On Thu, Jan 09, 2020 at 12:03:01PM -0800, Dan Williams wrote: > > So I'd find two options reasonably consistent: > > 1) Keep status quo where partitions are created and support DAX. > > 2) Stop partition creation altogether, if anyones wants to split pmem > > device further, he can use dm-linear for that (i.e., kpartx). > > > > But I'm not sure if the ship hasn't already sailed for option 2) to be > > feasible without angry users and Linus reverting the change. > > Christoph? I feel myself leaning more and more to the "keep pmem > partitions" camp. > > I don't see "drop partition support" effort ending well given the long > standing "ext4 fails to mount when dax is not available" precedent. Do we have any evidence of existing setups with DAX and partitions? Can we just throw in a patch to reject that case for now before actually removing the code and see if anyone screams. And fix ext4 up while we are at it. > I think the next least bad option is to have a dax_get_by_host() > variant that passes an offset and length pair rather than requiring a > later bdev_dax_pgoff() to recall the offset. This also prevents > needing to add another dax-device object representation. IFF we have to keep partition support, yes. But keeping it just seems like a really bad idea.
