libceph: return primary from ceph_calc_pg_acting()

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.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

2 files changed, 16 insertions, 14 deletions

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 f1cad21d1533..df9389ddd56c 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1651,19 +1651,21 @@ 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 */
@@ -1684,12 +1686,14 @@ 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;
 }