/* $OpenBSD: ext2fs.h,v 1.27 2024/07/15 13:27:36 martijn Exp $ */ /* $NetBSD: ext2fs.h,v 1.10 2000/01/28 16:00:23 bouyer Exp $ */ /* * Copyright (c) 1997 Manuel Bouyer. * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)fs.h 8.10 (Berkeley) 10/27/94 * Modified for ext2fs by Manuel Bouyer. */ #include <sys/endian.h> /* * Each disk drive contains some number of file systems. * A file system consists of a number of cylinder groups. * Each cylinder group has inodes and data. * * A file system is described by its super-block, which in turn * describes the cylinder groups. The super-block is critical * data and is replicated in each cylinder group to protect against * catastrophic loss. This is done at `newfs' time and the critical * super-block data does not change, so the copies need not be * referenced further unless disaster strikes. * * The first boot and super blocks are given in absolute disk addresses. * The byte-offset forms are preferred, as they don't imply a sector size. */ #define BBSIZE 1024 #define SBSIZE 1024 #define BBOFF ((off_t)(0)) #define SBOFF ((off_t)(BBOFF + BBSIZE)) #define BBLOCK ((daddr_t)(0)) #define SBLOCK ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE)) /* * Inodes are, like in UFS, 32-bit unsigned integers and therefore ufsino_t. * Disk blocks are 32-bit, if the filesystem isn't operating in 64-bit mode * (the incompatible ext4 64BIT flag). More work is needed to properly use * daddr_t as the disk block data type on both BE and LE architectures. * XXX disk blocks are simply u_int32_t for now. */ /* * MINBSIZE is the smallest allowable block size. * MINBSIZE must be big enough to hold a cylinder group block, * thus changes to (struct cg) must keep its size within MINBSIZE. * Note that super blocks are always of size SBSIZE, * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE. * FSIZE means fragment size. */ #define LOG_MINBSIZE 10 #define MINBSIZE (1 << LOG_MINBSIZE) #define LOG_MINFSIZE 10 #define MINFSIZE (1 << LOG_MINFSIZE) /* * The path name on which the file system is mounted is maintained * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in * the super block for this name. */ #define MAXMNTLEN 512 /* * MINFREE gives the minimum acceptable percentage of file system * blocks which may be free. If the freelist drops below this level * only the superuser may continue to allocate blocks. This may * be set to 0 if no reserve of free blocks is deemed necessary, * however throughput drops by fifty percent if the file system * is run at between 95% and 100% full; thus the minimum default * value of fs_minfree is 5%. However, to get good clustering * performance, 10% is a better choice. hence we use 10% as our * default value. With 10% free space, fragmentation is not a * problem, so we choose to optimize for time. */ #define MINFREE 5 /* * Super block for an ext2fs file system. */ struct ext2fs { u_int32_t e2fs_icount; /* Inode count */ u_int32_t e2fs_bcount; /* blocks count */ u_int32_t e2fs_rbcount; /* reserved blocks count */ u_int32_t e2fs_fbcount; /* free blocks count */ u_int32_t e2fs_ficount; /* free inodes count */ u_int32_t e2fs_first_dblock; /* first data block */ u_int32_t e2fs_log_bsize; /* block size = 1024*(2^e2fs_log_bsize) */ u_int32_t e2fs_log_fsize; /* fragment size log2 */ u_int32_t e2fs_bpg; /* blocks per group */ u_int32_t e2fs_fpg; /* frags per group */ u_int32_t e2fs_ipg; /* inodes per group */ u_int32_t e2fs_mtime; /* mount time */ u_int32_t e2fs_wtime; /* write time */ u_int16_t e2fs_mnt_count; /* mount count */ u_int16_t e2fs_max_mnt_count; /* max mount count */ u_int16_t e2fs_magic; /* magic number */ u_int16_t e2fs_state; /* file system state */ u_int16_t e2fs_beh; /* behavior on errors */ u_int16_t e2fs_minrev; /* minor revision level */ u_int32_t e2fs_lastfsck; /* time of last fsck */ u_int32_t e2fs_fsckintv; /* max time between fscks */ u_int32_t e2fs_creator; /* creator OS */ u_int32_t e2fs_rev; /* revision level */ u_int16_t e2fs_ruid; /* default uid for reserved blocks */ u_int16_t e2fs_rgid; /* default gid for reserved blocks */ /* EXT2_DYNAMIC_REV superblocks */ u_int32_t e2fs_first_ino; /* first non-reserved inode */ u_int16_t e2fs_inode_size; /* size of inode structure */ u_int16_t e2fs_block_group_nr; /* block grp number of this sblk*/ u_int32_t e2fs_features_compat; /* compatible feature set */ u_int32_t e2fs_features_incompat; /* incompatible feature set */ u_int32_t e2fs_features_rocompat; /* RO-compatible feature set */ u_int8_t e2fs_uuid[16]; /* 128-bit uuid for volume */ char e2fs_vname[16]; /* volume name */ char e2fs_fsmnt[64]; /* name mounted on */ u_int32_t e2fs_algo; /* For compression */ u_int8_t e2fs_prealloc; /* # of blocks to preallocate */ u_int8_t e2fs_dir_prealloc; /* # of blocks to preallocate for dir */ u_int16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */ /* Ext3 JBD2 journaling. */ u_int8_t e2fs_journal_uuid[16]; u_int32_t e2fs_journal_ino; u_int32_t e2fs_journal_dev; u_int32_t e2fs_last_orphan; /* start of list of inodes to delete */ u_int32_t e2fs_hash_seed[4]; /* htree hash seed */ u_int8_t e2fs_def_hash_version; u_int8_t e2fs_journal_backup_type; u_int16_t e2fs_gdesc_size; u_int32_t e2fs_default_mount_opts; u_int32_t e2fs_first_meta_bg; u_int32_t e2fs_mkfs_time; u_int32_t e2fs_journal_backup[17]; u_int32_t e2fs_bcount_hi; /* high bits of blocks count */ u_int32_t e2fs_rbcount_hi; /* high bits of reserved blocks count */ u_int32_t e2fs_fbcount_hi; /* high bits of free blocks count */ u_int16_t e2fs_min_extra_isize; /* all inodes have some bytes */ u_int16_t e2fs_want_extra_isize;/* inodes must reserve some bytes */ u_int32_t e2fs_flags; /* miscellaneous flags */ u_int16_t e2fs_raid_stride; /* RAID stride */ u_int16_t e2fs_mmpintv; /* seconds to wait in MMP checking */ u_int64_t e2fs_mmpblk; /* block for multi-mount protection */ u_int32_t e2fs_raid_stripe_wid; /* blocks on data disks (N * stride) */ u_int8_t e2fs_log_gpf; /* FLEX_BG group size */ u_int8_t e2fs_chksum_type; /* metadata checksum algorithm used */ u_int8_t e2fs_encrypt; /* versioning level for encryption */ u_int8_t e2fs_reserved_pad; u_int64_t e2fs_kbytes_written; /* number of lifetime kilobytes */ u_int32_t e2fs_snapinum; /* inode number of active snapshot */ u_int32_t e2fs_snapid; /* sequential ID of active snapshot */ u_int64_t e2fs_snaprbcount; /* rsvd blocks for