[Cluster-devel] [GFS2 PATCH] GFS2: Use gfs2_rbm_incr in rgblk_free

[Steven Whitehouse]

Hi,

Looks like a really nice optimisation. Now in the -nmw tree. Thanks,

Steve.

On 03/10/14 13:38, Bob Peterson wrote:
> Hi,
>
> This patch speeds up GFS2 unlink operations by using function
> gfs2_rbm_incr rather than continuously calculating the rbm.
>
> Regards,
>
> Bob Peterson
> Red Hat File Systems
>
> Signed-off-by: Bob Peterson <rpeterso at redhat.com>
> ---
> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
> index 55ef72d..7474c41 100644
> --- a/fs/gfs2/rgrp.c
> +++ b/fs/gfs2/rgrp.c
> @@ -2097,7 +2097,7 @@ static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, u64 bstart,
>   				     u32 blen, unsigned char new_state)
>   {
>   	struct gfs2_rbm rbm;
> -	struct gfs2_bitmap *bi;
> +	struct gfs2_bitmap *bi, *bi_prev = NULL;
>   
>   	rbm.rgd = gfs2_blk2rgrpd(sdp, bstart, 1);
>   	if (!rbm.rgd) {
> @@ -2106,18 +2106,22 @@ static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, u64 bstart,
>   		return NULL;
>   	}
>   
> +	gfs2_rbm_from_block(&rbm, bstart);
>   	while (blen--) {
> -		gfs2_rbm_from_block(&rbm, bstart);
>   		bi = rbm_bi(&rbm);
> -		bstart++;
> -		if (!bi->bi_clone) {
> -			bi->bi_clone = kmalloc(bi->bi_bh->b_size,
> -					       GFP_NOFS | __GFP_NOFAIL);
> -			memcpy(bi->bi_clone + bi->bi_offset,
> -			       bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
> +		if (bi != bi_prev) {
> +			if (!bi->bi_clone) {
> +				bi->bi_clone = kmalloc(bi->bi_bh->b_size,
> +						      GFP_NOFS | __GFP_NOFAIL);
> +				memcpy(bi->bi_clone + bi->bi_offset,
> +				       bi->bi_bh->b_data + bi->bi_offset,
> +				       bi->bi_len);
> +			}
> +			gfs2_trans_add_meta(rbm.rgd->rd_gl, bi->bi_bh);
> +			bi_prev = bi;
>   		}
> -		gfs2_trans_add_meta(rbm.rgd->rd_gl, bi->bi_bh);
>   		gfs2_setbit(&rbm, false, new_state);
> +		gfs2_rbm_incr(&rbm);
>   	}
>   
>   	return rbm.rgd;