a

exportfs/Makefile

@@ -0,0 +1,16 @@
+LIB=libexportfs.a
+CC=gcc
+CFLAGS=-I../include -I. -I.. -c -ggdb -D_THREAD_SAFE -pthread
+O=o
+
+OFILES=\
+	exportfs.$O\
+	exportsrv.$O
+
+$(LIB): $(OFILES)
+	ar r $(LIB) $(OFILES)
+	ranlib $(LIB)
+
+%.$O: %.c
+	$(CC) $(CFLAGS) $*.c
+

exportfs/exportfs.c

@@ -0,0 +1,503 @@
+/*
+ * exportfs - Export a plan 9 name space across a network
+ */
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#include <libsec.h>
+#include "drawterm.h"
+#define Extern
+#include "exportfs.h"
+
+/* #define QIDPATH	((1LL<<48)-1) */
+#define QIDPATH	((((vlong)1)<<48)-1)
+vlong newqid = 0;
+
+void (*fcalls[256])(Fsrpc*);
+
+/* accounting and debugging counters */
+int	filecnt;
+int	freecnt;
+int	qidcnt;
+int	qfreecnt;
+int	ncollision;
+int	netfd;
+
+int
+exportfs(int fd, int msgsz)
+{
+	char buf[ERRMAX], ebuf[ERRMAX];
+	Fsrpc *r;
+	int n;
+	char *dbfile, *srv, *file;
+	ulong initial;
+
+	fcalls[Tversion] = Xversion;
+	fcalls[Tauth] = Xauth;
+	fcalls[Tflush] = Xflush;
+	fcalls[Tattach] = Xattach;
+	fcalls[Twalk] = Xwalk;
+	fcalls[Topen] = slave;
+	fcalls[Tcreate] = Xcreate;
+	fcalls[Tclunk] = Xclunk;
+	fcalls[Tread] = slave;
+	fcalls[Twrite] = slave;
+	fcalls[Tremove] = Xremove;
+	fcalls[Tstat] = Xstat;
+	fcalls[Twstat] = Xwstat;
+
+	srvfd = -1;
+	netfd = fd;
+	//dbg = 1;
+
+	strcpy(buf, "this is buf");
+	strcpy(ebuf, "this is ebuf");
+	DEBUG(DFD, "exportfs: started\n");
+
+//	rfork(RFNOTEG);
+
+	messagesize = msgsz;
+	if(messagesize == 0){
+		messagesize = iounit(netfd);
+		if(messagesize == 0)
+			messagesize = 8192+IOHDRSZ;
+	}
+
+	Workq = emallocz(sizeof(Fsrpc)*Nr_workbufs);
+//	for(i=0; i<Nr_workbufs; i++)
+//		Workq[i].buf = emallocz(messagesize);
+	fhash = emallocz(sizeof(Fid*)*FHASHSIZE);
+
+	fmtinstall('F', fcallfmt);
+
+	initroot();
+
+	DEBUG(DFD, "exportfs: %s\n", buf);
+
+	/*
+	 * Start serving file requests from the network
+	 */
+	for(;;) {
+		r = getsbuf();
+		if(r == 0)
+			fatal("Out of service buffers");
+			
+		DEBUG(DFD, "read9p...");
+		n = read9pmsg(netfd, r->buf, messagesize);
+		if(n <= 0)
+			fatal(nil);
+
+		if(convM2S(r->buf, n, &r->work) == 0)
+			fatal("convM2S format error");
+
+		DEBUG(DFD, "%F\n", &r->work);
+		(fcalls[r->work.type])(r);
+	}
+}
+
+void
+reply(Fcall *r, Fcall *t, char *err)
+{
+	uchar *data;
+	int m, n;
+
+	t->tag = r->tag;
+	t->fid = r->fid;
+	if(err) {
+		t->type = Rerror;
+		t->ename = err;
+	}
+	else 
+		t->type = r->type + 1;
+
+	DEBUG(DFD, "\t%F\n", t);
+
+	data = malloc(messagesize);	/* not mallocz; no need to clear */
+	if(data == nil)
+		fatal(Enomem);
+	n = convS2M(t, data, messagesize);
+	if((m=write(netfd, data, n))!=n){
+		fprint(2, "wrote %d got %d (%r)\n", n, m);
+		fatal("write");
+	}
+	free(data);
+}
+
+Fid *
+getfid(int nr)
+{
+	Fid *f;
+
+	for(f = fidhash(nr); f; f = f->next)
+		if(f->nr == nr)
+			return f;
+
+	return 0;
+}
+
+int
+freefid(int nr)
+{
+	Fid *f, **l;
+	char buf[128];
+
+	l = &fidhash(nr);
+	for(f = *l; f; f = f->next) {
+		if(f->nr == nr) {
+			if(f->mid) {
+				sprint(buf, "/mnt/exportfs/%d", f->mid);
+				unmount(0, buf);
+				psmap[f->mid] = 0;
+			}
+			if(f->f) {
+				freefile(f->f);
+				f->f = nil;
+			}
+			*l = f->next;
+			f->next = fidfree;
+			fidfree = f;
+			return 1;
+		}
+		l = &f->next;
+	}
+
+	return 0;	
+}
+
+Fid *
+newfid(int nr)
+{
+	Fid *new, **l;
+	int i;
+
+	l = &fidhash(nr);
+	for(new = *l; new; new = new->next)
+		if(new->nr == nr)
+			return 0;
+
+	if(fidfree == 0) {
+		fidfree = emallocz(sizeof(Fid) * Fidchunk);
+
+		for(i = 0; i < Fidchunk-1; i++)
+			fidfree[i].next = &fidfree[i+1];
+
+		fidfree[Fidchunk-1].next = 0;
+	}
+
+	new = fidfree;
+	fidfree = new->next;
+
+	memset(new, 0, sizeof(Fid));
+	new->next = *l;
+	*l = new;
+	new->nr = nr;
+	new->fid = -1;
+	new->mid = 0;
+
+	return new;	
+}
+
+Fsrpc *
+getsbuf(void)
+{
+	static int ap;
+	int look, rounds;
+	Fsrpc *wb;
+	int small_instead_of_fast = 1;
+
+	if(small_instead_of_fast)
+		ap = 0;	/* so we always start looking at the beginning and reuse buffers */
+
+	for(rounds = 0; rounds < 10; rounds++) {
+		for(look = 0; look < Nr_workbufs; look++) {
+			if(++ap == Nr_workbufs)
+				ap = 0;
+			if(Workq[ap].busy == 0)
+				break;
+		}
+
+		if(look == Nr_workbufs){
+			sleep(10 * rounds);
+			continue;
+		}
+
+		wb = &Workq[ap];
+		wb->pid = 0;
+		wb->canint = 0;
+		wb->flushtag = NOTAG;
+		wb->busy = 1;
+		if(wb->buf == nil)	/* allocate buffers dynamically to keep size down */
+			wb->buf = emallocz(messagesize);
+		return wb;
+	}
+	fatal("No more work buffers");
+	return nil;
+}
+
+void
+freefile(File *f)
+{
+	File *parent, *child;
+
+Loop:
+	f->ref--;
+	if(f->ref > 0)
+		return;
+	freecnt++;
+	if(f->ref < 0) abort();
+	DEBUG(DFD, "free %s\n", f->name);
+	/* delete from parent */
+	parent = f->parent;
+	if(parent->child == f)
+		parent->child = f->childlist;
+	else{
+		for(child=parent->child; child->childlist!=f; child=child->childlist)
+			if(child->childlist == nil)
+				fatal("bad child list");
+		child->childlist = f->childlist;
+	}
+	freeqid(f->qidt);
+	free(f->name);
+	f->name = nil;
+	free(f);
+	f = parent;
+	if(f != nil)
+		goto Loop;
+}
+
+File *
+file(File *parent, char *name)
+{
+	Dir *dir;
+	char *path;
+	File *f;
+
+	DEBUG(DFD, "\tfile: 0x%p %s name %s\n", parent, parent->name, name);
+
+	path = makepath(parent, name);
+	dir = dirstat(path);
+	free(path);
+	if(dir == nil)
+		return nil;
+
+	for(f = parent->child; f; f = f->childlist)
+		if(strcmp(name, f->name) == 0)
+			break;
+
+	if(f == nil){
+		f = emallocz(sizeof(File));
+		f->name = estrdup(name);
+
+		f->parent = parent;
+		f->childlist = parent->child;
+		parent->child = f;
+		parent->ref++;
+		f->ref = 0;
+		filecnt++;
+	}
+	f->ref++;
+	f->qid.type = dir->qid.type;
+	f->qid.vers = dir->qid.vers;
+	f->qidt = uniqueqid(dir);
