From 711505e8f9effbf4f0ada3bfe8d25dbc7e86861e 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>
---
 PendingReleaseNotes             |  3 +++
 src/common/legacy_config_opts.h |  1 +
 src/common/options.cc           |  6 +++++-
 src/os/bluestore/BlueStore.cc   | 18 ++++++++++++++++++
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index af1c10f1843f..4d4513e99b38 100644
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -1,5 +1,8 @@
 >=16.0.0
 --------
+* New bluestore_rocksdb_options_annex config parameter. Complements
+  bluestore_rocksdb_options and allows setting rocksdb options without repeating
+  the existing defaults.
 * $pid expansion in config paths like `admin_socket` will now properly expand
   to the daemon pid for commands like `ceph-mds` or `ceph-osd`. Previously only
   `ceph-fuse`/`rbd-nbd` expanded `$pid` with the actual daemon pid.
diff --git a/src/common/legacy_config_opts.h b/src/common/legacy_config_opts.h
index 162b324fdaa8..08c26249f9ac 100644
--- a/src/common/legacy_config_opts.h
+++ b/src/common/legacy_config_opts.h
@@ -999,6 +999,7 @@ 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 57901687e77f..b268787ca4c2 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -4515,7 +4515,11 @@ 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,max_total_wal_size=1073741824")
-    .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(true)
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index e6535e2e8365..5e0a77a9d4d4 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -5651,6 +5651,14 @@ int BlueStore::_open_bluefs(bool create, bool read_only)
   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;
     r = RocksDBStore::ParseOptionsFromStringStatic(
@@ -6003,6 +6011,7 @@ int BlueStore::_open_db(bool create, bool to_repair_db, bool read_only)
   int r;
   ceph_assert(!(create && read_only));
   string options;
+  string options_annex;
   stringstream err;
   string kv_dir_fn;
   string kv_backend;
@@ -6014,6 +6023,15 @@ 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;
+    }
+
     if (cct->_conf.get_val<bool>("bluestore_rocksdb_cf")) {
       sharding_def = cct->_conf.get_val<std::string>("bluestore_rocksdb_cfs");
     }
-- 
2.47.3