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(dtog(fs, fs->fs_csaddr), >, fs->fs_ncg, %jd); 447 FCHK(fs->fs_csaddr, <, cgdmin(fs, dtog(fs, fs->fs_csaddr)), 448 %jd); 449 FCHK(dtog(fs, fs->fs_csaddr + howmany(fs->fs_cssize, 450 fs->fs_fsize)), >, dtog(fs, fs->fs_csaddr), %jd); 451 return (error); 452 } 453 if (fs->fs_magic == FS_UFS2_MAGIC) { 454 if ((flags & UFS_ALTSBLK) == 0) 455 FCHK2(fs->fs_sblockactualloc, !=, SBLOCK_UFS2, 456 fs->fs_sblockactualloc, !=, 0, %jd); 457 FCHK(fs->fs_sblockloc, !=, SBLOCK_UFS2, %#jx); 458 FCHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) * 459 sizeof(ufs2_daddr_t)), %jd); 460 FCHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs2_daddr_t), 461 %jd); 462 FCHK(fs->fs_inopb, !=, 463 fs->fs_bsize / sizeof(struct ufs2_dinode), %jd); 464 } else if (fs->fs_magic == FS_UFS1_MAGIC) { 465 if ((flags & UFS_ALTSBLK) == 0) 466 FCHK(fs->fs_sblockactualloc, >, SBLOCK_UFS1, %jd); 467 FCHK(fs->fs_sblockloc, <, 0, %jd); 468 FCHK(fs->fs_sblockloc, >, SBLOCK_UFS1, %jd); 469 FCHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs1_daddr_t), 470 %jd); 471 FCHK(fs->fs_inopb, !=, 472 fs->fs_bsize / sizeof(struct ufs1_dinode), %jd); 473 FCHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) * 474 sizeof(ufs1_daddr_t)), %jd); 475 WCHK(fs->fs_old_inodefmt, !=, FS_44INODEFMT, %jd); 476 WCHK(fs->fs_old_rotdelay, !=, 0, %jd); 477 WCHK(fs->fs_old_rps, !=, 60, %jd); 478 WCHK(fs->fs_old_nspf, !=, fs->fs_fsize / sectorsize, %jd); 479 FCHK(fs->fs_old_cpg, !=, 1, %jd); 480 WCHK(fs->fs_old_interleave, !=, 1, %jd); 481 WCHK(fs->fs_old_trackskew, !=, 0, %jd); 482 WCHK(fs->fs_old_cpc, !=, 0, %jd); 483 WCHK(fs->fs_old_postblformat, !=, 1, %jd); 484 FCHK(fs->fs_old_nrpos, !=, 1, %jd); 485 WCHK(fs->fs_old_spc, !=, fs->fs_fpg * fs->fs_old_nspf, %jd); 486 WCHK(fs->fs_old_nsect, !=, fs->fs_old_spc, %jd); 487 WCHK(fs->fs_old_npsect, !=, fs->fs_old_spc, %jd); 488 FCHK(fs->fs_old_ncyl, !=, fs->fs_ncg, %jd); 489 } else { 490 /* Bad magic number, so assume not a superblock */ 491 return (ENOENT); 492 } 493 FCHK(fs->fs_bsize, <, MINBSIZE, %jd); 494 FCHK(fs->fs_bsize, >, MAXBSIZE, %jd); 495 FCHK(fs->fs_bsize, <, roundup(sizeof(struct fs), DEV_BSIZE), %jd); 496 FCHK(powerof2(fs->fs_bsize), ==, 0, %jd); 497 FCHK(fs->fs_frag, <, 1, %jd); 498 FCHK(fs->fs_frag, >, MAXFRAG, %jd); 499 FCHK(fs->fs_frag, !=, numfrags(fs, fs->fs_bsize), %jd); 500 FCHK(fs->fs_fsize, <, sectorsize, %jd); 501 FCHK(fs->fs_fsize * fs->fs_frag, !=, fs->fs_bsize, %jd); 502 FCHK(powerof2(fs->fs_fsize), ==, 0, %jd); 503 FCHK(fs->fs_fpg, <, 3 * fs->fs_frag, %jd); 504 FCHK(fs->fs_ncg, <, 1, %jd); 505 FCHK(fs->fs_ipg, <, fs->fs_inopb, %jd); 506 FCHK((u_int64_t)fs->fs_ipg * fs->fs_ncg, >, 507 (((int64_t)(1)) << 32) - INOPB(fs), %jd); 508 FCHK(fs->fs_cstotal.cs_nifree, <, 0, %jd); 509 FCHK(fs->fs_cstotal.cs_nifree, >, (u_int64_t)fs->fs_ipg * fs->fs_ncg, 510 %jd); 511 FCHK(fs->fs_cstotal.cs_ndir, <, 0, %jd); 512 FCHK(fs->fs_cstotal.cs_ndir, >, 513 ((u_int64_t)fs->fs_ipg * fs->fs_ncg) - fs->fs_cstotal.cs_nifree, 514 %jd); 515 FCHK(fs->fs_sbsize, >, SBLOCKSIZE, %jd); 516 FCHK(fs->fs_sbsize, <, (signed)sizeof(struct fs), %jd); 517 FCHK(fs->fs_maxbsize, <, fs->fs_bsize, %jd); 518 FCHK(powerof2(fs->fs_maxbsize), ==, 0, %jd); 519 FCHK(fs->fs_maxbsize, >, FS_MAXCONTIG * fs->fs_bsize, %jd); 520 FCHK(fs->fs_bmask, !=, ~(fs->fs_bsize - 1), %#jx); 521 FCHK(fs->fs_fmask, !=, ~(fs->fs_fsize - 1), %#jx); 522 FCHK(fs->fs_qbmask, !=, ~fs->fs_bmask, %#jx); 523 FCHK(fs->fs_qfmask, !=, ~fs->fs_fmask, %#jx); 524 FCHK(fs->fs_bshift, !=, ILOG2(fs->fs_bsize), %jd); 525 FCHK(fs->fs_fshift, !=, ILOG2(fs->fs_fsize), %jd); 526 FCHK(fs->fs_fragshift, !=, ILOG2(fs->fs_frag), %jd); 527 FCHK(fs->fs_fsbtodb, !=, ILOG2(fs->fs_fsize / sectorsize), %jd); 528 FCHK(fs->fs_old_cgoffset, <, 0, %jd); 529 FCHK2(fs->fs_old_cgoffset, >, 0, ~fs->fs_old_cgmask, <, 0, %jd); 530 FCHK(fs->fs_old_cgoffset * (~fs->fs_old_cgmask), >, fs->fs_fpg, %jd); 531 FCHK(CGSIZE(fs), >, fs->fs_bsize, %jd); 532 /* 533 * If anything has failed up to this point, it is usafe to proceed 534 * as checks below may divide by zero or make other fatal calculations. 535 * So if we have any errors at this point, give up. 536 */ 537 if (error) 538 return (error); 539 FCHK(fs->fs_sbsize % sectorsize, !=, 0, %jd); 540 FCHK(fs->fs_ipg % fs->fs_inopb, !=, 0, %jd); 541 FCHK(fs->fs_sblkno, !=, roundup( 542 howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize), 543 fs->fs_frag), %jd); 544 FCHK(fs->fs_cblkno, !=, fs->fs_sblkno + 545 roundup(howmany(SBLOCKSIZE, fs->fs_fsize), fs->fs_frag), %jd); 546 FCHK(fs->fs_iblkno, !=, fs->fs_cblkno + fs->fs_frag, %jd); 547 FCHK(fs->fs_dblkno, !=, fs->fs_iblkno + fs->fs_ipg / INOPF(fs), %jd); 548 FCHK(fs->fs_cgsize, >, fs->fs_bsize, %jd); 549 FCHK(fs->fs_cgsize, <, fs->fs_fsize, %jd); 550 FCHK(fs->fs_cgsize % fs->fs_fsize, !=, 0, %jd); 551 /* 552 * This test is valid, however older versions of growfs failed 553 * to correctly update fs_dsize so will fail this test. Thus we 554 * exclude it from the requirements. 555 */ 556 #ifdef notdef 557 WCHK(fs->fs_dsize, !=, fs->fs_size - fs->fs_sblkno - 558 fs->fs_ncg * (fs->fs_dblkno - fs->fs_sblkno) - 559 howmany(fs->fs_cssize, fs->fs_fsize), %jd); 560 #endif 561 WCHK(fs->fs_metaspace, <, 0, %jd); 562 WCHK(fs->fs_metaspace, >, fs->fs_fpg / 2, %jd); 563 WCHK(fs->fs_minfree, >, 99, %jd%%); 564 maxfilesize = fs->fs_bsize * UFS_NDADDR - 1; 565 for (sizepb = fs->fs_bsize, i = 0; i < UFS_NIADDR; i++) { 566 sizepb *= NINDIR(fs); 567 maxfilesize += sizepb; 568 } 569 WCHK(fs->fs_maxfilesize, !=, maxfilesize, %jd); 570 /* 571 * These values have a tight interaction with each other that 572 * makes it hard to tightly bound them. So we can only check 573 * that they are within a broader possible range. 574 * 575 * The size cannot always be accurately determined, but ensure 576 * that it is consistent with the number of cylinder groups (fs_ncg) 577 * and the number of fragments per cylinder group (fs_fpg). Ensure 578 * that the summary information size is correct and that it starts 579 * and ends in the data area of the same cylinder group. 