From patchwork Mon Nov 26 02:17:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10697285 X-Patchwork-Delegate: snitzer@redhat.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B229E16B1 for ; Mon, 26 Nov 2018 02:18:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9D706293BD for ; Mon, 26 Nov 2018 02:18:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 911A129618; Mon, 26 Nov 2018 02:18:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id EBD1929927 for ; Mon, 26 Nov 2018 02:18:16 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A2A69308219B; Mon, 26 Nov 2018 02:18:15 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 79A861057062; Mon, 26 Nov 2018 02:18:15 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 3EDFC3F604; Mon, 26 Nov 2018 02:18:15 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id wAQ2ID6i020025 for ; Sun, 25 Nov 2018 21:18:13 -0500 Received: by smtp.corp.redhat.com (Postfix) id C89E72CD5B; Mon, 26 Nov 2018 02:18:13 +0000 (UTC) Delivered-To: dm-devel@redhat.com Received: from localhost (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1F0DD2D17B; Mon, 26 Nov 2018 02:18:04 +0000 (UTC) From: Ming Lei To: Jens Axboe Date: Mon, 26 Nov 2018 10:17:03 +0800 Message-Id: <20181126021720.19471-4-ming.lei@redhat.com> In-Reply-To: <20181126021720.19471-1-ming.lei@redhat.com> References: <20181126021720.19471-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-loop: dm-devel@redhat.com Cc: Mike Snitzer , linux-mm@kvack.org, dm-devel@redhat.com, Christoph Hellwig , Sagi Grimberg , "Darrick J . Wong" , Omar Sandoval , cluster-devel@redhat.com, linux-ext4@vger.kernel.org, Shaohua Li , Kent Overstreet , Boaz Harrosh , Gao Xiang , Coly Li , linux-raid@vger.kernel.org, Bob Peterson , linux-bcache@vger.kernel.org, Alexander Viro , Dave Chinner , David Sterba , Ming Lei , linux-block@vger.kernel.org, Theodore Ts'o , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org Subject: [dm-devel] [PATCH V12 03/20] block: remove the "cluster" flag X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Mon, 26 Nov 2018 02:18:16 +0000 (UTC) X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig The cluster flag implements some very old SCSI behavior. As far as I can tell the original intent was to enable or disable any kind of segment merging. But the actually visible effect to the LLDD is that it limits each segments to be inside a single page, which we can also affect by setting the maximum segment size and the segment boundary. Signed-off-by: Christoph Hellwig Replace virt boundary with segment boundary limit. Signed-off-by: Ming Lei Reviewed-by: Omar Sandoval --- block/blk-merge.c | 20 ++++++++------------ block/blk-settings.c | 3 --- block/blk-sysfs.c | 5 +---- drivers/scsi/scsi_lib.c | 20 ++++++++++++++++---- include/linux/blkdev.h | 6 ------ 5 files changed, 25 insertions(+), 29 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 6be04ef8da5b..e69d8f8ba819 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -195,7 +195,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, goto split; } - if (bvprvp && blk_queue_cluster(q)) { + if (bvprvp) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; if (!biovec_phys_mergeable(q, bvprvp, &bv)) @@ -295,10 +295,10 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, bool no_sg_merge) { struct bio_vec bv, bvprv = { NULL }; - int cluster, prev = 0; unsigned int seg_size, nr_phys_segs; struct bio *fbio, *bbio; struct bvec_iter iter; + bool prev = false; if (!bio) return 0; @@ -313,7 +313,6 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, } fbio = bio; - cluster = blk_queue_cluster(q); seg_size = 0; nr_phys_segs = 0; for_each_bio(bio) { @@ -325,7 +324,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, if (no_sg_merge) goto new_segment; - if (prev && cluster) { + if (prev) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; @@ -343,7 +342,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, nr_phys_segs++; bvprv = bv; - prev = 1; + prev = true; seg_size = bv.bv_len; } bbio = bio; @@ -396,9 +395,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, { struct bio_vec end_bv = { NULL }, nxt_bv; - if (!blk_queue_cluster(q)) - return 0; - if (bio->bi_seg_back_size + nxt->bi_seg_front_size > queue_max_segment_size(q)) return 