Hi Andrew,
Here is another device-dax fix that requires touching some mm code. When
device-dax is operating in huge-page mode we want it to behave like
hugetlbfs and fail attempts to split vmas into unaligned ranges. It
would be messy to teach the munmap path about device-dax alignment
constraints in the same (hstate) way that hugetlbfs communicates this
constraint. Instead, these patches introduce a new ->split() vm
operation.
---
Dan Williams (2):
mm, hugetlbfs: introduce ->split() to vm_operations_struct
device-dax: implement ->split() to catch invalid munmap attempts
drivers/dax/device.c | 12 ++++++++++++
include/linux/mm.h | 1 +
mm/hugetlb.c | 8 ++++++++
mm/mmap.c | 8 +++++---
4 files changed, 26 insertions(+), 3 deletions(-)