Linux-NFS Archive on lore.kernel.org
 help / color / Atom feed
* [PATCH] SUNRPC/cache: Allow garbage collection of invalid cache entries
@ 2020-01-14 16:57 Trond Myklebust
  0 siblings, 0 replies; only message in thread
From: Trond Myklebust @ 2020-01-14 16:57 UTC (permalink / raw)
  To: J. Bruce Fields; +Cc: linux-nfs

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.

Fixes: d6fc8821c2d2 ("SUNRPC/Cache: Always treat the invalid cache as unexpired")
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(-)

diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index f8603724fbee..0428dd23fd79 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -202,9 +202,6 @@ 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 52d927210d32..99d630150af6 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -65,13 +65,14 @@ 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;
@@ -114,17 +115,18 @@ 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);
-- 
2.24.1


^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-14 16:57 [PATCH] SUNRPC/cache: Allow garbage collection of invalid cache entries Trond Myklebust

Linux-NFS Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-nfs/0 linux-nfs/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-nfs linux-nfs/ https://lore.kernel.org/linux-nfs \
		linux-nfs@vger.kernel.org
	public-inbox-index linux-nfs

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-nfs


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git