0; @@ -415,12 +411,12 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, static inline void __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec, struct scatterlist *sglist, struct bio_vec *bvprv, - struct scatterlist **sg, int *nsegs, int *cluster) + struct scatterlist **sg, int *nsegs) { int nbytes = bvec->bv_len; - if (*sg && *cluster) { + if (*sg) { if ((*sg)->length + nbytes > queue_max_segment_size(q)) goto new_segment; if (!biovec_phys_mergeable(q, bvprv, bvec)) @@ -466,12 +462,12 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio, { struct bio_vec bvec, bvprv = { NULL }; struct bvec_iter iter; - int cluster = blk_queue_cluster(q), nsegs = 0; + int nsegs = 0; for_each_bio(bio) bio_for_each_segment(bvec, bio, iter) __blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg, - &nsegs, &cluster); + &nsegs); return nsegs; } diff --git a/block/blk-settings.c b/block/blk-settings.c index 3abe831e92c8..3e7038e475ee 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -56,7 +56,6 @@ void blk_set_default_limits(struct queue_limits *lim) lim->alignment_offset = 0; lim->io_opt = 0; lim->misaligned = 0; - lim->cluster = 1; lim->zoned = BLK_ZONED_NONE; } EXPORT_SYMBOL(blk_set_default_limits); @@ -547,8 +546,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->io_min = max(t->io_min, b->io_min); t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); - t->cluster &= b->cluster; - /* Physical block size a multiple of the logical block size? */ if (t->physical_block_size & (t->logical_block_size - 1)) { t->physical_block_size = t->logical_block_size; diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 80eef48fddc8..ef7b844a3e00 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -132,10 +132,7 @@ static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char * static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) { - if (blk_queue_cluster(q)) - return queue_var_show(queue_max_segment_size(q), (page)); - - return queue_var_show(PAGE_SIZE, (page)); + return queue_var_show(queue_max_segment_size(q), page); } static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 0df15cb738d2..78d6d05992b0 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1810,6 +1810,8 @@ static int scsi_map_queues(struct blk_mq_tag_set *set) void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) { struct device *dev = shost->dma_dev; + unsigned max_segment_size = dma_get_max_seg_size(dev); + unsigned long segment_boundary = shost->dma_boundary; /* * this limit is imposed by hardware restrictions @@ -1828,13 +1830,23 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) blk_queue_max_hw_sectors(q, shost->max_sectors); if (shost->unchecked_isa_dma) blk_queue_bounce_limit(q, BLK_BOUNCE_ISA); - blk_queue_segment_boundary(q, shost->dma_boundary); dma_set_seg_boundary(dev, shost->dma_boundary); - blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); + /* + * Clustering is a really old concept from the stone age of Linux + * SCSI support. But the basic idea is that we never give the + * driver a segment that spans multiple pages. For that we need + * to limit the segment size, and set the segment boundary so that + * we never merge a second segment which is no page aligned. + */ + if (!shost->use_clustering) { + max_segment_size = min_t(unsigned, max_segment_size, PAGE_SIZE); + segment_boundary = min_t(unsigned, segment_boundary, + PAGE_SIZE - 1); + } - if (!shost->use_clustering) - q->limits.cluster = 0; + blk_queue_max_segment_size(q, max_segment_size); + blk_queue_segment_boundary(q, segment_boundary); /* * Set a reasonable default alignment: The larger of 32-byte (dword), diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 9b53db06ad08..399a7a415609 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -341,7 +341,6 @@ struct queue_limits { unsigned char misaligned; unsigned char discard_misaligned; - unsigned char cluster; unsigned char raid_partial_stripes_expensive; enum blk_zoned_model zoned; }; @@ -660,11 +659,6 @@ static inline bool queue_is_mq(struct request_queue *q) return q->mq_ops; } -static inline unsigned int blk_queue_cluster(struct request_queue *q) -{ - return q->limits.cluster; -} - static inline enum blk_zoned_model blk_queue_zoned_model(struct request_queue *q) {