WIP "Heap" metadata storage scheme

cpp-btree

@@ -1 +1 @@
-Subproject commit 8de8b467acbca50cfd8835c20e0e379110f3b32b
+Subproject commit a21350e484cefa5728f23c227323b4b0822e738f

src/blockstore/blockstore.h

@@ -31,6 +31,7 @@
 #define DEFAULT_DATA_BLOCK_ORDER 17
 #define MIN_DATA_BLOCK_SIZE 4*1024
 #define MAX_DATA_BLOCK_SIZE 128*1024*1024
+#define MAX_META_BLOCK_SIZE 64*1024
 #define DEFAULT_BITMAP_GRANULARITY 4096
 
 #define BS_OP_MIN 1

src/blockstore/blockstore_disk.cpp

@@ -120,9 +120,9 @@ void blockstore_disk_t::parse_config(std::map<std::string, std::string> & config
     {
         throw std::runtime_error("meta_block_size must be a multiple of "+std::to_string(DIRECT_IO_ALIGNMENT));
     }
-    else if (meta_block_size > MAX_DATA_BLOCK_SIZE)
+    else if (meta_block_size > MAX_META_BLOCK_SIZE)
     {
-        throw std::runtime_error("meta_block_size must not exceed "+std::to_string(MAX_DATA_BLOCK_SIZE));
+        throw std::runtime_error("meta_block_size must not exceed "+std::to_string(MAX_META_BLOCK_SIZE));
     }
     if (data_offset % disk_alignment)
     {

src/blockstore/blockstore_flush.cpp

@@ -427,13 +427,6 @@ stop_flusher:
         printf("Flushing %jx:%jx v%ju\n", cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
         flusher->active_flushers++;
-        // Find it in clean_db
-        {
-            auto & clean_db = bs->clean_db_shard(cur.oid);
-            auto clean_it = clean_db.find(cur.oid);
-            old_clean_ver = (clean_it != clean_db.end() ? clean_it->second.version : 0);
-            old_clean_loc = (clean_it != clean_db.end() ? clean_it->second.location : UINT64_MAX);
-        }
         // Scan dirty versions of the object to determine what we need to read
         scan_dirty();
         // Writes and deletes shouldn't happen at the same time
@@ -912,6 +905,12 @@ void journal_flusher_co::calc_block_checksums(uint32_t *new_data_csums, bool ski
 
 void journal_flusher_co::scan_dirty()
 {
+    // Find it in clean_db
+    auto & clean_db = bs->clean_db_shard(cur.oid);
+    auto clean_it = clean_db.find(cur.oid);
+    old_clean_ver = (clean_it != clean_db.end() ? clean_it->second.version : 0);
+    old_clean_loc = (clean_it != clean_db.end() ? clean_it->second.location : UINT64_MAX);
+    auto old_clean_bitmap = (clean_it != clean_db.end() ? bs->get_clean_entry_bitmap(clean_it, 0) : NULL);
     dirty_it = dirty_start = dirty_end;
     v.clear();
     copy_count = 0;
@@ -1037,13 +1036,12 @@ void journal_flusher_co::scan_dirty()
             read_to_fill_incomplete = 0;
             return;
         }
-        uint8_t *bmp_ptr = bs->get_clean_entry_bitmap(old_clean_loc, 0);
         uint64_t fulfilled = 0;
         int last = v.size()-1;
         while (last >= 0 && (v[last].copy_flags & COPY_BUF_CSUM_FILL))
             last--;
         read_to_fill_incomplete = bs->fill_partial_checksum_blocks(
-            v, fulfilled, bmp_ptr, NULL, false, NULL, v[0].offset/bs->dsk.csum_block_size * bs->dsk.csum_block_size,
+            v, fulfilled, old_clean_bitmap, NULL, false, NULL, v[0].offset/bs->dsk.csum_block_size * bs->dsk.csum_block_size,
             ((v[last].offset+v[last].len-1) / bs->dsk.csum_block_size + 1) * bs->dsk.csum_block_size
         );
     }

src/blockstore/blockstore_impl.cpp

@@ -41,6 +41,8 @@ blockstore_impl_t::~blockstore_impl_t()
         free(metadata_buffer);
     if (clean_bitmaps)
         free(clean_bitmaps);
+    if (heap_meta.blocks)
+        delete[] heap_meta.blocks;
 }
 
 bool blockstore_impl_t::is_started()
@@ -424,13 +426,29 @@ blockstore_clean_db_t& blockstore_impl_t::clean_db_shard(object_id oid)
 {
     uint64_t pg_num = 0;
     uint64_t pool_id = (oid.inode >> (64-POOL_ID_BITS));
-    auto sh_it = clean_db_settings.find(pool_id);
+    auto sett_it = clean_db_settings.find(pool_id);
-    if (sh_it != clean_db_settings.end())
+    if (sett_it != clean_db_settings.end())
     {
         // like map_to_pg()
-        pg_num = (oid.stripe / sh_it->second.pg_stripe_size) % sh_it->second.pg_count + 1;
+        pg_num = (oid.stripe / sett_it->second.pg_stripe_size) % sett_it->second.pg_count + 1;
     }
-    return clean_db_shards[(pool_id << (64-POOL_ID_BITS)) | pg_num];
+    auto shard_id = (pool_id << (64-POOL_ID_BITS)) | pg_num;
+    if (dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP)
+    {
+        auto sh_it = clean_db_shards.find(shard_id);
+        if (sh_it == clean_db_shards.end())
+        {
+            // clean_db_t stores larger entries with heap_meta, but we disguise it as smaller clean_entry :)
+            // patched cpp-btree with extra_data
+            clean_db_shards[shard_id] = blockstore_clean_db_t(
+                sizeof(clean_entry_heap_t) - sizeof(clean_entry)
+                + (inmemory_meta ? dsk.clean_dyn_size : 2*dsk.clean_entry_bitmap_size)
+            );
+            return clean_db_shards[shard_id];
+        }
+        return sh_it->second;
+    }
+    return clean_db_shards[shard_id];
 }
 
 void blockstore_impl_t::reshard_clean_db(pool_id_t pool, uint32_t pg_count, uint32_t pg_stripe_size)

src/blockstore/blockstore_impl.h

@@ -96,6 +96,9 @@
 #define BLOCKSTORE_META_MAGIC_V1 0x726F747341544956l
 #define BLOCKSTORE_META_FORMAT_V1 1
 #define BLOCKSTORE_META_FORMAT_V2 2
+#define BLOCKSTORE_META_FORMAT_HEAP 3
+#define BLOCKSTORE_META_HEADER_V1_SIZE 36
+#define BLOCKSTORE_META_HEADER_V2_SIZE 48
 
 // metadata header (superblock)
 struct __attribute__((__packed__)) blockstore_meta_header_v1_t
@@ -119,6 +122,7 @@ struct __attribute__((__packed__)) blockstore_meta_header_v2_t
     uint32_t data_csum_type;
     uint32_t csum_block_size;
     uint32_t header_csum;
+    uint32_t block_id_bits; // 32 by default in heap meta
 };
 
 // 32 bytes = 24 bytes + block bitmap (4 bytes by default) + external attributes (also bitmap, 4 bytes by default)
@@ -140,6 +144,62 @@ struct __attribute__((__packed__)) clean_entry
     uint64_t location;
 };
 
+typedef uint32_t heap_block_num_t;
+
+// 50 = 16 (key=object_id) + 26 (value) + 8 (bitmap) + N (checksum) bytes per "clean" entry in memory
+struct __attribute__((__packed__)) clean_entry_heap_t
+{
+    uint64_t version;
+    uint64_t location; // UINT64_MAX = deleted
+    // previous versions invalidated by this version
+    heap_block_num_t prev_versions;
+    // metadata block number
+    heap_block_num_t meta_block;
+    // offset within block
+    uint16_t block_offset;
+    uint8_t bitmap[];
+};
+
+struct __attribute__((__packed__)) heap_meta_block_header_t
+{
+    uint64_t magic;
+    uint64_t seq_num;
+    uint32_t invalidates_blocks;
+};
+
+// 48+checksums = (40+bitmap)+checksums bytes per on-disk "heap" entry
+// for 128 KB block without checksums, it's 48 bytes - 84 entries per 4 kb metadata block
+// for 128 KB block with 4k checksums, it's 176 bytes - 22 entries per 4 kb metadata block
+// for 1 MB block without checksums, it's 80 bytes - 50 entries per 4 kb metadata block
+// for 1 MB block with 4k checksums, it's 1104 bytes O_o - only 3 entries per 4 kb metadata block
+// for 1 MB block with 32k checksums, it's 176 bytes again
+struct __attribute__((__packed__)) heap_meta_entry_t
+{
+    object_id oid;
+    uint64_t version;
+    uint64_t location; // UINT64_MAX = deleted
+    uint64_t reserved;
+    uint8_t bitmap[];
+};
+
+struct heap_meta_block_t
+{
+    heap_block_num_t offset = 0;
+    uint64_t seq_num = 0;
+    uint32_t used_space = 0;
+    std::vector<uint64_t> invalidates_blocks;
+};
+
+struct heap_meta_t
+{
+    heap_block_num_t block_count = 0;
+    heap_meta_block_t *blocks = NULL;
+    // used space => block number
+    std::multimap<uint32_t, heap_block_num_t> used_space_map;
+    heap_block_num_t cur_written_block = 0;
+    uint8_t *written_block_buf = NULL;
+};
+
 // 64 = 24 + 40 bytes per dirty entry in memory (obj_ver_id => dirty_entry). Plus checksums
 struct __attribute__((__packed__)) dirty_entry
 {
@@ -270,6 +330,8 @@ class blockstore_impl_t
 
     struct ring_consumer_t ring_consumer;
 
