1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)ffs_subr.c 8.5 (Berkeley) 3/21/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/param.h> 38 #include <sys/endian.h> 39 #include <sys/limits.h> 40 41 #ifndef _KERNEL 42 #include <stdio.h> 43 #include <string.h> 44 #include <stdlib.h> 45 #include <time.h> 46 #include <sys/errno.h> 47 #include <ufs/ufs/dinode.h> 48 #include <ufs/ffs/fs.h> 49 50 uint32_t calculate_crc32c(uint32_t, const void *, size_t); 51 uint32_t ffs_calc_sbhash(struct fs *); 52 struct malloc_type; 53 #define UFS_MALLOC(size, type, flags) malloc(size) 54 #define UFS_FREE(ptr, type) free(ptr) 55 #define maxphys MAXPHYS 56 57 #else /* _KERNEL */ 58 #include <sys/systm.h> 59 #include <sys/gsb_crc32.h> 60 #include <sys/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mount.h> 63 #include <sys/vnode.h> 64 #include <sys/bio.h> 65 #include <sys/buf.h> 66 #include <sys/ucred.h> 67 68 #include <ufs/ufs/quota.h> 69 #include <ufs/ufs/inode.h> 70 #include <ufs/ufs/extattr.h> 71 #include <ufs/ufs/ufsmount.h> 72 #include <ufs/ufs/ufs_extern.h> 73 #include <ufs/ffs/ffs_extern.h> 74 #include <ufs/ffs/fs.h> 75 76 #define UFS_MALLOC(size, type, flags) malloc(size, type, flags) 77 #define UFS_FREE(ptr, type) free(ptr, type) 78 79 #endif /* _KERNEL */ 80 81 /* 82 * Verify an inode check-hash. 83 */ 84 int 85 ffs_verify_dinode_ckhash(struct fs *fs, struct ufs2_dinode *dip) 86 { 87 uint32_t ckhash, save_ckhash; 88 89 /* 90 * Return success if unallocated or we are not doing inode check-hash. 91 */ 92 if (dip->di_mode == 0 || (fs->fs_metackhash & CK_INODE) == 0) 93 return (0); 94 /* 95 * Exclude di_ckhash from the crc32 calculation, e.g., always use 96 * a check-hash value of zero when calculating the check-hash. 97 */ 98 save_ckhash = dip->di_ckhash; 99 dip->di_ckhash = 0; 100 ckhash = calculate_crc32c(~0L, (void *)dip, sizeof(*dip)); 101 dip->di_ckhash = save_ckhash; 102 if (save_ckhash == ckhash) 103 return (0); 104 return (EINVAL); 105 } 106 107 /* 108 * Update an inode check-hash. 109 */ 110 void 111 ffs_update_dinode_ckhash(struct fs *fs, struct ufs2_dinode *dip) 112 { 113 114 if (dip->di_mode == 0 || (fs->fs_metackhash & CK_INODE) == 0) 115 return; 116 /* 117 * Exclude old di_ckhash from the crc32 calculation, e.g., always use 118 * a check-hash value of zero when calculating the new check-hash. 119 */ 120 dip->di_ckhash = 0; 121 dip->di_ckhash = calculate_crc32c(~0L, (void *)dip, sizeof(*dip)); 122 } 123 124 /* 125 * These are the low-level functions that actually read and write 126 * the superblock and its associated data. 127 */ 128 static off_t sblock_try[] = SBLOCKSEARCH; 129 static int readsuper(void *, struct fs **, off_t, int, 130 int (*)(void *, off_t, void **, int)); 131 static int validate_sblock(struct fs *, int); 132 133 /* 134 * Read a superblock from the devfd device. 135 * 136 * If an alternate superblock is specified, it is read. Otherwise the 137 * set of locations given in the SBLOCKSEARCH list is searched for a 138 * superblock. Memory is allocated for the superblock by the readfunc and 139 * is returned. If filltype is non-NULL, additional memory is allocated 140 * of type filltype and filled in with the superblock summary information. 141 * All memory is freed when any error is returned. 142 * 143 * If a superblock is found, zero is returned. Otherwise one of the 144 * following error values is returned: 145 * EIO: non-existent or truncated superblock. 146 * EIO: error reading summary information. 147 * ENOENT: no usable known superblock found. 148 * EILSEQ: filesystem with wrong byte order found. 149 * ENOMEM: failed to allocate space for the superblock. 150 * EINVAL: The previous newfs operation on this volume did not complete. 151 * The administrator must complete newfs before using this volume. 152 */ 153 int 154 ffs_sbget(void *devfd, struct fs **fsp, off_t sblock, int flags, 155 struct malloc_type *filltype, 156 int (*readfunc)(void *devfd, off_t loc, void **bufp, int size)) 157 { 158 struct fs *fs; 159 struct fs_summary_info *fs_si; 160 int i, error; 161 uint64_t size, blks; 162 uint8_t *space; 163 int32_t *lp; 164 char *buf; 165 166 fs = NULL; 167 *fsp = NULL; 168 if (sblock != UFS_STDSB) { 169 if ((error = readsuper(devfd, &fs, sblock, 170 flags | UFS_ALTSBLK, readfunc)) != 0) { 171 if (fs != NULL) 172 UFS_FREE(fs, filltype); 173 return (error); 174 } 175 } else { 176 for (i = 0; sblock_try[i] != -1; i++) { 177 if ((error = readsuper(devfd, &fs, sblock_try[i], 178 flags, readfunc)) == 0) { 179 if ((flags & UFS_NOCSUM) != 0) { 180 *fsp = fs; 181 return (0); 182 } 183 break; 184 } 185 if (fs != NULL) { 186 UFS_FREE(fs, filltype); 187 fs = NULL; 188 } 189 if (error == ENOENT) 190 continue; 191 return (error); 192 } 193 if (sblock_try[i] == -1) 194 return (ENOENT); 195 } 196 /* 197 * Read in the superblock summary information. 