05761677 is referenced by 619 patents and cites 12 patents.

Various versions of a computer file are provided without requiring copying the file or logging changed data, so that the files have consistent user data. A program module responds to a system call argument and allocates another node in file system tables and copies metadata information from the old node into the new node, so that both nodes contain the same data block allocation information. Portions of the module set shadow pointers in the old node to point to the new node, and in the new node to point to the old node. Changes to data are made with respect to the new node and fresh physical data blocks are allocated for the changed blocks. A method includes the steps of allocating a new node for storing file allocation information for another version of an existing file; logically connecting the new node to the existing node for file name and other purposes; and replacing node identification information in the directory with the new mode identification. In other steps the method replaces the current node identification information of a file in the directory with previous node identification information obtained from the current node; and logically disconnects the current node from the previous node.

Title
Computer system method and apparatus providing for various versions of a file without requiring data copy or log operations
Application Number
8/582465
Publication Number
5761677
Application Date
January 3, 1996
Publication Date
June 2, 1998
Inventor
Billy J Fuller
Colorado Springs
CO, US
Steven T Senator
Colorado Springs
CO, US
Agent
Homer L Holland & Hart Knearl
William J Kubida
Assignee
Sun Microsystems
CA, US
IPC
G06F 17/40
View Original Source