[PATCH] namespaces: add nsproxy

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.

[akpm@osdl.org: build fix]
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 1 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 89f666491d1f..c9e660ae47aa 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -27,6 +27,7 @@
 #include <linux/binfmts.h>
 #include <linux/mman.h>
 #include <linux/fs.h>
+#include <linux/nsproxy.h>
 #include <linux/capability.h>
 #include <linux/cpu.h>
 #include <linux/cpuset.h>
@@ -1116,8 +1117,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 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;
@@ -1262,6 +1265,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 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:
@@ -1606,6 +1611,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
         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);
 
@@ -1632,7 +1638,15 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
 
         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;
@@ -1668,8 +1682,10 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
                 }
 
                 task_unlock(current);
+                put_nsproxy(old_nsproxy);
         }
 
+bad_unshare_cleanup_semundo:
 bad_unshare_cleanup_fd:
         if (new_fd)
                 put_files_struct(new_fd);