580 */ 581 FCHK(fs->fs_size, <, 8 * fs->fs_frag, %jd); 582 FCHK(fs->fs_size, <=, ((int64_t)fs->fs_ncg - 1) * fs->fs_fpg, %jd); 583 FCHK(fs->fs_size, >, (int64_t)fs->fs_ncg * fs->fs_fpg, %jd); 584 /* 585 * If we are not requested to read in the csum data stop here 586 * as the correctness of the remaining values is only important 587 * to bound the space needed to be allocated to hold the csum data. 588 */ 589 if ((flags & UFS_NOCSUM) != 0) 590 return (error); 591 FCHK(fs->fs_csaddr, <, 0, %jd); 592 FCHK(fs->fs_cssize, !=, 593 fragroundup(fs, fs->fs_ncg * sizeof(struct csum)), %jd); 594 FCHK(dtog(fs, fs->fs_csaddr), >, fs->fs_ncg, %jd); 595 FCHK(fs->fs_csaddr, <, cgdmin(fs, dtog(fs, fs->fs_csaddr)), %jd); 596 FCHK(dtog(fs, fs->fs_csaddr + howmany(fs->fs_cssize, fs->fs_fsize)), >, 597 dtog(fs, fs->fs_csaddr), %jd); 598 /* 599 * With file system clustering it is possible to allocate 600 * many contiguous blocks. The kernel variable maxphys defines 601 * the maximum transfer size permitted by the controller and/or 602 * buffering. The fs_maxcontig parameter controls the maximum 603 * number of blocks that the filesystem will read or write 604 * in a single transfer. It is calculated when the filesystem 605 * is created as maxphys / fs_bsize. The loader uses a maxphys 606 * of 128K even when running on a system that supports larger 607 * values. If the filesystem was built on a system that supports 608 * a larger maxphys (1M is typical) it will have configured 609 * fs_maxcontig for that larger system. So we bound the upper 610 * allowable limit for fs_maxconfig to be able to at least 611 * work with a 1M maxphys on the smallest block size filesystem: 612 * 1M / 4096 == 256. There is no harm in allowing the mounting of 613 * filesystems that make larger than maxphys I/O requests because 614 * those (mostly 32-bit machines) can (very slowly) handle I/O 615 * requests that exceed maxphys. 616 */ 617 WCHK(fs->fs_maxcontig, <, 0, %jd); 618 WCHK(fs->fs_maxcontig, >, MAX(256, maxphys / fs->fs_bsize), %jd); 619 FCHK2(fs->fs_maxcontig, ==, 0, fs->fs_contigsumsize, !=, 0, %jd); 620 FCHK2(fs->fs_maxcontig, >, 1, fs->fs_contigsumsize, !=, 621 MIN(fs->fs_maxcontig, FS_MAXCONTIG), %jd); 622 return (error); 623 } 624 625 /* 626 * Make an extensive search to find a superblock. If the superblock 627 * in the standard place cannot be used, try looking for one of the 628 * backup superblocks. 629 * 630 * Flags are made up of the following or'ed together options: 631 * 632 * UFS_NOMSG indicates that superblock inconsistency error messages 633 * should not be printed. 634 * 635 * UFS_NOCSUM causes only the superblock itself to be returned, but does 636 * not read in any auxillary data structures like the cylinder group 637 * summary information. 638 */ 639 int 640 ffs_sbsearch(void *devfd, struct fs **fsp, int reqflags, 641 struct malloc_type *filltype, 642 int (*readfunc)(void *devfd, off_t loc, void **bufp, int size)) 643 { 644 struct fsrecovery *fsr; 645 struct fs *protofs; 646 void *fsrbuf; 647 char *cp; 648 long nocsum, flags, msg, cg; 649 off_t sblk, secsize; 650 int error; 651 652 msg = (reqflags & UFS_NOMSG) == 0; 653 nocsum = reqflags & UFS_NOCSUM; 654 /* 655 * Try normal superblock read and return it if it works. 