From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/include/linux/nsproxy.h | 85 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 kernel/include/linux/nsproxy.h (limited to 'kernel/include/linux/nsproxy.h') diff --git a/kernel/include/linux/nsproxy.h b/kernel/include/linux/nsproxy.h new file mode 100644 index 000000000..35fa08fd7 --- /dev/null +++ b/kernel/include/linux/nsproxy.h @@ -0,0 +1,85 @@ +#ifndef _LINUX_NSPROXY_H +#define _LINUX_NSPROXY_H + +#include +#include + +struct mnt_namespace; +struct uts_namespace; +struct ipc_namespace; +struct pid_namespace; +struct fs_struct; + +/* + * A structure to contain pointers to all per-process + * namespaces - fs (mount), uts, network, sysvipc, etc. + * + * The pid namespace is an exception -- it's accessed using + * task_active_pid_ns. The pid namespace here is the + * namespace that children will use. + * + * 'count' is the number of tasks holding a reference. + * The count for each namespace, then, will be the number + * of nsproxies pointing to it, not the number of tasks. + * + * The nsproxy is shared by tasks which share all namespaces. + * As soon as a single namespace is cloned or unshared, the + * nsproxy is copied. + */ +struct nsproxy { + atomic_t count; + struct uts_namespace *uts_ns; + struct ipc_namespace *ipc_ns; + struct mnt_namespace *mnt_ns; + struct pid_namespace *pid_ns_for_children; + struct net *net_ns; +}; +extern struct nsproxy init_nsproxy; + +/* + * the namespaces access rules are: + * + * 1. only current task is allowed to change tsk->nsproxy pointer or + * any pointer on the nsproxy itself. Current must hold the task_lock + * when changing tsk->nsproxy. + * + * 2. when accessing (i.e. reading) current task's namespaces - no + * precautions should be taken - just dereference the pointers + * + * 3. the access to other task namespaces is performed like this + * task_lock(task); + * nsproxy = task->nsproxy; + * if (nsproxy != NULL) { + * / * + * * work with the namespaces here + * * e.g. get the reference on one of them + * * / + * } / * + * * NULL task->nsproxy means that this task is + * * almost dead (zombie) + * * / + * task_unlock(task); + * + */ + +int copy_namespaces(unsigned long flags, struct task_struct *tsk); +void exit_task_namespaces(struct task_struct *tsk); +void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new); +void free_nsproxy(struct nsproxy *ns); +int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **, + struct cred *, struct fs_struct *); +int __init nsproxy_cache_init(void); + +static inline void put_nsproxy(struct nsproxy *ns) +{ + if (atomic_dec_and_test(&ns->count)) { + free_nsproxy(ns); + } +} + +static inline void get_nsproxy(struct nsproxy *ns) +{ + atomic_inc(&ns->count); +} + +#endif -- cgit 1.2.3-korg