ref: 25e4f8ae90bd66f124f6b96ffdf70ae00100d4c0
dir: /appl/lib/styxconv/new2old.b/
implement Styxconv;
include "sys.m";
sys: Sys;
include "osys.m";
include "nsys.m";
include "draw.m";
include "styx.m";
nstyx: Styx;
Tmsg, Rmsg: import nstyx;
include "ostyx.m";
ostyx: OStyx;
OTmsg, ORmsg: import ostyx;
include "styxconv.m";
# todo: map fids > ffff into 16 bits
DEBUG: con 1;
Fid: adt
{
fid: int;
isdir: int;
n: int; # size of last new client dirread request.
soff: int; # dir offset on old server.
coff: int; # dir offset on new client.
next: cyclic ref Fid;
};
Req: adt {
tag: int;
oldtag: int; # if it's a flush.
rp: ref Reqproc;
next: cyclic ref Req;
flushes: list of ref Rmsg.Flush; # flushes awaiting req finish.
};
Reqproc: adt {
newtmsg: chan of ref Tmsg; # convproc -> reqproc, once per req.
newrmsg: chan of ref Rmsg; # reqproc -> convproc, once per req
oldtmsg: chan of ref OTmsg; # reqproc -> convproc
oldrmsg: chan of ref ORmsg; # convproc -> reqproc
flushable: int;
new: fn(): ref Reqproc;
rpc: fn(rp: self ref Reqproc, otm: ref OTmsg): ref ORmsg;
};
tags: ref Req;
avail: chan of ref Reqproc;
fids: ref Fid;
nprocs := 0;
init()
{
sys = load Sys Sys->PATH;
if(sys == nil)
nomod("Sys", Sys->PATH);
nstyx = load Styx Styx->PATH;
if(nstyx == nil)
nomod("Styx", Styx->PATH);
ostyx = load OStyx OStyx->PATH;
if(ostyx == nil)
nomod("OStyx", OStyx->PATH);
ostyx->init();
nstyx->init();
avail = chan of ref Reqproc;
}
styxconv(newclient: ref Sys->FD, oldsrv: ref Sys->FD)
{
newtmsg := chan of ref Tmsg;
oldrmsg := chan of ref ORmsg;
killpids := chan[2] of int;
spawn readnewtmsgs(killpids, newclient, newtmsg);
spawn readoldrmsgs(killpids, oldsrv, oldrmsg);
converting:
for(;;)alt{
ntm := <-newtmsg =>
if(DEBUG)
sys->fprint(sys->fildes(2), "-> %s\n", ntm.text());
if(ntm == nil)
break converting;
ns2os(ntm, newclient, oldsrv);
orm := <-oldrmsg =>
if(DEBUG)
sys->fprint(sys->fildes(2), " <- %s\n", ostyx->rmsg2s(orm));
if(orm == nil)
break converting;
t := looktag(orm.tag);
if(t == nil){
warning("reply by old-server to non-existent tag");
break;
}
pick rm := orm {
Flush =>
ot := looktag(t.oldtag);
# if it's an Rflush of a request-in-progress,
# we send it to the reqproc, which
# can then clean up as it likes.
if(ot != nil){
if(ot.rp != nil){
if(ot.rp.flushable){
ot.rp.oldrmsg <-= rm;
# reqproc is bound to finish after a flush
reqreply(ot, newclient, oldsrv);
}else {
# hold flush reply for later
ot.flushes = ref Rmsg.Flush(rm.tag) :: ot.flushes;
}
break;
}
deletetag(t.oldtag);
}
NRsend(newclient, ref Rmsg.Flush(rm.tag));
deletetag(rm.tag);
* =>
if(t.rp != nil){
t.rp.oldrmsg <-= orm;
reqreply(t, newclient, oldsrv);
}else{
os2ns(orm, newclient);
deletetag(orm.tag);
}
}
}
# kill off active reqprocs
for(; tags != nil; tags = tags.next){
if(tags.rp != nil){
tags.rp.oldrmsg <-= nil;
nprocs--;
}
}
# kill off idle reqprocs
while(nprocs > 0){
rp := <-avail;
rp.newtmsg <-= nil;
nprocs--;
}
# kill off message readers
kill(<-killpids);
kill(<-killpids);
