1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: Utah Hdr: vn.c 1.13 94/04/02 39 * 40 * from: @(#)vn.c 8.6 (Berkeley) 4/1/94 41 * $FreeBSD: src/sys/dev/vn/vn.c,v 1.105.2.4 2001/11/18 07:11:00 dillon Exp $ 42 * $DragonFly: src/sys/dev/disk/vn/vn.c,v 1.10 2004/05/19 22:52:42 dillon Exp $ 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/kernel.h> 67 #include <sys/proc.h> 68 #include <sys/namei.h> 69 #include <sys/buf.h> 70 #include <sys/malloc.h> 71 #include <sys/mount.h> 72 #include <sys/vnode.h> 73 #include <sys/fcntl.h> 74 #include <sys/conf.h> 75 #include <sys/disklabel.h> 76 #include <sys/diskslice.h> 77 #include <sys/stat.h> 78 #include <sys/conf.h> 79 #include <sys/module.h> 80 #include <sys/vnioctl.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_object.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_pager.h> 86 #include <vm/vm_pageout.h> 87 #include <vm/swap_pager.h> 88 #include <vm/vm_extern.h> 89 #include <vm/vm_zone.h> 90 91 static d_ioctl_t vnioctl; 92 static d_open_t vnopen; 93 static d_close_t vnclose; 94 static d_psize_t vnsize; 95 static d_strategy_t vnstrategy; 96 97 #define CDEV_MAJOR 43 98 99 #define VN_BSIZE_BEST 8192 100 101 /* 102 * cdevsw 103 * D_DISK we want to look like a disk 104 * D_CANFREE We support B_FREEBUF 105 */ 106 107 static struct cdevsw vn_cdevsw = { 108 /* name */ "vn", 109 /* maj */ CDEV_MAJOR, 110 /* flags */ D_DISK|D_CANFREE, 111 /* port */ NULL, 112 /* clone */ NULL, 113 114 /* open */ vnopen, 115 /* close */ vnclose, 116 /* read */ physread, 117 /* write */ physwrite, 118 /* ioctl */ vnioctl, 119 /* poll */ nopoll, 120 /* mmap */ nommap, 121 /* strategy */ vnstrategy, 122 /* dump */ nodump, 123 /* psize */ vnsize 124 }; 125 126 #define getvnbuf() \ 127 ((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK)) 128 129 #define putvnbuf(bp) \ 130 free((caddr_t)(bp), M_DEVBUF) 131 132 struct vn_softc { 133 int sc_unit; 134 int sc_flags; /* flags */ 135 int sc_size; /* size of vn, sc_secsize scale */ 136 int sc_secsize; /* sector size */ 137 struct diskslices *sc_slices; 138 struct vnode *sc_vp; /* vnode if not NULL */ 139 vm_object_t sc_object; /* backing object if not NULL */ 140 struct ucred *sc_cred; /* credentials */ 141 int sc_maxactive; /* max # of active requests */ 142 struct buf sc_tab; /* transfer queue */ 143 u_long sc_options; /* options */ 144 dev_t sc_devlist; /* devices that refer to this unit */ 145 SLIST_ENTRY(vn_softc) sc_list; 146 }; 147 148 static SLIST_HEAD(, vn_softc) vn_list; 149 150 /* sc_flags */ 151 #define VNF_INITED 0x01 152 #define VNF_READONLY 0x02 153 154 static u_long vn_options; 155 156 #define IFOPT(vn,opt) if (((vn)->sc_options|vn_options) & (opt)) 157 #define TESTOPT(vn,opt) (((vn)->sc_options|vn_options) & (opt)) 158 159 static int vnsetcred (struct vn_softc *vn, struct ucred *cred); 160 static void vnclear (struct vn_softc *vn); 161 static int vn_modevent (module_t, int, void *); 162 static int vniocattach_file (struct vn_softc *, struct vn_ioctl *, dev_t dev, int flag, struct thread *p); 163 static int vniocattach_swap (struct vn_softc *, struct vn_ioctl *, dev_t dev, int flag, struct thread *p); 164 165 