fs.h

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/*-
 * 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.
 * 4. 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        8.13 (Berkeley) 3/21/95
 * $FreeBSD: releng/11.1/sys/ufs/ffs/fs.h 298804 2016-04-29 20:43:51Z pfg $
 */
 
#ifndef _UFS_FFS_FS_H_
#define _UFS_FFS_FS_H_
 
#include <vfs/mount.h>
#include <ufs/ufs/dinode.h>
 
/*
 * Each disk drive contains some number of filesystems.
 * A filesystem consists of a number of cylinder groups.
 * Each cylinder group has inodes and data.
 *
 * A filesystem 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.
 *
 * For filesystem fs, the offsets of the various blocks of interest
 * are given in the super block as:
 *      [fs->fs_sblkno]         Super-block
 *      [fs->fs_cblkno]         Cylinder group block
 *      [fs->fs_iblkno]         Inode blocks
 *      [fs->fs_dblkno]         Data blocks
 * The beginning of cylinder group cg in fs, is given by
 * the ``cgbase(fs, cg)'' macro.
 *
 * Depending on the architecture and the media, the superblock may
 * reside in any one of four places. For tiny media where every block 
 * counts, it is placed at the very front of the partition. Historically,
 * UFS1 placed it 8K from the front to leave room for the disk label and
 * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
 * room for the disk label and a bigger bootstrap, and for really piggy
 * systems we check at 256K from the front if the first three fail. In
 * all cases the size of the superblock will be SBLOCKSIZE. All values are
 * given in byte-offset form, so they do not imply a sector size. The
 * SBLOCKSEARCH specifies the order in which the locations should be searched.
 */
#define SBLOCK_FLOPPY        0
#define SBLOCK_UFS1       8192
#define SBLOCK_UFS2      65536
#define SBLOCK_PIGGY    262144
#define SBLOCKSIZE        8192
#define SBLOCKSEARCH \
        { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
 
/*
 * Max number of fragments per block. This value is NOT tweakable.
 */
#define MAXFRAG         8
 
/*
 * Addresses stored in inodes are capable of addressing fragments
 * of `blocks'. File system blocks of at most size MAXBSIZE can
 * be optionally broken into 2, 4, or 8 pieces, each of which is
 * addressable; these pieces may be DEV_BSIZE, or some multiple of
 * a DEV_BSIZE unit.
 *
 * Large files consist of exclusively large data blocks.  To avoid
 * undue wasted disk space, the last data block of a small file may be
 * allocated as only as many fragments of a large block as are
 * necessary.  The filesystem format retains only a single pointer
 * to such a fragment, which is a piece of a single large block that
 * has been divided.  The size of such a fragment is determinable from
 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
 *
 * The filesystem records space availability at the fragment level;
 * to determine block availability, aligned fragments are examined.
 */
 
/*
 * MINBSIZE is the smallest allowable block size.
 * In order to insure that it is possible to create files of size
 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
 * 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 SBLOCKSIZE,
 * and that both SBLOCKSIZE and MAXBSIZE must be >= MINBSIZE.
 */
#define MINBSIZE        4096
 
/*
 * The path name on which the filesystem is mounted is maintained
 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
 * the super block for this name.
 */
#define MAXMNTLEN       468
 
/*
 * The volume name for this filesystem is maintained in fs_volname.
 * MAXVOLLEN defines the length of the buffer allocated.
 */
#define MAXVOLLEN       32
 
/*
 * There is a 128-byte region in the superblock reserved for in-core
 * pointers to summary information. Originally this included an array
 * of pointers to blocks of struct csum; now there are just a few
 * pointers and the remaining space is padded with fs_ocsp[].
 *
 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
 * is taken away to point to a contiguous array of struct csum for
 * all cylinder groups; a second (fs_maxcluster) points to an array
 * of cluster sizes that is computed as cylinder groups are inspected,
 * and the third points to an array that tracks the creation of new
 * directories. A fourth pointer, fs_active, is used when creating
 * snapshots; it points to a bitmap of cylinder groups for which the
 * free-block bitmap has changed since the snapshot operation began.
 */
#define NOCSPTRS        ((128 / sizeof(void *)) - 4)
 
