1 /* $NetBSD: msdosfs_vfsops.c,v 1.138 2022/04/16 07:58:21 hannken Exp $ */ 2 3 /*- 4 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 5 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 6 * All rights reserved. 7 * Original code by Paul Popelka (paulp (at) uts.amdahl.com) (see below). 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by TooLs GmbH. 20 * 4. The name of TooLs GmbH may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 /* 35 * Written by Paul Popelka (paulp (at) uts.amdahl.com) 36 * 37 * You can do anything you want with this software, just don't say you wrote 38 * it, and don't remove this notice. 39 * 40 * This software is provided "as is". 41 * 42 * The author supplies this software to be publicly redistributed on the 43 * understanding that the author is not responsible for the correct 44 * functioning of this software in any circumstances and is not liable for 45 * any damages caused by this software. 46 * 47 * October 1992 48 */ 49 50 #include <sys/cdefs.h> 51 __KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.138 2022/04/16 07:58:21 hannken Exp $"); 52 53 #if defined(_KERNEL_OPT) 54 #include "opt_compat_netbsd.h" 55 #endif 56 57 #include <sys/param.h> 58 #include <sys/systm.h> 59 #include <sys/sysctl.h> 60 #include <sys/namei.h> 61 #include <sys/proc.h> 62 #include <sys/kernel.h> 63 #include <sys/vnode.h> 64 #include <miscfs/genfs/genfs.h> 65 #include <miscfs/specfs/specdev.h> /* XXX */ /* defines v_rdev */ 66 #include <sys/mount.h> 67 #include <sys/buf.h> 68 #include <sys/file.h> 69 #include <sys/device.h> 70 #include <sys/disklabel.h> 71 #include <sys/disk.h> 72 #include <sys/ioctl.h> 73 #include <sys/malloc.h> 74 #include <sys/dirent.h> 75 #include <sys/stat.h> 76 #include <sys/conf.h> 77 #include <sys/kauth.h> 78 #include <sys/module.h> 79 80 #include <fs/msdosfs/bpb.h> 81 #include <fs/msdosfs/bootsect.h> 82 #include <fs/msdosfs/direntry.h> 83 #include <fs/msdosfs/denode.h> 84 #include <fs/msdosfs/msdosfsmount.h> 85 #include <fs/msdosfs/fat.h> 86 87 MODULE(MODULE_CLASS_VFS, msdos, NULL); 88 89 #ifdef MSDOSFS_DEBUG 90 #define DPRINTF(fmt, ...) uprintf("%s(): " fmt "\n", __func__, ##__VA_ARGS__) 91 #else 92 #define DPRINTF(fmt, ...) 93 #endif 94 95 #define GEMDOSFS_BSIZE 512 96 97 #define MSDOSFS_NAMEMAX(pmp) \ 98 (pmp)->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12 99 100 int msdosfs_mountfs(struct vnode *, struct mount *, struct lwp *, 101 struct msdosfs_args *); 102 103 static int update_mp(struct mount *, struct msdosfs_args *); 104 105 MALLOC_JUSTDEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure"); 106 MALLOC_JUSTDEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOS FS FAT table"); 107 MALLOC_JUSTDEFINE(M_MSDOSFSTMP, "MSDOSFS temp", "MSDOS FS temp. structures"); 108 109 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc; 110 111 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = { 112 &msdosfs_vnodeop_opv_desc, 113 NULL, 114 }; 115 116 struct vfsops msdosfs_vfsops = { 117 .vfs_name = MOUNT_MSDOS, 118 .vfs_min_mount_data = sizeof (struct msdosfs_args), 119 .vfs_mount = msdosfs_mount, 120 .vfs_start = msdosfs_start, 121 .vfs_unmount = msdosfs_unmount, 122 .vfs_root = msdosfs_root, 123 .vfs_quotactl = (void *)eopnotsupp, 124 .vfs_statvfs = msdosfs_statvfs, 125 .vfs_sync = msdosfs_sync, 126 .vfs_vget = msdosfs_vget, 127 .vfs_loadvnode = msdosfs_loadvnode, 128 .vfs_fhtovp = msdosfs_fhtovp, 129 .vfs_vptofh = msdosfs_vptofh, 130 .vfs_init = msdosfs_init, 131 .vfs_reinit = msdosfs_reinit, 132 .vfs_done = msdosfs_done, 133 .vfs_mountroot = msdosfs_mountroot, 134 .vfs_snapshot = (void *)eopnotsupp, 135 .vfs_extattrctl = vfs_stdextattrctl, 136 .vfs_suspendctl = genfs_suspendctl, 137 .vfs_renamelock_enter = genfs_renamelock_enter, 138 .vfs_renamelock_exit = genfs_renamelock_exit, 139 .vfs_fsync = (void *)eopnotsupp, 140 .vfs_opv_descs = msdosfs_vnodeopv_descs 141 }; 142 143 SYSCTL_SETUP(msdosfs_sysctl_setup, "msdosfs sysctl") 144 { 145 sysctl_createv(clog, 0, NULL, NULL, 146 CTLFLAG_PERMANENT, 147 CTLTYPE_NODE, "msdosfs", 148 SYSCTL_DESCR("MS-DOS