From 766069e40c483b32cf4fd08ca71ad70e16de776d Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Fri, 5 Jun 2009 10:50:21 -0700
Subject: [PATCH] osd: handle removal of pool snaps

Use helper to build effective removed_snaps set (regardless of
whether they are explicitly specified in the pg_pool_t or implicity
via the pool snaps).  Keep a copy of that set in the OSD's PGPool
so we can track changes.
---
 src/TODO            |  1 -
 src/osd/OSD.cc      | 17 +++++++++--------
 src/osd/PG.h        |  3 ++-
 src/osd/osd_types.h | 14 ++++++++++++++
 4 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/src/TODO b/src/TODO
index ea76d3f4ffbd4..0eadb38bfebfb 100644
--- a/src/TODO
+++ b/src/TODO
@@ -36,7 +36,6 @@ later
 rados
 - snaps
   - use default pool contexts
-  - make snap removal work with the default pools (fix new_removed_snaps logic in OSD.cc)
 - merge pgs
 - destroy pg_pools
 - autosize pg_pools?
diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index eaf343d2e66ab..c3d734a388ce4 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -576,6 +576,8 @@ PGPool* OSD::_get_pool(int id)
     const pg_pool_t& pi = osdmap->get_pg_pool(id);
     p->info = pi;
     p->snapc = pi.get_snap_context();
+
+    pi.build_removed_snaps(p->removed_snaps);
   }
   dout(10) << "_get_pool " << p->id << " " << p->num_pg << " -> " << (p->num_pg+1) << dendl;
   p->num_pg++;
@@ -1940,11 +1942,10 @@ void OSD::handle_osd_map(MOSDMap *m)
       const pg_pool_t& pi = osdmap->get_pg_pool(p->first);
       if (pi.get_snap_epoch() == cur+1) {
 	PGPool *pool = p->second;
-	pool->new_removed_snaps = pi.removed_snaps;
-	pool->new_removed_snaps.subtract(pool->info.removed_snaps);
-	dout(10) << " pool " << p->first << " removed_snaps " << pool->info.removed_snaps
-		 << " -> " << pi.removed_snaps
-		 << ", new is " << pool->new_removed_snaps << ")"
+	pi.build_removed_snaps(pool->newly_removed_snaps);
+	pool->newly_removed_snaps.subtract(pool->removed_snaps);
+	dout(10) << " pool " << p->first << " removed_snaps " << pool->removed_snaps
+		 << ", newly so are " << pool->newly_removed_snaps << ")"
 		 << dendl;
 	pool->info = pi;
 	pool->snapc = pi.get_snap_context();
@@ -2081,9 +2082,9 @@ void OSD::advance_map(ObjectStore::Transaction& t)
     pg->lock();
 
     // adjust removed_snaps?
-    if (!pg->pool->new_removed_snaps.empty()) {
-      for (map<snapid_t,snapid_t>::iterator p = pg->pool->new_removed_snaps.m.begin();
-	   p != pg->pool->new_removed_snaps.m.end();
+    if (!pg->pool->newly_removed_snaps.empty()) {
+      for (map<snapid_t,snapid_t>::iterator p = pg->pool->newly_removed_snaps.m.begin();
+	   p != pg->pool->newly_removed_snaps.m.end();
 	   p++)
 	for (snapid_t t = 0; t < p->second; ++t)
 	  pg->info.snap_trimq.insert(p->first + t);
diff --git a/src/osd/PG.h b/src/osd/PG.h
index 91bcc0e19f72f..f7e61f3ad80f8 100644
--- a/src/osd/PG.h
+++ b/src/osd/PG.h
@@ -51,7 +51,8 @@ struct PGPool {
   pg_pool_t info;      
   SnapContext snapc;   // the default pool snapc, ready to go.
 
-  interval_set<snapid_t> new_removed_snaps;  // newly removed in the last epoch
+  interval_set<snapid_t> removed_snaps;      // current removed_snaps set
+  interval_set<snapid_t> newly_removed_snaps;  // newly removed in the last epoch
 
   PGPool(int i) : id(i), num_pg(0) {}
 
diff --git a/src/osd/osd_types.h b/src/osd/osd_types.h
index 9ed3ee4852d46..d684b300e7a5b 100644
--- a/src/osd/osd_types.h
+++ b/src/osd/osd_types.h
@@ -471,6 +471,20 @@ struct pg_pool_t {
       return snaps.count(s) == 0;
     return s <= get_snap_seq() && removed_snaps.contains(s);
   }
+  /*
+   * build set of known-removed sets from either pool snaps or
+   * explicit removed_snaps set.
+   */
+  void build_removed_snaps(interval_set<snapid_t>& rs) const {
+    if (snaps.size()) {
+      for (snapid_t s = 1; s <= get_snap_seq(); s = s + 1)
+	if (snaps.count(s) == 0)
+	  rs.insert(s);
+    } else {
+      rs = removed_snaps;
+    }
+  }
+
   SnapContext get_snap_context() const {
     vector<snapid_t> s(snaps.size());
     unsigned i = 0;
-- 
2.39.5