1 /* 2 * Copyright (c) 1990, 1993, 1995 3 * The Regents of the University of California. 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, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 34 * $FreeBSD$ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/event.h> 39 #include <sys/filio.h> 40 #include <sys/fcntl.h> 41 #include <sys/file.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/malloc.h> 46 #include <sys/poll.h> 47 #include <sys/proc.h> /* XXXKSE */ 48 #include <sys/signalvar.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/sx.h> 52 #include <sys/systm.h> 53 #include <sys/un.h> 54 #include <sys/unistd.h> 55 #include <sys/vnode.h> 56 #include <fs/fifofs/fifo.h> 57 58 /* 59 * This structure is associated with the FIFO vnode and stores 60 * the state associated with the FIFO. 61 */ 62 struct fifoinfo { 63 struct socket *fi_readsock; 64 struct socket *fi_writesock; 65 long fi_readers; 66 long fi_writers; 67 }; 68 69 static int fifo_print(struct vop_print_args *); 70 static int fifo_lookup(struct vop_lookup_args *); 71 static int fifo_open(struct vop_open_args *); 72 static int fifo_close(struct vop_close_args *); 73 static int fifo_inactive(struct vop_inactive_args *); 74 static int fifo_read(struct vop_read_args *); 75 static int fifo_write(struct vop_write_args *); 76 static int fifo_ioctl(struct vop_ioctl_args *); 77 static int fifo_poll(struct vop_poll_args *); 78 static int fifo_kqfilter(struct vop_kqfilter_args *); 79 static int fifo_pathconf(struct vop_pathconf_args *); 80 static int fifo_advlock(struct vop_advlock_args *); 81 82 static void filt_fifordetach(struct knote *kn); 83 static int filt_fiforead(struct knote *kn, long hint); 84 static void filt_fifowdetach(struct knote *kn); 85 static int filt_fifowrite(struct knote *kn, long hint); 86 87 static struct filterops fiforead_filtops = 88 { 1, NULL, filt_fifordetach, filt_fiforead }; 89 static struct filterops fifowrite_filtops = 90 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 91 92 vop_t **fifo_vnodeop_p; 93 static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 94 { &vop_default_desc, (vop_t *) vop_defaultop }, 95 { &vop_access_desc, (vop_t *) vop_ebadf }, 96 { &vop_advlock_desc, (vop_t *) fifo_advlock }, 97 { &vop_close_desc, (vop_t *) fifo_close }, 98 { &vop_create_desc, (vop_t *) vop_panic }, 99 { &vop_getattr_desc, (vop_t *) vop_ebadf }, 100 { &vop_getwritemount_desc, (vop_t *) vop_stdgetwritemount }, 101 { &vop_inactive_desc, (vop_t *) fifo_inactive }, 102 { &vop_ioctl_desc, (vop_t *) fifo_ioctl }, 103 { &vop_kqfilter_desc, (vop_t *) fifo_kqfilter }, 104 { &vop_lease_desc, (vop_t *) vop_null }, 105 { &vop_link_desc, (vop_t *) vop_panic }, 106 { &vop_lookup_desc, (vop_t *) fifo_lookup }, 107 { &vop_mkdir_desc, (vop_t *) vop_panic }, 108 { &vop_mknod_desc, (vop_t *) vop_panic }, 109 { &vop_open_desc, (vop_t *) fifo_open }, 110 { &vop_pathconf_desc, (vop_t *) fifo_pathconf }, 111 { &vop_poll_desc, (vop_t *) fifo_poll }, 112 { &vop_print_desc, (vop_t *) fifo_print }, 113 { &vop_read_desc, (vop_t *) fifo_read }, 114 { &vop_readdir_desc, (vop_t *) vop_panic }, 115 { &vop_readlink_desc, (vop_t *) vop_panic }, 116 { &vop_reallocblks_desc, (vop_t *) vop_panic }, 117 { &vop_reclaim_desc, (vop_t *) vop_null }, 118 { &vop_remove_desc, (vop_t *) vop_panic }, 119 { &vop_rename_desc, (vop_t *) vop_panic }, 120 { &vop_rmdir_desc, (vop_t *) vop_panic }, 121 { &vop_setattr_desc, (vop_t *) vop_ebadf }, 122 { &vop_symlink_desc, (vop_t *) vop_panic }, 123 { &vop_write_desc, (vop_t *) fifo_write }, 124 { NULL, NULL } 125 }; 126 static struct vnodeopv_desc fifo_vnodeop_opv_desc = 127 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 128 129 VNODEOP_SET(fifo_vnodeop_opv_desc); 130 131 int 132 fifo_vnoperate(ap) 133 struct vop_generic_args /* { 134 struct vnodeop_desc *a_desc; 135 <other random data follows, presumably> 136 } */ *ap; 137 { 138 return (VOCALL(fifo_vnodeop_p, ap->a_desc->vdesc_offset, ap)); 139 } 140 141 /* 142 * Trivial lookup routine that always fails. 143 */ 144 /* ARGSUSED */ 145 static int 146 fifo_lookup(ap) 147 struct vop_lookup_args /* { 148 struct vnode * a_dvp; 149 struct vnode ** a_vpp; 150 struct componentname * a_cnp; 151 } */ *ap; 152 { 153 154 *ap->a_vpp = NULL; 155 return (ENOTDIR); 156 } 157 158 /* 159 * Open called to set up a new instance of a fifo or 160 * to find an active instance of a fifo. 161 */ 162 /* ARGSUSED */ 163 static int 164 fifo_open(ap) 165 struct vop_open_args /* { 166 struct vnode *a_vp; 167 int a_mode; 168 struct ucred *a_cred; 169 struct thread *a_td; 170 } */ *ap; 171 { 172 struct vnode *vp = ap->a_vp; 173 struct fifoinfo *fip; 174 struct thread *td = ap->a_td; 175 struct socket *rso, *wso; 176 int error; 177 178 if ((fip = vp->v_fifoinfo) == NULL) { 179 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 180 vp->v_fifoinfo = fip; 181 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, 182 ap->a_td->td_ucred, ap->a_td); 183 if (error) { 184 free(fip, M_VNODE); 185 vp->v_fifoinfo = NULL; 186 return (error); 187 } 188 fip->fi_readsock = rso; 189 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, 190 ap->a_td->td_ucred, ap->a_td); 191 if (error) { 192 (void)soclose(rso); 193 free(fip, M_VNODE); 194 vp->v_fifoinfo = NULL; 195 return (error); 196 } 197 fip->fi_writesock = wso; 198 error = unp_connect2(wso, rso); 199 if (error) { 200 (void)soclose(wso); 201 (void)soclose(rso); 202 free(fip, M_VNODE); 203 vp->v_fifoinfo = NULL; 204 return (error); 205 } 206 fip->fi_readers = fip->fi_writers = 0; 207 wso->so_snd.sb_lowat = PIPE_BUF; 208 rso->so_state |= SS_CANTRCVMORE; 209 } 210 211 /* 212 * General access to fi_readers and fi_writers is protected using 213 * the vnode lock. 214 * 215 * Protect the increment of fi_readers and fi_writers and the 216 * associated calls to wakeup() with the vnode interlock in 217 * addition to the vnode lock. This allows the vnode lock to 218 * be dropped for the msleep() calls below, and using the vnode 219 * interlock as the msleep() mutex prevents the wakeup from 220 * being missed. 221 */ 222 VI_LOCK(vp); 223 if (ap->a_mode & FREAD) { 224 fip->fi_readers++; 225 if (fip->fi_readers == 1) { 226 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 227 if (fip->fi_writers > 0) { 228 wakeup(&fip->fi_writers); 229 VI_UNLOCK(vp); 230 sowwakeup(fip->fi_writesock); 231 VI_LOCK(vp); 232 } 233 } 234 } 235 if (ap->a_mode & FWRITE) { 236 fip->fi_writers++; 237 if (fip->fi_writers == 1) { 238 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 239 if (fip->fi_readers > 0) { 240 wakeup(&fip->fi_readers); 241 VI_UNLOCK(vp); 242 sorwakeup(fip->fi_writesock); 243 VI_LOCK(vp); 244 } 245 } 246 } 247 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) { 248 if (fip->fi_writers == 0) { 249 VOP_UNLOCK(vp, 0, td); 250 error = msleep(&fip->fi_readers, VI_MTX(vp), 251 PCATCH | PSOCK, "fifoor", 0); 252 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 253 if (error) { 254 fip->fi_readers--; 255 if (fip->fi_readers == 0) 256 socantsendmore(fip->fi_writesock); 257 return (error); 258 } 259 VI_LOCK(vp); 260 /* 261 * We must have got woken up because we had a writer. 