vnd.c revision 1.38
1 /* $NetBSD: vnd.c,v 1.38 1997/05/26 20:28:38 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 vndxfer { 99 struct buf *vx_bp; /* Pointer to parent buffer */ 100 int vx_error; 101 int vx_pending; /* # of pending aux buffers */ 102 }; 103 104 struct vndbuf { 105 struct buf vb_buf; 106 struct vndxfer *vb_xfer; 107 }; 108 109 #define getvndxfer() \ 110 ((struct vndxfer *)malloc(sizeof(struct vndxfer), M_DEVBUF, M_WAITOK)) 111 #define putvndxfer(vnx) \ 112 free((caddr_t)(vnx), M_DEVBUF) 113 #define getvndbuf() \ 114 ((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK)) 115 #define putvndbuf(vbp) \ 116 free((caddr_t)(vbp), M_DEVBUF) 117 118 struct vnd_softc { 119 int sc_flags; /* flags */ 120 size_t sc_size; /* size of vnd */ 121 struct vnode *sc_vp; /* vnode */ 122 struct ucred *sc_cred; /* credentials */ 123 int sc_maxactive; /* max # of active requests */ 124 struct buf sc_tab; /* transfer queue */ 125 char sc_xname[8]; /* XXX external name */ 126 struct disk sc_dkdev; /* generic disk device info */ 127 }; 128 129 /* sc_flags */ 130 #define VNF_ALIVE 0x01 131 #define VNF_INITED 0x02 132 #define VNF_WANTED 0x40 133 #define VNF_LOCKED 0x80 134 135 struct vnd_softc *vnd_softc; 136 int numvnd = 0; 137 138 /* called by main() at boot time */ 139 void vndattach __P((int)); 140 141 void vndclear __P((struct vnd_softc *)); 142 void vndstart __P((struct vnd_softc *)); 143 int vndsetcred __P((struct vnd_softc *, struct ucred *)); 144 void vndthrottle __P((struct vnd_softc *, struct vnode *)); 145 void vndiodone __P((struct buf *)); 146 void vndshutdown __P((void)); 147 148 static int vndlock __P((struct vnd_softc *)); 149 static void vndunlock __P((struct vnd_softc *)); 150 151 void 152 vndattach(num) 153 int num; 154 { 155 char *mem; 156 register u_long size; 157 158 if (num <= 0) 159 return; 160 size = num * sizeof(struct vnd_softc); 161 mem = malloc(size, M_DEVBUF, M_NOWAIT); 162 if (mem == NULL) { 163 printf("WARNING: no memory for vnode disks\n"); 164 return; 165 } 166 bzero(mem, size); 167 vnd_softc = (struct vnd_softc *)mem; 168 numvnd = num; 169 } 170 171 int 172 vndopen(dev, flags, mode, p) 173 dev_t dev; 174 int flags, mode; 175 struct proc *p; 176 { 177 int unit = vndunit(dev); 178 struct vnd_softc *sc; 179 int error = 0, part, pmask; 180 181 /* 182 * XXX Should support disklabels. 183 */ 184 185 #ifdef DEBUG 186 if (vnddebug & VDB_FOLLOW) 187 printf("vndopen(%x, %x, %x, %p)\n", dev, flags, mode, p); 188 #endif 189 if (unit >= numvnd) 190 return (ENXIO); 191 sc = &vnd_softc[unit]; 192 193 if ((error = vndlock(sc)) != 0) 194 return (error); 195 196 part = DISKPART(dev); 197 pmask = (1 << part); 198 199 /* Prevent our unit from being unconfigured while open. */ 200 switch (mode) { 201 case S_IFCHR: 202 sc->sc_dkdev.dk_copenmask |= pmask; 203 break; 204 205 case S_IFBLK: 206 sc->sc_dkdev.dk_bopenmask |= pmask; 207 break; 208 } 209 sc->sc_dkdev.dk_openmask = 210 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 211 212 vndunlock(sc); 213 return (0); 214 } 215 216 int 217 vndclose(dev, flags, mode, p) 218 dev_t dev; 219 int flags, mode; 220 struct proc *p; 221 { 222 int unit = vndunit(dev); 223 struct vnd_softc *sc; 224 int error = 0, part; 225 226 #ifdef DEBUG 227 if (vnddebug & VDB_FOLLOW) 228 printf("vndclose(%x, %x, %x, %p)\n", dev, flags, mode, p); 229 #endif 230 231 if (unit >= numvnd) 232 return (ENXIO); 233 sc = &vnd_softc[unit]; 234 235 if ((error = vndlock(sc)) != 0) 236 return (error); 237 238 part = DISKPART(dev); 239 240 /* ...that much closer to allowing unconfiguration... */ 241 switch (mode) { 242 case S_IFCHR: 243 sc->sc_dkdev.dk_copenmask &= ~(1 << part); 244 break; 245 246 case S_IFBLK: 247 sc->sc_dkdev.dk_bopenmask &= ~(1 << part); 248 break; 249 } 250 sc->sc_dkdev.dk_openmask = 251 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 252 253 vndunlock(sc); 254 return (0); 255 } 256 257 /* 258 * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. 259 * Note that this driver can only be used for swapping over NFS on the hp 260 * since nfs_strategy on the vax cannot handle u-areas and page tables. 261 */ 262 void 263 vndstrategy(bp) 264 register struct buf *bp; 265 { 266 int unit = vndunit(bp->b_dev); 267 struct vnd_softc *vnd = &vnd_softc[unit]; 268 struct vndbuf *nbp; 269 struct vndxfer *vnx; 270 int bn, bsize, resid; 271 caddr_t addr; 272 int sz, flags, error; 273 274 #ifdef DEBUG 275 if (vnddebug & VDB_FOLLOW) 276 printf("vndstrategy(%p): unit %d\n", bp, unit); 277 #endif 278 if ((vnd->sc_flags & VNF_INITED) == 0) { 279 bp->b_error = ENXIO; 280 bp->b_flags |= B_ERROR; 281 biodone(bp); 282 return; 283 } 284 bn = bp->b_blkno; 285 sz = howmany(bp->b_bcount, DEV_BSIZE); 286 bp->b_resid = bp->b_bcount; 287 if (bn < 0 || bn + sz > vnd->sc_size) { 288 if (bn != vnd->sc_size) { 289 bp->b_error = EINVAL; 290 bp->b_flags |= B_ERROR; 291 } 292 biodone(bp); 293 return; 294 } 295 bn = dbtob(bn); 296 bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize; 297 addr = bp->b_data; 298 flags = bp->b_flags | B_CALL; 299 300 /* Allocate a header for this transfer and link it to the buffer */ 301 vnx = getvndxfer(); 302 vnx->vx_error = 0; 303 vnx->vx_pending = 0; 304 vnx->vx_bp = bp; 305 306 for (resid = bp->b_resid; resid; resid -= sz) { 307 struct vnode *vp; 308 daddr_t nbn; 309 int off, s, nra; 310 311 nra = 0; 312 VOP_LOCK(vnd->sc_vp); 313 error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra); 314 VOP_UNLOCK(vnd->sc_vp); 315 316 #ifdef VND_FILLHOLES 317 if (error == 0 && (long)nbn == -1) { 318 int rw = (flags & B_READ) ? UIO_READ : UIO_WRITE; 319 sz = resid; 320 error = vn_rdwr(rw, vnd->sc_vp, addr, sz, 321 bn, UIO_SYSSPACE, 322 IO_SYNC | IO_NODELOCKED, 323 vnd->sc_cred, &resid, bp->b_proc); 324 bp->b_resid -= (sz - resid); 325 } 326 #else 327 if (error == 0 && (long)nbn == -1) 328 error = EIO; 329 #endif 330 331 /* 332 * If there was an error or a hole in the file...punt. 333 * Note that we may have to wait for any operations 334 * that we have already fired off before releasing 335 * the buffer. 