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 1.6 2003/07/21 05:50:38 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 /* autoq */ 0, 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 vn = dev->si_drv1; 184 if (!vn) { 185 SLIST_FOREACH(vn, &vn_list, sc_list) { 186 if (vn->sc_unit == unit) { 187 dev->si_drv2 = vn->sc_devlist; 188 vn->sc_devlist = dev; 189 dev->si_drv1 = vn; 190 break; 191 } 192 } 193 } 194 if (!vn) { 195 vn = malloc(sizeof *vn, M_DEVBUF, M_WAITOK); 196 if (!vn) 197 return (NULL); 198 bzero(vn, sizeof *vn); 199 vn->sc_unit = unit; 200 dev->si_drv1 = vn; 201 vn->sc_devlist = make_dev(&vn_cdevsw, 0, 202 UID_ROOT, GID_OPERATOR, 0640, "vn%d", unit); 203 vn->sc_devlist->si_drv1 = vn; 204 vn->sc_devlist->si_drv2 = NULL; 205 if (vn->sc_devlist != dev) { 206 dev->si_drv2 = vn->sc_devlist; 207 vn->sc_devlist = dev; 208 } 209 SLIST_INSERT_HEAD(&vn_list, vn, sc_list); 210 } 211 return (vn); 212 } 213 214 static int 215 vnopen(dev_t dev, int flags, int mode, struct thread *td) 216 { 217 struct vn_softc *vn; 218 219 /* 220 * Locate preexisting device 221 */ 222 223 if ((vn = dev->si_drv1) == NULL) 224 vn = vnfindvn(dev); 225 226 /* 227 * Update si_bsize fields for device. This data will be overriden by 228 * the slice/parition code for vn accesses through partitions, and 229 * used directly if you open the 'whole disk' device. 230 * 231 * si_bsize_best must be reinitialized in case VN has been 232 * reconfigured, plus make it at least VN_BSIZE_BEST for efficiency. 233 */ 234 dev->si_bsize_phys = vn->sc_secsize; 235 dev->si_bsize_best = vn->sc_secsize; 236 if (dev->si_bsize_best < VN_BSIZE_BEST) 237 dev->si_bsize_best = VN_BSIZE_BEST; 238 239 if ((flags & FWRITE) && (vn->sc_flags & VNF_READONLY)) 240 return (EACCES); 241 242 IFOPT(vn, VN_FOLLOW) 243 printf("vnopen(%s, 0x%x, 0x%x, %p)\n", 244 devtoname(dev), flags, mode, (void *)td); 245 246 /* 247 * Initialize label 248 */ 249 250 IFOPT(vn, VN_LABELS) { 251 if (vn->sc_flags & VNF_INITED) { 252 struct disklabel label; 253 254 /* Build label for whole disk. */ 255 bzero(&label, sizeof label); 256 label.d_secsize = vn->sc_secsize; 257 label.d_nsectors = 32; 258 label.d_ntracks = 64 / (vn->sc_secsize / DEV_BSIZE); 259 label.d_secpercyl = label.d_nsectors * label.d_ntracks; 260 label.d_ncylinders = vn->sc_size / label.d_secpercyl; 261 label.d_secperunit = vn->sc_size; 262 label.d_partitions[RAW_PART].p_size = vn->sc_size; 263 264 return (dsopen(dev, mode, 0, &vn->sc_slices, &label)); 265 } 266 if (dkslice(dev) != WHOLE_DISK_SLICE || 267 dkpart(dev) != RAW_PART || 268 mode != S_IFCHR) { 269 return (ENXIO); 270 } 271 } 272 return(0); 273 } 274 275 /* 276 * vnstrategy: 277 * 278 * Run strategy routine for VN device. We use VOP_READ/VOP_WRITE calls 279 * for vnode-backed vn's, and the new vm_pager_strategy() call for 280 * vm_object-backed vn's. 281 * 282 * Currently B_ASYNC is only partially handled - for OBJT_SWAP I/O only. 283 * 284 * NOTE: bp->b_blkno is DEV_BSIZE'd. We must generate bp->b_pblkno for 285 * our uio or vn_pager_strategy() call that is vn->sc_secsize'd 286 */ 287 288 static void 289 vnstrategy(struct buf *bp) 290 { 291 int unit; 292 struct vn_softc *vn; 293 int error; 294 295 unit = dkunit(bp->b_dev); 296 vn = bp->b_dev->si_drv1; 297 if (!vn) 298 vn = vnfindvn(bp->b_dev); 299 300 IFOPT(vn, VN_DEBUG) 301 printf("vnstrategy(%p): unit %d\n", bp, unit); 302 303 if ((vn->sc_flags & VNF_INITED) == 0) { 304 bp->b_error = ENXIO; 305 bp->b_flags |= B_ERROR; 306 biodone(bp); 307 return; 308 } 309 310 bp->b_resid = bp->b_bcount; 311 312 IFOPT(vn, VN_LABELS) { 313 if (vn->sc_slices != NULL && dscheck(bp, vn->sc_slices) <= 0) { 314 bp->b_flags |= B_INVAL; 315 biodone(bp); 316 return; 317 } 318 } else { 319 int pbn; /* in sc_secsize chunks */ 320 long sz; /* in sc_secsize chunks */ 321 322 /* 323 * Check for required alignment. Transfers must be a valid 324 * multiple of the sector size. 325 */ 326 if (bp->b_bcount % vn->sc_secsize != 0 || 327 bp->b_blkno % (vn->sc_secsize / DEV_BSIZE) != 0) { 328 bp->b_error = EINVAL; 329 bp->b_flags |= B_ERROR | B_INVAL; 330 biodone(bp); 331 return; 332 } 333 334 pbn = bp->b_blkno / (vn->sc_secsize / DEV_BSIZE); 335 sz = howmany(bp->b_bcount, vn->sc_secsize); 336 337 /* 338 * If out of bounds return an error. If at the EOF point, 339 * simply read or write less. 340 */ 341 if (pbn < 0 || pbn >= vn->sc_size) { 342 if (pbn != vn->sc_size) { 343 bp->b_error = EINVAL; 344 bp->b_flags |= B_ERROR | B_INVAL; 345 } 346 biodone(bp); 347 return; 348 } 349 350 /* 351 * If the request crosses EOF, truncate the request. 352 */ 353 if (pbn + sz > vn->sc_size) { 354 bp->b_bcount = (vn->sc_size - pbn) * vn->sc_secsize; 355 bp->b_resid = bp->b_bcount; 356 } 357 bp->b_pblkno = pbn; 358 } 359 360 if (vn->sc_vp && (bp->b_flags & B_FREEBUF)) { 361 /* 362 * Not handled for vnode-backed element yet. 363 */ 364 biodone(bp); 365 } else if (vn->sc_vp) { 366 /* 367 * VNODE I/O 368 * 369 * If an error occurs, we set B_ERROR but we do not set 370 * B_INVAL because (for a write anyway), the buffer is 371 * still valid. 372 */ 373 struct uio auio; 374 struct iovec aiov; 375 376 bzero(&auio, sizeof(auio)); 377 378 aiov.iov_base = bp->b_data; 379 aiov.iov_len = bp->b_bcount; 380 auio.uio_iov = &aiov; 381 auio.uio_iovcnt = 1; 382 auio.uio_offset = (vm_ooffset_t)bp->b_pblkno * vn->sc_secsize; 383 auio.uio_segflg = UIO_SYSSPACE; 384 if( bp->b_flags & B_READ) 385 auio.uio_rw = UIO_READ; 386 else 387 auio.uio_rw = UIO_WRITE; 388 auio.uio_resid = bp->b_bcount; 389 auio.uio_td = curthread; 390 vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY, curthread); 391 if (bp->b_flags & B_READ) 392 error = VOP_READ(vn->sc_vp, &auio, IO_DIRECT, vn->sc_cred); 393 else 394 error = VOP_WRITE(vn->sc_vp, &auio, IO_NOWDRAIN, vn->sc_cred); 395 VOP_UNLOCK(vn->sc_vp, 0, curthread); 396 bp->b_resid = auio.uio_resid; 397 398 if (error) { 399 bp->b_error = error; 400 bp->b_flags |= B_ERROR; 401 } 402 biodone(bp); 403 } else if (vn->sc_object) { 404 /* 405 * OBJT_SWAP I/O 406 * 407 * ( handles read, write, freebuf ) 408 * 409 * Note: if we pre-reserved swap, B_FREEBUF is disabled 410 */ 411 KASSERT((bp->b_bufsize & (vn->sc_secsize - 1)) == 0, 412 ("vnstrategy: buffer %p too small for