Changes: Replace ns_common in args to ns pointer and ns_ops, as we don't have the former.
https://jira.sw.ru/browse/PSBM-57362 ms commit a7306ed8d94a ("nsfs: add ioctl to get a parent namespace") Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships. In a future we will use this interface to dump and restore nested namespaces. Acked-by: Serge Hallyn <se...@hallyn.com> Signed-off-by: Andrei Vagin <ava...@openvz.org> Signed-off-by: Eric W. Biederman <ebied...@xmission.com> Signed-off-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com> --- fs/proc/namespaces.c | 6 ++++++ include/linux/proc_ns.h | 1 + kernel/pid_namespace.c | 20 ++++++++++++++++++++ kernel/user_namespace.c | 1 + 4 files changed, 28 insertions(+) diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 121b76d3fcd0..626d943b23f8 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -19,6 +19,8 @@ /* Returns a file descriptor that refers to an owning user namespace */ #define NS_GET_USERNS _IO(NSIO, 0x1) +/* Returns a file descriptor that refers to a parent namespace */ +#define NS_GET_PARENT _IO(NSIO, 0x2) static const struct proc_ns_operations *ns_entries[] = { #ifdef CONFIG_NET_NS @@ -175,6 +177,10 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, switch (ioctl) { case NS_GET_USERNS: return open_related_ns(mnt, ns, &userns_operations, ns_get_owner); + case NS_GET_PARENT: + if (!ns->ns_ops->get_parent) + return -EINVAL; + return open_related_ns(mnt, ns, ns->ns_ops, ns->ns_ops->get_parent); default: return -ENOTTY; } diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 3f71f8e1aa18..af898ed6fbad 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -17,6 +17,7 @@ struct proc_ns_operations { int (*install)(struct nsproxy *nsproxy, void *ns); unsigned int (*inum)(void *ns); struct user_namespace *(*owner)(void *ns); + void *(*get_parent)(void *ns, const struct proc_ns_operations *ns_ops); }; struct proc_ns { diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 1bab842a8e1e..38e2c2da1417 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -426,6 +426,24 @@ static struct user_namespace *pidns_owner(void *ns) return pid_ns->user_ns; } +static void *pidns_get_parent(void *ns, const struct proc_ns_operations *ns_ops) +{ + struct pid_namespace *active = task_active_pid_ns(current); + struct pid_namespace *pid_ns, *p; + + /* See if the parent is in the current namespace */ + pid_ns = p = ((struct pid_namespace *)ns)->parent; + for (;;) { + if (!p) + return ERR_PTR(-EPERM); + if (p == active) + break; + p = p->parent; + } + + return get_pid_ns(pid_ns); +} + const struct proc_ns_operations pidns_operations = { .name = "pid", .type = CLONE_NEWPID, @@ -434,6 +452,7 @@ const struct proc_ns_operations pidns_operations = { .install = pidns_install, .inum = pidns_inum, .owner = pidns_owner, + .get_parent = pidns_get_parent, }; const struct proc_ns_operations pidns_for_children_operations = { @@ -445,6 +464,7 @@ const struct proc_ns_operations pidns_for_children_operations = { .install = pidns_install, .inum = pidns_inum, .owner = pidns_owner, + .get_parent = pidns_get_parent, }; static __init int pid_namespaces_init(void) diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 9b145831e07c..87719ed7dc19 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -1096,6 +1096,7 @@ const struct proc_ns_operations userns_operations = { .install = userns_install, .inum = userns_inum, .owner = userns_owner, + .get_parent = ns_get_owner, }; static __init int user_namespaces_init(void) -- 2.13.6 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
