Re: [PATCH v4] generic/808: add a regression test for fiemap into an mmap range

[Anand Jain <anand.jain@oracle.com>]

On 3/20/24 21:16, Josef Bacik wrote:
> Btrfs had a deadlock that you could trigger by mmap'ing a large file and
> using that as the buffer for fiemap.  This test adds a c program to do
> this, and the fstest creates a large enough file and then runs the
> reproducer on the file.  Without the fix btrfs deadlocks, with the fix
> we pass fine.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
> v3->v4:
> - Rework this to use punch-alternating to generate a fragmented file.
> - Rework the _require's to reflect the new mode of fragmenting a file.
> 

> +# real QA test starts here
> +_supported_fs generic
> +_require_test
> +_require_test_program "fiemap-fault"
> +_require_test_program "punch-alternating"
> +_require_xfs_io_command "fpunch"
> +
> +dst=$TEST_DIR/$seq/fiemap-fault
> +
> +mkdir -p $TEST_DIR/$seq
> +
> +echo "Silence is golden"
> +
> +# Generate a file with lots of extents
> +blksz=$(_get_file_block_size $TEST_DIR)
> +$XFS_IO_PROG -f -c "pwrite -q 0 $((blksz * 10000))" $dst
> +$here/src/punch-alternating $dst
> +
> +# Now run the reproducer
> +$here/src/fiemap-fault $dst
> +
> +# success, all done
> +status=$?
> +exit

Reviewed-by: Anand Jain <anand.jain@oracle.com>

> +
A whitespace here, to be addressed during integration.

Thanks, Anand

> diff --git a/tests/generic/808.out b/tests/generic/808.out
> new file mode 100644
> index 00000000..88253428
> --- /dev/null
> +++ b/tests/generic/808.out
> @@ -0,0 +1,2 @@
> +QA output created by 808
> +Silence is golden