From cdd2b53a96d8d71278f97925d88bd4a0e509597f Mon Sep 17 00:00:00 2001
From: Samuel Just <sjust@redhat.com>
Date: Tue, 3 Nov 2020 19:37:10 -0800
Subject: [PATCH] crimson/os/seastore/segment_manager: add seastore_meta_t with
 uuid

Signed-off-by: Samuel Just <sjust@redhat.com>
---
 src/crimson/os/seastore/seastore_types.h            | 13 +++++++++++++
 src/crimson/os/seastore/segment_manager.h           |  2 +-
 src/crimson/os/seastore/segment_manager/block.cc    |  3 ++-
 src/crimson/os/seastore/segment_manager/block.h     |  8 ++++++++
 .../os/seastore/segment_manager/ephemeral.cc        |  2 ++
 src/crimson/os/seastore/segment_manager/ephemeral.h |  6 ++++++
 6 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/crimson/os/seastore/seastore_types.h b/src/crimson/os/seastore/seastore_types.h
index 56bf53b72fb..fd05767faf1 100644
--- a/src/crimson/os/seastore/seastore_types.h
+++ b/src/crimson/os/seastore/seastore_types.h
@@ -10,6 +10,7 @@
 #include "include/denc.h"
 #include "include/buffer.h"
 #include "include/cmp.h"
+#include "include/uuid.h"
 
 namespace crimson::os::seastore {
 
@@ -18,6 +19,17 @@ using depth_le_t = ceph_les32;
 
 using checksum_t = uint32_t;
 
+// Immutable metadata for seastore set a mkfs time
+struct seastore_meta_t {
+  uuid_d seastore_id;
+
+  DENC(seastore_meta_t, v, p) {
+    DENC_START(1, 1, p);
+    denc(v.seastore_id, p);
+    DENC_FINISH(p);
+  }
+};
+
 // Identifies segment location on disk, see SegmentManager,
 using segment_id_t = uint32_t;
 constexpr segment_id_t NULL_SEG_ID =
@@ -350,6 +362,7 @@ struct record_t {
 
 }
 
+WRITE_CLASS_DENC_BOUNDED(crimson::os::seastore::seastore_meta_t)
 WRITE_CLASS_DENC_BOUNDED(crimson::os::seastore::paddr_t)
 WRITE_CLASS_DENC_BOUNDED(crimson::os::seastore::journal_seq_t)
 WRITE_CLASS_DENC_BOUNDED(crimson::os::seastore::delta_info_t)
diff --git a/src/crimson/os/seastore/segment_manager.h b/src/crimson/os/seastore/segment_manager.h
index 79b1240c3dc..00b3cfc0c42 100644
--- a/src/crimson/os/seastore/segment_manager.h
+++ b/src/crimson/os/seastore/segment_manager.h
@@ -118,7 +118,7 @@ public:
     ceph_assert(get_size() % get_segment_size() == 0);
     return ((segment_id_t)(get_size() / get_segment_size()));
   }
-
+  virtual const seastore_meta_t &get_meta() const = 0;
 
   virtual ~SegmentManager() {}
 };
diff --git a/src/crimson/os/seastore/segment_manager/block.cc b/src/crimson/os/seastore/segment_manager/block.cc
index 8c8fa717014..6b74fc62f84 100644
--- a/src/crimson/os/seastore/segment_manager/block.cc
+++ b/src/crimson/os/seastore/segment_manager/block.cc
@@ -115,7 +115,8 @@ block_sm_superblock_t make_superblock(
     data.block_size,
     segments,
     data.block_size,
-    tracker_size + data.block_size
+    tracker_size + data.block_size,
+    config.meta
   };
 }
 
diff --git a/src/crimson/os/seastore/segment_manager/block.h b/src/crimson/os/seastore/segment_manager/block.h
index 0a8c3173400..927b13e4e94 100644
--- a/src/crimson/os/seastore/segment_manager/block.h
+++ b/src/crimson/os/seastore/segment_manager/block.h
@@ -24,6 +24,8 @@ struct block_sm_superblock_t {
   size_t segments = 0;
   uint64_t tracker_offset = 0;
   uint64_t first_segment_offset = 0;
+
+  seastore_meta_t meta;
     
   DENC(block_sm_superblock_t, v, p) {
     DENC_START(1, 1, p);
@@ -33,6 +35,7 @@ struct block_sm_superblock_t {
     denc(v.segments, p);
     denc(v.tracker_offset, p);
     denc(v.first_segment_offset, p);
+    denc(v.meta, p);
     DENC_FINISH(p);
   }
 };
@@ -146,6 +149,7 @@ public:
     std::string path;
     size_t segment_size = 0;
     size_t total_size = 0;
+    seastore_meta_t meta;
   };
   using mkfs_ertr = access_ertr;
   using mkfs_ret = mkfs_ertr::future<>;
@@ -199,6 +203,10 @@ private:
       addr.offset;
   }
 
+  const seastore_meta_t &get_meta() const {
+    return superblock.meta;
+  }
+
   std::vector<segment_state_t> segment_state;
 
   char *buffer = nullptr;
diff --git a/src/crimson/os/seastore/segment_manager/ephemeral.cc b/src/crimson/os/seastore/segment_manager/ephemeral.cc
index b58e842bb14..3250303adfb 100644
--- a/src/crimson/os/seastore/segment_manager/ephemeral.cc
+++ b/src/crimson/os/seastore/segment_manager/ephemeral.cc
@@ -96,6 +96,8 @@ EphemeralSegmentManager::init_ertr::future<> EphemeralSegmentManager::init()
     "Initing ephemeral segment manager with config {}",
     config);
 
+  meta = seastore_meta_t{};
+
   if (config.block_size % (4<<10) != 0) {
     return crimson::ct_error::invarg::make();
   }
diff --git a/src/crimson/os/seastore/segment_manager/ephemeral.h b/src/crimson/os/seastore/segment_manager/ephemeral.h
index 41e3591a2bc..9f19cb4d0c7 100644
--- a/src/crimson/os/seastore/segment_manager/ephemeral.h
+++ b/src/crimson/os/seastore/segment_manager/ephemeral.h
@@ -53,6 +53,7 @@ class EphemeralSegmentManager final : public SegmentManager {
   using segment_state_t = Segment::segment_state_t;
 
   const ephemeral_config_t config;
+  std::optional<seastore_meta_t> meta;
 
   size_t get_offset(paddr_t addr) {
     return (addr.segment * config.segment_size) + addr.offset;
@@ -93,6 +94,11 @@ public:
     return config.segment_size;
   }
 
+  const seastore_meta_t &get_meta() const final {
+    assert(meta);
+    return *meta;
+  }
+
   void remount();
 
   // public so tests can bypass segment interface when simpler
-- 
2.39.5