spec_vnops.c revision 1.127
1 /* $NetBSD: spec_vnops.c,v 1.127 2009/11/14 18:36:57 elad Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 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. Neither the name of the University nor the names of its contributors 42 * may be used to endorse or promote products derived from this software 43 * without specific prior written permission. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 * 57 * @(#)spec_vnops.c 8.15 (Berkeley) 7/14/95 58 */ 59 60 #include <sys/cdefs.h> 61 __KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.127 2009/11/14 18:36:57 elad Exp $"); 62 63 #include <sys/param.h> 64 #include <sys/proc.h> 65 #include <sys/systm.h> 66 #include <sys/kernel.h> 67 #include <sys/conf.h> 68 #include <sys/buf.h> 69 #include <sys/mount.h> 70 #include <sys/namei.h> 71 #include <sys/vnode.h> 72 #include <sys/stat.h> 73 #include <sys/errno.h> 74 #include <sys/ioctl.h> 75 #include <sys/poll.h> 76 #include <sys/file.h> 77 #include <sys/disklabel.h> 78 #include <sys/lockf.h> 79 #include <sys/tty.h> 80 #include <sys/kauth.h> 81 #include <sys/fstrans.h> 82 #include <sys/module.h> 83 84 #include <miscfs/genfs/genfs.h> 85 #include <miscfs/specfs/specdev.h> 86 87 /* symbolic sleep message strings for devices */ 88 const char devopn[] = "devopn"; 89 const char devio[] = "devio"; 90 const char devwait[] = "devwait"; 91 const char devin[] = "devin"; 92 const char devout[] = "devout"; 93 const char devioc[] = "devioc"; 94 const char devcls[] = "devcls"; 95 96 vnode_t *specfs_hash[SPECHSZ]; 97 98 /* 99 * This vnode operations vector is used for special device nodes 100 * created from whole cloth by the kernel. For the ops vector for 101 * vnodes built from special devices found in a filesystem, see (e.g) 102 * ffs_specop_entries[] in ffs_vnops.c or the equivalent for other 103 * filesystems. 104 */ 105 106 int (**spec_vnodeop_p)(void *); 107 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 108 { &vop_default_desc, vn_default_error }, 109 { &vop_lookup_desc, spec_lookup }, /* lookup */ 110 { &vop_create_desc, spec_create }, /* create */ 111 { &vop_mknod_desc, spec_mknod }, /* mknod */ 112 { &vop_open_desc, spec_open }, /* open */ 113 { &vop_close_desc, spec_close }, /* close */ 114 { &vop_access_desc, spec_access }, /* access */ 115 { &vop_getattr_desc, spec_getattr }, /* getattr */ 116 { &vop_setattr_desc, spec_setattr }, /* setattr */ 117 { &vop_read_desc, spec_read }, /* read */ 118 { &vop_write_desc, spec_write }, /* write */ 119 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */ 120 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 121 { &vop_poll_desc, spec_poll }, /* poll */ 122 { &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */ 123 { &vop_revoke_desc, spec_revoke }, /* revoke */ 124 { &vop_mmap_desc, spec_mmap }, /* mmap */ 125 { &vop_fsync_desc, spec_fsync }, /* fsync */ 126 { &vop_seek_desc, spec_seek }, /* seek */ 127 { &vop_remove_desc, spec_remove }, /* remove */ 128 { &vop_link_desc, spec_link }, /* link */ 129 { &vop_rename_desc, spec_rename }, /* rename */ 130 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 131 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 132 { &vop_symlink_desc, spec_symlink }, /* symlink */ 133 { &vop_readdir_desc, spec_readdir }, /* readdir */ 134 { &vop_readlink_desc, spec_readlink }, /* readlink */ 135 { &vop_abortop_desc, spec_abortop }, /* abortop */ 136 { &vop_inactive_desc, spec_inactive }, /* inactive */ 137 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 138 { &vop_lock_desc, spec_lock }, /* lock */ 139 { &vop_unlock_desc, spec_unlock }, /* unlock */ 140 { &vop_bmap_desc, spec_bmap }, /* bmap */ 141 { &vop_strategy_desc, spec_strategy }, /* strategy */ 142 { &vop_print_desc, spec_print }, /* print */ 143 { &vop_islocked_desc, spec_islocked }, /* islocked */ 144 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 145 { &vop_advlock_desc, spec_advlock }, /* advlock */ 146 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 147 { &vop_getpages_desc, spec_getpages }, /* getpages */ 148 { &vop_putpages_desc, spec_putpages }, /* putpages */ 149 { NULL, NULL } 150 }; 151 const struct vnodeopv_desc spec_vnodeop_opv_desc = 152 { &spec_vnodeop_p, spec_vnodeop_entries }; 153 154 static kauth_listener_t rawio_listener; 155 156 /* Returns true if vnode is /dev/mem or /dev/kmem. */ 157 bool 158 iskmemvp(struct vnode *vp) 159 { 160 return ((vp->v_type == VCHR) && iskmemdev(vp->v_rdev)); 161 } 162 163 /* 164 * Returns true if dev is /dev/mem or /dev/kmem. 165 */ 166 int 167 iskmemdev(dev_t dev) 168 { 169 /* mem_no is emitted by config(8) to generated devsw.c */ 170 extern const int mem_no; 171 172 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 173 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 174 } 175 176 static int 177 rawio_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 178 void *arg0, void *arg1, void *arg2, void *arg3) 179 { 180 int result; 181 182 result = KAUTH_RESULT_DEFER; 183 184 if ((action != KAUTH_DEVICE_RAWIO_SPEC) && 185 (action != KAUTH_DEVICE_RAWIO_PASSTHRU)) 186 return result; 187 188 /* Access is mandated by permissions. */ 189 result = KAUTH_RESULT_ALLOW; 190 191 return result; 192 } 193 194 void 195 spec_init(void) 196 { 197 198 rawio_listener = kauth_listen_scope(KAUTH_SCOPE_DEVICE, 199 rawio_listener_cb, NULL); 200 } 201 202 /* 203 * Initialize a vnode that represents a device. 204 */ 205 void 206 spec_node_init(vnode_t *vp, dev_t rdev) 207 { 208 specnode_t *sn; 209 specdev_t *sd; 210 vnode_t *vp2; 211 vnode_t **vpp; 212 213 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 214 KASSERT(vp->v_specnode == NULL); 215 216 /* 217 * Search the hash table for this device. If known, add a 218 * reference to the device structure. If not known, create 219 * a new entry to represent the device. In all cases add 220 * the vnode to the hash table. 221 */ 222 sn = kmem_alloc(sizeof(*sn), KM_SLEEP); 223 if (sn == NULL) { 224 /* XXX */ 225 panic("spec_node_init: unable to allocate memory"); 226 } 227 sd = kmem_alloc(sizeof(*sd), KM_SLEEP); 228 if (sd == NULL) { 229 /* XXX */ 230 panic("spec_node_init: unable to allocate memory"); 231 } 232 mutex_enter(&device_lock); 233 vpp = &specfs_hash[SPECHASH(rdev)]; 234 for (vp2 = *vpp; vp2 != NULL; vp2 = vp2->v_specnext) { 235 KASSERT(vp2->v_specnode != NULL); 236 if (rdev == vp2->v_rdev && vp->v_type == vp2->v_type) { 237 break; 238 } 239 } 240 if (vp2 == NULL) { 241 /* No existing record, create a new one. */ 242 sd->sd_rdev = rdev; 243 sd->sd_mountpoint = NULL; 244 sd->sd_lockf = NULL; 245 sd->sd_refcnt = 1; 246 sd->sd_opencnt = 0; 247 sd->sd_bdevvp = NULL; 248 sn->sn_dev = sd; 249 sd = NULL; 250 } else { 251 /* Use the existing record. */ 252 sn->sn_dev = vp2->v_specnode->sn_dev; 253 sn->sn_dev->sd_refcnt++; 254 } 255 /* Insert vnode into the hash chain. */ 256 sn->sn_opencnt = 0; 257 sn->sn_rdev = rdev; 258 sn->sn_gone = false; 259 vp->v_specnode = sn; 260 vp->v_specnext = *vpp; 261 *vpp = vp; 262 mutex_exit(&device_lock); 263 264 /* Free the record we allocated if unused. */ 265 if (sd != NULL) { 266 kmem_free(sd, sizeof(*sd)); 267 } 268 } 269 270 /* 271 * A vnode representing a special device is going away. Close 272 * the device if the vnode holds it open. 273 */ 274 void 275 spec_node_revoke(vnode_t *vp) 276 { 277 specnode_t *sn; 278 specdev_t *sd; 279 280 sn = vp->v_specnode; 281 sd = sn->sn_dev; 282 283 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 284 KASSERT(vp->v_specnode != NULL); 285 KASSERT((vp->v_iflag & VI_XLOCK) != 0); 286 KASSERT(sn->sn_gone == false); 287 288 mutex_enter(&device_lock); 289 KASSERT(sn->sn_opencnt <= sd->sd_opencnt); 290 if (sn->sn_opencnt != 0) { 291 sd->sd_opencnt -= (sn->sn_opencnt - 1); 292 sn->sn_opencnt = 1; 293 sn->sn_gone = true; 294 mutex_exit(&device_lock); 295 296 VOP_CLOSE(vp, FNONBLOCK, NOCRED); 297 298 mutex_enter(&device_lock); 299 KASSERT(sn->sn_opencnt == 0); 300 } 301 mutex_exit(&device_lock); 302 } 303 304 /* 305 * A vnode representing a special device is being recycled. 306 * Destroy the specfs component. 307 */ 308 void 309 spec_node_destroy(vnode_t *vp) 310 { 311 specnode_t *sn; 312 specdev_t *sd; 313 vnode_t **vpp, *vp2; 314 int refcnt; 315 316 sn = vp->v_specnode; 317 sd = sn->sn_dev; 318 319 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 320 KASSERT(vp->v_specnode != NULL); 321 KASSERT(sn->sn_opencnt == 0); 322 323 mutex_enter(&device_lock); 324 /* Remove from the hash and destroy the node. */ 325 vpp = &specfs_hash[SPECHASH(vp->v_rdev)]; 326 for (vp2 = *vpp;; vp2 = vp2->v_specnext) { 327 if (vp2 == NULL) { 328 panic("spec_node_destroy: corrupt hash"); 329 } 330 if (vp2 == vp) { 331 KASSERT(vp == *vpp); 332 *vpp = vp->v_specnext; 333 break; 334 } 335 if (vp2->v_specnext == vp) { 336 vp2->v_specnext = vp->v_specnext; 337 break; 338 } 339 } 340 sn = vp->v_specnode; 341 vp->v_specnode = NULL; 342 refcnt = sd->sd_refcnt--; 343 KASSERT(refcnt > 0); 344 mutex_exit(&device_lock); 345 346 /* If the device is no longer in use, destroy our record. */ 347 if (refcnt == 1) { 348 KASSERT(sd->sd_opencnt == 0); 349 KASSERT(sd->sd_bdevvp == NULL); 350 kmem_free(sd, sizeof(*sd)); 351 } 352 kmem_free(sn, sizeof(*sn)); 353 } 354 355 /* 356 * Trivial lookup routine that always fails. 357 */ 358 int 359 spec_lookup(void *v) 360 { 361 struct vop_lookup_args /* { 362 struct vnode *a_dvp; 363 struct vnode **a_vpp; 364 struct componentname *a_cnp; 365 } */ *ap = v; 366 367 *ap->a_vpp = NULL; 368 return (ENOTDIR); 369 } 370 371 /* 372 * Open a special file. 373 */ 374 /* ARGSUSED */ 375 int 376 spec_open(void *v) 377 { 378 struct vop_open_args /* { 379 struct vnode *a_vp; 380 int a_mode; 381 kauth_cred_t a_cred; 382 } */ *ap = v; 383 struct lwp *l; 384 struct vnode *vp; 385 dev_t dev; 386 int error; 387 struct partinfo pi; 388 enum kauth_device_req req; 389 specnode_t *sn; 390 specdev_t *sd; 391 392 u_int gen; 393 const char *name; 394 395 l = curlwp; 396 vp = ap->a_vp; 397 dev = vp->v_rdev; 398 sn = vp->v_specnode; 399 sd = sn->sn_dev; 400 name = NULL; 401 gen = 0; 402 403 /* 404 * Don't allow open if fs is mounted -nodev. 