From 23ec3e07c84c42162c56e7b5d9345fa29a72f9b4 Mon Sep 17 00:00:00 2001
From: Adam Kupczyk <akupczyk@redhat.com>
Date: Tue, 19 Jan 2021 15:07:16 +0100
Subject: [PATCH] tools/bluestore: Add command 'show-sharding' to
 ceph-bluestore-tool

Add command 'show-sharding' to ceph-bluestore-tool.

Signed-off-by: Adam Kupczyk <akupczyk@redhat.com>
(cherry picked from commit 882714e0c90e7c2492af47adf885141e57aee783)
---
 doc/man/8/ceph-bluestore-tool.rst  |  5 +++++
 src/kv/RocksDBStore.cc             | 19 +++++++++++++++++++
 src/kv/RocksDBStore.h              |  2 +-
 src/os/bluestore/bluestore_tool.cc | 28 ++++++++++++++++++++++------
 4 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/doc/man/8/ceph-bluestore-tool.rst b/doc/man/8/ceph-bluestore-tool.rst
index 2a1813e6968..bb67ccc71e7 100644
--- a/doc/man/8/ceph-bluestore-tool.rst
+++ b/doc/man/8/ceph-bluestore-tool.rst
@@ -24,6 +24,7 @@ Synopsis
 | **ceph-bluestore-tool** bluefs-bdev-migrate --path *osd path* --dev-target *new-device* --devs-source *device1* [--devs-source *device2*]
 | **ceph-bluestore-tool** free-dump|free-score --path *osd path* [ --allocator block/bluefs-wal/bluefs-db/bluefs-slow ]
 | **ceph-bluestore-tool** reshard --path *osd path* --sharding *new sharding* [ --sharding-ctrl *control string* ]
+| **ceph-bluestore-tool** show-sharding --path *osd path*
 
 
 Description
@@ -109,6 +110,10 @@ Commands
    Interrupted resharding does not corrupt data. It is always possible to continue previous resharding,
    or select any other sharding scheme, including reverting to original one.
 
+:command:`show-sharding` --path *osd path*
+
+   Show sharding that is currently applied to BlueStore's RocksDB.
+
 Options
 =======
 
diff --git a/src/kv/RocksDBStore.cc b/src/kv/RocksDBStore.cc
index c121734efaf..b7fa258638f 100644
--- a/src/kv/RocksDBStore.cc
+++ b/src/kv/RocksDBStore.cc
@@ -3330,3 +3330,22 @@ int RocksDBStore::reshard(const std::string& new_sharding, const RocksDBStore::r
 
   return r;
 }
+
+bool RocksDBStore::get_sharding(std::string& sharding) {
+  rocksdb::Status status;
+  std::string stored_sharding_text;
+  bool result = false;
+  sharding.clear();
+
+  status = env->FileExists(sharding_def_file);
+  if (status.ok()) {
+    status = rocksdb::ReadFileToString(env,
+				       sharding_def_file,
+				       &stored_sharding_text);
+    if(status.ok()) {
+      result = true;
+      sharding = stored_sharding_text;
+    }
+  }
+  return result;
+}
diff --git a/src/kv/RocksDBStore.h b/src/kv/RocksDBStore.h
index 969fe5bfe46..0735e115c36 100644
--- a/src/kv/RocksDBStore.h
+++ b/src/kv/RocksDBStore.h
@@ -516,7 +516,7 @@ public:
     bool   unittest_fail_after_successful_processing = false;
   };
   int reshard(const std::string& new_sharding, const resharding_ctrl* ctrl = nullptr);
-
+  bool get_sharding(std::string& sharding);
 
 };
 
diff --git a/src/os/bluestore/bluestore_tool.cc b/src/os/bluestore/bluestore_tool.cc
index 275f73c4c5f..12293fdfd1b 100644
--- a/src/os/bluestore/bluestore_tool.cc
+++ b/src/os/bluestore/bluestore_tool.cc
@@ -275,7 +275,8 @@ int main(int argc, char **argv)
         "free-dump, "
         "free-score, "
         "bluefs-stats, "
-        "reshard")
+        "reshard, "
+        "show-sharding")
     ;
   po::options_description po_all("All options");
   po_all.add(po_options).add(po_positional);
@@ -942,12 +943,8 @@ int main(int argc, char **argv)
       cerr << "error preparing db environment: " << cpp_strerror(r) << std::endl;
       exit(EXIT_FAILURE);
     }
-    if (r < 0) {
-      cerr << "error starting k-v inside bluestore: " << cpp_strerror(r) << std::endl;
-      exit(EXIT_FAILURE);
-    }
-    RocksDBStore* rocks_db = dynamic_cast<RocksDBStore*>(db_ptr);
     ceph_assert(db_ptr);
+    RocksDBStore* rocks_db = dynamic_cast<RocksDBStore*>(db_ptr);
     ceph_assert(rocks_db);
     r = rocks_db->reshard(new_sharding, &ctrl);
     if (r < 0) {
@@ -956,6 +953,25 @@ int main(int argc, char **argv)
       cout << "reshard success" << std::endl;
     }
     bluestore.close_db_environment();
+  } else if (action == "show-sharding") {
+    BlueStore bluestore(cct.get(), path);
+    KeyValueDB *db_ptr;
+    int r = bluestore.open_db_environment(&db_ptr, false);
+    if (r < 0) {
+      cerr << "error preparing db environment: " << cpp_strerror(r) << std::endl;
+      exit(EXIT_FAILURE);
+    }
+    ceph_assert(db_ptr);
+    RocksDBStore* rocks_db = dynamic_cast<RocksDBStore*>(db_ptr);
+    ceph_assert(rocks_db);
+    std::string sharding;
+    bool res = rocks_db->get_sharding(sharding);
+    bluestore.close_db_environment();
+    if (!res) {
+      cerr << "failed to retrieve sharding def" << std::endl;
+      exit(EXIT_FAILURE);
+    }
+    cout << sharding << std::endl;
   } else {
     cerr << "unrecognized action " << action << std::endl;
     return 1;
-- 
2.47.3