[PATCH 3/3][v2] jbd: replace potentially false assertion with if block

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

If an error occurs during jbd cache initialisation it is possible for the
journal_head_cache to be NULL when journal_destroy_journal_head_cache is
called. Replace the J_ASSERT with an if block to handle the situation
correctly.

Note that even with this fix things will break badly if jbd is statically
compiled in and cache initialisation fails.

Signed-off-by: Duane Griffin <duaneg@dghda.com
---
 fs/jbd/journal.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 1ecd005..f6a7c93 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -1641,9 +1641,10 @@ static int journal_init_journal_head_cache(void)
 
 static void journal_destroy_journal_head_cache(void)
 {
-	J_ASSERT(journal_head_cache != NULL);
-	kmem_cache_destroy(journal_head_cache);
-	journal_head_cache = NULL;
+	if (journal_head_cache) {
+		kmem_cache_destroy(journal_head_cache);
+		journal_head_cache = NULL;
+	}
 }
 
 /*
-- 
1.5.3.7