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 1.33 2007/05/17 03:20:08 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: There is a security issue involved with this driver. 52 * Once mounted all access to the contents of the "mapped" file via 53 * the special file is controlled by the permissions on the special 54 * file, the protection of the mapped file is ignored (effectively, 55 * by using root credentials in all transactions). 56 * 57 * NOTE 2: Doesn't interact with leases, should it? 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/proc.h> 64 #include <sys/nlookup.h> 65 #include <sys/buf.h> 66 #include <sys/malloc.h> 67 #include <sys/mount.h> 68 #include <sys/vnode.h> 69 #include <sys/fcntl.h> 70 #include <sys/conf.h> 71 #include <sys/disklabel.h> 72 #include <sys/diskslice.h> 73 #include <sys/disk.h> 74 #include <sys/stat.h> 75 #include <sys/module.h> 76 #include <sys/vnioctl.h> 77 78 #include <vm/vm.h> 79 #include <vm/vm_object.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_pager.h> 82 #include <vm/vm_pageout.h> 83 #include <vm/swap_pager.h> 84 #include <vm/vm_extern.h> 85 #include <vm/vm_zone.h> 86 87 static d_ioctl_t vnioctl; 88 static d_open_t vnopen; 89 static d_close_t vnclose; 90 static d_psize_t vnsize; 91 static d_strategy_t vnstrategy; 92 93 #define CDEV_MAJOR 43 94 95 #define VN_BSIZE_BEST 8192 96 97 /* 98 * dev_ops 99 * D_DISK we want to look like a disk 100 * D_CANFREE We support BUF_CMD_FREEBLKS 101 */ 102 103 static struct dev_ops vn_ops = { 104 { "vn", CDEV_MAJOR, D_DISK | D_CANFREE }, 105 .d_open = vnopen, 106 .d_close = vnclose, 107 .d_read = physread, 108 .d_write = physwrite, 109 .d_ioctl = vnioctl, 110 .d_strategy = vnstrategy, 111 .d_psize = vnsize 112 }; 113 114 struct vn_softc { 115 int sc_unit; 116 int sc_flags; /* flags */ 117 u_int64_t sc_size; /* size of vn, sc_secsize scale */ 118 int sc_secsize; /* sector size */ 119 struct diskslices *sc_slices; /* XXX fields from struct disk */ 120 struct disk_info sc_info; /* XXX fields from struct disk */ 121 struct vnode *sc_vp; /* vnode if not NULL */ 122 vm_object_t sc_object; /* backing object if not NULL */ 123 struct ucred *sc_cred; /* credentials */ 124 int sc_maxactive; /* max # of active requests */ 125 struct buf sc_tab; /* transfer queue */ 126 u_long sc_options; /* options */ 127 cdev_t sc_devlist; /* devices that refer to this unit */ 128 SLIST_ENTRY(vn_softc) sc_list; 129 }; 130 131 static SLIST_HEAD(, vn_softc) vn_list; 132 133 /* sc_flags */ 134 #define VNF_INITED 0x01 135 #define VNF_READONLY 0x02 136 137 static u_long vn_options; 138 139 #define IFOPT(vn,opt) if (((vn)->sc_options|vn_options) & (opt)) 140 #define TESTOPT(vn,opt) (((vn)->sc_options|vn_options) & (opt)) 141 142 static int vnsetcred (struct vn_softc *vn, struct ucred *cred); 143 static void