The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 2012
Filed:
Jul. 30, 2010
Thomas Eugene Engelsiepen, San Jose, CA (US);
Frank B. Schmuck, Campbell, CA (US);
Thomas Eugene Engelsiepen, San Jose, CA (US);
Frank B. Schmuck, Campbell, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method, system, and computer program product for creating and implementing file clones using reverse ditto references. A clone inode is created as a copy of an original inode. The clone inode and the original inode are indistinguishable to an end user. Each additional file clone created spawns a clone inode. An immutable clone-parent inode is created that contains the disk block addresses, while writable clones inode instead contain dittos linking the clone inode to data blocks referenced in the clone-parent inode. Data block address links in the original inode are moved to the new clone-parent inode and dittos replace the original data block address links in the original inode. When a clone file is updated, the new data is written to a new disk location and a corresponding ditto in the clone inode is replaced with a data block link address, keeping the data of the clone-parent inode intact.