656 * 657 * Suppress messages if it fails until we find out if 658 * failure can be avoided. 659 */ 660 flags = UFS_NOMSG | nocsum; 661 error = ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc); 662 /* 663 * If successful or endian error, no need to try further. 664 */ 665 if (error == 0 || error == EILSEQ) { 666 if (msg && error == EILSEQ) 667 printf("UFS superblock failed due to endian mismatch " 668 "between machine and filesystem\n"); 669 return (error); 670 } 671 /* 672 * First try: ignoring hash failures. 673 */ 674 flags |= UFS_NOHASHFAIL; 675 if (msg) 676 flags &= ~UFS_NOMSG; 677 if (ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc) == 0) 678 return (0); 679 /* 680 * Next up is to check if fields of the superblock that are 681 * needed to find backup superblocks are usable. 682 */ 683 if (msg) 684 printf("Attempted recovery for standard superblock: failed\n"); 685 flags = UFS_FSRONLY | UFS_NOHASHFAIL | UFS_NOMSG; 686 if (ffs_sbget(devfd, &protofs, UFS_STDSB, flags, filltype, 687 readfunc) == 0) { 688 if (msg) 689 printf("Attempt extraction of recovery data from " 690 "standard superblock.\n"); 691 } else { 692 /* 693 * Final desperation is to see if alternate superblock 694 * parameters have been saved in the boot area. 695 */ 696 if (msg) 697 printf("Attempted extraction of recovery data from " 698 "standard superblock: failed\nAttempt to find " 699 "boot zone recovery data.\n"); 700 /* 701 * Look to see if recovery information has been saved. 702 * If so we can generate a prototype superblock based 703 * on that information. 704 * 705 * We need fragments-per-group, number of cylinder groups, 706 * location of the superblock within the cylinder group, and 707 * the conversion from filesystem fragments to disk blocks. 708 * 709 * When building a UFS2 filesystem, newfs(8) stores these 710 * details at the end of the boot block area at the start 711 * of the filesystem partition. If they have been overwritten 712 * by a boot block, we fail. But usually they are there 713 * and we can use them. 714 * 715 * We could ask the underlying device for its sector size, 716 * but some devices lie. So we just try a plausible range. 717 */ 718 error = ENOENT; 719 fsrbuf = NULL; 720 for (secsize = dbtob(1); secsize <= SBLOCKSIZE; secsize *= 2) 721 if ((error = (*readfunc)(devfd, (SBLOCK_UFS2 - secsize), 722 &fsrbuf, secsize)) == 0) 723 break; 724 if (error != 0) 725 goto trynowarn; 726 cp = fsrbuf; /* type change to keep compiler happy */ 727 fsr = (struct fsrecovery *)&cp[secsize - sizeof *fsr]; 728 if (fsr->fsr_magic != FS_UFS2_MAGIC || 729 (protofs = UFS_MALLOC(SBLOCKSIZE, filltype, M_NOWAIT)) 730 == NULL) { 731 UFS_FREE(fsrbuf, filltype); 732 goto trynowarn; 733 } 734 memset(protofs, 0, sizeof(struct fs)); 735 protofs->fs_fpg = fsr->fsr_fpg; 736 protofs->fs_fsbtodb = fsr->fsr_fsbtodb; 737 protofs->fs_sblkno = fsr->fsr_sblkno; 738 protofs->fs_magic = fsr->fsr_magic; 739 protofs->fs_ncg = fsr->fsr_ncg; 740 UFS_FREE(fsrbuf, filltype); 741 } 742 /* 743 * Scan looking for alternative superblocks. 