upas/fs: rework the refcounting, use 64bit qid path, add checks

add function to check the refcounts for Mailbox and Message on a fid

use the full 64 bit of the qid.path, so we can use the full 32 bit for the id

instead of only maintaining refcount for the top message, msgincref() now
adds a reference to all its parent messages including self and top message.
then we can check in recursive delmessage() that all the parts have a zero
refcount.

remove the Fid.mtop field, it was never used.

make sure deletion and flag changes only affect the top message.

cachefree(): only look for top message in lru. sub-parts are never
added to the cache.

use the nparts field when reading sub-part of existing message, so
that we parse the index right in case the number of parts somehow
changed.

messages marked as Deleted but still in inbox should be written
to the index.

6 files changed, 189 insertions, 201 deletions

diff --git a/sys/src/cmd/upas/fs/cache.c b/sys/src/cmd/upas/fs/cache.c
index 8ac23a1ad..6620670fa 100644
--- a/sys/src/cmd/upas/fs/cache.c
+++ b/sys/src/cmd/upas/fs/cache.c
@@ -31,17 +31,29 @@ notecache(Mailbox *mb, Message *m, long sz)
 	addlru(mb, m);
 }
 
-static void
-cachefree0(Mailbox *mb, Message *m, int force)
+void
+cachefree(Mailbox *mb, Message *m, int force)
 {
-	long sz, i;
-	Message *s;
+	long i;
+	Message *s, **ll;
 
 	if(!force && mb->fetch == nil)
 		return;
+	if(Topmsg(mb, m)){
+		for(ll = &mb->lru; *ll != nil; ll = &((*ll)->lru)){
+			if(*ll == m){
+				mb->nlru--;
+				*ll = m->lru;
+				m->lru = nil;
+				break;
+			}
+		}
+		if(mb->decache)
+			mb->decache(mb, m);
+		mb->cached -= m->csize;
+	}
 	for(s = m->part; s; s = s->next)
 		cachefree(mb, s, force);
-	dprint("cachefree: %D	%p,	%p\n", m->fileid, m, m->start);
 	if(m->mallocd){
 		free(m->start);
 		m->mallocd = 0;
@@ -58,7 +70,6 @@ cachefree0(Mailbox *mb, Message *m, int force)
 		free(m->references[i]);
 		m->references[i] = 0;
 	}
-	sz = m->csize;
 	m->csize = 0;
 	m->start = 0;
 	m->end = 0;
@@ -69,30 +80,10 @@ cachefree0(Mailbox *mb, Message *m, int force)
 	m->bend = 0;
 	m->mheader = 0;
 	m->mhend = 0;
-	if(mb->decache)
-		mb->decache(mb, m);
 	m->decoded = 0;
 	m->converted = 0;
 	m->badchars = 0;
 	m->cstate &= ~(Cheader|Cbody);
-	if(Topmsg(mb, m))
-		mb->cached -= sz;
-}
-
-void
-cachefree(Mailbox *mb, Message *m, int force)
-{
-	Message **ll;
-
-	for(ll = &mb->lru; *ll != nil; ll = &((*ll)->lru)){
-		if(*ll == m){
-			mb->nlru--;
-			*ll = m->lru;
-			m->lru = nil;
-			break;
-		}
-	}
-	cachefree0(mb, m, force);
 }
 
 void
@@ -277,7 +268,8 @@ middlecache(Mailbox *mb, Message *m)
 	}
 	if(y == 0)
 		return 0;
-	dprint("middlecache %d [%D] %lud %lud\n", m->id, m->fileid, (ulong)(m->end - m->start), m->size);
+	dprint("middlecache %lud [%D] %lud %lud\n",
+		m->id, m->fileid, (ulong)(m->end - m->start), m->size);
 	return cachebody(mb, m);
 }
 
