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=-4.2 required=3.0 tests=BAYES_00,DKIM_ADSP_ALL, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D1A6FC433B4 for ; Sat, 15 May 2021 19:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5DBA61139 for ; Sat, 15 May 2021 19:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231436AbhEOTYa (ORCPT ); Sat, 15 May 2021 15:24:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231334AbhEOTY3 (ORCPT ); Sat, 15 May 2021 15:24:29 -0400 X-Greylist: delayed 1017 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sat, 15 May 2021 12:23:15 PDT Received: from mail.thorsten-knabe.de (mail.thorsten-knabe.de [IPv6:2a01:170:101e::d43c:8be2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03E73C061573 for ; Sat, 15 May 2021 12:23:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thorsten-knabe.de; s=dkim1; h=Content-Transfer-Encoding:Content-Type: MIME-Version:Date:Message-ID:Subject:To:From:Sender:Reply-To:Cc:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=vW/RcWJmY76BE49OBoxY2NG+uqS+Xjg2Ua3q28+r+RE=; b=ouLTuP7EeWz0FfFEFbGMZuj+td eOXf6ER7lZ0f56Z5g/Wj0i5B67FNI5t8xeqqjlflz5hI/66+wkpwlso6xEEah7TVgqDex7iK0r3v0 yCWS6i4IjmnjtpJWwXSXRirBZL1Ks30hq4Kcy/4FtDhiXGh0odWnu6QkdyPggKHzEZleNbVLbFr9t OUsSCL3AJ5PYtt14k1fl3MZoV7Hj95mbccr02PCzQMtkI0DE7YSHewu1UhaRKkiuoBEF7l5X5vNFP 7s4ZGMBFst/uZf0sNZr0cG95ImxNR+5LZKRqs+KsgZznGlhE8002GASEA5/KieluCWu9maYQvqc8w sEC34yNA==; Received: from tek01.intern.thorsten-knabe.de ([2a01:170:101e:1::a00:101]) by mail.thorsten-knabe.de with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1lhzbz-0006OX-UV for linux-bcache@vger.kernel.org; Sat, 15 May 2021 21:06:10 +0200 From: Thorsten Knabe To: linux-bcache@vger.kernel.org Subject: PROBLEM: bcache related kernel BUG() since Linux 5.12 Message-ID: <58f92cd7-38d1-bc16-2b5f-b68b2db2233b@thorsten-knabe.de> Date: Sat, 15 May 2021 21:06:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org Hello. Starting with Linux 5.12 bcache triggers a BUG() after a few minutes of usage. Linux up to 5.11.x is not affected by this bug. Environment: - Debian 10 AMD 64 - Kernel 5.12 - 5.12.4 - Filesystem ext4 - Backing device: degraded software RAID-6 (MD) with 3 of 4 disks active (unsure if the degraded RAID-6 has an effect or not) - Cache device: Single SSD Kernel log: May 12 20:22:24 tek04 kernel: nr_vecs=472 May 12 20:22:24 tek04 kernel: ------------[ cut here ]------------ May 12 20:22:24 tek04 kernel: kernel BUG at block/bio.c:53! May 12 20:22:24 tek04 kernel: invalid opcode: 0000 [#1] PREEMPT SMP PTI May 12 20:22:24 tek04 kernel: CPU: 1 PID: 1670 Comm: grep Tainted: G I 5.12.3 #2 May 12 20:22:24 tek04 kernel: Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X58 Deluxe, BIOS P2.20 10/30/2009 May 12 20:22:24 tek04 kernel: RIP: 0010:biovec_slab.cold.45+0xf/0x11 May 12 20:22:24 tek04 kernel: Code: b3 ae ff 89 c6 48 c7 c7 30 82 21 82 e8 03 81 fe ff b8 b6 ff ff ff e9 3d bc ae ff 0f b7 f7 48 c7 c7 c4 82 21 82 e8 ea 80 fe ff <0f> 0b 49 8b b4 24 d0 00 00 00 48 c7 c7 40 84 21 82 e8 d4 80 fe ff May 12 20:22:24 tek04 kernel: RSP: 0018:ffffc9000274b730 EFLAGS: 00010292 May 12 20:22:24 tek04 kernel: RAX: 