vnd.c revision 1.22
1 /* $NetBSD: vnd.c,v 1.22 1995/11/06 20:28:09 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: Utah $Hdr: vn.c 1.13 94/04/02$ 41 * 42 * @(#)vn.c 8.6 (Berkeley) 4/1/94 43 */ 44 45 /* 46 * Vnode disk driver. 47 * 48 * Block/character interface to a vnode. Allows one to treat a file 49 * as a disk (e.g. build a filesystem in it, mount it, etc.). 50 * 51 * NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode 52 * instead of a simple VOP_RDWR. We do this to avoid distorting the 53 * local buffer cache. 54 * 55 * NOTE 2: There is a security issue involved with this driver. 56 * Once mounted all access to the contents of the "mapped" file via 57 * the special file is controlled by the permissions on the special 58 * file, the protection of the mapped file is ignored (effectively, 59 * by using root credentials in all transactions). 60 * 61 * NOTE 3: Doesn't interact with leases, should it? 62 */ 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/namei.h> 67 #include <sys/proc.h> 68 #include <sys/errno.h> 69 #include <sys/dkstat.h> 70 #include <sys/buf.h> 71 #include <sys/malloc.h> 72 #include <sys/ioctl.h> 73 #include <sys/disklabel.h> 74 #include <sys/device.h> 75 #include <sys/disk.h> 76 #include <sys/stat.h> 77 #include <sys/conf.h> 78 #include <sys/mount.h> 79 #include <sys/vnode.h> 80 #include <sys/file.h> 81 #include <sys/uio.h> 82 83 #include <miscfs/specfs/specdev.h> 84 85 #include <dev/vndioctl.h> 86 87 #ifdef DEBUG 88 int dovndcluster = 1; 89 int vnddebug = 0x00; 90 #define VDB_FOLLOW 0x01 91 #define VDB_INIT 0x02 92 #define VDB_IO 0x04 93 #endif 94 95 #define b_cylin b_resid 96 97 #define vndunit(x) DISKUNIT(x) 98 99 struct vndbuf { 100 struct buf vb_buf; 101 struct buf *vb_obp; 102 }; 103 104 #define getvndbuf() \ 105 ((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK)) 106 #define putvndbuf(vbp) \ 107 free((caddr_t)(vbp), M_DEVBUF) 108 109 struct vnd_softc { 110 int sc_flags; /* flags */ 111 size_t sc_size; /* size of vnd */ 112 struct vnode *sc_vp; /* vnode */ 113 struct ucred *sc_cred; /* credentials */ 114 int sc_maxactive; /* max # of active requests */ 115 struct buf sc_tab; /* transfer queue */ 116 struct dkdevice sc_dkdev; /* generic disk device info */ 117 }; 118 119 /* sc_flags */ 120 #define VNF_ALIVE 0x01 121 #define VNF_INITED 0x02 122 #define VNF_WANTED 0x40 123 #define VNF_LOCKED 0x80 124 125 struct vnd_softc *vnd_softc; 126 int numvnd = 0; 127 128 /* {b,c}devsw[] function prototypes */ 129 dev_type_open(vndopen); 130 dev_type_close(vndclose); 131 dev_type_strategy(vndstrategy); 132 dev_type_ioctl(vndioctl); 133 dev_type_read(vndread); 134 dev_type_write(vndwrite); 135 136 /* called by main() at boot time */ 137 void vndattach __P((int)); 138 139 void vndclear __P((struct vnd_softc *)); 140 void vndstart __P((struct vnd_softc *)); 141 int vndsetcred __P((struct vnd_softc *, struct ucred *)); 142 void vndthrottle __P((struct vnd_softc *, struct vnode *)); 