ref: 5611a46d8fb04ec3fd60c05a1486743cea98a311
dir: /appl/cmd/disk/kfs.b/
implement Kfs;
#
# Copyright © 1991-2003 Lucent Technologies Inc.
# Limbo version Copyright © 2004 Vita Nuova Holdings Limited
#
#
# TO DO:
# - sync proc; Bmod; process structure
# - swiz?
include "sys.m";
sys: Sys;
Qid, Dir: import Sys;
DMEXCL, DMAPPEND, DMDIR: import Sys;
QTEXCL, QTAPPEND, QTDIR: import Sys;
include "draw.m";
include "styx.m";
styx: Styx;
Tmsg, Rmsg: import styx;
NOFID, OEXEC, ORCLOSE, OREAD, OWRITE, ORDWR, OTRUNC: import Styx;
IOHDRSZ: import Styx;
include "daytime.m";
daytime: Daytime;
now: import daytime;
include "arg.m";
Kfs: module
{
init: fn(nil: ref Draw->Context, nil: list of string);
};
MAXBUFSIZE: con 16*1024;
#
# fundamental constants
#
NAMELEN: con 28; # size of names, including null byte
NDBLOCK: con 6; # number of direct blocks in Dentry
MAXFILESIZE: con big 16r7FFFFFFF; # Plan 9's limit (kfs's size is signed)
SUPERADDR: con 1;
ROOTADDR: con 2;
QPDIR: con int (1<<31);
QPNONE: con 0;
QPROOT: con 1;
QPSUPER: con 2;
#
# don't change, these are the mode bits on disc
#
DALLOC: con 16r8000;
DDIR: con 16r4000;
DAPND: con 16r2000;
DLOCK: con 16r1000;
DREAD: con 4;
DWRITE: con 2;
DEXEC: con 1;
#
# other constants
#
MINUTE: con 60;
TLOCK: con 5*MINUTE;
NTLOCK: con 200; # number of active file locks
Buffering: con 1;
FID1, FID2, FID3: con 1+iota;
None: con 0; # user ID for "none"
Noworld: con 9999; # conventional id for "noworld" group
Lock: adt
{
c: chan of int;
new: fn(): ref Lock;
lock: fn(c: self ref Lock);
canlock: fn(c: self ref Lock): int;
unlock: fn(c: self ref Lock);
};
Dentry: adt
{
name: string;
uid: int;
gid: int;
muid: int; # not set by plan 9's kfs
mode: int; # mode bits on disc: DALLOC etc
qid: Qid; # 9p1 format on disc
size: big; # only 32-bits on disc, and Plan 9 limits it to signed
atime: int;
mtime: int;
iob: ref Iobuf; # locked block containing directory entry, when in memory
buf: array of byte; # pointer into block to packed directory entry, when in memory
mod: int; # bits of buf that need updating
unpack: fn(a: array of byte): ref Dentry;
get: fn(p: ref Iobuf, slot: int): ref Dentry;
geta: fn(d: ref Device, addr: int, slot: int, qpath: int, mode: int): (ref Dentry, string);
getd: fn(f: ref File, mode: int): (ref Dentry, string);
put: fn(d: self ref Dentry);
access: fn(d: self ref Dentry, f: int, uid: int);
change: fn(d: self ref Dentry, f: int);
release: fn(d: self ref Dentry);
getblk: fn(d: self ref Dentry, a: int, tag: int): ref Iobuf;
getblk1: fn(d: self ref Dentry, a: int, tag: int): ref Iobuf;
rel2abs: fn(d: self ref Dentry, a: int, tag: int, putb: int): int;
trunc: fn(d: self ref Dentry, uid: int);
update: fn(d: self ref Dentry);
print: fn(d: self ref Dentry);
};
Uname, Uids, Umode, Uqid, Usize, Utime: con 1<<iota; # Dentry.mod
#
# disc structure:
# Tag: pad[2] tag[2] path[4]
Tagsize: con 2+2+4;
Tag: adt
{
tag: int;
path: int;
unpack: fn(a: array of byte): Tag;
pack: fn(t: self Tag, a: array of byte);
};
Superb: adt
{
iob: ref Iobuf;
fstart: int;
fsize: int;
tfree: int;
qidgen: int; # generator for unique ids
fsok: int;
fbuf: array of byte; # nfree[4] free[FEPERBLK*4]; aliased into containing block
get: fn(dev: ref Device, flags: int): ref Superb;
touched: fn(s: self ref Superb);
put: fn(s: self ref Superb);
print: fn(s: self ref Superb);
pack: fn(s: self ref Superb, a: array of byte);
unpack: fn(a: array of byte): ref Superb;
};
Device: adt
{
fd: ref Sys->FD;
ronly: int;
# could put locks here if necessary
# partitioning by ds(3)
};
#
# one for each locked qid
#
Tlock: adt
{
dev: ref Device;
time: int;
qpath: int;
file: cyclic ref File; # TO DO: probably not needed
};
File: adt
{
qlock: chan of int;
qid: Qid;
wpath: ref Wpath;
tlock: cyclic ref Tlock; # if file is locked
fs: ref Device;
addr: int;
slot: int;
lastra: int; # read ahead address
fid: int;
uid: int;
open: int;
cons: int; # if opened by console
doffset: big; # directory reading
dvers: int;
dslot: int;
new: fn(fid: int): ref File;
access: fn(f: self ref File, d: ref Dentry, mode: int): int;
lock: fn(f: self ref File);
unlock: fn(f: self ref File);
};
FREAD, FWRITE, FREMOV, FWSTAT: con 1<<iota; # File.open
Chan: adt
{
fd: ref Sys->FD; # fd request came in on
# rlock, wlock: QLock; # lock for reading/writing messages on cp
flags: int;
flist: list of ref File; # active files
fqlock: chan of int;
# reflock: RWLock; # lock for Tflush
msize: int; # version
new: fn(fd: ref Sys->FD): ref Chan;
getfid: fn(c: self ref Chan, fid: int, flag: int): ref File;
putfid: fn(c: self ref Chan, f: ref File);
flock: fn(nil: self ref Chan);
funlock: fn(nil: self ref Chan);
};
Hiob: adt
{
link: ref Iobuf; # TO DO: eliminate circular list
lk: ref Lock;
niob: int;
newbuf: fn(h: self ref Hiob): ref Iobuf;
};
Iobuf: adt
{
qlock: chan of int;
dev: ref Device;
fore: cyclic ref Iobuf; # lru hash chain
back: cyclic ref Iobuf; # for lru
iobuf: array of byte; # only active while locked
xiobuf: array of byte; # "real" buffer pointer
addr: int;
flags: int;
get: fn(dev: ref Device, addr: int, flags: int):ref Iobuf;
put: fn(iob: self ref Iobuf);
lock: fn(iob: self ref Iobuf);
canlock: fn(iob: self ref Iobuf): int;
unlock: fn(iob: self ref Iobuf);
checktag: fn(iob: self ref Iobuf, tag: int, qpath: int): int;
settag: fn(iob: self ref Iobuf, tag: int, qpath: int);
};
Wpath: adt
{
up: cyclic ref Wpath; # pointer upwards in path
addr: int; # directory entry addr
slot: int; # directory entry slot
};
#
# error codes generated from the file server
#
Eaccess: con "access permission denied";
Ealloc: con "phase error -- directory entry not allocated";
Eauth: con "authentication failed";
Eauthmsg: con "kfs: authentication not required";
Ebadspc: con "attach -- bad specifier";
Ebadu: con "attach -- privileged user";
Ebroken: con "close/read/write -- lock is broken";
Echar: con "bad character in directory name";
Econvert: con "protocol botch";
Ecount: con "read/write -- count too big";
Edir1: con "walk -- in a non-directory";
Edir2: con "create -- in a non-directory";
Edot: con "create -- . and .. illegal names";
Eempty: con "remove -- directory not empty";
Eentry: con "directory entry not found";
Eexist: con "create -- file exists";
Efid: con "unknown fid";
Efidinuse: con "fid already in use";
Efull: con "file system full";
Elocked: con "open/create -- file is locked";
Emode: con "open/create -- unknown mode";
Ename: con "create/wstat -- bad character in file name";
Enotd: con "wstat -- attempt to change directory";
Enotg: con "wstat -- not in group";
Enotl: con "wstat -- attempt to change length";
Enotm: con "wstat -- unknown type/mode";
Enotu: con "wstat -- not owner";
Eoffset: con "read/write -- offset negative";
Eopen: con "read/write -- on non open fid";
Ephase: con "phase error -- cannot happen";
Eqid: con "phase error -- qid does not match";
Eqidmode: con "wstat -- qid.qtype/dir.mode mismatch";
Eronly: con "file system read only";
Ersc: con "it's russ's fault. bug him.";
Esystem: con "kfs system error";
Etoolong: con "name too long";
Etoobig: con "write -- file size limit";
Ewalk: con "walk -- too many (system wide)";
#
# tags on block
#
Tnone,
Tsuper, # the super block
Tdir, # directory contents
Tind1, # points to blocks
Tind2, # points to Tind1
Tfile, # file contents
Tfree, # in free list
Tbuck, # cache fs bucket
Tvirgo, # fake worm virgin bits
Tcache, # cw cache things
MAXTAG: con iota;
#
# flags to Iobuf.get
#
Bread, # read the block if miss
Bprobe, # return null if miss
Bmod, # set modified bit in buffer
Bimm, # set immediate bit in buffer
Bres: # never renamed
con 1<<iota;
#
# check flags
#
Crdall, # read all files
Ctag, # rebuild tags
Cpfile, # print files
Cpdir, # print directories
Cfree, # rebuild free list
Cream, # clear all bad tags
Cbad, # clear all bad blocks
Ctouch, # touch old dir and indir
Cquiet: # report just nasty things
con 1<<iota;
#
# buffer size variables, determined by RBUFSIZE
#
RBUFSIZE: int;
BUFSIZE: int;
DIRPERBUF: int;
INDPERBUF: int;
INDPERBUF2: int;
FEPERBUF: int;
emptyblock: array of byte;
wrenfd: ref Sys->FD;
thedevice: ref Device;
devnone: ref Device;
wstatallow := 0;
writeallow := 0;
writegroup := 0;
ream := 0;
readonly := 0;
noatime := 0;
localfs: con 1;
conschan: ref Chan;
consuid := -1;
consgid := -1;
debug := 0;
kfsname: string;
consoleout: chan of string;
mainlock: ref Lock;
pids: list of int;
noqid: Qid;
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
styx = load Styx Styx->PATH;
daytime = load Daytime Daytime->PATH;
styx->init();
arg := load Arg Arg->PATH;
if(arg == nil)
error(sys->sprint("can't load %s: %r", Arg->PATH));
arg->init(args);
arg->setusage("disk/kfs [-r [-b bufsize]] [-cADPRW] [-n name] kfsfile");
bufsize := 1024;
nocheck := 0;
while((o := arg->opt()) != 0)
case o {
'c' => nocheck = 1;
'r' => ream = 1;
'b' => bufsize = int arg->earg();
'D' => debug = !debug;
'P' => writeallow = 1;
'W' => wstatallow = 1;
'R' => readonly = 1;
'A' => noatime = 1; # mainly useful for flash
'n' => kfsname = arg->earg();
* => arg->usage();
}
args = arg->argv();
if(args == nil)
arg->usage();
arg = nil;
devnone = ref Device(nil, 1);
mainlock = Lock.new();
conschan = Chan.new(nil);
conschan.msize = Styx->MAXRPC;
mode := Sys->ORDWR;
if(readonly)
mode = Sys->OREAD;
wrenfd = sys->open(hd args, mode);
if(wrenfd == nil)
error(sys->sprint("can't open %s: %r", hd args));
thedevice = ref Device(wrenfd, readonly);
if(ream){
if(bufsize <= 0 || bufsize % 512 || bufsize > MAXBUFSIZE)
error(sys->sprint("invalid block size %d", bufsize));
RBUFSIZE = bufsize;
wrenream(thedevice);
}else{
if(!wreninit(thedevice))
error("kfs magic in trouble");
}
BUFSIZE = RBUFSIZE - Tagsize;
DIRPERBUF = BUFSIZE / Dentrysize;
INDPERBUF = BUFSIZE / 4;
INDPERBUF2 = INDPERBUF * INDPERBUF;
FEPERBUF = (BUFSIZE - Super1size - 4) / 4;
emptyblock = array[RBUFSIZE] of {* => byte 0};
iobufinit(30);
if(ream){
superream(thedevice, SUPERADDR);
rootream(thedevice, ROOTADDR);
wstatallow = writeallow = 1;
}
if(wrencheck(wrenfd))
error("kfs super/root in trouble");
if(!ream && !readonly && !superok(0)){
sys->print("kfs needs check\n");
if(!nocheck)
check(thedevice, Cquiet|Cfree);
}
(d, e) := Dentry.geta(thedevice, ROOTADDR, 0, QPROOT, Bread);
if(d != nil && !(d.mode & DDIR))
e = "not a directory";
if(e != nil)
error("bad root: "+e);
if(debug)
d.print();
d.put();
sys->pctl(Sys->FORKFD|Sys->NEWPGRP, nil);
sys->pctl(Sys->NEWFD, wrenfd.fd :: 0 :: 1 :: 2 :: nil);
wrenfd = sys->fildes(wrenfd.fd);
thedevice.fd = wrenfd;
c := chan of int;
if(Buffering){
spawn syncproc(c);
pid := <-c;
if(pid)
pids = pid :: pids;
}
spawn consinit(c);
pid := <- c;
if(pid)
pids = pid :: pids;
spawn kfs(sys->fildes(0));
}
error(s: string)
{
sys->fprint(sys->fildes(2), "kfs: %s\n", s);
for(; pids != nil; pids = tl pids)
kill(hd pids);
raise "fail:error";
}
panic(s: string)
{
sys->fprint(sys->fildes(2), "kfs: panic: %s\n", s);
for(; pids != nil; pids = tl pids)
kill(hd pids);
raise "panic";
}
syncproc(c: chan of int)
{
c <-= 0;
}
shutdown()
{
for(; pids != nil; pids = tl pids)
kill(hd pids);
# TO DO: when Bmod deferred, must sync
# sync super block
if(!readonly && superok(1)){
# ;
}
iobufclear();
}
kill(pid: int)
{
fd := sys->open("#p/"+string pid+"/ctl", Sys->OWRITE);
if(fd != nil)
sys->fprint(fd, "kill");
}
#
# limited file system support for console
#
kattach(fid: int): string
{
return applycons(ref Tmsg.Attach(1, fid, NOFID, "adm", "")).t1;
}
kopen(oldfid: int, newfid: int, names: array of string, mode: int): string
{
(r1, e1) := applycons(ref Tmsg.Walk(1, oldfid, newfid, names));
if(r1 != nil){
pick m := r1 {
Walk =>
if(len m.qids != len names){
kclose(newfid);
cprint(Eexist);
return Eexist;
}
* =>
return "unexpected reply";
}
(r1, e1) = applycons(ref Tmsg.Open(1, newfid, mode));
if(e1 != nil){
kclose(newfid);
cprint(sys->sprint("open: %s", e1));
}
}
return e1;
}
kread(fid: int, offset: int, nbytes: int): (array of byte, string)
{
(r, e) := applycons(ref Tmsg.Read(1, fid, big offset, nbytes));
if(r != nil){
pick m := r {
Read =>
return (m.data, nil);
* =>
return (nil, "unexpected reply");
}
}
cprint(sys->sprint("read error: %s", e));
return (nil, e);
}
kclose(fid: int)
{
applycons(ref Tmsg.Clunk(1, fid));
}
applycons(t: ref Tmsg): (ref Rmsg, string)
{
r := apply(conschan, t);
pick m := r {
Error =>
if(debug)
cprint(sys->sprint("%s: %s\n", t.text(), m.ename));
return (nil, m.ename);
}
return (r, nil);
}
#
# always reads /adm/users in userinit(), then
# optionally serves the command file, if used.
#
Req: adt {
nbytes: int;
rc: chan of (array of byte, string);
};
consinit(c: chan of int)
{
kattach(FID1);
userinit();
if(kfsname == nil){
c <-= 0;
exit;
}
cfname := "kfs."+kfsname+".cmd";
sys->bind("#s", "/chan", Sys->MBEFORE);
file := sys->file2chan("/chan", cfname);
if(file == nil)
error(sys->sprint("can't create /chan/%s: %r", cfname));
c <-= sys->pctl(0, nil);
consc := chan of string;
checkend := chan of int;
cdata: array of byte;
pending: ref Req;
cfid := -1;
for(;;) alt{
(nil, nbytes, fid, rc) := <-file.read =>
if(rc == nil)
break;
if(cfid == -1)
cfid = fid;
if(fid != cfid || pending != nil){
rc <-= (nil, "kfs.cmd is busy");
break;
}
if(cdata != nil){
cdata = reply(rc, nbytes, cdata);
break;
}
if(nbytes <= 0 || consoleout == nil){
rc <-= (nil, nil);
break;
}
pending = ref Req(nbytes, rc);
consc = consoleout;
(nil, data, fid, wc) := <-file.write =>
if(cfid == -1)
cfid = fid;
if(wc == nil){
if(fid == cfid){
cfid = -1;
pending = nil;
cdata = nil; # discard unread data from last command
if((consc = consoleout) == nil)
consc = chan of string;
}
break;
}
if(fid != cfid){
wc <-= (0, "kfs.cmd is busy");
break;
}
(nf, fld) := sys->tokenize(string data, " \t\n\r");
if(nf < 1){
wc <-= (0, "illegal kfs request");
break;
}
case hd fld {
"check" =>
if(consoleout != nil){
wc <-= (0, "check in progress");
break;
}
f := 0;
if(nf > 1){
f = checkflags(hd tl fld);
if(f < 0){
wc <-= (0, "illegal check flag: "+hd tl fld);
break;
}
}
consoleout = chan of string;
spawn checkproc(checkend, f);
wc <-= (len data, nil);
consc = consoleout;
"users" or "user" =>
cmd_users();
wc <-= (len data, nil);
"sync" =>
# nothing TO DO until writes are buffered
wc <-= (len data, nil);
"allow" =>
wstatallow = writeallow = 1;
wc <-= (len data, nil);
"allowoff" or "disallow" =>
wstatallow = writeallow = 0;
wc <-= (len data, nil);
* =>
wc <-= (0, "unknown kfs request");
continue;
}
<-checkend =>
consoleout = nil;
consc = chan of string;
s := <-consc =>
#sys->print("<-%s\n", s);
req := pending;
pending = nil;
if(req != nil)
cdata = reply(req.rc, req.nbytes, array of byte s);
else
cdata = array of byte s;
if(cdata != nil && cfid != -1)
consc = chan of string;
}
}
reply(rc: chan of (array of byte, string), nbytes: int, a: array of byte): array of byte
{
if(len a < nbytes)
nbytes = len a;
rc <-= (a[0:nbytes], nil);
if(nbytes == len a)
return nil;
return a[nbytes:];
}
checkproc(c: chan of int, flags: int)
{
mainlock.lock();
check(thedevice, flags);
mainlock.unlock();
c <-= 1;
}
#
# normal kfs service
#
kfs(rfd: ref Sys->FD)
{
cp := Chan.new(rfd);
while((t := Tmsg.read(rfd, cp.msize)) != nil){
if(debug)
sys->print("<- %s\n", t.text());
r := apply(cp, t);
pick m := r {
Error =>
r.tag = t.tag;
}
if(debug)
sys->print("-> %s\n", r.text());
rbuf := r.pack();
if(rbuf == nil)
panic("Rmsg.pack");
if(sys->write(rfd, rbuf, len rbuf) != len rbuf)
panic("mount write");
}
shutdown();
}
apply(cp: ref Chan, t: ref Tmsg): ref Rmsg
{
mainlock.lock(); # TO DO: this is just to keep console and kfs from colliding
r: ref Rmsg;
pick m := t {
Readerror =>
error(sys->sprint("mount read error: %s", m.error));
Version =>
r = rversion(cp, m);
Auth =>
r = rauth(cp, m);
Flush =>
r = rflush(cp, m);
Attach =>
r = rattach(cp, m);
Walk =>
r = rwalk(cp, m);
Open =>
r = ropen(cp, m);
Create =>
r = rcreate(cp, m);
Read =>
r = rread(cp, m);
Write =>
r = rwrite(cp, m);
Clunk =>
r = rclunk(cp, m);
Remove =>
r = rremove(cp, m);
Stat =>
r = rstat(cp, m);
Wstat =>
r = rwstat(cp, m);
* =>
panic("Styx mtype");
return nil;
}
mainlock.unlock();
return r;
}
rversion(cp: ref Chan, t: ref Tmsg.Version): ref Rmsg
{
cp.msize = RBUFSIZE+IOHDRSZ;
if(cp.msize < Styx->MAXRPC)
cp.msize = Styx->MAXRPC;
(msize, version) := styx->compatible(t, Styx->MAXRPC, Styx->VERSION);
if(msize < 256)
return ref Rmsg.Error(t.tag, "message size too small");
return ref Rmsg.Version(t.tag, msize, version);
}
rauth(nil: ref Chan, t: ref Tmsg.Auth): ref Rmsg
{
return ref Rmsg.Error(t.tag, Eauthmsg);
}
rflush(nil: ref Chan, t: ref Tmsg.Flush): ref Rmsg
{
# runlock(cp.reflock);
# wlock(cp.reflock);
# wunlock(cp.reflock);
# rlock(cp.reflock);
return ref Rmsg.Flush(t.tag);
}
err(t: ref Tmsg, s: string): ref Rmsg.Error
{
return ref Rmsg.Error(t.tag, s);
}
ferr(t: ref Tmsg, s: string, file: ref File, p: ref Iobuf): ref Rmsg.Error
{
if(p != nil)
p.put();
if(file != nil)
file.unlock();
return ref Rmsg.Error(t.tag, s);
}
File.new(fid: int): ref File
{
f := ref File;
f.qlock = chan[1] of int;
f.fid = fid;
f.cons = 0;
f.tlock = nil;
f.wpath = nil;
f.doffset = big 0;
f.dvers = 0;
f.dslot = 0;
f.uid = None;
f.cons = 0;
# f.cuid = None;
return f;
}
#
# returns a locked file structure
#
Chan.getfid(cp: self ref Chan, fid: int, flag: int): ref File
{
if(fid == NOFID)
return nil;
cp.flock();
for(l := cp.flist; l != nil; l = tl l){
f := hd l;
if(f.fid == fid){
cp.funlock();
if(flag)
return nil; # fid in use
f.lock();
if(f.fid == fid)
return f;
f.unlock();
cp.flock();
}
}
if(flag == 0){
sys->print("kfs: cannot find %H.%ud", cp, fid);
cp.funlock();
return nil;
}
f := File.new(fid);
f.lock();
cp.flist = f :: cp.flist;
cp.funlock();
return f;
}
Chan.putfid(cp: self ref Chan, f: ref File)
{
cp.flock();
nl: list of ref File;
for(x := cp.flist; x != nil; x = tl x)
if(hd x != f)
nl = hd x :: nl;
cp.flist = nl;
cp.funlock();
f.unlock();
}
File.lock(f: self ref File)
{
f.qlock <-= 1;
}
File.unlock(f: self ref File)
{
<-f.qlock;
}
Chan.new(fd: ref Sys->FD): ref Chan
{
c := ref Chan;
c.fd = fd;
c.fqlock = chan[1] of int;
# rlock, wlock: QLock; # lock for reading/writing messages on cp
c.flags = 0;
# reflock: RWLock; # lock for Tflush
c.msize = 0; # set by rversion
return c;
}
Chan.flock(c: self ref Chan)
{
c.fqlock <-= 1;
}
Chan.funlock(c: self ref Chan)
{
<-c.fqlock;
}
rattach(cp: ref Chan, t: ref Tmsg.Attach): ref Rmsg
{
if(t.aname != "" && t.aname != "main")
return err(t, Ebadspc);
file := cp.getfid(t.fid, 1);
if(file == nil)
return err(t, Efidinuse);
p := Iobuf.get(thedevice, ROOTADDR, Bread);
if(p == nil){
cp.putfid(file);
return err(t, "can't access root block");
}
d := Dentry.get(p, 0);
if(d == nil || p.checktag(Tdir, QPROOT) || (d.mode & DALLOC) == 0 || (d.mode & DDIR) == 0){
p.put();
cp.putfid(file);
return err(t, Ealloc);
}
if(file.access(d, DEXEC)){
p.put();
cp.putfid(file);
return err(t, Eaccess);
}
d.access(FREAD, file.uid);
file.fs = thedevice;
file.qid = d.qid;
file.addr = p.addr;
file.slot = 0;
file.open = 0;
file.uid = strtouid(t.uname);
file.wpath = nil;
p.put();
qid := file.qid;
file.unlock();
return ref Rmsg.Attach(t.tag, qid);
}
clone(nfile: ref File, file: ref File)
{
nfile.qid = file.qid;
nfile.wpath = file.wpath;
nfile.fs = file.fs;
nfile.addr = file.addr;
nfile.slot = file.slot;
nfile.uid = file.uid;
# nfile.cuid = None;
nfile.open = file.open & ~FREMOV;
}
walkname(file: ref File, wname: string): (string, Qid)
