[Devel] [PATCH 1/9] namespaces: add nsproxy

Serge E. Hallyn serue at us.ibm.com
Thu May 18 08:48:37 PDT 2006 

This patch adds a nsproxy structure to the task struct.  Later
patches will move the fs namespace pointer into this structure,
and introduce a new utsname namespace into the nsproxy.

The vserver and openvz functionality, then, would be implemented
in large part by virtualizing/isolating more and more resources
into namespaces, each contained in the nsproxy.

Signed-off-by: Serge Hallyn <serue at us.ibm.com>

---

 arch/alpha/kernel/init_task.c     |    2 +
 arch/arm/kernel/init_task.c       |    2 +
 arch/arm26/kernel/init_task.c     |    2 +
 arch/frv/kernel/init_task.c       |    2 +
 arch/h8300/kernel/init_task.c     |    2 +
 arch/i386/kernel/init_task.c      |    2 +
 arch/ia64/kernel/init_task.c      |    2 +
 arch/m32r/kernel/init_task.c      |    2 +
 arch/m68knommu/kernel/init_task.c |    2 +
 arch/mips/kernel/init_task.c      |    2 +
 arch/parisc/kernel/init_task.c    |    2 +
 arch/powerpc/kernel/init_task.c   |    2 +
 arch/s390/kernel/init_task.c      |    2 +
 arch/sh/kernel/init_task.c        |    2 +
 arch/sh64/kernel/init_task.c      |    2 +
 arch/sparc/kernel/init_task.c     |    2 +
 arch/sparc64/kernel/init_task.c   |    2 +
 arch/um/kernel/init_task.c        |    2 +
 arch/v850/kernel/init_task.c      |    2 +
 arch/x86_64/kernel/init_task.c    |    2 +
 include/linux/init_task.h         |    7 +++
 include/linux/nsproxy.h           |   45 +++++++++++++++++++++
 include/linux/sched.h             |    2 +
 kernel/Makefile                   |    2 -
 kernel/exit.c                     |    7 +++
 kernel/fork.c                     |   18 ++++++++-
 kernel/nsproxy.c                  |   78 +++++++++++++++++++++++++++++++++++++
 27 files changed, 197 insertions(+), 2 deletions(-)
 create mode 100644 include/linux/nsproxy.h
 create mode 100644 kernel/nsproxy.c

7c65cea6d1931f03867fad978f33072a4b0a4602
diff --git a/arch/alpha/kernel/init_task.c b/arch/alpha/kernel/init_task.c
index 835d09a..83d0902 100644
--- a/arch/alpha/kernel/init_task.c
+++ b/arch/alpha/kernel/init_task.c
@@ -5,6 +5,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 #include <asm/uaccess.h>
 
 
@@ -13,6 +14,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 struct task_struct init_task = INIT_TASK(init_task);
 
 EXPORT_SYMBOL(init_mm);
diff --git a/arch/arm/kernel/init_task.c b/arch/arm/kernel/init_task.c
index a00cca0..80f5eeb 100644
--- a/arch/arm/kernel/init_task.c
+++ b/arch/arm/kernel/init_task.c
@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -17,6 +18,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/arm26/kernel/init_task.c b/arch/arm26/kernel/init_task.c
index 4191565..678c7b5 100644
--- a/arch/arm26/kernel/init_task.c
+++ b/arch/arm26/kernel/init_task.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -20,6 +21,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/frv/kernel/init_task.c b/arch/frv/kernel/init_task.c
index 2299393..5ec2742 100644
--- a/arch/frv/kernel/init_task.c
+++ b/arch/frv/kernel/init_task.c
@@ -5,6 +5,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -15,6 +16,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/h8300/kernel/init_task.c b/arch/h8300/kernel/init_task.c
index 19272c2..ef5755a 100644
--- a/arch/h8300/kernel/init_task.c
+++ b/arch/h8300/kernel/init_task.c
@@ -8,6 +8,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -17,6 +18,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/i386/kernel/init_task.c b/arch/i386/kernel/init_task.c
index cff95d1..bd97f69 100644
--- a/arch/i386/kernel/init_task.c
+++ b/arch/i386/kernel/init_task.c
@@ -5,6 +5,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -15,6 +16,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/ia64/kernel/init_task.c b/arch/ia64/kernel/init_task.c
index b69c397..2d62471 100644
--- a/arch/ia64/kernel/init_task.c
+++ b/arch/ia64/kernel/init_task.c
@@ -12,6 +12,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -21,6 +22,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/m32r/kernel/init_task.c b/arch/m32r/kernel/init_task.c
index 9e508fd..0057475 100644
--- a/arch/m32r/kernel/init_task.c
+++ b/arch/m32r/kernel/init_task.c
@@ -7,6 +7,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -16,6 +17,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/m68knommu/kernel/init_task.c b/arch/m68knommu/kernel/init_task.c
index 3897043..b99fc6d 100644
--- a/arch/m68knommu/kernel/init_task.c
+++ b/arch/m68knommu/kernel/init_task.c
@@ -8,6 +8,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -17,6 +18,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/mips/kernel/init_task.c b/arch/mips/kernel/init_task.c
index aeda7f5..dfe47e6 100644
--- a/arch/mips/kernel/init_task.c
+++ b/arch/mips/kernel/init_task.c
@@ -4,6 +4,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/thread_info.h>
 #include <asm/uaccess.h>
@@ -14,6 +15,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/parisc/kernel/init_task.c b/arch/parisc/kernel/init_task.c
index 8384bf9..c0c43e2 100644
--- a/arch/parisc/kernel/init_task.c
+++ b/arch/parisc/kernel/init_task.c
@@ -28,6 +28,7 @@
 #include <linux/init.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -38,6 +39,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/powerpc/kernel/init_task.c b/arch/powerpc/kernel/init_task.c
index 941043a..e24ace6 100644
--- a/arch/powerpc/kernel/init_task.c
+++ b/arch/powerpc/kernel/init_task.c
@@ -5,6 +5,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 #include <asm/uaccess.h>
 
