1 /* 2 * Copyright (c) 1996 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Absolutely no warranty of function or purpose is made by the author 15 * John S. Dyson. 16 * 4. Modifications may be freely made to this file if the above conditions 17 * are met. 18 * 19 * $FreeBSD$ 20 */ 21 22 /* 23 * This file contains a high-performance replacement for the socket-based 24 * pipes scheme originally used in FreeBSD/4.4Lite. It does not support 25 * all features of sockets, but does do everything that pipes normally 26 * do. 27 */ 28 29 /* 30 * This code has two modes of operation, a small write mode and a large 31 * write mode. The small write mode acts like conventional pipes with 32 * a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the 33 * "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT 34 * and PIPE_SIZE in size, it is fully mapped and wired into the kernel, and 35 * the receiving process can copy it directly from the pages in the sending 36 * process. 37 * 38 * If the sending process receives a signal, it is possible that it will 39 * go away, and certainly its address space can change, because control 40 * is returned back to the user-mode side. In that case, the pipe code 41 * arranges to copy the buffer supplied by the user process, to a pageable 42 * kernel buffer, and the receiving process will grab the data from the 43 * pageable kernel buffer. Since signals don't happen all that often, 44 * the copy operation is normally eliminated. 45 * 46 * The constant PIPE_MINDIRECT is chosen to make sure that buffering will 47 * happen for small transfers so that the system will not spend all of 48 * its time context switching. PIPE_SIZE is constrained by the 49 * amount of kernel virtual memory. 50 */ 51 52 #include "opt_mac.h" 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/fcntl.h> 57 #include <sys/file.h> 58 #include <sys/filedesc.h> 59 #include <sys/filio.h> 60 #include <sys/kernel.h> 61 #include <sys/lock.h> 62 #include <sys/mac.h> 63 #include <sys/mutex.h> 64 #include <sys/ttycom.h> 65 #include <sys/stat.h> 66 #include <sys/malloc.h> 67 #include <sys/poll.h> 68 #include <sys/selinfo.h> 69 #include <sys/signalvar.h> 70 #include <sys/sysproto.h> 71 #include <sys/pipe.h> 72 #include <sys/proc.h> 73 #include <sys/vnode.h> 74 #include <sys/uio.h> 75 #include <sys/event.h> 76 77 #include <vm/vm.h> 78 #include <vm/vm_param.h> 79 #include <vm/vm_object.h> 80 #include <vm/vm_kern.h> 81 #include <vm/vm_extern.h> 82 #include <vm/pmap.h> 83 #include <vm/vm_map.h> 84 #include <vm/vm_page.h> 85 #include <vm/uma.h> 86 87 /* 88 * Use this define if you want to disable *fancy* VM things. Expect an 89 * approx 30% decrease in transfer rate. This could be useful for 90 * NetBSD or OpenBSD. 91 */ 92 /* #define PIPE_NODIRECT */ 93 94 /* 95 * interfaces to the outside world 96 */ 97 static fo_rdwr_t pipe_read; 98 static fo_rdwr_t pipe_write; 99 static fo_ioctl_t pipe_ioctl; 100 static fo_poll_t pipe_poll; 101 static fo_kqfilter_t pipe_kqfilter; 102 static fo_stat_t pipe_stat; 103 static fo_close_t pipe_close; 104 105 static struct fileops pipeops = { 106 pipe_read, pipe_write, pipe_ioctl, pipe_poll, pipe_kqfilter, 107 pipe_stat, pipe_close, DFLAG_PASSABLE 108 }; 109 110 static void filt_pipedetach(struct knote *kn); 111 static int filt_piperead(struct knote *kn, long hint); 112 static int filt_pipewrite(struct knote *kn, long hint); 113 114 static struct filterops pipe_rfiltops = 115 { 1, NULL, filt_pipedetach, filt_piperead }; 116 static struct filterops pipe_wfiltops = 117 { 1, NULL, filt_pipedetach, filt_pipewrite }; 118 119 #define PIPE_GET_GIANT(pipe) \ 120 do { \ 121 KASSERT(((pipe)->pipe_state & PIPE_LOCKFL) != 0, \ 122 ("%s:%d PIPE_GET_GIANT: line pipe not locked", \ 123 __FILE__, __LINE__)); \ 124 PIPE_UNLOCK(pipe); \ 125 mtx_lock(&Giant); \ 126 } while (0) 127 128 #define PIPE_DROP_GIANT(pipe) \ 129 do { \ 130 mtx_unlock(&Giant); \ 131 PIPE_LOCK(pipe); \ 132 } while (0) 133 134 /* 135 * Default pipe buffer size(s), this can be kind-of large now because pipe 136 * space is pageable. The pipe code will try to maintain locality of 137 * reference for performance reasons, so small amounts of outstanding I/O 138 * will not wipe the cache. 139 */ 140 #define MINPIPESIZE (PIPE_SIZE/3) 141 #define MAXPIPESIZE (2*PIPE_SIZE/3) 142 143 /* 144 * Maximum amount of kva for pipes -- this is kind-of a soft limit, but 145 * is there so that on large systems, we don't exhaust it. 146 */ 147 #define MAXPIPEKVA (8*1024*1024) 148 149 /* 150 * Limit for direct transfers, we cannot, of course limit 151 * the amount of kva for pipes in general though. 