{
#
# File must not have been opened for I/O by an open
# or create message and must represent a directory.
#
if(file.open != 0)
return (Emode, noqid);
(d, e) := Dentry.getd(file, Bread);
if(d == nil)
return (e, noqid);
if(!(d.mode & DDIR)){
d.put();
return (Edir1, noqid);
}
#
# For walked elements the implied user must
# have permission to search the directory.
#
if(file.access(d, DEXEC)){
d.put();
return (Eaccess, noqid);
}
d.access(FREAD, file.uid);
if(wname == "." || wname == ".." && file.wpath == nil){
d.put();
return (nil, file.qid);
}
d1: ref Dentry; # entry for wname, if found
slot: int;
if(wname == ".."){
d.put();
addr := file.wpath.addr;
slot = file.wpath.slot;
(d1, e) = Dentry.geta(file.fs, addr, slot, QPNONE, Bread);
if(d1 == nil)
return (e, noqid);
file.wpath = file.wpath.up;
}else{
Search:
for(addr := 0; ; addr++){
if(d.iob == nil){
(d, e) = Dentry.getd(file, Bread);
if(d == nil)
return (e, noqid);
}
p1 := d.getblk1(addr, 0);
if(p1 == nil || p1.checktag(Tdir, int d.qid.path)){
if(p1 != nil)
p1.put();
return (Eentry, noqid);
}
for(slot = 0; slot < DIRPERBUF; slot++){
d1 = Dentry.get(p1, slot);
if(!(d1.mode & DALLOC))
continue;
if(wname != d1.name)
continue;
#
# update walk path
#
file.wpath = ref Wpath(file.wpath, file.addr, file.slot);
slot += DIRPERBUF*addr;
break Search;
}
p1.put();
}
d.put();
}
file.addr = d1.iob.addr;
file.slot = slot;
file.qid = d1.qid;
d1.put();
return (nil, file.qid);
}
rwalk(cp: ref Chan, t: ref Tmsg.Walk): ref Rmsg
{
nfile, tfile: ref File;
q: Qid;
# The file identified by t.fid must be valid in the
# current session and must not have been opened for I/O
# by an open or create message.
if((file := cp.getfid(t.fid, 0)) == nil)
return err(t, Efid);
if(file.open != 0)
return ferr(t, Emode, file, nil);
# If newfid is not the same as fid, allocate a new file;
# a side effect is checking newfid is not already in use (error);
# if there are no names to walk this will be equivalent to a
# simple 'clone' operation.
# Otherwise, fid and newfid are the same and if there are names
# to walk make a copy of 'file' to be used during the walk as
# 'file' must only be updated on success.
# Finally, it's a no-op if newfid is the same as fid and t.nwname
# is 0.
nwqid := 0;
if(t.newfid != t.fid){
if((nfile = cp.getfid(t.newfid, 1)) == nil)
return ferr(t, Efidinuse, file, nil);
}
else if(len t.names != 0)
nfile = tfile = File.new(NOFID);
else{
file.unlock();
return ref Rmsg.Walk(t.tag, nil);
}
clone(nfile, file);
r := ref Rmsg.Walk(t.tag, array[len t.names] of Qid);
error: string;
for(nwname := 0; nwname < len t.names; nwname++){
(error, q) = walkname(nfile, t.names[nwname]);
if(error != nil)
break;
r.qids[nwqid++] = q;
}
if(len t.names == 0){
# Newfid must be different to fid (see above)
# so this is a simple 'clone' operation - there's
# nothing to do except unlock unless there's
# an error.
nfile.unlock();
if(error != nil)
cp.putfid(nfile);
}else if(nwqid < len t.names){
#
# Didn't walk all elements, 'clunk' nfile
# and leave 'file' alone.
# Clear error if some of the elements were
# walked OK.
#
if(nfile != tfile)
cp.putfid(nfile);
if(nwqid != 0)
error = nil;
r.qids = r.qids[0:nwqid];
}else{
#
# Walked all elements. If newfid is the same
# as fid must update 'file' from the temporary
# copy used during the walk.
# Otherwise just unlock (when using tfile there's
# no need to unlock as it's a local).
#
if(nfile == tfile){
file.qid = nfile.qid;
file.wpath = nfile.wpath;
file.addr = nfile.addr;
file.slot = nfile.slot;
}else
nfile.unlock();
}
file.unlock();
if(error != nil)
return err(t, error);
return r;
}
ropen(cp: ref Chan, f: ref Tmsg.Open): ref Rmsg
{
wok := cp == conschan || writeallow;
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
#
# if remove on close, check access here
#
ro := isro(file.fs) || (writegroup && !ingroup(file.uid, writegroup));
if(f.mode & ORCLOSE){
if(ro)
return ferr(f, Eronly, file, nil);
#
# check on parent directory of file to be deleted
#
if(file.wpath == nil || file.wpath.addr == file.addr)
return ferr(f, Ephase, file, nil);
p := Iobuf.get(file.fs, file.wpath.addr, Bread);
if(p == nil || p.checktag(Tdir, QPNONE))
return ferr(f, Ephase, file, p);
if((d := Dentry.get(p, file.wpath.slot)) == nil || !(d.mode & DALLOC))
return ferr(f, Ephase, file, p);
if(file.access(d, DWRITE))
return ferr(f, Eaccess, file, p);
p.put();
}
(d, e) := Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, nil);
p := d.iob;
qid := d.qid;
fmod: int;
case f.mode & 7 {
OREAD =>
if(file.access(d, DREAD) && !wok)
return ferr(f, Eaccess, file, p);
fmod = FREAD;
OWRITE =>
if((d.mode & DDIR) || (file.access(d, DWRITE) && !wok))
return ferr(f, Eaccess, file, p);
if(ro)
return ferr(f, Eronly, file, p);
fmod = FWRITE;
ORDWR =>
if((d.mode & DDIR)
|| (file.access(d, DREAD) && !wok)
|| (file.access(d, DWRITE) && !wok))
return ferr(f, Eaccess, file, p);
if(ro)
return ferr(f, Eronly, file, p);
fmod = FREAD+FWRITE;
OEXEC =>
if((d.mode & DDIR) || (file.access(d, DEXEC) && !wok))
return ferr(f, Eaccess, file, p);
fmod = FREAD;
* =>
return ferr(f, Emode, file, p);
}
if(f.mode & OTRUNC){
if((d.mode & DDIR) || (file.access(d, DWRITE) && !wok))
return ferr(f, Eaccess, file, p);
if(ro)
return ferr(f, Eronly, file, p);
}
if(d.mode & DLOCK){
if((t := tlocked(file, d)) == nil)
return ferr(f, Elocked, file, p);
file.tlock = t;
t.file = file;
}
if(f.mode & ORCLOSE)
fmod |= FREMOV;
file.open = fmod;
if((f.mode & OTRUNC) && !(d.mode & DAPND)){
d.trunc(file.uid);
qid.vers = d.qid.vers;
}
file.lastra = 1;
p.put();
file.unlock();
return ref Rmsg.Open(f.tag, qid, cp.msize-IOHDRSZ);
}
rcreate(cp: ref Chan, f: ref Tmsg.Create): ref Rmsg
{
wok := cp == conschan || writeallow;
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
if(isro(file.fs) || (writegroup && !ingroup(file.uid, writegroup)))
return ferr(f, Eronly, file, nil);
(d, e) := Dentry.getd(file, Bread);
if(e != nil)
return ferr(f, e, file, nil);
p := d.iob;
if(!(d.mode & DDIR))
return ferr(f, Edir2, file, p);
if(file.access(d, DWRITE) && !wok)
return ferr(f, Eaccess, file, p);
d.access(FREAD, file.uid);
#
# Check the name is valid and will fit in an old
# directory entry.
#
if((l := checkname9p2(f.name)) == 0)
return ferr(f, Ename, file, p);
if(l+1 > NAMELEN)
return ferr(f, Etoolong, file, p);
if(f.name == "." || f.name == "..")
return ferr(f, Edot, file, p);
addr1 := 0; # block with first empty slot, if any
slot1 := 0;
for(addr := 0; ; addr++){
if((p1 := d.getblk(addr, 0)) == nil){
if(addr1 != 0)
break;
p1 = d.getblk(addr, Tdir);
}
if(p1 == nil)
return ferr(f, Efull, file, p);
if(p1.checktag(Tdir, int d.qid.path)){
p1.put();
return ferr(f, Ephase, file, p);
}
for(slot := 0; slot < DIRPERBUF; slot++){
d1 := Dentry.get(p1, slot);
if(!(d1.mode & DALLOC)){
if(addr1 == 0){
addr1 = p1.addr;
slot1 = slot + addr*DIRPERBUF;
}
continue;
}
if(f.name == d1.name){
p1.put();
return ferr(f, Eexist, file, p);
}
}
p1.put();
}
fmod: int;
case f.mode & 7 {
OEXEC or
OREAD => # seems only useful to make directories
fmod = FREAD;
OWRITE =>
fmod = FWRITE;
ORDWR =>
fmod = FREAD+FWRITE;
* =>
return ferr(f, Emode, file, p);
}
if(f.perm & DMDIR)
if((f.mode & OTRUNC) || (f.perm & DMAPPEND) || (fmod & FWRITE))
return ferr(f, Eaccess, file, p);
# do it
path := qidpathgen(file.fs);
if((p1 := Iobuf.get(file.fs, addr1, Bread|Bimm|Bmod)) == nil)
return ferr(f, Ephase, file, p);
d1 := Dentry.get(p1, slot1);
if(d1 == nil || p1.checktag(Tdir, int d.qid.path)){
p.put();
return ferr(f, Ephase, file, p1);
}
if(d1.mode & DALLOC){
p.put();
return ferr(f, Ephase, file, p1);
}
d1.name = f.name;
if(cp == conschan){
d1.uid = consuid;
d1.gid = consgid;
}
else{
d1.uid = file.uid;
d1.gid = d.gid;
f.perm &= d.mode | ~8r666;
if(f.perm & DMDIR)
f.perm &= d.mode | ~8r777;
}
d1.qid.path = big path;
d1.qid.vers = 0;
d1.mode = DALLOC | (f.perm & 8r777);
if(f.perm & DMDIR)
d1.mode |= DDIR;
if(f.perm & DMAPPEND)
d1.mode |= DAPND;
t: ref Tlock;
if(f.perm & DMEXCL){
d1.mode |= DLOCK;
t = tlocked(file, d1);
# if nil, out of tlock structures
}
d1.access(FWRITE, file.uid);
d1.change(~0);
d1.update();
qid := mkqid(path, 0, d1.mode);
p1.put();
d.change(~0);
d.access(FWRITE, file.uid);
d.update();
p.put();
#
# do a walk to new directory entry
#
file.wpath = ref Wpath(file.wpath, file.addr, file.slot);
file.qid = qid;
file.tlock = t;
if(t != nil)
t.file = file;
file.lastra = 1;
if(f.mode & ORCLOSE)
fmod |= FREMOV;
file.open = fmod;
file.addr = addr1;
file.slot = slot1;
file.unlock();
return ref Rmsg.Create(f.tag, qid, cp.msize-IOHDRSZ);
}
dirread(cp: ref Chan, f: ref Tmsg.Read, file: ref File, d: ref Dentry): ref Rmsg
{
p1: ref Iobuf;
d1: ref Dentry;
count := f.count;
data := array[count] of byte;
offset := f.offset;
iounit := cp.msize-IOHDRSZ;
if(count > iounit)
count = iounit;
# Pick up where we left off last time if nothing has changed,
# otherwise must scan from the beginning.
addr, slot: int;
start: big;
if(offset == file.doffset){ # && file.qid.vers == file.dvers
addr = file.dslot/DIRPERBUF;
slot = file.dslot%DIRPERBUF;
start = offset;
}
else{
addr = 0;
slot = 0;
start = big 0;
}
nread := 0;
Dread:
