**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
LOG_DEBUG(log, "Freezing part {} snapshot will be placed at {}", part->name, backup_path);
        part->volume->getDisk()->createDirectories(backup_path);
        String backup_part_path = fs::path(backup_path) / relative_data_path / part->relative_path;
        if (auto part_in_memory = asInMemoryPart(part))
            part_in_memory->flushToDisk(fs::path(backup_path) / relative_data_path, part->relative_path, metadata_snapshot);
        else
            localBackup(part->volume->getDisk(), part->getFullRelativePath(), backup_part_path);
        part->volume->getDisk()->removeFileIfExists(fs::path(backup_part_path) / IMergeTreeDataPart::DELETE_ON_DESTROY_MARKER_FILE_NAME);
        part->is_frozen.store(true, std::memory_order_relaxed);
        result.push_back(PartitionCommandResultInfo{
            .partition_id = part->info.partition_id,
            .part_name = part->name,
            .backup_path = fs::path(part->volume->getDisk()->getPath()) / backup_path,
            .part_backup_path = fs::path(part->volume->getDisk()->getPath()) / backup_part_path,
            .backup_name = backup_name,
        });
        ++parts_processed;
    }
    LOG_DEBUG(log, "Freezed {} parts", parts_processed);
    return result;
}
PartitionCommandsResultInfo MergeTreeData::unfreezePartition(
    const ASTPtr & partition,
    const String & backup_name,
    ContextPtr local_context,
    TableLockHolder &)
{
    return unfreezePartitionsByMatcher(getPartitionMatcher(partition, local_context), backup_name, local_context);
}
PartitionCommandsResultInfo MergeTreeData::unfreezeAll(