merge

1 files changed, 503 insertions, 0 deletions

diff --git a/sys/src/cmd/exportfs/io.c b/sys/src/cmd/exportfs/io.c
new file mode 100644
index 000000000..ad1d7154b
--- /dev/null
+++ b/sys/src/cmd/exportfs/io.c
@@ -0,0 +1,503 @@
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#define Extern
+#include "exportfs.h"
+
+#define QIDPATH	((1LL<<48)-1)
+vlong newqid = 0;
+
+void (*fcalls[])(Fsrpc*) =
+{
+	[Tversion]	Xversion,
+	[Tauth]	Xauth,
+	[Tflush]	Xflush,
+	[Tattach]	Xattach,
+	[Twalk]		Xwalk,
+	[Topen]		slave,
+	[Tcreate]	Xcreate,
+	[Tclunk]	Xclunk,
+	[Tread]		slave,
+	[Twrite]	slave,
+	[Tremove]	Xremove,
+	[Tstat]		Xstat,
+	[Twstat]	Xwstat,
+};
+
+/* accounting and debugging counters */
+int	filecnt;
+int	freecnt;
+int	qidcnt;
+int	qfreecnt;
+int	ncollision;
+
+
+/*
+ * Start serving file requests from the network
+ */
+void
+io(void)
+{
+	Fsrpc *r;
+	int n;
+
+	for(;;) {
+		r = getsbuf();
+		n = read9pmsg(0, r->buf, messagesize);
+		if(n <= 0)
+			fatal(nil);
+		if(convM2S(r->buf, n, &r->work) != n)
+			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 n;
+
+	t->tag = r->tag;
+	t->fid = r->fid;
+	if(err != nil) {
+		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(write(1, data, n) != n){
+		/* not fatal, might have got a note due to flush */
+		fprint(2, "exportfs: short write in reply: %r\n");
+	}
+	free(data);
+}
+
+void
+mounterror(char *err)
+{
+	Fsrpc *r;
+	int n;
+
+	r = getsbuf();
+	r->work.tag = NOTAG;
+	r->work.fid = NOFID;
+	r->work.type = Rerror;
+	r->work.ename = err;
+	n = convS2M(&r->work, r->buf, messagesize);
+	write(1, r->buf, n);
+	exits(err);
+}
+
+Fid *
+getfid(int nr)
+{
+	Fid *f;
+
+	for(f = fidhash(nr); f != nil; f = f->next)
+		if(f->nr == nr)
+			return f;
+
+	return nil;
+}
+
+int
+freefid(int nr)
+{
+	Fid *f, **l;
+	char buf[128];
+
+	l = &fidhash(nr);
+	for(f = *l; f != nil; f = f->next) {
+		if(f->nr == nr) {
+			if(f->mid) {
+				snprint(buf, sizeof(buf), "/mnt/exportfs/%d", f->mid);
+				unmount(0, buf);
+				psmap[f->mid] = 0;
+			}
+			if(f->f != nil) {
+				freefile(f->f);
+				f->f = nil;
+			}
+			if(f->dir != nil){
+				free(f->dir);
+				f->dir = 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 != nil; new = new->next)
+		if(new->nr == nr)
+			return nil;
+
+	if(fidfree == nil) {
+		fidfree = emallocz(sizeof(Fid) * Fidchunk);
+
+		for(i = 0; i < Fidchunk-1; i++)
+			fidfree[i].next = &fidfree[i+1];
+
+		fidfree[Fidchunk-1].next = nil;
+	}
+
+	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;	
+}
+
+static struct {
+	Lock;
+	Fsrpc	*free;
+
+	/* statistics */
+	int	nalloc;
+	int	nfree;
+}	sbufalloc;
+
+Fsrpc *
+getsbuf(void)
+{
+	Fsrpc *w;
+
+	lock(&sbufalloc);
+	w = sbufalloc.free;
+	if(w != nil){
+		sbufalloc.free = w->next;
+		w->next = nil;
+		sbufalloc.nfree--;
+		unlock(&sbufalloc);
+	} else {
+		sbufalloc.nalloc++;
+		unlock(&sbufalloc);
+		w = emallocz(sizeof(*w) + messagesize);
+	}
+	w->flushtag = NOTAG;
+	return w;
+}
+
+void
+putsbuf(Fsrpc *w)
+{
+	w->flushtag = NOTAG;
+	lock(&sbufalloc);
+	w->next = sbufalloc.free;
+	sbufalloc.free = w;
+	sbufalloc.nfree++;
+	unlock(&sbufalloc);
+}
+
+void
+freefile(File *f)
+{
+	File *parent, *child;
+
+	while(--f->ref == 0){
+		freecnt++;
+		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);
+		free(f);
+		f = parent;
+	}
+}
+
+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);
+	if(patternfile != nil && excludefile(path)){
+		free(path);
+		return nil;
+	}
+	dir = dirstat(path);
+	free(path);
+	if(dir == nil)
+		return nil;
+
+	for(f = parent->child; f != nil; 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 == nil)
+		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 = emallocz(n);
+	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;
+
+	if(--q->ref)
+		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);
+	}
+	qidcnt++;
+	q = emallocz(sizeof(Qidtab));
+	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 != nil) {
+		va_start(arg, s);
+		vsnprint(buf, ERRMAX, s, arg);
+		va_end(arg);
+	}
+
+	/* Clear away the slave children */
+	for(m = Proclist; m != nil; m = m->next)
+		postnote(PNPROC, m->pid, "kill");
+
+	if(s != nil) {
+		DEBUG(DFD, "%s\n", buf);
+		sysfatal("%s", buf);	/* caution: buf could contain '%' */
+	} else
+		exits(nil);
+}
+
+void*
+emallocz(uint n)
+{
+	void *p;
+
+	p = mallocz(n, 1);
+	if(p == nil)
+		fatal(Enomem);
+	setmalloctag(p, getcallerpc(&n));
+	return p;
+}
+
+char*
+estrdup(char *s)
+{
+	char *t;
+
+	t = strdup(s);
+	if(t == nil)
+		fatal(Enomem);
+	setmalloctag(t, getcallerpc(&s));
+	return t;
+}