file system"), 149 NULL, 0, NULL, 0, 150 CTL_VFS, 4, CTL_EOL); 151 /* 152 * XXX the "4" above could be dynamic, thereby eliminating one 153 * more instance of the "number to vfs" mapping problem, but 154 * "4" is the order as taken from sys/mount.h 155 */ 156 } 157 158 static int 159 msdos_modcmd(modcmd_t cmd, void *arg) 160 { 161 int error; 162 163 switch (cmd) { 164 case MODULE_CMD_INIT: 165 error = vfs_attach(&msdosfs_vfsops); 166 if (error != 0) 167 break; 168 break; 169 case MODULE_CMD_FINI: 170 error = vfs_detach(&msdosfs_vfsops); 171 if (error != 0) 172 break; 173 break; 174 default: 175 error = ENOTTY; 176 break; 177 } 178 179 return (error); 180 } 181 182 static int 183 update_mp(struct mount *mp, struct msdosfs_args *argp) 184 { 185 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 186 int error; 187 188 pmp->pm_gid = argp->gid; 189 pmp->pm_uid = argp->uid; 190 pmp->pm_mask = argp->mask & ALLPERMS; 191 pmp->pm_dirmask = argp->dirmask & ALLPERMS; 192 pmp->pm_gmtoff = argp->gmtoff; 193 pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT; 194 195 /* 196 * GEMDOS knows nothing about win95 long filenames 197 */ 198 if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS) 199 pmp->pm_flags |= MSDOSFSMNT_NOWIN95; 200 201 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95) 202 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME; 203 else if (!(pmp->pm_flags & 204 (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) { 205 struct vnode *rtvp; 206 207 /* 208 * Try to divine whether to support Win'95 long filenames 209 */ 210 if (FAT32(pmp)) 211 pmp->pm_flags |= MSDOSFSMNT_LONGNAME; 212 else { 213 error = msdosfs_root(mp, LK_EXCLUSIVE, &rtvp); 214 if (error != 0) 215 return error; 216 pmp->pm_flags |= msdosfs_findwin95(VTODE(rtvp)) 217 ? MSDOSFSMNT_LONGNAME 218 : MSDOSFSMNT_SHORTNAME; 219 vput(rtvp); 220 } 221 } 222 223 mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp); 224 225 return 0; 226 } 227 228 int 229 msdosfs_mountroot(void) 230 { 231 struct mount *mp; 232 struct lwp *l = curlwp; /* XXX */ 233 int error; 234 struct msdosfs_args args; 235 236 if (device_class(root_device) != DV_DISK) 237 return (ENODEV); 238 239 if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) { 240 vrele(rootvp); 241 return (error); 242 } 243 244 args.flags = MSDOSFSMNT_VERSIONED; 245 args.uid = 0; 246 args.gid = 0; 247 args.mask = 0777; 248 args.version = MSDOSFSMNT_VERSION; 249 args.dirmask = 0777; 250 251 if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) { 252 vfs_unbusy(mp); 253 vfs_rele(mp); 254 return (error); 255 } 256 257 if ((error = update_mp(mp, &args)) != 0) { 258 (void)msdosfs_unmount(mp, 0); 259 vfs_unbusy(mp); 260 vfs_rele(mp); 261 vrele(rootvp); 262 return (error); 263 } 264 265 mountlist_append(mp); 266 (void)msdosfs_statvfs(mp, &mp->mnt_stat); 267 vfs_unbusy(mp); 268 return (0); 269 } 270 271 /* 272 * mp - path - addr in user space of mount point (ie /usr or whatever) 273 * data - addr in user space of mount params including the name of the block 274 * special file to treat as a filesystem. 275 */ 276 int 277 msdosfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 278 { 279 struct lwp *l = curlwp; 280 struct vnode *devvp; /* vnode for blk device to mount */ 281 struct msdosfs_args *args = data; /* holds data from mount request */ 282 /* msdosfs specific mount control block */ 283 struct msdosfsmount *pmp = NULL; 284 int error, flags; 285 mode_t accessmode; 286 287 if (args == NULL) 288 return EINVAL; 289 if (*data_len < sizeof *args) 290 return EINVAL; 291 292 if (mp->mnt_flag & MNT_GETARGS) { 293 pmp = VFSTOMSDOSFS(mp); 294 if (pmp == NULL) 295 return EIO; 296 args->fspec = NULL; 297 args->uid = pmp->pm_uid; 298 args->gid = pmp->pm_gid; 299 args->mask = pmp->pm_mask; 300 args->flags = pmp->pm_flags; 301 args->version = MSDOSFSMNT_VERSION; 302 args->dirmask = pmp->pm_dirmask; 303 args->gmtoff = pmp->pm_gmtoff; 304 *data_len = sizeof *args; 305 return 0; 306 } 307 308 /* 309 * If not versioned (i.e. using old mount_msdos(8)), fill in 310 * the additional structure items with suitable defaults. 