143 144 static int vndlock __P((struct vnd_softc *)); 145 static void vndunlock __P((struct vnd_softc *)); 146 147 void 148 vndattach(num) 149 int num; 150 { 151 char *mem; 152 register u_long size; 153 154 if (num <= 0) 155 return; 156 size = num * sizeof(struct vnd_softc); 157 mem = malloc(size, M_DEVBUF, M_NOWAIT); 158 if (mem == NULL) { 159 printf("WARNING: no memory for vnode disks\n"); 160 return; 161 } 162 bzero(mem, size); 163 vnd_softc = (struct vnd_softc *)mem; 164 numvnd = num; 165 } 166 167 int 168 vndopen(dev, flags, mode, p) 169 dev_t dev; 170 int flags, mode; 171 struct proc *p; 172 { 173 int unit = vndunit(dev); 174 struct vnd_softc *sc; 175 int error = 0, part, pmask; 176 177 /* 178 * XXX Should support disklabels. 179 */ 180 181 #ifdef DEBUG 182 if (vnddebug & VDB_FOLLOW) 183 printf("vndopen(%x, %x, %x, %x)\n", dev, flags, mode, p); 184 #endif 185 if (unit >= numvnd) 186 return (ENXIO); 187 sc = &vnd_softc[unit]; 188 189 if (error = vndlock(sc)) 190 return (error); 191 192 part = DISKPART(dev); 193 pmask = (1 << part); 194 195 /* Prevent our unit from being unconfigured while open. */ 196 switch (mode) { 197 case S_IFCHR: 198 sc->sc_dkdev.dk_copenmask |= pmask; 199 break; 200 201 case S_IFBLK: 202 sc->sc_dkdev.dk_bopenmask |= pmask; 203 break; 204 } 205 sc->sc_dkdev.dk_openmask = 206 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 207 208 vndunlock(sc); 209 return (0); 210 } 211 212 int 213 vndclose(dev, flags, mode, p) 214 dev_t dev; 215 int flags, mode; 216 struct proc *p; 217 { 218 int unit = vndunit(dev); 219 struct vnd_softc *sc; 220 int error = 0, part; 221 222 #ifdef DEBUG 223 if (vnddebug & VDB_FOLLOW) 224 printf("vndclose(%x, %x, %x, %x)\n", dev, flags, mode, p); 225 #endif 226 227 if (unit >= numvnd) 228 return (ENXIO); 229 sc = &vnd_softc[unit]; 230 231 if (error = vndlock(sc)) 232 return (error); 233 234 part = DISKPART(dev); 235 236 /* ...that much closer to allowing unconfiguration... */ 237 switch (mode) { 238 case S_IFCHR: 239 sc->sc_dkdev.dk_copenmask &= ~(1 << part); 240 break; 241 242 case S_IFBLK: 243 sc->sc_dkdev.dk_bopenmask &= ~(1 << part); 244 break; 245 } 246 sc->sc_dkdev.dk_openmask = 247 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 248 249 vndunlock(sc); 250 return (0); 251 } 252 253 /* 254 * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. 255 * Note that this driver can only be used for swapping over NFS on the hp 256 * since nfs_strategy on the vax cannot handle u-areas and page tables. 257 */ 258 void 259 vndstrategy(bp) 260 register struct buf *bp; 261 { 262 int unit = vndunit(bp->b_dev); 263 register struct vnd_softc *vnd = &vnd_softc[unit]; 264 register struct vndbuf *nbp; 265 register int bn, bsize, resid; 266 register caddr_t addr; 267 int sz, flags, error; 268 extern void vndiodone(); 269 270 #ifdef DEBUG 271 if (vnddebug & VDB_FOLLOW) 272 printf("vndstrategy(%x): unit %d\n", bp, unit); 273 #endif 274 if ((vnd->sc_flags & VNF_INITED) == 