msdosfs_vfsops.c revision 1.7.4.3
1 /*- 2 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 3 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 4 * All rights reserved. 5 * Original code by Paul Popelka (paulp (at) uts.amdahl.com) (see below). 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by TooLs GmbH. 18 * 4. The name of TooLs GmbH may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 27 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 30 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 /* 33 * Written by Paul Popelka (paulp (at) uts.amdahl.com) 34 * 35 * You can do anything you want with this software, just don't say you wrote 36 * it, and don't remove this notice. 37 * 38 * This software is provided "as is". 39 * 40 * The author supplies this software to be publicly redistributed on the 41 * understanding that the author is not responsible for the correct 42 * functioning of this software in any circumstances and is not liable for 43 * any damages caused by this software. 44 * 45 * October 1992 46 */ 47 48 #if HAVE_NBTOOL_CONFIG_H 49 #include "nbtool_config.h" 50 #endif 51 52 #include <sys/cdefs.h> 53 __KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.7.4.3 2014/08/20 00:05:09 tls Exp $"); 54 55 #include <sys/param.h> 56 57 #include <ffs/buf.h> 58 59 #include <fs/msdosfs/bpb.h> 60 #include <fs/msdosfs/bootsect.h> 61 #include <fs/msdosfs/direntry.h> 62 #include <fs/msdosfs/denode.h> 63 #include <fs/msdosfs/msdosfsmount.h> 64 #include <fs/msdosfs/fat.h> 65 66 #include <stdio.h> 67 #include <errno.h> 68 #include <stdlib.h> 69 #include <string.h> 70 #include <util.h> 71 72 #include "makefs.h" 73 #include "msdos.h" 74 #include "mkfs_msdos.h" 75 76 #ifdef MSDOSFS_DEBUG 77 #define DPRINTF(a) printf a 78 #else 79 #define DPRINTF(a) 80 #endif 81 82 struct msdosfsmount * 83 msdosfs_mount(struct vnode *devvp, int flags) 84 { 85 struct msdosfsmount *pmp = NULL; 86 struct buf *bp; 87 union bootsector *bsp; 88 struct byte_bpb33 *b33; 89 struct byte_bpb50 *b50; 90 struct byte_bpb710 *b710; 91 uint8_t SecPerClust; 92 int ronly = 0, error, tmp; 93 int bsize; 94 struct msdos_options *m = devvp->fs->fs_specific; 95 uint64_t psize = m->create_size; 96 unsigned secsize = 512; 97 98 DPRINTF(("%s(bread 0)\n", __func__)); 99 if ((error = bread(devvp, 0, secsize, NULL, 0, &bp)) != 0) 100 goto error_exit; 101 102 bsp = (union bootsector *)bp->b_data; 103 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB; 104 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB; 105 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB; 106 107 if (!(flags & MSDOSFSMNT_GEMDOSFS)) { 108 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 109 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) { 110 DPRINTF(("bootsig0 %d bootsig1 %d\n", 111 bsp->bs50.bsBootSectSig0, 112 bsp->bs50.bsBootSectSig1)); 113 error = EINVAL; 114 goto error_exit; 115 } 116 bsize = 0; 117 } else 118 bsize = 512; 119 120 pmp = ecalloc(1, sizeof *pmp); 121 /* 122 * Compute several useful quantities from the bpb in the 123 * bootsector. Copy in the dos 5 variant of the bpb then fix up 124 * the fields that are different between dos 5 and dos 3.3. 125 */ 126 SecPerClust = b50->bpbSecPerClust; 127 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec); 128 pmp->pm_ResSectors = getushort(b50->bpbResSectors); 129 pmp->pm_FATs = b50->bpbFATs; 130 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts); 131 pmp->pm_Sectors = getushort(b50->bpbSectors); 132 pmp->pm_FATsecs = getushort(b50->bpbFATsecs); 133 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack); 134 pmp->pm_Heads = getushort(b50->bpbHeads); 135 pmp->pm_Media = b50->bpbMedia; 136 137 DPRINTF(("%s(BytesPerSec=%u, ResSectors=%u, FATs=%d, RootDirEnts=%u, " 138 "Sectors=%u, FATsecs=%lu, SecPerTrack=%u, Heads=%u, Media=%u)\n", 139 __func__, pmp->pm_BytesPerSec, pmp->pm_ResSectors, pmp->pm_FATs, 140 pmp->pm_RootDirEnts, pmp->pm_Sectors, pmp->pm_FATsecs, 141 pmp->pm_SecPerTrack, pmp->pm_Heads, pmp->pm_Media)); 142 if (!(flags & MSDOSFSMNT_GEMDOSFS)) { 143 /* XXX - We should probably check more values here */ 144 if (!pmp->pm_BytesPerSec || !SecPerClust 145 || pmp->pm_SecPerTrack > 63) { 146 DPRINTF(("bytespersec %d secperclust %d " 147 "secpertrack %d\n", 148 pmp->pm_BytesPerSec, SecPerClust, 149 pmp->pm_SecPerTrack)); 150 error = EINVAL; 151 goto error_exit; 152 } 153 } 154 155 if (pmp->pm_Sectors == 0) { 156 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs); 157 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors); 158 } else { 159 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs); 160 pmp->pm_HugeSectors = pmp->pm_Sectors; 161 } 162 163 if (pmp->pm_RootDirEnts == 0) { 164 unsigned short vers = getushort(b710->bpbFSVers); 165 /* 166 * Some say that bsBootSectSig[23] must be zero, but 167 * Windows does not require this and some digital cameras 168 * do not set these to zero. Therefore, do not insist. 169 */ 170 if (pmp->pm_Sectors || pmp->pm_FATsecs || vers) { 171 DPRINTF(("sectors %d fatsecs %lu vers %d\n", 172 pmp->pm_Sectors, pmp->pm_FATsecs, vers)); 173 error = EINVAL; 174 goto error_exit; 175 } 176 pmp->pm_fatmask = FAT32_MASK; 177 pmp->pm_fatmult = 4; 178 pmp->pm_fatdiv = 1; 179 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs); 180 181 /* mirrorring is enabled if the FATMIRROR bit is not set */ 182 if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0) 183 pmp->pm_flags |= MSDOSFS_FATMIRROR; 184 else 185 pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM; 186 } else 187 pmp->pm_flags |= MSDOSFS_FATMIRROR; 188 189 if (flags & MSDOSFSMNT_GEMDOSFS) { 190 if (FAT32(pmp)) { 191 DPRINTF(("FAT32 for GEMDOS\n")); 192 /* 193 * GEMDOS doesn't know FAT32. 194 */ 195 error = EINVAL; 196 goto error_exit; 197 } 198 199 /* 200 * Check a few values (could do some more): 201 * - logical sector size: power of 2, >= block size 202 * - sectors per cluster: power of 2, >= 1 203 * - number of sectors: >= 1, <= size of partition 204 */ 205 if ( (SecPerClust == 0) 206 || (SecPerClust & (SecPerClust - 1)) 207 || (pmp->pm_BytesPerSec < bsize) 208 || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1)) 209 || (pmp->pm_HugeSectors == 0) 210 || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize) 211 > psize)) { 212 DPRINTF(("consistency checks for GEMDOS\n")); 213 error = EINVAL; 214 goto error_exit; 215 } 216 /* 217 * XXX - Many parts of the msdosfs driver seem to assume that 218 * the number of bytes per logical sector (BytesPerSec) will 219 * always be the same as the number of bytes per disk block 220 * Let's pretend it is. 221 */ 222 tmp = pmp->pm_BytesPerSec / bsize; 223 pmp->pm_BytesPerSec = bsize; 224 pmp->pm_HugeSectors *= tmp; 225 pmp->pm_HiddenSects *= tmp; 226 pmp->pm_ResSectors *= tmp; 227 pmp->pm_Sectors *= tmp; 228 pmp->pm_FATsecs *= tmp; 229 SecPerClust *= tmp; 230 } 231 232 /* Check that fs has nonzero FAT size */ 233 if (pmp->pm_FATsecs == 0) { 234 DPRINTF(("FATsecs is 0\n")); 235 error = EINVAL; 236 goto error_exit; 237 } 238 239 pmp->pm_fatblk = pmp->pm_ResSectors; 240 if (FAT32(pmp)) { 241 pmp->pm_rootdirblk = getulong(b710->bpbRootClust); 242 pmp->pm_firstcluster = pmp->pm_fatblk 243 + (pmp->pm_FATs * pmp->pm_FATsecs); 244 pmp->pm_fsinfo = getushort(b710->bpbFSInfo); 245 } else { 246 pmp->pm_rootdirblk = pmp->pm_fatblk + 247 (pmp->pm_FATs * pmp->pm_FATsecs); 248 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry) 249 + pmp->pm_BytesPerSec - 1) 250 / pmp->pm_BytesPerSec;/* in sectors */ 251 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; 252 } 253 254 pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) / 255 SecPerClust; 256 pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1; 257 pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec; 258 259 if (flags & MSDOSFSMNT_GEMDOSFS) { 260 if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) { 261 pmp->pm_fatmask = FAT12_MASK; 262 pmp->pm_fatmult = 3; 263 pmp->pm_fatdiv = 2; 264 } else { 265 pmp->pm_fatmask = FAT16_MASK; 266 pmp->pm_fatmult = 2; 267 pmp->pm_fatdiv = 1; 268 } 269 } else if (pmp->pm_fatmask == 0) { 270 if (pmp->pm_maxcluster 271 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) { 272 /* 273 * This will usually be a floppy disk. This size makes 274 * sure that one FAT entry will not be split across 275 * multiple blocks. 