}
# process one response from the request proc.
# request proc can respond by sending a new tmsg to the old server
# or by sending an rmsg to the new client, in which case
# it implicitly signals that it has finished processing the request.
# the actual reply might be an Rflush, signifying that
# the request has been aborted.
reqreply(t: ref Req, newclient: ref Sys->FD, oldsrv: ref Sys->FD)
{
rp := t.rp;
alt{
nrm := <-rp.newrmsg =>
# request is done when process sends rmsg
pick rm := nrm {
Flush =>
deletetag(t.tag);
}
deletetag(nrm.tag);
NRsend(newclient, nrm);
for(; t.flushes != nil; t.flushes = tl t.flushes)
NRsend(newclient, hd t.flushes);
otm := <-rp.oldtmsg =>
OTsend(oldsrv, otm);
}
}
# T messages: forward on, reply immediately, or start processing.
ns2os(tm0: ref Tmsg, newclient, oldsrv: ref Sys->FD)
{
otm: ref OTmsg;
t := ref Req(tm0.tag, -1, nil, nil, nil);
pick tm := tm0{
Readerror =>
exit;
Version =>
(s, v) := nstyx->compatible(tm, nstyx->MAXRPC, nil);
NRsend(newclient, ref Rmsg.Version(tm.tag, s, v));
return;
Auth =>
NRsend(newclient, ref Rmsg.Error(tm.tag, "authorization not required"));
return;
Walk =>
storetag(t);
t.rp = Reqproc.new();
t.rp.newtmsg <-= tm;
reqreply(t, newclient, oldsrv);
return;
Attach =>
otm = ref OTmsg.Attach(tm.tag, tm.fid, tm.uname, tm.aname);
Flush =>
t.oldtag = tm.oldtag;
otm = ref OTmsg.Flush(tm.tag, tm.oldtag);
Open =>
otm = ref OTmsg.Open(tm.tag, tm.fid, tm.mode);
Create =>
otm = ref OTmsg.Create(tm.tag, tm.fid, tm.perm, tm.mode, tm.name);
Read =>
fp := findfid(tm.fid);
count := tm.count;
offset := tm.offset;
if(fp != nil && fp.isdir){
fp.n = count;
count = (count/OStyx->DIRLEN)*OStyx->DIRLEN;
if(int offset != fp.coff){
NRsend(newclient, ref Rmsg.Error(tm.tag, "unexpected offset in dirread"));
return;
}
offset = big fp.soff;
}
otm = ref OTmsg.Read(tm.tag, tm.fid, count, offset);
Write =>
otm = ref OTmsg.Write(tm.tag, tm.fid, tm.offset, tm.data);
Clunk =>
otm = ref OTmsg.Clunk(tm.tag, tm.fid);
Remove =>
otm = ref OTmsg.Remove(tm.tag, tm.fid);
Stat =>
otm = ref OTmsg.Stat(tm.tag, tm.fid);
Wstat =>
otm = ref OTmsg.Wstat(tm.tag, tm.fid, nd2od(tm.stat));
* =>
fatal("bad T message");
}
storetag(t);
OTsend(oldsrv, otm);
}
# R messages: old to new
os2ns(orm0: ref ORmsg, newclient: ref Sys->FD)
{
rm: ref Rmsg;
rm = nil;
pick orm := orm0 {
Error =>
rm = ref Rmsg.Error(orm.tag, orm.err);
Flush =>
rm = ref Rmsg.Flush(orm.tag);
Clone =>
rm = ref Rmsg.Walk(orm.tag, nil);
Walk =>
fatal("walk rmsgs should be dealt with be walkreqproc");
Open =>
setfid(orm.fid, orm.qid);
rm = ref Rmsg.Open(orm.tag, oq2nq(orm.qid), 0);
Create =>
setfid(orm.fid, orm.qid);
rm = ref Rmsg.Create(orm.tag, oq2nq(orm.qid), 0);
Read =>
fp := findfid(orm.fid);
data := orm.data;
if(fp != nil && fp.isdir)
data = ods2nds(data, fp.n);
fp.coff += len data;
fp.soff += len orm.data;
rm = ref Rmsg.Read(orm.tag, data);
Write =>
rm = ref Rmsg.Write(orm.tag, orm.count);
Clunk =>
rm = ref Rmsg.Clunk(orm.tag);
deletefid(orm.fid);
