ref: b3e875d7db45fca0cde9f4efa12872f61afc54d7
dir: /dat.h/
typedef signed char s8;
typedef signed short s16;
typedef signed int s32;
typedef signed long long s64;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
typedef unsigned long long u64;
typedef struct Config Config;
typedef struct Data Data;
typedef struct Dentryhdr Dentryhdr;
typedef struct Dentry Dentry;
typedef struct Datahdr Datahdr;
typedef struct Indirect Indirect;
typedef struct Name Name;
typedef struct Super Super;
typedef struct Tlock Tlock;
typedef struct User User;
typedef struct Aux Aux;
enum
{
KiB = 1024ULL, /* Kibibytes */
MiB = KiB*KiB, /* Mibibytes */
GiB = KiB*MiB, /* Gibibytes */
TiB = KiB*GiB, /* Tibibytes */
Ngroups = 32, /* maximum number of groups an user can belong to */
None = 0, /* user ID for "none" */
Noworld = 9999, /* conventional id for "noworld" group */
Userlen = 32,
Servicelen = 128,
Nfirst = 6, /* length of name stored in Name */
Nsec = 1000ULL*1000*1000,
Usec = 1000ULL*1000,
Msec = 1000ULL,
Nbkp = 1,
Nrefresh = 3*Nsec,
/* for Dentry.flags and Data.flags */
Fsys = 0x80,/* for flagging .n, .nl and .nle files. Dentry.flags */
Fn = 1, /* .n Name index file format */
Fe = 2, /* Binary extents file format. TODO we are using text extents now */
In = 0, /* reli of .n file */
Inl = 1, /* reli of .nl file */
Inle= 2, /* reli of .nle file */
Nsys,
};
/*
* fundamental constants and types of the implementation
* changing any of these changes the layout on disk
* The very first block (index = 0) has the magic written at offset 256.
*
* Trying to keep the Qpath the same as the directory entry block number
* for the system files to help me identify numbers easily.
*
* derived constants
* Nindperblock number of block pointers in a block
*/
enum {
Blocksize = 512ULL, /* minimum data unit size */
Maxdatablockunits = 2048,
Nindperblock= (Blocksize-3*sizeof(u64))/sizeof(u64),/* number of pointers per block */
Nu64perblock= (Blocksize/sizeof(u64)), /* number of u64's in a block */
Dpathidx = (Blocksize/sizeof(u64) -1), /* index of path in the last data block, last u64 */
Ndblock = 46, /* number of direct blocks in a Dentry */
Niblock = 5, /* maximum depth of indirect blocks, can increase it to 9 without issues */
/* global block numbers. The bkp contents locations are calculated by ream() */
Bdmagic = 0, /* block number of first block. Bmagic conflicts with bio.h */
Bdconfig= 1, /* block number of /a/config dentry and contents */
Bdsuper = 2, /* block number of /a/super dentry and contents */
Bda = 3, /* block number of /a directory */
Bdanames= 4, /* block number of /a dir names directory */
Bdalnames= 5, /* block number of /a dir long names directory */
Bdalnamesextents= 6, /* block number of /a dir long names extents directory */
Bdusers = 7, /* block number of /a/users/ directory entry */
Bdusersnames= 8,/* block number of /a/users/ directory names */
Bduserslnames= 9,/* block number of /a/users/ directory long names */
Bduserslnamesextents= 10,/* block number of /a/users/ directory long names extents */
/* contents of blocks below change on use */
Bdbkp = 11, /* block number of /a/bkp directory */
Bdbkpnames= 12, /* block number of /a/bkp directory names */
Bdbkplnames= 13,/* block number of /a/bkp directory long names */
Bdbkplnamesextents= 14, /* block number of /a/bkp directory long names extents */
Bdusersinuse = 15, /* block number of /a/users/inuse dentry and contents */
Bdfrees = 16, /* block number of /a/frees dentry, text file of free extents */
/* no user writes allowed on blocks below Bdctl */
Bdctl = 17, /* block number of /a/ctl dentry, empty contents, virtual file */
Bdusersstaging = 18,/* block number of /a/users/staging dentry */
Bdroot = 19, /* block number of root directory */
Bdrootnames = 20, /* block number of root directory names */
Bdrootlnames = 21, /* block number of root directory long names */
Bdrootlnamesextents = 22, /* block number of root directory long names extents */
Nbused, /* blocks used up by default */
/* number of blocks used by the above and the backup blocks */
Nminblocks = Nbused+(Nbkp*3),
/* Qpnone is the Tag.path of free blocks/extents(Tfree),
and zero'ed out dentry blocks */
Qpnone = 0,
Qpconfig = Bdconfig, /* /a/config block Tag.qpath */
Qpsuper = Bdsuper, /* /a/super block Tag.qpath */
Qpa = Bda, /* /a */
Qpanames = Bdanames, /* /a */
Qpalnames = Bdalnames, /* /a */
Qpalnamesextents= Bdalnamesextents, /* /a */
Qpusers = Bdusers, /* /a/users block Tag.qpath */
Qpusersnames= Bdusersnames, /* /a/users block Tag.qpath */
Qpuserslnames= Bduserslnames, /* /a/users block Tag.qpath */
Qpuserslnamesextents= Bduserslnamesextents, /* /a/users block Tag.qpath */
Qpbkp = Bdbkp, /* /a/bkp block Tag.qpath */
Qpbkpnames = Bdbkpnames, /* /a/bkp block Tag.qpath */
Qpbkplnames = Bdbkplnames, /* /a/bkp block Tag.qpath */
Qpbkplnamesextents= Bdbkplnamesextents, /* /a/bkp block Tag.qpath */
Qpusersinuse= Bdusersinuse, /* /a/users/inuse block Tag.qpath */
Qpfrees = Bdfrees, /* /a/frees block Tag.qpath */
/* system qpaths */
Qpmagic = Bdrootlnamesextents+1, /* magic block Tag.qpath, could use Bdroot butt this avoids confusion by keeping the block numbers and qpaths distinct */
Qpconfig0, /* /a/bkp/config.0 block Tag.qpath */
Qpsuper0, /* /a/bkp/super.0 block Tag.qpath */
Qproot0, /* /a/bkp/root.0 block Tag.qpath */
Qproot = 32, /* /, so fscreate() and fswrite() can disallow any create's below */
Qprootnames,
Qprootlnames,
Qprootlnamesextents,
Qpctl, /* /a/ctl */
Qpusersstaging, /* /a/users/staging block Tag.qpath */
Nqidgen = 64,
/* check qpath for overflows - TODO, should be 2^64 */
Maxqpath = 72057594037927936ULL, /* 2^56 */
Nthdirty = 9, /* dirty byte is the 9th byte in the Tag */
};
#pragma pack on
/* DONT TOUCH, this is the disk structure */
/* no access time */
struct Dentryhdr
{
u8 tag;
u8 flags; /* attributes (names extents, names - hide system files) */
s16 uid;
s16 gid;
s16 muid; /* 8 */
u64 size; /* 0 for directories. For files, size in bytes of the content - 16 */
u64 pdblkno; /* block number of the parent directory entry. 0 for root. - 24 */
u64 pqpath; /* parent qid.path - 32 */
u64 preli; /* my reli in my parent's directory entry - 40 */
u64 mtime; /* modified time in nano seconds from epoch - 48 */
u64 qpath; /* unique identifier Qid.path 56 */
u32 version; /* Qid.version 60 */
u32 mode; /* same bits as defined in /sys/include/libc.h:/Dir\.mode/ - 64 */
};
struct Datahdr
{
u8 tag;
u8 flags; /* 0 for text, 1 for In Name file, 2 for extents */
u16 len;
u64 dblkno; /* block number of the directory entry */
};
#pragma pack off
enum {
/* size of identifiers used in a Tdata block */
Ddataidssize = sizeof(Datahdr) +sizeof(u64 /* trailing path */),
/* max possible size of data that can be stuffed into a Dentry */
Ddatasize = Blocksize -sizeof(Dentryhdr) -sizeof(u64 /* trailing path */),
Maxdatablocksize = Maxdatablockunits*Blocksize -Ddataidssize,
};
#pragma pack on
/* DONT TOUCH, these are all disk structures */
struct Super
{
u64 qidgen; /* generator for unique ids. starts from 1024. */
u64 fsok; /* fsck status, using 64 bits to keep it all aligned */
};
struct Dentry
{
Dentryhdr;
union
{
struct
{
u64 dblocks[Ndblock]; /* direct blocks. */
/* List of Tdata block numbers for files and
Tdentry block numbers for directories */
u64 iblocks[Niblock]; /* indirect blocks */
};
Super;
/* when size <= Ddatasize, store the data here itself */
s8 buf[Ddatasize];
};
u64 path; /* same as qid.path */
};
struct Indirect
{
u8 tagi; /* the suffix i to avoid union complaining about ambiguous fields */
u8 pad[7]; /* unused, to align to a multiple of 8 */
u64 dblkno; /* block number of the directory entry */
u64 bufa[Nindperblock];
u64 pathi; /* same as qid.path */
};
struct Data /* used to unmarshall the disk contents */
{
Datahdr;
u8 buf[1]; /* upto Maxdatablocksize, followed by u64 qid.path */
/* u64 path; same as qid.path at the end of the data content - check consistency */
};
struct Name
{
u16 namelen;
s8 name[Nfirst]; /* first 6 bytes. If longer, use noffset */
u64 noffset; /* offset where the name is stored in .nl - long names file */
};
#pragma pack off
/*
* array of qids that are locked
*/
struct Tlock
{
u64 time;
u64 qpath;
u64 dblkno;
Tlock *prev, *next;
};
struct Aux
{
u64 dblkno; /* directory entry absolute block number */
u64 pdblkno;/* block number of my parent's directory entry */
u64 pqpath;/* block number of my parent's directory entry */
u64 preli; /* my relative index in the parent's directory entry */
u8 flags; /* corresponds to Dentry.flags and Data.flags */
u16 uid;
u8 tlocked; /* for exclusive use files, flag to indicate lock */
u64 dri; /* directory index while reading a directory */
s8 *ctlmsg;
u32 nctlmsg;
/* u64 lastreadahead; TODO */
};
/*
every user is also a group with one user.