static int 166 vnclose(dev_t dev, int flags, int mode, struct thread *td) 167 { 168 struct vn_softc *vn = dev->si_drv1; 169 170 IFOPT(vn, VN_LABELS) 171 if (vn->sc_slices != NULL) 172 dsclose(dev, mode, vn->sc_slices); 173 return (0); 174 } 175 176 static struct vn_softc * 177 vnfindvn(dev_t dev) 178 { 179 int unit; 180 struct vn_softc *vn; 181 182 unit = dkunit(dev); 183 SLIST_FOREACH(vn, &vn_list, sc_list) { 184 if (vn->sc_unit == unit) { 185 dev->si_drv2 = vn->sc_devlist; 186 vn->sc_devlist = dev; 187 reference_dev(dev); 188 dev->si_drv1 = vn; 189 break; 190 } 191 } 192 if (vn == NULL) { 193 vn = malloc(sizeof *vn, M_DEVBUF, M_WAITOK | M_ZERO); 194 vn->sc_unit = unit; 195 dev->si_drv1 = vn; 196 vn->sc_devlist = make_dev(&vn_cdevsw, 0, UID_ROOT, 197 GID_OPERATOR, 0640, "vn%d", unit); 198 reference_dev(vn->sc_devlist); 199 vn->sc_devlist->si_drv1 = vn; 200 vn->sc_devlist->si_drv2 = NULL; 201 if (vn->sc_devlist != dev) { 202 dev->si_drv1 = vn; 203 dev->si_drv2 = vn->sc_devlist; 204 vn->sc_devlist = dev; 205 reference_dev(dev); 206 } 207 SLIST_INSERT_HEAD(&vn_list, vn, sc_list); 208 } 209 return (vn); 210 } 211 212 static int 213 vnopen(dev_t dev, int flags, int mode, struct thread *td) 214 { 215 struct vn_softc *vn; 216 217 /* 218 * Locate preexisting device 219 */ 220 221 if ((vn = dev->si_drv1) == NULL) 222 vn = vnfindvn(dev); 223 224 /* 225 * Update si_bsize fields for device. This data will be overriden by 226 * the slice/parition code for vn accesses through partitions, and 227 * used directly if you open the 'whole disk' device. 228 * 229 * si_bsize_best must be reinitialized in case VN has been 230 * reconfigured, plus make it at least VN_BSIZE_BEST for efficiency. 231 */ 232 dev->si_bsize_phys = vn->sc_secsize; 233 dev->si_bsize_best = vn->sc_secsize; 234 if (dev->si_bsize_best < VN_BSIZE_BEST) 235 dev->si_bsize_best = VN_BSIZE_BEST; 236 237 if ((flags & FWRITE) && (vn->sc_flags & VNF_READONLY)) 238 return (EACCES); 239 240 IFOPT(vn, VN_FOLLOW) 241 printf("vnopen(%s, 0x%x, 0x%x, %p)\n", 242 devtoname(dev), flags, mode, (void *)td); 243 244 /* 245 * Initialize label 246 */ 247 248 IFOPT(vn, VN_LABELS) { 249 if (vn->sc_flags & VNF_INITED) { 250 struct disklabel label; 251 252 /* Build label for whole disk. */ 253 bzero(&label, sizeof label); 254 label.d_secsize = vn->sc_secsize; 255 label.d_nsectors = 32; 256 label.d_ntracks = 64 / (vn->sc_secsize / DEV_BSIZE); 257 label.d_secpercyl = label.d_nsectors * label.d_ntracks; 258 label.d_ncylinders = vn->sc_size / label.d_secpercyl; 259 label.d_secperunit = vn->sc_size; 260 label.d_partitions[RAW_PART].p_size = vn->sc_size; 261 262 return (dsopen(dev, mode, 0, &vn->sc_slices, &label)); 263 } 264 if (dkslice(dev) != WHOLE_DISK_SLICE || 265 dkpart(dev) != RAW_PART || 266 mode != S_IFCHR) { 267 return (ENXIO); 268 } 269 } 270 return(0); 271 } 272 273 /* 274 * vnstrategy: 275 * 276 * Run strategy routine for VN device. We use VOP_READ/VOP_WRITE calls 277 * for vnode-backed vn's, and the new vm_pager_strategy() call for 278 * vm_object-backed vn's. 279 * 280 * Currently B_ASYNC is only partially handled - for OBJT_SWAP I/O only. 281 * 282 * NOTE: bp->b_blkno is