Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756954AbbEVIbW (ORCPT ); Fri, 22 May 2015 04:31:22 -0400 Received: from verein.lst.de ([213.95.11.211]:60681 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756473AbbEVIbP (ORCPT ); Fri, 22 May 2015 04:31:15 -0400 Date: Fri, 22 May 2015 10:31:13 +0200 From: Christoph Hellwig To: "Nicholas A. Bellinger" Cc: target-devel , linux-scsi , linux-kernel , Hannes Reinecke , Christoph Hellwig , Sagi Grimberg , "Paul E. McKenney" , Nicholas Bellinger , Chris Boot Subject: Re: [PATCH-v2 5/9] target: Convert se_portal_group->tpg_lun_list[] to RCU hlist Message-ID: <20150522083113.GC24640@lst.de> References: <1432275071-28882-1-git-send-email-nab@daterainc.com> <1432275071-28882-6-git-send-email-nab@daterainc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1432275071-28882-6-git-send-email-nab@daterainc.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1325 Lines: 31 > This patch converts the fixed size se_portal_group->tpg_lun_list[] > to use modern RCU with hlist_head in order to support an arbitary > number of se_lun ports per target endpoint. > > It includes dropping core_tpg_alloc_lun() from core_dev_add_lun(), > and calling it directly from target_fabric_make_lun() to allocate > a new se_lun. > > Also add a new target_fabric_port_release() configfs item callback > to invoke kfree_rcu() to release memory during se_lun->lun_group > shutdown. > > Also now that se_node_acl->lun_entry_hlist is using RCU, convert > existing tpg_lun_lock to struct mutex so core_tpg_add_node_to_devs() > can perform RCU updater logic without releasing ->tpg_lun_mutex. Still doesn't explain why core_tpg_clear_object_luns also disappears. > + hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) { > if (lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE) > continue; lun_status will always be active here as that's set and cleared at the same time as the list addition / removal. Which means that lun_status should go away in this patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/