262 * That (and not still having one) is the condition 263 * that we must wait for. 264 */ 265 } 266 } 267 if (ap->a_mode & FWRITE) { 268 if (ap->a_mode & O_NONBLOCK) { 269 if (fip->fi_readers == 0) { 270 VI_UNLOCK(vp); 271 fip->fi_writers--; 272 if (fip->fi_writers == 0) 273 socantrcvmore(fip->fi_readsock); 274 return (ENXIO); 275 } 276 } else { 277 if (fip->fi_readers == 0) { 278 VOP_UNLOCK(vp, 0, td); 279 error = msleep(&fip->fi_writers, VI_MTX(vp), 280 PCATCH | PSOCK, "fifoow", 0); 281 vn_lock(vp, 282 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); 283 if (error) { 284 fip->fi_writers--; 285 if (fip->fi_writers == 0) 286 socantrcvmore(fip->fi_readsock); 287 return (error); 288 } 289 /* 290 * We must have got woken up because we had 291 * a reader. That (and not still having one) 292 * is the condition that we must wait for. 293 */ 294 return (0); 295 } 296 } 297 } 298 VI_UNLOCK(vp); 299 return (0); 300 } 301 302 /* 303 * Vnode op for read 304 */ 305 /* ARGSUSED */ 306 static int 307 fifo_read(ap) 308 struct vop_read_args /* { 309 struct vnode *a_vp; 310 struct uio *a_uio; 311 int a_ioflag; 312 struct ucred *a_cred; 313 } */ *ap; 314 { 315 struct uio *uio = ap->a_uio; 316 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 317 struct thread *td = uio->uio_td; 318 int error; 319 320 #ifdef DIAGNOSTIC 321 if (uio->uio_rw != UIO_READ) 322 panic("fifo_read mode"); 323 #endif 324 if (uio->uio_resid == 0) 325 return (0); 326 if (ap->a_ioflag & IO_NDELAY) 327 rso->so_state |= SS_NBIO; 328 VOP_UNLOCK(ap->a_vp, 0, td); 329 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0, 330 (struct mbuf **)0, (int *)0); 331 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 332 if (ap->a_ioflag & IO_NDELAY) 333 rso->so_state &= ~SS_NBIO; 334 return (error); 335 } 336 337 /* 338 * Vnode op for write 339 */ 340 /* ARGSUSED */ 341 static int 342 fifo_write(ap) 343 struct vop_write_args /* { 344 struct vnode *a_vp; 345 struct uio *a_uio; 346 int a_ioflag; 347 struct ucred *a_cred; 348 } */ *ap; 349 { 350 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 351 struct thread *td = ap->a_uio->uio_td; 352 int error; 353 354 #ifdef DIAGNOSTIC 355 if (ap->a_uio->uio_rw != UIO_WRITE) 356 panic("fifo_write mode"); 357 #endif 358 if (ap->a_ioflag & IO_NDELAY) 359 wso->so_state |= SS_NBIO; 360 VOP_UNLOCK(ap->a_vp, 0, td); 361 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0, 362 (struct mbuf *)0, 0, td); 363 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 364 if (ap->a_ioflag & IO_NDELAY) 365 wso->so_state &= ~SS_NBIO; 366 return (error); 367 } 368 369 /* 370 * Device ioctl operation. 