From patchwork Mon Mar 29 07:58:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 412684 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 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 00ABEC433DB for ; Mon, 29 Mar 2021 08:18:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFAE7619B1 for ; Mon, 29 Mar 2021 08:18:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232561AbhC2ISF (ORCPT ); Mon, 29 Mar 2021 04:18:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:57206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232599AbhC2IQH (ORCPT ); Mon, 29 Mar 2021 04:16:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0C7D461996; Mon, 29 Mar 2021 08:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005743; bh=f4SrBsKx2dgW3UIsr+CYOr0HFYiWiaDu53knJp07cAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cjUco6+MFYO/hdEUXxQ1jxxlHVl0RulsGexnhqFlIXUZvuyEPgs0HQMSZyE2HsLiw PM3VHYRm3d/NKNXIBeeiSgIFU5P0/twx/DDXBYcaKrz0nOd01UYVfoS7Lj5YPeCnGk gqn0sSf9mCwt/tSWnuEmu/XPpC2H9aMh2DoEVXJQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Jeffery , Ming Lei , Laurence Oberman , Jens Axboe , Sasha Levin Subject: [PATCH 5.4 100/111] block: recalculate segment count for multi-segment discards correctly Date: Mon, 29 Mar 2021 09:58:48 +0200 Message-Id: <20210329075618.551953331@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075615.186199980@linuxfoundation.org> References: <20210329075615.186199980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Jeffery [ Upstream commit a958937ff166fc60d1c3a721036f6ff41bfa2821 ] When a stacked block device inserts a request into another block device using blk_insert_cloned_request, the request's nr_phys_segments field gets recalculated by a call to blk_recalc_rq_segments in blk_cloned_rq_check_limits. But blk_recalc_rq_segments does not know how to handle multi-segment discards. For disk types which can handle multi-segment discards like nvme, this results in discard requests which claim a single segment when it should report several, triggering a warning in nvme and causing nvme to fail the discard from the invalid state. WARNING: CPU: 5 PID: 191 at drivers/nvme/host/core.c:700 nvme_setup_discard+0x170/0x1e0 [nvme_core] ... nvme_setup_cmd+0x217/0x270 [nvme_core] nvme_loop_queue_rq+0x51/0x1b0 [nvme_loop] __blk_mq_try_issue_directly+0xe7/0x1b0 blk_mq_request_issue_directly+0x41/0x70 ? blk_account_io_start+0x40/0x50 dm_mq_queue_rq+0x200/0x3e0 blk_mq_dispatch_rq_list+0x10a/0x7d0 ? __sbitmap_queue_get+0x25/0x90 ? elv_rb_del+0x1f/0x30 ? deadline_remove_request+0x55/0xb0 ? dd_dispatch_request+0x181/0x210 __blk_mq_do_dispatch_sched+0x144/0x290 ? bio_attempt_discard_merge+0x134/0x1f0 __blk_mq_sched_dispatch_requests+0x129/0x180 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x47/0xe0 __blk_mq_delay_run_hw_queue+0x15b/0x170 blk_mq_sched_insert_requests+0x68/0xe0 blk_mq_flush_plug_list+0xf0/0x170 blk_finish_plug+0x36/0x50 xlog_cil_committed+0x19f/0x290 [xfs] xlog_cil_process_committed+0x57/0x80 [xfs] xlog_state_do_callback+0x1e0/0x2a0 [xfs] xlog_ioend_work+0x2f/0x80 [xfs] process_one_work+0x1b6/0x350 worker_thread+0x53/0x3e0 ? process_one_work+0x350/0x350 kthread+0x11b/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x22/0x30 This patch fixes blk_recalc_rq_segments to be aware of devices which can have multi-segment discards. It calculates the correct discard segment count by counting the number of bio as each discard bio is considered its own segment. Fixes: 1e739730c5b9 ("block: optionally merge discontiguous discard bios into a single request") Signed-off-by: David Jeffery Reviewed-by: Ming Lei Reviewed-by: Laurence Oberman Link: https://lore.kernel.org/r/20210211143807.GA115624@redhat Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-merge.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/blk-merge.c b/block/blk-merge.c index 86c4c1ef8742..03959bfe961c 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -370,6 +370,14 @@ unsigned int blk_recalc_rq_segments(struct request *rq) switch (bio_op(rq->bio)) { case REQ_OP_DISCARD: case REQ_OP_SECURE_ERASE: + if (queue_max_discard_segments(rq->q) > 1) { + struct bio *bio = rq->bio; + + for_each_bio(bio) + nr_phys_segs++; + return nr_phys_segs; + } + return 1; case REQ_OP_WRITE_ZEROES: return 0; case REQ_OP_WRITE_SAME: