On 05/23/2013 12:06 AM, Gao feng wrote:
User namespace will be enabled only when the idmap exist in configuration.
If you want disable user namespace,just remove these elements from XML.
If kernel doesn't support user namespace and idmap exist in configuration file, libvirt lxc will start failed and return "Kernel doesn't support user namespace" message.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> --- src/lxc/lxc_container.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index c74e3ca..618252c 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -2029,14 +2029,12 @@ cleanup:
static int userns_supported(void) { -#if 1 - /* - * put off using userns until uid mapping is implemented - */ - return 0; -#else return lxcContainerAvailable(LXC_CONTAINER_FEATURE_USER) == 0; -#endif +} + +static int userns_required(virDomainDefPtr def) +{ + return def->idmap.uidmap && def->idmap.gidmap; }
virArch lxcContainerGetAlt32bitArch(virArch arch) @@ -2116,9 +2114,15 @@ int lxcContainerStart(virDomainDefPtr def,
cflags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|SIGCHLD;
- if (userns_supported()) { - VIR_DEBUG("Enable user namespaces"); - cflags |= CLONE_NEWUSER; + if (userns_required(def)) { + if (userns_supported()) { + VIR_DEBUG("Enable user namespace"); + cflags |= CLONE_NEWUSER; + } else { + virReportSystemError(VIR_ERR_NO_KERNEL, "%s", + _("Kernel doesn't support user namespace")); + return -1; + }
Since this was pushed yesterday, my overnight Coverity run picked up a problem (resource leak because stack is not VIR_FREE()'d): 2118 /* allocate a stack for the container */ (1) Event alloc_arg: "virAllocN(void *, size_t, size_t)" allocates memory that is stored into "stack". [details] (2) Event cond_false: Condition "virAllocN(&stack, 1UL /* sizeof (*stack) */, stacksize) < 0", taking false branch Also see events: [var_assign][leaked_storage][leaked_storage] 2119 if (VIR_ALLOC_N(stack, stacksize) < 0) { 2120 virReportOOMError(); 2121 return -1; (3) Event if_end: End of if statement 2122 } (4) Event var_assign: Assigning: "stacktop" = "stack". Also see events: [alloc_arg][leaked_storage][leaked_storage] 2123 stacktop = stack + stacksize; 2124 2125 cflags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|SIGCHLD; 2126 (5) Event cond_true: Condition "userns_required(def)", taking true branch 2127 if (userns_required(def)) { (6) Event cond_false: Condition "userns_supported()", taking false branch 2128 if (userns_supported()) { 2129 VIR_DEBUG("Enable user namespace"); 2130 cflags |= CLONE_NEWUSER; (7) Event else_branch: Reached else branch 2131 } else { 2132 virReportSystemError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", 2133 _("Kernel doesn't support user namespace")); (8) Event leaked_storage: Variable "stacktop" going out of scope leaks the storage it points to. (9) Event leaked_storage: Variable "stack" going out of scope leaks the storage it points to. Also see events: [alloc_arg][var_assign] 2134 return -1; John
}
if (lxcNeedNetworkNamespace(def)) {