Extensible file system

Patent metadata

Field	Value
Publication number	US-9639554-B2
Application number	US-22948505-A
Country	US
Kind code	B2
Filing date	Sep 16, 2005
Priority date	Dec 17, 2004
Publication date	May 2, 2017
Grant date	May 2, 2017

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.

First claim

The embodiments of the invention in which and exclusive property or privilege is claimed are defined as follows:

1. A computing device comprising a file system and a computer readable storage medium that stores information within a volume on the computer readable storage medium, comprising:
the volume, the volume comprising:
a boot parameters component that specifies boot parameters for the file system;
a file allocation table component containing a file allocation table associated with the file system; and
a plurality of directory entries, each of the plurality of directory entries containing information designating the directory entry as either a primary directory entry or a secondary directory entry, each secondary directory entry being associated with a primary directory entry and defining metadata associated with the associated primary directory entry, each primary directory entry further containing information designating that primary directory entry as either a critical primary directory entry or a benign primary directory entry, and each secondary directory entry further containing information designating that secondary directory entry as either a critical secondary directory entry or a benign secondary directory entry;

the file system, when enumerating directory entries during a process of mounting the volume, preventing the volume from being mounted if the file system does not recognize a critical primary directory entry;
the file system, after the volume has been mounted, ignoring a benign primary directory entry if the file system does not recognize the benign primary directory entry;
the file system, after the volume has been mounted, ignoring a critical secondary directory entry and the primary directory entry with which it is associated if the file system does not recognize the critical secondary directory entry; and
the file system, after the volume has been mounted, ignoring a benign secondary directory entry if the file system does not recognize the benign secondary directory entry.

2. The computing device recited in claim 1 , wherein one of the critical primary directory entries contains an allocation bitmap defining storage media cluster availability.

3. The computing device recited in claim 1 , wherein one of the directory entries contains a volume identifier.

4. The computing device recited in claim 1 , wherein one of the primary directory entries contains a file name identifier.

5. The computing device recited in claim 4 , wherein the file name identifier comprises a full file name and a file name hash.

6. The computing device recited in claim 1 , wherein at least one secondary directory entry comprises an extensible secondary directory entry.

7. The computing device recited in claim 1 further comprising a manufacturer data component for specifying manufacture data structures.

8. The computing device recited in claim 1 , in which each of the plurality of directory entries is identified by a respective type value.

9. The computing device recited in claim 8 , in which the information designating a directory entry as a primary directory entry or a secondary directory entry is reflected in at least a part of its type value.

10. The computing device recited in claim 9 , in which the information designating a primary directory entry as either a critical primary directory entry or a benign primary directory entry is also reflected in at least a part of its type value, and in which the information designating a secondary directory entry as either a critical secondary directory entry or a benign secondary directory entry is also reflected in at least a part of its type value.

11. A method for accessing, by a file system, information stored on a volume of one of a plurality of different computer storage mediums that may be connected to the computing device when said one of the plurality of different computer storage mediums is connected to the computing device, wherein the volume of the computer storage medium connected to the computing device comprises a plurality of directory entries, each of the plurality of directory entries containing information designating the directory entry as either a primary directory entry or a secondary directory entry, each secondary directory entry being associated with a primary directory entry and defining metadata associated with the associated primary directory entry, each primary directory entry further containing information designating that primary directory entry as either a critical primary directory entry or a benign primary directory entry, and each secondary directory entry further containing information designating that secondary directory entry as either a critical secondary directory entry or a benign secondary directory entry, the method comprising:
reading, during a process of mounting the volume of the computer storage medium connected to the computing device, a directory entry designated as a critical primary directory entry;
determining whether the critical primary directory entry is recognized; and
based on a determination that the critical primary directory entry is not recognized, preventing the volume from being mounted.

12. The method of claim 11 , further comprising, after the volume has been mounted:
reading a directory entry designated as a benign primary directory entry;
determining whether the benign primary directory entry is recognized; and
based on a determination that the benign primary directory entry is not recognized, ignoring the benign primary directory entry.

13. The method of claim 11 , further comprising, after the volume has been mounted:
reading a directory entry designated as a critical secondary directory entry, that critical secondary directory entry being associated with another directory entry designated as a primary directory entry;
determining whether the critical secondary directory entry is recognized; and
based on a determination that the critical secondary directory entry is not recognized, ignoring the critical secondary directory entry and its associated primary directory entry.

14. The method of claim 11 , further comprising, after the volume has been mounted:
reading a directory entry designated as a benign secondary directory entry;
determining whether the benign secondary directory entry is recognized; and
based on a determination that the benign secondary directory entry is not recognized, ignoring the benign secondary directory entry.

15. A computer-readable storage medium on which computer-executable instructions are stored, the computer-executable instructions, when executed by a computing device, implementing a method for accessing, by a file system, information stored on a volume of the computing device of one of a plurality of different computer storage mediums that may be connected to the computing device when said one of the plurality of different computer storage mediums is connected to the computing device, wherein the volume of the computer storage medium connected to the computing device comprises a plurality of directory entries, each of the plurality of directory entries containing information designating the directory entry as either a primary directory entry or a secondary directory entry, each secondary directory entry being associated with a primary directory entry and defining metadata associated with the associated primary directory entry, each primary directory entry further containing information designating that primary directory entry as either a critical primary directory entry or a benign primary directory entry, and each secondary directory entry further containing infor

Assignees

• Pudipeddi Ravisankar V
• Ghotge Vishal V
• Havewala Sarosh C
• Thind Ravinder S
• Zbikowski Mark J
• Microsoft Technology Licensing Llc

Inventors

• Pudipeddi Ravisankar V
• Ghotge Vishal V
• Havewala Sarosh C
• Thind Ravinder S
• Zbikowski Mark J

Classifications

• G06F16/1794 Primary

  Details of file format conversion · CPC title

• G06F16/13

  File access structures, e.g. distributed indices (arrangements of input from, or output to, record carriers G06F3/06) · CPC title

• G06F16/164 Primary

  File meta data generation · CPC title

• G06F17/3012

  Physics · mapped topic

• G06F17/30179 Primary

  Physics · mapped topic