From fce8dc52172734630bd5d274dd4bdf9845948f92 Mon Sep 17 00:00:00 2001
Message-Id: <fce8dc52172734630bd5d274dd4bdf9845948f92@dist-git>
From: Eric Blake <eblake@redhat.com>
Date: Wed, 17 Dec 2014 03:09:02 -0700
Subject: [PATCH] getstats: add block.n.path stat

https://bugzilla.redhat.com/show_bug.cgi?id=1041569

I'm about to make block stats optionally more complex to cover
backing chains, where block.count will no longer equal the number
of <disks> for a domain.  For these reasons, it is nicer if the
statistics output includes the source path (for local files).
This patch doesn't add anything for network disks, although we
may decide to add that later.

With this patch, I now see the following for the same domain as
in the previous patch (one qcow2 file, and an empty cdrom drive):
$ virsh domstats --block foo
Domain: 'foo'
  block.count=2
  block.0.name=hda
  block.0.path=/var/lib/libvirt/images/foo.qcow2
  block.1.name=hdc

* src/libvirt-domain.c (virConnectGetAllDomainStats): Document
new field.
* tools/virsh.pod (domstats): Document new field.
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Return the new
stat for local files/block devices.
(QEMU_ADD_NAME_PARAM): Add parameter.
(qemuDomainGetStatsInterface): Update caller.

Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 7b499262cb6d2bc2361bc4cd3742c0cea331666f)

Conflicts:
	src/libvirt-domain.c - file split from libvirt.c
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/libvirt.c          |  3 +++
 src/qemu/qemu_driver.c | 11 +++++++----
 tools/virsh.pod        |  2 ++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/libvirt.c b/src/libvirt.c
index 1097693..2885965 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -21603,6 +21603,9 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
  * "block.<num>.name" - name of the block device <num> as string.
  *                      matches the target name (vda/sda/hda) of the
  *                      block device.
+ * "block.<num>.path" - string describing the source of block device <num>,
+ *                      if it is a file or block device (omitted for network
+ *                      sources and drives with no media inserted).
  * "block.<num>.rd.reqs" - number of read requests as unsigned long long.
  * "block.<num>.rd.bytes" - number of read bytes as unsigned long long.
  * "block.<num>.rd.times" - total time (ns) spent on reads as
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index f0935d6..03b62d8 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17898,11 +17898,11 @@ do { \
         goto cleanup; \
 } while (0)
 
-#define QEMU_ADD_NAME_PARAM(record, maxparams, type, num, name) \
+#define QEMU_ADD_NAME_PARAM(record, maxparams, type, subtype, num, name) \
 do { \
     char param_name[VIR_TYPED_PARAM_FIELD_LENGTH]; \
     snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH, \
-             "%s.%zu.name", type, num); \
+             "%s.%zu.%s", type, num, subtype); \
     if (virTypedParamsAddString(&(record)->params, \
                                 &(record)->nparams, \
                                 maxparams, \
@@ -17948,7 +17948,7 @@ qemuDomainGetStatsInterface(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
         memset(&tmp, 0, sizeof(tmp));
 
         QEMU_ADD_NAME_PARAM(record, maxparams,
-                            "net", i, dom->def->nets[i]->ifname);
+                            "net", "name", i, dom->def->nets[i]->ifname);
 
         if (virNetInterfaceStats(dom->def->nets[i]->ifname, &tmp) < 0) {
             virResetLastError();
@@ -18041,7 +18041,10 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver,
         qemuBlockStats *entry;
         virDomainDiskDefPtr disk = dom->def->disks[i];
 
-        QEMU_ADD_NAME_PARAM(record, maxparams, "block", i, disk->dst);
+        QEMU_ADD_NAME_PARAM(record, maxparams, "block", "name", i, disk->dst);
+        if (virStorageSourceIsLocalStorage(disk->src) && disk->src->path)
+            QEMU_ADD_NAME_PARAM(record, maxparams, "block", "path",
+                                i, disk->src->path);
 
         if (abbreviated || !disk->info.alias ||
             !(entry = virHashLookup(stats, disk->info.alias))) {
diff --git a/tools/virsh.pod b/tools/virsh.pod
index d88fa9f..beef855 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -871,6 +871,8 @@ I<--interface> returns:
 I<--block> returns:
 "block.count" - number of block devices on this domain,
 "block.<num>.name" - name of the target of the block device <num>,
+"block.<num>.path" - file source of block device <num>, if it is a
+local file or block device,
 "block.<num>.rd.reqs" - number of read requests,
 "block.<num>.rd.bytes" - number of read bytes,
 "block.<num>.rd.times" - total time (ns) spent on reads,
-- 
2.2.0