1 /* $OpenBSD: spec_vnops.c,v 1.100 2020/01/20 23:21:55 claudio Exp $ */ 2 /* $NetBSD: spec_vnops.c,v 1.29 1996/04/22 01:42:38 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)spec_vnops.c 8.8 (Berkeley) 11/21/94 33 */ 34 35 #include <sys/param.h> 36 #include <sys/proc.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/conf.h> 40 #include <sys/buf.h> 41 #include <sys/mount.h> 42 #include <sys/namei.h> 43 #include <sys/vnode.h> 44 #include <sys/lock.h> 45 #include <sys/stat.h> 46 #include <sys/errno.h> 47 #include <sys/ioctl.h> 48 #include <sys/fcntl.h> 49 #include <sys/disklabel.h> 50 #include <sys/lockf.h> 51 #include <sys/poll.h> 52 #include <sys/dkio.h> 53 #include <sys/malloc.h> 54 #include <sys/specdev.h> 55 #include <sys/unistd.h> 56 57 #include <uvm/uvm_extern.h> 58 59 #define v_lastr v_specinfo->si_lastr 60 61 int spec_open_clone(struct vop_open_args *); 62 63 struct vnodechain speclisth[SPECHSZ]; 64 65 const struct vops spec_vops = { 66 .vop_lookup = vop_generic_lookup, 67 .vop_create = spec_badop, 68 .vop_mknod = spec_badop, 69 .vop_open = spec_open, 70 .vop_close = spec_close, 71 .vop_access = spec_access, 72 .vop_getattr = spec_getattr, 73 .vop_setattr = spec_setattr, 74 .vop_read = spec_read, 75 .vop_write = spec_write, 76 .vop_ioctl = spec_ioctl, 77 .vop_poll = spec_poll, 78 .vop_kqfilter = spec_kqfilter, 79 .vop_revoke = vop_generic_revoke, 80 .vop_fsync = spec_fsync, 81 .vop_remove = spec_badop, 82 .vop_link = spec_badop, 83 .vop_rename = spec_badop, 84 .vop_mkdir = spec_badop, 85 .vop_rmdir = spec_badop, 86 .vop_symlink = spec_badop, 87 .vop_readdir = spec_badop, 88 .vop_readlink = spec_badop, 89 .vop_abortop = spec_badop, 90 .vop_inactive = spec_inactive, 91 .vop_reclaim = nullop, 92 .vop_lock = vop_generic_lock, 93 .vop_unlock = vop_generic_unlock, 94 .vop_islocked = vop_generic_islocked, 95 .vop_bmap = vop_generic_bmap, 96 .vop_strategy = spec_strategy, 97 .vop_print = spec_print, 98 .vop_pathconf = spec_pathconf, 99 .vop_advlock = spec_advlock, 100 .vop_bwrite = vop_generic_bwrite, 101 }; 102 103 /* 104 * Open a special file. 105 */ 106 int 107 spec_open(void *v) 108 { 109 struct vop_open_args *ap = v; 110 struct proc *p = ap->a_p; 111 struct vnode *vp = ap->a_vp; 112 struct vnode *bvp; 113 dev_t bdev; 114 dev_t dev = (dev_t)vp->v_rdev; 115 int maj = major(dev); 116 int error; 117 118 /* 119 * Don't allow open if fs is mounted -nodev. 120 */ 121 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 122 return (ENXIO); 123 124 switch (vp->v_type) { 125 126 case VCHR: 127 if ((u_int)maj >= nchrdev) 128 return (ENXIO); 129 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 130 /* 131 * When running in very secure mode, do not allow 132 * opens for writing of any disk character devices. 133 */ 134 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK) 135 return (EPERM); 136 /* 137 * When running in secure mode, do not allow opens 138 * for writing of /dev/mem, /dev/kmem, or character 139 * devices whose corresponding block devices are 140 * currently mounted. 141 */ 142 if (securelevel >= 1) { 143 if ((bdev = chrtoblk(dev)) != NODEV && 144 vfinddev(bdev, VBLK, &bvp) && 145 bvp->v_usecount > 0 && 146 (error = vfs_mountedon(bvp))) 147 return (error); 148 if (iskmemdev(dev)) 149 return (EPERM); 150 } 151 } 152 if (cdevsw[maj].d_type == D_TTY) 153 vp->v_flag |= VISTTY; 154 if (cdevsw[maj].d_flags & D_CLONE) 155 return (spec_open_clone(ap)); 156 VOP_UNLOCK(vp); 157 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p); 158 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 159 return (error); 160 161 case VBLK: 162 if ((u_int)maj >= nblkdev) 163 return (ENXIO); 164 /* 165 * When running in very secure mode, do not allow 166 * opens for writing of any disk block devices. 167 */ 168 if (securelevel >= 2 && ap->a_cred != FSCRED && 169 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) 170 return (EPERM); 171 /* 172 * Do not allow opens of block devices that are 173 * currently mounted. 174 */ 175 if ((error = vfs_mountedon(vp)) != 0) 176 return (error); 177 return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, p)); 178 case VNON: 179 case VLNK: 180 case VDIR: 181 case VREG: 182 case VBAD: 183 case VFIFO: 184 case VSOCK: 185 break; 186 } 187 return (0); 188 } 189 190 /* 191 * Vnode op for read 192 */ 193 int 194 spec_read(void *v) 195 { 196 struct vop_read_args *ap = v; 197 struct vnode *vp = ap->a_vp; 198 struct uio *uio = ap->a_uio; 199 struct proc *p = uio->uio_procp; 200 struct buf *bp; 201 daddr_t bn, nextbn, bscale; 202 int bsize; 203 struct partinfo dpart; 204 size_t n; 205 int on, majordev; 206 int (*ioctl)(dev_t, u_long, caddr_t, int, struct proc *); 207 int error = 0; 208 209 #ifdef DIAGNOSTIC 210 if (uio->uio_rw != UIO_READ) 211 panic("spec_read mode"); 212 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 213 panic("spec_read proc"); 214 #endif 215 if (uio->uio_resid == 0) 216 return (0); 217 218 switch (vp->v_type) { 219 220 case VCHR: 221 VOP_UNLOCK(vp); 222 error = (*cdevsw[major(vp->v_rdev)].d_read) 223 (vp->v_rdev, uio, ap->a_ioflag); 224 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 225 return (error); 226 227 case VBLK: 228 if (uio->uio_offset < 0) 229 return (EINVAL); 230 bsize = BLKDEV_IOSIZE; 231 if ((majordev = major(vp->v_rdev)) < nblkdev && 232 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 233 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 234 u_int32_t frag = 235 DISKLABELV1_FFS_FRAG(dpart.part->p_fragblock); 236 u_int32_t fsize = 237 DISKLABELV1_FFS_FSIZE(dpart.part->p_fragblock); 238 if (dpart.part->p_fstype == FS_BSDFFS && frag != 0 && 239 fsize != 0) 240 bsize = frag * fsize; 241 } 242 bscale = btodb(bsize); 243 do { 244 bn = btodb(uio->uio_offset) & ~(bscale - 1); 245 on = uio->uio_offset % bsize; 246 n = ulmin((bsize - on), uio->uio_resid); 247 if (vp->v_lastr + bscale == bn) { 248 nextbn = bn + bscale; 249 error = breadn(vp, bn, bsize, &nextbn, &bsize, 250 1, &bp); 251 } else 252 error = bread(vp, bn, bsize, &bp); 253 vp->v_lastr = bn; 254 n = ulmin(n, bsize - bp->b_resid); 255 if (error) { 256 brelse(bp); 257 return (error); 258 } 259 error = uiomove((char *)bp->b_data + on, n, uio); 260 brelse(bp); 