1 /* $NetBSD: spec_vnops.c,v 1.140 2013/07/20 23:00:08 dholland 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 1.140 2013/07/20 23:00:08 dholland 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 #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]; 104 105 /* 106 * This vnode operations vector is used for special device nodes 107 * created from whole cloth by the kernel. For the ops vector for 108 * vnodes built from special devices found in a filesystem, see (e.g) 109 * ffs_specop_entries[] in ffs_vnops.c or the equivalent for other 110 * filesystems. 111 */ 112 113 int (**spec_vnodeop_p)(void *); 114 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 115 { &vop_default_desc, vn_default_error }, 116 { &vop_lookup_desc, spec_lookup }, /* lookup */ 117 { &vop_create_desc, spec_create }, /* create */ 118 { &vop_mknod_desc, spec_mknod }, /* mknod */ 119 { &vop_open_desc, spec_open }, /* open */ 120 { &vop_close_desc, spec_close }, /* close */ 121 { &vop_access_desc, spec_access }, /* access */ 122 { &vop_getattr_desc, spec_getattr }, /* getattr */ 123 { &vop_setattr_desc, spec_setattr }, /* setattr */ 124 { &vop_read_desc, spec_read }, /* read */ 125 { &vop_write_desc, spec_write }, /* write */ 126 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */ 127 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 128 { &vop_poll_desc, spec_poll }, /* poll */ 129 { &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */ 130 { &vop_revoke_desc, spec_revoke }, /* revoke */ 131 { &vop_mmap_desc, spec_mmap }, /* mmap */ 132 { &vop_fsync_desc, spec_fsync }, /* fsync */ 133 { &vop_seek_desc, spec_seek }, /* seek */ 134 { &vop_remove_desc, spec_remove }, /* remove */ 135 { &vop_link_desc, spec_link }, /* link */ 136 { &vop_rename_desc, spec_rename }, /* rename */ 137 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 138 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 139 { &vop_symlink_desc, spec_symlink }, /* symlink */ 140 { &vop_readdir_desc, spec_readdir }, /* readdir */ 141 { &vop_readlink_desc, spec_readlink }, /* readlink */ 142 { &vop_abortop_desc, spec_abortop }, /* abortop */ 143 { &vop_inactive_desc, spec_inactive }, /* inactive */ 144 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 145 { &vop_lock_desc, spec_lock }, /* lock */ 146 { &vop_unlock_desc, spec_unlock }, /* unlock */ 147 { &vop_bmap_desc, spec_bmap }, /* bmap */ 148 { &vop_strategy_desc, spec_strategy }, /* strategy */ 149 { &vop_print_desc, spec_print }, /* print */ 150 { &vop_islocked_desc, spec_islocked }, /* islocked */ 151 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 152 { &vop_advlock_desc, spec_advlock }, /* advlock */ 153 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 154 { &vop_getpages_desc, spec_getpages }, /* getpages */ 155 { &vop_putpages_desc, spec_putpages }, /* putpages */ 156 { NULL, NULL } 157 }; 158 const struct vnodeopv_desc spec_vnodeop_opv_desc = 159 { &spec_vnodeop_p, spec_vnodeop_entries }; 160 161 static kauth_listener_t rawio_listener; 162 163 /* Returns true if vnode is /dev/mem or /dev/kmem. */ 164 bool 165 iskmemvp(struct vnode *vp) 166 { 167 return ((vp->v_type == VCHR) && iskmemdev(vp->v_rdev)); 168 } 169 170 /* 171 * Returns true if dev is /dev/mem or /dev/kmem. 172 */ 173 int 174 iskmemdev(dev_t dev) 175 { 176 /* mem_no is emitted by config(8) to generated devsw.c */ 177 extern const int mem_no; 178 179 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 180 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 181 } 182 183 static int 184 rawio_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 185 void *arg0, void *arg1, void *arg2, void *arg3) 186 { 187 int result; 188 189 result = KAUTH_RESULT_DEFER; 190 191 if ((action != KAUTH_DEVICE_RAWIO_SPEC) && 192 (action != KAUTH_DEVICE_RAWIO_PASSTHRU)) 193 return result; 194 195 /* Access is mandated by permissions. */ 196 result = KAUTH_RESULT_ALLOW; 197 198 return result; 199 } 200 201 void 202 spec_init(void) 203 { 204 205 rawio_listener = kauth_listen_scope(KAUTH_SCOPE_DEVICE, 206 rawio_listener_cb, NULL); 207 } 208 209 /* 210 * Initialize a vnode that represents a device. 211 */ 212 void 213 spec_node_init(vnode_t *vp, dev_t rdev) 214 { 215 specnode_t *sn; 216 specdev_t *sd; 217 vnode_t *vp2; 218 vnode_t **vpp; 219 220 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 221 KASSERT(vp->v_specnode == NULL); 222 223 /* 224 * Search the hash table for this device. If known, add a 225 * reference to the device structure. If not known, create 226 * a new entry to represent the device. In all cases add 227 * the vnode to the hash table. 228 */ 229 sn = kmem_alloc(sizeof(*sn), KM_SLEEP); 230 if (sn == NULL) { 231 /* XXX */ 232 panic("spec_node_init: unable to allocate memory"); 233 } 234 sd = kmem_alloc(sizeof(*sd), KM_SLEEP); 235 if (sd == NULL) { 236 /* XXX */ 237 panic("spec_node_init: unable to allocate memory"); 238 } 239 mutex_enter(&device_lock); 240 vpp = &specfs_hash[SPECHASH(rdev)]; 241 for (vp2 = *vpp; vp2 != NULL; vp2 = vp2->v_specnext) { 242 KASSERT(vp2->v_specnode != NULL); 243 if (rdev == vp2->v_rdev && vp->v_type == vp2->v_type) { 244 break; 245 } 246 } 247 if (vp2 == NULL) { 248 /* No existing record, create a new one. */ 249 sd->sd_rdev = rdev; 250 sd->sd_mountpoint = NULL; 251 sd->sd_lockf = NULL; 252 sd->sd_refcnt = 1; 253 sd->sd_opencnt = 0; 254 sd->sd_bdevvp = NULL; 255 sn->sn_dev = sd; 256 sd = NULL; 257 } else { 258 /* Use the existing record. */ 259 sn->sn_dev = vp2->v_specnode->sn_dev; 260 sn->sn_dev->sd_refcnt++; 261 } 262 /* Insert vnode into the hash chain. */ 263 sn->sn_opencnt = 0; 264 sn->sn_rdev = rdev; 265 sn->sn_gone = false; 266 vp->v_specnode = sn; 267 vp->v_specnext = *vpp; 268 *vpp = vp; 269 mutex_exit(&device_lock); 270 271 /* Free the record we allocated if unused. */ 272 if (sd != NULL) { 273 kmem_free(sd, sizeof(*sd)); 274 } 275 } 276 277 /* 278 * Lookup a vnode by device number and return it referenced. 279 */ 280 int 281 spec_node_lookup_by_dev(enum vtype type, dev_t dev, vnode_t **vpp) 282 { 283 int error; 284 vnode_t *vp; 285 286 mutex_enter(&device_lock); 287 for (vp = specfs_hash[SPECHASH(dev)]; vp; vp = vp->v_specnext) { 288 if (type == vp->v_type && dev == vp->v_rdev) { 289 mutex_enter(vp->v_interlock); 290 /* If clean or being cleaned, then ignore it. */ 291 if ((vp->v_iflag & (VI_CLEAN | VI_XLOCK)) == 0) 292 break; 293 mutex_exit(vp->v_interlock); 294 } 295 } 296 KASSERT(vp == NULL || mutex_owned(vp->v_interlock)); 297 if (vp == NULL) { 298 mutex_exit(&device_lock); 299 return ENOENT; 300 } 301 /* 302 * If it is an opened block device return the opened vnode. 303 */ 304 if (type == VBLK && vp->v_specnode->sn_dev->sd_bdevvp != NULL) { 305 mutex_exit(vp->v_interlock); 306 vp = vp->v_specnode->sn_dev->sd_bdevvp; 307 mutex_enter(vp->v_interlock); 308 } 309 mutex_exit(&device_lock); 310 error = vget(vp, 0); 311 if (error != 0) 312 return error; 313 *vpp = vp; 314 315 return 0; 316 } 317 318 /* 319 * Lookup a vnode by file system mounted on and return it referenced. 