3 files changed, 31 insertions, 14 deletions

diff --git a/include/linux/ceph/ceph_features.h b/include/linux/ceph/ceph_features.h
index ab0a54286e0d..76554cecaab2 100644
--- a/include/linux/ceph/ceph_features.h
+++ b/include/linux/ceph/ceph_features.h
@@ -34,6 +34,7 @@
 #define CEPH_FEATURE_REPLY_CREATE_INODE   (1<<27)
 #define CEPH_FEATURE_OSD_HBMSGS     (1<<28)
 #define CEPH_FEATURE_MDSENC         (1<<29)
+#define CEPH_FEATURE_OSDHASHPSPOOL  (1<<30)
 
 /*
  * Features supported.
@@ -45,7 +46,8 @@
          CEPH_FEATURE_OSDENC |                  \
          CEPH_FEATURE_CRUSH_TUNABLES |          \
          CEPH_FEATURE_CRUSH_TUNABLES2 |         \
-         CEPH_FEATURE_REPLY_CREATE_INODE)
+         CEPH_FEATURE_REPLY_CREATE_INODE |      \
+         CEPH_FEATURE_OSDHASHPSPOOL)
 
 #define CEPH_FEATURES_REQUIRED_DEFAULT   \
         (CEPH_FEATURE_NOSRCADDR |        \
diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index 35985125f118..c819190d1642 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -23,6 +23,8 @@ struct ceph_pg {
         uint32_t seed;
 };
 
+#define CEPH_POOL_FLAG_HASHPSPOOL  1
+
 struct ceph_pg_pool_info {
         struct rb_node node;
         s64 id;
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 378471644501..69bc4bf89e3e 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1127,18 +1127,16 @@ static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
         struct ceph_pg_mapping *pg;
         struct ceph_pg_pool_info *pool;
         int ruleno;
-        unsigned int poolid, ps, pps, t, r;
+        int r;
+        u32 pps;
 
-        poolid = pgid.pool;
-        ps = pgid.seed;
-
-        pool = __lookup_pg_pool(&osdmap->pg_pools, poolid);
+        pool = __lookup_pg_pool(&osdmap->pg_pools, pgid.pool);
         if (!pool)
                 return NULL;
 
         /* pg_temp? */
-        t = ceph_stable_mod(ps, pool->pg_num, pool->pgp_num_mask);
-        pgid.seed = t;
+        pgid.seed = ceph_stable_mod(pgid.seed, pool->pg_num,
+                                    pool->pgp_num_mask);
         pg = __lookup_pg_mapping(&osdmap->pg_temp, pgid);
         if (pg) {
                 *num = pg->len;
@@ -1149,20 +1147,35 @@ static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
         ruleno = crush_find_rule(osdmap->crush, pool->crush_ruleset,
                                  pool->type, pool->size);
         if (ruleno < 0) {
-                pr_err("no crush rule pool %d ruleset %d type %d size %d\n",
-                       poolid, pool->crush_ruleset, pool->type,
+                pr_err("no crush rule pool %lld ruleset %d type %d size %d\n",
+                       pgid.pool, pool->crush_ruleset, pool->type,
                        pool->size);
                 return NULL;
         }
 
-        pps = ceph_stable_mod(ps, pool->pgp_num, pool->pgp_num_mask);
-        pps += poolid;
+        if (pool->flags & CEPH_POOL_FLAG_HASHPSPOOL) {
+                /* hash pool id and seed sothat pool PGs do not overlap */
+                pps = crush_hash32_2(CRUSH_HASH_RJENKINS1,
+                                     ceph_stable_mod(pgid.seed, pool->pgp_num,
+                                                     pool->pgp_num_mask),
+                                     pgid.pool);
+        } else {
+                /*
+                 * legacy ehavior: add ps and pool together.  this is
+                 * not a great approach because the PGs from each pool
+                 * will overlap on top of each other: 0.5 == 1.4 ==
+                 * 2.3 == ...
+                 */
+                pps = ceph_stable_mod(pgid.seed, pool->pgp_num,
+                                      pool->pgp_num_mask) +
+                        (unsigned)pgid.pool;
+        }
         r = crush_do_rule(osdmap->crush, ruleno, pps, osds,
                           min_t(int, pool->size, *num),
                           osdmap->osd_weight);
         if (r < 0) {
-                pr_err("error %d from crush rule: pool %d ruleset %d type %d"
-                       " size %d\n", r, poolid, pool->crush_ruleset,
+                pr_err("error %d from crush rule: pool %lld ruleset %d type %d"
+                       " size %d\n", r, pgid.pool, pool->crush_ruleset,
                        pool->type, pool->size);
                 return NULL;
         }