0) { 275 bp->b_error = ENXIO; 276 bp->b_flags |= B_ERROR; 277 biodone(bp); 278 return; 279 } 280 bn = bp->b_blkno; 281 sz = howmany(bp->b_bcount, DEV_BSIZE); 282 bp->b_resid = bp->b_bcount; 283 if (bn < 0 || bn + sz > vnd->sc_size) { 284 if (bn != vnd->sc_size) { 285 bp->b_error = EINVAL; 286 bp->b_flags |= B_ERROR; 287 } 288 biodone(bp); 289 return; 290 } 291 bn = dbtob(bn); 292 bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize; 293 addr = bp->b_data; 294 flags = bp->b_flags | B_CALL; 295 for (resid = bp->b_resid; resid; resid -= sz) { 296 struct vnode *vp; 297 daddr_t nbn; 298 int off, s, nra; 299 300 nra = 0; 301 VOP_LOCK(vnd->sc_vp); 302 error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra); 303 VOP_UNLOCK(vnd->sc_vp); 304 if (error == 0 && (long)nbn == -1) 305 error = EIO; 306 #ifdef DEBUG 307 if (!dovndcluster) 308 nra = 0; 309 #endif 310 311 if (off = bn % bsize) 312 sz = bsize - off; 313 else 314 sz = (1 + nra) * bsize; 315 if (resid < sz) 316 sz = resid; 317 #ifdef DEBUG 318 if (vnddebug & VDB_IO) 319 printf("vndstrategy: vp %x/%x bn %x/%x sz %x\n", 320 vnd->sc_vp, vp, bn, nbn, sz); 321 #endif 322 323 nbp = getvndbuf(); 324 nbp->vb_buf.b_flags = flags; 325 nbp->vb_buf.b_bcount = sz; 326 nbp->vb_buf.b_bufsize = bp->b_bufsize; 327 nbp->vb_buf.b_error = 0; 328 if (vp->v_type == VBLK || vp->v_type == VCHR) 329 nbp->vb_buf.b_dev = vp->v_rdev; 330 else 331 nbp->vb_buf.b_dev = NODEV; 332 nbp->vb_buf.b_data = addr; 333 nbp->vb_buf.b_blkno = nbn + btodb(off); 334 nbp->vb_buf.b_proc = bp->b_proc; 335 nbp->vb_buf.b_iodone = vndiodone; 336 nbp->vb_buf.b_vp = vp; 337 nbp->vb_buf.b_rcred = vnd->sc_cred; /* XXX crdup? */ 338 nbp->vb_buf.b_wcred = vnd->sc_cred; /* XXX crdup? */ 339 nbp->vb_buf.b_dirtyoff = bp->b_dirtyoff; 340 nbp->vb_buf.b_dirtyend = bp->b_dirtyend; 341 nbp->vb_buf.b_validoff = bp->b_validoff; 342 nbp->vb_buf.b_validend = bp->b_validend; 343 344 /* save a reference to the old buffer */ 345 nbp->vb_obp = bp; 346 347 /* 348 * If there was an error or a hole in the file...punt. 349 * Note that we deal with this after the nbp allocation. 350 * This ensures that we properly clean up any operations 351 * that we have already fired off. 352 * 353 * XXX we could deal with holes here but it would be 354 * a hassle (in the write case). 355 */ 356 if (error) { 357 nbp->vb_buf.b_error = error; 358 nbp->vb_buf.b_flags |= B_ERROR; 359 bp->b_resid -= (resid - sz); 360 biodone(&nbp->vb_buf); 361 return; 362 } 363 /* 364 * Just sort by block number 365 */ 366 nbp->vb_buf.b_cylin = nbp->vb_buf.b_blkno; 367 s = splbio(); 368 disksort(&vnd->sc_tab, &nbp->vb_buf); 369 if (vnd->sc_tab.b_active < vnd->sc_maxactive) { 370 vnd->sc_tab.b_active++; 371 vndstart(vnd); 372 } 373 splx(s); 374 bn += sz; 375 addr += sz; 376 } 377 } 378 379 /* 380 * Feed requests sequentially. 381 * We do it this way to keep from flooding NFS servers if we are connected 382 * to an NFS file. This places the burden on the client rather than the 383 * server. 