198 */ 199 size = fs->fs_cssize; 200 blks = howmany(size, fs->fs_fsize); 201 if (fs->fs_contigsumsize > 0) 202 size += fs->fs_ncg * sizeof(int32_t); 203 size += fs->fs_ncg * sizeof(u_int8_t); 204 if ((fs_si = UFS_MALLOC(sizeof(*fs_si), filltype, M_NOWAIT)) == NULL) { 205 UFS_FREE(fs, filltype); 206 return (ENOMEM); 207 } 208 bzero(fs_si, sizeof(*fs_si)); 209 fs->fs_si = fs_si; 210 if ((space = UFS_MALLOC(size, filltype, M_NOWAIT)) == NULL) { 211 UFS_FREE(fs->fs_si, filltype); 212 UFS_FREE(fs, filltype); 213 return (ENOMEM); 214 } 215 fs->fs_csp = (struct csum *)space; 216 for (i = 0; i < blks; i += fs->fs_frag) { 217 size = fs->fs_bsize; 218 if (i + fs->fs_frag > blks) 219 size = (blks - i) * fs->fs_fsize; 220 buf = NULL; 221 error = (*readfunc)(devfd, 222 dbtob(fsbtodb(fs, fs->fs_csaddr + i)), (void **)&buf, size); 223 if (error) { 224 if (buf != NULL) 225 UFS_FREE(buf, filltype); 226 UFS_FREE(fs->fs_csp, filltype); 227 UFS_FREE(fs->fs_si, filltype); 228 UFS_FREE(fs, filltype); 229 return (error); 230 } 231 memcpy(space, buf, size); 232 UFS_FREE(buf, filltype); 233 space += size; 234 } 235 if (fs->fs_contigsumsize > 0) { 236 fs->fs_maxcluster = lp = (int32_t *)space; 237 for (i = 0; i < fs->fs_ncg; i++) 238 *lp++ = fs->fs_contigsumsize; 239 space = (uint8_t *)lp; 240 } 241 size = fs->fs_ncg * sizeof(u_int8_t); 242 fs->fs_contigdirs = (u_int8_t *)space; 243 bzero(fs->fs_contigdirs, size); 244 *fsp = fs; 245 return (0); 246 } 247 248 /* 249 * Try to read a superblock from the location specified by sblockloc. 250 * Return zero on success or an errno on failure. 251 */ 252 static int 253 readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int flags, 254 int (*readfunc)(void *devfd, off_t loc, void **bufp, int size)) 255 { 256 struct fs *fs; 257 int error, res; 258 uint32_t ckhash; 259 260 error = (*readfunc)(devfd, sblockloc, (void **)fsp, SBLOCKSIZE); 261 if (error != 0) 262 return (error); 263 fs = *fsp; 264 if (fs->fs_magic == FS_BAD_MAGIC) 265 return (EINVAL); 266 /* 267 * For UFS1 with a 65536 block size, the first backup superblock 268 * is at the same location as the UFS2 superblock. Since SBLOCK_UFS2 269 * is the first location checked, the first backup is the superblock 270 * that will be accessed. Here we fail the lookup so that we can 271 * retry with the correct location for the UFS1 superblock. 272 */ 273 if (fs->fs_magic == FS_UFS1_MAGIC && (flags & UFS_ALTSBLK) == 0 && 274 fs->fs_bsize == SBLOCK_UFS2 && sblockloc == SBLOCK_UFS2) 275 return (ENOENT); 276 if ((error = validate_sblock(fs, flags)) > 0) 277 return (error); 278 /* 279 * If the filesystem has been run on a kernel without 280 * metadata check hashes, disable them. 281 */ 282 if ((fs->fs_flags & FS_METACKHASH) == 0) 283 fs->fs_metackhash = 0; 284 /* 285 * Clear any check-hashes that are not maintained 286 * by this kernel. Also clear any unsupported flags. 287 */ 288 fs->fs_metackhash &= CK_SUPPORTED; 289 fs->fs_flags &= FS_SUPPORTED; 290 if (fs->fs_ckhash != (ckhash = ffs_calc_sbhash(fs))) { 291 if ((flags & (UFS_NOMSG | UFS_NOHASHFAIL)) == 292 (UFS_NOMSG | UFS_NOHASHFAIL)) 293 return (0); 294 if ((flags & UFS_NOMSG) != 0) 295 return (EINTEGRITY); 296 #ifdef _KERNEL 297 res = uprintf("Superblock check-hash failed: recorded " 298 "check-hash 0x%x != computed check-hash 0x%x%s\n", 299 fs->fs_ckhash, ckhash, 300 (flags & UFS_NOHASHFAIL) != 0 ? " (Ignored)" : ""); 301 #else 302 res = 0; 303 #endif 304 /* 305 * Print check-hash failure if no controlling terminal 306 * in kernel or always if in user-mode (libufs). 307 */ 308 if (res == 0) 309 printf("Superblock check-hash failed: recorded " 310 "check-hash 0x%x != computed check-hash " 311 "0x%x%s\n", fs->fs_ckhash, ckhash, 312 (flags & UFS_NOHASHFAIL) ? " (Ignored)" : ""); 313 if ((flags & UFS_NOHASHFAIL) != 0) 314 return (0); 315 return (EINTEGRITY); 316 } 317 /* Have to set for old filesystems that predate this field */ 318 fs->fs_sblockactualloc = sblockloc; 319 /* Not yet any summary information */ 320 fs->fs_si = NULL; 321 return (0); 322 } 323 324 /* 325 * Verify the filesystem values. 326 */ 327 #define ILOG2(num) (fls(num) - 1) 328 #ifdef STANDALONE_SMALL 329 #define MPRINT(...) do { } while (0) 330 #else 331 #define MPRINT(...) if (prtmsg) printf(__VA_ARGS__) 332 #endif 333 #define FCHK(lhs, op, rhs, fmt) \ 334 if (lhs op rhs) { \ 335 MPRINT("UFS%d superblock failed: %s (" #fmt ") %s %s (" \ 336 #fmt ")\n", fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2, \ 337 #lhs, (intmax_t)lhs, #op, #rhs, (intmax_t)rhs); \ 338 if (error < 0) \ 339 return (ENOENT); \ 340 if (error == 0) \ 341 error = ENOENT; \ 342 } 343 #define WCHK(lhs, op, rhs, fmt) \ 344 if (lhs op rhs) { \ 345 MPRINT("UFS%d superblock failed: %s (" #fmt ") %s %s (" \ 346 #fmt ")%s\n", fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2,\ 347 #lhs, (intmax_t)lhs, #op, #rhs, (intmax_t)rhs, wmsg);\ 348 if (error == 0) \ 349 error = warnerr; \ 350 if (warnerr == 0) \ 351 lhs = rhs; \ 352 } 353 #define FCHK2(lhs1, op1, rhs1, lhs2, op2, rhs2, fmt) \ 354 if (lhs1 op1 rhs1 && lhs2 op2 rhs2) { \ 355 MPRINT("UFS%d superblock failed: %s (" #fmt ") %s %s (" \ 356 #fmt ") && %s (" #fmt ") %s %s (" #fmt ")\n", \ 357 fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2, #lhs1, \ 358 (intmax_t)lhs1, #op1, #rhs1, (intmax_t)rhs1, #lhs2, \ 359 (intmax_t)lhs2, #op2, #rhs2, (intmax_t)rhs2); \ 360 if (error < 0) \ 361 return (ENOENT); \ 362 if (error == 0) \ 363 error = ENOENT; \ 364 } 365 366 static int 367 validate_sblock(struct fs *fs, int flags) 368 { 369 u_long i, sectorsize; 370 u_int64_t maxfilesize, sizepb; 371 int error, prtmsg, warnerr; 372 char *wmsg; 373 374 error = 0; 375 sectorsize = dbtob(1); 376 prtmsg = ((flags & UFS_NOMSG) == 0); 377 warnerr = (flags & UFS_NOWARNFAIL) == UFS_NOWARNFAIL ? 0 : ENOENT; 378 wmsg = warnerr ? "" : " (Ignored)"; 379 /* 380 * Check for endian mismatch between machine and filesystem. 381 */ 382 if (((fs->fs_magic != FS_UFS2_MAGIC) && 383 (bswap32(fs->fs_magic) == FS_UFS2_MAGIC)) || 384 ((fs->fs_magic != FS_UFS1_MAGIC) && 385 (bswap32(fs->fs_magic) == FS_UFS1_MAGIC))) { 386 MPRINT("UFS superblock failed due to endian mismatch " 387 "between machine and filesystem\n"); 388 return(EILSEQ); 389 } 390 /* 391 * If just validating for recovery, then do just the minimal 392 * checks needed for the superblock fields needed to find 393 * alternate superblocks. 394 */ 395 if ((flags & UFS_FSRONLY) == UFS_FSRONLY && 396 (fs->fs_magic == FS_UFS1_MAGIC || fs->fs_magic == FS_UFS2_MAGIC)) { 397 error = -1; /* fail on first error */ 398 if (fs->fs_magic == FS_UFS2_MAGIC) { 399 FCHK(fs->fs_sblockloc, !=, SBLOCK_UFS2, %#jx); 400 } else if (fs->fs_magic == FS_UFS1_MAGIC) { 401 FCHK(fs->fs_sblockloc, <, 0, %jd); 402 FCHK(fs->fs_sblockloc, >, SBLOCK_UFS1, %jd); 403 FCHK(fs->fs_old_ncyl, !=, fs->fs_ncg, %jd); 404 } 405 FCHK(fs->fs_frag, <, 1, %jd); 406 FCHK(fs->fs_frag, >, MAXFRAG, %jd); 407 FCHK(fs->fs_bsize, <, MINBSIZE, %jd); 408 FCHK(fs->fs_bsize, >, MAXBSIZE, %jd); 409 FCHK(fs->fs_bsize, <, roundup(sizeof(struct fs), DEV_BSIZE), 410 %jd); 411 FCHK(fs->fs_fsize, <, sectorsize, %jd); 412 FCHK(fs->fs_fsize * fs->fs_frag, !=, fs->fs_bsize, %jd); 413 FCHK(powerof2(fs->fs_fsize), ==, 0, %jd); 414 FCHK(fs->fs_sbsize, >, SBLOCKSIZE, %jd); 415 FCHK(fs->fs_sbsize, <, (signed)sizeof(struct fs), %jd); 416 FCHK(fs->fs_sbsize % sectorsize, !=, 0, %jd); 417 FCHK(fs->fs_fpg, <, 3 * fs->fs_frag, %jd); 418 FCHK(fs->fs_ncg, <, 1, %jd); 419 FCHK(fs->fs_fsbtodb, !=, ILOG2(fs->fs_fsize / sectorsize), %jd); 420 FCHK(fs->fs_old_cgoffset, <, 0, %jd); 421 FCHK2(fs->fs_old_cgoffset, >, 0, ~fs->fs_old_cgmask, <, 0, %jd); 422 FCHK(fs->fs_old_cgoffset * (~fs->fs_old_cgmask), >, fs->fs_fpg, 423 %jd); 424 FCHK(fs->fs_sblkno, !=, roundup( 425 howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize), 426 fs->fs_frag), %jd); 427 FCHK(CGSIZE(fs), >, fs->fs_bsize, %jd); 428 /* Only need to validate these if reading in csum data */ 429 if ((flags & UFS_NOCSUM) != 0) 430 return (error); 431 FCHK((u_int64_t)fs->fs_ipg * fs->fs_ncg, >, 432 (((int64_t)(1)) << 32) - INOPB(fs), %jd); 433 FCHK(fs->fs_cstotal.cs_nifree, <, 0, %jd); 434 FCHK(fs->fs_cstotal.cs_nifree, >, 435 (u_int64_t)fs->fs_ipg * fs->fs_ncg, %jd); 436 FCHK(fs->fs_cstotal.cs_ndir, >, 437 ((u_int64_t)fs->fs_ipg * fs->fs_ncg) - 438 fs->fs_cstotal.cs_nifree, %jd); 439 FCHK(fs->fs_size, <, 8 * fs->fs_frag, %jd); 440 FCHK(fs->fs_size, <=, ((int64_t)fs->fs_ncg - 1) * fs->fs_fpg, 441 %jd); 442 FCHK(fs->fs_size, >, (int64_t)fs->fs_ncg * fs->fs_fpg, %jd); 443 FCHK(fs->fs_csaddr, <, 0, %jd); 444 FCHK(fs->fs_cssize, !