320 */ 321 int 322 spec_node_lookup_by_mount(struct mount *mp, vnode_t **vpp) 323 { 324 int i, error; 325 vnode_t *vp, *vq; 326 327 mutex_enter(&device_lock); 328 for (i = 0, vq = NULL; i < SPECHSZ && vq == NULL; i++) { 329 for (vp = specfs_hash[i]; vp; vp = vp->v_specnext) { 330 if (vp->v_type != VBLK) 331 continue; 332 vq = vp->v_specnode->sn_dev->sd_bdevvp; 333 if (vq != NULL && vq->v_specmountpoint == mp) 334 break; 335 vq = NULL; 336 } 337 } 338 if (vq == NULL) { 339 mutex_exit(&device_lock); 340 return ENOENT; 341 } 342 mutex_enter(vq->v_interlock); 343 mutex_exit(&device_lock); 344 error = vget(vq, 0); 345 if (error != 0) 346 return error; 347 *vpp = vq; 348 349 return 0; 350 351 } 352 353 /* 354 * A vnode representing a special device is going away. Close 355 * the device if the vnode holds it open. 356 */ 357 void 358 spec_node_revoke(vnode_t *vp) 359 { 360 specnode_t *sn; 361 specdev_t *sd; 362 363 sn = vp->v_specnode; 364 sd = sn->sn_dev; 365 366 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 367 KASSERT(vp->v_specnode != NULL); 368 KASSERT((vp->v_iflag & VI_XLOCK) != 0); 369 KASSERT(sn->sn_gone == false); 370 371 mutex_enter(&device_lock); 372 KASSERT(sn->sn_opencnt <= sd->sd_opencnt); 373 if (sn->sn_opencnt != 0) { 374 sd->sd_opencnt -= (sn->sn_opencnt - 1); 375 sn->sn_opencnt = 1; 376 sn->sn_gone = true; 377 mutex_exit(&device_lock); 378 379 VOP_CLOSE(vp, FNONBLOCK, NOCRED); 380 381 mutex_enter(&device_lock); 382 KASSERT(sn->sn_opencnt == 0); 383 } 384 mutex_exit(&device_lock); 385 } 386 387 /* 388 * A vnode representing a special device is being recycled. 389 * Destroy the specfs component. 390 */ 391 void 392 spec_node_destroy(vnode_t *vp) 393 { 394 specnode_t *sn; 395 specdev_t *sd; 396 vnode_t **vpp, *vp2; 397 int refcnt; 398 399 sn = vp->v_specnode; 400 sd = sn->sn_dev; 401 402 KASSERT(vp->v_type == VBLK || vp->v_type == VCHR); 403 KASSERT(vp->v_specnode != NULL); 404 KASSERT(sn->sn_opencnt == 0); 405 406 mutex_enter(&device_lock); 407 /* Remove from the hash and destroy the node. */ 408 vpp = &specfs_hash[SPECHASH(vp->v_rdev)]; 409 for (vp2 = *vpp;; vp2 = vp2->v_specnext) { 410 if (vp2 == NULL) { 411 panic("spec_node_destroy: corrupt hash"); 412 } 413 if (vp2 == vp) { 414 KASSERT(vp == *vpp); 415 *vpp = vp->v_specnext; 416 break; 417 } 418 if (vp2->v_specnext == vp) { 419 vp2->v_specnext = vp->v_specnext; 420 break; 421 } 422 } 423 sn = vp->v_specnode; 424 vp->v_specnode = NULL; 425 refcnt = sd->sd_refcnt--; 426 KASSERT(refcnt > 0); 427 mutex_exit(&device_lock); 428 429 /* If the device is no longer in use, destroy our record. */ 430 if (refcnt == 1) { 431 KASSERT(sd->sd_opencnt == 0); 432 KASSERT(sd->sd_bdevvp == NULL); 433 kmem_free(sd, sizeof(*sd)); 434 } 435 kmem_free(sn, sizeof(*sn)); 436 } 437 438 /* 439 * Trivial lookup routine that always fails. 440 */ 441 int 442 spec_lookup(void *v) 443 { 444 struct vop_lookup_args /* { 445 struct vnode *a_dvp; 446 struct vnode **a_vpp; 447 struct componentname *a_cnp; 448 } */ *ap = v; 449 450 *ap->a_vpp = NULL; 451 return (ENOTDIR); 452 } 453 454 /* 455 * Open a special file. 456 */ 457 /* ARGSUSED */ 458 int 459 spec_open(void *v) 460 { 461 struct vop_open_args /* { 462 struct vnode *a_vp; 463 int a_mode; 464 kauth_cred_t a_cred; 465 } */ *ap = v; 466 struct lwp *l; 467 struct vnode *vp; 468 dev_t dev; 469 int error; 470 struct partinfo pi; 471 enum kauth_device_req req; 472 specnode_t *sn; 473 specdev_t *sd; 474 475 u_int gen; 476 const char *name; 477 478 l = curlwp; 479 vp = ap->a_vp; 480 dev = vp->v_rdev; 481 sn = vp->v_specnode; 482 sd = sn->sn_dev; 483 name = NULL; 484 gen = 0; 485 486 /* 487 * Don't allow open if fs is mounted -nodev. 488 */ 489 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 490 return (ENXIO); 491 492 switch (ap->a_mode & (FREAD | FWRITE)) { 493 case FREAD | FWRITE: 494 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_RW; 495 break; 496 case FWRITE: 497 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_WRITE; 498 break; 499 default: 500 req = KAUTH_REQ_DEVICE_RAWIO_SPEC_READ; 501 break; 502 } 503 504 switch (vp->v_type) { 505 case VCHR: 506 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 507 if (error != 0) 508 return (error); 509 510 /* 511 * Character devices can accept opens from multiple 512 * vnodes. 513 */ 514 mutex_enter(&device_lock); 515 if (sn->sn_gone) { 516 mutex_exit(&device_lock); 517 return (EBADF); 518 } 519 sd->sd_opencnt++; 520 sn->sn_opencnt++; 521 mutex_exit(&device_lock); 522 if (cdev_type(dev) == D_TTY) 523 vp->v_vflag |= VV_ISTTY; 524 VOP_UNLOCK(vp); 525 do { 526 const struct cdevsw *cdev; 527 528 gen = module_gen; 529 error = cdev_open(dev, ap->a_mode, S_IFCHR, l); 530 if (error != ENXIO) 531 break; 532 533 /* Check if we already have a valid driver */ 534 mutex_enter(&device_lock); 535 cdev = cdevsw_lookup(dev); 536 mutex_exit(&device_lock); 537 if (cdev != NULL) 538 break; 539 540 /* Get device name from devsw_conv array */ 541 if ((name = cdevsw_getname(major(dev))) == NULL) 542 break; 543 544 /* Try to autoload device module */ 545 (void) module_autoload(name, MODULE_CLASS_DRIVER); 546 } while (gen != module_gen); 547 548 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 549 break; 550 551 case VBLK: 552 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 553 if (error != 0) 554 return (error); 555 556 /* 557 * For block devices, permit only one open. The buffer 558 * cache cannot remain self-consistent with multiple 559 * vnodes holding a block device open. 560 */ 561 mutex_enter(&device_lock); 562 if (sn->sn_gone) { 563 mutex_exit(&device_lock); 564 return (EBADF); 565 } 566 if (sd->sd_opencnt != 0) { 567 mutex_exit(&device_lock); 568 return EBUSY; 569 } 570 sn->sn_opencnt = 1; 571 sd->sd_opencnt = 1; 572 sd->sd_bdevvp = vp; 573 mutex_exit(&device_lock); 574 do { 575 const struct bdevsw *bdev; 576 577 gen = module_gen; 578 error = bdev_open(dev, ap->a_mode, S_IFBLK, l); 579 if (error != ENXIO) 580 break; 581 582 /* Check if we already have a valid driver */ 583 mutex_enter(&device_lock); 584 bdev = bdevsw_lookup(dev); 585 mutex_exit(&device_lock); 586 if (bdev != NULL) 587 break; 588 589 /* Get device name from devsw_conv array */ 590 if ((name = bdevsw_getname(major(dev))) == NULL) 591 break; 592 593 VOP_UNLOCK(vp); 594 595 /* Try to autoload device module */ 596 (void) module_autoload(name, MODULE_CLASS_DRIVER); 597 598 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 599 } while (gen != module_gen); 600 601 break; 602 603 case VNON: 604 case VLNK: 605 case VDIR: 606 case VREG: 607 case VBAD: 608 case VFIFO: 609 case VSOCK: 610 default: 611 return 0; 612 } 613 614 mutex_enter(&device_lock); 615 if (sn->sn_gone) { 616 if (error == 0) 617 error = EBADF; 618 } else if (error != 0) { 619 sd->sd_opencnt--; 620 sn->sn_opencnt--; 621 if (vp->v_type == VBLK) 622 sd->sd_bdevvp = NULL; 623 624 } 625 mutex_exit(&device_lock); 626 627 if (cdev_type(dev) != D_DISK || error != 0) 628 return error; 629 630 if (vp->v_type == VCHR) 631 error = cdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 632 else 633 error = bdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 634 if (error == 0) 635 uvm_vnp_setsize(vp, 636 (voff_t)pi.disklab->d_secsize * pi.part->p_size); 637 return 0; 638 } 639 640 /* 641 * Vnode op for read 642 */ 643 /* ARGSUSED */ 644 int 645 spec_read(void *v) 