+    heap_meta_t heap_meta;
+
     std::map<pool_id_t, pool_shard_settings_t> clean_db_settings;
     std::map<pool_pg_id_t, blockstore_clean_db_t> clean_db_shards;
     std::map<uint64_t, int> no_inode_stats;
@@ -315,7 +377,7 @@ class blockstore_impl_t
     void open_data();
     void open_meta();
     void open_journal();
-    uint8_t* get_clean_entry_bitmap(uint64_t block_loc, int offset);
+    uint8_t* get_clean_entry_bitmap(blockstore_clean_db_t::iterator clean_it, int offset);
 
     blockstore_clean_db_t& clean_db_shard(object_id oid);
     void reshard_clean_db(pool_id_t pool_id, uint32_t pg_count, uint32_t pg_stripe_size);
@@ -343,9 +405,9 @@ class blockstore_impl_t
         uint64_t &fulfilled, uint32_t item_start, uint32_t item_end,
         uint32_t item_state, uint64_t item_version, uint64_t item_location,
         uint64_t journal_sector, uint8_t *csum, int *dyn_data);
-    bool fulfill_clean_read(blockstore_op_t *read_op, uint64_t & fulfilled,
+    bool fulfill_clean_read_journal(blockstore_op_t *read_op, uint64_t & fulfilled,
-        uint8_t *clean_entry_bitmap, int *dyn_data,
+        uint8_t *clean_entry_bitmap, int *dyn_data, uint32_t item_start, uint32_t item_end, uint64_t clean_loc, uint64_t clean_ver);
-        uint32_t item_start, uint32_t item_end, uint64_t clean_loc, uint64_t clean_ver);
+    bool fulfill_clean_read_meta(blockstore_op_t *read_op, uint64_t & fulfilled, blockstore_clean_db_t::iterator clean_it);
     int fill_partial_checksum_blocks(std::vector<copy_buffer_t> & rv, uint64_t & fulfilled,
         uint8_t *clean_entry_bitmap, int *dyn_data, bool from_journal, uint8_t *read_buf, uint64_t read_offset, uint64_t read_end);
     int pad_journal_read(std::vector<copy_buffer_t> & rv, copy_buffer_t & cp,
@@ -354,7 +416,7 @@ class blockstore_impl_t
     bool read_range_fulfilled(std::vector<copy_buffer_t> & rv, uint64_t & fulfilled, uint8_t *read_buf,
         uint8_t *clean_entry_bitmap, uint32_t item_start, uint32_t item_end);
     bool read_checksum_block(blockstore_op_t *op, int rv_pos, uint64_t &fulfilled, uint64_t clean_loc);
-    uint8_t* read_clean_meta_block(blockstore_op_t *read_op, uint64_t clean_loc, int rv_pos);
+    uint8_t* read_clean_meta_block(blockstore_op_t *op, blockstore_clean_db_t::iterator clean_it, int rv_pos);
     bool verify_padded_checksums(uint8_t *clean_entry_bitmap, uint8_t *csum_buf, uint32_t offset,
         iovec *iov, int n_iov, std::function<void(uint32_t, uint32_t, uint32_t)> bad_block_cb);
     bool verify_journal_checksums(uint8_t *csums, uint32_t offset,

