/* * exportfs - Export a plan 9 name space across a network */#include <u.h>#include <libc.h>#include <auth.h>#include <fcall.h>#define Extern#include "exportfs.h" #define	QIDMODE	(CHDIR|CHAPPEND|CHEXCL|CHMOUNT)ulong newqid = ~QIDMODE; void (*fcalls[])(Fsrpc*) ={	[Tnop]		Xnop,	[Tsession]	Xsession,	[Tflush]	Xflush,	[Tattach]	Xattach,	[Tclone]	Xclone,	[Twalk]		Xwalk,	[Topen]		slave,	[Tcreate]	Xcreate,	[Tclunk]	Xclunk,	[Tread]		slave,	[Twrite]	slave,	[Tremove]	Xremove,	[Tstat]		Xstat,	[Twstat]	Xwstat,	[Tclwalk]	Xclwalk,}; /* accounting and debugging counters */int	filecnt;int	freecnt;int	qidcnt;int	qfreecnt;int	ncollision; int	fflag;int	netfd;int	filter(int); voidusage(void){	fprint(2, "usage: %s [-as] [-c ctlfile]\n", argv0);	fatal("usage");} voidmain(int argc, char **argv){	char buf[128];	Fsrpc *r;	int n;	char *dbfile, *srv;	char user[NAMELEN]; 	dbfile = "/tmp/exportdb";	srv = nil; 	ARGBEGIN{	case 'a':	//	fprint(2, "srvauth\n");		if(srvauth(0, user) < 0)			fatal("srvauth");	//	fprint(2, "newns\n");		if(newns(user, 0) < 0)			fatal("newns");		putenv("service", "exportfs");		break; 	case 'd':		dbg++;		break; 	case 'f':		dbfile = EARGF(usage());		break; 	case 'F':		fflag++;		break; 	case 'r':		srv = EARGF(usage());		break; 	case 's':		srv = "/";		break; 	default:		usage();	}ARGEND	USED(argc, argv); 	if(dbg) {		n = create(dbfile, OWRITE|OTRUNC, 0666);		dup(n, DFD);		close(n);	} 	DEBUG(DFD, "exportfs: started\n"); 	rfork(RFNOTEG); 	Workq = mallocz(sizeof(Fsrpc)*Nr_workbufs, 1);	fhash = mallocz(sizeof(Fid*)*FHASHSIZE, 1); 	if(Workq == 0 || fhash == 0)		fatal("no initial memory");  	fmtinstall('F', fcallconv); 	/*	 * Get tree to serve from network connection,	 * check we can get there and ack the connection 	 */	if(srv) {		chdir(srv);		DEBUG(DFD, "invoked as server for %s", srv);	}	else {		buf[0] = 0;		n = read(0, buf, sizeof(buf));		if(n < 0) {			errstr(buf);			fprint(0, "read(0): %s", buf);			DEBUG(DFD, "read(0): %s", buf);			exits(buf);		}		buf[n] = 0;		if(chdir(buf) < 0) {			char ebuf[128];			errstr(ebuf);			fprint(0, "chdir(%d:\"%s\"): %s", n, buf, ebuf);			DEBUG(DFD, "chdir(%d:\"%s\"): %s", n, buf, ebuf);			exits(ebuf);		}	} 	DEBUG(DFD, "initing root\n");	initroot(); 	DEBUG(DFD, "exportfs: %s\n", buf); 	if(srv == nil && write(0, "OK", 2) != 2)		fatal("open ack write"); 	/*	 * push the fcall line discipline	 */	netfd = 0;	if(fflag)		netfd = filter(netfd); 	/*	 * Start serving file requests from the network	 */	for(;;) {		r = getsbuf();		if(r == 0)			fatal("Out of service buffers"); 		do			n = read9p(netfd, r->buf, sizeof(r->buf));		while(n == 0); 		if(n < 0)			fatal("server read"); 		if(convM2S(r->buf, &r->work, n) == 0)			fatal("format error"); 		DEBUG(DFD, "%F\n", &r->work);		(fcalls[r->work.type])(r);	}} voidreply(Fcall *r, Fcall *t, char *err){	char data[MAXFDATA+MAXMSG];	int n; 	t->tag = r->tag;	t->fid = r->fid;	if(err) {		t->type = Rerror;		strncpy(t->ename, err, ERRLEN);	}	else 		t->type = r->type + 1; 	DEBUG(DFD, "\t%F\n", t); 	n = convS2M(t, data);	if(write9p(netfd, data, n)!=n)		fatal("mount write");} Fid *getfid(int nr){	Fid *f; 	for(f = fidhash(nr); f; f = f->next)		if(f->nr == nr)			return f; 	return 0;} intfreefid(int nr){	Fid *f, **l;	char buf[128]; 	l = &fidhash(nr);	for(f = *l; f; f = f->next) {		if(f->nr == nr) {			if(f->mpend)				f->mpend->busy = 0;			if(f->mid) {				sprint(buf, "/mnt/exportfs/%d", f->mid);				unmount(0, buf);				psmap[f->mid] = 0;			}			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 = mallocz(sizeof(Fid) * Fidchunk, 1);		if(fidfree == 0)			fatal("out of memory"); 		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->mpend = 0;	new->mid = 0; 	return new;	} Fsrpc *getsbuf(void){	static int ap;	int look, rounds;	Fsrpc *wb; 	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; 		return wb;	}	fatal("No more work buffers");	return nil;} voidfreefile(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);	f = parent;	if(f != nil)		goto Loop;} File *file(File *parent, char *name){	Dir dir;	char buf[128];	File *f; 	DEBUG(DFD, "\tfile: 0x%p %s name %s\n", parent, parent->name, name); 	makepath(buf, parent, name);	if(dirstat(buf, &dir) < 0)		return nil; 	for(f = parent->child; f; f = f->childlist)		if(strcmp(name, f->name) == 0)			break; 	if(f == nil){		f = mallocz(sizeof(File), 1);		if(f == 0)			fatal("no memory");		strcpy(f->name, name); 		f->parent = parent;		f->childlist = parent->child;		parent->child = f;		parent->ref++;		f->ref = 0;		filecnt++;	}	f->ref++;	f->qid.vers = dir.qid.vers;	f->qidt = uniqueqid(&dir);	f->qid.path = f->qidt->uniqpath; 	f->inval = 0;	 	return f;} voidinitroot(void){	Dir dir; 	root = mallocz(sizeof(File), 1);	if(root == 0)		fatal("no memory"); 	strcpy(root->name, ".");	if(dirstat(root->name, &dir) < 0)		fatal("root stat"); 	root->ref = 1;	root->qid.vers = dir.qid.vers;	root->qidt = uniqueqid(&dir);	root->qid.path = root->qidt->uniqpath; 	psmpt = mallocz(sizeof(File), 1);	if(psmpt == 0)		fatal("no memory"); 	strcpy(psmpt->name, "/");	if(dirstat(psmpt->name, &dir) < 0)		return; 	psmpt->ref = 1;	psmpt->qid.vers = dir.qid.vers;	psmpt->qidt = uniqueqid(&dir);	psmpt->qid.path = psmpt->qidt->uniqpath; 	psmpt = file(psmpt, "mnt");	if(psmpt == 0)		return;	psmpt = file(psmpt, "exportfs");} voidmakepath(char *s, File *p, char *name){	int i;	char *c, *seg[256]; 	seg[0] = name;	for(i = 1; i < 100 && p; i++, p = p->parent)		seg[i] = p->name; 	while(i--) {		for(c = seg[i]; *c; c++)			*s++ = *c;		*s++ = '/';	}	while(s[-1] == '/')		s--;	*s = '\0';} intqidhash(ulong path){	int h, n; 	h = 0;	for(n=0; n<32; n+=Nqidbits){		h ^= path;		path >>= Nqidbits;	}	return h & (Nqidtab-1);} voidfreeqid(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;} intqidexists(ulong 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;

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