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Fix bad resharding due to the lack of iteration order in a hashmap

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This commit is contained in:
Vitaliy Filippov
2025-12-02 01:52:12 +03:00
parent 6e856c2719
commit 30c5a79772
1 changed files with 19 additions and 18 deletions
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src/blockstore/blockstore_heap.cpp
+19 -18
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@@ -817,31 +817,32 @@ void blockstore_heap_t::reshard(pool_id_t pool, uint32_t pg_count, uint32_t pg_s
{
return;
}
uint32_t old_pg_count = !pool_settings.pg_count ? 1 : pool_settings.pg_count;
uint64_t pool_id = (uint64_t)pool;
emhash7::HashMap<uint64_t, emhash7::HashMap<inode_t, emhash5::HashMap<uint64_t, uint64_t>>> new_shards;
auto sh_it = block_index.begin();
while (sh_it != block_index.end())
for (uint32_t pg_num = 0; pg_num <= old_pg_count; pg_num++)
{
if ((sh_it->first >> (64-POOL_ID_BITS)) == pool_id)
auto sh_it = block_index.find((pool_id << (64-POOL_ID_BITS)) | pg_num);
if (sh_it == block_index.end())
{
for (auto & inode_pair: sh_it->second)
{
inode_t inode = inode_pair.first;
for (auto & pair: inode_pair.second)
{
// like map_to_pg()
uint64_t pg_num = (pair.first / pg_stripe_size) % pg_count + 1;
uint64_t shard_id = (pool_id << (64-POOL_ID_BITS)) | pg_num;
new_shards[shard_id][inode][pair.first] = std::move(pair.second);
}
}
block_index.erase(sh_it++);
continue;
}
for (auto & inode_pair: sh_it->second)
{
inode_t inode = inode_pair.first;
for (auto & pair: inode_pair.second)
{
// like map_to_pg()
uint64_t pg_num = (pair.first / pg_stripe_size) % pg_count + 1;
uint64_t shard_id = (pool_id << (64-POOL_ID_BITS)) | pg_num;
new_shards[shard_id][inode][pair.first] = std::move(pair.second);
}
}
block_index.erase(sh_it);
}
for (sh_it = new_shards.begin(); sh_it != new_shards.end(); sh_it++)
for (auto sh_it = new_shards.begin(); sh_it != new_shards.end(); sh_it++)
{
auto & to = block_index[sh_it->first];
to.swap(sh_it->second);
block_index[sh_it->first] = std::move(sh_it->second);
}
pool_settings = (pool_shard_settings_t){
.pg_count = pg_count,