[libvirt] [PATCH 06/10] qemu: cgroup: Add functions to set cgroup image stuff on individual imgs

[Peter Krempa]

Add functions that will allow to set all the required cgroup stuff on
individual images taking a virStorageSourcePtr. Also convert functions
designed to setup whole backing chain to take advantage of the chagne.
---
 src/qemu/qemu_cgroup.c | 92 +++++++++++++++++++++++++++++++-------------------
 src/qemu/qemu_cgroup.h |  5 +++
 2 files changed, 62 insertions(+), 35 deletions(-)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index a31558f..df46d61 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -49,27 +49,37 @@ static const char *const defaultDeviceACL[] = {
 #define DEVICE_PTY_MAJOR 136
 #define DEVICE_SND_MAJOR 116

-static int
-qemuSetupDiskPathAllow(virDomainDiskDefPtr disk,
-                       const char *path,
-                       size_t depth ATTRIBUTE_UNUSED,
-                       void *opaque)
+int
+qemuSetupImageCgroup(virDomainObjPtr vm,
+                     virStorageSourcePtr src,
+                     bool readonly)
 {
-    virDomainObjPtr vm = opaque;
     qemuDomainObjPrivatePtr priv = vm->privateData;
     int ret;

-    VIR_DEBUG("Process path %s for disk", path);
-    ret = virCgroupAllowDevicePath(priv->cgroup, path,
-                                   (disk->readonly ? VIR_CGROUP_DEVICE_READ
+    if (!virCgroupHasController(priv->cgroup,
+                                VIR_CGROUP_CONTROLLER_DEVICES))
+        return 0;
+
+    if (!src->path ||
+        virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_NETWORK) {
+        VIR_DEBUG("Not updating cgroups for disk path '%s', type: %s",
+                  NULLSTR(src->path), virStorageTypeToString(src->type));
+        return 0;
+    }
+
+    VIR_DEBUG("Process path %s for disk", src->path);
+
+    ret = virCgroupAllowDevicePath(priv->cgroup, src->path,
+                                   (readonly ? VIR_CGROUP_DEVICE_READ
                                     : VIR_CGROUP_DEVICE_RW));
-    virDomainAuditCgroupPath(vm, priv->cgroup, "allow", path,
-                             disk->readonly ? "r" : "rw", ret == 0);
+    virDomainAuditCgroupPath(vm, priv->cgroup, "allow", src->path,
+                             readonly ? "r" : "rw", ret == 0);

     /* Get this for root squash NFS */
     if (ret < 0 &&
         virLastErrorIsSystemErrno(EACCES)) {
-        VIR_DEBUG("Ignoring EACCES for %s", path);
+        VIR_DEBUG("Ignoring EACCES for %s", src->path);
         virResetLastError();
         ret = 0;
     }
@@ -81,38 +91,51 @@ int
 qemuSetupDiskCgroup(virDomainObjPtr vm,
                     virDomainDiskDefPtr disk)
 {
-    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virStorageSourcePtr next;

-    if (!virCgroupHasController(priv->cgroup,
-                                VIR_CGROUP_CONTROLLER_DEVICES))
-        return 0;
+    for (next = disk->src; next; next = next->backingStore) {
+        if (qemuSetupImageCgroup(vm, next, disk->readonly) < 0)
+            return -1;

-    return virDomainDiskDefForeachPath(disk, true, qemuSetupDiskPathAllow, vm);
+    }
+
+    return 0;
 }


-static int
-qemuTeardownDiskPathDeny(virDomainDiskDefPtr disk ATTRIBUTE_UNUSED,
-                         const char *path,
-                         size_t depth ATTRIBUTE_UNUSED,
-                         void *opaque)
+int
+qemuTeardownImageCgroup(virDomainObjPtr vm,
+                        virStorageSourcePtr src)
 {
-    virDomainObjPtr vm = opaque;
     qemuDomainObjPrivatePtr priv = vm->privateData;
     int ret;

-    VIR_DEBUG("Process path %s for disk", path);
-    ret = virCgroupDenyDevicePath(priv->cgroup, path,
+    if (!virCgroupHasController(priv->cgroup,
+                                VIR_CGROUP_CONTROLLER_DEVICES))
+        return 0;
+
+    if (!src->path ||
+        virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_NETWORK) {
+        VIR_DEBUG("Not updating cgroups for disk path '%s', type: %s",
+                  NULLSTR(src->path), virStorageTypeToString(src->type));
+        return 0;
+    }
+
+    VIR_DEBUG("Process path %s for disk", src->path);
+
+    ret = virCgroupDenyDevicePath(priv->cgroup, src->path,
                                   VIR_CGROUP_DEVICE_RWM);
-    virDomainAuditCgroupPath(vm, priv->cgroup, "deny", path, "rwm", ret == 0);
+    virDomainAuditCgroupPath(vm, priv->cgroup, "deny", src->path,
+                             "rwm", ret == 0);

     /* Get this for root squash NFS */
     if (ret < 0 &&
         virLastErrorIsSystemErrno(EACCES)) {
-        VIR_DEBUG("Ignoring EACCES for %s", path);
+        VIR_DEBUG("Ignoring EACCES for %s", src->path);
         virResetLastError();
         ret = 0;
     }
+
     return ret;
 }

@@ -121,18 +144,17 @@ int
 qemuTeardownDiskCgroup(virDomainObjPtr vm,
                        virDomainDiskDefPtr disk)
 {
-    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virStorageSourcePtr next;

-    if (!virCgroupHasController(priv->cgroup,
-                                VIR_CGROUP_CONTROLLER_DEVICES))
-        return 0;
+    for (next = disk->src; next; next = next->backingStore) {
+        if (qemuTeardownImageCgroup(vm, next) < 0)
+            return -1;
+    }

-    return virDomainDiskDefForeachPath(disk,
-                                       true,
-                                       qemuTeardownDiskPathDeny,
-                                       vm);
+    return 0;
 }

+
 static int
 qemuSetupChrSourceCgroup(virDomainDefPtr def ATTRIBUTE_UNUSED,
                          virDomainChrSourceDefPtr dev,
diff --git a/src/qemu/qemu_cgroup.h b/src/qemu/qemu_cgroup.h
index 14404d1..3ee081e 100644
--- a/src/qemu/qemu_cgroup.h
+++ b/src/qemu/qemu_cgroup.h
@@ -29,8 +29,13 @@
 # include "domain_conf.h"
 # include "qemu_conf.h"

+int qemuSetupImageCgroup(virDomainObjPtr vm,
+                         virStorageSourcePtr src,
+                         bool readonly);
 int qemuSetupDiskCgroup(virDomainObjPtr vm,
                         virDomainDiskDefPtr disk);
+int qemuTeardownImageCgroup(virDomainObjPtr vm,
+                            virStorageSourcePtr src);
 int qemuTeardownDiskCgroup(virDomainObjPtr vm,
                            virDomainDiskDefPtr disk);
 int qemuSetupHostdevCGroup(virDomainObjPtr vm,
-- 
1.9.3