ext2fs.h revision 1.36.10.1
1 /* $NetBSD: ext2fs.h,v 1.36.10.1 2016/07/09 20:25:24 skrll Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 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 * @(#)fs.h 8.10 (Berkeley) 10/27/94 32 * Modified for ext2fs by Manuel Bouyer. 33 */ 34 35 /* 36 * Copyright (c) 1997 Manuel Bouyer. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 50 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 51 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 52 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 53 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 54 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 55 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 56 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 57 * 58 * @(#)fs.h 8.10 (Berkeley) 10/27/94 59 * Modified for ext2fs by Manuel Bouyer. 60 */ 61 62 #ifndef _UFS_EXT2FS_EXT2FS_H_ 63 #define _UFS_EXT2FS_EXT2FS_H_ 64 65 #include <sys/bswap.h> 66 67 /* 68 * Each disk drive contains some number of file systems. 69 * A file system consists of a number of cylinder groups. 70 * Each cylinder group has inodes and data. 71 * 72 * A file system is described by its super-block, which in turn 73 * describes the cylinder groups. The super-block is critical 74 * data and is replicated in each cylinder group to protect against 75 * catastrophic loss. This is done at `newfs' time and the critical 76 * super-block data does not change, so the copies need not be 77 * referenced further unless disaster strikes. 78 * 79 * The first boot and super blocks are given in absolute disk addresses. 80 * The byte-offset forms are preferred, as they don't imply a sector size. 81 */ 82 #define BBSIZE 1024 83 #define SBSIZE 1024 84 #define BBOFF ((off_t)(0)) 85 #define SBOFF ((off_t)(BBOFF + BBSIZE)) 86 #define BBLOCK ((daddr_t)(0)) 87 #define SBLOCK ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE)) 88 89 #define fsbtodb(fs, b) ((daddr_t)(b) << (fs)->e2fs_fsbtodb) 90 /* calculates (loc / fs->fs_bsize) */ 91 #define lblkno(fs, loc) ((loc) >> (fs->e2fs_bshift)) 92 #define blksize(fs, ip, lbn) ((fs)->e2fs_bsize) 93 94 /* 95 * Addresses stored in inodes are capable of addressing blocks 96 * XXX 97 */ 98 99 /* 100 * MINBSIZE is the smallest allowable block size. 101 * MINBSIZE must be big enough to hold a cylinder group block, 102 * thus changes to (struct cg) must keep its size within MINBSIZE. 103 * Note that super blocks are always of size SBSIZE, 104 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE. 105 */ 106 #define LOG_MINBSIZE 10 107 #define MINBSIZE (1 << LOG_MINBSIZE) 108 109 /* 110 * The path name on which the file system is mounted is maintained 111 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in 112 * the super block for this name. 113 */ 114 #define MAXMNTLEN 512 115 116 /* 117 * MINFREE gives the minimum acceptable percentage of file system 118 * blocks which may be free. If the freelist drops below this level 119 * only the superuser may continue to allocate blocks. This may 120 * be set to 0 if no reserve of free blocks is deemed necessary, 121 * however throughput drops by fifty percent if the file system 122 * is run at between 95% and 100% full; thus the minimum default 123 * value of fs_minfree is 5%. However, to get good clustering 124 * performance, 10% is a better choice. hence we use 10% as our 125 * default value. With 10% free space, fragmentation is not a 126 * problem, so we choose to optimize for time. 127 */ 128 #define MINFREE 5 129 130 /* 131 * Super block for an ext2fs file system. 