Displaying 3 results from an estimated 3 matches for "falloc_fl_punhch_hol".
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falloc_fl_punhch_hole
2018 Aug 02
1
Re: [PATCH 2/3] file: Support zero without ZERO_RANGE
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...
2018 Aug 02
0
[PATCH 2/3] file: Support zero without ZERO_RANGE
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)
fallocate(0)
Based on my tests this is much more efficient compared to manual
zeroing. The idea came from this qemu patch:
https://github.com/qemu/qemu/commit/1cdc3239f1bb
Here is an example run with NFS 4.2 without this change, converting
fedora 27 image created with virt-builder:
$ expor...
2018 Aug 02
10
[PATCH 0/3] file: Zero for block devices and older file systems
This is the second version to support efficient zero for block devices
on older kernels (e.g. RHEL 7.5), and file systems that do not support
yet FALLOC_FS_ZERO_RANGE (e.g. NFS 4.2).
Changes since v1:
- Split to smaller patches
- Skip linux only includes on other systems
- Skip code using BLKZEROOUT if the macro is not defined
- Try BLKZEROOUT only if the offset and count are aligned to device