[PATCH] jbd: tidy up revoke cache initialisation and destruction

["Duane Griffin" <duaneg@dghda.com>]

Make revocation cache destruction safe to call if initialisation fails
partially or entirely. This allows it to be used to cleanup in the case of
initialisation failure, simplifying that code slightly.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
---
 fs/jbd/revoke.c |   35 ++++++++++++++++++++---------------
 1 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c
index 1ef5c80..c1fcd62 100644
--- a/fs/jbd/revoke.c
+++ b/fs/jbd/revoke.c
@@ -166,33 +166,38 @@ static struct jbd_revoke_record_s *find_revoke_record(journal_t *journal,
 	return NULL;
 }
 
+void journal_destroy_revoke_caches(void)
+{
+	if (revoke_record_cache) {
+		kmem_cache_destroy(revoke_record_cache);
+		revoke_record_cache = NULL;
+	}
+	if (revoke_table_cache) {
+		kmem_cache_destroy(revoke_table_cache);
+		revoke_table_cache = NULL;
+	}
+}
+
 int __init journal_init_revoke_caches(void)
 {
+	J_ASSERT(!revoke_record_cache);
+	J_ASSERT(!revoke_table_cache);
+
 	revoke_record_cache = kmem_cache_create("revoke_record",
 					   sizeof(struct jbd_revoke_record_s),
 					   0,
 					   SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
 					   NULL);
-	if (revoke_record_cache == 0)
-		return -ENOMEM;
-
 	revoke_table_cache = kmem_cache_create("revoke_table",
 					   sizeof(struct jbd_revoke_table_s),
 					   0, SLAB_TEMPORARY, NULL);
-	if (revoke_table_cache == 0) {
-		kmem_cache_destroy(revoke_record_cache);
-		revoke_record_cache = NULL;
+
+	if (revoke_record_cache && revoke_table_cache) {
+		return 0;
+	} else {
+		journal_destroy_revoke_caches();
 		return -ENOMEM;
 	}
-	return 0;
-}
-
-void journal_destroy_revoke_caches(void)
-{
-	kmem_cache_destroy(revoke_record_cache);
-	revoke_record_cache = NULL;
-	kmem_cache_destroy(revoke_table_cache);
-	revoke_table_cache = NULL;
 }
 
 static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size)
-- 
1.5.3.7