| 1 | /* |
| 2 | * Copyright (c) 1989, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * %sccs.include.redist.c% |
| 6 | * |
| 7 | * @(#)spec_vnops.c 8.6 (Berkeley) %G% |
| 8 | */ |
| 9 | |
| 10 | #include <sys/param.h> |
| 11 | #include <sys/proc.h> |
| 12 | #include <sys/systm.h> |
| 13 | #include <sys/kernel.h> |
| 14 | #include <sys/conf.h> |
| 15 | #include <sys/buf.h> |
| 16 | #include <sys/mount.h> |
| 17 | #include <sys/namei.h> |
| 18 | #include <sys/vnode.h> |
| 19 | #include <sys/stat.h> |
| 20 | #include <sys/errno.h> |
| 21 | #include <sys/ioctl.h> |
| 22 | #include <sys/file.h> |
| 23 | #include <sys/disklabel.h> |
| 24 | #include <miscfs/specfs/specdev.h> |
| 25 | |
| 26 | /* symbolic sleep message strings for devices */ |
| 27 | char devopn[] = "devopn"; |
| 28 | char devio[] = "devio"; |
| 29 | char devwait[] = "devwait"; |
| 30 | char devin[] = "devin"; |
| 31 | char devout[] = "devout"; |
| 32 | char devioc[] = "devioc"; |
| 33 | char devcls[] = "devcls"; |
| 34 | |
| 35 | int (**spec_vnodeop_p)(); |
| 36 | struct vnodeopv_entry_desc spec_vnodeop_entries[] = { |
| 37 | { &vop_default_desc, vn_default_error }, |
| 38 | { &vop_lookup_desc, spec_lookup }, /* lookup */ |
| 39 | { &vop_create_desc, spec_create }, /* create */ |
| 40 | { &vop_mknod_desc, spec_mknod }, /* mknod */ |
| 41 | { &vop_open_desc, spec_open }, /* open */ |
| 42 | { &vop_close_desc, spec_close }, /* close */ |
| 43 | { &vop_access_desc, spec_access }, /* access */ |
| 44 | { &vop_getattr_desc, spec_getattr }, /* getattr */ |
| 45 | { &vop_setattr_desc, spec_setattr }, /* setattr */ |
| 46 | { &vop_read_desc, spec_read }, /* read */ |
| 47 | { &vop_write_desc, spec_write }, /* write */ |
| 48 | { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ |
| 49 | { &vop_select_desc, spec_select }, /* select */ |
| 50 | { &vop_mmap_desc, spec_mmap }, /* mmap */ |
| 51 | { &vop_fsync_desc, spec_fsync }, /* fsync */ |
| 52 | { &vop_seek_desc, spec_seek }, /* seek */ |
| 53 | { &vop_remove_desc, spec_remove }, /* remove */ |
| 54 | { &vop_link_desc, spec_link }, /* link */ |
| 55 | { &vop_rename_desc, spec_rename }, /* rename */ |
| 56 | { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ |
| 57 | { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ |
| 58 | { &vop_symlink_desc, spec_symlink }, /* symlink */ |
| 59 | { &vop_readdir_desc, spec_readdir }, /* readdir */ |
| 60 | { &vop_readlink_desc, spec_readlink }, /* readlink */ |
| 61 | { &vop_abortop_desc, spec_abortop }, /* abortop */ |
| 62 | { &vop_inactive_desc, spec_inactive }, /* inactive */ |
| 63 | { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ |
| 64 | { &vop_lock_desc, spec_lock }, /* lock */ |
| 65 | { &vop_unlock_desc, spec_unlock }, /* unlock */ |
| 66 | { &vop_bmap_desc, spec_bmap }, /* bmap */ |
| 67 | { &vop_strategy_desc, spec_strategy }, /* strategy */ |
| 68 | { &vop_print_desc, spec_print }, /* print */ |
| 69 | { &vop_islocked_desc, spec_islocked }, /* islocked */ |
| 70 | { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ |
| 71 | { &vop_advlock_desc, spec_advlock }, /* advlock */ |
| 72 | { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ |
| 73 | { &vop_valloc_desc, spec_valloc }, /* valloc */ |
| 74 | { &vop_vfree_desc, spec_vfree }, /* vfree */ |
| 75 | { &vop_truncate_desc, spec_truncate }, /* truncate */ |
| 76 | { &vop_update_desc, spec_update }, /* update */ |
| 77 | { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ |
| 78 | { (struct vnodeop_desc*)NULL, (int(*)())NULL } |
| 79 | }; |
| 80 | struct vnodeopv_desc spec_vnodeop_opv_desc = |
| 81 | { &spec_vnodeop_p, spec_vnodeop_entries }; |
| 82 | |
| 83 | /* |
| 84 | * Trivial lookup routine that always fails. |
| 85 | */ |
| 86 | int |
| 87 | spec_lookup(ap) |
| 88 | struct vop_lookup_args /* { |
| 89 | struct vnode *a_dvp; |
| 90 | struct vnode **a_vpp; |
| 91 | struct componentname *a_cnp; |
| 92 | } */ *ap; |
| 93 | { |
| 94 | |
| 95 | *ap->a_vpp = NULL; |
| 96 | return (ENOTDIR); |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Open a special file. |
| 101 | */ |
| 102 | /* ARGSUSED */ |
| 103 | spec_open(ap) |
| 104 | struct vop_open_args /* { |
| 105 | struct vnode *a_vp; |
| 106 | int a_mode; |
| 107 | struct ucred *a_cred; |
| 108 | struct proc *a_p; |
| 109 | } */ *ap; |
| 110 | { |
| 111 | struct vnode *bvp, *vp = ap->a_vp; |
| 112 | dev_t bdev, dev = (dev_t)vp->v_rdev; |
| 113 | register int maj = major(dev); |
| 114 | int error; |
| 115 | |
| 116 | /* |
| 117 | * Don't allow open if fs is mounted -nodev. |
| 118 | */ |
| 119 | if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) |
| 120 | return (ENXIO); |
| 121 | |
| 122 | switch (vp->v_type) { |
| 123 | |
| 124 | case VCHR: |
| 125 | if ((u_int)maj >= nchrdev) |
| 126 | return (ENXIO); |
| 127 | if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { |
| 128 | /* |
| 129 | * When running in very secure mode, do not allow |
| 130 | * opens for writing of any disk character devices. |
| 131 | */ |
| 132 | if (securelevel >= 2 && isdisk(dev, VCHR)) |
| 133 | return (EPERM); |
| 134 | /* |
| 135 | * When running in secure mode, do not allow opens |
| 136 | * for writing of /dev/mem, /dev/kmem, or character |
| 137 | * devices whose corresponding block devices are |
| 138 | * currently mounted. |
| 139 | */ |
| 140 | if (securelevel >= 1) { |
| 141 | if ((bdev = chrtoblk(dev)) != NODEV && |
| 142 | vfinddev(bdev, VBLK, &bvp) && |
| 143 | bvp->v_usecount > 0 && |
| 144 | (error = vfs_mountedon(bvp))) |
| 145 | return (error); |
| 146 | if (iskmemdev(dev)) |
| 147 | return (EPERM); |
| 148 | } |
| 149 | } |
| 150 | VOP_UNLOCK(vp); |
| 151 | error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p); |
| 152 | VOP_LOCK(vp); |
| 153 | return (error); |
| 154 | |
| 155 | case VBLK: |
| 156 | if ((u_int)maj >= nblkdev) |
| 157 | return (ENXIO); |
| 158 | /* |
