Re: [PATCH v5 1/8] dax: alloc_dax() return ERR_PTR(-EOPNOTSUPP) for CONFIG_DAX=n

Lukas Wunner
2024-02-13T06:32:28Z

On Mon, Feb 12, 2024 at 11:30:54AM -0500, Mathieu Desnoyers wrote:
> Change the return value from NULL to PTR_ERR(-EOPNOTSUPP) for
> CONFIG_DAX=n to be consistent with the fact that CONFIG_DAX=y
> never returns NULL.

All the callers of alloc_dax() only check for IS_ERR().

Doesn't this result in a change of behavior in all the callers?
Previously they'd ignore the NULL return value and continue,
now they'll error out.

Given that, seems dangerous to add a Fixes tag with a v4.0 commit
and thus risk regressing all stable kernels.

Thanks,

Lukas