for(;;){
if(d.iob == nil){
#
# This is just a check to ensure the entry hasn't
# gone away during the read of each directory block.
#
e: string;
(d, e) = Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, nil);
}
p1 = d.getblk1(addr, 0);
if(p1 == nil)
break;
if(p1.checktag(Tdir, QPNONE))
return ferr(f, Ephase, file, p1);
for(; slot < DIRPERBUF; slot++){
d1 = Dentry.get(p1, slot);
if(!(d1.mode & DALLOC))
continue;
dir := dir9p2(d1);
n := styx->packdirsize(dir);
if(n > count-nread){
p1.put();
break Dread;
}
data[nread:] = styx->packdir(dir);
start += big n;
if(start < offset)
continue;
if(count < n){
p1.put();
break Dread;
}
count -= n;
nread += n;
offset += big n;
}
p1.put();
slot = 0;
addr++;
}
file.doffset = offset;
file.dvers = file.qid.vers;
file.dslot = slot+DIRPERBUF*addr;
d.put();
file.unlock();
return ref Rmsg.Read(f.tag, data[0:nread]);
}
rread(cp: ref Chan, f: ref Tmsg.Read): ref Rmsg
{
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
if(!(file.open & FREAD))
return ferr(f, Eopen, file, nil);
count := f.count;
iounit := cp.msize-IOHDRSZ;
if(count < 0 || count > iounit)
return ferr(f, Ecount, file, nil);
offset := f.offset;
if(offset < big 0)
return ferr(f, Eoffset, file, nil);
(d, e) := Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, nil);
if((t := file.tlock) != nil){
tim := now();
if(t.time < tim || t.file != file){
d.put();
return ferr(f, Ebroken, file, nil);
}
# renew the lock
t.time = tim + TLOCK;
}
d.access(FREAD, file.uid);
if(d.mode & DDIR)
return dirread(cp, f, file, d);
if(offset+big count > d.size)
count = int (d.size - offset);
if(count < 0)
count = 0;
data := array[count] of byte;
nread := 0;
while(count > 0){
if(d.iob == nil){
# must check and reacquire entry
(d, e) = Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, nil);
}
addr := int (offset / big BUFSIZE);
if(addr == file.lastra+1)
; # dbufread(p, d, addr+1);
file.lastra = addr;
o := int (offset % big BUFSIZE);
n := BUFSIZE - o;
if(n > count)
n = count;
p1 := d.getblk1(addr, 0);
if(p1 != nil){
if(p1.checktag(Tfile, QPNONE)){
p1.put();
return ferr(f, Ephase, file, nil);
}
data[nread:] = p1.iobuf[o:o+n];
p1.put();
}else
data[nread:] = emptyblock[0:n];
count -= n;
nread += n;
offset += big n;
}
d.put();
file.unlock();
return ref Rmsg.Read(f.tag, data[0:nread]);
}
rwrite(cp: ref Chan, f: ref Tmsg.Write): ref Rmsg
{
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
if(!(file.open & FWRITE))
return ferr(f, Eopen, file, nil);
if(isro(file.fs) || (writegroup && !ingroup(file.uid, writegroup)))
return ferr(f, Eronly, file, nil);
count := len f.data;
if(count < 0 || count > cp.msize-IOHDRSZ)
return ferr(f, Ecount, file, nil);
offset := f.offset;
if(offset < big 0)
return ferr(f, Eoffset, file, nil);
(d, e) := Dentry.getd(file, Bread|Bmod);
if(d == nil)
return ferr(f, e, file, nil);
if((t := file.tlock) != nil){
tim := now();
if(t.time < tim || t.file != file){
d.put();
return ferr(f, Ebroken, file, nil);
}
# renew the lock
t.time = tim + TLOCK;
}
d.access(FWRITE, file.uid);
if(d.mode & DAPND)
offset = d.size;
end := offset + big count;
if(end > d.size){
if(end > MAXFILESIZE)
return ferr(f, Etoobig, file, nil);
d.size = end;
d.change(Usize);
}
d.update();
nwrite := 0;
while(count > 0){
if(d.iob == nil){
# must check and reacquire entry
(d, e) = Dentry.getd(file, Bread|Bmod);
if(d == nil)
return ferr(f, e, file, nil);
}
addr := int (offset / big BUFSIZE);
o := int (offset % big BUFSIZE);
n := BUFSIZE - o;
if(n > count)
n = count;
qpath := int d.qid.path;
p1 := d.getblk1(addr, Tfile);
if(p1 == nil)
return ferr(f, Efull, file, nil);
if(p1.checktag(Tfile, qpath)){
p1.put();
return ferr(f, Ealloc, file, nil);
}
p1.iobuf[o:] = f.data[nwrite:nwrite+n];
p1.flags |= Bmod;
p1.put();
count -= n;
nwrite += n;
offset += big n;
}
d.put();
file.unlock();
return ref Rmsg.Write(f.tag, nwrite);
}
doremove(f: ref File, iscon: int): string
{
if(isro(f.fs) || f.cons == 0 && (writegroup && !ingroup(f.uid, writegroup)))
return Eronly;
#
# check permission on parent directory of file to be deleted
#
if(f.wpath == nil || f.wpath.addr == f.addr)
return Ephase;
(d1, e1) := Dentry.geta(f.fs, f.wpath.addr, f.wpath.slot, QPNONE, Bread);
if(e1 != nil)
return e1;
if(!iscon && f.access(d1, DWRITE)){
d1.put();
return Eaccess;
}
d1.access(FWRITE, f.uid);
d1.put();
#
# check on file to be deleted
#
(d, e) := Dentry.getd(f, Bread);
if(e != nil)
return e;
#
# if deleting a directory, make sure it is empty
#
if(d.mode & DDIR)
for(addr:=0; (p1 := d.getblk(addr, 0)) != nil; addr++){
if(p1.checktag(Tdir, int d.qid.path)){
p1.put();
d.put();
return Ephase;
}
for(slot:=0; slot<DIRPERBUF; slot++){
d1 = Dentry.get(p1, slot);
if(!(d1.mode & DALLOC))
continue;
p1.put();
d.put();
return Eempty;
}
p1.put();
}
#
# do it
#
d.trunc(f.uid);
d.buf[0:] = emptyblock[0:Dentrysize];
d.put();
return nil;
}
clunk(cp: ref Chan, file: ref File, remove: int, wok: int): string
{
if((t := file.tlock) != nil){
if(t.file == file)
t.time = 0; # free the lock
file.tlock = nil;
}
if(remove)
error := doremove(file, wok);
file.open = 0;
file.wpath = nil;
cp.putfid(file);
return error;
}
rclunk(cp: ref Chan, t: ref Tmsg.Clunk): ref Rmsg
{
if((file := cp.getfid(t.fid, 0)) == nil)
return err(t, Efid);
clunk(cp, file, file.open & FREMOV, 0);
return ref Rmsg.Clunk(t.tag);
}
rremove(cp: ref Chan, t: ref Tmsg.Remove): ref Rmsg
{
if((file := cp.getfid(t.fid, 0)) == nil)
return err(t, Efid);
e := clunk(cp, file, 1, cp == conschan);
if(e != nil)
return err(t, e);
return ref Rmsg.Remove(t.tag);
}
rstat(cp: ref Chan, f: ref Tmsg.Stat): ref Rmsg
{
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
(d, e) := Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, nil);
dir := dir9p2(d);
if(d.qid.path == big QPROOT) # stat of root gives time
dir.atime = now();
d.put();
if(styx->packdirsize(dir) > cp.msize-IOHDRSZ)
return ferr(f, Ersc, file, nil);
file.unlock();
return ref Rmsg.Stat(f.tag, dir);
}
rwstat(cp: ref Chan, f: ref Tmsg.Wstat): ref Rmsg
{
if((file := cp.getfid(f.fid, 0)) == nil)
return err(f, Efid);
# if user none, can't do anything unless in allow mode
if(file.uid == None && !wstatallow)
return ferr(f, Eaccess, file, nil);
if(isro(file.fs) || (writegroup && !ingroup(file.uid, writegroup)))
return ferr(f, Eronly, file, nil);
#
# first get parent
#
p1: ref Iobuf;
d1: ref Dentry;
if(file.wpath != nil){
p1 = Iobuf.get(file.fs, file.wpath.addr, Bread);
if(p1 == nil)
return ferr(f, Ephase, file, p1);
d1 = Dentry.get(p1, file.wpath.slot);
if(d1 == nil || p1.checktag(Tdir, QPNONE) || !(d1.mode & DALLOC))
return ferr(f, Ephase, file, p1);
}
#
# now the file
#
(d, e) := Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, e, file, p1);
#
# Convert the message and fix up
# fields not to be changed.
#
dir := f.stat;
if(dir.uid == nil)
uid := d.uid;
else
uid = strtouid(dir.uid);
if(dir.gid == nil)
gid := d.gid;
else
gid = strtouid(dir.gid);
if(dir.name == nil)
dir.name = d.name;
else{
if((l := checkname9p2(dir.name)) == 0){
d.put();
return ferr(f, Ename, file, p1);
}
if(l+1 > NAMELEN){
d.put();
return ferr(f, Etoolong, file, p1);
}
}
# Before doing sanity checks, find out what the
# new 'mode' should be:
# if 'type' and 'mode' are both defaults, take the
# new mode from the old directory entry;
# else if 'type' is the default, use the new mode entry;
# else if 'mode' is the default, create the new mode from
# 'type' or'ed with the old directory mode;
# else neither are defaults, use the new mode but check
# it agrees with 'type'.
if(dir.qid.qtype == 16rFF && dir.mode == ~0){
dir.mode = d.mode & 8r777;
if(d.mode & DLOCK)
dir.mode |= DMEXCL;
if(d.mode & DAPND)
dir.mode |= DMAPPEND;
if(d.mode & DDIR)
dir.mode |= DMDIR;
}
else if(dir.qid.qtype == 16rFF){
# nothing to do
}
else if(dir.mode == ~0)
dir.mode = (dir.qid.qtype<<24)|(d.mode & 8r777);
else if(dir.qid.qtype != ((dir.mode>>24) & 16rFF)){
d.put();
return ferr(f, Eqidmode, file, p1);
}
# Check for unknown type/mode bits
# and an attempt to change the directory bit.
if(dir.mode & ~(DMDIR|DMAPPEND|DMEXCL|8r777)){
d.put();
return ferr(f, Enotm, file, p1);
}
if(d.mode & DDIR)
mode := DMDIR;
else
mode = 0;
if((dir.mode^mode) & DMDIR){
d.put();
return ferr(f, Enotd, file, p1);
}
if(dir.mtime == ~0)
dir.mtime = d.mtime;
if(dir.length == ~big 0)
dir.length = big d.size;
# Currently, can't change length.
if(dir.length != big d.size){
d.put();
return ferr(f, Enotl, file, p1);
}
# if chown,
# must be god
# wstatallow set to allow chown during boot
if(uid != d.uid && !wstatallow){
d.put();
return ferr(f, Enotu, file, p1);
}
# if chgroup,
# must be either
# a) owner and in new group
# b) leader of both groups
# wstatallow and writeallow are set to allow chgrp during boot
while(gid != d.gid){
if(wstatallow || writeallow)
break;
if(d.uid == file.uid && ingroup(file.uid, gid))
break;
if(leadgroup(file.uid, gid))
if(leadgroup(file.uid, d.gid))
break;
d.put();
return ferr(f, Enotg, file, p1);
}
# if rename,
# must have write permission in parent
while(d.name != dir.name){
# drop entry to prevent deadlock, then
# check that destination name is valid and unique
d.put();
if(checkname9p2(dir.name) == 0 || d1 == nil)
return ferr(f, Ename, file, p1);
if(dir.name == "." || dir.name == "..")
