From 2c0d3719ea6ad48d538e62a82ebad63c0f11d1fd Mon Sep 17 00:00:00 2001
From: Yingxin Cheng <yingxin.cheng@intel.com>
Date: Mon, 21 Sep 2020 10:15:38 +0800
Subject: [PATCH] crimson/seastore: implement read/write_onode_root()

Signed-off-by: Yingxin Cheng <yingxin.cheng@intel.com>
---
 src/crimson/os/seastore/cache.h               | 10 +++++++
 .../lba_manager/btree/btree_lba_manager.cc    |  3 ++-
 src/crimson/os/seastore/root_block.h          |  1 +
 src/crimson/os/seastore/transaction_manager.h | 26 +++++++++++++++++++
 4 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/crimson/os/seastore/cache.h b/src/crimson/os/seastore/cache.h
index eff6c52dad0..5eb68051c81 100644
--- a/src/crimson/os/seastore/cache.h
+++ b/src/crimson/os/seastore/cache.h
@@ -119,6 +119,16 @@ public:
   using get_root_ret = get_root_ertr::future<RootBlockRef>;
   get_root_ret get_root(Transaction &t);
 
+  /**
+   * get_root_fast
+   *
+   * returns t.root and assume it is already present/read in t
+   */
+  RootBlockRef get_root_fast(Transaction &t) {
+    assert(t.root);
+    return t.root;
+  }
+
   /**
    * get_extent
    *
diff --git a/src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.cc b/src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.cc
index 2b424a578fd..a837ae37e62 100644
--- a/src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.cc
+++ b/src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.cc
@@ -36,7 +36,8 @@ BtreeLBAManager::mkfs_ret BtreeLBAManager::mkfs(
         1,
         0,
         root_leaf->get_paddr(),
-        make_record_relative_paddr(0)};
+        make_record_relative_paddr(0),
+        L_ADDR_NULL};
     return mkfs_ertr::now();
   });
 }
diff --git a/src/crimson/os/seastore/root_block.h b/src/crimson/os/seastore/root_block.h
index 25322d769ea..4a5024caa62 100644
--- a/src/crimson/os/seastore/root_block.h
+++ b/src/crimson/os/seastore/root_block.h
@@ -18,6 +18,7 @@ struct __attribute__((aligned(8), packed)) root_t {
   depth_t segment_depth = 0;
   paddr_t lba_root_addr;
   paddr_t segment_root;
+  laddr_t onode_root = L_ADDR_NULL;
 
   void adjust_addrs_from_base(paddr_t base) {
     if (lba_root_addr.is_relative()) {
diff --git a/src/crimson/os/seastore/transaction_manager.h b/src/crimson/os/seastore/transaction_manager.h
index 18259a45b3c..674c33feabf 100644
--- a/src/crimson/os/seastore/transaction_manager.h
+++ b/src/crimson/os/seastore/transaction_manager.h
@@ -250,6 +250,32 @@ public:
     return segment_manager.release(id);
   }
 
+  /**
+   * read_onode_root
+   *
+   * Get onode-tree root logical address
+   */
+  using read_onode_root_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error
+    >;
+  using read_onode_root_ret = read_onode_root_ertr::future<laddr_t>;
+  read_onode_root_ret read_onode_root(Transaction &t) {
+    return cache.get_root(t).safe_then([](auto croot) {
+      return croot->get_root().onode_root;
+    });
+  }
+
+  /**
+   * write_onode_root
+   *
+   * Write onode-tree root logical address, must be called after read.
+   */
+  void write_onode_root(Transaction &t, laddr_t addr) {
+    auto croot = cache.get_root_fast(t);
+    croot = cache.duplicate_for_write(t, croot)->cast<RootBlock>();
+    croot->get_root().onode_root = addr;
+  }
+
   ~TransactionManager();
 
 private:
-- 
2.39.5