1 /* $NetBSD: spec_vnops.c,v 1.175 2018/09/03 16:29:35 riastradh 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 1.175 2018/09/03 16:29:35 riastradh 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_impl.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 #define SPECHSZ 64 97 #if ((SPECHSZ&(SPECHSZ-1)) == 0) 98 #define SPECHASH(rdev) (((rdev>>5)+(rdev))&(SPECHSZ-1)) 99 #else 100 #define SPECHASH(rdev) (((unsigned)((rdev>>5)+(rdev)))%SPECHSZ) 101 #endif 102 103 static vnode_t *specfs_hash[SPECHSZ]; 104 extern struct mount *dead_rootmount; 105 106 /* 107 * This vnode operations vector is used for special device nodes 108 * created from whole cloth by the kernel. For the ops vector for 109 * vnodes built from special devices found in a filesystem, see (e.g) 110 * ffs_specop_entries[] in ffs_vnops.c or the equivalent for other 111 * filesystems. 112 */ 113 114 int (**spec_vnodeop_p)(void *); 115 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 116 { &vop_default_desc, vn_default_error }, 117 { &vop_lookup_desc, spec_lookup }, /* lookup */ 118 { &vop_create_desc, spec_create }, /* create */ 119 { &vop_mknod_desc, spec_mknod }, /* mknod */ 120 { &vop_open_desc, spec_open }, /* open */ 121 { &vop_close_desc, spec_close }, /* close */ 122 { &vop_access_desc, spec_access }, /* access */ 123 { &vop_getattr_desc, spec_getattr }, /* getattr */ 124 { &vop_setattr_desc, spec_setattr }, /* setattr */ 125 { &vop_read_desc, spec_read }, /* read */ 126 { &vop_write_desc, spec_write }, /* write */ 127 { &vop_fallocate_desc, spec_fallocate }, /* fallocate */ 128 { &vop_fdiscard_desc, spec_fdiscard }, /* fdiscard */ 129 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */ 130 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 131 { &vop_poll_desc, spec_poll }, /* poll */ 132 { &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */ 133 { &vop_revoke_desc, spec_revoke }, /* revoke */ 134 { &vop_mmap_desc, spec_mmap }, /* mmap */ 135 { &vop_fsync_desc, spec_fsync }, /* fsync */ 136 { &vop_seek_desc, spec_seek }, /* seek */ 137 { &vop_remove_desc, spec_remove }, /* remove */ 138 { &vop_link_desc, spec_link }, /* link */ 139 { &vop_rename_desc, spec_rename }, /* rename */ 140 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 141 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 142 { &vop_symlink_desc, spec_symlink }, /* symlink */ 143 { &vop_readdir_desc, spec_readdir }, /* readdir */ 144 { &vop_readlink_desc, spec_readlink }, /* readlink */ 145 { &vop_abortop_desc, spec_abortop }, /* abortop */ 146 { &vop_inactive_desc, spec_inactive }, /* inactive */ 147 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 148 { &vop_lock_desc, spec_lock }, /* lock */ 149 { &vop_unlock_desc, spec_unlock }, /* unlock */ 150 { &vop_bmap_desc, spec_bmap }, /* bmap */ 151 { &vop_strategy_desc, spec_strategy }, /* strategy */ 152 { &vop_print_desc, spec_print }, /* print */ 153 { &vop_islocked_desc, spec_islocked }, /* islocked */ 154 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 155 { &vop_advlock_desc, spec_advlock }, /* advlock */ 156 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 157 { &vop_getpages_desc, spec_getpages }, /* getpages */ 158 { &vop_putpages_desc, spec_putpages }, /* putpages */ 159 { NULL, NULL } 160 }; 161 const struct vnodeopv_desc spec_vnodeop_opv_desc = 162 { &spec_vnodeop_p, spec_vnodeop_entries }; 163 164 static kauth_listener_t rawio_listener; 165 166 /* Returns true if vnode is /dev/mem or /dev/kmem. */ 167 bool 168 iskmemvp(struct vnode *vp) 169 { 170 return ((vp->v_type == VCHR) && iskmemdev(vp->v_rdev)); 171 } 172 173 /* 174 * Returns true if dev is /dev/mem or /dev/kmem. 175 */ 176 int 177 iskmemdev(dev_t dev) 178 { 179 /* mem_no is emitted by config(8) to generated devsw.c */ 180 extern const int mem_no; 181 182 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 