src/blockstore/blockstore_init.cpp

@@ -54,6 +54,7 @@ int blockstore_init_meta::loop()
     else if (wait_state == 4) goto resume_4;
     else if (wait_state == 5) goto resume_5;
     else if (wait_state == 6) goto resume_6;
+    else if (wait_state == 7) goto resume_7;
     printf("Reading blockstore metadata\n");
     if (bs->inmemory_meta)
         metadata_buffer = bs->metadata_buffer;
@@ -78,6 +79,7 @@ resume_1:
     if (iszero((uint64_t*)metadata_buffer, bs->dsk.meta_block_size / sizeof(uint64_t)))
     {
         {
+            memset(metadata_buffer, 0, bs->dsk.meta_block_size);
             blockstore_meta_header_v2_t *hdr = (blockstore_meta_header_v2_t *)metadata_buffer;
             hdr->zero = 0;
             hdr->magic = BLOCKSTORE_META_MAGIC_V1;
@@ -85,12 +87,19 @@ resume_1:
             hdr->meta_block_size = bs->dsk.meta_block_size;
             hdr->data_block_size = bs->dsk.data_block_size;
             hdr->bitmap_granularity = bs->dsk.bitmap_granularity;
+            if (bs->dsk.meta_format >= BLOCKSTORE_META_FORMAT_HEAP)
+            {
+                hdr->block_id_bits = sizeof(heap_block_num_t);
+            }
             if (bs->dsk.meta_format >= BLOCKSTORE_META_FORMAT_V2)
             {
                 hdr->data_csum_type = bs->dsk.data_csum_type;
                 hdr->csum_block_size = bs->dsk.csum_block_size;
                 hdr->header_csum = 0;
-                hdr->header_csum = crc32c(0, hdr, sizeof(*hdr));
+                hdr->header_csum = crc32c(0, hdr,
+                    bs->dsk.meta_format == BLOCKSTORE_META_FORMAT_V2
+                    ? BLOCKSTORE_META_HEADER_V2_SIZE
+                    : sizeof(*hdr));
             }
         }
         if (bs->readonly)
@@ -128,7 +137,7 @@ resume_1:
             );
             exit(1);
         }
-        if (hdr->version == BLOCKSTORE_META_FORMAT_V2)
+        if (hdr->version == BLOCKSTORE_META_FORMAT_HEAP)
         {
             uint32_t csum = hdr->header_csum;
             hdr->header_csum = 0;
@@ -138,6 +147,23 @@ resume_1:
                 exit(1);
             }
             hdr->header_csum = csum;
+            bs->dsk.meta_format = BLOCKSTORE_META_FORMAT_HEAP;
+            if (hdr->block_id_bits != sizeof(heap_block_num_t))
+            {
+                printf("Heap metadata block ID size (%u) is not supported by this build\n", hdr->block_id_bits);
+                exit(1);
+            }
+        }
+        else if (hdr->version == BLOCKSTORE_META_FORMAT_V2)
+        {
+            uint32_t csum = hdr->header_csum;
+            hdr->header_csum = 0;
+            if (crc32c(0, hdr, BLOCKSTORE_META_HEADER_V2_SIZE) != csum)
+            {
+                printf("Metadata header is corrupt (checksum mismatch).\n");
+                exit(1);
+            }
+            hdr->header_csum = csum;
             bs->dsk.meta_format = BLOCKSTORE_META_FORMAT_V2;
         }
         else if (hdr->version == BLOCKSTORE_META_FORMAT_V1)
@@ -152,11 +178,11 @@ resume_1:
             bs->dsk.meta_format = BLOCKSTORE_META_FORMAT_V1;
             printf("Warning: Starting with metadata in the old format without checksums, as stored on disk\n");
         }
-        else if (hdr->version > BLOCKSTORE_META_FORMAT_V2)
+        else
         {
             printf(
                 "Metadata format is too new for me (stored version is %ju, max supported %u).\n",
-                hdr->version, BLOCKSTORE_META_FORMAT_V2
+                hdr->version, BLOCKSTORE_META_FORMAT_HEAP
             );
             exit(1);
         }
@@ -181,7 +207,12 @@ resume_1:
     // Skip superblock
     md_offset = bs->dsk.meta_block_size;
     next_offset = md_offset;
-    entries_per_block = bs->dsk.meta_block_size / bs->dsk.clean_entry_size;
+    entries_per_block = bs->dsk.meta_block_size / bs->dsk.clean_entry_size; // FIXME only array
+    if (bs->dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP)
+    {
+        bs->heap_meta.blocks = new heap_meta_block_t[bs->dsk.meta_len / bs->dsk.meta_block_size];
+        bs->heap_meta.block_count = bs->dsk.meta_len / bs->dsk.meta_block_size;
+    }
     // Read the rest of the metadata
 resume_2:
     if (next_offset < bs->dsk.meta_len && submitted == 0)
@@ -225,9 +256,10 @@ resume_2:
             bool changed = false;
             for (uint64_t sector = 0; sector < bufs[i].size; sector += bs->dsk.meta_block_size)
             {
-                // handle <count> entries
+                auto this_changed = bs->dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP
-                if (handle_meta_block(bufs[i].buf + sector, entries_per_block,
+                    ? handle_heap_meta_block(bufs[i].buf + sector, bufs[i].offset + sector - md_offset)
-                    ((bufs[i].offset + sector - md_offset) / bs->dsk.meta_block_size) * entries_per_block))
+                    : handle_array_meta_block(bufs[i].buf + sector, bufs[i].offset + sector - md_offset);
+                if (this_changed)
                     changed = true;
             }
             if (changed && !bs->inmemory_meta && !bs->readonly)
@@ -254,6 +286,41 @@ resume_2:
         wait_state = 2;
         return 1;
     }
+    if (bs->dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP)
+    {
+        // build used_space index
+        for (heap_block_num_t i = 0; i < bs->heap_meta.block_count; i++)
+        {
+            bs->heap_meta.used_space_map.emplace(std::pair<uint32_t, heap_block_num_t>(bs->heap_meta.blocks[i].used_space, i));
+        }
+    }
+    if (heap_invalidated_block_seq.size() && !bs->readonly)
+    {
+        // zero out invalidated blocks not zeroed during the previous OSD execution
+        for (auto inv_seq: heap_invalidated_block_seq)
+        {
+            auto num_it = heap_block_by_seq.find(inv_seq);
+            if (num_it != heap_block_by_seq.end())
+                heap_invalidated_block_nums.push_back(num_it->second);
+        }
+        memset(metadata_buffer, 0, bs->dsk.meta_block_size);
+        for (i = 0; i < heap_invalidated_block_nums.size(); i++)
+        {
+            GET_SQE();
+            last_read_offset = heap_invalidated_block_nums[i]*bs->dsk.meta_block_size;
+            data->iov = { metadata_buffer, (size_t)bs->dsk.meta_block_size };
+            data->callback = [this](ring_data_t *data) { handle_event(data, -1); };
+            my_uring_prep_writev(sqe, bs->dsk.meta_fd, &data->iov, 1, bs->dsk.meta_offset + last_read_offset);
+            bs->ringloop->submit();
+            submitted++;
+resume_7:
+            if (submitted > 0)
+            {
+                wait_state = 7;
+                return 1;
+            }
+        }
+    }
     if (entries_to_zero.size() && !bs->inmemory_meta && !bs->readonly)
     {
         // we have to zero out additional entries
@@ -320,8 +387,9 @@ resume_6:
     return 0;
 }
 
-bool blockstore_init_meta::handle_meta_block(uint8_t *buf, uint64_t entries_per_block, uint64_t done_cnt)
+bool blockstore_init_meta::handle_array_meta_block(uint8_t *buf, uint64_t block_offset)
 {
+    uint64_t done_cnt = (block_offset / bs->dsk.meta_block_size) * entries_per_block;
     bool updated = false;
     uint64_t max_i = entries_per_block;
     if (max_i > bs->dsk.block_count-done_cnt)
@@ -411,6 +479,132 @@ bool blockstore_init_meta::handle_meta_block(uint8_t *buf, uint64_t entries_per_
     return updated;
 }
 
+static int bitmap_count_ones(uint8_t *bitmap, int size)
+{
+    int n = 0, i = 0;
+    for (; i <= size-sizeof(unsigned); i += sizeof(unsigned))
+    {
+        n += __builtin_popcount(*(unsigned*)(bitmap+i));
+    }
+    for (; i < size; i++)
+    {
+        n += __builtin_popcount(*(unsigned char*)(bitmap+i));
+    }
+    return n;
+}
+
+// v3 / heap / "cow" metadata block
+bool blockstore_init_meta::handle_heap_meta_block(uint8_t *buf, uint64_t block_offset)
+{
+    if ((block_offset / bs->dsk.meta_block_size) > (heap_block_num_t)-1)
+    {
+        fprintf(stderr, "Metadata area too large\n");
+        exit(1);
+    }
+    // Validate block CRC
+    uint32_t block_crc = *(uint32_t*)(buf + bs->dsk.meta_block_size - 4);
+    if (crc32c(0, buf, bs->dsk.meta_block_size-4) != block_crc)
+    {
+        return false;
+    }
+    // Validate header
+    heap_meta_block_header_t *hdr = (heap_meta_block_header_t*)buf;
+    if (hdr->magic != BLOCKSTORE_META_MAGIC_V1)
+    {
+        return false;
+    }
+    if (hdr->invalidates_blocks > (bs->dsk.meta_block_size-4-sizeof(heap_meta_block_header_t))/sizeof(uint64_t))
+    {
+        fprintf(stderr, "Metadata block at %jx contains too large invalidates_blocks count: %x\n", block_offset, hdr->invalidates_blocks);
+        exit(1);
+    }
+    if (heap_invalidated_block_seq.find(hdr->seq_num) != heap_invalidated_block_seq.end())
+    {
+        // Check if the block is invalidated and handled after the block that invalidates it
+        return false;
+    }
+    uint64_t hdr_size = sizeof(heap_meta_block_header_t) + hdr->invalidates_blocks*8;
+    heap_meta_block_t & blk = bs->heap_meta.blocks[block_offset/bs->dsk.meta_block_size];
+    blk.offset = block_offset;
+    blk.seq_num = hdr->seq_num;
+    blk.used_space = hdr_size + 4;
+    uint64_t *hdr_inv = (uint64_t*)(hdr + 1);
+    for (int i = 0; i < hdr->invalidates_blocks; i++)
+    {
+        blk.invalidates_blocks.push_back(hdr_inv[i]);
+        heap_invalidated_block_seq.insert(hdr_inv[i]);
+    }
+    heap_block_by_seq[hdr->seq_num] = block_offset;
+    // Process sub-blocks
+    uint64_t heap_entry_size = sizeof(heap_meta_entry_t) + bs->dsk.clean_dyn_size;
+    for (uint64_t pos = sizeof(heap_meta_block_header_t); pos < bs->dsk.meta_block_size-4; pos += heap_entry_size)
+    {
+        heap_meta_entry_t *diskentry = (heap_meta_entry_t*)(buf + pos);
+        if (!diskentry->oid.inode || !diskentry->version)
+        {
+            continue;
+        }
+        auto & clean_db = bs->clean_db_shard(diskentry->oid);
+        auto mementry = (clean_entry_heap_t*)(&clean_db[diskentry->oid]);
+        bool exists = mementry->version != 0;
+        if (exists && mementry->version >= diskentry->version)
+        {
+            if (mementry->version == diskentry->version)
+            {
+                // Voluntarily allow duplicates of in-memory entries with different
+                // bitmaps to support checksum updates with hole-punching
+                int old_count = bitmap_count_ones(mementry->bitmap, bs->dsk.clean_entry_bitmap_size);
+                int new_count = bitmap_count_ones(diskentry->bitmap, bs->dsk.clean_entry_bitmap_size);
+                if (old_count < new_count)
+                {
+                    continue;
+                }
+            }
+            else
+            {
+                continue;
+            }
+        }
+        blk.used_space += heap_entry_size;
+        if (exists && mementry->location != UINT64_MAX)
+        {
+            // free the previous block
+            uint64_t old_clean_loc = mementry->location >> bs->dsk.block_order;
+#ifdef BLOCKSTORE_DEBUG
+            printf("Free block %ju from %jx:%jx v%ju\n", 1+old_clean_loc,
+                diskentry->oid.inode, diskentry->oid.stripe, mementry->version);
+#endif
+            bs->data_alloc->set(old_clean_loc, false);
+            bs->inode_space_stats[diskentry->oid.inode] -= bs->dsk.data_block_size;
+            bs->used_blocks--;
+            bs->heap_meta.blocks[mementry->meta_block].used_space -= heap_entry_size;
+        }
+        if (diskentry->location != UINT64_MAX)
+        {
+            bs->data_alloc->set(diskentry->location >> bs->dsk.block_order, true);
+            bs->inode_space_stats[diskentry->oid.inode] += bs->dsk.data_block_size;
+            bs->used_blocks++;
+#ifdef BLOCKSTORE_DEBUG
+            printf("Allocate block (heap entry) %ju: %jx:%jx v%ju\n", 1 + (diskentry->location >> bs->dsk.block_order),
+                diskentry->oid.inode, diskentry->oid.stripe, diskentry->version);
+#endif
+        }
+        mementry->version = diskentry->version;
+        mementry->location = diskentry->location;
+        mementry->meta_block = block_offset / bs->dsk.meta_block_size;
+        mementry->block_offset = block_offset % bs->dsk.meta_block_size;
+        if (exists)
+        {
+            mementry->prev_versions++;
+        }
+        // Extra data: 2 bitmaps + checksums or just 2 bitmaps if inmemory_meta is disabled
+        memcpy(&mementry->bitmap, &diskentry->bitmap, bs->inmemory_meta ? bs->dsk.clean_dyn_size : 2*bs->dsk.clean_entry_bitmap_size);
+        entries_loaded++;
+    }
+    // We have to zero out headers of invalidated blocks, but we'll do it later
+    return false;
+}
+
 blockstore_init_journal::blockstore_init_journal(blockstore_impl_t *bs)
 {
     this->bs = bs;

src/blockstore/blockstore_init.h

@@ -28,7 +28,13 @@ class blockstore_init_meta
     unsigned entries_per_block = 0;
     int i = 0, j = 0;
     std::vector<uint64_t> entries_to_zero;
-    bool handle_meta_block(uint8_t *buf, uint64_t count, uint64_t done_cnt);
+
+    std::map<uint64_t, heap_block_num_t> heap_block_by_seq;
+    std::set<uint64_t> heap_invalidated_block_seq;
+    std::vector<heap_block_num_t> heap_invalidated_block_nums;
+
+    bool handle_array_meta_block(uint8_t *buf, uint64_t block_offset);
+    bool handle_heap_meta_block(uint8_t *buf, uint64_t block_offset);
     void handle_event(ring_data_t *data, int buf_num);
 public:
     blockstore_init_meta(blockstore_impl_t *bs);

src/blockstore/blockstore_open.cpp

@@ -110,6 +110,10 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config, bool init)
     {
         metadata_buf_size = 4*1024*1024;
     }
+    if (metadata_buf_size % dsk.meta_block_size)
+    {
+        metadata_buf_size = ((metadata_buf_size+dsk.meta_block_size-1) / dsk.meta_block_size) * dsk.meta_block_size;
+    }
     if (dsk.meta_device == dsk.data_device)
     {
         disable_meta_fsync = disable_data_fsync;

src/blockstore/blockstore_read.cpp

@@ -148,10 +148,14 @@ int blockstore_impl_t::fulfill_read(blockstore_op_t *read_op,
     return r;
 }
 
-uint8_t* blockstore_impl_t::get_clean_entry_bitmap(uint64_t block_loc, int offset)
+uint8_t* blockstore_impl_t::get_clean_entry_bitmap(blockstore_clean_db_t::iterator clean_it, int offset)
 {
+    if (dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP)
+    {
+        return ((uint8_t*)&clean_it->second) + sizeof(clean_entry_heap_t) + offset;
+    }
     uint8_t *clean_entry_bitmap;
-    uint64_t meta_loc = block_loc >> dsk.block_order;
+    uint64_t meta_loc = clean_it->second.location >> dsk.block_order;
     if (inmemory_meta)
     {
         uint64_t sector = (meta_loc / (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.meta_block_size;
@@ -159,7 +163,9 @@ uint8_t* blockstore_impl_t::get_clean_entry_bitmap(uint64_t block_loc, int offse
         clean_entry_bitmap = ((uint8_t*)metadata_buffer + sector + pos*dsk.clean_entry_size + sizeof(clean_disk_entry) + offset);
     }
     else
+    {
         clean_entry_bitmap = (uint8_t*)(clean_bitmaps + meta_loc*2*dsk.clean_entry_bitmap_size + offset);
+    }
     return clean_entry_bitmap;
 }
 
@@ -433,7 +439,7 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
                 if (!IS_JOURNAL(dirty.state))
                 {
                     // Read from data disk, possibly checking checksums
-                    if (!fulfill_clean_read(read_op, fulfilled, bmp_ptr, dyn_data,
+                    if (!fulfill_clean_read_journal(read_op, fulfilled, bmp_ptr, dyn_data,
                         dirty.offset, dirty.offset+dirty.len, dirty.location, dirty_it->first.version))
                     {
                         goto undo_read;
@@ -464,14 +470,13 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
             result_version = clean_it->second.version;
             if (read_op->bitmap)
             {
-                void *bmp_ptr = get_clean_entry_bitmap(clean_it->second.location, dsk.clean_entry_bitmap_size);
+                void *bmp_ptr = get_clean_entry_bitmap(clean_it, dsk.clean_entry_bitmap_size);
                 memcpy(read_op->bitmap, bmp_ptr, dsk.clean_entry_bitmap_size);
             }
         }
         if (fulfilled < read_op->len)
         {
-            if (!fulfill_clean_read(read_op, fulfilled, NULL, NULL, 0, dsk.data_block_size,
+            if (!fulfill_clean_read_meta(read_op, fulfilled, clean_it))
-                clean_it->second.location, clean_it->second.version))
             {
                 goto undo_read;
             }
@@ -581,40 +586,22 @@ int blockstore_impl_t::pad_journal_read(std::vector<copy_buffer_t> & rv, copy_bu
     return 0;
 }
 