132 */ 133 struct ext2fs { 134 uint32_t e2fs_icount; /* Inode count */ 135 uint32_t e2fs_bcount; /* blocks count */ 136 uint32_t e2fs_rbcount; /* reserved blocks count */ 137 uint32_t e2fs_fbcount; /* free blocks count */ 138 uint32_t e2fs_ficount; /* free inodes count */ 139 uint32_t e2fs_first_dblock; /* first data block */ 140 uint32_t e2fs_log_bsize; /* bsize = 1024*(2^e2fs_log_bsize) */ 141 uint32_t e2fs_fsize; /* fragment size */ 142 uint32_t e2fs_bpg; /* blocks per group */ 143 uint32_t e2fs_fpg; /* frags per group */ 144 uint32_t e2fs_ipg; /* inodes per group */ 145 uint32_t e2fs_mtime; /* mount time */ 146 uint32_t e2fs_wtime; /* write time */ 147 uint16_t e2fs_mnt_count; /* mount count */ 148 uint16_t e2fs_max_mnt_count; /* max mount count */ 149 uint16_t e2fs_magic; /* magic number */ 150 uint16_t e2fs_state; /* file system state */ 151 uint16_t e2fs_beh; /* behavior on errors */ 152 uint16_t e2fs_minrev; /* minor revision level */ 153 uint32_t e2fs_lastfsck; /* time of last fsck */ 154 uint32_t e2fs_fsckintv; /* max time between fscks */ 155 uint32_t e2fs_creator; /* creator OS */ 156 uint32_t e2fs_rev; /* revision level */ 157 uint16_t e2fs_ruid; /* default uid for reserved blocks */ 158 uint16_t e2fs_rgid; /* default gid for reserved blocks */ 159 /* EXT2_DYNAMIC_REV superblocks */ 160 uint32_t e2fs_first_ino; /* first non-reserved inode */ 161 uint16_t e2fs_inode_size; /* size of inode structure */ 162 uint16_t e2fs_block_group_nr; /* block grp number of this sblk*/ 163 uint32_t e2fs_features_compat; /* compatible feature set */ 164 uint32_t e2fs_features_incompat; /* incompatible feature set */ 165 uint32_t e2fs_features_rocompat; /* RO-compatible feature set */ 166 uint8_t e2fs_uuid[16]; /* 128-bit uuid for volume */ 167 char e2fs_vname[16]; /* volume name */ 168 char e2fs_fsmnt[64]; /* name mounted on */ 169 uint32_t e2fs_algo; /* For compression */ 170 uint8_t e2fs_prealloc; /* # of blocks to preallocate */ 171 uint8_t e2fs_dir_prealloc; /* # of blocks to preallocate for dir */ 172 uint16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */ 173 174 /* Additional fields */ 175 char e3fs_journal_uuid[16];/* uuid of journal superblock */ 176 uint32_t e3fs_journal_inum; /* inode number of journal file */ 177 uint32_t e3fs_journal_dev; /* device number of journal file */ 178 uint32_t e3fs_last_orphan; /* start of list of inodes to delete */ 179 uint32_t e3fs_hash_seed[4]; /* HTREE hash seed */ 180 char e3fs_def_hash_version;/* Default hash version to use */ 181 char e3fs_jnl_backup_type; 182 uint16_t e3fs_desc_size; /* size of group descriptor */ 183 uint32_t e3fs_default_mount_opts; 184 uint32_t e3fs_first_meta_bg; /* First metablock block group */ 185 uint32_t e3fs_mkfs_time; /* when the fs was created */ 186 uint32_t e3fs_jnl_blks[17]; /* backup of the journal inode */ 187 uint32_t e4fs_bcount_hi; /* high bits of blocks count */ 188 uint32_t e4fs_rbcount_hi; /* high bits of reserved blocks count */ 189 uint32_t e4fs_fbcount_hi; /* high bits of free blocks count */ 190 uint16_t e4fs_min_extra_isize; /* all inodes have some bytes */ 191 uint16_t e4fs_want_extra_isize;/* inodes must reserve some bytes */ 192 uint32_t e4fs_flags; /* miscellaneous flags */ 193 uint16_t e4fs_raid_stride; /* RAID stride */ 194 uint16_t e4fs_mmpintv; /* seconds to wait in MMP checking */ 195 uint64_t e4fs_mmpblk; /* block for multi-mount protection */ 196 uint32_t e4fs_raid_stripe_wid; /* blocks on data disks (N * stride) */ 197 uint8_t e4fs_log_gpf; /* FLEX_BG group size */ 198 uint8_t e4fs_chksum_type; /* metadata checksum algorithm used */ 199 uint8_t e4fs_encrypt; /* versioning level for encryption */ 200 