From bad9fba8ec6cd9d26552b2d9a93fa3bc28642e1f Mon Sep 17 00:00:00 2001
From: Derek Collison <derek@nats.io>
Date: Mon, 10 May 2021 19:24:58 -0700
Subject: [PATCH] Fix for store directory on disk prior to 2.2.3 without the
 'jetstream' directory.

Signed-off-by: Derek Collison <derek@nats.io>
---
 server/jetstream.go      | 47 ++++++++++++++++++++++++++++
 server/jetstream_test.go | 66 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)

diff --git a/server/jetstream.go b/server/jetstream.go
index ad6e5d51..4a80c19f 100644
--- a/server/jetstream.go
+++ b/server/jetstream.go
@@ -164,9 +164,56 @@ func (s *Server) EnableJetStream(config *JetStreamConfig) error {
 		cfg.StoreDir = filepath.Join(os.TempDir(), JetStreamStoreDir)
 	}
 
+	// We will consistently place the 'jetstream' directory under the storedir that was handed to us. Prior to 2.2.3 though
+	// we could have a directory on disk without the 'jetstream' directory. This will check and fix if needed.
+	s.checkStoreDir(&cfg)
+
 	return s.enableJetStream(cfg)
 }
 
+// Check to make sure directory has the jetstream directory.
+// We will have ot properly configured here now regardless, so need to look inside.
+func (s *Server) checkStoreDir(cfg *JetStreamConfig) {
+	fis, _ := ioutil.ReadDir(cfg.StoreDir)
+	// If we have nothing underneath us, could be just starting new, but if we see this we can check.
+	if len(fis) != 0 {
+		return
+	}
+	// Let's check the directory above. If it has us 'jetstream' but also other stuff that we can
+	// identify as accounts then we can fix.
+	fis, _ = ioutil.ReadDir(filepath.Dir(cfg.StoreDir))
+	// If just one that is us 'jetstream' and all is ok.
+	if len(fis) == 1 {
+		return
+	}
+
+	s.Warnf("JetStream store being migrated to a new directory structure")
+
+	for _, fi := range fis {
+		// Skip the 'jetstream' directory.
+		if fi.Name() == JetStreamStoreDir {
+			continue
+		}
+		// Let's see if this is an account.
+		if accName := fi.Name(); accName != _EMPTY_ {
+			_, ok := s.accounts.Load(accName)
+			if !ok {
+				if acc, err := s.lookupAccount(accName); err != nil && acc != nil {
+					ok = true
+				}
+			}
+			// If this seems to be an account go ahead and move the directory. This will include all assets
+			// like streams and consumers.
+			if ok {
+				old := filepath.Join(filepath.Dir(cfg.StoreDir), fi.Name())
+				new := filepath.Join(cfg.StoreDir, fi.Name())
+				s.Debugf("JetStream relocated %q to %q", old, new)
+				os.Rename(old, new)
+			}
+		}
+	}
+}
+
 // enableJetStream will start up the JetStream subsystem.
 func (s *Server) enableJetStream(cfg JetStreamConfig) error {
 	s.mu.Lock()
diff --git a/server/jetstream_test.go b/server/jetstream_test.go
index dae4bf03..2e070e40 100644
--- a/server/jetstream_test.go
+++ b/server/jetstream_test.go
@@ -9095,6 +9095,72 @@ func TestJetStreamServerResourcesConfig(t *testing.T) {
 	}
 }
 
+// From 2.2.2 to 2.2.3 we fixed a bug that would not consistently place a jetstream directory
+// under the store directory configured. However there were some cases where the directory was
+// created that way and therefore 2.2.3 would start and not recognize the existing accounts,
+// streams and consumers.
+func TestJetStreamStoreDirectoryFix(t *testing.T) {
+	sd := filepath.Join(os.TempDir(), "sd_test")
+	defer removeDir(t, sd)
+
+	conf := createConfFile(t, []byte(fmt.Sprintf("listen: 127.0.0.1:-1\njetstream: {store_dir: %q}\n", sd)))
+	defer removeFile(t, conf)
+
+	s, _ := RunServerWithConfig(conf)
+	defer s.Shutdown()
+
+	nc, js := jsClientConnect(t, s)
+	defer nc.Close()
+
+	if _, err := js.AddStream(&nats.StreamConfig{Name: "TEST"}); err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	if _, err := js.Publish("TEST", []byte("TSS")); err != nil {
+		t.Fatalf("Unexpected publish error: %v", err)
+	}
+	// Push based.
+	sub, err := js.SubscribeSync("TEST", nats.Durable("dlc"))
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	defer sub.Unsubscribe()
+
+	// Now shutdown the server.
+	nc.Close()
+	s.Shutdown()
+
+	// Now move stuff up from the jetstream directory etc.
+	jssd := filepath.Join(sd, JetStreamStoreDir)
+	fis, _ := ioutil.ReadDir(jssd)
+	// This will be accounts, move them up one directory.
+	for _, fi := range fis {
+		os.Rename(filepath.Join(jssd, fi.Name()), filepath.Join(sd, fi.Name()))
+	}
+	removeDir(t, jssd)
+
+	// Restart our server. Make sure our assets got moved.
+	s, _ = RunServerWithConfig(conf)
+	defer s.Shutdown()
+
+	nc, js = jsClientConnect(t, s)
+	defer nc.Close()
+
+	var names []string
+	for name := range js.StreamNames() {
+		names = append(names, name)
+	}
+	if len(names) != 1 {
+		t.Fatalf("Expected only 1 stream but got %d", len(names))
+	}
+	names = names[:0]
+	for name := range js.ConsumerNames("TEST") {
+		names = append(names, name)
+	}
+	if len(names) != 1 {
+		t.Fatalf("Expected only 1 consumer but got %d", len(names))
+	}
+}
+
 func TestJetStreamPushConsumersPullError(t *testing.T) {
 	s := RunBasicJetStreamServer()
 	defer s.Shutdown()