rgw: fix check_disk_state; add a strip_namespace function.

Use copies of the IoCtx rather than references so that
we can set locators without breaking stuff, and make use of the
on-disk locators which we just added.

Signed-off-by: Greg Farnum <gregory.farnum@dreamhost.com>

src/rgw/rgw_common.h

@@ -724,6 +724,35 @@ public:
     return true;
   }
 
+  /**
+   * Given a mangled object name and an empty namespace string, this
+   * function extracts the namespace into the string and sets the object
+   * name to be the unmangled version.
+   *
+   * It returns true after successfully doing so, or
+   * false if it fails.
+   */
+  static bool strip_namespace_from_object(string& obj, string& ns) {
+    ns.clear();
+    if (obj[0] != '_') {
+      return true;
+    }
+
+    size_t pos = obj.find('_', 1);
+    if (pos == string::npos) {
+      return false;
+    }
+
+    size_t period_pos = obj.find('.');
+    if (period_pos < pos) {
+      return false;
+    }
+
+    ns = obj.substr(1, pos-1);
+    obj = obj.substr(pos+1, string::npos);
+    return true;
+  }
+
   void encode(bufferlist& bl) const {
     __u8 struct_v = 2;
     ::encode(struct_v, bl);

src/rgw/rgw_rados.cc

@@ -2165,7 +2165,9 @@ int RGWRados::cls_bucket_list(rgw_bucket& bucket, string start, uint32_t num, ma
     if (!dirent.exists || !dirent.pending_map.empty()) {
       /* there are uncommitted ops. We need to check the current state,
        * and if the tags are old we need to do cleanup as well. */
-      r = check_disk_state(io_ctx, bucket, dirent, e, updates);
+      librados::IoCtx sub_ctx;
+      sub_ctx.dup(io_ctx);
+      r = check_disk_state(sub_ctx, bucket, dirent, e, updates);
       if (r < 0) {
         if (r == -ENOENT)
           continue;
@@ -2190,16 +2192,22 @@ int RGWRados::cls_bucket_list(rgw_bucket& bucket, string start, uint32_t num, ma
   return m.size();
 }
 
-int RGWRados::check_disk_state(librados::IoCtx& io_ctx,
+int RGWRados::check_disk_state(librados::IoCtx io_ctx,
                                rgw_bucket& bucket,
                                rgw_bucket_dir_entry& list_state,
                                RGWObjEnt& object,
                                bufferlist& suggested_updates)
 {
   rgw_obj obj;
-  std::string oid, key;
-  obj.init(bucket, list_state.name);
+  std::string oid, key, ns;
+  oid = list_state.name;
+  if (!rgw_obj::strip_namespace_from_object(oid, ns)) {
+    // well crap
+    assert(0 == "got bad object name off disk");
+  }
+  obj.init(bucket, oid, list_state.locator, ns);
   get_obj_bucket_and_oid_key(obj, bucket, oid, key);
+  io_ctx.locator_set_key(key);
   int r = io_ctx.stat(oid, &object.size, &object.mtime);
 
   list_state.pending_map.clear(); // we don't need this and it inflates size

src/rgw/rgw_rados.h

@@ -338,7 +338,7 @@ public:
    * and -errno on other failures. (-ENOENT is not a failure, and it
    * will encode that info as a suggested update.)
    */
-  int check_disk_state(librados::IoCtx& io_ctx,
+  int check_disk_state(librados::IoCtx io_ctx,
                        rgw_bucket& bucket,
                        rgw_bucket_dir_entry& list_state,
                        RGWObjEnt& object,