744 */ 745 flags = nocsum; 746 if (!msg) 747 flags |= UFS_NOMSG; 748 for (cg = 0; cg < protofs->fs_ncg; cg++) { 749 sblk = fsbtodb(protofs, cgsblock(protofs, cg)); 750 if (msg) 751 printf("Try cg %ld at sblock loc %jd\n", cg, 752 (intmax_t)sblk); 753 if (ffs_sbget(devfd, fsp, dbtob(sblk), flags, filltype, 754 readfunc) == 0) { 755 if (msg) 756 printf("Succeeded with alternate superblock " 757 "at %jd\n", (intmax_t)sblk); 758 UFS_FREE(protofs, filltype); 759 return (0); 760 } 761 } 762 UFS_FREE(protofs, filltype); 763 /* 764 * Our alternate superblock strategies failed. Our last ditch effort 765 * is to see if the standard superblock has only non-critical errors. 766 */ 767 trynowarn: 768 flags = UFS_NOWARNFAIL | UFS_NOMSG | nocsum; 769 if (msg) { 770 printf("Finding an alternate superblock failed.\nCheck for " 771 "only non-critical errors in standard superblock\n"); 772 flags &= ~UFS_NOMSG; 773 } 774 if (ffs_sbget(devfd, fsp, UFS_STDSB, flags, filltype, readfunc) != 0) { 775 if (msg) 776 printf("Failed, superblock has critical errors\n"); 777 return (ENOENT); 778 } 779 if (msg) 780 printf("Success, using standard superblock with " 781 "non-critical errors.\n"); 782 return (0); 783 } 784 785 /* 786 * Write a superblock to the devfd device from the memory pointed to by fs. 787 * Write out the superblock summary information if it is present. 788 * 789 * If the write is successful, zero is returned. Otherwise one of the 790 * following error values is returned: 791 * EIO: failed to write superblock. 792 * EIO: failed to write superblock summary information. 793 */ 794 int 795 ffs_sbput(void *devfd, struct fs *fs, off_t loc, 796 int (*writefunc)(void *devfd, off_t loc, void *buf, int size)) 797 { 798 int i, error, blks, size; 799 uint8_t *space; 800 801 /* 802 * If there is summary information, write it first, so if there 803 * is an error, the superblock will not be marked as clean. 804 */ 805 if (fs->fs_si != NULL && fs->fs_csp != NULL) { 806 blks = howmany(fs->fs_cssize, fs->fs_fsize); 807 space = (uint8_t *)fs->fs_csp; 808 for (i = 0; i < blks; i += fs->fs_frag) { 809 size = fs->fs_bsize; 810 if (i + fs->fs_frag > blks) 811 size = (blks - i) * fs->fs_fsize; 812 if ((error = (*writefunc)(devfd, 813 dbtob(fsbtodb(fs, fs->fs_csaddr + i)), 814 space, size)) != 0) 815 return (error); 816 space += size; 817 } 818 } 819 fs->fs_fmod = 0; 820 #ifndef _KERNEL 821 { 822 struct fs_summary_info *fs_si; 823 824 fs->fs_time = time(NULL); 825 /* Clear the pointers for the duration of writing. */ 826 fs_si = fs->fs_si; 827 fs->fs_si = NULL; 828 fs->fs_ckhash = ffs_calc_sbhash(fs); 829 error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize); 830 fs->fs_si = fs_si; 831 } 832 #else /* _KERNEL */ 833 fs->fs_time = time_second; 834 fs->fs_ckhash = ffs_calc_sbhash(fs); 835 error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize); 836 #endif /* _KERNEL */ 837 return (error); 838 } 839 840 /* 841 * Calculate the check-hash for a superblock. 