646 { 647 struct vop_read_args /* { 648 struct vnode *a_vp; 649 struct uio *a_uio; 650 int a_ioflag; 651 kauth_cred_t a_cred; 652 } */ *ap = v; 653 struct vnode *vp = ap->a_vp; 654 struct uio *uio = ap->a_uio; 655 struct lwp *l = curlwp; 656 struct buf *bp; 657 daddr_t bn; 658 int bsize, bscale; 659 struct partinfo dpart; 660 int n, on; 661 int error = 0; 662 663 #ifdef DIAGNOSTIC 664 if (uio->uio_rw != UIO_READ) 665 panic("spec_read mode"); 666 if (&uio->uio_vmspace->vm_map != kernel_map && 667 uio->uio_vmspace != curproc->p_vmspace) 668 panic("spec_read proc"); 669 #endif 670 if (uio->uio_resid == 0) 671 return (0); 672 673 switch (vp->v_type) { 674 675 case VCHR: 676 VOP_UNLOCK(vp); 677 error = cdev_read(vp->v_rdev, uio, ap->a_ioflag); 678 vn_lock(vp, LK_SHARED | LK_RETRY); 679 return (error); 680 681 case VBLK: 682 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 683 if (uio->uio_offset < 0) 684 return (EINVAL); 685 bsize = BLKDEV_IOSIZE; 686 687 /* 688 * dholland 20130616: XXX this logic should not be 689 * here. It is here because the old buffer cache 690 * demands that all accesses to the same blocks need 691 * to be the same size; but it only works for FFS and 692 * nowadays I think it'll fail silently if the size 693 * info in the disklabel is wrong. (Or missing.) The 694 * buffer cache needs to be smarter; or failing that 695 * we need a reliable way here to get the right block 696 * size; or a reliable way to guarantee that (a) the 697 * fs is not mounted when we get here and (b) any 698 * buffers generated here will get purged when the fs 699 * does get mounted. 700 */ 701 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 0) { 702 if (dpart.part->p_fstype == FS_BSDFFS && 703 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 704 bsize = dpart.part->p_frag * 705 dpart.part->p_fsize; 706 } 707 708 bscale = bsize >> DEV_BSHIFT; 709 do { 710 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 711 on = uio->uio_offset % bsize; 712 n = min((unsigned)(bsize - on), uio->uio_resid); 713 error = bread(vp, bn, bsize, NOCRED, 0, &bp); 714 if (error) { 715 return (error); 716 } 717 n = min(n, bsize - bp->b_resid); 718 error = uiomove((char *)bp->b_data + on, n, uio); 719 brelse(bp, 0); 720 } while (error == 0 && uio->uio_resid > 0 && n != 0); 721 return (error); 722 723 default: 724 panic("spec_read type"); 725 } 726 /* NOTREACHED */ 727 } 728 729 /* 730 * Vnode op for write 731 */ 732 /* ARGSUSED */ 733 int 734 spec_write(void *v) 735 { 736 struct vop_write_args /* { 737 struct vnode *a_vp; 738 struct uio *a_uio; 739 int a_ioflag; 740 kauth_cred_t a_cred; 741 } */ *ap = v; 742 struct vnode *vp = ap->a_vp; 743 struct uio *uio = ap->a_uio; 744 struct lwp *l = curlwp; 745 struct buf *bp; 746 daddr_t bn; 747 int bsize, bscale; 748 struct partinfo dpart; 749 int n, on; 750 int error = 0; 751 752 #ifdef DIAGNOSTIC 753 if (uio->uio_rw != UIO_WRITE) 754 panic("spec_write mode"); 755 if (&uio->uio_vmspace->vm_map != kernel_map && 756 uio->uio_vmspace != curproc->p_vmspace) 757 panic("spec_write proc"); 758 #endif 759 760 switch (vp->v_type) { 761 762 case VCHR: 763 VOP_UNLOCK(vp); 764 error = cdev_write(vp->v_rdev, uio, ap->a_ioflag); 765 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 766 return (error); 767 768 case VBLK: 769 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 770 if (uio->uio_resid == 0) 771 return (0); 772 if (uio->uio_offset < 0) 773 return (EINVAL); 774 bsize = BLKDEV_IOSIZE; 775 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 0) { 776 if (dpart.part->p_fstype == FS_BSDFFS && 777 