152 */ 153 #define LIMITPIPEKVA (16*1024*1024) 154 155 /* 156 * Limit the number of "big" pipes 157 */ 158 #define LIMITBIGPIPES 32 159 static int nbigpipe; 160 161 static int amountpipekva; 162 163 static void pipeinit(void *dummy __unused); 164 static void pipeclose(struct pipe *cpipe); 165 static void pipe_free_kmem(struct pipe *cpipe); 166 static int pipe_create(struct pipe **cpipep); 167 static __inline int pipelock(struct pipe *cpipe, int catch); 168 static __inline void pipeunlock(struct pipe *cpipe); 169 static __inline void pipeselwakeup(struct pipe *cpipe); 170 #ifndef PIPE_NODIRECT 171 static int pipe_build_write_buffer(struct pipe *wpipe, struct uio *uio); 172 static void pipe_destroy_write_buffer(struct pipe *wpipe); 173 static int pipe_direct_write(struct pipe *wpipe, struct uio *uio); 174 static void pipe_clone_write_buffer(struct pipe *wpipe); 175 #endif 176 static int pipespace(struct pipe *cpipe, int size); 177 178 static uma_zone_t pipe_zone; 179 180 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_ANY, pipeinit, NULL); 181 182 static void 183 pipeinit(void *dummy __unused) 184 { 185 pipe_zone = uma_zcreate("PIPE", sizeof(struct pipe), NULL, 186 NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 187 } 188 189 /* 190 * The pipe system call for the DTYPE_PIPE type of pipes 191 */ 192 193 /* ARGSUSED */ 194 int 195 pipe(td, uap) 196 struct thread *td; 197 struct pipe_args /* { 198 int dummy; 199 } */ *uap; 200 { 201 struct filedesc *fdp = td->td_proc->p_fd; 202 struct file *rf, *wf; 203 struct pipe *rpipe, *wpipe; 204 struct mtx *pmtx; 205 int fd, error; 206 207 KASSERT(pipe_zone != NULL, ("pipe_zone not initialized")); 208 209 pmtx = malloc(sizeof(*pmtx), M_TEMP, M_WAITOK | M_ZERO); 210 211 rpipe = wpipe = NULL; 212 if (pipe_create(&rpipe) || pipe_create(&wpipe)) { 213 pipeclose(rpipe); 214 pipeclose(wpipe); 215 free(pmtx, M_TEMP); 216 return (ENFILE); 217 } 218 219 rpipe->pipe_state |= PIPE_DIRECTOK; 220 wpipe->pipe_state |= PIPE_DIRECTOK; 221 222 error = falloc(td, &rf, &fd); 223 if (error) { 224 pipeclose(rpipe); 225 pipeclose(wpipe); 226 free(pmtx, M_TEMP); 227 return (error); 228 } 229 fhold(rf); 230 td->td_retval[0] = fd; 231 232 /* 233 * Warning: once we've gotten past allocation of the fd for the 234 * read-side, we can only drop the read side via fdrop() in order 235 * to avoid races against processes which manage to dup() the read 236 * side while we are blocked trying to allocate the write side. 237 */ 238 FILE_LOCK(rf); 239 rf->f_flag = FREAD | FWRITE; 240 rf->f_type = DTYPE_PIPE; 241 rf->f_data = rpipe; 242 rf->f_ops = &pipeops; 243 FILE_UNLOCK(rf); 244 error = falloc(td, &wf, &fd); 245 if (error) { 246 FILEDESC_LOCK(fdp); 247 if (fdp->fd_ofiles[td->td_retval[0]] == rf) { 248 fdp->fd_ofiles[td->td_retval[0]] = NULL; 249 FILEDESC_UNLOCK(fdp); 250 fdrop(rf, td); 251 } else 252 FILEDESC_UNLOCK(fdp); 253 fdrop(rf, td); 254 /* rpipe has been closed by fdrop(). */ 255 pipeclose(wpipe); 256 free(pmtx, M_TEMP); 257 return (error); 258 } 259 FILE_LOCK(wf); 260 wf->f_flag = FREAD | FWRITE; 261 wf->f_type = DTYPE_PIPE; 262 wf->f_data = wpipe; 263 wf->f_ops = &pipeops; 264 FILE_UNLOCK(wf); 265 td->td_retval[1] = fd; 266 rpipe->pipe_peer = wpipe; 267 wpipe->pipe_peer = rpipe; 268 #ifdef MAC 269 /* 270 * struct pipe represents a pipe endpoint. The MAC label is shared 271 * between the connected endpoints. As a result mac_init_pipe() and 272 * mac_create_pipe() should only be called on one of the endpoints 273 * after they have been connected. 274 */ 275 mac_init_pipe(rpipe); 276 mac_create_pipe(td->td_ucred, rpipe); 277 #endif 278 mtx_init(pmtx, "pipe mutex", NULL, MTX_DEF | MTX_RECURSE); 279 rpipe->pipe_mtxp = wpipe->pipe_mtxp = pmtx; 280 fdrop(rf, td); 281 282 return (0); 283 } 284 285 /* 286 * Allocate kva for pipe circular buffer, the space is pageable 287 * This routine will 'realloc' the size of a pipe safely, if it fails 288 * it will retain the old buffer. 289 * If it fails it will return ENOMEM. 290 */ 291 static int 292 pipespace(cpipe, size) 293 struct pipe *cpipe; 294 int size; 295 { 296 struct vm_object *object; 297 caddr_t buffer; 298 int npages, error; 299 300 GIANT_REQUIRED; 301 KASSERT(cpipe->pipe_mtxp == NULL || !mtx_owned(PIPE_MTX(cpipe)), 302 ("pipespace: pipe mutex locked")); 303 304 npages = round_page(size)/PAGE_SIZE; 305 /* 306 * Create an object, I don't like the idea of paging to/from 307 * kernel_object. 308 * XXX -- minor change needed here for NetBSD/OpenBSD VM systems. 309 */ 310 object = vm_object_allocate(OBJT_DEFAULT, npages); 311 buffer = (caddr_t) vm_map_min(kernel_map); 312 313 /* 314 * Insert the object into the kernel map, and allocate kva for it. 315 * The map entry is, by default, pageable. 316 * XXX -- minor change needed here for NetBSD/OpenBSD VM systems. 317 */ 318 error = vm_map_find(kernel_map, object, 0, 319 (vm_offset_t *) &buffer, size, 1, 320 VM_PROT_ALL, VM_PROT_ALL, 0); 321 322 if (error != KERN_SUCCESS) { 323 vm_object_deallocate(object); 324 return (ENOMEM); 325 } 326 327 /* free old resources if we're resizing */ 328 pipe_free_kmem(cpipe); 329 cpipe->pipe_buffer.object = object; 330 cpipe->pipe_buffer.buffer = buffer; 331 cpipe->pipe_buffer.size = size; 332 cpipe->pipe_buffer.in = 0; 333 cpipe->pipe_buffer.out = 0; 334 cpipe->pipe_buffer.cnt = 0; 335 atomic_add_int(&amountpipekva, cpipe->pipe_buffer.size); 336 return (0); 337 } 338 339 /* 340 * initialize and allocate VM and memory for pipe 341 */ 342 static int 343 pipe_create(cpipep) 344 struct pipe **cpipep; 345 { 346 struct pipe *cpipe; 347 int error; 348 349 *cpipep = uma_zalloc(pipe_zone, M_WAITOK); 350 if (*cpipep == NULL) 351 return (ENOMEM); 352 353 cpipe = *cpipep; 354 355 /* so pipespace()->pipe_free_kmem() doesn't follow junk pointer */ 356 cpipe->pipe_buffer.object = NULL; 357 #ifndef PIPE_NODIRECT 358 cpipe->pipe_map.kva = 0; 359 #endif 360 /* 361 * protect so pipeclose() doesn't follow a junk pointer 362 * if pipespace() fails. 363 */ 364 bzero(&cpipe->pipe_sel, sizeof(cpipe->pipe_sel)); 365 cpipe->pipe_state = 0; 366 cpipe->pipe_peer = NULL; 367 cpipe->pipe_busy = 0; 368 369 #ifndef PIPE_NODIRECT 370 /* 371 * pipe data structure initializations to support direct pipe I/O 372 */ 373 cpipe->pipe_map.cnt = 0; 374 cpipe->pipe_map.kva = 0; 375 cpipe->pipe_map.pos = 0; 376 cpipe->pipe_map.npages = 0; 377 /* cpipe->pipe_map.ms[] = invalid */ 378 #endif 379 380 cpipe->pipe_mtxp = NULL; /* avoid pipespace assertion */ 381 error = pipespace(cpipe, PIPE_SIZE); 382 if (error) 383 return (error); 384 385 vfs_timestamp(&cpipe->pipe_ctime); 386 cpipe->pipe_atime = cpipe->pipe_ctime; 387 cpipe->pipe_mtime = cpipe->pipe_ctime; 388 389 return (0); 390 } 391 392 393 /* 394 * lock a pipe for I/O, blocking other access 395 */ 396 static __inline int 397 pipelock(cpipe, catch) 398 struct pipe *cpipe; 399 int catch; 400 { 401 int error; 402 403 PIPE_LOCK_ASSERT(cpipe, MA_OWNED); 404 while (cpipe->pipe_state & PIPE_LOCKFL) { 405 cpipe->pipe_state |= PIPE_LWANT; 406 error = msleep(cpipe, PIPE_MTX(cpipe), 407 catch ? (PRIBIO | PCATCH) : PRIBIO, 408 "pipelk", 0); 409 if (error != 0) 410 return (error); 411 } 412 cpipe->pipe_state |= PIPE_LOCKFL; 413 return (0); 414 } 415 416 /* 417 * unlock a pipe I/O lock 418 */ 419 static __inline void 420 pipeunlock(cpipe) 421 struct pipe *cpipe; 422 { 423 424 PIPE_LOCK_ASSERT(cpipe, MA_OWNED); 425 cpipe->pipe_state &= ~PIPE_LOCKFL; 426 if (cpipe->pipe_state & PIPE_LWANT) { 427 cpipe->pipe_state &= ~PIPE_LWANT; 428 wakeup(cpipe); 429 } 430 } 431 432 static __inline void 433 pipeselwakeup(cpipe) 434 struct pipe *cpipe; 435 { 436 437 if (cpipe->pipe_state & PIPE_SEL) { 438 cpipe->pipe_state &= ~PIPE_SEL; 439 selwakeup(&cpipe->pipe_sel); 440 } 441 if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_sigio) 442 pgsigio(&cpipe->pipe_sigio, SIGIO, 0); 443 KNOTE(&cpipe->pipe_sel.si_note, 0); 444 } 445 446 /* ARGSUSED */ 447 static int 448 pipe_read(fp, uio, active_cred, flags, td) 449 struct file *fp; 450 struct uio *uio; 451 struct ucred *active_cred; 452 struct thread *td; 453 int flags; 454 { 455 struct pipe *rpipe = fp->f_data; 456 int error; 457 int nread = 0; 458 u_int size; 459 460 PIPE_LOCK(rpipe); 461 ++rpipe->pipe_busy; 462 error = pipelock(rpipe, 1); 463 if (error) 464 goto unlocked_error; 465 466 #ifdef MAC 467 error = mac_check_pipe_read(active_cred, rpipe); 468 if (error) 469 goto locked_error; 470 #endif 471 472 while (uio->uio_resid) { 473 /* 474 * normal pipe buffer receive 475 */ 476 if (rpipe->pipe_buffer.cnt > 0) { 477 size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out; 478 if (size > rpipe->pipe_buffer.cnt) 479 size = rpipe->pipe_buffer.cnt; 480 if (size > (u_int) uio->uio_resid) 481 size = (u_int) uio->uio_resid; 482 483 PIPE_UNLOCK(rpipe); 484 error = uiomove(&rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out], 485 size, uio); 486 PIPE_LOCK(rpipe); 487 if (error) 488 break; 489 490 rpipe->pipe_buffer.out += size; 491 if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size) 492 rpipe->pipe_buffer.out = 0; 493 494 rpipe->pipe_buffer.cnt -= size; 495 496 /* 497 * If there is no more to read in the pipe, reset 498 * its pointers to the beginning. This improves 499 * cache hit stats. 500 */ 501 if (rpipe->pipe_buffer.cnt == 0) { 502 rpipe->pipe_buffer.in = 0; 503 rpipe->pipe_buffer.out = 0; 504 } 505 nread += size; 506 #ifndef PIPE_NODIRECT 507 /* 508 * Direct copy, bypassing a kernel buffer. 