000000000000000b RBX: ffffc9000274b764 RCX: 0000000000000000 May 12 20:22:24 tek04 kernel: bch_count_backing_io_errors: 1 callbacks suppressed May 12 20:22:24 tek04 kernel: bcache: bch_count_backing_io_errors() md1: Read-ahead I/O failed on backing device, ignore May 12 20:22:24 tek04 kernel: RDX: ffff888333c5e400 RSI: ffff888333c57480 RDI: ffff888333c57480 May 12 20:22:24 tek04 kernel: RBP: 0000000000000800 R08: 0000000000000000 R09: c0000000ffffdfff May 12 20:22:24 tek04 kernel: R10: ffffc9000274b580 R11: ffffc9000274b578 R12: ffff8881170f0118 May 12 20:22:24 tek04 kernel: R13: ffff888109911b00 R14: ffff8881170f00d0 R15: 0000000000000800 May 12 20:22:24 tek04 kernel: FS: 00007f3a1ca7cb80(0000) GS:ffff888333c40000(0000) knlGS:0000000000000000 May 12 20:22:24 tek04 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 May 12 20:22:24 tek04 kernel: CR2: 00005628963f4fd0 CR3: 000000016c43c000 CR4: 00000000000006e0 May 12 20:22:24 tek04 kernel: Call Trace: May 12 20:22:24 tek04 kernel: bvec_alloc+0x22/0x90 May 12 20:22:24 tek04 kernel: bio_alloc_bioset+0x176/0x230 May 12 20:22:24 tek04 kernel: cached_dev_cache_miss+0x1a8/0x300 May 12 20:22:24 tek04 kernel: cache_lookup_fn+0x110/0x2e0 May 12 20:22:24 tek04 kernel: ? bch_ptr_invalid+0x10/0x10 May 12 20:22:24 tek04 kernel: ? bch_btree_iter_next_filter+0x1af/0x2d0 May 12 20:22:24 tek04 kernel: ? cache_lookup+0x190/0x190 May 12 20:22:24 tek04 kernel: bch_btree_map_keys_recurse+0x69/0x160 May 12 20:22:24 tek04 kernel: ? __bch_bset_search+0x315/0x440 May 12 20:22:24 tek04 kernel: ? downgrade_write+0xb0/0xb0 May 12 20:22:24 tek04 kernel: ? cache_lookup+0x190/0x190 May 12 20:22:24 tek04 kernel: bch_btree_map_keys_recurse+0xcf/0x160 May 12 20:22:24 tek04 kernel: ? raid5_make_request+0x5c4/0xaa0 May 12 20:22:24 tek04 kernel: ? recalibrate_cpu_khz+0x10/0x10 May 12 20:22:24 tek04 kernel: ? kmem_cache_alloc+0x30/0x400 May 12 20:22:24 tek04 kernel: ? rwsem_wake.isra.11+0x80/0x80 May 12 20:22:24 tek04 kernel: bch_btree_map_keys+0xf2/0x140 May 12 20:22:24 tek04 kernel: ? cache_lookup+0x190/0x190 May 12 20:22:24 tek04 kernel: cache_lookup+0xb1/0x190 May 12 20:22:24 tek04 kernel: cached_dev_submit_bio+0x9ab/0xc90 May 12 20:22:24 tek04 kernel: ? submit_bio_checks+0x197/0x4a0 May 12 20:22:24 tek04 kernel: ? kmem_cache_alloc+0x3b7/0x400 May 12 20:22:24 tek04 kernel: submit_bio_noacct+0x10e/0x4c0 May 12 20:22:24 tek04 kernel: submit_bio+0x2e/0x160 May 12 20:22:24 tek04 kernel: ? xa_load+0x66/0x70 May 12 20:22:24 tek04 kernel: ? bio_add_page+0x2f/0x70 May 12 20:22:24 tek04 kernel: ext4_mpage_readpages+0x1ae/0xa00 May 12 20:22:24 tek04 kernel: ? __mod_lruvec_state+0x29/0x60 May 12 20:22:24 tek04 kernel: read_pages+0x78/0x1d0 May 12 20:22:24 tek04 kernel: page_cache_ra_unbounded+0x127/0x1b0 May 12 20:22:24 tek04 kernel: filemap_get_pages+0x1d0/0x4a0 May 12 20:22:24 tek04 kernel: filemap_read+0x91/0x2d0 May 12 20:22:24 tek04 kernel: new_sync_read+0x103/0x180 May 12 20:22:24 tek04 kernel: vfs_read+0x11b/0x1b0 May 12 20:22:24 tek04 kernel: ksys_read+0x55/0xd0 May 12 20:22:24 tek04 kernel: do_syscall_64+0x33/0x80 May 12 20:22:24 tek04 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae May 12 20:22:24 tek04 kernel: RIP: 0033:0x7f3a1cb89461 May 12 20:22:24 tek04 kernel: Code: fe ff ff 50 48 8d 3d fe d0 09 00 e8 e9 03 02 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 99 62 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 41 54 49 89 d4 55 48 May 12 20:22:24 tek04 kernel: RSP: 002b:00007fff4052fff8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 May 12 20:22:24 tek04 kernel: RAX: ffffffffffffffda RBX: 0000000000018000 RCX: 00007f3a1cb89461 May 12 20:22:24 tek04 kernel: RDX: 0000000000018000 RSI: 000055ff0d01a000 RDI: 0000000000000004 May 12 20:22:24 tek04 kernel: RBP: 0000000000018000 R08: 0000000000000002 R09: 000055ff0d0194b0 May 12 20:22:24 tek04 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 000055ff0d01a000 May 12 20:22:24 tek04 kernel: R13: 0000000000000004 R14: 000055ff0d0194b0 R15: 0000000000000004 May 12 20:22:24 tek04 kernel: Modules linked in: cmac bnep intel_powerclamp snd_hda_codec_realtek snd_hda_codec_generic btusb ledtrig_audio snd_hda_codec_hdmi btrtl kvm_intel snd_hda_intel btbcm snd_intel_dspcfg btintel kvm snd_hda_codec irqbypass bluetooth serio_raw pcspkr hfcpci snd_hda_core iTCO_wdt evdev input_leds joydev sg snd_hwdep intel_pmc_bxt ecdh_generic rfkill iTCO_vendor_support mISDN_core ecc snd_pcm snd_timer tiny_power_button snd soundcore button i7core_edac acpi_cpufreq wmi nft_counter nf_log_ipv6 nf_log_ipv May 12 20:22:24 tek04 kernel: ---[ end trace 9a03f30c7b4aa246 ]--- May 12 20:22:25 tek04 kernel: RIP: 0010:biovec_slab.cold.45+0xf/0x11 May 12 20:22:25 tek04 kernel: Code: b3 ae ff 89 c6 48 c7 c7 30 82 21 82 e8 03 81 fe ff b8 b6 ff ff ff e9 3d bc ae ff 0f b7 f7 48 c7 c7 c4 82 21 82 e8 ea 80 fe ff <0f> 0b 49 8b b4 24 d0 00 00 00 48 c7 c7 40 84 21 82 e8 d4 80 fe ff May 12 20:22:25 tek04 kernel: RSP: 0018:ffffc9000274b730 EFLAGS: 00010292 May 12 20:22:25 tek04 kernel: RAX: 000000000000000b RBX: ffffc9000274b764 RCX: 0000000000000000 May 12 20:22:25 tek04 kernel: RDX: ffff888333c5e400 RSI: ffff888333c57480 RDI: ffff888333c57480 May 12 20:22:25 tek04 kernel: RBP: 0000000000000800 R08: 0000000000000000 R09: c0000000ffffdfff May 12 20:22:25 tek04 kernel: R10: ffffc9000274b580 R11: ffffc9000274b578 R12: ffff8881170f0118 May 12 20:22:25 tek04 kernel: R13: ffff888109911b00 R14: ffff8881170f00d0 R15: 0000000000000800 May 12 20:22:25 tek04 kernel: FS: 00007f3a1ca7cb80(0000) GS:ffff888333c40000(0000) knlGS:0000000000000000 May 12 20:22:25 tek04 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 May 12 20:22:25 tek04 kernel: CR2: 00005628963f4fd0 CR3: 000000016c43c000 CR4: 00000000000006e0 A printk has been added to line 52 of block/bio.c to dump the nr_vecs variable to the kernel log before the BUG(). Obviously nr_vecs (472 logged) is bigger than expected by bvec_alloc/bio_alloc_bioset (max 256), which finally triggers the BUG(). Removing the BUG() from line 52 of block/bio.c, thus basically restoring the Linux 5.11.x behavior of bvec_alloc/bio_alloc_bioset to just return NULL, when nr_vecs is too big seems to resolve the issue. Regards Thorsten -- ___ | | / E-Mail: linux@thorsten-knabe.de |horsten |/\nabe WWW: http://linux.thorsten-knabe.de