vnd.c revision 1.33
1 /* $NetBSD: vnd.c,v 1.33 1997/05/19 14:41:54 pk 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/buf.h> 70 #include <sys/malloc.h> 71 #include <sys/ioctl.h> 72 #include <sys/disklabel.h> 73 #include <sys/device.h> 74 #include <sys/disk.h> 75 #include <sys/stat.h> 76 #include <sys/mount.h> 77 #include <sys/vnode.h> 78 #include <sys/file.h> 79 #include <sys/uio.h> 80 #include <sys/conf.h> 81 82 #include <miscfs/specfs/specdev.h> 83 84 #include <dev/vndioctl.h> 85 86 #ifdef DEBUG 87 int dovndcluster = 1; 88 int vnddebug = 0x00; 89 #define VDB_FOLLOW 0x01 90 #define VDB_INIT 0x02 91 #define VDB_IO 0x04 92 #endif 93 94 #define b_cylin b_resid 95 96 #define vndunit(x) DISKUNIT(x) 97 98 struct vndbuf { 99 struct buf vb_buf; 100 struct buf *vb_obp; 101 }; 102 103 #define getvndbuf() \ 104 ((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK)) 105 #define putvndbuf(vbp) \ 106 free((caddr_t)(vbp), M_DEVBUF) 107 108 struct vnd_softc { 109 int sc_flags; /* flags */ 110 size_t sc_size; /* size of vnd */ 111 struct vnode *sc_vp; /* vnode */ 112 struct ucred *sc_cred; /* credentials */ 113 int sc_maxactive; /* max # of active requests */ 114 struct buf sc_tab; /* transfer queue */ 115 char sc_xname[8]; /* XXX external name */ 116 struct disk 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 /* called by main() at boot time */ 129 void vndattach __P((int)); 130 131 void vndclear __P((struct vnd_softc *)); 132 void vndstart __P((struct vnd_softc *)); 133 int vndsetcred __P((struct vnd_softc *, struct ucred *)); 134 void vndthrottle __P((struct vnd_softc *, struct vnode *)); 135 void vndiodone __P((struct buf *)); 136 void vndshutdown __P((void)); 137 138 static int vndlock __P((struct vnd_softc *)); 139 static void vndunlock __P((struct vnd_softc *)); 140 141 void 142 vndattach(num) 143 int num; 144 { 145 char *mem; 146 register u_long size; 147 148 if (num <= 0) 149 return; 150 size = num * sizeof(struct vnd_softc); 151 mem = malloc(size, M_DEVBUF, M_NOWAIT); 152 if (mem == NULL) { 153 printf("WARNING: no memory for vnode disks\n"); 154 return; 155 } 156 bzero(mem, size); 157 vnd_softc = (struct vnd_softc *)mem; 158 numvnd = num; 159 } 160 161 int 162 vndopen(dev, flags, mode, p) 163 dev_t dev; 164 int flags, mode; 165 struct proc *p; 166 { 167 int unit = vndunit(dev); 168 struct vnd_softc *sc; 169 int error = 0, part, pmask; 170 171 /* 172 * XXX Should support disklabels. 173 */ 174 175 #ifdef DEBUG 176 if (vnddebug & VDB_FOLLOW) 177 printf("vndopen(%x, %x, %x, %p)\n", dev, flags, mode, p); 178 #endif 179 if (unit >= numvnd) 180 return (ENXIO); 181 sc = &vnd_softc[unit]; 182 183 if ((error = vndlock(sc)) != 0) 184 return (error); 185 186 part = DISKPART(dev); 187 pmask = (1 << part); 188 189 /* Prevent our unit from being unconfigured while open. */ 190 switch (mode) { 191 case S_IFCHR: 192 sc->sc_dkdev.dk_copenmask |= pmask; 193 break; 194 195 case S_IFBLK: 196 sc->sc_dkdev.dk_bopenmask |= pmask; 197 break; 198 } 199 sc->sc_dkdev.dk_openmask = 200 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 201 202 vndunlock(sc); 203 return (0); 204 } 205 206 int 207 vndclose(dev, flags, mode, p) 208 dev_t dev; 209 int flags, mode; 210 struct proc *p; 211 { 212 int unit = vndunit(dev); 213 struct vnd_softc *sc; 214 int error = 0, part; 215 216 #ifdef DEBUG 217 if (vnddebug & VDB_FOLLOW) 218 printf("vndclose(%x, %x, %x, %p)\n", dev, flags, mode, p); 219 #endif 220 221 if (unit >= numvnd) 222 return (ENXIO); 223 sc = &vnd_softc[unit]; 224 225 if ((error = vndlock(sc)) != 0) 226 return (error); 227 228 part = DISKPART(dev); 229 230 /* ...that much closer to allowing unconfiguration... */ 231 switch (mode) { 232 case S_IFCHR: 233 sc->sc_dkdev.dk_copenmask &= ~(1 << part); 234 break; 235 236 case S_IFBLK: 237 sc->sc_dkdev.dk_bopenmask &= ~(1 << part); 238 break; 239 } 240 sc->sc_dkdev.dk_openmask = 241 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 242 243 vndunlock(sc); 244 return (0); 245 } 246 247 /* 248 * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. 249 * Note that this driver can only be used for swapping over NFS on the hp 250 * since nfs_strategy on the vax cannot handle u-areas and page tables. 251 */ 252 void 253 vndstrategy(bp) 254 register struct buf *bp; 255 { 256 int unit = vndunit(bp->b_dev); 257 register struct vnd_softc *vnd = &vnd_softc[unit]; 258 register struct vndbuf *nbp; 259 register int bn, bsize, resid; 260 register caddr_t addr; 261 int sz, flags, error; 262 263 #ifdef DEBUG 264 if (vnddebug & VDB_FOLLOW) 265 printf("vndstrategy(%p): unit %d\n", bp, unit); 266 #endif 267 if ((vnd->sc_flags & VNF_INITED) == 0) { 268 bp->b_error = ENXIO; 269 bp->b_flags |= B_ERROR; 270 biodone(bp); 271 return; 272 } 273 bn = bp->b_blkno; 274 sz = howmany(bp->b_bcount, DEV_BSIZE); 275 bp->b_resid = bp->b_bcount; 276 if (bn < 0 || bn + sz > vnd->sc_size) { 277 if (bn != vnd->sc_size) { 278 bp->b_error = EINVAL; 279 bp->b_flags |= B_ERROR; 280 } 281 biodone(bp); 282 return; 283 } 284 bn = dbtob(bn); 285 bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize; 286 addr = bp->b_data; 287 flags = bp->b_flags | B_CALL; 288 for (resid = bp->b_resid; resid; resid -= sz) { 289 struct vnode *vp; 290 daddr_t nbn; 291 int off, s, nra; 292 293 nra = 0; 294 VOP_LOCK(vnd->sc_vp); 295 error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra); 296 VOP_UNLOCK(vnd->sc_vp); 297 if (error == 0 && (long)nbn == -1) 298 error = EIO; 299 #ifdef DEBUG 300 if (!dovndcluster) 301 nra = 0; 302 #endif 303 304 if ((off = bn % bsize) != 0) 305 sz = bsize - off; 306 else 307 sz = (1 + nra) * bsize; 308 if (resid < sz) 309 sz = resid; 310 #ifdef DEBUG 311 if (vnddebug & VDB_IO) 312 printf("vndstrategy: vp %p/%p bn %x/%x sz %x\n", 313 vnd->sc_vp, vp, bn, nbn, sz); 314 #endif 