return ferr(f, Edot, file, p1);
for(addr := 0; ; addr++){
if((p := d1.getblk(addr, 0)) == nil)
break;
if(p.checktag(Tdir, int d1.qid.path)){
p.put();
continue;
}
for(slot := 0; slot < DIRPERBUF; slot++){
d = Dentry.get(p, slot);
if(!(d.mode & DALLOC))
continue;
if(dir.name == d.name){
p.put();
return ferr(f, Eexist, file, p1);
}
}
p.put();
}
# reacquire entry
(d, nil) = Dentry.getd(file, Bread);
if(d == nil)
return ferr(f, Ephase, file, p1);
if(wstatallow || writeallow) # set to allow rename during boot
break;
if(d1 == nil || file.access(d1, DWRITE)){
d.put();
return ferr(f, Eaccess, file, p1);
}
break;
}
# if mode/time, either
# a) owner
# b) leader of either group
mode = dir.mode & 8r777;
if(dir.mode & DMAPPEND)
mode |= DAPND;
if(dir.mode & DMEXCL)
mode |= DLOCK;
while(d.mtime != dir.mtime || ((d.mode^mode) & (DAPND|DLOCK|8r777))){
if(wstatallow) # set to allow chmod during boot
break;
if(d.uid == file.uid)
break;
if(leadgroup(file.uid, gid))
break;
if(leadgroup(file.uid, d.gid))
break;
d.put();
return ferr(f, Enotu, file, p1);
}
d.mtime = dir.mtime;
d.uid = uid;
d.gid = gid;
d.mode = (mode & (DAPND|DLOCK|8r777)) | (d.mode & (DALLOC|DDIR));
d.name = dir.name;
d.access(FWSTAT, file.uid);
d.change(~0);
d.put();
if(p1 != nil)
p1.put();
file.unlock();
return ref Rmsg.Wstat(f.tag);
}
superok(set: int): int
{
sb := Superb.get(thedevice, Bread|Bmod|Bimm);
ok := sb.fsok;
sb.fsok = set;
if(debug)
sb.print();
sb.touched();
sb.put();
return ok;
}
# little-endian
get2(a: array of byte, o: int): int
{
return (int a[o+1]<<8) | int a[o];
}
get2s(a: array of byte, o: int): int
{
v := (int a[o+1]<<8) | int a[o];
if(v & 16r8000)
v |= ~0 << 8;
return v;
}
get4(a: array of byte, o: int): int
{
return (int a[o+3]<<24) | (int a[o+2] << 16) | (int a[o+1]<<8) | int a[o];
}
put2(a: array of byte, o: int, v: int)
{
a[o] = byte v;
a[o+1] = byte (v>>8);
}
put4(a: array of byte, o: int, v: int)
{
a[o] = byte v;
a[o+1] = byte (v>>8);
a[o+2] = byte (v>>16);
a[o+3] = byte (v>>24);
}
Tag.unpack(a: array of byte): Tag
{
return Tag(get2(a,2), get4(a,4));
}
Tag.pack(t: self Tag, a: array of byte)
{
put2(a, 0, 0);
put2(a, 2, t.tag);
if(t.path != QPNONE)
put4(a, 4, t.path & ~QPDIR);
}
Superb.get(dev: ref Device, flags: int): ref Superb
{
p := Iobuf.get(dev, SUPERADDR, flags);
if(p == nil)
return nil;
if(p.checktag(Tsuper, QPSUPER)){
p.put();
return nil;
}
sb := Superb.unpack(p.iobuf);
sb.iob = p;
return sb;
}
Superb.touched(s: self ref Superb)
{
s.iob.flags |= Bmod;
}
Superb.put(sb: self ref Superb)
{
if(sb.iob == nil)
return;
if(sb.iob.flags & Bmod)
sb.pack(sb.iob.iobuf);
sb.iob.put();
sb.iob = nil;
}
# this is the disk structure
# Superb:
# Super1;
# Fbuf fbuf;
# Fbuf:
# nfree[4]
# free[] # based on BUFSIZE
# Super1:
# long fstart;
# long fsize;
# long tfree;
# long qidgen; # generator for unique ids
# long fsok; # file system ok
# long roraddr; # dump root addr
# long last; # last super block addr
# long next; # next super block addr
Ofstart: con 0;
Ofsize: con Ofstart+4;
Otfree: con Ofsize+4;
Oqidgen: con Otfree+4;
Ofsok: con Oqidgen+4;
Ororaddr: con Ofsok+4;
Olast: con Ororaddr+4;
Onext: con Olast+4;
Super1size: con Onext+4;
Superb.unpack(a: array of byte): ref Superb
{
s := ref Superb;
s.fstart = get4(a, Ofstart);
s.fsize = get4(a, Ofsize);
s.tfree = get4(a, Otfree);
s.qidgen = get4(a, Oqidgen);
s.fsok = get4(a, Ofsok);
s.fbuf = a[Super1size:];
return s;
}
Superb.pack(s: self ref Superb, a: array of byte)
{
put4(a, Ofstart, s.fstart);
put4(a, Ofsize, s.fsize);
put4(a, Otfree, s.tfree);
put4(a, Oqidgen, s.qidgen);
put4(a, Ofsok, s.fsok);
}
Superb.print(sb: self ref Superb)
{
sys->print("fstart=%ud fsize=%ud tfree=%ud qidgen=%ud fsok=%d\n",
sb.fstart, sb.fsize, sb.tfree, sb.qidgen, sb.fsok);
}
Dentry.get(p: ref Iobuf, slot: int): ref Dentry
{
if(p == nil)
return nil;
buf := p.iobuf[(slot%DIRPERBUF)*Dentrysize:];
d := Dentry.unpack(buf);
d.iob = p;
d.buf = buf;
return d;
}
Dentry.geta(fs: ref Device, addr: int, slot: int, qpath: int, mode: int): (ref Dentry, string)
{
p := Iobuf.get(fs, addr, mode);
if(p == nil || p.checktag(Tdir, qpath)){
if(p != nil)
p.put();
return (nil, Ealloc);
}
d := Dentry.get(p, slot);
if(d == nil || !(d.mode & DALLOC)){
p.put();
return (nil, Ealloc);
}
return (d, nil);
}
Dentry.getd(file: ref File, mode: int): (ref Dentry, string)
{
(d, e) := Dentry.geta(file.fs, file.addr, file.slot, QPNONE, mode); # QPNONE should be file.wpath's path
if(e != nil)
return (nil, e);
if(file.qid.path != d.qid.path || (file.qid.qtype&QTDIR) != (d.qid.qtype&QTDIR)){
d.put();
return (nil, Eqid);
}
return (d, nil);
}
# this is the disk structure:
# char name[NAMELEN];
# short uid;
# short gid; [2*2]
# ushort mode;
# #define DALLOC 0x8000
# #define DDIR 0x4000
# #define DAPND 0x2000
# #define DLOCK 0x1000
# #define DREAD 0x4
# #define DWRITE 0x2
# #define DEXEC 0x1
# [ushort muid] [2*2]
# Qid.path; [4]
# Qid.version; [4]
# long size; [4]
# long dblock[NDBLOCK];
# long iblock;
# long diblock;
# long atime;
# long mtime;
Oname: con 0;
Ouid: con Oname+NAMELEN;
Ogid: con Ouid+2;
Omode: con Ogid+2;
Omuid: con Omode+2;
Opath: con Omuid+2;
Overs: con Opath+4;
Osize: con Overs+4;
Odblock: con Osize+4;
Oiblock: con Odblock+NDBLOCK*4;
Odiblock: con Oiblock+4;
Oatime: con Odiblock+4;
Omtime: con Oatime+4;
Dentrysize: con Omtime+4;
Dentry.unpack(a: array of byte): ref Dentry
{
d := ref Dentry;
for(i:=0; i<NAMELEN; i++)
if(int a[i] == 0)
break;
d.name = string a[0:i];
d.uid = get2s(a, Ouid);
d.gid = get2s(a, Ogid);
d.mode = get2(a, Omode);
d.muid = get2(a, Omuid); # note: not set by Plan 9's kfs
d.qid = mkqid(get4(a, Opath), get4(a, Overs), d.mode);
d.size = big get4(a, Osize) & big 16rFFFFFFFF;
d.atime = get4(a, Oatime);
d.mtime = get4(a, Omtime);
d.mod = 0;
return d;
}
Dentry.change(d: self ref Dentry, f: int)
{
d.mod |= f;
}
Dentry.update(d: self ref Dentry)
{
f := d.mod;
d.mod = 0;
if(d.iob == nil || (d.iob.flags & Bmod) == 0){
if(f != 0)
panic("Dentry.update");
return;
}
a := d.buf;
if(f & Uname){
b := array of byte d.name;
for(i := 0; i < NAMELEN; i++)
if(i < len b)
a[i] = b[i];
else
a[i] = byte 0;
}
if(f & Uids){
put2(a, Ouid, d.uid);
put2(a, Ogid, d.gid);
}
if(f & Umode)
put2(a, Omode, d.mode);
if(f & Uqid){
path := int d.qid.path;
if(d.mode & DDIR)
path |= QPDIR;
put4(a, Opath, path);
put4(a, Overs, d.qid.vers);
}
if(f & Usize)
put4(a, Osize, int d.size);
if(f & Utime){
put4(a, Omtime, d.mtime);
put4(a, Oatime, d.atime);
}
d.iob.flags |= Bmod;
}
Dentry.access(d: self ref Dentry, f: int, uid: int)
{
if((p := d.iob) != nil && !readonly){
if((f & (FWRITE|FWSTAT)) == 0 && noatime)
return;
if(f & (FREAD|FWRITE|FWSTAT)){
d.atime = now();
put4(d.buf, Oatime, d.atime);
p.flags |= Bmod;
}
if(f & FWRITE){
d.mtime = now();
put4(d.buf, Omtime, d.mtime);
d.muid = uid;
put2(d.buf, Omuid, uid);
d.qid.vers++;
put4(d.buf, Overs, d.qid.vers);
p.flags |= Bmod;
}
}
}
#
# release the directory entry buffer and thus the
# lock on both buffer and entry, typically during i/o,
# to be reacquired later if needed
#
Dentry.release(d: self ref Dentry)
{
if(d.iob != nil){
d.update();
d.iob.put();
d.iob = nil;
d.buf = nil;
}
}
Dentry.getblk(d: self ref Dentry, a: int, tag: int): ref Iobuf
{
addr := d.rel2abs(a, tag, 0);
if(addr == 0)
return nil;
return Iobuf.get(thedevice, addr, Bread);