vnclear (struct vn_softc *vn); 144 static int vn_modevent (module_t, int, void *); 145 static int vniocattach_file (struct vn_softc *, struct vn_ioctl *, cdev_t dev, int flag, struct ucred *cred); 146 static int vniocattach_swap (struct vn_softc *, struct vn_ioctl *, cdev_t dev, int flag, struct ucred *cred); 147 148 static int 149 vnclose(struct dev_close_args *ap) 150 { 151 cdev_t dev = ap->a_head.a_dev; 152 struct vn_softc *vn = dev->si_drv1; 153 154 IFOPT(vn, VN_LABELS) 155 if (vn->sc_slices != NULL) 156 dsclose(dev, ap->a_devtype, vn->sc_slices); 157 return (0); 158 } 159 160 /* 161 * Called only when si_drv1 is NULL. Locate the associated vn node and 162 * attach the device to it. 163 */ 164 static struct vn_softc * 165 vnfindvn(cdev_t dev) 166 { 167 int unit; 168 struct vn_softc *vn; 169 170 unit = dkunit(dev); 171 SLIST_FOREACH(vn, &vn_list, sc_list) { 172 if (vn->sc_unit == unit) { 173 dev->si_drv1 = vn; 174 dev->si_drv2 = vn->sc_devlist; 175 vn->sc_devlist = dev; 176 reference_dev(dev); 177 break; 178 } 179 } 180 if (vn == NULL) { 181 vn = kmalloc(sizeof *vn, M_DEVBUF, M_WAITOK | M_ZERO); 182 vn->sc_unit = unit; 183 dev->si_drv1 = vn; 184 vn->sc_devlist = make_dev(&vn_ops, 0, UID_ROOT, 185 GID_OPERATOR, 0640, "vn%d", unit); 186 if (vn->sc_devlist->si_drv1 == NULL) { 187 reference_dev(vn->sc_devlist); 188 vn->sc_devlist->si_drv1 = vn; 189 vn->sc_devlist->si_drv2 = NULL; 190 } 191 if (vn->sc_devlist != dev) { 192 dev->si_drv1 = vn; 193 dev->si_drv2 = vn->sc_devlist; 194 vn->sc_devlist = dev; 195 reference_dev(dev); 196 } 197 SLIST_INSERT_HEAD(&vn_list, vn, sc_list); 198 } 199 return (vn); 200 } 201 202 static int 203 vnopen(struct dev_open_args *ap) 204 { 205 cdev_t dev = ap->a_head.a_dev; 206 struct vn_softc *vn; 207 struct disk_info *info; 208 209 /* 210 * Locate preexisting device 211 */ 212 213 if ((vn = dev->si_drv1) == NULL) 214 vn = vnfindvn(dev); 215 216 /* 217 * Update si_bsize fields for device. This data will be overriden by 218 * the slice/parition code for vn accesses through partitions, and 219 * used directly if you open the 'whole disk' device. 220 * 221 * si_bsize_best must be reinitialized in case VN has been 222 * reconfigured, plus make it at least VN_BSIZE_BEST for efficiency. 223 */ 224 dev->si_bsize_phys = vn->sc_secsize; 225 dev->si_bsize_best = vn->sc_secsize; 226 if (dev->si_bsize_best < VN_BSIZE_BEST) 227 dev->si_bsize_best = VN_BSIZE_BEST; 228 229 if ((ap->a_oflags & FWRITE) && (vn->sc_flags & VNF_READONLY)) 230 return (EACCES); 231 232 IFOPT(vn, VN_FOLLOW) 233 kprintf("vnopen(%s, 0x%x, 0x%x)\n", 234 devtoname(dev), ap->a_oflags, ap->a_devtype); 235 236 /* 237 * Initialize label 238 */ 239 240 IFOPT(vn, VN_LABELS) { 241 if (vn->sc_flags & VNF_INITED) { 242 info = &vn->sc_info; 243 bzero(info, sizeof(*info)); 244 info->d_media_blksize = vn->sc_secsize; 245 info->d_media_blocks = vn->sc_size; 246 /* 247 * reserve mbr sector for backwards compatibility 248 * when no slices exist. 