261 } while (error == 0 && uio->uio_resid > 0 && n != 0); 262 return (error); 263 264 default: 265 panic("spec_read type"); 266 } 267 /* NOTREACHED */ 268 } 269 270 int 271 spec_inactive(void *v) 272 { 273 struct vop_inactive_args *ap = v; 274 275 VOP_UNLOCK(ap->a_vp); 276 return (0); 277 } 278 279 /* 280 * Vnode op for write 281 */ 282 int 283 spec_write(void *v) 284 { 285 struct vop_write_args *ap = v; 286 struct vnode *vp = ap->a_vp; 287 struct uio *uio = ap->a_uio; 288 struct proc *p = uio->uio_procp; 289 struct buf *bp; 290 daddr_t bn, bscale; 291 int bsize; 292 struct partinfo dpart; 293 size_t n; 294 int on, majordev; 295 int (*ioctl)(dev_t, u_long, caddr_t, int, struct proc *); 296 int error = 0; 297 298 #ifdef DIAGNOSTIC 299 if (uio->uio_rw != UIO_WRITE) 300 panic("spec_write mode"); 301 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 302 panic("spec_write proc"); 303 #endif 304 305 switch (vp->v_type) { 306 307 case VCHR: 308 VOP_UNLOCK(vp); 309 error = (*cdevsw[major(vp->v_rdev)].d_write) 310 (vp->v_rdev, uio, ap->a_ioflag); 311 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 312 return (error); 313 314 case VBLK: 315 if (uio->uio_resid == 0) 316 return (0); 317 if (uio->uio_offset < 0) 318 return (EINVAL); 319 bsize = BLKDEV_IOSIZE; 320 if ((majordev = major(vp->v_rdev)) < nblkdev && 321 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 322 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 323 u_int32_t frag = 324 DISKLABELV1_FFS_FRAG(dpart.part->p_fragblock); 325 u_int32_t fsize = 326 DISKLABELV1_FFS_FSIZE(dpart.part->p_fragblock); 327 if (dpart.part->p_fstype == FS_BSDFFS && frag != 0 && 328 fsize != 0) 329 bsize = frag * fsize; 330 } 331 bscale = btodb(bsize); 332 do { 333 bn = btodb(uio->uio_offset) & ~(bscale - 1); 334 on = uio->uio_offset % bsize; 335 n = ulmin((bsize - on), uio->uio_resid); 336 error = bread(vp, bn, bsize, &bp); 337 n = ulmin(n, bsize - bp->b_resid); 338 if (error) { 339 brelse(bp); 340 return (error); 341 } 342 error = uiomove((char *)bp->b_data + on, n, uio); 343 if (n + on == bsize) 344 bawrite(bp); 345 else 346 bdwrite(bp); 347 } while (error == 0 && uio->uio_resid > 0 && n != 0); 348 return (error); 349 350 default: 351 panic("spec_write type"); 352 } 353 /* NOTREACHED */ 354 } 355 356 /* 357 * Device ioctl operation. 358 */ 359 int 360 spec_ioctl(void *v) 361 { 362 struct vop_ioctl_args *ap = v; 363 dev_t dev = ap->a_vp->v_rdev; 364 int maj = major(dev); 365 366 switch (ap->a_vp->v_type) { 367 368 case VCHR: 369 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 370 ap->a_fflag, ap->a_p)); 371 372 case VBLK: 373 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 374 ap->a_fflag, ap->a_p)); 375 376 default: 377 panic("spec_ioctl"); 378 /* NOTREACHED */ 379 } 380 } 381 382 int 383 spec_poll(void *v) 384 { 385 struct vop_poll_args *ap = v; 386 dev_t dev; 387 388 switch (ap->a_vp->v_type) { 389 390 default: 391 return (ap->a_events & 392 (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 393 394 case VCHR: 395 dev = ap->a_vp->v_rdev; 396 return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p); 397 } 398 } 399 int 400 spec_kqfilter(void *v) 401 { 402 struct vop_kqfilter_args *ap = v; 403 404 dev_t dev; 405 406 dev = ap->a_vp->v_rdev; 407 if (cdevsw[major(dev)].d_kqfilter) 408 return (*cdevsw[major(dev)].d_kqfilter)(dev, ap->a_kn); 409 return (EOPNOTSUPP); 410 } 411 412 /* 413 * Synch buffers associated with a block device 414 */ 415 int 416 spec_fsync(void *v) 417 { 418 struct vop_fsync_args *ap = v; 419 struct vnode *vp = ap->a_vp; 420 struct buf *bp; 421 struct buf *nbp; 422 int s; 423 424 if (vp->v_type == VCHR) 425 return (0); 426 /* 427 * Flush all dirty buffers associated with a block device. 428 */ 429 loop: 430 s = splbio(); 431 LIST_FOREACH_SAFE(bp, &vp->v_dirtyblkhd, b_vnbufs, nbp) { 432 if ((bp->b_flags & B_BUSY)) 433 continue; 434 if ((bp->b_flags & B_DELWRI) == 0) 435 panic("spec_fsync: not dirty"); 436 bremfree(bp); 437 buf_acquire(bp); 438 splx(s); 439 bawrite(bp); 440 goto loop; 441 } 442 if (ap->a_waitfor == MNT_WAIT) { 443 vwaitforio (vp, 0, "spec_fsync", INFSLP); 444 445 #ifdef DIAGNOSTIC 446 if (!LIST_EMPTY(&vp->v_dirtyblkhd)) { 447 splx(s); 448 vprint("spec_fsync: dirty", vp); 449 goto loop; 450 } 451 #endif 452 } 453 splx(s); 454 return (0); 455 } 456 457 int 458 spec_strategy(void *v) 459 { 460 struct vop_strategy_args *ap = v; 461 struct buf *bp = ap->a_bp; 462 int maj = major(bp->b_dev); 463 464 if (LIST_FIRST(&bp->b_dep) != NULL) 465 buf_start(bp); 466 467 (*bdevsw[maj].d_strategy)(bp); 468 return (0); 469 } 470 471 /* 472 * Device close routine 473 */ 474 int 475 spec_close(void *v) 476 { 477 struct vop_close_args *ap = v; 478 struct proc *p = ap->a_p; 479 struct vnode *vp = ap->a_vp; 480 dev_t dev = vp->v_rdev; 481 int (*devclose)(dev_t, int, int, struct proc *); 482 int mode, relock, error; 483 int clone = 0; 484 485 switch (vp->v_type) { 486 487 case VCHR: 488 /* 489 * Hack: a tty device that is a controlling terminal 490 * has a reference from the session structure. 491 * We cannot easily tell that a character device is 492 * a controlling terminal, unless it is the closing 493 * process' controlling terminal. In that case, 494 * if the reference count is 2 (this last descriptor 495 * plus the session), release the reference from the session. 496 */ 497 if (vcount(vp) == 2 && p != NULL && p->p_p->ps_pgrp && 498 vp == p->p_p->ps_pgrp->pg_session->s_ttyvp) { 499 vrele(vp); 500 p->p_p->ps_pgrp->pg_session->s_ttyvp = NULL; 501 } 502 if (cdevsw[major(dev)].d_flags & D_CLONE) { 503 clone = 1; 504 } else { 505 /* 506 * If the vnode is locked, then we are in the midst 507 * of forcably closing the device, otherwise we only 508 * close on last reference. 509 */ 510 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 511 return (0); 512 } 513 devclose = cdevsw[major(dev)].d_close; 514 mode = S_IFCHR; 515 break; 516 517 case VBLK: 518 /* 519 * On last close of a block device (that isn't mounted) 520 * we must invalidate any in core blocks, so that 521 * we can, for instance, change floppy disks. In order to do 522 * that, we must lock the vnode. If we are coming from 523 * vclean(), the vnode is already locked. 524 */ 525 if (!(vp->v_flag & VXLOCK)) 526 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 527 error = vinvalbuf(vp, V_SAVE, ap->a_cred, p, 0, INFSLP); 528 if (!(vp->v_flag & VXLOCK)) 529 VOP_UNLOCK(vp); 530 if (error) 531 return (error); 532 /* 533 * We do not want to really close the device if it 534 * is still in use unless we are trying to close it 535 * forcibly. Since every use (buffer, vnode, swap, cmap) 536 * holds a reference to the vnode, and because we mark 537 * any other vnodes that alias this device, when the 538 * sum of the reference counts on all the aliased 539 * vnodes descends to one, we are on last close. 540 */ 541 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 542 return (0); 543 devclose = bdevsw[major(dev)].d_close; 544 mode = S_IFBLK; 545 break; 546 547 default: 548 panic("spec_close: not special"); 549 } 550 551 /* release lock if held and this isn't coming from vclean() */ 552 relock = VOP_ISLOCKED(vp) && !(vp->v_flag & VXLOCK); 553 if (relock) 554 VOP_UNLOCK(vp); 555 error = (*devclose)(dev, ap->a_fflag, mode, p); 556 if (relock) 557 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 558 559 if (error == 0 && clone) { 560 struct vnode *pvp; 561 562 pvp = vp->v_specparent; /* get parent device */ 563 clrbit(pvp->v_specbitmap, minor(dev) >> CLONE_SHIFT); 564 vrele(pvp); 565 } 566 567 return (error); 568 } 569 570 int 571 spec_getattr(void *v) 572 { 573 struct vop_getattr_args *ap = v; 574 struct vnode *vp = ap->a_vp; 575 int error; 576 577 if (!(vp->v_flag & VCLONE)) 578 return (EBADF); 579 580 vn_lock(vp->v_specparent, LK_EXCLUSIVE|LK_RETRY); 581 error = VOP_GETATTR(vp->v_specparent, ap->a_vap, ap->a_cred, ap->a_p); 582 VOP_UNLOCK(vp->v_specparent); 583 584 return (error); 585 } 586 587 int 588 spec_setattr(void *v) 589 { 590 struct vop_getattr_args *ap = v; 591 struct proc *p = ap->a_p; 592 struct vnode *vp = ap->a_vp; 593 int error; 594 595 if (!(vp->v_flag & VCLONE)) 596 return (EBADF); 597 598 vn_lock(vp->v_specparent, LK_EXCLUSIVE|LK_RETRY); 599 error = VOP_SETATTR(vp->v_specparent, ap->a_vap, ap->a_cred, p); 600 VOP_UNLOCK(vp->v_specparent); 601 602 return (error); 603 } 604 605 int 606 spec_access(void *v) 607 { 608 struct vop_access_args *ap = v; 609 struct vnode *vp = ap->a_vp; 610 int error; 611 612 if (!(vp->v_flag & VCLONE)) 613 return (EBADF); 614 615 vn_lock(vp->v_specparent, LK_EXCLUSIVE|LK_RETRY); 616 error = VOP_ACCESS(vp->v_specparent, ap->a_mode, ap->a_cred, ap->a_p); 617 VOP_UNLOCK(vp->v_specparent); 618 619 return (error); 620 } 621 622 /* 623 * Print out the contents of a special device vnode. 624 */ 625 int 626 spec_print(void *v) 627 { 628 struct vop_print_args *ap = v; 629 630 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 631 minor(ap->a_vp->v_rdev)); 632 return 0; 633 } 634 635 /* 636 * Return POSIX pathconf information applicable to special devices. 