| 159 | * When running in very secure mode, do not allow |
| 160 | * opens for writing of any disk block devices. |
| 161 | */ |
| 162 | if (securelevel >= 2 && ap->a_cred != FSCRED && |
| 163 | (ap->a_mode & FWRITE) && isdisk(dev, VBLK)) |
| 164 | return (EPERM); |
| 165 | /* |
| 166 | * Do not allow opens of block devices that are |
| 167 | * currently mounted. |
| 168 | */ |
| 169 | if (error = vfs_mountedon(vp)) |
| 170 | return (error); |
| 171 | return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p)); |
| 172 | } |
| 173 | return (0); |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * Vnode op for read |
| 178 | */ |
| 179 | /* ARGSUSED */ |
| 180 | spec_read(ap) |
| 181 | struct vop_read_args /* { |
| 182 | struct vnode *a_vp; |
| 183 | struct uio *a_uio; |
| 184 | int a_ioflag; |
| 185 | struct ucred *a_cred; |
| 186 | } */ *ap; |
| 187 | { |
| 188 | register struct vnode *vp = ap->a_vp; |
| 189 | register struct uio *uio = ap->a_uio; |
| 190 | struct proc *p = uio->uio_procp; |
| 191 | struct buf *bp; |
| 192 | daddr_t bn, nextbn; |
| 193 | long bsize, bscale; |
| 194 | struct partinfo dpart; |
| 195 | int n, on, majordev, (*ioctl)(); |
| 196 | int error = 0; |
| 197 | dev_t dev; |
| 198 | |
| 199 | #ifdef DIAGNOSTIC |
| 200 | if (uio->uio_rw != UIO_READ) |
| 201 | panic("spec_read mode"); |
| 202 | if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) |
| 203 | panic("spec_read proc"); |
| 204 | #endif |
| 205 | if (uio->uio_resid == 0) |
| 206 | return (0); |
| 207 | |
| 208 | switch (vp->v_type) { |
| 209 | |
| 210 | case VCHR: |
| 211 | VOP_UNLOCK(vp); |
| 212 | error = (*cdevsw[major(vp->v_rdev)].d_read) |
| 213 | (vp->v_rdev, uio, ap->a_ioflag); |
| 214 | VOP_LOCK(vp); |
| 215 | return (error); |
| 216 | |
| 217 | case VBLK: |
| 218 | if (uio->uio_offset < 0) |
| 219 | return (EINVAL); |
| 220 | bsize = BLKDEV_IOSIZE; |
| 221 | dev = vp->v_rdev; |
| 222 | if ((majordev = major(dev)) < nblkdev && |
| 223 | (ioctl = bdevsw[majordev].d_ioctl) != NULL && |
| 224 | (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 && |
| 225 | dpart.part->p_fstype == FS_BSDFFS && |
| 226 | dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) |
| 227 | bsize = dpart.part->p_frag * dpart.part->p_fsize; |
| 228 | bscale = bsize / DEV_BSIZE; |
| 229 | do { |
| 230 | bn = (uio->uio_offset / DEV_BSIZE) &~ (bscale - 1); |
| 231 | on = uio->uio_offset % bsize; |
| 232 | n = min((unsigned)(bsize - on), uio->uio_resid); |
| 233 | if (vp->v_lastr + bscale == bn) { |
| 234 | nextbn = bn + bscale; |
| 235 | error = breadn(vp, bn, (int)bsize, &nextbn, |
| 236 | (int *)&bsize, 1, NOCRED, &bp); |
| 237 | } else |
| 238 | error = bread(vp, bn, (int)bsize, NOCRED, &bp); |
| 239 | vp->v_lastr = bn; |
| 240 | n = min(n, bsize - bp->b_resid); |
| 241 | if (error) { |
| 242 | brelse(bp); |
| 243 | return (error); |
| 244 | } |
| 245 | error = uiomove((char *)bp->b_data + on, n, uio); |
| 246 | if (n + on == bsize) |
