jbd: tidy up revoke cache initialisation and destruction

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>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c
index 8ff5a7b89b9ae6ef852b86f62d32e1de6b0b8b7c..c7bd649bbbdcfe032c46c52ed235bfda7a5e40e9 100644 (file)
--- a/fs/jbd/revoke.c
+++ b/fs/jbd/revoke.c
@@ -166,33 +166,43 @@ 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)
-               return -ENOMEM;
+               goto record_cache_failure;
 
        revoke_table_cache = kmem_cache_create("revoke_table",
                                           sizeof(struct jbd_revoke_table_s),
                                           0, SLAB_TEMPORARY, NULL);
-       if (!revoke_table_cache) {
-               kmem_cache_destroy(revoke_record_cache);
-               revoke_record_cache = NULL;
-               return -ENOMEM;
-       }
+       if (!revoke_table_cache)
+               goto table_cache_failure;
+
        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;
+table_cache_failure:
+       journal_destroy_revoke_caches();
+record_cache_failure:
+       return -ENOMEM;
 }
 
 static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size)