 static struct fs_struct init_fs = INIT_FS;
@@ -12,6 +13,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/s390/kernel/init_task.c b/arch/s390/kernel/init_task.c
index d73a740..0918921 100644
--- a/arch/s390/kernel/init_task.c
+++ b/arch/s390/kernel/init_task.c
@@ -11,6 +11,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -20,6 +21,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/sh/kernel/init_task.c b/arch/sh/kernel/init_task.c
index 44053ea..81caf0f 100644
--- a/arch/sh/kernel/init_task.c
+++ b/arch/sh/kernel/init_task.c
@@ -3,6 +3,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -12,6 +13,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/sh64/kernel/init_task.c b/arch/sh64/kernel/init_task.c
index de2d07d..0c95f40 100644
--- a/arch/sh64/kernel/init_task.c
+++ b/arch/sh64/kernel/init_task.c
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -23,6 +24,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 struct pt_regs fake_swapper_regs;
 
diff --git a/arch/sparc/kernel/init_task.c b/arch/sparc/kernel/init_task.c
index fc31de6..a73926d 100644
--- a/arch/sparc/kernel/init_task.c
+++ b/arch/sparc/kernel/init_task.c
@@ -3,6 +3,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -12,6 +13,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 struct task_struct init_task = INIT_TASK(init_task);
 
 EXPORT_SYMBOL(init_mm);
diff --git a/arch/sparc64/kernel/init_task.c b/arch/sparc64/kernel/init_task.c
index 329b38f..f1e9a4b 100644
--- a/arch/sparc64/kernel/init_task.c
+++ b/arch/sparc64/kernel/init_task.c
@@ -3,6 +3,7 @@
 #include <linux/sched.h>
 #include <linux/init_task.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -13,6 +14,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/um/kernel/init_task.c b/arch/um/kernel/init_task.c
index 49ed5dd..11188af 100644
--- a/arch/um/kernel/init_task.c
+++ b/arch/um/kernel/init_task.c
@@ -9,6 +9,7 @@
 #include "linux/sched.h"
 #include "linux/init_task.h"
 #include "linux/mqueue.h"
+#include "linux/nsproxy.h"
 #include "asm/uaccess.h"
 #include "asm/pgtable.h"
 #include "user_util.h"
@@ -17,6 +18,7 @@
 
 static struct fs_struct init_fs = INIT_FS;
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 static struct files_struct init_files = INIT_FILES;
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
diff --git a/arch/v850/kernel/init_task.c b/arch/v850/kernel/init_task.c
index ed2f93c..9d2de75 100644
--- a/arch/v850/kernel/init_task.c
+++ b/arch/v850/kernel/init_task.c
@@ -16,6 +16,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -25,6 +26,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS (init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM (init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/arch/x86_64/kernel/init_task.c b/arch/x86_64/kernel/init_task.c
index ce31d90..1c87ea0 100644
--- a/arch/x86_64/kernel/init_task.c
+++ b/arch/x86_64/kernel/init_task.c
@@ -5,6 +5,7 @@
 #include <linux/init_task.h>
 #include <linux/fs.h>
 #include <linux/mqueue.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -15,6 +16,7 @@ static struct files_struct init_files = 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct mm_struct init_mm = INIT_MM(init_mm);
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 EXPORT_SYMBOL(init_mm);
 
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 41ecbb8..79ec4ea 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -66,6 +66,12 @@
 	.session	= 1,						\
 }
 
+extern struct nsproxy init_nsproxy;
+#define INIT_NSPROXY(nsproxy) {						\
+	.count		= ATOMIC_INIT(1),				\
+	.nslock		= SPIN_LOCK_UNLOCKED,				\
+}
+
 #define INIT_SIGHAND(sighand) {						\
 	.count		= ATOMIC_INIT(1), 				\
 	.action		= { { { .sa_handler = NULL, } }, },		\
@@ -114,6 +120,7 @@ extern struct group_info init_groups;
 	.files		= &init_files,					\
 	.signal		= &init_signals,				\
 	.sighand	= &init_sighand,				\
+	.nsproxy	= &init_nsproxy,				\
 	.pending	= {						\
 		.list = LIST_HEAD_INIT(tsk.pending.list),		\
 		.signal = {{0}}},					\
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
new file mode 100644
index 0000000..7bdebfa
--- /dev/null
+++ b/include/linux/nsproxy.h
@@ -0,0 +1,45 @@
+#ifndef _LINUX_NSPROXY_H
+#define _LINUX_NSPROXY_H
+
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+
+/*
+ * A structure to contain pointers to all per-process
+ * namespaces - fs (mount), uts, network, sysvipc, etc.
+ *
+ * '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;
+	spinlock_t nslock;
+};
+extern struct nsproxy init_nsproxy;
+
+struct nsproxy *dup_namespaces(struct nsproxy *orig);
+int copy_namespaces(int flags, struct task_struct *tsk);
+void get_task_namespaces(struct task_struct *tsk);
+void free_nsproxy(struct nsproxy *ns);
+
+static inline void put_nsproxy(struct nsproxy *ns)
+{
+	if (atomic_dec_and_test(&ns->count)) {
+		free_nsproxy(ns);
+	}
+}
+
+static inline void exit_task_namespaces(struct task_struct *p)
+{
+	struct nsproxy *ns = p->nsproxy;
+	if (ns) {
+		put_nsproxy(ns);
+		p->nsproxy = NULL;
+	}
+}
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 29b7d4f..4c0bbb3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -236,6 +236,7 @@ extern signed long schedule_timeout_unin
 asmlinkage void schedule(void);
 
 struct namespace;
+struct nsproxy;
 
 /* Maximum number of active map areas.. This is a random (large) number */
 #define DEFAULT_MAX_MAP_COUNT	65536
@@ -808,6 +809,7 @@ struct task_struct {
 	struct files_struct *files;
 /* namespace */
 	struct namespace *namespace;
+	struct nsproxy *nsproxy;
 /* signal handlers */
 	struct signal_struct *signal;
 	struct sighand_struct *sighand;
diff --git a/kernel/Makefile b/kernel/Makefile
index 58908f9..215fb33 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -8,7 +8,7 @@ obj-y     = sched.o fork.o exec_domain.o
 	    signal.o sys.o kmod.o workqueue.o pid.o \
 	    rcupdate.o extable.o params.o posix-timers.o \
 	    kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
-	    hrtimer.o
+	    hrtimer.o nsproxy.o
 
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
 obj-$(CONFIG_FUTEX) += futex.o
diff --git a/kernel/exit.c b/kernel/exit.c
index e95b932..da2fc84 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -36,6 +36,7 @@
 #include <linux/compat.h>
 #include <linux/pipe_fs_i.h>
 #include <linux/audit.h> /* for audit_free() */
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -413,9 +414,14 @@ void daemonize(const char *name, ...)
 	fs = init_task.fs;
 	current->fs = fs;
 	atomic_inc(&fs->count);
+
 	exit_namespace(current);
+	exit_task_namespaces(current);
 	current->namespace = init_task.namespace;
+	current->nsproxy = init_task.nsproxy;
 	get_namespace(current->namespace);
+	get_task_namespaces(current);
+
  	exit_files(current);
 	current->files = init_task.files;
 	atomic_inc(&current->files->count);
@@ -919,6 +925,7 @@ fastcall NORET_TYPE void do_exit(long co
 	__exit_files(tsk);
 	__exit_fs(tsk);
 	exit_namespace(tsk);
+	exit_task_namespaces(tsk);
 	exit_thread();
 	cpuset_exit(tsk);
 	exit_keys(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index ac8100e..60303c3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -44,6 +44,7 @@
 #include <linux/rmap.h>
 #include <linux/acct.h>
 #include <linux/cn_proc.h>
+#include <linux/nsproxy.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -1060,8 +1061,10 @@ static task_t *copy_process(unsigned lon
 		goto bad_fork_cleanup_signal;
 	if ((retval = copy_keys(clone_flags, p)))
 		goto bad_fork_cleanup_mm;
-	if ((retval = copy_namespace(clone_flags, p)))
+	if ((retval = copy_namespaces(clone_flags, p)))
 		goto bad_fork_cleanup_keys;
+	if ((retval = copy_namespace(clone_flags, p)))
+		goto bad_fork_cleanup_namespaces;
 	retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
 	if (retval)
 		goto bad_fork_cleanup_namespace;
@@ -1218,6 +1221,8 @@ static task_t *copy_process(unsigned lon
 
 bad_fork_cleanup_namespace:
 	exit_namespace(p);
+bad_fork_cleanup_namespaces:
+	exit_task_namespaces(p);
 bad_fork_cleanup_keys:
 	exit_keys(p);
 bad_fork_cleanup_mm:
@@ -1559,6 +1564,7 @@ asmlinkage long sys_unshare(unsigned lon
 	struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
 	struct files_struct *fd, *new_fd = NULL;
 	struct sem_undo_list *new_ulist = NULL;
+	struct nsproxy *new_nsproxy, *old_nsproxy;
 
 	check_unshare_flags(&unshare_flags);
 
@@ -1585,7 +1591,15 @@ asmlinkage long sys_unshare(unsigned lon
 
 	if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist) {
 
+		old_nsproxy = current->nsproxy;
+		new_nsproxy = dup_namespaces(old_nsproxy);
+		if (!new_nsproxy) {
+			err = -ENOMEM;
+			goto bad_unshare_cleanup_semundo;
+		}
+
 		task_lock(current);
+		current->nsproxy = new_nsproxy;
 
 		if (new_fs) {
 			fs = current->fs;
@@ -1621,8 +1635,10 @@ asmlinkage long sys_unshare(unsigned lon
 		}
 
 		task_unlock(current);
+		put_nsproxy(old_nsproxy);
 	}
 
+bad_unshare_cleanup_semundo:
 bad_unshare_cleanup_fd:
 	if (new_fd)
 		put_files_struct(new_fd);
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
new file mode 100644
index 0000000..6f53df1
--- /dev/null
+++ b/kernel/nsproxy.c
@@ -0,0 +1,78 @@
+/*
+ *  Copyright (C) 2006 IBM Corporation
+ * 
+ *  Author: Serge Hallyn <serue at us.ibm.com> 
+ * 
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License as
+ *  published by the Free Software Foundation, version 2 of the
+ *  License.
+ */    
+
+#include <linux/compile.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/nsproxy.h>
+
+static inline void get_nsproxy(struct nsproxy *ns)
+{
+	atomic_inc(&ns->count);
+}
+
+void get_task_namespaces(struct task_struct *tsk)
+{
+	struct nsproxy *ns = tsk->nsproxy;
+	if (ns) {
+		get_nsproxy(ns);
+	}
+}
+
+/*
+ * creates a copy of "orig" with refcount 1.
+ * This does not grab references to the contained namespaces,
+ * so that needs to be done by dup_namespaces.
+ */
+static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
+{
+	struct nsproxy *ns;
+
+	ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL);
+	if (ns) {
+		memcpy(ns, orig, sizeof(struct nsproxy));
+		atomic_set(&ns->count, 1);
+	}
+	return ns;
+}
+
+/*
+ * copies the nsproxy, setting refcount to 1, and grabbing a
+ * reference to all contained namespaces.  Called from
+ * sys_unshare()
+ */
+struct nsproxy *dup_namespaces(struct nsproxy *orig)
+{
+	struct nsproxy *ns = clone_namespaces(orig);
+
+	return ns;
+}
+
+/*
+ * called from clone.  This now handles copy for nsproxy and all
+ * namespaces therein.
+ */
+int copy_namespaces(int flags, struct task_struct *tsk)
+{
+	struct nsproxy *old_ns = tsk->nsproxy;
+
+	if (!old_ns)
+		return 0;
+
+	get_nsproxy(old_ns);
+
+	return 0;
+}
+
+void free_nsproxy(struct nsproxy *ns)
+{
+		kfree(ns);
+}
-- 
1.1.6

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