journal: helper method to detect newer tags

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/src/journal/JournalMetadata.cc b/src/journal/JournalMetadata.cc
index a05aa5a907c..c24a96aa0ef 100644
--- a/src/journal/JournalMetadata.cc
+++ b/src/journal/JournalMetadata.cc
@@ -336,6 +336,66 @@ struct C_FlushCommitPosition : public Context {
   }
 };
 
+struct C_AssertActiveTag : public Context {
+  CephContext *cct;
+  librados::IoCtx &ioctx;
+  const std::string &oid;
+  AsyncOpTracker &async_op_tracker;
+  std::string client_id;
+  uint64_t tag_tid;
+  Context *on_finish;
+
+  bufferlist out_bl;
+
+  C_AssertActiveTag(CephContext *cct, librados::IoCtx &ioctx,
+                    const std::string &oid, AsyncOpTracker &async_op_tracker,
+                    const std::string &client_id, uint64_t tag_tid,
+                    Context *on_finish)
+    : cct(cct), ioctx(ioctx), oid(oid), async_op_tracker(async_op_tracker),
+      client_id(client_id), tag_tid(tag_tid), on_finish(on_finish) {
+    async_op_tracker.start_op();
+  }
+  virtual ~C_AssertActiveTag() {
+    async_op_tracker.finish_op();
+  }
+
+  void send() {
+    ldout(cct, 20) << "C_AssertActiveTag: " << __func__ << dendl;
+
+    librados::ObjectReadOperation op;
+    client::tag_list_start(&op, tag_tid, 2, client_id, boost::none);
+
+    librados::AioCompletion *comp = librados::Rados::aio_create_completion(
+      this, nullptr, &utils::rados_state_callback<
+        C_AssertActiveTag, &C_AssertActiveTag::handle_send>);
+
+    int r = ioctx.aio_operate(oid, comp, &op, &out_bl);
+    assert(r == 0);
+    comp->release();
+  }
+
+  void handle_send(int r) {
+    ldout(cct, 20) << "C_AssertActiveTag: " << __func__ << ": r=" << r << dendl;
+
+    std::set<cls::journal::Tag> tags;
+    if (r == 0) {
+      bufferlist::iterator it = out_bl.begin();
+      r = client::tag_list_finish(&it, &tags);
+    }
+
+    // NOTE: since 0 is treated as an uninitialized list filter, we need to
+    // load to entries and look at the last tid
+    if (r == 0 && !tags.empty() && tags.rbegin()->tid > tag_tid) {
+      r = -ESTALE;
+    }
+    complete(r);
+  }
+
+  virtual void finish(int r) {
+    on_finish->complete(r);
+  }
+};
+
 } // anonymous namespace
 
 JournalMetadata::JournalMetadata(ContextWQ *work_queue, SafeTimer *timer,
@@ -564,6 +624,16 @@ void JournalMetadata::set_active_set(uint64_t object_set, Context *on_finish) {
   m_active_set = object_set;
 }
 
+void JournalMetadata::assert_active_tag(uint64_t tag_tid, Context *on_finish) {
+  Mutex::Locker locker(m_lock);
+
+  C_AssertActiveTag *ctx = new C_AssertActiveTag(m_cct, m_ioctx, m_oid,
+                                                 m_async_op_tracker,
+                                                 m_client_id, tag_tid,
+                                                 on_finish);
+  ctx->send();
+}
+
 void JournalMetadata::flush_commit_position() {
   ldout(m_cct, 20) << __func__ << dendl;