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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 5F007C433C1 for ; Wed, 31 Mar 2021 01:59:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25FFB619B1 for ; Wed, 31 Mar 2021 01:59:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232883AbhCaB6a (ORCPT ); Tue, 30 Mar 2021 21:58:30 -0400 Received: from james.kirk.hungrycats.org ([174.142.39.145]:43758 "EHLO james.kirk.hungrycats.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230160AbhCaB63 (ORCPT ); Tue, 30 Mar 2021 21:58:29 -0400 Received: by james.kirk.hungrycats.org (Postfix, from userid 1002) id 25AE09F3B32; Tue, 30 Mar 2021 21:58:27 -0400 (EDT) Date: Tue, 30 Mar 2021 21:58:27 -0400 From: Zygo Blaxell To: Markus Schaaf Cc: linux-btrfs@vger.kernel.org Subject: Re: Any ideas what this warnings are about? Message-ID: <20210331015827.GV32440@hungrycats.org> References: <43acc426-d683-d1b6-729d-c6bc4a2fff4d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43acc426-d683-d1b6-729d-c6bc4a2fff4d@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Mar 30, 2021 at 08:05:56PM +0200, Markus Schaaf wrote: > Hi all, > > on one of my machines I'm seeing these warnings a lot lately: > > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 314 at fs/fs-writeback.c:2472 __writeback_inodes_sb_nr+0xb8/0xd0 > Modules linked in: iTCO_wdt wireguard curve25519_x86_64 libchacha20poly1305 intel_pmc_bxt iTCO_vendor_support chacha_x86_64 poly1305_x86_64 libblake2s blake2s_x86_64 ip6_udp_tunnel udp_tunnel libcurve25519_generic libchacha libblake2s_generic psmouse joydev mousedev pcspkr i2c_i801 i2c_smbus lpc_ich iptable_filter xt_nat xt_tcpudp intel_agp intel_gtt iptable_nat nf_nat qemu_fw_cfg nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 mac_hid vfat fat auth_rpcgss sunrpc fuse ip_tables x_tables btrfs blake2b_generic libcrc32c crc32c_generic xor raid6_pq dm_crypt cbc encrypted_keys trusted tpm usbhid dm_mod virtio_gpu virtio_dma_buf drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm virtio_scsi virtio_balloon virtio_net virtio_console net_failover agpgart failover crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper serio_raw sr_mod cdrom xhci_pci virtio_pci virtio_rng rng_core > CPU: 1 PID: 314 Comm: btrfs-transacti Tainted: G W 5.10.26-1-MANJARO #1 > Hardware name: Hetzner vServer, BIOS 20171111 11/11/2017 > RIP: 0010:__writeback_inodes_sb_nr+0xb8/0xd0 > Code: 0f b6 d1 48 8d 74 24 10 e8 35 fc ff ff 48 89 e7 e8 7d fb ff ff 48 8b 44 24 48 65 48 2b 04 25 28 00 00 00 75 09 48 83 c4 50 c3 <0f> 0b eb cf e8 df 8c 75 00 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f > RSP: 0018:ffffb1f5448f7d98 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff961185aa5488 RCX: 0000000000000000 > RDX: 0000000000000002 RSI: 0000000000004b45 RDI: ffff9611b7220000 > RBP: ffff9611b64d3958 R08: ffff961184efc800 R09: 0000000000000140 > R10: ffff9611859e6400 R11: ffff961192af3c10 R12: ffff9611838f7c00 > R13: ffff961185aa5000 R14: ffff961185aa5460 R15: 0000000000011a0f > FS: 0000000000000000(0000) GS:ffff9611fad00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f654bc76b58 CR3: 0000000002c60000 CR4: 00000000003506e0 > Call Trace: > btrfs_commit_transaction+0x448/0xbc0 [btrfs] > ? start_transaction+0xcc/0x5b0 [btrfs] > transaction_kthread+0x143/0x170 [btrfs] > ? btrfs_cleanup_transaction.isra.0+0x560/0x560 [btrfs] > kthread+0x133/0x150 > ? __kthread_bind_mask+0x60/0x60 > ret_from_fork+0x22/0x30 > ---[ end trace 3cefecf5d9d20b50 ]--- > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 758 at fs/fs-writeback.c:2472 __writeback_inodes_sb_nr+0xb8/0xd0 That bug was introduced in 4.15 as part of a fix for a deadlock bug. It's still there today. Not very high on anyone's TODO list as it's mostly harmless--btrfs can't be umounted during a transaction as the umount itself uses a transaction. The warning doesn't come from btrfs code, so we can't just turn it off. > Modules linked in: iTCO_wdt wireguard curve25519_x86_64 libchacha20poly1305 intel_pmc_bxt iTCO_vendor_support chacha_x86_64 poly1305_x86_64 libblake2s blake2s_x86_> > CPU: 0 PID: 758 Comm: journal-offline Tainted: G W 5.10.26-1-MANJARO #1 > Hardware name: Hetzner vServer, BIOS 20171111 11/11/2017 > RIP: 0010:__writeback_inodes_sb_nr+0xb8/0xd0 > Code: 0f b6 d1 48 8d 74 24 10 e8 35 fc ff ff 48 89 e7 e8 7d fb ff ff 48 8b 44 24 48 65 48 2b 04 25 28 00 00 00 75 09 48 83 c4 50 c3 <0f> 0b eb cf e8 df 8c 75 00 66> > RSP: 0018:ffffb1f540d7fd40 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff961185aa5488 RCX: 0000000000000000 > RDX: 0000000000000002 RSI: 0000000000004be5 RDI: ffff9611b7220000 > RBP: ffff961182209208 R08: ffff961184efc800 R09: 0000000000000140 > R10: ffff9611859e6400 R11: ffff961192af3c10 R12: ffff961183891200 > R13: ffff961185aa5000 R14: ffff961185aa5460 R15: ffff9611b65d5e10 > FS: 00007f654b80e640(0000) GS:ffff9611fac00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f654cf39010 CR3: 0000000003884000 CR4: 00000000003506f0 > Call Trace: > btrfs_commit_transaction+0x448/0xbc0 [btrfs] > ? btrfs_wait_ordered_range+0x1b8/0x210 [btrfs] > ? btrfs_sync_file+0x2b8/0x4e0 [btrfs] > btrfs_sync_file+0x343/0x4e0 [btrfs] > __x64_sys_fsync+0x34/0x60 > do_syscall_64+0x33/0x40 Normally you need to mount -o flushoncommit to trigger this warning. Maybe sync is triggering it too? > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7f654cf26deb > Code: 4a 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 33 f7 ff ff 8b 7c 24 0c 41 89 c0 b8 4a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89> > RSP: 002b:00007f654b80db10 EFLAGS: 00000293 ORIG_RAX: 000000000000004a > RAX: ffffffffffffffda RBX: 00005636c966b410 RCX: 00007f654cf26deb > RDX: 0000000000000002 RSI: 00007f654d169d43 RDI: 0000000000000016 > RBP: 00007f654d16c6f0 R08: 0000000000000000 R09: 00007f654b80e640 > R10: 0000000000000003 R11: 0000000000000293 R12: 0000000000000002 > R13: 00007ffc8bd7461f R14: 0000000000000000 R15: 00007f654b80e640 > ---[ end trace 3cefecf5d9d20b84 ]--- > > This is a KVM guest on an AMD host. A similar machine on an Intel host doesn't show this. > There is a single BTRFS filesystem on LUKS. It has been created like: > > mkfs.btrfs --csum blake2 -d single -m single /dev/mapper/rootfs > > I've tested Manjaro's 5.11.10 kernel too. No change. btrfs-check (5.11.1) shows nothing. > I've even recreated the filesystem. No change. Maybe the machine without warnings uses > the default hash. How can I find out? > > Thanks! > Markus