FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2fs.h
1 /*-
2 * modified for EXT2FS support in Lites 1.1
3 *
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
6 *
7 * $FreeBSD$
8 */
9 /*-
10 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
11 *
12 * Copyright (c) 2009 Aditya Sarawgi
13 * All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *
37 */
38
39 #ifndef _FS_EXT2FS_EXT2FS_H_
40 #define _FS_EXT2FS_EXT2FS_H_
41
42 #include <sys/types.h>
43
44 /*
45 * Super block for an ext2fs file system.
46 */
47 struct ext2fs {
48 uint32_t e2fs_icount; /* Inode count */
49 uint32_t e2fs_bcount; /* blocks count */
50 uint32_t e2fs_rbcount; /* reserved blocks count */
51 uint32_t e2fs_fbcount; /* free blocks count */
52 uint32_t e2fs_ficount; /* free inodes count */
53 uint32_t e2fs_first_dblock; /* first data block */
54 uint32_t e2fs_log_bsize; /* block size = 1024*(2^e2fs_log_bsize) */
55 uint32_t e2fs_log_fsize; /* fragment size */
56 uint32_t e2fs_bpg; /* blocks per group */
57 uint32_t e2fs_fpg; /* frags per group */
58 uint32_t e2fs_ipg; /* inodes per group */
59 uint32_t e2fs_mtime; /* mount time */
60 uint32_t e2fs_wtime; /* write time */
61 uint16_t e2fs_mnt_count; /* mount count */
62 uint16_t e2fs_max_mnt_count; /* max mount count */
63 uint16_t e2fs_magic; /* magic number */
64 uint16_t e2fs_state; /* file system state */
65 uint16_t e2fs_beh; /* behavior on errors */
66 uint16_t e2fs_minrev; /* minor revision level */
67 uint32_t e2fs_lastfsck; /* time of last fsck */
68 uint32_t e2fs_fsckintv; /* max time between fscks */
69 uint32_t e2fs_creator; /* creator OS */
70 uint32_t e2fs_rev; /* revision level */
71 uint16_t e2fs_ruid; /* default uid for reserved blocks */
72 uint16_t e2fs_rgid; /* default gid for reserved blocks */
73 /* EXT2_DYNAMIC_REV superblocks */
74 uint32_t e2fs_first_ino; /* first non-reserved inode */
75 uint16_t e2fs_inode_size; /* size of inode structure */
76 uint16_t e2fs_block_group_nr; /* block grp number of this sblk*/
77 uint32_t e2fs_features_compat; /* compatible feature set */
78 uint32_t e2fs_features_incompat; /* incompatible feature set */
79 uint32_t e2fs_features_rocompat; /* RO-compatible feature set */
80 uint8_t e2fs_uuid[16]; /* 128-bit uuid for volume */
81 char e2fs_vname[16]; /* volume name */
82 char e2fs_fsmnt[64]; /* name mounted on */
83 uint32_t e2fs_algo; /* For compression */
84 uint8_t e2fs_prealloc; /* # of blocks for old prealloc */
85 uint8_t e2fs_dir_prealloc; /* # of blocks for old prealloc dirs */
86 uint16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */
87 char e3fs_journal_uuid[16]; /* uuid of journal superblock */
88 uint32_t e3fs_journal_inum; /* inode number of journal file */
89 uint32_t e3fs_journal_dev; /* device number of journal file */
90 uint32_t e3fs_last_orphan; /* start of list of inodes to delete */
91 uint32_t e3fs_hash_seed[4]; /* HTREE hash seed */
92 char e3fs_def_hash_version;/* Default hash version to use */
93 char e3fs_jnl_backup_type;
94 uint16_t e3fs_desc_size; /* size of group descriptor */
95 uint32_t e3fs_default_mount_opts;
96 uint32_t e3fs_first_meta_bg; /* First metablock block group */
97 uint32_t e3fs_mkfs_time; /* when the fs was created */
98 uint32_t e3fs_jnl_blks[17]; /* backup of the journal inode */
99 uint32_t e4fs_bcount_hi; /* high bits of blocks count */
100 uint32_t e4fs_rbcount_hi; /* high bits of reserved blocks count */
101 uint32_t e4fs_fbcount_hi; /* high bits of free blocks count */
102 uint16_t e4fs_min_extra_isize; /* all inodes have some bytes */
