Add a helper that checks whether a give mount namespace is empty instead
of open-coding the specific data structure check. This also be will be
used in follow-up patches.
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
fs/mount.h | 5 +++++
fs/namespace.c | 4 ++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/mount.h b/fs/mount.h
index 820a79f1f735..e2501a724688 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -157,6 +157,11 @@ static inline bool mnt_ns_attached(const struct mount *mnt)
return !RB_EMPTY_NODE(&mnt->mnt_node);
}
+static inline bool mnt_ns_empty(const struct mnt_namespace *ns)
+{
+ return RB_EMPTY_ROOT(&ns->mounts);
+}
+
static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
{
struct mnt_namespace *ns = mnt->mnt_ns;
diff --git a/fs/namespace.c b/fs/namespace.c
index 9bcfb405b02b..1d3b524ef878 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5313,7 +5313,7 @@ static int grab_requested_root(struct mnt_namespace *ns, struct path *root)
* We have to find the first mount in our ns and use that, however it
* may not exist, so handle that properly.
*/
- if (RB_EMPTY_ROOT(&ns->mounts))
+ if (mnt_ns_empty(ns))
return -ENOENT;
first = child = ns->root;
@@ -5338,7 +5338,7 @@ static int do_statmount(struct kstatmount *s, u64 mnt_id, u64 mnt_ns_id,
int err;
/* Has the namespace already been emptied? */
- if (mnt_ns_id && RB_EMPTY_ROOT(&ns->mounts))
+ if (mnt_ns_id && mnt_ns_empty(ns))
return -ENOENT;
s->mnt = lookup_mnt_in_ns(mnt_id, ns);
--
2.47.2
