"Serge E. Hallyn" <[EMAIL PROTECTED]> writes: > Quoting Serge E. Hallyn ([EMAIL PROTECTED]): >> > Just skimming through your patch I don't expect we will need the list >> > of children, and not having should reduct our locking burden. >> >> Hmm, that's true. I can't see a reason for that. Thanks! > > BTW here is the new, slightly smaller patch: > >>From d17fbd87d97f64a0e879a7efbe5e1835fc573eae Mon Sep 17 00:00:00 2001 > From: Serge Hallyn <[EMAIL PROTECTED]> > Date: Thu, 19 Jun 2008 20:18:17 -0500 > Subject: [PATCH 1/1] user namespaces: introduce user_struct->user_namespace > relationship > > When a task does clone(CLONE_NEWNS), the task's user is the 'creator' of the > new user_namespace, and the user_namespace is tacked onto a list of those > created by this user. > > When we create or put a user in a namespace, we also do so for all creator > users up the creator chain. > > Changelog: > Jun 20: Eric Biederman pointed out the sibling/child_user_ns > list is unnecessary! > > Signed-off-by: Serge Hallyn <[EMAIL PROTECTED]> > --- > include/linux/sched.h | 1 + > include/linux/user_namespace.h | 1 + > kernel/user.c | 66 > +++++++++++++++++++++++++++++++++++++++- > kernel/user_namespace.c | 15 +++------ > 4 files changed, 72 insertions(+), 11 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 799bbdd..da1bcc6 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -604,6 +604,7 @@ struct user_struct { > /* Hash table maintenance information */ > struct hlist_node uidhash_node; > uid_t uid; > + struct user_namespace *user_namespace; > > #ifdef CONFIG_USER_SCHED > struct task_group *tg; > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index b5f41d4..f9477c3 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -13,6 +13,7 @@ struct user_namespace { > struct kref kref; > struct hlist_head uidhash_table[UIDHASH_SZ]; > struct user_struct *root_user; > + struct user_struct *creator; > }; > > extern struct user_namespace init_user_ns; > diff --git a/kernel/user.c b/kernel/user.c > index 865ecf5..e583be4 100644 > --- a/kernel/user.c > +++ b/kernel/user.c > @@ -21,6 +21,7 @@ struct user_namespace init_user_ns = { > .kref = { > .refcount = ATOMIC_INIT(2), > }, > + .creator = &root_user, > .root_user = &root_user, > }; > EXPORT_SYMBOL_GPL(init_user_ns); > @@ -53,6 +54,7 @@ struct user_struct root_user = { > .files = ATOMIC_INIT(0), > .sigpending = ATOMIC_INIT(0), > .locked_shm = 0, > + .user_namespace = &init_user_ns, > #ifdef CONFIG_USER_SCHED > .tg = &init_task_group, > #endif > @@ -71,6 +73,18 @@ static void uid_hash_remove(struct user_struct *up) > hlist_del_init(&up->uidhash_node); > } > > +void inc_user_and_creators(struct user_struct *user) > +{ > + struct user_namespace *ns = user->user_namespace; > + while (user) { > + atomic_inc(&user->__count); > + if (ns == ns->creator->user_namespace) > + return; > + user = ns->creator; > + ns = user->user_namespace; > + } > +} > +
This functionality appears unnecessary. Holding a count on the user and the user holding a count on it's user_namespace and the user_namespace holding a count on it's creator should be sufficient. Or am I missing something? Eric _______________________________________________ Containers mailing list [EMAIL PROTECTED] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel