ioctl FIBMAP for dax gone in v4.17-rc1

Xiong Zhou
2018-04-17T14:41:02Z

Hi,

FIBMAP ioctl call to file in pmem dax mountpoint, both xfs
and ext4, starts to fail on v4.17-rc1 Linus tree.

+fibmap: Invalid argument

Pass on v4.16.
Pass on non-dax mountpoint.

We got these in v4.17-rc1:
6e2608d xfs, dax: introduce xfs_dax_aops
fb094c9 ext2, dax: introduce ext2_dax_aops
5f0663b ext4, dax: introduce ext4_dax_aops

And we don't have ->bmap call in these aops, which may lead
to the ioctl call failure.

Do we have any plan of adding/supporting it ?

xfstests generic/223 covers this issue. If we are not going
to support this call for dax, we need to fix the testcase.

Thanks,
Xiong