qga/commands-posix.c | 17 +++++++++++++++++ qga/qapi-schema.json | 3 ++- 2 files changed, 19 insertions(+), 1 deletion(-)
From: Chen Hanxiao <chenhanxiao@gmail.com>
This patch adds support for getting the usage of mounted
filesystem.
It's very useful when we try to monitor guest's filesystem.
Use df of coreutils for reference.
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
---
qga/commands-posix.c | 17 +++++++++++++++++
qga/qapi-schema.json | 3 ++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 0dc219dbcf..0d93c47a5d 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -46,6 +46,7 @@ extern char **environ;
#include <arpa/inet.h>
#include <sys/socket.h>
#include <net/if.h>
+#include <sys/statvfs.h>
#ifdef FIFREEZE
#define CONFIG_FSFREEZE
@@ -1072,6 +1073,9 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
Error **errp)
{
GuestFilesystemInfo *fs = g_malloc0(sizeof(*fs));
+ struct statvfs buf;
+ unsigned long u100, used, nonroot_total;
+ int usage;
char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
mount->devmajor, mount->devminor);
@@ -1079,7 +1083,20 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
fs->type = g_strdup(mount->devtype);
build_guest_fsinfo_for_device(devpath, fs, errp);
+ if (statvfs(fs->mountpoint, &buf)) {
+ error_setg_errno(errp, errno, "Failed to get statvfs");
+ return NULL;
+ }
+
+ used = buf.f_blocks - buf.f_bfree;
+ u100 = 100 * used;
+ nonroot_total = used + buf.f_bavail;
+ usage = u100 / nonroot_total + (u100 % nonroot_total != 0);
+
+ fs->usage = usage;
+
g_free(devpath);
+
return fs;
}
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 17884c7c70..22c22d8a62 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -846,13 +846,14 @@
# @name: disk name
# @mountpoint: mount point path
# @type: file system type string
+# @usage: file system usage
# @disk: an array of disk hardware information that the volume lies on,
# which may be empty if the disk type is not supported
#
# Since: 2.2
##
{ 'struct': 'GuestFilesystemInfo',
- 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
+ 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str', 'usage': 'int',
'disk': ['GuestDiskAddress']} }
##
--
2.17.0
On 05/29/2018 10:01 PM, Chen Hanxiao wrote:
> From: Chen Hanxiao <chenhanxiao@gmail.com>
>
> This patch adds support for getting the usage of mounted
> filesystem.
> It's very useful when we try to monitor guest's filesystem.
> Use df of coreutils for reference.
>
> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
> ---
> @@ -1072,6 +1073,9 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
> Error **errp)
> {
> GuestFilesystemInfo *fs = g_malloc0(sizeof(*fs));
> + struct statvfs buf;
> + unsigned long u100, used, nonroot_total;
> + int usage;
> char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
> mount->devmajor, mount->devminor);
>
> @@ -1079,7 +1083,20 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
> fs->type = g_strdup(mount->devtype);
> build_guest_fsinfo_for_device(devpath, fs, errp);
>
> + if (statvfs(fs->mountpoint, &buf)) {
> + error_setg_errno(errp, errno, "Failed to get statvfs");
> + return NULL;
> + }
> +
> + used = buf.f_blocks - buf.f_bfree;
> + u100 = 100 * used;
> + nonroot_total = used + buf.f_bavail;
> + usage = u100 / nonroot_total + (u100 % nonroot_total != 0);
Why integral instead of floating point?
> +++ b/qga/qapi-schema.json
> @@ -846,13 +846,14 @@
> # @name: disk name
> # @mountpoint: mount point path
> # @type: file system type string
> +# @usage: file system usage
Needs more details. As written, it is an integer between 0 and 100; but
if you use floating point, a better description would be a fraction
between 0 and 1.
> # @disk: an array of disk hardware information that the volume lies on,
> # which may be empty if the disk type is not supported
> #
> # Since: 2.2
> ##
> { 'struct': 'GuestFilesystemInfo',
> - 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
> + 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str', 'usage': 'int',
> 'disk': ['GuestDiskAddress']} }
>
> ##
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
On 05/29/2018 10:19 PM, Eric Blake wrote: >> @@ -846,13 +846,14 @@ >> # @name: disk name >> # @mountpoint: mount point path >> # @type: file system type string >> +# @usage: file system usage > > Needs more details. As written, it is an integer between 0 and 100; but > if you use floating point, a better description would be a fraction > between 0 and 1. Also, missing a '(since 3.0)' designation. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
At 2018-05-30 11:19:27, "Eric Blake" <eblake@redhat.com> wrote:
>On 05/29/2018 10:01 PM, Chen Hanxiao wrote:
>> From: Chen Hanxiao <chenhanxiao@gmail.com>
>>
>> This patch adds support for getting the usage of mounted
>> filesystem.
>> It's very useful when we try to monitor guest's filesystem.
>> Use df of coreutils for reference.
>>
>> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
>> Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
>> ---
>
>> @@ -1072,6 +1073,9 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
>> Error **errp)
>> {
>> GuestFilesystemInfo *fs = g_malloc0(sizeof(*fs));
>> + struct statvfs buf;
>> + unsigned long u100, used, nonroot_total;
>> + int usage;
>> char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
>> mount->devmajor, mount->devminor);
>>
>> @@ -1079,7 +1083,20 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
>> fs->type = g_strdup(mount->devtype);
>> build_guest_fsinfo_for_device(devpath, fs, errp);
>>
>> + if (statvfs(fs->mountpoint, &buf)) {
>> + error_setg_errno(errp, errno, "Failed to get statvfs");
>> + return NULL;
>> + }
>> +
>> + used = buf.f_blocks - buf.f_bfree;
>> + u100 = 100 * used;
>> + nonroot_total = used + buf.f_bavail;
>> + usage = u100 / nonroot_total + (u100 % nonroot_total != 0);
>
>Why integral instead of floating point?
I followed the style of df from coreutils.
As the percentage already multiplied by 100,
I think it has enough precision.
>
>> +++ b/qga/qapi-schema.json
>> @@ -846,13 +846,14 @@
>> # @name: disk name
>> # @mountpoint: mount point path
>> # @type: file system type string
>> +# @usage: file system usage
>
>Needs more details. As written, it is an integer between 0 and 100; but
>if you use floating point, a better description would be a fraction
>between 0 and 1.
Will be updated in the following patch.
Regards,
- Chen
>
>> # @disk: an array of disk hardware information that the volume lies on,
>> # which may be empty if the disk type is not supported
>> #
>> # Since: 2.2
>> ##
>> { 'struct': 'GuestFilesystemInfo',
>> - 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
>> + 'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str', 'usage': 'int',
>> 'disk': ['GuestDiskAddress']} }
>>
>> ##
>>
>
>--
>Eric Blake, Principal Software Engineer
>Red Hat, Inc. +1-919-301-3266
>Virtualization: qemu.org | libvirt.org
On 05/30/2018 01:55 AM, Chen Hanxiao wrote: >>> + usage = u100 / nonroot_total + (u100 % nonroot_total != 0); >> >> Why integral instead of floating point? > > I followed the style of df from coreutils. > As the percentage already multiplied by 100, > I think it has enough precision. You're making an arbitrary policy decision. Give the client a floating point, and they can still truncate to print out a 2-digit percentage. But give them a percentage, and for a 2T disk image, they are forced to guess whether they are 20G high or low on usage, which starts to take a non-trivial amount of time to copy that much data. In other words, I think an int is wrong for being too imprecise. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
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