uint8_t e4fs_reserved_pad; 201 uint64_t e4fs_kbytes_written; /* number of lifetime kilobytes */ 202 uint32_t e4fs_snapinum; /* inode number of active snapshot */ 203 uint32_t e4fs_snapid; /* sequential ID of active snapshot */ 204 uint64_t e4fs_snaprbcount; /* rsvd blocks for active snapshot */ 205 uint32_t e4fs_snaplist; /* inode number for on-disk snapshot */ 206 uint32_t e4fs_errcount; /* number of file system errors */ 207 uint32_t e4fs_first_errtime; /* first time an error happened */ 208 uint32_t e4fs_first_errino; /* inode involved in first error */ 209 uint64_t e4fs_first_errblk; /* block involved of first error */ 210 uint8_t e4fs_first_errfunc[32];/* function where error happened */ 211 uint32_t e4fs_first_errline; /* line number where error happened */ 212 uint32_t e4fs_last_errtime; /* most recent time of an error */ 213 uint32_t e4fs_last_errino; /* inode involved in last error */ 214 uint32_t e4fs_last_errline; /* line number where error happened */ 215 uint64_t e4fs_last_errblk; /* block involved of last error */ 216 uint8_t e4fs_last_errfunc[32];/* function where error happened */ 217 uint8_t e4fs_mount_opts[64]; 218 uint32_t e4fs_usrquota_inum; /* inode for tracking user quota */ 219 uint32_t e4fs_grpquota_inum; /* inode for tracking group quota */ 220 uint32_t e4fs_overhead_clusters;/* overhead blocks/clusters */ 221 uint32_t e4fs_backup_bgs[2]; /* groups with sparse_super2 SBs */ 222 uint8_t e4fs_encrypt_algos[4];/* encryption algorithms in use */ 223 uint8_t e4fs_encrypt_pw_salt[16];/* salt used for string2key */ 224 uint32_t e4fs_lpf_ino; /* location of the lost+found inode */ 225 uint32_t e4fs_proj_quota_inum; /* inode for tracking project quota */ 226 uint32_t e4fs_chksum_seed; /* checksum seed */ 227 uint32_t e4fs_reserved[98]; /* padding to the end of the block */ 228 uint32_t e4fs_sbchksum; /* superblock checksum */ 229 }; 230 231 232 /* in-memory data for ext2fs */ 233 struct m_ext2fs { 234 struct ext2fs e2fs; 235 u_char e2fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 236 int8_t e2fs_ronly; /* mounted read-only flag */ 237 int8_t e2fs_fmod; /* super block modified flag */ 238 int8_t e2fs_uhash; /* 3 if hash should be signed, 0 if not */ 239 int32_t e2fs_bsize; /* block size */ 240 int32_t e2fs_bshift; /* ``lblkno'' calc of logical blkno */ 241 int32_t e2fs_bmask; /* ``blkoff'' calc of blk offsets */ 242 int64_t e2fs_qbmask; /* ~fs_bmask - for use with quad size */ 243 int32_t e2fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 244 int32_t e2fs_ncg; /* number of cylinder groups */ 245 int32_t e2fs_ngdb; /* number of group descriptor block */ 246 int32_t e2fs_ipb; /* number of inodes per block */ 247 int32_t e2fs_itpg; /* number of inode table per group */ 248 struct ext2_gd *e2fs_gd; /* group descripors */ 249 }; 250 251 252 253 /* 254 * Filesystem identification 255 */ 256 #define E2FS_MAGIC 0xef53 /* the ext2fs magic number */ 257 #define E2FS_REV0 0 /* GOOD_OLD revision */ 258 #define E2FS_REV1 1 /* Support compat/incompat features */ 259 260 /* compatible/incompatible features */ 261 #define EXT2F_COMPAT_PREALLOC 0x0001 262 #define EXT2F_COMPAT_AFS 0x0002 263 #define EXT2F_COMPAT_HASJOURNAL 0x0004 264 #define EXT2F_COMPAT_EXTATTR 0x0008 265 #define EXT2F_COMPAT_RESIZE 0x0010 266 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020 267 #define EXT2F_COMPAT_BITS \ 268 "\20" \ 269 "\06COMPAT_DIRHASHINDEX" \ 270 "\05COMPAT_RESIZE" \ 271 "\04COMPAT_EXTATTR" \ 272 "\03COMPAT_HASJOURNAL" \ 273 "\02COMPAT_AFS" \ 274 "\01COMPAT_PREALLOC" 275 276 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001 277 