From 09391cf38b1314203e6eeb43724cd51d63381c08 Mon Sep 17 00:00:00 2001
From: Yaming Kuang <yaming.kuang@gmail.com>
Date: Fri, 21 Feb 2025 18:15:42 -0700
Subject: [PATCH] add HB and vol meta svc register and recovery cb

---
 src/lib/homeblks_impl.cpp | 57 ++++++++++++++++++++++++++++++++-------
 src/lib/homeblks_impl.hpp |  9 ++++++-
 2 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/src/lib/homeblks_impl.cpp b/src/lib/homeblks_impl.cpp
index 772d1c3..1a10cf9 100644
--- a/src/lib/homeblks_impl.cpp
+++ b/src/lib/homeblks_impl.cpp
@@ -187,29 +187,66 @@ void HomeBlocksImpl::init_homestore() {
 }
 
 void HomeBlocksImpl::superblk_init() {
-    auto sb = homestore::superblk< homeblks_sb_t >(HB_META_NAME);
-    sb.create(sizeof(homeblks_sb_t));
-    sb->magic = HB_SB_MAGIC;
-    sb->version = HB_SB_VER;
-    sb->boot_cnt = 0;
-    sb->init_flag(0);
-    sb.write();
+    sb_ = homestore::superblk< homeblks_sb_t >(HB_META_NAME);
+    sb_.create(sizeof(homeblks_sb_t));
+    sb_->magic = HB_SB_MAGIC;
+    sb_->version = HB_SB_VER;
+    sb_->boot_cnt = 0;
+    sb_->init_flag(0);
+    sb_.write();
+}
+
+void HomeBlocksImpl::on_vol_meta_blk_found(sisl::byte_view const& buf, void* cookie) {
+    // auto sb = homestore::superblk< vol_sb_t >(VOL_META_NAME);
+    // sb.load(buf, cookie);
+    // TODO:
+}
+
+void HomeBlocksImpl::on_hb_meta_blk_found(sisl::byte_view const& buf, void* cookie) {
+    sb_ = homestore::superblk< homeblks_sb_t >(HB_META_NAME);
+    sb_.load(buf, cookie);
+    // sb verification
+    RELEASE_ASSERT_EQ(sb_->version, HB_SB_VER);
+    RELEASE_ASSERT_EQ(sb_->magic, HB_SB_MAGIC);
+
+    if (sb_->test_flag(SB_FLAGS_GRACEFUL_SHUTDOWN)) {
+        // if it is a gracefuln shutdown, this flag should be set again in shutdown routine;
+        sb_->clear_flag(SB_FLAGS_GRACEFUL_SHUTDOWN);
+        LOGI("System was shutdown gracefully");
+    } else {
+        LOGI("System experienced sudden crash since last boot");
+    }
+
+    ++sb_->boot_cnt;
+
+    // avoid doing sb meta blk write in callback which will cause deadlock;
+    // the 1st CP should flush all dirty SB before taking traffic;
 }
 
 void HomeBlocksImpl::register_metablk_cb() {
     // register some callbacks for metadata recovery;
     using namespace homestore;
+
+    // HomeBlks SB
     HomeStore::instance()->meta_service().register_handler(
         HB_META_NAME,
         [this](homestore::meta_blk* mblk, sisl::byte_view buf, size_t size) {
-            auto sb = homestore::superblk< homeblks_sb_t >(HB_META_NAME);
-            sb.load(buf, mblk);
+            on_hb_meta_blk_found(std::move(buf), voidptr_cast(mblk));
+        },
+        nullptr /*recovery_comp_cb*/, true /* do_crc */);
+
+    // Volume SB
+    HomeStore::instance()->meta_service().register_handler(
+        VOL_META_NAME,
+        [this](homestore::meta_blk* mblk, sisl::byte_view buf, size_t size) {
+            on_vol_meta_blk_found(std::move(buf), voidptr_cast(mblk));
         },
         nullptr /*recovery_comp_cb*/, true /* do_crc */);
 }
 
 void HomeBlocksImpl::on_init_complete() {
-    // TODO: register to meta service for HomeBlks meta block handler;
+    // this is called after HomeStore all recovery completed.
+    // Add anything that needs to be done here.
 }
 
 void HomeBlocksImpl::init_cp() {}
diff --git a/src/lib/homeblks_impl.hpp b/src/lib/homeblks_impl.hpp
index f2b6e8f..34ef546 100644
--- a/src/lib/homeblks_impl.hpp
+++ b/src/lib/homeblks_impl.hpp
@@ -63,11 +63,12 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
 
 private:
     inline static auto const HB_META_NAME = std::string("HomeBlks2");
+    inline static auto const VOL_META_NAME = std::string("Volume2");
     static constexpr uint64_t HB_SB_MAGIC{0xCEEDDEEB};
     static constexpr uint32_t HB_SB_VER{0x1};
     static constexpr uint64_t HS_CHUNK_SIZE = 2 * Gi;
     static constexpr uint32_t DATA_BLK_SIZE = 4096;
-    static constexpr uint32_t SB_FLAGS_CLEAN_SHUTDOWN{0x00000001};
+    static constexpr uint32_t SB_FLAGS_GRACEFUL_SHUTDOWN{0x00000001};
     static constexpr uint32_t SB_FLAGS_RESTRICTED{0x00000002};
 
 private:
@@ -80,6 +81,7 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
     std::map< volume_id_t, unique< Volume > > _volume_map;
 
     bool recovery_done_{false};
+    homestore::superblk< homeblks_sb_t > sb_;
 
 public:
     explicit HomeBlocksImpl(std::weak_ptr< HomeBlocksApplication >&& application);
@@ -129,8 +131,13 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
 
     void get_dev_info(shared< HomeBlocksApplication > app, std::vector< homestore::dev_info >& device_info,
                       bool& has_data_dev, bool& has_fast_dev);
+
     DevType get_device_type(std::string const& devname);
     auto defer() const { return folly::makeSemiFuture().via(executor_); }
+
+    // recovery apis
+    void on_hb_meta_blk_found(sisl::byte_view const& buf, void* cookie);
+    void on_vol_meta_blk_found(sisl::byte_view const& buf, void* cookie);
 };
 
 class HBIndexSvcCB : public homestore::IndexServiceCallbacks {