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Catch this file up with ufs/ffs/fs.h.

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PR:		51189
Submitted by:	Lukas Ertl <l.ertl@univie.ac.at>
This commit is contained in:
trhodes 2003-04-22 18:20:44 +00:00
parent b2c2ee3e26
commit 00ef1a6d38
1 changed files with 104 additions and 95 deletions
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199
share/man/man5/fs.5
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@ -71,122 +71,131 @@ The actual file system begins at sector
with the with the
.Em super-block .Em super-block
that is of size that is of size
.Dv SBSIZE . .Dv SBLOCKSIZE .
The following structure describes the super-block and is The following structure describes the super-block and is
from the file from the file
.Aq Pa ufs/ffs/fs.h : .Aq Pa ufs/ffs/fs.h :
.Bd -literal .Bd -literal
/* /*
* Super block for an FFS file system. * Super block for an FFS filesystem.
*/ */
struct fs { struct fs {
int32_t fs_firstfield; /* historic file system linked list, */ int32_t fs_firstfield; /* historic filesystem linked list, */
int32_t fs_unused_1; /* used for incore super blocks */ int32_t fs_unused_1; /* used for incore super blocks */
ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */ int32_t fs_sblkno; /* offset of super-block in filesys */
ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */ int32_t fs_cblkno; /* offset of cyl-block in filesys */
ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ int32_t fs_iblkno; /* offset of inode-blocks in filesys */
ufs_daddr_t fs_dblkno; /* offset of first data after cg */ int32_t fs_dblkno; /* offset of first data after cg */
int32_t fs_cgoffset; /* cylinder group offset in cylinder */ int32_t fs_old_cgoffset; /* cylinder group offset in cylinder */
int32_t fs_cgmask; /* used to calc mod fs_ntrak */ int32_t fs_old_cgmask; /* used to calc mod fs_ntrak */
time_t fs_time; /* last time written */ int32_t fs_old_time; /* last time written */
int32_t fs_size; /* number of blocks in fs */ int32_t fs_old_size; /* number of blocks in fs */
int32_t fs_dsize; /* number of data blocks in fs */ int32_t fs_old_dsize; /* number of data blocks in fs */
int32_t fs_ncg; /* number of cylinder groups */ int32_t fs_ncg; /* number of cylinder groups */
int32_t fs_bsize; /* size of basic blocks in fs */ int32_t fs_bsize; /* size of basic blocks in fs */
int32_t fs_fsize; /* size of frag 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 */ int32_t fs_frag; /* number of frags in a block in fs */
/* these are configuration parameters */ /* these are configuration parameters */
int32_t fs_minfree; /* minimum percentage of free blocks */ int32_t fs_minfree; /* minimum percentage of free blocks */
int32_t fs_rotdelay; /* num of ms for optimal next block */ int32_t fs_old_rotdelay; /* num of ms for optimal next block */
int32_t fs_rps; /* disk revolutions per second */ int32_t fs_old_rps; /* disk revolutions per second */
/* these fields can be computed from the others */ /* these fields can be computed from the others */
int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
int32_t fs_fshift; /* ``numfrags'' calc number of frags */ int32_t fs_fshift; /* ``numfrags'' calc number of frags */
/* these are configuration parameters */ /* these are configuration parameters */
int32_t fs_maxcontig; /* max number of contiguous blks */ int32_t fs_maxcontig; /* max number of contiguous blks */
int32_t fs_maxbpg; /* max number of blks per cyl group */ int32_t fs_maxbpg; /* max number of blks per cyl group */
/* these fields can be computed from the others */ /* these fields can be computed from the others */
int32_t fs_fragshift; /* block to frag shift */ int32_t fs_fragshift; /* block to frag shift */
int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
int32_t fs_sbsize; /* actual size of super block */ int32_t fs_sbsize; /* actual size of super block */
int32_t fs_csmask; /* csum block offset */ int32_t fs_spare1[2]; /* old fs_csmask */
int32_t fs_csshift; /* csum block number */ /* old fs_csshift */
int32_t fs_nindir; /* value of NINDIR */ int32_t fs_nindir; /* value of NINDIR */
