From 46e8a8db14ea838a3165e2858f96cd5fb0284890 Mon Sep 17 00:00:00 2001
From: Samuel Just <sjust@redhat.com>
Date: Thu, 19 Nov 2020 13:06:10 -0800
Subject: [PATCH] crimson/os/seastore/journal: add data and metadata checksums

Signed-off-by: Samuel Just <sjust@redhat.com>
---
 src/crimson/os/seastore/journal.cc | 78 ++++++++++++++++++++++--------
 src/crimson/os/seastore/journal.h  |  8 ++-
 2 files changed, 63 insertions(+), 23 deletions(-)

diff --git a/src/crimson/os/seastore/journal.cc b/src/crimson/os/seastore/journal.cc
index ad3b4355419..42fb038ea23 100644
--- a/src/crimson/os/seastore/journal.cc
+++ b/src/crimson/os/seastore/journal.cc
@@ -92,37 +92,70 @@ ceph::bufferlist Journal::encode_record(
   record_size_t rsize,
   record_t &&record)
 {
-  bufferlist metadatabl;
+  bufferlist data_bl;
+  for (auto &i: record.extents) {
+    data_bl.append(i.bl);
+  }
+
+  bufferlist bl;
   record_header_t header{
     rsize.mdlength,
     rsize.dlength,
-    0 /* checksum, TODO */,
-    record.deltas.size(),
-    record.extents.size(),
-    current_segment_nonce
+    (uint32_t)record.deltas.size(),
+    (uint32_t)record.extents.size(),
+    current_segment_nonce,
+    data_bl.crc32c(-1)
   };
-  encode(header, metadatabl);
+  encode(header, bl);
+
+  auto metadata_crc_filler = bl.append_hole(sizeof(uint32_t));
+
   for (const auto &i: record.extents) {
-    encode(extent_info_t(i), metadatabl);
+    encode(extent_info_t(i), bl);
   }
   for (const auto &i: record.deltas) {
-    encode(i, metadatabl);
+    encode(i, bl);
   }
-  bufferlist databl;
-  for (auto &i: record.extents) {
-    databl.claim_append(i.bl);
-  }
-  if (metadatabl.length() % block_size != 0) {
-    metadatabl.append(
-      ceph::bufferptr(
-	block_size - (metadatabl.length() % block_size)));
+  if (bl.length() % block_size != 0) {
+    bl.append_zero(
+      block_size - (bl.length() % block_size));
   }
+  ceph_assert(bl.length() == rsize.mdlength);
+
 
-  ceph_assert(metadatabl.length() == rsize.mdlength);
-  ceph_assert(databl.length() == rsize.dlength);
-  metadatabl.claim_append(databl);
-  ceph_assert(metadatabl.length() == (rsize.mdlength + rsize.dlength));
-  return metadatabl;
+  auto bliter = bl.cbegin();
+  auto metadata_crc = bliter.crc32c(
+    ceph::encoded_sizeof_bounded<record_header_t>(),
+    -1);
+  bliter += sizeof(checksum_t); /* crc hole again */
+  metadata_crc = bliter.crc32c(
+    bliter.get_remaining(),
+    metadata_crc);
+  ceph_le32 metadata_crc_le;
+  metadata_crc_le = metadata_crc;
+  metadata_crc_filler.copy_in(
+    sizeof(checksum_t),
+    reinterpret_cast<const char *>(&metadata_crc_le));
+
+  bl.claim_append(data_bl);
+  ceph_assert(bl.length() == (rsize.dlength + rsize.mdlength));
+
+  return bl;
+}
+
+bool Journal::validate_metadata(const bufferlist &bl)
+{
+  auto bliter = bl.cbegin();
+  auto test_crc = bliter.crc32c(
+    ceph::encoded_sizeof_bounded<record_header_t>(),
+    -1);
+  ceph_le32 recorded_crc_le;
+  ::decode(recorded_crc_le, bliter);
+  uint32_t recorded_crc = recorded_crc_le;
+  test_crc = bliter.crc32c(
+    bliter.get_remaining(),
+    test_crc);
+  return test_crc == recorded_crc;
 }
 
 Journal::write_record_ret Journal::write_record(
@@ -154,6 +187,7 @@ Journal::record_size_t Journal::get_encoded_record_length(
   const record_t &record) const {
   extent_len_t metadata =
     (extent_len_t)ceph::encoded_sizeof_bounded<record_header_t>();
+  metadata += sizeof(checksum_t) /* crc */;
   metadata += record.extents.size() *
     ceph::encoded_sizeof_bounded<extent_info_t>();
   extent_len_t data = 0;
@@ -421,6 +455,7 @@ std::optional<std::vector<delta_info_t>> Journal::try_decode_deltas(
 {
   auto bliter = bl.cbegin();
   bliter += ceph::encoded_sizeof_bounded<record_header_t>();
+  bliter += sizeof(checksum_t) /* crc */;
   bliter += header.extents  * ceph::encoded_sizeof_bounded<extent_info_t>();
   logger().debug("{}: decoding {} deltas", __func__, header.deltas);
   std::vector<delta_info_t> deltas(header.deltas);
@@ -440,6 +475,7 @@ std::optional<std::vector<extent_info_t>> Journal::try_decode_extent_infos(
 {
   auto bliter = bl.cbegin();
   bliter += ceph::encoded_sizeof_bounded<record_header_t>();
+  bliter += sizeof(checksum_t) /* crc */;
   logger().debug("{}: decoding {} extents", __func__, header.extents);
   std::vector<extent_info_t> extent_infos(header.extents);
   for (auto &&i : extent_infos) {
diff --git a/src/crimson/os/seastore/journal.h b/src/crimson/os/seastore/journal.h
index af0d0673a7b..c657ccb1f67 100644
--- a/src/crimson/os/seastore/journal.h
+++ b/src/crimson/os/seastore/journal.h
@@ -52,19 +52,20 @@ struct record_header_t {
   // Fixed portion
   extent_len_t  mdlength;       // block aligned, length of metadata
   extent_len_t  dlength;        // block aligned, length of data
-  checksum_t    full_checksum;  // checksum for full record (TODO)
   size_t deltas;                // number of deltas
   size_t extents;               // number of extents
   segment_nonce_t segment_nonce;// nonce of containing segment
+  checksum_t data_crc;          // crc of data payload
+
 
   DENC(record_header_t, v, p) {
     DENC_START(1, 1, p);
     denc(v.mdlength, p);
     denc(v.dlength, p);
-    denc(v.full_checksum, p);
     denc(v.deltas, p);
     denc(v.extents, p);
     denc(v.segment_nonce, p);
+    denc(v.data_crc, p);
     DENC_FINISH(p);
   }
 };
@@ -267,6 +268,9 @@ private:
     record_size_t rsize,
     record_t &&record);
 
+  /// validate metadata
+  static bool validate_metadata(const bufferlist &bl);
+
   /// do record write
   using write_record_ertr = crimson::errorator<
     crimson::ct_error::input_output_error>;
-- 
2.39.5