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Diffstat (limited to 'static/v10/man5/worm.5')
| -rw-r--r-- | static/v10/man5/worm.5 | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/static/v10/man5/worm.5 b/static/v10/man5/worm.5 new file mode 100644 index 00000000..f5b7872c --- /dev/null +++ b/static/v10/man5/worm.5 @@ -0,0 +1,103 @@ +.TH WORM 5 +.CT 1 dirs +.SH NAME +worm \- format of worm disks +.SH SYNOPSIS +.B #include <worm.h> +.SH DESCRIPTION +A +.SM WORM +disk is a linked list of `superblocks', roughly one for every +.I "worm write" +on the +.SM WORM. +The `governing' superblock is at block zero if it exists and +has a valid magic number; +otherwise the governing superblock is the last superblock in +the linked list starting at block 1. +(The link to the next superblock is preallocated +and thus the last superblock in the list will be unwritten.) +Each superblock has some status information and a pointer +to a set of `inodes' describing a set of files. +The status information for the +.SM WORM +is that of the governing superblock; +the set of files on the +.SM WORM +is the accumulation of all the superblocks +taken in order. +The structure of a superblock as given in the +include file is: +.LP +.EX +.ta \w'#define 'u +\w'unsigned 'u +\w'mment[128]; 'u +#define SMAGIC 0x21746967 +#define VLINK 1 /* linked list superblock */ +#define VBTREE 2 /* cbt superblock */ +typedef struct superblock +{ + long magic; /* magic number for superblock */ + unsigned short blocksize; /* physical size of blocks */ + short version; /* type of superblock */ + long nblocks; /* number of blocks on device */ + long zero; /* first logical data block */ + long nfree; /* number of free blocks */ + long ninodes; /* number of inodes */ + long ninochars; /* number of bytes of inode names */ + long binodes; /* start of inodes */ + long nextffree; /* next free file block */ + long nextsb; /* next superblock */ + short fd; /* fildes for device (in core) */ + char vol_id[128]; /* name the disk can be mounted as */ + char comment[128]; /* comments */ + long myblock; /* where this superblock is */ + long nF; /* bytes for .F (VBTREE) */ + long nT; /* bytes for .T (VBTREE) */ + long ctime; /* create time for this superblock */ +} superblock; +.EE +.PP +superblocks are padded with zeros to +.BR blocksize . +.PP +Following each +.B VLINK +superblock is a set of inodes, a string table, and then the data blocks +for the files described by the inodes. +Following a (there is at most one) +.B VBTREE +superblock +there is a set of inodes, a string table and the +.B .F +and +.B .T +files for a +.IR cbt (1) +database where the keys are filenames and the data is an inode number. +.LP +.EX +#define DMAGIC 0x3A746967 +typedef struct Inode +{ + long magic; /* magic number for Dirent */ + long block; /* starting block of file */ + long nbytes; /* bytes in file */ + long ctime; /* creation time */ + union { + char *n; /* core - name */ + long o; /* disk - offset into chars block */ + } name; /* filename */ + long pad1 /* to 32 bytes */ + short mode /* as in \fIstat\fP(2) */ + short uid /* owner */ + short gid /* owner */ + short pad2 /* to 32 bytes */ +} Inode +.EE +.PP +If the +.B block +field of an inode is negative, +the file has been deleted. +.SH "SEE ALSO" +.IR worm (8) |