On Wed, Mar 31, 2021 at 12:32:45PM +0200, Markus Schaaf wrote: > Am 31.03.21 um 03:58 schrieb Zygo Blaxell: > > > > ------------[ 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. > > That warning spams my logs every 1-5 minutes. There is no unmounting > happening.
The warning is complaining about a potential issue that could be triggered by umounting; however, the warning is generic to all filesystems, and btrfs has other mechanisms that prevent a problem. flushoncommit is the known trigger for this. You had not mentioned it, so I was theorizing about other possible triggers. > > > 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? > > I've looked again and yes, this "special" filesystem is mounted > flushoncommit and discard=async. Would it be better to not set these > options, for now? > > BR