Man page - pmem2_source_device_id(3)

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Manual

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
SEE ALSO

NAME

pmem2_source_device_id () - returns the unique identifier of a device

SYNOPSIS

#include <libpmem2.h>


struct pmem2_source;
int pmem2_source_device_id(const struct pmem2_source *source, char *id, size_t *len);

DESCRIPTION

The pmem2_source_device_id () function retrieves a unique identifier of all NVDIMMs backing the data source. This function has two operating modes:

if *id is NULL the function calculates a buffer length required for storing the identifier of the *source device and puts this length in *len The more hardware devices back the data source, the longer the length is.

if *id is not NULL it must point to a buffer of length *len provided by the previous call to this function. On success, pmem2_source_device_id () will store a unique identifier of all hardware devices backing the data source.

For details on how to use the unique identifier for detecting the unsafe shutdown please refer to libpmem2_unsafe_shutdown (7) manual page.

RETURN VALUE

The pmem2_source_device_id () function returns 0 on success. If the function fails, the *id and *len variables contents are left unmodified and a negative error code is returned.

ERRORS

The pmem2_source_device_id () can fail with the following errors:

On all systems:

PMEM2_E_BUFFER_TOO_SMALL - the provided buffer of length *len is too small to store the full identifier of the backing devices.

PMEM2_E_NOSUPP - the underlying platform does not expose hardware identification.

On Windows:

- errno equivalent of return code set by failing GetFinalPathNameByHandleW (), while trying to resolve the volume path from the file handle.

- errno set by failing malloc (3), while trying to allocate a buffer for storing volume path.

- errno equivalent of return code set by failing CreateFileW (), while trying to obtain a handle to the volume.

- errno equivalent of return code set by failing DeviceIoControl (), while trying to obtain volume USC value.

On Linux:

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

- errno set by failing ndctl_new (), while trying to initiate a new NDCTL library context.

SEE ALSO

fstat (2), errno (3), malloc (3), libpmem2_unsafe_shutdown (7), and <https://pmem.io>