81b1e3f91d
Patch series "selftests/mm: new test for FOLL_LONGTERM on file mappings". Let's add some selftests to make sure that: * R/O long-term pinning always works of file mappings * R/W long-term pinning always works in MAP_PRIVATE file mappings * R/W long-term pinning only works in MAP_SHARED mappings with special filesystems (shmem, hugetlb) and fails with other filesystems (ext4, btrfs, xfs). The tests make use of the gup_test kernel module to trigger ordinary GUP and GUP-fast, and liburing (similar to our COW selftests). Test with memfd, memfd hugetlb, tmpfile() and mkstemp(). The latter usually gives us a "real" filesystem (ext4, btrfs, xfs) where long-term pinning is expected to fail. Note that these selftests don't contain any actual reproducers for data corruptions in case R/W long-term pinning on problematic filesystems "would" work. Maybe we can later come up with a racy !FOLL_LONGTERM reproducer that can reuse an existing interface to trigger short-term pinning (I'll look into that next). On current mm/mm-unstable: # ./gup_longterm # [INFO] detected hugetlb page size: 2048 KiB # [INFO] detected hugetlb page size: 1048576 KiB TAP version 13 1..50 # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd ok 1 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with tmpfile ok 2 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with local tmpfile ok 3 Should have failed # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 4 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 5 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd ok 6 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with tmpfile ok 7 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with local tmpfile ok 8 Should have failed # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 9 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 10 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd ok 11 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with tmpfile ok 12 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with local tmpfile ok 13 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 14 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 15 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd ok 16 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with tmpfile ok 17 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with local tmpfile ok 18 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 19 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 20 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd ok 21 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with tmpfile ok 22 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with local tmpfile ok 23 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 24 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 25 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd ok 26 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with tmpfile ok 27 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with local tmpfile ok 28 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 29 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 30 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd ok 31 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with tmpfile ok 32 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with local tmpfile ok 33 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 34 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 35 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd ok 36 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with tmpfile ok 37 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with local tmpfile ok 38 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 39 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 40 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd ok 41 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with tmpfile ok 42 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with local tmpfile ok 43 Should have failed # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 44 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 45 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd ok 46 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with tmpfile ok 47 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with local tmpfile ok 48 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 49 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 50 Should have worked # Totals: pass:50 fail:0 xfail:0 xpass:0 skip:0 error:0 This patch (of 3): Let's factor detection out into vm_util, to be reused by a new test. Link: https://lkml.kernel.org/r/20230519102723.185721-1-david@redhat.com Link: https://lkml.kernel.org/r/20230519102723.185721-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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