| File: | src/usr.sbin/makefs/msdos/msdosfs_fat.c |
| Warning: | line 875, column 13 Access to field 'b_data' results in a dereference of a null pointer (loaded from variable 'bp') |
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| 1 | /* $OpenBSD: msdosfs_fat.c,v 1.7 2022/01/11 05:34:33 jsg Exp $ */ | |||
| 2 | /* $NetBSD: msdosfs_fat.c,v 1.31 2016/05/07 16:43:02 mlelstv Exp $ */ | |||
| 3 | ||||
| 4 | /*- | |||
| 5 | * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. | |||
| 6 | * Copyright (C) 1994, 1995, 1997 TooLs GmbH. | |||
| 7 | * All rights reserved. | |||
| 8 | * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). | |||
| 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 TooLs GmbH. | |||
| 21 | * 4. The name of TooLs GmbH may not be used to endorse or promote products | |||
| 22 | * derived from this software without specific prior written permission. | |||
| 23 | * | |||
| 24 | * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR | |||
| 25 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |||
| 26 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |||
| 27 | * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |||
| 28 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |||
| 29 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; | |||
| 30 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |||
| 31 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR | |||
| 32 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF | |||
| 33 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |||
| 34 | */ | |||
| 35 | /* | |||
| 36 | * Written by Paul Popelka (paulp@uts.amdahl.com) | |||
| 37 | * | |||
| 38 | * You can do anything you want with this software, just don't say you wrote | |||
| 39 | * it, and don't remove this notice. | |||
| 40 | * | |||
| 41 | * This software is provided "as is". | |||
| 42 | * | |||
| 43 | * The author supplies this software to be publicly redistributed on the | |||
| 44 | * understanding that the author is not responsible for the correct | |||
| 45 | * functioning of this software in any circumstances and is not liable for | |||
| 46 | * any damages caused by this software. | |||
| 47 | * | |||
| 48 | * October 1992 | |||
| 49 | */ | |||
| 50 | ||||
| 51 | #include <sys/types.h> | |||
| 52 | #include <sys/time.h> | |||
| 53 | ||||
| 54 | /* | |||
| 55 | * kernel include files. | |||
| 56 | */ | |||
| 57 | ||||
| 58 | #include "ffs/buf.h" | |||
| 59 | ||||
| 60 | /* | |||
| 61 | * msdosfs include files. | |||
| 62 | */ | |||
| 63 | #include <msdosfs/bpb.h> | |||
| 64 | #include "msdos/msdosfsmount.h" | |||
| 65 | #include "msdos/direntry.h" | |||
| 66 | #include "msdos/denode.h" | |||
| 67 | #include "msdos/fat.h" | |||
| 68 | #include "makefs.h" | |||
| 69 | ||||
| 70 | /* | |||
| 71 | * Fat cache stats. | |||
| 72 | */ | |||
| 73 | int fc_fileextends; /* # of file extends */ | |||
| 74 | int fc_lfcempty; /* # of time last file cluster cache entry | |||
| 75 | * was empty */ | |||
| 76 | int fc_bmapcalls; /* # of times pcbmap was called */ | |||
| 77 | ||||
| 78 | #define LMMAX20 20 | |||
| 79 | int fc_lmdistance[LMMAX20]; /* counters for how far off the last | |||
| 80 | * cluster mapped entry was. */ | |||
| 81 | int fc_largedistance; /* off by more than LMMAX */ | |||
| 82 | int fc_wherefrom, fc_whereto, fc_lastclust; | |||
| 83 | int pm_fatblocksize; | |||
| 84 | ||||
| 85 | #ifdef MSDOSFS_DEBUG | |||
| 86 | #define DPRINTF(a) printf a | |||
| 87 | #else | |||
| 88 | #define DPRINTF(a) | |||
| 89 | #endif | |||
| 90 | ||||
| 91 | static void fatblock(struct msdosfsmount *, u_long, u_long *, u_long *, | |||
| 92 | u_long *); | |||
| 93 | void updatefats(struct msdosfsmount *, struct mkfsbuf *, u_long); | |||
| 94 | static inline void usemap_free(struct msdosfsmount *, u_long); | |||
| 95 | static inline void usemap_alloc(struct msdosfsmount *, u_long); | |||
| 96 | static int fatchain(struct msdosfsmount *, u_long, u_long, u_long); | |||
| 97 | int chainlength(struct msdosfsmount *, u_long, u_long); | |||
| 98 | int chainalloc(struct msdosfsmount *, u_long, u_long, u_long, u_long *, | |||
| 99 | u_long *); | |||
| 100 | ||||
| 101 | static void | |||
| 102 | fatblock(struct msdosfsmount *pmp, u_long ofs, u_long *bnp, u_long *sizep, u_long *bop) | |||
| 103 | { | |||
| 104 | u_long bn, size; | |||
| 105 | ||||
| 106 | bn = ofs / pmp->pm_fatblocksize * pmp->pm_fatblocksec; | |||
| 107 | size = MINIMUM(pmp->pm_fatblocksec, pmp->pm_FATsecs - bn)(((pmp->pm_fatblocksec) < (pmp->pm_FATsecs - bn)) ? ( pmp->pm_fatblocksec) : (pmp->pm_FATsecs - bn)) | |||
| 108 | * pmp->pm_BytesPerSecpm_bpb.bpbBytesPerSec; | |||
| 109 | bn += pmp->pm_fatblk + pmp->pm_curfat * pmp->pm_FATsecs; | |||
| 110 | ||||
| 111 | DPRINTF(("%s(ofs=%lu bn=%lu, size=%lu, bo=%lu)\n", __func__, ofs, bn, | |||
| 112 | size, ofs % pmp->pm_fatblocksize)); | |||
| 113 | if (bnp
| |||
| 114 | *bnp = bn; | |||
| 115 | if (sizep
| |||
| 116 | *sizep = size; | |||
| 117 | if (bop
| |||
| 118 | *bop = ofs % pmp->pm_fatblocksize; | |||
| 119 | ||||
| 120 | pm_fatblocksize = pmp->pm_fatblocksize; | |||
| 121 | } | |||
| 122 | ||||
| 123 | /* | |||
| 124 | * Map the logical cluster number of a file into a physical disk sector | |||
| 125 | * that is filesystem relative. | |||
| 126 | * | |||
| 127 | * dep - address of denode representing the file of interest | |||
| 128 | * findcn - file relative cluster whose filesystem relative cluster number | |||
| 129 | * and/or block number are/is to be found | |||
| 130 | * bnp - address of where to place the file system relative block number. | |||
