From d9a44089ac7754e470dfdaf3658c3455b2d7f7dd Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 10 Nov 2025 16:08:22 +0100 Subject: [PATCH] fs: use boolean to indicate anonymous mount namespace Stop playing games with the namespace id and use a boolean instead: * This will remove the special-casing we need to do everywhere for mount namespaces. * It will allow us to use asserts on the namespace id for initial namespaces everywhere. * It will allow us to put anonymous mount namespaces on the namespaces trees in the future and thus make them available to statmount() and listmount(). Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-10-e8a9264e0fb9@kernel.org Signed-off-by: Christian Brauner --- fs/mount.h | 3 ++- fs/namespace.c | 5 +++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/mount.h b/fs/mount.h index f13a28752d0ba..2d28ef2a3aed6 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -27,6 +27,7 @@ struct mnt_namespace { unsigned int nr_mounts; /* # of mounts in the namespace */ unsigned int pending_mounts; refcount_t passive; /* number references not pinning @mounts */ + bool is_anon; } __randomize_layout; struct mnt_pcp { @@ -175,7 +176,7 @@ static inline bool is_local_mountpoint(const struct dentry *dentry) static inline bool is_anon_ns(struct mnt_namespace *ns) { - return ns->ns.ns_id == 0; + return ns->is_anon; } static inline bool anon_ns_root(const struct mount *m) diff --git a/fs/namespace.c b/fs/namespace.c index ad19530a13b22..efaff8680eafb 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -4093,8 +4093,9 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool a dec_mnt_namespaces(ucounts); return ERR_PTR(ret); } - if (!anon) - ns_tree_gen_id(new_ns); + ns_tree_gen_id(new_ns); + + new_ns->is_anon = anon; refcount_set(&new_ns->passive, 1); new_ns->mounts = RB_ROOT; init_waitqueue_head(&new_ns->poll); -- 2.47.3