| 247 | bp->b_flags |= B_AGE; |
| 248 | brelse(bp); |
| 249 | } while (error == 0 && uio->uio_resid > 0 && n != 0); |
| 250 | return (error); |
| 251 | |
| 252 | default: |
| 253 | panic("spec_read type"); |
| 254 | } |
| 255 | /* NOTREACHED */ |
| 256 | } |
| 257 | |
| 258 | /* |
| 259 | * Vnode op for write |
| 260 | */ |
| 261 | /* ARGSUSED */ |
| 262 | spec_write(ap) |
| 263 | struct vop_write_args /* { |
| 264 | struct vnode *a_vp; |
| 265 | struct uio *a_uio; |
| 266 | int a_ioflag; |
| 267 | struct ucred *a_cred; |
| 268 | } */ *ap; |
| 269 | { |
| 270 | register struct vnode *vp = ap->a_vp; |
| 271 | register struct uio *uio = ap->a_uio; |
| 272 | struct proc *p = uio->uio_procp; |
| 273 | struct buf *bp; |
| 274 | daddr_t bn; |
| 275 | int bsize, blkmask; |
| 276 | struct partinfo dpart; |
| 277 | register int n, on; |
| 278 | int error = 0; |
| 279 | |
| 280 | #ifdef DIAGNOSTIC |
| 281 | if (uio->uio_rw != UIO_WRITE) |
| 282 | panic("spec_write mode"); |
| 283 | if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) |
| 284 | panic("spec_write proc"); |
| 285 | #endif |
| 286 | |
| 287 | switch (vp->v_type) { |
| 288 | |
| 289 | case VCHR: |
| 290 | VOP_UNLOCK(vp); |
| 291 | error = (*cdevsw[major(vp->v_rdev)].d_write) |
| 292 | (vp->v_rdev, uio, ap->a_ioflag); |
| 293 | VOP_LOCK(vp); |
| 294 | return (error); |
| 295 | |
| 296 | case VBLK: |
| 297 | if (uio->uio_resid == 0) |
| 298 | return (0); |
| 299 | if (uio->uio_offset < 0) |
| 300 | return (EINVAL); |
| 301 | bsize = BLKDEV_IOSIZE; |
| 302 | if ((*bdevsw[major(vp->v_rdev)].d_ioctl)(vp->v_rdev, DIOCGPART, |
| 303 | (caddr_t)&dpart, FREAD, p) == 0) { |
| 304 | if (dpart.part->p_fstype == FS_BSDFFS && |
| 305 | dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) |
| 306 | bsize = dpart.part->p_frag * |
| 307 | dpart.part->p_fsize; |
| 308 | } |
| 309 | blkmask = (bsize / DEV_BSIZE) - 1; |
| 310 | do { |
| 311 | bn = (uio->uio_offset / DEV_BSIZE) &~ blkmask; |
| 312 | on = uio->uio_offset % bsize; |
| 313 | n = min((unsigned)(bsize - on), uio->uio_resid); |
| 314 | if (n == bsize) |
| 315 | bp = getblk(vp, bn, bsize, 0, 0); |
| 316 | else |
| 317 | error = bread(vp, bn, bsize, NOCRED, &bp); |
| 318 | n = min(n, bsize - bp->b_resid); |
| 319 | if (error) { |
| 320 | brelse(bp); |
| 321 | return (error); |
| 322 | } |
| 323 | error = uiomove((char *)bp->b_data + on, n, uio); |
| 324 | if (n + on == bsize) { |
| 325 | bp->b_flags |= B_AGE; |
| 326 | bawrite(bp); |
| 327 | } else |
| 328 | bdwrite(bp); |
| 329 | } while (error == 0 && uio->uio_resid > 0 && n != 0); |
| 330 | return (error); |
| 331 | |
| 332 | default: |
| 333 | panic("spec_write type"); |
| 334 | } |
| 335 | /* NOTREACHED */ |
| 336 | } |
| 337 | |
| 338 | /* |
| 339 | * Device ioctl operation. |
| 340 | */ |
| 341 | /* ARGSUSED */ |
| 342 | spec_ioctl(ap) |
| 343 | struct vop_ioctl_args /* { |
| 344 | struct vnode *a_vp; |
| 345 | int a_command; |
| 346 | caddr_t a_data; |
| 347 | int a_fflag; |
| 348 | struct ucred *a_cred; |
| 349 | struct proc *a_p; |
| 350 | } */ *ap; |
| 351 | { |
| 352 | dev_t dev = ap->a_vp->v_rdev; |
| 353 | |
| 354 | switch (ap->a_vp->v_type) { |
| 355 | |
| 356 | case VCHR: |
| 357 | return ((*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, |
| 358 | ap->a_fflag, ap->a_p)); |
| 359 | |
| 360 | case VBLK: |
| 361 | if (ap->a_command == 0 && (int)ap->a_data == B_TAPE) |
| 362 | if (bdevsw[major(dev)].d_flags & B_TAPE) |
| 363 | return (0); |
| 364 | else |
| 365 | return (1); |
| 366 | return ((*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data, |
| 367 | ap->a_fflag, ap->a_p)); |
| 368 | |
| 369 | default: |
| 370 | panic("spec_ioctl"); |
| 371 | /* NOTREACHED */ |
| 372 | } |
| 373 | } |
| 374 | |
| 375 | /* ARGSUSED */ |
| 376 | spec_select(ap) |
| 377 | struct vop_select_args /* { |
| 378 | struct vnode *a_vp; |
| 379 | int a_which; |
| 380 | int a_fflags; |
| 381 | struct ucred *a_cred; |
| 382 | struct proc *a_p; |
| 383 | } */ *ap; |
| 384 | { |
| 385 | register dev_t dev; |
| 386 | |
| 387 | switch (ap->a_vp->v_type) { |
| 388 | |
| 389 | default: |
| 390 | return (1); /* XXX */ |
| 391 | |
| 392 | case VCHR: |
| 393 | dev = ap->a_vp->v_rdev; |
| 394 | return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p); |
| 395 | } |
| 396 | } |
| 397 | /* |
| 398 | * Synch buffers associated with a block device |
| 399 | */ |
| 400 | /* ARGSUSED */ |
| 401 | int |
| 402 | spec_fsync(ap) |
| 403 | struct vop_fsync_args /* { |
| 404 | struct vnode *a_vp; |
| 405 | struct ucred *a_cred; |
| 406 | int a_waitfor; |
| 407 | struct proc *a_p; |
| 408 | } */ *ap; |
| 409 | { |
| 410 | register struct vnode *vp = ap->a_vp; |
| 411 | register struct buf *bp; |
| 412 | struct buf *nbp; |
| 413 | int s; |
| 414 | |
| 415 | if (vp->v_type == VCHR) |
| 416 | return (0); |
| 417 | /* |
| 418 | * Flush all dirty buffers associated with a block device. |
| 419 | */ |
| 420 | loop: |
| 421 | s = splbio(); |
| 422 | for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { |
| 423 | nbp = bp->b_vnbufs.le_next; |
| 424 | if ((bp->b_flags & B_BUSY)) |
| 425 | continue; |
| 426 | if ((bp->b_flags & B_DELWRI) == 0) |
| 427 | panic("spec_fsync: not dirty"); |
| 428 | bremfree(bp); |
| 429 | bp->b_flags |= B_BUSY; |
| 430 | splx(s); |
| 431 | bawrite(bp); |
| 432 | goto loop; |
| 433 | } |
| 434 | if (ap->a_waitfor == MNT_WAIT) { |
| 435 | while (vp->v_numoutput) { |
| 436 | vp->v_flag |= VBWAIT; |
| 437 | sleep((caddr_t)&vp->v_numoutput, PRIBIO + 1); |
| 438 | } |
| 439 | #ifdef DIAGNOSTIC |
| 440 | if (vp->v_dirtyblkhd.lh_first) { |
| 441 | vprint("spec_fsync: dirty", vp); |
| 442 | goto loop; |
| 443 | } |
| 444 | #endif |
| 445 | } |
| 446 | splx(s); |
| 447 | return (0); |
| 448 | } |
| 449 | |
| 450 | /* |
| 451 | * Just call the device strategy routine |
| 452 | */ |
| 453 | spec_strategy(ap) |
