[6/8] SUNRPC/cache: Allow garbage collection of invalid cache entries
diff mbox series

Message ID 20200301232145.1465430-7-trond.myklebust@hammerspace.com
State New
Headers show
Series
  • Bugfixes and tracing enhancements for knfsd
Related show

Commit Message

Trond Myklebust March 1, 2020, 11:21 p.m. UTC
If the cache entry never gets initialised, we want the garbage
collector to be able to evict it. Otherwise if the upcall daemon
fails to initialise the entry, we end up never expiring it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 include/linux/sunrpc/cache.h |  3 ---
 net/sunrpc/cache.c           | 36 +++++++++++++++++++-----------------
 2 files changed, 19 insertions(+), 20 deletions(-)

Patch
diff mbox series

diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 656882a50991..532cdbda43da 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -209,9 +209,6 @@  static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
 
 static inline bool cache_is_expired(struct cache_detail *detail, struct cache_head *h)
 {
-	if (!test_bit(CACHE_VALID, &h->flags))
-		return false;
-
 	return  (h->expiry_time < seconds_since_boot()) ||
 		(detail->flush_time >= h->last_refresh);
 }
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 5e14513603cb..b7ddb2affb7e 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -64,13 +64,14 @@  static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(tmp, head, cache_list) {
-		if (detail->match(tmp, key)) {
-			if (cache_is_expired(detail, tmp))
-				continue;
-			tmp = cache_get_rcu(tmp);
-			rcu_read_unlock();
-			return tmp;
-		}
+		if (!detail->match(tmp, key))
+			continue;
+		if (test_bit(CACHE_VALID, &tmp->flags) &&
+		    cache_is_expired(detail, tmp))
+			continue;
+		tmp = cache_get_rcu(tmp);
+		rcu_read_unlock();
+		return tmp;
 	}
 	rcu_read_unlock();
 	return NULL;
@@ -113,17 +114,18 @@  static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
 
 	/* check if entry appeared while we slept */
 	hlist_for_each_entry_rcu(tmp, head, cache_list) {
-		if (detail->match(tmp, key)) {
-			if (cache_is_expired(detail, tmp)) {
-				sunrpc_begin_cache_remove_entry(tmp, detail);
-				freeme = tmp;
-				break;
-			}
-			cache_get(tmp);
-			spin_unlock(&detail->hash_lock);
-			cache_put(new, detail);
-			return tmp;
+		if (!detail->match(tmp, key))
+			continue;
+		if (test_bit(CACHE_VALID, &tmp->flags) &&
+		    cache_is_expired(detail, tmp)) {
+			sunrpc_begin_cache_remove_entry(tmp, detail);
+			freeme = tmp;
+			break;
 		}
+		cache_get(tmp);
+		spin_unlock(&detail->hash_lock);
+		cache_put(new, detail);
+		return tmp;
 	}
 
 	hlist_add_head_rcu(&new->cache_list, head);