From e1184bde63a7ed92fb99fc4eba4b4abdf6a01815 Mon Sep 17 00:00:00 2001

Message-Id: <e1184bde63a7ed92fb99fc4eba4b4abdf6a01815@dist-git>

From: Pavel Hrdina <phrdina@redhat.com>

Date: Mon, 1 Jul 2019 17:06:27 +0200

Subject: [PATCH] vircgroup: extract v1 detect functions

MIME-Version: 1.0

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Content-Transfer-Encoding: 8bit

Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>

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

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

(cherry picked from commit 42a3fcc02bcaec4a0c037a5c59ca63f3fc90e90f)

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

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

Message-Id: <3a918fc4eda51c5e9aff5efc93fe14886470578e.1561993100.git.phrdina@redhat.com>

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

---

 src/util/vircgroup.c        | 138 ++-----------------------------

 src/util/vircgroupbackend.h |  14 ++++

 src/util/vircgroupv1.c      | 158 ++++++++++++++++++++++++++++++++++++

 3 files changed, 180 insertions(+), 130 deletions(-)

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

index 9d644d37d1..10c99a66fd 100644

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

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

@@ -235,82 +235,6 @@ virCgroupPartitionEscape(char **path)

 }

-static int

-virCgroupResolveMountLink(const char *mntDir,

-                          const char *typeStr,

-                          virCgroupControllerPtr controller)

-{

-    VIR_AUTOFREE(char *) linkSrc = NULL;

-    VIR_AUTOFREE(char *) tmp = NULL;

-    char *dirName;

-    struct stat sb;

-

-    if (VIR_STRDUP(tmp, mntDir) < 0)

-        return -1;

-

-    dirName = strrchr(tmp, '/');

-    if (!dirName) {

-        virReportError(VIR_ERR_INTERNAL_ERROR,

-                       _("Missing '/' separator in cgroup mount '%s'"), tmp);

-        return -1;

-    }

-

-    if (!strchr(dirName + 1, ','))

-        return 0;

-

-    *dirName = '\0';

-    if (virAsprintf(&linkSrc, "%s/%s", tmp, typeStr) < 0)

-        return -1;

-    *dirName = '/';

-

-    if (lstat(linkSrc, &sb) < 0) {

-        if (errno == ENOENT) {

-            VIR_WARN("Controller %s co-mounted at %s is missing symlink at %s",

-                     typeStr, tmp, linkSrc);

-        } else {

-            virReportSystemError(errno, _("Cannot stat %s"), linkSrc);

-            return -1;

-        }

-    } else {

-        if (!S_ISLNK(sb.st_mode)) {

-            VIR_WARN("Expecting a symlink at %s for controller %s",

-                     linkSrc, typeStr);

-        } else {

-            VIR_STEAL_PTR(controller->linkPoint, linkSrc);

-        }

-    }

-

-    return 0;

-}

-

-

-static bool

-virCgroupMountOptsMatchController(const char *mntOpts,

-                                  const char *typeStr)

-{

-    const char *tmp = mntOpts;

-    int typeLen = strlen(typeStr);

-

-    while (tmp) {

-        const char *next = strchr(tmp, ',');

-        int len;

-        if (next) {

-            len = next - tmp;

-            next++;

-        } else {

-            len = strlen(tmp);

-        }

-

-        if (typeLen == len && STREQLEN(typeStr, tmp, len))

-            return true;

-

-        tmp = next;

-    }

-

-    return false;

-}

-

-

 /*

  * Process /proc/mounts figuring out what controllers are

  * mounted and where

@@ -318,7 +242,6 @@ virCgroupMountOptsMatchController(const char *mntOpts,

 static int

 virCgroupDetectMounts(virCgroupPtr group)

 {

-    size_t i;

     FILE *mounts = NULL;

     struct mntent entry;

     char buf[CGROUP_MAX_VAL];

@@ -331,34 +254,11 @@ virCgroupDetectMounts(virCgroupPtr group)

     }

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

-        if (STRNEQ(entry.mnt_type, "cgroup"))

-            continue;

-

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

-            const char *typestr = virCgroupControllerTypeToString(i);

-

-            if (virCgroupMountOptsMatchController(entry.mnt_opts, typestr)) {

-                /* Note that the lines in /proc/mounts have the same

-                 * order than the mount operations, and that there may

-                 * be duplicates due to bind mounts. This means

-                 * that the same mount point may be processed more than

-                 * once. We need to save the results of the last one,

-                 * and we need to be careful to release the memory used

-                 * by previous processing. */

-                virCgroupControllerPtr controller = &group->controllers[i];