311 */ 312 if ((args->flags & MSDOSFSMNT_VERSIONED) == 0) { 313 args->version = 1; 314 args->dirmask = args->mask; 315 } 316 317 /* 318 * Reset GMT offset for pre-v3 mount structure args. 319 */ 320 if (args->version < 3) 321 args->gmtoff = 0; 322 323 /* 324 * If updating, check whether changing from read-only to 325 * read/write; if there is no device name, that's all we do. 326 */ 327 if (mp->mnt_flag & MNT_UPDATE) { 328 pmp = VFSTOMSDOSFS(mp); 329 error = 0; 330 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && 331 (mp->mnt_flag & MNT_RDONLY)) { 332 flags = WRITECLOSE; 333 if (mp->mnt_flag & MNT_FORCE) 334 flags |= FORCECLOSE; 335 error = vflush(mp, NULLVP, flags); 336 } 337 if (!error && (mp->mnt_flag & MNT_RELOAD)) 338 /* not yet implemented */ 339 error = EOPNOTSUPP; 340 if (error) { 341 DPRINTF("vflush %d", error); 342 return (error); 343 } 344 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && 345 (mp->mnt_iflag & IMNT_WANTRDWR)) { 346 /* 347 * If upgrade to read-write by non-root, then verify 348 * that user has necessary permissions on the device. 349 * 350 * Permission to update a mount is checked higher, so 351 * here we presume updating the mount is okay (for 352 * example, as far as securelevel goes) which leaves us 353 * with the normal check. 354 */ 355 devvp = pmp->pm_devvp; 356 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 357 error = kauth_authorize_system(l->l_cred, 358 KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_DEVICE, 359 mp, devvp, KAUTH_ARG(VREAD | VWRITE)); 360 VOP_UNLOCK(devvp); 361 DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error); 362 if (error) 363 return (error); 364 365 pmp->pm_flags &= ~MSDOSFSMNT_RONLY; 366 } 367 if (args->fspec == NULL) { 368 DPRINTF("missing fspec"); 369 return EINVAL; 370 } 371 } 372 /* 373 * Not an update, or updating the name: look up the name 374 * and verify that it refers to a sensible block device. 375 */ 376 error = namei_simple_user(args->fspec, 377 NSM_FOLLOW_NOEMULROOT, &devvp); 378 if (error != 0) { 379 DPRINTF("namei %d", error); 380 return (error); 381 } 382 383 if (devvp->v_type != VBLK) { 384 DPRINTF("not block"); 385 vrele(devvp); 386 return (ENOTBLK); 387 } 388 if (bdevsw_lookup(devvp->v_rdev) == NULL) { 389 DPRINTF("no block switch"); 390 vrele(devvp); 391 return (ENXIO); 392 } 393 /* 394 * If mount by non-root, then verify that user has necessary 395 * permissions on the device. 396 */ 397 accessmode = VREAD; 398 if ((mp->mnt_flag & MNT_RDONLY) == 0) 399 accessmode |= VWRITE; 400 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 401 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 402 KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode)); 403 VOP_UNLOCK(devvp); 404 if (error) { 405 DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error); 406 vrele(devvp); 407 return (error); 408 } 409 if ((mp->mnt_flag & MNT_UPDATE) == 0) { 410 int xflags; 411 412 if (mp->mnt_flag & MNT_RDONLY) 413 xflags = FREAD; 414 else 415 xflags = FREAD|FWRITE; 416 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 417 error = VOP_OPEN(devvp, xflags, FSCRED); 418 VOP_UNLOCK(devvp); 419 if (error) { 420 DPRINTF("VOP_OPEN %d", error); 421 goto fail; 422 } 423 error = msdosfs_mountfs(devvp, mp, l, args); 424 if (error) { 425 DPRINTF("msdosfs_mountfs %d", error); 426 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 427 (void) VOP_CLOSE(devvp, xflags, NOCRED); 428 VOP_UNLOCK(devvp); 429 goto fail; 430 } 431 #ifdef MSDOSFS_DEBUG /* only needed for the printf below */ 432 pmp = VFSTOMSDOSFS(mp); 433 #endif 434 } else { 435 vrele(devvp); 436 if (devvp != pmp->pm_devvp) { 437 DPRINTF("devvp %p pmp %p", devvp, pmp->pm_devvp); 438 return (EINVAL); /* needs translation */ 439 } 440 } 441 if ((error = update_mp(mp, args)) != 0) { 442 msdosfs_unmount(mp, MNT_FORCE); 443 DPRINTF("update_mp %d", error); 444 return error; 445 } 446 447 #ifdef MSDOSFS_DEBUG 448 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap); 449 #endif 450 return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE, 