crimson/os/seastore/journal: factor out read_segment_header

Signed-off-by: Samuel Just <sjust@redhat.com>

diff --git a/src/crimson/os/seastore/journal.cc b/src/crimson/os/seastore/journal.cc
index b5bbe1d7d73492c67f2f66153e8d8678a9ecfd74..fbe61bf8e90634bd6d952ddbc4f013822cb4e162 100644 (file)
--- a/src/crimson/os/seastore/journal.cc
+++ b/src/crimson/os/seastore/journal.cc
@@ -204,6 +204,45 @@ Journal::roll_journal_segment()
     );
 }
 
+Journal::read_segment_header_ret
+Journal::read_segment_header(segment_id_t segment)
+{
+  return segment_manager.read(paddr_t{segment, 0}, block_size
+  ).handle_error(
+    read_segment_header_ertr::pass_further{},
+    crimson::ct_error::assert_all{}
+  ).safe_then([=](bufferptr bptr) -> read_segment_header_ret {
+    logger().debug("segment {} bptr size {}", segment, bptr.length());
+
+    segment_header_t header;
+    bufferlist bl;
+    bl.push_back(bptr);
+
+    logger().debug(
+      "find_replay_segments: segment {} block crc {}",
+      segment,
+      bl.begin().crc32c(block_size, 0));
+
+    auto bp = bl.cbegin();
+    try {
+      decode(header, bp);
+    } catch (ceph::buffer::error &e) {
+      logger().debug(
+       "find_replay_segments: segment {} unable to decode "
+       "header, skipping",
+       segment);
+      return crimson::ct_error::enodata::make();
+    }
+    logger().debug(
+      "find_replay_segments: segment {} header {}",
+      segment,
+      header);
+    return read_segment_header_ret(
+      read_segment_header_ertr::ready_future_marker{},
+      header);
+  });
+}
+
 Journal::open_for_write_ret Journal::open_for_write()
 {
   return roll_journal_segment().safe_then([this](auto seq) {
@@ -227,32 +266,19 @@ Journal::find_replay_segments_fut Journal::find_replay_segments()
        boost::make_counting_iterator(segment_id_t{0}),
        boost::make_counting_iterator(segment_manager.get_num_segments()),
        [this, &segments](auto i) {
-         return segment_manager.read(paddr_t{i, 0}, block_size
-         ).safe_then([this, &segments, i](bufferptr bptr) mutable {
-           logger().debug("segment {} bptr size {}", i, bptr.length());
-           segment_header_t header;
-           bufferlist bl;
-           bl.push_back(bptr);
-
-           logger().debug(
-             "find_replay_segments: segment {} block crc {}",
-             i,
-             bl.begin().crc32c(block_size, 0));
-
-           auto bp = bl.cbegin();
-           try {
-             decode(header, bp);
-           } catch (ceph::buffer::error &e) {
+         return read_segment_header(i
+         ).safe_then([this, &segments, i](auto header) mutable {
+           if (generate_nonce(
+                 header.journal_segment_seq,
+                 segment_manager.get_meta()) != header.segment_nonce) {
              logger().debug(
-               "find_replay_segments: segment {} unable to decode "
-               "header, skipping",
-               i);
+               "find_replay_segments: nonce mismatch segment {} header {}",
+               i,
+               header);
+             assert(0 == "impossible");
              return find_replay_segments_ertr::now();
            }
-           logger().debug(
-             "find_replay_segments: segment {} header {}",
-             i,
-             header);
+
            segments.emplace_back(i, std::move(header));
            return find_replay_segments_ertr::now();
          }).handle_error(
@@ -262,6 +288,12 @@ Journal::find_replay_segments_fut Journal::find_replay_segments()
                i);
              return find_replay_segments_ertr::now();
            }),
+           crimson::ct_error::enodata::handle([i](auto) {
+             logger().debug(
+               "find_replay_segments: segment {} header undecodable",
+               i);
+             return find_replay_segments_ertr::now();
+           }),
            find_replay_segments_ertr::pass_further{},
            crimson::ct_error::assert_all{}
          );

diff --git a/src/crimson/os/seastore/journal.h b/src/crimson/os/seastore/journal.h
index c925233b08f28817b6fc6706e1ffd5e8cdf29fff..d950b809be660efb04759388d5ed08b1b4026b1f 100644 (file)
--- a/src/crimson/os/seastore/journal.h
+++ b/src/crimson/os/seastore/journal.h
@@ -283,6 +283,15 @@ private:
   /// returns true iff current segment has insufficient space
   bool needs_roll(segment_off_t length) const;
 
+  using read_segment_header_ertr = crimson::errorator<
+    crimson::ct_error::enoent,
+    crimson::ct_error::enodata,
+    crimson::ct_error::input_output_error
+    >;
+  using read_segment_header_ret = read_segment_header_ertr::future<
+    segment_header_t>;
+  read_segment_header_ret read_segment_header(segment_id_t segment);
+
   /// return ordered vector of segments to replay
   using replay_segments_t = std::vector<
     std::pair<journal_seq_t, segment_header_t>>;