Remove =>
rm = ref Rmsg.Remove(orm.tag);
deletefid(orm.fid);
Stat =>
rm = ref Rmsg.Stat(orm.tag, od2nd(orm.stat));
Wstat =>
rm = ref Rmsg.Wstat(orm.tag);
Attach =>
newfid(orm.fid, orm.qid.path & OSys->CHDIR);
rm = ref Rmsg.Attach(orm.tag, oq2nq(orm.qid));
* =>
fatal("bad R message");
}
NRsend(newclient, rm);
}
Reqproc.rpc(rp: self ref Reqproc, otm: ref OTmsg): ref ORmsg
{
rp.oldtmsg <-= otm;
m := <-rp.oldrmsg;
if(m == nil)
exit;
return m;
}
Reqproc.new(): ref Reqproc
{
alt{
rp := <-avail =>
return rp;
* =>
rp := ref Reqproc(
chan of ref Tmsg,
chan of ref Rmsg,
chan of ref OTmsg,
chan of ref ORmsg,
1);
spawn reqproc(rp);
nprocs++;
return rp;
}
}
reqproc(rp: ref Reqproc)
{
for(;;){
tm := <-rp.newtmsg;
if(tm == nil)
return;
rm: ref Rmsg;
pick m := tm {
Walk =>
rm = walkreq(m, rp);
* =>
fatal("non-walk req passed to reqproc");
}
rp.flushable = 1;
rp.newrmsg <-= rm;
avail <-= rp;
}
}
# note that although this is in a separate process,
# whenever it's not in Reqproc.rpc, the styxconv
# process is blocked, so although state is shared,
# there are no race conditions.
walkreq(tm: ref Tmsg.Walk, rp: ref Reqproc): ref Rmsg
{
cloned := 0;
n := len tm.names;
if(tm.newfid != tm.fid){
cloned = 1;
pick rm := rp.rpc(ref OTmsg.Clone(tm.tag, tm.fid, tm.newfid)) {
Clone =>
;
Error =>
return ref Rmsg.Error(tm.tag, rm.err);
Flush =>
return ref Rmsg.Flush(rm.tag);
* =>
fatal("unexpected reply to OTmsg.Clone");
}
cloned = 1;
}
qids := array[n] of NSys->Qid;
finalqid: OSys->Qid;
# make sure we don't get flushed in an unwindable state.
rp.flushable = n == 1 || cloned;
for(i := 0; i < n; i++){
pick rm := rp.rpc(ref OTmsg.Walk(tm.tag, tm.newfid, tm.names[i])) {
Walk =>
qids[i] = oq2nq(rm.qid);
finalqid = rm.qid;
Flush =>
if(cloned){
rp.flushable = 0;
rp.rpc(ref OTmsg.Clunk(tm.tag, tm.newfid));
}
return ref Rmsg.Flush(rm.tag);
Error =>
if(cloned){
rp.flushable = 0;
rp.rpc(ref OTmsg.Clunk(tm.tag, tm.newfid));
}
if(i == 0)
return ref Rmsg.Error(tm.tag, rm.err);
return ref Rmsg.Walk(tm.tag, qids[0:i]);
}
}
if(cloned)
clonefid(tm.fid, tm.newfid);
if(n > 0)
setfid(tm.newfid, finalqid);
return ref Rmsg.Walk(tm.tag, qids);
}
storetag(t: ref Req)
{
t.next = tags;
tags = t;
}
looktag(tag: int): ref Req
{
for(t := tags; t != nil; t = t.next)
if(t.tag == tag)
return t;
return nil;
}
deletetag(tag: int)
{
prev: ref Req;
t := tags;
while(t != nil){
if(t.tag == tag){
next := t.next;
t.next = nil;
if(prev != nil)
prev.next = next;
else
tags = next;
t = next;
}else{
prev = t;
t = t.next;
}
}
}
newfid(fid: int, isdir: int): ref Fid
{
f := ref Fid;
f.fid = fid;
f.isdir = isdir;
f.n = f.soff = f.coff = 0;
f.next = fids;
fids = f;
return f;
}
clonefid(ofid: int, fid: int): ref Fid
{
if((f := findfid(ofid)) != nil){
nf := newfid(fid, f.isdir);
return nf;
}
warning("clone of non-existent fid");
return newfid(fid, 0);
}
deletefid(fid: int)
{
lf: ref Fid;
for(f := fids; f != nil; f = f.next){
if(f.fid == fid){
if(lf == nil)
fids = f.next;
else
lf.next = f.next;