physio", bp)); 413 414 if ((bp->b_flags & B_FREEBUF) && TESTOPT(vn, VN_RESERVE)) { 415 biodone(bp); 416 } else { 417 vm_pager_strategy(vn->sc_object, bp); 418 } 419 } else { 420 bp->b_flags |= B_ERROR; 421 bp->b_error = EINVAL; 422 biodone(bp); 423 } 424 } 425 426 /* ARGSUSED */ 427 static int 428 vnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 429 { 430 struct vn_softc *vn; 431 struct vn_ioctl *vio; 432 int error; 433 u_long *f; 434 435 vn = dev->si_drv1; 436 IFOPT(vn,VN_FOLLOW) 437 printf("vnioctl(%s, 0x%lx, %p, 0x%x, %p): unit %d\n", 438 devtoname(dev), cmd, (void *)data, flag, (void *)td, 439 dkunit(dev)); 440 441 switch (cmd) { 442 case VNIOCATTACH: 443 case VNIOCDETACH: 444 case VNIOCGSET: 445 case VNIOCGCLEAR: 446 case VNIOCUSET: 447 case VNIOCUCLEAR: 448 goto vn_specific; 449 } 450 451 IFOPT(vn,VN_LABELS) { 452 if (vn->sc_slices != NULL) { 453 error = dsioctl(dev, cmd, data, flag, &vn->sc_slices); 454 if (error != ENOIOCTL) 455 return (error); 456 } 457 if (dkslice(dev) != WHOLE_DISK_SLICE || 458 dkpart(dev) != RAW_PART) 459 return (ENOTTY); 460 } 461 462 vn_specific: 463 464 error = suser(td); 465 if (error) 466 return (error); 467 468 vio = (struct vn_ioctl *)data; 469 f = (u_long*)data; 470 switch (cmd) { 471 472 case VNIOCATTACH: 473 if (vn->sc_flags & VNF_INITED) 474 return(EBUSY); 475 476 if (vio->vn_file == NULL) 477 error = vniocattach_swap(vn, vio, dev, flag, td); 478 else 479 error = vniocattach_file(vn, vio, dev, flag, td); 480 break; 481 482 case VNIOCDETACH: 483 if ((vn->sc_flags & VNF_INITED) == 0) 484 return(ENXIO); 485 /* 486 * XXX handle i/o in progress. Return EBUSY, or wait, or 487 * flush the i/o. 488 * XXX handle multiple opens of the device. Return EBUSY, 489 * or revoke the fd's. 490 * How are these problems handled for removable and failing 491 * hardware devices? (Hint: They are not) 492 */ 493 vnclear(vn); 494 IFOPT(vn, VN_FOLLOW) 495 printf("vnioctl: CLRed\n"); 496 break; 497 498 case VNIOCGSET: 499 vn_options |= *f; 500 *f = vn_options; 501 break; 502 503 case VNIOCGCLEAR: 504 vn_options &= ~(*f); 505 *f = vn_options; 506 break; 507 508 case VNIOCUSET: 509 vn->sc_options |= *f; 510 *f = vn->sc_options; 511 break; 512 513 case VNIOCUCLEAR: 514 vn->sc_options &= ~(*f); 515 *f = vn->sc_options; 516 break; 517 518 default: 519 error = ENOTTY; 520 break; 521 } 522 return(error); 523 } 524 525 /* 526 * vniocattach_file: 527 * 528 * Attach a file to a VN partition. Return the size in the vn_size 529 * field. 530 */ 531 532 static int 533 vniocattach_file(vn, vio, dev, flag, td) 534 struct vn_softc *vn; 535 struct vn_ioctl *vio; 536 dev_t dev; 537 int flag; 538 struct thread *td; 539 { 540 struct vattr vattr; 541 struct nameidata nd; 542 int error, flags; 543 struct proc *p = td->td_proc; 544 545 KKASSERT(p != NULL); 546 547 flags = FREAD|FWRITE; 548 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, td); 549 error = vn_open(&nd, flags, 0); 550 if (error) { 551 if (error != EACCES && error != EPERM && error != EROFS) 552 return (error); 553 flags &= ~FWRITE; 554 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, td); 555 