On Mon, Apr 20, 2020 at 06:07:38PM +0100, fdmanana@xxxxxxxxxx wrote:
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> Currently we are limiting the range for zero range operations to stay
> within the i_size boundary. This is not optimal because like this we lose
> coverage of the filesystem's zero range implementation, since zero range
> operations are allowed to cross the i_size. Fix this by limiting the range
> to 'maxfilelen' and not 'file_size', and update the 'file_size' after each
> zero range operation if needed.
>
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
Thanks for the fixup. Looks good to me now:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> ltp/fsx.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/ltp/fsx.c b/ltp/fsx.c
> index 9d598a4f..56479eda 100644
> --- a/ltp/fsx.c
> +++ b/ltp/fsx.c
> @@ -1244,6 +1244,17 @@ do_zero_range(unsigned offset, unsigned length, int keep_size)
> }
>
> memset(good_buf + offset, '\0', length);
> +
> + if (!keep_size && end_offset > file_size) {
> + /*
> + * If there's a gap between the old file size and the offset of
> + * the zero range operation, fill the gap with zeroes.
> + */
> + if (offset > file_size)
> + memset(good_buf + file_size, '\0', offset - file_size);
> +
> + file_size = end_offset;
> + }
> }
>
> #else
> @@ -2141,7 +2152,7 @@ have_op:
> do_punch_hole(offset, size);
> break;
> case OP_ZERO_RANGE:
> - TRIM_OFF_LEN(offset, size, file_size);
> + TRIM_OFF_LEN(offset, size, maxfilelen);
> do_zero_range(offset, size, keep_size);
> break;
> case OP_COLLAPSE_RANGE:
> --
> 2.11.0
>
