Host Storage Segment Allocation with Section-Level Garbage Collection

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Solution Overview

Problem

Existing file systems in computing systems face inefficiencies in managing data storage, particularly in allocating segments for write operations when empty sections are not available, leading to suboptimal performance.

Innovation Solution

A host device controller manages data storage in segments, reallocating valid segments to empty or victim sections for write operations, and performs garbage collection to optimize segment allocation, maintaining a log structure file system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the file system allocates segments for write operations only from empty sections, then the log structure file system integrity is maintained, but write operation efficiency deteriorates when no empty sections are available

Engineering Contradiction:

Improvelog structure file system integrityVSAvoidwrite operation efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies garbage collection to recover segments from victim sections by identifying and discarding invalid data, then making these recovered segments available for new write operations. This resolves the contradiction by providing additional segment sources without compromising log structure integrity, as the garbage collection process carefully manages segment validity states.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The patent introduces dynamic segment allocation by allowing the file system to transition segments between different states (empty, valid, invalid, victim) based on runtime conditions. When empty sections are exhausted, the system dynamically recovers segments from victim sections through garbage collection, enabling flexible adaptation to storage conditions while maintaining log structure requirements.

Inventive Principle:

Principle #15Dynamics

2Quantity of substance

If garbage collection is performed to recover segments from victim sections, then segment availability for write operations is improved, but storage device load and operation time increase

Engineering Contradiction:

Improveavailable segments for write operationsVSAvoidgarbage collection operation time

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The patent performs garbage collection proactively to recover segments before they are critically needed, preparing valid segments in advance for future write operations. By anticipating segment exhaustion and performing recovery operations beforehand, the system reduces the impact of garbage collection on write performance and ensures segments are ready when needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements continuous or periodic garbage collection operations that run in the background, maintaining a supply of valid segments continuously available for write operations. This continuous management ensures that segment recovery is an ongoing process rather than a disruptive batch operation, smoothing out performance impacts.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS12474850B2Storage device, host device, and computing system

Publication Date: 2025.11.18 SK HYNIX INC

AI summary

In an embodiment of the disclosed technology, a controller of a host device may manage data stored in a storage device, on the basis of a section which corresponds to a super block of the storage device and includes at least two segments. It is possible to provide measures enabling limited overwrite of a full section including a valid segment and allowing allocation and garbage collection to be performed by the unit of segment, thereby efficiently using a storage space while maintaining a log structure file system of the storage device.