Re: [PATCH 09/12] target: Convert se_portal_group->tpg_lun_list[] to RCU hlist

From: Christoph Hellwig <hch@lst.de>
To: "Nicholas A. Bellinger" <nab@daterainc.com>
Cc: target-devel <target-devel@vger.kernel.org>,
	linux-scsi <linux-scsi@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Hannes Reinecke <hare@suse.de>,
	Sagi Grimberg <sagig@mellanox.com>,
	Nicholas Bellinger <nab@linux-iscsi.org>,
	Juergen Gross <jgross@suse.com>
Subject: Re: [PATCH 09/12] target: Convert se_portal_group->tpg_lun_list[] to RCU hlist
Date: Wed, 13 May 2015 08:24:58 +0200	[thread overview]
Message-ID: <20150513062458.GA21426@lst.de> (raw)
In-Reply-To: <1431422736-29125-10-git-send-email-nab@daterainc.com>

> FIXME: Figure out how sbp-target se_lun usage should work

The Xen usage also looks really weird.  Maybe Juergen can explain what
scsiback_add_translation_entry is trying to do?  Note that I think both
sbp and xen really should be working on node ACLs.  Right now both
of them oly supported autogenerated ACLs, so in practice it doesn't
matter, but keeping the data structure use clean is a goal on it's own.

> @@ -281,8 +281,6 @@ int iscsit_tpg_del_portal_group(
>  		return -EPERM;
>  	}
>  
> -	core_tpg_clear_object_luns(&tpg->tpg_se_tpg);
> -

How does the removal of tis function including it's only caller
in the iscsi code ﬁit into the picture?  The only explanation I could come
up with is that it wasn't even needed before, in which case it should be
dropped in a seaprate, properly documented patch.

> +static void target_fabric_port_release(struct config_item *item)
> +{
> +	struct se_lun *lun = container_of(to_config_group(item),
> +					  struct se_lun, lun_group);
> +
> +	call_rcu(&lun->rcu_head, target_lun_callrcu);

Just use kfree_rcu here.