From: Chen Hanxiao <chenhanxiao@gmail.com>

This patch adds support for getting the usage of mounted
filesystem.
The usage of fs stored as used_bytes and total_bytes.
It's very useful when we try to monitor guest's filesystem.

Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>

---
v2:
   add description in qapi-schema and version numbers
v3:
   use float for usage to get more precision.
v4:
   make usage a best-effort query and mark it as optional.
v5:
   report used-bytes and total-bytes in usage

 qga/commands-posix.c | 19 +++++++++++++++++++
 qga/qapi-schema.json | 14 +++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 0dc219dbcf..83192f284c 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));
+    GuestFsUsage *usage;
+    struct statvfs buf;
+    unsigned long used, nonroot_total, fr_size;
     char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
                                     mount->devmajor, mount->devminor);
 
@@ -1079,7 +1083,22 @@ 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)) {
+        fs->has_usage = false;
+    } else {
+        fr_size = buf.f_frsize;
+        used = buf.f_blocks - buf.f_bfree;
+        nonroot_total = used + buf.f_bavail;
+        usage = g_malloc0(sizeof(*usage));
+        usage->used_bytes = used * fr_size;
+        usage->total_bytes = nonroot_total * fr_size;
+
+        fs->has_usage = true;
+        fs->usage = usage;
+    }
+
     g_free(devpath);
+
     return fs;
 }
 
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 17884c7c70..2f742474f6 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -840,12 +840,24 @@
            'bus-type': 'GuestDiskBusType',
            'bus': 'int', 'target': 'int', 'unit': 'int'} }
 
+##
+# @GuestFsUsage:
+#
+# @used-bytes:  file system used bytes
+# @total-bytes: file system total bytes for nonroot user
+#
+# Since: 3.0
+##
+{ 'struct': 'GuestFsUsage',
+  'data': {'used-bytes': 'uint64', 'total-bytes': 'uint64'} }
+
 ##
 # @GuestFilesystemInfo:
 #
 # @name: disk name
 # @mountpoint: mount point path
 # @type: file system type string
+# @usage: file system usage struct (since 3.0)
 # @disk: an array of disk hardware information that the volume lies on,
 #        which may be empty if the disk type is not supported
 #
@@ -853,7 +865,7 @@
 ##
 { 'struct': 'GuestFilesystemInfo',
   'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
-           'disk': ['GuestDiskAddress']} }
+           '*usage': 'GuestFsUsage', 'disk': ['GuestDiskAddress']} }
 
 ##
 # @guest-get-fsinfo:
-- 
2.17.0

On 06/01/2018 10:27 AM, Chen Hanxiao wrote:
> From: Chen Hanxiao <chenhanxiao@gmail.com>
> 
> This patch adds support for getting the usage of mounted
> filesystem.
> The usage of fs stored as used_bytes and total_bytes.
> It's very useful when we try to monitor guest's filesystem.
> 
> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> Cc: Eric Blake <eblake@redhat.com>
> Cc: Daniel P. Berrangé <berrange@redhat.com>
> Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
> 

> +++ b/qga/qapi-schema.json
> @@ -840,12 +840,24 @@
>              'bus-type': 'GuestDiskBusType',
>              'bus': 'int', 'target': 'int', 'unit': 'int'} }
>   
> +##
> +# @GuestFsUsage:
> +#
> +# @used-bytes:  file system used bytes
> +# @total-bytes: file system total bytes for nonroot user
> +#
> +# Since: 3.0
> +##
> +{ 'struct': 'GuestFsUsage',
> +  'data': {'used-bytes': 'uint64', 'total-bytes': 'uint64'} }

That seems like pointless nesting on the wire, unless we have plans of 
reusing this type in other API calls.  Is it any easier...

> +
>   ##
>   # @GuestFilesystemInfo:
>   #
>   # @name: disk name
>   # @mountpoint: mount point path
>   # @type: file system type string
> +# @usage: file system usage struct (since 3.0)
>   # @disk: an array of disk hardware information that the volume lies on,
>   #        which may be empty if the disk type is not supported
>   #
> @@ -853,7 +865,7 @@
>   ##
>   { 'struct': 'GuestFilesystemInfo',
>     'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
> -           'disk': ['GuestDiskAddress']} }
> +           '*usage': 'GuestFsUsage', 'disk': ['GuestDiskAddress']} }

...to just inline '*used-bytes' and '*total-bytes' here?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

在 2018-06-01 23:47:04，"Eric Blake" <eblake@redhat.com> 写道：
>On 06/01/2018 10:27 AM, Chen Hanxiao wrote:
>> From: Chen Hanxiao <chenhanxiao@gmail.com>
>> 
>> This patch adds support for getting the usage of mounted
>> filesystem.
>> The usage of fs stored as used_bytes and total_bytes.
>> It's very useful when we try to monitor guest's filesystem.
>> 
>> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
>> Cc: Eric Blake <eblake@redhat.com>
>> Cc: Daniel P. Berrangé <berrange@redhat.com>
>> Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
>> 
>
>> +++ b/qga/qapi-schema.json
>> @@ -840,12 +840,24 @@
>>              'bus-type': 'GuestDiskBusType',
>>              'bus': 'int', 'target': 'int', 'unit': 'int'} }
>>   
>> +##
>> +# @GuestFsUsage:
>> +#
>> +# @used-bytes:  file system used bytes
>> +# @total-bytes: file system total bytes for nonroot user
>> +#
>> +# Since: 3.0
>> +##
>> +{ 'struct': 'GuestFsUsage',
>> +  'data': {'used-bytes': 'uint64', 'total-bytes': 'uint64'} }
>
>That seems like pointless nesting on the wire, unless we have plans of 
>reusing this type in other API calls.  Is it any easier...
>
>> +
>>   ##
>>   # @GuestFilesystemInfo:
>>   #
>>   # @name: disk name
>>   # @mountpoint: mount point path
>>   # @type: file system type string
>> +# @usage: file system usage struct (since 3.0)
>>   # @disk: an array of disk hardware information that the volume lies on,
>>   #        which may be empty if the disk type is not supported
>>   #
>> @@ -853,7 +865,7 @@
>>   ##
>>   { 'struct': 'GuestFilesystemInfo',
>>     'data': {'name': 'str', 'mountpoint': 'str', 'type': 'str',
>> -           'disk': ['GuestDiskAddress']} }
>> +           '*usage': 'GuestFsUsage', 'disk': ['GuestDiskAddress']} }
>
>...to just inline '*used-bytes' and '*total-bytes' here?
>

I just want to group them together, and use one has_XXX.

I'll make a some fix for this.
Thanks for you advice.

Regards,
- Chen