-bool blockstore_impl_t::fulfill_clean_read(blockstore_op_t *read_op, uint64_t & fulfilled,
+bool blockstore_impl_t::fulfill_clean_read_journal(blockstore_op_t *read_op, uint64_t & fulfilled,
     uint8_t *clean_entry_bitmap, int *dyn_data, uint32_t item_start, uint32_t item_end, uint64_t clean_loc, uint64_t clean_ver)
 {
-    bool from_journal = clean_entry_bitmap != NULL;
-    if (!clean_entry_bitmap)
-    {
-        // NULL clean_entry_bitmap means we're reading from data, not from the journal,
-        // and the bitmap location is obvious
-        clean_entry_bitmap = get_clean_entry_bitmap(clean_loc, 0);
-    }
     if (dsk.csum_block_size > dsk.bitmap_granularity)
     {
         auto & rv = PRIV(read_op)->read_vec;
-        int req = fill_partial_checksum_blocks(rv, fulfilled, clean_entry_bitmap, dyn_data, from_journal,
+        int req = fill_partial_checksum_blocks(rv, fulfilled, clean_entry_bitmap, dyn_data, true,
             (uint8_t*)read_op->buf, read_op->offset, read_op->offset+read_op->len);
-        if (!inmemory_meta && !from_journal && req > 0)
-        {
-            // Read checksums from disk
-            uint8_t *csum_buf = read_clean_meta_block(read_op, clean_loc, rv.size()-req);
-            for (int i = req; i > 0; i--)
-            {
-                rv[rv.size()-i].csum_buf = csum_buf;
-            }
-        }
         for (int i = req; i > 0; i--)
         {
             if (!read_checksum_block(read_op, i, fulfilled, clean_loc))
-            {
                 return false;
-            }
         }
         PRIV(read_op)->clean_block_used = req > 0;
     }
-    else if (from_journal)
+    else
     {
         // Don't scan bitmap - journal writes don't have holes (internal bitmap)!
         uint8_t *csum = !dsk.csum_block_size ? 0 : (clean_entry_bitmap + dsk.clean_entry_bitmap_size +
@@ -635,6 +622,43 @@ bool blockstore_impl_t::fulfill_clean_read(blockstore_op_t *read_op, uint64_t &
             assert(fulfill_read(read_op, fulfilled, item_end, dsk.data_block_size, (BS_ST_DELETE | BS_ST_STABLE), 0, 0, 0, NULL, NULL));
         }
     }
+    // Increment reference counter if clean data is being read from the disk
+    if (PRIV(read_op)->clean_block_used)
+    {
+        auto & uo = used_clean_objects[clean_loc];
+        uo.refs++;
+        if (dsk.csum_block_size && flusher->is_mutated(clean_loc))
+            uo.was_changed = true;
+        PRIV(read_op)->clean_block_used = clean_loc;
+    }
+    return true;
+}
+
+bool blockstore_impl_t::fulfill_clean_read_meta(blockstore_op_t *read_op, uint64_t & fulfilled, blockstore_clean_db_t::iterator clean_it)
+{
+    uint8_t *clean_entry_bitmap = get_clean_entry_bitmap(clean_it, 0);
+    uint64_t clean_loc = clean_it->second.location;
+    if (dsk.csum_block_size > dsk.bitmap_granularity)
+    {
+        auto & rv = PRIV(read_op)->read_vec;
+        int req = fill_partial_checksum_blocks(rv, fulfilled, clean_entry_bitmap, NULL, false,
+            (uint8_t*)read_op->buf, read_op->offset, read_op->offset+read_op->len);
+        if (!inmemory_meta && req > 0)
+        {
+            // Read checksums from disk
+            uint8_t *csum_buf = read_clean_meta_block(read_op, clean_it, rv.size()-req);
+            for (int i = req; i > 0; i--)
+            {
+                rv[rv.size()-i].csum_buf = csum_buf;
+            }
+        }
+        for (int i = req; i > 0; i--)
+        {
+            if (!read_checksum_block(read_op, i, fulfilled, clean_loc))
+                return false;
+        }
+        PRIV(read_op)->clean_block_used = req > 0;
+    }
     else
     {
         bool csum_done = !dsk.csum_block_size || inmemory_meta;
@@ -662,13 +686,13 @@ bool blockstore_impl_t::fulfill_clean_read(blockstore_op_t *read_op, uint64_t &
                 if (!csum_done)
                 {
                     // Read checksums from disk
-                    csum_buf = read_clean_meta_block(read_op, clean_loc, PRIV(read_op)->read_vec.size());
+                    csum_buf = read_clean_meta_block(read_op, clean_it, PRIV(read_op)->read_vec.size());
                     csum_done = true;
                 }
                 uint8_t *csum = !dsk.csum_block_size ? 0 : (csum_buf + 2*dsk.clean_entry_bitmap_size + bmp_start*(dsk.data_csum_type & 0xFF));
                 if (!fulfill_read(read_op, fulfilled, bmp_start * dsk.bitmap_granularity,
                     bmp_end * dsk.bitmap_granularity, (BS_ST_BIG_WRITE | BS_ST_STABLE), 0,
-                    clean_loc + bmp_start * dsk.bitmap_granularity, 0, csum, dyn_data))
+                    clean_loc + bmp_start * dsk.bitmap_granularity, 0, csum, NULL))
                 {
                     return false;
                 }
@@ -688,11 +712,22 @@ bool blockstore_impl_t::fulfill_clean_read(blockstore_op_t *read_op, uint64_t &
     return true;
 }
 
