On Mon, Sep 3, 2018 at 12:10 AM Vlad Buslov <vla...@mellanox.com> wrote:
>
> Recent refactoring of add_metainfo() caused use_all_metadata() to add
> metainfo to ife action metalist without taking reference to module. This
> causes warning in module_put called from ife action cleanup function.
>
> Implement add_metainfo_and_get_ops() function that returns with reference
> to module taken if metainfo was added successfully, and call it from
> use_all_metadata(), instead of calling __add_metainfo() directly.
Good catch!
I thought every entry in ifeoplist must hold a refcnt to its module, looks
like I was wrong.
> read_lock(&ife_mod_lock);
> list_for_each_entry(o, &ifeoplist, list) {
> - rc = __add_metainfo(o, ife, o->metaid, NULL, 0, true, exists);
> + rc = add_metainfo_and_get_ops(o, ife, o->metaid, NULL, 0,
> true,
> + exists);
> if (rc == 0)
> installed += 1;
I am afraid you have to rollback on failure inside this loop, that is,
releasing all previous module refcnt properly on error.
