bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1989, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)dead_vnops.c        8.3 (Berkeley) 5/14/95
  64  */
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/time.h>
  69 #include <sys/vnode_internal.h>
  70 #include <sys/errno.h>
  71 #include <sys/namei.h>
  72 #include <sys/buf.h>
  73 #include <vfs/vfs_support.h>
  74
  75 /*
  76  * Prototypes for dead operations on vnodes.
  77  */
  78 int     dead_badop(void *);
  79 int     dead_ebadf(void *);
  80 int     dead_lookup(struct vnop_lookup_args *);
  81 #define dead_create (int (*)(struct  vnop_create_args *))dead_badop
  82 #define dead_mknod (int (*)(struct  vnop_mknod_args *))dead_badop
  83 int     dead_open(struct vnop_open_args *);
  84 #define dead_close (int (*)(struct  vnop_close_args *))nullop
  85 #define dead_access (int (*)(struct  vnop_access_args *))dead_ebadf
  86 #define dead_getattr (int (*)(struct  vnop_getattr_args *))dead_ebadf
  87 #define dead_setattr (int (*)(struct  vnop_setattr_args *))dead_ebadf
  88 int     dead_read(struct vnop_read_args *);
  89 int     dead_write(struct vnop_write_args *);
  90 int     dead_ioctl(struct vnop_ioctl_args *);
  91 int     dead_select(struct vnop_select_args *);
  92 #define dead_mmap (int (*)(struct  vnop_mmap_args *))dead_badop
  93 #define dead_fsync (int (*)(struct  vnop_fsync_args *))nullop
  94 #define dead_remove (int (*)(struct  vnop_remove_args ))dead_badop
  95 #define dead_link (int (*)(struct  vnop_link_args *))dead_badop
  96 #define dead_rename (int (*)(struct  vnop_rename_args *))dead_badop
  97 #define dead_mkdir (int (*)(struct  vnop_mkdir_args *))dead_badop
  98 #define dead_rmdir (int (*)(struct  vnop_rmdir_args *))dead_badop
  99 #define dead_symlink (int (*)(struct  vnop_symlink_args *))dead_badop
 100 #define dead_readdir (int (*)(struct  vnop_readdir_args *))dead_ebadf
 101 #define dead_readlink (int (*)(struct  vnop_readlink_args *))dead_ebadf
 102 #define dead_inactive (int (*)(struct  vnop_inactive_args *))nullop
 103 #define dead_reclaim (int (*)(struct  vnop_reclaim_args *))nullop
 104 int     dead_strategy(struct vnop_strategy_args *);
 105 #define dead_pathconf (int (*)(struct  vnop_pathconf_args *))dead_ebadf
 106 #define dead_advlock (int (*)(struct  vnop_advlock_args *))dead_ebadf
 107 #define dead_bwrite (int (*)(struct  vnop_bwrite_args *))nullop
 108 int     dead_pagein(struct vnop_pagein_args *);
 109 int     dead_pageout(struct vnop_pageout_args *);
 110 int dead_blktooff(struct vnop_blktooff_args *);
 111 int dead_offtoblk(struct vnop_offtoblk_args *);
 112 int dead_blockmap(struct vnop_blockmap_args *);
 113
 114 #define VOPFUNC int (*)(void *)
 115 int (**dead_vnodeop_p)(void *);
 116 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 117         { &vnop_default_desc, (VOPFUNC)vn_default_error },
 118         { &vnop_lookup_desc, (VOPFUNC)dead_lookup },    /* lookup */
 119         { &vnop_create_desc, (VOPFUNC)dead_create },    /* create */
 120         { &vnop_open_desc, (VOPFUNC)dead_open },                /* open */
 121         { &vnop_mknod_desc, (VOPFUNC)dead_mknod },              /* mknod */
 122         { &vnop_close_desc, (VOPFUNC)dead_close },      /* close */
 123         { &vnop_access_desc, (VOPFUNC)dead_access },    /* access */
 124         { &vnop_getattr_desc, (VOPFUNC)dead_getattr },  /* getattr */
 125         { &vnop_setattr_desc, (VOPFUNC)dead_setattr },  /* setattr */
 126         { &vnop_read_desc, (VOPFUNC)dead_read },                /* read */
 127         { &vnop_write_desc, (VOPFUNC)dead_write },      /* write */
 128         { &vnop_ioctl_desc, (VOPFUNC)dead_ioctl },      /* ioctl */
 129         { &vnop_select_desc, (VOPFUNC)dead_select },    /* select */