-uint8_t* blockstore_impl_t::read_clean_meta_block(blockstore_op_t *op, uint64_t clean_loc, int rv_pos)
+uint8_t* blockstore_impl_t::read_clean_meta_block(blockstore_op_t *op, blockstore_clean_db_t::iterator clean_it, int rv_pos)
 {
+    uint64_t sector, pos;
     auto & rv = PRIV(op)->read_vec;
-    auto sector = ((clean_loc >> dsk.block_order) / (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.meta_block_size;
+    if (dsk.meta_format == BLOCKSTORE_META_FORMAT_HEAP)
-    auto pos = ((clean_loc >> dsk.block_order) % (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.clean_entry_size;
+    {
+        auto clean_heap_entry = (clean_entry_heap_t*)(&clean_it->second);
+        sector = clean_heap_entry->meta_block * dsk.meta_block_size;
+        pos = clean_heap_entry->block_offset;
+    }
+    else
+    {
+        auto clean_loc = clean_it->second.location;
+        sector = ((clean_loc >> dsk.block_order) / (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.meta_block_size;
+        pos = ((clean_loc >> dsk.block_order) % (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.clean_entry_size;
+    }
     uint8_t *buf = (uint8_t*)memalign_or_die(MEM_ALIGNMENT, dsk.meta_block_size);
     rv.insert(rv.begin()+rv_pos, (copy_buffer_t){
         .copy_flags = COPY_BUF_META_BLOCK|COPY_BUF_CSUM_FILL,
@@ -807,11 +842,6 @@ bool blockstore_impl_t::verify_clean_padded_checksums(blockstore_op_t *op, uint6
     if (from_journal)
         return verify_padded_checksums(dyn_data, dyn_data + dsk.clean_entry_bitmap_size, offset, iov, n_iov, bad_block_cb);
     clean_loc = (clean_loc >> dsk.block_order) << dsk.block_order;
-    if (!dyn_data)
-    {
-        assert(inmemory_meta);
-        dyn_data = get_clean_entry_bitmap(clean_loc, 0);
-    }
     return verify_padded_checksums(dyn_data, dyn_data + 2*dsk.clean_entry_bitmap_size, offset, iov, n_iov, bad_block_cb);
 }
 
@@ -869,8 +899,18 @@ void blockstore_impl_t::handle_read_event(ring_data_t *data, blockstore_op_t *op
                         auto & uo = used_clean_objects.at((rv[i].disk_offset >> dsk.block_order) << dsk.block_order);
                         if (!uo.was_changed)
                         {
+                            bool from_journal = (rv[i].copy_flags & COPY_BUF_JOURNALED_BIG);
+                            auto csum_buf = rv[i].csum_buf;
+                            if (!from_journal && !csum_buf)
+                            {
+                                assert(inmemory_meta);
+                                auto & clean_db = clean_db_shard(op->oid);
+                                auto clean_it = clean_db.find(op->oid);
+                                assert(clean_it != clean_db.end());
+                                csum_buf = get_clean_entry_bitmap(clean_it, 0);
+                            }
                             verify_clean_padded_checksums(
-                                op, rv[i].disk_offset, rv[i].csum_buf, (rv[i].copy_flags & COPY_BUF_JOURNALED_BIG), iov, n_iov,
+                                op, rv[i].disk_offset, csum_buf, from_journal, iov, n_iov,
                                 [&](uint32_t bad_block, uint32_t calc_csum, uint32_t stored_csum)
                                 {
                                     ok = false;
@@ -1019,7 +1059,7 @@ int blockstore_impl_t::read_bitmap(object_id oid, uint64_t target_version, void
             *result_version = clean_it->second.version;
         if (bitmap)
         {
-            void *bmp_ptr = get_clean_entry_bitmap(clean_it->second.location, dsk.clean_entry_bitmap_size);
+            void *bmp_ptr = get_clean_entry_bitmap(clean_it, dsk.clean_entry_bitmap_size);
             memcpy(bitmap, bmp_ptr, dsk.clean_entry_bitmap_size);
         }
         return 0;

src/blockstore/blockstore_write.cpp

@@ -57,7 +57,7 @@ bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
             version = clean_it->second.version + 1;
             if (!is_del)
             {
-                void *bmp_ptr = get_clean_entry_bitmap(clean_it->second.location, dsk.clean_entry_bitmap_size);
+                void *bmp_ptr = get_clean_entry_bitmap(clean_it, dsk.clean_entry_bitmap_size);
                 memcpy(dyn_ptr, bmp_ptr, dsk.clean_entry_bitmap_size);
             }
         }
@@ -341,7 +341,7 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
             cancel_all_writes(op, dirty_it, -ENOSPC);
             return 2;
         }
-        if (inmemory_meta)
+        if (inmemory_meta && dsk.meta_format != BLOCKSTORE_META_FORMAT_HEAP)
         {
             // Check once more that metadata entry is zeroed (the reverse means a bug or corruption)
             uint64_t sector = (loc / (dsk.meta_block_size / dsk.clean_entry_size)) * dsk.meta_block_size;