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/sched/signal.h> 15 #include <linux/uio.h> 16 #include <linux/miscdevice.h> 17 #include <linux/pagemap.h> 18 #include <linux/file.h> 19 #include <linux/slab.h> 20 #include <linux/pipe_fs_i.h> 21 #include <linux/swap.h> 22 #include <linux/splice.h> 23 #include <linux/sched.h> 24 25 MODULE_ALIAS_MISCDEV(FUSE_MINOR); 26 MODULE_ALIAS("devname:fuse"); 27 28 /* Ordinary requests have even IDs, while interrupts IDs are odd */ 29 #define FUSE_INT_REQ_BIT (1ULL << 0) 30 #define FUSE_REQ_ID_STEP (1ULL << 1) 31 32 static struct kmem_cache *fuse_req_cachep; 33 34 static struct fuse_dev *fuse_get_dev(struct file *file) 35 { 36 /* 37 * Lockless access is OK, because file->private data is set 38 * once during mount and is valid until the file is released. 39 */ 40 return READ_ONCE(file->private_data); 41 } 42 43 static void fuse_request_init(struct fuse_req *req, struct page **pages, 44 struct fuse_page_desc *page_descs, 45 unsigned npages) 46 { 47 INIT_LIST_HEAD(&req->list); 48 INIT_LIST_HEAD(&req->intr_entry); 49 init_waitqueue_head(&req->waitq); 50 refcount_set(&req->count, 1); 51 req->pages = pages; 52 req->page_descs = page_descs; 53 req->max_pages = npages; 54 __set_bit(FR_PENDING, &req->flags); 55 } 56 57 static struct page **fuse_req_pages_alloc(unsigned int npages, gfp_t flags, 58 struct fuse_page_desc **desc) 59 { 60 struct page **pages; 61 62 pages = kzalloc(npages * (sizeof(struct page *) + 63 sizeof(struct fuse_page_desc)), flags); 64 *desc = (void *) pages + npages * sizeof(struct page *); 65 66 return pages; 67 } 68 69 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags) 70 { 71 struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags); 72 if (req) { 73 struct page **pages = NULL; 74 struct fuse_page_desc *page_descs = NULL; 75 76 WARN_ON(npages > FUSE_MAX_MAX_PAGES); 77 if (npages > FUSE_REQ_INLINE_PAGES) { 78 pages = fuse_req_pages_alloc(npages, flags, 79 &page_descs); 80 if (!pages) { 81 kmem_cache_free(fuse_req_cachep, req); 82 return NULL; 83 } 84 } else if (npages) { 85 pages = req->inline_pages; 86 page_descs = req->inline_page_descs; 87 } 88 89 fuse_request_init(req, pages, page_descs, npages); 90 } 91 return req; 92 } 93 94 struct fuse_req *fuse_request_alloc(unsigned npages) 95 { 96 return __fuse_request_alloc(npages, GFP_KERNEL); 97 } 98 EXPORT_SYMBOL_GPL(fuse_request_alloc); 99 100 struct fuse_req *fuse_request_alloc_nofs(unsigned npages) 101 { 102 return __fuse_request_alloc(npages, GFP_NOFS); 103 } 104 105 static void fuse_req_pages_free(struct fuse_req *req) 106 { 107 if (req->pages != req->inline_pages) 108 kfree(req->pages); 109 } 110 111 bool fuse_req_realloc_pages(struct fuse_conn *fc, struct fuse_req *req, 112 gfp_t flags) 113 { 114 struct page **pages; 115 struct fuse_page_desc *page_descs; 116 unsigned int npages = min_t(unsigned int, 117 max_t(unsigned int, req->max_pages * 2, 118 FUSE_DEFAULT_MAX_PAGES_PER_REQ), 119 fc->max_pages); 120 WARN_ON(npages <= req->max_pages); 121 122 pages = fuse_req_pages_alloc(npages, flags, &page_descs); 123 if (!pages) 124 return false; 125 126 memcpy(pages, req->pages, sizeof(struct page *) * req->max_pages); 127 memcpy(page_descs, req->page_descs, 128 sizeof(struct fuse_page_desc) * req->max_pages); 129 fuse_req_pages_free(req); 130 req->pages = pages; 131 req->page_descs = page_descs; 132 req->max_pages = npages; 133 134 return true; 135 } 136 137 void fuse_request_free(struct fuse_req *req) 138 { 139 fuse_req_pages_free(req); 140 kmem_cache_free(fuse_req_cachep, req); 141 } 142 143 void __fuse_get_request(struct fuse_req *req) 144 { 145 refcount_inc(&req->count); 146 } 147 148 /* Must be called with > 1 refcount */ 149 static void __fuse_put_request(struct fuse_req *req) 150 { 151 refcount_dec(&req->count); 152 } 153 154 void fuse_set_initialized(struct fuse_conn *fc) 155 { 156 /* Make sure stores before this are seen on another CPU */ 157 smp_wmb(); 158 fc->initialized = 1; 159 } 160 161 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background) 162 { 163 return !fc->initialized || (for_background && fc->blocked); 164 } 165 166 static void fuse_drop_waiting(struct fuse_conn *fc) 167 { 168 if (fc->connected) { 169 atomic_dec(&fc->num_waiting); 170 } else if (atomic_dec_and_test(&fc->num_waiting)) { 171 /* wake up aborters */ 172 wake_up_all(&fc->blocked_waitq); 173 } 174 } 175 176 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages, 177 bool for_background) 178 { 179 struct fuse_req *req; 180 int err; 181 atomic_inc(&fc->num_waiting); 182 183 if (fuse_block_alloc(fc, for_background)) { 184 err = -EINTR; 185 if (wait_event_killable_exclusive(fc->blocked_waitq, 186 !fuse_block_alloc(fc, for_background))) 187 goto out; 188 } 189 /* Matches smp_wmb() in fuse_set_initialized() */ 190 smp_rmb(); 191 192 err = -ENOTCONN; 193 if (!fc->connected) 194 goto out; 195 196 err = -ECONNREFUSED; 197 if (fc->conn_error) 198 goto out; 199 200 req = fuse_request_alloc(npages); 201 err = -ENOMEM; 202 if (!req) { 203 if (for_background) 204 wake_up(&fc->blocked_waitq); 205 goto out; 206 } 207 208 req->in.h.uid = from_kuid(fc->user_ns, current_fsuid()); 209 req->in.h.gid = from_kgid(fc->user_ns, current_fsgid()); 210 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); 211 212 __set_bit(FR_WAITING, &req->flags); 213 if (for_background) 214 __set_bit(FR_BACKGROUND, &req->flags); 215 216 if (unlikely(req->in.h.uid == ((uid_t)-1) || 217 req->in.h.gid == ((gid_t)-1))) { 218 fuse_put_request(fc, req); 219 return ERR_PTR(-EOVERFLOW); 220 } 221 return req; 222 223 out: 224 fuse_drop_waiting(fc); 225 return ERR_PTR(err); 226 } 227 228 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages) 229 { 230 return __fuse_get_req(fc, npages, false); 231 } 232 EXPORT_SYMBOL_GPL(fuse_get_req); 233 234 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc, 235 unsigned npages) 236 { 237 return __fuse_get_req(fc, npages, true); 238 } 239 EXPORT_SYMBOL_GPL(fuse_get_req_for_background); 240 241 /* 242 * Return request in fuse_file->reserved_req. However that may 243 * currently be in use. If that is the case, wait for it to become 244 * available. 245 */ 246 static struct fuse_req *get_reserved_req(struct fuse_conn *fc, 247 struct file *file) 248 { 249 struct fuse_req *req = NULL; 250 struct fuse_file *ff = file->private_data; 251 252 do { 253 wait_event(fc->reserved_req_waitq, ff->reserved_req); 254 spin_lock(&fc->lock); 255 if (ff->reserved_req) { 256 req = ff->reserved_req; 257 ff->reserved_req = NULL; 258 req->stolen_file = get_file(file); 259 } 260 spin_unlock(&fc->lock); 261 } while (!req); 262 263 return req; 264 } 265 266 /* 267 * Put stolen request back into fuse_file->reserved_req 268 */ 269 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req) 270 { 271 struct file *file = req->stolen_file; 272 struct fuse_file *ff = file->private_data; 273 274 WARN_ON(req->max_pages); 275 spin_lock(&fc->lock); 276 memset(req, 0, sizeof(*req)); 277 fuse_request_init(req, NULL, NULL, 0); 278 BUG_ON(ff->reserved_req); 279 ff->reserved_req = req; 280 wake_up_all(&fc->reserved_req_waitq); 281 spin_unlock(&fc->lock); 282 fput(file); 283 } 284 285 /* 286 * Gets a requests for a file operation, always succeeds 287 * 288 * This is used for sending the FLUSH request, which must get to 289 * userspace, due to POSIX locks which may need to be unlocked. 290 * 291 * If allocation fails due to OOM, use the reserved request in 292 * fuse_file. 293 * 294 * This is very unlikely to deadlock accidentally, since the 295 * filesystem should not have it's own file open. If deadlock is 296 * intentional, it can still be broken by "aborting" the filesystem. 