371 */ 372 /* ARGSUSED */ 373 static int 374 fifo_ioctl(ap) 375 struct vop_ioctl_args /* { 376 struct vnode *a_vp; 377 u_long a_command; 378 caddr_t a_data; 379 int a_fflag; 380 struct ucred *a_cred; 381 struct thread *a_td; 382 } */ *ap; 383 { 384 struct file filetmp; /* Local, so need not be locked. */ 385 int error; 386 387 if (ap->a_command == FIONBIO) 388 return (0); 389 if (ap->a_fflag & FREAD) { 390 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 391 filetmp.f_cred = ap->a_cred; 392 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 393 ap->a_td->td_ucred, ap->a_td); 394 if (error) 395 return (error); 396 } 397 if (ap->a_fflag & FWRITE) { 398 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 399 filetmp.f_cred = ap->a_cred; 400 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 401 ap->a_td->td_ucred, ap->a_td); 402 if (error) 403 return (error); 404 } 405 return (0); 406 } 407 408 /* ARGSUSED */ 409 static int 410 fifo_kqfilter(ap) 411 struct vop_kqfilter_args /* { 412 struct vnode *a_vp; 413 struct knote *a_kn; 414 } */ *ap; 415 { 416 struct fifoinfo *fi = ap->a_vp->v_fifoinfo; 417 struct socket *so; 418 struct sockbuf *sb; 419 420 switch (ap->a_kn->kn_filter) { 421 case EVFILT_READ: 422 ap->a_kn->kn_fop = &fiforead_filtops; 423 so = fi->fi_readsock; 424 sb = &so->so_rcv; 425 break; 426 case EVFILT_WRITE: 427 ap->a_kn->kn_fop = &fifowrite_filtops; 428 so = fi->fi_writesock; 429 sb = &so->so_snd; 430 break; 431 default: 432 return (1); 433 } 434 435 ap->a_kn->kn_hook = (caddr_t)so; 436 437 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext); 438 sb->sb_flags |= SB_KNOTE; 439 440 return (0); 441 } 442 443 static void 444 filt_fifordetach(struct knote *kn) 445 { 446 struct socket *so = (struct socket *)kn->kn_hook; 447 448 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext); 449 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note)) 450 so->so_rcv.sb_flags &= ~SB_KNOTE; 451 } 452 453 static int 454 filt_fiforead(struct knote *kn, long hint) 455 { 456 struct socket *so = (struct socket *)kn->kn_hook; 457 458 kn->kn_data = so->so_rcv.sb_cc; 459 if (so->so_state & SS_CANTRCVMORE) { 460 kn->kn_flags |= EV_EOF; 461 return (1); 462 } 463 kn->kn_flags &= ~EV_EOF; 464 return (kn->kn_data > 0); 465 } 466 467 static void 468 filt_fifowdetach(struct knote *kn) 469 { 470 struct socket *so = (struct socket *)kn->kn_hook; 471 472 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext); 473 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note)) 474 so->so_snd.sb_flags &= ~SB_KNOTE; 475 } 476 477 static int 478 filt_fifowrite(struct knote *kn, long hint) 479 { 480 struct socket *so = (struct socket *)kn->kn_hook; 481 482 kn->kn_data = sbspace(&so->so_snd); 483 if (so->so_state & SS_CANTSENDMORE) { 484 kn->kn_flags |= EV_EOF; 485 return (1); 486 } 487 kn->kn_flags &= ~EV_EOF; 488 return (kn->kn_data >= so->so_snd.sb_lowat); 489 } 490 491 /* ARGSUSED */ 492 static int 493 fifo_poll(ap) 494 struct vop_poll_args /* { 495 struct vnode *a_vp; 496 int a_events; 497 struct ucred *a_cred; 498 struct thread *a_td; 499 } */ *ap; 500 { 501 struct file filetmp; 502 int events, revents = 0; 503 504 events = ap->a_events & 505 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 506 if (events) { 507 /* 508 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 509 * not, then convert the first two to the last one. This 510 * tells the socket poll function to ignore EOF so that we 511 * block if there is no writer (and no data). Callers can 512 * set POLLINIGNEOF to get non-blocking behavior. 513 */ 514 if (events & (POLLIN | POLLRDNORM) && 515 !