cls_cas: dynamically adjust resolution of chunk_obj_refcount

Most objects will have few refs, but some will have many. Retain as much information about references as we can for both cases, without exploding the size of encoded refs. Signed-off-by: Sage Weil <[email protected]>
JiYou · May 27, 2020 · c263117 · c263117
1 parent cc9d83e
commit c263117
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Showing 4 changed files with 380 additions and 32 deletions.
diff --git a/src/cls/cas/cls_cas.cc b/src/cls/cas/cls_cas.cc
@@ -26,7 +26,7 @@ static int chunk_read_refcount(
   chunk_obj_refcount *objr)
 {
   bufferlist bl;
-  objr->refs.clear();
+  objr->clear();
   int ret = cls_cxx_getxattr(hctx, CHUNK_REFCOUNT_ATTR, &bl);
   if (ret == -ENODATA) {
     return 0;
@@ -88,7 +88,7 @@ static int chunk_create_or_get_ref(cls_method_context_t hctx,
     if (ret < 0) {
       return ret;
     }
-    objr.refs.insert(op.source);
+    objr.get(op.source);
     ret = chunk_set_refcount(hctx, objr);
     if (ret < 0) {
       return ret;
@@ -107,10 +107,9 @@ static int chunk_create_or_get_ref(cls_method_context_t hctx,
     CLS_LOG(10, "inc ref oid=%s\n",
 	    op.source.oid.name.c_str());
 
-    if (objr.refs.count(op.source)) {
+    if (!objr.get(op.source)) {
       return -EEXIST;
     }
-    objr.refs.insert(op.source);
 
     ret = chunk_set_refcount(hctx, objr);
     if (ret < 0) {
@@ -143,10 +142,9 @@ static int chunk_get_ref(cls_method_context_t hctx,
   // existing chunk; inc ref
   CLS_LOG(10, "oid=%s\n", op.source.oid.name.c_str());
 
-  if (objr.refs.count(op.source)) {
+  if (!objr.get(op.source)) {
     return -EEXIST;
   }
-  objr.refs.insert(op.source);
 
   ret = chunk_set_refcount(hctx, objr);
   if (ret < 0) {
@@ -173,19 +171,12 @@ static int chunk_put_ref(cls_method_context_t hctx,
   if (ret < 0)
     return ret;
 
-  if (objr.refs.empty()) {// shouldn't happen!
-    CLS_LOG(0, "ERROR was called without any references!\n");
-    return -ENOLINK;
-  }
-
-  auto p = objr.refs.find(op.source);
-  if (p == objr.refs.end()) {
+  if (!objr.put(op.source)) {
     CLS_LOG(10, "oid=%s (no ref)\n", op.source.oid.name.c_str());
     return -ENOLINK;
   }
-  objr.refs.erase(p);
 
-  if (objr.refs.empty()) {
+  if (objr.empty()) {
     CLS_LOG(10, "oid=%s (last ref)\n", op.source.oid.name.c_str());
     return cls_cxx_remove(hctx);
   }