509 */ 510 } else if ((size = rpipe->pipe_map.cnt) && 511 (rpipe->pipe_state & PIPE_DIRECTW)) { 512 caddr_t va; 513 if (size > (u_int) uio->uio_resid) 514 size = (u_int) uio->uio_resid; 515 516 va = (caddr_t) rpipe->pipe_map.kva + 517 rpipe->pipe_map.pos; 518 PIPE_UNLOCK(rpipe); 519 error = uiomove(va, size, uio); 520 PIPE_LOCK(rpipe); 521 if (error) 522 break; 523 nread += size; 524 rpipe->pipe_map.pos += size; 525 rpipe->pipe_map.cnt -= size; 526 if (rpipe->pipe_map.cnt == 0) { 527 rpipe->pipe_state &= ~PIPE_DIRECTW; 528 wakeup(rpipe); 529 } 530 #endif 531 } else { 532 /* 533 * detect EOF condition 534 * read returns 0 on EOF, no need to set error 535 */ 536 if (rpipe->pipe_state & PIPE_EOF) 537 break; 538 539 /* 540 * If the "write-side" has been blocked, wake it up now. 541 */ 542 if (rpipe->pipe_state & PIPE_WANTW) { 543 rpipe->pipe_state &= ~PIPE_WANTW; 544 wakeup(rpipe); 545 } 546 547 /* 548 * Break if some data was read. 549 */ 550 if (nread > 0) 551 break; 552 553 /* 554 * Unlock the pipe buffer for our remaining processing. We 555 * will either break out with an error or we will sleep and 556 * relock to loop. 557 */ 558 pipeunlock(rpipe); 559 560 /* 561 * Handle non-blocking mode operation or 562 * wait for more data. 563 */ 564 if (fp->f_flag & FNONBLOCK) { 565 error = EAGAIN; 566 } else { 567 rpipe->pipe_state |= PIPE_WANTR; 568 if ((error = msleep(rpipe, PIPE_MTX(rpipe), 569 PRIBIO | PCATCH, 570 "piperd", 0)) == 0) 571 error = pipelock(rpipe, 1); 572 } 573 if (error) 574 goto unlocked_error; 575 } 576 } 577 #ifdef MAC 578 locked_error: 579 #endif 580 pipeunlock(rpipe); 581 582 /* XXX: should probably do this before getting any locks. */ 583 if (error == 0) 584 vfs_timestamp(&rpipe->pipe_atime); 585 unlocked_error: 586 --rpipe->pipe_busy; 587 588 /* 589 * PIPE_WANT processing only makes sense if pipe_busy is 0. 590 */ 591 if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) { 592 rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW); 593 wakeup(rpipe); 594 } else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) { 595 /* 596 * Handle write blocking hysteresis. 597 */ 598 if (rpipe->pipe_state & PIPE_WANTW) { 599 rpipe->pipe_state &= ~PIPE_WANTW; 600 wakeup(rpipe); 601 } 602 } 603 604 if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF) 605 pipeselwakeup(rpipe); 606 607 PIPE_UNLOCK(rpipe); 608 return (error); 609 } 610 611 #ifndef PIPE_NODIRECT 612 /* 613 * Map the sending processes' buffer into kernel space and wire it. 614 * This is similar to a physical write operation. 615 */ 616 static int 617 pipe_build_write_buffer(wpipe, uio) 618 struct pipe *wpipe; 619 struct uio *uio; 620 { 621 u_int size; 622 int i; 623 vm_offset_t addr, endaddr, paddr; 624 625 GIANT_REQUIRED; 626 PIPE_LOCK_ASSERT(wpipe, MA_NOTOWNED); 627 628 size = (u_int) uio->uio_iov->iov_len; 629 if (size > wpipe->pipe_buffer.size) 630 size = wpipe->pipe_buffer.size; 631 632 endaddr = round_page((vm_offset_t)uio->uio_iov->iov_base + size); 633 addr = trunc_page((vm_offset_t)uio->uio_iov->iov_base); 634 for (i = 0; addr < endaddr; addr += PAGE_SIZE, i++) { 635 vm_page_t m; 636 637 /* 638 * vm_fault_quick() can sleep. Consequently, 639 * vm_page_lock_queue() and vm_page_unlock_queue() 640 * should not be performed outside of this loop. 641 */ 642 if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0 || 643 (paddr = pmap_extract(vmspace_pmap(curproc->p_vmspace), 644 addr)) == 0) { 645 int j; 646 647 vm_page_lock_queues(); 648 for (j = 0; j < i; j++) 649 vm_page_unwire(wpipe->pipe_map.ms[j], 1); 650 vm_page_unlock_queues(); 651 return (EFAULT); 652 } 653 654 m = PHYS_TO_VM_PAGE(paddr); 655 vm_page_lock_queues(); 656 vm_page_wire(m); 657 vm_page_unlock_queues(); 658 wpipe->pipe_map.ms[i] = m; 659 } 660 661 /* 662 * set up the control block 663 */ 664 wpipe->pipe_map.npages = i; 665 wpipe->pipe_map.pos = 666 ((vm_offset_t) uio->uio_iov->iov_base) & PAGE_MASK; 667 wpipe->pipe_map.cnt = size; 668 669 /* 670 * and map the buffer 671 */ 672 if (wpipe->pipe_map.kva == 0) { 673 /* 674 * We need to allocate space for an extra page because the 675 * address range might (will) span pages at times. 676 */ 677 wpipe->pipe_map.kva = kmem_alloc_pageable(kernel_map, 678 wpipe->pipe_buffer.size + PAGE_SIZE); 679 atomic_add_int(&amountpipekva, 680 wpipe->pipe_buffer.size + PAGE_SIZE); 681 } 682 pmap_qenter(wpipe->pipe_map.kva, wpipe->pipe_map.ms, 683 wpipe->pipe_map.npages); 684 685 /* 686 * and update the uio data 687 */ 688 689 uio->uio_iov->iov_len -= size; 690 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + size; 691 if (uio->uio_iov->iov_len == 0) 692 uio->uio_iov++; 693 uio->uio_resid -= size; 694 uio->uio_offset += size; 695 return (0); 696 } 697 698 /* 699 * unmap and unwire the process buffer 700 */ 701 static void 702 pipe_destroy_write_buffer(wpipe) 703 struct pipe *wpipe; 704 { 705 int i; 706 707 GIANT_REQUIRED; 708 PIPE_LOCK_ASSERT(wpipe, MA_NOTOWNED); 709 710 if (wpipe->pipe_map.kva) { 711 pmap_qremove(wpipe->pipe_map.kva, wpipe->pipe_map.npages); 712 713 if (amountpipekva > MAXPIPEKVA) { 714 vm_offset_t kva = wpipe->pipe_map.kva; 715 wpipe->pipe_map.kva = 0; 716 kmem_free(kernel_map, kva, 717 wpipe->pipe_buffer.size + PAGE_SIZE); 718 atomic_subtract_int(&amountpipekva, 719 wpipe->pipe_buffer.size + PAGE_SIZE); 720 } 721 } 722 vm_page_lock_queues(); 723 for (i = 0; i < wpipe->pipe_map.npages; i++) 724 vm_page_unwire(wpipe->pipe_map.ms[i], 1); 725 vm_page_unlock_queues(); 726 wpipe->pipe_map.npages = 0; 727 } 728 