.error = -E2BIG; 1289 request_end(fc, req); 1290 goto restart; 1291 } 1292 spin_lock(&fpq->lock); 1293 list_add(&req->list, &fpq->io); 1294 spin_unlock(&fpq->lock); 1295 cs->req = req; 1296 err = fuse_copy_one(cs, &in->h, sizeof(in->h)); 1297 if (!err) 1298 err = fuse_copy_args(cs, in->numargs, in->argpages, 1299 (struct fuse_arg *) in->args, 0); 1300 fuse_copy_finish(cs); 1301 spin_lock(&fpq->lock); 1302 clear_bit(FR_LOCKED, &req->flags); 1303 if (!fpq->connected) { 1304 err = -ENODEV; 1305 goto out_end; 1306 } 1307 if (err) { 1308 req->out.h.error = -EIO; 1309 goto out_end; 1310 } 1311 if (!test_bit(FR_ISREPLY, &req->flags)) { 1312 err = reqsize; 1313 goto out_end; 1314 } 1315 list_move_tail(&req->list, &fpq->processing); 1316 spin_unlock(&fpq->lock); 1317 set_bit(FR_SENT, &req->flags); 1318 /* matches barrier in request_wait_answer() */ 1319 smp_mb__after_atomic(); 1320 if (test_bit(FR_INTERRUPTED, &req->flags)) 1321 queue_interrupt(fiq, req); 1322 1323 return reqsize; 1324 1325 out_end: 1326 if (!test_bit(FR_PRIVATE, &req->flags)) 1327 list_del_init(&req->list); 1328 spin_unlock(&fpq->lock); 1329 request_end(fc, req); 1330 return err; 1331 1332 err_unlock: 1333 spin_unlock(&fiq->waitq.lock); 1334 return err; 1335 } 1336 1337 static int fuse_dev_open(struct inode *inode, struct file *file) 1338 { 1339 /* 1340 * The fuse device's file's private_data is used to hold 1341 * the fuse_conn(ection) when it is mounted, and is used to 1342 * keep track of whether the file has been mounted already. 1343 */ 1344 file->private_data = NULL; 1345 return 0; 1346 } 1347 1348 static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) 1349 { 1350 struct fuse_copy_state cs; 1351 struct file *file = iocb->ki_filp; 1352 struct fuse_dev *fud = fuse_get_dev(file); 1353 1354 if (!fud) 1355 return -EPERM; 1356 1357 if (!iter_is_iovec(to)) 1358 return -EINVAL; 1359 1360 fuse_copy_init(&cs, 1, to); 1361 1362 return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to)); 1363 } 1364 1365 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, 1366 struct pipe_inode_info *pipe, 1367 size_t len, unsigned int flags) 1368 { 1369 int ret; 1370 int page_nr = 0; 1371 int do_wakeup = 0; 1372 struct pipe_buffer *bufs; 1373 struct fuse_copy_state cs; 1374 struct fuse_dev *fud = fuse_get_dev(in); 1375 1376 if (!fud) 1377 return -EPERM; 1378 1379 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL); 1380 if (!bufs) 1381 return -ENOMEM; 1382 1383 fuse_copy_init(&cs, 1, NULL); 1384 cs.pipebufs = bufs; 1385 cs.pipe = pipe; 1386 ret = fuse_dev_do_read(fud, in, &cs, len); 1387 if (ret < 0) 1388 goto out; 1389 1390 ret = 0; 1391 pipe_lock(pipe); 1392 1393 if (!pipe->readers) { 1394 send_sig(SIGPIPE, current, 0); 1395 if (!ret) 1396 ret = -EPIPE; 1397 goto out_unlock; 1398 } 1399 1400 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) { 1401 ret = -EIO; 1402 goto out_unlock; 1403 } 1404 1405 while (page_nr < cs.nr_segs) { 1406 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 1407 struct pipe_buffer *buf = pipe->bufs + newbuf; 1408 1409 buf->page = bufs[page_nr].page; 1410 buf->offset = bufs[page_nr].offset; 1411 buf->len = bufs[page_nr].len; 1412 /* 1413 * Need to be careful about this. Having buf->ops in module 1414 * code can Oops if the buffer persists after module unload. 