405 */ 406 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 407 return (ENXIO); 408 409 switch (ap->a_mode & (FREAD | FWRITE)) { 410 case FREAD | FWRITE: 411 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_RW; 412 break; 413 case FWRITE: 414 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_WRITE; 415 break; 416 default: 417 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_READ; 418 break; 419 } 420 421 switch (vp->v_type) { 422 case VCHR: 423 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 424 if (error != 0) 425 return (error); 426 427 /* 428 * Character devices can accept opens from multiple 429 * vnodes. 430 */ 431 mutex_enter(&device_lock); 432 if (sn->sn_gone) { 433 mutex_exit(&device_lock); 434 return (EBADF); 435 } 436 sd->sd_opencnt++; 437 sn->sn_opencnt++; 438 mutex_exit(&device_lock); 439 if (cdev_type(dev) == D_TTY) 440 vp->v_vflag |= VV_ISTTY; 441 VOP_UNLOCK(vp, 0); 442 do { 443 const struct cdevsw *cdev; 444 445 gen = module_gen; 446 error = cdev_open(dev, ap->a_mode, S_IFCHR, l); 447 if (error != ENXIO) 448 break; 449 450 /* Check if we already have a valid driver */ 451 mutex_enter(&device_lock); 452 cdev = cdevsw_lookup(dev); 453 mutex_exit(&device_lock); 454 if (cdev != NULL) 455 break; 456 457 /* Get device name from devsw_conv array */ 458 if ((name = cdevsw_getname(major(dev))) == NULL) 459 break; 460 461 /* Try to autoload device module */ 462 mutex_enter(&module_lock); 463 (void) module_autoload(name, MODULE_CLASS_DRIVER); 464 mutex_exit(&module_lock); 465 } while (gen != module_gen); 466 467 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 468 break; 469 470 case VBLK: 471 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 472 if (error != 0) 473 return (error); 474 475 /* 476 * For block devices, permit only one open. The buffer 477 * cache cannot remain self-consistent with multiple 478 * vnodes holding a block device open. 479 */ 480 mutex_enter(&device_lock); 481 if (sn->sn_gone) { 482 mutex_exit(&device_lock); 483 return (EBADF); 484 } 485 if (sd->sd_opencnt != 0) { 486 mutex_exit(&device_lock); 487 return EBUSY; 488 } 489 sn->sn_opencnt = 1; 490 sd->sd_opencnt = 1; 491 sd->sd_bdevvp = vp; 492 mutex_exit(&device_lock); 493 do { 494 const struct bdevsw *bdev; 495 496 gen = module_gen; 497 error = bdev_open(dev, ap->a_mode, S_IFBLK, l); 498 if (error != ENXIO) 499 break; 500 501 /* Check if we already have a valid driver */ 502 mutex_enter(&device_lock); 503 bdev = bdevsw_lookup(dev); 504 mutex_exit(&device_lock); 505 if (bdev != NULL) 506 break; 507 508 /* Get device name from devsw_conv array */ 509 if ((name = bdevsw_getname(major(dev))) == NULL) 510 break; 511 512 VOP_UNLOCK(vp, 0); 513 514 /* Try to autoload device module */ 515 mutex_enter(&module_lock); 516 (void) module_autoload(name, MODULE_CLASS_DRIVER); 517 mutex_exit(&module_lock); 518 519 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 520 } while (gen != module_gen); 521 522 break; 523 524 case VNON: 525 case VLNK: 526 case VDIR: 527 case VREG: 528 case VBAD: 529 case VFIFO: 530 case VSOCK: 531 default: 532 return 0; 533 } 534 535 mutex_enter(&device_lock); 536 if (sn->sn_gone) { 537 if (error == 0) 538 error = EBADF; 539 } else if (error != 0) { 540 sd->sd_opencnt--; 541 sn->sn_opencnt--; 542 if (vp->v_type == VBLK) 543 sd->sd_bdevvp = NULL; 544 545 } 546 mutex_exit(&device_lock); 547 548 if (cdev_type(dev) != D_DISK || error != 0) 549 return error; 550 551 if (vp->v_type == VCHR) 552 error = cdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 553 else 554 error = bdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 555 if (error == 0) 556 uvm_vnp_setsize(vp, 557 (voff_t)pi.disklab->d_secsize * pi.part->p_size); 