On Tue, Jun 10, 2025 at 09:21:39AM +0100, Al Viro wrote:
> The logics used for tucking under existing mount differs for original
> and copies; copies do a mount hash lookup to see if mountpoint to be is
> already overmounted, while the original is told explicitly.
>
> But the same logics that is used for copies works for the original,
> at which point the only place where we get very close to eliminating
> the need of passing 'beneath' flag to attach_recursive_mnt().
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
> fs/namespace.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/fs/namespace.c b/fs/namespace.c
> index 50c46c084b13..0e43301abb91 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -2675,9 +2675,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
> }
>
> mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt);
> - if (beneath)
> - mnt_change_mountpoint(source_mnt, smp, top_mnt);
> - commit_tree(source_mnt);
> + hlist_add_head(&source_mnt->mnt_hash, &tree_list);
Please add a comment here. Right now it's easy to understand even with
your mnt_change_mountpoint() changes. Afterwards the cases are folded
and imho that leaves readers wondering why that's correct.
>
> hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) {
> struct mount *q;
> --
> 2.39.5
>
