ext2fs.h revision 1.37
1 /* $NetBSD: ext2fs.h,v 1.37 2016/06/03 15:35:48 christos 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 int32_t e2fs_bsize; /* block size */ 239 int32_t e2fs_bshift; /* ``lblkno'' calc of logical blkno */ 240 int32_t e2fs_bmask; /* ``blkoff'' calc of blk offsets */ 241 int64_t e2fs_qbmask; /* ~fs_bmask - for use with quad size */ 242 int32_t e2fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 243 int32_t e2fs_ncg; /* number of cylinder groups */ 244 int32_t e2fs_ngdb; /* number of group descriptor block */ 245 int32_t e2fs_ipb; /* number of inodes per block */ 246 int32_t e2fs_itpg; /* number of inode table per group */ 247 struct ext2_gd *e2fs_gd; /* group descripors */ 248 }; 249 250 251 252 /* 253 * Filesystem identification 254 */ 255 #define E2FS_MAGIC 0xef53 /* the ext2fs magic number */ 256 #define E2FS_REV0 0 /* GOOD_OLD revision */ 257 #define E2FS_REV1 1 /* Support compat/incompat features */ 258 259 /* compatible/incompatible features */ 260 #define EXT2F_COMPAT_PREALLOC 0x0001 261 #define EXT2F_COMPAT_AFS 0x0002 262 #define EXT2F_COMPAT_HASJOURNAL 0x0004 263 #define EXT2F_COMPAT_EXTATTR 0x0008 264 #define EXT2F_COMPAT_RESIZE 0x0010 265 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020 266 #define EXT2F_COMPAT_BITS \ 267 "\20" \ 268 "\06COMPAT_DIRHASHINDEX" \ 269 "\05COMPAT_RESIZE" \ 270 "\04COMPAT_EXTATTR" \ 271 "\03COMPAT_HASJOURNAL" \ 272 "\02COMPAT_AFS" \ 273 "\01COMPAT_PREALLOC" 274 275 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001 276 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002 277 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004 278 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008 279 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010 280 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020 281 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040 282 #define EXT2F_ROCOMPAT_BITS \ 283 "\20" \ 284 "\07ROCOMPAT_EXTRA_ISIZE" \ 285 "\06ROCOMPAT_DIR_NLINK" \ 286 "\05ROCOMPAT_GDT_CSUM" \ 287 "\04ROCOMPAT_HUGE_FILE" \ 288 "\03ROCOMPAT_BTREE_DIR" \ 289 "\02ROCOMPAT_LARGEFILE" \ 290 "\01ROCOMPAT_SPARSESUPER" 291 292 #define EXT2F_INCOMPAT_COMP 0x0001 293 #define EXT2F_INCOMPAT_FTYPE 0x0002 294 #define EXT2F_INCOMPAT_REPLAY_JOURNAL 0x0004 295 #define EXT2F_INCOMPAT_USES_JOURNAL 0x0008 296 #define EXT2F_INCOMPAT_META_BG 0x0010 297 #define EXT2F_INCOMPAT_EXTENTS 0x0040 298 #define EXT2F_INCOMPAT_64BIT 0x0080 299 #define EXT2F_INCOMPAT_MMP 0x0100 300 #define EXT2F_INCOMPAT_FLEX_BG 0x0200 301 #define EXT2F_INCOMPAT_BITS \ 302 "\20" \ 303 "\012INCOMPAT_FLEX_BG" \ 304 "\011INCOMPAT_MMP" \ 305 "\010INCOMPAT_64BIT" \ 306 "\07INCOMPAT_EXTENTS" \ 307 "\05INCOMPAT_META_BG" \ 308 "\04INCOMPAT_USES_JOURNAL" \ 309 "\03INCOMPAT_REPLAY_JOURNAL" \ 310 "\02INCOMPAT_FTYPE" \ 311 "\01INCOMPAT_COMP" 312 313 /* 314 * Features supported in this implementation 315 * 316 * We support the following REV1 features: 317 * - EXT2F_ROCOMPAT_SPARSESUPER 318 * superblock backups stored only in cg_has_sb(bno) groups 319 * - EXT2F_ROCOMPAT_LARGEFILE 320 * use e2di_dacl in struct ext2fs_dinode to store 321 * upper 32bit of size for >2GB files 322 * - EXT2F_INCOMPAT_FTYPE 323 * store file type to e2d_type in struct ext2fs_direct 324 * (on REV0 e2d_namlen is uint16_t and no e2d_type, like ffs) 325 */ 326 #define EXT2F_COMPAT_SUPP 0x0000 327 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER \ 328 | EXT2F_ROCOMPAT_LARGEFILE \ 329 | EXT2F_ROCOMPAT_HUGE_FILE) 330 #define EXT2F_INCOMPAT_SUPP (EXT2F_INCOMPAT_FTYPE \ 331 | EXT2F_INCOMPAT_EXTENTS) 332 333 /* 334 * Definitions of behavior on errors 335 */ 336 #define E2FS_BEH_CONTINUE 1 /* continue operation */ 337 #define E2FS_BEH_READONLY 2 /* remount fs read only */ 338 #define E2FS_BEH_PANIC 3 /* cause panic */ 339 #define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE 340 341 /* 342 * OS identification 343 */ 344 #define E2FS_OS_LINUX 0 345 #define E2FS_OS_HURD 1 346 #define E2FS_OS_MASIX 2 347 #define E2FS_OS_FREEBSD 3 348 #define E2FS_OS_LITES 4 349 350 /* 351 * Filesystem clean flags 352 */ 353 #define E2FS_ISCLEAN 0x01 354 #define E2FS_ERRORS 0x02 355 356 /* ext2 file system block group descriptor */ 357 358 struct ext2_gd { 359 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */ 360 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */ 361 uint32_t ext2bgd_i_tables; /* inodes table block */ 362 uint16_t ext2bgd_nbfree; /* number of free blocks */ 363 uint16_t ext2bgd_nifree; /* number of free inodes */ 364 uint16_t ext2bgd_ndirs; /* number of directories */ 365 uint16_t reserved; 366 uint32_t reserved2[3]; 367 }; 368 369 370 /* 371 * If the EXT2F_ROCOMPAT_SPARSESUPER flag is set, the cylinder group has a 372 * copy of the super and cylinder group descriptors blocks only if it's 373 * 1, a power of 3, 5 or 7 374 */ 375 376 static __inline int cg_has_sb(int) __unused; 377 static __inline int 378 cg_has_sb(int i) 379 { 380 int a3, a5, a7; 381 382 if (i == 0 || i == 1) 383 return 1; 384 for (a3 = 3, a5 = 5, a7 = 7; 385 a3 <= i || a5 <= i || a7 <= i; 386 a3 *= 3, a5 *= 5, a7 *= 7) 387 if (i == a3 || i == a5 || i == a7) 388 return 1; 389 return 0; 390 } 391 392 /* EXT2FS metadatas are stored in little-endian byte order. These macros 393 * helps reading theses metadatas 394 */ 395 396 #if BYTE_ORDER == LITTLE_ENDIAN 397 # define h2fs16(x) (x) 398 # define h2fs32(x) (x) 399 # define h2fs64(x) (x) 400 # define fs2h16(x) (x) 401 # define fs2h32(x) (x) 402 # define fs2h64(x) (x) 403 # define e2fs_sbload(old, new) memcpy((new), (old), SBSIZE); 404 # define e2fs_cgload(old, new, size) memcpy((new), (old), (size)); 405 # define e2fs_sbsave(old, new) memcpy((new), (old), SBSIZE); 406 # define e2fs_cgsave(old, new, size) memcpy((new), (old), (size)); 407 #else 408 void e2fs_sb_bswap(struct ext2fs *, struct ext2fs *); 409 void e2fs_cg_bswap(struct ext2_gd *, struct ext2_gd *, int); 410 # define h2fs16(x) bswap16(x) 411 # define h2fs32(x) bswap32(x) 412 # define h2fs64(x) bswap64(x) 413 # define fs2h16(x) bswap16(x) 414 # define fs2h32(x) bswap32(x) 415 # define fs2h64(x) bswap64(x) 416 # define e2fs_sbload(old, new) e2fs_sb_bswap((old), (new)) 417 # define e2fs_cgload(old, new, size) e2fs_cg_bswap((old), (new), (size)); 418 # define e2fs_sbsave(old, new) e2fs_sb_bswap((old), (new)) 419 # define e2fs_cgsave(old, new, size) e2fs_cg_bswap((old), (new), (size)); 420 #endif 421 422 /* 423 * Turn file system block numbers into disk block addresses. 424 * This maps file system blocks to device size blocks. 425 */ 426 #define EXT2_FSBTODB(fs, b) ((b) << (fs)->e2fs_fsbtodb) 427 #define EXT2_DBTOFSB(fs, b) ((b) >> (fs)->e2fs_fsbtodb) 428 429 /* 430 * Macros for handling inode numbers: 431 * inode number to file system block offset. 432 * inode number to cylinder group number. 433 * inode number to file system block address. 434 */ 435 #define ino_to_cg(fs, x) (((x) - 1) / (fs)->e2fs.e2fs_ipg) 436 #define ino_to_fsba(fs, x) \ 437 ((fs)->e2fs_gd[ino_to_cg((fs), (x))].ext2bgd_i_tables + \ 438 (((x) - 1) % (fs)->e2fs.e2fs_ipg) / (fs)->e2fs_ipb) 439 #define ino_to_fsbo(fs, x) (((x) - 1) % (fs)->e2fs_ipb) 440 441 /* 442 * Give cylinder group number for a file system block. 443 * Give cylinder group block number for a file system block. 444 */ 445 #define dtog(fs, d) (((d) - (fs)->e2fs.e2fs_first_dblock) / (fs)->e2fs.e2fs_fpg) 446 #define dtogd(fs, d) \ 447 (((d) - (fs)->e2fs.e2fs_first_dblock) % (fs)->e2fs.e2fs_fpg) 448 449 /* 450 * The following macros optimize certain frequently calculated 451 * quantities by using shifts and masks in place of divisions 452 * modulos and multiplications. 453 */ 454 #define ext2_blkoff(fs, loc) /* calculates (loc % fs->e2fs_bsize) */ \ 455 ((loc) & (fs)->e2fs_qbmask) 456 #define ext2_lblktosize(fs, blk) /* calculates (blk * fs->e2fs_bsize) */ \ 457 ((blk) << (fs)->e2fs_bshift) 458 #define ext2_lblkno(fs, loc) /* calculates (loc / fs->e2fs_bsize) */ \ 459 ((loc) >> (fs)->e2fs_bshift) 460 #define ext2_blkroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ 461 (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) 462 #define ext2_fragroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ 463 (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) 464 /* 465 * Determine the number of available frags given a 466 * percentage to hold in reserve. 467 */ 468 #define freespace(fs) \ 469 ((fs)->e2fs.e2fs_fbcount - (fs)->e2fs.e2fs_rbcount) 470 471 /* 472 * Number of indirects in a file system block. 473 */ 474 #define EXT2_NINDIR(fs) ((fs)->e2fs_bsize / sizeof(uint32_t)) 475 476 #endif /* !_UFS_EXT2FS_EXT2FS_H_ */ 477
Indexes created Mon Oct 20 10:10:01 GMT 2025