558 return 0; 559 } 560 561 /* 562 * Vnode op for read 563 */ 564 /* ARGSUSED */ 565 int 566 spec_read(void *v) 567 { 568 struct vop_read_args /* { 569 struct vnode *a_vp; 570 struct uio *a_uio; 571 int a_ioflag; 572 kauth_cred_t a_cred; 573 } */ *ap = v; 574 struct vnode *vp = ap->a_vp; 575 struct uio *uio = ap->a_uio; 576 struct lwp *l = curlwp; 577 struct buf *bp; 578 daddr_t bn; 579 int bsize, bscale; 580 struct partinfo dpart; 581 int n, on; 582 int error = 0; 583 584 #ifdef DIAGNOSTIC 585 if (uio->uio_rw != UIO_READ) 586 panic("spec_read mode"); 587 if (&uio->uio_vmspace->vm_map != kernel_map && 588 uio->uio_vmspace != curproc->p_vmspace) 589 panic("spec_read proc"); 590 #endif 591 if (uio->uio_resid == 0) 592 return (0); 593 594 switch (vp->v_type) { 595 596 case VCHR: 597 VOP_UNLOCK(vp, 0); 598 error = cdev_read(vp->v_rdev, uio, ap->a_ioflag); 599 vn_lock(vp, LK_SHARED | LK_RETRY); 600 return (error); 601 602 case VBLK: 603 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 604 if (uio->uio_offset < 0) 605 return (EINVAL); 606 bsize = BLKDEV_IOSIZE; 607 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 0) { 608 if (dpart.part->p_fstype == FS_BSDFFS && 609 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 610 bsize = dpart.part->p_frag * 611 dpart.part->p_fsize; 612 } 613 bscale = bsize >> DEV_BSHIFT; 614 do { 615 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 616 on = uio->uio_offset % bsize; 617 n = min((unsigned)(bsize - on), uio->uio_resid); 618 error = bread(vp, bn, bsize, NOCRED, 0, &bp); 619 n = min(n, bsize - bp->b_resid); 620 if (error) { 621 brelse(bp, 0); 622 return (error); 623 } 624 error = uiomove((char *)bp->b_data + on, n, uio); 625 brelse(bp, 0); 626 } while (error == 0 && uio->uio_resid > 0 && n != 0); 627 return (error); 628 629 default: 630 panic("spec_read type"); 631 } 632 /* NOTREACHED */ 633 } 634 635 /* 636 * Vnode op for write 637 */ 638 /* ARGSUSED */ 639 int 640 spec_write(void *v) 641 { 642 struct vop_write_args /* { 643 struct vnode *a_vp; 644 struct uio *a_uio; 645 int a_ioflag; 646 kauth_cred_t a_cred; 647 } */ *ap = v; 648 struct vnode *vp = ap->a_vp; 649 struct uio *uio = ap->a_uio; 650 struct lwp *l = curlwp; 651 struct buf *bp; 652 daddr_t bn; 653 int bsize, bscale; 654 struct partinfo dpart; 655 int n, on; 656 int error = 0; 657 658 #ifdef DIAGNOSTIC 659 if (uio->uio_rw != UIO_WRITE) 660 panic("spec_write mode"); 661 if (&uio->uio_vmspace->vm_map != kernel_map && 662 uio->uio_vmspace != curproc->p_vmspace) 663 panic("spec_write proc"); 664 #endif 665 666 switch (vp->v_type) { 667 668 case VCHR: 669 VOP_UNLOCK(vp, 0); 670 error = cdev_write(vp->v_rdev, uio, ap->a_ioflag); 671 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 672 return (error); 673 674 case VBLK: 675 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 676 if (uio->uio_resid == 0) 677 return (0); 678 if (uio->uio_offset < 0) 679 return (EINVAL); 680 bsize = BLKDEV_IOSIZE; 681 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 0) { 682 if (dpart.part->p_fstype == FS_BSDFFS && 683 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 684 bsize = dpart.part->p_frag * 685 dpart.part->p_fsize; 686 } 687 bscale = bsize >> DEV_BSHIFT; 688 do { 689 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 690 on = uio->uio_offset % bsize; 691 n = min((unsigned)(bsize - on), uio->uio_resid); 692 if (n == bsize) 693 bp = getblk(vp, bn, bsize, 0, 0); 694 else 695 error = bread(vp, bn, bsize, NOCRED, 696 B_MODIFY, &bp); 697 if (error) { 698 brelse(bp, 0); 699 return (error); 700 } 701 n = min(n, bsize - bp->b_resid); 702 error = uiomove((char *)bp->b_data + on, n, uio); 703 if (error) 704 brelse(bp, 0); 705 else { 706 if (n + on == bsize) 707 bawrite(bp); 708 else 709 bdwrite(bp); 710 error = bp->b_error; 711 } 712 } while (error == 0 && uio->uio_resid > 0 && n != 0); 713 return (error); 714 715 default: 716 panic("spec_write type"); 717 } 718 /* NOTREACHED */ 719 } 720 721 /* 722 * Device ioctl operation. 723 */ 724 /* ARGSUSED */ 725 int 726 spec_ioctl(void *v) 727 { 728 struct vop_ioctl_args /* { 729 struct vnode *a_vp; 730 u_long a_command; 731 void *a_data; 732 int a_fflag; 733 kauth_cred_t a_cred; 734 } */ *ap = v; 735 struct vnode *vp; 736 dev_t dev; 737 738 /* 739 * Extract all the info we need from the vnode, taking care to 740 * avoid a race with VOP_REVOKE(). 741 */ 742 743 vp = ap->a_vp; 744 dev = NODEV; 745 mutex_enter(&vp->v_interlock); 746 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specnode) { 747 dev = vp->v_rdev; 748 } 749 mutex_exit(&vp->v_interlock); 750 if (dev == NODEV) { 751 return ENXIO; 752 } 753 754 switch (vp->v_type) { 755 756 case VCHR: 757 return cdev_ioctl(dev, ap->a_command, ap->a_data, 758 ap->a_fflag, curlwp); 759 760 case VBLK: 761 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 762 return bdev_ioctl(dev, ap->a_command, ap->a_data, 763 ap->a_fflag, curlwp); 764 765 default: 766 panic("spec_ioctl"); 767 /* NOTREACHED */ 768 } 769 } 770 771 /* ARGSUSED */ 772 int 773 spec_poll(void *v) 774 { 775 struct vop_poll_args /* { 776 struct vnode *a_vp; 777 int a_events; 778 } */ *ap = v; 779 struct vnode *vp; 780 dev_t dev; 781 782 /* 783 * Extract all the info we need from the vnode, taking care to 784 * avoid a race with VOP_REVOKE(). 785 */ 786 787 vp = ap->a_vp; 788 dev = NODEV; 789 mutex_enter(&vp->v_interlock); 790 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specnode) { 791 dev = vp->v_rdev; 792 } 793 mutex_exit(&vp->v_interlock); 794 if (dev == NODEV) { 795 return POLLERR; 796 } 797 798 switch (vp->v_type) { 799 800 case VCHR: 801 return cdev_poll(dev, ap->a_events, curlwp); 802 803 default: 804 return (genfs_poll(v)); 805 } 806 } 807 808 /* ARGSUSED */ 809 int 810 spec_kqfilter(void *v) 811 { 812 struct vop_kqfilter_args /* { 813 struct vnode *a_vp; 814 struct proc *a_kn; 815 } */ *ap = v; 816 dev_t dev; 817 818 switch (ap->a_vp->v_type) { 819 820 case VCHR: 821 dev = ap->a_vp->v_rdev; 822 return cdev_kqfilter(dev, ap->a_kn); 823 default: 824 /* 825 * Block devices don't support kqfilter, and refuse it 826 * for any other files (like those vflush()ed) too. 827 */ 828 return (EOPNOTSUPP); 829 } 830 } 831 832 /* 833 * Allow mapping of only D_DISK. This is called only for VBLK. 834 */ 835 int 836 spec_mmap(void *v) 837 { 838 struct vop_mmap_args /* { 839 struct vnode *a_vp; 840 vm_prot_t a_prot; 841 kauth_cred_t a_cred; 842 } */ *ap = v; 843 struct vnode *vp = ap->a_vp; 844 845 KASSERT(vp->v_type == VBLK); 846 if (bdev_type(vp->v_rdev) != D_DISK) 847 return EINVAL; 848 849 return 0; 850 } 851 852 /* 853 * Synch buffers associated with a block device 854 */ 855 /* ARGSUSED */ 856 int 857 spec_fsync(void *v) 858 { 859 struct vop_fsync_args /* { 860 struct vnode *a_vp; 861 kauth_cred_t a_cred; 862 int a_flags; 863 off_t offlo; 864 off_t offhi; 865 } */ *ap = v; 866 struct vnode *vp = ap->a_vp; 867 struct mount *mp; 868 int error; 