ObjectStore: Add "need_journal" interface to make aware of journal device

Impl feature #9580

Signed-off-by: Haomai Wang <haomaiwang@gmail.com>

src/ceph_osd.cc

@@ -107,6 +107,7 @@ int main(int argc, const char **argv)
   bool get_journal_fsid = false;
   bool get_osd_fsid = false;
   bool get_cluster_fsid = false;
+  bool check_need_journal = false;
   std::string dump_pg_log;
 
   std::string val;
@@ -136,6 +137,8 @@ int main(int argc, const char **argv)
       get_osd_fsid = true;
     } else if (ceph_argparse_flag(args, i, "--get-journal-fsid", "--get-journal-uuid", (char*)NULL)) {
       get_journal_fsid = true;
+    } else if (ceph_argparse_flag(args, i, "--check-needs-journal", (char*)NULL)) {
+      check_need_journal = true;
     } else {
       ++i;
     }
@@ -308,6 +311,14 @@ int main(int argc, const char **argv)
     exit(r);
   }
 
+  if (check_need_journal) {
+    if (store->check_need_journal())
+      cout << "yes" << std::endl;
+    else
+      cout << "no" << std::endl;
+    exit(0);
+  }
+
   string magic;
   uuid_d cluster_fsid, osd_fsid;
   int w;

src/os/FileStore.h

@@ -96,6 +96,7 @@ public:
     return target_version;
   }
 
+  bool need_journal() { return true; }
   int peek_journal_fsid(uuid_d *fsid);
 
   struct FSPerfTracker {

src/os/KeyValueStore.h

@@ -484,6 +484,7 @@ class KeyValueStore : public ObjectStore,
   uint32_t get_target_version() {
     return target_version;
   }
+  bool need_journal() { return false; };
   int peek_journal_fsid(uuid_d *id) {
     *id = fsid;
     return 0;

src/os/MemStore.h

@@ -242,6 +242,7 @@ public:
     return 1;
   }
 
+  bool need_journal() { return false; };
   int peek_journal_fsid(uuid_d *fsid);
 
   bool test_mount_in_use() {

src/os/ObjectStore.h

@@ -1248,6 +1248,14 @@ public:
    */
   virtual uint32_t get_target_version() = 0;
 
+  /**
+   * check whether need journal device
+   *
+   * It's not constant for backend store. FileStore could have journaless mode
+   * and KeyValueStore could have journal device for special backend.
+   */
+  virtual bool need_journal() = 0;
+
   /**
    * check the journal uuid/fsid, without opening
    */