EXTENSIBLE FILE SYSTEM

• US 20090265400A1
• Filed: 06/27/2009
• Published: 10/22/2009
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Havewala, Sarosh C., Thind, Ravinder S., Ghotge, Vishal V., Zbikowski, Mark J., Pudipeddi, Ravisankar V.
• Granted Patent: US 9,575,988 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/164 File meta data generation
• CPC Class Codes: G06F 16/1794 Details of file format conversion

Abstract

An extensible file system format for portable storage media is provided. The extensible file system format includes the specification of primary and secondary directory entry types that may be custom defined. The primary and secondary directory entry types can be further classified as critical and benign directory entries.

Claims

1. A computer readable storage medium having computer executable instructions for storing data stored in an extensible file system format, the extensible file system format having a file directory structure comprising:

a primary directory entry component for specifying data in a root directory of the extensible file system format, the primary directory entry defining a new object, the primary directory comprising either a critical primary directory entry component or a benign primary directory component, wherein;

if the primary directory entry comprises a critical primary directory compound and if the critical primary directory entry component is not implemented by a particular computing device, the extensible file system format is determined to be incompatible and not readable by the computing device, and

if the primary directory entry comprises a benign primary directory entry component and if the benign primary directory entry component is not implemented by a particular computing device, data stored in the computer readable storage medium associated with the benign primary directory component is ignored by the computing device; and

an optional secondary entry component corresponding to the primary directory entry component and defining metadata associated with the primary directory entry component, the metadata defining a qualifier to the object, the optional secondary entry component comprising at least one of a critical secondary directory entry component and a benign secondary directory entry component, wherein;

if the optional secondary entry component comprises a critical secondary directory component and if the critical secondary directory entry component is not implemented by the particular computing device, data stored in the computer readable storage medium associated with the critical secondary directory entry component and with the primary directory entry component associated with the critical secondary directory entry component is ignored by the computing device, and

if the optional secondary entry component comprises a benign secondary directory entry component and if the benign secondary directory entry component is not implemented by the particular computing device, data stored in the computer readable storage medium associated with the benign secondary directory entry component is ignored by the computing device.

2. The computer readable medium of claim 1, wherein the primary directory entry component is a critical primary directory component that must be understood by the file system in order to mount a volume corresponding to the extensible file system format.

3. The computer readable medium of claim 1 further comprising:

two secondary entry components corresponding to the primary directory entry component and defining metadata associated with the primary directory entry.

4. The computer readable medium of claim 1 wherein the primary directory entry component corresponds to an allocation bitmap defining cluster availability within the storage medium.

5. The computer readable medium of claim 1 wherein the primary directory entry component corresponds to a volume identifier.

6. The computer readable medium of claim 1 wherein the secondary directory entry component corresponds to a file name identifier.

7. The computer readable medium of claim 6 wherein the file name identifier includes a full file name and a file name hash.

8. The computer readable medium of claim 1 wherein the at least one secondary entry corresponds to an extensible secondary directory entry.

9. The computer readable medium of claim 1 further comprising:

a manufacturer data component for specifying manufacturer data structures for use with the extensible file system format.

10. The computer readable medium of claim 1 wherein when the critical secondary directory entry component is not implemented by the particular computing device, data stored in the computer readable medium associated with any benign secondary directory entry components associated with the primary directory entry component that is associated with the critical secondary directory entry component is ignored by the computing device.

11. The computer readable medium of claim 1 further comprising:

a boot parameters component for specifying boot parameters for the extensible file system format.

12. The computer readable medium of claim 1 further comprising:

a file allocation table component for defining a file allocation table associated with the extensible file system format.