}
#
# same as Dentry.buf but calls d.release
# to reduce interference.
#
Dentry.getblk1(d: self ref Dentry, a: int, tag: int): ref Iobuf
{
addr := d.rel2abs(a, tag, 1);
if(addr == 0)
return nil;
return Iobuf.get(thedevice, addr, Bread);
}
Dentry.rel2abs(d: self ref Dentry, a: int, tag: int, putb: int): int
{
if(a < 0){
sys->print("Dentry.rel2abs: neg\n");
return 0;
}
p := d.iob;
if(p == nil || d.buf == nil)
panic("nil iob");
data := d.buf;
qpath := int d.qid.path;
dev := p.dev;
if(a < NDBLOCK){
addr := get4(data, Odblock+a*4);
if(addr == 0 && tag){
addr = balloc(dev, tag, qpath);
put4(data, Odblock+a*4, addr);
p.flags |= Bmod|Bimm;
}
if(putb)
d.release();
return addr;
}
a -= NDBLOCK;
if(a < INDPERBUF){
addr := get4(data, Oiblock);
if(addr == 0 && tag){
addr = balloc(dev, Tind1, qpath);
put4(data, Oiblock, addr);
p.flags |= Bmod|Bimm;
}
if(putb)
d.release();
return indfetch(dev, qpath, addr, a, Tind1, tag);
}
a -= INDPERBUF;
if(a < INDPERBUF2){
addr := get4(data, Odiblock);
if(addr == 0 && tag){
addr = balloc(dev, Tind2, qpath);
put4(data, Odiblock, addr);
p.flags |= Bmod|Bimm;
}
if(putb)
d.release();
addr = indfetch(dev, qpath, addr, a/INDPERBUF, Tind2, Tind1);
return indfetch(dev, qpath, addr, a%INDPERBUF, Tind1, tag);
}
if(putb)
d.release();
sys->print("Dentry.buf: trip indirect\n");
return 0;
}
indfetch(dev: ref Device, path: int, addr: int, a: int, itag: int, tag: int): int
{
if(addr == 0)
return 0;
bp := Iobuf.get(dev, addr, Bread);
if(bp == nil){
sys->print("ind fetch bp = nil\n");
return 0;
}
if(bp.checktag(itag, path)){
sys->print("ind fetch tag\n");
bp.put();
return 0;
}
addr = get4(bp.iobuf, a*4);
if(addr == 0 && tag){
addr = balloc(dev, tag, path);
if(addr != 0){
put4(bp.iobuf, a*4, addr);
bp.flags |= Bmod;
if(localfs || tag == Tdir)
bp.flags |= Bimm;
bp.settag(itag, path);
}
}
bp.put();
return addr;
}
balloc(dev: ref Device, tag: int, qpath: int): int
{
# TO DO: cache superblock to reduce pack/unpack
sb := Superb.get(dev, Bread|Bmod);
if(sb == nil)
panic("balloc: super block");
n := get4(sb.fbuf, 0);
n--;
sb.tfree--;
if(n < 0 || n >= FEPERBUF)
panic("balloc: bad freelist");
a := get4(sb.fbuf, 4+n*4);
if(n == 0){
if(a == 0){
sb.tfree = 0;
sb.touched();
sb.put();
return 0;
}
bp := Iobuf.get(dev, a, Bread);
if(bp == nil || bp.checktag(Tfree, QPNONE)){
if(bp != nil)
bp.put();
sb.put();
return 0;
}
sb.fbuf[0:] = bp.iobuf[0:(FEPERBUF+1)*4];
sb.touched();
bp.put();
}else{
put4(sb.fbuf, 0, n);
sb.touched();
}
bp := Iobuf.get(dev, a, Bmod);
bp.iobuf[0:] = emptyblock;
bp.settag(tag, qpath);
if(tag == Tind1 || tag == Tind2 || tag == Tdir)
bp.flags |= Bimm;
bp.put();
sb.put();
return a;
}
bfree(dev: ref Device, addr: int, d: int)
{
if(addr == 0)
return;
if(d > 0){
d--;
p := Iobuf.get(dev, addr, Bread);
if(p != nil){
for(i:=INDPERBUF-1; i>=0; i--){
a := get4(p.iobuf, i*4);
bfree(dev, a, d);
}
p.put();
}
}
# stop outstanding i/o
p := Iobuf.get(dev, addr, Bprobe);
if(p != nil){
p.flags &= ~(Bmod|Bimm);
p.put();
}
s := Superb.get(dev, Bread|Bmod);
if(s == nil)
panic("bfree: super block");
addfree(dev, addr, s);
s.put();
}
addfree(dev: ref Device, addr: int, sb: ref Superb)
{
if(addr >= sb.fsize){
sys->print("addfree: bad addr %ud\n", addr);
return;
}
n := get4(sb.fbuf, 0);
if(n < 0 || n > FEPERBUF)
panic("addfree: bad freelist");
if(n >= FEPERBUF){
p := Iobuf.get(dev, addr, Bmod);
if(p == nil)
panic("addfree: Iobuf.get");
p.iobuf[0:] = sb.fbuf[0:(1+FEPERBUF)*4];
sb.fbuf[0:] = emptyblock[0:(1+FEPERBUF)*4]; # clear it for debugging
p.settag(Tfree, QPNONE);
p.put();
n = 0;
}
put4(sb.fbuf, 4+n*4, addr);
put4(sb.fbuf, 0, n+1);
sb.tfree++;
if(addr >= sb.fsize)
sb.fsize = addr+1;
sb.touched();
}
qidpathgen(dev: ref Device): int
{
sb := Superb.get(dev, Bread|Bmod);
if(sb == nil)
panic("qidpathgen: super block");
sb.qidgen++;
path := sb.qidgen;
sb.touched();
sb.put();
return path;
}
Dentry.trunc(d: self ref Dentry, uid: int)
{
p := d.iob;
data := d.buf;
bfree(p.dev, get4(data, Odiblock), 2);
put4(data, Odiblock, 0);
bfree(p.dev, get4(data, Oiblock), 1);
put4(data, Oiblock, 0);
for(i:=NDBLOCK-1; i>=0; i--){
bfree(p.dev, get4(data, Odblock+i*4), 0);
put4(data, Odblock+i*4, 0);
}
d.size = big 0;
d.change(Usize);
p.flags |= Bmod|Bimm;
d.access(FWRITE, uid);
d.update();
}
Dentry.put(d: self ref Dentry)
{
p := d.iob;
if(p == nil || d.buf == nil)
return;
d.update();
p.put();
d.iob = nil;
d.buf = nil;
}
Dentry.print(d: self ref Dentry)
{
sys->print("name=%#q uid=%d gid=%d mode=#%8.8ux qid.path=#%bux qid.vers=%ud size=%bud\n",
d.name, d.uid, d.gid, d.mode, d.qid.path, d.qid.vers, d.size);
p := d.iob;
if(p != nil && (data := p.iobuf) != nil){
sys->print("\tdblock=");
for(i := 0; i < NDBLOCK; i++)
sys->print(" %d", get4(data, Odblock+i*4));
sys->print(" iblock=%ud diblock=%ud\n", get4(data, Oiblock), get4(data, Odiblock));
}
}
HWidth: con 5; # buffers per line
hiob: array of ref Hiob;
iobufinit(niob: int)
{
nhiob := niob/HWidth;
while(!prime(nhiob))
nhiob++;
hiob = array[nhiob] of {* => ref Hiob(nil, Lock.new(), 0)};
# allocate the buffers now
for(i := 0; i < len hiob; i++){
h := hiob[i];
while(h.niob < HWidth)
h.newbuf();
}
}
iobufclear()
{
# eliminate the cyclic references
for(i := 0; i < len hiob; i++){
h := hiob[i];
while(--h.niob >= 0){
p := hiob[i].link;
hiob[i].link = p.fore;
p.fore = p.back = nil;
p = nil;
}
}
}
prime(n: int): int
{
if((n%2) == 0)
return 0;
for(i:=3;; i+=2) {
if((n%i) == 0)
return 0;
if(i*i >= n)
return 1;
}
}
Hiob.newbuf(hb: self ref Hiob): ref Iobuf
{
# hb must be locked
p := ref Iobuf;
p.qlock = chan[1] of int;
q := hb.link;
if(q != nil){
p.fore = q;
p.back = q.back;
q.back = p;
p.back.fore = p;
}else{
hb.link = p;
p.fore = p;
p.back = p;
}
p.dev = devnone;
p.addr = -1;
p.flags = 0;
p.xiobuf = array[RBUFSIZE] of byte;
hb.niob++;
return p;
}
Iobuf.get(dev: ref Device, addr: int, flags: int): ref Iobuf
{
hb := hiob[addr%len hiob];
p: ref Iobuf;
Search:
for(;;){
hb.lk.lock();
s := hb.link;
# see if it's active
p = s;
do{
if(p.addr == addr && p.dev == dev){
if(p != s){
p.back.fore = p.fore;
p.fore.back = p.back;
p.fore = s;
p.back = s.back;
s.back = p;
p.back.fore = p;
hb.link = p;
}
hb.lk.unlock();
p.lock();
if(p.addr != addr || p.dev != dev){
# lost race
p.unlock();
continue Search;
}
p.flags |= flags;
p.iobuf = p.xiobuf;
return p;
}
}while((p = p.fore) != s);
if(flags == Bprobe){
hb.lk.unlock();
return nil;
}
# steal the oldest unlocked buffer
do{
p = s.back;
if(p.canlock()){
# TO DO: if Bmod, write it out and restart Hashed
# for now we needn't because Iobuf.put is synchronous
if(p.flags & Bmod)
sys->print("Bmod unexpected (%ud)\n", p.addr);
hb.link = p;
p.dev = dev;
p.addr = addr;
p.flags = flags;
break Search;
}
s = p;
}while(p != hb.link);
# no unlocked blocks available; add a new one
p = hb.newbuf();
p.lock(); # return it locked
break;
}
p.dev = dev;
p.addr = addr;
p.flags = flags;
hb.lk.unlock();
p.iobuf = p.xiobuf;
if(flags & Bread){
if(wrenread(dev.fd, addr, p.iobuf)){
eprint(sys->sprint("error reading block %ud: %r", addr));
p.flags = 0;
p.dev = devnone;
p.addr = -1;
p.iobuf = nil;
p.unlock();
return nil;
}
}
return p;
}
Iobuf.put(p: self ref Iobuf)
{
if(p.flags & Bmod)
p.flags |= Bimm; # temporary; see comment in Iobuf.get
if(p.flags & Bimm){
if(!(p.flags & Bmod))
eprint(sys->sprint("imm and no mod (%d)", p.addr));
if(!wrenwrite(p.dev.fd, p.addr, p.iobuf))
p.flags &= ~(Bmod|Bimm);
else
panic(sys->sprint("error writing block %ud: %r", p.addr));
}
p.iobuf = nil;
p.unlock();
}
Iobuf.lock(p: self ref Iobuf)
{
p.qlock <-= 1;
}
Iobuf.canlock(p: self ref Iobuf): int
{
alt{
p.qlock <-= 1 =>
return 1;
* =>
return 0;
}
}
Iobuf.unlock(p: self ref Iobuf)
{
<-p.qlock;
}
File.access(f: self ref File, d: ref Dentry, m: int): int
{
if(wstatallow)
return 0;
# none gets only other permissions
if(f.uid != None){
if(f.uid == d.uid) # owner
if((m<<6) & d.mode)
return 0;
if(ingroup(f.uid, d.gid)) # group membership
if((m<<3) & d.mode)
return 0;