451 mp->mnt_op->vfs_name, mp, l); 452 453 fail: 454 vrele(devvp); 455 return (error); 456 } 457 458 int 459 msdosfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct msdosfs_args *argp) 460 { 461 struct msdosfsmount *pmp; 462 struct buf *bp; 463 dev_t dev = devvp->v_rdev; 464 union bootsector *bsp; 465 struct byte_bpb33 *b33; 466 struct byte_bpb50 *b50; 467 struct byte_bpb710 *b710; 468 uint8_t SecPerClust; 469 int ronly, error, BlkPerSec; 470 uint64_t psize; 471 unsigned secsize; 472 u_long fatbytes, fatblocksecs; 473 474 /* Flush out any old buffers remaining from a previous use. */ 475 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); 476 error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0); 477 VOP_UNLOCK(devvp); 478 if (error) 479 return (error); 480 481 ronly = (mp->mnt_flag & MNT_RDONLY) != 0; 482 483 bp = NULL; /* both used in error_exit */ 484 pmp = NULL; 485 486 error = getdisksize(devvp, &psize, &secsize); 487 if (error) { 488 if (argp->flags & MSDOSFSMNT_GEMDOSFS) 489 goto error_exit; 490 491 /* ok, so it failed. we most likely don't need the info */ 492 secsize = DEV_BSIZE; 493 psize = 0; 494 error = 0; 495 } 496 if (secsize < DEV_BSIZE) { 497 DPRINTF("Invalid block secsize (%d < DEV_BSIZE)", secsize); 498 error = EINVAL; 499 goto error_exit; 500 } 501 502 if (argp->flags & MSDOSFSMNT_GEMDOSFS) { 503 if (secsize != GEMDOSFS_BSIZE) { 504 DPRINTF("Invalid block secsize %d for GEMDOS", secsize); 505 error = EINVAL; 506 goto error_exit; 507 } 508 } 509 510 /* 511 * Read the boot sector of the filesystem, and then check the 512 * boot signature. If not a dos boot sector then error out. 513 */ 514 if (secsize < sizeof(*b50)) { 515 DPRINTF("50 bootsec %u\n", secsize); 516 error = EINVAL; 517 goto error_exit; 518 } 519 if ((error = bread(devvp, 0, secsize, 0, &bp)) != 0) 520 goto error_exit; 521 bsp = (union bootsector *)bp->b_data; 522 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB; 523 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB; 524 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB; 525 526 #if 0 527 /* 528 * Some FAT partition, for example Raspberry Pi Pico's 529 * USB mass storage, does not have exptected BOOTSIGs. 530 * According to FreeBSD's comment, some PC-9800/9821 531 * FAT floppy disks have similar problems. 532 */ 533 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) { 534 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 535 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) { 536 DPRINTF("bootsig0 %d bootsig1 %d", 537 bsp->bs50.bsBootSectSig0, 538 bsp->bs50.bsBootSectSig1); 539 error = EINVAL; 540 goto error_exit; 541 } 542 } 543 #endif 544 545 pmp = malloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK|M_ZERO); 546 pmp->pm_mountp = mp; 547 548 /* 549 * Compute several useful quantities from the bpb in the 550 * bootsector. Copy in the dos 5 variant of the bpb then fix up 551 * the fields that are different between dos 5 and dos 3.3. 552 */ 553 SecPerClust = b50->bpbSecPerClust; 554 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec); 555 pmp->pm_ResSectors = getushort(b50->bpbResSectors); 556 pmp->pm_FATs = b50->bpbFATs; 557 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts); 558 pmp->pm_Sectors = getushort(b50->bpbSectors); 559 pmp->pm_FATsecs = getushort(b50->bpbFATsecs); 560 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack); 561 pmp->pm_Heads = getushort(b50->bpbHeads); 562 pmp->pm_Media = b50->bpbMedia; 563 564 if (pmp->pm_Sectors == 0) { 565 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs); 566 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors); 567 } else { 568 if (secsize < sizeof(*b33)) { 569 DPRINTF("33 bootsec %u\n", secsize); 570 error = EINVAL; 571 goto error_exit; 572 } 573 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs); 574 pmp->pm_HugeSectors = pmp->pm_Sectors; 575 } 576 577 /* 578 * Sanity checks, from the FAT specification: 579 * - sectors per cluster: >= 1, power of 2 580 * - logical sector size: >= 1, power of 2 581 * - cluster size: <= max FS block size 582 * - number of sectors: >= 1 583 */ 584 if ((SecPerClust == 0) || !powerof2(SecPerClust) || 585 (pmp->pm_BytesPerSec == 0) || !powerof2(pmp->pm_BytesPerSec) || 586 (SecPerClust * pmp->pm_BytesPerSec > MAXBSIZE) || 587 (pmp->pm_HugeSectors == 0)) { 588 DPRINTF("consistency checks"); 589 error = EINVAL; 590 goto error_exit; 591 } 592 593 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS) && 594 (pmp->pm_SecPerTrack > 63)) { 595 DPRINTF("SecPerTrack %d", pmp->pm_SecPerTrack); 596 error = EINVAL; 597 goto error_exit; 598 } 599 600 if (pmp->pm_RootDirEnts == 0) { 601 if (secsize < sizeof(*b710)) { 602 DPRINTF("710 bootsec %u\n", secsize); 603 error = EINVAL; 604 goto error_exit; 605 } 606 unsigned short FSVers = getushort(b710->bpbFSVers); 607 unsigned short ExtFlags = getushort(b710->bpbExtFlags); 608 /* 609 * Some say that bsBootSectSig[23] must be zero, but 610 * Windows does not require this and some digital cameras 611 * do not set these to zero. Therefore, do not insist. 612 */ 613 if (pmp->pm_Sectors || pmp->pm_FATsecs || FSVers) { 614 DPRINTF("Sectors %d FATsecs %lu FSVers %d", 615 pmp->pm_Sectors, pmp->pm_FATsecs, FSVers); 616 error = EINVAL; 617 goto error_exit; 618 } 619 pmp->pm_fatmask = FAT32_MASK; 620 pmp->pm_fatmult = 4; 621 pmp->pm_fatdiv = 1; 622 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs); 623 624 /* Mirroring is enabled if the FATMIRROR bit is not set. */ 625 if ((ExtFlags & FATMIRROR) == 0) 626 pmp->pm_flags |= MSDOSFS_FATMIRROR; 627 else 628 pmp->pm_curfat = ExtFlags & FATNUM; 629 } else 630 pmp->pm_flags |= MSDOSFS_FATMIRROR; 631 632 if (argp->flags & MSDOSFSMNT_GEMDOSFS) { 633 if (FAT32(pmp)) { 634 /* GEMDOS doesn't know FAT32. */ 635 DPRINTF("FAT32 for GEMDOS"); 636 error = EINVAL; 637 goto error_exit; 638 } 639 640 /* 641 * Check a few values (could do some more): 642 * - logical sector size: >= block size 643 * - number of sectors: <= size of partition 644 */ 645 if ((pmp->pm_BytesPerSec < GEMDOSFS_BSIZE) || 646 (pmp->pm_HugeSectors * 647 (pmp->pm_BytesPerSec / GEMDOSFS_BSIZE) > psize)) { 648 DPRINTF("consistency checks for GEMDOS"); 649 error = EINVAL; 650 goto error_exit; 651 } 652 /* 653 * XXX - Many parts of the msdosfs driver seem to assume that 654 * the number of bytes per logical sector (BytesPerSec) will 655 * always be the same as the number of bytes per disk block 656 * Let's pretend it is. 657 */ 658 BlkPerSec = pmp->pm_BytesPerSec / GEMDOSFS_BSIZE; 659 pmp->pm_BytesPerSec = GEMDOSFS_BSIZE; 660 pmp->pm_HugeSectors *= BlkPerSec; 661 pmp->pm_HiddenSects *= BlkPerSec; 662 pmp->pm_ResSectors *= BlkPerSec; 663 pmp->pm_Sectors *= BlkPerSec; 664 pmp->pm_FATsecs *= BlkPerSec; 665 SecPerClust *= BlkPerSec; 666 } 667 668 /* Check that fs has nonzero FAT size */ 669 if (pmp->pm_FATsecs == 0) { 670 DPRINTF("FATsecs is 0"); 671 error = EINVAL; 672 goto error_exit; 673 } 674 675 pmp->pm_fatblk = pmp->pm_ResSectors; 676 if (FAT32(pmp)) { 677 if (secsize < sizeof(*b710)) { 678 DPRINTF("710 bootsec %u\n", secsize); 679 error = EINVAL; 680 goto error_exit; 681 } 682 pmp->pm_rootdirblk = getulong(b710->bpbRootClust); 683 pmp->pm_firstcluster = pmp->pm_fatblk 684 + (pmp->pm_FATs * pmp->pm_FATsecs); 685 pmp->pm_fsinfo = getushort(b710->bpbFSInfo); 686 } else { 687 pmp->pm_rootdirblk = pmp->pm_fatblk + 688 (pmp->pm_FATs * pmp->pm_FATsecs); 689 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry) 690 + pmp->pm_BytesPerSec - 1) 691 / pmp->pm_BytesPerSec;/* in sectors */ 692 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; 693 } 694 695 pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) / 696 SecPerClust; 697 pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1; 698 pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec; 699 700 if (argp->flags & MSDOSFSMNT_GEMDOSFS) { 701 if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) { 702 pmp->pm_fatmask = FAT12_MASK; 703 pmp->pm_fatmult = 3; 704 pmp->pm_fatdiv = 2; 705 } else { 706 pmp->pm_fatmask = FAT16_MASK; 707 pmp->pm_fatmult = 2; 708 pmp->pm_fatdiv = 1; 709 } 710 } else if (pmp->pm_fatmask == 0) { 711 if (pmp->pm_maxcluster 712 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) { 713 /* 714 * This will usually be a floppy disk. This size makes 715 * sure that one FAT entry will not be split across 716 * multiple blocks. 