Merge sys_clone()/sys_unshare() nsproxy and namespace handling
sys_clone() and sys_unshare() both makes copies of nsproxy and its associated
namespaces. But they have different code paths.
This patch merges all the nsproxy and its associated namespace copy/clone
handling (as much as possible). Posted on container list earlier for
feedback.
- Create a new nsproxy and its associated namespaces and pass it back to
caller to attach it to right process.
- Changed all copy_*_ns() routines to return a new copy of namespace
instead of attaching it to task->nsproxy.
- Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines.
- Removed unnessary !ns checks from copy_*_ns() and added BUG_ON()
just incase.
- Get rid of all individual unshare_*_ns() routines and make use of
copy_*_ns() instead.
[akpm@osdl.org: cleanups, warning fix]
[clg@fr.ibm.com: remove dup_namespaces() declaration]
[serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval]
[akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/namespace.c b/fs/namespace.c
index fd999ca..be5e56b 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1441,10 +1441,9 @@
* Allocate a new namespace structure and populate it with contents
* copied from the namespace of the passed in task structure.
*/
-struct mnt_namespace *dup_mnt_ns(struct task_struct *tsk,
+static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
struct fs_struct *fs)
{
- struct mnt_namespace *mnt_ns = tsk->nsproxy->mnt_ns;
struct mnt_namespace *new_ns;
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL;
struct vfsmount *p, *q;
@@ -1509,36 +1508,21 @@
return new_ns;
}
-int copy_mnt_ns(int flags, struct task_struct *tsk)
+struct mnt_namespace *copy_mnt_ns(int flags, struct mnt_namespace *ns,
+ struct fs_struct *new_fs)
{
- struct mnt_namespace *ns = tsk->nsproxy->mnt_ns;
struct mnt_namespace *new_ns;
- int err = 0;
- if (!ns)
- return 0;
-
+ BUG_ON(!ns);
get_mnt_ns(ns);
if (!(flags & CLONE_NEWNS))
- return 0;
+ return ns;
- if (!capable(CAP_SYS_ADMIN)) {
- err = -EPERM;
- goto out;
- }
+ new_ns = dup_mnt_ns(ns, new_fs);
- new_ns = dup_mnt_ns(tsk, tsk->fs);
- if (!new_ns) {
- err = -ENOMEM;
- goto out;
- }
-
- tsk->nsproxy->mnt_ns = new_ns;
-
-out:
put_mnt_ns(ns);
- return err;
+ return new_ns;
}
asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name,