From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD246C33C9B for ; Tue, 7 Jan 2020 19:25:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAEA520656 for ; Tue, 7 Jan 2020 19:25:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728652AbgAGTZm (ORCPT ); Tue, 7 Jan 2020 14:25:42 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:39793 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728307AbgAGTZm (ORCPT ); Tue, 7 Jan 2020 14:25:42 -0500 Received: by mail-pj1-f68.google.com with SMTP id t101so208814pjb.4 for ; Tue, 07 Jan 2020 11:25:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ciKn95KNQqdf1ABU2Qcefo6cuXq8TcXvGcUbEueCHnE=; b=tnGTD1TSIp1Dbk1RGqMotsF+fYAj38zxIn7ustkyAY5DDwuk5wVZA/Nc5KQt0vgYXY oj1EAOApNHexF8bS+bLprplCqFUynxMVQui+dlVAorKUrpdEqHnwPcdGcN3Cvdf/RJU3 T3Cv9Dd1RXrax+Db+b3Gu212wkGjc1BV2hKCqpAE8BinRBaYDPUZ/SRT8+09mfIfPhsM ardlfvCkjmBh8e+bQR5m/5Cthc1D9hdMqbiFNGljlgUrSxapcJtTpXJmM/l665l1fmUN TWLuX9xhMTnaRDgLwqgfGQLi7paTspdIYnd9LopQPReex3dXJBFwa3cawM4aHzXUyuNP 6DXg== X-Gm-Message-State: APjAAAWUk1d7p5Yg2DTtejHt1+z/I7ZyNMiiuwdbWdgTuNJIT5tuCeih oY1jNWfmXhZJhZ+B5JrySiU= X-Google-Smtp-Source: APXvYqxMAwo5MWXIqulm7EvO01hAcPdGpvueTmHV9IklQpOw5s2fWMGunHzR8YN6nqZ3GEXFxzBujg== X-Received: by 2002:a17:90a:b008:: with SMTP id x8mr1504265pjq.106.1578425141228; Tue, 07 Jan 2020 11:25:41 -0800 (PST) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id c2sm329051pjq.27.2020.01.07.11.25.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jan 2020 11:25:40 -0800 (PST) From: Bart Van Assche To: "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-scsi@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Hannes Reinecke , Johannes Thumshirn , Ming Lei , Can Guo , Avri Altman , Bean Huo , Stanley Chu , Tomas Winkler Subject: [PATCH 1/4] Introduce {init,exit}_cmd_priv() Date: Tue, 7 Jan 2020 11:25:28 -0800 Message-Id: <20200107192531.73802-2-bvanassche@acm.org> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog In-Reply-To: <20200107192531.73802-1-bvanassche@acm.org> References: <20200107192531.73802-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The current behavior of the SCSI core is to clear driver-private data before preparing a request for submission to the SCSI LLD. Make it possible for SCSI LLDs to disable clearing of driver-private data. These hooks will be used by a later patch, namely "ufs: Let the SCSI core allocate per-command UFS data". Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Ming Lei Cc: Can Guo Cc: Avri Altman Cc: Bean Huo Cc: Stanley Chu Cc: Tomas Winkler Signed-off-by: Bart Van Assche --- drivers/scsi/scsi_lib.c | 29 +++++++++++++++++++++++------ include/scsi/scsi_host.h | 3 +++ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 97af9bf54b22..f0ea614ee49b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1127,7 +1127,7 @@ void scsi_del_cmd_from_list(struct scsi_cmnd *cmd) } } -/* Called after a request has been started. */ +/* 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; @@ -1135,7 +1135,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) struct request *rq = blk_mq_rq_from_pdu(cmd); unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS; unsigned long jiffies_at_alloc; - int retries; + int retries, to_clear; bool in_flight; if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) { @@ -1146,9 +1146,15 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) 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 */ - memset((char *)cmd + sizeof(cmd->req), 0, - sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); + /* + * 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; @@ -1742,6 +1748,7 @@ static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, const bool unchecked_isa_dma = shost->unchecked_isa_dma; struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); struct scatterlist *sg; + int ret = 0; if (unchecked_isa_dma) cmd->flags |= SCMD_UNCHECKED_ISA_DMA; @@ -1757,14 +1764,24 @@ static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost); } - return 0; + if (shost->hostt->init_cmd_priv) { + ret = shost->hostt->init_cmd_priv(shost, cmd); + if (ret < 0) + scsi_free_sense_buffer(unchecked_isa_dma, + cmd->sense_buffer); + } + + return ret; } static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, unsigned int hctx_idx) { + struct Scsi_Host *shost = set->driver_data; struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); + if (shost->hostt->exit_cmd_priv) + shost->hostt->exit_cmd_priv(shost, cmd); scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA, cmd->sense_buffer); } diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index f577647bf5f2..1fa81f9b063f 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -62,6 +62,9 @@ struct scsi_host_template { void __user *arg); #endif + int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); + int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); + /* * The queuecommand function is used to queue up a scsi * command block to the LLDD. When the driver finished