bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)dead_vnops.c        8.3 (Berkeley) 5/14/95
  56  */
  57
  58 #include <sys/param.h>
  59 #include <sys/systm.h>
  60 #include <sys/time.h>
  61 #include <sys/vnode.h>
  62 #include <sys/errno.h>
  63 #include <sys/namei.h>
  64 #include <sys/buf.h>
  65 #include <vfs/vfs_support.h>
  66
  67 /*
  68  * Prototypes for dead operations on vnodes.
  69  */
  70 int     dead_badop(),
  71         dead_ebadf();
  72 int     dead_lookup __P((struct vop_lookup_args *));
  73 #define dead_create ((int (*) __P((struct  vop_create_args *)))dead_badop)
  74 #define dead_mknod ((int (*) __P((struct  vop_mknod_args *)))dead_badop)
  75 int     dead_open __P((struct vop_open_args *));
  76 #define dead_close ((int (*) __P((struct  vop_close_args *)))nullop)
  77 #define dead_access ((int (*) __P((struct  vop_access_args *)))dead_ebadf)
  78 #define dead_getattr ((int (*) __P((struct  vop_getattr_args *)))dead_ebadf)
  79 #define dead_setattr ((int (*) __P((struct  vop_setattr_args *)))dead_ebadf)
  80 int     dead_read __P((struct vop_read_args *));
  81 int     dead_write __P((struct vop_write_args *));
  82 int     dead_ioctl __P((struct vop_ioctl_args *));
  83 int     dead_select __P((struct vop_select_args *));
  84 #define dead_mmap ((int (*) __P((struct  vop_mmap_args *)))dead_badop)
  85 #define dead_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
  86 #define dead_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
  87 #define dead_remove ((int (*) __P((struct  vop_remove_args *)))dead_badop)
  88 #define dead_link ((int (*) __P((struct  vop_link_args *)))dead_badop)
  89 #define dead_rename ((int (*) __P((struct  vop_rename_args *)))dead_badop)
  90 #define dead_mkdir ((int (*) __P((struct  vop_mkdir_args *)))dead_badop)
  91 #define dead_rmdir ((int (*) __P((struct  vop_rmdir_args *)))dead_badop)
  92 #define dead_symlink ((int (*) __P((struct  vop_symlink_args *)))dead_badop)
  93 #define dead_readdir ((int (*) __P((struct  vop_readdir_args *)))dead_ebadf)
  94 #define dead_readlink ((int (*) __P((struct  vop_readlink_args *)))dead_ebadf)
  95 #define dead_abortop ((int (*) __P((struct  vop_abortop_args *)))dead_badop)
  96 #define dead_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
  97 #define dead_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
  98 int     dead_lock __P((struct vop_lock_args *));
  99 #define dead_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
 100 int     dead_bmap __P((struct vop_bmap_args *));
 101 int     dead_strategy __P((struct vop_strategy_args *));
 102 int     dead_print __P((struct vop_print_args *));
 103 #define dead_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
 104 #define dead_pathconf ((int (*) __P((struct  vop_pathconf_args *)))dead_ebadf)
 105 #define dead_advlock ((int (*) __P((struct  vop_advlock_args *)))dead_ebadf)
 106 #define dead_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))dead_badop)
 107 #define dead_valloc ((int (*) __P((struct  vop_valloc_args *)))dead_badop)
 108 #define dead_vfree ((int (*) __P((struct  vop_vfree_args *)))dead_badop)
 109 #define dead_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
 110 #define dead_update ((int (*) __P((struct  vop_update_args *)))nullop)
 111 #define dead_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
 112 int     dead_pagein __P((struct vop_pagein_args *));
 113 int     dead_pageout __P((struct vop_pageout_args *));
 114 int dead_blktooff __P((struct vop_blktooff_args *));
 115 int dead_offtoblk __P((struct vop_offtoblk_args *));
 116 int dead_cmap __P((struct vop_cmap_args *));
 117
 118 #define VOPFUNC int (*)(void *)
 119 int (**dead_vnodeop_p)(void *);
