Microsoft Technology Licensing, LLC

John Kalkman

Jered D Aasheim

Yongqi Yang

An open-architecture transactional file system is described. In one described implementation, a file system comprises a plurality of interchangeable and/or customizable logic layers configured to manage operations on behalf of an application when the application makes data requests to a data source. Functionality associated with the file system is augmentable by substituting and/or modifying one or more of the plurality of interchangeable and/or customizable logic layers, respectively, enabling the file system to function with many different types of data sources.

Open-architecture file system

A transactional file system developed to function with flash memory is described. The file system performs power-failure detection and ensures data integrity in the event of a power failure. In one described implementation, a power failure event can be detected by a file system, components of the file system, or individual modules in the form or computer-executable instructions and/or logic. Meta-information is stored at a location on a flash medium indicated by a write pointer if a computer device shuts-down according to a normal shutdown mode. During initialization of the computer, a check is performed whether the meta-information is present in the location on the flash medium indicated by the write pointer. If the meta-information is present, then a conclusion is made that the computer shutdown according to the normal shutdown mode.

Power failure detection in a flash memory device

Power failure detection and correction in a flash memory device

A transactional file system developed to function with flash memory is described. The file system provides for efficient storage of file system meta-information, performs robust transaction logging, and performs other related features. In one described implementation, metadata is stored in-line with data. In another embodiment, a transaction log is maintained by storing transaction information associated with requests to perform file transactions. The transaction information is stored at arbitrary physical sector addresses on the flash medium. In still another embodiment, a transaction log is stored in a physical sector of a flash medium. The transaction log contains transaction information associated with performing a file request. Metadata is written into a spare area of the physical sector indicating that the physical sector contains transaction information.

Transactional file system for flash memory

One or more secondary data structures are maintained containing mappings of logical flash memory addresses to physical flash memory addresses. Each secondary data structure has a predetermined capacity of mappings. A master data structure is also maintained containing a pointer to each of the one or more secondary data structures. Additional secondary data structures are allocated as needed to provide capacity for additional mappings. One or more counters associated with each of the one or more secondary data structures, respectively, provides an indication of when each of the one or more secondary data structures reaches the predetermined capacity of mappings.

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Woodinville, WA, United States of America

John Kalkman