276 */ 277 pmp->pm_fatmask = FAT12_MASK; 278 pmp->pm_fatmult = 3; 279 pmp->pm_fatdiv = 2; 280 } else { 281 pmp->pm_fatmask = FAT16_MASK; 282 pmp->pm_fatmult = 2; 283 pmp->pm_fatdiv = 1; 284 } 285 } 286 if (FAT12(pmp)) 287 pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec; 288 else 289 pmp->pm_fatblocksize = MAXBSIZE; 290 291 pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec; 292 pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1; 293 294 /* 295 * Compute mask and shift value for isolating cluster relative byte 296 * offsets and cluster numbers from a file offset. 297 */ 298 pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec; 299 pmp->pm_crbomask = pmp->pm_bpcluster - 1; 300 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1; 301 302 DPRINTF(("%s(fatmask=%lu, fatmult=%u, fatdiv=%u, fatblocksize=%lu, " 303 "fatblocksec=%lu, bnshift=%lu, pbcluster=%lu, crbomask=%lu, " 304 "cnshift=%lu)\n", 305 __func__, pmp->pm_fatmask, pmp->pm_fatmult, pmp->pm_fatdiv, 306 pmp->pm_fatblocksize, pmp->pm_fatblocksec, pmp->pm_bnshift, 307 pmp->pm_bpcluster, pmp->pm_crbomask, pmp->pm_cnshift)); 308 /* 309 * Check for valid cluster size 310 * must be a power of 2 311 */ 312 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) { 313 DPRINTF(("bpcluster %lu cnshift %lu\n", 314 pmp->pm_bpcluster, pmp->pm_cnshift)); 315 error = EINVAL; 316 goto error_exit; 317 } 318 319 /* 320 * Release the bootsector buffer. 321 */ 322 brelse(bp, BC_AGE); 323 bp = NULL; 324 325 /* 326 * Check FSInfo. 327 */ 328 if (pmp->pm_fsinfo) { 329 struct fsinfo *fp; 330 331 /* 332 * XXX If the fsinfo block is stored on media with 333 * 2KB or larger sectors, is the fsinfo structure 334 * padded at the end or in the middle? 335 */ 336 DPRINTF(("%s(bread %lu)\n", __func__, 337 (unsigned long)de_bn2kb(pmp, pmp->pm_fsinfo))); 338 if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo), 339 pmp->pm_BytesPerSec, NULL, 0, &bp)) != 0) 340 goto error_exit; 341 fp = (struct fsinfo *)bp->b_data; 342 if (!memcmp(fp->fsisig1, "RRaA", 4) 343 && !memcmp(fp->fsisig2, "rrAa", 4) 344 && !memcmp(fp->fsisig3, "\0\0\125\252", 4) 345 && !memcmp(fp->fsisig4, "\0\0\125\252", 4)) 346 pmp->pm_nxtfree = getulong(fp->fsinxtfree); 347 else 348 pmp->pm_fsinfo = 0; 349 brelse(bp, 0); 350 bp = NULL; 351 } 352 353 /* 354 * Check and validate (or perhaps invalidate?) the fsinfo structure? 355 * XXX 356 */ 357 if (pmp->pm_fsinfo) { 358 if ((pmp->pm_nxtfree == 0xffffffffUL) || 359 (pmp->pm_nxtfree > pmp->pm_maxcluster)) 360 pmp->pm_fsinfo = 0; 361 } 362 363 /* 364 * Allocate memory for the bitmap of allocated clusters, and then 365 * fill it in. 366 */ 367 pmp->pm_inusemap = ecalloc(sizeof(*pmp->pm_inusemap), 368 ((pmp->pm_maxcluster + N_INUSEBITS) / N_INUSEBITS)); 369 /* 370 * fillinusemap() needs pm_devvp. 371 */ 372 pmp->pm_dev = 0; 373 pmp->pm_devvp = devvp; 374 375 /* 376 * Have the inuse map filled in. 377 */ 378 if ((error = fillinusemap(pmp)) != 0) { 379 DPRINTF(("fillinusemap %d\n", error)); 380 goto error_exit; 381 } 382 383 /* 384 * Finish up. 385 */ 386 if (ronly) 387 pmp->pm_flags |= MSDOSFSMNT_RONLY; 388 else 389 pmp->pm_fmod = 1; 390 391 /* 392 * If we ever do quotas for DOS filesystems this would be a place 393 * to fill in the info in the msdosfsmount structure. You dolt, 394 * quotas on dos filesystems make no sense because files have no 395 * owners on dos filesystems. of course there is some empty space 396 * in the directory entry where we could put uid's and gid's. 397 */ 398 399 return pmp; 400 401 error_exit: 402 if (bp) 403 brelse(bp, BC_AGE); 404 if (pmp) { 405 if (pmp->pm_inusemap) 406 free(pmp->pm_inusemap); 407 free(pmp); 408 } 409 errno = error; 410 return NULL; 411 } 412 413 int 414 msdosfs_root(struct msdosfsmount *pmp, struct vnode *vp) { 415 struct denode *ndep; 416 int error; 417 418 *vp = *pmp->pm_devvp; 419 if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0) { 420 errno = error; 421 return -1; 422 } 423 vp->v_data = ndep; 424 return 0; 425 } 426
Indexes created Sat Oct 11 19:10:01 GMT 2025