libvirt/SOURCES/libvirt-util-vircgroupv2-separate-return-values-of-virCgroupV2EnableController.patch

From 3980cde103a2804abc62a2eb3bcea39cccf20286 Mon Sep 17 00:00:00 2001
Message-Id: <3980cde103a2804abc62a2eb3bcea39cccf20286@dist-git>
From: Pavel Hrdina <phrdina@redhat.com>
Date: Mon, 1 Jul 2019 17:08:20 +0200
Subject: [PATCH] util: vircgroupv2: separate return values of
 virCgroupV2EnableController
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In order to skip controllers that we are not able to activate we need
to return different return value so the caller can decide what to do.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
(cherry picked from commit 29a94a3fefeea0fb29b0b9f485c83c49b5bdae71)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1689297

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Message-Id: <d0356666404a39fd0d6499490f60df17f3ee90b5.1561993100.git.phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/util/vircgroupv2.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
index 98d313bf82..a67d5cfe04 100644
--- a/src/util/vircgroupv2.c
+++ b/src/util/vircgroupv2.c
@@ -352,22 +352,40 @@ virCgroupV2PathOfController(virCgroupPtr group,
 }
 
 
+/**
+ * virCgroupV2EnableController:
+ *
+ * Returns: -1 on fatal error
+ *          -2 if we failed to write into cgroup.subtree_control
+ *          0 on success
+ */
 static int
 virCgroupV2EnableController(virCgroupPtr parent,
-                            int controller)
+                            int controller,
+                            bool report)
 {
     VIR_AUTOFREE(char *) val = NULL;
+    VIR_AUTOFREE(char *) path = NULL;
 
     if (virAsprintf(&val, "+%s",
                     virCgroupV2ControllerTypeToString(controller)) < 0) {
         return -1;
     }
 
-    if (virCgroupSetValueStr(parent, controller,
-                             "cgroup.subtree_control", val) < 0) {
+    if (virCgroupPathOfController(parent, controller,
+                                  "cgroup.subtree_control", &path) < 0) {
         return -1;
     }
 
+    if (virFileWriteStr(path, val, 0) < 0) {
+        if (report) {
+            virReportSystemError(errno,
+                                 _("Failed to enable controller '%s' for '%s'"),
+                                 val, path);
+        }
+        return -2;
+    }
+
     return 0;
 }
 
@@ -405,13 +423,15 @@ virCgroupV2MakeGroup(virCgroupPtr parent ATTRIBUTE_UNUSED,
 
             if (virCgroupV2HasController(parent, VIR_CGROUP_CONTROLLER_CPU) &&
                 virCgroupV2EnableController(parent,
-                                            VIR_CGROUP_CONTROLLER_CPU) < 0) {
+                                            VIR_CGROUP_CONTROLLER_CPU,
+                                            true) < 0) {
                 return -1;
             }
 
             if (virCgroupV2HasController(parent, VIR_CGROUP_CONTROLLER_CPUSET) &&
                 virCgroupV2EnableController(parent,
-                                            VIR_CGROUP_CONTROLLER_CPUSET) < 0) {
+                                            VIR_CGROUP_CONTROLLER_CPUSET,
+                                            true) < 0) {
                 return -1;
             }
         } else {
@@ -424,7 +444,7 @@ virCgroupV2MakeGroup(virCgroupPtr parent ATTRIBUTE_UNUSED,
                 if (i == VIR_CGROUP_CONTROLLER_CPUACCT)
                     continue;
 
-                if (virCgroupV2EnableController(parent, i) < 0)
+                if (virCgroupV2EnableController(parent, i, true) < 0)
                     return -1;
             }
         }
-- 
2.22.0