103 uint16_t e4fs_want_extra_isize;/* inodes must reserve some bytes */
104 uint32_t e4fs_flags; /* miscellaneous flags */
105 uint16_t e4fs_raid_stride; /* RAID stride */
106 uint16_t e4fs_mmpintv; /* seconds to wait in MMP checking */
107 uint64_t e4fs_mmpblk; /* block for multi-mount protection */
108 uint32_t e4fs_raid_stripe_wid; /* blocks on data disks (N * stride) */
109 uint8_t e4fs_log_gpf; /* FLEX_BG group size */
110 uint8_t e4fs_chksum_type; /* metadata checksum algorithm used */
111 uint8_t e4fs_encrypt; /* versioning level for encryption */
112 uint8_t e4fs_reserved_pad;
113 uint64_t e4fs_kbytes_written; /* number of lifetime kilobytes */
114 uint32_t e4fs_snapinum; /* inode number of active snapshot */
115 uint32_t e4fs_snapid; /* sequential ID of active snapshot */
116 uint64_t e4fs_snaprbcount; /* reserved blocks for active snapshot */
117 uint32_t e4fs_snaplist; /* inode number for on-disk snapshot */
118 uint32_t e4fs_errcount; /* number of file system errors */
119 uint32_t e4fs_first_errtime; /* first time an error happened */
120 uint32_t e4fs_first_errino; /* inode involved in first error */
121 uint64_t e4fs_first_errblk; /* block involved of first error */
122 uint8_t e4fs_first_errfunc[32];/* function where error happened */
123 uint32_t e4fs_first_errline; /* line number where error happened */
124 uint32_t e4fs_last_errtime; /* most recent time of an error */
125 uint32_t e4fs_last_errino; /* inode involved in last error */
126 uint32_t e4fs_last_errline; /* line number where error happened */
127 uint64_t e4fs_last_errblk; /* block involved of last error */
128 uint8_t e4fs_last_errfunc[32]; /* function where error happened */
129 uint8_t e4fs_mount_opts[64];
130 uint32_t e4fs_usrquota_inum; /* inode for tracking user quota */
131 uint32_t e4fs_grpquota_inum; /* inode for tracking group quota */
132 uint32_t e4fs_overhead_clusters;/* overhead blocks/clusters */
133 uint32_t e4fs_backup_bgs[2]; /* groups with sparse_super2 SBs */
134 uint8_t e4fs_encrypt_algos[4];/* encryption algorithms in use */
135 uint8_t e4fs_encrypt_pw_salt[16];/* salt used for string2key */
136 uint32_t e4fs_lpf_ino; /* location of the lost+found inode */
137 uint32_t e4fs_proj_quota_inum; /* inode for tracking project quota */
138 uint32_t e4fs_chksum_seed; /* checksum seed */
139 uint32_t e4fs_reserved[98]; /* padding to the end of the block */
140 uint32_t e4fs_sbchksum; /* superblock checksum */
141 };
142
143 /*
144 * The path name on which the file system is mounted is maintained
145 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
146 * the super block for this name.
147 */
148 #define MAXMNTLEN 512
149
150 /*
151 * In-Memory Superblock
152 */
153
154 struct m_ext2fs {
155 struct ext2fs * e2fs;
156 char e2fs_fsmnt[MAXMNTLEN];/* name mounted on */
157 char e2fs_ronly; /* mounted read-only flag */
158 char e2fs_fmod; /* super block modified flag */
159 uint64_t e2fs_bcount; /* blocks count */
160 uint64_t e2fs_rbcount; /* reserved blocks count */
161 uint64_t e2fs_fbcount; /* free blocks count */
162 uint32_t e2fs_ficount; /* free inodes count */
163 uint32_t e2fs_bsize; /* Block size */
164 uint32_t e2fs_bshift; /* calc of logical block no */
165 uint32_t e2fs_bpg; /* Number of blocks per group */
166 int64_t e2fs_qbmask; /* = s_blocksize -1 */
167 uint32_t e2fs_fsbtodb; /* Shift to get disk block */
168 uint32_t e2fs_ipg; /* Number of inodes per group */
169 uint32_t e2fs_ipb; /* Number of inodes per block */
170 uint32_t e2fs_itpg; /* Number of inode table per group */
