Introduce the container object and its managemenent functions,
in particular the creation/deletion of containers and the
linkage between the container object and the task.
By default, if the task->container object is NULL, then the task belongs
to the default global container.
Signed-off-by: Hubertus Franke <[email protected]>
---
include/linux/container.h | 37 ++++++++++++
include/linux/sched.h | 10 +++
kernel/Makefile | 3
kernel/container.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 189 insertions(+), 1 deletion(-)
Index: linux-2.6.15/include/linux/container.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/include/linux/container.h 2006-01-17 08:37:08.000000000 -0500
@@ -0,0 +1,37 @@
+
+#ifndef _LINUX_CONTAINER_H
+#define _LINUX_CONTAINER_H
+
+/* number of containers will depend on many constraints, which will have to
+ * be integrated here as they become apparent
+ */
+
+
+#define MAX_NR_CONTAINERS MAX_NR_PIDSPACES
+
+#define MAX_CONTAINER_NAME_LEN 32
+
+struct container_struct {
+ spinlock_t lock;
+ char name[MAX_CONTAINER_NAME_LEN];
+ int pidspace_id;
+ struct task_struct *init_proc; /* root proc */
+ int init_pid; /* pid of root */
+ atomic_t tcount; /* thread count */
+
+ /* and all the other things that will be necessary to track
+ * for a container
+ */
+};
+
+/****************************************************************
+ * Container Management Functions
+ ****************************************************************/
+
+extern struct container_struct *container_find(const char *container_name);
+extern int container_new (const char *container_name);
+extern void container_attach (struct task_struct *task);
+extern void container_detach (struct task_struct *task);
+
+#endif
+
Index: linux-2.6.15/include/linux/sched.h
===================================================================
--- linux-2.6.15.orig/include/linux/sched.h 2006-01-17 08:37:07.000000000 -0500
+++ linux-2.6.15/include/linux/sched.h 2006-01-17 08:37:08.000000000 -0500
@@ -36,6 +36,7 @@
#include <linux/seccomp.h>
#include <linux/auxvec.h> /* For AT_VECTOR_SIZE */
+#include <linux/container.h>
struct exec_domain;
@@ -857,6 +858,7 @@
int cpuset_mems_generation;
#endif
atomic_t fs_excl; /* holding fs exclusive resources */
+ struct container_struct *container;
};
static inline pid_t process_group(const struct task_struct *tsk)
@@ -964,6 +966,14 @@
return process_group(p);
}
+static inline unsigned int task_pidspace_id(const struct task_struct *p)
+{
+ if (p->container)
+ return p->container->pidspace_id;
+ else
+ return DEFAULT_PIDSPACE;
+}
+
extern void free_task(struct task_struct *tsk);
extern void __put_task_struct(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
Index: linux-2.6.15/kernel/Makefile
===================================================================
--- linux-2.6.15.orig/kernel/Makefile 2006-01-17 08:17:29.000000000 -0500
+++ linux-2.6.15/kernel/Makefile 2006-01-17 08:37:08.000000000 -0500
@@ -7,7 +7,8 @@
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
- kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o
+ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o \
+ container.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
Index: linux-2.6.15/kernel/container.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/kernel/container.c 2006-01-17 08:37:08.000000000 -0500
@@ -0,0 +1,140 @@
+/*
+ * Management of Containers
+ *
+ * Copyright (C) Hubertus Franke, IBM Corp. 2005 <[email protected]>
+ *
+ */
+
+/* Changes
+ *
+ * 11/22/2005: Created
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <linux/proc_fs.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/container.h>
+
+#define DPRINTK( fmt, args... ) // printk( "%s: " fmt, __FUNCTION__, ##args )
+
+static struct container_struct *containers[MAX_NR_CONTAINERS];
+static DEFINE_SPINLOCK(container_lock);
+
+/****************************************************************
+ * Container Management
+ ****************************************************************/
+
+void container_attach(struct task_struct *task)
+{
+ struct container_struct *container = task->container;
+
+ if (!container)
+ return;
+ atomic_inc(&container->tcount);
+
+ DPRINTK("c=<%p:%s> atask=<%x:%x:%s>\n",
+ container, container->name,
+ task_pid(task), task_vpid(task), task->comm);
+}
+
+void container_detach(struct task_struct *task)
+{
+ struct container_struct *container = task->container;
+ unsigned long flags;
+ int empty;
+
+ if (!container)
+ return;
+
+ DPRINTK("c=<%p:%s> dtask=<%x:%x:%s>\n",
+ container, container->name,
+ task_pid(task), task_vpid(task), task->comm);
+
+ task->container = NULL;
+ if (unlikely(task == container->init_proc)) {
+ container->init_proc = NULL;
+ container->init_pid = 0;
+ memset(container->name, 0, MAX_CONTAINER_NAME_LEN);
+ }
+ empty = atomic_dec_and_test(&container->tcount);
+ if (!empty)
+ return;
+
+ /* we are the last process, so lets destroy the container */
+
+ DPRINTK("c=<%p:%s> destroy container exiting root proc\n",
+ container, container->name);
+
+ spin_lock_irqsave(&container_lock,flags);
+ containers[container->pidspace_id] = NULL;
+ pidspace_free(container->pidspace_id);
+
+ spin_lock(&container->lock);
+ /* ANYTHING UNDER THE LOCK */
+ spin_unlock(&container->lock);
+
+ spin_unlock_irqrestore(&container_lock,flags);
+
+ kfree(container);
+}
+
+/*
+ * create a new container and make the caller the virtual init_proc
+ * of the container
+ */
+
+int container_new(const char *container_name)
+{
+ struct container_struct *newc = NULL;
+ unsigned long flags;
+ int i;
+ int rc;
+
+ newc = kmalloc(sizeof(struct container_struct),GFP_KERNEL);
+ if (newc == NULL)
+ return -ENOMEM;
+ memset(newc,0,sizeof(struct container_struct));
+ strncpy(newc->name, container_name, MAX_CONTAINER_NAME_LEN-1);
+ newc->init_proc = current;
+ newc->init_pid = task_pid(current);
+ atomic_set(&newc->tcount,0);
+
+ spin_lock_irqsave(&container_lock,flags);
+ for ( i=1; i<MAX_NR_CONTAINERS; i++) {
+ struct container_struct *cptr = containers[i];
+
+ if (cptr == NULL)
+ break;
+ if (strncmp(container_name, cptr->name, MAX_CONTAINER_NAME_LEN) == 0) {
+ rc = -EEXIST;
+ goto out_unlock_free;
+ }
+ }
+ if ( i == MAX_NR_CONTAINERS ) {
+ rc = -ENOMEM;
+ goto out_unlock_free;
+ }
+
+ spin_lock_init(&newc->lock);
+ pidspace_init(i);
+ newc->pidspace_id = i;
+ containers[i] = newc;
+ DPRINTK("created container #%d: %s\n", newc->pidspace_id, newc->name);
+ current->container = newc;
+ container_attach(current);
+ rc = 0;
+ goto out_unlock;
+
+out_unlock_free:
+ kfree(newc);
+out_unlock:
+ spin_unlock_irqrestore(&container_lock,flags);
+ return rc;
+}
+
--
-
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