183 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 184 } 185 186 static int 187 rawio_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 188 void *arg0, void *arg1, void *arg2, void *arg3) 189 { 190 int result; 191 192 result = KAUTH_RESULT_DEFER; 193 194 if ((action != KAUTH_DEVICE_RAWIO_SPEC) && 195 (action != KAUTH_DEVICE_RAWIO_PASSTHRU)) 196 return result; 197 198 /* Access is mandated by permissions. */ 199 result = KAUTH_RESULT_ALLOW; 200 201 return result; 202 } 203 204 void 205 spec_init(void) 206 { 207 208 rawio_listener = kauth_listen_scope(KAUTH_SCOPE_DEVICE, 209 rawio_listener_cb, NULL); 210 } 211 212 /* 213 * Initialize a vnode that represents a device. 214 */ 215 void 216 spec_node_init(vnode_t *vp, dev_t rdev) 217 { 218 specnode_t *sn; 219 specdev_t *sd; 220 vnode_t *vp2; 221 vnode_t **vpp; 222 223 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 224 KASSERT(vp->v_specnode == NULL); 225 226 /* 227 * Search the hash table for this device. If known, add a 228 * reference to the device structure. If not known, create 229 * a new entry to represent the device. In all cases add 230 * the vnode to the hash table. 231 */ 232 sn = kmem_alloc(sizeof(*sn), KM_SLEEP); 233 sd = kmem_alloc(sizeof(*sd), KM_SLEEP); 234 mutex_enter(&device_lock); 235 vpp = &specfs_hash[SPECHASH(rdev)]; 236 for (vp2 = *vpp; vp2 != NULL; vp2 = vp2->v_specnext) { 237 KASSERT(vp2->v_specnode != NULL); 238 if (rdev == vp2->v_rdev && vp->v_type == vp2->v_type) { 239 break; 240 } 241 } 242 if (vp2 == NULL) { 243 /* No existing record, create a new one. */ 244 sd->sd_rdev = rdev; 245 sd->sd_mountpoint = NULL; 246 sd->sd_lockf = NULL; 247 sd->sd_refcnt = 1; 248 sd->sd_opencnt = 0; 249 sd->sd_bdevvp = NULL; 250 sn->sn_dev = sd; 251 sd = NULL; 252 } else { 253 /* Use the existing record. */ 254 sn->sn_dev = vp2->v_specnode->sn_dev; 255 sn->sn_dev->sd_refcnt++; 256 } 257 /* Insert vnode into the hash chain. */ 258 sn->sn_opencnt = 0; 259 sn->sn_rdev = rdev; 260 sn->sn_gone = false; 261 vp->v_specnode = sn; 262 vp->v_specnext = *vpp; 263 *vpp = vp; 264 mutex_exit(&device_lock); 265 266 /* Free the record we allocated if unused. */ 267 if (sd != NULL) { 268 kmem_free(sd, sizeof(*sd)); 269 } 270 } 271 272 /* 273 * Lookup a vnode by device number and return it referenced. 274 */ 275 int 276 spec_node_lookup_by_dev(enum vtype type, dev_t dev, vnode_t **vpp) 277 { 278 int error; 279 vnode_t *vp; 280 281 mutex_enter(&device_lock); 282 for (vp = specfs_hash[SPECHASH(dev)]; vp; vp = vp->v_specnext) { 283 if (type == vp->v_type && dev == vp->v_rdev) { 284 mutex_enter(vp->v_interlock); 285 /* If clean or being cleaned, then ignore it. */ 286 if (vdead_check(vp, VDEAD_NOWAIT) == 0) 287 break; 288 mutex_exit(vp->v_interlock); 289 } 290 } 291 KASSERT(vp == NULL || mutex_owned(vp->v_interlock)); 292 if (vp == NULL) { 293 mutex_exit(&device_lock); 294 return ENOENT; 295 } 296 /* 297 * If it is an opened block device return the opened vnode. 298 */ 299 if (type == VBLK && vp->v_specnode->sn_dev->sd_bdevvp != NULL) { 300 mutex_exit(vp->v_interlock); 301 vp = vp->v_specnode->sn_dev->sd_bdevvp; 302 mutex_enter(vp->v_interlock); 303 } 304 mutex_exit(&device_lock); 305 error = vcache_vget(vp); 306 if (error != 0) 307 return error; 308 *vpp = vp; 309 310 return 0; 311 } 312 313 /* 314 * Lookup a vnode by file system mounted on and return it referenced. 315 */ 316 int 317 spec_node_lookup_by_mount(struct mount *mp, vnode_t **vpp) 318 { 319 int i, error; 320 vnode_t *vp, *vq; 321 322 mutex_enter(&device_lock); 323 for (i = 0, vq = NULL; i < SPECHSZ && vq == NULL; i++) { 324 for (vp = specfs_hash[i]; vp; vp = vp->v_specnext) { 325 if (vp->v_type != VBLK) 326 continue; 327 vq = vp->v_specnode->sn_dev->sd_bdevvp; 328 if (vq != NULL && 329 vq->v_specnode->sn_dev->sd_mountpoint == mp) 330 break; 331 vq = NULL; 332 } 333 } 334 if (vq == NULL) { 335 mutex_exit(&device_lock); 336 return ENOENT; 337 } 338 mutex_enter(vq->v_interlock); 339 mutex_exit(&device_lock); 340 error = vcache_vget(vq); 341 if (error != 0) 342 return error; 343 *vpp = vq; 344 345 return 0; 346 347 } 348 349 /* 350 * Get the file system mounted on this block device. 