On Fri, 27 Mar 2026 20:03:05 +0800 Li Wang <[email protected]> wrote:
> hugetlb_dio test uses sub-page offsets (pagesize / 2) to verify that
> hugepages used as DIO user buffers are correctly unpinned at completion.
>
> However, on filesystems with a logical block size larger than half the
> page size (e.g., 4K-sector block devices), these unaligned DIO writes
> are rejected with -EINVAL, causing the test to fail unexpectedly.
>
> Add get_dio_alignment() to query the filesystem's required DIO alignment
> via statx(STATX_DIOALIGN) and pass it to run_dio_using_hugetlb(). Skip
> individual test cases whose write length is not a multiple of the
> alignment, so that aligned cases are still tested.
>
> === Reproduce Steps ===
>
> # dd if=/dev/zero of=/tmp/test.img bs=1M count=512
> # losetup --sector-size 4096 /dev/loop0 /tmp/test.img
> # mkfs.xfs /dev/loop0
> # mkdir -p /mnt/dio_test
> # mount /dev/loop0 /mnt/dio_test
>
> // Modify test to open /mnt/dio_test and rebuild it:
> - fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT, 0664);
> + fd = open("/mnt/dio_test", O_TMPFILE | O_RDWR | O_DIRECT, 0664);
>
> # getconf PAGESIZE
> 4096
>
> # echo 100 >/proc/sys/vm/nr_hugepages
>
> # ./hugetlb_dio
> TAP version 13
> 1..4
> # No. Free pages before allocation : 100
> # No. Free pages after munmap : 100
> ok 1 free huge pages from 0-12288
> Bail out! Error writing to file
> : Invalid argument (22)
> # Planned tests != run tests (4 != 1)
> # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
>
> ...
>
> v2:
> - Pass dio_align as a parameter to run_dio_using_hugetlb()
> instead of generally page_size/2 alignment check.
>
Whee, AI review has decided that pre glibc-2.36 is a problem (last time
it was pre-2.37).
And it's forgotten the previous fs-doesnt-support-DIO issues. Did you
alter that?
The get_dio_alignment-before-ksft_print_header thing seems legit.
https://sashiko.dev/#/patchset/[email protected]