return;
}
lf = f;
}
}
findfid(fid: int): ref Fid
{
for(f := fids; f != nil; f = f.next)
if(f.fid == fid)
return f;
return nil;
}
setfid(fid: int, qid: OSys->Qid)
{
f := findfid(fid);
if(f == nil){
warning(sys->sprint("cannot find fid %d", fid));
}else{
f.isdir = qid.path & OSys->CHDIR;
}
}
om2nm(om: int): int
{
# DMDIR == CHDIR
return om;
}
nm2om(m: int): int
{
# DMDIR == CHDIR
return m&~(NSys->DMAPPEND|NSys->DMEXCL|NSys->DMAUTH);
}
oq2nq(oq: OSys->Qid): NSys->Qid
{
q: NSys->Qid;
isdir := oq.path&OSys->CHDIR;
q.path = big (oq.path&~OSys->CHDIR);
q.vers = oq.vers;
q.qtype = 0;
if(isdir)
q.qtype |= NSys->QTDIR;
return q;
}
nq2oq(q: NSys->Qid): OSys->Qid
{
oq: OSys->Qid;
isdir := q.qtype&NSys->QTDIR;
oq.path = int q.path;
oq.vers = q.vers;
if(isdir)
oq.path |= OSys->CHDIR;
return oq;
}
od2nd(od: OSys->Dir): NSys->Dir
{
d: NSys->Dir;
d.name = od.name;
d.uid = od.uid;
d.gid = od.gid;
d.muid = od.uid;
d.qid = oq2nq(od.qid);
d.mode = om2nm(od.mode);
d.atime = od.atime;
d.mtime = od.mtime;
d.length = big od.length;
d.dtype = od.dtype;
d.dev = od.dev;
return d;
}
nd2od(d: NSys->Dir): OSys->Dir
{
od: OSys->Dir;
od.name = d.name;
od.uid = d.uid;
od.gid = d.gid;
od.qid = nq2oq(d.qid);
od.mode = nm2om(d.mode);
od.atime = d.atime;
od.mtime = d.mtime;
od.length = int d.length;
od.dtype = d.dtype;
od.dev = d.dev;
return od;
}
ods2nds(ob: array of byte, max: int): array of byte
{
od: OSys->Dir;
m := len ob;
if(m % OStyx->DIRLEN != 0)
fatal(sys->sprint("bad dir len %d", m));
m /= OStyx->DIRLEN;
n := 0;
p := ob;
for(i := 0; i < m; i++){
(p, od) = ostyx->convM2D(p);
d := od2nd(od);
nn := nstyx->packdirsize(d);
if(n+nn > max) # might just happen with long file names
break;
n += nn;
}
m = i;
b := array[n] of byte;
n = 0;
p = ob;
for(i = 0; i < m; i++){
(p, od) = ostyx->convM2D(p);
d := od2nd(od);
q := nstyx->packdir(d);
nn := len q;
b[n: ] = q[0: nn];
n += nn;
}
return b;
}
OTsend(fd: ref Sys->FD, otm: ref OTmsg): int
{
if(DEBUG)
sys->fprint(sys->fildes(2), " -> %s\n", ostyx->tmsg2s(otm));
s := array[OStyx->MAXRPC] of byte;
n := ostyx->tmsg2d(otm, s);
if(n < 0)
return -1;
return sys->write(fd, s, n);
}
NRsend(fd: ref Sys->FD, rm: ref Rmsg): int
{
if(DEBUG)
sys->fprint(sys->fildes(2), "<- %s\n", rm.text());
s := rm.pack();
if(s == nil)
return -1;
return sys->write(fd, s, len s);
}
readnewtmsgs(pidc: chan of int, newclient: ref Sys->FD, newtmsg: chan of ref Tmsg)
{
pidc <-= sys->pctl(0, nil);
for(;;){
newtmsg <-= Tmsg.read(newclient, nstyx->MAXRPC);
}
}
readoldrmsgs(pidc: chan of int, oldsrv: ref Sys->FD, oldrmsg: chan of ref ORmsg)
{
pidc <-= sys->pctl(0, nil);
for(;;){
oldrmsg <-= ORmsg.read(oldsrv);
}
}
warning(err: string)
{
sys->fprint(sys->fildes(2), "warning: %s\n", err);
}
fatal(err: string)
{
sys->fprint(sys->fildes(2), "%s\n", err);
exit;
}
nomod(mod: string, path: string)
{
fatal(sys->sprint("can't load %s(%s): %r", mod, path));
}
kill(pid: int)
{
sys->fprint(sys->open("#p/"+string pid+"/ctl", Sys->OWRITE), "kill");
}