@@ -292,7 +284,7 @@ cacheheaders(Mailbox *mb, Message *m)
 		return 0;
 	if(!Topmsg(mb, m))
 		return middlecache(mb, m);
-	dprint("cacheheaders %d %D\n", m->id, m->fileid);
+	dprint("cacheheaders %lud %D\n", m->id, m->fileid);
 	if(m->size < 10000)
 		r = fetch(mb, m, 0, m->size);
 	else for(r = 0; (o = m->end - m->start) < m->size; ){
@@ -327,7 +319,7 @@ digestmessage(Mailbox *mb, Message *m)
 		m->deleted = Dup;	/* no dups allowed */
 	}else
 		mtreeadd(mb, m);
-	dprint("%d %#A\n", m->id, m->digest);
+	dprint("%lud %#A\n", m->id, m->digest);
 }
 
 int
@@ -337,10 +329,10 @@ cachebody(Mailbox *mb, Message *m)
 
 	while(!Topmsg(mb, m))
 		m = m->whole;
-	if(!mb->fetch || m->cstate&Cbody)
+	if(mb->fetch == nil || m->cstate&Cbody)
 		return 0;
 	o = m->end - m->start;
-	dprint("cachebody %d [%D] %lud %lud %s", m->id, m->fileid, o, m->size, cstate(m));
+	dprint("cachebody %lud [%D] %lud %lud %s", m->id, m->fileid, o, m->size, cstate(m));
 	if(o < m->size)
 	if(fetch(mb, m, o, m->size - o) < 0)
 		return -1;
@@ -389,7 +381,7 @@ insurecache(Mailbox *mb, Message *m)
 {
 	if(m->deleted || !m->inmbox)
 		return -1;
-	msgincref(m);
+	msgincref(mb, m);
 	cacheidx(mb, m);
 	if((m->cstate & Cidx) == 0){
 		logmsg(m, "%s: can't cache: %s: %r", mb->path, m->name);
diff --git a/sys/src/cmd/upas/fs/dat.h b/sys/src/cmd/upas/fs/dat.h
index ff55a9960..653232383 100644
--- a/sys/src/cmd/upas/fs/dat.h
+++ b/sys/src/cmd/upas/fs/dat.h
@@ -74,7 +74,7 @@ struct Idx {
 
 typedef struct Message Message;
 struct Message {
-	int	id;
+	ulong	id;
 	int	refs;
 	int	subname;
 	char	name[12];
@@ -152,7 +152,7 @@ typedef struct Mailbox Mailbox;
 struct Mailbox {
 	int	refs;
 	Mailbox	*next;
-	int	id;
+	ulong	id;
 	int	flags;
 	char	rmflags;
 	char	dolock;		/* lock when syncing? */
@@ -209,7 +209,6 @@ int		insurecache(Mailbox*, Message*);
 void		putcache(Mailbox*, Message*);		/* asymmetricial */
 void		cachefree(Mailbox*, Message*, int);
 
-Message*	gettopmsg(Mailbox*, Message*);
 char*		syncmbox(Mailbox*, int);
 void*		emalloc(ulong);
 void*		erealloc(void*, ulong);
@@ -223,13 +222,12 @@ int		wraptls(int, char*);
 
 void		eprint(char*, ...);
 void		iprint(char *, ...);
-int		newid(void);
 char*		newmbox(char*, char*, int, Mailbox**);
 void		freembox(char*);
 char*		removembox(char*, int);
 void		syncallmboxes(void);
 void		logmsg(Message*, char*, ...);
-void		msgincref(Message*);
+void		msgincref(Mailbox*, Message*);
 void		msgdecref(Mailbox*, Message*);
 void		mboxincref(Mailbox*);
 void		mboxdecref(Mailbox*);
@@ -306,7 +304,7 @@ enum {
 	Qmboxctl,
 };
 
-#define PATH(id, f)	((((id) & 0xfffff)<<10) | (f))
+#define PATH(id, f)	(((uvlong)(id)<<10) | (f))
 #define FILE(p)		((p) & 0x3ff)
 
 /* hash table to aid in name lookup, all files have an entry */
@@ -314,16 +312,16 @@ typedef struct Hash Hash;
 struct Hash {
 	Hash	*next;
 	char	*name;
-	ulong	ppath;
+	uvlong	ppath;
 	Qid	qid;
 	Mailbox	*mb;
 	Message	*m;
 };
 