+	f->qid.path = f->qidt->uniqpath;
+
+	f->inval = 0;
+
+	free(dir);
+
+	return f;
+}
+
+void
+initroot(void)
+{
+	Dir *dir;
+
+	root = emallocz(sizeof(File));
+	root->name = estrdup(".");
+
+	dir = dirstat(root->name);
+	if(dir == nil)
+		fatal("root stat");
+
+	root->ref = 1;
+	root->qid.vers = dir->qid.vers;
+	root->qidt = uniqueqid(dir);
+	root->qid.path = root->qidt->uniqpath;
+	root->qid.type = QTDIR;
+	free(dir);
+
+	psmpt = emallocz(sizeof(File));
+	psmpt->name = estrdup("/");
+
+	dir = dirstat(psmpt->name);
+	if(dir == nil)
+		return;
+
+	psmpt->ref = 1;
+	psmpt->qid.vers = dir->qid.vers;
+	psmpt->qidt = uniqueqid(dir);
+	psmpt->qid.path = psmpt->qidt->uniqpath;
+	free(dir);
+
+	psmpt = file(psmpt, "mnt");
+	if(psmpt == 0)
+		return;
+	psmpt = file(psmpt, "exportfs");
+}
+
+char*
+makepath(File *p, char *name)
+{
+	int i, n;
+	char *c, *s, *path, *seg[256];
+
+	seg[0] = name;
+	n = strlen(name)+2;
+	for(i = 1; i < 256 && p; i++, p = p->parent){
+		seg[i] = p->name;
+		n += strlen(p->name)+1;
+	}
+	path = malloc(n);
+	if(path == nil)
+		fatal("out of memory");
+	s = path;
+
+	while(i--) {
+		for(c = seg[i]; *c; c++)
+			*s++ = *c;
+		*s++ = '/';
+	}
+	while(s[-1] == '/')
+		s--;
+	*s = '\0';
+
+	return path;
+}
+
+int
+qidhash(vlong path)
+{
+	int h, n;
+
+	h = 0;
+	for(n=0; n<64; n+=Nqidbits){
+		h ^= path;
+		path >>= Nqidbits;
+	}
+	return h & (Nqidtab-1);
+}
+
+void
+freeqid(Qidtab *q)
+{
+	ulong h;
+	Qidtab *l;
+
+	q->ref--;
+	if(q->ref > 0)
+		return;
+	qfreecnt++;
+	h = qidhash(q->path);
+	if(qidtab[h] == q)
+		qidtab[h] = q->next;
+	else{
+		for(l=qidtab[h]; l->next!=q; l=l->next)
+			if(l->next == nil)
+				fatal("bad qid list");
+		l->next = q->next;
+	}
+	free(q);
+}
+
+Qidtab*
+qidlookup(Dir *d)
+{
+	ulong h;
+	Qidtab *q;
+
+	h = qidhash(d->qid.path);
+	for(q=qidtab[h]; q!=nil; q=q->next)
+		if(q->type==d->type && q->dev==d->dev && q->path==d->qid.path)
+			return q;
+	return nil;
+}
+
+int
+qidexists(vlong path)
+{
+	int h;
+	Qidtab *q;
+
+	for(h=0; h<Nqidtab; h++)
+		for(q=qidtab[h]; q!=nil; q=q->next)
+			if(q->uniqpath == path)
+				return 1;
+	return 0;
+}
+
+Qidtab*
+uniqueqid(Dir *d)
+{
+	ulong h;
+	vlong path;
+	Qidtab *q;
+
+	q = qidlookup(d);
+	if(q != nil){
+		q->ref++;
+		return q;
+	}
+	path = d->qid.path;
+	while(qidexists(path)){
+		DEBUG(DFD, "collision on %s\n", d->name);
+		/* collision: find a new one */
+		ncollision++;
+		path &= QIDPATH;
+		++newqid;
+		if(newqid >= (1<<16)){
+			DEBUG(DFD, "collision wraparound\n");
+			newqid = 1;
+		}
+		path |= newqid<<48;
+		DEBUG(DFD, "assign qid %.16llux\n", path);
+	}
+	q = mallocz(sizeof(Qidtab), 1);
+	if(q == nil)
+		fatal("no memory for qid table");
+	qidcnt++;
+	q->ref = 1;
+	q->type = d->type;
+	q->dev = d->dev;
+	q->path = d->qid.path;
+	q->uniqpath = path;
+	h = qidhash(d->qid.path);
+	q->next = qidtab[h];
+	qidtab[h] = q;
+	return q;
+}
+
+void
+fatal(char *s, ...)
