crimson/os/seastore: return ghobject_t::max as the end when list_objects

reaches the end of the listing

Signed-off-by: Xuehan Xu <[email protected]>

src/crimson/os/seastore/seastore.cc

@@ -695,7 +695,7 @@ SeaStore::Shard::list_objects(CollectionRef ch,
 	    using list_iertr = OnodeManager::list_onodes_iertr;
 	    using repeat_ret = list_iertr::future<seastar::stop_iteration>;
             return trans_intr::repeat(
-              [this, &t, &ret, &limit,
+              [this, &t, &ret, &limit, end,
 	       filter, ranges = get_ranges(ch, start, end, filter)
 	      ]() mutable -> repeat_ret {
 		if (limit == 0 || ranges.empty()) {
@@ -711,7 +711,8 @@ SeaStore::Shard::list_objects(CollectionRef ch,
 		DEBUGT("pstart {}, pend {}, limit {}", t, pstart, pend, limit);
 		return onode_manager->list_onodes(
 		  t, pstart, pend, limit
-		).si_then([&limit, &ret, pend](auto &&_ret) mutable {
+		).si_then([&limit, &ret, pend, &t, last=ranges.empty(), end]
+			  (auto &&_ret) mutable {
 		  auto &next_objects = std::get<0>(_ret);
 		  auto &ret_objects = std::get<0>(ret);
 		  ret_objects.insert(
@@ -721,6 +722,12 @@ SeaStore::Shard::list_objects(CollectionRef ch,
 		  std::get<1>(ret) = std::get<1>(_ret);
 		  assert(limit >= next_objects.size());
 		  limit -= next_objects.size();
+		  LOG_PREFIX(SeaStore::list_objects);
+		  DEBUGT("got {} objects, left limit {}",
+		    t, next_objects.size(), limit);
+		  if (last && std::get<1>(ret) == pend) {
+		    std::get<1>(ret) = end;
+		  }
 		  assert(limit == 0 ||
 			 std::get<1>(ret) == pend ||
 			 std::get<1>(ret) == ghobject_t::get_max());

src/crimson/os/seastore/seastore.h

@@ -144,6 +144,8 @@ class SeaStore final : public FuturizedStore {
       CollectionRef c,
       const ghobject_t& oid) final;
 
+    /// std::get<1>(ret) returns end if and only if the listing has listed all
+    /// the items within the range, otherwise it returns the next key to be listed.
     seastar::future<std::tuple<std::vector<ghobject_t>, ghobject_t>> list_objects(
       CollectionRef c,
       const ghobject_t& start,

src/test/crimson/seastore/test_seastore.cc

@@ -602,7 +602,7 @@ struct seastore_test_t :
 	  EXPECT_GE(next, right_bound);
 	} else {
 	  // next <= *correct_end since *correct_end is the next object to list
-	  EXPECT_LE(next, *correct_end);
+	  EXPECT_LE(listed.back(), *correct_end);
 	  // next > *(correct_end - 1) since we already listed it
 	  EXPECT_GT(next, *(correct_end - 1));
 	}