171 uint32_t e2fs_fsize; /* Size of fragments per block */
172 uint32_t e2fs_fpb; /* Number of fragments per block */
173 uint32_t e2fs_fpg; /* Number of fragments per group */
174 uint32_t e2fs_gdbcount; /* Number of group descriptors */
175 uint32_t e2fs_gcount; /* Number of groups */
176 uint32_t e2fs_isize; /* Size of inode */
177 uint32_t e2fs_total_dir; /* Total number of directories */
178 uint8_t *e2fs_contigdirs; /* (u) # of contig. allocated dirs */
179 char e2fs_wasvalid; /* valid at mount time */
180 off_t e2fs_maxfilesize;
181 struct ext2_gd *e2fs_gd; /* Group Descriptors */
182 int32_t e2fs_contigsumsize; /* size of cluster summary array */
183 int32_t *e2fs_maxcluster; /* max cluster in each cyl group */
184 struct csum *e2fs_clustersum; /* cluster summary in each cyl group */
185 int32_t e2fs_uhash; /* 3 if hash should be signed, 0 if not */
186 uint32_t e2fs_csum_seed; /* sb checksum seed */
187 uint64_t e2fs_maxsymlinklen; /* max size of short symlink */
188 };
189
190 /* cluster summary information */
191
192 struct csum {
193 int8_t cs_init; /* cluster summary has been initialized */
194 int32_t *cs_sum; /* cluster summary array */
195 };
196
197 /*
198 * The second extended file system magic number
199 */
200 #define E2FS_MAGIC 0xEF53
201
202 /*
203 * Revision levels
204 */
205 #define E2FS_REV0 0 /* The good old (original) format */
206 #define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */
207
208 #define E2FS_REV0_INODE_SIZE 128
209
210 /*
211 * Metadata checksum algorithm codes
212 */
213 #define EXT4_CRC32C_CHKSUM 1
214
215 /*
216 * compatible/incompatible features
217 */
218 #define EXT2F_COMPAT_PREALLOC 0x0001
219 #define EXT2F_COMPAT_IMAGIC_INODES 0x0002
220 #define EXT2F_COMPAT_HASJOURNAL 0x0004
221 #define EXT2F_COMPAT_EXT_ATTR 0x0008
222 #define EXT2F_COMPAT_RESIZE 0x0010
223 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020
224 #define EXT2F_COMPAT_LAZY_BG 0x0040
225 #define EXT2F_COMPAT_EXCLUDE_BITMAP 0x0100
226 #define EXT2F_COMPAT_SPARSESUPER2 0x0200
227
228 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
229 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002
230 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
231 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008
232 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010
233 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020
234 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040
235 #define EXT2F_ROCOMPAT_HAS_SNAPSHOT 0x0080
236 #define EXT2F_ROCOMPAT_QUOTA 0x0100
237 #define EXT2F_ROCOMPAT_BIGALLOC 0x0200
238 #define EXT2F_ROCOMPAT_METADATA_CKSUM 0x0400
239 #define EXT2F_ROCOMPAT_REPLICA 0x0800
240 #define EXT2F_ROCOMPAT_READONLY 0x1000
241 #define EXT2F_ROCOMPAT_PROJECT 0x2000
242
243 #define EXT2F_INCOMPAT_COMP 0x0001
244 #define EXT2F_INCOMPAT_FTYPE 0x0002
245 #define EXT2F_INCOMPAT_RECOVER 0x0004
246 #define EXT2F_INCOMPAT_JOURNAL_DEV 0x0008
247 #define EXT2F_INCOMPAT_META_BG 0x0010
248 #define EXT2F_INCOMPAT_EXTENTS 0x0040
249 #define EXT2F_INCOMPAT_64BIT 0x0080
250 #define EXT2F_INCOMPAT_MMP 0x0100
251 #define EXT2F_INCOMPAT_FLEX_BG 0x0200
252 #define EXT2F_INCOMPAT_EA_INODE 0x0400
253 #define EXT2F_INCOMPAT_DIRDATA 0x1000
254 #define EXT2F_INCOMPAT_CSUM_SEED 0x2000
255 #define EXT2F_INCOMPAT_LARGEDIR 0x4000
256 #define EXT2F_INCOMPAT_INLINE_DATA 0x8000
257 #define EXT2F_INCOMPAT_ENCRYPT 0x10000
258
259 struct ext2_feature
260 {
261 int mask;
262 const char *name;
263 };
264
265 static const struct ext2_feature compat[] = {