297 */ 298 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, 299 struct file *file) 300 { 301 struct fuse_req *req; 302 303 atomic_inc(&fc->num_waiting); 304 wait_event(fc->blocked_waitq, fc->initialized); 305 /* Matches smp_wmb() in fuse_set_initialized() */ 306 smp_rmb(); 307 req = fuse_request_alloc(0); 308 if (!req) 309 req = get_reserved_req(fc, file); 310 311 req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid()); 312 req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid()); 313 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); 314 315 __set_bit(FR_WAITING, &req->flags); 316 __clear_bit(FR_BACKGROUND, &req->flags); 317 return req; 318 } 319 320 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) 321 { 322 if (refcount_dec_and_test(&req->count)) { 323 if (test_bit(FR_BACKGROUND, &req->flags)) { 324 /* 325 * We get here in the unlikely case that a background 326 * request was allocated but not sent 327 */ 328 spin_lock(&fc->bg_lock); 329 if (!fc->blocked) 330 wake_up(&fc->blocked_waitq); 331 spin_unlock(&fc->bg_lock); 332 } 333 334 if (test_bit(FR_WAITING, &req->flags)) { 335 __clear_bit(FR_WAITING, &req->flags); 336 fuse_drop_waiting(fc); 337 } 338 339 if (req->stolen_file) 340 put_reserved_req(fc, req); 341 else 342 fuse_request_free(req); 343 } 344 } 345 EXPORT_SYMBOL_GPL(fuse_put_request); 346 347 static unsigned len_args(unsigned numargs, struct fuse_arg *args) 348 { 349 unsigned nbytes = 0; 350 unsigned i; 351 352 for (i = 0; i < numargs; i++) 353 nbytes += args[i].size; 354 355 return nbytes; 356 } 357 358 static u64 fuse_get_unique(struct fuse_iqueue *fiq) 359 { 360 fiq->reqctr += FUSE_REQ_ID_STEP; 361 return fiq->reqctr; 362 } 363 364 static unsigned int fuse_req_hash(u64 unique) 365 { 366 return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS); 367 } 368 369 static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req) 370 { 371 req->in.h.len = sizeof(struct fuse_in_header) + 372 len_args(req->in.numargs, (struct fuse_arg *) req->in.args); 373 list_add_tail(&req->list, &fiq->pending); 374 wake_up_locked(&fiq->waitq); 375 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 376 } 377 378 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, 379 u64 nodeid, u64 nlookup) 380 { 381 struct fuse_iqueue *fiq = &fc->iq; 382 383 forget->forget_one.nodeid = nodeid; 384 forget->forget_one.nlookup = nlookup; 385 386 spin_lock(&fiq->waitq.lock); 387 if (fiq->connected) { 388 fiq->forget_list_tail->next = forget; 389 fiq->forget_list_tail = forget; 390 wake_up_locked(&fiq->waitq); 391 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 392 } else { 393 kfree(forget); 394 } 395 spin_unlock(&fiq->waitq.lock); 396 } 397 398 static void flush_bg_queue(struct fuse_conn *fc) 399 { 400 struct fuse_iqueue *fiq = &fc->iq; 401 402 while (fc->active_background < fc->max_background && 403 !list_empty(&fc->bg_queue)) { 404 struct fuse_req *req; 405 406 req = list_first_entry(&fc->bg_queue, struct fuse_req, list); 407 list_del(&req->list); 408 fc->active_background++; 409 spin_lock(&fiq->waitq.lock); 410 req->in.h.unique = fuse_get_unique(fiq); 411 queue_request(fiq, req); 412 spin_unlock(&fiq->waitq.lock); 413 } 414 } 415 416 /* 417 * This function is called when a request is finished. Either a reply 418 * has arrived or it was aborted (and not yet sent) or some error 419 * occurred during communication with userspace, or the device file 420 * was closed. The requester thread is woken up (if still waiting), 421 * the 'end' callback is called if given, else the reference to the 422 * request is released 423 */ 424 static void request_end(struct fuse_conn *fc, struct fuse_req *req) 425 { 426 struct fuse_iqueue *fiq = &fc->iq; 427 428 if (test_and_set_bit(FR_FINISHED, &req->flags)) 429 goto put_request; 430 431 spin_lock(&fiq->waitq.lock); 432 list_del_init(&req->intr_entry); 433 spin_unlock(&fiq->waitq.lock); 434 WARN_ON(test_bit(FR_PENDING, &req->flags)); 435 WARN_ON(test_bit(FR_SENT, &req->flags)); 436 if (test_bit(FR_BACKGROUND, &req->flags)) { 437 spin_lock(&fc->bg_lock); 438 clear_bit(FR_BACKGROUND, &req->flags); 439 if (fc->num_background == fc->max_background) { 440 fc->blocked = 0; 441 wake_up(&fc->blocked_waitq); 442 } else if (!fc->blocked) { 443 /* 444 * Wake up next waiter, if any. It's okay to use 445 * waitqueue_active(), as we've already synced up 446 * fc->blocked with waiters with the wake_up() call 447 * above. 448 */ 449 if (waitqueue_active(&fc->blocked_waitq)) 450 wake_up(&fc->blocked_waitq); 451 } 452 453 if (fc->num_background == fc->congestion_threshold && fc->sb) { 454 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC); 455 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC); 456 } 457 fc->num_background--; 458 fc->active_background--; 459 flush_bg_queue(fc); 460 spin_unlock(&fc->bg_lock); 461 } 462 wake_up(&req->waitq); 463 if (req->end) 464 req->end(fc, req); 465 put_request: 466 fuse_put_request(fc, req); 467 } 468 469 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req) 470 { 471 spin_lock(&fiq->waitq.lock); 472 if (test_bit(FR_FINISHED, &req->flags)) { 473 spin_unlock(&fiq->waitq.lock); 474 return; 475 } 476 if (list_empty(&req->intr_entry)) { 477 list_add_tail(&req->intr_entry, &fiq->interrupts); 478 wake_up_locked(&fiq->waitq); 479 } 480 spin_unlock(&fiq->waitq.lock); 481 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 482 } 483 484 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req) 485 { 486 struct fuse_iqueue *fiq = &fc->iq; 487 int err; 488 489 if (!fc->no_interrupt) { 490 /* Any signal may interrupt this */ 491 err = wait_event_interruptible(req->waitq, 492 test_bit(FR_FINISHED, &req->flags)); 493 if (!err) 494 return; 495 496 set_bit(FR_INTERRUPTED, &req->flags); 497 /* matches barrier in fuse_dev_do_read() */ 498 smp_mb__after_atomic(); 499 if (test_bit(FR_SENT, &req->flags)) 500 queue_interrupt(fiq, req); 501 } 502 503 if (!test_bit(FR_FORCE, &req->flags)) { 504 /* Only fatal signals may interrupt this */ 505 err = wait_event_killable(req->waitq, 506 test_bit(FR_FINISHED, &req->flags)); 507 if (!err) 508 return; 509 510 spin_lock(&fiq->waitq.lock); 511 /* Request is not yet in userspace, bail out */ 512 if (test_bit(FR_PENDING, &req->flags)) { 513 list_del(&req->list); 514 spin_unlock(&fiq->waitq.lock); 515 __fuse_put_request(req); 516 req->out.h.error = -EINTR; 517 return; 518 } 519 spin_unlock(&fiq->waitq.lock); 520 } 521 522 /* 523 * Either request is already in userspace, or it was forced. 524 * Wait it out. 525 */ 526 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags)); 527 } 528 529 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) 530 { 531 struct fuse_iqueue *fiq = &fc->iq; 532 533 BUG_ON(test_bit(FR_BACKGROUND, &req->flags)); 534 spin_lock(&fiq->waitq.lock); 535 if (!fiq->connected) { 536 spin_unlock(&fiq->waitq.lock); 537 req->out.h.error = -ENOTCONN; 538 } else { 539 req->in.h.unique = fuse_get_unique(fiq); 540 queue_request(fiq, req); 541 /* acquire extra reference, since request is still needed 542 after request_end() */ 543 __fuse_get_request(req); 544 spin_unlock(&fiq->waitq.lock); 545 546 request_wait_answer(fc, req); 547 /* Pairs with smp_wmb() in request_end() */ 548 smp_rmb(); 549 } 550 } 551 552 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) 553 { 554 __set_bit(FR_ISREPLY, &req->flags); 555 if (!test_bit(FR_WAITING, &req->flags)) { 556 __set_bit(FR_WAITING, &req->flags); 557 atomic_inc(&fc->num_waiting); 558 } 559 __fuse_request_send(fc, req); 560 } 561 EXPORT_SYMBOL_GPL(fuse_request_send); 562 563 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) 564 { 565 