**Describe the bug**
```
5828589:2021.04.27 03:13:08.824665 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828590:2021.04.27 03:13:08.824778 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828591:2021.04.27 03:13:08.824823 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828623:2021.04.27 03:13:08.824951 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828624:2021.04.27 03:13:08.824995 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828625:2021.04.27 03:13:08.825147 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828643:2021.04.27 03:13:08.831273 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828644:2021.04.27 03:13:08.831658 [ 3358 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.
5828648:2021.04.27 03:13:08.832767 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828649:2021.04.27 03:13:08.833210 [ 6101 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.

```

https://clickhouse-test-reports.s3.yandex.net/0/9bb4d8769f1064ada4cce6b26d8ff61c11356965/stress_test_(debug).html#fail1
{
        const auto & src_relative_data_path = src_part_in_memory->storage.relative_data_path;
        auto flushed_part_path = src_part_in_memory->getRelativePathForPrefix(tmp_part_prefix);
        src_part_in_memory->flushToDisk(src_relative_data_path, flushed_part_path, metadata_snapshot);
        src_part_path = fs::path(src_relative_data_path) / flushed_part_path / "";
    }
    LOG_DEBUG(log, "Cloning part {} to {}", fullPath(disk, src_part_path), fullPath(disk, dst_part_path));
    localBackup(disk, src_part_path, dst_part_path);
    disk->removeFileIfExists(fs::path(dst_part_path) / IMergeTreeDataPart::DELETE_ON_DESTROY_MARKER_FILE_NAME);
    auto single_disk_volume = std::make_shared<SingleDiskVolume>(disk->getName(), disk, 0);
    auto dst_data_part = createPart(dst_part_name, dst_part_info, single_disk_volume, tmp_dst_part_name);
    dst_data_part->is_temp = true;
    dst_data_part->loadColumnsChecksumsIndexes(require_part_metadata, true);
    dst_data_part->modification_time = disk->getLastModified(dst_part_path).epochTime();
    return dst_data_part;
}
String MergeTreeData::getFullPathOnDisk(const DiskPtr & disk) const
{
    return disk->getPath() + relative_data_path;
}
DiskPtr MergeTreeData::getDiskForPart(const String & part_name, const String & additional_path) const
{
    const auto disks = getStoragePolicy()->getDisks();
    for (const DiskPtr & disk : disks)
        for (auto it = disk->iterateDirectory(relative_data_path + additional_path); it->isValid(); it->next())
            if (it->name() == part_name)
                return disk;
    return nullptr;
}
std::optional<String> MergeTreeData::getFullRelativePathForPart(const String & part_name, const String & additional_path) const