From b7b78809f1e9790b08a2f5a49de96be1131e5010 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Thu, 31 Jan 2019 17:33:57 -0600
Subject: [PATCH] os/bluestore: add bluestore_ignore_data_csum option

This option just suppresses the EIO errors.  We still get the messages
in the logs, though.  This can be useful when you are in dire straights
and prefer some data to no data.

Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/common/legacy_config_opts.h | 1 +
 src/common/options.cc           | 5 +++++
 src/os/bluestore/BlueStore.cc   | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/src/common/legacy_config_opts.h b/src/common/legacy_config_opts.h
index a71d2dac51a3..3d456cc7741e 100644
--- a/src/common/legacy_config_opts.h
+++ b/src/common/legacy_config_opts.h
@@ -970,6 +970,7 @@ OPTION(bluestore_block_wal_path, OPT_STR)
 OPTION(bluestore_block_wal_size, OPT_U64) // rocksdb wal
 OPTION(bluestore_block_wal_create, OPT_BOOL)
 OPTION(bluestore_block_preallocate_file, OPT_BOOL) //whether preallocate space if block/db_path/wal_path is file rather that block device.
+OPTION(bluestore_ignore_data_csum, OPT_BOOL)
 OPTION(bluestore_csum_type, OPT_STR) // none|xxhash32|xxhash64|crc32c|crc32c_16|crc32c_8
 OPTION(bluestore_retry_disk_reads, OPT_U64)
 OPTION(bluestore_min_alloc_size, OPT_U32)
diff --git a/src/common/options.cc b/src/common/options.cc
index 245cac9af8f1..d3d437fda6a8 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -4202,6 +4202,11 @@ std::vector<Option> get_global_options() {
     .set_flag(Option::FLAG_CREATE)
     .set_description("Preallocate file created via bluestore_block*_create"),
 
+    Option("bluestore_ignore_data_csum", Option::TYPE_BOOL, Option::LEVEL_DEV)
+    .set_default(false)
+    .set_flag(Option::FLAG_RUNTIME)
+    .set_description("Ignore checksum errors on read and do not generate an EIO error"),
+
     Option("bluestore_csum_type", Option::TYPE_STR, Option::LEVEL_ADVANCED)
     .set_default("crc32c")
     .set_enum_allowed({"none", "crc32c", "crc32c_16", "crc32c_8", "xxhash32", "xxhash64"})
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index f52b4868979b..e4de32e6fd11 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -8678,6 +8678,9 @@ int BlueStore::_verify_csum(OnodeRef& o,
     }
   }
   logger->tinc(l_bluestore_csum_lat, mono_clock::now() - start);
+  if (cct->_conf->bluestore_ignore_data_csum) {
+    return 0;
+  }
   return r;
 }
 
-- 
2.47.3