=, 445 fragroundup(fs, fs->fs_ncg * sizeof(struct csum)), %jd); 446 FCHK(fs->fs_csaddr + howmany(fs->fs_cssize, fs->fs_fsize), >, 447 fs->fs_size, %jd); 448 FCHK(fs->fs_csaddr, <, cgdmin(fs, dtog(fs, fs->fs_csaddr)), 449 %jd); 450 FCHK(dtog(fs, fs->fs_csaddr + howmany(fs->fs_cssize, 451 fs->fs_fsize)), >, dtog(fs, fs->fs_csaddr), %jd); 452 return (error); 453 } 454 if (fs->fs_magic == FS_UFS2_MAGIC) { 455 if ((flags & UFS_ALTSBLK) == 0) 456 FCHK2(fs->fs_sblockactualloc, !=, SBLOCK_UFS2, 457 fs->fs_sblockactualloc, !=, 0, %jd); 458 FCHK(fs->fs_sblockloc, !=, SBLOCK_UFS2, %#jx); 459 FCHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) * 460 sizeof(ufs2_daddr_t)), %jd); 461 FCHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs2_daddr_t), 462 %jd); 463 FCHK(fs->fs_inopb, !=, 464 fs->fs_bsize / sizeof(struct ufs2_dinode), %jd); 465 } else if (fs->fs_magic == FS_UFS1_MAGIC) { 466 if ((flags & UFS_ALTSBLK) == 0) 467 FCHK(fs->fs_sblockactualloc, >, SBLOCK_UFS1, %jd); 468 FCHK(fs->fs_sblockloc, <, 0, %jd); 469 FCHK(fs->fs_sblockloc, >, SBLOCK_UFS1, %jd); 470 FCHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs1_daddr_t), 471 %jd); 472 FCHK(fs->fs_inopb, !=, 473 fs->fs_bsize / sizeof(struct ufs1_dinode), %jd); 474 FCHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) * 475 sizeof(ufs1_daddr_t)), %jd); 476 WCHK(fs->fs_old_inodefmt, !=, FS_44INODEFMT, %jd); 477 WCHK(fs->fs_old_rotdelay, !=, 0, %jd); 478 WCHK(fs->fs_old_rps, !=, 60, %jd); 479 WCHK(fs->fs_old_nspf, !=, fs->fs_fsize / sectorsize, %jd); 480 FCHK(fs->fs_old_cpg, !=, 1, %jd); 481 WCHK(fs->fs_old_interleave, !=, 1, %jd); 482 WCHK(fs->fs_old_trackskew, !=, 0, %jd); 483 WCHK(fs->fs_old_cpc, !=, 0, %jd); 484 WCHK(fs->fs_old_postblformat, !=, 1, %jd); 485 FCHK(fs->fs_old_nrpos, !=, 1, %jd); 486 WCHK(fs->fs_old_spc, !=, fs->fs_fpg * fs->fs_old_nspf, %jd); 487 WCHK(fs->fs_old_nsect, !=, fs->fs_old_spc, %jd); 488 WCHK(fs->fs_old_npsect, !=, fs->fs_old_spc, %jd); 489 FCHK(fs->fs_old_ncyl, !=, fs->fs_ncg, %jd); 490 } else { 491 /* Bad magic number, so assume not a superblock */ 492 return (ENOENT); 493 } 494 FCHK(fs->fs_bsize, <, MINBSIZE, %jd); 495 FCHK(fs->fs_bsize, >, MAXBSIZE, %jd); 496 FCHK(fs->fs_bsize, <, roundup(sizeof(struct fs), DEV_BSIZE), %jd); 497 FCHK(powerof2(fs->fs_bsize), ==, 0, %jd); 498 FCHK(fs->fs_frag, <, 1, %jd); 499 FCHK(fs->fs_frag, >, MAXFRAG, %jd); 500 FCHK(fs->fs_frag, !=, numfrags(fs, fs->fs_bsize), %jd); 501 FCHK(fs->fs_fsize, <, sectorsize, %jd); 502 FCHK(fs->fs_fsize * fs->fs_frag, !=, fs->fs_bsize, %jd); 503 FCHK(powerof2(fs->fs_fsize), ==, 0, %jd); 504 FCHK(fs->fs_fpg, <, 3 * fs->fs_frag, %jd); 505 FCHK(fs->fs_ncg, <, 1, %jd); 506 FCHK(fs->fs_ipg, <, fs->fs_inopb, %jd); 507 FCHK((u_int64_t)fs->fs_ipg * fs->fs_ncg, >, 508 (((int64_t)(1)) << 32) - INOPB(fs), %jd); 509 FCHK(fs->fs_cstotal.cs_nifree, <, 0, %jd); 510 FCHK(fs->fs_cstotal.cs_nifree, >, (u_int64_t)fs->fs_ipg * fs->fs_ncg, 511 %jd); 512 FCHK(fs->fs_cstotal.cs_ndir, <, 0, %jd); 513 FCHK(fs->fs_cstotal.cs_ndir, >, 514 ((u_int64_t)fs->fs_ipg * fs->fs_ncg) - fs->fs_cstotal.cs_nifree, 515 %jd); 516 FCHK(fs->fs_sbsize, >, SBLOCKSIZE, %jd); 517 FCHK(fs->fs_sbsize, <, (signed)sizeof(struct fs), %jd); 518 /* fix for misconfigured filesystems */ 519 if (fs->fs_maxbsize == 0) 520 fs->fs_maxbsize = fs->fs_bsize; 521 FCHK(fs->fs_maxbsize, <, fs->fs_bsize, %jd); 522 FCHK(powerof2(fs->fs_maxbsize), ==, 0, %jd); 523 FCHK(fs->fs_maxbsize, >, FS_MAXCONTIG * fs->fs_bsize, %jd); 524 FCHK(fs->fs_bmask, !=, ~(fs->fs_bsize - 1), %#jx); 525 FCHK(fs->fs_fmask, !=, ~(fs->fs_fsize - 1), %#jx); 526 FCHK(fs->fs_qbmask, !=, ~fs->fs_bmask, %#jx); 527 FCHK(fs->fs_qfmask, !=, ~fs->fs_fmask, %#jx); 528 FCHK(fs->fs_bshift, !=, ILOG2(fs->fs_bsize), %jd); 529 FCHK(fs->fs_fshift, !=, ILOG2(fs->fs_fsize), %jd); 530 FCHK(fs->fs_fragshift, !=, ILOG2(fs->fs_frag), %jd); 531 FCHK(fs->fs_fsbtodb, !=, ILOG2(fs->fs_fsize / sectorsize), %jd); 532 FCHK(fs->fs_old_cgoffset, <, 0, %jd); 533 FCHK2(fs->fs_old_cgoffset, >, 0, ~fs->fs_old_cgmask, <, 0, %jd); 534 FCHK(fs->fs_old_cgoffset * (~fs->fs_old_cgmask), >, fs->fs_fpg, %jd); 535 FCHK(CGSIZE(fs), >, fs->fs_bsize, %jd); 536 /* 537 * If anything has failed up to this point, it is usafe to proceed 538 * as checks below may divide by zero or make other fatal calculations. 