1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 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@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@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 /* $NetBSD: msdosfs_vfsops.c,v 1.10 2016/01/30 09:59:27 mlelstv Exp $ */ 52 __FBSDID("$FreeBSD$"); 53 54 #include <sys/param.h> 55 #include <sys/mount.h> 56 57 #include <errno.h> 58 #include <stdbool.h> 59 #include <stdio.h> 60 #include <string.h> 61 #include <stdlib.h> 62 #include <util.h> 63 64 #include <vfs/msdosfs/bootsect.h> 65 #include <vfs/msdosfs/bpb.h> 66 #include "msdos/denode.h" 67 #include <vfs/msdosfs/fat.h> 68 #include <vfs/msdosfs/msdosfsmount.h> 69 70 #include <mkfs_msdos.h> 71 72 #include "makefs.h" 73 #include "msdos.h" 74 75 struct msdosfsmount * 76 m_msdosfs_mount(struct m_vnode *devvp) 77 { 78 struct msdosfsmount *pmp = NULL; 79 struct m_buf *bp; 80 union bootsector *bsp; 81 struct byte_bpb33 *b33; 82 struct byte_bpb50 *b50; 83 struct byte_bpb710 *b710; 84 uint8_t SecPerClust; 85 int ronly = 0, error; 86 int bsize; 87 unsigned secsize = 512; 88 89 MSDOSFS_DPRINTF(("%s(bread 0)\n", __func__)); 90 if ((error = bread((void *)devvp, 0, secsize, 0, &bp)) != 0) 91 goto error_exit; 92 93 bsp = (union bootsector *)bp->b_data; 94 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB; 95 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB; 96 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB; 97 98 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 || 99 bsp->bs50.bsBootSectSig1 != BOOTSIG1) { 100 MSDOSFS_DPRINTF(("bootsig0 %d bootsig1 %d\n", 101 bsp->bs50.bsBootSectSig0, 102 bsp->bs50.bsBootSectSig1)); 103 error = EINVAL; 104 goto error_exit; 105 } 106 bsize = 0; 107 108 pmp = ecalloc(1, sizeof(*pmp)); 109 /* 110 * Compute several useful quantities from the bpb in the 111 * bootsector. Copy in the dos 5 variant of the bpb then fix up 112 * the fields that are different between dos 5 and dos 3.3. 113 */ 114 SecPerClust = b50->bpbSecPerClust; 115 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec); 116 pmp->pm_ResSectors = getushort(b50->bpbResSectors); 117 pmp->pm_FATs = b50->bpbFATs; 118 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts); 119 pmp->pm_Sectors = getushort(b50->bpbSectors); 120 pmp->pm_FATsecs = getushort(b50->bpbFATsecs); 121 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack); 122 pmp->pm_Heads = getushort(b50->bpbHeads); 123 pmp->pm_Media = b50->bpbMedia; 124 125 MSDOSFS_DPRINTF(("%s(BytesPerSec=%u, ResSectors=%u, FATs=%d, " 126 "RootDirEnts=%u, Sectors=%u, FATsecs=%lu, SecPerTrack=%u, " 127 "Heads=%u, Media=%u)\n", 128 __func__, pmp->pm_BytesPerSec, pmp->pm_ResSectors, 129 pmp->pm_FATs, pmp->pm_RootDirEnts, pmp->pm_Sectors, 130 pmp->pm_FATsecs, pmp->pm_SecPerTrack, pmp->pm_Heads, 131 pmp->pm_Media)); 132 133 /* XXX - We should probably check more values here */ 134 if (!pmp->pm_BytesPerSec || !SecPerClust 135 || pmp->pm_SecPerTrack > 63) { 136 MSDOSFS_DPRINTF(("bytespersec %d secperclust %d " 137 "secpertrack %d\n", pmp->pm_BytesPerSec, 138 SecPerClust, pmp->pm_SecPerTrack)); 139 error = EINVAL; 140 goto error_exit; 141 } 142 143 if (pmp->pm_Sectors == 0) { 144 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs); 145 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors); 146 } else { 147 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs); 148 pmp->pm_HugeSectors = pmp->pm_Sectors; 149 } 150 151 pmp->pm_flags = 0; 152 if (pmp->pm_RootDirEnts == 0) { 153 unsigned short vers = getushort(b710->bpbFSVers); 154 /* 155 * Some say that bsBootSectSig[23] must be zero, but 156 * Windows does not require this and some digital cameras 157 * do not set these to zero. Therefore, do not insist. 158 */ 159 if (pmp->pm_Sectors || pmp->pm_FATsecs || vers) { 160 MSDOSFS_DPRINTF(("sectors %d fatsecs %lu vers %d\n", 161 pmp->pm_Sectors, pmp->pm_FATsecs, vers)); 162 error = EINVAL; 163 goto error_exit; 164 } 165 pmp->pm_fatmask = FAT32_MASK; 166 pmp->pm_fatmult = 4; 167 pmp->pm_fatdiv = 1; 168 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs); 169 170 /* mirrorring is enabled if the FATMIRROR bit is not set */ 171 if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0) 172 pmp->pm_flags |= MSDOSFS_FATMIRROR; 173 else 174 pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM; 175 } else 176 pmp->pm_flags |= MSDOSFS_FATMIRROR; 177 178 /* Check that fs has nonzero FAT size */ 179 if (pmp->pm_FATsecs == 0) { 180 MSDOSFS_DPRINTF(("FATsecs is 0\n")); 181 error = EINVAL; 182 goto error_exit; 183 } 184 185 pmp->pm_fatblk = pmp->pm_ResSectors; 186 if (FAT32(pmp)) { 187 pmp->pm_rootdirblk = getulong(b710->bpbRootClust); 188 pmp->pm_firstcluster = pmp->pm_fatblk 189 + (pmp->pm_FATs * pmp->pm_FATsecs); 190 pmp->pm_fsinfo = getushort(b710->bpbFSInfo); 191 } else { 192 pmp->pm_rootdirblk = pmp->pm_fatblk + 193 (pmp->pm_FATs * pmp->pm_FATsecs); 194 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry) 195 + pmp->pm_BytesPerSec - 1) 196 / pmp->pm_BytesPerSec;/* in sectors */ 197 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; 198 } 199 200 pmp->pm_maxcluster = ((pmp->pm_HugeSectors - pmp->pm_firstcluster) / 201 SecPerClust) + 1; 202 /* XXX unused + non existent in DragonFly */ 203 //pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec; 204 205 if (pmp->pm_fatmask == 0) { 206 if (pmp->pm_maxcluster 207 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) { 208 /* 209 * This will usually be a floppy disk. This size makes 210 * sure that one FAT entry will not be split across 211 * multiple blocks. 212 */ 213 pmp->pm_fatmask = FAT12_MASK; 214 pmp->pm_fatmult = 3; 215 pmp->pm_fatdiv = 2; 216 } else { 217 pmp->pm_fatmask = FAT16_MASK; 218 pmp->pm_fatmult = 2; 219 pmp->pm_fatdiv = 1; 220 } 221 } 222 if (FAT12(pmp)) 223 pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec; 224 else 225 pmp->pm_fatblocksize = MAXBSIZE; 226 227 pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec; 228 pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1; 229 230 /* 231 * Compute mask and shift value for isolating cluster relative byte 232 * offsets and cluster numbers from a file offset. 233 */ 234 pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec; 235 pmp->pm_crbomask = pmp->pm_bpcluster - 1; 236 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1; 237 238 MSDOSFS_DPRINTF(("%s(fatmask=%lu, fatmult=%u, fatdiv=%u, " 239 "fatblocksize=%lu, fatblocksec=%lu, bnshift=%lu, pbcluster=%lu, " 240 "crbomask=%lu, cnshift=%lu)\n", 241 __func__, (unsigned long)pmp->pm_fatmask, pmp->pm_fatmult, 242 pmp->pm_fatdiv, pmp->pm_fatblocksize, pmp->pm_fatblocksec, 243 pmp->pm_bnshift, pmp->pm_bpcluster, pmp->pm_crbomask, 244 pmp->pm_cnshift)); 245 /* 246 * Check for valid cluster size 247 * must be a power of 2 248 */ 249 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) { 250 MSDOSFS_DPRINTF(("bpcluster %lu cnshift %lu\n", 251 pmp->pm_bpcluster, pmp->pm_cnshift)); 252 error = EINVAL; 253 goto error_exit; 254 } 255 256 /* 257 * Release the bootsector buffer. 258 */ 259 brelse(bp); 260 bp = NULL; 261 262 /* 263 * Check FSInfo. 264 */ 265 if (pmp->pm_fsinfo) { 266 struct fsinfo *fp; 267 268 /* 269 * XXX If the fsinfo block is stored on media with 270 * 2KB or larger sectors, is the fsinfo structure 271 * padded at the end or in the middle? 272 */ 273 if ((error = bread((void *)devvp, pmp->pm_fsinfo, 274 pmp->pm_BytesPerSec, 0, &bp)) != 0) 275 goto error_exit; 276 fp = (struct fsinfo *)bp->b_data; 277 if (!memcmp(fp->fsisig1, "RRaA", 4) 278 && !memcmp(fp->fsisig2, "rrAa", 4) 279 && !memcmp(fp->fsisig3, "\0\0\125\252", 4)) 280 pmp->pm_nxtfree = getulong(fp->fsinxtfree); 281 else 282 pmp->pm_fsinfo = 0; 283 brelse(bp); 284 bp = NULL; 285 } 286 287 /* 288 * Check and validate (or perhaps invalidate?) the fsinfo structure? 289 * XXX 290 */ 291 if (pmp->pm_fsinfo) { 292 if ((pmp->pm_nxtfree == 0xffffffffUL) || 293 (pmp->pm_nxtfree > pmp->pm_maxcluster)) 294 pmp->pm_fsinfo = 0; 295 } 296 297 /* 298 * Allocate memory for the bitmap of allocated clusters, and then 299 * fill it in. 300 */ 301 pmp->pm_inusemap = ecalloc(sizeof(*pmp->pm_inusemap), 302 ((pmp->pm_maxcluster + N_INUSEBITS) / N_INUSEBITS)); 303 /* 304 * fillinusemap() needs pm_devvp. 305 */ 306 /* XXX unused + not compiled when MAKEFS in DragonFly */ 307 //pmp->pm_dev = 0; 308 pmp->pm_devvp = (void *)devvp; 309 310 /* 311 * Have the inuse map filled in. 312 */ 313 if ((error = fillinusemap(pmp)) != 0) { 314 MSDOSFS_DPRINTF(("fillinusemap %d\n", error)); 315 goto error_exit; 316 } 317 318 /* 319 * Finish up. 320 */ 321 if (ronly) 322 pmp->pm_flags |= MSDOSFSMNT_RONLY; 323 else 324 pmp->pm_fmod = 1; 325 326 /* 327 * If we ever do quotas for DOS filesystems this would be a place 328 * to fill in the info in the msdosfsmount structure. You dolt, 329 * quotas on dos filesystems make no sense because files have no 330 * owners on dos filesystems. of course there is some empty space 331 * in the directory entry where we could put uid's and gid's. 332 */ 333 334 return pmp; 335 336 error_exit: 337 if (bp) 338 brelse(bp); 339 if (pmp) { 340 if (pmp->pm_inusemap) 341 free(pmp->pm_inusemap); 342 free(pmp); 343 } 344 errno = error; 345 return NULL; 346 } 347 348 int 349 msdosfs_root(struct msdosfsmount *pmp, struct m_vnode *vp) { 350 struct denode *ndep; 351 int error; 352 353 *vp = *(struct m_vnode *)pmp->pm_devvp; 354 if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0) { 355 errno = error; 356 return -1; 357 } 358 vp->v_data = ndep; 359 return 0; 360 } 361 362 /* 363 * If we have an FSInfo block, update it. 364 */ 365 int 366 msdosfs_fsiflush(struct msdosfsmount *pmp) 367 { 368 struct fsinfo *fp; 369 struct m_buf *bp; 370 int error; 371 372 if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) { 373 error = 0; 374 goto out; 375 } 376 error = bread((void *)pmp->pm_devvp, pmp->pm_fsinfo, 377 pmp->pm_BytesPerSec, NOCRED, &bp); 378 if (error != 0) { 379 brelse(bp); 380 goto out; 381 } 382 fp = (struct fsinfo *)bp->b_data; 383 putulong(fp->fsinfree, pmp->pm_freeclustercount); 384 putulong(fp->fsinxtfree, pmp->pm_nxtfree); 385 pmp->pm_flags &= ~MSDOSFS_FSIMOD; 386 error = bwrite(bp); 387 388 out: 389 return (error); 390 } 391