From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from stargate.chelsio.com ([12.32.117.8]:5130 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756262AbdDMHpA (ORCPT ); Thu, 13 Apr 2017 03:45:00 -0400 Date: Thu, 13 Apr 2017 13:14:55 +0530 From: Varun Prakash To: "Nicholas A. Bellinger" Cc: Bart Van Assche , target-devel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 2/6] target/iscsi: Call .iscsit_release_cmd() once Message-ID: <20170413074454.GA1724@chelsio.com> References: <20170330171244.8346-1-bart.vanassche@sandisk.com> <20170330171244.8346-3-bart.vanassche@sandisk.com> <1491173945.8846.48.camel@haakon3.risingtidesystems.com> <20170404050649.GA1662@chelsio.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170404050649.GA1662@chelsio.com> Sender: stable-owner@vger.kernel.org List-ID: Hi Nicholas, On Tue, Apr 04, 2017 at 10:36:50AM +0530, Varun Prakash wrote: > Hi Nicholas and Bart, > > On Sun, Apr 02, 2017 at 03:59:05PM -0700, Nicholas A. Bellinger wrote: > > On Thu, 2017-03-30 at 10:12 -0700, Bart Van Assche wrote: > > > While releasing a command __iscsit_free_cmd() can be called multiple > > > times but .iscsit_release_cmd() must be called only once. Hence move > > > the .iscsit_release_cmd() call into iscsit_release_cmd(). The latter > > > function is only called once per command. The only driver that defines > > > the .iscsit_release_cmd() callback is the cxgbit driver so this change > > > only affects the cxgbit driver. > > > > > > Fixes: 7ec811a8e9c3 ("iscsi-target: add void (*iscsit_release_cmd)()") > > > Signed-off-by: Bart Van Assche > > > Cc: Varun Prakash > > > Cc: Nicholas Bellinger > > > Cc: > > > --- > > > drivers/target/iscsi/iscsi_target_util.c | 15 +++++++++------ > > > 1 file changed, 9 insertions(+), 6 deletions(-) > > > > > > > Applied to target-pending/for-next, but dropping the stable CC' because > > the single caller in cxgbit_release_cmd() is already checking to ensure > > resources are only released on the first invocation. > > > > So it's not a bug-fix. > > In case of DDP cxgbit driver assigns cmd->se_cmd.t_data_sg to ttinfo->sgl > and calls dma_map_sg(), cxgbit_release_cmd() calls dma_unmap_sg(), it needs > a valid sg(ttinfo->sgl), before calling iscsit_release_cmd() > cmd->se_cmd.t_data_sg gets freed so ttinfo->sgl will not be valid if we move > ->iscsit_release_cmd() to iscsit_release_cmd(). Please drop this patch, it will regress cxgbit driver, with this patch scatterlist is freed before calling ->iscsit_release_cmd(), cxgbit calls dma_unmap_sg() so scatterlist should not be freed before calling ->iscst_release_cmd(). Thanks Varun