2.3.85 FSCTL_SET_ZERO_DATA Request
The FSCTL_SET_ZERO_DATA request message requests that the server fill the specified range of the file (associated with the handle on which this FSCTL was invoked) with zeros. The message contains a FILE_ZERO_DATA_INFORMATION element.
The FILE_ZERO_DATA_INFORMATION element is as follows.
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1 |
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2 |
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3 |
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FileOffset |
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BeyondFinalZero |
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... |
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FileOffset (8 bytes): A 64-bit signed integer that contains the file offset of the start of the range to set to zeros, in bytes. The value of this field MUST be greater than or equal to 0.
BeyondFinalZero (8 bytes): A 64-bit signed integer that contains the byte offset of the first byte beyond the last zeroed byte. The value of this field MUST be greater than or equal to 0.
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How an implementation zeros data within a file is implementation-dependent. A file system MAY choose to deallocate regions of disk space that have been zeroed.<83>