On Tue, Apr 17, 2018 at 10:40 AM, Andreas Dilger <[email protected]> wrote: > On Apr 17, 2018, at 10:57 AM, Darrick J. Wong <[email protected]> wrote: >> >> On Tue, Apr 17, 2018 at 09:53:47AM -0700, Dan Williams wrote: >>> On Tue, Apr 17, 2018 at 9:10 AM, Christoph Hellwig <[email protected]> >>> wrote: >>>> On Tue, Apr 17, 2018 at 10:40:59PM +0800, Xiong Zhou wrote: >>>>> 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. >>>> >>>> Not supporting ->bmap is a good thing as it is hightly dangerous. >>> >>> I take this to mean "don't fix, it is another casualty of dax being >>> experimental and it won't be coming back". I can get on board with >>> that. >>> >>> Otherwise, I was about to send a series adding bmap to >>> {xfs,ext2,ext4}_dax_ops. >> >> Frankly I'd rather see the swapfile code learn how to iomap and then we >> can get rid of bmap in xfs entirely. > > Is anyone still using LILO to boot? It needed FIBMAP support to map the > kernel image for booting. I don't know if Grub needs FIBMAP support for > the early boot stages or not (it has minimal filesystem support in the > later stages), but it would be a shame if it wasn't possible to boot an > all-NVRAM system as a result of a missing ->bmap() method. Alternately, > convince the Grub folks to use FIEMAP if that is available...
For boot the recommendation is to use the BTT (block-translation-table) to provide a sector-atomic block device for the system-partition. Such a configuration does not support DAX mode operation, so there should be no conflict. The EFI system partition is also FAT in most cases which does not support DAX. _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
