Re: [PATCH 29/33] libceph: return primary from ceph_calc_pg_acting()

[Alex Elder <elder@ieee.org>]

On 03/27/2014 01:18 PM, Ilya Dryomov wrote:
> In preparation for adding support for primary_temp, stop assuming
> primaryness: add a primary out parameter to ceph_calc_pg_acting() and
> change call sites accordingly.  Primary is now specified separately
> from the order of osds in the set.

And the primary is no longer going to be assumed to
be the first.  This is good to hear.

Reviewed-by: Alex Elder <elder@linaro.org>


> 
> Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
> ---
>  include/linux/ceph/osdmap.h |    2 +-
>  net/ceph/osd_client.c       |   10 ++++------
>  net/ceph/osdmap.c           |   20 ++++++++++++--------
>  3 files changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
> index b0c8f8490663..561ea896c657 100644
> --- a/include/linux/ceph/osdmap.h
> +++ b/include/linux/ceph/osdmap.h
> @@ -212,7 +212,7 @@ extern int ceph_oloc_oid_to_pg(struct ceph_osdmap *osdmap,
>  
>  extern int ceph_calc_pg_acting(struct ceph_osdmap *osdmap,
>  			       struct ceph_pg pgid,
> -			       int *osds);
> +			       int *osds, int *primary);
>  extern int ceph_calc_pg_primary(struct ceph_osdmap *osdmap,
>  				struct ceph_pg pgid);
>  
> diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
> index 6f64eec18851..b4157dc22199 100644
> --- a/net/ceph/osd_client.c
> +++ b/net/ceph/osd_client.c
> @@ -1333,7 +1333,7 @@ static int __map_request(struct ceph_osd_client *osdc,
>  {
>  	struct ceph_pg pgid;
>  	int acting[CEPH_PG_MAX_SIZE];
> -	int o = -1, num = 0;
> +	int num, o;
>  	int err;
>  	bool was_paused;
>  
> @@ -1346,11 +1346,9 @@ static int __map_request(struct ceph_osd_client *osdc,
>  	}
>  	req->r_pgid = pgid;
>  
> -	err = ceph_calc_pg_acting(osdc->osdmap, pgid, acting);
> -	if (err > 0) {
> -		o = acting[0];
> -		num = err;
> -	}
> +	num = ceph_calc_pg_acting(osdc->osdmap, pgid, acting, &o);
> +	if (num < 0)
> +		num = 0;
>  
>  	was_paused = req->r_paused;
>  	req->r_paused = __req_should_be_paused(osdc, req);
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 1963623bd488..7193b012ee02 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -1644,19 +1644,21 @@ static int apply_temps(struct ceph_osdmap *osdmap,
>  /*
>   * Calculate acting set for given pgid.
>   *
> - * Return acting set length, or error.
> + * Return acting set length, or error.  *primary is set to acting
> + * primary osd id, or -1 if acting set is empty or on error.
>   */
>  int ceph_calc_pg_acting(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
> -			int *osds)
> +			int *osds, int *primary)
>  {
>  	struct ceph_pg_pool_info *pool;
>  	u32 pps;
>  	int len;
> -	int primary;
>  
>  	pool = __lookup_pg_pool(&osdmap->pg_pools, pgid.pool);
> -	if (!pool)
> -		return 0;
> +	if (!pool) {
> +		*primary = -1;
> +		return -ENOENT;
> +	}
>  
>  	if (pool->flags & CEPH_POOL_FLAG_HASHPSPOOL) {
>  		/* hash pool id and seed so that pool PGs do not overlap */
> @@ -1677,12 +1679,14 @@ int ceph_calc_pg_acting(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
>  	}
>  
>  	len = pg_to_raw_osds(osdmap, pool, pgid, pps, osds);
> -	if (len < 0)
> +	if (len < 0) {
> +		*primary = -1;
>  		return len;
> +	}
>  
> -	len = raw_to_up_osds(osdmap, pool, osds, len, &primary);
> +	len = raw_to_up_osds(osdmap, pool, osds, len, primary);
>  
> -	len = apply_temps(osdmap, pool, pgid, osds, len, &primary);
> +	len = apply_temps(osdmap, pool, pgid, osds, len, primary);
>  
>  	return len;
>  }
>