| 131 | * If this pointer is null then don't return this quantity. | |||
| 132 | * cnp - address of where to place the file system relative cluster number. | |||
| 133 | * If this pointer is null then don't return this quantity. | |||
| 134 | * | |||
| 135 | * NOTE: Either bnp or cnp must be non-null. | |||
| 136 | * This function has one side effect. If the requested file relative cluster | |||
| 137 | * is beyond the end of file, then the actual number of clusters in the file | |||
| 138 | * is returned in *cnp. This is useful for determining how long a directory is. | |||
| 139 | * If cnp is null, nothing is returned. | |||
| 140 | */ | |||
| 141 | int | |||
| 142 | pcbmap(struct denode *dep, u_long findcn, daddr_t *bnp, u_long *cnp, int *sp) | |||
| 143 | /* findcn: file relative cluster to get */ | |||
| 144 | /* bnp: returned filesys rel sector number */ | |||
| 145 | /* cnp: returned cluster number */ | |||
| 146 | /* sp: returned block size */ | |||
| 147 | { | |||
| 148 | int error; | |||
| 149 | u_long i; | |||
| 150 | u_long cn; | |||
| 151 | u_long prevcn = 0; /* XXX: prevcn could be used uninitialized */ | |||
| 152 | u_long byteoffset; | |||
| 153 | u_long bn; | |||
| 154 | u_long bo; | |||
| 155 | struct mkfsbuf *bp = NULL((void*)0); | |||
| 156 | u_long bp_bn = -1; | |||
| 157 | struct msdosfsmount *pmp = dep->de_pmp; | |||
| 158 | u_long bsize; | |||
| 159 | ||||
| 160 | fc_bmapcalls++; | |||
| 161 | ||||
| 162 | /* | |||
| 163 | * If they don't give us someplace to return a value then don't | |||
| 164 | * bother doing anything. | |||
| 165 | */ | |||
| 166 | if (bnp == NULL((void*)0) && cnp == NULL((void*)0) && sp == NULL((void*)0)) | |||
| 167 | return (0); | |||
| 168 | ||||
| 169 | cn = dep->de_StartCluster; | |||
| 170 | DPRINTF(("%s(start cluster=%lu)\n", __func__, cn)); | |||
| 171 | /* | |||
| 172 | * The "file" that makes up the root directory is contiguous, | |||
| 173 | * permanently allocated, of fixed size, and is not made up of | |||
| 174 | * clusters. If the cluster number is beyond the end of the root | |||
| 175 | * directory, then return the number of clusters in the file. | |||
| 176 | */ | |||
| 177 | if (cn == MSDOSFSROOT0) { | |||
| 178 | if (dep->de_Attributes & ATTR_DIRECTORY0x10) { | |||
| 179 | if (de_cn2off(pmp, findcn)((findcn) << (pmp)->pm_cnshift) >= dep->de_FileSize) { | |||
| 180 | if (cnp) | |||
| 181 | *cnp = de_bn2cn(pmp, pmp->pm_rootdirsize)((pmp->pm_rootdirsize) >> ((pmp)->pm_cnshift - (pmp )->pm_bnshift)); | |||
| 182 | DPRINTF(("%s(root, %lu ETOOBIG)\n", __func__, | |||
| 183 | de_cn2off(pmp, findcn))); | |||
| 184 | return (E2BIG7); | |||
| 185 | } | |||
| 186 | if (bnp) | |||
| 187 | *bnp = pmp->pm_rootdirblk + de_cn2bn(pmp, findcn)((findcn) << ((pmp)->pm_cnshift - (pmp)->pm_bnshift )); | |||
| 188 | if (cnp) | |||
| 189 | *cnp = MSDOSFSROOT0; | |||
| 190 | if (sp) | |||
| 191 | *sp = MINIMUM(pmp->pm_bpcluster,(((pmp->pm_bpcluster) < (dep->de_FileSize - ((findcn ) << (pmp)->pm_cnshift))) ? (pmp->pm_bpcluster) : (dep->de_FileSize - ((findcn) << (pmp)->pm_cnshift ))) | |||
| 192 | dep->de_FileSize - de_cn2off(pmp, findcn))(((pmp->pm_bpcluster) < (dep->de_FileSize - ((findcn ) << (pmp)->pm_cnshift))) ? (pmp->pm_bpcluster) : (dep->de_FileSize - ((findcn) << (pmp)->pm_cnshift ))); | |||
| 193 | DPRINTF(("%s(root, bn=%lu, cn=%u)\n", __func__, | |||
| 194 | pmp->pm_rootdirblk + de_cn2bn(pmp, findcn), | |||
| 195 | MSDOSFSROOT)); | |||
| 196 | return (0); | |||
| 197 | } else { /* just an empty file */ | |||
| 198 | if (cnp) | |||
| 199 | *cnp = 0; | |||
| 200 | DPRINTF(("%s(root, empty ETOOBIG)\n", __func__)); | |||
| 201 | return (E2BIG7); | |||
| 202 | } | |||
| 203 | } | |||
| 204 | ||||
| 205 | /* | |||
| 206 | * All other files do I/O in cluster sized blocks | |||
| 207 | */ | |||
| 208 | if (sp) | |||
| 209 | *sp = pmp->pm_bpcluster; | |||
| 210 | ||||
| 211 | /* | |||
| 212 | * Rummage around in the FAT cache, maybe we can avoid tromping | |||
| 213 | * thru every FAT entry for the file. And, keep track of how far | |||
| 214 | * off the cache was from where we wanted to be. | |||
| 215 | */ | |||
| 216 | i = 0; | |||
| 217 | fc_lookup(dep, findcn, &i, &cn); | |||
| 218 | DPRINTF(("%s(bpcluster=%lu i=%lu cn=%lu\n", __func__, pmp->pm_bpcluster, | |||
| 219 | i, cn)); | |||
| 220 | if ((bn = findcn - i) >= LMMAX20) { | |||
| 221 | fc_largedistance++; | |||
| 222 | fc_wherefrom = i; | |||
| 223 | fc_whereto = findcn; | |||
| 224 | fc_lastclust = dep->de_fc[FC_LASTFC1].fc_frcn; | |||
| 225 | } else | |||
| 226 | fc_lmdistance[bn]++; | |||
| 227 | ||||
| 228 | /* | |||
| 229 | * Handle all other files or directories the normal way. | |||
| 230 | */ | |||
| 231 | for (; i < findcn; i++) { | |||
| 232 | /* | |||
| 233 | * Stop with all reserved clusters, not just with EOF. | |||
| 234 | */ | |||
| 235 | if (cn >= (CLUST_RSRVD0xfffffff6 & pmp->pm_fatmask)) | |||
| 236 | goto hiteof; | |||
| 237 | ||||
| 238 | /* | |||
| 239 | * Also stop when cluster is not in the filesystem | |||
| 240 | */ | |||
| 241 | if (cn < CLUST_FIRST2 || cn > pmp->pm_maxcluster) { | |||
| 242 | DPRINTF(("%s(cn, %lu not in %lu..%lu)\n", __func__, | |||
| 243 | cn, (u_long)CLUST_FIRST, pmp->pm_maxcluster)); | |||
| 244 | if (bp) | |||
| 245 | brelse(bp, 0); | |||
| 246 | return (EINVAL22); | |||
| 247 | } | |||
| 248 | ||||
| 249 | byteoffset = FATOFS(pmp, cn)((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv); | |||
| 250 | fatblock(pmp, byteoffset, &bn, &bsize, &bo); | |||
| 251 | if (bn != bp_bn) { | |||
| 252 | if (bp) | |||
| 253 | brelse(bp, 0); | |||
| 254 | error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), bsize, | |||
| 255 | 0, &bp); | |||
| 256 | if (error) { | |||
| 257 | DPRINTF(("%s(bread, %d)\n", __func__, error)); | |||
| 258 | return (error); | |||
| 259 | } | |||
| 260 | bp_bn = bn; | |||
| 261 | } | |||
| 262 | prevcn = cn; | |||
| 263 | if (bo >= bsize) { | |||
| 264 | if (bp) | |||
| 265 | brelse(bp, 0); | |||
| 266 | DPRINTF(("%s(block, %lu >= %lu)\n", __func__, bo, | |||
| 267 | bsize)); | |||
| 268 | return (EIO5); | |||
| 269 | } | |||
| 270 | KASSERT(bp != NULL); | |||
| 271 | if (FAT32(pmp)(pmp->pm_fatmask == 0x0fffffff)) | |||
| 272 | cn = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 273 | else | |||
| 274 | cn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 275 | if (FAT12(pmp)(pmp->pm_fatmask == 0x00000fff) && (prevcn & 1)) | |||
| 276 | cn >>= 4; | |||
| 277 | DPRINTF(("%s(cn=%lu masked=%lu)\n", __func__, cn, | |||
| 278 | cn & pmp->pm_fatmask)); | |||
| 279 | cn &= pmp->pm_fatmask; | |||
| 280 | } | |||
| 281 | ||||
| 282 | if (!MSDOSFSEOF(cn, pmp->pm_fatmask)(((cn) & 0xfffffff8) == (0xfffffff8 & (pmp->pm_fatmask )))) { | |||
| 283 | if (bp) | |||
| 284 | brelse(bp, 0); | |||
| 285 | if (bnp) | |||
| 286 | *bnp = cntobn(pmp, cn)((((cn)-2) << (((pmp))->pm_cnshift - ((pmp))->pm_bnshift )) + (pmp)->pm_firstcluster); | |||
| 287 | if (cnp) | |||
| 288 | *cnp = cn; | |||
| 289 | DPRINTF(("%s(bn=%lu, cn=%lu)\n", __func__, cntobn(pmp, cn), | |||
| 290 | cn)); | |||
| 291 | fc_setcache(dep, FC_LASTMAP, i, cn)(dep)->de_fc[0].fc_frcn = i; (dep)->de_fc[0].fc_fsrcn = cn;; | |||
| 292 | return (0); | |||
| 293 | } | |||
| 294 | ||||
| 295 | hiteof:; | |||
| 296 | if (cnp) | |||
| 297 | *cnp = i; | |||
| 298 | if (bp) | |||
| 299 | brelse(bp, 0); | |||
| 300 | /* update last file cluster entry in the FAT cache */ | |||
| 301 | fc_setcache(dep, FC_LASTFC, i - 1, prevcn)(dep)->de_fc[1].fc_frcn = i - 1; (dep)->de_fc[1].fc_fsrcn = prevcn;; | |||
| 302 | DPRINTF(("%s(eof, %lu)\n", __func__, i)); | |||
| 303 | return (E2BIG7); | |||
| 304 | } | |||
| 305 | ||||
| 306 | /* | |||
| 307 | * Find the closest entry in the FAT cache to the cluster we are looking | |||
| 308 | * for. | |||
| 309 | */ | |||
| 310 | void | |||
| 311 | fc_lookup(struct denode *dep, u_long findcn, u_long *frcnp, u_long *fsrcnp) | |||
| 312 | { | |||
| 313 | int i; | |||
| 314 | u_long cn; | |||
| 315 | struct fatcache *closest = 0; | |||
| 316 | ||||
| 317 | for (i = 0; i < FC_SIZE3; i++) { | |||
| 318 | cn = dep->de_fc[i].fc_frcn; | |||
| 319 | if (cn != FCE_EMPTY0xffffffff && cn <= findcn) { | |||
| 320 | if (closest == 0 || cn > closest->fc_frcn) | |||
| 321 | closest = &dep->de_fc[i]; | |||
| 322 | } | |||
| 323 | } | |||
| 324 | if (closest) { | |||
| 325 | *frcnp = closest->fc_frcn; | |||
| 326 | *fsrcnp = closest->fc_fsrcn; | |||
| 327 | } | |||
| 328 | } | |||
| 329 | ||||
| 330 | /* | |||
| 331 | * Purge the FAT cache in denode dep of all entries relating to file | |||
| 332 | * relative cluster frcn and beyond. | |||
| 333 | */ | |||
| 334 | void | |||
| 335 | fc_purge(struct denode *dep, u_int frcn) | |||
| 336 | { | |||
| 337 | int i; | |||
| 338 | struct fatcache *fcp; | |||
| 339 | ||||
| 340 | fcp = dep->de_fc; | |||
| 341 | for (i = 0; i < FC_SIZE3; i++, fcp++) { | |||
| 342 | if (fcp->fc_frcn >= frcn) | |||
| 343 | fcp->fc_frcn = FCE_EMPTY0xffffffff; | |||
| 344 | } | |||
| 345 | } | |||
| 346 | ||||
| 347 | /* | |||
| 348 | * Update the FAT. | |||
| 349 | * If mirroring the FAT, update all copies, with the first copy as last. | |||
| 350 | * Else update only the current FAT (ignoring the others). | |||
| 351 | * | |||
| 352 | * pmp - msdosfsmount structure for filesystem to update | |||
| 353 | * bp - addr of modified FAT block | |||
| 354 | * fatbn - block number relative to begin of filesystem of the modified FAT block. | |||
| 355 | */ | |||
| 356 | void | |||
| 357 | updatefats(struct msdosfsmount *pmp, struct mkfsbuf *bp, u_long fatbn) | |||
| 358 | { | |||
| 359 | int i, error; | |||
| 360 | struct mkfsbuf *bpn; | |||
| 361 | ||||
| 362 | DPRINTF(("%s(pmp %p, bp %p, fatbn %lu)\n", __func__, pmp, bp, fatbn)); | |||
| 363 | ||||
| 364 | /* | |||
| 365 | * If we have an FSInfo block, update it. | |||
| 366 | */ | |||
| 367 | if (pmp->pm_fsinfo) { | |||
| 368 | u_long cn = pmp->pm_nxtfree; | |||
| 369 | ||||
| 370 | if (pmp->pm_freeclustercount | |||
| 371 | && (pmp->pm_inusemap[cn / N_INUSEBITS(8 * sizeof(u_int))] | |||
| 372 | & (1 << (cn % N_INUSEBITS(8 * sizeof(u_int)))))) { | |||
| 373 | /* | |||
| 374 | * The cluster indicated in FSInfo isn't free | |||
| 375 | * any longer. Got get a new free one. | |||
| 376 | */ | |||
| 377 | for (cn = 0; cn < pmp->pm_maxcluster; cn++) | |||
| 378 | if (pmp->pm_inusemap[cn / N_INUSEBITS(8 * sizeof(u_int))] != (u_int)-1) | |||
| 379 | break; | |||
| 380 | pmp->pm_nxtfree = cn | |||
| 381 | + ffs(pmp->pm_inusemap[cn / N_INUSEBITS(8 * sizeof(u_int))] | |||
| 382 | ^ (u_int)-1) - 1; | |||
| 383 | } | |||
| 384 | /* | |||
| 385 | * XXX If the fsinfo block is stored on media with | |||
| 386 | * 2KB or larger sectors, is the fsinfo structure | |||
| 387 | * padded at the end or in the middle? | |||
| 388 | */ | |||
| 389 | if (bread(pmp->pm_devvp, de_bn2kb(pmp, pmp->pm_fsinfo)((pmp->pm_fsinfo) << ((pmp)->pm_bnshift - 9)), | |||
| 390 | pmp->pm_BytesPerSecpm_bpb.bpbBytesPerSec, B_MODIFY0, &bpn) != 0) { | |||
| 391 | /* | |||
| 392 | * Ignore the error, but turn off FSInfo update for the future. | |||
| 393 | */ | |||
| 394 | pmp->pm_fsinfo = 0; | |||
| 395 | } else { | |||
| 396 | struct fsinfo *fp = (struct fsinfo *)bpn->b_data; | |||
| 397 | ||||
| 398 | putulong(fp->fsinfree, pmp->pm_freeclustercount)(*((u_int32_t *)(fp->fsinfree)) = (pmp->pm_freeclustercount )); | |||
| 399 | putulong(fp->fsinxtfree, pmp->pm_nxtfree)(*((u_int32_t *)(fp->fsinxtfree)) = (pmp->pm_nxtfree)); | |||
| 400 | if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT0x40000000) | |||
| 401 | bwrite(bpn); | |||
| 402 | else | |||
| 403 | bdwrite(bpn)bwrite(bpn); | |||
| 404 | } | |||
| 405 | } | |||
| 406 | ||||
| 407 | if (pmp->pm_flags & MSDOSFS_FATMIRROR0x20000000) { | |||
| 408 | /* | |||
| 409 | * Now copy the block(s) of the modified FAT to the other copies of | |||
| 410 | * the FAT and write them out. This is faster than reading in the | |||
| 411 | * other FATs and then writing them back out. This could tie up | |||
| 412 | * the FAT for quite a while. Preventing others from accessing it. | |||
| 413 | * To prevent us from going after the FAT quite so much we use | |||
| 414 | * delayed writes, unless they specified "synchronous" when the | |||
| 415 | * filesystem was mounted. If synch is asked for then use | |||
| 416 | * bwrite()'s and really slow things down. | |||
| 417 | */ | |||
| 418 | for (i = 1; i < pmp->pm_FATspm_bpb.bpbFATs; i++) { | |||
| 419 | fatbn += pmp->pm_FATsecs; | |||
| 420 | /* getblk() never fails */ | |||
| 421 | bpn = getblk(pmp->pm_devvp, de_bn2kb(pmp, fatbn)((fatbn) << ((pmp)->pm_bnshift - 9)), | |||
| 422 | bp->b_bcount, 0, 0); | |||
| 423 | memcpy(bpn->b_data, bp->b_data, bp->b_bcount); | |||
| 424 | if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT0x40000000) { | |||
| 425 | error = bwrite(bpn); | |||
| 426 | if (error) | |||
| 427 | printf("%s: copy FAT %d (error=%d)\n", | |||
| 428 | __func__, i, error); | |||
| 429 | } else | |||
| 430 | bdwrite(bpn)bwrite(bpn); | |||
| 431 | } | |||
| 432 | } | |||
| 433 | ||||
| 434 | /* | |||
| 435 | * Write out the first (or current) FAT last. | |||
| 436 | */ | |||
| 437 | if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT0x40000000) { | |||
| 438 | error = bwrite(bp); | |||
| 439 | if (error) | |||
| 440 | printf("%s: write FAT (error=%d)\n", | |||
| 441 | __func__, error); | |||
| 442 | } else | |||
| 443 | bdwrite(bp)bwrite(bp); | |||
| 444 | /* | |||
| 445 | * Maybe update fsinfo sector here? | |||
| 446 | */ | |||
| 447 | } | |||
| 448 | ||||
| 449 | /* | |||
| 450 | * Updating entries in 12 bit FATs is a pain in the butt. | |||
| 451 | * | |||
| 452 | * The following picture shows where nibbles go when moving from a 12 bit | |||
| 453 | * cluster number into the appropriate bytes in the FAT. | |||
| 454 | * | |||
| 455 | * byte m byte m+1 byte m+2 | |||
| 456 | * +----+----+ +----+----+ +----+----+ | |||
| 457 | * | 0 1 | | 2 3 | | 4 5 | FAT bytes | |||
| 458 | * +----+----+ +----+----+ +----+----+ | |||
| 459 | * | |||
| 460 | * +----+----+----+ +----+----+----+ | |||
| 461 | * | 3 0 1 | | 4 5 2 | | |||
| 462 | * +----+----+----+ +----+----+----+ | |||
| 463 | * cluster n cluster n+1 | |||
| 464 | * | |||
| 465 | * Where n is even. m = n + (n >> 2) | |||
| 466 | * | |||
| 467 | */ | |||
| 468 | static inline void | |||
| 469 | usemap_alloc(struct msdosfsmount *pmp, u_long cn) | |||
| 470 | { | |||
| 471 | ||||
| 472 | pmp->pm_inusemap[cn / N_INUSEBITS(8 * sizeof(u_int))] |= 1 << (cn % N_INUSEBITS(8 * sizeof(u_int))); | |||
| 473 | pmp->pm_freeclustercount--; | |||
| 474 | } | |||
| 475 | ||||
| 476 | static inline void | |||
| 477 | usemap_free(struct msdosfsmount *pmp, u_long cn) | |||
| 478 | { | |||
| 479 | ||||
| 480 | pmp->pm_freeclustercount++; | |||
| 481 | pmp->pm_inusemap[cn / N_INUSEBITS(8 * sizeof(u_int))] &= ~(1 << (cn % N_INUSEBITS(8 * sizeof(u_int)))); | |||
| 482 | } | |||
| 483 | ||||
| 484 | int | |||
| 485 | clusterfree(struct msdosfsmount *pmp, u_long cluster, u_long *oldcnp) | |||
| 486 | { | |||
| 487 | int error; | |||
| 488 | u_long oldcn; | |||
| 489 | ||||
| 490 | usemap_free(pmp, cluster); | |||
| 491 | error = fatentry(FAT_GET_AND_SET(0x0001 | 0x0002), pmp, cluster, &oldcn, MSDOSFSFREE0); | |||
| 492 | if (error) { | |||
| 493 | usemap_alloc(pmp, cluster); | |||
| 494 | return (error); | |||
| 495 | } | |||
| 496 | /* | |||
| 497 | * If the cluster was successfully marked free, then update | |||
| 498 | * the count of free clusters, and turn off the "allocated" | |||
| 499 | * bit in the "in use" cluster bit map. | |||
| 500 | */ | |||
| 501 | if (oldcnp) | |||
| 502 | *oldcnp = oldcn; | |||
| 503 | return (0); | |||
| 504 | } | |||
| 505 | ||||
| 506 | /* | |||
| 507 | * Get or Set or 'Get and Set' the cluster'th entry in the FAT. | |||
| 508 | * | |||
| 509 | * function - whether to get or set a fat entry | |||
| 510 | * pmp - address of the msdosfsmount structure for the filesystem | |||
| 511 | * whose FAT is to be manipulated. | |||
| 512 | * cn - which cluster is of interest | |||
| 513 | * oldcontents - address of a word that is to receive the contents of the | |||
| 514 | * cluster'th entry if this is a get function | |||
| 515 | * newcontents - the new value to be written into the cluster'th element of | |||
| 516 | * the FAT if this is a set function. | |||
| 517 | * | |||
| 518 | * This function can also be used to free a cluster by setting the FAT entry | |||
| 519 | * for a cluster to 0. | |||
| 520 | * | |||
| 521 | * All copies of the FAT are updated if this is a set function. NOTE: If | |||
| 522 | * fatentry() marks a cluster as free it does not update the inusemap in | |||
| 523 | * the msdosfsmount structure. This is left to the caller. | |||
| 524 | */ | |||
| 525 | int | |||
| 526 | fatentry(int function, struct msdosfsmount *pmp, u_long cn, u_long *oldcontents, u_long newcontents) | |||
| 527 | { | |||
| 528 | int error; | |||
| 529 | u_long readcn; | |||
| 530 | u_long bn, bo, bsize, byteoffset; | |||
| 531 | struct mkfsbuf *bp; | |||
| 532 | ||||
| 533 | DPRINTF(("%s(func %d, pmp %p, clust %lu, oldcon %p, newcon " "%lx)\n", | |||
| 534 | __func__, function, pmp, cn, oldcontents, newcontents)); | |||
| 535 | ||||
| 536 | #ifdef DIAGNOSTIC | |||
| 537 | /* | |||
| 538 | * Be sure they asked us to do something. | |||
| 539 | */ | |||
| 540 | if ((function & (FAT_SET0x0002 | FAT_GET0x0001)) == 0) { | |||
| 541 | DPRINTF(("%s(): function code doesn't specify get or set\n", | |||
| 542 | __func__)); | |||
| 543 | return (EINVAL22); | |||
| 544 | } | |||
| 545 | ||||
| 546 | /* | |||
| 547 | * If they asked us to return a cluster number but didn't tell us | |||
| 548 | * where to put it, give them an error. | |||
| 549 | */ | |||
| 550 | if ((function & FAT_GET0x0001) && oldcontents == NULL((void*)0)) { | |||
| 551 | DPRINTF(("%s(): get function with no place to put result\n", | |||
| 552 | __func__)); | |||
| 553 | return (EINVAL22); | |||
| 554 | } | |||
| 555 | #endif | |||
| 556 | ||||
| 557 | /* | |||
| 558 | * Be sure the requested cluster is in the filesystem. | |||
| 559 | */ | |||
| 560 | if (cn < CLUST_FIRST2 || cn > pmp->pm_maxcluster) | |||
| 561 | return (EINVAL22); | |||
| 562 | ||||
| 563 | byteoffset = FATOFS(pmp, cn)((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv); | |||
| 564 | fatblock(pmp, byteoffset, &bn, &bsize, &bo); | |||
| 565 | if ((error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), bsize, | |||
| 566 | 0, &bp)) != 0) { | |||
| 567 | return (error); | |||
| 568 | } | |||
| 569 | ||||
| 570 | if (function & FAT_GET0x0001) { | |||
| 571 | if (FAT32(pmp)(pmp->pm_fatmask == 0x0fffffff)) | |||
| 572 | readcn = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 573 | else | |||
| 574 | readcn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 575 | if (FAT12(pmp)(pmp->pm_fatmask == 0x00000fff) & (cn & 1)) | |||
| 576 | readcn >>= 4; | |||
| 577 | readcn &= pmp->pm_fatmask; | |||
| 578 | *oldcontents = readcn; | |||
| 579 | } | |||
| 580 | if (function & FAT_SET0x0002) { | |||
| 581 | switch (pmp->pm_fatmask) { | |||
| 582 | case FAT12_MASK0x00000fff: | |||
| 583 | readcn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 584 | if (cn & 1) { | |||
| 585 | readcn &= 0x000f; | |||
| 586 | readcn |= newcontents << 4; | |||
| 587 | } else { | |||
| 588 | readcn &= 0xf000; | |||
| 589 | readcn |= newcontents & 0xfff; | |||
| 590 | } | |||
| 591 | putushort((char *)bp->b_data + bo, readcn)(*((u_int16_t *)((char *)bp->b_data + bo)) = (readcn)); | |||
| 592 | break; | |||
| 593 | case FAT16_MASK0x0000ffff: | |||
| 594 | putushort((char *)bp->b_data + bo, newcontents)(*((u_int16_t *)((char *)bp->b_data + bo)) = (newcontents) ); | |||
| 595 | break; | |||
| 596 | case FAT32_MASK0x0fffffff: | |||
| 597 | /* | |||
| 598 | * According to spec we have to retain the | |||
| 599 | * high order bits of the FAT entry. | |||
| 600 | */ | |||
| 601 | readcn = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 602 | readcn &= ~FAT32_MASK0x0fffffff; | |||
| 603 | readcn |= newcontents & FAT32_MASK0x0fffffff; | |||
| 604 | putulong((char *)bp->b_data + bo, readcn)(*((u_int32_t *)((char *)bp->b_data + bo)) = (readcn)); | |||
| 605 | break; | |||
| 606 | } | |||
| 607 | updatefats(pmp, bp, bn); | |||
| 608 | bp = NULL((void*)0); | |||
| 609 | pmp->pm_fmod = 1; | |||
| 610 | } | |||
| 611 | if (bp) | |||
| 612 | brelse(bp, 0); | |||
| 613 | return (0); | |||
| 614 | } | |||
| 615 | ||||
| 616 | /* | |||
| 617 | * Update a contiguous cluster chain | |||
| 618 | * | |||
| 619 | * pmp - mount point | |||
| 620 | * start - first cluster of chain | |||
| 621 | * count - number of clusters in chain | |||
| 622 | * fillwith - what to write into FAT entry of last cluster | |||
| 623 | */ | |||
| 624 | static int | |||
| 625 | fatchain(struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith) | |||
| 626 | { | |||
| 627 | int error; | |||
| 628 | u_long bn, bo, bsize, byteoffset, readcn, newc; | |||
| 629 | struct mkfsbuf *bp; | |||
| 630 | ||||
| 631 | DPRINTF(("%s(pmp %p, start %lu, count %lu, fillwith %lx)\n", __func__, | |||
| 632 | pmp, start, count, fillwith)); | |||
| 633 | /* | |||
| 634 | * Be sure the clusters are in the filesystem. | |||
| 635 | */ | |||
| 636 | if (start < CLUST_FIRST2 || start + count - 1 > pmp->pm_maxcluster) | |||
| 637 | return (EINVAL22); | |||
| 638 | ||||
| 639 | while (count > 0) { | |||
| 640 | byteoffset = FATOFS(pmp, start)((start) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv); | |||
| 641 | fatblock(pmp, byteoffset, &bn, &bsize, &bo); | |||
| 642 | error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), bsize, | |||
| 643 | B_MODIFY0, &bp); | |||
| 644 | if (error) { | |||
| 645 | return (error); | |||
| 646 | } | |||
| 647 | while (count > 0) { | |||
| 648 | start++; | |||
| 649 | newc = --count > 0 ? start : fillwith; | |||
| 650 | switch (pmp->pm_fatmask) { | |||
| 651 | case FAT12_MASK0x00000fff: | |||
| 652 | readcn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 653 | if (start & 1) { | |||
| 654 | readcn &= 0xf000; | |||
| 655 | readcn |= newc & 0xfff; | |||
| 656 | } else { | |||
| 657 | readcn &= 0x000f; | |||
| 658 | readcn |= newc << 4; | |||
| 659 | } | |||
| 660 | putushort((char *)bp->b_data + bo, readcn)(*((u_int16_t *)((char *)bp->b_data + bo)) = (readcn)); | |||
| 661 | bo++; | |||
| 662 | if (!(start & 1)) | |||
| 663 | bo++; | |||
| 664 | break; | |||
| 665 | case FAT16_MASK0x0000ffff: | |||
| 666 | putushort((char *)bp->b_data + bo, newc)(*((u_int16_t *)((char *)bp->b_data + bo)) = (newc)); | |||
| 667 | bo += 2; | |||
| 668 | break; | |||
| 669 | case FAT32_MASK0x0fffffff: | |||
| 670 | readcn = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 671 | readcn &= ~pmp->pm_fatmask; | |||
| 672 | readcn |= newc & pmp->pm_fatmask; | |||
| 673 | putulong((char *)bp->b_data + bo, readcn)(*((u_int32_t *)((char *)bp->b_data + bo)) = (readcn)); | |||
| 674 | bo += 4; | |||
| 675 | break; | |||
| 676 | } | |||
| 677 | if (bo >= bsize) | |||
| 678 | break; | |||
| 679 | } | |||
| 680 | updatefats(pmp, bp, bn); | |||
| 681 | } | |||
| 682 | pmp->pm_fmod = 1; | |||
| 683 | return (0); | |||
| 684 | } | |||
| 685 | ||||
| 686 | /* | |||
| 687 | * Check the length of a free cluster chain starting at start. | |||
| 688 | * | |||
| 689 | * pmp - mount point | |||
| 690 | * start - start of chain | |||
| 691 | * count - maximum interesting length | |||
| 692 | */ | |||
| 693 | int | |||
| 694 | chainlength(struct msdosfsmount *pmp, u_long start, u_long count) | |||
| 695 | { | |||
| 696 | u_long idx, max_idx; | |||
| 697 | u_int map; | |||
| 698 | u_long len; | |||
| 699 | ||||
| 700 | max_idx = pmp->pm_maxcluster / N_INUSEBITS(8 * sizeof(u_int)); | |||
| 701 | idx = start / N_INUSEBITS(8 * sizeof(u_int)); | |||
| 702 | start %= N_INUSEBITS(8 * sizeof(u_int)); | |||
| 703 | map = pmp->pm_inusemap[idx]; | |||
| 704 | map &= ~((1 << start) - 1); | |||
| 705 | if (map) { | |||
| 706 | len = ffs(map) - 1 - start; | |||
| 707 | return (len > count ? count : len); | |||
| 708 | } | |||
| 709 | len = N_INUSEBITS(8 * sizeof(u_int)) - start; | |||
| 710 | if (len >= count) | |||
| 711 | return (count); | |||
| 712 | while (++idx <= max_idx) { | |||
| 713 | if (len >= count) | |||
| 714 | break; | |||
| 715 | if ((map = pmp->pm_inusemap[idx]) != 0) { | |||
| 716 | len += ffs(map) - 1; | |||
| 717 | break; | |||
| 718 | } | |||
| 719 | len += N_INUSEBITS(8 * sizeof(u_int)); | |||
| 720 | } | |||
| 721 | return (len > count ? count : len); | |||
| 722 | } | |||
| 723 | ||||
| 724 | /* | |||
| 725 | * Allocate contiguous free clusters. | |||
| 726 | * | |||
| 727 | * pmp - mount point. | |||
| 728 | * start - start of cluster chain. | |||
| 729 | * count - number of clusters to allocate. | |||
| 730 | * fillwith - put this value into the FAT entry for the | |||
| 731 | * last allocated cluster. | |||
| 732 | * retcluster - put the first allocated cluster's number here. | |||
| 733 | * got - how many clusters were actually allocated. | |||
| 734 | */ | |||
| 735 | int | |||
| 736 | chainalloc(struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith, u_long *retcluster, u_long *got) | |||
| 737 | { | |||
| 738 | int error; | |||
| 739 | u_long cl, n; | |||
| 740 | ||||
| 741 | for (cl = start, n = count; n-- > 0;) | |||
| 742 | usemap_alloc(pmp, cl++); | |||
| 743 | if ((error = fatchain(pmp, start, count, fillwith)) != 0) | |||
| 744 | return (error); | |||
| 745 | ||||
| 746 | DPRINTF(("%s(): allocated cluster chain at %lu (%lu clusters)\n", | |||
| 747 | __func__, start, count)); | |||
| 748 | if (retcluster) | |||
| 749 | *retcluster = start; | |||
| 750 | if (got) | |||
| 751 | *got = count; | |||
| 752 | return (0); | |||
| 753 | } | |||
| 754 | ||||
| 755 | /* | |||
| 756 | * Allocate contiguous free clusters. | |||
| 757 | * | |||
| 758 | * pmp - mount point. | |||
| 759 | * start - preferred start of cluster chain. | |||
| 760 | * count - number of clusters requested. | |||
| 761 | * fillwith - put this value into the FAT entry for the | |||
| 762 | * last allocated cluster. | |||
| 763 | * retcluster - put the first allocated cluster's number here. | |||
| 764 | * got - how many clusters were actually allocated. | |||
| 765 | */ | |||
| 766 | int | |||
| 767 | clusteralloc(struct msdosfsmount *pmp, u_long start, u_long count, u_long *retcluster, u_long *got) | |||
| 768 | { | |||
| 769 | u_long idx; | |||
| 770 | u_long len, newst, foundl, cn, l; | |||
| 771 | u_long foundcn = 0; /* XXX: foundcn could be used uninitialized */ | |||
| 772 | u_long fillwith = CLUST_EOFE0xffffffff; | |||
| 773 | u_int map; | |||
| 774 | ||||
| 775 | DPRINTF(("%s(): find %lu clusters\n", __func__, count)); | |||
| 776 | if (start) { | |||
| 777 | if ((len = chainlength(pmp, start, count)) >= count) | |||
| 778 | return (chainalloc(pmp, start, count, fillwith, retcluster, got)); | |||
| 779 | } else { | |||
| 780 | /* | |||
| 781 | * This is a new file, initialize start | |||
| 782 | */ | |||
| 783 | struct timeval tv; | |||
| 784 | ||||
| 785 | microtime(&tv)gettimeofday((&tv), ((void*)0)); | |||
| 786 | start = (tv.tv_usec >> 10) | tv.tv_usec; | |||
| 787 | len = 0; | |||
| 788 | } | |||
| 789 | ||||
| 790 | /* | |||
| 791 | * Start at a (pseudo) random place to maximize cluster runs | |||
| 792 | * under multiple writers. | |||
| 793 | */ | |||
| 794 | newst = (start * 1103515245 + 12345) % (pmp->pm_maxcluster + 1); | |||
| 795 | foundl = 0; | |||
| 796 | ||||
| 797 | for (cn = newst; cn <= pmp->pm_maxcluster;) { | |||
| 798 | idx = cn / N_INUSEBITS(8 * sizeof(u_int)); | |||
| 799 | map = pmp->pm_inusemap[idx]; | |||
| 800 | map |= (1 << (cn % N_INUSEBITS(8 * sizeof(u_int)))) - 1; | |||
| 801 | if (map != (u_int)-1) { | |||
| 802 | cn = idx * N_INUSEBITS(8 * sizeof(u_int)) + ffs(map^(u_int)-1) - 1; | |||
| 803 | if ((l = chainlength(pmp, cn, count)) >= count) | |||
| 804 | return (chainalloc(pmp, cn, count, fillwith, retcluster, got)); | |||
| 805 | if (l > foundl) { | |||
| 806 | foundcn = cn; | |||
| 807 | foundl = l; | |||
| 808 | } | |||
| 809 | cn += l + 1; | |||
| 810 | continue; | |||
| 811 | } | |||
| 812 | cn += N_INUSEBITS(8 * sizeof(u_int)) - cn % N_INUSEBITS(8 * sizeof(u_int)); | |||
| 813 | } | |||
| 814 | for (cn = 0; cn < newst;) { | |||
| 815 | idx = cn / N_INUSEBITS(8 * sizeof(u_int)); | |||
| 816 | map = pmp->pm_inusemap[idx]; | |||
| 817 | map |= (1 << (cn % N_INUSEBITS(8 * sizeof(u_int)))) - 1; | |||
| 818 | if (map != (u_int)-1) { | |||
| 819 | cn = idx * N_INUSEBITS(8 * sizeof(u_int)) + ffs(map^(u_int)-1) - 1; | |||
| 820 | if ((l = chainlength(pmp, cn, count)) >= count) | |||
| 821 | return (chainalloc(pmp, cn, count, fillwith, retcluster, got)); | |||
| 822 | if (l > foundl) { | |||
| 823 | foundcn = cn; | |||
| 824 | foundl = l; | |||
| 825 | } | |||
| 826 | cn += l + 1; | |||
| 827 | continue; | |||
| 828 | } | |||
| 829 | cn += N_INUSEBITS(8 * sizeof(u_int)) - cn % N_INUSEBITS(8 * sizeof(u_int)); | |||
| 830 | } | |||
| 831 | ||||
| 832 | if (!foundl) | |||
| 833 | return (ENOSPC28); | |||
| 834 | ||||
| 835 | if (len) | |||
| 836 | return (chainalloc(pmp, start, len, fillwith, retcluster, got)); | |||
| 837 | else | |||
| 838 | return (chainalloc(pmp, foundcn, foundl, fillwith, retcluster, got)); | |||
| 839 | } | |||
| 840 | ||||
| 841 | ||||
| 842 | /* | |||
| 843 | * Free a chain of clusters. | |||
| 844 | * | |||
| 845 | * pmp - address of the msdosfs mount structure for the filesystem | |||
| 846 | * containing the cluster chain to be freed. | |||
| 847 | * startcluster - number of the 1st cluster in the chain of clusters to be | |||
| 848 | * freed. | |||
| 849 | */ | |||
| 850 | int | |||
| 851 | freeclusterchain(struct msdosfsmount *pmp, u_long cluster) | |||
| 852 | { | |||
| 853 | int error; | |||
| 854 | struct mkfsbuf *bp = NULL((void*)0); | |||
| ||||
| 855 | u_long bn, bo, bsize, byteoffset; | |||
| 856 | u_long readcn, lbn = -1; | |||
| 857 | ||||
| 858 | while (cluster >= CLUST_FIRST2 && cluster <= pmp->pm_maxcluster) { | |||
| 859 | byteoffset = FATOFS(pmp, cluster)((cluster) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv); | |||
| 860 | fatblock(pmp, byteoffset, &bn, &bsize, &bo); | |||
| 861 | if (lbn != bn) { | |||
| 862 | if (bp) | |||
| 863 | updatefats(pmp, bp, lbn); | |||
| 864 | error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), bsize, | |||
| 865 | B_MODIFY0, &bp); | |||
| 866 | if (error) { | |||
| 867 | return (error); | |||
| 868 | } | |||
| 869 | lbn = bn; | |||
| 870 | } | |||
| 871 | usemap_free(pmp, cluster); | |||
| 872 | KASSERT(bp != NULL); | |||
| 873 | switch (pmp->pm_fatmask) { | |||
| 874 | case FAT12_MASK0x00000fff: | |||
| 875 | readcn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| ||||
| 876 | if (cluster & 1) { | |||
| 877 | cluster = readcn >> 4; | |||
| 878 | readcn &= 0x000f; | |||
| 879 | readcn |= MSDOSFSFREE0 << 4; | |||
| 880 | } else { | |||
| 881 | cluster = readcn; | |||
| 882 | readcn &= 0xf000; | |||
| 883 | readcn |= MSDOSFSFREE0 & 0xfff; | |||
| 884 | } | |||
| 885 | putushort((char *)bp->b_data + bo, readcn)(*((u_int16_t *)((char *)bp->b_data + bo)) = (readcn)); | |||
| 886 | break; | |||
| 887 | case FAT16_MASK0x0000ffff: | |||
| 888 | cluster = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 889 | putushort((char *)bp->b_data + bo, MSDOSFSFREE)(*((u_int16_t *)((char *)bp->b_data + bo)) = (0)); | |||
| 890 | break; | |||
| 891 | case FAT32_MASK0x0fffffff: | |||
| 892 | cluster = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 893 | putulong((char *)bp->b_data + bo,(*((u_int32_t *)((char *)bp->b_data + bo)) = ((0 & 0x0fffffff ) | (cluster & ~0x0fffffff))) | |||
| 894 | (MSDOSFSFREE & FAT32_MASK) | (cluster & ~FAT32_MASK))(*((u_int32_t *)((char *)bp->b_data + bo)) = ((0 & 0x0fffffff ) | (cluster & ~0x0fffffff))); | |||
| 895 | break; | |||
| 896 | } | |||
| 897 | cluster &= pmp->pm_fatmask; | |||
| 898 | } | |||
| 899 | if (bp) | |||
| 900 | updatefats(pmp, bp, bn); | |||
| 901 | return (0); | |||
| 902 | } | |||
| 903 | ||||
| 904 | /* | |||
| 905 | * Read in FAT blocks looking for free clusters. For every free cluster | |||
| 906 | * found turn off its corresponding bit in the pm_inusemap. | |||
| 907 | */ | |||
| 908 | int | |||
| 909 | fillinusemap(struct msdosfsmount *pmp) | |||
| 910 | { | |||
| 911 | struct mkfsbuf *bp = NULL((void*)0); | |||
| 912 | u_long cn, readcn; | |||
| 913 | int error; | |||
| 914 | u_long bn, bo, bsize, byteoffset; | |||
| 915 | ||||
| 916 | /* | |||
| 917 | * Mark all clusters in use, we mark the free ones in the FAT scan | |||
| 918 | * loop further down. | |||
| 919 | */ | |||
| 920 | for (cn = 0; cn < (pmp->pm_maxcluster + N_INUSEBITS(8 * sizeof(u_int))) / N_INUSEBITS(8 * sizeof(u_int)); cn++) | |||
| 921 | pmp->pm_inusemap[cn] = (u_int)-1; | |||
| 922 | ||||
| 923 | /* | |||
| 924 | * Figure how many free clusters are in the filesystem by ripping | |||
| 925 | * through the FAT counting the number of entries whose content is | |||
| 926 | * zero. These represent free clusters. | |||
| 927 | */ | |||
| 928 | pmp->pm_freeclustercount = 0; | |||
| 929 | for (cn = CLUST_FIRST2; cn <= pmp->pm_maxcluster; cn++) { | |||
| 930 | byteoffset = FATOFS(pmp, cn)((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv); | |||
| 931 | bo = byteoffset % pmp->pm_fatblocksize; | |||
| 932 | if (!bo || !bp) { | |||
| 933 | /* Read new FAT block */ | |||
| 934 | if (bp) | |||
| 935 | brelse(bp, 0); | |||
| 936 | fatblock(pmp, byteoffset, &bn, &bsize, NULL((void*)0)); | |||
| 937 | error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), bsize, | |||
| 938 | 0, &bp); | |||
| 939 | if (error) { | |||
| 940 | return (error); | |||
| 941 | } | |||
| 942 | } | |||
| 943 | if (FAT32(pmp)(pmp->pm_fatmask == 0x0fffffff)) | |||
| 944 | readcn = getulong((char *)bp->b_data + bo)*((u_int32_t *)((char *)bp->b_data + bo)); | |||
| 945 | else | |||
| 946 | readcn = getushort((char *)bp->b_data + bo)*((u_int16_t *)((char *)bp->b_data + bo)); | |||
| 947 | if (FAT12(pmp)(pmp->pm_fatmask == 0x00000fff) && (cn & 1)) | |||
| 948 | readcn >>= 4; | |||
| 949 | readcn &= pmp->pm_fatmask; | |||
| 950 | ||||
| 951 | if (readcn == 0) | |||
| 952 | usemap_free(pmp, cn); | |||
| 953 | } | |||
| 954 | if (bp) | |||
| 955 | brelse(bp, 0); | |||
| 956 | return (0); | |||
| 957 | } | |||
| 958 | ||||
| 959 | /* | |||
| 960 | * Allocate a new cluster and chain it onto the end of the file. | |||
| 961 | * | |||
| 962 | * dep - the file to extend | |||
| 963 | * count - number of clusters to allocate | |||
| 964 | * bpp - where to return the address of the buf header for the first new | |||
| 965 | * file block | |||
| 966 | * ncp - where to put cluster number of the first newly allocated cluster | |||
| 967 | * If this pointer is 0, do not return the cluster number. | |||
| 968 | * flags - see fat.h | |||
| 969 | * | |||
| 970 | * NOTE: This function is not responsible for turning on the DE_UPDATE bit of | |||
| 971 | * the de_flag field of the denode and it does not change the de_FileSize | |||
| 972 | * field. This is left for the caller to do. | |||
| 973 | */ | |||
| 974 | ||||
| 975 | int | |||
| 976 | extendfile(struct denode *dep, u_long count, struct mkfsbuf **bpp, u_long *ncp, int flags) | |||
| 977 | { | |||
| 978 | int error; | |||
| 979 | u_long frcn = 0, cn, got; | |||
| 980 | struct msdosfsmount *pmp = dep->de_pmp; | |||
| 981 | struct mkfsbuf *bp; | |||
| 982 | ||||
| 983 | /* | |||
| 984 | * Don't try to extend the root directory | |||
| 985 | */ | |||
| 986 | if (dep->de_StartCluster == MSDOSFSROOT0 | |||
| 987 | && (dep->de_Attributes & ATTR_DIRECTORY0x10)) { | |||
| 988 | DPRINTF(("%s(): attempt to extend root directory\n", __func__)); | |||
| 989 | return (ENOSPC28); | |||
| 990 | } | |||
| 991 | ||||
| 992 | /* | |||
| 993 | * If the "file's last cluster" cache entry is empty, and the file | |||
| 994 | * is not empty, then fill the cache entry by calling pcbmap(). | |||
| 995 | */ | |||
| 996 | fc_fileextends++; | |||
| 997 | if (dep->de_fc[FC_LASTFC1].fc_frcn == FCE_EMPTY0xffffffff && | |||
| 998 | dep->de_StartCluster != 0) { | |||
| 999 | fc_lfcempty++; | |||
| 1000 | error = pcbmap(dep, CLUST_END0xffffffff, 0, &cn, 0); | |||
| 1001 | /* we expect it to return E2BIG */ | |||
| 1002 | if (error != E2BIG7) | |||
| 1003 | return (error); | |||
| 1004 | } | |||
| 1005 | ||||
| 1006 | fc_last_to_nexttolast(dep)do { (dep)->de_fc[2].fc_frcn = (dep)->de_fc[1].fc_frcn; (dep)->de_fc[2].fc_fsrcn = (dep)->de_fc[1].fc_fsrcn; } while (0); | |||
| 1007 | ||||
| 1008 | while (count > 0) { | |||
| 1009 | ||||
| 1010 | /* | |||
| 1011 | * Allocate a new cluster chain and cat onto the end of the | |||
| 1012 | * file. If the file is empty we make de_StartCluster point | |||
| 1013 | * to the new block. Note that de_StartCluster being 0 is | |||
| 1014 | * sufficient to be sure the file is empty since we exclude | |||
| 1015 | * attempts to extend the root directory above, and the root | |||
| 1016 | * dir is the only file with a startcluster of 0 that has | |||
| 1017 | * blocks allocated (sort of). | |||
| 1018 | */ | |||
| 1019 | ||||
| 1020 | if (dep->de_StartCluster == 0) | |||
| 1021 | cn = 0; | |||
| 1022 | else | |||
| 1023 | cn = dep->de_fc[FC_LASTFC1].fc_fsrcn + 1; | |||
| 1024 | error = clusteralloc(pmp, cn, count, &cn, &got); | |||
| 1025 | if (error) | |||
| 1026 | return (error); | |||
| 1027 | ||||
| 1028 | count -= got; | |||
| 1029 | ||||
| 1030 | /* | |||
| 1031 | * Give them the filesystem relative cluster number if they want | |||
| 1032 | * it. | |||
| 1033 | */ | |||
| 1034 | if (ncp) { | |||
| 1035 | *ncp = cn; | |||
| 1036 | ncp = NULL((void*)0); | |||
| 1037 | } | |||
| 1038 | ||||
| 1039 | if (dep->de_StartCluster == 0) { | |||
| 1040 | dep->de_StartCluster = cn; | |||
| 1041 | frcn = 0; | |||
| 1042 | } else { | |||
| 1043 | error = fatentry(FAT_SET0x0002, pmp, | |||
| 1044 | dep->de_fc[FC_LASTFC1].fc_fsrcn, | |||
| 1045 | 0, cn); | |||
| 1046 | if (error) { | |||
| 1047 | clusterfree(pmp, cn, NULL((void*)0)); | |||
| 1048 | return (error); | |||
| 1049 | } | |||
| 1050 | frcn = dep->de_fc[FC_LASTFC1].fc_frcn + 1; | |||
| 1051 | } | |||
| 1052 | ||||
| 1053 | /* | |||
| 1054 | * Update the "last cluster of the file" entry in the | |||
| 1055 | * denode's FAT cache. | |||
| 1056 | */ | |||
| 1057 | ||||
| 1058 | fc_setcache(dep, FC_LASTFC, frcn + got - 1, cn + got - 1)(dep)->de_fc[1].fc_frcn = frcn + got - 1; (dep)->de_fc[ 1].fc_fsrcn = cn + got - 1;; | |||
| 1059 | if ((flags & DE_CLEAR1) && | |||
| 1060 | (dep->de_Attributes & ATTR_DIRECTORY0x10)) { | |||
| 1061 | while (got-- > 0) { | |||
| 1062 | bp = getblk(pmp->pm_devvp, | |||
| 1063 | de_bn2kb(pmp, cntobn(pmp, cn++))((((((cn++)-2) << (((pmp))->pm_cnshift - ((pmp))-> pm_bnshift)) + (pmp)->pm_firstcluster)) << ((pmp)-> pm_bnshift - 9)), | |||
| 1064 | pmp->pm_bpcluster, 0, 0); | |||
| 1065 | clrbuf(bp)memset((bp)->b_data, 0, (u_int)(bp)->b_bcount); | |||
| 1066 | if (bpp) { | |||
| 1067 | *bpp = bp; | |||
| 1068 | bpp = NULL((void*)0); | |||
| 1069 | } else { | |||
| 1070 | bdwrite(bp)bwrite(bp); | |||
| 1071 | } | |||
| 1072 | } | |||
| 1073 | } | |||
| 1074 | } | |||
| 1075 | ||||
| 1076 | return (0); | |||
| 1077 | } |