249 */ 250 info->d_dsflags = DSO_COMPATMBR; 251 252 info->d_secpertrack = 32; 253 info->d_nheads = 64 / (vn->sc_secsize / DEV_BSIZE); 254 info->d_secpercyl = info->d_secpertrack * 255 info->d_nheads; 256 info->d_ncylinders = vn->sc_size / info->d_secpercyl; 257 258 return (dsopen(dev, ap->a_devtype, 0, 259 &vn->sc_slices, info)); 260 } 261 if (dkslice(dev) != WHOLE_DISK_SLICE || 262 dkpart(dev) != RAW_PART || 263 ap->a_devtype != S_IFCHR) { 264 return (ENXIO); 265 } 266 } 267 return(0); 268 } 269 270 /* 271 * vnstrategy: 272 * 273 * Run strategy routine for VN device. We use VOP_READ/VOP_WRITE calls 274 * for vnode-backed vn's, and the new vm_pager_strategy() call for 275 * vm_object-backed vn's. 276 * 277 * Currently B_ASYNC is only partially handled - for OBJT_SWAP I/O only. 278 */ 279 static int 280 vnstrategy(struct dev_strategy_args *ap) 281 { 282 cdev_t dev = ap->a_head.a_dev; 283 struct bio *bio = ap->a_bio; 284 struct buf *bp; 285 struct bio *nbio; 286 int unit; 287 struct vn_softc *vn; 288 int error; 289 290 unit = dkunit(dev); 291 if ((vn = dev->si_drv1) == NULL) 292 vn = vnfindvn(dev); 293 294 bp = bio->bio_buf; 295 296 IFOPT(vn, VN_DEBUG) 297 kprintf("vnstrategy(%p): unit %d\n", bp, unit); 298 299 if ((vn->sc_flags & VNF_INITED) == 0) { 300 bp->b_error = ENXIO; 301 bp->b_flags |= B_ERROR; 302 biodone(bio); 303 return(0); 304 } 305 306 bp->b_resid = bp->b_bcount; 307 308 IFOPT(vn, VN_LABELS) { 309 /* 310 * The vnode device is using disk/slice label support. 311 * 312 * The dscheck() function is called for validating the 313 * slices that exist ON the vnode device itself, and 314 * translate the "slice-relative" block number, again. 315 * dscheck() will call biodone() and return NULL if 316 * we are at EOF or beyond the device size. 317 */ 318 if (vn->sc_slices == NULL) { 319 nbio = bio; 320 } else if ((nbio = dscheck(dev, bio, vn->sc_slices)) == NULL) { 321 goto done; 322 } 323 } else { 324 int64_t pbn; /* in sc_secsize chunks */ 325 long sz; /* in sc_secsize chunks */ 326 327 /* 328 * Check for required alignment. Transfers must be a valid 329 * multiple of the sector size. 330 */ 331 if (bp->b_bcount % vn->sc_secsize != 0 || 332 bio->bio_offset % vn->sc_secsize != 0) { 333 goto bad; 334 } 335 336 pbn = bio->bio_offset / vn->sc_secsize; 337 sz = howmany(bp->b_bcount, vn->sc_secsize); 338 339 /* 340 * Check for an illegal pbn or EOF truncation 341 */ 342 if (pbn < 0) 343 goto bad; 344 if (pbn + sz > vn->sc_size) { 345 if (pbn > vn->sc_size || (bp->b_flags & B_BNOCLIP)) 346 goto bad; 347 if (pbn == vn->sc_size) { 348 bp->b_resid = bp->b_bcount; 349 bp->b_flags |= B_INVAL; 350 goto done; 351 } 352 bp->b_bcount = (vn->sc_size - pbn) * vn->sc_secsize; 353 } 354 nbio = push_bio(bio); 355 nbio->bio_offset = pbn * vn->sc_secsize; 356 } 357 358 /* 359 * Use the translated nbio from this point on 360 */ 361 if (vn->sc_vp && bp->b_cmd == BUF_CMD_FREEBLKS) { 362 /* 363 * Freeblks is not handled for vnode-backed elements yet. 364 */ 365 bp->b_resid = 0; 366 /* operation complete */ 367 } else if (vn->sc_vp) { 368 /* 369 * VNODE I/O 370 * 371 * If an error occurs, we set B_ERROR but we do not set 372 * B_INVAL because (for a write anyway), the buffer is 373 * still valid. 374 */ 375 struct uio auio; 376 struct iovec aiov; 377 378 bzero(&auio, sizeof(auio)); 379 380 aiov.iov_base = bp->b_data; 381 aiov.iov_len = bp->b_bcount; 382 auio.uio_iov = &aiov; 383 auio.uio_iovcnt = 1; 384 auio.uio_offset = nbio->bio_offset; 385 auio.uio_segflg = UIO_SYSSPACE; 386 if (bp->b_cmd == BUF_CMD_READ) 387 auio.uio_rw = UIO_READ; 388 else 389 auio.uio_rw = UIO_WRITE; 390 auio.uio_resid = bp->b_bcount; 391 auio.uio_td = curthread; 392 vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY); 393 if (bp->b_cmd == BUF_CMD_READ) 394 error = VOP_READ(vn->sc_vp, &auio, IO_DIRECT, vn->sc_cred); 395 else 396 error = VOP_WRITE(vn->sc_vp, &auio, IO_NOWDRAIN, vn->sc_cred); 397 vn_unlock(vn->sc_vp); 398 bp->b_resid = auio.uio_resid; 399 if (error) { 400 bp->b_error = error; 401 bp->b_flags |= B_ERROR; 402 } 403 /* operation complete */ 404 } else if (vn->sc_object) { 405 /* 406 * OBJT_SWAP I/O (handles read, write, freebuf) 407 * 408 * We have nothing to do if freeing blocks on a reserved 409 * swap area, othrewise execute the op. 410 */ 411 if (bp->b_cmd == BUF_CMD_FREEBLKS && TESTOPT(vn, VN_RESERVE)) { 412 bp->b_resid = 0; 413 /* operation complete */ 414 } else { 415 vm_pager_strategy(vn->sc_object, nbio); 416 return(0); 417 /* NOT REACHED */ 418 } 419 } else { 420 bp->b_resid = bp->b_bcount; 421 bp->b_flags |= B_ERROR | B_INVAL; 422 bp->b_error = EINVAL; 423 /* operation complete */ 424 } 425 biodone(nbio); 426 return(0); 427 428 /* 429 * Shortcuts / check failures on the original bio (not nbio). 430 */ 431 bad: 432 bp->b_error = EINVAL; 433 bp->b_flags |= B_ERROR | B_INVAL; 434 done: 435 biodone(bio); 436 return(0); 437 } 438 439 /* ARGSUSED */ 440 static int 441 vnioctl(struct dev_ioctl_args *ap) 442 { 443 cdev_t dev = ap->a_head.a_dev; 444 struct vn_softc *vn; 445 struct vn_ioctl *vio; 446 int error; 447 u_long *f; 448 449 vn = dev->si_drv1; 450 IFOPT(vn,VN_FOLLOW) { 451 kprintf("vnioctl(%s, 0x%lx, %p, 0x%x): unit %d\n", 452 devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag, 453 dkunit(dev)); 454 } 455 456 switch (ap->a_cmd) { 457 case VNIOCATTACH: 458 case VNIOCDETACH: 459 case VNIOCGSET: 460 case VNIOCGCLEAR: 461 case VNIOCUSET: 462 case VNIOCUCLEAR: 463 goto vn_specific; 464 } 465 466 IFOPT(vn,VN_LABELS) { 