[libvirt] [PATCHv3 13/26] qemu: cgroup: Setup only the top level disk image for read-write access
Only the top level gets writes, so the rest of the backing chain
requires only read-only access.
---
src/qemu/qemu_cgroup.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 1deafb7..97229c4 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -49,10 +49,11 @@ static const char *const defaultDeviceACL[] = {
#define DEVICE_PTY_MAJOR 136
#define DEVICE_SND_MAJOR 116
-int
-qemuSetImageCgroup(virDomainObjPtr vm,
- virStorageSourcePtr src,
- bool deny)
+static int
+qemuSetImageCgroupInternal(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ bool deny,
+ bool forceReadonly)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
int perms = VIR_CGROUP_DEVICE_READ;
@@ -76,7 +77,7 @@ qemuSetImageCgroup(virDomainObjPtr vm,
ret = virCgroupDenyDevicePath(priv->cgroup, src->path, perms);
} else {
- if (!src->readonly)
+ if (!src->readonly && !forceReadonly)
perms |= VIR_CGROUP_DEVICE_WRITE;
VIR_DEBUG("Allow path %s, perms: %s",
@@ -104,14 +105,27 @@ qemuSetImageCgroup(virDomainObjPtr vm,
int
+qemuSetImageCgroup(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ bool deny)
+{
+ return qemuSetImageCgroupInternal(vm, src, deny, false);
+}
+
+
+int
qemuSetupDiskCgroup(virDomainObjPtr vm,
virDomainDiskDefPtr disk)
{
virStorageSourcePtr next;
+ bool forceReadonly = false;
for (next = disk->src; next; next = next->backingStore) {
- if (qemuSetImageCgroup(vm, next, false) < 0)
+ if (qemuSetImageCgroupInternal(vm, next, false, forceReadonly) < 0)
return -1;
+
+ /* setup only the top level image for read-write */
+ forceReadonly = true;
}
return 0;
--
1.9.3