diff options
| author | Christian Brauner <brauner@kernel.org> | 2025-11-10 16:08:25 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-11-11 10:01:31 +0100 |
| commit | 2b60d56acc5b4fcab29fc323e6b82597ec78596f (patch) | |
| tree | 32b4faef78383006f70071e63972f9a2c3763bcb | |
| parent | 657aeb436d70c66583cb2b5b6c65ca64bcf503a8 (diff) | |
ns: add asserts for initial namespace reference counts
They always remain fixed at one. Notice when that assumptions is broken.
Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-13-e8a9264e0fb9@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | include/linux/ns_common.h | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 5b8f2f0163d7..dfb6b798ba82 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -60,10 +60,17 @@ static __always_inline __must_check int __ns_ref_active_read(const struct ns_com return atomic_read(&ns->__ns_ref_active); } +static __always_inline __must_check int __ns_ref_read(const struct ns_common *ns) +{ + return refcount_read(&ns->__ns_ref); +} + static __always_inline __must_check bool __ns_ref_put(struct ns_common *ns) { - if (is_ns_init_id(ns)) + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); return false; + } if (refcount_dec_and_test(&ns->__ns_ref)) { VFS_WARN_ON_ONCE(__ns_ref_active_read(ns)); return true; @@ -73,31 +80,32 @@ static __always_inline __must_check bool __ns_ref_put(struct ns_common *ns) static __always_inline __must_check bool __ns_ref_get(struct ns_common *ns) { - if (is_ns_init_id(ns)) + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); return true; + } if (refcount_inc_not_zero(&ns->__ns_ref)) return true; VFS_WARN_ON_ONCE(__ns_ref_active_read(ns)); return false; } -static __always_inline __must_check int __ns_ref_read(const struct ns_common *ns) -{ - return refcount_read(&ns->__ns_ref); -} - static __always_inline void __ns_ref_inc(struct ns_common *ns) { - if (is_ns_init_id(ns)) + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); return; + } refcount_inc(&ns->__ns_ref); } static __always_inline __must_check bool __ns_ref_dec_and_lock(struct ns_common *ns, spinlock_t *ns_lock) { - if (is_ns_init_id(ns)) + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); return false; + } return refcount_dec_and_lock(&ns->__ns_ref, ns_lock); } |