539 * So if we have any errors at this point, give up. 540 */ 541 if (error) 542 return (error); 543 FCHK(fs->fs_sbsize % sectorsize, !=, 0, %jd); 544 FCHK(fs->fs_ipg % fs->fs_inopb, !=, 0, %jd); 545 FCHK(fs->fs_sblkno, !=, roundup( 546 howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize), 547 fs->fs_frag), %jd); 548 FCHK(fs->fs_cblkno, !=, fs->fs_sblkno + 549 roundup(howmany(SBLOCKSIZE, fs->fs_fsize), fs->fs_frag), %jd); 550 FCHK(fs->fs_iblkno, !=, fs->fs_cblkno + fs->fs_frag, %jd); 551 FCHK(fs->fs_dblkno, !=, fs->fs_iblkno + fs->fs_ipg / INOPF(fs), %jd); 552 FCHK(fs->fs_cgsize, >, fs->fs_bsize, %jd); 553 FCHK(fs->fs_cgsize, <, fs->fs_fsize, %jd); 554 FCHK(fs->fs_cgsize % fs->fs_fsize, !=, 0, %jd); 555 /* 556 * This test is valid, however older versions of growfs failed 557 * to correctly update fs_dsize so will fail this test. Thus we 558 * exclude it from the requirements. 559 */ 560 #ifdef notdef 561 WCHK(fs->fs_dsize, !=, fs->fs_size - fs->fs_sblkno - 562 fs->fs_ncg * (fs->fs_dblkno - fs->fs_sblkno) - 563 howmany(fs->fs_cssize, fs->fs_fsize), %jd); 564 #endif 565 WCHK(fs->fs_metaspace, <, 0, %jd); 566 WCHK(fs->fs_metaspace, >, fs->fs_fpg / 2, %jd); 567 WCHK(fs->fs_minfree, >, 99, %jd%%); 568 maxfilesize = fs->fs_bsize * UFS_NDADDR - 1; 569 for (sizepb = fs->fs_bsize, i = 0; i < UFS_NIADDR; i++) { 570 sizepb *= NINDIR(fs); 571 maxfilesize += sizepb; 572 } 573 WCHK(fs->fs_maxfilesize, !=, maxfilesize, %jd); 574 /* 575 * These values have a tight interaction with each other that 576 * makes it hard to tightly bound them. So we can only check 577 * that they are within a broader possible range. 578 * 579 * The size cannot always be accurately determined, but ensure 580 * that it is consistent with the number of cylinder groups (fs_ncg) 581 * and the number of fragments per cylinder group (fs_fpg). Ensure 582 * that the summary information size is correct and that it starts 583 * and ends in the data area of the same cylinder group. 584 */ 585 FCHK(fs->fs_size, <, 8 * fs->fs_frag, %jd); 586 FCHK(fs->fs_size, <=, ((int64_t)fs->fs_ncg - 1) * fs->fs_fpg, %jd); 587 FCHK(fs->fs_size, >, (int64_t)fs->fs_ncg * fs->fs_fpg, %jd); 588 /* 589 * If we are not requested to read in the csum data stop here 590 * as the correctness of the remaining values is only important 591 * to bound the space needed to be allocated to hold the csum data. 592 */ 593 if ((flags & UFS_NOCSUM) != 0) 594 return (error); 595 FCHK(fs->fs_csaddr, <, 0, %jd); 596 FCHK(fs->fs_cssize, !=, 597 fragroundup(fs, fs->fs_ncg * sizeof(struct csum)), %jd); 598 FCHK(fs->fs_csaddr + howmany(fs->fs_cssize, fs->fs_fsize), >, 599 fs->fs_size, %jd); 600 FCHK(fs->fs_csaddr, <, cgdmin(fs, dtog(fs, fs->fs_csaddr)), %jd); 601 FCHK(dtog(fs, fs->fs_csaddr + howmany(fs->fs_cssize, fs->fs_fsize)), >, 602 dtog(fs, fs->fs_csaddr), %jd); 603 /* 604 * With file system clustering it is possible to allocate 605 * many contiguous blocks. The kernel variable maxphys defines 606 * the maximum transfer size permitted by the controller and/or 607 * buffering. The fs_maxcontig parameter controls the maximum 608 * number of blocks that the filesystem will read or write 609 * in a single transfer. It is calculated when the filesystem 610 * is created as maxphys / fs_bsize. The loader uses a maxphys 611 * of 128K even when running on a system that supports larger 612 * values. If the filesystem was built on a system that supports 613 * a larger maxphys (1M is typical) it will have configured 614 * fs_maxcontig for that larger system. So we bound the upper 615 * allowable limit for fs_maxconfig to be able to at least 616 * work with a 1M maxphys on the smallest block size filesystem: 617 * 1M / 4096 == 256. There is no harm in allowing the mounting of 618 * filesystems that make larger than maxphys I/O requests because 619 * those (mostly 32-bit machines) can (very slowly) handle I/O 620 * requests that exceed maxphys. 621 */ 622 WCHK(fs->fs_maxcontig, <, 0, %jd); 623 WCHK(fs->fs_maxcontig, >, MAX(256, maxphys / fs->fs_bsize), %jd); 624 FCHK2(fs->fs_maxcontig, ==, 0, fs->fs_contigsumsize, !=, 0, %jd); 625 FCHK2(fs->fs_maxcontig, >, 1, fs->fs_contigsumsize, !=, 626 MIN(fs->fs_maxcontig, FS_MAXCONTIG), %jd); 627 return (error); 628 } 629 630 /* 631 * Make an extensive search to find a superblock. If the superblock 632 * in the standard place cannot be used, try looking for one of the 633 * backup superblocks. 634 * 635 * Flags are made up of the following or'ed together options: 636 * 637 * UFS_NOMSG indicates that superblock inconsistency error messages 638 * should not be printed. 639 * 640 * UFS_NOCSUM causes only the superblock itself to be returned, but does 641 * not read in any auxillary data structures like the cylinder group 642 * summary information. 643 */ 644 int 645 ffs_sbsearch(void *devfd, struct fs **fsp, int reqflags, 646 struct malloc_type *filltype, 647 int (*readfunc)(void *devfd, off_t loc, void **bufp, int size)) 648 { 649 struct fsrecovery *fsr; 650 struct fs *protofs; 651 void *fsrbuf; 652 char *cp; 653 long nocsum, flags, msg, cg; 654 off_t sblk, secsize; 655 int error; 656 657 msg = (reqflags & UFS_NOMSG) == 0; 658 nocsum = reqflags & UFS_NOCSUM; 659 /* 660 * Try normal superblock read and return it if it works. 661 * 662 * Suppress messages if it fails until we find out if 663 * failure can be avoided. 664 */ 665 flags = UFS_NOMSG | nocsum; 666 error = ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc); 667 /* 668 * If successful or endian error, no need to try further. 669 */ 670 if (error == 0 || error == EILSEQ) { 671 if (msg && error == EILSEQ) 672 printf("UFS superblock failed due to endian mismatch " 673 "between machine and filesystem\n"); 674 return (error); 675 } 676 /* 677 * First try: ignoring hash failures. 678 */ 679 flags |= UFS_NOHASHFAIL; 680 if (msg) 681 flags &= ~UFS_NOMSG; 682 if (ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc) == 0) 683 return (0); 684 /* 685 * Next up is to check if fields of the superblock that are 686 * needed to find backup superblocks are usable. 687 */ 688 if (msg) 689 printf("Attempted recovery for standard superblock: failed\n"); 690 flags = UFS_FSRONLY | UFS_NOHASHFAIL | UFS_NOCSUM | UFS_NOMSG; 691 if (ffs_sbget(devfd, &protofs, UFS_STDSB, flags, filltype, 692 readfunc) == 0) { 693 if (msg) 694 printf("Attempt extraction of recovery data from " 695 "standard superblock.\n"); 696 } else { 697 /* 698 * Final desperation is to see if alternate superblock 699 * parameters have been saved in the boot area. 700 */ 701 if (msg) 702 printf("Attempted extraction of recovery data from " 703 "standard superblock: failed\nAttempt to find " 704 "boot zone recovery data.\n"); 705 /* 706 * Look to see if recovery information has been saved. 707 * If so we can generate a prototype superblock based 708 * on that information. 709 * 710 * We need fragments-per-group, number of cylinder groups, 711 * location of the superblock within the cylinder group, and 712 * the conversion from filesystem fragments to disk blocks. 713 * 714 * When building a UFS2 filesystem, newfs(8) stores these 715 * details at the end of the boot block area at the start 716 * of the filesystem partition. If they have been overwritten 717 * by a boot block, we fail. But usually they are there 718 * and we can use them. 719 * 720 * We could ask the underlying device for its sector size, 721 * but some devices lie. So we just try a plausible range. 722 */ 723 error = ENOENT; 724 fsrbuf = NULL; 725 for (secsize = dbtob(1); secsize <= SBLOCKSIZE; secsize *= 2) 726 if ((error = (*readfunc)(devfd, (SBLOCK_UFS2 - secsize), 727 &fsrbuf, secsize)) == 0) 728 break; 729 if (error != 0) 730 goto trynowarn; 731 cp = fsrbuf; /* type change to keep compiler happy */ 732 fsr = (struct fsrecovery *)&cp[secsize - sizeof *fsr]; 733 if (fsr->fsr_magic != FS_UFS2_MAGIC || 734 (protofs = UFS_MALLOC(SBLOCKSIZE, filltype, M_NOWAIT)) 735 == NULL) { 736 UFS_FREE(fsrbuf, filltype); 737 goto trynowarn; 738 } 739 memset(protofs, 0, sizeof(struct fs)); 740 protofs->fs_fpg = fsr->fsr_fpg; 741 protofs->fs_fsbtodb = fsr->fsr_fsbtodb; 742 protofs->fs_sblkno = fsr->fsr_sblkno; 743 protofs->fs_magic = fsr->fsr_magic; 744 protofs->fs_ncg = fsr->fsr_ncg; 745 UFS_FREE(fsrbuf, filltype); 746 } 747 /* 748 * Scan looking for alternative superblocks. 749 */ 750 flags = nocsum; 751 if (!msg) 752 flags |= UFS_NOMSG; 753 for (cg = 0; cg < protofs->fs_ncg; cg++) { 754 sblk = fsbtodb(protofs, cgsblock(protofs, cg)); 755 if (msg) 756 printf("Try cg %ld at sblock loc %jd\n", cg, 757 (intmax_t)sblk); 758 if (ffs_sbget(devfd, fsp, dbtob(sblk), flags, filltype, 759 readfunc) == 0) { 760 if (msg) 761 printf("Succeeded with alternate superblock " 762 "at %jd\n", (intmax_t)sblk); 763 UFS_FREE(protofs, filltype); 764 return (0); 765 } 766 } 767 UFS_FREE(protofs, filltype); 768 /* 769 * Our alternate superblock strategies failed. Our last ditch effort 770 * is to see if the standard superblock has only non-critical errors. 