int32_t fs_inopb; /* value of INOPB */ int32_t fs_inopb; /* value of INOPB */
int32_t fs_nspf; /* value of NSPF */ int32_t fs_old_nspf; /* value of NSPF */
/* yet another configuration parameter */ /* yet another configuration parameter */
int32_t fs_optim; /* optimization preference, see below */ int32_t fs_optim; /* optimization preference, see below */
/* these fields are derived from the hardware */ int32_t fs_old_npsect; /* # sectors/track including spares */
int32_t fs_npsect; /* # sectors/track including spares */ int32_t fs_old_interleave; /* hardware sector interleave */
int32_t fs_interleave; /* hardware sector interleave */ int32_t fs_old_trackskew; /* sector 0 skew, per track */
int32_t fs_trackskew; /* sector 0 skew, per track */ int32_t fs_id[2]; /* unique filesystem id */
/* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
int32_t fs_id[2]; /* unique file system id*/
/* sizes determined by number of cylinder groups and their sizes */ /* sizes determined by number of cylinder groups and their sizes */
ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ 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_cssize; /* size of cyl grp summary area */
int32_t fs_cgsize; /* cylinder group size */ int32_t fs_cgsize; /* cylinder group size */
/* these fields are derived from the hardware */ int32_t fs_spare2; /* old fs_ntrak */
int32_t fs_ntrak; /* tracks per cylinder */ int32_t fs_old_nsect; /* sectors per track */
int32_t fs_nsect; /* sectors per track */ int32_t fs_old_spc; /* sectors per cylinder */
int32_t fs_spc; /* sectors per cylinder */ int32_t fs_old_ncyl; /* cylinders in filesystem */
/* this comes from the disk driver partitioning */ int32_t fs_old_cpg; /* cylinders per group */
int32_t fs_ncyl; /* cylinders in file system */ int32_t fs_ipg; /* inodes per group */
/* these fields can be computed from the others */ int32_t fs_fpg; /* blocks per group * fs_frag */
int32_t fs_cpg; /* cylinders per group */
int32_t fs_ipg; /* inodes per group */
int32_t fs_fpg; /* blocks per group * fs_frag */
/* this data must be re-computed after crashes */ /* this data must be re-computed after crashes */
struct csum fs_cstotal;/* cylinder summary information */ struct csum fs_old_cstotal; /* cylinder summary information */
/* these fields are cleared at mount time */ /* these fields are cleared at mount time */
int8_t fs_fmod; /* super block modified flag */ int8_t fs_fmod; /* super block modified flag */
int8_t fs_clean; /* file system is clean flag */ int8_t fs_clean; /* filesystem is clean flag */
int8_t fs_ronly; /* mounted read-only flag */ int8_t fs_ronly; /* mounted read-only flag */
int8_t fs_flags; /* currently unused flag */ int8_t fs_old_flags; /* old FS_ flags */
u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 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 */ /* these fields retain the current block allocation info */
int32_t fs_cgrotor; /* last cg searched */ int32_t fs_cgrotor; /* last cg searched */
struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */ void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
int32_t *fs_maxcluster;/* max cluster in each cyl group */ u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
int32_t fs_cpc; /* cyl per cycle in postbl */ struct csum *fs_csp; /* cg summary info buffer for fs_cs */
int16_t fs_opostbl[16][8]; /* old rotation block list head */ int32_t *fs_maxcluster; /* max cluster in each cyl group */
int32_t fs_sparecon[50]; /* reserved for future constants */ u_int *fs_active; /* used by snapshots to track fs */
int32_t fs_contigsumsize; /* size of cluster summary array */ int32_t fs_old_cpc; /* cyl per cycle in postbl */
int32_t fs_maxsymlinklen;/* max length of an internal symlink */ int32_t fs_maxbsize; /* maximum blocking factor permitted */
int32_t fs_inodefmt; /* format of on-disk inodes */ int64_t fs_sparecon64[17]; /* old rotation block list head */
u_int64_t fs_maxfilesize;/* maximum representable file size */ int64_t fs_sblockloc; /* byte offset of standard superblock */