-

-                VIR_FREE(controller->mountPoint);

-                VIR_FREE(controller->linkPoint);

-                if (VIR_STRDUP(controller->mountPoint, entry.mnt_dir) < 0)

-                    goto cleanup;

-

-                /* If it is a co-mount it has a filename like "cpu,cpuacct"

-                 * and we must identify the symlink path */

-                if (virCgroupResolveMountLink(entry.mnt_dir, typestr,

-                                              controller) < 0) {

-                    goto cleanup;

-                }

-            }

+        if (group->backend->detectMounts(group,

+                                         entry.mnt_type,

+                                         entry.mnt_opts,

+                                         entry.mnt_dir) < 0) {

+            goto cleanup;

         }

     }

@@ -432,7 +332,6 @@ virCgroupDetectPlacement(virCgroupPtr group,

                          pid_t pid,

                          const char *path)

 {

-    size_t i;

     FILE *mapping  = NULL;

     char line[1024];

     int ret = -1;

@@ -472,30 +371,9 @@ virCgroupDetectPlacement(virCgroupPtr group,

         controllers++;

         selfpath++;

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

-            const char *typestr = virCgroupControllerTypeToString(i);

-

-            if (virCgroupMountOptsMatchController(controllers, typestr) &&

-                group->controllers[i].mountPoint != NULL &&

-                group->controllers[i].placement == NULL) {

-                /*

-                 * selfpath == "/" + path="" -> "/"

-                 * selfpath == "/libvirt.service" + path == "" -> "/libvirt.service"

-                 * selfpath == "/libvirt.service" + path == "foo" -> "/libvirt.service/foo"

-                 */

-                if (i == VIR_CGROUP_CONTROLLER_SYSTEMD) {

-                    if (VIR_STRDUP(group->controllers[i].placement,

-                                   selfpath) < 0)

-                        goto cleanup;

-                } else {

-                    if (virAsprintf(&group->controllers[i].placement,

-                                    "%s%s%s", selfpath,

-                                    (STREQ(selfpath, "/") ||

-                                     STREQ(path, "") ? "" : "/"),

-                                    path) < 0)

-                        goto cleanup;

-                }

-            }

+        if (group->backend->detectPlacement(group, path, controllers,

+                                            selfpath) < 0) {

+            goto cleanup;

         }

     }

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

index 81ee597fc8..fadc7efdcf 100644

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

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

@@ -45,6 +45,18 @@ typedef int

 (*virCgroupCopyMountsCB)(virCgroupPtr group,

                          virCgroupPtr parent);

+typedef int

+(*virCgroupDetectMountsCB)(virCgroupPtr group,

+                           const char *mntType,

+                           const char *mntOpts,

+                           const char *mntDir);

+

+typedef int

+(*virCgroupDetectPlacementCB)(virCgroupPtr group,

+                              const char *path,

+                              const char *controllers,

+                              const char *selfpath);

+

 struct _virCgroupBackend {

     virCgroupBackendType type;

@@ -52,6 +64,8 @@ struct _virCgroupBackend {

     virCgroupAvailableCB available;

     virCgroupValidateMachineGroupCB validateMachineGroup;

     virCgroupCopyMountsCB copyMounts;

+    virCgroupDetectMountsCB detectMounts;

+    virCgroupDetectPlacementCB detectPlacement;

 };

 typedef struct _virCgroupBackend virCgroupBackend;

 typedef virCgroupBackend *virCgroupBackendPtr;

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

index 50b58ab413..bd9f28f6e9 100644

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

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

@@ -23,6 +23,7 @@

 #if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R

 # include <mntent.h>

 #endif

+#include <sys/stat.h>

 #include "internal.h"

@@ -38,6 +39,7 @@

 #include "virlog.h"

 #include "virstring.h"

 #include "virsystemd.h"

+#include "virerror.h"

 VIR_LOG_INIT("util.cgroup");

@@ -181,12 +183,168 @@ virCgroupV1CopyMounts(virCgroupPtr group,

 }

+static int

+virCgroupV1ResolveMountLink(const char *mntDir,

+                            const char *typeStr,

+                            virCgroupControllerPtr controller)

+{

+    VIR_AUTOFREE(char *) linkSrc = NULL;

+    VIR_AUTOFREE(char *) tmp = NULL;

+    char *dirName;

+    struct stat sb;

+

+    if (VIR_STRDUP(tmp, mntDir) < 0)

+        return -1;

+

+    dirName = strrchr(tmp, '/');

+    if (!dirName) {

+        virReportError(VIR_ERR_INTERNAL_ERROR,

+                       _("Missing '/' separator in cgroup mount '%s'"), tmp);

