[Cluster-devel] [GFS2 PATCH 1/2] GFS2: Move glock superblock pointer to field gl_name

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On 09/07/15 19:25, Bob Peterson wrote:
> What uniquely identifies a glock in the glock hash table is not
> gl_name, but gl_name and its superblock pointer. This patch makes
> the gl_name field correspond to a unique glock identifier. That will
> allow us to simplify hashing with a future patch, since the hash
> algorithm can then take the gl_name and hash its components in one
> operation.
> ---
[snip]
> diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
> index a1ec7c2..4de7853 100644
> --- a/fs/gfs2/incore.h
> +++ b/fs/gfs2/incore.h
> @@ -205,11 +205,13 @@ enum {
>   struct lm_lockname {
>   	u64 ln_number;
>   	unsigned int ln_type;
> +	struct gfs2_sbd *ln_sbd;
>   };
>   
This looks like its adding a hole on 64 bit arches... can we swap the 
order of ln_type and ln_sbd, or even make the sbd the first element of 
this? That way a memcmp of two of lm_locknames doesn't have to include 
the hole in the comparison, which I assume is what you want here?

Steve.