1415 */ 1416 buf->ops = &nosteal_pipe_buf_ops; 1417 1418 pipe->nrbufs++; 1419 page_nr++; 1420 ret += buf->len; 1421 1422 if (pipe->files) 1423 do_wakeup = 1; 1424 } 1425 1426 out_unlock: 1427 pipe_unlock(pipe); 1428 1429 if (do_wakeup) { 1430 smp_mb(); 1431 if (waitqueue_active(&pipe->wait)) 1432 wake_up_interruptible(&pipe->wait); 1433 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); 1434 } 1435 1436 out: 1437 for (; page_nr < cs.nr_segs; page_nr++) 1438 page_cache_release(bufs[page_nr].page); 1439 1440 kfree(bufs); 1441 return ret; 1442 } 1443 1444 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size, 1445 struct fuse_copy_state *cs) 1446 { 1447 struct fuse_notify_poll_wakeup_out outarg; 1448 int err = -EINVAL; 1449 1450 if (size != sizeof(outarg)) 1451 goto err; 1452 1453 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1454 if (err) 1455 goto err; 1456 1457 fuse_copy_finish(cs); 1458 return fuse_notify_poll_wakeup(fc, &outarg); 1459 1460 err: 1461 fuse_copy_finish(cs); 1462 return err; 1463 } 1464 1465 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size, 1466 struct fuse_copy_state *cs) 1467 { 1468 struct fuse_notify_inval_inode_out outarg; 1469 int err = -EINVAL; 1470 1471 if (size != sizeof(outarg)) 1472 goto err; 1473 1474 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1475 if (err) 1476 goto err; 1477 fuse_copy_finish(cs); 1478 1479 down_read(&fc->killsb); 1480 err = -ENOENT; 1481 if (fc->sb) { 1482 err = fuse_reverse_inval_inode(fc->sb, outarg.ino, 1483 outarg.off, outarg.len); 1484 } 1485 up_read(&fc->killsb); 1486 return err; 1487 1488 err: 1489 fuse_copy_finish(cs); 1490 return err; 1491 } 1492 1493 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size, 1494 struct fuse_copy_state *cs) 1495 { 1496 struct fuse_notify_inval_entry_out outarg; 1497 int err = -ENOMEM; 1498 char *buf; 1499 struct qstr name; 1500 1501 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); 1502 if (!buf) 1503 goto err; 1504 1505 err = -EINVAL; 1506 if (size < sizeof(outarg)) 1507 goto err; 1508 1509 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1510 if (err) 1511 goto err; 1512 1513 err = -ENAMETOOLONG; 1514 if (outarg.namelen > FUSE_NAME_MAX) 1515 goto err; 1516 1517 err = -EINVAL; 1518 if (size != sizeof(outarg) + outarg.namelen + 1) 1519 goto err; 1520 1521 name.name = buf; 1522 name.len = outarg.namelen; 1523 err = fuse_copy_one(cs, buf, outarg.namelen + 1); 1524 if (err) 1525 goto err; 1526 fuse_copy_finish(cs); 1527 buf[outarg.namelen] = 0; 1528 name.hash = full_name_hash(name.name, name.len); 1529 1530 down_read(&fc->killsb); 1531 err = -ENOENT; 1532 if (fc->sb) 1533 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name); 1534 up_read(&fc->killsb); 1535 kfree(buf); 1536 return err; 1537 1538 err: 1539 kfree(buf); 1540 fuse_copy_finish(cs); 1541 return err; 1542 } 1543 1544 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size, 1545 struct fuse_copy_state *cs) 1546 { 1547 struct fuse_notify_delete_out outarg; 1548 int err = -ENOMEM; 1549 char *buf; 1550 struct qstr name; 1551 1552 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); 1553 if (!buf) 1554 goto err; 1555 1556 err = -EINVAL; 1557 if (size < sizeof(outarg)) 1558 goto err; 1559 1560 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1561 if (err) 1562 goto err; 1563 1564 err = -ENAMETOOLONG; 1565 if (outarg.namelen > FUSE_NAME_MAX) 1566 goto err; 1567 1568 err = -EINVAL; 1569 if (size != sizeof(outarg) + outarg.namelen + 1) 1570 goto err; 1571 1572 name.name = buf; 1573 name.len = outarg.namelen; 1574 err = fuse_copy_one(cs, buf, outarg.namelen + 1); 1575 if (err) 1576 goto err; 1577 fuse_copy_finish(cs); 1578 buf[outarg.namelen] = 0; 1579 name.hash = full_name_hash(name.name, name.len); 1580 1581 down_read(&fc->killsb); 1582 err = -ENOENT; 1583 if (fc->sb) 1584 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 1585 outarg.child, &name); 1586 up_read(&fc->killsb); 1587 kfree(buf); 1588 return err; 1589 1590 err: 1591 kfree(buf); 1592 fuse_copy_finish(cs); 1593 return err; 1594 } 1595 1596 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size, 1597 struct fuse_copy_state *cs) 1598 { 1599 struct fuse_notify_store_out outarg; 1600 struct inode *inode; 1601 struct address_space *mapping; 1602 u64 nodeid; 1603 int err; 1604 pgoff_t index; 1605 unsigned int offset; 1606 unsigned int num; 1607 loff_t file_size; 1608 loff_t end; 1609 1610 err = -EINVAL; 1611 if (size < sizeof(outarg)) 1612 goto out_finish; 1613 1614 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1615 if (err) 1616 goto out_finish; 1617 1618 err = -EINVAL; 1619 if (size - sizeof(outarg) != outarg.size) 1620 goto out_finish; 1621 1622 nodeid = outarg.nodeid; 1623 1624 down_read(&fc->killsb); 1625 1626 err = -ENOENT; 1627 if (!fc->sb) 1628 goto out_up_killsb; 1629 1630 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid); 1631 if (!inode) 1632 goto out_up_killsb; 1633 1634 mapping = inode->i_mapping; 1635 index = outarg.offset >> PAGE_CACHE_SHIFT; 1636 offset = outarg.offset & ~PAGE_CACHE_MASK; 1637 file_size = i_size_read(inode); 1638 end = outarg.offset + outarg.size; 1639 if (end > file_size) { 1640 file_size = end; 1641 fuse_write_update_size(inode, file_size); 1642 } 1643 1644 num = outarg.size; 1645 while (num) { 1646 struct page *page; 1647 unsigned int this_num; 1648 1649 err = -ENOMEM; 1650 page = find_or_create_page(mapping, index, 1651 mapping_gfp_mask(mapping)); 1652 if (!page) 1653 goto out_iput; 1654 1655 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset); 1656 err = fuse_copy_page(cs, &page, offset, this_num, 0); 1657 if (!err && offset == 0 && 1658 (this_num == PAGE_CACHE_SIZE || file_size == end)) 1659 SetPageUptodate(page); 1660 unlock_page(page); 1661 page_cache_release(page); 1662 1663 if (err) 1664 goto out_iput; 1665 1666 num -= this_num; 1667 offset = 0; 1668 index++; 1669 } 1670 1671 err = 0; 1672 1673 out_iput: 1674 iput(inode); 1675 out_up_killsb: 1676 up_read(&fc->killsb); 1677 out_finish: 1678 fuse_copy_finish(cs); 1679 return err; 1680 } 1681 1682 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req) 1683 { 1684 release_pages(req->pages, req->num_pages, false); 1685 } 1686 1687 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, 1688 struct fuse_notify_retrieve_out *outarg) 1689 { 1690 int err; 1691 struct address_space *mapping = inode->i_mapping; 1692 struct fuse_req *req; 1693 pgoff_t index; 1694 loff_t file_size; 1695 unsigned int num; 1696 unsigned