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2.1.4.2 Algorithm for Detecting If Open Files Exist Under a Directory

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The inputs for this algorithm are:

  • RootDirectory: The DirectoryFile indicating the top-level directory under which to search for open files.

  • Open: The Open for the request that is calling this algorithm.

  • Operation: A code describing the operation being processed, as specified in section 2.1.4.12.

  • OpParams: Parameters associated with Operation, passed in from the calling request, as specified in section 2.1.4.12.

The output is a Boolean. If the return value is TRUE, then no open files exist under the directory; if FALSE, then at least one open exists even after attempting to break oplocks.

Pseudocode for the algorithm is as follows:

  • For each Link in RootDirectory.DirectoryList:

    • // Check for oplock breaks in this directory.

    • If Link.File.OpenList contains an Open with Open.Link equal to Link:

      • For each Stream in Link.File.StreamList:

        • If Stream.Oplock is not empty and Stream.Oplock.State contains either BATCH_OPLOCK or HANDLE_CACHING, the object store MUST check for an oplock break according to the algorithm in section 2.1.4.12, with input values as follows:

          • Open equal to this algorithm's Open.

          • Oplock equal to Stream.Oplock.

          • Operation equal to this algorithm's Operation.

          • OpParams equal to this algorithm's OpParams.

        • EndIf

      • EndFor

    • EndIf

    • // See if all oplock holders have gotten out of the way.

    • If Link.File.OpenList contains an Open with Open.Link equal to Link:

      • Return FALSE  // An open still exists; deny the operation.

    • EndIf

    • // Recurse into any subdirectories.

    • If Link.File.FileType is DirectoryFile, determine whether Link.File contains open files as specified in section 2.1.4.2, with input values as follows:

      • RootDirectory equal to Link.File.

      • Open equal to this algorithms's Open.

      • Operation equal to this algorithms's Operation.

      • OpParams equal to this algorithms's OpParams.

    • EndIf

    • If Link.File contains open files as determined above:

      • Return FALSE.  // An open exists deeper in the directory hierarchy.

    • EndIf

  • EndFor

  • Return TRUE  // No opens remaining.