/*
 * A summary of contiguous blocks of various sizes is maintained
 * in each cylinder group. Normally this is set by the initial
 * value of fs_maxcontig. To conserve space, a maximum summary size
 * is set by FS_MAXCONTIG.
 */
#define FS_MAXCONTIG    16
 
/*
 * MINFREE gives the minimum acceptable percentage of filesystem
 * 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 filesystem
 * 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         8
#define DEFAULTOPT      FS_OPTTIME
 
/*
 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
 * tune the layout preferences for directories within a filesystem.
 * His algorithm can be tuned by adjusting the following parameters
 * which tell the system the average file size and the average number
 * of files per directory. These defaults are well selected for typical
 * filesystems, but may need to be tuned for odd cases like filesystems
 * being used for squid caches or news spools.
 */
#define AVFILESIZ       16384   /* expected average file size */
#define AFPDIR          64      /* expected number of files per directory */
 
/*
 * The maximum number of snapshot nodes that can be associated
 * with each filesystem. This limit affects only the number of
 * snapshot files that can be recorded within the superblock so
 * that they can be found when the filesystem is mounted. However,
 * maintaining too many will slow the filesystem performance, so
 * having this limit is a good idea.
 */
#define FSMAXSNAP 20
 
/*
 * Used to identify special blocks in snapshots:
 *
 * BLK_NOCOPY - A block that was unallocated at the time the snapshot
 *      was taken, hence does not need to be copied when written.
 * BLK_SNAP - A block held by another snapshot that is not needed by this
 *      snapshot. When the other snapshot is freed, the BLK_SNAP entries
 *      are converted to BLK_NOCOPY. These are needed to allow fsck to
 *      identify blocks that are in use by other snapshots (which are
 *      expunged from this snapshot).
 */
#define BLK_NOCOPY ((ufs2_daddr_t)(1))
#define BLK_SNAP ((ufs2_daddr_t)(2))
 
/*
 * Sysctl values for the fast filesystem.
 */
#define FFS_ADJ_REFCNT           1      /* adjust inode reference count */
#define FFS_ADJ_BLKCNT           2      /* adjust inode used block count */
#define FFS_BLK_FREE             3      /* free range of blocks in map */
#define FFS_DIR_FREE             4      /* free specified dir inodes in map */
#define FFS_FILE_FREE            5      /* free specified file inodes in map */
#define FFS_SET_FLAGS            6      /* set filesystem flags */
#define FFS_ADJ_NDIR             7      /* adjust number of directories */
#define FFS_ADJ_NBFREE           8      /* adjust number of free blocks */
#define FFS_ADJ_NIFREE           9      /* adjust number of free inodes */
#define FFS_ADJ_NFFREE          10      /* adjust number of free frags */
#define FFS_ADJ_NUMCLUSTERS     11      /* adjust number of free clusters */
#define FFS_SET_CWD             12      /* set current directory */
#define FFS_SET_DOTDOT          13      /* set inode number for ".." */
#define FFS_UNLINK              14      /* remove a name in the filesystem */
#define FFS_SET_INODE           15      /* update an on-disk inode */
#define FFS_SET_BUFOUTPUT       16      /* set buffered writing on descriptor */
#define FFS_MAXID               16      /* number of valid ffs ids */
 
/*
 * Command structure passed in to the filesystem to adjust filesystem values.
 */
#define FFS_CMD_VERSION         0x19790518      /* version ID */
struct fsck_cmd {
        int32_t version;        /* version of command structure */
        int32_t handle;         /* reference to filesystem to be changed */
        int64_t value;          /* inode or block number to be affected */
        int64_t size;           /* amount or range to be adjusted */
        int64_t spare;          /* reserved for future use */
};
 
/*
 * Per cylinder group information; summarized in blocks allocated
 * from first cylinder group data blocks.  These blocks have to be
 * read in from fs_csaddr (size fs_cssize) in addition to the
 * super block.
 */
struct csum {
        int32_t cs_ndir;                /* number of directories */
        int32_t cs_nbfree;              /* number of free blocks */
        int32_t cs_nifree;              /* number of free inodes */
        int32_t cs_nffree;              /* number of free frags */
};
struct csum_total {
        int64_t cs_ndir;                /* number of directories */
        int64_t cs_nbfree;              /* number of free blocks */
        int64_t cs_nifree;              /* number of free inodes */
        int64_t cs_nffree;              /* number of free frags */
        int64_t cs_numclusters;         /* number of free clusters */
        int64_t cs_spare[3];            /* future expansion */
};
 
/*
 * Super block for an FFS filesystem.
 */
struct fs {
        int32_t  fs_firstfield;         /* historic filesystem linked list, */
        int32_t  fs_unused_1;           /*     used for incore super blocks */
        int32_t  fs_sblkno;             /* offset of super-block in filesys */
        int32_t  fs_cblkno;             /* offset of cyl-block in filesys */
        int32_t  fs_iblkno;             /* offset of inode-blocks in filesys */
        int32_t  fs_dblkno;             /* offset of first data after cg */
        int32_t  fs_old_cgoffset;       /* cylinder group offset in cylinder */
        int32_t  fs_old_cgmask;         /* used to calc mod fs_ntrak */
        int32_t  fs_old_time;           /* last time written */
        int32_t  fs_old_size;           /* number of blocks in fs */
        int32_t  fs_old_dsize;          /* number of data blocks in fs */
        u_int32_t fs_ncg;               /* number of cylinder groups */
        int32_t  fs_bsize;              /* size of basic blocks in fs */
        int32_t  fs_fsize;              /* size of frag blocks in fs */
        int32_t  fs_frag;               /* number of frags in a block in fs */
/* these are configuration parameters */
        int32_t  fs_minfree;            /* minimum percentage of free blocks */
        int32_t  fs_old_rotdelay;       /* num of ms for optimal next block */
        int32_t  fs_old_rps;            /* disk revolutions per second */
/* these fields can be computed from the others */
        int32_t  fs_bmask;              /* ``blkoff'' calc of blk offsets */
        int32_t  fs_fmask;              /* ``fragoff'' calc of frag offsets */
        int32_t  fs_bshift;             /* ``lblkno'' calc of logical blkno */
        int32_t  fs_fshift;             /* ``numfrags'' calc number of frags */
/* these are configuration parameters */
        int32_t  fs_maxcontig;          /* max number of contiguous blks */
        int32_t  fs_maxbpg;             /* max number of blks per cyl group */
/* these fields can be computed from the others */
        int32_t  fs_fragshift;          /* block to frag shift */
        int32_t  fs_fsbtodb;            /* fsbtodb and dbtofsb shift constant */
        int32_t  fs_sbsize;             /* actual size of super block */
        int32_t  fs_spare1[2];          /* old fs_csmask */
                                        /* old fs_csshift */
        int32_t  fs_nindir;             /* value of NINDIR */
        u_int32_t fs_inopb;             /* value of INOPB */
        int32_t  fs_old_nspf;           /* value of NSPF */
/* yet another configuration parameter */
        int32_t  fs_optim;              /* optimization preference, see below */
        int32_t  fs_old_npsect;         /* # sectors/track including spares */
        int32_t  fs_old_interleave;     /* hardware sector interleave */
        int32_t  fs_old_trackskew;      /* sector 0 skew, per track */
        int32_t  fs_id[2];              /* unique filesystem id */
/* sizes determined by number of cylinder groups and their sizes */
        int32_t  fs_old_csaddr;         /* blk addr of cyl grp summary area */
        int32_t  fs_cssize;             /* size of cyl grp summary area */
        int32_t  fs_cgsize;             /* cylinder group size */
        int32_t  fs_spare2;             /* old fs_ntrak */
        int32_t  fs_old_nsect;          /* sectors per track */
        int32_t  fs_old_spc;            /* sectors per cylinder */
        int32_t  fs_old_ncyl;           /* cylinders in filesystem */
        int32_t  fs_old_cpg;            /* cylinders per group */
        u_int32_t fs_ipg;               /* inodes per group */
        int32_t  fs_fpg;                /* blocks per group * fs_frag */