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS) 566 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE; 567 568 if (fc->minor < 9) { 569 switch (args->in.h.opcode) { 570 case FUSE_LOOKUP: 571 case FUSE_CREATE: 572 case FUSE_MKNOD: 573 case FUSE_MKDIR: 574 case FUSE_SYMLINK: 575 case FUSE_LINK: 576 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 577 break; 578 case FUSE_GETATTR: 579 case FUSE_SETATTR: 580 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 581 break; 582 } 583 } 584 if (fc->minor < 12) { 585 switch (args->in.h.opcode) { 586 case FUSE_CREATE: 587 args->in.args[0].size = sizeof(struct fuse_open_in); 588 break; 589 case FUSE_MKNOD: 590 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE; 591 break; 592 } 593 } 594 } 595 596 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args) 597 { 598 struct fuse_req *req; 599 ssize_t ret; 600 601 req = fuse_get_req(fc, 0); 602 if (IS_ERR(req)) 603 return PTR_ERR(req); 604 605 /* Needs to be done after fuse_get_req() so that fc->minor is valid */ 606 fuse_adjust_compat(fc, args); 607 608 req->in.h.opcode = args->in.h.opcode; 609 req->in.h.nodeid = args->in.h.nodeid; 610 req->in.numargs = args->in.numargs; 611 memcpy(req->in.args, args->in.args, 612 args->in.numargs * sizeof(struct fuse_in_arg)); 613 req->out.argvar = args->out.argvar; 614 req->out.numargs = args->out.numargs; 615 memcpy(req->out.args, args->out.args, 616 args->out.numargs * sizeof(struct fuse_arg)); 617 fuse_request_send(fc, req); 618 ret = req->out.h.error; 619 if (!ret && args->out.argvar) { 620 BUG_ON(args->out.numargs != 1); 621 ret = req->out.args[0].size; 622 } 623 fuse_put_request(fc, req); 624 625 return ret; 626 } 627 628 bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req) 629 { 630 bool queued = false; 631 632 WARN_ON(!test_bit(FR_BACKGROUND, &req->flags)); 633 if (!test_bit(FR_WAITING, &req->flags)) { 634 __set_bit(FR_WAITING, &req->flags); 635 atomic_inc(&fc->num_waiting); 636 } 637 __set_bit(FR_ISREPLY, &req->flags); 638 spin_lock(&fc->bg_lock); 639 if (likely(fc->connected)) { 640 fc->num_background++; 641 if (fc->num_background == fc->max_background) 642 fc->blocked = 1; 643 if (fc->num_background == fc->congestion_threshold && fc->sb) { 644 set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC); 645 set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC); 646 } 647 list_add_tail(&req->list, &fc->bg_queue); 648 flush_bg_queue(fc); 649 queued = true; 650 } 651 spin_unlock(&fc->bg_lock); 652 653 return queued; 654 } 655 656 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req) 657 { 658 WARN_ON(!req->end); 659 if (!fuse_request_queue_background(fc, req)) { 660 req->out.h.error = -ENOTCONN; 661 req->end(fc, req); 662 fuse_put_request(fc, req); 663 } 664 } 665 EXPORT_SYMBOL_GPL(fuse_request_send_background); 666 667 static int fuse_request_send_notify_reply(struct fuse_conn *fc, 668 struct fuse_req *req, u64 unique) 669 { 670 int err = -ENODEV; 671 struct fuse_iqueue *fiq = &fc->iq; 672 673 __clear_bit(FR_ISREPLY, &req->flags); 674 req->in.h.unique = unique; 675 spin_lock(&fiq->waitq.lock); 676 if (fiq->connected) { 677 queue_request(fiq, req); 678 err = 0; 679 } 680 spin_unlock(&fiq->waitq.lock); 681 682 return err; 683 } 684 685 void fuse_force_forget(struct file *file, u64 nodeid) 686 { 687 struct inode *inode = file_inode(file); 688 struct fuse_conn *fc = get_fuse_conn(inode); 689 struct fuse_req *req; 690 struct fuse_forget_in inarg; 691 692 memset(&inarg, 0, sizeof(inarg)); 693 inarg.nlookup = 1; 694 req = fuse_get_req_nofail_nopages(fc, file); 695 req->in.h.opcode = FUSE_FORGET; 696 req->in.h.nodeid = nodeid; 697 req->in.numargs = 1; 698 req->in.args[0].size = sizeof(inarg); 699 req->in.args[0].value = &inarg; 700 __clear_bit(FR_ISREPLY, &req->flags); 701 __fuse_request_send(fc, req); 702 /* ignore errors */ 703 fuse_put_request(fc, req); 704 } 705 706 /* 707 * Lock the request. Up to the next unlock_request() there mustn't be 708 * anything that could cause a page-fault. If the request was already 709 * aborted bail out. 710 */ 711 static int lock_request(struct fuse_req *req) 712 { 713 int err = 0; 714 if (req) { 715 spin_lock(&req->waitq.lock); 716 if (test_bit(FR_ABORTED, &req->flags)) 717 err = -ENOENT; 718 else 719 set_bit(FR_LOCKED, &req->flags); 720 spin_unlock(&req->waitq.lock); 721 } 722 return err; 723 } 724 725 /* 726 * Unlock request. If it was aborted while locked, caller is responsible 727 * for unlocking and ending the request. 728 */ 729 static int unlock_request(struct fuse_req *req) 730 { 731 int err = 0; 732 if (req) { 733 spin_lock(&req->waitq.lock); 734 if (test_bit(FR_ABORTED, &req->flags)) 735 err = -ENOENT; 736 else 737 clear_bit(FR_LOCKED, &req->flags); 738 spin_unlock(&req->waitq.lock); 739 } 740 return err; 741 } 742 743 struct fuse_copy_state { 744 int write; 745 struct fuse_req *req; 746 struct iov_iter *iter; 747 struct pipe_buffer *pipebufs; 748 struct pipe_buffer *currbuf; 749 struct pipe_inode_info *pipe; 750 unsigned long nr_segs; 751 struct page *pg; 752 unsigned len; 753 unsigned offset; 754 unsigned move_pages:1; 755 }; 756 757 static void fuse_copy_init(struct fuse_copy_state *cs, int write, 758 struct iov_iter *iter) 759 { 760 memset(cs, 0, sizeof(*cs)); 761 cs->write = write; 762 cs->iter = iter; 763 } 764 765 /* Unmap and put previous page of userspace buffer */ 766 static void fuse_copy_finish(struct fuse_copy_state *cs) 767 { 768 if (cs->currbuf) { 769 struct pipe_buffer *buf = cs->currbuf; 770 771 if (cs->write) 772 buf->len = PAGE_SIZE - cs->len; 773 cs->currbuf = NULL; 774 } else if (cs->pg) { 775 if (cs->write) { 776 flush_dcache_page(cs->pg); 777 set_page_dirty_lock(cs->pg); 778 } 779 put_page(cs->pg); 780 } 781 cs->pg = NULL; 782 } 783 784 /* 785 * Get another pagefull of userspace buffer, and map it to kernel 786 * address space, and lock request 787 */ 788 static int fuse_copy_fill(struct fuse_copy_state *cs) 789 { 790 struct page *page; 791 int err; 792 793 err = unlock_request(cs->req); 794 if (err) 795 return err; 796 797 fuse_copy_finish(cs); 798 if (cs->pipebufs) { 799 struct pipe_buffer *buf = cs->pipebufs; 800 801 if (!cs->write) { 802 err = pipe_buf_confirm(cs->pipe, buf); 803 if (err) 804 return err; 805 806 BUG_ON(!cs->nr_segs); 807 cs->currbuf = buf; 808 cs->pg = buf->page; 809 cs->offset = buf->offset; 810 cs->len = buf->len; 811 cs->pipebufs++; 812 cs->nr_segs--; 813 } else { 814 if (cs->nr_segs == cs->pipe->buffers) 815 return -EIO; 816 817 page = alloc_page(GFP_HIGHUSER); 818 if (!page) 819 return -ENOMEM; 820 821 buf->page = page; 822 buf->offset = 0; 823 buf->len = 0; 824 825 cs->currbuf = buf; 826 cs->pg = page; 827 cs->offset = 0; 828 cs->len = PAGE_SIZE; 829 cs->pipebufs++; 830 cs->nr_segs++; 831 } 832 } else { 833 size_t off; 834 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off); 835 if (err < 0) 836 return err; 837 BUG_ON(!err); 838 cs->len = err; 839 cs->offset = off; 840 cs->pg = page; 841 iov_iter_advance(cs->iter, err); 842 } 843 844 return lock_request(cs->req); 845 } 846 847 /* Do as much copy to/from userspace buffer as we can */ 848 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size) 849 { 850 unsigned ncpy = min(*size, cs->len); 851 if (val) { 852 void *pgaddr = kmap_atomic(cs->pg); 853 void *buf = pgaddr + cs->offset; 854 855 if (cs->write) 856 memcpy(buf, *val, ncpy); 857 else 858 memcpy(*val, buf, ncpy); 859 860 kunmap_atomic(pgaddr); 861 *val += ncpy; 862 } 863 *size -= ncpy; 864 cs->len -= ncpy; 865 cs->offset += ncpy; 866 return ncpy; 867 } 868 869 static int fuse_check_page(struct page *page) 870 { 871 if (page_mapcount(page) || 872 page->mapping != NULL || 873 page_count(page) != 1 || 874 (page->flags & PAGE_FLAGS_CHECK_AT_PREP & 875 ~(1 << PG_locked | 876 1 << PG_referenced | 877 1 << PG_uptodate | 878 1 << PG_lru | 879 1 << PG_active | 880 1 << PG_reclaim))) { 881 printk(KERN_WARNING "fuse: trying to steal weird page\n"); 882 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); 883 return 1; 884 } 885 return 0; 886 } 887 888 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 889 { 890 int err; 891 struct page *oldpage = *pagep; 892 struct page *newpage; 893 struct pipe_buffer *buf = cs->pipebufs; 894 895 err = unlock_request(cs->req); 896 if (err) 897 return err; 898 899 fuse_copy_finish(cs); 900 901 err = pipe_buf_confirm(cs->pipe, buf); 902 if (err) 903 return err; 904 905 BUG_ON(!cs->nr_segs); 906 cs->currbuf = buf; 907 cs->len = buf->len; 908 cs->pipebufs++; 909 cs->nr_segs--; 910 911 if (cs->len != PAGE_SIZE) 912 goto out_fallback; 913 914 if (pipe_buf_steal(cs->pipe, buf) != 0) 915 goto out_fallback; 916 917 newpage = buf->page; 918 919 if (!PageUptodate(newpage)) 920 SetPageUptodate(newpage); 921 922 ClearPageMappedToDisk(newpage); 923 924 if (fuse_check_page(newpage) != 0) 925 goto out_fallback_unlock; 926 927 /* 928 * This is a new and locked page, it shouldn't be mapped or 929 * have any special flags on it 930 */ 931 if (WARN_ON(page_mapped(oldpage))) 932 goto out_fallback_unlock; 933 if (WARN_ON(page_has_private(oldpage))) 934 goto out_fallback_unlock; 935 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage))) 936 goto out_fallback_unlock; 937 if (WARN_ON(PageMlocked(oldpage))) 938 goto out_fallback_unlock; 939 940 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL); 941 if (err) { 942 unlock_page(newpage); 943 return err; 944 } 945 946 get_page(newpage); 947 948 if (!(buf->flags & PIPE_BUF_FLAG_LRU)) 949 lru_cache_add_file(newpage); 950 951 err = 0; 952 spin_lock(&cs->req->waitq.lock); 953 if (test_bit(FR_ABORTED, &cs->req->flags)) 954 err = -ENOENT; 955 else 956 *pagep = newpage; 957 spin_unlock(&cs->req->waitq.lock); 958 959 if (err) { 960 unlock_page(newpage); 961 put_page(newpage); 962 return err; 963 } 964 965 unlock_page(oldpage); 966 put_page(oldpage); 967 cs->len = 0; 968 969 return 0; 970 971 out_fallback_unlock: 972 unlock_page(newpage); 973 out_fallback: 974 cs->pg = buf->page; 975 cs->offset = buf->offset; 976 977 err = lock_request(cs->req); 978 if (err) 979 return err; 980 981 return 1; 982 } 983 984 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page, 985 unsigned offset, unsigned count) 986 { 987 struct pipe_buffer *buf; 988 int err; 989 990 if (cs->nr_segs == cs->pipe->buffers) 991 return -EIO; 992 993 err = unlock_request(cs->req); 994 if (err) 995 return err; 996 997 fuse_copy_finish(cs); 998 999 buf = cs->pipebufs; 1000 get_page(page); 1001 buf->page = page; 1002 buf->offset = offset; 1003 buf->len = count; 1004 1005 cs->pipebufs++; 1006 cs->nr_segs++; 1007 cs->len = 0; 1008 1009 return 0; 1010 } 1011 1012 /* 1013 * Copy a page in the request to/from the userspace buffer. Must be 1014 * done atomically 1015 */ 1016 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep, 1017 unsigned offset, unsigned count, int zeroing) 1018 { 1019 int err; 1020 struct page *page = *pagep; 1021 1022 if (page && zeroing && count < PAGE_SIZE) 1023 clear_highpage(page); 1024 1025 while (count) { 1026 if (cs->write && cs->pipebufs && page) { 1027 return fuse_ref_page(cs, page, offset, count); 1028 } else if (!cs->len) { 1029 if (cs->move_pages && page && 1030 offset == 0 && count == PAGE_SIZE) { 1031 err = fuse_try_move_page(cs, pagep); 1032 if (err <= 0) 1033 return err; 1034 } else { 1035 err = fuse_copy_fill(cs); 1036 if (err) 1037 return err; 1038 } 1039 } 1040 if (page) { 1041 void *mapaddr = kmap_atomic(page); 1042 void *buf = mapaddr + offset; 1043 offset += fuse_copy_do(cs, &buf, &count); 1044 kunmap_atomic(mapaddr); 1045 } else 1046 offset += fuse_copy_do(cs, NULL, &count); 1047 } 1048 if (page && !cs->write) 1049 flush_dcache_page(page); 1050 return 0; 1051 } 1052 1053 /* Copy pages in the request to/from userspace buffer */ 1054 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, 1055 int zeroing) 1056 { 1057 unsigned i; 1058 struct fuse_req *req = cs->req; 1059 1060 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) { 1061 int err; 1062 unsigned offset = req->page_descs[i].offset; 1063 unsigned count = min(nbytes, req->page_descs[i].length); 1064 1065 err = fuse_copy_page(cs, &req->pages[i], offset, count, 1066 zeroing); 1067 if (err) 1068 return err; 1069 1070 nbytes -= count; 1071 } 1072 return 0; 1073 } 1074 1075 /* Copy a single argument in the request to/from userspace buffer */ 1076 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size) 1077 { 1078 while (size) { 1079 if (!cs->len) { 1080 int err = fuse_copy_fill(cs); 1081 if (err) 1082 return err; 1083 } 1084 fuse_copy_do(cs, &val, &size); 1085 } 1086 return 0; 1087 } 1088 1089 /* Copy request arguments to/from userspace buffer */ 1090 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs, 1091 unsigned argpages, struct fuse_arg *args, 1092 int zeroing) 1093 { 1094 int err = 0; 1095 unsigned i; 1096 1097 for (i = 0; !err && i < numargs; i++) { 1098 struct fuse_arg *arg = &args[i]; 1099 if (i == numargs - 1 && argpages) 1100 err = fuse_copy_pages(cs, arg->size, zeroing); 1101 else 1102 err = fuse_copy_one(cs, arg->value, arg->size); 1103 } 1104 return err; 1105 } 1106 1107 static int forget_pending(struct fuse_iqueue *fiq) 1108 { 1109 return fiq->forget_list_head.next != NULL; 1110 } 1111 1112 static int request_pending(struct fuse_iqueue *fiq) 1113 { 1114 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) || 1115 forget_pending(fiq); 1116 } 1117 1118 /* 1119 * Transfer an interrupt request to userspace 1120 * 1121 * Unlike other requests this is assembled on demand, without a need 1122 * to allocate a separate fuse_req structure. 1123 * 1124 * Called with fiq->waitq.lock held, releases it 1125 */ 1126 static int fuse_read_interrupt(struct fuse_iqueue *fiq, 1127 struct fuse_copy_state *cs, 1128 size_t nbytes, struct fuse_req *req) 1129 __releases(fiq->waitq.lock) 1130 { 1131 struct fuse_in_header ih; 1132 struct fuse_interrupt_in arg; 1133 unsigned reqsize = sizeof(ih) + sizeof(arg); 1134 int err; 1135 1136 list_del_init(&req->intr_entry); 1137 memset(&ih, 0, sizeof(ih)); 1138 memset(&arg, 0, sizeof(arg)); 1139 ih.len = reqsize; 1140 ih.opcode = FUSE_INTERRUPT; 1141 ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT); 1142 arg.unique = req->in.h.unique; 1143 1144 spin_unlock(&fiq->waitq.lock); 1145 if (nbytes < reqsize) 1146 return -EINVAL; 1147 1148 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1149 if (!err) 1150 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1151 fuse_copy_finish(cs); 1152 1153 return err ? err : reqsize; 1154 } 1155 1156 static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq, 1157 unsigned max, 1158 unsigned *countp) 1159 { 1160 struct fuse_forget_link *head = fiq->forget_list_head.next; 1161 struct fuse_forget_link **newhead = &head; 1162 unsigned count; 1163 1164 for (count = 0; *newhead != NULL && count < max; count++) 1165 newhead = &(*newhead)->next; 1166 1167 fiq->forget_list_head.next = *newhead; 1168 *newhead = NULL; 1169 if (fiq->forget_list_head.next == NULL) 1170 fiq->forget_list_tail = &fiq->forget_list_head; 1171 1172 if (countp != NULL) 1173 *countp = count; 1174 1175 return head; 1176 } 1177 1178 static int fuse_read_single_forget(struct fuse_iqueue *fiq, 1179 struct fuse_copy_state *cs, 1180 size_t nbytes) 1181 __releases(fiq->waitq.lock) 1182 { 1183 int err; 1184 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL); 1185 struct fuse_forget_in arg = { 1186 .nlookup = forget->forget_one.nlookup, 1187 }; 1188 struct fuse_in_header ih = { 1189 .opcode = FUSE_FORGET, 1190 .nodeid = forget->forget_one.nodeid, 1191 .unique = fuse_get_unique(fiq), 1192 .len = sizeof(ih) + sizeof(arg), 1193 }; 1194 1195 spin_unlock(&fiq->waitq.lock); 1196 kfree(forget); 1197 if (nbytes < ih.len) 1198 return -EINVAL; 1199 1200 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1201 if (!err) 1202 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1203 fuse_copy_finish(cs); 1204 1205 if (err) 1206 return err; 1207 1208 return ih.len; 1209 } 1210 1211 static int fuse_read_batch_forget(struct fuse_iqueue *fiq, 1212 struct fuse_copy_state *cs, size_t nbytes) 1213 __releases(fiq->waitq.lock) 1214 { 1215 int err; 1216 unsigned max_forgets; 1217 unsigned count; 1218 struct fuse_forget_link *head; 1219 struct fuse_batch_forget_in arg = { .count = 0 }; 1220 struct fuse_in_header ih = { 1221 .opcode = FUSE_BATCH_FORGET, 1222 .unique = fuse_get_unique(fiq), 1223 .len = sizeof(ih) + sizeof(arg), 1224 }; 1225 1226 if (nbytes < ih.len) { 1227 spin_unlock(&fiq->waitq.lock); 1228 return -EINVAL; 1229 } 1230 1231 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one); 1232 head = dequeue_forget(fiq, max_forgets, &count); 1233 spin_unlock(&fiq->waitq.lock); 1234 1235 arg.count = count; 1236 ih.len += count * sizeof(struct fuse_forget_one); 1237 err = fuse_copy_one(cs, &ih, sizeof(ih)); 1238 if (!err) 1239 err = fuse_copy_one(cs, &arg, sizeof(arg)); 1240 1241 while (head) { 1242 struct fuse_forget_link *forget = head; 1243 1244 if (!err) { 1245 err = fuse_copy_one(cs, &forget->forget_one, 1246 sizeof(forget->forget_one)); 1247 } 1248 head = forget->next; 1249 kfree(forget); 1250 } 1251 1252 fuse_copy_finish(cs); 1253 1254 if (err) 1255 return err; 1256 1257 return ih.len; 1258 } 1259 1260 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq, 1261 struct fuse_copy_state *cs, 1262 size_t nbytes) 1263 __releases(fiq->waitq.lock) 1264 { 1265 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL) 1266 return fuse_read_single_forget(fiq, cs, nbytes); 1267 else 1268 return fuse_read_batch_forget(fiq, cs, nbytes); 1269 } 1270 1271 /* 1272 * Read a single request into the userspace filesystem's buffer. This 1273 * function waits until a request is available, then removes it from 1274 * the pending list and copies request data to userspace buffer. If 1275 * no reply is needed (FORGET) or request has been aborted or there 1276 * was an error during the copying then it's finished by calling 1277 * request_end(). Otherwise add it to the processing list, and set 1278 * the 'sent' flag. 1279 */ 1280 static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, 1281 struct fuse_copy_state *cs, size_t nbytes) 1282 { 1283 ssize_t err; 1284 struct fuse_conn *fc = fud->fc; 1285 struct fuse_iqueue *fiq = &fc->iq; 1286 struct fuse_pqueue *fpq = &fud->pq; 1287 struct fuse_req *req; 1288 struct fuse_in *in; 1289 unsigned reqsize; 1290 unsigned int hash; 1291 1292 restart: 1293 spin_lock(&fiq->waitq.lock); 1294 err = -EAGAIN; 1295 if ((file->f_flags & O_NONBLOCK) && fiq->connected && 1296 !request_pending(fiq)) 1297 goto err_unlock; 1298 1299 err = wait_event_interruptible_exclusive_locked(fiq->waitq, 1300 !fiq->connected || request_pending(fiq)); 1301 if (err) 1302 goto err_unlock; 1303 1304 if (!fiq->connected) { 1305 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV; 1306 goto err_unlock; 1307 } 1308 1309 if (!list_empty(&fiq->interrupts)) { 1310 req = list_entry(fiq->interrupts.next, struct fuse_req, 1311 intr_entry); 1312 return fuse_read_interrupt(fiq, cs, nbytes, req); 1313 } 1314 1315 if (forget_pending(fiq)) { 1316 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0) 1317 return fuse_read_forget(fc, fiq, cs, nbytes); 1318 1319 if (fiq->forget_batch <= -8) 1320 fiq->forget_batch = 16; 1321 } 1322 1323 req = list_entry(fiq->pending.next, struct fuse_req, list); 1324 clear_bit(FR_PENDING, &req->flags); 1325 list_del_init(&req->list); 1326 spin_unlock(&fiq->waitq.lock); 1327 1328 in = &req->in; 1329 reqsize = in->h.len; 1330 1331 /* If request is too large, reply with an error and restart the read */ 1332 if (nbytes < reqsize) { 1333 req->out.h.error = -EIO; 1334 /* SETXATTR is special, since it may contain too large data */ 1335 if (in->h.opcode == FUSE_SETXATTR) 1336 req->out.h.error = -E2BIG; 1337 request_end(fc, req); 1338 goto restart; 1339 } 1340 spin_lock(&fpq->lock); 1341 list_add(&req->list, &fpq->io); 1342 spin_unlock(&fpq->lock); 1343 cs->req = req; 1344 err = fuse_copy_one(cs, &in->h, sizeof(in->h)); 1345 if (!err) 1346 err = fuse_copy_args(cs, in->numargs, in->argpages, 1347 (struct fuse_arg *) in->args, 0); 1348 fuse_copy_finish(cs); 1349 spin_lock(&fpq->lock); 1350 clear_bit(FR_LOCKED, &req->flags); 1351 if (!fpq->connected) { 1352 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV; 1353 goto out_end; 1354 } 1355 if (err) { 1356 req->out.h.error = -EIO; 1357 goto out_end; 1358 } 1359 if (!test_bit(FR_ISREPLY, &req->flags)) { 1360 err = reqsize; 1361 goto out_end; 1362 } 1363 hash = fuse_req_hash(req->in.h.unique); 1364 list_move_tail(&req->list, &fpq->processing[hash]); 1365 __fuse_get_request(req); 1366 set_bit(FR_SENT, &req->flags); 1367 spin_unlock(&fpq->lock); 1368 /* matches barrier in request_wait_answer() */ 1369 smp_mb__after_atomic(); 1370 if (test_bit(FR_INTERRUPTED, &req->flags)) 1371 queue_interrupt(fiq, req); 1372 fuse_put_request(fc, req); 1373 1374 return reqsize; 1375 1376 out_end: 1377 if (!test_bit(FR_PRIVATE, &req->flags)) 1378 list_del_init(&req->list); 1379 spin_unlock(&fpq->lock); 1380 request_end(fc, req); 1381 return err; 1382 1383 err_unlock: 1384 spin_unlock(&fiq->waitq.lock); 1385 return err; 1386 } 1387 1388 static int fuse_dev_open(struct inode *inode, struct file *file) 1389 { 1390 /* 1391 * The fuse device's file's private_data is used to hold 1392 * the fuse_conn(ection) when it is mounted, and is used to 1393 * keep track of whether the file has been mounted already. 1394 */ 1395 file->private_data = NULL; 1396 return 0; 1397 } 1398 1399 static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) 1400 { 1401 struct fuse_copy_state cs; 1402 struct file *file = iocb->ki_filp; 1403 struct fuse_dev *fud = fuse_get_dev(file); 1404 1405 if (!fud) 1406 return -EPERM; 1407 1408 if (!iter_is_iovec(to)) 1409 return -EINVAL; 1410 1411 fuse_copy_init(&cs, 1, to); 1412 1413 return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to)); 1414 } 1415 1416 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, 1417 struct pipe_inode_info *pipe, 1418 size_t len, unsigned int flags) 1419 { 1420 int total, ret; 1421 int page_nr = 0; 1422 struct pipe_buffer *bufs; 1423 struct fuse_copy_state cs; 1424 struct fuse_dev *fud = fuse_get_dev(in); 1425 1426 if (!fud) 1427 return -EPERM; 1428 1429 bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer), 1430 GFP_KERNEL); 1431 if (!bufs) 1432 return -ENOMEM; 1433 1434 fuse_copy_init(&cs, 1, NULL); 1435 cs.pipebufs = bufs; 1436 cs.pipe = pipe; 1437 ret = fuse_dev_do_read(fud, in, &cs, len); 1438 if (ret < 0) 1439 goto out; 1440 1441 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) { 1442 ret = -EIO; 1443 goto out; 1444 } 1445 1446 for (ret = total = 0; page_nr < cs.nr_segs; total += ret) { 1447 /* 1448 * Need to be careful about this. Having buf->ops in module 1449 * code can Oops if the buffer persists after module unload. 1450 */ 1451 bufs[page_nr].ops = &nosteal_pipe_buf_ops; 1452 bufs[page_nr].flags = 0; 1453 ret = add_to_pipe(pipe, &bufs[page_nr++]); 1454 if (unlikely(ret < 0)) 1455 break; 1456 } 1457 if (total) 1458 ret = total; 1459 out: 1460 for (; page_nr < cs.nr_segs; page_nr++) 1461 put_page(bufs[page_nr].page); 1462 1463 kvfree(bufs); 1464 return ret; 1465 } 1466 1467 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size, 1468 struct fuse_copy_state *cs) 1469 { 1470 struct fuse_notify_poll_wakeup_out outarg; 1471 int err = -EINVAL; 1472 1473 if (size != sizeof(outarg)) 1474 goto err; 1475 1476 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1477 if (err) 1478 goto err; 1479 1480 fuse_copy_finish(cs); 1481 return fuse_notify_poll_wakeup(fc, &outarg); 1482 1483 err: 1484 fuse_copy_finish(cs); 1485 return err; 1486 } 1487 1488 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size, 1489 struct fuse_copy_state *cs) 1490 { 1491 struct fuse_notify_inval_inode_out outarg; 1492 int err = -EINVAL; 1493 1494 if (size != sizeof(outarg)) 1495 goto err; 1496 1497 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1498 if (err) 1499 goto err; 1500 fuse_copy_finish(cs); 1501 1502 down_read(&fc->killsb); 1503 err = -ENOENT; 1504 if (fc->sb) { 1505 err = fuse_reverse_inval_inode(fc->sb, outarg.ino, 1506 outarg.off, outarg.len); 1507 } 1508 up_read(&fc->killsb); 1509 return err; 1510 1511 err: 1512 fuse_copy_finish(cs); 1513 return err; 1514 } 1515 1516 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size, 1517 struct fuse_copy_state *cs) 1518 { 1519 struct fuse_notify_inval_entry_out outarg; 1520 int err = -ENOMEM; 1521 char *buf; 1522 struct qstr name; 1523 1524 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); 1525 if (!buf) 1526 goto err; 1527 1528 err = -EINVAL; 1529 if (size < sizeof(outarg)) 1530 goto err; 1531 1532 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1533 if (err) 1534 goto err; 1535 1536 err = -ENAMETOOLONG; 1537 if (outarg.namelen > FUSE_NAME_MAX) 1538 goto err; 1539 1540 err = -EINVAL; 1541 if (size != sizeof(outarg) + outarg.namelen + 1) 1542 goto err; 1543 1544 name.name = buf; 1545 name.len = outarg.namelen; 1546 err = fuse_copy_one(cs, buf, outarg.namelen + 1); 1547 if (err) 1548 goto err; 1549 fuse_copy_finish(cs); 1550 buf[outarg.namelen] = 0; 1551 1552 down_read(&fc->killsb); 1553 err = -ENOENT; 1554 if (fc->sb) 1555 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name); 1556 up_read(&fc->killsb); 1557 kfree(buf); 1558 return err; 1559 1560 err: 1561 kfree(buf); 1562 fuse_copy_finish(cs); 1563 return err; 1564 } 1565 1566 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size, 1567 struct fuse_copy_state *cs) 1568 { 1569 struct fuse_notify_delete_out outarg; 1570 int err = -ENOMEM; 1571 char *buf; 1572 struct qstr name; 1573 1574 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL); 1575 if (!buf) 1576 goto err; 1577 1578 err = -EINVAL; 1579 if (size < sizeof(outarg)) 1580 goto err; 1581 1582 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1583 if (err) 1584 goto err; 1585 1586 err = -ENAMETOOLONG; 1587 if (outarg.namelen > FUSE_NAME_MAX) 1588 goto err; 1589 1590 err = -EINVAL; 1591 if (size != sizeof(outarg) + outarg.namelen + 1) 1592 goto err; 1593 1594 name.name = buf; 1595 name.len = outarg.namelen; 1596 err = fuse_copy_one(cs, buf, outarg.namelen + 1); 1597 if (err) 1598 goto err; 1599 fuse_copy_finish(cs); 1600 buf[outarg.namelen] = 0; 1601 1602 down_read(&fc->killsb); 1603 err = -ENOENT; 1604 if (fc->sb) 1605 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 1606 outarg.child, &name); 1607 up_read(&fc->killsb); 1608 kfree(buf); 1609 return err; 1610 1611 err: 1612 kfree(buf); 1613 fuse_copy_finish(cs); 1614 return err; 1615 } 1616 1617 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size, 1618 struct fuse_copy_state *cs) 1619 { 1620 struct fuse_notify_store_out outarg; 1621 struct inode *inode; 1622 struct address_space *mapping; 1623 u64 nodeid; 1624 int err; 1625 pgoff_t index; 1626 unsigned int offset; 1627 unsigned int num; 1628 loff_t file_size; 1629 loff_t end; 1630 1631 err = -EINVAL; 1632 if (size < sizeof(outarg)) 1633 goto out_finish; 1634 1635 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1636 if (err) 1637 goto out_finish; 1638 1639 err = -EINVAL; 1640 if (size - sizeof(outarg) != outarg.size) 1641 goto out_finish; 1642 1643 nodeid = outarg.nodeid; 1644 1645 down_read(&fc->killsb); 1646 1647 err = -ENOENT; 1648 if (!fc->sb) 1649 goto out_up_killsb; 1650 1651 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid); 1652 if (!inode) 1653 goto out_up_killsb; 1654 1655 mapping = inode->i_mapping; 1656 index = outarg.offset >> PAGE_SHIFT; 1657 offset = outarg.offset & ~PAGE_MASK; 1658 file_size = i_size_read(inode); 1659 end = outarg.offset + outarg.size; 1660 if (end > file_size) { 1661 file_size = end; 1662 fuse_write_update_size(inode, file_size); 1663 } 1664 1665 num = outarg.size; 1666 while (num) { 1667 struct page *page; 1668 unsigned int this_num; 1669 1670 err = -ENOMEM; 1671 page = find_or_create_page(mapping, index, 1672 mapping_gfp_mask(mapping)); 1673 if (!page) 1674 goto out_iput; 1675 1676 this_num = min_t(unsigned, num, PAGE_SIZE - offset); 1677 err = fuse_copy_page(cs, &page, offset, this_num, 0); 1678 if (!err && offset == 0 && 1679 (this_num == PAGE_SIZE || file_size == end)) 1680 SetPageUptodate(page); 1681 unlock_page(page); 1682 put_page(page); 1683 1684 if (err) 1685 goto out_iput; 1686 1687 num -= this_num; 1688 offset = 0; 1689 index++; 1690 } 1691 1692 err = 0; 1693 1694 out_iput: 1695 iput(inode); 1696 out_up_killsb: 1697 up_read(&fc->killsb); 1698 out_finish: 1699 fuse_copy_finish(cs); 1700 return err; 1701 } 1702 1703 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req) 1704 { 1705 release_pages(req->pages, req->num_pages); 1706 } 1707 1708 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, 1709 struct fuse_notify_retrieve_out *outarg) 1710 { 1711 int err; 1712 struct address_space *mapping = inode->i_mapping; 1713 struct fuse_req *req; 1714 pgoff_t index; 1715 loff_t file_size; 1716 unsigned int num; 1717 unsigned int offset; 1718 size_t total_len = 0; 1719 unsigned int num_pages; 1720 1721 offset = outarg->offset & ~PAGE_MASK; 1722 file_size = i_size_read(inode); 1723 1724 num = outarg->size; 1725 if (outarg->offset > file_size) 1726 num = 0; 1727 else if (outarg->offset + num > file_size) 1728 num = file_size - outarg->offset; 1729 1730 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; 1731 num_pages = min(num_pages, fc->max_pages); 1732 1733 req = fuse_get_req(fc, num_pages); 1734 if (IS_ERR(req)) 1735 return PTR_ERR(req); 1736 1737 req->in.h.opcode = FUSE_NOTIFY_REPLY; 1738 req->in.h.nodeid = outarg->nodeid; 1739 req->in.numargs = 2; 1740 req->in.argpages = 1; 1741 req->page_descs[0].offset = offset; 1742 req->end = fuse_retrieve_end; 1743 1744 index = outarg->offset >> PAGE_SHIFT; 1745 1746 while (num && req->num_pages < num_pages) { 1747 struct page *page; 1748 unsigned int this_num; 1749 1750 page = find_get_page(mapping, index); 1751 if (!page) 1752 break; 1753 1754 this_num = min_t(unsigned, num, PAGE_SIZE - offset); 1755 req->pages[req->num_pages] = page; 1756 req->page_descs[req->num_pages].length = this_num; 1757 req->num_pages++; 1758 1759 offset = 0; 1760 num -= this_num; 1761 total_len += this_num; 1762 index++; 1763 } 1764 req->misc.retrieve_in.offset = outarg->offset; 1765 req->misc.retrieve_in.size = total_len; 1766 req->in.args[0].size = sizeof(req->misc.retrieve_in); 1767 req->in.args[0].value = &req->misc.retrieve_in; 1768 req->in.args[1].size = total_len; 1769 1770 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique); 1771 if (err) 1772 fuse_retrieve_end(fc, req); 1773 1774 return err; 1775 } 1776 1777 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size, 1778 struct fuse_copy_state *cs) 1779 { 1780 struct fuse_notify_retrieve_out outarg; 1781 struct inode *inode; 1782 int err; 1783 1784 err = -EINVAL; 1785 if (size != sizeof(outarg)) 1786 goto copy_finish; 1787 1788 err = fuse_copy_one(cs, &outarg, sizeof(outarg)); 1789 if (err) 1790 goto copy_finish; 1791 1792 fuse_copy_finish(cs); 1793 1794 down_read(&fc->killsb); 1795 err = -ENOENT; 1796 if (fc->sb) { 1797 u64 nodeid = outarg.nodeid; 1798 1799 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid); 1800 if (inode) { 1801 err = fuse_retrieve(fc, inode, &outarg); 1802 iput(inode); 1803 } 1804 } 1805 up_read(&fc->killsb); 1806 1807 return err; 1808 1809 copy_finish: 1810 fuse_copy_finish(cs); 1811 return err; 1812 } 1813 1814 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, 1815 unsigned int size, struct fuse_copy_state *cs) 1816 { 1817 /* Don't try to move pages (yet) */ 1818 cs->move_pages = 0; 1819 1820 switch (code) { 1821 case FUSE_NOTIFY_POLL: 1822 return fuse_notify_poll(fc, size, cs); 1823 1824 case FUSE_NOTIFY_INVAL_INODE: 1825 return fuse_notify_inval_inode(fc, size, cs); 1826 1827 case FUSE_NOTIFY_INVAL_ENTRY: 1828 return fuse_notify_inval_entry(fc, size, cs); 1829 1830 case FUSE_NOTIFY_STORE: 1831 return fuse_notify_store(fc, size, cs); 1832 1833 case FUSE_NOTIFY_RETRIEVE: 1834 return fuse_notify_retrieve(fc, size, cs); 1835 1836 case FUSE_NOTIFY_DELETE: 1837 return fuse_notify_delete(fc, size, cs); 1838 1839 default: 1840 fuse_copy_finish(cs); 1841 return -EINVAL; 1842 } 1843 } 1844 1845 /* Look up request on processing list by unique ID */ 1846 static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique) 1847 { 1848 unsigned int hash = fuse_req_hash(unique); 1849 struct fuse_req *req; 1850 1851 list_for_each_entry(req, &fpq->processing[hash], list) { 1852 if (req->in.h.unique == unique) 1853 return req; 1854 } 1855 return NULL; 1856 } 1857 1858 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out, 1859 unsigned nbytes) 1860 { 1861 unsigned reqsize = sizeof(struct fuse_out_header); 1862 1863 if (out->h.error) 1864 return nbytes != reqsize ? -EINVAL : 0; 1865 1866 reqsize += len_args(out->numargs, out->args); 1867 1868 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar)) 1869 return -EINVAL; 1870 else if (reqsize > nbytes) { 1871 struct fuse_arg *lastarg = &out->args[out->numargs-1]; 1872 unsigned diffsize = reqsize - nbytes; 1873 if (diffsize > lastarg->size) 1874 return -EINVAL; 1875 lastarg->size -= diffsize; 1876 } 1877 return fuse_copy_args(cs, out->numargs, out->argpages, out->args, 1878 out->page_zeroing); 1879 } 1880 1881 /* 1882 * Write a single reply to a request. First the header is copied from 1883 * the write buffer. The request is then searched on the processing 1884 * list by the unique ID found in the header. If found, then remove 1885 * it from the list and copy the rest of the buffer to the request. 1886 * The request is finished by calling request_end() 1887 */ 1888 static ssize_t fuse_dev_do_write(struct fuse_dev *fud, 1889 struct fuse_copy_state *cs, size_t nbytes) 1890 { 1891 int err; 1892 struct fuse_conn *fc = fud->fc; 1893 struct fuse_pqueue *fpq = &fud->pq; 1894 struct fuse_req *req; 1895 struct fuse_out_header oh; 1896 1897 if (nbytes < sizeof(struct fuse_out_header)) 1898 return -EINVAL; 1899 1900 err = fuse_copy_one(cs, &oh, sizeof(oh)); 1901 if (err) 1902 goto err_finish; 1903 1904 err = -EINVAL; 1905 if (oh.len != nbytes) 1906 goto err_finish; 1907 1908 /* 1909 * Zero oh.unique indicates unsolicited notification message 1910 * and error contains notification code. 1911 */ 1912 if (!oh.unique) { 1913 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs); 1914 return err ? err : nbytes; 1915 } 1916 1917 err = -EINVAL; 1918 if (oh.error <= -1000 || oh.error > 0) 1919 goto err_finish; 1920 1921 spin_lock(&fpq->lock); 1922 err = -ENOENT; 1923 if (!fpq->connected) 1924 goto err_unlock_pq; 1925 1926 req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT); 1927 if (!req) 1928 goto err_unlock_pq; 1929 1930 /* Is it an interrupt reply ID? */ 1931 if (oh.unique & FUSE_INT_REQ_BIT) { 1932 __fuse_get_request(req); 1933 spin_unlock(&fpq->lock); 1934 1935 err = -EINVAL; 1936 if (nbytes != sizeof(struct fuse_out_header)) { 1937 fuse_put_request(fc, req); 1938 goto err_finish; 1939 } 1940 1941 if (oh.error == -ENOSYS) 1942 fc->no_interrupt = 1; 1943 else if (oh.error == -EAGAIN) 1944 queue_interrupt(&fc->iq, req); 1945 fuse_put_request(fc, req); 1946 1947 fuse_copy_finish(cs); 1948 return nbytes; 1949 } 1950 1951 clear_bit(FR_SENT, &req->flags); 1952 list_move(&req->list, &fpq->io); 1953 req->out.h = oh; 1954 set_bit(FR_LOCKED, &req->flags); 1955 spin_unlock(&fpq->lock); 1956 cs->req = req; 1957 if (!req->out.page_replace) 1958 cs->move_pages = 0; 1959 1960 err = copy_out_args(cs, &req->out, nbytes); 1961 fuse_copy_finish(cs); 1962 1963 spin_lock(&fpq->lock); 1964 clear_bit(FR_LOCKED, &req->flags); 1965 if (!fpq->connected) 1966 err = -ENOENT; 1967 else if (err) 1968 req->out.h.error = -EIO; 1969 if (!test_bit(FR_PRIVATE, &req->flags)) 1970 list_del_init(&req->list); 1971 spin_unlock(&fpq->lock); 1972 1973 request_end(fc, req); 1974 1975 return err ? err : nbytes; 1976 1977 err_unlock_pq: 1978 spin_unlock(&fpq->lock); 1979 err_finish: 1980 fuse_copy_finish(cs); 1981 return err; 1982 } 1983 1984 static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from) 1985 { 1986 struct fuse_copy_state cs; 1987 struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp); 1988 1989 if (!fud) 1990 return -EPERM; 1991 1992 if (!iter_is_iovec(from)) 1993 return -EINVAL; 1994 1995 fuse_copy_init(&cs, 0, from); 1996 1997 return fuse_dev_do_write(fud, &cs, iov_iter_count(from)); 1998 } 1999 2000 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 2001 struct file *out, loff_t *ppos, 2002 size_t len, unsigned int flags) 2003 { 2004 unsigned nbuf; 2005 unsigned idx; 2006 struct pipe_buffer *bufs; 2007 struct fuse_copy_state cs; 2008 struct fuse_dev *fud; 2009 size_t rem; 2010 ssize_t ret; 2011 2012 fud = fuse_get_dev(out); 2013 if (!fud) 2014 return -EPERM; 2015 2016 pipe_lock(pipe); 2017 2018 bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer), 2019 GFP_KERNEL); 2020 if (!bufs) { 2021 pipe_unlock(pipe); 2022 return -ENOMEM; 2023 } 2024 2025 nbuf = 0; 2026 rem = 0; 2027 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++) 2028 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len; 2029 2030 ret = -EINVAL; 2031 if (rem < len) { 2032 pipe_unlock(pipe); 2033 goto out; 2034 } 2035 2036 rem = len; 2037 while (rem) { 2038 struct pipe_buffer *ibuf; 2039 struct pipe_buffer *obuf; 2040 2041 BUG_ON(nbuf >= pipe->buffers); 2042 BUG_ON(!pipe->nrbufs); 2043 ibuf = &pipe->bufs[pipe->curbuf]; 2044 obuf = &bufs[nbuf]; 2045 2046 if (rem >= ibuf->len) { 2047 *obuf = *ibuf; 2048 ibuf->ops = NULL; 2049 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); 2050 pipe->nrbufs--; 2051 } else { 2052 pipe_buf_get(pipe, ibuf); 2053 *obuf = *ibuf; 2054 obuf->flags &= ~PIPE_BUF_FLAG_GIFT; 2055 obuf->len = rem; 2056 ibuf->offset += obuf->len; 2057 ibuf->len -= obuf->len; 2058 } 2059 nbuf++; 2060 rem -= obuf->len; 2061 } 2062 pipe_unlock(pipe); 2063 2064 fuse_copy_init(&cs, 0, NULL); 2065 cs.pipebufs = bufs; 2066 cs.nr_segs = nbuf; 2067 cs.pipe = pipe; 2068 2069 if (flags & SPLICE_F_MOVE) 2070 cs.move_pages = 1; 2071 2072 ret = fuse_dev_do_write(fud, &cs, len); 2073 2074 for (idx = 0; idx < nbuf; idx++) 2075 pipe_buf_release(pipe, &bufs[idx]); 2076 2077 out: 2078 kvfree(bufs); 2079 return ret; 2080 } 2081 2082 static __poll_t fuse_dev_poll(struct file *file, poll_table *wait) 