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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 83482C19425 for ; Wed, 9 Dec 2020 15:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54D1122B4B for ; Wed, 9 Dec 2020 15:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731424AbgLIPyv (ORCPT ); Wed, 9 Dec 2020 10:54:51 -0500 Received: from forward2-smtp.messagingengine.com ([66.111.4.226]:41047 "EHLO forward2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728826AbgLIPyv (ORCPT ); Wed, 9 Dec 2020 10:54:51 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailforward.nyi.internal (Postfix) with ESMTP id 12FD7194399D; Wed, 9 Dec 2020 03:42:33 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Wed, 09 Dec 2020 03:42:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=Voc4Oo ITFyMRDbyjjKyDwRCzAWb46iPvavHbUBXzi58=; b=YdtMf5Xie4Py+gWHkNKCLl +faitDCGePhb6B/IY36t0prgtC6qkeb6GaebOChTIEFqMwEZGapt1x+hJnHcFh1n moJjtX2Y0CvdPF7kdOl+FnFnEQcF5UG+F1czcOo7Q1pN7wHzxnKluRM5fuC7zzBS hAzY5RnWDUUAACYiaw/GqEEdd522E65SVDJVbX5COn8ThJF6R2otvO1iIIpfm5ya erkhfiPwsbAD+Zfd9FfRjRuLOEbZ0p4dt/gDjzhLcbTXLFWnYaRxkus24G6UTrc1 N7C6YbVzkBdln/qG9REfChC8nezHUuqmJWbavtic3atL5yQRiLJMqU/tPcs+z76g == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrudejjedguddvvdcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertd dttdflnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdho rhhgqeenucggtffrrghtthgvrhhnpeeiteevheeuvdfhtdfgvdeiieehheefleevveehje duteevueevledujeejgfetheenucfkphepkeefrdekiedrjeegrdeigeenucevlhhushht vghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhh drtghomh X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id B81CB240064; Wed, 9 Dec 2020 03:42:31 -0500 (EST) Subject: FAILED: patch "[PATCH] dm: fix IO splitting" failed to apply to 5.9-stable tree To: snitzer@redhat.com, axboe@kernel.dk, bjohnsto@redhat.com, jdorminy@redhat.com, ktkhai@virtuozzo.com Cc: From: Date: Wed, 09 Dec 2020 09:43:49 +0100 Message-ID: <160750342912147@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3ee16db390b42b8a21f2ad2ea2518f3469c6e532 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 30 Nov 2020 10:57:43 -0500 Subject: [PATCH] dm: fix IO splitting Commit 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") caused a couple regressions: 1) Using lcm_not_zero() when stacking chunk_sectors was a bug because chunk_sectors must reflect the most limited of all devices in the IO stack. 2) DM targets that set max_io_len but that do _not_ provide an .iterate_devices method no longer had there IO split properly. And commit 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") also caused a regression where DM no longer supported varied (per target) IO splitting. The implication being the potential for severely reduced performance for IO stacks that use a DM target like dm-cache to hide performance limitations of a slower device (e.g. one that requires 4K IO splitting). Coming full circle: Fix all these issues by discontinuing stacking chunk_sectors up using ti->max_io_len in dm_calculate_queue_limits(), add optional chunk_sectors override argument to blk_max_size_offset() and update DM's max_io_len() to pass ti->max_io_len to its blk_max_size_offset() call. Passing in an optional chunk_sectors override to blk_max_size_offset() allows for code reuse of block's centralized calculation for max IO size based on provided offset and split boundary. Fixes: 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") Fixes: 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") Cc: stable@vger.kernel.org Reported-by: John Dorminy Reported-by: Bruce Johnston Reported-by: Kirill Tkhai Reviewed-by: John Dorminy Signed-off-by: Mike Snitzer Reviewed-by: Jens Axboe diff --git a/block/blk-merge.c b/block/blk-merge.c index bcf5e4580603..97b7c2821565 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -144,7 +144,7 @@ static struct bio *blk_bio_write_same_split(struct request_queue *q, 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); + 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; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 2073ee8d18f4..7eeb7c4169c9 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -18,7 +18,6 @@ #include #include #include -#include #include #include #include @@ -1449,10 +1448,6 @@ int dm_calculate_queue_limits(struct dm_table *table, zone_sectors = ti_limits.chunk_sectors; } - /* Stack chunk_sectors if target-specific splitting is required */ - if (ti->max_io_len) - ti_limits.chunk_sectors = lcm_not_zero(ti->max_io_len, - ti_limits.chunk_sectors); /* Set I/O hints portion of queue limits */ if (ti->type->io_hints) ti->type->io_hints(ti, &ti_limits); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 98866e725f25..f7eb3d2964f3 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1039,15 +1039,18 @@ static sector_t max_io_len(struct dm_target *ti, sector_t sector) sector_t max_len; /* - * Does the target need to split even further? - * - q->limits.chunk_sectors reflects ti->max_io_len so - * blk_max_size_offset() provides required splitting. - * - blk_max_size_offset() also respects q->limits.max_sectors + * Does the target need to split IO even further? + * - varied (per target) IO splitting is a tenet of DM; this + * explains why stacked chunk_sectors based splitting via + * blk_max_size_offset() isn't possible here. So pass in + * ti->max_io_len to override stacked chunk_sectors. */ - max_len = blk_max_size_offset(ti->table->md->queue, - target_offset); - if (len > max_len) - len = max_len; + if (ti->max_io_len) { + max_len = blk_max_size_offset(ti->table->md->queue, + target_offset, ti->max_io_len); + if (len > max_len) + len = max_len; + } return len; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 639cae2c158b..24ae504cf77d 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1073,11 +1073,12 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, * file system requests. */ static inline unsigned int blk_max_size_offset(struct request_queue *q, - sector_t offset) + sector_t offset, + unsigned int chunk_sectors) { - unsigned int chunk_sectors = q->limits.chunk_sectors; - - if (!chunk_sectors) + if (!chunk_sectors && q->limits.chunk_sectors) + chunk_sectors = q->limits.chunk_sectors; + else return q->limits.max_sectors; if (likely(is_power_of_2(chunk_sectors))) @@ -1101,7 +1102,7 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq, req_op(rq) == REQ_OP_SECURE_ERASE) return blk_queue_get_max_sectors(q, req_op(rq)); - return min(blk_max_size_offset(q, offset), + return min(blk_max_size_offset(q, offset, 0), blk_queue_get_max_sectors(q, req_op(rq))); }