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| author | Dan Williams <dan.j.williams@intel.com> | 2017-11-29 16:10:28 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-05 11:26:28 +0100 |
| commit | c6c78a1d4561880c744d3ec932264b264a879e7c (patch) | |
| tree | 07bd93d6bc6a586ac2d890debacd139aab36af6f /mm/hugetlb.c | |
| parent | bf55918cb4fb374000ad1d063b207a17a93e8726 (diff) | |
| download | linux-stable-c6c78a1d4561880c744d3ec932264b264a879e7c.tar.gz linux-stable-c6c78a1d4561880c744d3ec932264b264a879e7c.tar.bz2 linux-stable-c6c78a1d4561880c744d3ec932264b264a879e7c.zip | |
mm, hugetlbfs: introduce ->split() to vm_operations_struct
commit 31383c6865a578834dd953d9dbc88e6b19fe3997 upstream.
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 <dan.j.williams@intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 2d2ff5e8bf2b..a2233d722ff9 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3125,6 +3125,13 @@ static void hugetlb_vm_op_close(struct vm_area_struct *vma) } } +static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) +{ + if (addr & ~(huge_page_mask(hstate_vma(vma)))) + return -EINVAL; + return 0; +} + /* * We cannot handle pagefaults against hugetlb pages at all. They cause * handle_mm_fault() to try to instantiate regular-sized pages in the @@ -3141,6 +3148,7 @@ const struct vm_operations_struct hugetlb_vm_ops = { .fault = hugetlb_vm_op_fault, .open = hugetlb_vm_op_open, .close = hugetlb_vm_op_close, + .split = hugetlb_vm_op_split, }; static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |