osd: Replace unused EC offset translation function with useful one.

The old chunk_aligned_shard_offset_to_ro_offset was not only unused, it
didn't actually have the correct logic. We replace it here with similar,
but more useful function that will be used in sparse reads for EC

Signed-off-by: Alex Ainscow <aainscow@uk.ibm.com>

diff --git a/src/osd/ECUtil.h b/src/osd/ECUtil.h
index deaf39cd53fa90221bc0354d49f3afb83663e4da..342101829a674347e38f6c9273ebb28f9c90e65b 100644 (file)
--- a/src/osd/ECUtil.h
+++ b/src/osd/ECUtil.h
@@ -766,9 +766,10 @@ public:
     return ((len + stripe_width - 1) / stripe_width) * chunk_size;
   }
 
-  uint64_t chunk_aligned_shard_offset_to_ro_offset(uint64_t offset) const {
-    ceph_assert(offset % chunk_size == 0);
-    return (offset / chunk_size) * stripe_width;
+  uint64_t shard_offset_to_ro_offset(shard_id_t shard, uint64_t offset) const {
+    raw_shard_id_t raw_shard = get_raw_shard(shard);
+    auto result = std::lldiv(offset, chunk_size);
+    return result.quot * stripe_width + (int)raw_shard * chunk_size + result.rem;
   }
 
   std::pair<uint64_t, uint64_t> chunk_aligned_ro_range_to_shard_ro_range(

diff --git a/src/test/osd/TestECBackend.cc b/src/test/osd/TestECBackend.cc
index 082a7dd1d52ebebf60f73ac738eb66824585d28e..697f4a1a99512f357b2e6910bc26c739f206f3e8 100644 (file)
--- a/src/test/osd/TestECBackend.cc
+++ b/src/test/osd/TestECBackend.cc
@@ -56,7 +56,7 @@ TEST(ECUtil, stripe_info_t)
 
   ASSERT_EQ(s.aligned_ro_offset_to_chunk_offset(2*swidth),
            2*s.get_chunk_size());
-  ASSERT_EQ(s.chunk_aligned_shard_offset_to_ro_offset(2*s.get_chunk_size()),
+  ASSERT_EQ(s.shard_offset_to_ro_offset(shard_id_t(0), 2*s.get_chunk_size()),
            2*s.get_stripe_width());
 
   // Stripe 1 + 1 chunk for 10 stripes needs to read 11 stripes starting