From patchwork Fri Jun 4 19:58:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Satya Tangirala X-Patchwork-Id: 12300653 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 1FE2DC4743D for ; Fri, 4 Jun 2021 19:59:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECCF4613FE for ; Fri, 4 Jun 2021 19:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231296AbhFDUB0 (ORCPT ); Fri, 4 Jun 2021 16:01:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231280AbhFDUB0 (ORCPT ); Fri, 4 Jun 2021 16:01:26 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D09AC061767 for ; Fri, 4 Jun 2021 12:59:39 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id f8-20020a17090a9b08b0290153366612f7so5808654pjp.1 for ; Fri, 04 Jun 2021 12:59:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=RhhC1LCT8rPaij2tSlm0EtMdQdPIQzsHGIcTpwsWNJI=; b=O5mhaoiyKYAf2FfzdD/uW/qz8fTJnrej2bs/W7+lu74g5LgAj7VlgD7D4tFnxJb3he FQbQj+/C80HEGpU5SqGAk3NUW++OIXrCIruLKlmdOOq72YQ1ivruOsm625RttnnlH3jv dfOUu+3qLLNLfHZ40l4Mwrt9XygrfzDx6yNyNIlRu3H88Bmztyfi2DqV5KaZIsQww/Ni b47SNv6Pj/chBs7UKNLalXZDEhy8yL/fyVuuuVyjt6fW74CcqxSweP3GgM+1j977nB2z 4HaEp6V3+5ZgX4f78Sb8QxR0LAfzDLfZ9I6sF0rVsIp2r2k0qtRiGOHtnKwH+Cqv0btx GV3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=RhhC1LCT8rPaij2tSlm0EtMdQdPIQzsHGIcTpwsWNJI=; b=HvFgkxZKQfM3qCptmfIO3Cu2pBk/4CkFt0z1rC0qjsdTabCq8/0Q/Nxt9x7Grqxbaw mELXPXa0UVmc1Di/kbmF4W3fCN5zyNkEzBcgRWzfUXtRLAaZ3mOSDK2mIA5Tx9XELwDf pkY52hfDyRPg/u56nkt7iMVm5rliEwtdvKJCKlsH3fmT+8LFnbkgVi3ZAdtbNL1Qk79p OfcQt/RIFI1olzRBBxlDC5Feu4eYz1wuXEqvEcHrTR2xRJVi5r1xEdlbR2o7A0XmJnyY mDGxZnxFaBGZAE6CpS3DTG8yfijvSryHf94k44Zsb3Z5Puj8nJ/szowxKUXr8LLIHtFi h2Fg== X-Gm-Message-State: AOAM533HVQiWLtHp/tWX1pVkky0XpZJ6O8YsMsn1rA6+/LGU9KGCudh2 wptDWzljq1vgyw6IffR+N/euUxVEu6vsD+GXKJxk3+YV//68/sofc6ii8/0tZJBY92lI8Qlkgaz toCKZbnYIvCZKsvXhC1h5jo+qhHg4+dfV9qtt2NGfB+h0fhyikSX5k7z4U0gFtUIoGJnZ X-Google-Smtp-Source: ABdhPJx1/zbo9ivQFwgi7Hpi4EofsvvDKRafsmvEDyXZ3uBeDnv6H1UMIk6kN5bWlssKX/hbIujAVa0yiXM= X-Received: from satyaprateek.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:1092]) (user=satyat job=sendgmr) by 2002:a17:902:a5c9:b029:f7:9f7e:aa2f with SMTP id t9-20020a170902a5c9b02900f79f7eaa2fmr5978686plq.54.1622836778802; Fri, 04 Jun 2021 12:59:38 -0700 (PDT) Date: Fri, 4 Jun 2021 19:58:59 +0000 In-Reply-To: <20210604195900.2096121-1-satyat@google.com> Message-Id: <20210604195900.2096121-10-satyat@google.com> Mime-Version: 1.0 References: <20210604195900.2096121-1-satyat@google.com> X-Mailer: git-send-email 2.32.0.rc1.229.g3e70b5a671-goog Subject: [PATCH v3 09/10] blk-merge: Ensure bios aren't split in middle of a crypto data unit From: Satya Tangirala To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jens Axboe , Eric Biggers , Satya Tangirala Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Update get_max_io_size() to return a value aligned to bio_required_sector_alignment(). With this change, and the changes to blk_ksm_register() that restrict the supported data unit sizes based on the queue's limits, blk_bio_segment_split() won't split bios in the middle of a data unit anymore Signed-off-by: Satya Tangirala --- block/blk-merge.c | 49 ++++++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 18 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 4d97fb6dd226..00266e4ab05f 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -135,27 +135,39 @@ static struct bio *blk_bio_write_same_split(struct request_queue *q, /* * Return the maximum number of sectors from the start of a bio that may be - * submitted as a single request to a block device. If enough sectors remain, - * align the end to the physical block size. Otherwise align the end to the - * logical block size. This approach minimizes the number of non-aligned - * requests that are submitted to a block device if the start of a bio is not - * aligned to a physical block boundary. + * submitted as a single request to a block device. Tries to align the end to + * the physical block size, while also aligning the returned number of sectors + * to bio_required_sector_alignment(). This approach minimizes the number of + * non-aligned requests that are submitted to a block device if the start of a + * bio is not aligned to a physical block boundary. + * + * More clearly, there are two conditions we're interested in satisfying. + * + * Condition 1) We absolutely must have @return divisible by the + * bio_required_sector_alignment(bio). + * + * Condition 2) *If possible*, while still satisfying Condition 1, we would like + * to have start_offset + @return divisible by physical block size in sectors + * (pbs). */ static inline unsigned get_max_io_size(struct request_queue *q, struct bio *bio) { - unsigned sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector, 0); - unsigned max_sectors = sectors; - unsigned pbs = queue_physical_block_size(q) >> SECTOR_SHIFT; - unsigned lbs = queue_logical_block_size(q) >> SECTOR_SHIFT; - unsigned start_offset = bio->bi_iter.bi_sector & (pbs - 1); - - max_sectors += start_offset; - max_sectors &= ~(pbs - 1); - if (max_sectors > start_offset) - return max_sectors - start_offset; - - return sectors & ~(lbs - 1); + unsigned int start_offset = bio->bi_iter.bi_sector; + unsigned int sectors = blk_max_size_offset(q, start_offset, 0); + unsigned int pbs = queue_physical_block_size(q) >> SECTOR_SHIFT; + unsigned int req_sector_align = bio_required_sector_alignment(bio); + unsigned int pbs_aligned_sector = round_down(start_offset + sectors, pbs); + + /* + * If we can return a pbs aligned endpoint while satisfying Condition 1, + * then do so. + */ + if (pbs_aligned_sector > start_offset && + IS_ALIGNED(pbs_aligned_sector - start_offset, req_sector_align)) + return pbs_aligned_sector - start_offset; + + return round_down(sectors, req_sector_align); } static inline unsigned get_max_segment_size(const struct request_queue *q, @@ -235,6 +247,7 @@ static bool bvec_split_segs(const struct request_queue *q, * following is guaranteed for the cloned bio: * - That it has at most get_max_io_size(@q, @bio) sectors. * - That it has at most queue_max_segments(@q) segments. + * - That the number of sectors is aligned to bio_required_sector_alignment(@bio). * * Except for discard requests the cloned bio will point at the bi_io_vec of * the original bio. It is the responsibility of the caller to ensure that the @@ -286,7 +299,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, * big IO can be trival, disable iopoll when split needed. */ bio->bi_opf &= ~REQ_HIPRI; - + sectors = round_down(sectors, bio_required_sector_alignment(bio)); return bio_split(bio, sectors, GFP_NOIO, bs); }