351 */ 352 struct mount * 353 spec_node_getmountedfs(vnode_t *devvp) 354 { 355 struct mount *mp; 356 357 KASSERT(devvp->v_type == VBLK); 358 mp = devvp->v_specnode->sn_dev->sd_mountpoint; 359 360 return mp; 361 } 362 363 /* 364 * Set the file system mounted on this block device. 365 */ 366 void 367 spec_node_setmountedfs(vnode_t *devvp, struct mount *mp) 368 { 369 370 KASSERT(devvp->v_type == VBLK); 371 KASSERT(devvp->v_specnode->sn_dev->sd_mountpoint == NULL || mp == NULL); 372 devvp->v_specnode->sn_dev->sd_mountpoint = mp; 373 } 374 375 /* 376 * A vnode representing a special device is going away. Close 377 * the device if the vnode holds it open. 378 */ 379 void 380 spec_node_revoke(vnode_t *vp) 381 { 382 specnode_t *sn; 383 specdev_t *sd; 384 385 sn = vp->v_specnode; 386 sd = sn->sn_dev; 387 388 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 389 KASSERT(vp->v_specnode != NULL); 390 KASSERT(sn->sn_gone == false); 391 392 mutex_enter(&device_lock); 393 KASSERT(sn->sn_opencnt <= sd->sd_opencnt); 394 if (sn->sn_opencnt != 0) { 395 sd->sd_opencnt -= (sn->sn_opencnt - 1); 396 sn->sn_opencnt = 1; 397 sn->sn_gone = true; 398 mutex_exit(&device_lock); 399 400 VOP_CLOSE(vp, FNONBLOCK, NOCRED); 401 402 mutex_enter(&device_lock); 403 KASSERT(sn->sn_opencnt == 0); 404 } 405 mutex_exit(&device_lock); 406 } 407 408 /* 409 * A vnode representing a special device is being recycled. 410 * Destroy the specfs component. 411 */ 412 void 413 spec_node_destroy(vnode_t *vp) 414 { 415 specnode_t *sn; 416 specdev_t *sd; 417 vnode_t **vpp, *vp2; 418 int refcnt; 419 420 sn = vp->v_specnode; 421 sd = sn->sn_dev; 422 423 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 424 KASSERT(vp->v_specnode != NULL); 425 KASSERT(sn->sn_opencnt == 0); 426 427 mutex_enter(&device_lock); 428 /* Remove from the hash and destroy the node. */ 429 vpp = &specfs_hash[SPECHASH(vp->v_rdev)]; 430 for (vp2 = *vpp;; vp2 = vp2->v_specnext) { 431 if (vp2 == NULL) { 432 panic("spec_node_destroy: corrupt hash"); 433 } 434 if (vp2 == vp) { 435 KASSERT(vp == *vpp); 436 *vpp = vp->v_specnext; 437 break; 438 } 439 if (vp2->v_specnext == vp) { 440 vp2->v_specnext = vp->v_specnext; 441 break; 442 } 443 } 444 sn = vp->v_specnode; 445 vp->v_specnode = NULL; 446 refcnt = sd->sd_refcnt--; 447 KASSERT(refcnt > 0); 448 mutex_exit(&device_lock); 449 450 /* If the device is no longer in use, destroy our record. */ 451 if (refcnt == 1) { 452 KASSERT(sd->sd_opencnt == 0); 453 KASSERT(sd->sd_bdevvp == NULL); 454 kmem_free(sd, sizeof(*sd)); 455 } 456 kmem_free(sn, sizeof(*sn)); 457 } 458 459 /* 460 * Trivial lookup routine that always fails. 461 */ 462 int 463 spec_lookup(void *v) 464 { 465 struct vop_lookup_v2_args /* { 466 struct vnode *a_dvp; 467 struct vnode **a_vpp; 468 struct componentname *a_cnp; 469 } */ *ap = v; 470 471 *ap->a_vpp = NULL; 472 return (ENOTDIR); 473 } 474 475 typedef int (*spec_ioctl_t)(dev_t, u_long, void *, int, struct lwp *); 476 477 /* 478 * Open a special file. 479 */ 480 /* ARGSUSED */ 481 int 482 spec_open(void *v) 483 { 484 struct vop_open_args /* { 485 struct vnode *a_vp; 486 int a_mode; 487 kauth_cred_t a_cred; 488 } */ *ap = v; 489 struct lwp *l; 490 struct vnode *vp; 491 dev_t dev; 492 int error; 493 enum kauth_device_req req; 494 specnode_t *sn; 495 specdev_t *sd; 496 spec_ioctl_t ioctl; 497 u_int gen; 498 const char *name; 499 struct partinfo pi; 500 501 l = curlwp; 502 vp = ap->a_vp; 503 dev = vp->v_rdev; 504 sn = vp->v_specnode; 505 sd = sn->sn_dev; 506 name = NULL; 507 gen = 0; 508 509 /* 510 * Don't allow open if fs is mounted -nodev. 