From 31383c6865a578834dd953d9dbc88e6b19fe3997 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 Nov 2017 16:10:28 -0800 Subject: mm, hugetlbfs: introduce ->split() to vm_operations_struct Patch series "device-dax: fix unaligned munmap handling" 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. This patch (of 2): The device-dax interface has similar constraints as hugetlbfs in that it requires the munmap path to unmap in huge page aligned units. Rather than add more custom vma handling code in __split_vma() introduce a new vm operation to perform this vma specific check. Link: http://lkml.kernel.org/r/151130418135.4029.6783191281930729710.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Signed-off-by: Dan Williams Cc: Jeff Moyer Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index ee073146aaa7..b3b6a7e313e9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -377,6 +377,7 @@ enum page_entry_size { struct vm_operations_struct { void (*open)(struct vm_area_struct * area); void (*close)(struct vm_area_struct * area); + int (*split)(struct vm_area_struct * area, unsigned long addr); int (*mremap)(struct vm_area_struct * area); int (*fault)(struct vm_fault *vmf); int (*huge_fault)(struct vm_fault *vmf, enum page_entry_size pe_size); -- cgit v1.2.3