Merge pull request ceph#65166 from myoungwon/wip-fix-rbm-mergeable-block

crimson/os/seastore: correct possible mergeable size for ool extents

Reviewed-by: Xuehan Xu <[email protected]>

Author: Matan-B

src/crimson/os/seastore/extent_placement_manager.cc

@@ -1073,7 +1073,7 @@ RandomBlockOolWriter::do_write(
 
     // TODO : allocate a consecutive address based on a transaction
     if (writes.size() != 0 &&
-        writes.back().offset + writes.back().bp.length() == paddr) {
+	writes.back().offset + writes.back().get_mergeable_length() == paddr) {
       // We can write both the currrent extent and the previous one at once
       // if the extents are located in a row
       if (writes.back().mergeable_bps.size() == 0) {

src/crimson/os/seastore/extent_placement_manager.h

@@ -195,6 +195,17 @@ class RandomBlockOolWriter : public ExtentOolWriter {
     ceph::bufferptr bp;
     RandomBlockManager* rbm;
     std::list<ceph::bufferptr> mergeable_bps;
+
+    extent_len_t get_mergeable_length() const {
+      if (mergeable_bps.size() == 0) {
+	return bp.length();
+      }
+      extent_len_t len = 0;
+      for (auto &p : mergeable_bps) {
+	len += p.length();
+      }
+      return len;
+    }
   };
   alloc_write_iertr::future<> do_write(
     Transaction& t,