bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2000 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) 1989, 1993
  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  *      @(#)dead_vnops.c        8.3 (Berkeley) 5/14/95
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/time.h>
  67 #include <sys/vnode_internal.h>
  68 #include <sys/errno.h>
  69 #include <sys/namei.h>
  70 #include <sys/buf.h>
  71 #include <vfs/vfs_support.h>
  72
  73 /*
  74  * Prototypes for dead operations on vnodes.
  75  */
  76 int     dead_badop(void *);
  77 int     dead_ebadf(void *);
  78 int     dead_lookup(struct vnop_lookup_args *);
  79 #define dead_create (int (*)(struct  vnop_create_args *))dead_badop
  80 #define dead_mknod (int (*)(struct  vnop_mknod_args *))dead_badop
  81 int     dead_open(struct vnop_open_args *);
  82 #define dead_close (int (*)(struct  vnop_close_args *))nullop
  83 #define dead_access (int (*)(struct  vnop_access_args *))dead_ebadf
  84 #define dead_getattr (int (*)(struct  vnop_getattr_args *))dead_ebadf
  85 #define dead_setattr (int (*)(struct  vnop_setattr_args *))dead_ebadf
  86 int     dead_read(struct vnop_read_args *);
  87 int     dead_write(struct vnop_write_args *);
  88 int     dead_ioctl(struct vnop_ioctl_args *);
  89 int     dead_select(struct vnop_select_args *);
  90 #define dead_mmap (int (*)(struct  vnop_mmap_args *))dead_badop
  91 #define dead_fsync (int (*)(struct  vnop_fsync_args *))nullop
  92 #define dead_remove (int (*)(struct  vnop_remove_args ))dead_badop
  93 #define dead_link (int (*)(struct  vnop_link_args *))dead_badop
  94 #define dead_rename (int (*)(struct  vnop_rename_args *))dead_badop
  95 #define dead_mkdir (int (*)(struct  vnop_mkdir_args *))dead_badop
  96 #define dead_rmdir (int (*)(struct  vnop_rmdir_args *))dead_badop
  97 #define dead_symlink (int (*)(struct  vnop_symlink_args *))dead_badop
  98 #define dead_readdir (int (*)(struct  vnop_readdir_args *))dead_ebadf
  99 #define dead_readlink (int (*)(struct  vnop_readlink_args *))dead_ebadf
 100 #define dead_inactive (int (*)(struct  vnop_inactive_args *))nullop
 101 #define dead_reclaim (int (*)(struct  vnop_reclaim_args *))nullop
 102 int     dead_strategy(struct vnop_strategy_args *);
 103 #define dead_pathconf (int (*)(struct  vnop_pathconf_args *))dead_ebadf
 104 #define dead_advlock (int (*)(struct  vnop_advlock_args *))dead_ebadf
 105 #define dead_bwrite (int (*)(struct  vnop_bwrite_args *))nullop
 106 int     dead_pagein(struct vnop_pagein_args *);
 107 int     dead_pageout(struct vnop_pageout_args *);
 108 int dead_blktooff(struct vnop_blktooff_args *);
 109 int dead_offtoblk(struct vnop_offtoblk_args *);
 110 int dead_blockmap(struct vnop_blockmap_args *);
 111
 112 #define VOPFUNC int (*)(void *)
 113 int (**dead_vnodeop_p)(void *);
 114 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 115         { &vnop_default_desc, (VOPFUNC)vn_default_error },
 116         { &vnop_lookup_desc, (VOPFUNC)dead_lookup },    /* lookup */
 117         { &vnop_create_desc, (VOPFUNC)dead_create },    /* create */
 118         { &vnop_open_desc, (VOPFUNC)dead_open },                /* open */
 119         { &vnop_mknod_desc, (VOPFUNC)dead_mknod },              /* mknod */
 120         { &vnop_close_desc, (VOPFUNC)dead_close },      /* close */
 121         { &vnop_access_desc, (VOPFUNC)dead_access },    /* access */
 122         { &vnop_getattr_desc, (VOPFUNC)dead_getattr },  /* getattr */
 123         { &vnop_setattr_desc, (VOPFUNC)dead_setattr },  /* setattr */
 124         { &vnop_read_desc, (VOPFUNC)dead_read },                /* read */
 125         { &vnop_write_desc, (VOPFUNC)dead_write },      /* write */
 126         { &vnop_ioctl_desc, (VOPFUNC)dead_ioctl },      /* ioctl */
 127         { &vnop_select_desc, (VOPFUNC)dead_select },    /* select */
 128         { &vnop_mmap_desc, (VOPFUNC)dead_mmap },                /* mmap */
 129         { &vnop_fsync_desc, (VOPFUNC)dead_fsync },      /* fsync */
 130         { &vnop_remove_desc, (VOPFUNC)dead_remove },    /* remove */
 131         { &vnop_link_desc, (VOPFUNC)dead_link },                /* link */
 132         { &vnop_rename_desc, (VOPFUNC)dead_rename },    /* rename */
 133         { &vnop_mkdir_desc, (VOPFUNC)dead_mkdir },      /* mkdir */
 134         { &vnop_rmdir_desc, (VOPFUNC)dead_rmdir },      /* rmdir */
 135         { &vnop_symlink_desc, (VOPFUNC)dead_symlink },  /* symlink */
 136         { &vnop_readdir_desc, (VOPFUNC)dead_readdir },  /* readdir */
 137         { &vnop_readlink_desc, (VOPFUNC)dead_readlink },        /* readlink */
 138         { &vnop_inactive_desc, (VOPFUNC)dead_inactive },        /* inactive */
 139         { &vnop_reclaim_desc, (VOPFUNC)dead_reclaim },  /* reclaim */
 140         { &vnop_strategy_desc, (VOPFUNC)dead_strategy },        /* strategy */
 141         { &vnop_pathconf_desc, (VOPFUNC)dead_pathconf },        /* pathconf */
 142         { &vnop_advlock_desc, (VOPFUNC)dead_advlock },  /* advlock */
 143         { &vnop_bwrite_desc, (VOPFUNC)dead_bwrite },    /* bwrite */
 144         { &vnop_pagein_desc, (VOPFUNC)err_pagein },     /* Pagein */
 145         { &vnop_pageout_desc, (VOPFUNC)err_pageout },   /* Pageout */
 146         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
 147         { &vnop_blktooff_desc, (VOPFUNC)dead_blktooff },        /* blktooff */
 148         { &vnop_offtoblk_desc, (VOPFUNC)dead_offtoblk },        /* offtoblk */
 149         { &vnop_blockmap_desc, (VOPFUNC)dead_blockmap },                /* blockmap */
 150         { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
 151 };
 152 struct vnodeopv_desc dead_vnodeop_opv_desc =
 153         { &dead_vnodeop_p, dead_vnodeop_entries };
 154
 155 /*
 156  * Trivial lookup routine that always fails.
 157  */
 158 /* ARGSUSED */
 159 int
 160 dead_lookup(ap)
 161         struct vnop_lookup_args /* {
 162                 struct vnode * a_dvp;
 163                 struct vnode ** a_vpp;
 164                 struct componentname * a_cnp;
 165                 vfs_context_t a_context;
 166         } */ *ap;
 167 {
 168
 169         *ap->a_vpp = NULL;
 170         return (ENOTDIR);
 171 }
 172
 173 /*
 174  * Open always fails as if device did not exist.
 175  */
 176 /* ARGSUSED */
 177 int
 178 dead_open(ap)
 179         struct vnop_open_args /* {
 180                 struct vnode *a_vp;
 181                 int  a_mode;
 182                 vfs_context_t a_context;
 183         } */ *ap;
 184 {
 185
 186         return (ENXIO);
 187 }
 188
 189 /*
 190  * Vnode op for read
 191  */
 192 /* ARGSUSED */
 193 int
 194 dead_read(ap)
 195         struct vnop_read_args /* {
 196                 struct vnode *a_vp;
 197                 struct uio *a_uio;
 198                 int  a_ioflag;
 199                 vfs_context_t a_context;
 200         } */ *ap;
 201 {
 202
 203         if (chkvnlock(ap->a_vp))
 204                 panic("dead_read: lock");
 205         /*
 206          * Return EOF for character devices, EIO for others
 207          */
 208         if (ap->a_vp->v_type != VCHR)
 209                 return (EIO);
 210         return (0);
 211 }
 212
 213 /*
 214  * Vnode op for write
 215  */
 216 /* ARGSUSED */
 217 int
 218 dead_write(ap)
 219         struct vnop_write_args /* {
 220                 struct vnode *a_vp;
 221                 struct uio *a_uio;
 222                 int  a_ioflag;
 223                 vfs_context_t a_context;
 224         } */ *ap;
 225 {
 226
 227         if (chkvnlock(ap->a_vp))
 228                 panic("dead_write: lock");
 229         return (EIO);
 230 }
 231
 232 /*
 233  * Device ioctl operation.
 234  */
 235 /* ARGSUSED */
 236 int
 237 dead_ioctl(ap)
 238         struct vnop_ioctl_args /* {
 239                 struct vnode *a_vp;
 240                 u_long a_command;
 241                 caddr_t  a_data;
 242                 int  a_fflag;
 243                 vfs_context_t a_context;
 244         } */ *ap;
 245 {
 246
 247         if (!chkvnlock(ap->a_vp))
 248                 return (EBADF);
 249         return (VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap));
 250 }
 251
 252 /* ARGSUSED */
 253 int
 254 dead_select(ap)
 255         struct vnop_select_args /* {
 256                 struct vnode *a_vp;
 257                 int  a_which;
 258                 int  a_fflags;
 259                 kauth_cred_t a_cred;
 260                 void *a_wql;
 261                 struct proc *a_p;
 262         } */ *ap;
 263 {
 264
 265         /*
 266          * Let the user find out that the descriptor is gone.
 267          */
 268         return (1);
 269 }
 270
 271 /*
 272  * Just call the device strategy routine
 273  */
 274 int
 275 dead_strategy(ap)
 276         struct vnop_strategy_args /* {
 277                 struct buf *a_bp;
 278         } */ *ap;
 279 {
 280
 281         if (buf_vnode(ap->a_bp) == NULL || !chkvnlock(buf_vnode(ap->a_bp))) {
 282                 buf_seterror(ap->a_bp, EIO);
 283                 buf_biodone(ap->a_bp);
 284                 return (EIO);
 285         }
 286         return (VNOP_STRATEGY(ap->a_bp));
 287 }
 288
 289 /*
 290  * Wait until the vnode has finished changing state.
 291  */
 292 int
 293 dead_blockmap(ap)
 294         struct vnop_blockmap_args /* {
 295                 struct vnode *a_vp;
 296                 off_t a_foffset;
 297                 size_t a_size;
 298                 daddr64_t *a_bpn;
 299                 size_t *a_run;
 300                 void *a_poff;
 301                 int flags;
 302                 vfs_context_t a_context;
 303         } */ *ap;
 304 {
 305
 306         if (!chkvnlock(ap->a_vp))
 307                 return (EIO);
 308         return (VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
 309                          ap->a_run, ap->a_poff, ap->a_flags, ap->a_context));
 310 }
 311
 312 /*
 313  * Empty vnode failed operation
 314  */
 315 /* ARGSUSED */
 316 int
 317 dead_ebadf(void *dummy)
 318 {
 319
 320         return (EBADF);
 321 }
 322
 323 /*
 324  * Empty vnode bad operation
 325  */
 326 /* ARGSUSED */
 327 int
 328 dead_badop(void *dummy)
 329 {
 330
 331         panic("dead_badop called");
 332         /* NOTREACHED */
 333 }
 334
 335 /*
 336  * Empty vnode null operation
 337  */
 338 /* ARGSUSED */
 339 int
 340 dead_nullop(void *dummy)
 341 {
 342
 343         return (0);
 344 }
 345
 346 /*
 347  * We have to wait during times when the vnode is
 348  * in a state of change.
 349  */
 350 int
 351 chkvnlock(__unused vnode_t vp)
 352 {
 353         return (0);
 354 }
 355
 356
 357 /* Blktooff */
 358 int
 359 dead_blktooff(ap)
 360         struct vnop_blktooff_args /* {
 361                 struct vnode *a_vp;
 362                 daddr64_t a_lblkno;
 363                 off_t *a_offset;
 364         } */ *ap;
 365 {
 366     if (!chkvnlock(ap->a_vp))
 367                 return (EIO);
 368
 369         *ap->a_offset = (off_t)-1;      /* failure */
 370         return (0);
 371 }
 372 /* Blktooff */
 373 int
 374 dead_offtoblk(ap)
 375 struct vnop_offtoblk_args /* {
 376         struct vnode *a_vp;
 377         off_t a_offset;
 378         daddr64_t *a_lblkno;
 379         } */ *ap;
 380 {
 381     if (!chkvnlock(ap->a_vp))
 382                 return (EIO);
 383
 384         *ap->a_lblkno = (daddr64_t)-1;  /* failure */
 385         return (0);
 386 }