error = vn_open(&nd, flags, 0); 556 if (error) 557 return (error); 558 } 559 NDFREE(&nd, NDF_ONLY_PNBUF); 560 if (nd.ni_vp->v_type != VREG || 561 (error = VOP_GETATTR(nd.ni_vp, &vattr, td))) { 562 VOP_UNLOCK(nd.ni_vp, 0, td); 563 (void) vn_close(nd.ni_vp, flags, td); 564 return (error ? error : EINVAL); 565 } 566 VOP_UNLOCK(nd.ni_vp, 0, td); 567 vn->sc_secsize = DEV_BSIZE; 568 vn->sc_vp = nd.ni_vp; 569 570 /* 571 * If the size is specified, override the file attributes. Note that 572 * the vn_size argument is in PAGE_SIZE sized blocks. 573 */ 574 if (vio->vn_size) 575 vn->sc_size = (quad_t)vio->vn_size * PAGE_SIZE / vn->sc_secsize; 576 else 577 vn->sc_size = vattr.va_size / vn->sc_secsize; 578 error = vnsetcred(vn, p->p_ucred); 579 if (error) { 580 (void) vn_close(nd.ni_vp, flags, td); 581 return(error); 582 } 583 vn->sc_flags |= VNF_INITED; 584 if (flags == FREAD) 585 vn->sc_flags |= VNF_READONLY; 586 IFOPT(vn, VN_LABELS) { 587 /* 588 * Reopen so that `ds' knows which devices are open. 589 * If this is the first VNIOCSET, then we've 590 * guaranteed that the device is the cdev and that 591 * no other slices or labels are open. Otherwise, 592 * we rely on VNIOCCLR not being abused. 593 */ 594 error = vnopen(dev, flag, S_IFCHR, td); 595 if (error) 596 vnclear(vn); 597 } 598 IFOPT(vn, VN_FOLLOW) 599 printf("vnioctl: SET vp %p size %x blks\n", 600 vn->sc_vp, vn->sc_size); 601 return(0); 602 } 603 604 /* 605 * vniocattach_swap: 606 * 607 * Attach swap backing store to a VN partition of the size specified 608 * in vn_size. 609 */ 610 611 static int 612 vniocattach_swap(vn, vio, dev, flag, td) 613 struct vn_softc *vn; 614 struct vn_ioctl *vio; 615 dev_t dev; 616 int flag; 617 struct thread *td; 618 { 619 int error; 620 struct proc *p = td->td_proc; 621 622 KKASSERT(p != NULL); 623 /* 624 * Range check. Disallow negative sizes or any size less then the 625 * size of a page. Then round to a page. 626 */ 627 628 if (vio->vn_size <= 0) 629 return(EDOM); 630 631 /* 632 * Allocate an OBJT_SWAP object. 633 * 634 * sc_secsize is PAGE_SIZE'd 635 * 636 * vio->vn_size is in PAGE_SIZE'd chunks. 637 * sc_size must be in PAGE_SIZE'd chunks. 638 * Note the truncation. 639 */ 640 641 vn->sc_secsize = PAGE_SIZE; 642 vn->sc_size = vio->vn_size; 643 vn->sc_object = 644 vm_pager_allocate(OBJT_SWAP, NULL, vn->sc_secsize * (vm_ooffset_t)vio->vn_size, VM_PROT_DEFAULT, 0); 645 IFOPT(vn, VN_RESERVE) { 646 if (swap_pager_reserve(vn->sc_object, 0, vn->sc_size) < 0) { 647 vm_pager_deallocate(vn->sc_object); 648 vn->sc_object = NULL; 649 return(EDOM); 650 } 651 } 652 vn->sc_flags |= VNF_INITED; 653 654 error = vnsetcred(vn, p->p_ucred); 655 if (error == 0) { 656 IFOPT(vn, VN_LABELS) { 657 /* 658 * Reopen so that `ds' knows which devices are open. 659 * If this is the first VNIOCSET, then we've 660 * guaranteed that the device is the cdev and that 661 * no other slices or labels are open. Otherwise, 662 * we rely on VNIOCCLR not being abused. 