DEV_BSIZE'd. We must generate bp->b_pblkno for 283 * our uio or vn_pager_strategy() call that is vn->sc_secsize'd 284 */ 285 286 static void 287 vnstrategy(struct buf *bp) 288 { 289 int unit; 290 struct vn_softc *vn; 291 int error; 292 293 unit = dkunit(bp->b_dev); 294 if ((vn = bp->b_dev->si_drv1) == NULL) 295 vn = vnfindvn(bp->b_dev); 296 297 IFOPT(vn, VN_DEBUG) 298 printf("vnstrategy(%p): unit %d\n", bp, unit); 299 300 if ((vn->sc_flags & VNF_INITED) == 0) { 301 bp->b_error = ENXIO; 302 bp->b_flags |= B_ERROR; 303 biodone(bp); 304 return; 305 } 306 307 bp->b_resid = bp->b_bcount; 308 309 IFOPT(vn, VN_LABELS) { 310 if (vn->sc_slices != NULL && dscheck(bp, vn->sc_slices) <= 0) { 311 bp->b_flags |= B_INVAL; 312 biodone(bp); 313 return; 314 } 315 } else { 316 int pbn; /* in sc_secsize chunks */ 317 long sz; /* in sc_secsize chunks */ 318 319 /* 320 * Check for required alignment. Transfers must be a valid 321 * multiple of the sector size. 322 */ 323 if (bp->b_bcount % vn->sc_secsize != 0 || 324 bp->b_blkno % (vn->sc_secsize / DEV_BSIZE) != 0) { 325 bp->b_error = EINVAL; 326 bp->b_flags |= B_ERROR | B_INVAL; 327 biodone(bp); 328 return; 329 } 330 331 pbn = bp->b_blkno / (vn->sc_secsize / DEV_BSIZE); 332 sz = howmany(bp->b_bcount, vn->sc_secsize); 333 334 /* 335 * If out of bounds return an error. If at the EOF point, 336 * simply read or write less. 337 */ 338 if (pbn < 0 || pbn >= vn->sc_size) { 339 if (pbn != vn->sc_size) { 340 bp->b_error = EINVAL; 341 bp->b_flags |= B_ERROR | B_INVAL; 342 } 343 biodone(bp); 344 return; 345 } 346 347 /* 348 * If the request crosses EOF, truncate the request. 349 */ 350 if (pbn + sz > vn->sc_size) { 351 bp->b_bcount = (vn->sc_size - pbn) * vn->sc_secsize; 352 bp->b_resid = bp->b_bcount; 353 } 354 bp->b_pblkno = pbn; 355 } 356 357 if (vn->sc_vp && (bp->b_flags & B_FREEBUF)) { 358 /* 359 * Not handled for vnode-backed element yet. 360 */ 361 biodone(bp); 362 } else if (vn->sc_vp) { 363 /* 364 * VNODE I/O 365 * 366 * If an error occurs, we set B_ERROR but we do not set 367 * B_INVAL because (for a write anyway), the buffer is 368 * still valid. 369 */ 370 struct uio auio; 371 struct iovec aiov; 372 373 bzero(&auio, sizeof(auio)); 374 375 aiov.iov_base = bp->b_data; 376 aiov.iov_len = bp->b_bcount; 377 auio.uio_iov = &aiov; 378 auio.uio_iovcnt = 1; 379 auio.uio_offset = (vm_ooffset_t)bp->b_pblkno * vn->sc_secsize; 380 auio.uio_segflg = UIO_SYSSPACE; 381 if( bp->b_flags & B_READ) 382 auio.uio_rw = UIO_READ; 383 else 384 auio.uio_rw = UIO_WRITE; 385 auio.uio_resid = bp->b_bcount; 386 auio.uio_td = curthread; 387 vn_lock(vn->sc_vp, NULL, LK_EXCLUSIVE | LK_RETRY, curthread); 388 if (bp->b_flags & B_READ) 389 error = VOP_READ(vn->sc_vp, &auio, IO_DIRECT, vn->sc_cred); 390 else 391 error = VOP_WRITE(vn->sc_vp, &auio, IO_NOWDRAIN, vn->sc_cred); 392 VOP_UNLOCK(vn->sc_vp, NULL, 0, curthread); 393 bp->b_resid = auio.uio_resid; 394 395 if (error) { 396 bp->b_error = error; 397 bp->b_flags |= B_ERROR; 398 } 399 biodone(bp); 400 } else if (vn->sc_object) { 401 /* 402 * OBJT_SWAP I/O 403 * 404 * ( handles read, write, freebuf ) 405 * 406 * Note: if we pre-reserved swap, B_FREEBUF is disabled 