From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: [PATCH v3 0/5] scsi_debug: add write scattered support Date: Sat, 23 Dec 2017 12:48:09 -0500 Message-ID: <20171223174814.3902-1-dgilbert@interlog.com> Return-path: Received: from smtp.infotech.no ([82.134.31.41]:49699 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752688AbdLWRsi (ORCPT ); Sat, 23 Dec 2017 12:48:38 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, Bart.VanAssche@wdc.com, hare@suse.de, Douglas Gilbert While testing the WRITE SCATTERED command support in a new sg3_utils utility (sg_write_x) it was helpful to have a target that supported this command. This command might be attractive to other kernel subsystems. Even if end devices don't support this command yet, it would most likely be a performance win if SCSI LLDs supported it (by breaking it down to a series of WRITE commands), as that would cut down the overhead of the block layer, the ULD (e.g. sd) and the SCSI midlevel. Changes since v2: - remove over-zealous sanity check (lbdof >= bt_len) that rejected valid invocations - change a kzalloc() failure to return SCSI_MLQUEUE_HOST_BUSY as requested by reviewer Changes since original version: - fix problem when fake_rw=1, identify media access commands better with following rename - rename FF_DIRECT_IO to FF_MEDIA_IO - apply reviewer suggestions (Bart Van Assche) - expand in-code comments Douglas Gilbert (5): scsi_debug: tab, kstrto changes scsi_debug: fix group_number mask scsi_debug: do_device_access add sg offset argument scsi_debug: ARRAY_SIZE and FF_MEDIA_IO scsi_debug: add resp_write_scat function drivers/scsi/scsi_debug.c | 541 +++++++++++++++++++++++++++++++--------------- 1 file changed, 366 insertions(+), 175 deletions(-) -- 2.14.1