ref: 44d3d0c337b3b5078cb56a5853dfc2156124ecc6
dir: /dat.h/
typedef struct Blk Blk;
typedef struct Amsg Amsg;
typedef struct Gefs Gefs;
typedef struct Fmsg Fmsg;
typedef struct Fid Fid;
typedef struct Msg Msg;
typedef struct Key Key;
typedef struct Val Val;
typedef struct Kvp Kvp;
typedef struct Xdir Xdir;
typedef struct Bptr Bptr;
typedef struct Bfree Bfree;
typedef struct Path Path;
typedef struct Scan Scan;
typedef struct Dent Dent;
typedef struct Scanp Scanp;
typedef struct Arena Arena;
typedef struct Arange Arange;
typedef struct Bucket Bucket;
typedef struct Chan Chan;
typedef struct Tree Tree;
typedef struct Oplog Oplog;
typedef struct Mount Mount;
typedef struct User User;
enum {
KiB = 1024ULL,
MiB = 1024ULL*KiB,
GiB = 1024ULL*MiB,
TiB = 1024ULL*GiB,
Lgblk = 13,
Blksz = (1ULL<<Lgblk),
Nrefbuf = 1024, /* number of ref incs before syncing */
Nfidtab = 1024, /* number of fit hash entries */
Ndtab = 1024, /* number of dir tab entries */
Max9p = 16*KiB, /* biggest message size we're willing to negotiate */
Nsec = 1000*1000*1000, /* nanoseconds to the second */
Maxname = 256, /* maximum size of a name element */
Maxent = 9+Maxname+1, /* maximum size of ent key, with terminator */
Maxproc = 8, /* maximum number of worker procs */
/*
* Kpmax must be no more than 1/4 of pivspc, or
* there is no way to get a valid split of a
* maximally filled tree.
*/
Loghdsz = 8, /* log hash */
Keymax = 128, /* key data limit */
Inlmax = 512, /* inline data limit */
Ptrsz = 24, /* off, hash, gen */
Pptrsz = 26, /* off, hash, gen, fill */
Fillsz = 2, /* block fill count */
Offksz = 17, /* type, qid, off */
Snapsz = 9, /* tag, snapid */
Dpfxsz = 9,
Ndead = 8, /* number of deadlist heads */
Deadsz = 8+8+8+8+8, /* prev, head, head hash, tail, tail hash */
Treesz = 4+4+8+Ptrsz+Ndead*Deadsz, /* ref, height, gen, root, deadlist */
Kvmax = Keymax + Inlmax, /* Key and value */
Kpmax = Keymax + Ptrsz, /* Key and pointer */
Wstatmax = 4+8+8+8, /* mode, size, atime, mtime */
Hdrsz = 10,
Rootsz = 4+Ptrsz, /* root pointer */
Blkspc = Blksz - Hdrsz,
Bufspc = Blkspc / 2,
Pivspc = Blkspc - Bufspc,
Logspc = Blkspc - Loghdsz,
Leafspc = Blkspc,
Msgmax = 1 + (Kvmax > Kpmax ? Kvmax : Kpmax)
};
enum {
/*
* dent: pqid[8] qid[8] -- a directory entry key.
* ptr: off[8] hash[8] -- a key for an Dir block.
