xref: /freebsd/sys/fs/ext2fs/ext2fs.h (revision a0409676120c1e558d0ade943019934e0f15118d)
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 };
188 
189 /* cluster summary information */
190 
191 struct csum {
192 	int8_t   cs_init; /* cluster summary has been initialized */
193 	int32_t *cs_sum;  /* cluster summary array */
194 };
195 
196 /*
197  * The second extended file system magic number
198  */
199 #define	E2FS_MAGIC		0xEF53
200 
201 /*
202  * Revision levels
203  */
204 #define	E2FS_REV0		0	/* The good old (original) format */
205 #define	E2FS_REV1		1	/* V2 format w/ dynamic inode sizes */
206 
207 #define	E2FS_REV0_INODE_SIZE 128
208 
209 /*
210  * Metadata checksum algorithm codes
211  */
212 #define EXT4_CRC32C_CHKSUM		1
213 
214 /*
215  * compatible/incompatible features
216  */
217 #define	EXT2F_COMPAT_PREALLOC		0x0001
218 #define	EXT2F_COMPAT_IMAGIC_INODES	0x0002
219 #define	EXT2F_COMPAT_HASJOURNAL		0x0004
220 #define	EXT2F_COMPAT_EXT_ATTR		0x0008
221 #define	EXT2F_COMPAT_RESIZE		0x0010
222 #define	EXT2F_COMPAT_DIRHASHINDEX	0x0020
223 #define	EXT2F_COMPAT_LAZY_BG		0x0040
224 #define	EXT2F_COMPAT_EXCLUDE_BITMAP	0x0100
225 #define	EXT2F_COMPAT_SPARSESUPER2	0x0200
226 
227 #define	EXT2F_ROCOMPAT_SPARSESUPER	0x0001
228 #define	EXT2F_ROCOMPAT_LARGEFILE	0x0002
229 #define	EXT2F_ROCOMPAT_BTREE_DIR	0x0004
230 #define	EXT2F_ROCOMPAT_HUGE_FILE	0x0008
231 #define	EXT2F_ROCOMPAT_GDT_CSUM		0x0010
232 #define	EXT2F_ROCOMPAT_DIR_NLINK	0x0020
233 #define	EXT2F_ROCOMPAT_EXTRA_ISIZE	0x0040
234 #define	EXT2F_ROCOMPAT_HAS_SNAPSHOT	0x0080
235 #define	EXT2F_ROCOMPAT_QUOTA		0x0100
236 #define	EXT2F_ROCOMPAT_BIGALLOC		0x0200
237 #define	EXT2F_ROCOMPAT_METADATA_CKSUM	0x0400
238 #define	EXT2F_ROCOMPAT_REPLICA		0x0800
239 #define	EXT2F_ROCOMPAT_READONLY		0x1000
240 #define	EXT2F_ROCOMPAT_PROJECT		0x2000
241 
242 #define	EXT2F_INCOMPAT_COMP		0x0001
243 #define	EXT2F_INCOMPAT_FTYPE		0x0002
244 #define	EXT2F_INCOMPAT_RECOVER		0x0004
245 #define	EXT2F_INCOMPAT_JOURNAL_DEV	0x0008
246 #define	EXT2F_INCOMPAT_META_BG		0x0010
247 #define	EXT2F_INCOMPAT_EXTENTS		0x0040
248 #define	EXT2F_INCOMPAT_64BIT		0x0080
249 #define	EXT2F_INCOMPAT_MMP		0x0100
250 #define	EXT2F_INCOMPAT_FLEX_BG		0x0200
251 #define	EXT2F_INCOMPAT_EA_INODE		0x0400
252 #define	EXT2F_INCOMPAT_DIRDATA		0x1000
253 #define	EXT2F_INCOMPAT_CSUM_SEED	0x2000
254 #define	EXT2F_INCOMPAT_LARGEDIR		0x4000
255 #define	EXT2F_INCOMPAT_INLINE_DATA	0x8000
256 #define	EXT2F_INCOMPAT_ENCRYPT		0x10000
257 
258 struct ext2_feature
259 {
260 	int mask;
261 	const char *name;
262 };
263 
264 static const struct ext2_feature compat[] = {
265 	{ EXT2F_COMPAT_PREALLOC,       "dir_prealloc"    },
266 	{ EXT2F_COMPAT_IMAGIC_INODES,  "imagic_inodes"   },
267 	{ EXT2F_COMPAT_HASJOURNAL,     "has_journal"     },
268 	{ EXT2F_COMPAT_EXT_ATTR,       "ext_attr"        },
269 	{ EXT2F_COMPAT_RESIZE,         "resize_inode"    },
270 	{ EXT2F_COMPAT_DIRHASHINDEX,   "dir_index"       },
271 	{ EXT2F_COMPAT_EXCLUDE_BITMAP, "snapshot_bitmap" },
272 	{ EXT2F_COMPAT_SPARSESUPER2,   "sparse_super2"   }
273 };
274 
275 static const struct ext2_feature ro_compat[] = {
276 	{ EXT2F_ROCOMPAT_SPARSESUPER,    "sparse_super"  },
277 	{ EXT2F_ROCOMPAT_LARGEFILE,      "large_file"    },
278 	{ EXT2F_ROCOMPAT_BTREE_DIR,      "btree_dir"     },
279 	{ EXT2F_ROCOMPAT_HUGE_FILE,      "huge_file"     },
