mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
Catch this file up with ufs/ffs/fs.h.
PR: 51189 Submitted by: Lukas Ertl <l.ertl@univie.ac.at>
This commit is contained in:
Tom Rhodes
parent
2e9d00a15d
commit
3301bb2349
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=113858
@ -71,122 +71,131 @@ The actual file system begins at sector
|
||||
with the
|
||||
.Em super-block
|
||||
that is of size
|
||||
.Dv SBSIZE .
|
||||
.Dv SBLOCKSIZE .
|
||||
The following structure describes the super-block and is
|
||||
from the file
|
||||
.Aq Pa ufs/ffs/fs.h :
|
||||
.Bd -literal
|
||||
/*
|
||||
* Super block for an FFS file system.
|
||||
* Super block for an FFS filesystem.
|
||||
*/
|
||||
struct fs {
|
||||
int32_t fs_firstfield; /* historic file system linked list, */
|
||||
int32_t fs_unused_1; /* used for incore super blocks */
|
||||
ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
|
||||
ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
|
||||
ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
|
||||
ufs_daddr_t fs_dblkno; /* offset of first data after cg */
|
||||
int32_t fs_cgoffset; /* cylinder group offset in cylinder */
|
||||
int32_t fs_cgmask; /* used to calc mod fs_ntrak */
|
||||
time_t fs_time; /* last time written */
|
||||
int32_t fs_size; /* number of blocks in fs */
|
||||
int32_t fs_dsize; /* number of data blocks in fs */
|
||||
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 */
|
||||
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 */
|
||||
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_rotdelay; /* num of ms for optimal next block */
|
||||
int32_t fs_rps; /* disk revolutions per second */
|
||||
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 */
|
||||
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 */
|
||||
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_csmask; /* csum block offset */
|
||||
int32_t fs_csshift; /* csum block number */
|
||||
int32_t fs_nindir; /* value of NINDIR */
|
||||
int32_t fs_inopb; /* value of INOPB */
|
||||
int32_t fs_nspf; /* value of NSPF */
|
||||
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 */
|
||||
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 */
|
||||
/* these fields are derived from the hardware */
|
||||
int32_t fs_npsect; /* # sectors/track including spares */
|
||||
int32_t fs_interleave; /* hardware sector interleave */
|
||||
int32_t fs_trackskew; /* sector 0 skew, per track */
|
||||
/* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
|
||||
int32_t fs_id[2]; /* unique file system id*/
|
||||
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 */
|
||||
ufs_daddr_t fs_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 */
|
||||
/* these fields are derived from the hardware */
|
||||
int32_t fs_ntrak; /* tracks per cylinder */
|
||||
int32_t fs_nsect; /* sectors per track */
|
||||
int32_t fs_spc; /* sectors per cylinder */
|
||||
/* this comes from the disk driver partitioning */
|
||||
int32_t fs_ncyl; /* cylinders in file system */
|
||||
/* these fields can be computed from the others */
|
||||
int32_t fs_cpg; /* cylinders per group */
|
||||
int32_t fs_ipg; /* inodes per group */
|
||||
int32_t fs_fpg; /* blocks per group * fs_frag */
|
||||
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 */
|
||||
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_cstotal;/* cylinder summary information */
|
||||
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; /* file system is clean flag */
|
||||
int8_t fs_ronly; /* mounted read-only flag */
|
||||
int8_t fs_flags; /* currently unused flag */
|
||||
u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
|
||||
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 */
|
||||
struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
|
||||
int32_t *fs_maxcluster;/* max cluster in each cyl group */
|
||||
int32_t fs_cpc; /* cyl per cycle in postbl */
|
||||
int16_t fs_opostbl[16][8]; /* old rotation block list head */
|
||||
int32_t fs_sparecon[50]; /* reserved for future constants */
|
||||
int32_t fs_contigsumsize; /* size of cluster summary array */
|
||||
int32_t fs_maxsymlinklen;/* max length of an internal symlink */
|
||||
int32_t fs_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_postblformat;/* format of positional layout tables */
|
||||
int32_t fs_nrpos; /* number of rotational positions */
|
||||
int32_t fs_postbloff; /* (u_int16) rotation block list head */
|
||||
int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
|
||||
int32_t fs_magic; /* magic number */
|
||||
u_int8_t fs_space[1]; /* list of blocks for each rotation */
|
||||
/* actually longer */
|
||||
int32_t fs_cgrotor; /* last cg searched */
|
||||
void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
|
||||
u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
|
||||
struct csum *fs_csp; /* cg summary info buffer for fs_cs */
|
||||
int32_t *fs_maxcluster; /* max cluster in each cyl group */
|
||||
u_int *fs_active; /* 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_sparecon64[17]; /* old rotation block list head */
|
||||
int64_t fs_sblockloc; /* byte offset of standard superblock */
|
||||
struct csum_total fs_cstotal; /* 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; /* blocks in process of being freed */
|
||||
int32_t fs_pendinginodes; /* inodes in process of being freed */
|
||||
int32_t fs_snapinum[FSMAXSNAP]; /* list of snapshot inode numbers */
|
||||
int32_t fs_avgfilesize; /* expected average file size */
|
||||
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_OKAY 0x7c269d38 /* superblock checksum */
|
||||
#define FS_42INODEFMT -1 /* 4.2BSD inode format */
|
||||
#define FS_44INODEFMT 2 /* 4.4BSD inode format */
|
||||
#define FS_UFS1_MAGIC 0x011954 /* UFS1 fast filesystem magic number */
|
||||
#define FS_UFS2_MAGIC 0x19540119 /* UFS2 fast filesystem 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 */
|
||||
|
||||
/*
|
||||
* Rotational layout table format types
|
||||
*/
|
||||
#define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
|
||||
#define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
|
||||
.Ed
|
||||
.Pp
|
||||
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.
|
||||
.Pp
|
||||
The element
|
||||
.Fa fs_rotdelay
|
||||
.Fa fs_old_rotdelay
|
||||
gives the minimum number of milliseconds to initiate
|
||||
another disk transfer on the same cylinder.
|
||||
It is used in determining the rotationally optimal
|
||||
layout for disk blocks within a file;
|
||||
the default value for
|
||||
.Fa fs_rotdelay
|
||||
.Fa fs_old_rotdelay
|
||||
is 2ms.
|
||||
.Pp
|
||||
Each file system has a statically allocated number of inodes.
|
||||
@ -304,7 +313,7 @@ thus changes to
|
||||
must keep its size within
|
||||
.Dv MINBSIZE .
|
||||
Note that super-blocks are never more than size
|
||||
.Dv SBSIZE .
|
||||
.Dv SBLOCKSIZE .
|
||||
.Pp
|
||||
The path name on which the file system is mounted is maintained in
|
||||
.Fa fs_fsmnt .
|
||||
@ -336,7 +345,7 @@ The
|
||||
.Em "Super-block for a file system" :
|
||||
The size of the rotational layout tables
|
||||
is limited by the fact that the super-block is of size
|
||||
.Dv SBSIZE .
|
||||
.Dv SBLOCKSIZE .
|
||||
The size of these tables is
|
||||
.Em inversely
|
||||
proportional to the block
|
||||
|
||||
Loading…
Reference in New Issue
Block a user