* dir: serialized Xdir
*/
Kdat, /* qid[8] off[8] => ptr[16]: pointer to data page */
Kent, /* pqid[8] name[n] => dir[n]: serialized Dir */
Klabel, /* name[] => snapid[]: snapshot label */
Ktref, /* tag[8] = snapid[] scratch snapshot label */
Ksnap, /* sid[8] => ref[8], tree[52]: snapshot root */
Ksuper, /* qid[8] => pqid[8]: parent dir */
Kdirty, /* [0] => [0]: mark dirty unmount */
};
enum {
Bdirty = 1 << 0,
Bqueued = 1 << 1,
Bfinal = 1 << 2,
Bcached = 1 << 3,
};
//#define Efs "i will not buy this fs, it is scratched"
#define Eimpl "not implemented"
#define Efs (abort(), "fs broke")
#define Eio "i/o error"
#define Efid "unknown fid"
#define Etype "invalid fid type"
#define Edscan "invalid dir scan offset"
#define Eexist "does not exist"
#define Ebotch "protocol botch"
#define Emode "unknown mode"
#define Efull "file system full"
#define Eauth "authentication failed"
#define Elength "name too long"
#define Eperm "permission denied"
#define Einuse "resource in use"
#define Ebadf "invalid file"
#define Emem "out of memory"
#define Ename "create/wstat -- bad character in file name"
#define Enomem "out of memory"
#define Eattach "attach required"
#define Enosnap "attach -- bad specifier"
#define Edir "invalid directory"
#define Esyntax "syntax error"
#define Enouser "user does not exist"
#define Efsize "file too big"
#define Ebadu "attach -- unknown user or failed authentication"
#define Erdonly "file system read only"
#define Ewstatb "wstat -- unknown bits in qid.type/mode"
#define Ewstatd "wstat -- attempt to change directory"
#define Ewstatg "wstat -- not in group"
#define Ewstatl "wstat -- attempt to make length negative"
#define Ewstatm "wstat -- attempt to change muid"
#define Ewstato "wstat -- not owner or group leader"
#define Ewstatp "wstat -- attempt to change qid.path"
#define Ewstatq "wstat -- qid.type/dir.mode mismatch"
#define Ewstatu "wstat -- not owner"
#define Ewstatv "wstat -- attempt to change qid.vers"
#define Enempty "remove -- directory not empty"
//#define Echar "bad character in directory name"
//#define Eopen "read/write -- on non open fid"
//#define Ecount "read/write -- count too big"
//#define Ealloc "phase error -- directory entry not allocated"
//#define Eqid "phase error -- qid does not match"
//#define Eaccess "access permission denied"
//#define Eentry "directory entry not found"
//#define Emode "open/create -- unknown mode"
//#define Edir1 "walk -- in a non-directory"
//#define Edir2 "create -- in a non-directory"
//#define Ephase "phase error -- cannot happen"
//#define Eexist "create/wstat -- file exists"
//#define Edot "create/wstat -- . and .. illegal names"
//#define Ewalk "walk -- too many (system wide)"
//#define Eoffset "read/write -- offset negative"
//#define Elocked "open/create -- file is locked"
//#define Ebroken "read/write -- lock is broken"
//#define Eauth "attach -- authentication failed"
//#define Eauth2 "read/write -- authentication unimplemented"
//#define Etoolong "name too long"
//#define Efidinuse "fid in use"
//#define Econvert "protocol botch"
//#define Eversion "version conversion"
//#define Eauthnone "auth -- user 'none' requires no authentication"
//#define Eauthdisabled "auth -- authentication disabled", /* development */
//#define Eauthfile "auth -- out of auth files"
/*
* All metadata blocks share a common header:
*
* type[2]
*
* The None type is reserved for file data blocks
* and refcount blocks.
*
* The superblock has this layout:
* version[8] always "gefs0001"
* blksz[4] block size in bytes
* bufsz[4] portion of leaf nodes
* allocated to buffers,
* in bytes
* hdrsz[4] size of tree node header,
* in bytes.
* height[4] tree height of root node
* rootb[8] address of root in last
* snapshot.
* rooth[8] hash of root node
* narena[4] number of arenas in tree
* arenasz[8] maximum size of arenas;
* they may be smaller.
* gen[8] The flush generation
*
* The arena zone blocks have this layout, and
* are overwritten in place:
*
* log[8] The head of the alloc log
* logh[8] The hash of the alloc log
*
* The log blocks have this layout, and are one of
* two types of blocks that get overwritten in place:
*
* hash[8] The hash of the previous log block
*
* The remainder of the block is filled with log
* entries. Each log entry has at least 8 bytes
* of entry. Some are longer. The opcode is or'ed
* into the low order bits of the first vlong.
