From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Linton Subject: [PATCH] SG_SCSI_RESET ioctl should only perform requested operation Date: Mon, 4 Feb 2013 14:17:14 -0600 Message-ID: <5110174A.4080808@tributary.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from relay.ihostexchange.net ([66.46.182.58]:4899 "EHLO relay.ihostexchange.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754840Ab3BDURW (ORCPT ); Mon, 4 Feb 2013 15:17:22 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Linux Scsi >>From all the documentation I've found, it is not clear that users of the SG_SCSI_RESET ioctl may have their requests progress up the hierarchy of reset operations. Basically, requests for a SCSI_TRY_RESET_DEVICE may eventually result in a TARGET, BUS, or HOST reset. The sg_reset utility hints at the error handling, but actually leads the user to believe that they should reissue the sg_reset command themselves to enact more aggressive reset functions. It also says: "Note that a host reset and a bus reset may cause collateral damage." In the interest of error isolation, I have attached a patch which changes the behavior. The existing behavior is obviously intentional, but I don't believe its the best choice. There are other alternatives to this patch. For one, to avoid the possibility of breaking an existing application, maybe SG_SCSI_RESET needs some new values like "SG_SCSI_RESET_DEVICE_ONLY". While leaving the existing operations alone. Just in case... Signed-off-by: Jeremy Linton --- diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index c1b05a8..6f05bc2 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1999,19 +1999,13 @@ scsi_reset_provider(struct scsi_device *dev, int flag) switch (flag) { case SCSI_TRY_RESET_DEVICE: rtn = scsi_try_bus_device_reset(scmd); - if (rtn == SUCCESS) - break; - /* FALLTHROUGH */ + break; case SCSI_TRY_RESET_TARGET: rtn = scsi_try_target_reset(scmd); - if (rtn == SUCCESS) - break; - /* FALLTHROUGH */ + break; case SCSI_TRY_RESET_BUS: rtn = scsi_try_bus_reset(scmd); - if (rtn == SUCCESS) - break; - /* FALLTHROUGH */ + break; case SCSI_TRY_RESET_HOST: rtn = scsi_try_host_reset(scmd); break;