/* this data must be re-computed after crashes */
        struct  csum fs_old_cstotal;    /* cylinder summary information */
/* these fields are cleared at mount time */
        int8_t   fs_fmod;               /* super block modified flag */
        int8_t   fs_clean;              /* filesystem is clean flag */
        int8_t   fs_ronly;              /* mounted read-only flag */
        int8_t   fs_old_flags;          /* old FS_ flags */
        u_char   fs_fsmnt[MAXMNTLEN];   /* name mounted on */
        u_char   fs_volname[MAXVOLLEN]; /* volume name */
        u_int64_t fs_swuid;             /* system-wide uid */
        int32_t  fs_pad;                /* due to alignment of fs_swuid */
/* these fields retain the current block allocation info */
        int32_t  fs_cgrotor;            /* last cg searched */
        void    *fs_ocsp[NOCSPTRS];     /* padding; was list of fs_cs buffers */
        u_int8_t *fs_contigdirs;        /* (u) # of contig. allocated dirs */
        struct  csum *fs_csp;           /* (u) cg summary info buffer */
        int32_t *fs_maxcluster;         /* (u) max cluster in each cyl group */
        u_int   *fs_active;             /* (u) used by snapshots to track fs */
        int32_t  fs_old_cpc;            /* cyl per cycle in postbl */
        int32_t  fs_maxbsize;           /* maximum blocking factor permitted */
        int64_t  fs_unrefs;             /* number of unreferenced inodes */
        int64_t  fs_providersize;       /* size of underlying GEOM provider */
        int64_t  fs_metaspace;          /* size of area reserved for metadata */
        int64_t  fs_sparecon64[14];     /* old rotation block list head */
        int64_t  fs_sblockloc;          /* byte offset of standard superblock */
        struct  csum_total fs_cstotal;  /* (u) cylinder summary information */
        ufs_time_t fs_time;             /* last time written */
        int64_t  fs_size;               /* number of blocks in fs */
        int64_t  fs_dsize;              /* number of data blocks in fs */
        ufs2_daddr_t fs_csaddr;         /* blk addr of cyl grp summary area */
        int64_t  fs_pendingblocks;      /* (u) blocks being freed */
        u_int32_t fs_pendinginodes;     /* (u) inodes being freed */
        uint32_t fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
        u_int32_t fs_avgfilesize;       /* expected average file size */
        u_int32_t fs_avgfpdir;          /* expected # of files per directory */
        int32_t  fs_save_cgsize;        /* save real cg size to use fs_bsize */
        ufs_time_t fs_mtime;            /* Last mount or fsck time. */
        int32_t  fs_sujfree;            /* SUJ free list */
        int32_t  fs_sparecon32[23];     /* reserved for future constants */
        int32_t  fs_flags;              /* see FS_ flags below */
        int32_t  fs_contigsumsize;      /* size of cluster summary array */ 
        int32_t  fs_maxsymlinklen;      /* max length of an internal symlink */
        int32_t  fs_old_inodefmt;       /* format of on-disk inodes */
        u_int64_t fs_maxfilesize;       /* maximum representable file size */
        int64_t  fs_qbmask;             /* ~fs_bmask for use with 64-bit size */
        int64_t  fs_qfmask;             /* ~fs_fmask for use with 64-bit size */
        int32_t  fs_state;              /* validate fs_clean field */
        int32_t  fs_old_postblformat;   /* format of positional layout tables */
        int32_t  fs_old_nrpos;          /* number of rotational positions */
        int32_t  fs_spare5[2];          /* old fs_postbloff */
                                        /* old fs_rotbloff */
        int32_t  fs_magic;              /* magic number */
};
 
/* Sanity checking. */
#ifdef CTASSERT
CTASSERT(sizeof(struct fs) == 1376);
#endif
 
/*
 * Filesystem identification
 */
#define FS_UFS1_MAGIC   0x011954        /* UFS1 fast filesystem magic number */
#define FS_UFS2_MAGIC   0x19540119      /* UFS2 fast filesystem magic number */
#define FS_BAD_MAGIC    0x19960408      /* UFS incomplete newfs magic number */
#define FS_OKAY         0x7c269d38      /* superblock checksum */
#define FS_42INODEFMT   -1              /* 4.2BSD inode format */
#define FS_44INODEFMT   2               /* 4.4BSD inode format */
 
/*
 * Preference for optimization.
 */
#define FS_OPTTIME      0       /* minimize allocation time */
#define FS_OPTSPACE     1       /* minimize disk fragmentation */
 
/*
 * Filesystem flags.
 *
 * The FS_UNCLEAN flag is set by the kernel when the filesystem was
 * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates
 * that the filesystem should be managed by the soft updates code.
 * Note that the FS_NEEDSFSCK flag is set and cleared only by the
 * fsck utility. It is set when background fsck finds an unexpected
 * inconsistency which requires a traditional foreground fsck to be
 * run. Such inconsistencies should only be found after an uncorrectable
 * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when
 * it has successfully cleaned up the filesystem. The kernel uses this
 * flag to enforce that inconsistent filesystems be mounted read-only.
 * The FS_INDEXDIRS flag when set indicates that the kernel maintains
 * on-disk auxiliary indexes (such as B-trees) for speeding directory
 * accesses. Kernels that do not support auxiliary indices clear the
 * flag to indicate that the indices need to be rebuilt (by fsck) before
 * they can be used.
 *
 * FS_ACLS indicates that POSIX.1e ACLs are administratively enabled
 * for the file system, so they should be loaded from extended attributes,
 * observed for access control purposes, and be administered by object
 * owners.  FS_NFS4ACLS indicates that NFSv4 ACLs are administratively
 * enabled.  This flag is mutually exclusive with FS_ACLS.  FS_MULTILABEL
 * indicates that the TrustedBSD MAC Framework should attempt to back MAC
 * labels into extended attributes on the file system rather than maintain
 * a single mount label for all objects.
 */
#define FS_UNCLEAN      0x0001  /* filesystem not clean at mount */
#define FS_DOSOFTDEP    0x0002  /* filesystem using soft dependencies */
#define FS_NEEDSFSCK    0x0004  /* filesystem needs sync fsck before mount */
#define FS_SUJ          0x0008  /* Filesystem using softupdate journal */
#define FS_ACLS         0x0010  /* file system has POSIX.1e ACLs enabled */
#define FS_MULTILABEL   0x0020  /* file system is MAC multi-label */
#define FS_GJOURNAL     0x0040  /* gjournaled file system */
#define FS_FLAGS_UPDATED 0x0080 /* flags have been moved to new location */
#define FS_NFS4ACLS     0x0100  /* file system has NFSv4 ACLs enabled */
#define FS_INDEXDIRS    0x0200  /* kernel supports indexed directories */
#define FS_TRIM         0x0400  /* issue BIO_DELETE for deleted blocks */
 
/*
 * Macros to access bits in the fs_active array.
 */
#define ACTIVECGNUM(fs, cg)     ((fs)->fs_active[(cg) / (NBBY * sizeof(int))])
#define ACTIVECGOFF(cg)         (1 << ((cg) % (NBBY * sizeof(int))))
#define ACTIVESET(fs, cg)       do {                                    \
        if ((fs)->fs_active)                                            \
                ACTIVECGNUM((fs), (cg)) |= ACTIVECGOFF((cg));           \
} while (0)
#define ACTIVECLEAR(fs, cg)     do {                                    \
        if ((fs)->fs_active)                                            \
                ACTIVECGNUM((fs), (cg)) &= ~ACTIVECGOFF((cg));          \
} while (0)
 
/*
 * The size of a cylinder group is calculated by CGSIZE. The maximum size
 * is limited by the fact that cylinder groups are at most one block.
 * Its size is derived from the size of the maps maintained in the
 * cylinder group and the (struct cg) size.
 */
#define CGSIZE(fs) \
    /* base cg */       (sizeof(struct cg) + sizeof(int32_t) + \
    /* old btotoff */   (fs)->fs_old_cpg * sizeof(int32_t) + \
    /* old boff */      (fs)->fs_old_cpg * sizeof(u_int16_t) + \
    /* inode map */     howmany((fs)->fs_ipg, NBBY) + \
    /* block map */     howmany((fs)->fs_fpg, NBBY) +\
    /* if present */    ((fs)->fs_contigsumsize <= 0 ? 0 : \
    /* cluster sum */   (fs)->fs_contigsumsize * sizeof(int32_t) + \
    /* cluster map */   howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))
 
/*
 * The minimal number of cylinder groups that should be created.
 */
#define MINCYLGRPS      4
 