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002 278 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004 279 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008 280 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010 281 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020 282 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040 283 #define EXT2F_ROCOMPAT_BITS \ 284 "\20" \ 285 "\07ROCOMPAT_EXTRA_ISIZE" \ 286 "\06ROCOMPAT_DIR_NLINK" \ 287 "\05ROCOMPAT_GDT_CSUM" \ 288 "\04ROCOMPAT_HUGE_FILE" \ 289 "\03ROCOMPAT_BTREE_DIR" \ 290 "\02ROCOMPAT_LARGEFILE" \ 291 "\01ROCOMPAT_SPARSESUPER" 292 293 #define EXT2F_INCOMPAT_COMP 0x0001 294 #define EXT2F_INCOMPAT_FTYPE 0x0002 295 #define EXT2F_INCOMPAT_REPLAY_JOURNAL 0x0004 296 #define EXT2F_INCOMPAT_USES_JOURNAL 0x0008 297 #define EXT2F_INCOMPAT_META_BG 0x0010 298 #define EXT2F_INCOMPAT_EXTENTS 0x0040 299 #define EXT2F_INCOMPAT_64BIT 0x0080 300 #define EXT2F_INCOMPAT_MMP 0x0100 301 #define EXT2F_INCOMPAT_FLEX_BG 0x0200 302 #define EXT2F_INCOMPAT_BITS \ 303 "\20" \ 304 "\012INCOMPAT_FLEX_BG" \ 305 "\011INCOMPAT_MMP" \ 306 "\010INCOMPAT_64BIT" \ 307 "\07INCOMPAT_EXTENTS" \ 308 "\05INCOMPAT_META_BG" \ 309 "\04INCOMPAT_USES_JOURNAL" \ 310 "\03INCOMPAT_REPLAY_JOURNAL" \ 311 "\02INCOMPAT_FTYPE" \ 312 "\01INCOMPAT_COMP" 313 314 /* 315 * Features supported in this implementation 316 * 317 * We support the following REV1 features: 318 * - EXT2F_ROCOMPAT_SPARSESUPER 319 * superblock backups stored only in cg_has_sb(bno) groups 320 * - EXT2F_ROCOMPAT_LARGEFILE 321 * use e2di_dacl in struct ext2fs_dinode to store 322 * upper 32bit of size for >2GB files 323 * - EXT2F_INCOMPAT_FTYPE 324 * store file type to e2d_type in struct ext2fs_direct 325 * (on REV0 e2d_namlen is uint16_t and no e2d_type, like ffs) 326 */ 327 #define EXT2F_COMPAT_SUPP 0x0000 328 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER \ 329 | EXT2F_ROCOMPAT_LARGEFILE \ 330 | EXT2F_ROCOMPAT_HUGE_FILE) 331 #define EXT2F_INCOMPAT_SUPP (EXT2F_INCOMPAT_FTYPE \ 332 | EXT2F_INCOMPAT_EXTENTS) 333 334 /* 335 * Feature set definitions 336 */ 337 #define EXT2_HAS_COMPAT_FEATURE(sb, mask) \ 338 ((sb)->e2fs.e2fs_features_compat & htole32(mask)) 339 340 /* 341 * Definitions of behavior on errors 342 */ 343 #define E2FS_BEH_CONTINUE 1 /* continue operation */ 344 #define E2FS_BEH_READONLY 2 /* remount fs read only */ 345 #define E2FS_BEH_PANIC 3 /* cause panic */ 346 #define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE 347 348 /* 349 * OS identification 350 */ 351 #define E2FS_OS_LINUX 0 352 #define E2FS_OS_HURD 1 353 #define E2FS_OS_MASIX 2 354 #define E2FS_OS_FREEBSD 3 355 #define E2FS_OS_LITES 4 356 357 /* 358 * Filesystem clean flags 359 */ 360 #define E2FS_ISCLEAN 0x01 361 #define E2FS_ERRORS 0x02 362 363 /* ext2 file system block group descriptor */ 364 365 struct ext2_gd { 366 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */ 367 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */ 368 uint32_t ext2bgd_i_tables; /* inodes table block */ 369 uint16_t ext2bgd_nbfree; /* number of free blocks */ 370 uint16_t ext2bgd_nifree; /* number of free inodes */ 371 uint16_t ext2bgd_ndirs; /* number of directories */ 372 uint16_t reserved; 373 uint32_t reserved2[3]; 374 }; 375 376 377 /* 378 * If the EXT2F_ROCOMPAT_SPARSESUPER flag is set, the cylinder group has a 379 * copy of the super and cylinder group descriptors blocks only if it's 380 * 1, a power of 3, 5 or 7 381 */ 382 383 static __inline int cg_has_sb(int) __unused; 384 static __inline int 385 cg_has_sb(int i) 386 { 387 int a3, a5, a7; 388 389 if (i == 0 || i == 1) 390 return 1; 391 for (a3 = 3, a5 = 