663 */ 664 error = vnopen(dev, flag, S_IFCHR, td); 665 } 666 } 667 if (error == 0) { 668 IFOPT(vn, VN_FOLLOW) { 669 printf("vnioctl: SET vp %p size %x\n", 670 vn->sc_vp, vn->sc_size); 671 } 672 } 673 if (error) 674 vnclear(vn); 675 return(error); 676 } 677 678 /* 679 * Duplicate the current processes' credentials. Since we are called only 680 * as the result of a SET ioctl and only root can do that, any future access 681 * to this "disk" is essentially as root. Note that credentials may change 682 * if some other uid can write directly to the mapped file (NFS). 683 */ 684 int 685 vnsetcred(struct vn_softc *vn, struct ucred *cred) 686 { 687 char *tmpbuf; 688 int error = 0; 689 690 /* 691 * Set credits in our softc 692 */ 693 694 if (vn->sc_cred) 695 crfree(vn->sc_cred); 696 vn->sc_cred = crdup(cred); 697 698 /* 699 * Horrible kludge to establish credentials for NFS XXX. 700 */ 701 702 if (vn->sc_vp) { 703 struct uio auio; 704 struct iovec aiov; 705 706 tmpbuf = malloc(vn->sc_secsize, M_TEMP, M_WAITOK); 707 bzero(&auio, sizeof(auio)); 708 709 aiov.iov_base = tmpbuf; 710 aiov.iov_len = vn->sc_secsize; 711 auio.uio_iov = &aiov; 712 auio.uio_iovcnt = 1; 713 auio.uio_offset = 0; 714 auio.uio_rw = UIO_READ; 715 auio.uio_segflg = UIO_SYSSPACE; 716 auio.uio_resid = aiov.iov_len; 717 vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY, curthread); 718 error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); 719 VOP_UNLOCK(vn->sc_vp, 0, curthread); 720 free(tmpbuf, M_TEMP); 721 } 722 return (error); 723 } 724 725 void 726 vnclear(struct vn_softc *vn) 727 { 728 struct thread *td = curthread; /* XXX */ 729 730 IFOPT(vn, VN_FOLLOW) 731 printf("vnclear(%p): vp=%p\n", vn, vn->sc_vp); 732 if (vn->sc_slices != NULL) 733 dsgone(&vn->sc_slices); 734 vn->sc_flags &= ~VNF_INITED; 735 if (vn->sc_vp != NULL) { 736 (void)vn_close(vn->sc_vp, vn->sc_flags & VNF_READONLY ? 737 FREAD : (FREAD|FWRITE), td); 738 vn->sc_vp = NULL; 739 } 740 vn->sc_flags &= ~VNF_READONLY; 741 if (vn->sc_cred) { 742 crfree(vn->sc_cred); 743 vn->sc_cred = NULL; 744 } 745 if (vn->sc_object != NULL) { 746 vm_pager_deallocate(vn->sc_object); 747 vn->sc_object = NULL; 748 } 749 vn->sc_size = 0; 750 } 751 752 static int 753 vnsize(dev_t dev) 754 { 755 struct vn_softc *vn; 756 757 vn = dev->si_drv1; 758 if (!vn) 759 return(-1); 760 if ((vn->sc_flags & VNF_INITED) == 0) 761 return(-1); 762 763 return(vn->sc_size); 764 } 765 766 static int 767 vn_modevent(module_t mod, int type, void *data) 768 { 769 struct vn_softc *vn; 770 dev_t dev; 771 772 switch (type) { 773 case MOD_LOAD: 774 cdevsw_add(&vn_cdevsw); 775 break; 776 777 case MOD_UNLOAD: 778 /* fall through */ 779 case MOD_SHUTDOWN: 780 for (;;) { 781 vn = SLIST_FIRST(&vn_list); 782 if (!vn) 783 break; 784 SLIST_REMOVE_HEAD(&vn_list, sc_list); 785 if (vn->sc_flags & VNF_INITED) 786 vnclear(vn); 787 /* Cleanup all dev_t's that refer to this unit */ 788 while ((dev = vn->sc_devlist) != NULL) { 789 vn->sc_devlist = dev->si_drv2; 790 dev->si_drv1 = dev->si_drv2 = NULL; 791 /* If the last one, destroy it. */ 792 if (vn->sc_devlist == NULL) 793 destroy_dev(dev); 794 } 795 free(vn, M_DEVBUF); 796 } 797 cdevsw_remove(&vn_cdevsw); 798 break; 799 default: 800 break; 801 } 802 return 0; 803 } 804 805 DEV_MODULE(vn, vn_modevent, 0); 806