}
#
# other access for everyone except members of group "noworld"
#
if(m & d.mode){
#
# walk directories regardless.
# otherwise it's impossible to get
# from the root to noworld's directories.
#
if((d.mode & DDIR) && (m == DEXEC))
return 0;
if(!ingroup(f.uid, Noworld))
return 0;
}
return 1;
}
tagname(t: int): string
{
case t {
Tnone => return "Tnone";
Tsuper => return "Tsuper";
Tdir => return "Tdir";
Tind1 => return "Tind1";
Tind2 => return "Tind2";
Tfile => return "Tfile";
Tfree => return "Tfree";
Tbuck => return "Tbuck";
Tvirgo => return "Tvirgo";
Tcache => return "Tcache";
* => return sys->sprint("%d", t);
}
}
Iobuf.checktag(p: self ref Iobuf, tag: int, qpath: int): int
{
t := Tag.unpack(p.iobuf[BUFSIZE:]);
if(t.tag != tag){
if(1)
eprint(sys->sprint(" tag = %s; expected %s; addr = %ud\n",
tagname(t.tag), tagname(tag), p.addr));
return 2;
}
if(qpath != QPNONE){
qpath &= ~QPDIR;
if(qpath != t.path){
if(qpath == (t.path&~QPDIR)) # old bug
return 0;
if(1)
eprint(sys->sprint(" tag/path = %ux; expected %s/%ux\n",
t.path, tagname(tag), qpath));
return 1;
}
}
return 0;
}
Iobuf.settag(p: self ref Iobuf, tag: int, qpath: int)
{
Tag(tag, qpath).pack(p.iobuf[BUFSIZE:]);
p.flags |= Bmod;
}
badmagic := 0;
wmagic := "kfs wren device\n";
wrenream(dev: ref Device)
{
if(RBUFSIZE % 512)
panic(sys->sprint("kfs: bad buffersize(%d): restart a multiple of 512", RBUFSIZE));
if(RBUFSIZE > MAXBUFSIZE)
panic(sys->sprint("kfs: bad buffersize(%d): must be at most %d", RBUFSIZE, MAXBUFSIZE));
sys->print("kfs: reaming the file system using %d byte blocks\n", RBUFSIZE);
buf := array[RBUFSIZE] of {* => byte 0};
buf[256:] = sys->aprint("%s%d\n", wmagic, RBUFSIZE);
if(sys->seek(dev.fd, big 0, 0) < big 0 || sys->write(dev.fd, buf, len buf) != len buf)
panic("can't ream disk");
}
wreninit(dev: ref Device): int
{
(ok, nil) := sys->fstat(dev.fd);
if(ok < 0)
return 0;
buf := array[MAXBUFSIZE] of byte;
sys->seek(dev.fd, big 0, 0);
n := sys->read(dev.fd, buf, len buf);
if(n < len buf)
return 0;
badmagic = 0;
RBUFSIZE = 1024;
if(string buf[256:256+len wmagic] != wmagic){
badmagic = 1;
return 0;
}
RBUFSIZE = int string buf[256+len wmagic:256+len wmagic+12];
if(RBUFSIZE % 512)
error("bad block size");
return 1;
}
wrenread(fd: ref Sys->FD, addr: int, a: array of byte): int
{
return sys->pread(fd, a, len a, big addr * big RBUFSIZE) != len a;
}
wrenwrite(fd: ref Sys->FD, addr: int, a: array of byte): int
{
return sys->pwrite(fd, a, len a, big addr * big RBUFSIZE) != len a;
}
wrentag(buf: array of byte, tag: int, qpath: int): int
{
t := Tag.unpack(buf[BUFSIZE:]);
return t.tag != tag || (qpath&~QPDIR) != t.path;
}
wrencheck(fd: ref Sys->FD): int
{
if(badmagic)
return 1;
buf := array[RBUFSIZE] of byte;
if(wrenread(fd, SUPERADDR, buf) || wrentag(buf, Tsuper, QPSUPER) ||
wrenread(fd, ROOTADDR, buf) || wrentag(buf, Tdir, QPROOT))
return 1;
d0 := Dentry.unpack(buf);
if(d0.mode & DALLOC)
return 0;
return 1;
}
wrensize(dev: ref Device): int
{
(ok, d) := sys->fstat(dev.fd);
if(ok < 0)
return -1;
return int (d.length / big RBUFSIZE);
}
checkname9p2(s: string): int
{
for(i := 0; i < len s; i++)
if(s[i] <= 8r40)
return 0;
return styx->utflen(s);
}
isro(d: ref Device): int
{
return d == nil || d.ronly;
}
tlocks: list of ref Tlock;
tlocked(f: ref File, d: ref Dentry): ref Tlock
{
tim := now();
path := int d.qid.path;
t1: ref Tlock;
for(l := tlocks; l != nil; l = tl l){
t := hd l;
if(t.qpath == path && t.time >= tim && t.dev == f.fs)
return nil; # it's locked
if(t.file == nil || t1 == nil && t.time < tim)
t1 = t;
}
t := t1;
if(t == nil)
t = ref Tlock;
t.dev = f.fs;
t.qpath = path;
t.time = tim + TLOCK;
tlocks = t :: tlocks;
return t;
}
mkqid(path: int, vers: int, mode: int): Qid
{
qid: Qid;
qid.path = big (path & ~QPDIR);
qid.vers = vers;
qid.qtype = 0;
if(mode & DDIR)
qid.qtype |= QTDIR;
if(mode & DAPND)
qid.qtype |= QTAPPEND;
if(mode & DLOCK)
qid.qtype |= QTEXCL;
return qid;
}
dir9p2(d: ref Dentry): Sys->Dir
{
dir: Sys->Dir;
dir.name = d.name;
dir.uid = uidtostr(d.uid);
dir.gid = uidtostr(d.gid);
dir.muid = uidtostr(d.muid);
dir.qid = d.qid;
dir.mode = d.mode & 8r777;
if(d.mode & DDIR)
dir.mode |= DMDIR;
if(d.mode & DAPND)
dir.mode |= DMAPPEND;
if(d.mode & DLOCK)
dir.mode |= DMEXCL;
dir.atime = d.atime;
dir.mtime = d.mtime;
dir.length = big d.size;
dir.dtype = 0;
dir.dev = 0;
return dir;
}
rootream(dev: ref Device, addr: int)
{
p := Iobuf.get(dev, addr, Bmod|Bimm);
p.iobuf[0:] = emptyblock;
p.settag(Tdir, QPROOT);
d := Dentry.get(p, 0);
d.name = "/";
d.uid = -1;
d.gid = -1;
d.mode = DALLOC | DDIR |
((DREAD|DWRITE|DEXEC) << 6) |
((DREAD|DWRITE|DEXEC) << 3) |
((DREAD|DWRITE|DEXEC) << 0);
d.qid.path = big QPROOT;
d.qid.vers = 0;
d.qid.qtype = QTDIR;
d.atime = now();
d.mtime = d.atime;
d.change(~0);
d.access(FREAD|FWRITE, -1);
d.update();
p.put();
}
superream(dev: ref Device, addr: int)
{
fsize := wrensize(dev);
if(fsize <= 0)
panic("file system device size");
p := Iobuf.get(dev, addr, Bmod|Bimm);
p.iobuf[0:] = emptyblock;
p.settag(Tsuper, QPSUPER);
sb := ref Superb;
sb.iob = p;
sb.fstart = 1;
sb.fsize = fsize;
sb.qidgen = 10;
sb.tfree = 0;
sb.fsok = 0;
sb.fbuf = p.iobuf[Super1size:];
put4(sb.fbuf, 0, 1); # nfree = 1
for(i := fsize-1; i>=addr+2; i--)
addfree(dev, i, sb);
sb.put();
}
eprint(s: string)
{
sys->print("kfs: %s\n", s);
}
#
# /adm/users
#
# uid:user:leader:members[,...]
User: adt {
uid: int;
name: string;
leader: int;
mem: list of int;
};
users: list of ref User;
admusers := array[] of {
(-1, "adm", "adm"),
(None, "none", "adm"),
(Noworld, "noworld", nil),
(10000, "sys", nil),
(10001, "upas", "upas"),
(10002, "bootes", "bootes"),
(10006, "inferno", nil),
};
userinit()
{
if(!cmd_users() && users == nil){
cprint("initializing minimal user table");
defaultusers();
}
writegroup = strtouid("write");
}
cmd_users(): int
{
if(kopen(FID1, FID2, array[] of {"adm", "users"}, OREAD) != nil)
return 0;
buf: array of byte;
for(off := 0;;){
(a, e) := kread(FID2, off, Styx->MAXFDATA);
if(e != nil){
cprint("/adm/users read error: "+e);
return 0;
}
if(len a == 0)
break;
off += len a;
if(buf != nil){
c := array[len buf + len a] of byte;
if(buf != nil)
c[0:] = buf;
c[len buf:] = a;
buf = c;
}else
buf = a;
}
kclose(FID2);
# (uid:name:lead:mem,...\n)+
(nl, lines) := sys->tokenize(string buf, "\n");
if(nl == 0){
cprint("empty /adm/users");
return 0;
}
oldusers := users;
users = nil;
# first pass: enter id:name
for(l := lines; l != nil; l = tl l){
uid, name, r: string;
s := hd l;
if(s == "" || s[0] == '#')
continue;
(uid, r) = field(s, ':');
(name, r) = field(r, ':');
if(uid == nil || name == nil || string int uid != uid){
cprint("invalid /adm/users line: "+hd l);
users = oldusers;
return 0;
}
adduser(int uid, name, nil, nil);
}
# second pass: groups and leaders
for(l = lines; l != nil; l = tl l){
s := hd l;
if(s == "" || s[0] == '#')
continue;
name, lead, mem, r: string;
(nil, r) = field(s, ':'); # skip id
(name, r) = field(r, ':');
(lead, mem) = field(r, ':');
(nil, mems) := sys->tokenize(mem, ",\n");
if(name == nil || lead == nil && mems == nil)
continue;
u := finduname(name);
if(lead != nil){
lu := strtouid(lead);
if(lu != None)
u.leader = lu;
else if(lead != nil)
u.leader = u.uid; # mimic kfs not fs
}
mids: list of int = nil;
for(; mems != nil; mems = tl mems){
lu := strtouid(hd mems);
if(lu != None)
mids = lu :: mids;
}
u.mem = mids;
}
if(debug)
for(x := users; x != nil; x = tl x){
u := hd x;
sys->print("%d : %q : %d :", u.uid, u.name, u.leader);
for(y := u.mem; y != nil; y = tl y)
sys->print(" %d", hd y);
sys->print("\n");
}
return 1;
}
field(s: string, c: int): (string, string)
{
for(i := 0; i < len s; i++)
if(s[i] == c)
return (s[0:i], s[i+1:]);
return (s, nil);
}
defaultusers()
{
for(i := 0; i < len admusers; i++){
(id, name, leader) := admusers[i];
adduser(id, name, leader, nil);
}
}
finduname(s: string): ref User
{
for(l := users; l != nil; l = tl l){
u := hd l;
if(u.name == s)
return u;
}
return nil;
}
uidtostr(id: int): string
{
if(id == None)
return "none";
for(l := users; l != nil; l = tl l){
u := hd l;
if(u.uid == id)
return u.name;
}
return sys->sprint("#%d", id);
}
leadgroup(ui: int, gi: int): int
{
for(l := users; l != nil; l = tl l){
u := hd l;
if(u.uid == gi){
if(u.leader == ui)
return 1;
if(u.leader == 0)
return ingroup(ui, gi);
return 0;
}
}
return 0;
}
strtouid(s: string): int
{
if(s == "none")
return None;
u := finduname(s);
if(u != nil)
return u.uid;
return 0;
}
ingroup(uid: int, gid: int): int
{
if(uid == gid)
return 1;
for(l := users; l != nil; l = tl l){
u := hd l;
if(u.uid == gid){
for(m := u.mem; m != nil; m = tl m)
if(hd m == uid)
return 1;
return 0;
}
}
return 0;
}
baduname(s: string): int
{
n := checkname9p2(s);
if(n == 0 || n+1 > NAMELEN || s == "." || s == ".."){
sys->print("kfs: illegal user name %q\n", s);
return 1;
}
return 0;
}
adduser(id: int, name: string, leader: string, mem: list of string)
{
if(baduname(name))
return;
for(l := users; l != nil; l = tl l){
u := hd l;
if(u.uid == id){
sys->print("kfs: duplicate user ID %d (name %q)\n", id, u.name);
return;
}else if(u.name == name){
sys->print("kfs: duplicate user name %q (id %d)\n", name, u.uid);
return;
}
}
if(name == leader)
lid := id;
else if(leader == nil)
lid = 0;
else if(!baduname(leader))
lid = strtouid(leader);
else
return;
memid: list of int;
for(; mem != nil; mem = tl mem){
if(baduname(hd mem))
return;
x := strtouid(hd mem);
if(x != 0)
memid = x :: memid;
}
u := ref User(id, name, lid, memid);
users = u :: users;
}
Lock.new(): ref Lock
{
return ref Lock(chan[1] of int);
}
Lock.lock(l: self ref Lock)
{
l.c <-= 1;
}
Lock.canlock(l: self ref Lock): int
{
alt{
l.c <-= 1 =>
return 1;
* =>
return 0;
}
}
Lock.unlock(l: self ref Lock)
{
<-l.c;
}
#
# kfs check, could be a separate module if that seemed important
#
MAXDEPTH: con 100;
MAXNAME: con 4000;
Map: adt {
lo, hi: int;
bits: array of byte;
nbad: int;
ndup: int;
nmark: int;
new: fn(lo, hi: int): ref Map;
isset: fn(b: self ref Map, a: int): int;
mark: fn(b: self ref Map, a: int): string;
};
Check: adt {
dev: ref Device;
amap: ref Map;
qmap: ref Map;
name: string;
nfiles: int;
maxq: int;
mod: int;
flags: int;
oldblock: int;
depth: int;