842 */ 843 uint32_t 844 ffs_calc_sbhash(struct fs *fs) 845 { 846 uint32_t ckhash, save_ckhash; 847 848 /* 849 * A filesystem that was using a superblock ckhash may be moved 850 * to an older kernel that does not support ckhashes. The 851 * older kernel will clear the FS_METACKHASH flag indicating 852 * that it does not update hashes. When the disk is moved back 853 * to a kernel capable of ckhashes it disables them on mount: 854 * 855 * if ((fs->fs_flags & FS_METACKHASH) == 0) 856 * fs->fs_metackhash = 0; 857 * 858 * This leaves (fs->fs_metackhash & CK_SUPERBLOCK) == 0) with an 859 * old stale value in the fs->fs_ckhash field. Thus the need to 860 * just accept what is there. 861 */ 862 if ((fs->fs_metackhash & CK_SUPERBLOCK) == 0) 863 return (fs->fs_ckhash); 864 865 save_ckhash = fs->fs_ckhash; 866 fs->fs_ckhash = 0; 867 /* 868 * If newly read from disk, the caller is responsible for 869 * verifying that fs->fs_sbsize <= SBLOCKSIZE. 870 */ 871 ckhash = calculate_crc32c(~0L, (void *)fs, fs->fs_sbsize); 872 fs->fs_ckhash = save_ckhash; 873 return (ckhash); 874 } 875 876 /* 877 * Update the frsum fields to reflect addition or deletion 878 * of some frags. 879 */ 880 void 881 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt) 882 { 883 int inblk; 884 int field, subfield; 885 int siz, pos; 886 887 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; 888 fragmap <<= 1; 889 for (siz = 1; siz < fs->fs_frag; siz++) { 890 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) 891 continue; 892 field = around[siz]; 893 subfield = inside[siz]; 894 for (pos = siz; pos <= fs->fs_frag; pos++) { 895 if ((fragmap & field) == subfield) { 896 fraglist[siz] += cnt; 897 pos += siz; 898 field <<= siz; 899 subfield <<= siz; 900 } 901 field <<= 1; 902 subfield <<= 1; 903 } 904 } 905 } 906 907 /* 908 * block operations 909 * 910 * check if a block is available 911 */ 912 int 913 ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h) 914 { 915 unsigned char mask; 916 917 switch ((int)fs->fs_frag) { 918 case 8: 919 return (cp[h] == 0xff); 920 case 4: 921 mask = 0x0f << ((h & 0x1) << 2); 922 return ((cp[h >> 1] & mask) == mask); 923 case 2: 924 mask = 0x03 << ((h & 0x3) << 1); 925 return ((cp[h >> 2] & mask) == mask); 926 case 1: 927 mask = 0x01 << (h & 0x7); 928 return ((cp[h >> 3] & mask) == mask); 929 default: 930 #ifdef _KERNEL 931 panic("ffs_isblock"); 932 #endif 933 break; 934 } 935 return (0); 936 } 937 938 /* 939 * check if a block is free 940 */ 941 int 942 ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h) 943 { 944 945 switch ((int)fs->fs_frag) { 946 case 8: 947 return (cp[h] == 0); 948 case 4: 949 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); 950 case 2: 951 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); 952 case 1: 953 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); 954 default: 955 #ifdef _KERNEL 956 panic("ffs_isfreeblock"); 957 #endif 958 break; 959 } 960 return (0); 961 } 962 963 /* 964 * take a block out of the map 965 */ 966 void 967 ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h) 968 { 969 970 