+{
+	char buf[ERRMAX];
+	va_list arg;
+	Proc *m;
+
+	if (s) {
+		va_start(arg, s);
+		vsnprint(buf, ERRMAX, s, arg);
+		va_end(arg);
+	}
+
+	/* Clear away the slave children */
+//	for(m = Proclist; m; m = m->next)
+//		postnote(PNPROC, m->pid, "kill");
+
+	DEBUG(DFD, "%s\n", buf);
+	if (s) 
+		sysfatal(buf);
+	else
+		exits(nil);
+}
+

exportfs/exportfs.h

@@ -0,0 +1,148 @@
+/*
+ * exportfs.h - definitions for exporting file server
+ */
+
+#define DEBUG		if(!dbg){}else fprint
+#define DFD		2
+#define fidhash(s)	fhash[s%FHASHSIZE]
+
+#define Proc	Exproc
+
+
+typedef struct Fsrpc Fsrpc;
+typedef struct Fid Fid;
+typedef struct File File;
+typedef struct Proc Proc;
+typedef struct Qidtab Qidtab;
+
+struct Fsrpc
+{
+	int	busy;		/* Work buffer has pending rpc to service */
+	int	pid;		/* Pid of slave process executing the rpc */
+	int	canint;		/* Interrupt gate */
+	int	flushtag;	/* Tag on which to reply to flush */
+	Fcall work;		/* Plan 9 incoming Fcall */
+	uchar	*buf;	/* Data buffer */
+};
+
+struct Fid
+{
+	int	fid;		/* system fd for i/o */
+	File	*f;		/* File attached to this fid */
+	int	mode;
+	int	nr;		/* fid number */
+	int	mid;		/* Mount id */
+	Fid	*next;		/* hash link */
+};
+
+struct File
+{
+	char	*name;
+	int	ref;
+	Qid	qid;
+	Qidtab	*qidt;
+	int	inval;
+	File	*parent;
+	File	*child;
+	File	*childlist;
+};
+
+struct Proc
+{
+	int	pid;
+	int	busy;
+	Proc	*next;
+};
+
+struct Qidtab
+{
+	int	ref;
+	int	type;
+	int	dev;
+	vlong	path;
+	vlong	uniqpath;
+	Qidtab	*next;
+};
+
+enum
+{
+	MAXPROC		= 50,
+	FHASHSIZE	= 64,
+	Nr_workbufs 	= 50,
+	Fidchunk	= 1000,
+	Npsmpt		= 32,
+	Nqidbits		= 5,
+	Nqidtab		= (1<<Nqidbits),
+};
+
+#define Enomem Exenomem
+#define Ebadfix Exebadfid
+#define Enotdir Exenotdir
+#define Edupfid Exedupfid
+#define Eopen Exeopen
+#define Exmnt Exexmnt
+#define Emip Exemip
+#define Enopsmt Exenopsmt
+
+extern char Ebadfid[];
+extern char Enotdir[];
+extern char Edupfid[];
+extern char Eopen[];
+extern char Exmnt[];
+extern char Enomem[];
+extern char Emip[];
+extern char Enopsmt[];
+
+Extern Fsrpc	*Workq;
+Extern int  	dbg;
+Extern File	*root;
+Extern File	*psmpt;
+Extern Fid	**fhash;
+Extern Fid	*fidfree;
+Extern Proc	*Proclist;
+Extern char	psmap[Npsmpt];
+Extern Qidtab	*qidtab[Nqidtab];
+Extern ulong	messagesize;
+Extern int		srvfd;
+
+/* File system protocol service procedures */
+void Xattach(Fsrpc*);
+void Xauth(Fsrpc*);
+void Xclunk(Fsrpc*); 
+void Xcreate(Fsrpc*);
+void Xflush(Fsrpc*); 
+void Xnop(Fsrpc*);
+void Xremove(Fsrpc*);
+void Xstat(Fsrpc*);
+void Xversion(Fsrpc*);
+void Xwalk(Fsrpc*);
+void Xwstat(Fsrpc*);
+void slave(Fsrpc*);
+
+void	reply(Fcall*, Fcall*, char*);
+Fid 	*getfid(int);
+int	freefid(int);
+Fid	*newfid(int);
+Fsrpc	*getsbuf(void);
+void	initroot(void);
+void	fatal(char*, ...);
+char*	makepath(File*, char*);
+File	*file(File*, char*);
+void	freefile(File*);
+void	slaveopen(Fsrpc*);
+void	slaveread(Fsrpc*);
+void	slavewrite(Fsrpc*);
+void	blockingslave(void*);
