bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2000-2019 Apple 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 int     chkvnlock(vnode_t vp);
  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 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 117         { .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)vn_default_error },
 118         { .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)dead_lookup },    /* lookup */
 119         { .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)dead_create },    /* create */
 120         { .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)dead_open },                /* open */
 121         { .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)dead_mknod },              /* mknod */
 122         { .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)dead_close },      /* close */
 123         { .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)dead_access },    /* access */
 124         { .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)dead_getattr },  /* getattr */
 125         { .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)dead_setattr },  /* setattr */
 126         { .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)dead_read },                /* read */
 127         { .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)dead_write },      /* write */
 128         { .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)dead_ioctl },      /* ioctl */
 129         { .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)dead_select },    /* select */
 130         { .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)dead_mmap },                /* mmap */
 131         { .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)dead_fsync },      /* fsync */
 132         { .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)dead_remove },    /* remove */
 133         { .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)dead_link },                /* link */
 134         { .opve_op = &vnop_rename_desc, .opve_impl = (VOPFUNC)dead_rename },    /* rename */
 135         { .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)dead_mkdir },      /* mkdir */
 136         { .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)dead_rmdir },      /* rmdir */
 137         { .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)dead_symlink },  /* symlink */
 138         { .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)dead_readdir },  /* readdir */
 139         { .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)dead_readlink },        /* readlink */
 140         { .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)dead_inactive },        /* inactive */
 141         { .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)dead_reclaim },  /* reclaim */
 142         { .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)dead_strategy },        /* strategy */
 143         { .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)dead_pathconf },        /* pathconf */
 144         { .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)dead_advlock },  /* advlock */
 145         { .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)dead_bwrite },    /* bwrite */
 146         { .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein },     /* Pagein */
 147         { .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout },   /* Pageout */
 148         { .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */
 149         { .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)dead_blktooff },        /* blktooff */
 150         { .opve_op = &vnop_offtoblk_desc, .opve_impl = (VOPFUNC)dead_offtoblk },        /* offtoblk */
 151         { .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)dead_blockmap },                /* blockmap */
 152         { .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (VOPFUNC)NULL }
 153 };
 154 const struct vnodeopv_desc dead_vnodeop_opv_desc =
 155 { .opv_desc_vector_p = &dead_vnodeop_p, .opv_desc_ops = dead_vnodeop_entries };
 156
 157 /*
 158  * Trivial lookup routine that always fails.
 159  */
 160 /* ARGSUSED */
 161 int
 162 dead_lookup(struct vnop_lookup_args *ap)
 163 {
 164         *ap->a_vpp = NULL;
 165         return ENOTDIR;
 166 }
 167
 168 /*
 169  * Open always fails as if device did not exist.
 170  */
 171 /* ARGSUSED */
 172 int
 173 dead_open(__unused struct vnop_open_args *ap)
 174 {
 175         return ENXIO;
 176 }
 177
 178 /*
 179  * Vnode op for read
 180  */
 181 /* ARGSUSED */
 182 int
 183 dead_read(struct vnop_read_args *ap)
 184 {
 185         if (chkvnlock(ap->a_vp)) {
 186                 panic("dead_read: lock");
 187         }
 188         /*
 189          * Return EOF for character devices, EIO for others
 190          */
 191         if (ap->a_vp->v_type != VCHR) {
 192                 return EIO;
 193         }
 194         return 0;
 195 }
 196
 197 /*
 198  * Vnode op for write
 199  */
 200 /* ARGSUSED */
 201 int
 202 dead_write(struct vnop_write_args *ap)
 203 {
 204         if (chkvnlock(ap->a_vp)) {
 205                 panic("dead_write: lock");
 206         }
 207         return EIO;
 208 }
 209
 210 /*
 211  * Device ioctl operation.
 212  */
 213 /* ARGSUSED */
 214 int
 215 dead_ioctl(struct vnop_ioctl_args *ap)
 216 {
 217         if (!chkvnlock(ap->a_vp)) {
 218                 return EBADF;
 219         }
 220         return VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap);
 221 }
 222
 223 /* ARGSUSED */
 224 int
 225 dead_select(__unused struct vnop_select_args *ap)
 226 {
 227         /*
 228          * Let the user find out that the descriptor is gone.
 229          */
 230         return 1;
 231 }
 232
 233 /*
 234  * Just call the device strategy routine
 235  */
 236 int
 237 dead_strategy(struct vnop_strategy_args *ap)
 238 {
 239         if (buf_vnode(ap->a_bp) == NULL || !chkvnlock(buf_vnode(ap->a_bp))) {
 240                 buf_seterror(ap->a_bp, EIO);
 241                 buf_biodone(ap->a_bp);
 242                 return EIO;
 243         }
 244         return VNOP_STRATEGY(ap->a_bp);
 245 }
 246
 247 /*
 248  * Wait until the vnode has finished changing state.
 249  */
 250 int
 251 dead_blockmap(struct vnop_blockmap_args *ap)
 252 {
 253         if (!chkvnlock(ap->a_vp)) {
 254                 return EIO;
 255         }
 256         return VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
 257                    ap->a_run, ap->a_poff, ap->a_flags, ap->a_context);
 258 }
 259
 260 /*
 261  * Empty vnode failed operation
 262  */
 263 /* ARGSUSED */
 264 int
 265 dead_ebadf(__unused void *dummy)
 266 {
 267         return EBADF;
 268 }
 269
 270 /*
 271  * Empty vnode bad operation
 272  */
 273 /* ARGSUSED */
 274 int
 275 dead_badop(__unused void *dummy)
 276 {
 277         panic("dead_badop called");
 278         /* NOTREACHED */
 279         return -1;
 280 }
 281
 282 /*
 283  * We have to wait during times when the vnode is
 284  * in a state of change.
 285  */
 286 int
 287 chkvnlock(__unused vnode_t vp)
 288 {
 289         return 0;
 290 }
 291
 292
 293 /* Blktooff */
 294 int
 295 dead_blktooff(struct vnop_blktooff_args *ap)
 296 {
 297         if (!chkvnlock(ap->a_vp)) {
 298                 return EIO;
 299         }
 300
 301         *ap->a_offset = (off_t)-1;      /* failure */
 302         return 0;
 303 }
 304 /* Blktooff */
 305 int
 306 dead_offtoblk(struct vnop_offtoblk_args *ap)
 307 {
 308         if (!chkvnlock(ap->a_vp)) {
 309                 return EIO;
 310         }
 311
 312         *ap->a_lblkno = (daddr64_t)-1;  /* failure */
 313         return 0;
 314 }