336 * 337 * XXX we could deal with holes here but it would be 338 * a hassle (in the write case). 339 */ 340 if (error || (long)nbn == -1) { 341 vnx->vx_error = error; 342 if (vnx->vx_pending == 0) { 343 if (error) { 344 bp->b_error = error; 345 bp->b_flags |= B_ERROR; 346 } 347 putvndxfer(vnx); 348 biodone(bp); 349 } 350 return; 351 } 352 353 #ifdef DEBUG 354 if (!dovndcluster) 355 nra = 0; 356 #endif 357 358 if ((off = bn % bsize) != 0) 359 sz = bsize - off; 360 else 361 sz = (1 + nra) * bsize; 362 if (resid < sz) 363 sz = resid; 364 #ifdef DEBUG 365 if (vnddebug & VDB_IO) 366 printf("vndstrategy: vp %p/%p bn %x/%x sz %x\n", 367 vnd->sc_vp, vp, bn, nbn, sz); 368 #endif 369 370 nbp = getvndbuf(); 371 nbp->vb_buf.b_flags = flags; 372 nbp->vb_buf.b_bcount = sz; 373 nbp->vb_buf.b_bufsize = bp->b_bufsize; 374 nbp->vb_buf.b_error = 0; 375 if (vp->v_type == VBLK || vp->v_type == VCHR) 376 nbp->vb_buf.b_dev = vp->v_rdev; 377 else 378 nbp->vb_buf.b_dev = NODEV; 379 nbp->vb_buf.b_data = addr; 380 nbp->vb_buf.b_blkno = nbn + btodb(off); 381 nbp->vb_buf.b_proc = bp->b_proc; 382 nbp->vb_buf.b_iodone = vndiodone; 383 nbp->vb_buf.b_vp = vp; 384 nbp->vb_buf.b_rcred = vnd->sc_cred; /* XXX crdup? */ 385 nbp->vb_buf.b_wcred = vnd->sc_cred; /* XXX crdup? */ 386 if (bp->b_dirtyend == 0) { 387 nbp->vb_buf.b_dirtyoff = 0; 388 nbp->vb_buf.b_dirtyend = sz; 389 } else { 390 nbp->vb_buf.b_dirtyoff = 391 max(0, bp->b_dirtyoff - (bp->b_bcount - resid)); 392 nbp->vb_buf.b_dirtyend = 393 min(sz, 394 max(0, bp->b_dirtyend - (bp->b_bcount-resid))); 395 } 396 if (bp->b_validend == 0) { 397 nbp->vb_buf.b_validoff = 0; 398 nbp->vb_buf.b_validend = sz; 399 } else { 400 nbp->vb_buf.b_validoff = 401 max(0, bp->b_validoff - (bp->b_bcount - resid)); 402 nbp->vb_buf.b_validend = 403 min(sz, 404 max(0, bp->b_validend - (bp->b_bcount-resid))); 405 } 406 407 nbp->vb_xfer = vnx; 408 vnx->vx_pending++; 409 410 /* 411 * Just sort by block number 412 */ 413 nbp->vb_buf.b_cylin = nbp->vb_buf.b_blkno; 414 s = splbio(); 415 disksort(&vnd->sc_tab, &nbp->vb_buf); 416 if (vnd->sc_tab.b_active < vnd->sc_maxactive) { 417 vnd->sc_tab.b_active++; 418 vndstart(vnd); 419 } 420 splx(s); 421 bn += sz; 422 addr += sz; 423 } 424 } 425 426 /* 427 * Feed requests sequentially. 428 * We do it this way to keep from flooding NFS servers if we are connected 429 * to an NFS file. This places the burden on the client rather than the 430 * server. 431 */ 432 void 433 vndstart(vnd) 434 register struct vnd_softc *vnd; 435 { 436 register struct buf *bp; 437 438 /* 439 * Dequeue now since lower level strategy routine might 440 * queue using same links 441 */ 442 bp = vnd->sc_tab.b_actf; 443 vnd->sc_tab.b_actf = bp->b_actf; 444 #ifdef DEBUG 445 if (vnddebug & VDB_IO) 446 printf("vndstart(%ld): bp %p vp %p blkno %x addr %p cnt %lx\n", 447 (long) (vnd-vnd_softc), bp, bp->b_vp, bp->b_blkno, 448 bp->b_data, bp->b_bcount); 449 #endif 450 451 /* Instrumentation. */ 452 disk_busy(&vnd->sc_dkdev); 453 454 if ((bp->b_flags & B_READ) == 0) 455 bp->b_vp->v_numoutput++; 456 VOP_STRATEGY(bp); 