315 316 nbp = getvndbuf(); 317 nbp->vb_buf.b_flags = flags; 318 nbp->vb_buf.b_bcount = sz; 319 nbp->vb_buf.b_bufsize = bp->b_bufsize; 320 nbp->vb_buf.b_error = 0; 321 if (vp->v_type == VBLK || vp->v_type == VCHR) 322 nbp->vb_buf.b_dev = vp->v_rdev; 323 else 324 nbp->vb_buf.b_dev = NODEV; 325 nbp->vb_buf.b_data = addr; 326 nbp->vb_buf.b_blkno = nbn + btodb(off); 327 nbp->vb_buf.b_proc = bp->b_proc; 328 nbp->vb_buf.b_iodone = vndiodone; 329 nbp->vb_buf.b_vp = vp; 330 nbp->vb_buf.b_rcred = vnd->sc_cred; /* XXX crdup? */ 331 nbp->vb_buf.b_wcred = vnd->sc_cred; /* XXX crdup? */ 332 if (bp->b_dirtyend == 0) { 333 nbp->vb_buf.b_dirtyoff = 0; 334 nbp->vb_buf.b_dirtyend = sz; 335 } else { 336 nbp->vb_buf.b_dirtyoff = 337 max(0, bp->b_dirtyoff - (bp->b_bcount - resid)); 338 nbp->vb_buf.b_dirtyend = 339 min(sz, bp->b_dirtyend - (bp->b_bcount - resid)); 340 } 341 if (bp->b_validend == 0) { 342 nbp->vb_buf.b_validoff = 0; 343 nbp->vb_buf.b_validend = sz; 344 } else { 345 nbp->vb_buf.b_validoff = 346 max(0, bp->b_validoff - (bp->b_bcount - resid)); 347 nbp->vb_buf.b_validend = 348 min(sz, bp->b_validend - (bp->b_bcount - resid)); 349 } 350 351 /* save a reference to the old buffer */ 352 nbp->vb_obp = bp; 353 354 /* 355 * If there was an error or a hole in the file...punt. 356 * Note that we deal with this after the nbp allocation. 357 * This ensures that we properly clean up any operations 358 * that we have already fired off. 359 * 360 * XXX we could deal with holes here but it would be 361 * a hassle (in the write case). 362 */ 363 if (error) { 364 nbp->vb_buf.b_error = error; 365 nbp->vb_buf.b_flags |= B_ERROR; 366 bp->b_resid -= (resid - sz); 367 biodone(&nbp->vb_buf); 368 return; 369 } 370 /* 371 * Just sort by block number 372 */ 373 nbp->vb_buf.b_cylin = nbp->vb_buf.b_blkno; 374 s = splbio(); 375 disksort(&vnd->sc_tab, &nbp->vb_buf); 376 if (vnd->sc_tab.b_active < vnd->sc_maxactive) { 377 vnd->sc_tab.b_active++; 378 vndstart(vnd); 379 } 380 splx(s); 381 bn += sz; 382 addr += sz; 383 } 384 } 385 386 /* 387 * Feed requests sequentially. 388 * We do it this way to keep from flooding NFS servers if we are connected 389 * to an NFS file. This places the burden on the client rather than the 390 * server. 391 */ 392 void 393 vndstart(vnd) 394 register struct vnd_softc *vnd; 395 { 396 register struct buf *bp; 397 398 /* 399 * Dequeue now since lower level strategy routine might 400 * queue using same links 401 */ 402 bp = vnd->sc_tab.b_actf; 403 vnd->sc_tab.b_actf = bp->b_actf; 404 #ifdef DEBUG 405 if (vnddebug & VDB_IO) 406 printf("vndstart(%ld): bp %p vp %p blkno %x addr %p cnt %lx\n", 407 (long) (vnd-vnd_softc), bp, bp->b_vp, bp->b_blkno, 408 bp->b_data, bp->b_bcount); 409 #endif 410 411 /* Instrumentation. */ 412 disk_busy(&vnd->sc_dkdev); 413 414 if ((bp->b_flags & B_READ) == 0) 415 bp->b_vp->v_numoutput++; 416 VOP_STRATEGY(bp); 417 } 418 419 