| Message ID | 159611038719.535980.13960315152927389105.stgit@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | proc: Introduce /proc/namespaces/ directory to expose namespaces lineary | expand |
On Thu, Jul 30, 2020 at 02:59:47PM +0300, Kirill Tkhai wrote: > Convert user namespace to use generic counter. > > Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> > --- Looks good! Acked-by: Christian Brauner <christian.brauner@ubuntu.com> > include/linux/user_namespace.h | 5 ++--- > kernel/user.c | 2 +- > kernel/user_namespace.c | 4 ++-- > 3 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index 6ef1c7109fc4..64cf8ebdc4ec 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -57,7 +57,6 @@ struct user_namespace { > struct uid_gid_map uid_map; > struct uid_gid_map gid_map; > struct uid_gid_map projid_map; > - atomic_t count; > struct user_namespace *parent; > int level; > kuid_t owner; > @@ -109,7 +108,7 @@ void dec_ucount(struct ucounts *ucounts, enum ucount_type type); > static inline struct user_namespace *get_user_ns(struct user_namespace *ns) > { > if (ns) > - atomic_inc(&ns->count); > + refcount_inc(&ns->ns.count); > return ns; > } > > @@ -119,7 +118,7 @@ extern void __put_user_ns(struct user_namespace *ns); > > static inline void put_user_ns(struct user_namespace *ns) > { > - if (ns && atomic_dec_and_test(&ns->count)) > + if (ns && refcount_dec_and_test(&ns->ns.count)) > __put_user_ns(ns); > } > > diff --git a/kernel/user.c b/kernel/user.c > index b1635d94a1f2..a2478cddf536 100644 > --- a/kernel/user.c > +++ b/kernel/user.c > @@ -55,7 +55,7 @@ struct user_namespace init_user_ns = { > }, > }, > }, > - .count = ATOMIC_INIT(3), > + .ns.count = REFCOUNT_INIT(3), Note-to-self: I really wish we'd had a comment in cases where the refcount isn't set to 1 but to something like 3. Otherwise one always needs to dig up the reasons why. :) > .owner = GLOBAL_ROOT_UID, > .group = GLOBAL_ROOT_GID, > .ns.inum = PROC_USER_INIT_INO, > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index 87804e0371fe..7c2bbe8f3e45 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -111,7 +111,7 @@ int create_user_ns(struct cred *new) > goto fail_free; > ns->ns.ops = &userns_operations; > > - atomic_set(&ns->count, 1); > + refcount_set(&ns->ns.count, 1); > /* Leave the new->user_ns reference with the new user namespace. */ > ns->parent = parent_ns; > ns->level = parent_ns->level + 1; > @@ -197,7 +197,7 @@ static void free_user_ns(struct work_struct *work) > kmem_cache_free(user_ns_cachep, ns); > dec_user_namespaces(ucounts); > ns = parent; > - } while (atomic_dec_and_test(&parent->count)); > + } while (refcount_dec_and_test(&parent->ns.count)); > } > > void __put_user_ns(struct user_namespace *ns) > >
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 6ef1c7109fc4..64cf8ebdc4ec 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -57,7 +57,6 @@ struct user_namespace { struct uid_gid_map uid_map; struct uid_gid_map gid_map; struct uid_gid_map projid_map; - atomic_t count; struct user_namespace *parent; int level; kuid_t owner; @@ -109,7 +108,7 @@ void dec_ucount(struct ucounts *ucounts, enum ucount_type type); static inline struct user_namespace *get_user_ns(struct user_namespace *ns) { if (ns) - atomic_inc(&ns->count); + refcount_inc(&ns->ns.count); return ns; } @@ -119,7 +118,7 @@ extern void __put_user_ns(struct user_namespace *ns); static inline void put_user_ns(struct user_namespace *ns) { - if (ns && atomic_dec_and_test(&ns->count)) + if (ns && refcount_dec_and_test(&ns->ns.count)) __put_user_ns(ns); } diff --git a/kernel/user.c b/kernel/user.c index b1635d94a1f2..a2478cddf536 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -55,7 +55,7 @@ struct user_namespace init_user_ns = { }, }, }, - .count = ATOMIC_INIT(3), + .ns.count = REFCOUNT_INIT(3), .owner = GLOBAL_ROOT_UID, .group = GLOBAL_ROOT_GID, .ns.inum = PROC_USER_INIT_INO, diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 87804e0371fe..7c2bbe8f3e45 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -111,7 +111,7 @@ int create_user_ns(struct cred *new) goto fail_free; ns->ns.ops = &userns_operations; - atomic_set(&ns->count, 1); + refcount_set(&ns->ns.count, 1); /* Leave the new->user_ns reference with the new user namespace. */ ns->parent = parent_ns; ns->level = parent_ns->level + 1; @@ -197,7 +197,7 @@ static void free_user_ns(struct work_struct *work) kmem_cache_free(user_ns_cachep, ns); dec_user_namespaces(ucounts); ns = parent; - } while (atomic_dec_and_test(&parent->count)); + } while (refcount_dec_and_test(&parent->ns.count)); } void __put_user_ns(struct user_namespace *ns)
Convert user namespace to use generic counter. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> --- include/linux/user_namespace.h | 5 ++--- kernel/user.c | 2 +- kernel/user_namespace.c | 4 ++-- 3 files changed, 5 insertions(+), 6 deletions(-)