[PATCH] identifier to nsproxy

Add an identifier to nsproxy.  The default init_ns_proxy has identifier 0 and
allocated nsproxies are given -1.

This identifier will be used by a new syscall sys_bind_ns.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 5c4989172f7e..90c5f9a07730 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -75,6 +75,7 @@ extern struct nsproxy init_nsproxy;
 #define INIT_NSPROXY(nsproxy) {                                         \
         .count          = ATOMIC_INIT(1),                               \
         .nslock         = __SPIN_LOCK_UNLOCKED(nsproxy.nslock),         \
+        .id             = 0,                                            \
         .uts_ns         = &init_uts_ns,                                 \
         .mnt_ns         = NULL,                                         \
         INIT_IPC_NS(ipc_ns)                                             \
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 0aba1b1a39c7..27f37c1ec1d9 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -23,6 +23,7 @@ struct ipc_namespace;
 struct nsproxy {
         atomic_t count;
         spinlock_t nslock;
+        unsigned long id;
         struct uts_namespace *uts_ns;
         struct ipc_namespace *ipc_ns;
         struct mnt_namespace *mnt_ns;
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index bd9cb435dfe0..f223c15c18e9 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -45,8 +45,10 @@ static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
         struct nsproxy *ns;
 
         ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
-        if (ns)
+        if (ns) {
                 atomic_set(&ns->count, 1);
+                ns->id = -1;
+        }
         return ns;
 }