 120 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 121         { &vop_default_desc, (VOPFUNC)vn_default_error },
 122         { &vop_lookup_desc, (VOPFUNC)dead_lookup },     /* lookup */
 123         { &vop_create_desc, (VOPFUNC)dead_create },     /* create */
 124         { &vop_mknod_desc, (VOPFUNC)dead_mknod },       /* mknod */
 125         { &vop_open_desc, (VOPFUNC)dead_open },         /* open */
 126         { &vop_close_desc, (VOPFUNC)dead_close },       /* close */
 127         { &vop_access_desc, (VOPFUNC)dead_access },     /* access */
 128         { &vop_getattr_desc, (VOPFUNC)dead_getattr },   /* getattr */
 129         { &vop_setattr_desc, (VOPFUNC)dead_setattr },   /* setattr */
 130         { &vop_read_desc, (VOPFUNC)dead_read },         /* read */
 131         { &vop_write_desc, (VOPFUNC)dead_write },       /* write */
 132         { &vop_ioctl_desc, (VOPFUNC)dead_ioctl },       /* ioctl */
 133         { &vop_select_desc, (VOPFUNC)dead_select },     /* select */
 134         { &vop_mmap_desc, (VOPFUNC)dead_mmap },         /* mmap */
 135         { &vop_fsync_desc, (VOPFUNC)dead_fsync },       /* fsync */
 136         { &vop_seek_desc, (VOPFUNC)dead_seek },         /* seek */
 137         { &vop_remove_desc, (VOPFUNC)dead_remove },     /* remove */
 138         { &vop_link_desc, (VOPFUNC)dead_link },         /* link */
 139         { &vop_rename_desc, (VOPFUNC)dead_rename },     /* rename */
 140         { &vop_mkdir_desc, (VOPFUNC)dead_mkdir },       /* mkdir */
 141         { &vop_rmdir_desc, (VOPFUNC)dead_rmdir },       /* rmdir */
 142         { &vop_symlink_desc, (VOPFUNC)dead_symlink },   /* symlink */
 143         { &vop_readdir_desc, (VOPFUNC)dead_readdir },   /* readdir */
 144         { &vop_readlink_desc, (VOPFUNC)dead_readlink }, /* readlink */
 145         { &vop_abortop_desc, (VOPFUNC)dead_abortop },   /* abortop */
 146         { &vop_inactive_desc, (VOPFUNC)dead_inactive }, /* inactive */
 147         { &vop_reclaim_desc, (VOPFUNC)dead_reclaim },   /* reclaim */
 148         { &vop_lock_desc, (VOPFUNC)dead_lock },         /* lock */
 149         { &vop_unlock_desc, (VOPFUNC)dead_unlock },     /* unlock */
 150         { &vop_bmap_desc, (VOPFUNC)dead_bmap },         /* bmap */
 151         { &vop_strategy_desc, (VOPFUNC)dead_strategy }, /* strategy */
 152         { &vop_print_desc, (VOPFUNC)dead_print },       /* print */
 153         { &vop_islocked_desc, (VOPFUNC)dead_islocked }, /* islocked */
 154         { &vop_pathconf_desc, (VOPFUNC)dead_pathconf }, /* pathconf */
 155         { &vop_advlock_desc, (VOPFUNC)dead_advlock },   /* advlock */
 156         { &vop_blkatoff_desc, (VOPFUNC)dead_blkatoff }, /* blkatoff */
 157         { &vop_valloc_desc, (VOPFUNC)dead_valloc },     /* valloc */
 158         { &vop_vfree_desc, (VOPFUNC)dead_vfree },       /* vfree */
 159         { &vop_truncate_desc, (VOPFUNC)dead_truncate }, /* truncate */
 160         { &vop_update_desc, (VOPFUNC)dead_update },     /* update */
 161         { &vop_bwrite_desc, (VOPFUNC)dead_bwrite },     /* bwrite */
 162         { &vop_pagein_desc, (VOPFUNC)err_pagein },      /* Pagein */
 163         { &vop_pageout_desc, (VOPFUNC)err_pageout },    /* Pageout */
 164         { &vop_copyfile_desc, (VOPFUNC)err_copyfile },  /* Copyfile */
 165         { &vop_blktooff_desc, (VOPFUNC)dead_blktooff }, /* blktooff */
 166         { &vop_offtoblk_desc, (VOPFUNC)dead_offtoblk }, /* offtoblk */
 167         { &vop_cmap_desc, (VOPFUNC)dead_cmap },         /* cmap */
 168         { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
 169 };
 170 struct vnodeopv_desc dead_vnodeop_opv_desc =
 171         { &dead_vnodeop_p, dead_vnodeop_entries };
 172
 173 /*
 174  * Trivial lookup routine that always fails.