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 778 bsize = dpart.part->p_frag * 779 dpart.part->p_fsize; 780 } 781 bscale = bsize >> DEV_BSHIFT; 782 do { 783 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 784 on = uio->uio_offset % bsize; 785 n = min((unsigned)(bsize - on), uio->uio_resid); 786 if (n == bsize) 787 bp = getblk(vp, bn, bsize, 0, 0); 788 else 789 error = bread(vp, bn, bsize, NOCRED, 790 B_MODIFY, &bp); 791 if (error) { 792 return (error); 793 } 794 n = min(n, bsize - bp->b_resid); 795 error = uiomove((char *)bp->b_data + on, n, uio); 796 if (error) 797 brelse(bp, 0); 798 else { 799 if (n + on == bsize) 800 bawrite(bp); 801 else 802 bdwrite(bp); 803 error = bp->b_error; 804 } 805 } while (error == 0 && uio->uio_resid > 0 && n != 0); 806 return (error); 807 808 default: 809 panic("spec_write type"); 810 } 811 /* NOTREACHED */ 812 } 813 814 /* 815 * Device ioctl operation. 816 */ 817 /* ARGSUSED */ 818 int 819 spec_ioctl(void *v) 820 { 821 struct vop_ioctl_args /* { 822 struct vnode *a_vp; 823 u_long a_command; 824 void *a_data; 825 int a_fflag; 826 kauth_cred_t a_cred; 827 } */ *ap = v; 828 struct vnode *vp; 829 dev_t dev; 830 831 /* 832 * Extract all the info we need from the vnode, taking care to 833 * avoid a race with VOP_REVOKE(). 834 */ 835 836 vp = ap->a_vp; 837 dev = NODEV; 838 mutex_enter(vp->v_interlock); 839 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specnode) { 840 dev = vp->v_rdev; 841 } 842 mutex_exit(vp->v_interlock); 843 if (dev == NODEV) { 844 return ENXIO; 845 } 846 847 switch (vp->v_type) { 848 849 case VCHR: 850 return cdev_ioctl(dev, ap->a_command, ap->a_data, 851 ap->a_fflag, curlwp); 852 853 case VBLK: 854 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 855 return bdev_ioctl(dev, ap->a_command, ap->a_data, 856 ap->a_fflag, curlwp); 857 858 default: 859 panic("spec_ioctl"); 860 /* NOTREACHED */ 861 } 862 } 863 864 /* ARGSUSED */ 865 int 866 spec_poll(void *v) 867 { 868 struct vop_poll_args /* { 869 struct vnode *a_vp; 870 int a_events; 871 } */ *ap = v; 872 struct vnode *vp; 873 dev_t dev; 874 875 /* 876 * Extract all the info we need from the vnode, taking care to 877 * avoid a race with VOP_REVOKE(). 878 */ 879 880 vp = ap->a_vp; 881 dev = NODEV; 882 mutex_enter(vp->v_interlock); 883 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specnode) { 884 dev = vp->v_rdev; 885 } 886 mutex_exit(vp->v_interlock); 887 if (dev == NODEV) { 888 return POLLERR; 889 } 890 891 switch (vp->v_type) { 892 893 case VCHR: 894 return cdev_poll(dev, ap->a_events, curlwp); 895 896 default: 897 return (genfs_poll(v)); 898 } 899 } 900 901 /* ARGSUSED */ 902 int 903 spec_kqfilter(void *v) 904 { 905 struct vop_kqfilter_args /* { 906 struct vnode *a_vp; 907 struct proc *a_kn; 908 } */ *ap = v; 909 dev_t dev; 910 911 switch (ap->a_vp->v_type) { 912 913 case VCHR: 914 dev = ap->a_vp->v_rdev; 915 return cdev_kqfilter(dev, ap->a_kn); 916 default: 917 /* 918 * Block devices don't support kqfilter, and refuse it 919 * for any other files (like those vflush()ed) too. 920 */ 921 return (EOPNOTSUPP); 922 } 923 } 924 925 /* 926 * Allow mapping of only D_DISK. This is called only for VBLK. 927 */ 928 int 929 spec_mmap(void *v) 930 { 931 struct vop_mmap_args /* { 932 struct vnode *a_vp; 933 vm_prot_t a_prot; 934 kauth_cred_t a_cred; 935 } */ *ap = v; 936 struct vnode *vp = ap->a_vp; 937 938 KASSERT(vp->v_type == VBLK); 939 if (bdev_type(vp->v_rdev) != D_DISK) 940 return EINVAL; 941 942 return 0; 943 } 944 945 /* 946 * Synch buffers associated with a block device 947 */ 948 /* ARGSUSED */ 949 int 950 spec_fsync(void *v) 951 { 952 struct vop_fsync_args /* { 953 struct vnode *a_vp; 954 kauth_cred_t a_cred; 955 int a_flags; 956 off_t offlo; 957 off_t offhi; 958 } */ *ap = v; 959 struct vnode *vp = ap->a_vp; 960 struct mount *mp; 961 int error; 962 963 if (vp->v_type == VBLK) { 964 if ((mp = vp->v_specmountpoint) != NULL) { 965 error = VFS_FSYNC(mp, vp, ap->a_flags); 966 if (error != EOPNOTSUPP) 967 return error; 968 } 969 return vflushbuf(vp, ap->a_flags); 970 } 971 return (0); 972 } 973 974 /* 975 * Just call the device strategy routine 976 */ 977 int 978 spec_strategy(void *v) 979 { 980 struct vop_strategy_args /* { 981 struct vnode *a_vp; 982 struct buf *a_bp; 983 } */ *ap = v; 984 struct vnode *vp = ap->a_vp; 985 struct buf *bp = ap->a_bp; 986 int error; 987 988 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 989 990 error = 0; 991 bp->b_dev = vp->v_rdev; 992 993 if (!(bp->b_flags & B_READ)) 994 error = fscow_run(bp, false); 995 996 if (error) { 997 bp->b_error = error; 998 bp->b_resid = bp->b_bcount; 999 biodone(bp); 1000 return (error); 1001 } 1002 1003 bdev_strategy(bp); 1004 1005 return (0); 1006 } 1007 1008 int 1009 spec_inactive(void *v) 1010 { 1011 struct vop_inactive_args /* { 1012 struct vnode *a_vp; 1013 struct proc *a_l; 1014 } */ *ap = v; 1015 1016 VOP_UNLOCK(ap->a_vp); 1017 return (0); 1018 } 1019 1020 /* 1021 * This is a noop, simply returning what one has been given. 1022 */ 1023 int 1024 spec_bmap(void *v) 1025 { 1026 struct vop_bmap_args /* { 1027 struct vnode *a_vp; 1028 daddr_t a_bn; 1029 struct vnode **a_vpp; 1030 daddr_t *a_bnp; 1031 int *a_runp; 1032 } */ *ap = v; 1033 1034 if (ap->a_vpp != NULL) 1035 *ap->a_vpp = ap->a_vp; 1036 if (ap->a_bnp != NULL) 1037 *ap->a_bnp = ap->a_bn; 1038 if (ap->a_runp != NULL) 1039 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 1040 return (0); 1041 } 1042 1043 /* 1044 * Device close routine 1045 */ 1046 /* ARGSUSED */ 1047 int 1048 spec_close(void *v) 1049 { 1050 struct vop_close_args /* { 1051 struct vnode *a_vp; 1052 int a_fflag; 1053 kauth_cred_t a_cred; 1054 } */ *ap = v; 1055 struct vnode *vp = ap->a_vp; 1056 struct session *sess; 1057 dev_t dev = vp->v_rdev; 1058 int mode, error, flags, flags1, count; 1059 specnode_t *sn; 1060 specdev_t *sd; 1061 1062 flags = vp->v_iflag; 1063 sn = vp->v_specnode; 1064 sd = sn->sn_dev; 1065 1066 switch (vp->v_type) { 1067 1068 case VCHR: 1069 /* 1070 * Hack: a tty device that is a controlling terminal 1071 * has a reference from the session structure. We 1072 * cannot easily tell that a character device is a 1073 * controlling terminal, unless it is the closing 1074 * process' controlling terminal. In that case, if the 1075 * open count is 1 release the reference from the 1076 * session. Also, remove the link from the tty back to 1077 * the session and pgrp. 1078 * 1079 * XXX V. fishy. 1080 */ 1081 mutex_enter(proc_lock); 1082 sess = curlwp->l_proc->p_session; 1083 if (sn->sn_opencnt == 1 && vp == sess->s_ttyvp) { 1084 mutex_spin_enter(&tty_lock); 1085 sess->s_ttyvp = NULL; 1086 if (sess->s_ttyp->t_session != NULL) { 1087 sess->s_ttyp->t_pgrp = NULL; 1088 sess->s_ttyp->t_session = NULL; 1089 mutex_spin_exit(&tty_lock); 1090 /* Releases proc_lock. */ 1091 proc_sessrele(sess); 1092 } else { 1093 mutex_spin_exit(&tty_lock); 1094 if (sess->s_ttyp->t_pgrp != NULL) 1095 panic("spec_close: spurious pgrp ref"); 1096 mutex_exit(proc_lock); 1097 } 1098 vrele(vp); 1099 } else 1100 mutex_exit(proc_lock); 1101 1102 /* 1103 * If the vnode is locked, then we are in the midst 1104 * of forcably closing the device, otherwise we only 1105 * close on last reference. 