Re: [PATCH v4 2/6] mounts: keep list of mounts in an rbtree

On 30/10/23 17:06, Miklos Szeredi wrote:

On Mon, Oct 30, 2023 at 6:45 AM Ian Kent [off-list ref] wrote:

quoted

Is fs/namespace.c:iterate_mounts() a problem?

It's called from:

1) ./kernel/audit_tree.c:709: if (iterate_mounts(compare_root,
2) ./kernel/audit_tree.c:839:    err = iterate_mounts(tag_mount, tree, mnt);
3) ./kernel/audit_tree.c:917:        failed = iterate_mounts(tag_mount,
tree, tagged);


  From functions 1) audit_trim_trees(), 2) audit_add_tree_rule() and

3) audit_tag_tree().

So that interface works like this:

  - collect_mounts() creates a temporary copy of a mount tree, mounts
are chained on mnt_list.

Right, sorry for the noise, I didn't look far enough.


Ian

  - iterate_mounts() is used to do some work on the temporary tree

  - drop_collected_mounts() frees the temporary tree

These mounts are never installed in a namespace.  My guess is that a
private copy is used instead of the original mount tree to prevent
races.

Thanks,
Miklos