switch ((int)fs->fs_frag) { 971 case 8: 972 cp[h] = 0; 973 return; 974 case 4: 975 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); 976 return; 977 case 2: 978 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); 979 return; 980 case 1: 981 cp[h >> 3] &= ~(0x01 << (h & 0x7)); 982 return; 983 default: 984 #ifdef _KERNEL 985 panic("ffs_clrblock"); 986 #endif 987 break; 988 } 989 } 990 991 /* 992 * put a block into the map 993 */ 994 void 995 ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h) 996 { 997 998 switch ((int)fs->fs_frag) { 999 case 8: 1000 cp[h] = 0xff; 1001 return; 1002 case 4: 1003 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); 1004 return; 1005 case 2: 1006 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); 1007 return; 1008 case 1: 1009 cp[h >> 3] |= (0x01 << (h & 0x7)); 1010 return; 1011 default: 1012 #ifdef _KERNEL 1013 panic("ffs_setblock"); 1014 #endif 1015 break; 1016 } 1017 } 1018 1019 /* 1020 * Update the cluster map because of an allocation or free. 1021 * 1022 * Cnt == 1 means free; cnt == -1 means allocating. 1023 */ 1024 void 1025 ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt) 1026 { 1027 int32_t *sump; 1028 int32_t *lp; 1029 u_char *freemapp, *mapp; 1030 int i, start, end, forw, back, map; 1031 u_int bit; 1032 1033 if (fs->fs_contigsumsize <= 0) 1034 return; 1035 freemapp = cg_clustersfree(cgp); 1036 sump = cg_clustersum(cgp); 1037 /* 1038 * Allocate or clear the actual block. 1039 */ 1040 if (cnt > 0) 1041 setbit(freemapp, blkno); 1042 else 1043 clrbit(freemapp, blkno); 1044 /* 1045 * Find the size of the cluster going forward. 1046 */ 1047 start = blkno + 1; 1048 end = start + fs->fs_contigsumsize; 1049 if (end >= cgp->cg_nclusterblks) 1050 end = cgp->cg_nclusterblks; 1051 mapp = &freemapp[start / NBBY]; 1052 map = *mapp++; 1053 bit = 1U << (start % NBBY); 1054 for (i = start; i < end; i++) { 1055 if ((map & bit) == 0) 1056 break; 1057 if ((i & (NBBY - 1)) != (NBBY - 1)) { 1058 bit <<= 1; 1059 } else { 1060 map = *mapp++; 1061 bit = 1; 1062 } 1063 } 1064 forw = i - start; 1065 /* 1066 * Find the size of the cluster going backward. 1067 */ 1068 start = blkno - 1; 1069 end = start - fs->fs_contigsumsize; 1070 if (end < 0) 1071 end = -1; 1072 mapp = &freemapp[start / NBBY]; 1073 map = *mapp--; 1074 bit = 1U << (start % NBBY); 1075 for (i = start; i > end; i--) { 1076 if ((map & bit) == 0) 1077 break; 1078 if ((i & (NBBY - 1)) != 0) { 1079 bit >>= 1; 1080 } else { 1081 map = *mapp--; 1082 bit = 1U << (NBBY - 1); 1083 } 1084 } 1085 back = start - i; 1086 /* 1087 * Account for old cluster and the possibly new forward and 1088 * back clusters. 1089 */ 1090 i = back + forw + 1; 1091 if (i > fs->fs_contigsumsize) 1092 i = fs->fs_contigsumsize; 1093 sump[i] += cnt; 1094 if (back > 0) 1095 sump[back] -= cnt; 1096 if (forw > 0) 1097 sump[forw] -= cnt; 1098 /* 1099 * Update cluster summary information. 1100 */ 1101 lp = &sump[fs->fs_contigsumsize]; 1102 for (i = fs->fs_contigsumsize; i > 0; i--) 1103 if (*lp-- > 0) 1104 break; 1105 fs->fs_maxcluster[cgp->cg_cgx] = i; 1106 } 1107