Re: [PATCH 2/3] jbd2: replace potentially false assertion with if block

[Andreas Dilger <adilger@sun.com>]

On Mar 07, 2008  01:31 +0000, Duane Griffin wrote:
> If an error occurs during jbd2 cache initialisation it is possible for the
> journal_head_cache to be NULL when jbd2_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 jbd2 is statically
> compiled in and cache initialisation fails.

It would probably be prudent to verify that these caches are initialized
at journal_load() time and either re-try to create the cache, and/or report
an error in that case and refuse to continue mounting.

Also, I note that journal_init_journal_head_cache() is comparing pointers
to "0", a style no-no...

> Signed-off-by: Duane Griffin <duaneg@dghda.com>

Acked-by: Andreas Dilger <adilger@sun.com>
> ---
>  fs/jbd2/journal.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index 96ba846..0d8a595 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1985,9 +1985,10 @@ static int journal_init_jbd2_journal_head_cache(void)
>  
>  static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
>  {
> -	J_ASSERT(jbd2_journal_head_cache != NULL);
> -	kmem_cache_destroy(jbd2_journal_head_cache);
> -	jbd2_journal_head_cache = NULL;
> +	if (jbd2_journal_head_cache) {
> +		kmem_cache_destroy(jbd2_journal_head_cache);
> +		jbd2_journal_head_cache = NULL;
> +	}
>  }
>  
>  /*
> -- 
> 1.5.3.7
> 
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Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.