int offset; 1697 size_t total_len = 0; 1698 int num_pages; 1699 1700 offset = outarg->offset & ~PAGE_CACHE_MASK; 1701 file_size = i_size_read(inode); 1702 1703 num = outarg->size; 1704 if (outarg->offset > file_size) 1705 num = 0; 1706 else if (outarg->offset + num > file_size) 1707 num = file_size - outarg->offset; 1708 1709 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; 1710 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ); 1711 1712 req = fuse_get_req(fc, num_pages); 1713 if (IS_ERR(req)) 1714 return PTR_ERR(req); 1715 1716 req->in.h.opcode = FUSE_NOTIFY_REPLY; 1717 req->in.h.nodeid = outarg->nodeid; 1718 req->in.numargs = 2; 1719 req->in.argpages = 1; 1720 req->page_descs[0].offset = offset; 1721 req->end = fuse_retrieve_end; 1722 1723 index = outarg->offset >> PAGE_CACHE_SHIFT; 1724 1725 while (num && req->num_pages < num_pages) { 1726 struct page *page; 1727 unsigned int this_num; 1728 1729 page = find_get_page(mapping, index); 1730 if (!page) 1731 break; 1732 1733 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset); 1734 req->pages[req->num_pages] = page; 1735 req->page_descs[req->num_pages].length = this_num; 1736 req->num_pages++; 1737 1738 offset = 0; 1739 num -= this_num; 1740 total_len += this_num; 1741 index++; 1742 } 1743 req->misc.retrieve_in.offset = outarg->offset; 1744 req->misc.retrieve_in.size = total_len; 1745 req->in.args[0].size = sizeof(req->misc.retrieve_in); 1746 req->in.args[0].value = &req->misc.retrieve_in; 1747 req->in.args[1].size = total_len; 1748 1749 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique); 1750 if (err) 1751 fuse_retrieve_end(fc, req); 1752 1753 return err; 1754 } 1755 1756 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size, 1757 struct fuse_copy_state *cs) 1758 { 1759 struct fuse_notify_retrieve_out outarg; 1760 struct inode *inode; 1761 int err; 1762 1763 err = -EINVAL; 1764 if (size != sizeof(outarg)) 1765 goto copy_finish; 1766 1767 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1768 if (err) 1769 goto copy_finish; 1770 1771 fuse_copy_finish(cs); 1772 1773 down_read(&fc->killsb); 1774 err = -ENOENT; 1775 if (fc->sb) { 1776 u64 nodeid = outarg.nodeid; 1777 1778 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid); 1779 if (inode) { 1780 err = fuse_retrieve(fc, inode, &outarg); 1781 iput(inode); 1782 } 1783 } 1784 up_read(&fc->killsb); 1785 1786 return err; 1787 1788 copy_finish: 1789 fuse_copy_finish(cs); 1790 return err; 1791 } 1792 1793 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, 1794 unsigned int size, struct fuse_copy_state *cs) 1795 { 1796 /* Don't try to move pages (yet) */ 1797 cs->move_pages = 0; 1798 1799 switch (code) { 1800 case FUSE_NOTIFY_POLL: 1801 return fuse_notify_poll(fc, size, cs); 1802 1803 case FUSE_NOTIFY_INVAL_INODE: 1804 return fuse_notify_inval_inode(fc, size, cs); 1805 1806 case FUSE_NOTIFY_INVAL_ENTRY: 1807 return fuse_notify_inval_entry(fc, size, cs); 1808 1809 case FUSE_NOTIFY_STORE: 1810 return fuse_notify_store(fc, size, cs); 1811 1812 case FUSE_NOTIFY_RETRIEVE: 1813 return fuse_notify_retrieve(fc, size, cs); 1814 1815 case FUSE_NOTIFY_DELETE: 1816 return fuse_notify_delete(fc, size, cs); 1817 1818 default: 1819 fuse_copy_finish(cs); 1820 return -EINVAL; 1821 } 1822 } 1823 