729 /* 730 * In the case of a signal, the writing process might go away. This 731 * code copies the data into the circular buffer so that the source 732 * pages can be freed without loss of data. 733 */ 734 static void 735 pipe_clone_write_buffer(wpipe) 736 struct pipe *wpipe; 737 { 738 int size; 739 int pos; 740 741 PIPE_LOCK_ASSERT(wpipe, MA_OWNED); 742 size = wpipe->pipe_map.cnt; 743 pos = wpipe->pipe_map.pos; 744 745 wpipe->pipe_buffer.in = size; 746 wpipe->pipe_buffer.out = 0; 747 wpipe->pipe_buffer.cnt = size; 748 wpipe->pipe_state &= ~PIPE_DIRECTW; 749 750 PIPE_GET_GIANT(wpipe); 751 bcopy((caddr_t) wpipe->pipe_map.kva + pos, 752 wpipe->pipe_buffer.buffer, size); 753 pipe_destroy_write_buffer(wpipe); 754 PIPE_DROP_GIANT(wpipe); 755 } 756 757 /* 758 * This implements the pipe buffer write mechanism. Note that only 759 * a direct write OR a normal pipe write can be pending at any given time. 760 * If there are any characters in the pipe buffer, the direct write will 761 * be deferred until the receiving process grabs all of the bytes from 762 * the pipe buffer. Then the direct mapping write is set-up. 763 */ 764 static int 765 pipe_direct_write(wpipe, uio) 766 struct pipe *wpipe; 767 struct uio *uio; 768 { 769 int error; 770 771 retry: 772 PIPE_LOCK_ASSERT(wpipe, MA_OWNED); 773 while (wpipe->pipe_state & PIPE_DIRECTW) { 774 if (wpipe->pipe_state & PIPE_WANTR) { 775 wpipe->pipe_state &= ~PIPE_WANTR; 776 wakeup(wpipe); 777 } 778 wpipe->pipe_state |= PIPE_WANTW; 779 error = msleep(wpipe, PIPE_MTX(wpipe), 780 PRIBIO | PCATCH, "pipdww", 0); 781 if (error) 782 goto error1; 783 if (wpipe->pipe_state & PIPE_EOF) { 784 error = EPIPE; 785 goto error1; 786 } 787 } 788 wpipe->pipe_map.cnt = 0; /* transfer not ready yet */ 789 if (wpipe->pipe_buffer.cnt > 0) { 790 if (wpipe->pipe_state & PIPE_WANTR) { 791 wpipe->pipe_state &= ~PIPE_WANTR; 792 wakeup(wpipe); 793 } 794 795 wpipe->pipe_state |= PIPE_WANTW; 796 error = msleep(wpipe, PIPE_MTX(wpipe), 797 PRIBIO | PCATCH, "pipdwc", 0); 798 if (error) 799 goto error1; 800 if (wpipe->pipe_state & PIPE_EOF) { 801 error = EPIPE; 802 goto error1; 803 } 804 goto retry; 805 } 806 807 wpipe->pipe_state |= PIPE_DIRECTW; 808 809 pipelock(wpipe, 0); 810 PIPE_GET_GIANT(wpipe); 811 error = pipe_build_write_buffer(wpipe, uio); 812 PIPE_DROP_GIANT(wpipe); 813 pipeunlock(wpipe); 814 if (error) { 815 wpipe->pipe_state &= ~PIPE_DIRECTW; 816 goto error1; 817 } 818 819 error = 0; 820 while (!error && (wpipe->pipe_state & PIPE_DIRECTW)) { 821 if (wpipe->pipe_state & PIPE_EOF) { 822 pipelock(wpipe, 0); 823 PIPE_GET_GIANT(wpipe); 824 pipe_destroy_write_buffer(wpipe); 825 PIPE_DROP_GIANT(wpipe); 826 pipeunlock(wpipe); 827 pipeselwakeup(wpipe); 828 error = EPIPE; 829 goto error1; 830 } 831 if (wpipe->pipe_state & PIPE_WANTR) { 832 wpipe->pipe_state &= ~PIPE_WANTR; 833 wakeup(wpipe); 834 } 835 pipeselwakeup(wpipe); 836 error = msleep(wpipe, PIPE_MTX(wpipe), PRIBIO | PCATCH, 837 "pipdwt", 0); 838 } 839 840 pipelock(wpipe,0); 841 if (wpipe->pipe_state & PIPE_DIRECTW) { 842 /* 843 * this bit of trickery substitutes a kernel buffer for 844 * the process that might be going away. 845 */ 846 pipe_clone_write_buffer(wpipe); 847 } else { 848 PIPE_GET_GIANT(wpipe); 849 pipe_destroy_write_buffer(wpipe); 850 PIPE_DROP_GIANT(wpipe); 851 } 852 pipeunlock(wpipe); 853 return (error); 854 855 error1: 856 wakeup(wpipe); 857 return (error); 858 } 859 #endif 860 861 static int 862 pipe_write(fp, uio, active_cred, flags, td) 863 struct file *fp; 864 struct uio *uio; 865 struct ucred *active_cred; 866 struct thread *td; 867 int flags; 868 { 869 int error = 0; 870 int orig_resid; 871 struct pipe *wpipe, *rpipe; 872 873 rpipe = fp->f_data; 874 wpipe = rpipe->pipe_peer; 875 876 PIPE_LOCK(rpipe); 877 /* 878 * detect loss of pipe read side, issue SIGPIPE if lost. 879 */ 880 if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) { 881 PIPE_UNLOCK(rpipe); 882 return (EPIPE); 883 } 884 #ifdef MAC 885 error = mac_check_pipe_write(active_cred, wpipe); 886 if (error) { 887 PIPE_UNLOCK(rpipe); 888 return (error); 889 } 890 #endif 891 ++wpipe->pipe_busy; 892 893 /* 894 * If it is advantageous to resize the pipe buffer, do 895 * so. 896 */ 897 if ((uio->uio_resid > PIPE_SIZE) && 898 (nbigpipe < LIMITBIGPIPES) && 899 (wpipe->pipe_state & PIPE_DIRECTW) == 0 && 900 (wpipe->pipe_buffer.size <= PIPE_SIZE) && 901 (wpipe->pipe_buffer.cnt == 0)) { 902 903 if ((error = pipelock(wpipe, 1)) == 0) { 904 PIPE_GET_GIANT(wpipe); 905 if (pipespace(wpipe, BIG_PIPE_SIZE) == 0) 906 nbigpipe++; 907 PIPE_DROP_GIANT(wpipe); 908 pipeunlock(wpipe); 909 } 910 } 911 912 /* 913 * If an early error occured unbusy and return, waking up any pending 914 * readers. 