[PATCH 10/17] fs: use boolean to indicate anonymous mount namespace
From: Christian Brauner <brauner@kernel.org>
Date: 2025-11-10 15:09:33
Also in:
bpf, cgroups, linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
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(). Signed-off-by: Christian Brauner <brauner@kernel.org> --- 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 f13a28752d0b..2d28ef2a3aed 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 ad19530a13b2..efaff8680eaf 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