On Mon, Aug 25, 2025 at 05:43:16AM +0100, Al Viro wrote:
> ... and document the locking requirements of __has_locked_children()
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
> fs/namespace.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/namespace.c b/fs/namespace.c
> index 59948cbf9c47..eabb0d996c6a 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -2373,6 +2373,7 @@ void dissolve_on_fput(struct vfsmount *mnt)
> }
> }
>
> +/* locks: namespace_shared && pinned(mnt) || mount_locked_reader */
> static bool __has_locked_children(struct mount *mnt, struct dentry *dentry)
> {
> struct mount *child;
> @@ -2389,12 +2390,8 @@ static bool __has_locked_children(struct mount *mnt, struct dentry *dentry)
>
> bool has_locked_children(struct mount *mnt, struct dentry *dentry)
> {
> - bool res;
> -
> - read_seqlock_excl(&mount_lock);
> - res = __has_locked_children(mnt, dentry);
> - read_sequnlock_excl(&mount_lock);
> - return res;
> + scoped_guard(mount_locked_reader)
> + return __has_locked_children(mnt, dentry);
Agree with Linus, this should just use a plain guard().
