From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Battersby Subject: [PATCH][SCSI] scsi-mq: fix requests that use a separate CDB buffer Date: Fri, 22 Aug 2014 15:53:39 -0400 Message-ID: <53F79FC3.6040907@cybernetics.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-scsi@vger.kernel.org, "James E.J. Bottomley" , Jens Axboe Cc: linux-kernel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org This patch fixes code such as the following with scsi-mq enabled: rq = blk_get_request(...); blk_rq_set_block_pc(rq); rq->cmd = my_cmd_buffer; /* separate CDB buffer */ blk_execute_rq_nowait(...); Code like this appears in e.g. sg_start_req() in drivers/scsi/sg.c (for large CDBs only). Without this patch, scsi_mq_prep_fn() will set rq->cmd back to rq->__cmd, causing the wrong CDB to be sent to the device. Signed-off-by: Tony Battersby --- For inclusion in 3.17 only. diff -urpN linux-3.17.0-rc1-a/block/blk-core.c linux-3.17.0-rc1-b/block/blk-core.c --- linux-3.17.0-rc1-a/block/blk-core.c 2014-08-16 12:40:26.000000000 -0400 +++ linux-3.17.0-rc1-b/block/blk-core.c 2014-08-22 14:03:33.000000000 -0400 @@ -1252,7 +1252,6 @@ void blk_rq_set_block_pc(struct request rq->__sector = (sector_t) -1; rq->bio = rq->biotail = NULL; memset(rq->__cmd, 0, sizeof(rq->__cmd)); - rq->cmd = rq->__cmd; } EXPORT_SYMBOL(blk_rq_set_block_pc); diff -urpN linux-3.17.0-rc1-a/block/blk-mq.c linux-3.17.0-rc1-b/block/blk-mq.c --- linux-3.17.0-rc1-a/block/blk-mq.c 2014-08-16 12:40:26.000000000 -0400 +++ linux-3.17.0-rc1-b/block/blk-mq.c 2014-08-22 14:02:32.000000000 -0400 @@ -172,6 +172,8 @@ static void blk_mq_rq_ctx_init(struct re /* tag was already set */ rq->errors = 0; + rq->cmd = rq->__cmd; + rq->extra_len = 0; rq->sense_len = 0; rq->resid_len = 0; diff -urpN linux-3.17.0-rc1-a/drivers/scsi/scsi_lib.c linux-3.17.0-rc1-b/drivers/scsi/scsi_lib.c --- linux-3.17.0-rc1-a/drivers/scsi/scsi_lib.c 2014-08-16 12:40:26.000000000 -0400 +++ linux-3.17.0-rc1-b/drivers/scsi/scsi_lib.c 2014-08-22 14:02:32.000000000 -0400 @@ -1808,7 +1808,6 @@ static int scsi_mq_prep_fn(struct reques cmd->tag = req->tag; - req->cmd = req->__cmd; cmd->cmnd = req->cmd; cmd->prot_op = SCSI_PROT_NORMAL;