e3222c4ecc
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>
42 lines
818 B
C
42 lines
818 B
C
#ifndef _NAMESPACE_H_
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#define _NAMESPACE_H_
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#ifdef __KERNEL__
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#include <linux/mount.h>
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#include <linux/sched.h>
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#include <linux/nsproxy.h>
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struct mnt_namespace {
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atomic_t count;
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struct vfsmount * root;
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struct list_head list;
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wait_queue_head_t poll;
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int event;
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};
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extern struct mnt_namespace *copy_mnt_ns(int, struct mnt_namespace *,
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struct fs_struct *);
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extern void __put_mnt_ns(struct mnt_namespace *ns);
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static inline void put_mnt_ns(struct mnt_namespace *ns)
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{
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if (atomic_dec_and_lock(&ns->count, &vfsmount_lock))
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/* releases vfsmount_lock */
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__put_mnt_ns(ns);
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}
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static inline void exit_mnt_ns(struct task_struct *p)
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{
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struct mnt_namespace *ns = p->nsproxy->mnt_ns;
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if (ns)
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put_mnt_ns(ns);
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}
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static inline void get_mnt_ns(struct mnt_namespace *ns)
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{
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atomic_inc(&ns->count);
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}
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#endif
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#endif
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