Merge pull request eBay#415 from hkadayam/bitset_fix

Fixed the number of chunks issue

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomestoreConan(ConanFile):
     name = "homestore"
-    version = "6.4.43"
+    version = "6.4.44"
     homepage = "https://github.com/eBay/Homestore"
     description = "HomeStore Storage Engine"
     topics = ("ebay", "nublox")

src/lib/device/hs_super_blk.h

@@ -183,7 +183,9 @@ class hs_super_blk {
     static uint64_t chunk_super_block_size(const dev_info& dinfo);
     static uint64_t chunk_info_bitmap_size(const dev_info& dinfo) {
         // Chunk bitmap area has bitmap of max_chunks rounded off to 4k page
-        return sisl::round_up(std::max(1u, hs_super_blk::max_chunks_in_pdev(dinfo) / 8), 4096);
+        // add 4KB headroom for bitmap serialized header
+        auto bytes = sisl::round_up(hs_super_blk::max_chunks_in_pdev(dinfo), 8) / 8 + 4096;
+        return sisl::round_up(bytes, 4096);
     }
 
     static uint64_t total_size(const dev_info& dinfo) { return total_used_size(dinfo) + future_padding_size(dinfo); }
@@ -197,13 +199,10 @@ class hs_super_blk {
         return (dinfo.dev_type == HSDevType::Fast) ? EXTRA_SB_SIZE_FOR_FAST_DEVICE : EXTRA_SB_SIZE_FOR_DATA_DEVICE;
     }
     static uint32_t max_chunks_in_pdev(const dev_info& dinfo) {
-        uint64_t min_chunk_size =
-            (dinfo.dev_type == HSDevType::Fast) ? MIN_CHUNK_SIZE_FAST_DEVICE : MIN_CHUNK_SIZE_DATA_DEVICE;
-#ifdef _PRERELEASE
-        auto chunk_size = iomgr_flip::instance()->get_test_flip< long >("set_minimum_chunk_size");
-        if (chunk_size) { min_chunk_size = chunk_size.get(); }
-#endif
-        return (dinfo.dev_size - 1) / min_chunk_size + 1;
+        uint64_t min_c_size = min_chunk_size(dinfo.dev_type);
+        // Do not round up , for a device with 128MB and min_chunk_size = 16MB, we should get 8 chunks
+        // for a device with 100MB and min_chunk_size = 16MB, we should get 6 chunks, not 7.
+        return dinfo.dev_size / min_c_size;
     }
     static uint32_t min_chunk_size(HSDevType dtype) {
         uint64_t min_chunk_size = (dtype == HSDevType::Fast) ? MIN_CHUNK_SIZE_FAST_DEVICE : MIN_CHUNK_SIZE_DATA_DEVICE;

src/lib/device/physical_dev.cpp

@@ -220,8 +220,11 @@ void PhysicalDev::submit_batch() { m_drive_iface->submit_batch(); }
 
 //////////////////////////// Chunk Creation/Load related methods /////////////////////////////////////////
 void PhysicalDev::format_chunks() {
-    m_chunk_info_slots = std::make_unique< sisl::Bitset >(hs_super_blk::chunk_info_bitmap_size(m_dev_info));
-    auto bitmap_mem = m_chunk_info_slots->serialize(m_pdev_info.dev_attr.align_size);
+    m_chunk_info_slots = std::make_unique< sisl::Bitset >(std::max(1u, hs_super_blk::max_chunks_in_pdev(m_dev_info)),
+                                                          /* align size */ 4096);
+    auto bitmap_mem = m_chunk_info_slots->serialize(/* align size */ 4096);
+    HS_REL_ASSERT_LE(bitmap_mem->size(), hs_super_blk::chunk_info_bitmap_size(m_dev_info),
+                     "Chunk info serialized bitmap mismatch with expected size");
     write_super_block(bitmap_mem->cbytes(), bitmap_mem->size(), hs_super_blk::chunk_sb_offset());
 }
 
@@ -235,7 +238,7 @@ std::vector< shared< Chunk > > PhysicalDev::create_chunks(const std::vector< uin
 
     try {
         while (chunks_remaining > 0) {
-            auto b = m_chunk_info_slots->get_next_contiguous_n_reset_bits(0u, chunks_remaining);
+            auto b = m_chunk_info_slots->get_next_contiguous_n_reset_bits(0u, std::nullopt, 1u, chunks_remaining);
             if (b.nbits == 0) { throw std::out_of_range("System has no room for additional chunk"); }
 
             buf = hs_utils::iobuf_alloc(chunk_info::size * b.nbits, sisl::buftag::superblk,

src/tests/test_pdev.cpp

@@ -44,8 +44,10 @@ SISL_OPTION_GROUP(test_pdev,
                    ::cxxopts::value< uint32_t >()->default_value("2"), "number"),
                   (data_dev_size_mb, "", "data_dev_size_mb", "size of each data device in MB",
                    ::cxxopts::value< uint64_t >()->default_value("1024"), "number"),
+                  // in OrderlyChunkOpsWithRestart UT, we need to create 10 chunks on fast drive
+                  // ensure fast dev has > min_chunk_size_fast(32M) * 10 capacity.
                   (fast_dev_size_mb, "", "fast_dev_size_mb", "size of each fast device in MB",
-                   ::cxxopts::value< uint64_t >()->default_value("100"), "number"),
+                   ::cxxopts::value< uint64_t >()->default_value("400"), "number"),
                   (spdk, "", "spdk", "spdk", ::cxxopts::value< bool >()->default_value("false"), "true or false"));
 
 std::vector< std::string > g_data_dev_names;