From 83fee0e55c5bbc3085fa390dee77c148b51374b4 Mon Sep 17 00:00:00 2001
From: Igor Fedotov <ifedotov@suse.com>
Date: Tue, 22 Dec 2020 00:01:52 +0300
Subject: [PATCH] os/bluestore: introduce bluestore_rocksdb_options_annex
 config parameter.

This simplifies modifying a subset of rocksdb settings since it
eliminates the need to re-provide bluestore's rocksdb settings.

Signed-off-by: Igor Fedotov <ifedotov@suse.com>
(cherry picked from commit 711505e8f9effbf4f0ada3bfe8d25dbc7e86861e)

 Conflicts:
  (trivial)	PendingReleaseNotes
  (trivial)	src/common/options.cc
  (trivial)	src/os/bluestore/BlueStore.cc
---
 PendingReleaseNotes             |  4 ++++
 src/common/legacy_config_opts.h |  1 +
 src/common/options.cc           |  6 +++++-
 src/os/bluestore/BlueStore.cc   | 17 +++++++++++++++++
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index 508bc63cafd6..0cd6c40da3f1 100644
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -6,6 +6,10 @@
   This improves out of the box performance of Ceph by allowing more PGs 
   to be created for a given pool.
 
+* New bluestore_rocksdb_options_annex config parameter. Complements
+  bluestore_rocksdb_options and allows setting rocksdb options without repeating
+  the existing defaults.
+
 15.2.8
 ------
 * $pid expansion in config paths like `admin_socket` will now properly expand
diff --git a/src/common/legacy_config_opts.h b/src/common/legacy_config_opts.h
index 68364bbb9626..3abaf52bb9e5 100644
--- a/src/common/legacy_config_opts.h
+++ b/src/common/legacy_config_opts.h
@@ -1014,6 +1014,7 @@ OPTION(bluestore_bitmapallocator_span_size, OPT_INT) // must be power of 2 align
 OPTION(bluestore_max_deferred_txc, OPT_U64)
 OPTION(bluestore_max_defer_interval, OPT_U64)
 OPTION(bluestore_rocksdb_options, OPT_STR)
+OPTION(bluestore_rocksdb_options_annex, OPT_STR)
 OPTION(bluestore_fsck_on_mount, OPT_BOOL)
 OPTION(bluestore_fsck_on_mount_deep, OPT_BOOL)
 OPTION(bluestore_fsck_quick_fix_on_mount, OPT_BOOL)
diff --git a/src/common/options.cc b/src/common/options.cc
index 693ed4c5f893..165aa6f6453d 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -4434,7 +4434,11 @@ std::vector<Option> get_global_options() {
 
     Option("bluestore_rocksdb_options", Option::TYPE_STR, Option::LEVEL_ADVANCED)
     .set_default("compression=kNoCompression,max_write_buffer_number=4,min_write_buffer_number_to_merge=1,recycle_log_file_num=4,write_buffer_size=268435456,writable_file_max_buffer_size=0,compaction_readahead_size=2097152,max_background_compactions=2")
-    .set_description("Rocksdb options"),
+    .set_description("Full set of rocksdb settings to override"),
+
+    Option("bluestore_rocksdb_options_annex", Option::TYPE_STR, Option::LEVEL_ADVANCED)
+    .set_default("")
+    .set_description("An addition to bluestore_rocksdb_options. Allows setting rocksdb options without repeating the existing defaults."),
 
     Option("bluestore_rocksdb_cf", Option::TYPE_BOOL, Option::LEVEL_ADVANCED)
     .set_default(false)
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 2425580ceebf..48e2f11df574 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -5771,6 +5771,14 @@ int BlueStore::_open_bluefs(bool create)
   if (bluefs_layout.shared_bdev == BlueFS::BDEV_SLOW) {
 
     string options = cct->_conf->bluestore_rocksdb_options;
+    string options_annex = cct->_conf->bluestore_rocksdb_options_annex;
+    if (!options_annex.empty()) {
+      if (!options.empty() &&
+        *options.rbegin() != ',') {
+        options += ',';
+      }
+      options += options_annex;
+    }
 
     rocksdb::Options rocks_opts;
     int r = RocksDBStore::ParseOptionsFromStringStatic(
@@ -5973,6 +5981,7 @@ int BlueStore::_open_db(bool create, bool to_repair_db, bool read_only)
   ceph_assert(!(create && read_only));
   string fn = path + "/db";
   string options;
+  string options_annex;
   stringstream err;
   std::shared_ptr<Int64ArrayMergeOperator> merge_op(new Int64ArrayMergeOperator);
 
@@ -6121,6 +6130,14 @@ int BlueStore::_open_db(bool create, bool to_repair_db, bool read_only)
 
   if (kv_backend == "rocksdb") {
     options = cct->_conf->bluestore_rocksdb_options;
+    options_annex = cct->_conf->bluestore_rocksdb_options_annex;
+    if (!options_annex.empty()) {
+      if (!options.empty() &&
+        *options.rbegin() != ',') {
+        options += ',';
+      }
+      options += options_annex;
+    }
 
     map<string,string> cf_map;
     cct->_conf.with_val<string>("bluestore_rocksdb_cfs",
-- 
2.47.3