457 } 458 459 void 460 vndiodone(bp) 461 struct buf *bp; 462 { 463 register struct vndbuf *vbp = (struct vndbuf *) bp; 464 register struct vndxfer *vnx = (struct vndxfer *)vbp->vb_xfer; 465 register struct buf *pbp = vnx->vx_bp; 466 register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)]; 467 int s, resid; 468 469 s = splbio(); 470 #ifdef DEBUG 471 if (vnddebug & VDB_IO) 472 printf("vndiodone(%ld): vbp %p vp %p blkno %x addr %p cnt %lx\n", 473 (long) (vnd-vnd_softc), vbp, vbp->vb_buf.b_vp, 474 vbp->vb_buf.b_blkno, vbp->vb_buf.b_data, 475 vbp->vb_buf.b_bcount); 476 #endif 477 478 resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid; 479 pbp->b_resid -= resid; 480 disk_unbusy(&vnd->sc_dkdev, resid); 481 vnx->vx_pending--; 482 483 if (vbp->vb_buf.b_error) { 484 #ifdef DEBUG 485 if (vnddebug & VDB_IO) 486 printf("vndiodone: vbp %p error %d\n", vbp, 487 vbp->vb_buf.b_error); 488 #endif 489 vnx->vx_error = vbp->vb_buf.b_error; 490 } 491 putvndbuf(vbp); 492 493 /* 494 * Wrap up this transaction if it has run to completion or, in 495 * case of an error, when all auxiliary buffers have returned. 496 */ 497 if (pbp->b_resid == 0 || (vnx->vx_error && vnx->vx_pending == 0)) { 498 499 if (vnx->vx_error != 0) { 500 pbp->b_flags |= B_ERROR; 501 pbp->b_error = vnx->vx_error; 502 } 503 putvndxfer(vnx); 504 #ifdef DEBUG 505 if (vnddebug & VDB_IO) 506 printf("vndiodone: pbp %p iodone\n", pbp); 507 #endif 508 biodone(pbp); 509 } 510 511 if (vnd->sc_tab.b_actf) 512 vndstart(vnd); 513 else 514 vnd->sc_tab.b_active--; 515 splx(s); 516 } 517 518 /* ARGSUSED */ 519 int 520 vndread(dev, uio, flags) 521 dev_t dev; 522 struct uio *uio; 523 int flags; 524 { 525 int unit = vndunit(dev); 526 struct vnd_softc *sc; 527 528 #ifdef DEBUG 529 if (vnddebug & VDB_FOLLOW) 530 printf("vndread(%x, %p)\n", dev, uio); 531 #endif 532 533 if (unit >= numvnd) 534 return (ENXIO); 535 sc = &vnd_softc[unit]; 536 537 if ((sc->sc_flags & VNF_INITED) == 0) 538 return (ENXIO); 539 540 return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio)); 541 } 542 543 /* ARGSUSED */ 544 int 545 vndwrite(dev, uio, flags) 546 dev_t dev; 547 struct uio *uio; 548 int flags; 549 { 550 int unit = vndunit(dev); 551 struct vnd_softc *sc; 552 553 #ifdef DEBUG 554 if (vnddebug & VDB_FOLLOW) 555 printf("vndwrite(%x, %p)\n", dev, uio); 556 #endif 557 558 if (unit >= numvnd) 559 return (ENXIO); 560 sc = &vnd_softc[unit]; 561 562 if ((sc->sc_flags & VNF_INITED) == 0) 563 return (ENXIO); 564 565 return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio)); 566 } 567 568 /* ARGSUSED */ 569 int 570 vndioctl(dev, cmd, data, flag, p) 571 dev_t dev; 572 u_long cmd; 573 caddr_t data; 574 int flag; 575 struct proc *p; 576 { 577 int unit = vndunit(dev); 578 register struct vnd_softc *vnd; 579 struct vnd_ioctl *vio; 580 struct vattr vattr; 581 struct nameidata nd; 582 int error, part, pmask; 583 584 #ifdef DEBUG 585 if (vnddebug & VDB_FOLLOW) 586 printf("vndioctl(%x, %lx, %p, %x, %p): unit %d\n", 587 dev, cmd, data, flag, p, unit); 588 #endif 589 error = suser(p->p_ucred, &p->p_acflag); 590 if (error) 591 return (error); 592 if (unit >= numvnd) 593 return (ENXIO); 594 595 vnd = &vnd_softc[unit]; 596 vio = (struct vnd_ioctl *)data; 597 switch (cmd) { 598 599 case VNDIOCSET: 600 if (vnd->sc_flags & VNF_INITED) 601 return (EBUSY); 602 603 if ((error = vndlock(vnd)) != 0) 604 return (error); 605 606 /* 607 * Always open for read and write. 