 130         { &vnop_mmap_desc, (VOPFUNC)dead_mmap },                /* mmap */
 131         { &vnop_fsync_desc, (VOPFUNC)dead_fsync },      /* fsync */
 132         { &vnop_remove_desc, (VOPFUNC)dead_remove },    /* remove */
 133         { &vnop_link_desc, (VOPFUNC)dead_link },                /* link */
 134         { &vnop_rename_desc, (VOPFUNC)dead_rename },    /* rename */
 135         { &vnop_mkdir_desc, (VOPFUNC)dead_mkdir },      /* mkdir */
 136         { &vnop_rmdir_desc, (VOPFUNC)dead_rmdir },      /* rmdir */
 137         { &vnop_symlink_desc, (VOPFUNC)dead_symlink },  /* symlink */
 138         { &vnop_readdir_desc, (VOPFUNC)dead_readdir },  /* readdir */
 139         { &vnop_readlink_desc, (VOPFUNC)dead_readlink },        /* readlink */
 140         { &vnop_inactive_desc, (VOPFUNC)dead_inactive },        /* inactive */
 141         { &vnop_reclaim_desc, (VOPFUNC)dead_reclaim },  /* reclaim */
 142         { &vnop_strategy_desc, (VOPFUNC)dead_strategy },        /* strategy */
 143         { &vnop_pathconf_desc, (VOPFUNC)dead_pathconf },        /* pathconf */
 144         { &vnop_advlock_desc, (VOPFUNC)dead_advlock },  /* advlock */
 145         { &vnop_bwrite_desc, (VOPFUNC)dead_bwrite },    /* bwrite */
 146         { &vnop_pagein_desc, (VOPFUNC)err_pagein },     /* Pagein */
 147         { &vnop_pageout_desc, (VOPFUNC)err_pageout },   /* Pageout */
 148         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
 149         { &vnop_blktooff_desc, (VOPFUNC)dead_blktooff },        /* blktooff */
 150         { &vnop_offtoblk_desc, (VOPFUNC)dead_offtoblk },        /* offtoblk */
 151         { &vnop_blockmap_desc, (VOPFUNC)dead_blockmap },                /* blockmap */
 152         { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
 153 };
 154 struct vnodeopv_desc dead_vnodeop_opv_desc =
 155         { &dead_vnodeop_p, dead_vnodeop_entries };
 156
 157 /*
 158  * Trivial lookup routine that always fails.
 159  */
 160 /* ARGSUSED */
 161 int
 162 dead_lookup(ap)
 163         struct vnop_lookup_args /* {
 164                 struct vnode * a_dvp;
 165                 struct vnode ** a_vpp;
 166                 struct componentname * a_cnp;
 167                 vfs_context_t a_context;
 168         } */ *ap;
 169 {
 170
 171         *ap->a_vpp = NULL;
 172         return (ENOTDIR);
 173 }
 174
 175 /*
 176  * Open always fails as if device did not exist.
 177  */
 178 /* ARGSUSED */
 179 int
 180 dead_open(ap)
 181         struct vnop_open_args /* {
 182                 struct vnode *a_vp;
 183                 int  a_mode;
 184                 vfs_context_t a_context;
 185         } */ *ap;
 186 {
 187
 188         return (ENXIO);
 189 }
 190
 191 /*
 192  * Vnode op for read
 193  */
 194 /* ARGSUSED */
 195 int
 196 dead_read(ap)
 197         struct vnop_read_args /* {
 198                 struct vnode *a_vp;
 199                 struct uio *a_uio;
 200                 int  a_ioflag;
 201                 vfs_context_t a_context;
 202         } */ *ap;
 203 {
 204
 205         if (chkvnlock(ap->a_vp))
 206                 panic("dead_read: lock");
 207         /*
 208          * Return EOF for character devices, EIO for others
 209          */
 210         if (ap->a_vp->v_type != VCHR)
 211                 return (EIO);
 212         return (0);
 213 }
 214
 215 /*
 216  * Vnode op for write
 217  */
 218 /* ARGSUSED */
 219 int
 220 dead_write(ap)
 221         struct vnop_write_args /* {
 222                 struct vnode *a_vp;
 223                 struct uio *a_uio;
 224                 int  a_ioflag;
 225                 vfs_context_t a_context;
 226         } */ *ap;
 227 {
 228
 229         if (chkvnlock(ap->a_vp))
 230                 panic("dead_write: lock");
 231         return (EIO);
 232 }
 233
 234 /*
 235  * Device ioctl operation.
