On 2024-02-13 14:07, Dan Williams wrote:
Lukas Wunner wrote:
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.
Oh, good catch, yes that Fixes tag should be:
4e4ced93794a dax: Move mandatory ->zero_page_range() check in alloc_dax()
...as that was the one that updated the alloc_dax() calling convention
without fixing up the CONFIG_DAX=n case.
This is a pre-requisite for restoring DAX operation on ARM32.
I'll change the Fixes tag in this commit to:
Fixes: 4e4ced93794a ("dax: Move mandatory ->zero_page_range() check in alloc_dax()")
for v6.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
