bsd/miscfs/fifofs/fifo_vnops.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1990, 1993, 1995
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)fifo_vnops.c        8.4 (Berkeley) 8/10/94
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/proc.h>
  66 #include <sys/time.h>
  67 #include <sys/namei.h>
  68 #include <sys/vnode_internal.h>
  69 #include <sys/socket.h>
  70 #include <sys/socketvar.h>
  71 #include <sys/stat.h>
  72 #include <sys/systm.h>
  73 #include <sys/ioctl.h>
  74 #include <sys/file_internal.h>
  75 #include <sys/errno.h>
  76 #include <sys/malloc.h>
  77 #include <miscfs/fifofs/fifo.h>
  78 #include <vfs/vfs_support.h>
  79
  80 #define VOPFUNC int (*)(void *)
  81
  82 extern int      soo_ioctl(struct fileproc *fp, u_long cmd, caddr_t data, struct proc *p);
  83 extern int      soo_select(struct fileproc *fp, int which, void * wql, struct proc *p);
  84
  85 int (**fifo_vnodeop_p)(void *);
  86 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
  87         { &vnop_default_desc, (VOPFUNC)vn_default_error },
  88         { &vnop_lookup_desc, (VOPFUNC)fifo_lookup },            /* lookup */
  89         { &vnop_create_desc, (VOPFUNC)err_create },             /* create */
  90         { &vnop_mknod_desc, (VOPFUNC)err_mknod },               /* mknod */
  91         { &vnop_open_desc, (VOPFUNC)fifo_open },                        /* open */
  92         { &vnop_close_desc, (VOPFUNC)fifo_close },              /* close */
  93         { &vnop_access_desc, (VOPFUNC)fifo_access },            /* access */
  94         { &vnop_getattr_desc, (VOPFUNC)fifo_getattr },          /* getattr */
  95         { &vnop_setattr_desc, (VOPFUNC)fifo_setattr },          /* setattr */
  96         { &vnop_read_desc, (VOPFUNC)fifo_read },                        /* read */
  97         { &vnop_write_desc, (VOPFUNC)fifo_write },              /* write */
  98         { &vnop_ioctl_desc, (VOPFUNC)fifo_ioctl },              /* ioctl */
  99         { &vnop_select_desc, (VOPFUNC)fifo_select },            /* select */
 100         { &vnop_revoke_desc, (VOPFUNC)fifo_revoke },            /* revoke */
 101         { &vnop_mmap_desc, (VOPFUNC)err_mmap },                 /* mmap */
 102         { &vnop_fsync_desc, (VOPFUNC)fifo_fsync },              /* fsync */
 103         { &vnop_remove_desc, (VOPFUNC)err_remove },             /* remove */
 104         { &vnop_link_desc, (VOPFUNC)err_link },                 /* link */
 105         { &vnop_rename_desc, (VOPFUNC)err_rename },             /* rename */
 106         { &vnop_mkdir_desc, (VOPFUNC)err_mkdir },               /* mkdir */
 107         { &vnop_rmdir_desc, (VOPFUNC)err_rmdir },               /* rmdir */
 108         { &vnop_symlink_desc, (VOPFUNC)err_symlink },           /* symlink */
 109         { &vnop_readdir_desc, (VOPFUNC)err_readdir },           /* readdir */
 110         { &vnop_readlink_desc, (VOPFUNC)err_readlink },         /* readlink */
 111         { &vnop_inactive_desc, (VOPFUNC)fifo_inactive },                /* inactive */
 112         { &vnop_reclaim_desc, (VOPFUNC)fifo_reclaim },          /* reclaim */
 113         { &vnop_strategy_desc, (VOPFUNC)err_strategy },         /* strategy */
 114         { &vnop_pathconf_desc, (VOPFUNC)fifo_pathconf },                /* pathconf */
 115         { &vnop_advlock_desc, (VOPFUNC)fifo_advlock },          /* advlock */
 116         { &vnop_bwrite_desc, (VOPFUNC)fifo_bwrite },            /* bwrite */
 117         { &vnop_pagein_desc, (VOPFUNC)err_pagein },             /* Pagein */
 118         { &vnop_pageout_desc, (VOPFUNC)err_pageout },           /* Pageout */
 119         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile },         /* Copyfile */
 120         { &vnop_blktooff_desc, (VOPFUNC)err_blktooff },         /* blktooff */
 121         { &vnop_offtoblk_desc, (VOPFUNC)err_offtoblk },         /* offtoblk */
 122         { &vnop_blockmap_desc, (VOPFUNC)err_blockmap },                 /* blockmap */
 123         { (struct vnodeop_desc*)NULL, (int(*)())NULL }
 124 };
 125 struct vnodeopv_desc fifo_vnodeop_opv_desc =
 126         { &fifo_vnodeop_p, fifo_vnodeop_entries };
 127
 128 /*
 129  * Trivial lookup routine that always fails.
 130  */
 131 /* ARGSUSED */
 132 int
 133 fifo_lookup(ap)
 134         struct vnop_lookup_args /* {
 135                 struct vnode * a_dvp;
 136                 struct vnode ** a_vpp;
 137                 struct componentname * a_cnp;
 138                 vfs_context_t a_context;
 139         } */ *ap;
 140 {
 141
 142         *ap->a_vpp = NULL;
 143         return (ENOTDIR);
 144 }
 145
 146 /*
 147  * Open called to set up a new instance of a fifo or
 148  * to find an active instance of a fifo.
 149  */
 150 /* ARGSUSED */
 151 int
 152 fifo_open(ap)
 153         struct vnop_open_args /* {
 154                 struct vnode *a_vp;
 155                 int  a_mode;
 156                 vfs_context_t a_context;
 157         } */ *ap;
 158 {
 159         struct vnode *vp = ap->a_vp;
 160         struct fifoinfo *fip;
 161         struct socket *rso, *wso;
 162         int error;
 163
 164         vnode_lock(vp);
 165
 166 retry:
 167
 168         fip = vp->v_fifoinfo;
 169
 170         if (fip == (struct fifoinfo *)0)
 171                 panic("fifo_open with no fifoinfo");
 172
 173         if ((fip->fi_flags & FIFO_CREATED) == 0) {
 174                 if (fip->fi_flags & FIFO_INCREATE) {
 175                         fip->fi_flags |= FIFO_CREATEWAIT;
 176                         error = msleep(&fip->fi_flags, &vp->v_lock, PRIBIO | PCATCH, "fifocreatewait", 0);
 177                         if (error) {
 178                                 vnode_unlock(vp);
 179                                 return(error);
 180                         }
 181                         goto retry;
 182                 } else {
 183                         fip->fi_flags |= FIFO_INCREATE;
 184                         vnode_unlock(vp);
 185                         if ( (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) ) {
 186                                 goto bad1;
 187                         }
 188                         fip->fi_readsock = rso;
 189
 190                         if ( (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) ) {
 191                                 (void)soclose(rso);
 192                                 goto bad1;
 193                         }
 194                         fip->fi_writesock = wso;
 195
 196                         if ( (error = soconnect2(wso, rso)) ) {
 197                                 (void)soclose(wso);
 198                                 (void)soclose(rso);
 199                                 goto bad1;
 200                         }
 201                         fip->fi_readers = fip->fi_writers = 0;
 202
 203                 socket_lock(wso, 1);
 204                         wso->so_state |= SS_CANTRCVMORE;
 205                         wso->so_snd.sb_lowat = PIPE_BUF;
 206 #if 0
 207                         /* Because all the unp is protected by single mutex
 208                          * doing it in two step may actually cause problems
 209                          * as it opens up window between the drop and acquire
 210                          */
 211                 socket_unlock(wso, 1);
 212
 213                 socket_lock(rso, 1);
 214 #endif
 215                         rso->so_state |= SS_CANTSENDMORE;
 216                 socket_unlock(wso, 1);
 217
 218                         vnode_lock(vp);
 219                         fip->fi_flags |= FIFO_CREATED;
 220                         fip->fi_flags &= ~FIFO_INCREATE;
 221
 222                         if ((fip->fi_flags & FIFO_CREATEWAIT)) {
 223                                 fip->fi_flags &= ~FIFO_CREATEWAIT;
 224                                 wakeup(&fip->fi_flags);
 225                         }
 226                         /* vnode lock is held  to process further */
 227                 }
 228         }
 229
 230         /* vnode is locked at this point */
 231         /* fifo in created already */
 232         if (ap->a_mode & FREAD) {
 233                 fip->fi_readers++;
 234                 if (fip->fi_readers == 1) {
 235                         socket_lock(fip->fi_writesock, 1);
 236                         fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
 237                         socket_unlock(fip->fi_writesock, 1);
 238
 239                         if (fip->fi_writers > 0)
 240                                 wakeup((caddr_t)&fip->fi_writers);
 241                 }
 242         }
 243         if (ap->a_mode & FWRITE) {
 244                 fip->fi_writers++;
 245                 if (fip->fi_writers == 1) {
 246                         socket_lock(fip->fi_readsock, 1);
 247                         fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
 248                         socket_unlock(fip->fi_readsock, 1);
 249
 250                         if (fip->fi_readers > 0)
 251                                 wakeup((caddr_t)&fip->fi_readers);
 252                 }
 253         }
 254         if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
 255                 if (fip->fi_writers == 0) {
 256                         error = msleep((caddr_t)&fip->fi_readers, &vp->v_lock,
 257                                         PCATCH | PSOCK, "fifoor", 0);
 258                         if (error)
 259                                 goto bad;
 260                         if (fip->fi_readers == 1) {
 261                                 if (fip->fi_writers > 0)
 262                                         wakeup((caddr_t)&fip->fi_writers);
 263                         }
 264                 }
 265         }
 266         if (ap->a_mode & FWRITE) {
 267                 if (ap->a_mode & O_NONBLOCK) {
 268                         if (fip->fi_readers == 0) {
 269                                         error = ENXIO;
 270                                         goto bad;
 271                         }
 272                 } else {
 273                         if (fip->fi_readers == 0) {
 274                                 error = msleep((caddr_t)&fip->fi_writers,&vp->v_lock,
 275                                                 PCATCH | PSOCK, "fifoow", 0);
 276                                 if (error)
 277                                         goto bad;
 278                                 if (fip->fi_writers == 1) {
 279                                         if (fip->fi_readers > 0)
 280                                                 wakeup((caddr_t)&fip->fi_readers);
 281                                 }
 282                         }
 283                 }
 284         }
 285
 286         vnode_unlock(vp);
 287         return (0);
 288 bad:
 289         fifo_close_internal(vp, ap->a_mode, ap->a_context, 1);
 290
 291         vnode_unlock(vp);
 292         return (error);
 293 bad1:
 294         vnode_lock(vp);
 295
 296         fip->fi_flags &= ~FIFO_INCREATE;
 297
 298         if ((fip->fi_flags & FIFO_CREATEWAIT)) {
 299                 fip->fi_flags &= ~FIFO_CREATEWAIT;
 300                 wakeup(&fip->fi_flags);
 301         }
 302         vnode_unlock(vp);
 303
 304         return (error);
 305 }
 306
 307 /*
 308  * Vnode op for read
 309  */
 310 int
 311 fifo_read(ap)
 312         struct vnop_read_args /* {
 313                 struct vnode *a_vp;
 314                 struct uio *a_uio;
 315                 int  a_ioflag;
 316                 vfs_context_t a_context;
 317         } */ *ap;
 318 {
 319         struct uio *uio = ap->a_uio;
 320         struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
 321         int error, startresid;
 322         int rflags;
 323
 324 #if DIAGNOSTIC
 325         if (uio->uio_rw != UIO_READ)
 326                 panic("fifo_read mode");
 327 #endif
 328         if (uio_resid(uio) == 0)
 329                 return (0);
 330
 331         rflags = (ap->a_ioflag & IO_NDELAY) ? MSG_NBIO : 0;
 332
 333         // LP64todo - fix this!
 334         startresid = uio_resid(uio);
 335
 336         /* fifo conformance - if we have a reader open on the fifo but no
 337          * writers then we need to make sure we do not block.  We do that by
 338          * checking the receive buffer and if empty set error to EWOULDBLOCK.