608 * This is probably bogus, but it lets vn_open() 609 * weed out directories, sockets, etc. so we don't 610 * have to worry about them. 611 */ 612 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vnd_file, p); 613 if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) { 614 vndunlock(vnd); 615 return(error); 616 } 617 error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p); 618 if (error) { 619 VOP_UNLOCK(nd.ni_vp); 620 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 621 vndunlock(vnd); 622 return(error); 623 } 624 VOP_UNLOCK(nd.ni_vp); 625 vnd->sc_vp = nd.ni_vp; 626 vnd->sc_size = btodb(vattr.va_size); /* note truncation */ 627 if ((error = vndsetcred(vnd, p->p_ucred)) != 0) { 628 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 629 vndunlock(vnd); 630 return(error); 631 } 632 vndthrottle(vnd, vnd->sc_vp); 633 vio->vnd_size = dbtob(vnd->sc_size); 634 vnd->sc_flags |= VNF_INITED; 635 #ifdef DEBUG 636 if (vnddebug & VDB_INIT) 637 printf("vndioctl: SET vp %p size %lx\n", 638 vnd->sc_vp, (unsigned long) vnd->sc_size); 639 #endif 640 641 /* Attach the disk. */ 642 bzero(vnd->sc_xname, sizeof(vnd->sc_xname)); /* XXX */ 643 sprintf(vnd->sc_xname, "vnd%d", unit); /* XXX */ 644 vnd->sc_dkdev.dk_name = vnd->sc_xname; 645 disk_attach(&vnd->sc_dkdev); 646 647 vndunlock(vnd); 648 649 break; 650 651 case VNDIOCCLR: 652 if ((vnd->sc_flags & VNF_INITED) == 0) 653 return (ENXIO); 654 655 if ((error = vndlock(vnd)) != 0) 656 return (error); 657 658 /* 659 * Don't unconfigure if any other partitions are open 660 * or if both the character and block flavors of this 661 * partition are open. 662 */ 663 part = DISKPART(dev); 664 pmask = (1 << part); 665 if ((vnd->sc_dkdev.dk_openmask & ~pmask) || 666 ((vnd->sc_dkdev.dk_bopenmask & pmask) && 667 (vnd->sc_dkdev.dk_copenmask & pmask))) { 668 vndunlock(vnd); 669 return (EBUSY); 670 } 671 672 vndclear(vnd); 673 #ifdef DEBUG 674 if (vnddebug & VDB_INIT) 675 printf("vndioctl: CLRed\n"); 676 #endif 677 678 /* Detatch the disk. */ 679 disk_detach(&vnd->sc_dkdev); 680 681 vndunlock(vnd); 682 683 break; 684 685 /* 686 * XXX Should support disklabels. 687 */ 688 689 default: 690 return(ENOTTY); 691 } 692 693 return (0); 694 } 695 696 /* 697 * Duplicate the current processes' credentials. Since we are called only 698 * as the result of a SET ioctl and only root can do that, any future access 699 * to this "disk" is essentially as root. Note that credentials may change 700 * if some other uid can write directly to the mapped file (NFS). 