This patch series attempts to solve the coherency problem seen when a hole is punched in the region(s) of the mapping (associated with the memfd) that overlaps with pages registered with a udmabuf fd.
The first patch introduces a new mmu notifier to let drivers know when a new page is faulted into a mapping (backed by shmem or hugetlbfs). The second patch updates the udmabuf driver to register a handler for receiving mapping updates in order to update its list with new pages. The last patch adds two new tests to the udmabuf selftest to test the huge page support and also FALLOC_FL_PUNCH_HOLE. Cc: David Hildenbrand <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Peter Xu <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Gerd Hoffmann <[email protected]> Cc: Dongwon Kim <[email protected]> Cc: Junxiao Chang <[email protected]> Vivek Kasireddy (3): mm/mmu_notifier: Add a new notifier for mapping updates (new pages) udmabuf: Replace pages when there is FALLOC_FL_PUNCH_HOLE in memfd selftests/dma-buf/udmabuf: Add tests for huge pages and FALLOC_FL_PUNCH_HOLE drivers/dma-buf/udmabuf.c | 172 ++++++++++++++++++ include/linux/mmu_notifier.h | 27 +++ mm/hugetlb.c | 9 +- mm/mmu_notifier.c | 17 ++ mm/shmem.c | 7 +- .../selftests/drivers/dma-buf/udmabuf.c | 165 ++++++++++++++++- 6 files changed, 391 insertions(+), 6 deletions(-) -- 2.39.2
