[sheepdog] [PATCH 2/9] sheep: recover from local if possible

[Liu Yuan]

On 05/07/2013 01:45 AM, MORITA Kazutaka wrote:
> From: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
> 
> Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
> ---
>  sheep/recovery.c |   17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/sheep/recovery.c b/sheep/recovery.c
> index dc38dac..688058a 100644
> --- a/sheep/recovery.c
> +++ b/sheep/recovery.c
> @@ -141,7 +141,7 @@ static int do_recover_object(struct recovery_work *rw)
>  	struct vnode_info *old;
>  	uint64_t oid = rw->oids[rw->done];
>  	uint32_t epoch = rw->epoch, tgt_epoch = rw->epoch;
> -	int nr_copies, ret, i;
> +	int nr_copies, ret, i, start = 0;
>  
>  	old = grab_vnode_info(rw->old_vinfo);
>  
> @@ -149,13 +149,26 @@ again:
>  	sd_dprintf("try recover object %"PRIx64" from epoch %"PRIu32, oid,
>  		   tgt_epoch);
>  
> -	/* Let's do a breadth-first search */
>  	nr_copies = get_obj_copy_number(oid, old->nr_zones);
> +	/* find local node first to try to recover from local */
>  	for (i = 0; i < nr_copies; i++) {
>  		const struct sd_vnode *tgt_vnode;
>  
>  		tgt_vnode = oid_to_vnode(old->vnodes, old->nr_vnodes, oid, i);
>  
> +		if (vnode_is_local(tgt_vnode)) {
> +			start = i;
> +			break;
> +		}
> +	}
> +
> +	/* Let's do a breadth-first search */
> +	for (i = 0; i < nr_copies; i++) {
> +		const struct sd_vnode *tgt_vnode;
> +		int idx = (i + start) % nr_copies;
> +
> +		tgt_vnode = oid_to_vnode(old->vnodes, old->nr_vnodes, oid, idx);
> +
>  		if (is_invalid_vnode(tgt_vnode, rw->cur_vinfo->nodes,
>  				     rw->cur_vinfo->nr_nodes))
>  			continue;
> 

I think we'd better stop bloating the do_recover_object by squashing
more lines. How about putting all these two for loop in
recover_object_from_replica(), thus duplicate vnode_is_local() will be
eliminated and resulting in smaller function do_recover_object.

Thanks,
Yuan