(events & POLLINIGNEOF)) { 516 events &= ~(POLLIN | POLLRDNORM); 517 events |= POLLINIGNEOF; 518 } 519 520 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 521 filetmp.f_cred = ap->a_cred; 522 if (filetmp.f_data) 523 revents |= soo_poll(&filetmp, events, 524 ap->a_td->td_ucred, ap->a_td); 525 526 /* Reverse the above conversion. */ 527 if ((revents & POLLINIGNEOF) && 528 !(ap->a_events & POLLINIGNEOF)) { 529 revents |= (ap->a_events & (POLLIN | POLLRDNORM)); 530 revents &= ~POLLINIGNEOF; 531 } 532 } 533 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND); 534 if (events) { 535 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 536 filetmp.f_cred = ap->a_cred; 537 if (filetmp.f_data) { 538 revents |= soo_poll(&filetmp, events, 539 ap->a_td->td_ucred, ap->a_td); 540 } 541 } 542 return (revents); 543 } 544 545 /* 546 * Device close routine 547 */ 548 /* ARGSUSED */ 549 static int 550 fifo_close(ap) 551 struct vop_close_args /* { 552 struct vnode *a_vp; 553 int a_fflag; 554 struct ucred *a_cred; 555 struct thread *a_td; 556 } */ *ap; 557 { 558 struct vnode *vp = ap->a_vp; 559 struct thread *td = ap->a_td; 560 struct fifoinfo *fip = vp->v_fifoinfo; 561 562 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 563 564 if (ap->a_fflag & FREAD) { 565 fip->fi_readers--; 566 if (fip->fi_readers == 0) 567 socantsendmore(fip->fi_writesock); 568 } 569 if (ap->a_fflag & FWRITE) { 570 fip->fi_writers--; 571 if (fip->fi_writers == 0) 572 socantrcvmore(fip->fi_readsock); 573 } 574 VOP_UNLOCK(vp, 0, td); 575 return (0); 576 } 577 578 static int 579 fifo_inactive(ap) 580 struct vop_inactive_args /* { 581 struct vnode *a_vp; 582 struct thread *a_td; 583 } */ *ap; 584 { 585 struct vnode *vp = ap->a_vp; 586 struct fifoinfo *fip = vp->v_fifoinfo; 587 588 VI_LOCK(vp); 589 if (fip != NULL && vp->v_usecount == 0) { 590 vp->v_fifoinfo = NULL; 591 VI_UNLOCK(vp); 592 (void)soclose(fip->fi_readsock); 593 (void)soclose(fip->fi_writesock); 594 FREE(fip, M_VNODE); 595 } 596 VOP_UNLOCK(vp, 0, ap->a_td); 597 return (0); 598 } 599 600 601 /* 602 * Print out internal contents of a fifo vnode. 603 */ 604 int 605 fifo_printinfo(vp) 606 struct vnode *vp; 607 { 608 register struct fifoinfo *fip = vp->v_fifoinfo; 609 610 printf(", fifo with %ld readers and %ld writers", 611 fip->fi_readers, fip->fi_writers); 612 return (0); 613 } 614 615 /* 616 * Print out the contents of a fifo vnode. 617 */ 618 static int 619 fifo_print(ap) 620 struct vop_print_args /* { 621 struct vnode *a_vp; 622 } */ *ap; 623 { 624 fifo_printinfo(ap->a_vp); 625 printf("\n"); 626 return (0); 627 } 628 629 /* 630 * Return POSIX pathconf information applicable to fifo's. 631 */ 632 static int 633 fifo_pathconf(ap) 634 struct vop_pathconf_args /* { 635 struct vnode *a_vp; 636 int a_name; 637 int *a_retval; 638 } */ *ap; 639 { 640 641 switch (ap->a_name) { 642 case _PC_LINK_MAX: 643 *ap->a_retval = LINK_MAX; 644 return (0); 645 case _PC_PIPE_BUF: 646 *ap->a_retval = PIPE_BUF; 647 return (0); 648 case _PC_CHOWN_RESTRICTED: 649 *ap->a_retval = 1; 650 return (0); 651 default: 652 return (EINVAL); 653 } 654 /* NOTREACHED */ 655 } 656 657 /* 658 * Fifo advisory byte-level locks. 659 */ 660 /* ARGSUSED */ 661 static int 662 fifo_advlock(ap) 663 struct vop_advlock_args /* { 664 struct vnode *a_vp; 665 caddr_t a_id; 666 int a_op; 667 struct flock *a_fl; 668 int a_flags; 669 } */ *ap; 670 { 671 672 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 673 } 674