libceph: pg_upmap[_items] infrastructure

pg_temp and pg_upmap encodings are the same (PG -> array of osds),
except for the incremental remove: it's an empty mapping in new_pg_temp
for pg_temp and a separate old_pg_upmap set for pg_upmap.  (This isn't
to allow for empty pg_upmap mappings -- apparently, pg_temp just wasn't
looked at as an example for pg_upmap encoding.)

Reuse __decode_pg_temp() for decoding pg_upmap and new_pg_upmap.
__decode_pg_temp() stores into pg_temp union member, but since pg_upmap
union member is identical, reading through pg_upmap later is OK.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index fe6d189bdd30..c612cff81f5c 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -143,10 +143,14 @@ struct ceph_pg_mapping {
                 struct {
                         int len;
                         int osds[];
-                } pg_temp;
+                } pg_temp, pg_upmap;
                 struct {
                         int osd;
                 } primary_temp;
+                struct {
+                        int len;
+                        int from_to[][2];
+                } pg_upmap_items;
         };
 };
 
@@ -165,6 +169,10 @@ struct ceph_osdmap {
         struct rb_root pg_temp;
         struct rb_root primary_temp;
 
+        /* remap (post-CRUSH, pre-up) */
+        struct rb_root pg_upmap;        /* PG := raw set */
+        struct rb_root pg_upmap_items;  /* from -> to within raw set */
+
         u32 *osd_primary_affinity;
 
         struct rb_root pg_pools;