* These ops take the following form:
*
* Alloc, Free:
* off[8] len[8]
* Alloc1, Free1:
* off[8]
* Ref:
* off[8]
* Flush:
* gen[8]
*
* Pivots have the following layout:
*
* nval[2]
* valsz[2]
* nbuf[2]
* bufsz[2]
*
* Leaves have the following layout:
*
* nval[2]
* valsz[2]
* pad[4]sure,
*
* Within these nodes, pointers have the following
* layout:
*
* off[8] hash[8] fill[2]
*/
enum {
Tnone,
Traw,
Tsuper,
Tarena,
Tlog,
Tpivot,
Tleaf,
};
enum {
Vinl, /* Inline value */
Vref, /* Block pointer */
};
enum {
GBraw = 1<<0,
GBwrite = 1<<1,
GBnochk = 1<<2,
};
enum {
Onop, /* nothing */
Oinsert, /* new kvp */
Odelete, /* delete kvp */
Oclearb, /* free block ptr if exists */
Owstat, /* kvp dirent */
Orefsnap, /* increment snap refcount */
Ounrefsnap, /* decrement snap refcount */
Nmsgtype, /* maximum message type */
};
/*
* Wstat ops come with associated data, in the order
* of the bit flags.
*/
enum{
/* wstat flags */
Owsize = 1<<0, /* [8]fsize: update file size */
Owmode = 1<<1, /* [4]mode: update file mode */
Owmtime = 1<<2, /* [8]mtime: update mtime, in nsec */
Owatime = 1<<3, /* [8]atime: update atime, in nsec */
Owuid = 1<<4, /* [4]uid: set uid */
Owgid = 1<<5, /* [4]uid: set gid */
Owmuid = 1<<6, /* [4]uid: set muid */
};
/*
* Operations for the allocation log.
*/
enum {
LogNop, /* unused */
/* 1-wide entries */
LogAlloc1, /* alloc a block */
LogFree1, /* free a block */
LogChain, /* point to next log block */
LogEnd, /* last entry in log */
/* 2-wide entries */
#define Log2wide LogAlloc
LogAlloc, /* alloc a range */
LogFree, /* free a range */
LogDead , /* deadlist a block */
};
enum {
AOnone,
AOsnap,
AOsync,
};
struct Bptr {
vlong addr;
vlong hash;
vlong gen;
};
struct Oplog {
Bptr head;
Blk *tail; /* tail block open for writing */
};
struct Arange {
Avl;
vlong off;
vlong len;
};
struct Bucket {
Lock;
Blk *b;
};
struct Amsg {
int op;
int fd;
union {
struct { /* AOsnap */
char old[128];
char new[128];
};
struct { /* AOsync */
int halt;
};
};
};
struct Fmsg {
Fcall;
int fd; /* the fd to repsond on */
int sz; /* the size of the message buf */
Amsg *a; /* admin messages */
uchar buf[];
};
struct Tree {
Lock lk;
Tree *snext;
long memref; /* number of in-memory references to this */
int dirty;
int ref; /* number of on-disk references to this */
int ht;
Bptr bp;
vlong gen;
vlong prev[Ndead];
Oplog dead[Ndead];
};
struct Bfree {
Bptr bp;
Bfree *next;
};
struct User {
int id;
int lead;
int *memb;
int nmemb;
char name[128];
};
/*
* Overall state of the file sytem.
* Shadows the superblock contents.
*/
struct Gefs {
/* immutable data */
int blksz; /* immutable */
int bufsz; /* immutable */
int pivsz; /* immutable */
int hdrsz; /* immutable */
QLock snaplk; /* snapshot lock */
Mount *mounts;
Tree *osnap;
Blk *super;
Chan *wrchan;
Chan *rdchan;
int nproc;
Lock activelk;
int active[Maxproc];
int lastactive[Maxproc];
Lock freelk;
Bfree *freep;
Bfree *freehd;
int fd;
long broken;
long rdonly;
/* root snapshot tree */
Tree snap;
uvlong nextqid;
uvlong nextgen;
/* arena allocation */
Arena *arenas;
int narena;
long roundrobin;
vlong arenasz;
/* user list */
RWLock userlk;
User *users;
int nusers;
/* fid hash table */
Lock fidtablk;
Fid *fidtab[Nfidtab];
/* dent hash table */
Lock dtablk;
Dent *dtab[Ndtab];
/* protected by lrulk */
Lock lrulk;
Bucket *cache;
Blk *chead;
Blk *ctail;
int ccount;
int cmax;
};
struct Arena {
Lock;
Avltree *free;
Avltree *partial;
Blk **queue;
int nqueue;
Blk *b; /* arena block */
Blk **q; /* write queue */
vlong nq;
Oplog log;
};
struct Key{
char *k;
int nk;
};
struct Val {
short nv;
char *v;
};
struct Kvp {
Key;
Val;
};
struct Msg {
char op;
Kvp;
};
struct Xdir {
/* file data */
Qid qid; /* unique id from server */
int mode; /* permissions */
vlong atime; /* last read time: nsec */
vlong mtime; /* last write time: nsec */
uvlong length; /* file length */
int uid; /* owner name */
int gid; /* group name */
int muid; /* last modifier name */
char *name; /* last element of path */
};
struct Dent {
RWLock;
Key;
Xdir;
Dent *next;
long ref;
char buf[Maxent];
};
struct Mount {
Mount *next;
long ref;
vlong gen;
int uid;
char *name;
Tree *root;
};
struct Fid {
Lock;
Fid *next;
/*
* if opened with OEXEC, we want to use a snapshot,
* instead of the most recent root, to prevent
* paging in the wrong executable.
*/
char snap[64];
Mount *mnt;
u32int fid;
vlong qpath;
long ref;
int mode;
int iounit;
int duid;
int dgid;
int dmode;
Scan *scan; /* in progres scan */
Dent *dent; /* (pqid, name) ref, modified on rename */
};
enum {
POmod,
POrot,
POsplit,
POmerge,
};
struct Path {
/* Flowing down for flush */
Msg *ins; /* inserted values, bounded by lo..hi */
Blk *b; /* to shadow */
int idx; /* insert at */
int lo; /* key range */
int hi; /* key range */
int sz; /* size of range */
/* Flowing up from flush */
int op; /* change done along path */
Blk *m; /* node merged against, for post-update free */
Blk *nl; /* new left */
Blk *nr; /* new right, if we split or rotated */
int midx; /* modification index */
int npull; /* number of messages successfully pulled */
int pullsz; /* size of pulled messages */
};
struct Scanp {
int bi;
int vi;
Blk *b;
};
struct Scan {
vlong offset; /* last read offset */
Tree root;
int done;
int overflow;
int present;
Kvp kv;
Key pfx;
char kvbuf[Kvmax];
char pfxbuf[Keymax];
Scanp *path;
};
struct Blk {
/* cache entry */
Blk *cnext;
Blk *cprev;
Blk *hnext;
/* Freelist entry */
Blk *fnext;
long flag;
/* serialized to disk in header */
short type; /* @0, for all */
short nval; /* @2, for Leaf, Pivot: data[0:2] */
short valsz; /* @4, for Leaf, Pivot: data[2:4] */
short nbuf; /* @6, for Pivot */
short bufsz; /* @8, for Pivot */
vlong logsz; /* for allocation log */
vlong lognxt; /* for allocation log */
uintptr freed; /* debug */
Bptr bp;
long ref;
char *data;
char buf[Blksz];
};
struct Chan {
int size; /* size of queue */
long count; /* how many in queue (semaphore) */
long avail; /* how many available to send (semaphore) */
Lock rl, wl; /* circular pointers */
void **rp;
void **wp;
void* args[]; /* list of saved pointers, [->size] */
};