*/
struct User
{
s16 id; /* user id */
s16 lid; /* id of the leader of group */
char name[Userlen]; /* user name */
s16 *members;/* list of member id's belonging to this group */
int nmembers;/* number of members in this group */
int nalloc; /* allocated space members */
User *prev, *next; /* linked list sorted by id */
};
/* storing this in ascii to the Bdconfig block */
struct Bkp
{
u64 srcbno; /* source of the backup */
u64 dest[Nbkp]; /* destinations written to */
};
struct Config
{
u64 size; /* size from dirfstat */
u64 nblocks; /* size in blocks */
struct Bkp config;
struct Bkp super;
struct Bkp root;
char service[Servicelen];
};
enum
{
Nworks = 1024, /* make this a parameter? */
Nworkers = 32, /* make this a parameter? */
Nuserserrmsg = 64,
};
/*
* error codes generated from the file server
*/
enum
{
Eaccess = 1,
Ealloc,
Eauth,
Eauthmsg,
Ebadname,
Ebadspc,
Ebadu,
Ebroken,
Echar,
Econvert,
Ecount,
Edexist,
Edir1,
Edir2,
Edirty,
Edot,
Eempty,
Eentry,
Eexist,
Efid,
Efidinuse,
Efull,
Einval,
Einvread,
Einvwrite,
Einvusers,
Elocked,
Emode,
Ename,
Enomem,
Enotd,
Enotdir,
Enotfound,
Enotg,
Enotl,
Enotm,
Enotu,
Enotw,
Enouser,
Enousers,
Eoffset,
Eopen,
Eperm,
Ephase,
Eqid,
Eqidmode,
Eronly,
Ersc,
Eshutdown,
Esystem,
Etoolong,
Ewalk,
MAXERR
};
/*
* tags on block
*/
/* DONT TOUCH, this is in disk structures */
/* the first 512 bytes holds the magic.
Not bothering with a tag for 1 Unit. Use Tdentry for that.
*/
/* also, the order from Tdata to Tmaxind is exploited in indirck() & isdirty() */
enum
{
Tblank = 0,
Tfree = 0, /* free block */
Tnone = 0,
Tdata, /* actual file contents */
Tdentry, /* directory entry, size = Dentrysize */
/* Tdata & indirect blocks are last, to allow for greater depth */
Tind0, /* contains a list of Tdata block numbers for files
and Tdentry block numbers for directories.*/
Tind1, /* contains a list of Tind0 block numbers */
Tind2, /* contains a list of Tind1 block numbers */
Tind3, /* contains a list of Tind1 block numbers */
Tind4, /* contains a list of Tind1 block numbers */
/* gap for more indirect block depth in future.
It can be put upto Tind7 without needing any code changes */
Maxtind, /* should be Tind0+Niblock */
MAXTAG = Maxtind,
Tmaxind = Maxtind - 1,
};
/*
* flags to getbuf
*/
enum
{
Breadonly = 1,/* read the block, cannot write to it */
Bwritable = 0,
Bfreshalloc = 1,/* newly allocated block, no contents on the disk */
Bused = 0,/* has contents on the disk */
};
#define SECOND(n) (n)
#define MINUTE(n) (n*SECOND(60))
#define HOUR(n) (n*MINUTE(60))
#define DAY(n) (n*HOUR(24))
#define TLOCK MINUTE(5)
extern char* errstring[MAXERR];
extern char service[Servicelen];
extern char *tagnames[];
extern char *devfile; /* device file path */
extern int devfd ; /* device fd */
extern int writeallow;
extern int wstatallow;
extern int allownone;
extern u8 readonly;
extern u8 shuttingdown;
extern u8 noauth;
/* used by panic() */
extern char *procname;
extern Config config;
extern char userserrmsg[Nuserserrmsg];
Config *parseconfig(s8 *cfg, Config *c);
typedef struct Errenv Errenv;
struct Errenv /* Error environment */
{
jmp_buf label[16];
u8 nlabel;
};
extern s8 err[ERRMAX];
extern Errenv **envpp;
void nexterror(void);
void error(s8 *fmt, ...);
extern void showerrenv(char *msg);
#define poperror() (*envpp)->nlabel--
/* #define waserror() (showerrenv("waserror before\n"), (*envpp)->nlabel++, setjmp((*envpp)->label[(*envpp)->nlabel-1])) */
#define waserror() ((*envpp)->nlabel++, setjmp((*envpp)->label[(*envpp)->nlabel-1]))