From 8b35858852e5c170410d4462fdf2bb19659b8894 Mon Sep 17 00:00:00 2001

Message-Id: <8b35858852e5c170410d4462fdf2bb19659b8894@dist-git>

From: Pavel Hrdina <phrdina@redhat.com>

Date: Mon, 1 Jul 2019 17:08:09 +0200

Subject: [PATCH] vircgroup: introduce virCgroupKillRecursiveCB

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

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The rewrite to support cgroup v2 missed this function.  In cgroup v2

we have different files to track tasks.

We would fail to remove cgroup on non-systemd OSes if there is any

extra process assigned to guest cgroup because we would not kill any

process form the guest cgroup.

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

(cherry picked from commit b532546823fde032fe827d41735a0d591c3bc0b8)

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

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

Message-Id: <2414a178eb8aba977e7369bba0b37a18cdfec654.1561993100.git.phrdina@redhat.com>

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

---

 src/util/vircgroup.c        | 69 ++++++++++++++++++++-----------------

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

 src/util/vircgrouppriv.h    |  8 +++++

 src/util/vircgroupv1.c      | 16 +++++++++

 src/util/vircgroupv2.c      | 16 +++++++++

 5 files changed, 84 insertions(+), 32 deletions(-)

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

index 069f1ae396..736b5043a8 100644

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

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

@@ -2431,33 +2431,15 @@ virCgroupRemove(virCgroupPtr group)

 }

-static int

-virCgroupPathOfAnyController(virCgroupPtr group,

-                             const char *name,

-                             char **keypath)

-{

-    size_t i;

-    int controller;

-

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

-        if (group->backends[i]) {

-            controller = group->backends[i]->getAnyController(group);

-            if (controller >= 0)

-                return virCgroupPathOfController(group, controller, name, keypath);

-        }

-    }

-

-    virReportSystemError(ENOSYS, "%s",

-                         _("No controllers are mounted"));

-    return -1;

-}

-

-

 /*

  * Returns 1 if some PIDs are killed, 0 if none are killed, or -1 on error

  */

 static int

-virCgroupKillInternal(virCgroupPtr group, int signum, virHashTablePtr pids)

+virCgroupKillInternal(virCgroupPtr group,

+                      int signum,

+                      virHashTablePtr pids,

+                      int controller,

+                      const char *taskFile)

 {

     int ret = -1;

     bool killedAny = false;

@@ -2467,7 +2449,7 @@ virCgroupKillInternal(virCgroupPtr group, int signum, virHashTablePtr pids)

     VIR_DEBUG("group=%p path=%s signum=%d pids=%p",

               group, group->path, signum, pids);

-    if (virCgroupPathOfAnyController(group, "tasks", &keypath) < 0)

+    if (virCgroupPathOfController(group, controller, taskFile, &keypath) < 0)

         return -1;

     /* PIDs may be forking as we kill them, so loop

@@ -2553,10 +2535,12 @@ virCgroupPidCopy(const void *name)

 }

-static int

+int

 virCgroupKillRecursiveInternal(virCgroupPtr group,

                                int signum,

                                virHashTablePtr pids,

+                               int controller,

+                               const char *taskFile,

                                bool dormdir)

 {

     int ret = -1;

@@ -2570,11 +2554,13 @@ virCgroupKillRecursiveInternal(virCgroupPtr group,

     VIR_DEBUG("group=%p path=%s signum=%d pids=%p",

               group, group->path, signum, pids);

-    if (virCgroupPathOfAnyController(group, "", &keypath) < 0)

+    if (virCgroupPathOfController(group, controller, "", &keypath) < 0)

         return -1;

-    if ((rc = virCgroupKillInternal(group, signum, pids)) < 0)

+    if ((rc = virCgroupKillInternal(group, signum, pids,

+                                    controller, taskFile)) < 0) {

         goto cleanup;

+    }

     if (rc == 1)

         killedAny = true;

@@ -2598,7 +2584,7 @@ virCgroupKillRecursiveInternal(virCgroupPtr group,

             goto cleanup;

         if ((rc = virCgroupKillRecursiveInternal(subgroup, signum, pids,

-                                                 true)) < 0)

+                                                 controller, taskFile, true)) < 0)

             goto cleanup;

         if (rc == 1)

             killedAny = true;

@@ -2624,8 +2610,10 @@ virCgroupKillRecursiveInternal(virCgroupPtr group,

 int

 virCgroupKillRecursive(virCgroupPtr group, int signum)

 {

-    int ret;

-    VIR_DEBUG("group=%p path=%s signum=%d", group, group->path, signum);

+    int ret = 0;

+    int rc;

+    size_t i;

