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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9B90C433EF for ; Mon, 22 Nov 2021 17:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239972AbhKVRlu (ORCPT ); Mon, 22 Nov 2021 12:41:50 -0500 Received: from mail-pj1-f45.google.com ([209.85.216.45]:45985 "EHLO mail-pj1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232963AbhKVRlt (ORCPT ); Mon, 22 Nov 2021 12:41:49 -0500 Received: by mail-pj1-f45.google.com with SMTP id gb13-20020a17090b060d00b001a674e2c4a8so507605pjb.4 for ; Mon, 22 Nov 2021 09:38:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=yZh1YYYEzZ+KpjHgtkVKRS202CaMlzmdEZ7ABaH7YiU=; b=dDWyqx/Dc31tMZRpEhSLQehA4o80cI2c11YV1Gb9aqk4FvWLYIyz+t2cBJ7QoNKn5p Alk4vdDGZptqmL0FPz6wTZ0Hix79H93DdxSpHzCW2OjyNRsAQgKdGnLF9BH2btiT66Hj JLp80C/uhzPCaInnVZxCPOMXTXzBi3FrxR5WArQUjmlMPRMvra0avd7ZmlWHdufh8NU/ buYcyGdX9QP6RF/7Dk2hYaFp296ogwqbdVgpSDWIp/M3z6l8ym+mOT4UB1iD42/uoU5u 0XKxqGEZtHX2CtsJbGwS3FLIgQScRSe21L0rJaD9nb+AgdmD91806ULxfpuv/Mcj5vgO CGcg== X-Gm-Message-State: AOAM533rvjUyOsiVf12c8c79KEq5RmvCK30pZ9dDp0G8tzwMlvI8R97U JIvEmDQcDw5VKOIjZBDUMOE= X-Google-Smtp-Source: ABdhPJzASrTRuLE4vP628ovwAV3PlIkzDz6mjV0GUu/i639BT11Wfxkl80543NYRrKiHIZ/0qsv7VQ== X-Received: by 2002:a17:90b:3b43:: with SMTP id ot3mr33827804pjb.205.1637602723005; Mon, 22 Nov 2021 09:38:43 -0800 (PST) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:3432:c377:2744:1125]) by smtp.gmail.com with ESMTPSA id j8sm9930778pfc.8.2021.11.22.09.38.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Nov 2021 09:38:42 -0800 (PST) Subject: Re: [PATCH v2 01/20] block: Add a flag for internal commands To: John Garry , "Martin K . Petersen" Cc: Jaegeuk Kim , Adrian Hunter , linux-scsi@vger.kernel.org, Hannes Reinecke , Jens Axboe , Christoph Hellwig , Ming Lei References: <20211119195743.2817-1-bvanassche@acm.org> <20211119195743.2817-2-bvanassche@acm.org> From: Bart Van Assche Message-ID: Date: Mon, 22 Nov 2021 09:38:41 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 11/22/21 12:46 AM, John Garry wrote: > On 19/11/2021 19:57, Bart Van Assche wrote: >> From: Hannes Reinecke > >> Some drivers use a single tag space for requests submitted by the block >> layer and driver-internal requests. Driver-internal requests will never >> pass through the block layer but require a valid tag. This patch adds a >> new request flag REQ_INTERNAL. > > I'm not sure on the name. Don't we already use term "internal" for > elevator request tag? I don't see how any confusion could arise between "internal_tag" and "REQ_INTERNAL" since in both cases the context is made clear - either the request tag or the request in its entirety. >> to mark such requests and a terminates any >> such commands in blk_execute_rq_nowait() with a WARN_ON_ONCE() to signal >> such an invalid usage. > > FYI, I have been working on a different stream, that allows us to send > the reserved request through the block layer, as we need it for poll > mode support. The reason is that we need to send reserved requests on > specific HW queues, which may be polling. However poll mode support only > allows us to poll requests with bios, so that's a problem ATM. Please use REQ_OP_DRV_* without REQ_INTERNAL for requests that need to be sent through the block layer. Thanks, Bart.