1824 /* Look up request on processing list by unique ID */ 1825 static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique) 1826 { 1827 struct fuse_req *req; 1828 1829 list_for_each_entry(req, &fpq->processing, list) { 1830 if (req->in.h.unique == unique || req->intr_unique == unique) 1831 return req; 1832 } 1833 return NULL; 1834 } 1835 1836 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out, 1837 unsigned nbytes) 1838 { 1839 unsigned reqsize = sizeof(struct fuse_out_header); 1840 1841 if (out->h.error) 1842 return nbytes != reqsize ? -EINVAL : 0; 1843 1844 reqsize += len_args(out->numargs, out->args); 1845 1846 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar)) 1847 return -EINVAL; 1848 else if (reqsize > nbytes) { 1849 struct fuse_arg *lastarg = &out->args[out->numargs-1]; 1850 unsigned diffsize = reqsize - nbytes; 1851 if (diffsize > lastarg->size) 1852 return -EINVAL; 1853 lastarg->size -= diffsize; 1854 } 1855 return fuse_copy_args(cs, out->numargs, out->argpages, out->args, 1856 out->page_zeroing); 1857 } 1858 1859 /* 1860 * Write a single reply to a request. First the header is copied from 1861 * the write buffer. The request is then searched on the processing 1862 * list by the unique ID found in the header. If found, then remove 1863 * it from the list and copy the rest of the buffer to the request. 1864 * The request is finished by calling request_end() 1865 */ 1866 static ssize_t fuse_dev_do_write(struct fuse_dev *fud, 1867 struct fuse_copy_state *cs, size_t nbytes) 1868 { 1869 int err; 1870 struct fuse_conn *fc = fud->fc; 1871 struct fuse_pqueue *fpq = &fud->pq; 1872 struct fuse_req *req; 1873 struct fuse_out_header oh; 1874 1875 if (nbytes < sizeof(struct fuse_out_header)) 1876 return -EINVAL; 1877 1878 err = fuse_copy_one(cs, &oh, sizeof(oh)); 1879 if (err) 1880 goto err_finish; 1881 1882 err = -EINVAL; 1883 if (oh.len != nbytes) 1884 goto err_finish; 1885 1886 /* 1887 * Zero oh.unique indicates unsolicited notification message 1888 * and error contains notification code. 1889 */ 1890 if (!oh.unique) { 1891 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs); 1892 return err ? err : nbytes; 1893 } 1894 1895 err = -EINVAL; 1896 if (oh.error <= -1000 || oh.error > 0) 1897 goto err_finish; 1898 1899 spin_lock(&fpq->lock); 1900 err = -ENOENT; 1901 if (!fpq->connected) 1902 goto err_unlock_pq; 1903 1904 req = request_find(fpq, oh.unique); 1905 if (!req) 1906 goto err_unlock_pq; 1907 1908 /* Is it an interrupt reply? */ 1909 if (req->intr_unique == oh.unique) { 1910 spin_unlock(&fpq->lock); 1911 1912 err = -EINVAL; 1913 if (nbytes != sizeof(struct fuse_out_header)) 1914 goto err_finish; 1915 1916 if (oh.error == -ENOSYS) 1917 fc->no_interrupt = 1; 1918 else if (oh.error == -EAGAIN) 1919 queue_interrupt(&fc->iq, req); 1920 1921 fuse_copy_finish(cs); 1922 return nbytes; 1923 } 1924 1925 clear_bit(FR_SENT, &req->flags); 1926 list_move(&req->list, &fpq->io); 1927 req->out.h = oh; 1928 set_bit(FR_LOCKED, &req->flags); 1929 spin_unlock(&fpq->lock); 1930 cs->req = req; 1931 if (!req->out.page_replace) 1932 cs->move_pages = 0; 1933 1934 err = copy_out_args(cs, &req->out, nbytes); 1935 fuse_copy_finish(cs); 1936 1937 spin_lock(&fpq->lock); 1938 clear_bit(FR_LOCKED, &req->flags); 1939 if (!fpq->connected) 1940 err = -ENOENT; 1941 else if (err) 1942 req->out.h.error = -EIO; 1943 if (!test_bit(FR_PRIVATE, &req->flags)) 1944 list_del_init(&req->list); 1945 spin_unlock(&fpq->lock); 1946 1947 request_end(fc, req); 1948 1949 return err ? err : nbytes; 1950 1951 err_unlock_pq: 1952 spin_unlock(&fpq->lock); 1953 err_finish: 1954 fuse_copy_finish(cs); 1955 return err; 1956 } 1957 1958 static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from) 1959 { 1960 struct fuse_copy_state cs; 1961 struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp); 1962 1963 if (!fud) 1964 return -EPERM; 1965 1966 if (!iter_is_iovec(from)) 1967 return -EINVAL; 1968 1969 fuse_copy_init(&cs, 0, from); 1970 1971 return fuse_dev_do_write(fud, &cs, iov_iter_count(from)); 1972 } 1973 1974 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 1975 struct file *out, loff_t *ppos, 1976 size_t len, unsigned int flags) 1977 { 1978 unsigned nbuf; 1979 unsigned idx; 1980 struct pipe_buffer *bufs; 1981 struct fuse_copy_state cs; 1982 struct fuse_dev *fud; 1983 size_t rem; 1984 ssize_t ret; 1985 1986 fud = fuse_get_dev(out); 1987 if (!fud) 1988 return -EPERM; 1989 1990 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL); 1991 if (!bufs) 1992 return -ENOMEM; 1993 1994 pipe_lock(pipe); 1995 nbuf = 0; 1996 rem = 0; 1997 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++) 1998 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len; 1999 2000 ret = -EINVAL; 2001 if (rem < len) { 2002 pipe_unlock(pipe); 2003 goto out; 2004 } 2005 2006 rem = len; 2007 while (rem) { 2008 struct pipe_buffer *ibuf; 2009 struct pipe_buffer *obuf; 2010 2011 BUG_ON(nbuf >= pipe->buffers); 2012 BUG_ON(!pipe->nrbufs); 2013 ibuf = &pipe->bufs[pipe->curbuf]; 2014 obuf = &bufs[nbuf]; 2015 2016 if (rem >= ibuf->len) { 2017 *obuf = *ibuf; 2018 ibuf->ops = NULL; 2019 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); 2020 pipe->nrbufs--; 2021 } else { 2022 ibuf->ops->get(pipe, ibuf); 2023 *obuf = *ibuf; 2024 obuf->flags &= ~PIPE_BUF_FLAG_GIFT; 2025 obuf->len = rem; 2026 ibuf->offset += obuf->len; 2027 ibuf->len -= obuf->len; 2028 } 2029 nbuf++; 2030 rem -= obuf->len; 2031 } 2032 pipe_unlock(pipe); 2033 2034 fuse_copy_init(&cs, 0, NULL); 2035 cs.pipebufs = bufs; 2036 cs.nr_segs = nbuf; 2037 cs.pipe = pipe; 2038 2039 if (flags & SPLICE_F_MOVE) 2040 cs.move_pages = 1; 2041 2042 ret = fuse_dev_do_write(fud, &cs, len); 2043 2044 for (idx = 0; idx < nbuf; idx++) { 2045 struct pipe_buffer *buf = &bufs[idx]; 2046 buf->ops->release(pipe, buf); 2047 } 2048 out: 2049 kfree(bufs); 2050 return ret; 2051 } 2052 2053 static unsigned fuse_dev_poll(struct file *file, poll_table *wait) 2054 { 2055 unsigned mask = POLLOUT | POLLWRNORM; 2056 struct fuse_iqueue *fiq; 2057 struct fuse_dev *fud = fuse_get_dev(file); 2058 2059 if (!fud) 2060 return POLLERR; 2061 2062 fiq = &fud->fc->iq; 2063 poll_wait(file, &fiq->waitq, wait); 2064 2065 spin_lock(&fiq->waitq.lock); 2066 if (!fiq->connected) 2067 mask = POLLERR; 2068 else if (request_pending(fiq)) 2069 mask |= POLLIN | POLLRDNORM; 2070 spin_unlock(&fiq->waitq.lock); 2071 2072 return mask; 2073 } 2074 2075 /* 2076 * Abort all requests on the given list (pending or processing) 2077 * 2078 * This function releases and reacquires