Re: [PATCH 1/4] target: Obtain se_node_acl->acl_kref during get_initiator_node_acl

From: Christoph Hellwig
Date: Fri Jan 08 2016 - 03:14:20 EST


> mutex_lock(&tpg->acl_node_mutex);
> acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
> + /*
> + * Obtain the acl_kref now, which will be dropped upon the
> + * release of se_sess memory within transport_free_session().
> + */
> + if (acl)
> + kref_get(&acl->acl_kref);

Ð think the comment is highly confusing as it's about one of the
callers, while the function has many.

I'd suggest you move it to core_tpg_check_initiator_node_acl instead.

Also I think iscsit_build_sendtargets_response will need a put on
the nacl, otherwise you'll leak references.

While we're at it - is there any god reason to keep acl_pr_ref_count
as a separate entity from acl_kref?

> void transport_free_session(struct se_session *se_sess)
> {
> + struct se_node_acl *se_nacl = se_sess->se_node_acl;
> + /*
> + * Drop the se_node_acl->nacl_kref obtained from within
> + * core_tpg_get_initiator_node_acl().
> + */
> + if (se_nacl) {
> + se_sess->se_node_acl = NULL;

Whats the point of zeroing se_node_acl just before freeing se_sess?

> /*
> * If last kref is dropping now for an explicit NodeACL, awake sleeping
> * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
> - * removal context.
> + * removal context from within transport_free_session() code.
> */

The comment neds to move to transport_free_session. Or maybe just removed
given that it's obvious from the code flow.