771 */ 772 trynowarn: 773 flags = UFS_NOWARNFAIL | UFS_NOMSG | nocsum; 774 if (msg) { 775 printf("Finding an alternate superblock failed.\nCheck for " 776 "only non-critical errors in standard superblock\n"); 777 flags &= ~UFS_NOMSG; 778 } 779 if (ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc) != 0) { 780 if (msg) 781 printf("Failed, superblock has critical errors\n"); 782 return (ENOENT); 783 } 784 if (msg) 785 printf("Success, using standard superblock with " 786 "non-critical errors.\n"); 787 return (0); 788 } 789 790 /* 791 * Write a superblock to the devfd device from the memory pointed to by fs. 792 * Write out the superblock summary information if it is present. 793 * 794 * If the write is successful, zero is returned. Otherwise one of the 795 * following error values is returned: 796 * EIO: failed to write superblock. 797 * EIO: failed to write superblock summary information. 798 */ 799 int 800 ffs_sbput(void *devfd, struct fs *fs, off_t loc, 801 int (*writefunc)(void *devfd, off_t loc, void *buf, int size)) 802 { 803 int i, error, blks, size; 804 uint8_t *space; 805 806 /* 807 * If there is summary information, write it first, so if there 808 * is an error, the superblock will not be marked as clean. 809 */ 810 if (fs->fs_si != NULL && fs->fs_csp != NULL) { 811 blks = howmany(fs->fs_cssize, fs->fs_fsize); 812 space = (uint8_t *)fs->fs_csp; 813 for (i = 0; i < blks; i += fs->fs_frag) { 814 size = fs->fs_bsize; 815 if (i + fs->fs_frag > blks) 816 size = (blks - i) * fs->fs_fsize; 817 if ((error = (*writefunc)(devfd, 818 dbtob(fsbtodb(fs, fs->fs_csaddr + i)), 819 space, size)) != 0) 820 return (error); 821 space += size; 822 } 823 } 824 fs->fs_fmod = 0; 825 #ifndef _KERNEL 826 { 827 struct fs_summary_info *fs_si; 828 829 fs->fs_time = time(NULL); 830 /* Clear the pointers for the duration of writing. */ 831 fs_si = fs->fs_si; 832 fs->fs_si = NULL; 833 fs->fs_ckhash = ffs_calc_sbhash(fs); 834 error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize); 835 fs->fs_si = fs_si; 836 } 837 #else /* _KERNEL */ 838 fs->fs_time = time_second; 839 fs->fs_ckhash = ffs_calc_sbhash(fs); 840 error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize); 841 #endif /* _KERNEL */ 842 return (error); 843 } 844 845 /* 846 * Calculate the check-hash for a superblock. 847 */ 848 uint32_t 849 ffs_calc_sbhash(struct fs *fs) 850 { 851 uint32_t ckhash, save_ckhash; 852 853 /* 854 * A filesystem that was using a superblock ckhash may be moved 855 * to an older kernel that does not support ckhashes. The 856 * older kernel will clear the FS_METACKHASH flag indicating 857 * that it does not update hashes. When the disk is moved back 858 * to a kernel capable of ckhashes it disables them on mount: 859 * 860 * if ((fs->fs_flags & FS_METACKHASH) == 0) 861 * fs->fs_metackhash = 0; 862 * 863 * This leaves (fs->fs_metackhash & CK_SUPERBLOCK) == 0) with an 864 * old stale value in the fs->fs_ckhash field. Thus the need to 865 * just accept what is there. 866 */ 867 if ((fs->fs_metackhash & CK_SUPERBLOCK) == 0) 868 return (fs->fs_ckhash); 869 870 save_ckhash = fs->fs_ckhash; 871 fs->fs_ckhash = 0; 872 /* 873 * If newly read from disk, the caller is responsible for 874 * verifying that fs->fs_sbsize <= SBLOCKSIZE. 875 */ 876 ckhash = calculate_crc32c(~0L, (void *)fs, fs->fs_sbsize); 877 fs->fs_ckhash = save_ckhash; 878 return (ckhash); 879 } 880 881 /* 882 * Update the frsum fields to reflect addition or deletion 883 * of some frags. 884 */ 885 void 886 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt) 887 { 888 int inblk; 889 int field, subfield; 890 int siz, pos; 891 892 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 893 fragmap <<= 1; 894 for (siz = 1; siz < fs->fs_frag; siz++) { 895 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 896 continue; 897 field = around[siz]; 898 subfield = inside[siz]; 899 for (pos = siz; pos <= fs->fs_frag; pos++) { 900 if ((fragmap & field) == subfield) { 901 fraglist[siz] += cnt; 902 pos += siz; 903 field <<= siz; 904 subfield <<= siz; 905 } 906 field <<= 1; 907 subfield <<= 1; 908 } 909 } 910 } 911 912 /* 913 * block operations 914 * 915 * check if a block is available 916 */ 917 int 918 ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h) 919 { 920 unsigned char mask; 921 922 switch ((int)fs->fs_frag) { 923 case 8: 924 return (cp[h] == 0xff); 925 case 4: 926 mask = 0x0f << ((h & 0x1) << 2); 927 return ((cp[h >> 1] & mask) == mask); 928 case 2: 929 mask = 0x03 << ((h & 0x3) << 1); 930 return ((cp[h >> 2] & mask) == mask); 931 case 1: 932 mask = 0x01 << (h & 0x7); 933 return ((cp[h >> 3] & mask) == mask); 934 default: 935 #ifdef _KERNEL 936 panic("ffs_isblock"); 937 #endif 938 break; 939 } 940 return (0); 941 } 942 943 /* 944 * check if a block is free 945 */ 946 int 947 ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h) 948 { 949 950 switch ((int)fs->fs_frag) { 951 case 8: 952 return (cp[h] == 0); 953 case 4: 954 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); 955 case 2: 956 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); 957 case 1: 958 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); 959 default: 960 #ifdef _KERNEL 961 panic("ffs_isfreeblock"); 962 #endif 963 break; 964 } 965 return (0); 966 } 967 968 /* 969 * take a block out of the map 970 */ 971 void 972 ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h) 973 { 974 975 switch ((int)fs->fs_frag) { 976 case 8: 977 cp[h] = 0; 978 return; 979 case 4: 980 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 981 return; 982 case 2: 983 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 984 return; 985 case 1: 986 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 987 return; 988 default: 989 #ifdef _KERNEL 990 panic("ffs_clrblock"); 991 #endif 992 break; 993 } 994 } 995 996 /* 997 * put a block into the map 998 */ 999 void 1000 ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h) 1001 { 1002 1003 switch ((int)fs->fs_frag) { 1004 case 8: 1005 cp[h] = 0xff; 1006 return; 1007 case 4: 1008 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 1009 return; 1010 case 2: 1011 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 1012 return; 1013 case 1: 1014 cp[h >> 3] |= (0x01 << (h & 0x7)); 1015 return; 1016 default: 1017 #ifdef _KERNEL 1018 panic("ffs_setblock"); 1019 #endif 1020 break; 1021 } 1022 } 1023 1024 /* 1025 * Update the cluster map because of an allocation or free. 1026 * 1027 * Cnt == 1 means free; cnt == -1 means allocating. 1028 */ 1029 void 1030 ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt) 1031 { 1032 int32_t *sump; 1033 int32_t *lp; 1034 u_char *freemapp, *mapp; 1035 int i, start, end, forw, back, map; 1036 u_int bit; 1037 1038 if (fs->fs_contigsumsize <= 0) 1039 return; 1040 freemapp = cg_clustersfree(cgp); 1041 sump = cg_clustersum(cgp); 1042 /* 1043 * Allocate or clear the actual block. 1044 */ 1045 if (cnt > 0) 1046 setbit(freemapp, blkno); 1047 else 1048 clrbit(freemapp, blkno); 1049 /* 1050 * Find the size of the cluster going forward. 1051 */ 1052 start = blkno + 1; 1053 end = start + fs->fs_contigsumsize; 1054 if (end >= cgp->cg_nclusterblks) 1055 end = cgp->cg_nclusterblks; 1056 mapp = &freemapp[start / NBBY]; 1057 map = *mapp++; 1058 bit = 1U << (start % NBBY); 1059 for (i = start; i < end; i++) { 1060 if ((map & bit) == 0) 1061 break; 1062 if ((i & (NBBY - 1)) != (NBBY - 1)) { 1063 bit <<= 1; 1064 } else { 1065 map = *mapp++; 1066 bit = 1; 1067 } 1068 } 1069 forw = i - start; 1070 /* 1071 * Find the size of the cluster going backward. 1072 */ 1073 start = blkno - 1; 1074 end = start - fs->fs_contigsumsize; 1075 if (end < 0) 1076 end = -1; 1077 mapp = &freemapp[start / NBBY]; 1078 map = *mapp--; 1079 bit = 1U << (start % NBBY); 1080 for (i = start; i > end; i--) { 1081 if ((map & bit) == 0) 1082 break; 1083 if ((i & (NBBY - 1)) != 0) { 1084 bit >>= 1; 1085 } else { 1086 map = *mapp--; 1087 bit = 1U << (NBBY - 1); 1088 } 1089 } 1090 back = start - i; 1091 /* 1092 * Account for old cluster and the possibly new forward and 1093 * back clusters. 1094 */ 1095 i = back + forw + 1; 1096 if (i > fs->fs_contigsumsize) 1097 i = fs->fs_contigsumsize; 1098 sump[i] += cnt; 1099 if (back > 0) 1100 sump[back] -= cnt; 1101 if (forw > 0) 1102 sump[forw] -= cnt; 1103 /* 1104 * Update cluster summary information. 1105 */ 1106 lp = &sump[fs->fs_contigsumsize]; 1107 for (i = fs->fs_contigsumsize; i > 0; i--) 1108 if (*lp-- > 0) 1109 break; 1110 fs->fs_maxcluster[cgp->cg_cgx] = i; 1111 } 1112