266 { EXT2F_COMPAT_PREALLOC, "dir_prealloc" },
267 { EXT2F_COMPAT_IMAGIC_INODES, "imagic_inodes" },
268 { EXT2F_COMPAT_HASJOURNAL, "has_journal" },
269 { EXT2F_COMPAT_EXT_ATTR, "ext_attr" },
270 { EXT2F_COMPAT_RESIZE, "resize_inode" },
271 { EXT2F_COMPAT_DIRHASHINDEX, "dir_index" },
272 { EXT2F_COMPAT_EXCLUDE_BITMAP, "snapshot_bitmap" },
273 { EXT2F_COMPAT_SPARSESUPER2, "sparse_super2" }
274 };
275
276 static const struct ext2_feature ro_compat[] = {
277 { EXT2F_ROCOMPAT_SPARSESUPER, "sparse_super" },
278 { EXT2F_ROCOMPAT_LARGEFILE, "large_file" },
279 { EXT2F_ROCOMPAT_BTREE_DIR, "btree_dir" },
280 { EXT2F_ROCOMPAT_HUGE_FILE, "huge_file" },
281 { EXT2F_ROCOMPAT_GDT_CSUM, "uninit_groups" },
282 { EXT2F_ROCOMPAT_DIR_NLINK, "dir_nlink" },
283 { EXT2F_ROCOMPAT_EXTRA_ISIZE, "extra_isize" },
284 { EXT2F_ROCOMPAT_HAS_SNAPSHOT, "snapshot" },
285 { EXT2F_ROCOMPAT_QUOTA, "quota" },
286 { EXT2F_ROCOMPAT_BIGALLOC, "bigalloc" },
287 { EXT2F_ROCOMPAT_METADATA_CKSUM, "metadata_csum" },
288 { EXT2F_ROCOMPAT_REPLICA, "replica" },
289 { EXT2F_ROCOMPAT_READONLY, "ro" },
290 { EXT2F_ROCOMPAT_PROJECT, "project" }
291 };
292
293 static const struct ext2_feature incompat[] = {
294 { EXT2F_INCOMPAT_COMP, "compression" },
295 { EXT2F_INCOMPAT_FTYPE, "filetype" },
296 { EXT2F_INCOMPAT_RECOVER, "needs_recovery" },
297 { EXT2F_INCOMPAT_JOURNAL_DEV, "journal_dev" },
298 { EXT2F_INCOMPAT_META_BG, "meta_bg" },
299 { EXT2F_INCOMPAT_EXTENTS, "extents" },
300 { EXT2F_INCOMPAT_64BIT, "64bit" },
301 { EXT2F_INCOMPAT_MMP, "mmp" },
302 { EXT2F_INCOMPAT_FLEX_BG, "flex_bg" },
303 { EXT2F_INCOMPAT_EA_INODE, "ea_inode" },
304 { EXT2F_INCOMPAT_DIRDATA, "dirdata" },
305 { EXT2F_INCOMPAT_CSUM_SEED, "metadata_csum_seed" },
306 { EXT2F_INCOMPAT_LARGEDIR, "large_dir" },
307 { EXT2F_INCOMPAT_INLINE_DATA, "inline_data" },
308 { EXT2F_INCOMPAT_ENCRYPT, "encrypt" }
309 };
310
311 /*
312 * Features supported in this implementation
313 *
314 * We support the following REV1 features:
315 * - EXT2F_ROCOMPAT_SPARSESUPER
316 * - EXT2F_ROCOMPAT_LARGEFILE
317 * - EXT2F_ROCOMPAT_EXTRA_ISIZE
318 * - EXT2F_INCOMPAT_FTYPE
319 *
320 * We partially (read-only) support the following EXT4 features:
321 * - EXT2F_ROCOMPAT_HUGE_FILE
322 * - EXT2F_INCOMPAT_EXTENTS
323 *
324 */
325 #define EXT2F_COMPAT_SUPP EXT2F_COMPAT_DIRHASHINDEX
326 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \
327 EXT2F_ROCOMPAT_LARGEFILE | \
328 EXT2F_ROCOMPAT_GDT_CSUM | \
329 EXT2F_ROCOMPAT_METADATA_CKSUM | \
330 EXT2F_ROCOMPAT_DIR_NLINK | \
331 EXT2F_ROCOMPAT_HUGE_FILE | \
332 EXT2F_ROCOMPAT_EXTRA_ISIZE)
333 #define EXT2F_INCOMPAT_SUPP (EXT2F_INCOMPAT_FTYPE | \
334 EXT2F_INCOMPAT_META_BG | \
335 EXT2F_INCOMPAT_EXTENTS | \
336 EXT2F_INCOMPAT_64BIT | \
337 EXT2F_INCOMPAT_FLEX_BG | \
338 EXT2F_INCOMPAT_CSUM_SEED)
339
340 /* Assume that user mode programs are passing in an ext2fs superblock, not
341 * a kernel struct super_block. This will allow us to call the feature-test
342 * macros from user land. */
343 #define EXT2_SB(sb) (sb)
344
345 /*
346 * Feature set definitions
347 */
348 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
349 ( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_compat) & mask)
350 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
351 ( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_rocompat) & mask)
352 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
353 ( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_incompat) & mask)
354
355 /*
356 * File clean flags
357 */
358 #define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */
359 #define E2FS_ERRORS 0x0002 /* Errors detected */
360
361 /*
362 * Filesystem miscellaneous flags
363 */
364 #define E2FS_SIGNED_HASH 0x0001
365 #define E2FS_UNSIGNED_HASH 0x0002
366
367 #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not in use */
368 #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not in use */
369 #define EXT2_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */
370
371 /* ext2 file system block group descriptor */
372
373 struct ext2_gd {
374 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */
375 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */
376 uint32_t ext2bgd_i_tables; /* inodes table block */
377 uint16_t ext2bgd_nbfree; /* number of free blocks */
378 uint16_t ext2bgd_nifree; /* number of free inodes */
379 uint16_t ext2bgd_ndirs; /* number of directories */
380 uint16_t ext4bgd_flags; /* block group flags */
381 uint32_t ext4bgd_x_bitmap; /* snapshot exclusion bitmap loc. */
382 uint16_t ext4bgd_b_bmap_csum; /* block bitmap checksum */
383 uint16_t ext4bgd_i_bmap_csum; /* inode bitmap checksum */
384 uint16_t ext4bgd_i_unused; /* unused inode count */
385 uint16_t ext4bgd_csum; /* group descriptor checksum */
386 uint32_t ext4bgd_b_bitmap_hi; /* high bits of blocks bitmap block */
387 uint32_t ext4bgd_i_bitmap_hi; /* high bits of inodes bitmap block */
388 uint32_t ext4bgd_i_tables_hi; /* high bits of inodes table block */
389 uint16_t ext4bgd_nbfree_hi; /* high bits of number of free blocks */
390 uint16_t ext4bgd_nifree_hi; /* high bits of number of free inodes */
391 uint16_t ext4bgd_ndirs_hi; /* high bits of number of directories */
392 uint16_t ext4bgd_i_unused_hi; /* high bits of unused inode count */
393 uint32_t ext4bgd_x_bitmap_hi; /* high bits of snapshot exclusion */
394 uint16_t ext4bgd_b_bmap_csum_hi;/* high bits of block bitmap checksum */
395 uint16_t ext4bgd_i_bmap_csum_hi;/* high bits of inode bitmap checksum */
396 uint32_t ext4bgd_reserved;
397 };
398
399 #define E2FS_REV0_GD_SIZE (sizeof(struct ext2_gd) / 2)
400 #define E2FS_64BIT_GD_SIZE (sizeof(struct ext2_gd))
401
402 /*
403 * Macro-instructions used to manage several block sizes
404 */
405 #define EXT2_MIN_BLOCK_LOG_SIZE 10
406 #define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize)
407 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
408 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize)
409
410 /*
411 * Macro-instructions used to manage fragments
412 */
413 #define EXT2_MIN_FRAG_SIZE 1024
414 #define EXT2_MIN_FRAG_LOG_SIZE 10
415 #define EXT2_MAX_FRAG_LOG_SIZE 30
416 #define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize)
417 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb)
418
419 /*
420 * Macro-instructions used to manage group descriptors
421 */
422 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg)
423 #define EXT2_DESCS_PER_BLOCK(s) (EXT2_HAS_INCOMPAT_FEATURE((s), \
424 EXT2F_INCOMPAT_64BIT) ? ((s)->e2fs_bsize / sizeof(struct ext2_gd)) : \
425 ((s)->e2fs_bsize / E2FS_REV0_GD_SIZE))
426
427 /*
428 * Macro-instructions used to manage inodes
429 */
430 #define EXT2_FIRST_INO(s) (le32toh((EXT2_SB(s)->e2fs->e2fs_rev) == \
431 E2FS_REV0) ? EXT2_FIRSTINO : le32toh(EXT2_SB(s)->e2fs->e2fs_first_ino))
432
433 /*
434 * Linux major/minor values limits
435 */
436 #define EXT2_MINORBITS (20)
437 #define EXT2_MAJOR_MAX (0xffffffff >> EXT2_MINORBITS)
438 #define EXT2_MINOR_MAX ((1 << EXT2_MINORBITS) - 1)
439
440 #endif /* !_FS_EXT2FS_EXT2FS_H_ */
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