pmem2_source_size3

Usage

Overview

The pmem2_source_size() function retrieves the size of the file in bytes pointed by file descriptor or handle stored in the source and puts it in *size.

This function is a portable replacement for OS-specific APIs. On Linux, it hides the quirkiness of Device DAX size detection.

Return value

The pmem2_source_size() function returns 0 on success. If the function fails, the *size variable is left unmodified and a negative error code is returned.

Errors

The pmem2_source_size() can fail with the following errors:

On all systems:

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PMEM2_E_INVALID_FILE_HANDLE - source contains an invalid file handle.

On Windows:

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PMEM2_E_INVALID_FILE_TYPE - handle points to a resource that is not a regular file.

On Linux:

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PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a directory, block device, pipe, or socket.

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PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a character device other than Device DAX.

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PMEM2_E_INVALID_SIZE_FORMAT - kernel query for Device DAX size returned data in invalid format.

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-errno set by failing fstat(2), while trying to validate the file descriptor.

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-errno set by failing realpath(3), while trying to determine whether fd points to a Device DAX.

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-errno set by failing open(2), while trying to determine Device DAX’s size.

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-errno set by failing read(2), while trying to determine Device DAX’s size.

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-errno set by failing strtoull(3), while trying to determine Device DAX’s size.

On FreeBSD:

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PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a directory, block device, pipe, socket, or character device.

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-errno set by failing fstat(2), while trying to validate the file descriptor.