717 */ 718 pmp->pm_fatmask = FAT12_MASK; 719 pmp->pm_fatmult = 3; 720 pmp->pm_fatdiv = 2; 721 } else { 722 pmp->pm_fatmask = FAT16_MASK; 723 pmp->pm_fatmult = 2; 724 pmp->pm_fatdiv = 1; 725 } 726 } 727 728 /* validate cluster count against FAT */ 729 if ((pmp->pm_maxcluster & pmp->pm_fatmask) != pmp->pm_maxcluster) { 730 DPRINTF("maxcluster %lu outside of mask %#lx\n", 731 pmp->pm_maxcluster, pmp->pm_fatmask); 732 error = EINVAL; 733 goto error_exit; 734 } 735 736 /* validate FAT size */ 737 fatbytes = (pmp->pm_maxcluster+1) * pmp->pm_fatmult / pmp->pm_fatdiv; 738 fatblocksecs = howmany(fatbytes, pmp->pm_BytesPerSec); 739 740 if (pmp->pm_FATsecs < fatblocksecs) { 741 DPRINTF("FATsecs %lu < real %lu\n", pmp->pm_FATsecs, 742 fatblocksecs); 743 error = EINVAL; 744 goto error_exit; 745 } 746 747 if (FAT12(pmp)) { 748 /* 749 * limit block size to what is needed to read a FAT block 750 * to not exceed MAXBSIZE 751 */ 752 pmp->pm_fatblocksec = uimin(3, fatblocksecs); 753 pmp->pm_fatblocksize = pmp->pm_fatblocksec 754 * pmp->pm_BytesPerSec; 755 } else { 756 pmp->pm_fatblocksize = MAXBSIZE; 757 pmp->pm_fatblocksec = pmp->pm_fatblocksize 758 / pmp->pm_BytesPerSec; 759 } 760 761 pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1; 762 763 /* 764 * Compute mask and shift value for isolating cluster relative byte 765 * offsets and cluster numbers from a file offset. 766 */ 767 pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec; 768 pmp->pm_crbomask = pmp->pm_bpcluster - 1; 769 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1; 770 771 /* 772 * Check for valid cluster size 773 * must be a power of 2 774 */ 775 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) { 776 DPRINTF("bpcluster %lu cnshift %lu", pmp->pm_bpcluster, 777 pmp->pm_cnshift); 778 error = EINVAL; 779 goto error_exit; 780 } 781 782 /* 783 * Cluster size must be within limit of MAXBSIZE. 784 * Many FAT filesystems will not have clusters larger than 785 * 32KiB due to limits in Windows versions before Vista. 786 */ 787 if (pmp->pm_bpcluster > MAXBSIZE) { 788 DPRINTF("bpcluster %lu > MAXBSIZE %d", 789 pmp->pm_bpcluster, MAXBSIZE); 790 error = EINVAL; 791 goto error_exit; 792 } 793 794 /* 795 * Release the bootsector buffer. 796 */ 797 brelse(bp, BC_AGE); 798 bp = NULL; 799 800 /* 801 * Check FSInfo. 802 */ 803 if (pmp->pm_fsinfo) { 804 struct fsinfo *fp; 805 const int rdsz = roundup(sizeof(*fp), pmp->pm_BytesPerSec); 806 807 /* 808 * XXX If the fsinfo block is stored on media with 809 * 2KB or larger sectors, is the fsinfo structure 810 * padded at the end or in the middle? 811 */ 812 if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo), 813 rdsz, 0, &bp)) != 0) 814 goto error_exit; 815 fp = (struct fsinfo *)bp->b_data; 816 if (!memcmp(fp->fsisig1, "RRaA", 4) 817 && !memcmp(fp->fsisig2, "rrAa", 4) 818 && !memcmp(fp->fsisig3, "\0\0\125\252", 4) 819 && !memcmp(fp->fsisig4, "\0\0\125\252", 4)) 820 pmp->pm_nxtfree = getulong(fp->fsinxtfree); 821 else 822 pmp->pm_fsinfo = 0; 823 brelse(bp, 0); 824 bp = NULL; 825 } 826 827 /* 828 * Check and validate (or perhaps invalidate?) the fsinfo structure? 829 * XXX 830 */ 831 if (pmp->pm_fsinfo) { 832 if ((pmp->pm_nxtfree == 0xffffffffUL) || 833 (pmp->pm_nxtfree > pmp->pm_maxcluster)) 834 pmp->pm_fsinfo = 0; 835 } 836 837 /* 838 * Allocate memory for the bitmap of allocated clusters, and then 839 * fill it in. 840 */ 841 pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS) 842 / N_INUSEBITS) 843 * sizeof(*pmp->pm_inusemap), 844 M_MSDOSFSFAT, M_WAITOK); 845 846 /* 847 * fillinusemap() needs pm_devvp. 848 */ 849 pmp->pm_dev = dev; 850 pmp->pm_devvp = devvp; 851 852 /* 853 * Have the inuse map filled in. 854 */ 855 if ((error = msdosfs_fillinusemap(pmp)) != 0) { 856 DPRINTF("fillinusemap %d", error); 857 goto error_exit; 858 } 859 860 /* 861 * If they want FAT updates to be synchronous then let them suffer 862 * the performance degradation in exchange for the on disk copy of 863 * the FAT being correct just about all the time. I suppose this 864 * would be a good thing to turn on if the kernel is still flakey. 