+void	reopen(Fid *f);
+void	noteproc(int, char*);
+void	flushaction(void*, char*);
+void	pushfcall(char*);
+Qidtab* uniqueqid(Dir*);
+void	freeqid(Qidtab*);
+char*	estrdup(char*);
+void*	emallocz(uint);
+int		readmessage(int, char*, int);
+
+#define notify
+#define noted
+#define exits

exportfs/exportsrv.c

@@ -0,0 +1,679 @@
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#define Extern	extern
+#include "exportfs.h"
+
+char Ebadfid[] = "Bad fid";
+char Enotdir[] = "Not a directory";
+char Edupfid[] = "Fid already in use";
+char Eopen[] = "Fid already opened";
+char Exmnt[] = "Cannot .. past mount point";
+char Emip[] = "Mount in progress";
+char Enopsmt[] = "Out of pseudo mount points";
+char Enomem[] = "No memory";
+char Eversion[] = "Bad 9P2000 version";
+
+int iounit(int x)
+{
+	return 8192+IOHDRSZ;
+}
+
+void*
+emallocz(ulong n)
+{
+	void *v;
+
+	v = mallocz(n, 1);
+	if(v == nil)
+		panic("out of memory");
+	return v;
+}
+
+ulong messagesize;
+
+void
+Xversion(Fsrpc *t)
+{
+	Fcall rhdr;
+
+	if(t->work.msize > messagesize)
+		t->work.msize = messagesize;
+	messagesize = t->work.msize;
+	if(strncmp(t->work.version, "9P2000", 6) != 0){
+		reply(&t->work, &rhdr, Eversion);
+		return;
+	}
+	rhdr.version = "9P2000";
+	rhdr.msize = t->work.msize;
+	reply(&t->work, &rhdr, 0);
+	t->busy = 0;
+}
+
+void
+Xauth(Fsrpc *t)
+{
+	Fcall rhdr;
+
+	reply(&t->work, &rhdr, "exportfs: authentication not required");
+	t->busy = 0;
+}
+
+void
+Xflush(Fsrpc *t)
+{
+	Fsrpc *w, *e;
+	Fcall rhdr;
+
+	e = &Workq[Nr_workbufs];
+
+	for(w = Workq; w < e; w++) {
+		if(w->work.tag == t->work.oldtag) {
+			DEBUG(DFD, "\tQ busy %d pid %d can %d\n", w->busy, w->pid, w->canint);
+			if(w->busy && w->pid) {
+				w->flushtag = t->work.tag;
+				DEBUG(DFD, "\tset flushtag %d\n", t->work.tag);
+			//	if(w->canint)
+			//		postnote(PNPROC, w->pid, "flush");
+				t->busy = 0;
+				return;
+			}
+		}
+	}
+
+	reply(&t->work, &rhdr, 0);
+	DEBUG(DFD, "\tflush reply\n");
+	t->busy = 0;
+}
+
+void
+Xattach(Fsrpc *t)
+{
+	int i, nfd;
+	Fcall rhdr;
+	Fid *f;
+	char buf[128];
+
+	f = newfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+
+	if(srvfd >= 0){
+/*
+		if(psmpt == 0){
+		Nomount:
+			reply(&t->work, &rhdr, Enopsmt);
+			t->busy = 0;
+			freefid(t->work.fid);
+			return;
+		}
+		for(i=0; i<Npsmpt; i++)
+			if(psmap[i] == 0)
+				break;
+		if(i >= Npsmpt)
+			goto Nomount;
+		sprint(buf, "%d", i);
+		f->f = file(psmpt, buf);
+		if(f->f == nil)
+			goto Nomount;
+		sprint(buf, "/mnt/exportfs/%d", i);
+		nfd = dup(srvfd, -1);
+		if(amount(nfd, buf, MREPL|MCREATE, t->work.aname) < 0){
+			errstr(buf, sizeof buf);
+			reply(&t->work, &rhdr, buf);
+			t->busy = 0;
+			freefid(t->work.fid);
+			close(nfd);
+			return;
+		}
+		psmap[i] = 1;
+		f->mid = i;
+*/
+	}else{
+		f->f = root;
+		f->f->ref++;
+	}
+
+	rhdr.qid = f->f->qid;
+	reply(&t->work, &rhdr, 0);
+	t->busy = 0;
+}
+
+Fid*
+clonefid(Fid *f, int new)
+{
+	Fid *n;
+
+	n = newfid(new);
