Browse Prior Art Database

Combined File Operations for Simplified Recovery

IP.com Disclosure Number: IPCOM000102151D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Gregg, L: AUTHOR [+3]

Abstract

Combined file operations of close and rename are described in the following information. The combination appears as a single "atomic" operation to the host computer which initiated the operation. This reduces the number of transition states and simplifies recovery operations.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Combined File Operations for Simplified Recovery

       Combined file operations of close and rename are
described in the following information.  The combination appears as a
single "atomic" operation to the host computer which initiated the
operation.  This reduces the number of transition states and
simplifies recovery operations.

      The unique feature of this file system is:
      -  a combined "close and rename" operation
      -  which appears "atomic" to the host environment
         because it is
         implemented in an outboard IOP (I/O Processor).

      This atomic operation simplifies both the code needed to deal
with failure situations, and the amount of user involvement required
for recovery.

      The file system includes a combination command "close and
rename".  This operation is atomic to the user.  That is, the user
either has an open file, or at the completion of this command there
is a file which has been successfully closed and also given a new
name.

      Further, the implementation of this combined function is in an
outboard IOP, not in the host processor.  This means that the
bookkeeping for intermediate states was not simply hidden in the
operating system or hidden in the Licensed Internal Code.  Instead it
was completely eliminated from the host and operating system.  See
the figure for a simple diagram.

      To provide an extra level of control on the rename process the
command explicitly allows replacement of an existing file, or the
more restrictive renaming only if the new file name does not already
exist.

      This new command requires as parameters:
      -  the existing open file...