config_plex: don't allocate a rangelock struct.

lockrange: correctly expand rangelock struct, including expanding a
	   null struct.  Previously lockrange would attempt to lock a
	   NULL pointer under these circumstances.

Reported-by:	Ian Freislich <iang@uunet.co.za>

1 files changed, 3 insertions, 2 deletions

diff --git a/sys/dev/vinum/vinumlock.c b/sys/dev/vinum/vinumlock.c
index 9daf64d..8bc1320 100644
--- a/sys/dev/vinum/vinumlock.c
+++ b/sys/dev/vinum/vinumlock.c
@@ -268,10 +268,11 @@ lockrange(daddr_t stripe, struct buf *bp, struct plex *plex)
 	if (foundlocks >= plex->alloclocks) {		    /* searched the lot, */
 	    newlock = plex->alloclocks;
 	    EXPAND(plex->lock, struct rangelock, plex->alloclocks, INITIAL_LOCKS);
+	    pos = &plex->lock[newlock];
 	    while (newlock < plex->alloclocks)
 		plex->lock[newlock++].stripe = 0;
-	}
-	pos = lock;					    /* put it at the end */
+	} else
+	    pos = lock;					    /* put it at the end */
     }
     pos->stripe = stripe;
     pos->bp = bp;