void 420 vndiodone(bp) 421 struct buf *bp; 422 { 423 register struct vndbuf *vbp = (struct vndbuf *) bp; 424 register struct buf *pbp = vbp->vb_obp; 425 register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)]; 426 int s; 427 428 s = splbio(); 429 #ifdef DEBUG 430 if (vnddebug & VDB_IO) 431 printf("vndiodone(%ld): vbp %p vp %p blkno %x addr %p cnt %lx\n", 432 (long) (vnd-vnd_softc), vbp, vbp->vb_buf.b_vp, 433 vbp->vb_buf.b_blkno, vbp->vb_buf.b_data, 434 vbp->vb_buf.b_bcount); 435 #endif 436 437 if (vbp->vb_buf.b_error) { 438 #ifdef DEBUG 439 if (vnddebug & VDB_IO) 440 printf("vndiodone: vbp %p error %d\n", vbp, 441 vbp->vb_buf.b_error); 442 #endif 443 pbp->b_flags |= B_ERROR; 444 pbp->b_error = biowait(&vbp->vb_buf); 445 } 446 pbp->b_resid -= vbp->vb_buf.b_bcount; 447 putvndbuf(vbp); 448 disk_unbusy(&vnd->sc_dkdev, (pbp->b_bcount - pbp->b_resid)); 449 if (pbp->b_resid == 0) { 450 #ifdef DEBUG 451 if (vnddebug & VDB_IO) 452 printf("vndiodone: pbp %p iodone\n", pbp); 453 #endif 454 biodone(pbp); 455 } 456 if (vnd->sc_tab.b_actf) 457 vndstart(vnd); 458 else 459 vnd->sc_tab.b_active--; 460 splx(s); 461 } 462 463 /* ARGSUSED */ 464 int 465 vndread(dev, uio, flags) 466 dev_t dev; 467 struct uio *uio; 468 int flags; 469 { 470 int unit = vndunit(dev); 471 struct vnd_softc *sc; 472 473 #ifdef DEBUG 474 if (vnddebug & VDB_FOLLOW) 475 printf("vndread(%x, %p)\n", dev, uio); 476 #endif 477 478 if (unit >= numvnd) 479 return (ENXIO); 480 sc = &vnd_softc[unit]; 481 482 if ((sc->sc_flags & VNF_INITED) == 0) 483 return (ENXIO); 484 485 return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio)); 486 } 487 488 /* ARGSUSED */ 489 int 490 vndwrite(dev, uio, flags) 491 dev_t dev; 492 struct uio *uio; 493 int flags; 494 { 495 int unit = vndunit(dev); 496 struct vnd_softc *sc; 497 498 #ifdef DEBUG 499 if (vnddebug & VDB_FOLLOW) 500 printf("vndwrite(%x, %p)\n", dev, uio); 501 #endif 502 503 if (unit >= numvnd) 504 return (ENXIO); 505 sc = &vnd_softc[unit]; 506 507 if ((sc->sc_flags & VNF_INITED) == 0) 508 return (ENXIO); 509 510 return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio)); 511 } 512 513 /* ARGSUSED */ 514 int 515 vndioctl(dev, cmd, data, flag, p) 516 dev_t dev; 517 u_long cmd; 518 caddr_t data; 519 int flag; 520 struct proc *p; 521 { 522 int unit = vndunit(dev); 523 register struct vnd_softc *vnd; 524 struct vnd_ioctl *vio; 525 struct vattr vattr; 526 struct nameidata nd; 527 int error, part, pmask; 528 529 #ifdef DEBUG 530 if (vnddebug & VDB_FOLLOW) 531 printf("vndioctl(%x, %lx, %p, %x, %p): unit %d\n", 532 dev, cmd, data, flag, p, unit); 533 #endif 534 error = suser(p->p_ucred, &p->p_acflag); 535 if (error) 536 return (error); 537 if (unit >= numvnd) 538 return (ENXIO); 539 540 vnd = &vnd_softc[unit]; 541 vio = (struct vnd_ioctl *)data; 542 switch (cmd) { 543 544 case VNDIOCSET: 545 if (vnd->sc_flags & VNF_INITED) 546 return (EBUSY); 547 548 if ((error = vndlock(vnd)) != 0) 549 return (error); 550 551 /* 552 * Always open for read and write. 