active snapshot */ u_int32_t e2fs_snaplist; /* inode number for on-disk snapshot */ u_int32_t e2fs_errcount; /* number of file system errors */ u_int32_t e2fs_first_errtime; /* first time an error happened */ u_int32_t e2fs_first_errino; /* inode involved in first error */ u_int64_t e2fs_first_errblk; /* block involved of first error */ u_int8_t e2fs_first_errfunc[32];/* function where error happened */ u_int32_t e2fs_first_errline; /* line number where error happened */ u_int32_t e2fs_last_errtime; /* most recent time of an error */ u_int32_t e2fs_last_errino; /* inode involved in last error */ u_int32_t e2fs_last_errline; /* line number where error happened */ u_int64_t e2fs_last_errblk; /* block involved of last error */ u_int8_t e2fs_last_errfunc[32];/* function where error happened */ u_int8_t e2fs_mount_opts[64]; u_int32_t e2fs_usrquota_inum; /* inode for tracking user quota */ u_int32_t e2fs_grpquota_inum; /* inode for tracking group quota */ u_int32_t e2fs_overhead_clusters;/* overhead blocks/clusters */ u_int32_t e2fs_backup_bgs[2]; /* groups with sparse_super2 SBs */ u_int8_t e2fs_encrypt_algos[4];/* encryption algorithms in use */ u_int8_t e2fs_encrypt_pw_salt[16];/* salt used for string2key */ u_int32_t e2fs_lpf_ino; /* location of the lost+found inode */ u_int32_t e2fs_proj_quota_inum; /* inode for tracking project quota */ u_int32_t e2fs_chksum_seed; /* checksum seed */ u_int32_t e2fs_reserved[98]; /* padding to the end of the block */ u_int32_t e2fs_sbchksum; /* superblock checksum */ }; /* in-memory data for ext2fs */ struct m_ext2fs { struct ext2fs e2fs; u_char e2fs_fsmnt[MAXMNTLEN]; /* name mounted on */ int8_t e2fs_ronly; /* mounted read-only flag */ int8_t e2fs_fmod; /* super block modified flag */ int32_t e2fs_fsize; /* fragment size */ int32_t e2fs_bsize; /* block size */ int32_t e2fs_bshift; /* ``lblkno'' calc of logical blkno */ int32_t e2fs_bmask; /* ``blkoff'' calc of blk offsets */ int64_t e2fs_qbmask; /* ~fs_bmask - for use with quad size */ int32_t e2fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ int32_t e2fs_ncg; /* number of cylinder groups */ int32_t e2fs_ngdb; /* number of group descriptor block */ int32_t e2fs_ipb; /* number of inodes per block */ int32_t e2fs_itpg; /* number of inode table per group */ off_t e2fs_maxfilesize; /* depends on LARGE/HUGE flags */ struct ext2_gd *e2fs_gd; /* group descriptors */ }; static inline int e2fs_overflow(struct m_ext2fs *fs, off_t lower, off_t value) { return (value < lower || value > fs->e2fs_maxfilesize); } /* * Filesystem identification */ #define E2FS_MAGIC 0xef53 /* the ext2fs magic number */ #define E2FS_REV0 0 /* revision levels */ #define E2FS_REV1 1 /* revision levels */ /* compatible/incompatible features */ #define EXT2F_COMPAT_PREALLOC 0x0001 #define EXT2F_COMPAT_IMAGIC_INODES 0x0002 #define EXT2F_COMPAT_HAS_JOURNAL 0x0004 #define EXT2F_COMPAT_EXT_ATTR 0x0008 #define EXT2F_COMPAT_RESIZE 0x0010 #define EXT2F_COMPAT_DIR_INDEX 0x0020 #define EXT2F_COMPAT_SPARSE_SUPER2 0x0200 #define EXT2F_ROCOMPAT_SPARSE_SUPER 0x0001 #define EXT2F_ROCOMPAT_LARGE_FILE 0x0002 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040 #define EXT2F_ROCOMPAT_QUOTA 0x0100 #define EXT2F_ROCOMPAT_BIGALLOC 0x0200 #define EXT2F_ROCOMPAT_METADATA_CKSUM 0x0400 #define EXT2F_ROCOMPAT_READONLY 0x1000 #define EXT2F_ROCOMPAT_PROJECT 0x2000 #define EXT2F_INCOMPAT_COMP 0x0001 #define EXT2F_INCOMPAT_FTYPE 0x0002 #define EXT2F_INCOMPAT_RECOVER 0x0004 #define EXT2F_INCOMPAT_JOURNAL_DEV 0x0008 #define EXT2F_INCOMPAT_META_BG 0x0010 #define EXT2F_INCOMPAT_EXTENTS 0x0040 #define EXT2F_INCOMPAT_64BIT 0x0080 #define EXT2F_INCOMPAT_MMP 0x0100 #define EXT2F_INCOMPAT_FLEX_BG 0x0200 #define EXT2F_INCOMPAT_EA_INODE 0x0400 #define EXT2F_INCOMPAT_DIRDATA 0x1000 #define EXT2F_INCOMPAT_CSUM_SEED 0x2000 #define EXT2F_INCOMPAT_LARGEDIR 0x4000 #define EXT2F_INCOMPAT_INLINE_DATA 0x8000 #define EXT2F_INCOMPAT_ENCRYPT 0x10000 struct ext2_feature { uint32_t mask; const char *name; }; static const struct ext2_feature ro_compat[] = { { EXT2F_ROCOMPAT_SPARSE_SUPER, "sparse_super" }, { EXT2F_ROCOMPAT_LARGE_FILE, "large_file" }, { EXT2F_ROCOMPAT_BTREE_DIR, "btree_dir" }, { EXT2F_ROCOMPAT_HUGE_FILE, "huge_file" }, { EXT2F_ROCOMPAT_GDT_CSUM, "uninit_bg" }, { EXT2F_ROCOMPAT_DIR_NLINK, "dir_nlink" }, { EXT2F_ROCOMPAT_EXTRA_ISIZE, "extra_isize" }, { EXT2F_ROCOMPAT_QUOTA, "quota" }, { EXT2F_ROCOMPAT_BIGALLOC, "bigalloc" }, { EXT2F_ROCOMPAT_METADATA_CKSUM, "metadata_csum" }, { EXT2F_ROCOMPAT_READONLY, "read-only" }, { EXT2F_ROCOMPAT_PROJECT, "project" } }; static const struct ext2_feature incompat[] = { { EXT2F_INCOMPAT_COMP, "compression" }, { EXT2F_INCOMPAT_FTYPE, "filetype" }, { EXT2F_INCOMPAT_RECOVER, "needs_recovery" }, { EXT2F_INCOMPAT_JOURNAL_DEV, "journal_dev" }, { EXT2F_INCOMPAT_META_BG, "meta_bg" }, { EXT2F_INCOMPAT_EXTENTS, "extents" }, { EXT2F_INCOMPAT_64BIT, "64bit" }, { EXT2F_INCOMPAT_MMP, "mmp" }, { EXT2F_INCOMPAT_FLEX_BG, "flex_bg" }, { EXT2F_INCOMPAT_EA_INODE, "ea_inode" }, { EXT2F_INCOMPAT_DIRDATA, "dirdata" }, { EXT2F_INCOMPAT_CSUM_SEED, "metadata_csum_seed" }, { EXT2F_INCOMPAT_LARGEDIR, "large_dir" }, { EXT2F_INCOMPAT_INLINE_DATA, "inline_data" }, { EXT2F_INCOMPAT_ENCRYPT, "encrypt" } }; /* features supported in this implementation */ #define EXT2F_COMPAT_SUPP 0x0000 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSE_SUPER | \ EXT2F_ROCOMPAT_LARGE_FILE) #define EXT2F_INCOMPAT_SUPP (EXT2F_INCOMPAT_FTYPE) #define EXT4F_RO_INCOMPAT_SUPP (EXT2F_INCOMPAT_EXTENTS | \ EXT2F_INCOMPAT_FLEX_BG | \ EXT2F_INCOMPAT_META_BG | \ EXT2F_INCOMPAT_RECOVER) /* * Definitions of behavior on errors */ #define E2FS_BEH_CONTINUE 1 /* continue operation */ #define E2FS_BEH_READONLY 2 /* remount fs read only */ #define E2FS_BEH_PANIC 3 /* cause panic */ #define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE /* * OS identification */ #define E2FS_OS_LINUX 0 #define E2FS_OS_HURD 1 #define E2FS_OS_MASIX 2 /* * Filesystem clean flags */ #define E2FS_ISCLEAN 0x01 #define E2FS_ERRORS 0x02 /* ext2 file system block group descriptor */ struct ext2_gd { u_int32_t ext2bgd_b_bitmap; /* blocks bitmap block */ u_int32_t ext2bgd_i_bitmap; /* inodes bitmap block */ u_int32_t ext2bgd_i_tables; /* inodes table block */ u_int16_t ext2bgd_nbfree; /* number of free blocks */ u_int16_t ext2bgd_nifree; /* number of free inodes */ u_int16_t