 236  */
 237 /* ARGSUSED */
 238 int
 239 dead_ioctl(ap)
 240         struct vnop_ioctl_args /* {
 241                 struct vnode *a_vp;
 242                 u_long a_command;
 243                 caddr_t  a_data;
 244                 int  a_fflag;
 245                 vfs_context_t a_context;
 246         } */ *ap;
 247 {
 248
 249         if (!chkvnlock(ap->a_vp))
 250                 return (EBADF);
 251         return (VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap));
 252 }
 253
 254 /* ARGSUSED */
 255 int
 256 dead_select(ap)
 257         struct vnop_select_args /* {
 258                 struct vnode *a_vp;
 259                 int  a_which;
 260                 int  a_fflags;
 261                 kauth_cred_t a_cred;
 262                 void *a_wql;
 263                 struct proc *a_p;
 264         } */ *ap;
 265 {
 266
 267         /*
 268          * Let the user find out that the descriptor is gone.
 269          */
 270         return (1);
 271 }
 272
 273 /*
 274  * Just call the device strategy routine
 275  */
 276 int
 277 dead_strategy(ap)
 278         struct vnop_strategy_args /* {
 279                 struct buf *a_bp;
 280         } */ *ap;
 281 {
 282
 283         if (buf_vnode(ap->a_bp) == NULL || !chkvnlock(buf_vnode(ap->a_bp))) {
 284                 buf_seterror(ap->a_bp, EIO);
 285                 buf_biodone(ap->a_bp);
 286                 return (EIO);
 287         }
 288         return (VNOP_STRATEGY(ap->a_bp));
 289 }
 290
 291 /*
 292  * Wait until the vnode has finished changing state.
 293  */
 294 int
 295 dead_blockmap(ap)
 296         struct vnop_blockmap_args /* {
 297                 struct vnode *a_vp;
 298                 off_t a_foffset;
 299                 size_t a_size;
 300                 daddr64_t *a_bpn;
 301                 size_t *a_run;
 302                 void *a_poff;
 303                 int flags;
 304                 vfs_context_t a_context;
 305         } */ *ap;
 306 {
 307
 308         if (!chkvnlock(ap->a_vp))
 309                 return (EIO);
 310         return (VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
 311                          ap->a_run, ap->a_poff, ap->a_flags, ap->a_context));
 312 }
 313
 314 /*
 315  * Empty vnode failed operation
 316  */
 317 /* ARGSUSED */
 318 int
 319 dead_ebadf(void *dummy)
 320 {
 321
 322         return (EBADF);
 323 }
 324
 325 /*
 326  * Empty vnode bad operation
 327  */
 328 /* ARGSUSED */
 329 int
 330 dead_badop(void *dummy)
 331 {
 332
 333         panic("dead_badop called");
 334         /* NOTREACHED */
 335 }
 336
 337 /*
 338  * Empty vnode null operation
 339  */
 340 /* ARGSUSED */
 341 int
 342 dead_nullop(void *dummy)
 343 {
 344
 345         return (0);
 346 }
 347
 348 /*
 349  * We have to wait during times when the vnode is
 350  * in a state of change.
 351  */
 352 int
 353 chkvnlock(__unused vnode_t vp)
 354 {
 355         return (0);
 356 }
 357
 358
 359 /* Blktooff */
 360 int
 361 dead_blktooff(ap)
 362         struct vnop_blktooff_args /* {
 363                 struct vnode *a_vp;
 364                 daddr64_t a_lblkno;
 365                 off_t *a_offset;
 366         } */ *ap;
 367 {
 368     if (!chkvnlock(ap->a_vp))
 369                 return (EIO);
 370
 371         *ap->a_offset = (off_t)-1;      /* failure */
 372         return (0);
 373 }
 374 /* Blktooff */
 375 int
 376 dead_offtoblk(ap)
 377 struct vnop_offtoblk_args /* {
 378         struct vnode *a_vp;
 379         off_t a_offset;
 380         daddr64_t *a_lblkno;
 381         } */ *ap;
 382 {
 383     if (!chkvnlock(ap->a_vp))
 384                 return (EIO);
 385
 386         *ap->a_lblkno = (daddr64_t)-1;  /* failure */
 387         return (0);
 388 }