2083 { 2084 __poll_t mask = EPOLLOUT | EPOLLWRNORM; 2085 struct fuse_iqueue *fiq; 2086 struct fuse_dev *fud = fuse_get_dev(file); 2087 2088 if (!fud) 2089 return EPOLLERR; 2090 2091 fiq = &fud->fc->iq; 2092 poll_wait(file, &fiq->waitq, wait); 2093 2094 spin_lock(&fiq->waitq.lock); 2095 if (!fiq->connected) 2096 mask = EPOLLERR; 2097 else if (request_pending(fiq)) 2098 mask |= EPOLLIN | EPOLLRDNORM; 2099 spin_unlock(&fiq->waitq.lock); 2100 2101 return mask; 2102 } 2103 2104 /* 2105 * Abort all requests on the given list (pending or processing) 2106 * 2107 * This function releases and reacquires fc->lock 2108 */ 2109 static void end_requests(struct fuse_conn *fc, struct list_head *head) 2110 { 2111 while (!list_empty(head)) { 2112 struct fuse_req *req; 2113 req = list_entry(head->next, struct fuse_req, list); 2114 req->out.h.error = -ECONNABORTED; 2115 clear_bit(FR_SENT, &req->flags); 2116 list_del_init(&req->list); 2117 request_end(fc, req); 2118 } 2119 } 2120 2121 static void end_polls(struct fuse_conn *fc) 2122 { 2123 struct rb_node *p; 2124 2125 p = rb_first(&fc->polled_files); 2126 2127 while (p) { 2128 struct fuse_file *ff; 2129 ff = rb_entry(p, struct fuse_file, polled_node); 2130 wake_up_interruptible_all(&ff->poll_wait); 2131 2132 p = rb_next(p); 2133 } 2134 } 2135 2136 /* 2137 * Abort all requests. 2138 * 2139 * Emergency exit in case of a malicious or accidental deadlock, or just a hung 2140 * filesystem. 2141 * 2142 * The same effect is usually achievable through killing the filesystem daemon 2143 * and all users of the filesystem. The exception is the combination of an 2144 * asynchronous request and the tricky deadlock (see 2145 * Documentation/filesystems/fuse.txt). 2146 * 2147 * Aborting requests under I/O goes as follows: 1: Separate out unlocked 2148 * requests, they should be finished off immediately. Locked requests will be 2149 * finished after unlock; see unlock_request(). 2: Finish off the unlocked 2150 * requests. It is possible that some request will finish before we can. This 2151 * is OK, the request will in that case be removed from the list before we touch 2152 * it. 2153 */ 2154 void fuse_abort_conn(struct fuse_conn *fc, bool is_abort) 2155 { 2156 struct fuse_iqueue *fiq = &fc->iq; 2157 2158 spin_lock(&fc->lock); 2159 if (fc->connected) { 2160 struct fuse_dev *fud; 2161 struct fuse_req *req, *next; 2162 LIST_HEAD(to_end); 2163 unsigned int i; 2164 2165 /* Background queuing checks fc->connected under bg_lock */ 2166 spin_lock(&fc->bg_lock); 2167 fc->connected = 0; 2168 spin_unlock(&fc->bg_lock); 2169 2170 fc->aborted = is_abort; 2171 fuse_set_initialized(fc); 2172 list_for_each_entry(fud, &fc->devices, entry) { 2173 struct fuse_pqueue *fpq = &fud->pq; 2174 2175 spin_lock(&fpq->lock); 2176 fpq->connected = 0; 2177 list_for_each_entry_safe(req, next, &fpq->io, list) { 2178 req->out.h.error = -ECONNABORTED; 2179 spin_lock(&req->waitq.lock); 2180 set_bit(FR_ABORTED, &req->flags); 2181 if (!test_bit(FR_LOCKED, &req->flags)) { 2182 set_bit(FR_PRIVATE, &req->flags); 2183 __fuse_get_request(req); 2184 list_move(&req->list, &to_end); 2185 } 2186 spin_unlock(&req->waitq.lock); 2187 } 2188 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 2189 list_splice_tail_init(&fpq->processing[i], 2190 &to_end); 2191 spin_unlock(&fpq->lock); 2192 } 2193 spin_lock(&fc->bg_lock); 2194 fc->blocked = 0; 2195 fc->max_background = UINT_MAX; 2196 flush_bg_queue(fc); 2197 spin_unlock(&fc->bg_lock); 2198 2199 spin_lock(&fiq->waitq.lock); 2200 fiq->connected = 0; 2201 list_for_each_entry(req, &fiq->pending, list) 2202 clear_bit(FR_PENDING, &req->flags); 2203 list_splice_tail_init(&fiq->pending, &to_end); 2204 while (forget_pending(fiq)) 2205 kfree(dequeue_forget(fiq, 1, NULL)); 2206 wake_up_all_locked(&fiq->waitq); 2207 spin_unlock(&fiq->waitq.lock); 2208 kill_fasync(&fiq->fasync, SIGIO, POLL_IN); 2209 end_polls(fc); 2210 wake_up_all(&fc->blocked_waitq); 2211 spin_unlock(&fc->lock); 2212 2213 end_requests(fc, &to_end); 2214 } else { 2215 spin_unlock(&fc->lock); 2216 } 2217 } 2218 EXPORT_SYMBOL_GPL(fuse_abort_conn); 2219 2220 void fuse_wait_aborted(struct fuse_conn *fc) 2221 { 2222 wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0); 2223 } 2224 2225 int fuse_dev_release(struct inode *inode, struct file *file) 2226 { 2227 struct fuse_dev *fud = fuse_get_dev(file); 2228 2229 if (fud) { 2230 struct fuse_conn *fc = fud->fc; 2231 struct fuse_pqueue *fpq = &fud->pq; 2232 LIST_HEAD(to_end); 2233 unsigned int i; 2234 2235 spin_lock(&fpq->lock); 2236 WARN_ON(!list_empty(&fpq->io)); 2237 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 2238 list_splice_init(&fpq->processing[i], &to_end); 2239 spin_unlock(&fpq->lock); 2240 2241 end_requests(fc, &to_end); 2242 2243 /* Are we the last open device? */ 2244 if (atomic_dec_and_test(&fc->dev_count)) { 2245 WARN_ON(fc->iq.fasync != NULL); 2246 fuse_abort_conn(fc, false); 2247 } 2248 fuse_dev_free(fud); 2249 } 2250 return 0; 2251 } 2252 EXPORT_SYMBOL_GPL(fuse_dev_release); 2253 2254 static int fuse_dev_fasync(int fd, struct file *file, int on) 2255 { 2256 struct fuse_dev *fud = fuse_get_dev(file); 2257 2258 if (!fud) 2259 return -EPERM; 2260 2261 /* No locking - fasync_helper does its own locking */ 2262 return fasync_helper(fd, file, on, &fud->fc->iq.fasync); 2263 } 2264 2265 static int fuse_device_clone(struct fuse_conn *fc, struct file *new) 2266 { 2267 struct fuse_dev *fud; 2268 2269 if (new->private_data) 2270 return -EINVAL; 2271 2272 fud = fuse_dev_alloc(fc); 2273 if (!fud) 2274 return -ENOMEM; 2275 2276 new->private_data = fud; 2277 atomic_inc(&fc->dev_count); 2278 2279 return 0; 2280 } 2281 2282 static long fuse_dev_ioctl(struct file *file, unsigned int cmd, 2283 unsigned long arg) 2284 { 2285 int err = -ENOTTY; 2286 2287 if (cmd == FUSE_DEV_IOC_CLONE) { 2288 int oldfd; 2289 2290 err = -EFAULT; 2291 if (!get_user(oldfd, (__u32 __user *) arg)) { 2292 struct file *old = fget(oldfd); 2293 2294 err = -EINVAL; 2295 if (old) { 2296 struct fuse_dev *fud = NULL; 2297 2298 /* 2299 * Check against file->f_op because CUSE 2300 * uses the same ioctl handler. 2301 */ 2302 if (old->f_op == file->f_op && 2303 old->f_cred->user_ns == file->f_cred->user_ns) 2304 fud = fuse_get_dev(old); 2305 2306 if (fud) { 2307 mutex_lock(&fuse_mutex); 2308 err = fuse_device_clone(fud->fc, file); 2309 mutex_unlock(&fuse_mutex); 2310 } 2311 fput(old); 2312 } 2313 } 2314 } 2315 return err; 2316 } 2317 2318 const struct file_operations fuse_dev_operations = { 2319 .owner = THIS_MODULE, 2320 .open = fuse_dev_open, 2321 .llseek = no_llseek, 2322 .read_iter = fuse_dev_read, 2323 .splice_read = fuse_dev_splice_read, 2324 .write_iter = fuse_dev_write, 2325 .splice_write = fuse_dev_splice_write, 2326 .poll = fuse_dev_poll, 2327 .release = fuse_dev_release, 2328 .fasync = fuse_dev_fasync, 2329 .unlocked_ioctl = fuse_dev_ioctl, 2330 .compat_ioctl = fuse_dev_ioctl, 2331 }; 2332 EXPORT_SYMBOL_GPL(fuse_dev_operations); 2333 2334 static struct miscdevice fuse_miscdevice = { 2335 .minor = FUSE_MINOR, 2336 .name = "fuse", 2337 .fops = &fuse_dev_operations, 2338 }; 2339 2340 int __init fuse_dev_init(void) 2341 { 2342 int err = -ENOMEM; 2343 fuse_req_cachep = kmem_cache_create("fuse_request", 2344 sizeof(struct fuse_req), 2345 0, 0, NULL); 2346 if (!fuse_req_cachep) 2347 goto out; 2348 2349 err = misc_register(&fuse_miscdevice); 2350 if (err) 2351 goto out_cache_clean; 2352 2353 return 0; 2354 2355 out_cache_clean: 2356 kmem_cache_destroy(fuse_req_cachep); 2357 out: 2358 return err; 2359 } 2360 2361 void fuse_dev_cleanup(void) 2362 { 2363 misc_deregister(&fuse_miscdevice); 2364 kmem_cache_destroy(fuse_req_cachep); 2365 } 2366