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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>
58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
#ifndef _LINUX_NSPROXY_H
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#define _LINUX_NSPROXY_H
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#include <linux/spinlock.h>
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#include <linux/sched.h>
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struct mnt_namespace;
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struct uts_namespace;
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struct ipc_namespace;
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struct pid_namespace;
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/*
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* A structure to contain pointers to all per-process
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* namespaces - fs (mount), uts, network, sysvipc, etc.
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*
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* 'count' is the number of tasks holding a reference.
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* The count for each namespace, then, will be the number
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* of nsproxies pointing to it, not the number of tasks.
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*
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* The nsproxy is shared by tasks which share all namespaces.
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* As soon as a single namespace is cloned or unshared, the
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* nsproxy is copied.
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*/
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struct nsproxy {
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atomic_t count;
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spinlock_t nslock;
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struct uts_namespace *uts_ns;
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struct ipc_namespace *ipc_ns;
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struct mnt_namespace *mnt_ns;
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struct pid_namespace *pid_ns;
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};
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extern struct nsproxy init_nsproxy;
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int copy_namespaces(int flags, struct task_struct *tsk);
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void get_task_namespaces(struct task_struct *tsk);
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void free_nsproxy(struct nsproxy *ns);
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int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **,
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struct fs_struct *);
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static inline void put_nsproxy(struct nsproxy *ns)
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{
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if (atomic_dec_and_test(&ns->count)) {
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free_nsproxy(ns);
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}
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}
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static inline void exit_task_namespaces(struct task_struct *p)
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{
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struct nsproxy *ns = p->nsproxy;
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if (ns) {
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task_lock(p);
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p->nsproxy = NULL;
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task_unlock(p);
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put_nsproxy(ns);
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}
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}
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#endif
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