407 */ 408 KASSERT((bp->b_bufsize & (vn->sc_secsize - 1)) == 0, 409 ("vnstrategy: buffer %p too small for physio", bp)); 410 411 if ((bp->b_flags & B_FREEBUF) && TESTOPT(vn, VN_RESERVE)) { 412 biodone(bp); 413 } else { 414 vm_pager_strategy(vn->sc_object, bp); 415 } 416 } else { 417 bp->b_flags |= B_ERROR; 418 bp->b_error = EINVAL; 419 biodone(bp); 420 } 421 } 422 423 /* ARGSUSED */ 424 static int 425 vnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 426 { 427 struct vn_softc *vn; 428 struct vn_ioctl *vio; 429 int error; 430 u_long *f; 431 432 vn = dev->si_drv1; 433 IFOPT(vn,VN_FOLLOW) 434 printf("vnioctl(%s, 0x%lx, %p, 0x%x, %p): unit %d\n", 435 devtoname(dev), cmd, (void *)data, flag, (void *)td, 436 dkunit(dev)); 437 438 switch (cmd) { 439 case VNIOCATTACH: 440 case VNIOCDETACH: 441 case VNIOCGSET: 442 case VNIOCGCLEAR: 443 case VNIOCUSET: 444 case VNIOCUCLEAR: 445 goto vn_specific; 446 } 447 448 IFOPT(vn,VN_LABELS) { 449 if (vn->sc_slices != NULL) { 450 error = dsioctl(dev, cmd, data, flag, &vn->sc_slices); 451 if (error != ENOIOCTL) 452 return (error); 453 } 454 if (dkslice(dev) != WHOLE_DISK_SLICE || 455 dkpart(dev) != RAW_PART) 456 return (ENOTTY); 457 } 458 459 vn_specific: 460 461 error = suser(td); 462 if (error) 463 return (error); 464 465 vio = (struct vn_ioctl *)data; 466 f = (u_long*)data; 467 switch (cmd) { 468 469 case VNIOCATTACH: 470 if (vn->sc_flags & VNF_INITED) 471 return(EBUSY); 472 473 if (vio->vn_file == NULL) 474 error = vniocattach_swap(vn, vio, dev, flag, td); 475 else 476 error = vniocattach_file(vn, vio, dev, flag, td); 477 break; 478 479 case VNIOCDETACH: 480 if ((vn->sc_flags & VNF_INITED) == 0) 481 return(ENXIO); 482 /* 483 * XXX handle i/o in progress. Return EBUSY, or wait, or 484 * flush the i/o. 485 * XXX handle multiple opens of the device. Return EBUSY, 486 * or revoke the fd's. 487 * How are these problems handled for removable and failing 488 * hardware devices? (Hint: They are not) 489 */ 490 vnclear(vn); 491 IFOPT(vn, VN_FOLLOW) 492 printf("vnioctl: CLRed\n"); 493 break; 494 495 case VNIOCGSET: 496 vn_options |= *f; 497 *f = vn_options; 498 break; 499 500 case VNIOCGCLEAR: 501 vn_options &= ~(*f); 502 *f = vn_options; 503 break; 504 505 case VNIOCUSET: 506 vn->sc_options |= *f; 507 *f = vn->sc_options; 508 break; 509 510 case VNIOCUCLEAR: 511 vn->sc_options &= ~(*f); 512 *f = vn->sc_options; 513 break; 514 515 default: 516 error = ENOTTY; 517 break; 518 } 519 return(error); 520 } 521 522 /* 523 * vniocattach_file: 524 * 525 * Attach a file to a VN partition. Return the size in the vn_size 526 * field. 527 */ 528 529 static int 530 vniocattach_file(vn, vio, dev, flag, td) 531 struct vn_softc *vn; 532 struct vn_ioctl *vio; 533 dev_t dev; 534 int flag; 535 struct thread *td; 536 { 537 struct vattr vattr; 538 struct nameidata nd; 539 int error, flags; 540 struct proc *p = td->td_proc; 541 542 KKASSERT(p != NULL); 543 544 flags = FREAD|FWRITE; 545 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, UIO_USERSPACE, vio->vn_file, td); 546 error = vn_open(&nd, flags, 0); 547 if (error) { 548 if (error != EACCES && error != EPERM && error != EROFS) 549 return (error); 550 flags &= ~FWRITE; 551 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, 552 UIO_USERSPACE, vio->vn_file, td); 553 error = vn_open(&nd, flags, 0); 554 if (error) 555 return (error); 556 } 557 NDFREE(&nd, NDF_ONLY_PNBUF); 558 if (nd.ni_vp->v_type != VREG || 559 (error = VOP_GETATTR(nd.ni_vp, &vattr, td))) { 560 VOP_UNLOCK(nd.ni_vp, NULL, 0, td); 561 (void) vn_close(nd.ni_vp, flags, td); 562 return (error ? error : EINVAL); 563 } 564 VOP_UNLOCK(nd.ni_vp, NULL, 0, td); 565 vn->sc_secsize = DEV_BSIZE; 566 vn->sc_vp = nd.ni_vp; 567 568 /* 569 * If the size is specified, override the file attributes. Note that 570 * the vn_size argument is in PAGE_SIZE sized blocks. 571 */ 572 if (vio->vn_size) 573 vn->sc_size = (quad_t)vio->vn_size * PAGE_SIZE / vn->sc_secsize; 574 else 575 vn->sc_size = vattr.va_size / vn->sc_secsize; 576 error = vnsetcred(vn, p->p_ucred); 577 if (error) { 578 (void) vn_close(nd.ni_vp, flags, td); 579 return(error); 580 } 581 vn->sc_flags |= VNF_INITED; 582 if (flags == FREAD) 583 vn->sc_flags |= VNF_READONLY; 584 IFOPT(vn, VN_LABELS) { 585 /* 586 * Reopen so that `ds' knows which devices are open. 587 * If this is the first VNIOCSET, then we've 588 * guaranteed that the device is the cdev and that 589 * no other slices or labels are open. Otherwise, 590 * we rely on VNIOCCLR not being abused. 591 */ 592 error = vnopen(dev, flag, S_IFCHR, td); 593 if (error) 594 vnclear(vn); 595 } 596 IFOPT(vn, VN_FOLLOW) 597 printf("vnioctl: SET vp %p size %x blks\n", 598 vn->sc_vp, vn->sc_size); 599 return(0); 600 } 601 602 /* 603 * vniocattach_swap: 604 * 605 * Attach swap backing store to a VN partition of the size specified 606 * in vn_size. 607 */ 608 609 static int 610 vniocattach_swap(vn, vio, dev, flag, td) 611 struct vn_softc *vn; 612 struct vn_ioctl *vio; 613 dev_t dev; 614 int flag; 615 struct thread *td; 616 { 617 int error; 618 struct proc *p = td->td_proc; 619 620 KKASSERT(p != NULL); 621 /* 622 * Range check. Disallow negative sizes or any size less then the 623 * size of a page. Then round to a page. 624 */ 625 626 if (vio->vn_size <= 0) 627 return(EDOM); 628 629 /* 630 * Allocate an OBJT_SWAP object. 631 * 632 * sc_secsize is PAGE_SIZE'd 633 * 634 * vio->vn_size is in PAGE_SIZE'd chunks. 635 * sc_size must be in PAGE_SIZE'd chunks. 636 * Note the truncation. 637 */ 638 639 vn->sc_secsize = PAGE_SIZE; 640 vn->sc_size = vio->vn_size; 641 vn->sc_object = 642 vm_pager_allocate(OBJT_SWAP, NULL, vn->sc_secsize * (vm_ooffset_t)vio->vn_size, VM_PROT_DEFAULT, 0); 643 IFOPT(vn, VN_RESERVE) { 644 if (swap_pager_reserve(vn->sc_object, 0, vn->sc_size) < 0) { 645 vm_pager_deallocate(vn->sc_object); 646 vn->sc_object = NULL; 647 return(EDOM); 648 } 649 } 650 vn->sc_flags |= VNF_INITED; 651 652 error = vnsetcred(vn, p->p_ucred); 653 if (error == 0) { 654 IFOPT(vn, VN_LABELS) { 655 /* 656 * Reopen so that `ds' knows which devices are open. 657 * If this is the first VNIOCSET, then we've 658 * guaranteed that the device is the cdev and that 659 * no other slices or labels are open. Otherwise, 660 * we rely on VNIOCCLR not being abused. 