511 */ 512 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 513 return (ENXIO); 514 515 switch (ap->a_mode & (FREAD | FWRITE)) { 516 case FREAD | FWRITE: 517 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_RW; 518 break; 519 case FWRITE: 520 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_WRITE; 521 break; 522 default: 523 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_READ; 524 break; 525 } 526 527 switch (vp->v_type) { 528 case VCHR: 529 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 530 if (error != 0) 531 return (error); 532 533 /* 534 * Character devices can accept opens from multiple 535 * vnodes. 536 */ 537 mutex_enter(&device_lock); 538 if (sn->sn_gone) { 539 mutex_exit(&device_lock); 540 return (EBADF); 541 } 542 sd->sd_opencnt++; 543 sn->sn_opencnt++; 544 mutex_exit(&device_lock); 545 if (cdev_type(dev) == D_TTY) 546 vp->v_vflag |= VV_ISTTY; 547 VOP_UNLOCK(vp); 548 do { 549 const struct cdevsw *cdev; 550 551 gen = module_gen; 552 error = cdev_open(dev, ap->a_mode, S_IFCHR, l); 553 if (error != ENXIO) 554 break; 555 556 /* Check if we already have a valid driver */ 557 mutex_enter(&device_lock); 558 cdev = cdevsw_lookup(dev); 559 mutex_exit(&device_lock); 560 if (cdev != NULL) 561 break; 562 563 /* Get device name from devsw_conv array */ 564 if ((name = cdevsw_getname(major(dev))) == NULL) 565 break; 566 567 /* Try to autoload device module */ 568 (void) module_autoload(name, MODULE_CLASS_DRIVER); 569 } while (gen != module_gen); 570 571 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 572 break; 573 574 case VBLK: 575 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 576 if (error != 0) 577 return (error); 578 579 /* 580 * For block devices, permit only one open. The buffer 581 * cache cannot remain self-consistent with multiple 582 * vnodes holding a block device open. 583 * 584 * Treat zero opencnt with non-NULL mountpoint as open. 585 * This may happen after forced detach of a mounted device. 586 */ 587 mutex_enter(&device_lock); 588 if (sn->sn_gone) { 589 mutex_exit(&device_lock); 590 return (EBADF); 591 } 592 if (sd->sd_opencnt != 0 || sd->sd_mountpoint != NULL) { 593 mutex_exit(&device_lock); 594 return EBUSY; 595 } 596 sn->sn_opencnt = 1; 597 sd->sd_opencnt = 1; 598 sd->sd_bdevvp = vp; 599 mutex_exit(&device_lock); 600 do { 601 const struct bdevsw *bdev; 602 603 gen = module_gen; 604 error = bdev_open(dev, ap->a_mode, S_IFBLK, l); 605 if (error != ENXIO) 606 break; 607 608 /* Check if we already have a valid driver */ 609 mutex_enter(&device_lock); 610 bdev = bdevsw_lookup(dev); 611 mutex_exit(&device_lock); 612 if (bdev != NULL) 613 break; 614 615 /* Get device name from devsw_conv array */ 616 if ((name = bdevsw_getname(major(dev))) == NULL) 617 break; 618 619 VOP_UNLOCK(vp); 620 621 /* Try to autoload device module */ 622 (void) module_autoload(name, MODULE_CLASS_DRIVER); 623 624 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 625 } while (gen != module_gen); 626 627 break; 628 629 case VNON: 630 case VLNK: 631 case VDIR: 632 case VREG: 633 case VBAD: 634 case VFIFO: 635 case VSOCK: 636 default: 637 return 0; 638 } 639 640 mutex_enter(&device_lock); 641 if (sn->sn_gone) { 642 if (error == 0) 643 error = EBADF; 644 } else if (error != 0) { 645 sd->sd_opencnt--; 646 sn->sn_opencnt--; 647 if (vp->v_type == VBLK) 648 sd->sd_bdevvp = NULL; 649 650 } 651 mutex_exit(&device_lock); 652 653 if (cdev_type(dev) != D_DISK || error != 0) 654 return error; 655 656 657 ioctl = vp->v_type == VCHR ? cdev_ioctl : bdev_ioctl; 658 error = (*ioctl)(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, curlwp); 659 if (error == 0) 660 uvm_vnp_setsize(vp, (voff_t)pi.pi_secsize * pi.pi_size); 661 662 return 0; 663 } 664 665 /* 666 * Vnode op for read 667 */ 668 /* ARGSUSED */ 669 int 670 spec_read(void *v) 671 { 672 struct vop_read_args /* { 673 struct vnode *a_vp; 674 struct uio *a_uio; 675 int a_ioflag; 676 kauth_cred_t a_cred; 677 } */ *ap = v; 678 struct vnode *vp = ap->a_vp; 679 struct uio *uio = ap->a_uio; 680 struct lwp *l = curlwp; 681 struct buf *bp; 682 daddr_t bn; 683 int bsize, bscale; 684 struct partinfo pi; 685 int n, on; 686 int error = 0; 687 688 KASSERT(uio->uio_rw == UIO_READ); 689 KASSERTMSG(VMSPACE_IS_KERNEL_P(uio->uio_vmspace) || 690 uio->uio_vmspace == curproc->p_vmspace, 691 "vmspace belongs to neither kernel nor curproc"); 692 693 if (uio->uio_resid == 0) 694 return (0); 695 696 switch (vp->v_type) { 697 698 case VCHR: 699 VOP_UNLOCK(vp); 700 error = cdev_read(vp->v_rdev, uio, ap->a_ioflag); 701 vn_lock(vp, LK_SHARED | LK_RETRY); 702 return (error); 703 704 case VBLK: 705 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 706 if (uio->uio_offset < 0) 707 return (EINVAL); 708 709 if (bdev_ioctl(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, l) == 0) 710 bsize = pi.pi_bsize; 711 else 712 bsize = BLKDEV_IOSIZE; 713 714 bscale = bsize >> DEV_BSHIFT; 715 do { 716 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 717 on = uio->uio_offset % bsize; 718 n = uimin((unsigned)(bsize - on), uio->uio_resid); 719 error = bread(vp, bn, bsize, 0, &bp); 720 if (error) { 721 return (error); 722 } 723 n = uimin(n, bsize - bp->b_resid); 724 error = uiomove((char *)bp->b_data + on, n, uio); 725 brelse(bp, 0); 726 } while (error == 0 && uio->uio_resid > 0 && n != 0); 727 return (error); 728 729 default: 730 panic("spec_read type"); 731 } 732 /* NOTREACHED */ 733 } 734 735 /* 736 * Vnode op for write 737 */ 738 /* ARGSUSED */ 739 int 740 spec_write(void *v) 741 { 742 struct vop_write_args /* { 743 struct vnode *a_vp; 744 struct uio *a_uio; 745 int a_ioflag; 746 kauth_cred_t a_cred; 747 } */ *ap = v; 748 struct vnode *vp = ap->a_vp; 749 struct uio *uio = ap->a_uio; 750 struct lwp *l = curlwp; 751 struct buf *bp; 752 daddr_t bn; 753 int bsize, bscale; 754 struct partinfo pi; 755 int n, on; 756 int error = 0; 757 758 KASSERT(uio->uio_rw == UIO_WRITE); 759 KASSERTMSG(VMSPACE_IS_KERNEL_P(uio->uio_vmspace) || 760 uio->uio_vmspace == curproc->p_vmspace, 761 "vmspace belongs to neither kernel nor curproc"); 762 763 switch (vp->v_type) { 764 765 case VCHR: 766 VOP_UNLOCK(vp); 767 error = cdev_write(vp->v_rdev, uio, ap->a_ioflag); 768 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 769 return (error); 770 771 case VBLK: 772 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 773 if (uio->uio_resid == 0) 774 return (0); 775 if (uio->uio_offset < 0) 776 return (EINVAL); 777 778 if (bdev_ioctl(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, l) == 0) 779 bsize = pi.pi_bsize; 780 else 781 bsize = BLKDEV_IOSIZE; 782 783 bscale = bsize >> DEV_BSHIFT; 784 do { 785 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 786 on = uio->uio_offset % bsize; 787 n = uimin((unsigned)(bsize - on), uio->uio_resid); 788 if (n == bsize) 789 bp = getblk(vp, bn, bsize, 0, 0); 790 else 791 error = bread(vp, bn, bsize, B_MODIFY, &bp); 792 if (error) { 793 return (error); 794 } 795 n = uimin(n, bsize - bp->b_resid); 796 error = uiomove((char *)bp->b_data + on, n, uio); 797 if (error) 798 brelse(bp, 0); 799 else { 800 if (n + on == bsize) 801 bawrite(bp); 802 else 803 bdwrite(bp); 804 error = bp->b_error; 805 } 806 } while (error == 0 && uio->uio_resid > 0 && n != 0); 807 return (error); 808 809 default: 810 panic("spec_write type"); 811 } 812 /* NOTREACHED */ 813 } 814 815 /* 816 * fdiscard, which on disk devices becomes TRIM. 817 */ 818 int 819 spec_fdiscard(void *v) 820 { 821 struct vop_fdiscard_args /* { 822 struct vnode *a_vp; 823 off_t a_pos; 824 off_t a_len; 825 } */ *ap = v; 826 struct vnode *vp; 827 dev_t dev; 828 829 vp = ap->a_vp; 830 dev = NODEV; 831 832 mutex_enter(vp->v_interlock); 833 