553 * This is probably bogus, but it lets vn_open() 554 * weed out directories, sockets, etc. so we don't 555 * have to worry about them. 556 */ 557 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vnd_file, p); 558 if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) { 559 vndunlock(vnd); 560 return(error); 561 } 562 error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p); 563 if (error) { 564 VOP_UNLOCK(nd.ni_vp); 565 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 566 vndunlock(vnd); 567 return(error); 568 } 569 VOP_UNLOCK(nd.ni_vp); 570 vnd->sc_vp = nd.ni_vp; 571 vnd->sc_size = btodb(vattr.va_size); /* note truncation */ 572 if ((error = vndsetcred(vnd, p->p_ucred)) != 0) { 573 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 574 vndunlock(vnd); 575 return(error); 576 } 577 vndthrottle(vnd, vnd->sc_vp); 578 vio->vnd_size = dbtob(vnd->sc_size); 579 vnd->sc_flags |= VNF_INITED; 580 #ifdef DEBUG 581 if (vnddebug & VDB_INIT) 582 printf("vndioctl: SET vp %p size %lx\n", 583 vnd->sc_vp, (unsigned long) vnd->sc_size); 584 #endif 585 586 /* Attach the disk. */ 587 bzero(vnd->sc_xname, sizeof(vnd->sc_xname)); /* XXX */ 588 sprintf(vnd->sc_xname, "vnd%d", unit); /* XXX */ 589 vnd->sc_dkdev.dk_name = vnd->sc_xname; 590 disk_attach(&vnd->sc_dkdev); 591 592 vndunlock(vnd); 593 594 break; 595 596 case VNDIOCCLR: 597 if ((vnd->sc_flags & VNF_INITED) == 0) 598 return (ENXIO); 599 600 if ((error = vndlock(vnd)) != 0) 601 return (error); 602 603 /* 604 * Don't unconfigure if any other partitions are open 605 * or if both the character and block flavors of this 606 * partition are open. 607 */ 608 part = DISKPART(dev); 609 pmask = (1 << part); 610 if ((vnd->sc_dkdev.dk_openmask & ~pmask) || 611 ((vnd->sc_dkdev.dk_bopenmask & pmask) && 612 (vnd->sc_dkdev.dk_copenmask & pmask))) { 613 vndunlock(vnd); 614 return (EBUSY); 615 } 616 617 vndclear(vnd); 618 #ifdef DEBUG 619 if (vnddebug & VDB_INIT) 620 printf("vndioctl: CLRed\n"); 621 #endif 622 623 /* Detatch the disk. */ 624 disk_detach(&vnd->sc_dkdev); 625 626 vndunlock(vnd); 627 628 break; 629 630 /* 631 * XXX Should support disklabels. 632 */ 633 634 default: 635 return(ENOTTY); 636 } 637 638 return (0); 639 } 640 641 /* 642 * Duplicate the current processes' credentials. Since we are called only 643 * as the result of a SET ioctl and only root can do that, any future access 644 * to this "disk" is essentially as root. Note that credentials may change 645 * if some other uid can write directly to the mapped file (NFS). 