661 */ 662 error = vnopen(dev, flag, S_IFCHR, td); 663 } 664 } 665 if (error == 0) { 666 IFOPT(vn, VN_FOLLOW) { 667 printf("vnioctl: SET vp %p size %x\n", 668 vn->sc_vp, vn->sc_size); 669 } 670 } 671 if (error) 672 vnclear(vn); 673 return(error); 674 } 675 676 /* 677 * Duplicate the current processes' credentials. Since we are called only 678 * as the result of a SET ioctl and only root can do that, any future access 679 * to this "disk" is essentially as root. Note that credentials may change 680 * if some other uid can write directly to the mapped file (NFS). 681 */ 682 int 683 vnsetcred(struct vn_softc *vn, struct ucred *cred) 684 { 685 char *tmpbuf; 686 int error = 0; 687 688 /* 689 * Set credits in our softc 690 */ 691 692 if (vn->sc_cred) 693 crfree(vn->sc_cred); 694 vn->sc_cred = crdup(cred); 695 696 /* 697 * Horrible kludge to establish credentials for NFS XXX. 698 */ 699 700 if (vn->sc_vp) { 701 struct uio auio; 702 struct iovec aiov; 703 704 tmpbuf = malloc(vn->sc_secsize, M_TEMP, M_WAITOK); 705 bzero(&auio, sizeof(auio)); 706 707 aiov.iov_base = tmpbuf; 708 aiov.iov_len = vn->sc_secsize; 709 auio.uio_iov = &aiov; 710 auio.uio_iovcnt = 1; 711 auio.uio_offset = 0; 712 auio.uio_rw = UIO_READ; 713 auio.uio_segflg = UIO_SYSSPACE; 714 auio.uio_resid = aiov.iov_len; 715 vn_lock(vn->sc_vp, NULL, LK_EXCLUSIVE | LK_RETRY, curthread); 716 error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); 717 VOP_UNLOCK(vn->sc_vp, NULL, 0, curthread); 718 free(tmpbuf, M_TEMP); 719 } 720 return (error); 721 } 722 723 void 724 vnclear(struct vn_softc *vn) 725 { 726 struct thread *td = curthread; /* XXX */ 727 728 IFOPT(vn, VN_FOLLOW) 729 printf("vnclear(%p): vp=%p\n", vn, vn->sc_vp); 730 if (vn->sc_slices != NULL) 731 dsgone(&vn->sc_slices); 732 vn->sc_flags &= ~VNF_INITED; 733 if (vn->sc_vp != NULL) { 734 (void)vn_close(vn->sc_vp, vn->sc_flags & VNF_READONLY ? 735 FREAD : (FREAD|FWRITE), td); 736 vn->sc_vp = NULL; 737 } 738 vn->sc_flags &= ~VNF_READONLY; 739 if (vn->sc_cred) { 740 crfree(vn->sc_cred); 741 vn->sc_cred = NULL; 742 } 743 if (vn->sc_object != NULL) { 744 vm_pager_deallocate(vn->sc_object); 745 vn->sc_object = NULL; 746 } 747 vn->sc_size = 0; 748 } 749 750 static int 751 vnsize(dev_t dev) 752 { 753 struct vn_softc *vn; 754 755 vn = dev->si_drv1; 756 if (!vn) 757 return(-1); 758 if ((vn->sc_flags & VNF_INITED) == 0) 759 return(-1); 760 761 return(vn->sc_size); 762 } 763 764 static int 765 vn_modevent(module_t mod, int type, void *data) 766 { 767 struct vn_softc *vn; 768 dev_t dev; 769 770 switch (type) { 771 case MOD_LOAD: 772 cdevsw_add(&vn_cdevsw, 0, 0); 773 break; 774 case MOD_UNLOAD: 775 /* fall through */ 776 case MOD_SHUTDOWN: 777 for (;;) { 778 vn = SLIST_FIRST(&vn_list); 779 if (!vn) 780 break; 781 SLIST_REMOVE_HEAD(&vn_list, sc_list); 782 if (vn->sc_flags & VNF_INITED) 783 vnclear(vn); 784 /* Cleanup all dev_t's that refer to this unit */ 785 while ((dev = vn->sc_devlist) != NULL) { 786 vn->sc_devlist = dev->si_drv2; 787 dev->si_drv1 = dev->si_drv2 = NULL; 788 destroy_dev(dev); 789 } 790 free(vn, M_DEVBUF); 791 } 792 cdevsw_remove(&vn_cdevsw, -1, 0); 793 break; 794 default: 795 break; 796 } 797 return 0; 798 } 799 800 DEV_MODULE(vn, vn_modevent, 0); 801