maxdepth: int;
check: fn(c: self ref Check);
touch: fn(c: self ref Check, a: int): int;
checkdir: fn(c: self ref Check, a: int, qpath: int): int;
checkindir: fn(c: self ref Check, a: int, d: ref Dentry, qpath: int): int;
maked: fn(c: self ref Check, a: int, s: int, qpath: int): ref Dentry;
modd: fn(c: self ref Check, a: int, s: int, d: ref Dentry);
fsck: fn(c: self ref Check, d: ref Dentry): int;
xread: fn(c: self ref Check, a: int, qpath: int);
xtag: fn(c: self ref Check, a: int, tag: int, qpath: int): ref Iobuf;
ckfreelist: fn(c: self ref Check, sb: ref Superb);
mkfreelist: fn(c: self ref Check, sb: ref Superb);
amark: fn(c: self ref Check, a: int): int;
fmark: fn(c: self ref Check, a: int): int;
missing: fn(c: self ref Check, sb: ref Superb);
qmark: fn(c: self ref Check, q: int);
};
check(dev: ref Device, flag: int)
{
#mainlock.wlock();
#mainlock.wunlock();
c := ref Check;
c.dev = dev;
c.nfiles = 0;
c.maxq = 0;
c.mod = 0;
c.flags = flag;
c.oldblock = 0;
c.depth = 0;
c.maxdepth = 0;
c.check();
}
checkflags(s: string): int
{
f := 0;
for(i := 0; i < len s; i++)
case s[i] {
'r' => f |= Crdall;
't' => f |= Ctag;
'P' => f |= Cpfile;
'p' => f |= Cpdir;
'f' => f |= Cfree;
'c' => f |= Cream;
'd' => f |= Cbad;
'w' => f |= Ctouch;
'q' => f |= Cquiet;
'v' => ; # old verbose flag; ignored
* => return -1;
}
return f;
}
Check.check(c: self ref Check)
{
sbaddr := SUPERADDR;
p := c.xtag(sbaddr, Tsuper, QPSUPER);
if(p == nil){
cprint(sys->sprint("bad superblock"));
return;
}
sb := Superb.unpack(p.iobuf);
sb.iob = p;
fstart := sb.fstart;
if(fstart != 1){
cprint(sys->sprint("invalid superblock"));
return;
}
fsize := sb.fsize;
if(fsize < fstart || fsize > wrensize(c.dev)){
cprint(sys->sprint("invalid size in superblock"));
return;
}
c.amap = Map.new(fstart, fsize);
nqid := sb.qidgen+100; # not as much of a botch
if(nqid > 1024*1024*8)
nqid = 1024*1024*8;
if(nqid < 64*1024)
nqid = 64*1024;
c.qmap = Map.new(0, nqid);
c.mod = 0;
c.depth = 0;
c.maxdepth = 0;
if(c.amark(sbaddr))
{}
if(!(c.flags & Cquiet))
cprint(sys->sprint("checking file system: %s", "main"));
c.nfiles = 0;
c.maxq = 0;
d := c.maked(ROOTADDR, 0, QPROOT);
if(d != nil){
if(c.amark(ROOTADDR))
{}
if(c.fsck(d))
c.modd(ROOTADDR, 0, d);
if(--c.depth != 0)
cprint("depth not zero on return");
}
if(sb.qidgen < c.maxq)
cprint(sys->sprint("qid generator low path=%d maxq=%d", sb.qidgen, c.maxq));
nqbad := c.qmap.nbad + c.qmap.ndup;
c.qmap = nil; # could use to implement resequence
ndup := c.amap.ndup;
nused := c.amap.nmark;
c.amap.ndup = c.amap.nmark = 0; # reset for free list counts
if(c.flags & Cfree){
c.name = "free list";
c.mkfreelist(sb);
sb.qidgen = c.maxq;
p.settag(Tsuper, QPNONE);
}else
c.ckfreelist(sb);
nbad := c.amap.nbad;
nfdup := c.amap.ndup;
nfree := c.amap.nmark;
# leave amap for missing, below
if(c.mod){
cprint("file system was modified");
p.settag(Tsuper, QPNONE);
}
if(!(c.flags & Cquiet)){
cprint(sys->sprint("%8d files", c.nfiles));
cprint(sys->sprint("%8d blocks in the file system", fsize-fstart));
cprint(sys->sprint("%8d used blocks", nused));
cprint(sys->sprint("%8d free blocks", sb.tfree));
}
if(!(c.flags & Cfree)){
if(nfree != sb.tfree)
cprint(sys->sprint("%8d free blocks found", nfree));
if(nfdup)
cprint(sys->sprint("%8d blocks duplicated in the free list", nfdup));
if(fsize-fstart-nused-nfree)
cprint(sys->sprint("%8d missing blocks", fsize-fstart-nused-nfree));
}
if(ndup)
cprint(sys->sprint("%8d address duplications", ndup));
if(nbad)
cprint(sys->sprint("%8d bad block addresses", nbad));
if(nqbad)
cprint(sys->sprint("%8d bad qids", nqbad));
if(!(c.flags & Cquiet))
cprint(sys->sprint("%8d maximum qid path", c.maxq));
c.missing(sb);
sb.put();
}
Check.touch(c: self ref Check, a: int): int
{
if((c.flags&Ctouch) && a){
p := Iobuf.get(c.dev, a, Bread|Bmod);
if(p != nil)
p.put();
return 1;
}
return 0;
}
Check.checkdir(c: self ref Check, a: int, qpath: int): int
{
ns := len c.name;
dmod := c.touch(a);
for(i:=0; i<DIRPERBUF; i++){
nd := c.maked(a, i, qpath);
if(nd == nil)
break;
if(c.fsck(nd)){
c.modd(a, i, nd);
dmod++;
}
c.depth--;
c.name = c.name[0:ns];
}
c.name = c.name[0:ns];
return dmod;
}
Check.checkindir(c: self ref Check, a: int, d: ref Dentry, qpath: int): int
{
dmod := c.touch(a);
p := c.xtag(a, Tind1, qpath);
if(p == nil)
return dmod;
for(i:=0; i<INDPERBUF; i++){
a = get4(p.iobuf, i*4);
if(a == 0)
continue;
if(c.amark(a)){
if(c.flags & Cbad){
put4(p.iobuf, i*4, 0);
p.flags |= Bmod;
}
continue;
}
if(d.mode & DDIR)
dmod += c.checkdir(a, qpath);
else if(c.flags & Crdall)
c.xread(a, qpath);
}
p.put();
return dmod;
}
Check.fsck(c: self ref Check, d: ref Dentry): int
{
p: ref Iobuf;
i: int;
a, qpath: int;
if(++c.depth >= c.maxdepth){
c.maxdepth = c.depth;
if(c.maxdepth >= MAXDEPTH){
cprint(sys->sprint("max depth exceeded: %s", c.name));
return 0;
}
}
dmod := 0;
if(!(d.mode & DALLOC))
return 0;
c.nfiles++;
ns := len c.name;
i = styx->utflen(d.name);
if(i >= NAMELEN){
d.name[NAMELEN-1] = 0; # TO DO: not quite right
cprint(sys->sprint("%q.name (%q) not terminated", c.name, d.name));
return 0;
}
ns += i;
if(ns >= MAXNAME){
cprint(sys->sprint("%q.name (%q) name too large", c.name, d.name));
return 0;
}
c.name += d.name;
if(d.mode & DDIR){
if(ns > 1)
c.name += "/";
if(c.flags & Cpdir)
cprint(sys->sprint("%s", c.name));
} else if(c.flags & Cpfile)
cprint(sys->sprint("%s", c.name));
qpath = int d.qid.path & ~QPDIR;
c.qmark(qpath);
if(qpath > c.maxq)
c.maxq = qpath;
for(i=0; i<NDBLOCK; i++){
a = get4(d.buf, Odblock+i*4);
if(a == 0)
continue;
if(c.amark(a)){
put4(d.buf, Odblock+i*4, 0);
dmod++;
continue;
}
if(d.mode & DDIR)
dmod += c.checkdir(a, qpath);
else if(c.flags & Crdall)
c.xread(a, qpath);
}
a = get4(d.buf, Oiblock);
if(a){
if(c.amark(a)){
put4(d.buf, Oiblock, 0);
dmod++;
}
else
dmod += c.checkindir(a, d, qpath);
}
a = get4(d.buf, Odiblock);
if(a && c.amark(a)){
put4(d.buf, Odiblock, 0);
return dmod + 1;
}
dmod += c.touch(a);
p = c.xtag(a, Tind2, qpath);
if(p != nil){
for(i=0; i<INDPERBUF; i++){
a = get4(p.iobuf, i*4);
if(a == 0)
continue;
if(c.amark(a)){
if(c.flags & Cbad){
put4(p.iobuf, i*4, 0);
p.flags |= Bmod;
}
continue;
}
dmod += c.checkindir(a, d, qpath);
}
p.put();
}
return dmod;
}
Check.ckfreelist(c: self ref Check, sb: ref Superb)
{
c.name = "free list";
cprint(sys->sprint("check %s", c.name));
fb := sb.fbuf;
a := SUPERADDR;
p: ref Iobuf;
lo := 0;
hi := 0;
for(;;){
n := get4(fb, 0); # nfree
if(n < 0 || n > FEPERBUF){
cprint(sys->sprint("check: nfree bad %d", a));
break;
}
for(i:=1; i<n; i++){
a = get4(fb, 4+i*4); # free[i]
if(a && !c.fmark(a)){
if(!lo || lo > a)
lo = a;
if(!hi || hi < a)
hi = a;
}
}
a = get4(fb, 4); # free[0]
if(a == 0)
break;
if(c.fmark(a))
break;
if(!lo || lo > a)
lo = a;
if(!hi || hi < a)
hi = a;
if(p != nil)
p.put();
p = c.xtag(a, Tfree, QPNONE);
if(p == nil)
break;
fb = p.iobuf;
}
if(p != nil)
p.put();
cprint(sys->sprint("lo = %d; hi = %d", lo, hi));
}
#
# make freelist from scratch
#
Check.mkfreelist(c: self ref Check, sb: ref Superb)
{
sb.fbuf[0:] = emptyblock[0:(FEPERBUF+1)*4];
sb.tfree = 0;
put4(sb.fbuf, 0, 1); # nfree = 1
for(a:=sb.fsize-sb.fstart-1; a >= 0; a--){
i := a>>3;
if(i < 0 || i >= len c.amap.bits)
continue;
b := byte (1 << (a&7));
if((c.amap.bits[i] & b) != byte 0)
continue;
addfree(c.dev, sb.fstart+a, sb);
c.amap.bits[i] |= b;
}
sb.iob.flags |= Bmod;
}
#
# makes a copy of a Dentry's representation on disc so that
# the rest of the much larger iobuf can be freed.
#
Check.maked(c: self ref Check, a: int, s: int, qpath: int): ref Dentry
{
p := c.xtag(a, Tdir, qpath);
if(p == nil)
return nil;
d := Dentry.get(p, s);
if(d == nil)
return nil;
copy := array[len d.buf] of byte;
copy[0:] = d.buf;
d.put();
d.buf = copy;
return d;
}
Check.modd(c: self ref Check, a: int, s: int, d1: ref Dentry)
{
if(!(c.flags & Cbad))
return;
p := Iobuf.get(c.dev, a, Bread);
d := Dentry.get(p, s);
if(d == nil){
if(p != nil)
p.put();
return;
}
d.buf[0:] = d1.buf;
p.flags |= Bmod;
p.put();
}
Check.xread(c: self ref Check, a: int, qpath: int)
{
p := c.xtag(a, Tfile, qpath);
if(p != nil)
p.put();
}
Check.xtag(c: self ref Check, a: int, tag: int, qpath: int): ref Iobuf
{
if(a == 0)
return nil;
p := Iobuf.get(c.dev, a, Bread);
if(p == nil){
cprint(sys->sprint("check: \"%s\": xtag: p null", c.name));
if(c.flags & (Cream|Ctag)){
p = Iobuf.get(c.dev, a, Bmod);
if(p != nil){
p.iobuf[0:] = emptyblock;
p.settag(tag, qpath);
c.mod++;
return p;
}
}
return nil;
}
if(p.checktag(tag, qpath)){
cprint(sys->sprint("check: \"%s\": xtag: checktag", c.name));
if(c.flags & Cream)
p.iobuf[0:] = emptyblock;
if(c.flags & (Cream|Ctag)){
p.settag(tag, qpath);
c.mod++;
}
return p;
}
return p;
}
Check.amark(c: self ref Check, a: int): int
{
e := c.amap.mark(a);
if(e != nil){
cprint(sys->sprint("check: \"%s\": %s %d", c.name, e, a));
return e != "dup"; # don't clear dup blocks because rm might repair
}
return 0;
}
Check.fmark(c: self ref Check,a: int): int
{
e := c.amap.mark(a);
if(e != nil){
cprint(sys->sprint("check: \"%s\": %s %d", c.name, e, a));
return 1;
}
return 0;
}
Check.missing(c: self ref Check, sb: ref Superb)
{
n := 0;
for(a:=sb.fsize-sb.fstart-1; a>=0; a--){
i := a>>3;
b := byte (1 << (a&7));
if((c.amap.bits[i] & b) == byte 0){
cprint(sys->sprint("missing: %d", sb.fstart+a));
n++;
}
if(n > 10){
cprint(sys->sprint(" ..."));
break;
}
}
}
Check.qmark(c: self ref Check, qpath: int)
{
e := c.qmap.mark(qpath);
if(e != nil){
if(c.qmap.nbad+c.qmap.ndup < 20)
cprint(sys->sprint("check: \"%s\": qid %s 0x%ux", c.name, e, qpath));
}
}
Map.new(lo, hi: int): ref Map
{
m := ref Map;
n := (hi-lo+7)>>3;
m.bits = array[n] of {* => byte 0};
m.lo = lo;
m.hi = hi;
m.nbad = 0;
m.ndup = 0;
m.nmark = 0;
return m;
}
Map.isset(m: self ref Map, i: int): int
{
if(i < m.lo || i >= m.hi)
return -1; # hard to say
i -= m.lo;
return (m.bits[i>>3] & byte (1<<(i&7))) != byte 0;
}
Map.mark(m: self ref Map, i: int): string
{
if(i < m.lo || i >= m.hi){
m.nbad++;
return "out of range";
}
i -= m.lo;
b := byte (1 << (i&7));
i >>= 3;
if((m.bits[i] & b) != byte 0){
m.ndup++;
return "dup";
}
m.bits[i] |= b;
m.nmark++;
return nil;
}
cprint(s: string)
{
if(consoleout != nil)
consoleout <-= s+"\n";
else
eprint(s);
}