+    virCgroupBackendPtr *backends = virCgroupBackendGetAll();

     virHashTablePtr pids = virHashCreateFull(100,

                                              NULL,

                                              virCgroupPidCode,

@@ -2633,10 +2621,27 @@ virCgroupKillRecursive(virCgroupPtr group, int signum)

                                              virCgroupPidCopy,

                                              NULL);

-    ret = virCgroupKillRecursiveInternal(group, signum, pids, false);

+    VIR_DEBUG("group=%p path=%s signum=%d", group, group->path, signum);

+    if (!backends) {

+        ret = -1;

+        goto cleanup;

+    }

+

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

+        if (backends[i]) {

+            rc = backends[i]->killRecursive(group, signum, pids);

+            if (rc < 0) {

+                ret = -1;

+                goto cleanup;

+            }

+            if (rc > 0)

+                ret = rc;

+        }

+    }

+

+ cleanup:

     virHashFree(pids);

-

     return ret;

 }

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

index bc60b44643..a825dc4be7 100644

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

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

@@ -24,6 +24,7 @@

 # include "internal.h"

 # include "vircgroup.h"

+# include "virhash.h"

 # define CGROUP_MAX_VAL 512

@@ -128,6 +129,11 @@ typedef int

 (*virCgroupHasEmptyTasksCB)(virCgroupPtr cgroup,

                             int controller);

+typedef int

+(*virCgroupKillRecursiveCB)(virCgroupPtr group,

+                            int signum,

+                            virHashTablePtr pids);

+

 typedef int

 (*virCgroupBindMountCB)(virCgroupPtr group,

                         const char *oldroot,

@@ -370,6 +376,7 @@ struct _virCgroupBackend {

     virCgroupRemoveCB remove;

     virCgroupAddTaskCB addTask;

     virCgroupHasEmptyTasksCB hasEmptyTasks;

+    virCgroupKillRecursiveCB killRecursive;

     virCgroupBindMountCB bindMount;

     virCgroupSetOwnerCB setOwner;

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

index 8f24b0891e..6067f5cdc8 100644

--- a/src/util/vircgrouppriv.h

+++ b/src/util/vircgrouppriv.h

@@ -123,4 +123,12 @@ int virCgroupNewDomainPartition(virCgroupPtr partition,

 int virCgroupRemoveRecursively(char *grppath);

+

+int virCgroupKillRecursiveInternal(virCgroupPtr group,

+                                   int signum,

+                                   virHashTablePtr pids,

+                                   int controller,

+                                   const char *taskFile,

+                                   bool dormdir);

+

 #endif /* __VIR_CGROUP_PRIV_H__ */

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

index 3147084f21..7098dc5644 100644

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

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

@@ -758,6 +758,21 @@ virCgroupV1HasEmptyTasks(virCgroupPtr cgroup,

 }

+static int

+virCgroupV1KillRecursive(virCgroupPtr group,

+                         int signum,

+                         virHashTablePtr pids)

+{

+    int controller = virCgroupV1GetAnyController(group);

+

+    if (controller < 0)

+        return -1;

+

+    return virCgroupKillRecursiveInternal(group, signum, pids, controller,

+                                          "tasks", false);

+}

+

+

 static char *

 virCgroupV1IdentifyRoot(virCgroupPtr group)

 {

@@ -2042,6 +2057,7 @@ virCgroupBackend virCgroupV1Backend = {

     .remove = virCgroupV1Remove,

     .addTask = virCgroupV1AddTask,

     .hasEmptyTasks = virCgroupV1HasEmptyTasks,

+    .killRecursive = virCgroupV1KillRecursive,

     .bindMount = virCgroupV1BindMount,

     .setOwner = virCgroupV1SetOwner,

diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c

index bff2f78d7e..5652fcfffb 100644

--- a/src/util/vircgroupv2.c

+++ b/src/util/vircgroupv2.c

@@ -463,6 +463,21 @@ virCgroupV2HasEmptyTasks(virCgroupPtr cgroup,

 }

+static int

+virCgroupV2KillRecursive(virCgroupPtr group,

+                         int signum,

+                         virHashTablePtr pids)

+{

+    int controller = virCgroupV2GetAnyController(group);

+

+    if (controller < 0)

+        return -1;

+

+    return virCgroupKillRecursiveInternal(group, signum, pids, controller,

+                                          "cgroup.threads", false);

+}

+

+

 static int

 virCgroupV2BindMount(virCgroupPtr group,

                      const char *oldroot,

@@ -1559,6 +1574,7 @@ virCgroupBackend virCgroupV2Backend = {

     .remove = virCgroupV2Remove,

     .addTask = virCgroupV2AddTask,

     .hasEmptyTasks = virCgroupV2HasEmptyTasks,

+    .killRecursive = virCgroupV2KillRecursive,

     .bindMount = virCgroupV2BindMount,

     .setOwner = virCgroupV2SetOwner,

-- 

2.22.0