384 */ 385 void 386 vndstart(vnd) 387 register struct vnd_softc *vnd; 388 { 389 register struct buf *bp; 390 391 /* 392 * Dequeue now since lower level strategy routine might 393 * queue using same links 394 */ 395 bp = vnd->sc_tab.b_actf; 396 vnd->sc_tab.b_actf = bp->b_actf; 397 #ifdef DEBUG 398 if (vnddebug & VDB_IO) 399 printf("vndstart(%d): bp %x vp %x blkno %x addr %x cnt %x\n", 400 vnd-vnd_softc, bp, bp->b_vp, bp->b_blkno, bp->b_data, 401 bp->b_bcount); 402 #endif 403 if ((bp->b_flags & B_READ) == 0) 404 bp->b_vp->v_numoutput++; 405 VOP_STRATEGY(bp); 406 } 407 408 void 409 vndiodone(vbp) 410 register struct vndbuf *vbp; 411 { 412 register struct buf *pbp = vbp->vb_obp; 413 register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)]; 414 int s; 415 416 s = splbio(); 417 #ifdef DEBUG 418 if (vnddebug & VDB_IO) 419 printf("vndiodone(%d): vbp %x vp %x blkno %x addr %x cnt %x\n", 420 vnd-vnd_softc, vbp, vbp->vb_buf.b_vp, vbp->vb_buf.b_blkno, 421 vbp->vb_buf.b_data, vbp->vb_buf.b_bcount); 422 #endif 423 if (vbp->vb_buf.b_error) { 424 #ifdef DEBUG 425 if (vnddebug & VDB_IO) 426 printf("vndiodone: vbp %x error %d\n", vbp, 427 vbp->vb_buf.b_error); 428 #endif 429 pbp->b_flags |= B_ERROR; 430 pbp->b_error = biowait(&vbp->vb_buf); 431 } 432 pbp->b_resid -= vbp->vb_buf.b_bcount; 433 putvndbuf(vbp); 434 if (pbp->b_resid == 0) { 435 #ifdef DEBUG 436 if (vnddebug & VDB_IO) 437 printf("vndiodone: pbp %x iodone\n", pbp); 438 #endif 439 biodone(pbp); 440 } 441 if (vnd->sc_tab.b_actf) 442 vndstart(vnd); 443 else 444 vnd->sc_tab.b_active--; 445 splx(s); 446 } 447 448 /* ARGSUSED */ 449 int 450 vndread(dev, uio, flags) 451 dev_t dev; 452 struct uio *uio; 453 int flags; 454 { 455 int unit = vndunit(dev); 456 struct vnd_softc *sc; 457 458 #ifdef DEBUG 459 if (vnddebug & VDB_FOLLOW) 460 printf("vndread(%x, %x)\n", dev, uio); 461 #endif 462 463 if (unit >= numvnd) 464 return (ENXIO); 465 sc = &vnd_softc[unit]; 466 467 if ((sc->sc_flags & VNF_INITED) == 0) 468 return (ENXIO); 469 470 return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio)); 471 } 472 473 /* ARGSUSED */ 474 int 475 vndwrite(dev, uio, flags) 476 dev_t dev; 477 struct uio *uio; 478 int flags; 479 { 480 int unit = vndunit(dev); 481 struct vnd_softc *sc; 482 483 #ifdef DEBUG 484 if (vnddebug & VDB_FOLLOW) 485 printf("vndwrite(%x, %x)\n", dev, uio); 486 #endif 487 488 if (unit >= numvnd) 489 return (ENXIO); 490 sc = &vnd_softc[unit]; 491 492 if ((sc->sc_flags & VNF_INITED) == 0) 493 return (ENXIO); 494 495 return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio)); 496 } 497 498 /* ARGSUSED */ 499 int 500 vndioctl(dev, cmd, data, flag, p) 501 dev_t dev; 502 u_long cmd; 503 caddr_t data; 504 int flag; 505 struct proc *p; 506 { 507 int unit = vndunit(dev); 508 register struct vnd_softc *vnd; 509 struct vnd_ioctl *vio; 510 struct vattr vattr; 511 struct nameidata nd; 512 int error, part, pmask, s; 513 514 #ifdef DEBUG 515 if (vnddebug & VDB_FOLLOW) 516 printf("vndioctl(%x, %lx, %x, %x, %x): unit %d\n", 517 dev, cmd, data, flag, p, unit); 518 #endif 519 error = suser(p->p_ucred, &p->p_acflag); 520 if (error) 521 return (error); 522 if (unit >= numvnd) 523 return (ENXIO); 524 525 vnd = &vnd_softc[unit]; 526 vio = (struct vnd_ioctl *)data; 527 switch (cmd) { 528 529 case VNDIOCSET: 530 if (vnd->sc_flags & VNF_INITED) 531 return (EBUSY); 532 533 if (error = vndlock(vnd)) 534 return (error); 535 536 /* 537 * Always open for read and write. 538 * This is probably bogus, but it lets vn_open() 539 * weed out directories, sockets, etc. so we don't 540 * have to worry about them. 541 */ 542 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vnd_file, p); 543 if (error = vn_open(&nd, FREAD|FWRITE, 0)) { 544 vndunlock(vnd); 545 return(error); 546 } 547 if (error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p)) { 548 VOP_UNLOCK(nd.ni_vp); 549 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 550 vndunlock(vnd); 551 return(error); 552 } 553 VOP_UNLOCK(nd.ni_vp); 554 vnd->sc_vp = nd.ni_vp; 555 vnd->sc_size = btodb(vattr.va_size); /* note truncation */ 556 if (error = vndsetcred(vnd, p->p_ucred)) { 557 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 558 vndunlock(vnd); 559 return(error); 560 } 561 vndthrottle(vnd, vnd->sc_vp); 562 vio->vnd_size = dbtob(vnd->sc_size); 563 vnd->sc_flags |= VNF_INITED; 564 #ifdef DEBUG 565 if (vnddebug & VDB_INIT) 566 printf("vndioctl: SET vp %x size %x\n", 567 vnd->sc_vp, vnd->sc_size); 568 #endif 569 570 vndunlock(vnd); 571 572 break; 573 574 case VNDIOCCLR: 575 if ((vnd->sc_flags & VNF_INITED) == 0) 576 return (ENXIO); 577 578 if (error = vndlock(vnd)) 579 return (error); 580 581 /* 582 * Don't unconfigure if any other partitions are open 583 * or if both the character and block flavors of this 584 * partition are open. 585 */ 586 part = DISKPART(dev); 587 pmask = (1 << part); 588 if ((vnd->sc_dkdev.dk_openmask & ~pmask) || 589 ((vnd->sc_dkdev.dk_bopenmask & pmask) && 590 (vnd->sc_dkdev.dk_copenmask & pmask))) { 591 vndunlock(vnd); 592 return (EBUSY); 593 } 594 595 vndclear(vnd); 596 #ifdef DEBUG 597 if (vnddebug & VDB_INIT) 598 printf("vndioctl: CLRed\n"); 599 #endif 600 601 /* This must be atomic. */ 602 s = splhigh(); 603 vndunlock(vnd); 604 bzero(vnd, sizeof(struct vnd_softc)); 605 splx(s); 606 607 break; 608 609 /* 610 * XXX Should support disklabels. 611 */ 612 613 default: 614 return(ENOTTY); 615 } 616 617 return (0); 618 } 619 620 /* 621 * Duplicate the current processes' credentials. Since we are called only 622 * as the result of a SET ioctl and only root can do that, any future access 623 * to this "disk" is essentially as root. Note that credentials may change 624 * if some other uid can write directly to the mapped file (NFS). 