/*
 * Convert cylinder group to base address of its global summary info.
 */
#define fs_cs(fs, indx) fs_csp[indx]
 
/*
 * Cylinder group block for a filesystem.
 */
#define CG_MAGIC        0x090255
struct cg {
        int32_t  cg_firstfield;         /* historic cyl groups linked list */
        int32_t  cg_magic;              /* magic number */
        int32_t  cg_old_time;           /* time last written */
        u_int32_t cg_cgx;               /* we are the cgx'th cylinder group */
        int16_t  cg_old_ncyl;           /* number of cyl's this cg */
        int16_t  cg_old_niblk;          /* number of inode blocks this cg */
        u_int32_t cg_ndblk;             /* number of data blocks this cg */
        struct   csum cg_cs;            /* cylinder summary information */
        u_int32_t cg_rotor;             /* position of last used block */
        u_int32_t cg_frotor;            /* position of last used frag */
        u_int32_t cg_irotor;            /* position of last used inode */
        u_int32_t cg_frsum[MAXFRAG];    /* counts of available frags */
        int32_t  cg_old_btotoff;        /* (int32) block totals per cylinder */
        int32_t  cg_old_boff;           /* (u_int16) free block positions */
        u_int32_t cg_iusedoff;          /* (u_int8) used inode map */
        u_int32_t cg_freeoff;           /* (u_int8) free block map */
        u_int32_t cg_nextfreeoff;       /* (u_int8) next available space */
        u_int32_t cg_clustersumoff;     /* (u_int32) counts of avail clusters */
        u_int32_t cg_clusteroff;                /* (u_int8) free cluster map */
        u_int32_t cg_nclusterblks;      /* number of clusters this cg */
        u_int32_t cg_niblk;             /* number of inode blocks this cg */
        u_int32_t cg_initediblk;                /* last initialized inode */
        u_int32_t cg_unrefs;            /* number of unreferenced inodes */
        int32_t  cg_sparecon32[2];      /* reserved for future use */
        ufs_time_t cg_time;             /* time last written */
        int64_t  cg_sparecon64[3];      /* reserved for future use */
        u_int8_t cg_space[1];           /* space for cylinder group maps */
/* actually longer */
};
 
/*
 * Macros for access to cylinder group array structures
 */
#define cg_chkmagic(cgp) ((cgp)->cg_magic == CG_MAGIC)
#define cg_inosused(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))
#define cg_blksfree(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))
#define cg_clustersfree(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
#define cg_clustersum(cgp) \
    ((int32_t *)((uintptr_t)(cgp) + (cgp)->cg_clustersumoff))
 
/*
 * Turn filesystem block numbers into disk block addresses.
 * This maps filesystem blocks to device size blocks.
 */
#define fsbtodb(fs, b)  ((daddr_t)(b) << (fs)->fs_fsbtodb)
#define dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)
 
/*
 * Cylinder group macros to locate things in cylinder groups.
 * They calc filesystem addresses of cylinder group data structures.
 */
#define cgbase(fs, c)   (((ufs2_daddr_t)(fs)->fs_fpg) * (c))
#define cgdata(fs, c)   (cgdmin(fs, c) + (fs)->fs_metaspace)    /* data zone */
#define cgmeta(fs, c)   (cgdmin(fs, c))                         /* meta data */
#define cgdmin(fs, c)   (cgstart(fs, c) + (fs)->fs_dblkno)      /* 1st data */
#define cgimin(fs, c)   (cgstart(fs, c) + (fs)->fs_iblkno)      /* inode blk */
#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno)      /* super blk */
#define cgtod(fs, c)    (cgstart(fs, c) + (fs)->fs_cblkno)      /* cg block */
#define cgstart(fs, c)                                                  \
       ((fs)->fs_magic == FS_UFS2_MAGIC ? cgbase(fs, c) :               \
       (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask))))
 
/*
 * Macros for handling inode numbers:
 *     inode number to filesystem block offset.
 *     inode number to cylinder group number.
 *     inode number to filesystem block address.
 */
#define ino_to_cg(fs, x)        (((ino_t)(x)) / (fs)->fs_ipg)
#define ino_to_fsba(fs, x)                                              \
        ((ufs2_daddr_t)(cgimin(fs, ino_to_cg(fs, (ino_t)(x))) +         \
            (blkstofrags((fs), ((((ino_t)(x)) % (fs)->fs_ipg) / INOPB(fs))))))
#define ino_to_fsbo(fs, x)      (((ino_t)(x)) % INOPB(fs))
 
