pidns: call pid_ns_prepare_proc() from create_pid_namespace()

Reorganize proc_get_sb() so it can be called before the struct pid of the
first process is allocated.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric W. Biederman 2011-03-23 16:43:13 -07:00 committed by Linus Torvalds
parent 45a68628d3
commit 4308eebbeb
3 changed files with 16 additions and 26 deletions

View File

@ -43,17 +43,6 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
struct pid_namespace *ns;
struct proc_inode *ei;
if (proc_mnt) {
/* Seed the root directory with a pid so it doesn't need
* to be special in base.c. I would do this earlier but
* the only task alive when /proc is mounted the first time
* is the init_task and it doesn't have any pids.
*/
ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
if (!ei->pid)
ei->pid = find_get_pid(1);
}
if (flags & MS_KERNMOUNT)
ns = (struct pid_namespace *)data;
else
@ -71,16 +60,16 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
return ERR_PTR(err);
}
ei = PROC_I(sb->s_root->d_inode);
if (!ei->pid) {
rcu_read_lock();
ei->pid = get_pid(find_pid_ns(1, ns));
rcu_read_unlock();
}
sb->s_flags |= MS_ACTIVE;
}
ei = PROC_I(sb->s_root->d_inode);
if (!ei->pid) {
rcu_read_lock();
ei->pid = get_pid(find_pid_ns(1, ns));
rcu_read_unlock();
}
return dget(sb->s_root);
}

View File

@ -1187,12 +1187,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
pid = alloc_pid(p->nsproxy->pid_ns);
if (!pid)
goto bad_fork_cleanup_io;
if (clone_flags & CLONE_NEWPID) {
retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
if (retval < 0)
goto bad_fork_free_pid;
}
}
p->pid = pid_nr(pid);

View File

@ -14,6 +14,7 @@
#include <linux/err.h>
#include <linux/acct.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#define BITS_PER_PAGE (PAGE_SIZE*8)
@ -72,7 +73,7 @@ static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_p
{
struct pid_namespace *ns;
unsigned int level = parent_pid_ns->level + 1;
int i;
int i, err = -ENOMEM;
ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL);
if (ns == NULL)
@ -96,14 +97,20 @@ static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_p
for (i = 1; i < PIDMAP_ENTRIES; i++)
atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE);
err = pid_ns_prepare_proc(ns);
if (err)
goto out_put_parent_pid_ns;
return ns;
out_put_parent_pid_ns:
put_pid_ns(parent_pid_ns);
out_free_map:
kfree(ns->pidmap[0].page);
out_free:
kmem_cache_free(pid_ns_cachep, ns);
out:
return ERR_PTR(-ENOMEM);
return ERR_PTR(err);
}
static void destroy_pid_namespace(struct pid_namespace *ns)