[Cluster-devel] [GFS2 PATCH] GFS2: eliminate i_generation from memory

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

We still need that, it is the generation number for NFS. Although it is
also identical to the no_formal_ino in recent kernels,

Steve.

On Wed, 2011-03-23 at 09:37 -0400, Bob Peterson wrote:
> Hi,
> 
> Since GFS2 doesn't rely upon generation numbers like GFS1, we do not
> need to copy the generation number into memory and out of memory.
> This patch eliminates the variable from the in-core structure and
> will reduce the memory requirements of GFS2.
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> --
> diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
> index 870a89d..2329296 100644
> --- a/fs/gfs2/incore.h
> +++ b/fs/gfs2/incore.h
> @@ -272,7 +272,6 @@ struct gfs2_inode {
>  	struct inode i_inode;
>  	u64 i_no_addr;
>  	u64 i_no_formal_ino;
> -	u64 i_generation;
>  	u64 i_eattr;
>  	unsigned long i_flags;		/* GIF_... */
>  	struct gfs2_glock *i_gl; /* Move into i_gh? */
> diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
> index 97d54a2..b4e416a 100644
> --- a/fs/gfs2/inode.c
> +++ b/fs/gfs2/inode.c
> @@ -261,7 +261,6 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
>  	ip->i_inode.i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);
>  
>  	ip->i_goal = be64_to_cpu(str->di_goal_meta);
> -	ip->i_generation = be64_to_cpu(str->di_generation);
>  
>  	ip->i_diskflags = be32_to_cpu(str->di_flags);
>  	gfs2_set_inode_flags(&ip->i_inode);
> @@ -626,7 +625,6 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
>  	di->di_major = cpu_to_be32(MAJOR(dev));
>  	di->di_minor = cpu_to_be32(MINOR(dev));
>  	di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
> -	di->di_generation = cpu_to_be64(*generation);
>  	di->di_flags = 0;
>  
>  	if (S_ISREG(mode)) {
> @@ -944,7 +942,6 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
>  
>  	str->di_goal_meta = cpu_to_be64(ip->i_goal);
>  	str->di_goal_data = cpu_to_be64(ip->i_goal);
> -	str->di_generation = cpu_to_be64(ip->i_generation);
>  
>  	str->di_flags = cpu_to_be32(ip->i_diskflags);
>  	str->di_height = cpu_to_be16(ip->i_height);
>