5, a7 = 7; 392 a3 <= i || a5 <= i || a7 <= i; 393 a3 *= 3, a5 *= 5, a7 *= 7) 394 if (i == a3 || i == a5 || i == a7) 395 return 1; 396 return 0; 397 } 398 399 /* EXT2FS metadatas are stored in little-endian byte order. These macros 400 * helps reading theses metadatas 401 */ 402 403 #if BYTE_ORDER == LITTLE_ENDIAN 404 # define h2fs16(x) (x) 405 # define h2fs32(x) (x) 406 # define h2fs64(x) (x) 407 # define fs2h16(x) (x) 408 # define fs2h32(x) (x) 409 # define fs2h64(x) (x) 410 # define e2fs_sbload(old, new) memcpy((new), (old), SBSIZE); 411 # define e2fs_cgload(old, new, size) memcpy((new), (old), (size)); 412 # define e2fs_sbsave(old, new) memcpy((new), (old), SBSIZE); 413 # define e2fs_cgsave(old, new, size) memcpy((new), (old), (size)); 414 #else 415 void e2fs_sb_bswap(struct ext2fs *, struct ext2fs *); 416 void e2fs_cg_bswap(struct ext2_gd *, struct ext2_gd *, int); 417 # define h2fs16(x) bswap16(x) 418 # define h2fs32(x) bswap32(x) 419 # define h2fs64(x) bswap64(x) 420 # define fs2h16(x) bswap16(x) 421 # define fs2h32(x) bswap32(x) 422 # define fs2h64(x) bswap64(x) 423 # define e2fs_sbload(old, new) e2fs_sb_bswap((old), (new)) 424 # define e2fs_cgload(old, new, size) e2fs_cg_bswap((old), (new), (size)); 425 # define e2fs_sbsave(old, new) e2fs_sb_bswap((old), (new)) 426 # define e2fs_cgsave(old, new, size) e2fs_cg_bswap((old), (new), (size)); 427 #endif 428 429 /* 430 * Turn file system block numbers into disk block addresses. 431 * This maps file system blocks to device size blocks. 432 */ 433 #define EXT2_FSBTODB(fs, b) ((b) << (fs)->e2fs_fsbtodb) 434 #define EXT2_DBTOFSB(fs, b) ((b) >> (fs)->e2fs_fsbtodb) 435 436 /* 437 * Macros for handling inode numbers: 438 * inode number to file system block offset. 439 * inode number to cylinder group number. 440 * inode number to file system block address. 441 */ 442 #define ino_to_cg(fs, x) (((x) - 1) / (fs)->e2fs.e2fs_ipg) 443 #define ino_to_fsba(fs, x) \ 444 ((fs)->e2fs_gd[ino_to_cg((fs), (x))].ext2bgd_i_tables + \ 445 (((x) - 1) % (fs)->e2fs.e2fs_ipg) / (fs)->e2fs_ipb) 446 #define ino_to_fsbo(fs, x) (((x) - 1) % (fs)->e2fs_ipb) 447 448 /* 449 * Give cylinder group number for a file system block. 450 * Give cylinder group block number for a file system block. 451 */ 452 #define dtog(fs, d) (((d) - (fs)->e2fs.e2fs_first_dblock) / (fs)->e2fs.e2fs_fpg) 453 #define dtogd(fs, d) \ 454 (((d) - (fs)->e2fs.e2fs_first_dblock) % (fs)->e2fs.e2fs_fpg) 455 456 /* 457 * The following macros optimize certain frequently calculated 458 * quantities by using shifts and masks in place of divisions 459 * modulos and multiplications. 460 */ 461 #define ext2_blkoff(fs, loc) /* calculates (loc % fs->e2fs_bsize) */ \ 462 ((loc) & (fs)->e2fs_qbmask) 463 #define ext2_lblktosize(fs, blk) /* calculates (blk * fs->e2fs_bsize) */ \ 464 ((blk) << (fs)->e2fs_bshift) 465 #define ext2_lblkno(fs, loc) /* calculates (loc / fs->e2fs_bsize) */ \ 466 ((loc) >> (fs)->e2fs_bshift) 467 #define ext2_blkroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ 468 (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) 469 #define ext2_fragroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ 470 (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) 471 /* 472 * Determine the number of available frags given a 473 * percentage to hold in reserve. 474 */ 475 #define freespace(fs) \ 476 ((fs)->e2fs.e2fs_fbcount - (fs)->e2fs.e2fs_rbcount) 477 478 /* 479 * Number of indirects in a file system block. 480 */ 481 #define EXT2_NINDIR(fs) ((fs)->e2fs_bsize / sizeof(uint32_t)) 482 483 #endif /* !_UFS_EXT2FS_EXT2FS_H_ */ 484
Indexes created Thu Oct 23 22:10:10 GMT 2025