467 if (vn->sc_slices != NULL) { 468 error = dsioctl(dev, ap->a_cmd, ap->a_data, 469 ap->a_fflag, 470 &vn->sc_slices, &vn->sc_info); 471 if (error != ENOIOCTL) 472 return (error); 473 } 474 if (dkslice(dev) != WHOLE_DISK_SLICE || 475 dkpart(dev) != RAW_PART) 476 return (ENOTTY); 477 } 478 479 vn_specific: 480 481 error = suser_cred(ap->a_cred, 0); 482 if (error) 483 return (error); 484 485 vio = (struct vn_ioctl *)ap->a_data; 486 f = (u_long*)ap->a_data; 487 488 switch (ap->a_cmd) { 489 case VNIOCATTACH: 490 if (vn->sc_flags & VNF_INITED) 491 return(EBUSY); 492 493 if (vio->vn_file == NULL) 494 error = vniocattach_swap(vn, vio, dev, ap->a_fflag, ap->a_cred); 495 else 496 error = vniocattach_file(vn, vio, dev, ap->a_fflag, ap->a_cred); 497 break; 498 499 case VNIOCDETACH: 500 if ((vn->sc_flags & VNF_INITED) == 0) 501 return(ENXIO); 502 /* 503 * XXX handle i/o in progress. Return EBUSY, or wait, or 504 * flush the i/o. 505 * XXX handle multiple opens of the device. Return EBUSY, 506 * or revoke the fd's. 507 * How are these problems handled for removable and failing 508 * hardware devices? (Hint: They are not) 509 */ 510 vnclear(vn); 511 IFOPT(vn, VN_FOLLOW) 512 kprintf("vnioctl: CLRed\n"); 513 break; 514 515 case VNIOCGSET: 516 vn_options |= *f; 517 *f = vn_options; 518 break; 519 520 case VNIOCGCLEAR: 521 vn_options &= ~(*f); 522 *f = vn_options; 523 break; 524 525 case VNIOCUSET: 526 vn->sc_options |= *f; 527 *f = vn->sc_options; 528 break; 529 530 case VNIOCUCLEAR: 531 vn->sc_options &= ~(*f); 532 *f = vn->sc_options; 533 break; 534 535 default: 536 error = ENOTTY; 537 break; 538 } 539 return(error); 540 } 541 542 /* 543 * vniocattach_file: 544 * 545 * Attach a file to a VN partition. Return the size in the vn_size 546 * field. 547 */ 548 549 static int 550 vniocattach_file(struct vn_softc *vn, struct vn_ioctl *vio, cdev_t dev, 551 int flag, struct ucred *cred) 552 { 553 struct vattr vattr; 554 struct nlookupdata nd; 555 int error, flags; 556 struct vnode *vp; 557 558 flags = FREAD|FWRITE; 559 error = nlookup_init(&nd, vio->vn_file, 560 UIO_USERSPACE, NLC_FOLLOW|NLC_LOCKVP); 561 if (error) 562 return (error); 563 if ((error = vn_open(&nd, NULL, flags, 0)) != 0) { 564 if (error != EACCES && error != EPERM && error != EROFS) 565 goto done; 566 flags &= ~FWRITE; 567 nlookup_done(&nd); 568 error = nlookup_init(&nd, vio->vn_file, UIO_USERSPACE, NLC_FOLLOW|NLC_LOCKVP); 569 if (error) 570 return (error); 571 if ((error = vn_open(&nd, NULL, flags, 0)) != 0) 572 goto done; 573 } 574 vp = nd.nl_open_vp; 575 if (vp->v_type != VREG || 576 (error = VOP_GETATTR(vp, &vattr))) { 577 if (error == 0) 578 error = EINVAL; 579 goto done; 580 } 581 vn_unlock(vp); 582 vn->sc_secsize = DEV_BSIZE; 583 vn->sc_vp = vp; 584 nd.nl_open_vp = NULL; 585 586 /* 587 * If the size is specified, override the file attributes. Note that 588 * the vn_size argument is in PAGE_SIZE sized blocks. 