- Check the result of malloc(M_NOWAIT) in replay_alloc(). The caller

  (replay_alloc()) knows how to handle replay_alloc() failure.
- Eliminate 'freed_one' variable, it is not needed - when no entry is found
  rce will be NULL.
- Add locking assertions where we expect a rc_lock to be held.

Reviewed by:	rmacklem
MFC after:	2 weeks

1 files changed, 25 insertions, 20 deletions

diff --git a/sys/rpc/replay.c b/sys/rpc/replay.c
index 2e92017689a1..1bd5378d9fbe 100644
--- a/sys/rpc/replay.c
+++ b/sys/rpc/replay.c
@@ -113,8 +113,12 @@ replay_alloc(struct replay_cache *rc,
 {
 	struct replay_cache_entry *rce;
 
+	mtx_assert(&rc->rc_lock, MA_OWNED);
+
 	rc->rc_count++;
 	rce = malloc(sizeof(*rce), M_RPC, M_NOWAIT|M_ZERO);
+	if (!rce)
+		return (NULL);
 	rce->rce_hash = h;
 	rce->rce_msg = *msg;
 	bcopy(addr, &rce->rce_addr, addr->sa_len);
@@ -129,6 +133,8 @@ static void
 replay_free(struct replay_cache *rc, struct replay_cache_entry *rce)
 {
 
+	mtx_assert(&rc->rc_lock, MA_OWNED);
+
 	rc->rc_count--;
 	TAILQ_REMOVE(&rc->rc_cache[rce->rce_hash], rce, rce_link);
 	TAILQ_REMOVE(&rc->rc_all, rce, rce_alllink);
@@ -143,26 +149,25 @@ static void
 replay_prune(struct replay_cache *rc)
 {
 	struct replay_cache_entry *rce;
-	bool_t freed_one;
-
-	if (rc->rc_count >= REPLAY_MAX || rc->rc_size > rc->rc_maxsize) {
-		do {
-			freed_one = FALSE;
-			/*
-			 * Try to free an entry. Don't free in-progress entries
-			 */
-			TAILQ_FOREACH_REVERSE(rce, &rc->rc_all,
-			    replay_cache_list, rce_alllink) {
-				if (rce->rce_repmsg.rm_xid) {
-					replay_free(rc, rce);
-					freed_one = TRUE;
-					break;
-				}
-			}
-		} while (freed_one
-		    && (rc->rc_count >= REPLAY_MAX
-			|| rc->rc_size > rc->rc_maxsize));
-	}
+
+	mtx_assert(&rc->rc_lock, MA_OWNED);
+
+	if (rc->rc_count < REPLAY_MAX && rc->rc_size <= rc->rc_maxsize)
+		return;
+
+	do {
+		/*
+		 * Try to free an entry. Don't free in-progress entries.
+		 */
+		TAILQ_FOREACH_REVERSE(rce, &rc->rc_all, replay_cache_list,
+		    rce_alllink) {
+			if (rce->rce_repmsg.rm_xid)
+				break;
+		}
+		if (rce)
+			replay_free(rc, rce);
+	} while (rce && (rc->rc_count >= REPLAY_MAX
+	    || rc->rc_size > rc->rc_maxsize));
 }
 
 enum replay_state