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=-5.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A8C28C433E0 for ; Wed, 5 Aug 2020 23:16:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80A692177B for ; Wed, 5 Aug 2020 23:16:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="RedmrbDY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726013AbgHEXQL (ORCPT ); Wed, 5 Aug 2020 19:16:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725996AbgHEXQJ (ORCPT ); Wed, 5 Aug 2020 19:16:09 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AF2EC061756 for ; Wed, 5 Aug 2020 16:16:09 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id s15so14110050pgc.8 for ; Wed, 05 Aug 2020 16:16:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=mX2RQWIeukytd4cMjhvK2ERywuLZIUHHxAhzXb8p2CI=; b=RedmrbDYX8xHeYwBAyAMe59kGo6ejds4t+fKQDTHMHVZoIiRoXnp4eetVKZsqZHvwp bqEa8dXP/bjqtUXZco7PnDuarFsJZZ+0SOLSAkZe6au6PqS/zfZhse/wsReGuyYCDPoZ d/Uh/xAzUKc6Q05Las/S09motL9sXLvpByuOUy+OUqik3Konpp/RoaoMOO5PbFlA06GR 2gpNpMxRLB6FIWqnW8q5bysp7XVnQrsC9pPMu0IVvfJIfQn79jx6r94rbbHt4SWz+SGE Ps2M5P4EPLv6QpD0+ajMO5TjQEgHAl4iANb5kH+o9uXBTGe1IWue0N+6UoZ/nVp6B8CJ fXxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=mX2RQWIeukytd4cMjhvK2ERywuLZIUHHxAhzXb8p2CI=; b=TFYNZjSl2NAloqNwbjid+p5cS83C8TBcyAZzPI86HlfGPsRSJYMYZynzwMex2OL2oJ iPtJzJ8yMublCgEXy9L11YM5VIa99V8a4N8LJuqo/uRT4W3Spp8pun1AFz4r6xv+84nX l+pxge4+D0fL2n6cvGFySXGSyvqyBRnhnozkNTyODvnLlaAi+InR6nfFLwONuh0lz+4f E0VzlNluiBR++2Sv7EjAzvAQ9HI2+F3Lp+aiuR1KlaLrPSMsFciMv2IAjK8O1hsQsmmR /kVTO1OF2JP3V4UOUuvnXsigTBK2RrHFoj6jqHs3nSB5io6IEA/YlYpp1daUDzIxEjem uj3g== X-Gm-Message-State: AOAM530xDPcr/6kPn/nZx3eVEylJnFTZsgICPLKTtqCcUZU3ca9wKWyE Yvlqad05Pnejb7qE71gTKCd9nw== X-Google-Smtp-Source: ABdhPJxdhapAiWis8V0esUSVfVlcLDvYs+fpc50sa9uce/UQJLnj8/1rVj6gBsGtyKYnT4OhMkVUCw== X-Received: by 2002:aa7:9241:: with SMTP id 1mr5877013pfp.188.1596669368189; Wed, 05 Aug 2020 16:16:08 -0700 (PDT) Received: from [192.168.1.182] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id e4sm5160490pfd.204.2020.08.05.16.16.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 05 Aug 2020 16:16:07 -0700 (PDT) Subject: Re: [PATCH v4] block: check queue's limits.discard_granularity in __blkdev_issue_discard() To: Coly Li , linux-block@vger.kernel.org Cc: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, Ming Lei , Hannes Reinecke , Jack Wang , Bart Van Assche , Christoph Hellwig , "Darrick J . Wong" , Enzo Matsumiya , Evan Green , "Martin K . Petersen" , Xiao Ni References: <20200805172503.45121-1-colyli@suse.de> From: Jens Axboe Message-ID: Date: Wed, 5 Aug 2020 17:16:05 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200805172503.45121-1-colyli@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-bcache-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org On 8/5/20 11:25 AM, Coly Li wrote: > If create a loop device with a backing NVMe SSD, current loop device > driver doesn't correctly set its queue's