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authorPavel Emelyanov <xemul@openvz.org>2007-10-18 23:40:11 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:40 -0700
commit6f4e643353aea52d80f33960bd88954a7c074f0f (patch)
tree5b7e452f7e31be89f06a52a2c077183b7fe74c3b /fs/proc/root.c
parent130f77ecb2e7d5ac3e53e620f55e374f4a406b20 (diff)
pid namespaces: initialize the namespace's proc_mnt
The namespace's proc_mnt must be kern_mount-ed to make this pointer always valid, independently of whether the user space mounted the proc or not. This solves raced in proc_flush_task, etc. with the proc_mnt switching from NULL to not-NULL. The initialization is done after the init's pid is created and hashed to make proc_get_sb() finr it and get for root inode. Sice the namespace holds the vfsmnt, vfsmnt holds the superblock and the superblock holds the namespace we must explicitly break this circle to destroy all the stuff. This is done after the init of the namespace dies. Running a few steps forward - when init exits it will kill all its children, so no proc_mnt will be needed after its death. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/root.c')
-rw-r--r--fs/proc/root.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 94e9d734384..ec9cb3b6c93 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -212,6 +212,22 @@ struct proc_dir_entry proc_root = {
.parent = &proc_root,
};
+int pid_ns_prepare_proc(struct pid_namespace *ns)
+{
+ struct vfsmount *mnt;
+
+ mnt = kern_mount_data(&proc_fs_type, ns);
+ if (IS_ERR(mnt))
+ return PTR_ERR(mnt);
+
+ return 0;
+}
+
+void pid_ns_release_proc(struct pid_namespace *ns)
+{
+ mntput(ns->proc_mnt);
+}
+
EXPORT_SYMBOL(proc_symlink);
EXPORT_SYMBOL(proc_mkdir);
EXPORT_SYMBOL(create_proc_entry);