701 */ 702 int 703 vndsetcred(vnd, cred) 704 register struct vnd_softc *vnd; 705 struct ucred *cred; 706 { 707 struct uio auio; 708 struct iovec aiov; 709 char *tmpbuf; 710 int error; 711 712 vnd->sc_cred = crdup(cred); 713 tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); 714 715 /* XXX: Horrible kludge to establish credentials for NFS */ 716 aiov.iov_base = tmpbuf; 717 aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size)); 718 auio.uio_iov = &aiov; 719 auio.uio_iovcnt = 1; 720 auio.uio_offset = 0; 721 auio.uio_rw = UIO_READ; 722 auio.uio_segflg = UIO_SYSSPACE; 723 auio.uio_resid = aiov.iov_len; 724 VOP_LOCK(vnd->sc_vp); 725 error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred); 726 VOP_UNLOCK(vnd->sc_vp); 727 728 free(tmpbuf, M_TEMP); 729 return (error); 730 } 731 732 /* 733 * Set maxactive based on FS type 734 */ 735 void 736 vndthrottle(vnd, vp) 737 register struct vnd_softc *vnd; 738 struct vnode *vp; 739 { 740 #ifdef NFS 741 extern int (**nfsv2_vnodeop_p) __P((void *)); 742 743 if (vp->v_op == nfsv2_vnodeop_p) 744 vnd->sc_maxactive = 2; 745 else 746 #endif 747 vnd->sc_maxactive = 8; 748 749 if (vnd->sc_maxactive < 1) 750 vnd->sc_maxactive = 1; 751 } 752 753 void 754 vndshutdown() 755 { 756 register struct vnd_softc *vnd; 757 758 for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++) 759 if (vnd->sc_flags & VNF_INITED) 760 vndclear(vnd); 761 } 762 763 void 764 vndclear(vnd) 765 register struct vnd_softc *vnd; 766 { 767 register struct vnode *vp = vnd->sc_vp; 768 struct proc *p = curproc; /* XXX */ 769 770 #ifdef DEBUG 771 if (vnddebug & VDB_FOLLOW) 772 printf("vndclear(%p): vp %p\n", vnd, vp); 773 #endif 774 vnd->sc_flags &= ~VNF_INITED; 775 if (vp == (struct vnode *)0) 776 panic("vndioctl: null vp"); 777 (void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p); 778 crfree(vnd->sc_cred); 779 vnd->sc_vp = (struct vnode *)0; 780 vnd->sc_cred = (struct ucred *)0; 781 vnd->sc_size = 0; 782 } 783 784 int 785 vndsize(dev) 786 dev_t dev; 787 { 788 int unit = vndunit(dev); 789 register struct vnd_softc *vnd = &vnd_softc[unit]; 790 791 if (unit >= numvnd || (vnd->sc_flags & VNF_INITED) == 0) 792 return(-1); 793 return(vnd->sc_size); 794 } 795 796 int 797 vnddump(dev, blkno, va, size) 798 dev_t dev; 799 daddr_t blkno; 800 caddr_t va; 801 size_t size; 802 { 803 804 /* Not implemented. */ 805 return ENXIO; 806 } 807 808 /* 809 * Wait interruptibly for an exclusive lock. 810 * 811 * XXX 812 * Several drivers do this; it should be abstracted and made MP-safe. 813 */ 814 static int 815 vndlock(sc) 816 struct vnd_softc *sc; 817 { 818 int error; 819 820 while ((sc->sc_flags & VNF_LOCKED) != 0) { 821 sc->sc_flags |= VNF_WANTED; 822 if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0) 823 return (error); 824 } 825 sc->sc_flags |= VNF_LOCKED; 826 return (0); 827 } 828 829 /* 830 * Unlock and wake up any waiters. 831 */ 832 static void 833 vndunlock(sc) 834 struct vnd_softc *sc; 835 { 836 837 sc->sc_flags &= ~VNF_LOCKED; 838 if ((sc->sc_flags & VNF_WANTED) != 0) { 839 sc->sc_flags &= ~VNF_WANTED; 840 wakeup(sc); 841 } 842 } 843
Indexes created Mon Sep 29 21:09:56 GMT 2025