From 4308eebbeb2026827d4492ce8c23d99f7f144a82 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 23 Mar 2011 16:43:13 -0700 Subject: [PATCH] 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 Signed-off-by: Daniel Lezcano Cc: Oleg Nesterov Cc: Alexey Dobriyan Acked-by: Serge E. Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/root.c | 25 +++++++------------------ kernel/fork.c | 6 ------ kernel/pid_namespace.c | 11 +++++++++-- 3 files changed, 16 insertions(+), 26 deletions(-) diff --git a/fs/proc/root.c b/fs/proc/root.c index ef9fa8e24ad..e5e2bfa7a03 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -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); } diff --git a/kernel/fork.c b/kernel/fork.c index 17aed4378ed..457fff2e17e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -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); diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index a5aff94e1f0..e9c9adc84ca 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -14,6 +14,7 @@ #include #include #include +#include #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) -- 2.20.1