[Libguestfs] [PATCH 2/3] file: Support zero without ZERO_RANGE
Richard W.M. Jones
rjones at redhat.com
Thu Aug 2 19:28:19 UTC 2018
On Thu, Aug 02, 2018 at 10:05:28PM +0300, Nir Soffer wrote:
> File systems not supporting FALLOC_FL_ZERO_RANGE yet fall back to manual
> zeroing.
>
> We can avoid this by combining two fallocate calls:
>
> fallocate(FALLOC_FL_PUNHCH_HOLE)
"PUNCH"
> fallocate(0)
> +#ifdef FALLOC_FL_PUNCH_HOLE
> + /* If we can punch hole but may not trim, we can combine punching hole and
> + fallocate to zero a range. This is expected to be more efficient than
> + writing zeros manually. */
Although we can fix this before pushing so there's no need to submit a
new version, it's better if the comment style sticks to the same as
used elsewhere, ie:
/* Commmnt
* More comment
*/
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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