+        return -1;

+    }

+

+    if (!strchr(dirName + 1, ','))

+        return 0;

+

+    *dirName = '\0';

+    if (virAsprintf(&linkSrc, "%s/%s", tmp, typeStr) < 0)

+        return -1;

+    *dirName = '/';

+

+    if (lstat(linkSrc, &sb) < 0) {

+        if (errno == ENOENT) {

+            VIR_WARN("Controller %s co-mounted at %s is missing symlink at %s",

+                     typeStr, tmp, linkSrc);

+        } else {

+            virReportSystemError(errno, _("Cannot stat %s"), linkSrc);

+            return -1;

+        }

+    } else {

+        if (!S_ISLNK(sb.st_mode)) {

+            VIR_WARN("Expecting a symlink at %s for controller %s",

+                     linkSrc, typeStr);

+        } else {

+            VIR_STEAL_PTR(controller->linkPoint, linkSrc);

+        }

+    }

+

+    return 0;

+}

+

+

+static bool

+virCgroupV1MountOptsMatchController(const char *mntOpts,

+                                    const char *typeStr)

+{

+    const char *tmp = mntOpts;

+    int typeLen = strlen(typeStr);

+

+    while (tmp) {

+        const char *next = strchr(tmp, ',');

+        int len;

+        if (next) {

+            len = next - tmp;

+            next++;

+        } else {

+            len = strlen(tmp);

+        }

+

+        if (typeLen == len && STREQLEN(typeStr, tmp, len))

+            return true;

+

+        tmp = next;

+    }

+

+    return false;

+}

+

+

+static int

+virCgroupV1DetectMounts(virCgroupPtr group,

+                        const char *mntType,

+                        const char *mntOpts,

+                        const char *mntDir)

+{

+    size_t i;

+

+    if (STRNEQ(mntType, "cgroup"))

+        return 0;

+

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

+        const char *typestr = virCgroupV1ControllerTypeToString(i);

+

+        if (virCgroupV1MountOptsMatchController(mntOpts, typestr)) {

+            /* Note that the lines in /proc/mounts have the same

+             * order than the mount operations, and that there may

+             * be duplicates due to bind mounts. This means

+             * that the same mount point may be processed more than

+             * once. We need to save the results of the last one,

+             * and we need to be careful to release the memory used

+             * by previous processing. */

+            virCgroupControllerPtr controller = &group->controllers[i];

+

+            VIR_FREE(controller->mountPoint);

+            VIR_FREE(controller->linkPoint);

+            if (VIR_STRDUP(controller->mountPoint, mntDir) < 0)

+                return -1;

+

+            /* If it is a co-mount it has a filename like "cpu,cpuacct"

+             * and we must identify the symlink path */

+            if (virCgroupV1ResolveMountLink(mntDir, typestr, controller) < 0)

+                return -1;

+        }

+    }

+

+    return 0;

+}

+

+

+static int

+virCgroupV1DetectPlacement(virCgroupPtr group,

+                           const char *path,

+                           const char *controllers,

+                           const char *selfpath)

+{

+    size_t i;

+

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

+        const char *typestr = virCgroupV1ControllerTypeToString(i);

+

+        if (virCgroupV1MountOptsMatchController(controllers, typestr) &&

+            group->controllers[i].mountPoint != NULL &&

+            group->controllers[i].placement == NULL) {

+            /*

+             * selfpath == "/" + path="" -> "/"

+             * selfpath == "/libvirt.service" + path == "" -> "/libvirt.service"

+             * selfpath == "/libvirt.service" + path == "foo" -> "/libvirt.service/foo"

+             */

+            if (i == VIR_CGROUP_CONTROLLER_SYSTEMD) {

+                if (VIR_STRDUP(group->controllers[i].placement,

+                               selfpath) < 0)

+                    return -1;

+            } else {

+                if (virAsprintf(&group->controllers[i].placement,

+                                "%s%s%s", selfpath,

+                                (STREQ(selfpath, "/") ||

+                                 STREQ(path, "") ? "" : "/"),

+                                path) < 0)

+                    return -1;

+            }

+        }

+    }

+

+    return 0;

+}

+

+

 virCgroupBackend virCgroupV1Backend = {

     .type = VIR_CGROUP_BACKEND_TYPE_V1,

     .available = virCgroupV1Available,

     .validateMachineGroup = virCgroupV1ValidateMachineGroup,

     .copyMounts = virCgroupV1CopyMounts,

+    .detectMounts = virCgroupV1DetectMounts,

+    .detectPlacement = virCgroupV1DetectPlacement,

 };

-- 

2.22.0