869 870 if (vp->v_type == VBLK) { 871 if ((mp = vp->v_specmountpoint) != NULL) { 872 error = VFS_FSYNC(mp, vp, ap->a_flags | FSYNC_VFS); 873 if (error != EOPNOTSUPP) 874 return error; 875 } 876 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0); 877 } 878 return (0); 879 } 880 881 /* 882 * Just call the device strategy routine 883 */ 884 int 885 spec_strategy(void *v) 886 { 887 struct vop_strategy_args /* { 888 struct vnode *a_vp; 889 struct buf *a_bp; 890 } */ *ap = v; 891 struct vnode *vp = ap->a_vp; 892 struct buf *bp = ap->a_bp; 893 int error; 894 895 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 896 897 error = 0; 898 bp->b_dev = vp->v_rdev; 899 900 if (!(bp->b_flags & B_READ)) 901 error = fscow_run(bp, false); 902 903 if (error) { 904 bp->b_error = error; 905 biodone(bp); 906 return (error); 907 } 908 909 bdev_strategy(bp); 910 911 return (0); 912 } 913 914 int 915 spec_inactive(void *v) 916 { 917 struct vop_inactive_args /* { 918 struct vnode *a_vp; 919 struct proc *a_l; 920 } */ *ap = v; 921 922 VOP_UNLOCK(ap->a_vp, 0); 923 return (0); 924 } 925 926 /* 927 * This is a noop, simply returning what one has been given. 928 */ 929 int 930 spec_bmap(void *v) 931 { 932 struct vop_bmap_args /* { 933 struct vnode *a_vp; 934 daddr_t a_bn; 935 struct vnode **a_vpp; 936 daddr_t *a_bnp; 937 int *a_runp; 938 } */ *ap = v; 939 940 if (ap->a_vpp != NULL) 941 *ap->a_vpp = ap->a_vp; 942 if (ap->a_bnp != NULL) 943 *ap->a_bnp = ap->a_bn; 944 if (ap->a_runp != NULL) 945 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 946 return (0); 947 } 948 949 /* 950 * Device close routine 951 */ 952 /* ARGSUSED */ 953 int 954 spec_close(void *v) 955 { 956 struct vop_close_args /* { 957 struct vnode *a_vp; 958 int a_fflag; 959 kauth_cred_t a_cred; 960 } */ *ap = v; 961 struct vnode *vp = ap->a_vp; 962 struct session *sess; 963 dev_t dev = vp->v_rdev; 964 int mode, error, flags, flags1, count; 965 specnode_t *sn; 966 specdev_t *sd; 967 968 flags = vp->v_iflag; 969 sn = vp->v_specnode; 970 sd = sn->sn_dev; 971 972 switch (vp->v_type) { 973 974 case VCHR: 975 /* 976 * Hack: a tty device that is a controlling terminal 977 * has a reference from the session structure. We 978 * cannot easily tell that a character device is a 979 * controlling terminal, unless it is the closing 980 * process' controlling terminal. In that case, if the 981 * open count is 1 release the reference from the 982 * session. Also, remove the link from the tty back to 983 * the session and pgrp. 984 * 985 * XXX V. fishy. 986 */ 987 mutex_enter(proc_lock); 988 sess = curlwp->l_proc->p_session; 989 if (sn->sn_opencnt == 1 && vp == sess->s_ttyvp) { 990 mutex_spin_enter(&tty_lock); 991 sess->s_ttyvp = NULL; 992 if (sess->s_ttyp->t_session != NULL) { 993 sess->s_ttyp->t_pgrp = NULL; 994 sess->s_ttyp->t_session = NULL; 995 mutex_spin_exit(&tty_lock); 996 /* Releases proc_lock. */ 997 proc_sessrele(sess); 998 } else { 999 mutex_spin_exit(&tty_lock); 1000 if (sess->s_ttyp->t_pgrp != NULL) 1001 panic("spec_close: spurious pgrp ref"); 1002 mutex_exit(proc_lock); 1003 } 1004 vrele(vp); 1005 } else 1006 mutex_exit(proc_lock); 1007 1008 /* 1009 * If the vnode is locked, then we are in the midst 1010 * of forcably closing the device, otherwise we only 1011 * close on last reference. 1012 */ 1013 mode = S_IFCHR; 1014 break; 1015 1016 case VBLK: 1017 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 1018 /* 1019 * On last close of a block device (that isn't mounted) 1020 * we must invalidate any in core blocks, so that 1021 * we can, for instance, change floppy disks. 1022 */ 1023 error = vinvalbuf(vp, V_SAVE, ap->a_cred, curlwp, 0, 0); 1024 if (error) 1025 return (error); 1026 /* 1027 * We do not want to really close the device if it 1028 * is still in use unless we are trying to close it 1029 * forcibly. Since every use (buffer, vnode, swap, cmap) 1030 * holds a reference to the vnode, and because we mark 1031 * any other vnodes that alias this device, when the 1032 * sum of the reference counts on all the aliased 1033 * vnodes descends to one, we are on last close. 1034 */ 1035 mode = S_IFBLK; 1036 break; 1037 1038 default: 1039 panic("spec_close: not special"); 1040 } 1041 1042 mutex_enter(&device_lock); 1043 sn->sn_opencnt--; 1044 count = --sd->sd_opencnt; 1045 if (vp->v_type == VBLK) 1046 sd->sd_bdevvp = NULL; 1047 mutex_exit(&device_lock); 1048 1049 if (count != 0) 1050 return 0; 1051 1052 flags1 = ap->a_fflag; 1053 1054 /* 1055 * if VI_XLOCK is set, then we're going away soon, so make this 1056 * non-blocking. Also ensures that we won't wedge in vn_lock below. 1057 */ 1058 if (flags & VI_XLOCK) 1059 flags1 |= FNONBLOCK; 1060 1061 /* 1062 * If we're able to block, release the vnode lock & reacquire. We 1063 * might end up sleeping for someone else who wants our queues. They 1064 * won't get them if we hold the vnode locked. Also, if VI_XLOCK is 1065 * set, don't release the lock as we won't be able to regain it. 1066 */ 1067 if (!(flags1 & FNONBLOCK)) 1068 VOP_UNLOCK(vp, 0); 1069 1070 if (vp->v_type == VBLK) 1071 error = bdev_close(dev, flags1, mode, curlwp); 1072 else 1073 error = cdev_close(dev, flags1, mode, curlwp); 1074 1075 if (!(flags1 & FNONBLOCK)) 1076 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1077 1078 return (error); 1079 } 1080 1081 /* 1082 * Print out the contents of a special device vnode. 1083 */ 1084 int 1085 spec_print(void *v) 1086 { 1087 struct vop_print_args /* { 1088 struct vnode *a_vp; 1089 } */ *ap = v; 1090 1091 printf("dev %llu, %llu\n", (unsigned long long)major(ap->a_vp->v_rdev), 1092 (unsigned long long)minor(ap->a_vp->v_rdev)); 1093 return 0; 1094 } 1095 1096 /* 1097 * Return POSIX pathconf information applicable to special devices. 1098 */ 1099 int 1100 spec_pathconf(void *v) 1101 { 1102 struct vop_pathconf_args /* { 1103 struct vnode *a_vp; 1104 int a_name; 1105 register_t *a_retval; 1106 } */ *ap = v; 1107 1108 switch (ap->a_name) { 1109 case _PC_LINK_MAX: 1110 *ap->a_retval = LINK_MAX; 1111 return (0); 1112 case _PC_MAX_CANON: 1113 *ap->a_retval = MAX_CANON; 1114 return (0); 1115 case _PC_MAX_INPUT: 1116 *ap->a_retval = MAX_INPUT; 1117 return (0); 1118 case _PC_PIPE_BUF: 1119 *ap->a_retval = PIPE_BUF; 1120 return (0); 1121 case _PC_CHOWN_RESTRICTED: 1122 *ap->a_retval = 1; 1123 return (0); 1124 case _PC_VDISABLE: 1125 *ap->a_retval = _POSIX_VDISABLE; 1126 return (0); 1127 case _PC_SYNC_IO: 1128 *ap->a_retval = 1; 1129 return (0); 1130 default: 1131 return (EINVAL); 1132 } 1133 /* NOTREACHED */ 1134 } 1135 1136 /* 1137 * Advisory record locking support. 1138 */ 1139 int 1140 spec_advlock(void *v) 1141 { 1142 struct vop_advlock_args /* { 1143 struct vnode *a_vp; 1144 void *a_id; 1145 int a_op; 1146 struct flock *a_fl; 1147 int a_flags; 1148 } */ *ap = v; 1149 struct vnode *vp = ap->a_vp; 1150 1151 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 1152 } 1153
Indexes created Wed Sep 24 15:09:51 GMT 2025