From patchwork Tue Feb 22 14:04:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 545180 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC1DEC433F5 for ; Tue, 22 Feb 2022 14:05:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232630AbiBVOFW (ORCPT ); Tue, 22 Feb 2022 09:05:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232621AbiBVOFT (ORCPT ); Tue, 22 Feb 2022 09:05:19 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80FFD15F0B7; Tue, 22 Feb 2022 06:04:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=Avrg//JxLSwYTuHSUzz2IyuKEamxIoHran7EmqDFVDU=; b=n6CBsb6ZhOoIBfusKn2rASxkUl 3DQaiOkXSykHVB7Js3KmAc39/H0EghSFOaP3tuXSssxfJ9PgdePCBpN+YQqUJUA90oCja8UD+MVZf Cw09UofdCldIO/tQtnLgSm3LEidD8b37jvOskLv+NyM9gaxekaxf8o7In1qtdKo24XvL3ZoKaWKLA XGv7LJtadKXjJFeghv1ZEveFbFwRr0BqwO6+8iFYya8WJRvEL1Fjs0vHqR42OgMjNiFXlRM8UKRkf alxVBWrM6Q1nRxWhOcHCY77huPG3l3ctKk5tnJAAcDWv2O/EDGuuBRLih5skyh5ucEtnTBX6+n6op JQ6J9DBw==; Received: from [2001:4bb8:198:f8fc:c22a:ebfc:be8d:63c2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMVmf-009nQy-Og; Tue, 22 Feb 2022 14:04:54 +0000 From: Christoph Hellwig To: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org Subject: [PATCH 3/8] scsi: don't memset the entire scsi_cmnd in scsi_init_command Date: Tue, 22 Feb 2022 15:04:38 +0100 Message-Id: <20220222140443.589882-4-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220222140443.589882-1-hch@lst.de> References: <20220222140443.589882-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Replace the big fat memset that requires saving and restoring various fields with just initializing those fields that need initialization. All the clearing to 0 ismoved to scsi_prepare_cmd as scsi_ioctl_reset alreadly uses kzalloc to allocate a pre-zeroed command. This is still conservative and can probably be optimizated further. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche --- drivers/scsi/scsi_lib.c | 61 ++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 32 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index a1c18ba5e8d38..960795d469d8c 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1163,45 +1163,17 @@ static void scsi_cleanup_rq(struct request *rq) /* Called before a request is prepared. See also scsi_mq_prep_fn(). */ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) { - void *buf = cmd->sense_buffer; - void *prot = cmd->prot_sdb; struct request *rq = scsi_cmd_to_rq(cmd); - unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS; - unsigned long jiffies_at_alloc; - int retries, to_clear; - bool in_flight; - int budget_token = cmd->budget_token; - - if (!blk_rq_is_passthrough(rq) && !(flags & SCMD_INITIALIZED)) { - flags |= SCMD_INITIALIZED; + + if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { + cmd->flags |= SCMD_INITIALIZED; scsi_initialize_rq(rq); } - jiffies_at_alloc = cmd->jiffies_at_alloc; - retries = cmd->retries; - in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); - /* - * Zero out the cmd, except for the embedded scsi_request. Only clear - * the driver-private command data if the LLD does not supply a - * function to initialize that data. - */ - to_clear = sizeof(*cmd) - sizeof(cmd->req); - if (!dev->host->hostt->init_cmd_priv) - to_clear += dev->host->hostt->cmd_size; - memset((char *)cmd + sizeof(cmd->req), 0, to_clear); - cmd->device = dev; - cmd->sense_buffer = buf; - cmd->prot_sdb = prot; - cmd->flags = flags; + cmd->flags &= SCMD_PRESERVED_FLAGS; INIT_LIST_HEAD(&cmd->eh_entry); INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); - cmd->jiffies_at_alloc = jiffies_at_alloc; - cmd->retries = retries; - if (in_flight) - __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); - cmd->budget_token = budget_token; - } static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, @@ -1586,10 +1558,35 @@ static blk_status_t scsi_prepare_cmd(struct request *req) struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); struct scsi_device *sdev = req->q->queuedata; struct Scsi_Host *shost = sdev->host; + bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); struct scatterlist *sg; scsi_init_command(sdev, cmd); + cmd->eh_eflags = 0; + cmd->allowed = 0; + cmd->prot_type = 0; + cmd->prot_flags = 0; + cmd->submitter = 0; + cmd->cmd_len = 0; + cmd->cmnd = NULL; + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); + cmd->underflow = 0; + cmd->transfersize = 0; + cmd->host_scribble = NULL; + cmd->result = 0; + cmd->extra_len = 0; + cmd->state = 0; + if (in_flight) + __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); + + /* + * Only clear the driver-private command data if the LLD does not supply + * a function to initialize that data. + */ + if (!shost->hostt->init_cmd_priv) + memset(cmd + 1, 0, shost->hostt->cmd_size); + cmd->prot_op = SCSI_PROT_NORMAL; if (blk_rq_bytes(req)) cmd->sc_data_direction = rq_dma_dir(req);