shithub: riscv

Info  •  Files  •  Log  •  Branches

upas/fs: make sure mbox is locked during msgdecref() in rclunk()

--- a/sys/src/cmd/upas/fs/fs.c

+++ b/sys/src/cmd/upas/fs/fs.c

@@ -1442,17 +1442,17 @@

 	/* coherence(); */

 	f->fid = -1;

 	f->open = 0;

-	if(f->mtop){

-		qlock(f->mb);

-		msgdecref(f->mb, f->mtop);

-		qunlock(f->mb);

-	}

+	mb = f->mb;

+	if(mb != nil)

+		qlock(mb);

+	if(f->mtop)

+		msgdecref(mb, f->mtop);

 	if(f->m)

-		msgdecref(f->mb, gettopmsg(f->mb, f->m));

+		msgdecref(mb, gettopmsg(mb, f->m));

 	f->m = f->mtop = nil;

-	mb = f->mb;

 	if(mb != nil){

 		f->mb = nil;

+		qunlock(mb);

 		assert(mb->refs > 0);

 		qlock(&mbllock);

 		mboxdecref(mb);