From 7103e74e335652f2a28b1dad0a2f2028398a600d Mon Sep 17 00:00:00 2001
From: David Zafman <dzafman@redhat.com>
Date: Thu, 3 Sep 2015 19:43:35 -0700
Subject: [PATCH] osd: Better SnapSet scrub checking (find issues instead of
 asserting)

Signed-off-by: David Zafman <dzafman@redhat.com>
(cherry picked from commit 3b381caaad20c683a330e8b7a4e1c017abcb60df)
---
 src/osd/ReplicatedPG.cc | 48 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 8 deletions(-)

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index 15a6ae7c311c1..784b87e248d4c 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -11498,17 +11498,49 @@ void ReplicatedPG::_scrub(
 
       dout(20) << __func__ << " " << mode << " matched clone " << soid << dendl;
 
-      stat.num_bytes += snapset.get().get_clone_bytes(soid.snap);
-
-      if (oi && oi.get().size != snapset.get().clone_size[*curclone]) {
+      if (snapset->clone_size.count(soid.snap) == 0) {
 	osd->clog->error() << mode << " " << info.pgid << " " << soid
-			  << " size " << oi.get().size << " != clone_size "
-			  << snapset.get().clone_size[*curclone];
+			   << " is missing in clone_size";
 	++scrubber.shallow_errors;
-      }
+      } else {
+        if (oi && oi->size != snapset->clone_size[soid.snap]) {
+	  osd->clog->error() << mode << " " << info.pgid << " " << soid
+			     << " size " << oi->size << " != clone_size "
+			     << snapset->clone_size[*curclone];
+	  ++scrubber.shallow_errors;
+        }
 
-      // verify overlap?
-      // ...
+        if (snapset->clone_overlap.count(soid.snap) == 0) {
+	  osd->clog->error() << mode << " " << info.pgid << " " << soid
+			     << " is missing in clone_overlap";
+	  ++scrubber.shallow_errors;
+        } else {
+	  // This checking is based on get_clone_bytes().  The first 2 asserts
+	  // can't happen because we know we have a clone_size and
+	  // a clone_overlap.  Now we check that the interval_set won't
+	  // cause the last assert.
+	  uint64_t size = snapset->clone_size.find(soid.snap)->second;
+	  const interval_set<uint64_t> &overlap =
+	        snapset->clone_overlap.find(soid.snap)->second;
+	  bool bad_interval_set = false;
+	  for (interval_set<uint64_t>::const_iterator i = overlap.begin();
+	       i != overlap.end(); ++i) {
+	    if (size < i.get_len()) {
+	      bad_interval_set = true;
+	      break;
+	    }
+	    size -= i.get_len();
+	  }
+
+	  if (bad_interval_set) {
+	    osd->clog->error() << mode << " " << info.pgid << " " << soid
+			       << " bad interval_set in clone_overlap";
+	    ++scrubber.shallow_errors;
+	  } else {
+            stat.num_bytes += snapset->get_clone_bytes(soid.snap);
+	  }
+        }
+      }
 
       // what's next?
       ++curclone;
-- 
2.39.5