/*
 * Give cylinder group number for a filesystem block.
 * Give cylinder group block number for a filesystem block.
 */
#define dtog(fs, d)     ((d) / (fs)->fs_fpg)
#define dtogd(fs, d)    ((d) % (fs)->fs_fpg)
 
/*
 * Extract the bits for a block from a map.
 * Compute the cylinder and rotational position of a cyl block addr.
 */
#define blkmap(fs, map, loc) \
    (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
 
/*
 * 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->fs_bsize) */ \
        ((loc) & (fs)->fs_qbmask)
#define fragoff(fs, loc)        /* calculates (loc % fs->fs_fsize) */ \
        ((loc) & (fs)->fs_qfmask)
#define lfragtosize(fs, frag)   /* calculates ((off_t)frag * fs->fs_fsize) */ \
        (((off_t)(frag)) << (fs)->fs_fshift)
#define lblktosize(fs, blk)     /* calculates ((off_t)blk * fs->fs_bsize) */ \
        (((off_t)(blk)) << (fs)->fs_bshift)
/* Use this only when `blk' is known to be small, e.g., < NDADDR. */
#define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
        ((blk) << (fs)->fs_bshift)
#define lblkno(fs, loc)         /* calculates (loc / fs->fs_bsize) */ \
        ((loc) >> (fs)->fs_bshift)
#define numfrags(fs, loc)       /* calculates (loc / fs->fs_fsize) */ \
        ((loc) >> (fs)->fs_fshift)
#define blkroundup(fs, size)    /* calculates roundup(size, fs->fs_bsize) */ \
        (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
#define fragroundup(fs, size)   /* calculates roundup(size, fs->fs_fsize) */ \
        (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
#define fragstoblks(fs, frags)  /* calculates (frags / fs->fs_frag) */ \
        ((frags) >> (fs)->fs_fragshift)
#define blkstofrags(fs, blks)   /* calculates (blks * fs->fs_frag) */ \
        ((blks) << (fs)->fs_fragshift)
#define fragnum(fs, fsb)        /* calculates (fsb % fs->fs_frag) */ \
        ((fsb) & ((fs)->fs_frag - 1))
#define blknum(fs, fsb)         /* calculates rounddown(fsb, fs->fs_frag) */ \
        ((fsb) &~ ((fs)->fs_frag - 1))
 
/*
 * Determine the number of available frags given a
 * percentage to hold in reserve.
 */
#define freespace(fs, percentreserved) \
        (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
        (fs)->fs_cstotal.cs_nffree - \
        (((off_t)((fs)->fs_dsize)) * (percentreserved) / 100))
 
/*
 * Determining the size of a file block in the filesystem.
 */
#define blksize(fs, ip, lbn) \
        (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
            ? (fs)->fs_bsize \
            : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
#define sblksize(fs, size, lbn) \
        (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
          ? (fs)->fs_bsize \
          : (fragroundup(fs, blkoff(fs, (size)))))
 
/*
 * Number of indirects in a filesystem block.
 */
#define NINDIR(fs)      ((fs)->fs_nindir)
 
/*
 * Indirect lbns are aligned on NDADDR addresses where single indirects
 * are the negated address of the lowest lbn reachable, double indirects
 * are this lbn - 1 and triple indirects are this lbn - 2.  This yields
 * an unusual bit order to determine level.
 */
static inline int
lbn_level(ufs_lbn_t lbn)
{
        if (lbn >= 0)
                return 0;
        switch (lbn & 0x3) {
        case 0:
                return (0);
        case 1:
                break;
        case 2:
                return (2);
        case 3:
                return (1);
        default:
                break;
        }
        return (-1);
}
 
static inline ufs_lbn_t
lbn_offset(struct fs *fs, int level)
{
        ufs_lbn_t res;
 
        for (res = 1; level > 0; level--)
                res *= NINDIR(fs);
        return (res);
}
 
/*
 * Number of inodes in a secondary storage block/fragment.
 */
#define INOPB(fs)       ((fs)->fs_inopb)
#define INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)
 
/*
 * Softdep journal record format.
 */
 
#define JOP_ADDREF      1       /* Add a reference to an inode. */
#define JOP_REMREF      2       /* Remove a reference from an inode. */
#define JOP_NEWBLK      3       /* Allocate a block. */
#define JOP_FREEBLK     4       /* Free a block or a tree of blocks. */
#define JOP_MVREF       5       /* Move a reference from one off to another. */
#define JOP_TRUNC       6       /* Partial truncation record. */
#define JOP_SYNC        7       /* fsync() complete record. */
 
#define JREC_SIZE       32      /* Record and segment header size. */
 
#define SUJ_MIN         (4 * 1024 * 1024)       /* Minimum journal size */
#define SUJ_MAX         (32 * 1024 * 1024)      /* Maximum journal size */
#define SUJ_FILE        ".sujournal"            /* Journal file name */
 
/*
 * Size of the segment record header.  There is at most one for each disk
 * block in the journal.  The segment header is followed by an array of
 * records.  fsck depends on the first element in each record being 'op'
 * and the second being 'ino'.  Segments may span multiple disk blocks but
 * the header is present on each.
 */
struct jsegrec {
        uint64_t        jsr_seq;        /* Our sequence number */
        uint64_t        jsr_oldest;     /* Oldest valid sequence number */
        uint16_t        jsr_cnt;        /* Count of valid records */
        uint16_t        jsr_blocks;     /* Count of device bsize blocks. */
        uint32_t        jsr_crc;        /* 32bit crc of the valid space */
        ufs_time_t      jsr_time;       /* timestamp for mount instance */
};
 
/*
 * Reference record.  Records a single link count modification.
 */
struct jrefrec {
        uint32_t        jr_op;
        uint32_t        jr_ino;
        uint32_t        jr_parent;
        uint16_t        jr_nlink;
        uint16_t        jr_mode;
        int64_t         jr_diroff;
        uint64_t        jr_unused;
};
 
/*
 * Move record.  Records a reference moving within a directory block.  The
 * nlink is unchanged but we must search both locations.
 */
struct jmvrec {
        uint32_t        jm_op;
        uint32_t        jm_ino;
        uint32_t        jm_parent;
        uint16_t        jm_unused;
        int64_t         jm_oldoff;
        int64_t         jm_newoff;
};
 
/*
 * Block record.  A set of frags or tree of blocks starting at an indirect are
 * freed or a set of frags are allocated.
 */
struct jblkrec {
        uint32_t        jb_op;
        uint32_t        jb_ino;
        ufs2_daddr_t    jb_blkno;
        ufs_lbn_t       jb_lbn;
        uint16_t        jb_frags;
        uint16_t        jb_oldfrags;
        uint32_t        jb_unused;
};
 
/*
 * Truncation record.  Records a partial truncation so that it may be
 * completed at check time.  Also used for sync records.
 */
struct jtrncrec {
        uint32_t        jt_op;
        uint32_t        jt_ino;
        int64_t         jt_size;
        uint32_t        jt_extsize;
        uint32_t        jt_pad[3];
};
 
union jrec {
        struct jsegrec  rec_jsegrec;
        struct jrefrec  rec_jrefrec;
        struct jmvrec   rec_jmvrec;
        struct jblkrec  rec_jblkrec;
        struct jtrncrec rec_jtrncrec;
};
 
#ifdef CTASSERT
CTASSERT(sizeof(struct jsegrec) == JREC_SIZE);
CTASSERT(sizeof(struct jrefrec) == JREC_SIZE);
CTASSERT(sizeof(struct jmvrec) == JREC_SIZE);
CTASSERT(sizeof(struct jblkrec) == JREC_SIZE);
CTASSERT(sizeof(struct jtrncrec) == JREC_SIZE);
CTASSERT(sizeof(union jrec) == JREC_SIZE);
#endif
 
extern int inside[], around[];
extern u_char *fragtbl[];
 
/*
 * IOCTLs used for filesystem write suspension.
 */
#define UFSSUSPEND      _IOW('U', 1, fsid_t)
#define UFSRESUME       _IO('U', 2)
 
#endif