fc->lock 2079 */ 2080 static void end_requests(struct fuse_conn *fc, struct list_head *head) 2081 { 2082 while (!list_empty(head)) { 2083 struct fuse_req *req; 2084 req = list_entry(head->next, struct fuse_req, list); 2085 req->out.h.error = -ECONNABORTED; 2086 clear_bit(FR_PENDING, &req->flags); 2087 clear_bit(FR_SENT, &req->flags); 2088 list_del_init(&req->list); 2089 request_end(fc, req); 2090 } 2091 } 2092 2093 static void end_polls(struct fuse_conn *fc) 2094 { 2095 struct rb_node *p; 2096 2097 p = rb_first(&fc->polled_files); 2098 2099 while (p) { 2100 struct fuse_file *ff; 2101 ff = rb_entry(p, struct fuse_file, polled_node); 2102 wake_up_interruptible_all(&ff->poll_wait); 2103 2104 p = rb_next(p); 2105 } 2106 } 2107 2108 /* 2109 * Abort all requests. 2110 * 2111 * Emergency exit in case of a malicious or accidental deadlock, or just a hung 2112 * filesystem. 2113 * 2114 * The same effect is usually achievable through killing the filesystem daemon 2115 * and all users of the filesystem. The exception is the combination of an 2116 * asynchronous request and the tricky deadlock (see 2117 * Documentation/filesystems/fuse.txt). 2118 * 2119 * Aborting requests under I/O goes as follows: 1: Separate out unlocked 2120 * requests, they should be finished off immediately. Locked requests will be 2121 * finished after unlock; see unlock_request(). 2: Finish off the unlocked 2122 * requests. It is possible that some request will finish before we can. This 2123 * is OK, the request will in that case be removed from the list before we touch 2124 * it. 2125 */ 2126 void fuse_abort_conn(struct fuse_conn *fc) 2127 { 2128 struct fuse_iqueue *fiq = &fc->iq; 2129 2130 spin_lock(&fc->lock); 2131 if (fc->connected) { 2132 struct fuse_dev *fud; 2133 struct fuse_req *req, *next; 2134 LIST_HEAD(to_end1); 2135 LIST_HEAD(to_end2); 2136 2137 fc->connected = 0; 2138 fc->blocked = 0; 2139 fuse_set_initialized(fc); 2140 list_for_each_entry(fud, &fc->devices, entry) { 2141 struct fuse_pqueue *fpq = &fud->pq; 2142 2143 spin_lock(&fpq->lock); 2144 fpq->connected = 0; 2145 list_for_each_entry_safe(req, next, &fpq->io, list) { 2146 req->out.h.error = -ECONNABORTED; 2147 spin_lock(&req->waitq.lock); 2148 set_bit(FR_ABORTED, &req->flags); 2149 if (!test_bit(FR_LOCKED, &req->flags)) { 2150 set_bit(FR_PRIVATE, &req->flags); 2151 list_move(&req->list, &to_end1); 2152 } 2153 spin_unlock(&req->waitq.lock); 2154 } 2155 list_splice_init(&fpq->processing, &to_end2); 2156 spin_unlock(&fpq->lock); 2157 } 2158 fc->max_background = UINT_MAX; 2159 flush_bg_queue(fc); 2160 2161 spin_lock(&fiq->waitq.lock); 2162 fiq->connected = 0; 2163 list_splice_init(&fiq->pending, &to_end2); 2164 while (forget_pending(fiq)) 2165 kfree(dequeue_forget(fiq, 1, NULL)); 2166 wake_up_all_locked(&fiq->waitq); 2167 spin_unlock(&fiq->waitq.lock); 2168 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 2169 end_polls(fc); 2170 wake_up_all(&fc->blocked_waitq); 2171 spin_unlock(&fc->lock); 2172 2173 while (!list_empty(&to_end1)) { 2174 req = list_first_entry(&to_end1, struct fuse_req, list); 2175 __fuse_get_request(req); 2176 list_del_init(&req->list); 2177 request_end(fc, req); 2178 } 2179 end_requests(fc, &to_end2); 2180 } else { 2181 spin_unlock(&fc->lock); 2182 } 2183 } 2184 EXPORT_SYMBOL_GPL(fuse_abort_conn); 2185 2186 int fuse_dev_release(struct inode *inode, struct file *file) 2187 { 2188 struct fuse_dev *fud = fuse_get_dev(file); 2189 2190 if (fud) { 2191 struct fuse_conn *fc = fud->fc; 2192 struct fuse_pqueue *fpq = &fud->pq; 2193 2194 WARN_ON(!list_empty(&fpq->io)); 2195 end_requests(fc, &fpq->processing); 2196 /* Are we the last open device? */ 2197 if (atomic_dec_and_test(&fc->dev_count)) { 2198 WARN_ON(fc->iq.fasync != NULL); 2199 fuse_abort_conn(fc); 2200 } 2201 fuse_dev_free(fud); 2202 } 2203 return 0; 2204 } 2205 EXPORT_SYMBOL_GPL(fuse_dev_release); 2206 2207 static int fuse_dev_fasync(int fd, struct file *file, int on) 2208 { 2209 struct fuse_dev *fud = fuse_get_dev(file); 2210 2211 if (!fud) 2212 return -EPERM; 2213 2214 /* No locking - fasync_helper does its own locking */ 2215 return fasync_helper(fd, file, on, &fud->fc->iq.fasync); 2216 } 2217 2218 static int fuse_device_clone(struct fuse_conn *fc, struct file *new) 2219 { 2220 struct fuse_dev *fud; 2221 2222 if (new->private_data) 2223 return -EINVAL; 2224 2225 fud = fuse_dev_alloc(fc); 2226 if (!fud) 2227 return -ENOMEM; 2228 2229 new->private_data = fud; 2230 atomic_inc(&fc->dev_count); 2231 2232 return 0; 2233 } 2234 2235 static long fuse_dev_ioctl(struct file *file, unsigned int cmd, 2236 unsigned long arg) 2237 { 2238 int err = -ENOTTY; 2239 2240 if (cmd == FUSE_DEV_IOC_CLONE) { 2241 int oldfd; 2242 2243 err = -EFAULT; 2244 if (!get_user(oldfd, (__u32 __user *) arg)) { 2245 struct file *old = fget(oldfd); 2246 2247 err = -EINVAL; 2248 if (old) { 2249 struct fuse_dev *fud = NULL; 2250 2251 /* 2252 * Check against file->f_op because CUSE 2253 * uses the same ioctl handler. 2254 */ 2255 if (old->f_op == file->f_op && 2256 old->f_cred->user_ns == file->f_cred->user_ns) 2257 fud = fuse_get_dev(old); 2258 2259 if (fud) { 2260 mutex_lock(&fuse_mutex); 2261 err = fuse_device_clone(fud->fc, file); 2262 mutex_unlock(&fuse_mutex); 2263 } 2264 fput(old); 2265 } 2266 } 2267 } 2268 return err; 2269 } 2270 2271 const struct file_operations fuse_dev_operations = { 2272 .owner = THIS_MODULE, 2273 .open = fuse_dev_open, 2274 .llseek = no_llseek, 2275 .read_iter = fuse_dev_read, 2276 .splice_read = fuse_dev_splice_read, 2277 .write_iter = fuse_dev_write, 2278 .splice_write = fuse_dev_splice_write, 2279 .poll = fuse_dev_poll, 2280 .release = fuse_dev_release, 2281 .fasync = fuse_dev_fasync, 2282 .unlocked_ioctl = fuse_dev_ioctl, 2283 .compat_ioctl = fuse_dev_ioctl, 2284 }; 2285 EXPORT_SYMBOL_GPL(fuse_dev_operations); 2286 2287 static struct miscdevice fuse_miscdevice = { 2288 .minor = FUSE_MINOR, 2289 .name = "fuse", 2290 .fops = &fuse_dev_operations, 2291 }; 2292 2293 int __init fuse_dev_init(void) 2294 { 2295 int err = -ENOMEM; 2296 fuse_req_cachep = kmem_cache_create("fuse_request", 2297 sizeof(struct fuse_req), 2298 0, 0, NULL); 2299 if (!fuse_req_cachep) 2300 goto out; 2301 2302 err = misc_register(&fuse_miscdevice); 2303 if (err) 2304 goto out_cache_clean; 2305 2306 return 0; 2307 2308 out_cache_clean: 2309 kmem_cache_destroy(fuse_req_cachep); 2310 out: 2311 return err; 2312 } 2313 2314 void fuse_dev_cleanup(void) 2315 { 2316 misc_deregister(&fuse_miscdevice); 2317 kmem_cache_destroy(fuse_req_cachep); 2318 } 2319