ext2bgd_ndirs; /* number of directories */ u_int16_t reserved; u_int32_t reserved2[3]; }; /* * If the EXT2F_ROCOMPAT_SPARSE_SUPER flag is set, the cylinder group has a * copy of the super and cylinder group descriptors blocks only if it's * a power of 3, 5 or 7 */ static __inline__ int cg_has_sb(int) __attribute__((__unused__)); static __inline int cg_has_sb(int i) { int a3 ,a5 , a7; if (i == 0 || i == 1) return 1; for (a3 = 3, a5 = 5, a7 = 7; a3 <= i || a5 <= i || a7 <= i; a3 *= 3, a5 *= 5, a7 *= 7) if (i == a3 || i == a5 || i == a7) return 1; return 0; } /* * Ext2 metadata is stored in little-endian byte order. * JBD2 journal used in ext3 and ext4 is big-endian! */ #if BYTE_ORDER == LITTLE_ENDIAN #define e2fs_sbload(old, new) memcpy((new), (old), SBSIZE); #define e2fs_cgload(old, new, size) memcpy((new), (old), (size)); #define e2fs_sbsave(old, new) memcpy((new), (old), SBSIZE); #define e2fs_cgsave(old, new, size) memcpy((new), (old), (size)); #else void e2fs_sb_bswap(struct ext2fs *, struct ext2fs *); void e2fs_cg_bswap(struct ext2_gd *, struct ext2_gd *, int); #define e2fs_sbload(old, new) e2fs_sb_bswap((old), (new)) #define e2fs_cgload(old, new, size) e2fs_cg_bswap((old), (new), (size)); #define e2fs_sbsave(old, new) e2fs_sb_bswap((old), (new)) #define e2fs_cgsave(old, new, size) e2fs_cg_bswap((old), (new), (size)); #endif /* * Turn file system block numbers into disk block addresses. * This maps file system blocks to device size blocks. */ #define fsbtodb(fs, b) ((b) << (fs)->e2fs_fsbtodb) #define dbtofsb(fs, b) ((b) >> (fs)->e2fs_fsbtodb) /* * Macros for handling inode numbers: * inode number to file system block offset. * inode number to cylinder group number. * inode number to file system block address. */ #define ino_to_cg(fs, x) (((x) - 1) / (fs)->e2fs.e2fs_ipg) #define ino_to_fsba(fs, x) \ ((fs)->e2fs_gd[ino_to_cg(fs, x)].ext2bgd_i_tables + \ (((x)-1) % (fs)->e2fs.e2fs_ipg)/(fs)->e2fs_ipb) #define ino_to_fsbo(fs, x) (((x)-1) % (fs)->e2fs_ipb) /* * Give cylinder group number for a file system block. * Give cylinder group block number for a file system block. */ #define dtog(fs, d) (((d) - (fs)->e2fs.e2fs_first_dblock) / (fs)->e2fs.e2fs_fpg) #define dtogd(fs, d) \ (((d) - (fs)->e2fs.e2fs_first_dblock) % (fs)->e2fs.e2fs_fpg) /* * The following macros optimize certain frequently calculated * quantities by using shifts and masks in place of divisions * modulos and multiplications. */ #define blkoff(fs, loc) /* calculates (loc % fs->e2fs_bsize) */ \ ((loc) & (fs)->e2fs_qbmask) #define lblktosize(fs, blk) /* calculates (blk * fs->e2fs_bsize) */ \ ((blk) << (fs)->e2fs_bshift) #define lblkno(fs, loc) /* calculates (loc / fs->e2fs_bsize) */ \ ((loc) >> (fs)->e2fs_bshift) #define blkroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) #define fragroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \ (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask) /* * Determine the number of available frags given a * percentage to hold in reserve. */ #define freespace(fs) \ ((fs)->e2fs.e2fs_fbcount - (fs)->e2fs.e2fs_rbcount) /* * Number of indirects in a file system block. */ #define NINDIR(fs) ((fs)->e2fs_bsize / sizeof(u_int32_t))