915 */ 916 if (error) { 917 --wpipe->pipe_busy; 918 if ((wpipe->pipe_busy == 0) && 919 (wpipe->pipe_state & PIPE_WANT)) { 920 wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR); 921 wakeup(wpipe); 922 } 923 PIPE_UNLOCK(rpipe); 924 return(error); 925 } 926 927 orig_resid = uio->uio_resid; 928 929 while (uio->uio_resid) { 930 int space; 931 932 #ifndef PIPE_NODIRECT 933 /* 934 * If the transfer is large, we can gain performance if 935 * we do process-to-process copies directly. 936 * If the write is non-blocking, we don't use the 937 * direct write mechanism. 938 * 939 * The direct write mechanism will detect the reader going 940 * away on us. 941 */ 942 if ((uio->uio_iov->iov_len >= PIPE_MINDIRECT) && 943 (fp->f_flag & FNONBLOCK) == 0 && 944 (wpipe->pipe_map.kva || (amountpipekva < LIMITPIPEKVA)) && 945 (uio->uio_iov->iov_len >= PIPE_MINDIRECT)) { 946 error = pipe_direct_write(wpipe, uio); 947 if (error) 948 break; 949 continue; 950 } 951 #endif 952 953 /* 954 * Pipe buffered writes cannot be coincidental with 955 * direct writes. We wait until the currently executing 956 * direct write is completed before we start filling the 957 * pipe buffer. We break out if a signal occurs or the 958 * reader goes away. 959 */ 960 retrywrite: 961 while (wpipe->pipe_state & PIPE_DIRECTW) { 962 if (wpipe->pipe_state & PIPE_WANTR) { 963 wpipe->pipe_state &= ~PIPE_WANTR; 964 wakeup(wpipe); 965 } 966 error = msleep(wpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, 967 "pipbww", 0); 968 if (wpipe->pipe_state & PIPE_EOF) 969 break; 970 if (error) 971 break; 972 } 973 if (wpipe->pipe_state & PIPE_EOF) { 974 error = EPIPE; 975 break; 976 } 977 978 space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; 979 980 /* Writes of size <= PIPE_BUF must be atomic. */ 981 if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF)) 982 space = 0; 983 984 if (space > 0 && (wpipe->pipe_buffer.cnt < PIPE_SIZE)) { 985 if ((error = pipelock(wpipe,1)) == 0) { 986 int size; /* Transfer size */ 987 int segsize; /* first segment to transfer */ 988 989 /* 990 * It is possible for a direct write to 991 * slip in on us... handle it here... 992 */ 993 if (wpipe->pipe_state & PIPE_DIRECTW) { 994 pipeunlock(wpipe); 995 goto retrywrite; 996 } 997 /* 998 * If a process blocked in uiomove, our 999 * value for space might be bad. 1000 * 1001 * XXX will we be ok if the reader has gone 1002 * away here? 1003 */ 1004 if (space > wpipe->pipe_buffer.size - 1005 wpipe->pipe_buffer.cnt) { 1006 pipeunlock(wpipe); 1007 goto retrywrite; 1008 } 1009 1010 /* 1011 * Transfer size is minimum of uio transfer 1012 * and free space in pipe buffer. 1013 */ 1014 if (space > uio->uio_resid) 1015 size = uio->uio_resid; 1016 else 1017 size = space; 1018 /* 1019 * First segment to transfer is minimum of 1020 * transfer size and contiguous space in 1021 * pipe buffer. If first segment to transfer 1022 * is less than the transfer size, we've got 1023 * a wraparound in the buffer. 1024 */ 1025 segsize = wpipe->pipe_buffer.size - 1026 wpipe->pipe_buffer.in; 1027 if (segsize > size) 1028 segsize = size; 1029 1030 /* Transfer first segment */ 1031 1032 PIPE_UNLOCK(rpipe); 1033 error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in], 1034 segsize, uio); 1035 PIPE_LOCK(rpipe); 1036 1037 if (error == 0 && segsize < size) { 1038 /* 1039 * Transfer remaining part now, to 1040 * support atomic writes. Wraparound 1041 * happened. 1042 */ 1043 if (wpipe->pipe_buffer.in + segsize != 1044 wpipe->pipe_buffer.size) 1045 panic("Expected pipe buffer wraparound disappeared"); 1046 1047 PIPE_UNLOCK(rpipe); 1048 error = uiomove(&wpipe->pipe_buffer.buffer[0], 1049 size - segsize, uio); 1050 PIPE_LOCK(rpipe); 1051 } 1052 if (error == 0) { 1053 wpipe->pipe_buffer.in += size; 1054 if (wpipe->pipe_buffer.in >= 1055 wpipe->pipe_buffer.size) { 1056 if (wpipe->pipe_buffer.in != size - segsize + wpipe->pipe_buffer.size) 1057 panic("Expected wraparound bad"); 1058 wpipe->pipe_buffer.in = size - segsize; 1059 } 1060 1061 wpipe->pipe_buffer.cnt += size; 1062 if (wpipe->pipe_buffer.cnt > wpipe->pipe_buffer.size) 1063 panic("Pipe buffer overflow"); 1064 1065 } 1066 pipeunlock(wpipe); 1067 } 1068 if (error) 1069 break; 1070 1071 } else { 1072 /* 1073 * If the "read-side" has been blocked, wake it up now. 1074 */ 1075 if (wpipe->pipe_state & PIPE_WANTR) { 1076 wpipe->pipe_state &= ~PIPE_WANTR; 1077 wakeup(wpipe); 1078 } 1079 1080 /* 1081 * don't block on non-blocking I/O 1082 */ 1083 if (fp->f_flag & FNONBLOCK) { 1084 error = EAGAIN; 1085 break; 1086 } 1087 1088 /* 1089 * We have no more space and have something to offer, 1090 * wake up select/poll. 1091 */ 1092 pipeselwakeup(wpipe); 1093 1094 wpipe->pipe_state |= PIPE_WANTW; 1095 error = msleep(wpipe, PIPE_MTX(rpipe), 1096 PRIBIO | PCATCH, "pipewr", 0); 1097 if (error != 0) 1098 break; 1099 /* 1100 * If read side wants to go away, we just issue a signal 1101 * to ourselves. 