+	if(n == 0) {
+		n = getfid(new);
+		if(n == 0)
+			fatal("inconsistent fids");
+		if(n->fid >= 0)
+			close(n->fid);
+		freefid(new);
+		n = newfid(new);
+		if(n == 0)
+			fatal("inconsistent fids2");
+	}
+	n->f = f->f;
+	n->f->ref++;
+	return n;
+}
+
+void
+Xwalk(Fsrpc *t)
+{
+	char err[ERRMAX], *e;
+	Fcall rhdr;
+	Fid *f, *nf;
+	File *wf;
+	int i;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+
+	nf = nil;
+	if(t->work.newfid != t->work.fid){
+		nf = clonefid(f, t->work.newfid);
+		f = nf;
+	}
+
+	rhdr.nwqid = 0;
+	e = nil;
+	for(i=0; i<t->work.nwname; i++){
+		if(i == MAXWELEM){
+			e = "Too many path elements";
+			break;
+		}
+
+		if(strcmp(t->work.wname[i], "..") == 0) {
+			if(f->f->parent == nil) {
+				e = Exmnt;
+				break;
+			}
+			wf = f->f->parent;
+			wf->ref++;
+			goto Accept;
+		}
+	
+		wf = file(f->f, t->work.wname[i]);
+		if(wf == 0){
+			errstr(err, sizeof err);
+			e = err;
+			break;
+		}
+    Accept:
+		freefile(f->f);
+		rhdr.wqid[rhdr.nwqid++] = wf->qid;
+		f->f = wf;
+		continue;
+	}
+
+	if(nf!=nil && (e!=nil || rhdr.nwqid!=t->work.nwname))
+		freefid(t->work.newfid);
+	if(rhdr.nwqid > 0)
+		e = nil;
+	reply(&t->work, &rhdr, e);
+	t->busy = 0;
+}
+
+void
+Xclunk(Fsrpc *t)
+{
+	Fcall rhdr;
+	Fid *f;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+
+	if(f->fid >= 0)
+		close(f->fid);
+
+	freefid(t->work.fid);
+	reply(&t->work, &rhdr, 0);
+	t->busy = 0;
+}
+
+void
+Xstat(Fsrpc *t)
+{
+	char err[ERRMAX], *path;
+	Fcall rhdr;
+	Fid *f;
+	Dir *d;
+	int s;
+	uchar *statbuf;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+	if(f->fid >= 0)
+		d = dirfstat(f->fid);
+	else {
+		path = makepath(f->f, "");
+		d = dirstat(path);
+		free(path);
+	}
+
+	if(d == nil) {
+		errstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+		t->busy = 0;
+		return;
+	}
+
+	d->qid.path = f->f->qidt->uniqpath;
+	s = sizeD2M(d);
+	statbuf = emallocz(s);
+	s = convD2M(d, statbuf, s);
+	free(d);
+	rhdr.nstat = s;
+	rhdr.stat = statbuf;
+	reply(&t->work, &rhdr, 0);
+	free(statbuf);
+	t->busy = 0;
+}
+
+static int
+getiounit(int fd)
+{
+	int n;
+
+	n = iounit(fd);
+	if(n > messagesize-IOHDRSZ)
+		n = messagesize-IOHDRSZ;
+	return n;
+}
+
+void
+Xcreate(Fsrpc *t)
+{
+	char err[ERRMAX], *path;
+	Fcall rhdr;
+	Fid *f;
+	File *nf;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+	
+
+	path = makepath(f->f, t->work.name);
+	f->fid = create(path, t->work.mode, t->work.perm);
+	free(path);
+	if(f->fid < 0) {
+		errstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+		t->busy = 0;
+		return;
+	}
+
+	nf = file(f->f, t->work.name);
+	if(nf == 0) {
+		errstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+		t->busy = 0;
+		return;
+	}
+
+	f->mode = t->work.mode;
+	freefile(f->f);
+	f->f = nf;
+	rhdr.qid = f->f->qid;
+	rhdr.iounit = getiounit(f->fid);
+	reply(&t->work, &rhdr, 0);
+	t->busy = 0;
+}
+
+void
+Xremove(Fsrpc *t)
+{
+	char err[ERRMAX], *path;
+	Fcall rhdr;
