Re: [PATCH 26/33] libceph: introduce pg_to_raw_osds() and raw_to_up_osds() helpers

[Alex Elder <elder@ieee.org>]

On 03/27/2014 01:18 PM, Ilya Dryomov wrote:
> pg_to_raw_osds() helper for computing a raw (crush) set, which can
> contain non-existant and down osds.
> 
> raw_to_up_osds() helper for pruning non-existant and down osds from the
> raw set, therefore transforming it into an up set, and determining up
> primary.

Looks good.

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

> Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
> ---
>  net/ceph/osdmap.c |   76 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 76 insertions(+)
> 
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 3ac2098972ea..ee095e07cf98 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -1514,6 +1514,82 @@ static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
>  }
>  
>  /*
> + * Calculate raw (crush) set for given pgid.
> + *
> + * Return raw set length, or error.
> + */
> +static int pg_to_raw_osds(struct ceph_osdmap *osdmap,
> +			  struct ceph_pg_pool_info *pool,
> +			  struct ceph_pg pgid, u32 pps, int *osds)
> +{
> +	int ruleno;
> +	int len;
> +
> +	/* crush */
> +	ruleno = crush_find_rule(osdmap->crush, pool->crush_ruleset,
> +				 pool->type, pool->size);
> +	if (ruleno < 0) {
> +		pr_err("no crush rule: pool %lld ruleset %d type %d size %d\n",
> +		       pgid.pool, pool->crush_ruleset, pool->type,
> +		       pool->size);
> +		return -ENOENT;
> +	}
> +
> +	len = do_crush(osdmap, ruleno, pps, osds,
> +		       min_t(int, pool->size, CEPH_PG_MAX_SIZE),
> +		       osdmap->osd_weight, osdmap->max_osd);
> +	if (len < 0) {
> +		pr_err("error %d from crush rule %d: pool %lld ruleset %d type %d size %d\n",
> +		       len, ruleno, pgid.pool, pool->crush_ruleset,
> +		       pool->type, pool->size);
> +		return len;
> +	}
> +
> +	return len;
> +}
> +
> +/*
> + * Given raw set, calculate up set and up primary.
> + *
> + * Return up set length.  *primary is set to up primary osd id, or -1
> + * if up set is empty.
> + */
> +static int raw_to_up_osds(struct ceph_osdmap *osdmap,
> +			  struct ceph_pg_pool_info *pool,
> +			  int *osds, int len, int *primary)
> +{
> +	int up_primary = -1;
> +	int i;
> +
> +	if (ceph_can_shift_osds(pool)) {
> +		int removed = 0;
> +
> +		for (i = 0; i < len; i++) {
> +			if (ceph_osd_is_down(osdmap, osds[i])) {
> +				removed++;
> +				continue;
> +			}
> +			if (removed)
> +				osds[i - removed] = osds[i];
> +		}
> +
> +		len -= removed;
> +		if (len > 0)
> +			up_primary = osds[0];
> +	} else {
> +		for (i = len - 1; i >= 0; i--) {
> +			if (ceph_osd_is_down(osdmap, osds[i]))
> +				osds[i] = CRUSH_ITEM_NONE;
> +			else
> +				up_primary = osds[i];
> +		}
> +	}
> +
> +	*primary = up_primary;
> +	return len;
> +}
> +
> +/*
>   * Return acting set for given pgid.
>   */
>  int ceph_calc_pg_acting(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
>