From ef9730515e001d77637a77eb89950f70fd5e7f5a Mon Sep 17 00:00:00 2001
From: Yehuda Sadeh <yehuda@redhat.com>
Date: Tue, 22 Sep 2015 14:53:42 -0700
Subject: [PATCH] cls_rgw: fix bucket listing when dealing with invisible
 entries

Fixes: #12913

The bucket listing logic was broken when dealing with invisible entries.
Need to read keys until we can fetch all the requested entries, or
determine that there are no more entries. Anything else requires
a change to the protocol.

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
---
 src/cls/rgw/cls_rgw.cc | 83 ++++++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 36 deletions(-)

diff --git a/src/cls/rgw/cls_rgw.cc b/src/cls/rgw/cls_rgw.cc
index db488e40fb62c..980884a9f099b 100644
--- a/src/cls/rgw/cls_rgw.cc
+++ b/src/cls/rgw/cls_rgw.cc
@@ -423,54 +423,65 @@ int rgw_bucket_list(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
   bufferlist bl;
 
   map<string, bufferlist> keys;
+  std::map<string, bufferlist>::iterator kiter;
   string start_key;
   encode_list_index_key(hctx, op.start_obj, &start_key);
-  rc = get_obj_vals(hctx, start_key, op.filter_prefix, op.num_entries + 1, &keys);
-  if (rc < 0)
-    return rc;
+  bool done = false;
+  uint32_t left_to_read = op.num_entries + 1;
 
-  std::map<string, struct rgw_bucket_dir_entry>& m = new_dir.m;
-  std::map<string, bufferlist>::iterator kiter = keys.begin();
-  uint32_t i;
+  do {
+    rc = get_obj_vals(hctx, start_key, op.filter_prefix, left_to_read, &keys);
+    if (rc < 0)
+      return rc;
 
-  bool done = false;
+    std::map<string, struct rgw_bucket_dir_entry>& m = new_dir.m;
 
-  for (i = 0; i < op.num_entries && kiter != keys.end(); ++i, ++kiter) {
-    struct rgw_bucket_dir_entry entry;
+    done = keys.empty();
 
-    if (!bi_is_objs_index(kiter->first)) {
-      done = true;
-      break;
-    }
+    for (kiter = keys.begin(); kiter != keys.end(); ++kiter) {
+      struct rgw_bucket_dir_entry entry;
 
-    bufferlist& entrybl = kiter->second;
-    bufferlist::iterator eiter = entrybl.begin();
-    try {
-      ::decode(entry, eiter);
-    } catch (buffer::error& err) {
-      CLS_LOG(1, "ERROR: rgw_bucket_list(): failed to decode entry, key=%s\n", kiter->first.c_str());
-      return -EINVAL;
-    }
+      if (!bi_is_objs_index(kiter->first)) {
+        done = true;
+        break;
+      }
 
-    cls_rgw_obj_key key;
-    uint64_t ver;
-    decode_list_index_key(kiter->first, &key, &ver);
+      bufferlist& entrybl = kiter->second;
+      bufferlist::iterator eiter = entrybl.begin();
+      try {
+        ::decode(entry, eiter);
+      } catch (buffer::error& err) {
+        CLS_LOG(1, "ERROR: rgw_bucket_list(): failed to decode entry, key=%s\n", kiter->first.c_str());
+        return -EINVAL;
+      }
 
-    if (!entry.is_valid()) {
-      CLS_LOG(20, "entry %s[%s] is not valid\n", key.name.c_str(), key.instance.c_str());
-      continue;
-    }
+      cls_rgw_obj_key key;
+      uint64_t ver;
+      decode_list_index_key(kiter->first, &key, &ver);
 
-    if (!op.list_versions && !entry.is_visible()) {
-      CLS_LOG(20, "entry %s[%s] is not visible\n", key.name.c_str(), key.instance.c_str());
-      continue;
-    }
-    m[kiter->first] = entry;
+      start_key = kiter->first;
+      CLS_LOG(20, "start_key=%s len=%d", start_key.c_str(), start_key.size());
 
-    CLS_LOG(20, "got entry %s[%s] m.size()=%d\n", key.name.c_str(), key.instance.c_str(), (int)m.size());
-  }
+      if (!entry.is_valid()) {
+        CLS_LOG(20, "entry %s[%s] is not valid\n", key.name.c_str(), key.instance.c_str());
+        continue;
+      }
+
+      if (!op.list_versions && !entry.is_visible()) {
+        CLS_LOG(20, "entry %s[%s] is not visible\n", key.name.c_str(), key.instance.c_str());
+        continue;
+      }
+      if (m.size() < op.num_entries) {
+        m[kiter->first] = entry;
+      }
+      left_to_read--;
+
+      CLS_LOG(20, "got entry %s[%s] m.size()=%d\n", key.name.c_str(), key.instance.c_str(), (int)m.size());
+    }
+  } while (left_to_read > 0 && !done);
 
-  ret.is_truncated = (kiter != keys.end() && !done);
+  ret.is_truncated = (left_to_read == 0) && /* we found more entries than we were requested, meaning response is truncated */
+                     !done;
 
   ::encode(ret, *out);
   return 0;
-- 
2.39.5