589 */ 590 if (vio->vn_size) 591 vn->sc_size = vio->vn_size * PAGE_SIZE / vn->sc_secsize; 592 else 593 vn->sc_size = vattr.va_size / vn->sc_secsize; 594 error = vnsetcred(vn, cred); 595 if (error) { 596 vn->sc_vp = NULL; 597 vn_close(vp, flags); 598 goto done; 599 } 600 vn->sc_flags |= VNF_INITED; 601 if (flags == FREAD) 602 vn->sc_flags |= VNF_READONLY; 603 IFOPT(vn, VN_LABELS) { 604 /* 605 * Reopen so that `ds' knows which devices are open. 606 * If this is the first VNIOCSET, then we've 607 * guaranteed that the device is the cdev and that 608 * no other slices or labels are open. Otherwise, 609 * we rely on VNIOCCLR not being abused. 610 */ 611 error = dev_dopen(dev, flag, S_IFCHR, cred); 612 if (error) 613 vnclear(vn); 614 } 615 IFOPT(vn, VN_FOLLOW) 616 kprintf("vnioctl: SET vp %p size %llx blks\n", 617 vn->sc_vp, vn->sc_size); 618 done: 619 nlookup_done(&nd); 620 return(error); 621 } 622 623 /* 624 * vniocattach_swap: 625 * 626 * Attach swap backing store to a VN partition of the size specified 627 * in vn_size. 628 */ 629 630 static int 631 vniocattach_swap(struct vn_softc *vn, struct vn_ioctl *vio, cdev_t dev, 632 int flag, struct ucred *cred) 633 { 634 int error; 635 636 /* 637 * Range check. Disallow negative sizes or any size less then the 638 * size of a page. Then round to a page. 639 */ 640 641 if (vio->vn_size <= 0) 642 return(EDOM); 643 644 /* 645 * Allocate an OBJT_SWAP object. 646 * 647 * sc_secsize is PAGE_SIZE'd 648 * 649 * vio->vn_size is in PAGE_SIZE'd chunks. 650 * sc_size must be in PAGE_SIZE'd chunks. 651 * Note the truncation. 652 */ 653 654 vn->sc_secsize = PAGE_SIZE; 655 vn->sc_size = vio->vn_size; 656 vn->sc_object = vm_pager_allocate(OBJT_SWAP, NULL, 657 vn->sc_secsize * (off_t)vio->vn_size, 658 VM_PROT_DEFAULT, 0); 659 IFOPT(vn, VN_RESERVE) { 660 if (swap_pager_reserve(vn->sc_object, 0, vn->sc_size) < 0) { 661 vm_pager_deallocate(vn->sc_object); 662 vn->sc_object = NULL; 663 return(EDOM); 664 } 665 } 666 vn->sc_flags |= VNF_INITED; 667 668 error = vnsetcred(vn, cred); 669 if (error == 0) { 670 IFOPT(vn, VN_LABELS) { 671 /* 672 * Reopen so that `ds' knows which devices are open. 673 * If this is the first VNIOCSET, then we've 674 * guaranteed that the device is the cdev and that 675 * no other slices or labels are open. Otherwise, 676 * we rely on VNIOCCLR not being abused. 677 */ 678 error = dev_dopen(dev, flag, S_IFCHR, cred); 679 } 680 } 681 if (error == 0) { 682 IFOPT(vn, VN_FOLLOW) { 683 kprintf("vnioctl: SET vp %p size %llx\n", 684 vn->sc_vp, vn->sc_size); 685 } 686 } 687 if (error) 688 vnclear(vn); 689 return(error); 690 } 691 692 /* 693 * Duplicate the current processes' credentials. Since we are called only 694 * as the result of a SET ioctl and only root can do that, any future access 695 * to this "disk" is essentially as root. Note that credentials may change 696 * if some other uid can write directly to the mapped file (NFS). 697 */ 698 int 699 vnsetcred(struct vn_softc *vn, struct ucred *cred) 700 { 701 char *tmpbuf; 702 int error = 0; 703 704 /* 705 * Set credits in our softc 706 */ 707 708 if (vn->sc_cred) 709 crfree(vn->sc_cred); 710 vn->sc_cred = crdup(cred); 711 712 /* 713 * Horrible kludge to establish credentials for NFS XXX. 714 */ 715 716 if (vn->sc_vp) { 717 struct uio auio; 718 struct iovec aiov; 719 720 tmpbuf = kmalloc(vn->sc_secsize, M_TEMP, M_WAITOK); 721 bzero(&auio, sizeof(auio)); 722 723 aiov.iov_base = tmpbuf; 724 aiov.iov_len = vn->sc_secsize; 725 auio.uio_iov = &aiov; 726 auio.uio_iovcnt = 1; 727 auio.uio_offset = 0; 728 auio.uio_rw = UIO_READ; 729 auio.uio_segflg = UIO_SYSSPACE; 730 auio.uio_resid = aiov.iov_len; 731 vn_lock(vn->sc_vp, LK_EXCLUSIVE | LK_RETRY); 732 error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred); 733 vn_unlock(vn->sc_vp); 734 kfree(tmpbuf, M_TEMP); 735 } 736 return (error); 737 } 738 739 void 740 vnclear(struct vn_softc *vn) 741 { 742 IFOPT(vn, VN_FOLLOW) 743 kprintf("vnclear(%p): vp=%p\n", vn, vn->sc_vp); 744 if (vn->sc_slices != NULL) 745 dsgone(&vn->sc_slices); 746 vn->sc_flags &= ~VNF_INITED; 747 if (vn->sc_vp != NULL) { 748 vn_close(vn->sc_vp, 749 (vn->sc_flags & VNF_READONLY) ? FREAD : (FREAD|FWRITE)); 750 vn->sc_vp = NULL; 751 } 752 vn->sc_flags &= ~VNF_READONLY; 753 if (vn->sc_cred) { 754 crfree(vn->sc_cred); 755 vn->sc_cred = NULL; 756 } 757 if (vn->sc_object != NULL) { 758 vm_pager_deallocate(vn->sc_object); 759 vn->sc_object = NULL; 760 } 761 vn->sc_size = 0; 762 } 763 764 static int 765 vnsize(struct dev_psize_args *ap) 766 { 767 cdev_t dev = ap->a_head.a_dev; 768 struct vn_softc *vn; 769 770 vn = dev->si_drv1; 771 if (!vn) 772 return(ENXIO); 773 if ((vn->sc_flags & VNF_INITED) == 0) 774 return(ENXIO); 775 ap->a_result = (int64_t)vn->sc_size; 776 return(0); 777 } 778 779 static int 780 vn_modevent(module_t mod, int type, void *data) 781 { 782 struct vn_softc *vn; 783 cdev_t dev; 784 785 switch (type) { 786 case MOD_LOAD: 787 dev_ops_add(&vn_ops, 0, 0); 788 break; 789 case MOD_UNLOAD: 790 /* fall through */ 791 case MOD_SHUTDOWN: 792 while ((vn = SLIST_FIRST(&vn_list)) != NULL) { 793 SLIST_REMOVE_HEAD(&vn_list, sc_list); 794 if (vn->sc_flags & VNF_INITED) 795 vnclear(vn); 796 /* Cleanup all cdev_t's that refer to this unit */ 797 while ((dev = vn->sc_devlist) != NULL) { 798 vn->sc_devlist = dev->si_drv2; 799 dev->si_drv1 = dev->si_drv2 = NULL; 800 destroy_dev(dev); 801 } 802 kfree(vn, M_DEVBUF); 803 } 804 dev_ops_remove(&vn_ops, 0, 0); 805 break; 806 default: 807 break; 808 } 809 return 0; 810 } 811 812 DEV_MODULE(vn, vn_modevent, 0); 813