625 */ 626 int 627 vndsetcred(vnd, cred) 628 register struct vnd_softc *vnd; 629 struct ucred *cred; 630 { 631 struct uio auio; 632 struct iovec aiov; 633 char *tmpbuf; 634 int error; 635 636 vnd->sc_cred = crdup(cred); 637 tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); 638 639 /* XXX: Horrible kludge to establish credentials for NFS */ 640 aiov.iov_base = tmpbuf; 641 aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size)); 642 auio.uio_iov = &aiov; 643 auio.uio_iovcnt = 1; 644 auio.uio_offset = 0; 645 auio.uio_rw = UIO_READ; 646 auio.uio_segflg = UIO_SYSSPACE; 647 auio.uio_resid = aiov.iov_len; 648 VOP_LOCK(vnd->sc_vp); 649 error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred); 650 VOP_UNLOCK(vnd->sc_vp); 651 652 free(tmpbuf, M_TEMP); 653 return (error); 654 } 655 656 /* 657 * Set maxactive based on FS type 658 */ 659 void 660 vndthrottle(vnd, vp) 661 register struct vnd_softc *vnd; 662 struct vnode *vp; 663 { 664 #ifdef NFSCLIENT 665 extern int (**nfsv2_vnodeop_p)(); 666 667 if (vp->v_op == nfsv2_vnodeop_p) 668 vnd->sc_maxactive = 2; 669 else 670 #endif 671 vnd->sc_maxactive = 8; 672 673 if (vnd->sc_maxactive < 1) 674 vnd->sc_maxactive = 1; 675 } 676 677 void 678 vndshutdown() 679 { 680 register struct vnd_softc *vnd; 681 682 for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++) 683 if (vnd->sc_flags & VNF_INITED) 684 vndclear(vnd); 685 } 686 687 void 688 vndclear(vnd) 689 register struct vnd_softc *vnd; 690 { 691 register struct vnode *vp = vnd->sc_vp; 692 struct proc *p = curproc; /* XXX */ 693 694 #ifdef DEBUG 695 if (vnddebug & VDB_FOLLOW) 696 printf("vndclear(%x): vp %x\n", vp); 697 #endif 698 vnd->sc_flags &= ~VNF_INITED; 699 if (vp == (struct vnode *)0) 700 panic("vndioctl: null vp"); 701 (void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p); 702 crfree(vnd->sc_cred); 703 vnd->sc_vp = (struct vnode *)0; 704 vnd->sc_cred = (struct ucred *)0; 705 vnd->sc_size = 0; 706 } 707 708 int 709 vndsize(dev) 710 dev_t dev; 711 { 712 int unit = vndunit(dev); 713 register struct vnd_softc *vnd = &vnd_softc[unit]; 714 715 if (unit >= numvnd || (vnd->sc_flags & VNF_INITED) == 0) 716 return(-1); 717 return(vnd->sc_size); 718 } 719 720 int 721 vnddump(dev, blkno, va, size) 722 dev_t dev; 723 daddr_t blkno; 724 caddr_t va; 725 size_t size; 726 { 727 728 /* Not implemented. */ 729 return ENXIO; 730 } 731 732 /* 733 * Wait interruptibly for an exclusive lock. 734 * 735 * XXX 736 * Several drivers do this; it should be abstracted and made MP-safe. 737 */ 738 static int 739 vndlock(sc) 740 struct vnd_softc *sc; 741 { 742 int error; 743 744 while ((sc->sc_flags & VNF_LOCKED) != 0) { 745 sc->sc_flags |= VNF_WANTED; 746 if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0) 747 return (error); 748 } 749 sc->sc_flags |= VNF_LOCKED; 750 return (0); 751 } 752 753 /* 754 * Unlock and wake up any waiters. 755 */ 756 static void 757 vndunlock(sc) 758 struct vnd_softc *sc; 759 { 760 761 sc->sc_flags &= ~VNF_LOCKED; 762 if ((sc->sc_flags & VNF_WANTED) != 0) { 763 sc->sc_flags &= ~VNF_WANTED; 764 wakeup(sc); 765 } 766 } 767
Indexes created Tue Sep 30 06:09:59 GMT 2025