646 */ 647 int 648 vndsetcred(vnd, cred) 649 register struct vnd_softc *vnd; 650 struct ucred *cred; 651 { 652 struct uio auio; 653 struct iovec aiov; 654 char *tmpbuf; 655 int error; 656 657 vnd->sc_cred = crdup(cred); 658 tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); 659 660 /* XXX: Horrible kludge to establish credentials for NFS */ 661 aiov.iov_base = tmpbuf; 662 aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size)); 663 auio.uio_iov = &aiov; 664 auio.uio_iovcnt = 1; 665 auio.uio_offset = 0; 666 auio.uio_rw = UIO_READ; 667 auio.uio_segflg = UIO_SYSSPACE; 668 auio.uio_resid = aiov.iov_len; 669 VOP_LOCK(vnd->sc_vp); 670 error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred); 671 VOP_UNLOCK(vnd->sc_vp); 672 673 free(tmpbuf, M_TEMP); 674 return (error); 675 } 676 677 /* 678 * Set maxactive based on FS type 679 */ 680 void 681 vndthrottle(vnd, vp) 682 register struct vnd_softc *vnd; 683 struct vnode *vp; 684 { 685 #ifdef NFS 686 extern int (**nfsv2_vnodeop_p) __P((void *)); 687 688 if (vp->v_op == nfsv2_vnodeop_p) 689 vnd->sc_maxactive = 2; 690 else 691 #endif 692 vnd->sc_maxactive = 8; 693 694 if (vnd->sc_maxactive < 1) 695 vnd->sc_maxactive = 1; 696 } 697 698 void 699 vndshutdown() 700 { 701 register struct vnd_softc *vnd; 702 703 for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++) 704 if (vnd->sc_flags & VNF_INITED) 705 vndclear(vnd); 706 } 707 708 void 709 vndclear(vnd) 710 register struct vnd_softc *vnd; 711 { 712 register struct vnode *vp = vnd->sc_vp; 713 struct proc *p = curproc; /* XXX */ 714 715 #ifdef DEBUG 716 if (vnddebug & VDB_FOLLOW) 717 printf("vndclear(%p): vp %p\n", vnd, vp); 718 #endif 719 vnd->sc_flags &= ~VNF_INITED; 720 if (vp == (struct vnode *)0) 721 panic("vndioctl: null vp"); 722 (void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p); 723 crfree(vnd->sc_cred); 724 vnd->sc_vp = (struct vnode *)0; 725 vnd->sc_cred = (struct ucred *)0; 726 vnd->sc_size = 0; 727 } 728 729 int 730 vndsize(dev) 731 dev_t dev; 732 { 733 int unit = vndunit(dev); 734 register struct vnd_softc *vnd = &vnd_softc[unit]; 735 736 if (unit >= numvnd || (vnd->sc_flags & VNF_INITED) == 0) 737 return(-1); 738 return(vnd->sc_size); 739 } 740 741 int 742 vnddump(dev, blkno, va, size) 743 dev_t dev; 744 daddr_t blkno; 745 caddr_t va; 746 size_t size; 747 { 748 749 /* Not implemented. */ 750 return ENXIO; 751 } 752 753 /* 754 * Wait interruptibly for an exclusive lock. 755 * 756 * XXX 757 * Several drivers do this; it should be abstracted and made MP-safe. 758 */ 759 static int 760 vndlock(sc) 761 struct vnd_softc *sc; 762 { 763 int error; 764 765 while ((sc->sc_flags & VNF_LOCKED) != 0) { 766 sc->sc_flags |= VNF_WANTED; 767 if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0) 768 return (error); 769 } 770 sc->sc_flags |= VNF_LOCKED; 771 return (0); 772 } 773 774 /* 775 * Unlock and wake up any waiters. 776 */ 777 static void 778 vndunlock(sc) 779 struct vnd_softc *sc; 780 { 781 782 sc->sc_flags &= ~VNF_LOCKED; 783 if ((sc->sc_flags & VNF_WANTED) != 0) { 784 sc->sc_flags &= ~VNF_WANTED; 785 wakeup(sc); 786 } 787 } 788
Indexes created Mon Sep 29 21:09:56 GMT 2025