Transactional file system

• US 7,613,698 B2
• Filed: 02/14/2005
• Issued: 11/03/2009
• Est. Priority Date: 03/30/2000
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Miller, Thomas J., Atkinson, Robert G., Verma, Surendra
• Primary Examiner(s): Woo; Issac M
• Assistant Examiner(s): Yen; Syling
• Application Number:
  US11/057,935
• Publication Number:
  US 20050149525A1
• Time in Patent Office: 1,723 Days
• Field of Search: 707/7, 707/1, 707/8, 707/103.R, 707/200
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1865 Transactional file systems
• CPC Class Codes: Y10S 707/959 Network
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99937 Sorting
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A transactional file system wherein multiple file system operations may be performed as a transaction. An application specifies that file system-related operations are to be handled as a transaction, and the application is given a file handle associated with a transaction context. For file system requests associated with a transaction context, a file system component manages the operations consistent with transactional behavior. The component handles namespace logging operations in a multiple-level log that facilitates logging and recovery. Page data is logged separate from the main log, with a unique signature that enables the log to determine whether a page was fully flushed to disk prior to a system crash.

Claims

1. In a computing environment, a system comprising:

a processor; and

a computer-readable storage medium having stored thereon a plurality of service modules executable by the processor, the plurality of service modules including;

a multiple-level logging service, the multi-level logging service module including;

a lower-level file system logging mechanism for logging, in a first log, low level operations corresponding to a first file; and

a higher-level transactional file system logging mechanism for logging, in a second log, higher level information, the higher-level transactional file system logging mechanism treating the low level information of the first log as data for the second log; and

a decision-making service module for determining whether higher-level logged operations actually occurred, wherein the decision-making service module is adapted to determine that lower-level logged operations have successfully committed, wherein lower-level logged operations commit subsequent to successfully committing a related higher-level logged operation, and wherein determining that lower-level logged operations have successfully committed necessarily indicates to the decision-making service module that previous higher-level logged operations actually occurred; and

wherein the second log contains a first log sequence number identifying the higher-level operation associated with the log entry and wherein the first file has an associated second log sequence number identifying the last committed higher-level operation; and

wherein the first log sequence number being less than or equal to the second log sequence necessarily indicates that the higher-level operation associated with the first log sequence number occurred prior to the low level operation being committed.

2. The system as recited in claim 1, wherein the first log which logs low-level operations is an NT File System log.

3. The system as recited in claim 1, wherein the lower-level file system logging mechanism logs metadata corresponding to the low level operations rather than the actual data that are written to the first file, and wherein the higher-level transaction file system logging mechanism logs data corresponding to the actual data written to the first file.