865 */ 866 if (mp->mnt_flag & MNT_SYNCHRONOUS) 867 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT; 868 869 /* 870 * Finish up. 871 */ 872 if (ronly) 873 pmp->pm_flags |= MSDOSFSMNT_RONLY; 874 else 875 pmp->pm_fmod = 1; 876 mp->mnt_data = pmp; 877 mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev; 878 mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_MSDOS); 879 mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0]; 880 mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp); 881 mp->mnt_flag |= MNT_LOCAL; 882 mp->mnt_iflag |= IMNT_SHRLOOKUP; 883 mp->mnt_dev_bshift = pmp->pm_bnshift; 884 mp->mnt_fs_bshift = pmp->pm_cnshift; 885 886 /* 887 * If we ever do quotas for DOS filesystems this would be a place 888 * to fill in the info in the msdosfsmount structure. You dolt, 889 * quotas on dos filesystems make no sense because files have no 890 * owners on dos filesystems. of course there is some empty space 891 * in the directory entry where we could put uid's and gid's. 892 */ 893 894 spec_node_setmountedfs(devvp, mp); 895 896 return (0); 897 898 error_exit: 899 if (bp) 900 brelse(bp, BC_AGE); 901 if (pmp) { 902 if (pmp->pm_inusemap) 903 free(pmp->pm_inusemap, M_MSDOSFSFAT); 904 free(pmp, M_MSDOSFSMNT); 905 mp->mnt_data = NULL; 906 } 907 return (error); 908 } 909 910 int 911 msdosfs_start(struct mount *mp, int flags) 912 { 913 914 return (0); 915 } 916 917 /* 918 * Unmount the filesystem described by mp. 919 */ 920 int 921 msdosfs_unmount(struct mount *mp, int mntflags) 922 { 923 struct msdosfsmount *pmp; 924 int error, flags; 925 926 flags = 0; 927 if (mntflags & MNT_FORCE) 928 flags |= FORCECLOSE; 929 if ((error = vflush(mp, NULLVP, flags)) != 0) 930 return (error); 931 pmp = VFSTOMSDOSFS(mp); 932 if (pmp->pm_devvp->v_type != VBAD) 933 spec_node_setmountedfs(pmp->pm_devvp, NULL); 934 #ifdef MSDOSFS_DEBUG 935 { 936 struct vnode *vp = pmp->pm_devvp; 937 938 printf("msdosfs_umount(): just before calling VOP_CLOSE()\n"); 939 printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n", 940 vp->v_vflag | vp->v_iflag | vp->v_uflag, vrefcnt(vp), 941 vp->v_writecount, vp->v_holdcnt); 942 printf("mount %p, op %p\n", 943 vp->v_mount, vp->v_op); 944 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n", 945 vp->v_cleanblkhd.lh_first, 946 vp->v_dirtyblkhd.lh_first, 947 vp->v_numoutput, vp->v_type); 948 printf("union %p, tag %d, data[0] %08x, data[1] %08x\n", 949 vp->v_socket, vp->v_tag, 950 ((u_int *)vp->v_data)[0], 951 ((u_int *)vp->v_data)[1]); 952 } 953 #endif 954 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY); 955 (void) VOP_CLOSE(pmp->pm_devvp, 956 pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED); 957 vput(pmp->pm_devvp); 958 msdosfs_fh_destroy(pmp); 959 free(pmp->pm_inusemap, M_MSDOSFSFAT); 960 free(pmp, M_MSDOSFSMNT); 961 mp->mnt_data = NULL; 962 mp->mnt_flag &= ~MNT_LOCAL; 963 return (0); 964 } 965 966 int 967 msdosfs_root(struct mount *mp, int lktype, struct vnode **vpp) 968 { 969 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 970 int error; 971 972 #ifdef MSDOSFS_DEBUG 973 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp); 974 #endif 975 if ((error = msdosfs_deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, 976 vpp)) != 0) 977 return error; 978 error = vn_lock(*vpp, lktype); 979 if (error) { 980 vrele(*vpp); 981 *vpp = NULL; 982 return error; 983 } 984 return 0; 985 } 986 987 int 988 msdosfs_statvfs(struct mount *mp, struct statvfs *sbp) 989 { 990 struct msdosfsmount *pmp; 991 992 pmp = VFSTOMSDOSFS(mp); 993 sbp->f_bsize = pmp->pm_bpcluster; 994 sbp->f_frsize = sbp->f_bsize; 995 sbp->f_iosize = pmp->pm_bpcluster; 996 sbp->f_blocks = pmp->pm_nmbrofclusters; 997 sbp->f_bfree = pmp->pm_freeclustercount; 998 sbp->f_bavail = pmp->pm_freeclustercount; 999 sbp->f_bresvd = 0; 1000 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */ 1001 sbp->f_ffree = 0; /* what to put in here? */ 1002 sbp->f_favail = 0; /* what to put in here? */ 1003 sbp->f_fresvd = 0; 1004 copy_statvfs_info(sbp, mp); 1005 return (0); 1006 } 1007 1008 struct msdosfs_sync_ctx { 1009 int waitfor; 1010 }; 1011 1012 static bool 1013 msdosfs_sync_selector(void *cl, struct vnode *vp) 1014 { 1015 struct msdosfs_sync_ctx *c = cl; 1016 struct denode *dep; 1017 1018 KASSERT(mutex_owned(vp->v_interlock)); 1019 1020 dep = VTODE(vp); 1021 if (c->waitfor == MNT_LAZY || vp->v_type == VNON || 1022 dep == NULL || (((dep->de_flag & 1023 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) && 1024 (LIST_EMPTY(&vp->v_dirtyblkhd) && 1025 (vp->v_iflag & VI_ONWORKLST) == 0))) 1026 return false; 1027 return true; 1028 } 1029 1030 int 1031 msdosfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred) 1032 { 1033 struct vnode *vp; 1034 struct vnode_iterator *marker; 1035 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 1036 int error, allerror = 0; 1037 struct msdosfs_sync_ctx ctx; 1038 1039 /* 1040 * If we ever switch to not updating all of the FATs all the time, 1041 * this would be the place to update them from the first one. 1042 */ 1043 if (pmp->pm_fmod != 0) { 1044 if (pmp->pm_flags & MSDOSFSMNT_RONLY) 1045 panic("msdosfs_sync: rofs mod"); 1046 else { 1047 /* update FATs here */ 1048 } 1049 } 1050 /* 1051 * Write back each (modified) denode. 1052 */ 1053 vfs_vnode_iterator_init(mp, &marker); 1054 ctx.waitfor = waitfor; 1055 while ((vp = vfs_vnode_iterator_next(marker, msdosfs_sync_selector, 1056 &ctx))) 1057 { 1058 error = vn_lock(vp, LK_EXCLUSIVE); 1059 if (error) { 1060 vrele(vp); 1061 continue; 1062 } 1063 if ((error = VOP_FSYNC(vp, cred, 1064 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0) 1065 allerror = error; 1066 vput(vp); 1067 } 1068 vfs_vnode_iterator_destroy(marker); 1069 1070 /* 1071 * Force stale file system control information to be flushed. 1072 */ 1073 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY); 1074 if ((error = VOP_FSYNC(pmp->pm_devvp, cred, 1075 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0) 1076 allerror = error; 1077 VOP_UNLOCK(pmp->pm_devvp); 1078 return (allerror); 1079 } 1080 1081 int 1082 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int lktype, struct vnode **vpp) 1083 { 1084 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp); 1085 struct defid defh; 1086 uint32_t gen; 1087 int error; 1088 1089 if (fhp->fid_len != sizeof(struct defid)) { 1090 DPRINTF("fid_len %d %zd", fhp->fid_len, sizeof(struct defid)); 1091 return EINVAL; 1092 } 1093 memcpy(&defh, fhp, sizeof(defh)); 1094 error = msdosfs_fh_lookup(pmp, defh.defid_dirclust, defh.defid_dirofs, 1095 &gen); 1096 if (error == 0 && gen != defh.defid_gen) 1097 error = ESTALE; 1098 if (error) { 1099 *vpp = NULLVP; 1100 return error; 1101 } 1102 error = msdosfs_deget(pmp, defh.defid_dirclust, defh.defid_dirofs, vpp); 1103 if (error) { 1104 DPRINTF("deget %d", error); 1105 *vpp = NULLVP; 1106 return error; 1107 } 1108 error = vn_lock(*vpp, lktype); 1109 if (error) { 1110 vrele(*vpp); 1111 *vpp = NULLVP; 1112 return error; 1113 } 1114 return 0; 1115 } 1116 1117 int 1118 msdosfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size) 1119 { 1120 struct msdosfsmount *pmp = VFSTOMSDOSFS(vp->v_mount); 1121 struct denode *dep; 1122 struct defid defh; 1123 int error; 1124 1125 if (*fh_size < sizeof(struct defid)) { 1126 *fh_size = sizeof(struct defid); 1127 return E2BIG; 1128 } 1129 *fh_size = sizeof(struct defid); 1130 dep = VTODE(vp); 1131 memset(&defh, 0, sizeof(defh)); 1132 defh.defid_len = sizeof(struct defid); 1133 defh.defid_dirclust = dep->de_dirclust; 1134 defh.defid_dirofs = dep->de_diroffset; 1135 error = msdosfs_fh_enter(pmp, dep->de_dirclust, dep->de_diroffset, 1136 &defh.defid_gen); 1137 if (error == 0) 1138 memcpy(fhp, &defh, sizeof(defh)); 1139 return error; 1140 } 1141 1142 int 1143 msdosfs_vget(struct mount *mp, ino_t ino, int lktype, 1144 struct vnode **vpp) 1145 { 1146 1147 return (EOPNOTSUPP); 1148 } 1149
Indexes created Wed Sep 24 22:09:59 GMT 2025