int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ struct csum_total fs_cstotal; /* cylinder summary information */
int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ ufs_time_t fs_time; /* last time written */
int32_t fs_state; /* validate fs_clean field */ int64_t fs_size; /* number of blocks in fs */
int32_t fs_postblformat;/* format of positional layout tables */ int64_t fs_dsize; /* number of data blocks in fs */
int32_t fs_nrpos; /* number of rotational positions */ ufs2_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
int32_t fs_postbloff; /* (u_int16) rotation block list head */ int64_t fs_pendingblocks; /* blocks in process of being freed */
int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */ int32_t fs_pendinginodes; /* inodes in process of being freed */
int32_t fs_magic; /* magic number */ int32_t fs_snapinum[FSMAXSNAP]; /* list of snapshot inode numbers */
u_int8_t fs_space[1]; /* list of blocks for each rotation */ int32_t fs_avgfilesize; /* expected average file size */
/* actually longer */ int32_t fs_avgfpdir; /* expected # of files per directory */
int32_t fs_save_cgsize; /* save real cg size to use fs_bsize */
int32_t fs_sparecon32[26]; /* 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 */
}; };
/* /*
* File system identification * Filesystem identification
*/ */
#define FS_MAGIC 0x011954 /* the fast file system magic number */ #define FS_UFS1_MAGIC 0x011954 /* UFS1 fast filesystem magic number */
#define FS_OKAY 0x7c269d38 /* superblock checksum */ #define FS_UFS2_MAGIC 0x19540119 /* UFS2 fast filesystem magic number */
#define FS_42INODEFMT -1 /* 4.2BSD inode format */ #define FS_OKAY 0x7c269d38 /* superblock checksum */
#define FS_44INODEFMT 2 /* 4.4BSD inode format */ #define FS_42INODEFMT -1 /* 4.2BSD inode format */
#define FS_44INODEFMT 2 /* 4.4BSD inode format */
/* /*
* Preference for optimization. * Preference for optimization.
*/ */
#define FS_OPTTIME 0 /* minimize allocation time */ #define FS_OPTTIME 0 /* minimize allocation time */
#define FS_OPTSPACE 1 /* minimize disk fragmentation */ #define FS_OPTSPACE 1 /* minimize disk fragmentation */
/*
* Rotational layout table format types
*/
#define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
#define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
.Ed .Ed
.Pp .Pp
Each disk drive contains some number of file systems. Each disk drive contains some number of file systems.
@ -275,13 +284,13 @@ rotational positions, the resolution of the
summary information is 2ms for a typical 3600 rpm drive. summary information is 2ms for a typical 3600 rpm drive.
.Pp .Pp
The element The element
.Fa fs_rotdelay .Fa fs_old_rotdelay
gives the minimum number of milliseconds to initiate gives the minimum number of milliseconds to initiate
another disk transfer on the same cylinder. another disk transfer on the same cylinder.
It is used in determining the rotationally optimal It is used in determining the rotationally optimal
layout for disk blocks within a file; layout for disk blocks within a file;
the default value for the default value for
.Fa fs_rotdelay .Fa fs_old_rotdelay
is 2ms. is 2ms.
.Pp .Pp
Each file system has a statically allocated number of inodes. Each file system has a statically allocated number of inodes.
@ -304,7 +313,7 @@ thus changes to
must keep its size within must keep its size within
.Dv MINBSIZE . .Dv MINBSIZE .
Note that super-blocks are never more than size Note that super-blocks are never more than size
.Dv SBSIZE . .Dv SBLOCKSIZE .
.Pp .Pp
The path name on which the file system is mounted is maintained in The path name on which the file system is mounted is maintained in
.Fa fs_fsmnt . .Fa fs_fsmnt .
@ -336,7 +345,7 @@ The
.Em "Super-block for a file system" : .Em "Super-block for a file system" :
The size of the rotational layout tables The size of the rotational layout tables
is limited by the fact that the super-block is of size is limited by the fact that the super-block is of size
.Dv SBSIZE . .Dv SBLOCKSIZE .
The size of these tables is The size of these tables is
.Em inversely .Em inversely
proportional to the block proportional to the block