osd: Optimized EC backfill interval has wrong versions

Bug in the optimized EC code creating the backfill
interval on the primary. It is creating a map with
the object version for each backfilling shard. When
there are multiple backfill targets the code was
overwriting oi.version with the version
for a shard that has had partial writes which
can result in the object not being backfilled.

Can manifest as a data integirty issue, scrub
error or snapshot corruption.

Signed-off-by: Bill Scales <[email protected]>

Author: bill-scales

src/crimson/osd/recovery_backend.cc

@@ -270,8 +270,9 @@ RecoveryBackend::scan_for_backfill_primary(
 	bool added_default = false;
 	for (auto & shard: backfill_targets) {
 	  if (shard_versions.contains(shard.shard)) {
-	    version = shard_versions.at(shard.shard);
-	    version_map->emplace(object, std::make_pair(shard.shard, version));
+	    auto shard_version = shard_versions.at(shard.shard);
+	    version_map->emplace(object, std::make_pair(shard.shard,
+							shard_version));
 	  } else if (!added_default) {
 	    version_map->emplace(object, std::make_pair(shard_id_t::NO_SHARD,
 							version));

src/osd/PrimaryLogPG.cc

@@ -14491,9 +14491,9 @@ void PrimaryLogPG::scan_range_primary(
       bool added_default = false;
       for (auto & shard: backfill_targets) {
 	if (shard_versions.contains(shard.shard)) {
-	  version = shard_versions.at(shard.shard);
+	  auto shard_version = shard_versions.at(shard.shard);
 	  bi->objects.insert(make_pair(*p, std::make_pair(shard.shard,
-							  version)));
+							  shard_version)));
 	} else if (!added_default) {
 	  bi->objects.insert(make_pair(*p, std::make_pair(shard_id_t::NO_SHARD,
 							  version)));