1106 */ 1107 mode = S_IFCHR; 1108 break; 1109 1110 case VBLK: 1111 KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp); 1112 /* 1113 * On last close of a block device (that isn't mounted) 1114 * we must invalidate any in core blocks, so that 1115 * we can, for instance, change floppy disks. 1116 */ 1117 error = vinvalbuf(vp, V_SAVE, ap->a_cred, curlwp, 0, 0); 1118 if (error) 1119 return (error); 1120 /* 1121 * We do not want to really close the device if it 1122 * is still in use unless we are trying to close it 1123 * forcibly. Since every use (buffer, vnode, swap, cmap) 1124 * holds a reference to the vnode, and because we mark 1125 * any other vnodes that alias this device, when the 1126 * sum of the reference counts on all the aliased 1127 * vnodes descends to one, we are on last close. 1128 */ 1129 mode = S_IFBLK; 1130 break; 1131 1132 default: 1133 panic("spec_close: not special"); 1134 } 1135 1136 mutex_enter(&device_lock); 1137 sn->sn_opencnt--; 1138 count = --sd->sd_opencnt; 1139 if (vp->v_type == VBLK) 1140 sd->sd_bdevvp = NULL; 1141 mutex_exit(&device_lock); 1142 1143 if (count != 0) 1144 return 0; 1145 1146 flags1 = ap->a_fflag; 1147 1148 /* 1149 * if VI_XLOCK is set, then we're going away soon, so make this 1150 * non-blocking. Also ensures that we won't wedge in vn_lock below. 1151 */ 1152 if (flags & VI_XLOCK) 1153 flags1 |= FNONBLOCK; 1154 1155 /* 1156 * If we're able to block, release the vnode lock & reacquire. We 1157 * might end up sleeping for someone else who wants our queues. They 1158 * won't get them if we hold the vnode locked. Also, if VI_XLOCK is 1159 * set, don't release the lock as we won't be able to regain it. 1160 */ 1161 if (!(flags1 & FNONBLOCK)) 1162 VOP_UNLOCK(vp); 1163 1164 if (vp->v_type == VBLK) 1165 error = bdev_close(dev, flags1, mode, curlwp); 1166 else 1167 error = cdev_close(dev, flags1, mode, curlwp); 1168 1169 if (!(flags1 & FNONBLOCK)) 1170 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1171 1172 return (error); 1173 } 1174 1175 /* 1176 * Print out the contents of a special device vnode. 1177 */ 1178 int 1179 spec_print(void *v) 1180 { 1181 struct vop_print_args /* { 1182 struct vnode *a_vp; 1183 } */ *ap = v; 1184 1185 printf("dev %llu, %llu\n", (unsigned long long)major(ap->a_vp->v_rdev), 1186 (unsigned long long)minor(ap->a_vp->v_rdev)); 1187 return 0; 1188 } 1189 1190 /* 1191 * Return POSIX pathconf information applicable to special devices. 1192 */ 1193 int 1194 spec_pathconf(void *v) 1195 { 1196 struct vop_pathconf_args /* { 1197 struct vnode *a_vp; 1198 int a_name; 1199 register_t *a_retval; 1200 } */ *ap = v; 1201 1202 switch (ap->a_name) { 1203 case _PC_LINK_MAX: 1204 *ap->a_retval = LINK_MAX; 1205 return (0); 1206 case _PC_MAX_CANON: 1207 *ap->a_retval = MAX_CANON; 1208 return (0); 1209 case _PC_MAX_INPUT: 1210 *ap->a_retval = MAX_INPUT; 1211 return (0); 1212 case _PC_PIPE_BUF: 1213 *ap->a_retval = PIPE_BUF; 1214 return (0); 1215 case _PC_CHOWN_RESTRICTED: 1216 *ap->a_retval = 1; 1217 return (0); 1218 case _PC_VDISABLE: 1219 *ap->a_retval = _POSIX_VDISABLE; 1220 return (0); 1221 case _PC_SYNC_IO: 1222 *ap->a_retval = 1; 1223 return (0); 1224 default: 1225 return (EINVAL); 1226 } 1227 /* NOTREACHED */ 1228 } 1229 1230 /* 1231 * Advisory record locking support. 1232 */ 1233 int 1234 spec_advlock(void *v) 1235 { 1236 struct vop_advlock_args /* { 1237 struct vnode *a_vp; 1238 void *a_id; 1239 int a_op; 1240 struct flock *a_fl; 1241 int a_flags; 1242 } */ *ap = v; 1243 struct vnode *vp = ap->a_vp; 1244 1245 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 1246 } 1247