1102 */ 1103 if (wpipe->pipe_state & PIPE_EOF) { 1104 error = EPIPE; 1105 break; 1106 } 1107 } 1108 } 1109 1110 --wpipe->pipe_busy; 1111 1112 if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { 1113 wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR); 1114 wakeup(wpipe); 1115 } else if (wpipe->pipe_buffer.cnt > 0) { 1116 /* 1117 * If we have put any characters in the buffer, we wake up 1118 * the reader. 1119 */ 1120 if (wpipe->pipe_state & PIPE_WANTR) { 1121 wpipe->pipe_state &= ~PIPE_WANTR; 1122 wakeup(wpipe); 1123 } 1124 } 1125 1126 /* 1127 * Don't return EPIPE if I/O was successful 1128 */ 1129 if ((wpipe->pipe_buffer.cnt == 0) && 1130 (uio->uio_resid == 0) && 1131 (error == EPIPE)) { 1132 error = 0; 1133 } 1134 1135 if (error == 0) 1136 vfs_timestamp(&wpipe->pipe_mtime); 1137 1138 /* 1139 * We have something to offer, 1140 * wake up select/poll. 1141 */ 1142 if (wpipe->pipe_buffer.cnt) 1143 pipeselwakeup(wpipe); 1144 1145 PIPE_UNLOCK(rpipe); 1146 return (error); 1147 } 1148 1149 /* 1150 * we implement a very minimal set of ioctls for compatibility with sockets. 1151 */ 1152 static int 1153 pipe_ioctl(fp, cmd, data, active_cred, td) 1154 struct file *fp; 1155 u_long cmd; 1156 void *data; 1157 struct ucred *active_cred; 1158 struct thread *td; 1159 { 1160 struct pipe *mpipe = fp->f_data; 1161 #ifdef MAC 1162 int error; 1163 #endif 1164 1165 PIPE_LOCK(mpipe); 1166 1167 #ifdef MAC 1168 error = mac_check_pipe_ioctl(active_cred, mpipe, cmd, data); 1169 if (error) 1170 return (error); 1171 #endif 1172 1173 switch (cmd) { 1174 1175 case FIONBIO: 1176 PIPE_UNLOCK(mpipe); 1177 return (0); 1178 1179 case FIOASYNC: 1180 if (*(int *)data) { 1181 mpipe->pipe_state |= PIPE_ASYNC; 1182 } else { 1183 mpipe->pipe_state &= ~PIPE_ASYNC; 1184 } 1185 PIPE_UNLOCK(mpipe); 1186 return (0); 1187 1188 case FIONREAD: 1189 if (mpipe->pipe_state & PIPE_DIRECTW) 1190 *(int *)data = mpipe->pipe_map.cnt; 1191 else 1192 *(int *)data = mpipe->pipe_buffer.cnt; 1193 PIPE_UNLOCK(mpipe); 1194 return (0); 1195 1196 case FIOSETOWN: 1197 PIPE_UNLOCK(mpipe); 1198 return (fsetown(*(int *)data, &mpipe->pipe_sigio)); 1199 1200 case FIOGETOWN: 1201 PIPE_UNLOCK(mpipe); 1202 *(int *)data = fgetown(&mpipe->pipe_sigio); 1203 return (0); 1204 1205 /* This is deprecated, FIOSETOWN should be used instead. */ 1206 case TIOCSPGRP: 1207 PIPE_UNLOCK(mpipe); 1208 return (fsetown(-(*(int *)data), &mpipe->pipe_sigio)); 1209 1210 /* This is deprecated, FIOGETOWN should be used instead. */ 1211 case TIOCGPGRP: 1212 PIPE_UNLOCK(mpipe); 1213 *(int *)data = -fgetown(&mpipe->pipe_sigio); 1214 return (0); 1215 1216 } 1217 PIPE_UNLOCK(mpipe); 1218 return (ENOTTY); 1219 } 1220 1221 static int 1222 pipe_poll(fp, events, active_cred, td) 1223 struct file *fp; 1224 int events; 1225 struct ucred *active_cred; 1226 struct thread *td; 1227 { 1228 struct pipe *rpipe = fp->f_data; 1229 struct pipe *wpipe; 1230 int revents = 0; 1231 #ifdef MAC 1232 int error; 1233 #endif 1234 1235 wpipe = rpipe->pipe_peer; 1236 PIPE_LOCK(rpipe); 1237 #ifdef MAC 1238 error = mac_check_pipe_poll(active_cred, rpipe); 1239 if (error) 1240 goto locked_error; 1241 #endif 1242 if (events & (POLLIN | POLLRDNORM)) 1243 if ((rpipe->pipe_state & PIPE_DIRECTW) || 1244 (rpipe->pipe_buffer.cnt > 0) || 1245 (rpipe->pipe_state & PIPE_EOF)) 1246 revents |= events & (POLLIN | POLLRDNORM); 1247 1248 if (events & (POLLOUT | POLLWRNORM)) 1249 if (wpipe == NULL || (wpipe->pipe_state & PIPE_EOF) || 1250 (((wpipe->pipe_state & PIPE_DIRECTW) == 0) && 1251 (wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) 1252 revents |= events & (POLLOUT | POLLWRNORM); 1253 1254 if ((rpipe->pipe_state & PIPE_EOF) || 1255 (wpipe == NULL) || 1256 (wpipe->pipe_state & PIPE_EOF)) 1257 revents |= POLLHUP; 1258 1259 if (revents == 0) { 1260 if (events & (POLLIN | POLLRDNORM)) { 1261 selrecord(td, &rpipe->pipe_sel); 1262 rpipe->pipe_state |= PIPE_SEL; 1263 } 1264 1265 if (events & (POLLOUT | POLLWRNORM)) { 1266 selrecord(td, &wpipe->pipe_sel); 1267 wpipe->pipe_state |= PIPE_SEL; 1268 } 1269 } 1270 #ifdef MAC 1271 locked_error: 1272 #endif 1273 PIPE_UNLOCK(rpipe); 1274 1275 return (revents); 1276 } 1277 1278 /* 1279 * We shouldn't need locks here as we're doing a read and this should 1280 * be a natural race. 1281 */ 1282 static int 1283 pipe_stat(fp, ub, active_cred, td) 1284 struct file *fp; 1285 struct stat *ub; 1286 struct ucred *active_cred; 1287 struct thread *td; 1288 { 1289 struct pipe *pipe = fp->f_data; 1290 #ifdef MAC 1291 int error; 1292 1293 PIPE_LOCK(pipe); 1294 error = mac_check_pipe_stat(active_cred, pipe); 1295 PIPE_UNLOCK(pipe); 1296 if (error) 1297 return (error); 1298 #endif 1299 bzero(ub, sizeof(*ub)); 1300 ub->st_mode = S_IFIFO; 1301 ub->st_blksize = pipe->pipe_buffer.size; 1302 ub->st_size = pipe->pipe_buffer.cnt; 1303 ub->st_blocks = (ub->st_size + ub->st_blksize - 1) / ub->st_blksize; 1304 ub->st_atimespec = pipe->pipe_atime; 1305 ub->st_mtimespec = pipe->pipe_mtime; 1306 ub->st_ctimespec = pipe->pipe_ctime; 1307 ub->st_uid = fp->f_cred->cr_uid; 1308 ub->st_gid = fp->f_cred->cr_gid; 1309 /* 1310 * Left as 0: st_dev, st_ino, st_nlink, st_rdev, st_flags, st_gen. 1311 * XXX (st_dev, st_ino) should be unique. 1312 */ 1313 return (0); 1314 } 1315 1316 /* ARGSUSED */ 1317 static int 1318 pipe_close(fp, td) 1319 struct file *fp; 1320 struct thread *td; 1321 { 1322 struct pipe *cpipe = fp->f_data; 1323 1324 fp->f_ops = &badfileops; 1325 fp->f_data = NULL; 1326 funsetown(&cpipe->pipe_sigio); 1327 pipeclose(cpipe); 1328 return (0); 1329 } 1330 1331 static void 1332 pipe_free_kmem(cpipe) 1333 struct pipe *cpipe; 1334 { 1335 1336 GIANT_REQUIRED; 1337 KASSERT(cpipe->pipe_mtxp == NULL || !mtx_owned(PIPE_MTX(cpipe)), 1338 ("pipespace: pipe mutex locked")); 1339 1340 if (cpipe->pipe_buffer.buffer != NULL) { 1341 if (cpipe->pipe_buffer.size > PIPE_SIZE) 1342 --nbigpipe; 1343 atomic_subtract_int(&amountpipekva, cpipe->pipe_buffer.size); 1344 kmem_free(kernel_map, 1345 (vm_offset_t)cpipe->pipe_buffer.buffer, 1346 cpipe->pipe_buffer.size); 1347 cpipe->pipe_buffer.buffer = NULL; 1348 } 1349 #ifndef PIPE_NODIRECT 1350 if (cpipe->pipe_map.kva != 0) { 1351 atomic_subtract_int(&amountpipekva, 1352 cpipe->pipe_buffer.size + PAGE_SIZE); 1353 kmem_free(kernel_map, 1354 cpipe->pipe_map.kva, 1355 cpipe->pipe_buffer.size + PAGE_SIZE); 1356 cpipe->pipe_map.cnt = 0; 1357 cpipe->pipe_map.kva = 0; 1358 cpipe->pipe_map.pos = 0; 1359 cpipe->pipe_map.npages = 0; 1360 } 1361 #endif 1362 } 1363 1364 /* 1365 * shutdown the pipe 1366 */ 1367 static void 1368 pipeclose(cpipe) 1369 struct pipe *cpipe; 1370 { 1371 struct pipe *ppipe; 1372 int hadpeer; 1373 1374 if (cpipe == NULL) 1375 return; 1376 1377 hadpeer = 0; 1378 1379 /* partially created pipes won't have a valid mutex. */ 1380 if (PIPE_MTX(cpipe) != NULL) 1381 PIPE_LOCK(cpipe); 1382 1383 pipeselwakeup(cpipe); 1384 1385 /* 1386 * If the other side is blocked, wake it up saying that 1387 * we want to close it down. 1388 */ 1389 while (cpipe->pipe_busy) { 1390 wakeup(cpipe); 1391 cpipe->pipe_state |= PIPE_WANT | PIPE_EOF; 1392 msleep(cpipe, PIPE_MTX(cpipe), PRIBIO, "pipecl", 0); 1393 } 1394 1395 #ifdef MAC 1396 if (cpipe->pipe_label != NULL && cpipe->pipe_peer == NULL) 1397 mac_destroy_pipe(cpipe); 1398 #endif 1399 1400 /* 1401 * Disconnect from peer 1402 */ 1403 if ((ppipe = cpipe->pipe_peer) != NULL) { 1404 hadpeer++; 1405 pipeselwakeup(ppipe); 1406 1407 ppipe->pipe_state |= PIPE_EOF; 1408 wakeup(ppipe); 1409 KNOTE(&ppipe->pipe_sel.si_note, 0); 1410 ppipe->pipe_peer = NULL; 1411 } 1412 /* 1413 * free resources 1414 */ 1415 if (PIPE_MTX(cpipe) != NULL) { 1416 PIPE_UNLOCK(cpipe); 1417 if (!hadpeer) { 1418 mtx_destroy(PIPE_MTX(cpipe)); 1419 free(PIPE_MTX(cpipe), M_TEMP); 1420 } 1421 } 1422 mtx_lock(&Giant); 1423 pipe_free_kmem(cpipe); 1424 uma_zfree(pipe_zone, cpipe); 1425 mtx_unlock(&Giant); 1426 } 1427 1428 /*ARGSUSED*/ 1429 static int 1430 pipe_kqfilter(struct file *fp, struct knote *kn) 1431 { 1432 struct pipe *cpipe; 1433 1434 cpipe = kn->kn_fp->f_data; 1435 switch (kn->kn_filter) { 1436 case EVFILT_READ: 1437 kn->kn_fop = &pipe_rfiltops; 1438 break; 1439 case EVFILT_WRITE: 1440 kn->kn_fop = &pipe_wfiltops; 1441 cpipe = cpipe->pipe_peer; 1442 if (cpipe == NULL) 1443 /* other end of pipe has been closed */ 1444 return (EBADF); 1445 break; 1446 default: 1447 return (1); 1448 } 1449 kn->kn_hook = cpipe; 1450 1451 PIPE_LOCK(cpipe); 1452 SLIST_INSERT_HEAD(&cpipe->pipe_sel.si_note, kn, kn_selnext); 1453 PIPE_UNLOCK(cpipe); 1454 return (0); 1455 } 1456 1457 static void 1458 filt_pipedetach(struct knote *kn) 1459 { 1460 struct pipe *cpipe = (struct pipe *)kn->kn_hook; 1461 1462 PIPE_LOCK(cpipe); 1463 SLIST_REMOVE(&cpipe->pipe_sel.si_note, kn, knote, kn_selnext); 1464 PIPE_UNLOCK(cpipe); 1465 } 1466 1467 /*ARGSUSED*/ 1468 static int 1469 filt_piperead(struct knote *kn, long hint) 1470 { 1471 struct pipe *rpipe = kn->kn_fp->f_data; 1472 struct pipe *wpipe = rpipe->pipe_peer; 1473 1474 PIPE_LOCK(rpipe); 1475 kn->kn_data = rpipe->pipe_buffer.cnt; 1476 if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW)) 1477 kn->kn_data = rpipe->pipe_map.cnt; 1478 1479 if ((rpipe->pipe_state & PIPE_EOF) || 1480 (wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) { 1481 kn->kn_flags |= EV_EOF; 1482 PIPE_UNLOCK(rpipe); 1483 return (1); 1484 } 1485 PIPE_UNLOCK(rpipe); 1486 return (kn->kn_data > 0); 1487 } 1488 1489 /*ARGSUSED*/ 1490 static int 1491 filt_pipewrite(struct knote *kn, long hint) 1492 { 1493 struct pipe *rpipe = kn->kn_fp->f_data; 1494 struct pipe *wpipe = rpipe->pipe_peer; 1495 1496 PIPE_LOCK(rpipe); 1497 if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) { 1498 kn->kn_data = 0; 1499 kn->kn_flags |= EV_EOF; 1500 PIPE_UNLOCK(rpipe); 1501 return (1); 1502 } 1503 kn->kn_data = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; 1504 if (wpipe->pipe_state & PIPE_DIRECTW) 1505 kn->kn_data = 0; 1506 1507 PIPE_UNLOCK(rpipe); 1508 return (kn->kn_data >= PIPE_BUF); 1509 } 1510