From 0dcb8bdc63970be07228108f602a7425612bd1fe Mon Sep 17 00:00:00 2001

Message-Id: <0dcb8bdc63970be07228108f602a7425612bd1fe@dist-git>

From: Pavel Hrdina <phrdina@redhat.com>

Date: Mon, 1 Jul 2019 17:06:23 +0200

Subject: [PATCH] vircgroup: extract virCgroupV1Available

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Reviewed-by: Ján Tomko <jtomko@redhat.com>

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

(cherry picked from commit 57d35b72c9049348b36382ce88bee32553e0fae5)

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

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

Message-Id: <c54c63779affc0f0a30224fd8001aa53fff9df52.1561993100.git.phrdina@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/util/vircgroup.c        | 28 ++++++++--------------------

 src/util/vircgroupbackend.h |  7 +++++++

 src/util/vircgroupv1.c      | 35 +++++++++++++++++++++++++++++++++++

 3 files changed, 50 insertions(+), 20 deletions(-)

diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c

index d55f411daa..47a3b9ed58 100644

--- a/src/util/vircgroup.c

+++ b/src/util/vircgroup.c

@@ -51,6 +51,7 @@

 #include "virutil.h"

 #include "viralloc.h"

+#include "vircgroupbackend.h"

 #include "virerror.h"

 #include "virlog.h"

 #include "virfile.h"

@@ -64,8 +65,6 @@

 VIR_LOG_INIT("util.cgroup");

-#define CGROUP_MAX_VAL 512

-

 #define VIR_FROM_THIS VIR_FROM_CGROUP

 #define CGROUP_NB_TOTAL_CPU_STAT_PARAM 3

@@ -132,29 +131,18 @@ virCgroupGetDevicePermsString(int perms)

 bool

 virCgroupAvailable(void)

 {

-    bool ret = false;

-    FILE *mounts = NULL;

-    struct mntent entry;

-    char buf[CGROUP_MAX_VAL];

+    size_t i;

+    virCgroupBackendPtr *backends = virCgroupBackendGetAll();

-    if (!virFileExists("/proc/cgroups"))

+    if (!backends)

         return false;

-    if (!(mounts = fopen("/proc/mounts", "r")))

-        return false;

-

-    while (getmntent_r(mounts, &entry, buf, sizeof(buf)) != NULL) {

-        /* We're looking for at least one 'cgroup' fs mount,

-         * which is *not* a named mount. */

-        if (STREQ(entry.mnt_type, "cgroup") &&

-            !strstr(entry.mnt_opts, "name=")) {

-            ret = true;

-            break;

-        }

+    for (i = 0; i < VIR_CGROUP_BACKEND_TYPE_LAST; i++) {

+        if (backends[i] && backends[i]->available())

+            return true;

     }

-    VIR_FORCE_FCLOSE(mounts);

-    return ret;

+    return false;

 }

diff --git a/src/util/vircgroupbackend.h b/src/util/vircgroupbackend.h

index db052485a8..88f51416b0 100644

--- a/src/util/vircgroupbackend.h

+++ b/src/util/vircgroupbackend.h

@@ -25,14 +25,21 @@

 # include "vircgroup.h"

+# define CGROUP_MAX_VAL 512

 typedef enum {

     VIR_CGROUP_BACKEND_TYPE_V1 = 0,

     VIR_CGROUP_BACKEND_TYPE_LAST,

 } virCgroupBackendType;

+typedef bool

+(*virCgroupAvailableCB)(void);

+

 struct _virCgroupBackend {

     virCgroupBackendType type;

+

+    /* Mandatory callbacks that need to be implemented for every backend. */

+    virCgroupAvailableCB available;

 };

 typedef struct _virCgroupBackend virCgroupBackend;

 typedef virCgroupBackend *virCgroupBackendPtr;

diff --git a/src/util/vircgroupv1.c b/src/util/vircgroupv1.c

index 4dda7865f1..73045b1109 100644

--- a/src/util/vircgroupv1.c

+++ b/src/util/vircgroupv1.c

@@ -20,6 +20,10 @@

  */

 #include <config.h>

+#if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R

+# include <mntent.h>

+#endif

+

 #include "internal.h"

 #define __VIR_CGROUP_ALLOW_INCLUDE_PRIV_H__

@@ -29,6 +33,7 @@

 #include "vircgroup.h"

 #include "vircgroupbackend.h"

 #include "vircgroupv1.h"

+#include "virfile.h"

 #include "virlog.h"

 VIR_LOG_INIT("util.cgroup");

@@ -43,8 +48,38 @@ VIR_ENUM_IMPL(virCgroupV1Controller, VIR_CGROUP_CONTROLLER_LAST,

               "name=systemd");

+/* We're looking for at least one 'cgroup' fs mount,

+ * which is *not* a named mount. */

+static bool

+virCgroupV1Available(void)

+{

+    bool ret = false;

+    FILE *mounts = NULL;

+    struct mntent entry;

+    char buf[CGROUP_MAX_VAL];

+

+    if (!virFileExists("/proc/cgroups"))

+        return false;

+

+    if (!(mounts = fopen("/proc/mounts", "r")))

+        return false;

+

+    while (getmntent_r(mounts, &entry, buf, sizeof(buf)) != NULL) {

+        if (STREQ(entry.mnt_type, "cgroup") && !strstr(entry.mnt_opts, "name=")) {

+            ret = true;

+            break;

+        }

+    }

+

+    VIR_FORCE_FCLOSE(mounts);

+    return ret;

+}

+

+

 virCgroupBackend virCgroupV1Backend = {

     .type = VIR_CGROUP_BACKEND_TYPE_V1,

+

+    .available = virCgroupV1Available,

 };

-- 

2.22.0