embarassing off-by-one error that causes 
a clean venti shutdown to make the very last
written block unindexed.  ironically, a non-clean
shutdown works just fine.


Reference: /n/sources/patch/applied/venti-oops
Date: Tue Apr  1 22:22:31 CES 2008
Signed-off-by: rsc@swtch.com

--- /sys/src/cmd/venti/srv/icache.c	Tue Apr  1 22:21:57 2008
+++ /sys/src/cmd/venti/srv/icache.c	Tue Apr  1 22:21:56 2008
@@ -498,7 +498,7 @@
 	trace(TraceProc, "icachedirty enter");
 	qlock(&icache.lock);
 	for(ie = icache.dirty.next; ie != &icache.dirty; ie=ie->next){
-		if(ie->state == IEDirty && ie->ia.addr < limit){
+		if(ie->state == IEDirty && ie->ia.addr <= limit){
 			h = hashbits(ie->score, 32);
 			if(lo <= h && h <= hi){
 				ie->nextdirty = dirty;