if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode != NULL) { 834 dev = vp->v_rdev; 835 } 836 mutex_exit(vp->v_interlock); 837 838 if (dev == NODEV) { 839 return ENXIO; 840 } 841 842 switch (vp->v_type) { 843 case VCHR: 844 // this is not stored for character devices 845 //KASSERT(vp == vp->v_specnode->sn_dev->sd_cdevvp); 846 return cdev_discard(dev, ap->a_pos, ap->a_len); 847 case VBLK: 848 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 849 return bdev_discard(dev, ap->a_pos, ap->a_len); 850 default: 851 panic("spec_fdiscard: not a device\n"); 852 } 853 } 854 855 /* 856 * Device ioctl operation. 857 */ 858 /* ARGSUSED */ 859 int 860 spec_ioctl(void *v) 861 { 862 struct vop_ioctl_args /* { 863 struct vnode *a_vp; 864 u_long a_command; 865 void *a_data; 866 int a_fflag; 867 kauth_cred_t a_cred; 868 } */ *ap = v; 869 struct vnode *vp; 870 dev_t dev; 871 872 /* 873 * Extract all the info we need from the vnode, taking care to 874 * avoid a race with VOP_REVOKE(). 875 */ 876 877 vp = ap->a_vp; 878 dev = NODEV; 879 mutex_enter(vp->v_interlock); 880 if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode) { 881 dev = vp->v_rdev; 882 } 883 mutex_exit(vp->v_interlock); 884 if (dev == NODEV) { 885 return ENXIO; 886 } 887 888 switch (vp->v_type) { 889 890 case VCHR: 891 return cdev_ioctl(dev, ap->a_command, ap->a_data, 892 ap->a_fflag, curlwp); 893 894 case VBLK: 895 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 896 return bdev_ioctl(dev, ap->a_command, ap->a_data, 897 ap->a_fflag, curlwp); 898 899 default: 900 panic("spec_ioctl"); 901 /* NOTREACHED */ 902 } 903 } 904 905 /* ARGSUSED */ 906 int 907 spec_poll(void *v) 908 { 909 struct vop_poll_args /* { 910 struct vnode *a_vp; 911 int a_events; 912 } */ *ap = v; 913 struct vnode *vp; 914 dev_t dev; 915 916 /* 917 * Extract all the info we need from the vnode, taking care to 918 * avoid a race with VOP_REVOKE(). 919 */ 920 921 vp = ap->a_vp; 922 dev = NODEV; 923 mutex_enter(vp->v_interlock); 924 if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode) { 925 dev = vp->v_rdev; 926 } 927 mutex_exit(vp->v_interlock); 928 if (dev == NODEV) { 929 return POLLERR; 930 } 931 932 switch (vp->v_type) { 933 934 case VCHR: 935 return cdev_poll(dev, ap->a_events, curlwp); 936 937 default: 938 return (genfs_poll(v)); 939 } 940 } 941 942 /* ARGSUSED */ 943 int 944 spec_kqfilter(void *v) 945 { 946 struct vop_kqfilter_args /* { 947 struct vnode *a_vp; 948 struct proc *a_kn; 949 } */ *ap = v; 950 dev_t dev; 951 952 switch (ap->a_vp->v_type) { 953 954 case VCHR: 955 dev = ap->a_vp->v_rdev; 956 return cdev_kqfilter(dev, ap->a_kn); 957 default: 958 /* 959 * Block devices don't support kqfilter, and refuse it 960 * for any other files (like those vflush()ed) too. 961 */ 962 return (EOPNOTSUPP); 963 } 964 } 965 966 /* 967 * Allow mapping of only D_DISK. This is called only for VBLK. 968 */ 969 int 970 spec_mmap(void *v) 971 { 972 struct vop_mmap_args /* { 973 struct vnode *a_vp; 974 vm_prot_t a_prot; 975 kauth_cred_t a_cred; 976 } */ *ap = v; 977 struct vnode *vp = ap->a_vp; 978 979 KASSERT(vp->v_type == VBLK); 980 if (bdev_type(vp->v_rdev) != D_DISK) 981 return EINVAL; 982 983 return 0; 984 } 985 986 /* 987 * Synch buffers associated with a block device 988 */ 989 /* ARGSUSED */ 990 int 991 spec_fsync(void *v) 992 { 993 struct vop_fsync_args /* { 994 struct vnode *a_vp; 995 kauth_cred_t a_cred; 996 int a_flags; 997 off_t offlo; 998 off_t offhi; 999 } */ *ap = v; 1000 struct vnode *vp = ap->a_vp; 1001 struct mount *mp; 1002 int error; 1003 1004 if (vp->v_type == VBLK) { 1005 if ((mp = spec_node_getmountedfs(vp)) != NULL) { 1006 error = VFS_FSYNC(mp, vp, ap->a_flags); 1007 if (error != EOPNOTSUPP) 1008 return error; 1009 } 1010 return vflushbuf(vp, ap->a_flags); 1011 } 1012 return (0); 1013 } 1014 1015 /* 1016 * Just call the device strategy routine 1017 */ 1018 int 1019 spec_strategy(void *v) 1020 { 1021 struct vop_strategy_args /* { 1022 struct vnode *a_vp; 1023 struct buf *a_bp; 1024 } */ *ap = v; 1025 struct vnode *vp = ap->a_vp; 1026 struct buf *bp = ap->a_bp; 1027 dev_t dev; 1028 int error; 1029 1030 dev = NODEV; 1031 1032 /* 1033 * Extract all the info we need from the vnode, taking care to 1034 * avoid a race with VOP_REVOKE(). 1035 */ 1036 1037 mutex_enter(vp->v_interlock); 1038 if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode != NULL) { 1039 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 1040 dev = vp->v_rdev; 1041 } 1042 mutex_exit(vp->v_interlock); 1043 1044 if (dev == NODEV) { 1045 error = ENXIO; 1046 goto out; 1047 } 1048 bp->b_dev = dev; 1049 1050 if (!(bp->b_flags & B_READ)) { 1051 #ifdef DIAGNOSTIC 1052 if (bp->b_vp && bp->b_vp->v_type == VBLK) { 1053 struct mount *mp = spec_node_getmountedfs(bp->b_vp); 1054 1055 if (mp && (mp->mnt_flag & MNT_RDONLY)) { 1056 printf("%s blk %"PRId64" written while ro!\n", 1057 mp->mnt_stat.f_mntonname, bp->b_blkno); 1058 } 1059 } 1060 #endif /* DIAGNOSTIC */ 1061 error = fscow_run(bp, false); 1062 if (error) 1063 goto out; 1064 } 1065 bdev_strategy(bp); 1066 1067 return 0; 1068 1069 out: 1070 bp->b_error = error; 1071 bp->b_resid = bp->b_bcount; 1072 biodone(bp); 1073 1074 return error; 1075 } 1076 1077 int 1078 spec_inactive(void *v) 1079 { 1080 struct vop_inactive_v2_args /* { 1081 struct vnode *a_vp; 1082 struct bool *a_recycle; 1083 } */ *ap = v; 1084 1085 KASSERT(ap->a_vp->v_mount == dead_rootmount); 1086 *ap->a_recycle = true; 1087 1088 return 0; 1089 } 1090 1091 int 1092 spec_reclaim(void *v) 1093 { 1094 struct vop_reclaim_v2_args /* { 1095 struct vnode *a_vp; 1096 } */ *ap = v; 1097 struct vnode *vp = ap->a_vp; 1098 1099 VOP_UNLOCK(vp); 1100 1101 KASSERT(vp->v_mount == dead_rootmount); 1102 return 0; 1103 } 1104 1105 /* 1106 * This is a noop, simply returning what one has been given. 1107 */ 1108 int 1109 spec_bmap(void *v) 1110 { 1111 struct vop_bmap_args /* { 1112 struct vnode *a_vp; 1113 daddr_t a_bn; 1114 struct vnode **a_vpp; 1115 daddr_t *a_bnp; 1116 int *a_runp; 1117 } */ *ap = v; 1118 1119 if (ap->a_vpp != NULL) 1120 *ap->a_vpp = ap->a_vp; 1121 if (ap->a_bnp != NULL) 1122 *ap->a_bnp = ap->a_bn; 1123 if (ap->a_runp != NULL) 1124 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 1125 return (0); 1126 } 1127 1128 /* 1129 * Device close routine 1130 */ 1131 /* ARGSUSED */ 1132 int 1133 spec_close(void *v) 1134 { 1135 struct vop_close_args /* { 1136 struct vnode *a_vp; 1137 int a_fflag; 1138 kauth_cred_t a_cred; 1139 } */ *ap = v; 1140 struct vnode *vp = ap->a_vp; 1141 struct session *sess; 1142 dev_t dev = vp->v_rdev; 1143 int flags = ap->a_fflag; 1144 int mode, error, count; 1145 specnode_t *sn; 1146 specdev_t *sd; 1147 1148 mutex_enter(vp->v_interlock); 1149 sn = vp->v_specnode; 1150 sd = sn->sn_dev; 1151 /* 1152 * If we're going away soon, make this non-blocking. 1153 * Also ensures that we won't wedge in vn_lock below. 1154 */ 1155 if (vdead_check(vp, VDEAD_NOWAIT) != 0) 1156 flags |= FNONBLOCK; 1157 mutex_exit(vp->v_interlock); 1158 1159 switch (vp->v_type) { 1160 1161 case VCHR: 1162 /* 1163 * Hack: a tty device that is a controlling terminal 1164 * has a reference from the session structure. We 1165 * cannot easily tell that a character device is a 1166 * controlling terminal, unless it is the closing 1167 * process' controlling terminal. In that case, if the 1168 * open count is 1 release the reference from the 1169 * session. Also, remove the link from the tty back to 1170 * the session and pgrp. 1171 * 1172 * XXX V. fishy. 1173 */ 1174 mutex_enter(proc_lock); 1175 sess = curlwp->l_proc->p_session; 1176 if (sn->sn_opencnt == 1 && vp == sess->s_ttyvp) { 1177 mutex_spin_enter(&tty_lock); 1178 sess->s_ttyvp = NULL; 1179 if (sess->s_ttyp->t_session != NULL) { 1180 sess->s_ttyp->t_pgrp = NULL; 1181 sess->s_ttyp->t_session = NULL; 1182 mutex_spin_exit(&tty_lock); 1183 /* Releases proc_lock. */ 1184 proc_sessrele(sess); 1185 } else { 1186 mutex_spin_exit(&tty_lock); 1187 if (sess->s_ttyp->t_pgrp != NULL) 1188 panic("spec_close: spurious pgrp ref"); 1189 mutex_exit(proc_lock); 1190 } 1191 vrele(vp); 1192 } else 1193 mutex_exit(proc_lock); 1194 1195 /* 1196 * If the vnode is locked, then we are in the midst 1197 * of forcably closing the device, otherwise we only 1198 * close on last reference. 1199 */ 1200 mode = S_IFCHR; 1201 break; 1202 1203 case VBLK: 1204 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 1205 /* 1206 * On last close of a block device (that isn't mounted) 1207 * we must invalidate any in core blocks, so that 1208 * we can, for instance, change floppy disks. 1209 */ 1210 error = vinvalbuf(vp, V_SAVE, ap->a_cred, curlwp, 0, 0); 1211 if (error) 1212 return (error); 1213 /* 1214 * We do not want to really close the device if it 1215 * is still in use unless we are trying to close it 1216 * forcibly. Since every use (buffer, vnode, swap, cmap) 1217 * holds a reference to the vnode, and because we mark 1218 * any other vnodes that alias this device, when the 1219 * sum of the reference counts on all the aliased 1220 * vnodes descends to one, we are on last close. 1221 */ 1222 mode = S_IFBLK; 1223 break; 1224 1225 default: 1226 panic("spec_close: not special"); 1227 } 1228 1229 mutex_enter(&device_lock); 1230 sn->sn_opencnt--; 1231 count = --sd->sd_opencnt; 1232 if (vp->v_type == VBLK) 1233 sd->sd_bdevvp = NULL; 1234 mutex_exit(&device_lock); 1235 1236 if (count != 0 && (vp->v_type != VCHR || !(cdev_flags(dev) & D_MCLOSE))) 1237 return 0; 1238 1239 /* 1240 * If we're able to block, release the vnode lock & reacquire. We 1241 * might end up sleeping for someone else who wants our queues. They 1242 * won't get them if we hold the vnode locked. 1243 */ 1244 if (!(flags & FNONBLOCK)) 1245 VOP_UNLOCK(vp); 1246 1247 if (vp->v_type == VBLK) 1248 error = bdev_close(dev, flags, mode, curlwp); 1249 else 1250 error = cdev_close(dev, flags, mode, curlwp); 1251 1252 if (!(flags & FNONBLOCK)) 1253 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1254 1255 return (error); 1256 } 1257 1258 /* 1259 * Print out the contents of a special device vnode. 1260 */ 1261 int 1262 spec_print(void *v) 1263 { 1264 struct vop_print_args /* { 1265 struct vnode *a_vp; 1266 } */ *ap = v; 1267 1268 printf("dev %llu, %llu\n", (unsigned long long)major(ap->a_vp->v_rdev), 1269 (unsigned long long)minor(ap->a_vp->v_rdev)); 1270 return 0; 1271 } 1272 1273 /* 1274 * Return POSIX pathconf information applicable to special devices. 1275 */ 1276 int 1277 spec_pathconf(void *v) 1278 { 1279 struct vop_pathconf_args /* { 1280 struct vnode *a_vp; 1281 int a_name; 1282 register_t *a_retval; 1283 } */ *ap = v; 1284 1285 switch (ap->a_name) { 1286 case _PC_LINK_MAX: 1287 *ap->a_retval = LINK_MAX; 1288 return (0); 1289 case _PC_MAX_CANON: 1290 *ap->a_retval = MAX_CANON; 1291 return (0); 1292 case _PC_MAX_INPUT: 1293 *ap->a_retval = MAX_INPUT; 1294 return (0); 1295 case _PC_PIPE_BUF: 1296 *ap->a_retval = PIPE_BUF; 1297 return (0); 1298 case _PC_CHOWN_RESTRICTED: 1299 *ap->a_retval = 1; 1300 return (0); 1301 case _PC_VDISABLE: 1302 *ap->a_retval = _POSIX_VDISABLE; 1303 return (0); 1304 case _PC_SYNC_IO: 1305 *ap->a_retval = 1; 1306 return (0); 1307 default: 1308 return (EINVAL); 1309 } 1310 /* NOTREACHED */ 1311 } 1312 1313 /* 1314 * Advisory record locking support. 1315 */ 1316 int 1317 spec_advlock(void *v) 1318 { 1319 struct vop_advlock_args /* { 1320 struct vnode *a_vp; 1321 void *a_id; 1322 int a_op; 1323 struct flock *a_fl; 1324 int a_flags; 1325 } */ *ap = v; 1326 struct vnode *vp = ap->a_vp; 1327 1328 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 1329 } 1330