 339          * If error is set to EWOULDBLOCK we skip the call into soreceive
 340          */
 341         error = 0;
 342         if (ap->a_vp->v_fifoinfo->fi_writers < 1) {
 343                 socket_lock(rso, 1);
 344                 error = (rso->so_rcv.sb_cc == 0) ? EWOULDBLOCK : 0;
 345                 socket_unlock(rso, 1);
 346         }
 347
 348         /* skip soreceive to avoid blocking when we have no writers */
 349         if (error != EWOULDBLOCK) {
 350                 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0,
 351                                                 (struct mbuf **)0, &rflags);
 352         }
 353         else {
 354                 /* clear EWOULDBLOCK and return EOF (zero) */
 355                 error = 0;
 356         }
 357         /*
 358          * Clear EOF indication after first such return.
 359          */
 360         if (uio_resid(uio) == startresid) {
 361                 socket_lock(rso, 1);
 362                 rso->so_state &= ~SS_CANTRCVMORE;
 363                 socket_unlock(rso, 1);
 364         }
 365         return (error);
 366 }
 367
 368 /*
 369  * Vnode op for write
 370  */
 371 int
 372 fifo_write(ap)
 373         struct vnop_write_args /* {
 374                 struct vnode *a_vp;
 375                 struct uio *a_uio;
 376                 int  a_ioflag;
 377                 vfs_context_t a_context;
 378         } */ *ap;
 379 {
 380         struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
 381         int error;
 382
 383 #if DIAGNOSTIC
 384         if (ap->a_uio->uio_rw != UIO_WRITE)
 385                 panic("fifo_write mode");
 386 #endif
 387         error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0,
 388                        (struct mbuf *)0, (ap->a_ioflag & IO_NDELAY) ? MSG_NBIO : 0);
 389
 390         return (error);
 391 }
 392
 393 /*
 394  * Device ioctl operation.
 395  */
 396 int
 397 fifo_ioctl(ap)
 398         struct vnop_ioctl_args /* {
 399                 struct vnode *a_vp;
 400                 int  a_command;
 401                 caddr_t  a_data;
 402                 int  a_fflag;
 403                 vfs_context_t a_context;
 404         } */ *ap;
 405 {
 406         struct proc *p = vfs_context_proc(ap->a_context);
 407         struct fileproc filetmp;
 408         struct fileglob filefg;
 409         int error;
 410
 411         if (ap->a_command == FIONBIO)
 412                 return (0);
 413         bzero(&filetmp, sizeof(struct fileproc));
 414         filetmp.f_fglob = &filefg;
 415         if (ap->a_fflag & FREAD) {
 416                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
 417                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, p);
 418                 if (error)
 419                         return (error);
 420         }
 421         if (ap->a_fflag & FWRITE) {
 422                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
 423                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, p);
 424                 if (error)
 425                         return (error);
 426         }
 427         return (0);
 428 }
 429
 430 int
 431 fifo_select(ap)
 432         struct vnop_select_args /* {
 433                 struct vnode *a_vp;
 434                 int  a_which;
 435                 int  a_fflags;
 436                 void * a_wql;
 437                 vfs_context_t a_context;
 438         } */ *ap;
 439 {
 440         struct proc *p = vfs_context_proc(ap->a_context);
 441         struct fileproc filetmp;
 442         struct fileglob filefg;
 443         int ready;
 444
 445         bzero(&filetmp, sizeof(struct fileproc));
 446         filetmp.f_fglob = &filefg;
 447         if (ap->a_which & FREAD) {
 448                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
 449                 ready = soo_select(&filetmp, ap->a_which, ap->a_wql, p);
 450                 if (ready)
 451                         return (ready);
 452         }
 453         if (ap->a_which & FWRITE) {
 454                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
 455                 ready = soo_select(&filetmp, ap->a_which, ap->a_wql, p);
