[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] qemu-img info: show nocow info
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH] qemu-img info: show nocow info |
Date: |
Wed, 02 Jul 2014 07:03:26 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 |
On 07/02/2014 03:50 AM, Chunyan Liu wrote:
> Add nocow info in 'qemu-img info' output to show whether the file
> currently has NOCOW flag set or not.
>
> Signed-off-by: Chunyan Liu <address@hidden>
> ---
> block/qapi.c | 25 +++++++++++++++++++++++++
> qapi/block-core.json | 3 ++-
> 2 files changed, 27 insertions(+), 1 deletion(-)
>
> +
> + /* get NOCOW info */
> + fd = qemu_open(bs->filename, O_RDONLY | O_NONBLOCK);
> + if (fd >= 0) {
> + if (ioctl(fd, FS_IOC_GETFLAGS, &attr) == 0 && (attr & FS_NOCOW_FL)) {
> + info->has_nocow = true;
> + info->nocow = true;
Better is:
if (ioctl... == 0) {
info->has_nocow = true;
info->nocow = !!(attr & FS_NOCOW_FL)
}
to explicitly document the cases where we know nocow works but is not
set (and omitting it in cases where nocow doesn't exist because of the fs)
> +++ b/qapi/block-core.json
> @@ -126,7 +126,8 @@
> '*backing-filename': 'str', '*full-backing-filename': 'str',
> '*backing-filename-format': 'str', '*snapshots': ['SnapshotInfo'],
> '*backing-image': 'ImageInfo',
> - '*format-specific': 'ImageInfoSpecific' } }
> + '*format-specific': 'ImageInfoSpecific',
> + '*nocow': 'bool' } }
Missing documentation. When adding that, remember to add '(since 2.2)'
(or even since 2.1 if you think this is a bug fix that should go in
during hard freeze)
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature