[PATCH] jbd2: 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/jbd2/revoke.c |   35 ++++++++++++++++++++---------------
 1 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 07e4703..5a020f1 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -167,33 +167,38 @@ static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
 	return NULL;
 }
 
+void jbd2_journal_destroy_revoke_caches(void)
+{
+	if (jbd2_revoke_record_cache) {
+		kmem_cache_destroy(jbd2_revoke_record_cache);
+		jbd2_revoke_record_cache = NULL;
+	}
+	if (jbd2_revoke_table_cache) {
+		kmem_cache_destroy(jbd2_revoke_table_cache);
+		jbd2_revoke_table_cache = NULL;
+	}
+}
+
 int __init jbd2_journal_init_revoke_caches(void)
 {
+	J_ASSERT(!jbd2_revoke_record_cache);
+	J_ASSERT(!jbd2_revoke_table_cache);
+
 	jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
 					   sizeof(struct jbd2_revoke_record_s),
 					   0,
 					   SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
 					   NULL);
-	if (jbd2_revoke_record_cache == 0)
-		return -ENOMEM;
-
 	jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
 					   sizeof(struct jbd2_revoke_table_s),
 					   0, SLAB_TEMPORARY, NULL);
-	if (jbd2_revoke_table_cache == 0) {
-		kmem_cache_destroy(jbd2_revoke_record_cache);
-		jbd2_revoke_record_cache = NULL;
+
+	if (jbd2_revoke_table_cache && jbd2_revoke_table_cache) {
+		return 0;
+	} else {
+		jbd2_journal_destroy_revoke_caches();
 		return -ENOMEM;
 	}
-	return 0;
-}
-
-void jbd2_journal_destroy_revoke_caches(void)
-{
-	kmem_cache_destroy(jbd2_revoke_record_cache);
-	jbd2_revoke_record_cache = NULL;
-	kmem_cache_destroy(jbd2_revoke_table_cache);
-	jbd2_revoke_table_cache = NULL;
 }
 
 static struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size)
-- 
1.5.3.7