pidns: Use task_active_pid_ns where appropriate

The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
aka ns_of_pid(task_pid(tsk)) should have the same number of
cache line misses with the practical difference that
ns_of_pid(task_pid(tsk)) is released later in a processes life.

Furthermore by using task_active_pid_ns it becomes trivial
to write an unshare implementation for the the pid namespace.

So I have used task_active_pid_ns everywhere I can.

In fork since the pid has not yet been attached to the
process I use ns_of_pid, to achieve the same effect.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2010-03-02 14:51:53 -08:00
parent 49f4d8b93c
commit 17cf22c33e
12 changed files with 16 additions and 15 deletions

View File

@ -1094,7 +1094,7 @@ static int show_spu_loadavg(struct seq_file *s, void *private)
LOAD_INT(c), LOAD_FRAC(c),
count_active_contexts(),
atomic_read(&nr_spu_contexts),
current->nsproxy->pid_ns->last_pid);
task_active_pid_ns(current)->last_pid);
return 0;
}

View File

@ -123,7 +123,7 @@ void mconsole_log(struct mc_request *req)
void mconsole_proc(struct mc_request *req)
{
struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt;
struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt;
char *buf;
int len;
struct file *file;

View File

@ -33,6 +33,7 @@
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include "binder.h"
@ -2344,7 +2345,7 @@ retry:
if (t->from) {
struct task_struct *sender = t->from->proc->tsk;
tr.sender_pid = task_tgid_nr_ns(sender,
current->nsproxy->pid_ns);
task_active_pid_ns(current));
} else {
tr.sender_pid = 0;
}

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@ -710,7 +710,7 @@ static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
struct vfsmount *proc_mnt;
int err = -ENOENT;
proc_mnt = mntget(current->nsproxy->pid_ns->proc_mnt);
proc_mnt = mntget(task_active_pid_ns(current)->proc_mnt);
if (IS_ERR(proc_mnt))
goto out;

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@ -106,7 +106,7 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
ns = (struct pid_namespace *)data;
options = NULL;
} else {
ns = current->nsproxy->pid_ns;
ns = task_active_pid_ns(current);
options = data;
}

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@ -3390,7 +3390,7 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
{
struct cgroup_pidlist *l;
/* don't need task_nsproxy() if we're looking at ourself */
struct pid_namespace *ns = current->nsproxy->pid_ns;
struct pid_namespace *ns = task_active_pid_ns(current);
/*
* We can't drop the pidlist_mutex before taking the l->mutex in case

View File

@ -6155,7 +6155,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
event->parent = parent_event;
event->ns = get_pid_ns(current->nsproxy->pid_ns);
event->ns = get_pid_ns(task_active_pid_ns(current));
event->id = atomic64_inc_return(&perf_event_id);
event->state = PERF_EVENT_STATE_INACTIVE;

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@ -1442,7 +1442,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (thread_group_leader(p)) {
if (is_child_reaper(pid))
p->nsproxy->pid_ns->child_reaper = p;
ns_of_pid(pid)->child_reaper = p;
p->signal->leader_pid = pid;
p->signal->tty = tty_kref_get(current->signal->tty);

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@ -84,7 +84,7 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
goto out_ipc;
}
new_nsp->pid_ns = copy_pid_ns(flags, task_cred_xxx(tsk, user_ns), task_active_pid_ns(tsk));
new_nsp->pid_ns = copy_pid_ns(flags, task_cred_xxx(tsk, user_ns), tsk->nsproxy->pid_ns);
if (IS_ERR(new_nsp->pid_ns)) {
err = PTR_ERR(new_nsp->pid_ns);
goto out_pid;

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@ -345,7 +345,7 @@ EXPORT_SYMBOL_GPL(find_pid_ns);
struct pid *find_vpid(int nr)
{
return find_pid_ns(nr, current->nsproxy->pid_ns);
return find_pid_ns(nr, task_active_pid_ns(current));
}
EXPORT_SYMBOL_GPL(find_vpid);
@ -429,7 +429,7 @@ struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
struct task_struct *find_task_by_vpid(pid_t vnr)
{
return find_task_by_pid_ns(vnr, current->nsproxy->pid_ns);
return find_task_by_pid_ns(vnr, task_active_pid_ns(current));
}
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
@ -484,7 +484,7 @@ EXPORT_SYMBOL_GPL(pid_nr_ns);
pid_t pid_vnr(struct pid *pid)
{
return pid_nr_ns(pid, current->nsproxy->pid_ns);
return pid_nr_ns(pid, task_active_pid_ns(current));
}
EXPORT_SYMBOL_GPL(pid_vnr);
@ -495,7 +495,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
rcu_read_lock();
if (!ns)
ns = current->nsproxy->pid_ns;
ns = task_active_pid_ns(current);
if (likely(pid_alive(task))) {
if (type != PIDTYPE_PID)
task = task->group_leader;

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@ -1752,7 +1752,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
* see comment in do_notify_parent() about the following 4 lines
*/
rcu_read_lock();
info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent));
info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
rcu_read_unlock();

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@ -1344,7 +1344,7 @@ static ssize_t binary_sysctl(const int *name, int nlen,
goto out_putname;
}
mnt = current->nsproxy->pid_ns->proc_mnt;
mnt = task_active_pid_ns(current)->proc_mnt;
file = file_open_root(mnt->mnt_root, mnt, pathname, flags);
result = PTR_ERR(file);
if (IS_ERR(file))