637 */ 638 int 639 spec_pathconf(void *v) 640 { 641 struct vop_pathconf_args *ap = v; 642 int error = 0; 643 644 switch (ap->a_name) { 645 case _PC_LINK_MAX: 646 *ap->a_retval = LINK_MAX; 647 break; 648 case _PC_MAX_CANON: 649 *ap->a_retval = MAX_CANON; 650 break; 651 case _PC_MAX_INPUT: 652 *ap->a_retval = MAX_INPUT; 653 break; 654 case _PC_CHOWN_RESTRICTED: 655 *ap->a_retval = 1; 656 break; 657 case _PC_VDISABLE: 658 *ap->a_retval = _POSIX_VDISABLE; 659 break; 660 case _PC_TIMESTAMP_RESOLUTION: 661 *ap->a_retval = 1; 662 break; 663 default: 664 error = EINVAL; 665 break; 666 } 667 668 return (error); 669 } 670 671 /* 672 * Special device advisory byte-level locks. 673 */ 674 int 675 spec_advlock(void *v) 676 { 677 struct vop_advlock_args *ap = v; 678 struct vnode *vp = ap->a_vp; 679 680 return (lf_advlock(&vp->v_speclockf, (off_t)0, ap->a_id, 681 ap->a_op, ap->a_fl, ap->a_flags)); 682 } 683 684 /* 685 * Special device bad operation 686 */ 687 int 688 spec_badop(void *v) 689 { 690 691 panic("spec_badop called"); 692 /* NOTREACHED */ 693 } 694 695 /* 696 * Copyright (c) 2006 Pedro Martelletto <pedro@ambientworks.net> 697 * Copyright (c) 2006 Thordur Bjornsson <thib@openbsd.org> 698 * 699 * Permission to use, copy, modify, and distribute this software for any 700 * purpose with or without fee is hereby granted, provided that the above 701 * copyright notice and this permission notice appear in all copies. 702 * 703 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 704 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 705 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 706 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 707 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 708 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 709 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 710 */ 711 712 #ifdef CLONE_DEBUG 713 #define DNPRINTF(m...) do { printf(m); } while (0) 714 #else 715 #define DNPRINTF(m...) /* nothing */ 716 #endif 717 718 int 719 spec_open_clone(struct vop_open_args *ap) 720 { 721 struct vnode *cvp, *vp = ap->a_vp; 722 struct cloneinfo *cip; 723 int error, i; 724 725 DNPRINTF("cloning vnode\n"); 726 727 if (minor(vp->v_rdev) >= (1 << CLONE_SHIFT)) 728 return (ENXIO); 729 730 for (i = 1; i < CLONE_MAPSZ * NBBY; i++) 731 if (isclr(vp->v_specbitmap, i)) { 732 setbit(vp->v_specbitmap, i); 733 break; 734 } 735 736 if (i == CLONE_MAPSZ * NBBY) 737 return (EBUSY); /* too many open instances */ 738 739 error = cdevvp(makedev(major(vp->v_rdev), 740 (i << CLONE_SHIFT) | minor(vp->v_rdev)), &cvp); 741 if (error) { 742 clrbit(vp->v_specbitmap, i); 743 return (error); /* out of vnodes */ 744 } 745 746 VOP_UNLOCK(vp); 747 748 error = cdevsw[major(vp->v_rdev)].d_open(cvp->v_rdev, ap->a_mode, 749 S_IFCHR, ap->a_p); 750 751 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 752 753 if (error) { 754 vput(cvp); 755 clrbit(vp->v_specbitmap, i); 756 return (error); /* device open failed */ 757 } 758 759 cvp->v_flag |= VCLONE; 760 761 cip = malloc(sizeof(struct cloneinfo), M_TEMP, M_WAITOK); 762 cip->ci_data = vp->v_data; 763 cip->ci_vp = cvp; 764 765 cvp->v_specparent = vp; 766 vp->v_flag |= VCLONED; 767 vp->v_data = cip; 768 769 DNPRINTF("clone of vnode %p is vnode %p\n", vp, cvp); 770 771 return (0); /* device cloned */ 772 } 773