280 	{ EXT2F_ROCOMPAT_GDT_CSUM,       "uninit_groups" },
281 	{ EXT2F_ROCOMPAT_DIR_NLINK,      "dir_nlink"     },
282 	{ EXT2F_ROCOMPAT_EXTRA_ISIZE,    "extra_isize"   },
283 	{ EXT2F_ROCOMPAT_HAS_SNAPSHOT,   "snapshot"      },
284 	{ EXT2F_ROCOMPAT_QUOTA,          "quota"         },
285 	{ EXT2F_ROCOMPAT_BIGALLOC,       "bigalloc"      },
286 	{ EXT2F_ROCOMPAT_METADATA_CKSUM, "metadata_csum" },
287 	{ EXT2F_ROCOMPAT_REPLICA,        "replica"       },
288 	{ EXT2F_ROCOMPAT_READONLY,       "ro"            },
289 	{ EXT2F_ROCOMPAT_PROJECT,        "project"       }
290 };
291 
292 static const struct ext2_feature incompat[] = {
293 	{ EXT2F_INCOMPAT_COMP,        "compression"        },
294 	{ EXT2F_INCOMPAT_FTYPE,       "filetype"           },
295 	{ EXT2F_INCOMPAT_RECOVER,     "needs_recovery"     },
296 	{ EXT2F_INCOMPAT_JOURNAL_DEV, "journal_dev"        },
297 	{ EXT2F_INCOMPAT_META_BG,     "meta_bg"            },
298 	{ EXT2F_INCOMPAT_EXTENTS,     "extents"            },
299 	{ EXT2F_INCOMPAT_64BIT,       "64bit"              },
300 	{ EXT2F_INCOMPAT_MMP,         "mmp"                },
301 	{ EXT2F_INCOMPAT_FLEX_BG,     "flex_bg"            },
302 	{ EXT2F_INCOMPAT_EA_INODE,    "ea_inode"           },
303 	{ EXT2F_INCOMPAT_DIRDATA,     "dirdata"            },
304 	{ EXT2F_INCOMPAT_CSUM_SEED,   "metadata_csum_seed" },
305 	{ EXT2F_INCOMPAT_LARGEDIR,    "large_dir"          },
306 	{ EXT2F_INCOMPAT_INLINE_DATA, "inline_data"        },
307 	{ EXT2F_INCOMPAT_ENCRYPT,     "encrypt"            }
308 };
309 
310 /*
311  * Features supported in this implementation
312  *
313  * We support the following REV1 features:
314  * - EXT2F_ROCOMPAT_SPARSESUPER
315  * - EXT2F_ROCOMPAT_LARGEFILE
316  * - EXT2F_ROCOMPAT_EXTRA_ISIZE
317  * - EXT2F_INCOMPAT_FTYPE
318  *
319  * We partially (read-only) support the following EXT4 features:
320  * - EXT2F_ROCOMPAT_HUGE_FILE
321  * - EXT2F_INCOMPAT_EXTENTS
322  *
323  */
324 #define	EXT2F_COMPAT_SUPP		EXT2F_COMPAT_DIRHASHINDEX
325 #define	EXT2F_ROCOMPAT_SUPP		(EXT2F_ROCOMPAT_SPARSESUPER | \
326 					 EXT2F_ROCOMPAT_LARGEFILE | \
327 					 EXT2F_ROCOMPAT_GDT_CSUM | \
328 					 EXT2F_ROCOMPAT_METADATA_CKSUM | \
329 					 EXT2F_ROCOMPAT_DIR_NLINK | \
330 					 EXT2F_ROCOMPAT_HUGE_FILE | \
331 					 EXT2F_ROCOMPAT_EXTRA_ISIZE)
332 #define	EXT2F_INCOMPAT_SUPP		(EXT2F_INCOMPAT_FTYPE | \
333 					 EXT2F_INCOMPAT_META_BG | \
334 					 EXT2F_INCOMPAT_EXTENTS | \
335 					 EXT2F_INCOMPAT_64BIT | \
336 					 EXT2F_INCOMPAT_FLEX_BG | \
337 					 EXT2F_INCOMPAT_CSUM_SEED)
338 
339 /* Assume that user mode programs are passing in an ext2fs superblock, not
340  * a kernel struct super_block.  This will allow us to call the feature-test
341  * macros from user land. */
342 #define	EXT2_SB(sb)	(sb)
343 
344 /*
345  * Feature set definitions
346  */
347 #define	EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
348 	( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_compat) & mask)
349 #define	EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
350 	( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_rocompat) & mask)
351 #define	EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
352 	( le32toh(EXT2_SB(sb)->e2fs->e2fs_features_incompat) & mask)
353 
354 /*
355  * File clean flags
356  */
357 #define	E2FS_ISCLEAN			0x0001	/* Unmounted cleanly */
358 #define	E2FS_ERRORS			0x0002	/* Errors detected */
359 
360 /*
361  * Filesystem miscellaneous flags
362  */
363 #define	E2FS_SIGNED_HASH	0x0001
364 #define	E2FS_UNSIGNED_HASH	0x0002
365 
366 #define	EXT2_BG_INODE_UNINIT	0x0001	/* Inode table/bitmap not in use */
367 #define	EXT2_BG_BLOCK_UNINIT	0x0002	/* Block bitmap not in use */
368 #define	EXT2_BG_INODE_ZEROED	0x0004	/* On-disk itable initialized to zero */
369 
370 /* ext2 file system block group descriptor */
371 
372 struct ext2_gd {
373 	uint32_t ext2bgd_b_bitmap;	/* blocks bitmap block */
374 	uint32_t ext2bgd_i_bitmap;	/* inodes bitmap block */
375 	uint32_t ext2bgd_i_tables;	/* inodes table block  */
376 	uint16_t ext2bgd_nbfree;	/* number of free blocks */
377 	uint16_t ext2bgd_nifree;	/* number of free inodes */
378 	uint16_t ext2bgd_ndirs;		/* number of directories */
379 	uint16_t ext4bgd_flags;		/* block group flags */
380 	uint32_t ext4bgd_x_bitmap;	/* snapshot exclusion bitmap loc. */
381 	uint16_t ext4bgd_b_bmap_csum;	/* block bitmap checksum */
382 	uint16_t ext4bgd_i_bmap_csum;	/* inode bitmap checksum */
383 	uint16_t ext4bgd_i_unused;	/* unused inode count */
384 	uint16_t ext4bgd_csum;		/* group descriptor checksum */
385 	uint32_t ext4bgd_b_bitmap_hi;	/* high bits of blocks bitmap block */
386 	uint32_t ext4bgd_i_bitmap_hi;	/* high bits of inodes bitmap block */
387 	uint32_t ext4bgd_i_tables_hi;	/* high bits of inodes table block */
388 	uint16_t ext4bgd_nbfree_hi;	/* high bits of number of free blocks */
389 	uint16_t ext4bgd_nifree_hi;	/* high bits of number of free inodes */
390 	uint16_t ext4bgd_ndirs_hi;	/* high bits of number of directories */
391 	uint16_t ext4bgd_i_unused_hi;	/* high bits of unused inode count */
392 	uint32_t ext4bgd_x_bitmap_hi;   /* high bits of snapshot exclusion */
393 	uint16_t ext4bgd_b_bmap_csum_hi;/* high bits of block bitmap checksum */
394 	uint16_t ext4bgd_i_bmap_csum_hi;/* high bits of inode bitmap checksum */
395 	uint32_t ext4bgd_reserved;
396 };
397 
398 #define	E2FS_REV0_GD_SIZE (sizeof(struct ext2_gd) / 2)
399 #define	E2FS_64BIT_GD_SIZE (sizeof(struct ext2_gd))
400 
401 /*
402  * Macro-instructions used to manage several block sizes
403  */
404 #define	EXT2_MIN_BLOCK_LOG_SIZE		  10
405 #define	EXT2_BLOCK_SIZE(s)		((s)->e2fs_bsize)
406 #define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
407 #define	EXT2_INODE_SIZE(s)		(EXT2_SB(s)->e2fs_isize)
408 
409 /*
410  * Macro-instructions used to manage fragments
411  */
412 #define	EXT2_MIN_FRAG_SIZE		1024
413 #define	EXT2_MIN_FRAG_LOG_SIZE		10
414 #define	EXT2_MAX_FRAG_LOG_SIZE		30
415 #define	EXT2_FRAG_SIZE(s)		(EXT2_SB(s)->e2fs_fsize)
416 #define	EXT2_FRAGS_PER_BLOCK(s)		(EXT2_SB(s)->e2fs_fpb)
417 
418 /*
419  * Macro-instructions used to manage group descriptors
420  */
421 #define	EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->e2fs_bpg)
422 #define	EXT2_DESCS_PER_BLOCK(s)		(EXT2_HAS_INCOMPAT_FEATURE((s),  \
423     EXT2F_INCOMPAT_64BIT) ? ((s)->e2fs_bsize / sizeof(struct ext2_gd)) : \
424     ((s)->e2fs_bsize / E2FS_REV0_GD_SIZE))
425 
426 /*
427  * Macro-instructions used to manage inodes
428  */
429 #define	EXT2_FIRST_INO(s)	(le32toh((EXT2_SB(s)->e2fs->e2fs_rev) == \
430     E2FS_REV0) ? EXT2_FIRSTINO : le32toh(EXT2_SB(s)->e2fs->e2fs_first_ino))
431 
432 #endif	/* !_FS_EXT2FS_EXT2FS_H_ */
433