Mon, Jul 25, 2022 at 10:56:50PM CEST, jacob.e.keller@intel.com wrote:

Recent versions of the kernel support the DEVLINK_ATTR_DRY_RUN attribute
which allows requesting a dry run of a command. A dry run is simply
a request to validate that a command would work, without performing any
destructive changes.

The attribute is supported by the devlink flash update as a way to
validate an update, including potentially the binary image, without
modifying the device.

Add a "dry_run" option to the command line parsing which will enable
this attribute when requested.

To avoid potential issues, only allow the attribute to be added to
commands when the kernel recognizes it. This is important because some
commands do not perform strict validation. If we were to add the
attribute without this check, an old kernel may silently accept the
command and perform an update even when dry_run was requested.

Before adding the attribute, check the maximum attribute from the
CTRL_CMD_GETFAMILY and make sure that the kernel recognizes the
DEVLINK_ATTR_DRY_RUN attribute.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>

Reviewed-by: Jiri Pirko <redacted>