+	Fid *f;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+
+	path = makepath(f->f, "");
+	DEBUG(DFD, "\tremove: %s\n", path);
+	if(remove(path) < 0) {
+		free(path);
+		errstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+		t->busy = 0;
+		return;
+	}
+	free(path);
+
+	f->f->inval = 1;
+	if(f->fid >= 0)
+		close(f->fid);
+	freefid(t->work.fid);
+
+	reply(&t->work, &rhdr, 0);
+	t->busy = 0;
+}
+
+void
+Xwstat(Fsrpc *t)
+{
+	char err[ERRMAX], *path;
+	Fcall rhdr;
+	Fid *f;
+	int s;
+	char *strings;
+	Dir d;
+
+	f = getfid(t->work.fid);
+	if(f == 0) {
+		reply(&t->work, &rhdr, Ebadfid);
+		t->busy = 0;
+		return;
+	}
+	strings = emallocz(t->work.nstat);	/* ample */
+	if(convM2D(t->work.stat, t->work.nstat, &d, strings) < 0){
+		rerrstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+		t->busy = 0;
+		free(strings);
+		return;
+	}
+
+	if(f->fid >= 0)
+		s = dirfwstat(f->fid, &d);
+	else {
+		path = makepath(f->f, "");
+		s = dirwstat(path, &d);
+		free(path);
+	}
+	if(s < 0) {
+		rerrstr(err, sizeof err);
+		reply(&t->work, &rhdr, err);
+	}
+	else {
+		/* wstat may really be rename */
+		if(strcmp(d.name, f->f->name)!=0 && strcmp(d.name, "")!=0){
+			free(f->f->name);
+			f->f->name = estrdup(d.name);
+		}
+		reply(&t->work, &rhdr, 0);
+	}
+	free(strings);
+	t->busy = 0;
+}
+
+void
+slave(Fsrpc *f)
+{
+	Proc *p;
+	int pid;
+	static int nproc;
+
+	for(;;) {
+		for(p = Proclist; p; p = p->next) {
+			if(p->busy == 0) {
+				f->pid = p->pid;
+				p->busy = 1;
+				pid = rendezvous(p->pid, (ulong)f);
+				if(pid != p->pid)
+					fatal("rendezvous sync fail");
+				return;
+			}	
+		}
+
+		if(++nproc > MAXPROC)
+			fatal("too many procs");
+
+		pid = kproc("slave", blockingslave, nil);
+		DEBUG(DFD, "slave pid %d\n", pid);
+		if(pid == -1)
+			fatal("kproc");
+
+		p = malloc(sizeof(Proc));
+		if(p == 0)
+			fatal("out of memory");
+
+		p->busy = 0;
+		p->pid = pid;
+		p->next = Proclist;
+		Proclist = p;
+
+DEBUG(DFD, "parent %d rendez\n", pid);
+		rendezvous(pid, (ulong)p);
+DEBUG(DFD, "parent %d went\n", pid);
+	}
+}
+
+void
+blockingslave(void *x)
+{
+	Fsrpc *p;
+	Fcall rhdr;
+	Proc *m;
+	int pid;
+
+	USED(x);
+
+	notify(flushaction);
+
+	pid = getpid();
+
+DEBUG(DFD, "blockingslave %d rendez\n", pid);
+	m = (Proc*)rendezvous(pid, 0);
+DEBUG(DFD, "blockingslave %d rendez got %p\n", pid, m);
+	
+	for(;;) {
+		p = (Fsrpc*)rendezvous(pid, pid);
+		if((int)p == ~0)			/* Interrupted */
+			continue;
+
+		DEBUG(DFD, "\tslave: %d %F b %d p %d\n", pid, &p->work, p->busy, p->pid);
+		if(p->flushtag != NOTAG)
+			goto flushme;
+
+		switch(p->work.type) {
+		case Tread:
+			slaveread(p);
+			break;
+
+		case Twrite:
+			slavewrite(p);
+			break;
+
+		case Topen:
+			slaveopen(p);
+			break;
+
+		default:
+			reply(&p->work, &rhdr, "exportfs: slave type error");
+		}
+		if(p->flushtag != NOTAG) {
+flushme:
+			p->work.type = Tflush;
+			p->work.tag = p->flushtag;
+			reply(&p->work, &rhdr, 0);
+		}
+		p->busy = 0;
+		m->busy = 0;
+	}
+}
+
+int
+openmount(int sfd)
+{
+	werrstr("openmount not implemented");
+	return -1;
+}
+
+void
+slaveopen(Fsrpc *p)
+{
+	char err[ERRMAX], *path;
+	Fcall *work, rhdr;
+	Fid *f;
+	Dir *d;
+
+	work = &p->work;
+
+	f = getfid(work->fid);
+	if(f == 0) {
+		reply(work, &rhdr, Ebadfid);
+		return;
+	}
+	if(f->fid >= 0) {
+		close(f->fid);
+		f->fid = -1;
+	}
+	
+	path = makepath(f->f, "");
+	DEBUG(DFD, "\topen: %s %d\n", path, work->mode);
+
+	p->canint = 1;
+	if(p->flushtag != NOTAG){
+		free(path);
+		return;
+	}
+	/* There is a race here I ignore because there are no locks */
+	f->fid = open(path, work->mode);
+	free(path);
+	p->canint = 0;
+	if(f->fid < 0 || (d = dirfstat(f->fid)) == nil) {
+	Error:
+		errstr(err, sizeof err);
+		reply(work, &rhdr, err);
+		return;
+	}
+	f->f->qid = d->qid;
+	free(d);
+	if(f->f->qid.type & QTMOUNT){	/* fork new exportfs for this */
+		f->fid = openmount(f->fid);
+		if(f->fid < 0)
+			goto Error;
+	}
+
+	DEBUG(DFD, "\topen: fd %d\n", f->fid);
+	f->mode = work->mode;
+	rhdr.iounit = getiounit(f->fid);
+	rhdr.qid = f->f->qid;
+	reply(work, &rhdr, 0);
+}
+
+void
+slaveread(Fsrpc *p)
+{
+	Fid *f;
+	int n, r;
+	Fcall *work, rhdr;
+	char *data, err[ERRMAX];
+
+	work = &p->work;
+
+	f = getfid(work->fid);
+	if(f == 0) {
+		reply(work, &rhdr, Ebadfid);
+		return;
+	}
+
+	n = (work->count > messagesize-IOHDRSZ) ? messagesize-IOHDRSZ : work->count;
+	p->canint = 1;
+	if(p->flushtag != NOTAG)
+		return;
+	data = malloc(n);
+	if(data == nil)
+		fatal(Enomem);
+
+	/* can't just call pread, since directories must update the offset */
+	r = pread(f->fid, data, n, work->offset);
+	p->canint = 0;
+	if(r < 0) {
+		free(data);
+		errstr(err, sizeof err);
+		reply(work, &rhdr, err);
+		return;
+	}
+
+	DEBUG(DFD, "\tread: fd=%d %d bytes\n", f->fid, r);
+
+	rhdr.data = data;
+	rhdr.count = r;
+	reply(work, &rhdr, 0);
+	free(data);
+}
+
+void
+slavewrite(Fsrpc *p)
+{
+	char err[ERRMAX];
+	Fcall *work, rhdr;
+	Fid *f;
+	int n;
+
+	work = &p->work;
+
+	f = getfid(work->fid);
+	if(f == 0) {
+		reply(work, &rhdr, Ebadfid);
+		return;
+	}
+
+	n = (work->count > messagesize-IOHDRSZ) ? messagesize-IOHDRSZ : work->count;
+	p->canint = 1;
+	if(p->flushtag != NOTAG)
+		return;
+	n = pwrite(f->fid, work->data, n, work->offset);
+	p->canint = 0;
+	if(n < 0) {
+		errstr(err, sizeof err);
+		reply(work, &rhdr, err);
+		return;
+	}
+
+	DEBUG(DFD, "\twrite: %d bytes fd=%d\n", n, f->fid);
+
+	rhdr.count = n;
+	reply(work, &rhdr, 0);
+}
+
+void
+reopen(Fid *f)
+{
+	USED(f);
+	fatal("reopen");
+}
+
+void
+flushaction(void *a, char *cause)
+{
+	USED(a);
+	if(strncmp(cause, "sys:", 4) == 0 && !strstr(cause, "pipe")) {
+		fprint(2, "exportsrv: note: %s\n", cause);
+		exits("noted");
+	}
+	if(strncmp(cause, "kill", 4) == 0)
+		noted(NDFLT);
+
+	noted(NCONT);
+}

exportfs/mkfile

@@ -0,0 +1,11 @@
+<$DSRC/mkfile-$CONF
+TARG=libexportfs.$L
+
+OFILES=\
+	exportfs.$O\
+	exportsrv.$O
+
+HFILES=\
+	exportfs.h
+
+<$DSRC/mklib-$CONF