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