 175  */
 176 /* ARGSUSED */
 177 int
 178 dead_lookup(ap)
 179         struct vop_lookup_args /* {
 180                 struct vnode * a_dvp;
 181                 struct vnode ** a_vpp;
 182                 struct componentname * a_cnp;
 183         } */ *ap;
 184 {
 185
 186         *ap->a_vpp = NULL;
 187         return (ENOTDIR);
 188 }
 189
 190 /*
 191  * Open always fails as if device did not exist.
 192  */
 193 /* ARGSUSED */
 194 int
 195 dead_open(ap)
 196         struct vop_open_args /* {
 197                 struct vnode *a_vp;
 198                 int  a_mode;
 199                 struct ucred *a_cred;
 200                 struct proc *a_p;
 201         } */ *ap;
 202 {
 203
 204         return (ENXIO);
 205 }
 206
 207 /*
 208  * Vnode op for read
 209  */
 210 /* ARGSUSED */
 211 int
 212 dead_read(ap)
 213         struct vop_read_args /* {
 214                 struct vnode *a_vp;
 215                 struct uio *a_uio;
 216                 int  a_ioflag;
 217                 struct ucred *a_cred;
 218         } */ *ap;
 219 {
 220
 221         if (chkvnlock(ap->a_vp))
 222                 panic("dead_read: lock");
 223         /*
 224          * Return EOF for character devices, EIO for others
 225          */
 226         if (ap->a_vp->v_type != VCHR)
 227                 return (EIO);
 228         return (0);
 229 }
 230
 231 /*
 232  * Vnode op for write
 233  */
 234 /* ARGSUSED */
 235 int
 236 dead_write(ap)
 237         struct vop_write_args /* {
 238                 struct vnode *a_vp;
 239                 struct uio *a_uio;
 240                 int  a_ioflag;
 241                 struct ucred *a_cred;
 242         } */ *ap;
 243 {
 244
 245         if (chkvnlock(ap->a_vp))
 246                 panic("dead_write: lock");
 247         return (EIO);
 248 }
 249
 250 /*
 251  * Device ioctl operation.
 252  */
 253 /* ARGSUSED */
 254 int
 255 dead_ioctl(ap)
 256         struct vop_ioctl_args /* {
 257                 struct vnode *a_vp;
 258                 u_long a_command;
 259                 caddr_t  a_data;
 260                 int  a_fflag;
 261                 struct ucred *a_cred;
 262                 struct proc *a_p;
 263         } */ *ap;
 264 {
 265
 266         if (!chkvnlock(ap->a_vp))
 267                 return (EBADF);
 268         return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
 269 }
 270
 271 /* ARGSUSED */
 272 int
 273 dead_select(ap)
 274         struct vop_select_args /* {
 275                 struct vnode *a_vp;
 276                 int  a_which;
 277                 int  a_fflags;
 278                 struct ucred *a_cred;
 279                 struct proc *a_p;
 280         } */ *ap;
 281 {
 282
 283         /*
 284          * Let the user find out that the descriptor is gone.
 285          */
 286         return (1);
 287 }
 288
 289 /*
 290  * Just call the device strategy routine
 291  */
 292 int
 293 dead_strategy(ap)
 294         struct vop_strategy_args /* {
 295                 struct buf *a_bp;
 296         } */ *ap;
 297 {
 298
 299         if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
 300                 ap->a_bp->b_flags |= B_ERROR;
 301                 biodone(ap->a_bp);
 302                 return (EIO);
 303         }
 304         return (VOP_STRATEGY(ap->a_bp));
 305 }
 306
 307 /*
 308  * Wait until the vnode has finished changing state.
 309  */
 310 int
 311 dead_lock(ap)
 312         struct vop_lock_args /* {
 313                 struct vnode *a_vp;
 314         } */ *ap;
 315 {
 316
 317         struct vnode *vp = ap->a_vp;
 318
 319         /*
 320          * Since we are not using the lock manager, we must clear
 321          * the interlock here.
 322          */
 323         if (ap->a_flags & LK_INTERLOCK) {
 324                 simple_unlock(&vp->v_interlock);
 325                 ap->a_flags &= ~LK_INTERLOCK;
 326         }
 327         if (!chkvnlock(ap->a_vp))
 328                 return (0);
 329         return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
 330 }
 331
 332 /*
 333  * Wait until the vnode has finished changing state.
 334  */
 335 int
 336 dead_bmap(ap)
 337         struct vop_bmap_args /* {
 338                 struct vnode *a_vp;
 339                 daddr_t  a_bn;
 340                 struct vnode **a_vpp;
 341                 daddr_t *a_bnp;
 342                 int *a_runp;
 343         } */ *ap;
 344 {
 345
 346         if (!chkvnlock(ap->a_vp))
 347                 return (EIO);
 348         return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
 349 }
 350
 351 /*
 352  * Wait until the vnode has finished changing state.
 353  */
 354 int
 355 dead_cmap(ap)
 356         struct vop_cmap_args /* {
 357                 struct vnode *a_vp;
 358                 off_t a_foffset;
 359                 size_t a_size;
 360                 daddr_t *a_bpn;
 361                 size_t *a_run;
 362                 void *a_poff;
 363         } */ *ap;
 364 {
 365
 366         if (!chkvnlock(ap->a_vp))
 367                 return (EIO);
 368         return (VOP_CMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn, ap->a_run, ap->a_poff));
 369 }
 370
 371 /*
 372  * Print out the contents of a dead vnode.
 373  */
 374 /* ARGSUSED */
 375 int
 376 dead_print(ap)
 377         struct vop_print_args /* {
 378                 struct vnode *a_vp;
 379         } */ *ap;
 380 {
 381
 382         printf("tag VT_NON, dead vnode\n");
 383 }
 384
 385 /*
 386  * Empty vnode failed operation
 387  */
 388 int
 389 dead_ebadf()
 390 {
 391
 392         return (EBADF);
 393 }
 394
 395 /*
 396  * Empty vnode bad operation
 397  */
 398 int
 399 dead_badop()
 400 {
 401
 402         panic("dead_badop called");
 403         /* NOTREACHED */
 404 }
 405
 406 /*
 407  * Empty vnode null operation
 408  */
 409 int
 410 dead_nullop()
 411 {
 412
 413         return (0);
 414 }
 415
 416 /*
 417  * We have to wait during times when the vnode is
 418  * in a state of change.
 419  */
 420 int
 421 chkvnlock(vp)
 422         register struct vnode *vp;
 423 {
 424         int locked = 0;
 425
 426         while (vp->v_flag & VXLOCK) {
 427                 vp->v_flag |= VXWANT;
 428                 sleep((caddr_t)vp, PINOD);
 429                 locked = 1;
 430         }
 431         return (locked);
 432 }
 433
 434
 435 /* Blktooff */
 436 int
 437 dead_blktooff(ap)
 438         struct vop_blktooff_args /* {
 439                 struct vnode *a_vp;
 440                 daddr_t a_lblkno;
 441                 off_t *a_offset;
 442         } */ *ap;
 443 {
 444     if (!chkvnlock(ap->a_vp))
 445                 return (EIO);
 446
 447         *ap->a_offset = (off_t)-1;      /* failure */
 448         return (0);
 449 }
 450 /* Blktooff */
 451 int
 452 dead_offtoblk(ap)
 453 struct vop_offtoblk_args /* {
 454         struct vnode *a_vp;
 455         off_t a_offset;
 456         daddr_t *a_lblkno;
 457         } */ *ap;
 458 {
 459     if (!chkvnlock(ap->a_vp))
 460                 return (EIO);
 461
 462         *ap->a_lblkno = (daddr_t)-1;    /* failure */
 463         return (0);
 464 }