 456                 if (ready)
 457                         return (ready);
 458         }
 459         return (0);
 460 }
 461
 462 int
 463 fifo_inactive(__unused struct vnop_inactive_args *ap)
 464 {
 465         return (0);
 466 }
 467
 468
 469 /*
 470  * Device close routine
 471  */
 472 int
 473 fifo_close(ap)
 474         struct vnop_close_args /* {
 475                 struct vnode *a_vp;
 476                 int  a_fflag;
 477                 vfs_context_t a_context;
 478         } */ *ap;
 479 {
 480         return fifo_close_internal(ap->a_vp, ap->a_fflag, ap->a_context, 0);
 481 }
 482
 483 int
 484 fifo_close_internal(vnode_t vp, int fflag, __unused vfs_context_t context, int locked)
 485 {
 486         register struct fifoinfo *fip = vp->v_fifoinfo;
 487         int error1, error2;
 488         struct socket *rso;
 489         struct socket *wso;
 490
 491         if (!locked)
 492                 vnode_lock(vp);
 493
 494         if ((fip->fi_flags & FIFO_CREATED) == 0) {
 495                 if (!locked)
 496                         vnode_unlock(vp);
 497                 return(0);
 498
 499         }
 500
 501         if (fflag & FREAD) {
 502                 fip->fi_readers--;
 503                 if (fip->fi_readers == 0){
 504                         socket_lock(fip->fi_writesock, 1);
 505                         socantsendmore(fip->fi_writesock);
 506                         socket_unlock(fip->fi_writesock, 1);
 507                 }
 508         }
 509
 510         if (fflag & FWRITE) {
 511                 fip->fi_writers--;
 512                 if (fip->fi_writers == 0) {
 513                         socket_lock(fip->fi_readsock, 1);
 514                         socantrcvmore(fip->fi_readsock);
 515                         socket_unlock(fip->fi_readsock, 1);
 516                 }
 517         }
 518 #if 0
 519         if (vnode_isinuse_locked(vp, 0, 1)) {
 520                 if (!locked)
 521                         vnode_unlock(vp);
 522                 return (0);
 523         }
 524 #endif
 525
 526         if (fip->fi_writers || fip->fi_readers) {
 527                 if (!locked)
 528                         vnode_unlock(vp);
 529                 return (0);
 530         }
 531
 532         wso = fip->fi_writesock;
 533         rso = fip->fi_readsock;
 534         fip->fi_readsock = 0;
 535         fip->fi_writesock = 0;
 536         fip->fi_flags &= ~FIFO_CREATED;
 537         if (!locked)
 538                 vnode_unlock(vp);
 539         error1 = soclose(rso);
 540         error2 = soclose(wso);
 541
 542         if (error1)
 543                 return (error1);
 544         return (error2);
 545 }
 546
 547
 548 /*
 549  * Print out internal contents of a fifo vnode.
 550  */
 551 void
 552 fifo_printinfo(vp)
 553         struct vnode *vp;
 554 {
 555         register struct fifoinfo *fip = vp->v_fifoinfo;
 556
 557         printf(", fifo with %d readers and %d writers",
 558                 fip->fi_readers, fip->fi_writers);
 559 }
 560
 561 /*
 562  * Return POSIX pathconf information applicable to fifo's.
 563  */
 564 int
 565 fifo_pathconf(ap)
 566         struct vnop_pathconf_args /* {
 567                 struct vnode *a_vp;
 568                 int a_name;
 569                 int *a_retval;
 570                 vfs_context_t a_context;
 571         } */ *ap;
 572 {
 573
 574         switch (ap->a_name) {
 575         case _PC_LINK_MAX:
 576                 *ap->a_retval = LINK_MAX;
 577                 return (0);
 578         case _PC_PIPE_BUF:
 579                 *ap->a_retval = PIPE_BUF;
 580                 return (0);
 581         case _PC_CHOWN_RESTRICTED:
 582                 *ap->a_retval = 1;
 583                 return (0);
 584         default:
 585                 return (EINVAL);
 586         }
 587         /* NOTREACHED */
 588 }
 589
 590 /*
 591  * Fifo failed operation
 592  */
 593 int
 594 fifo_ebadf(__unused void *dummy)
 595 {
 596
 597         return (EBADF);
 598 }
 599
 600 /*
 601  * Fifo advisory byte-level locks.
 602  */
 603 int
 604 fifo_advlock(__unused struct vnop_advlock_args *ap)
 605 {
 606
 607         return (ENOTSUP);
 608 }
 609