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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 816ECC433E2 for ; Sat, 12 Sep 2020 13:53:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2208B20855 for ; Sat, 12 Sep 2020 13:53:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cD3F052V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725860AbgILNxO (ORCPT ); Sat, 12 Sep 2020 09:53:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25017 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbgILNxN (ORCPT ); Sat, 12 Sep 2020 09:53:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599918791; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XR6u7TqERwThyNfZzYWgsg0Rr430L8zf9OdQe8Komps=; b=cD3F052V9OSPCEdZLey+NGmKMUrPllXZCHMP2ydt3zCUrtfepwPhcoHWxm6oYmn+AcXCaD VrkQJ+6qVYbm4KkB23kShoZh0msu+gyMPGcYAQWm5zLYVdc4y93qQI75MQUETq5j0ODj1u 9u4rteTZc1/uooKw1FwCXX7Nk5lCcms= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-51-tVGkUyi3Mm-ZZ6UZli9Okg-1; Sat, 12 Sep 2020 09:53:09 -0400 X-MC-Unique: tVGkUyi3Mm-ZZ6UZli9Okg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 224961074651; Sat, 12 Sep 2020 13:53:08 +0000 (UTC) Received: from T590 (ovpn-12-84.pek2.redhat.com [10.72.12.84]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E60C360BF1; Sat, 12 Sep 2020 13:52:56 +0000 (UTC) Date: Sat, 12 Sep 2020 21:52:52 +0800 From: Ming Lei To: Mike Snitzer Cc: Vijayendra Suman , dm-devel@redhat.com, linux-block@vger.kernel.org Subject: Re: [PATCH 1/3] block: fix blk_rq_get_max_sectors() to flow more carefully Message-ID: <20200912135252.GA210077@T590> References: <20200911215338.44805-1-snitzer@redhat.com> <20200911215338.44805-2-snitzer@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200911215338.44805-2-snitzer@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Sep 11, 2020 at 05:53:36PM -0400, Mike Snitzer wrote: > blk_queue_get_max_sectors() has been trained for REQ_OP_WRITE_SAME and > REQ_OP_WRITE_ZEROES yet blk_rq_get_max_sectors() didn't call it for > those operations. Actually WRITE_SAME & WRITE_ZEROS are handled by the following if chunk_sectors is set: return min(blk_max_size_offset(q, offset), blk_queue_get_max_sectors(q, req_op(rq))); > Also, there is no need to avoid blk_max_size_offset() if > 'chunk_sectors' isn't set because it falls back to 'max_sectors'. > > Signed-off-by: Mike Snitzer > --- > include/linux/blkdev.h | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index bb5636cc17b9..453a3d735d66 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -1070,17 +1070,24 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq, > sector_t offset) > { > struct request_queue *q = rq->q; > + int op; > + unsigned int max_sectors; > > if (blk_rq_is_passthrough(rq)) > return q->limits.max_hw_sectors; > > - if (!q->limits.chunk_sectors || > - req_op(rq) == REQ_OP_DISCARD || > - req_op(rq) == REQ_OP_SECURE_ERASE) > - return blk_queue_get_max_sectors(q, req_op(rq)); > + op = req_op(rq); > + max_sectors = blk_queue_get_max_sectors(q, op); > > - return min(blk_max_size_offset(q, offset), > - blk_queue_get_max_sectors(q, req_op(rq))); > + switch (op) { > + case REQ_OP_DISCARD: > + case REQ_OP_SECURE_ERASE: > + case REQ_OP_WRITE_SAME: > + case REQ_OP_WRITE_ZEROES: > + return max_sectors; > + } > + > + return min(blk_max_size_offset(q, offset), max_sectors); > } It depends if offset & chunk_sectors limit for WRITE_SAME & WRITE_ZEROS needs to be considered. Thanks, Ming