| 454 | struct vop_strategy_args /* { |
| 455 | struct buf *a_bp; |
| 456 | } */ *ap; |
| 457 | { |
| 458 | |
| 459 | (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); |
| 460 | return (0); |
| 461 | } |
| 462 | |
| 463 | /* |
| 464 | * This is a noop, simply returning what one has been given. |
| 465 | */ |
| 466 | spec_bmap(ap) |
| 467 | struct vop_bmap_args /* { |
| 468 | struct vnode *a_vp; |
| 469 | daddr_t a_bn; |
| 470 | struct vnode **a_vpp; |
| 471 | daddr_t *a_bnp; |
| 472 | } */ *ap; |
| 473 | { |
| 474 | |
| 475 | if (ap->a_vpp != NULL) |
| 476 | *ap->a_vpp = ap->a_vp; |
| 477 | if (ap->a_bnp != NULL) |
| 478 | *ap->a_bnp = ap->a_bn; |
| 479 | return (0); |
| 480 | } |
| 481 | |
| 482 | /* |
| 483 | * At the moment we do not do any locking. |
| 484 | */ |
| 485 | /* ARGSUSED */ |
| 486 | spec_lock(ap) |
| 487 | struct vop_lock_args /* { |
| 488 | struct vnode *a_vp; |
| 489 | } */ *ap; |
| 490 | { |
| 491 | |
| 492 | return (0); |
| 493 | } |
| 494 | |
| 495 | /* ARGSUSED */ |
| 496 | spec_unlock(ap) |
| 497 | struct vop_unlock_args /* { |
| 498 | struct vnode *a_vp; |
| 499 | } */ *ap; |
| 500 | { |
| 501 | |
| 502 | return (0); |
| 503 | } |
| 504 | |
| 505 | /* |
| 506 | * Device close routine |
| 507 | */ |
| 508 | /* ARGSUSED */ |
| 509 | spec_close(ap) |
| 510 | struct vop_close_args /* { |
| 511 | struct vnode *a_vp; |
| 512 | int a_fflag; |
| 513 | struct ucred *a_cred; |
| 514 | struct proc *a_p; |
| 515 | } */ *ap; |
| 516 | { |
| 517 | register struct vnode *vp = ap->a_vp; |
| 518 | dev_t dev = vp->v_rdev; |
| 519 | int (*devclose) __P((dev_t, int, int, struct proc *)); |
| 520 | int mode, error; |
| 521 | |
| 522 | switch (vp->v_type) { |
| 523 | |
| 524 | case VCHR: |
| 525 | /* |
| 526 | * Hack: a tty device that is a controlling terminal |
| 527 | * has a reference from the session structure. |
| 528 | * We cannot easily tell that a character device is |
| 529 | * a controlling terminal, unless it is the closing |
| 530 | * process' controlling terminal. In that case, |
| 531 | * if the reference count is 2 (this last descriptor |
| 532 | * plus the session), release the reference from the session. |
| 533 | */ |
| 534 | if (vcount(vp) == 2 && ap->a_p && |
| 535 | vp == ap->a_p->p_session->s_ttyvp) { |
| 536 | vrele(vp); |
| 537 | ap->a_p->p_session->s_ttyvp = NULL; |
| 538 | } |
| 539 | /* |
| 540 | * If the vnode is locked, then we are in the midst |
| 541 | * of forcably closing the device, otherwise we only |
| 542 | * close on last reference. |
| 543 | */ |
| 544 | if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) |
| 545 | return (0); |
| 546 | devclose = cdevsw[major(dev)].d_close; |
| 547 | mode = S_IFCHR; |
| 548 | break; |
| 549 | |
| 550 | case VBLK: |
| 551 | /* |
| 552 | * On last close of a block device (that isn't mounted) |
| 553 | * we must invalidate any in core blocks, so that |
| 554 | * we can, for instance, change floppy disks. |
| 555 | */ |
| 556 | if (error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0)) |
| 557 | return (error); |
| 558 | /* |
| 559 | * We do not want to really close the device if it |
| 560 | * is still in use unless we are trying to close it |
| 561 | * forcibly. Since every use (buffer, vnode, swap, cmap) |
| 562 | * holds a reference to the vnode, and because we mark |
| 563 | * any other vnodes that alias this device, when the |
| 564 | * sum of the reference counts on all the aliased |
| 565 | * vnodes descends to one, we are on last close. |
| 566 | */ |
| 567 | if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) |
| 568 | return (0); |
| 569 | devclose = bdevsw[major(dev)].d_close; |
| 570 | mode = S_IFBLK; |
| 571 | break; |
| 572 | |
| 573 | default: |
| 574 | panic("spec_close: not special"); |
| 575 | } |
| 576 | |
| 577 | return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * Print out the contents of a special device vnode. |
| 582 | */ |
| 583 | spec_print(ap) |
| 584 | struct vop_print_args /* { |
| 585 | struct vnode *a_vp; |
| 586 | } */ *ap; |
| 587 | { |
| 588 | |
| 589 | printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), |
| 590 | minor(ap->a_vp->v_rdev)); |
| 591 | } |
| 592 | |
| 593 | /* |
| 594 | * Return POSIX pathconf information applicable to special devices. |
| 595 | */ |
| 596 | spec_pathconf(ap) |
| 597 | struct vop_pathconf_args /* { |
| 598 | struct vnode *a_vp; |
| 599 | int a_name; |
| 600 | int *a_retval; |
| 601 | } */ *ap; |
| 602 | { |
| 603 | |
| 604 | switch (ap->a_name) { |
| 605 | case _PC_LINK_MAX: |
| 606 | *ap->a_retval = LINK_MAX; |
| 607 | return (0); |
| 608 | case _PC_MAX_CANON: |
| 609 | *ap->a_retval = MAX_CANON; |
| 610 | return (0); |
| 611 | case _PC_MAX_INPUT: |
| 612 | *ap->a_retval = MAX_INPUT; |
| 613 | return (0); |
| 614 | case _PC_PIPE_BUF: |
| 615 | *ap->a_retval = PIPE_BUF; |
| 616 | return (0); |
| 617 | case _PC_CHOWN_RESTRICTED: |
| 618 | *ap->a_retval = 1; |
| 619 | return (0); |
| 620 | case _PC_VDISABLE: |
| 621 | *ap->a_retval = _POSIX_VDISABLE; |
| 622 | return (0); |
| 623 | default: |
| 624 | return (EINVAL); |
| 625 | } |
| 626 | /* NOTREACHED */ |
| 627 | } |
| 628 | |
| 629 | /* |
| 630 | * Special device advisory byte-level locks. |
| 631 | */ |
| 632 | /* ARGSUSED */ |
| 633 | spec_advlock(ap) |
| 634 | struct vop_advlock_args /* { |
| 635 | struct vnode *a_vp; |
| 636 | caddr_t a_id; |
| 637 | int a_op; |
| 638 | struct flock *a_fl; |
| 639 | int a_flags; |
| 640 | } */ *ap; |
| 641 | { |
| 642 | |
| 643 | return (EOPNOTSUPP); |
| 644 | } |
| 645 | |
| 646 | /* |
| 647 | * Special device failed operation |
| 648 | */ |
| 649 | spec_ebadf() |
| 650 | { |
| 651 | |
| 652 | return (EBADF); |
| 653 | } |
| 654 | |
| 655 | /* |
| 656 | * Special device bad operation |
| 657 | */ |
| 658 | spec_badop() |
| 659 | { |
| 660 | |
| 661 | panic("spec_badop called"); |
| 662 | /* NOTREACHED */ |
| 663 | } |