From: Sage Weil <sage@newdream.net>
Date: Sat, 11 Feb 2012 22:55:06 +0000 (-0800)
Subject: osd: filter trimming|purged snaps out of op SnapContext
X-Git-Tag: v0.42~31
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=7c6dff487171deb37852e2fb059dcb6e3af65702;p=ceph.git

osd: filter trimming|purged snaps out of op SnapContext

We can receive an op with an old SnapContext that includes snaps that we've
already trimmed or are in the process of trimming.  Filter them out!
Otherwise we will recreate and add links into collections we've already
marked as removed, and we'll get things like ENOTEMPTY when we try to
remove them.  Or just leave them laying around.

Fixes: #1949
Signed-off-by: Sage Weil <sage@newdream.net>
---

diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index edaae82123aa..146d57ebb7a3 100644
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -2262,6 +2262,36 @@ void PG::update_snap_collections(vector<pg_log_entry_t> &log_entries,
   }
 }
 
+/**
+ * filter trimming|trimmed snaps out of snapcontext
+ */
+void PG::filter_snapc(SnapContext& snapc)
+{
+  bool filtering = false;
+  vector<snapid_t> newsnaps;
+  for (vector<snapid_t>::iterator p = snapc.snaps.begin();
+       p != snapc.snaps.end();
+       ++p) {
+    if (snap_trimq.contains(*p) || info.purged_snaps.contains(*p)) {
+      if (!filtering) {
+	// start building a new vector with what we've seen so far
+	dout(10) << "filter_snapc filtering " << snapc << dendl;
+	newsnaps.insert(newsnaps.begin(), snapc.snaps.begin(), p);
+	filtering = true;
+      }
+      dout(20) << "filter_snapc  removing trimq|purged snap " << *p << dendl;
+    } else {
+      if (filtering)
+	newsnaps.push_back(*p);  // continue building new vector
+    }
+  }
+  if (filtering) {
+    snapc.snaps.swap(newsnaps);
+    dout(10) << "filter_snapc  result " << snapc << dendl;
+  }
+}
+
+
 void PG::adjust_local_snaps()
 {
   interval_set<snapid_t> to_remove;
diff --git a/src/osd/PG.h b/src/osd/PG.h
index 02466b9a8e92..791cd6721ed1 100644
--- a/src/osd/PG.h
+++ b/src/osd/PG.h
@@ -1310,6 +1310,7 @@ public:
   coll_t make_snap_collection(ObjectStore::Transaction& t, snapid_t sn);
   void update_snap_collections(vector<pg_log_entry_t> &log_entries,
 			       ObjectStore::Transaction& t);
+  void filter_snapc(SnapContext& snapc);
   void adjust_local_snaps();
 
   void log_weirdness();
diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index b98a4e6308ef..e42c317af072 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -2427,6 +2427,9 @@ void ReplicatedPG::make_writeable(OpContext *ctx)
     snapc.snaps = ctx->new_snapset.snaps;
     dout(10) << " using newer snapc " << snapc << dendl;
   }
+
+  if (ctx->obs->exists)
+    filter_snapc(snapc);
   
   if (ctx->obs->exists &&               // head exist(ed)
       snapc.snaps.size() &&                 // there are snaps