limits.discard_granularity and > leaves it as 0. If a discard request at LBA 0 on this loop device, in > __blkdev_issue_discard() the calculated req_sects will be 0, and a zero > length discard request will trigger a BUG() panic in generic block layer > code at block/blk-mq.c:563. > > [ 955.565006][ C39] ------------[ cut here ]------------ > [ 955.559660][ C39] invalid opcode: 0000 [#1] SMP NOPTI > [ 955.622171][ C39] CPU: 39 PID: 248 Comm: ksoftirqd/39 Tainted: G E 5.8.0-default+ #40 > [ 955.622171][ C39] Hardware name: Lenovo ThinkSystem SR650 -[7X05CTO1WW]-/-[7X05CTO1WW]-, BIOS -[IVE160M-2.70]- 07/17/2020 > [ 955.622175][ C39] RIP: 0010:blk_mq_end_request+0x107/0x110 > [ 955.622177][ C39] Code: 48 8b 03 e9 59 ff ff ff 48 89 df 5b 5d 41 5c e9 9f ed ff ff 48 8b 35 98 3c f4 00 48 83 c7 10 48 83 c6 19 e8 cb 56 c9 ff eb cb <0f> 0b 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 54 > [ 955.622179][ C39] RSP: 0018:ffffb1288701fe28 EFLAGS: 00010202 > [ 955.749277][ C39] RAX: 0000000000000001 RBX: ffff956fffba5080 RCX: 0000000000004003 > [ 955.749278][ C39] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 > [ 955.749279][ C39] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > [ 955.749279][ C39] R10: ffffb1288701fd28 R11: 0000000000000001 R12: ffffffffa8e05160 > [ 955.749280][ C39] R13: 0000000000000004 R14: 0000000000000004 R15: ffffffffa7ad3a1e > [ 955.749281][ C39] FS: 0000000000000000(0000) GS:ffff95bfbda00000(0000) knlGS:0000000000000000 > [ 955.749282][ C39] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 955.749282][ C39] CR2: 00007f6f0ef766a8 CR3: 0000005a37012002 CR4: 00000000007606e0 > [ 955.749283][ C39] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 955.749284][ C39] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 955.749284][ C39] PKRU: 55555554 > [ 955.749285][ C39] Call Trace: > [ 955.749290][ C39] blk_done_softirq+0x99/0xc0 > [ 957.550669][ C39] __do_softirq+0xd3/0x45f > [ 957.550677][ C39] ? smpboot_thread_fn+0x2f/0x1e0 > [ 957.550679][ C39] ? smpboot_thread_fn+0x74/0x1e0 > [ 957.550680][ C39] ? smpboot_thread_fn+0x14e/0x1e0 > [ 957.550684][ C39] run_ksoftirqd+0x30/0x60 > [ 957.550687][ C39] smpboot_thread_fn+0x149/0x1e0 > [ 957.886225][ C39] ? sort_range+0x20/0x20 > [ 957.886226][ C39] kthread+0x137/0x160 > [ 957.886228][ C39] ? kthread_park+0x90/0x90 > [ 957.886231][ C39] ret_from_fork+0x22/0x30 > [ 959.117120][ C39] ---[ end trace 3dacdac97e2ed164 ]--- > > This is the procedure to reproduce the panic, > # modprobe scsi_debug delay=0 dev_size_mb=2048 max_queue=1 > # losetup -f /dev/nvme0n1 --direct-io=on > # blkdiscard /dev/loop0 -o 0 -l 0x200 > > This patch fixes the issue by checking q->limits.discard_granularity in > __blkdev_issue_discard() before composing the discard bio. If the value > is 0, then prints a warning oops information and returns -EOPNOTSUPP to > the caller to indicate that this buggy device driver doesn't support > discard request. Applied, thanks. -- Jens Axboe