-uint	hash(char*);
-Hash	*hlook(ulong, char*);
-void	henter(ulong, char*, Qid, Message*, Mailbox*);
-void	hfree(ulong, char*);
+ulong	hash(char*);
+Hash	*hlook(uvlong, char*);
+void	henter(uvlong, char*, Qid, Message*, Mailbox*);
+void	hfree(uvlong, char*);
 
 char	*intern(char*);
 void	idxfree(Idx*);
diff --git a/sys/src/cmd/upas/fs/fs.c b/sys/src/cmd/upas/fs/fs.c
index 9f7ba2b64..52e7cc6ab 100644
--- a/sys/src/cmd/upas/fs/fs.c
+++ b/sys/src/cmd/upas/fs/fs.c
@@ -14,7 +14,6 @@ struct Fid
 	Fid	*next;
 	Mailbox	*mb;
 	Message	*m;
-	Message *mtop;		/* top level message */
 
 	long	foff;		/* offset/DIRLEN of finger */
 	Message	*fptr;		/* pointer to message at off */
@@ -132,8 +131,6 @@ static QLock	synclock;
 void
 sanemsg(Message *m)
 {
-	assert(m->refs < 100);
-	assert(m->next != m);
 	if(m->end < m->start)
 		abort();
 	if(m->ballocd && (m->start <= m->body && m->end >= m->body))
@@ -769,13 +766,10 @@ doclone(Fid *f, int nfid)
 		return nil;
 	nf->busy = 1;
 	nf->open = 0;
-	nf->mb = f->mb;
-	if(nf->mb)
+	if(nf->mb = f->mb)
 		mboxincref(nf->mb);
 	if(nf->m = f->m)
-		msgincref(gettopmsg(nf->mb, nf->m));
-	if(nf->mtop = f->mtop)
-		msgincref(nf->mtop);
+		msgincref(nf->mb, nf->m);
 	nf->qid = f->qid;
 	return nf;
 }
@@ -798,9 +792,10 @@ dowalk(Fid *f, char *name)
 {
 	char *rv, *p;
 	int t, t1;
-	Mailbox *mb;
 	Hash *h;
 
+	if(f->qid.type != QTDIR)
+		return Enotdir;
 	t = FILE(f->qid.path);
 	rv = Enotexist;
 
@@ -815,26 +810,16 @@ retry:
 	}else
 		h = hlook(f->qid.path, name);
 	if(h != nil){
+		if(h->mb)
+			mboxincref(h->mb);
+		if(h->m)
+			msgincref(h->mb, h->m);
 		if(f->m)
-			msgdecref(f->mb, gettopmsg(f->mb, f->m));
-		if(f->mb && f->mb != h->mb)
+			msgdecref(f->mb, f->m);
+		if(f->mb)
 			mboxdecref(f->mb);
-		f->mb = h->mb;
 		f->m = h->m;
-		if(f->m)
-			msgincref(gettopmsg(f->mb, f->m));
-		switch(t){
-		case Qtop:
-			if(f->mb)
-				mboxincref(f->mb);
-			break;
-		case Qmbox:
-			if(f->m){
-				msgincref(f->m);
-				f->mtop = f->m;
-			}
-			break;
-		}
+		f->mb = h->mb;
 		f->qid = h->qid;
 		if(t1 < Qmax)
 			f->qid.path = PATH(f->m->id, t1);	/* sleezy speedup */
@@ -842,18 +827,9 @@ retry:
 	}else if((p = strchr(name, '.')) != nil && *name != '.'){
 		*p = 0;
 		goto retry;
-	}
-
-	if(rv == nil)
-		return rv;
-
-	if(strcmp(name, ".") == 0)
-		return nil;
-
-	if(f->qid.type != QTDIR)
-		return Enotdir;
-
-	if(strcmp(name, "..") == 0){
+	} else if(strcmp(name, ".") == 0){
+		rv = nil;
+	} else if(strcmp(name, "..") == 0){
 		switch(t){
 		case Qtop:
 			f->qid.path = PATH(0, Qtop);
@@ -864,20 +840,19 @@ retry:
 			f->qid.path = PATH(0, Qtop);
 			f->qid.type = QTDIR;
 			f->qid.vers = 0;
-			mb = f->mb;
+			mboxdecref(f->mb);
 			f->mb = nil;
-			mboxdecref(mb);
 			break;
 		case Qdir:
 			if(Topmsg(f->mb, f->m)){
 				f->qid.path = PATH(f->mb->id, Qmbox);
 				f->qid.type = QTDIR;
 				f->qid.vers = f->mb->vers;
-				msgdecref(f->mb, f->mtop);
 				msgdecref(f->mb, f->m);
-				f->m = f->mtop = nil;
+				f->m = nil;
 			} else {
-				/* refs don't change; still the same message */
+				msgincref(f->mb, f->m->whole);
+				msgdecref(f->mb, f->m);
 				f->m = f->m->whole;
 				f->qid.path = PATH(f->m->id, Qdir);
 				f->qid.type = QTDIR;
@@ -987,6 +962,8 @@ readtopdir(Fid*, uchar *buf, long off, int cnt, int blen)
 	pos += m;
 		
 	for(mb = mbl; mb != nil; mb = mb->next){
+		assert(mb->refs > 0);
+
 		mkstat(&d, mb, nil, Qmbox);
 		m = convD2M(&d, &buf[n], blen - n);
 		if(off <= pos){
@@ -1008,6 +985,8 @@ readmboxdir(Fid *f, uchar *buf, long off, int cnt, int blen)
 	long pos;
 	Message *msg;
 
+	assert(f->mb->refs > 0);
+
 	if(off == 0)
 		syncmbox(f->mb, 1);
 
@@ -1198,7 +1177,6 @@ rwrite(Fid *f)
 {
 	char *argvbuf[1024], **argv, file[Pathlen], *err, *v0;
 	int i, t, argc, flags;
-	Message *m;
 
 	t = FILE(f->qid.path);
 	rhdr.count = thdr.count;
@@ -1288,21 +1266,19 @@ rwrite(Fid *f)
 		}
 		return Ebadctl;
 	case Qmboxctl:
-		if(f->mb && f->mb->ctl){
-			argc = tokenize(thdr.data, argv, nelem(argvbuf));
-			if(argc == 0)
-				return Ebadctl;
-			return f->mb->ctl(f->mb, argc, argv);
-		}
-		break;
+		if(f->mb->ctl == nil)
+			break;
+		argc = tokenize(thdr.data, argv, nelem(argvbuf));
+		if(argc == 0)
+			return Ebadctl;
+		return f->mb->ctl(f->mb, argc, argv);
 	case Qflags:
 		/*
 		 * modifying flags on subparts is a little strange.
 		 */
-		if(!f->mb || !f->m)
+		if(!Topmsg(f->mb, f->m))
 			break;
-		m = gettopmsg(f->mb, f->m);
-		return modflags(f->mb, m, thdr.data);
+		return modflags(f->mb, f->m, thdr.data);
 	}
 	return Eperm;
 }
@@ -1310,21 +1286,17 @@ rwrite(Fid *f)
 char*
 rclunk(Fid *f)
 {
-	Mailbox *mb;
-
 	f->busy = 1;
 	/* coherence(); */
 	f->fid = -1;
 	f->open = 0;
-	mb = f->mb;
-	if(f->mtop)
-		msgdecref(mb, f->mtop);
-	if(f->m)
-		msgdecref(mb, gettopmsg(mb, f->m));
-	f->m = f->mtop = nil;
-	if(mb){
+	if(f->m != nil){
+		msgdecref(f->mb, f->m);
+		f->m = nil;
+	}
+	if(f->mb != nil){
+		mboxdecref(f->mb);
 		f->mb = nil;
-		mboxdecref(mb);
 	}
 	f->busy = 0;
 	return 0;
@@ -1333,7 +1305,7 @@ rclunk(Fid *f)
 char *
 rremove(Fid *f)
 {
-	if(f->m != nil && f->m->deleted == 0)
+	if(f->mb != nil && f->m != nil && Topmsg(f->mb, f->m) && f->m->deleted == 0)
 		f->m->deleted = Deleted;
 	return rclunk(f);
 }
@@ -1357,6 +1329,28 @@ rwstat(Fid*)
 	return Eperm;
 }
 
+static Fid*
+checkfid(Fid *f)
+{
+	switch(FILE(f->qid.path)){
+	case Qtop:
+	case Qctl:
+		assert(f->mb == nil);
+		assert(f->m == nil);
+		break;
+	case Qmbox:
+	case Qmboxctl:
+		assert(f->mb != nil && f->mb->refs > 0);
+		assert(f->m == nil);
+		break;
+	default:
+		assert(f->mb != nil && f->mb->refs > 0);
+		assert(f->m != nil && f->m->refs > 0);
+		break;
+	}
+	return f;
+}
+
 Fid*
 newfid(int fid)
 {
@@ -1365,7 +1359,7 @@ newfid(int fid)
 	ff = 0;
 	for(f = fids; f; f = f->next)
 		if(f->fid == fid)
-			return f;
+			return checkfid(f);
 		else if(!ff && !f->busy)
 			ff = f;
 	if(ff){
@@ -1475,20 +1469,6 @@ reader(void)
 	}
 }
 
-int
-newid(void)
-{
-	int rv;
-	static int id;
-	static Lock idlock;
-
-	lock(&idlock);
-	rv = ++id;
-	unlock(&idlock);
-
-	return rv;
-}
-
 void
 error(char *s)
 {
@@ -1600,10 +1580,10 @@ readheader(Message *m, char *buf, int off, int cnt)
 	return to - buf;
 }
 
-uint
+ulong
 hash(char *s)
 {
-	uint c, h;
+	ulong c, h;
 
 	h = 0;
 	while(c = *s++)
@@ -1613,9 +1593,9 @@ hash(char *s)
 }
 
 Hash*
-hlook(ulong ppath, char *name)
+hlook(uvlong ppath, char *name)
 {
-	int h;
+	ulong h;
 	Hash *hp;
 
 	h = (hash(name)+ppath) % nelem(htab);
@@ -1626,9 +1606,9 @@ hlook(ulong ppath, char *name)
 }
 
 void
-henter(ulong ppath, char *name, Qid qid, Message *m, Mailbox *mb)
+henter(uvlong ppath, char *name, Qid qid, Message *m, Mailbox *mb)
 {
-	int h;
+	ulong h;
 	Hash *hp, **l;
 
 	h = (hash(name)+ppath) % nelem(htab);
@@ -1650,9 +1630,9 @@ henter(ulong ppath, char *name, Qid qid, Message *m, Mailbox *mb)
 }
 
 void
-hfree(ulong ppath, char *name)
+hfree(uvlong ppath, char *name)
 {
-	int h;
+	ulong h;
 	Hash *hp, **l;
 
 	h = (hash(name)+ppath) % nelem(htab);
diff --git a/sys/src/cmd/upas/fs/idx.c b/sys/src/cmd/upas/fs/idx.c
index 975211760..cce59c1b5 100644
--- a/sys/src/cmd/upas/fs/idx.c
+++ b/sys/src/cmd/upas/fs/idx.c
@@ -366,18 +366,20 @@ dead:
 			/*
 			 * read in mutable information.
 			 * currently this is only flags
+			 * and nparts.
 			 */
 			redux++;
 			if(level == 0)
 				m->deleted &= ~Dmark;
-			if(m->nparts)
+			n = m->nparts;
+			m->nparts = strtoul(f[21], 0, 0);
 			if(rdidx(b, mb, m, m->nparts, level + 1) == -1)
 				goto dead;
 			ll = &m->next;
-			idprint("%d seen before %d... %.2ux", level, m->id, m->cstate);
+			idprint("%d seen before %lud... %.2ux", level, m->id, m->cstate);
 			flags = m->flags;
 			m->flags |= strtoul(f[1], 0, 16);
-			if(flags != m->flags)
+			if(flags != m->flags || n != m->nparts)
 				m->cstate |= Cidxstale;
 			m->cstate |= Cidx;
 			idprint("→%.2ux\n", m->cstate);
@@ -385,7 +387,7 @@ dead:
 			continue;
 		}
 		m = newmessage(parent);
-		idprint("%d new %d %#A\n", level, m->id, digest);
+		idprint("%d new %lud %#A\n", level, m->id, digest);
 		m->digest = digest;
 		m->flags = strtoul(f[1], 0, 16);
 		m->fileid = rdfileid(f[2], level);
diff --git a/sys/src/cmd/upas/fs/mbox.c b/sys/src/cmd/upas/fs/mbox.c
index 9c6e23c02..a77996fd4 100644
--- a/sys/src/cmd/upas/fs/mbox.c
+++ b/sys/src/cmd/upas/fs/mbox.c
@@ -191,6 +191,20 @@ initheaders(void)
 		head[i].len = strlen(head[i].type);
 }
 
+static ulong
+newid(void)
+{
+	ulong rv;
+	static ulong id;
+	static Lock idlock;
+
+	lock(&idlock);
+	rv = ++id;
+	unlock(&idlock);
+
+	return rv;
+}
+
 char*
 newmbox(char *path, char *name, int flags, Mailbox **r)
 {
@@ -271,50 +285,42 @@ freembox(char *name)
 {
 	Mailbox **l, *mb;
 
-	for(l=&mbl; *l != nil; l=&(*l)->next)
-		if(strcmp(name, (*l)->name) == 0){
-			mb = *l;
+	for(l = &mbl; (mb = *l) != nil; l = &mb->next)
+		if(strcmp(name, mb->name) == 0){
 			*l = mb->next;
+			mb->next = nil;
+			hfree(PATH(0, Qtop), mb->name);
+			if(mb->ctl)
+				hfree(PATH(mb->id, Qmbox), "ctl");
 			mboxdecref(mb);
 			break;
 		}
-	hfree(PATH(0, Qtop), name);
-}
-
-void
-syncallmboxes(void)
-{
-	char *err;
-	Mailbox *m;
-
-	for(m = mbl; m != nil; m = m->next)
-		if(err = syncmbox(m, 0))
-			eprint("syncmbox: %s\n", err);
 }
 
-
 char*
 removembox(char *name, int flags)
 {
-	int found;
-	Mailbox **l, *mb;
+	Mailbox *mb;
 
-	found = 0;
-	for(l=&mbl; *l != nil; l=&(*l)->next)
-		if(strcmp(name, (*l)->path) == 0){
-			mb = *l;
-			*l = mb->next;
+	for(mb = mbl; mb != nil; mb = mb->next)
+		if(strcmp(name, mb->path) == 0){
 			mb->flags |= ORCLOSE;
 			mb->rmflags = flags;
-			mboxdecref(mb);
-			found = 1;
-			break;
+			freembox(mb->name);
+			return 0;
 		}
-	hfree(PATH(0, Qtop), name);
+	return "maibox not found";
+}
 
-	if(found == 0)
-		return "maibox not found";
-	return 0;
+void
+syncallmboxes(void)
+{
+	Mailbox *mb;
+	char *err;
+
+	for(mb = mbl; mb != nil; mb = mb->next)
+		if(err = syncmbox(mb, 0))
+			eprint("syncmbox: %s\n", err);
 }
 
 /*
@@ -347,7 +353,7 @@ rxtotm(Message *m, Tm *tm)
 	return r;
 }
 
-Message*
+static Message*
 gettopmsg(Mailbox *mb, Message *m)
 {
 	while(!Topmsg(mb, m))
@@ -355,7 +361,7 @@ gettopmsg(Mailbox *mb, Message *m)
 	return m;
 }
 
-void
+static void
 datesec(Mailbox *mb, Message *m)
 {
 	vlong v;
@@ -1011,31 +1017,32 @@ delmessage(Mailbox *mb, Message *m)
 {
 	Message **l;
 
+	assert(m->refs == 0);
+	while(m->part)
+		delmessage(mb, m->part);
+
 	mb->vers++;
 	msgfreed++;
 
-	if(m->whole != m){
+	if(m != m->whole){
 		/* unchain from parent */
 		for(l = &m->whole->part; *l && *l != m; l = &(*l)->next)
 			;
 		if(*l != nil)
 			*l = m->next;
-
+		m->next = nil;
 		/* clear out of name lookup hash table */
 		if(m->whole->whole == m->whole)
 			hfree(PATH(mb->id, Qmbox), m->name);
 		else
 			hfree(PATH(m->whole->id, Qdir), m->name);
 		hfree(PATH(m->id, Qdir), "xxx");		/* sleezy speedup */
-	}
-	if(Topmsg(mb, m)){
-		if(m != mb->root)
+
+		if(Topmsg(mb, m))
 			mtreedelete(mb, m);
 		cachefree(mb, m, 1);
+		idxfree(m);
 	}
-	idxfree(m);
-	while(m->part)
-		delmessage(mb, m->part);
 	free(m->unixfrom);
 	free(m->unixheader);
 	free(m->date822);
@@ -1093,7 +1100,7 @@ flagmessages(int argc, char **argv)
 
 	if(argc%2)
 		return "bad flags";
-	for(mb = mbl; mb; mb = mb->next)
+	for(mb = mbl; mb != nil; mb = mb->next)
 		if(strcmp(*argv, mb->name) == 0)
 			break;
 	if(mb == nil)
@@ -1114,21 +1121,33 @@ flagmessages(int argc, char **argv)
 }
 
 void
-msgincref(Message *m)
+msgincref(Mailbox *mb, Message *m)
 {
-	m->refs++;
+	assert(mb->refs > 0);
+	for(;; m = m->whole){
+		assert(m->refs >= 0);
+		m->refs++;
+		if(Topmsg(mb, m))
+			break;
+	}
 }
 
 void
 msgdecref(Mailbox *mb, Message *m)
 {
-	assert(m->refs > 0);
-	m->refs--;
-	if(m->refs == 0){
-		if(m->deleted)
-			syncmbox(mb, 1);
-		else
-			putcache(mb, m);
+	assert(mb->refs >= 0);
+	for(;; m = m->whole){
+		assert(m->refs > 0);
+		m->refs--;
+		if(Topmsg(mb, m)){
+			if(m->refs == 0){
+				if(m->deleted)
+					syncmbox(mb, 1);
+				else
+					putcache(mb, m);
+			}
+			break;
+		}
 	}
 }
 
@@ -1156,21 +1175,18 @@ void
 mboxdecref(Mailbox *mb)
 {
 	assert(mb->refs > 0);
-	mb->refs--;
-	if(mb->refs == 0){
-		syncmbox(mb, 1);
-		delmessage(mb, mb->root);
-		if(mb->ctl)
-			hfree(PATH(mb->id, Qmbox), "ctl");
-		if(mb->close)
-			mb->close(mb);
-		if(mb->flags & ORCLOSE && mb->remove)
-		if(mb->remove(mb, mb->rmflags))
-			rmidx(mb->path, mb->rmflags);
-		free(mb->mtree);
-		free(mb->d);
-		free(mb);
-	}
+	if(--mb->refs)
+		return;
+	syncmbox(mb, 1);
+	delmessage(mb, mb->root);
+	if(mb->close)
+		mb->close(mb);
+	if(mb->flags & ORCLOSE && mb->remove)
+	if(mb->remove(mb, mb->rmflags))
+		rmidx(mb->path, mb->rmflags);
+	free(mb->mtree);
+	free(mb->d);
+	free(mb);
 }
 
 
diff --git a/sys/src/cmd/upas/fs/mkfile b/sys/src/cmd/upas/fs/mkfile
index 28bf669e9..bbf141fc3 100644
--- a/sys/src/cmd/upas/fs/mkfile
+++ b/sys/src/cmd/upas/fs/mkfile
@@ -1,7 +1,7 @@
 </$objtype/mkfile
 <../mkupas
 
-TARG=	fs\
+TARG=fs
 
 OFILES=\
 	cache.$O\