On 12/3/2018 1:16 PM, Anton Nefedov wrote:
> Current write_zeroes implementation is good enough to satisfy this flag too
>
> Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
> Reviewed-by: Alberto Garcia <berto@igalia.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
strictly speaking this patch differs from v8 as well
(rebase required an extra change, see below)
so perhaps I should have stripped the review tags too
> ---
> block/file-posix.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 7f2cc63..2136df9 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -560,7 +560,10 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
> }
> if (S_ISREG(st.st_mode)) {
> s->discard_zeroes = true;
> +#ifdef CONFIG_FALLOCATE
> s->has_fallocate = true;
> + bs->supported_zero_flags |= BDRV_REQ_ALLOCATE;
> +#endif
> }
> if (S_ISBLK(st.st_mode)) {
> #ifdef BLKDISCARDZEROES
> @@ -595,10 +598,11 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
> #ifdef CONFIG_XFS
> if (platform_test_xfs_fd(s->fd)) {
> s->is_xfs = true;
> + bs->supported_zero_flags |= BDRV_REQ_ALLOCATE;
> }
> #endif
>
> - bs->supported_zero_flags = s->discard_zeroes ? BDRV_REQ_MAY_UNMAP : 0;
> + bs->supported_zero_flags |= s->discard_zeroes ? BDRV_REQ_MAY_UNMAP : 0;
> ret = 0;
(this change is new in v9)
> fail:
> if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
> @@ -1416,6 +1420,10 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
> }
> s->has_fallocate = false;
> }
> +
> + if (!s->has_fallocate) {
> + aiocb->bs->supported_zero_flags &= ~BDRV_REQ_ALLOCATE;
> + }
> #endif
>
> return -ENOTSUP;
>