File Block Initialization Using To-Be-Zeroed Bits
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Solution Overview
Problem
Conventional file systems face inefficiencies and performance issues when initializing pre-allocated files, as they need to zero out all blocks at creation time, which is time-consuming and wasteful, especially for large files, and can lead to security vulnerabilities if stale data is accessed.
Innovation Solution
The method involves delaying the initialization of file blocks by using To-Be-Zeroed (TBZ) bits in file descriptors to track un-initialized blocks, allowing for asynchronous or delayed zeroing during the first write operation or subsequent writes, reducing unnecessary disk operations and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all file blocks are zeroed out at creation time, then security is improved by preventing access to stale data, but initialization time and disk operations increase significantly
Solution Approach 1:
The patent applies preliminary action by setting TBZ (to-be-zeroed) bits in file descriptors to mark un-initialized blocks before actual zeroing occurs. This allows the system to prepare for security requirements in advance without immediately performing the time-consuming zeroing operation, thus resolving the contradiction between security and initialization time.
Solution Approach 2:
The patent makes the zeroing process dynamic by allowing blocks to be zeroed on-demand based on actual access patterns. The TBZ bits enable the system to dynamically determine which blocks need zeroing, transforming the static upfront zeroing approach into a flexible, adaptive process that balances security requirements with performance considerations.
2Reliability
If all file blocks are zeroed out at creation time, then security against stale data access is improved, but disk operations and system overhead increase
Solution Approach 1:
The patent applies partial action by zeroing only the specific blocks that are actually needed and marked with TBZ bits, rather than zeroing all blocks in advance. This eliminates redundant zeroing operations on blocks that may never be accessed, improving disk operations efficiency while maintaining security for the blocks that are actually used.
Solution Approach 2:
The system uses TBZ bits in file descriptors to self-track which blocks require zeroing, eliminating the need for external tracking mechanisms. This self-service approach reduces system overhead by using existing file descriptor structures to manage the zeroing process efficiently.
3Productivity
If pre-allocated files are created without zeroing blocks, then initialization performance is improved, but security vulnerabilities arise from potential stale data access
Solution Approach 1:
The patent applies preliminary action by setting TBZ bits to mark blocks that need zeroing before they are accessed. This allows files to be created quickly without immediate zeroing (maintaining performance) while still preparing for security requirements by identifying which blocks will need protection when they are actually used.
Solution Approach 2:
The TBZ bits act as an intermediary mechanism between file creation and security zeroing. They provide a bridge that allows deferred zeroing while maintaining security control, enabling the system to balance performance and security by mediating between the desire for fast file creation and the need for secure data initialization.
Data Source
AI summary
A method and system is provided for initializing files such as, for example and without limitation, pre-allocated files or raw device mapping (RDM) files, by delaying initializing file blocks. In accordance with one or more embodiments of the present invention, file blocks are associated with corresponding indicators to track un-initialized blocks.