On Thu, Feb 27, 2020 at 07:28:41PM -0800, Dan Williams wrote: > "don't perform generic memory-error-handling, there's an fs that owns > this daxdev and wants to disposition errors". The fs/dax.c > infrastructure that sets up ->index and ->mapping would still need to > be there for ext4 until its ready to take on the same responsibility. > Last I checked the ext4 reverse mapping implementation was not as > capable as XFS. This goes back to why the initial design avoided > relying on not universally available / stable reverse-mapping > facilities and opted for extending the generic mm/memory-failure.c > implementation. The important but is that we stop using ->index and ->mapping when XFS is used as that enables using DAX+reflinks, which actually is the most requested DAX feature on XFS (way more than silly runtime flag switches for example).
