https://bugzilla.kernel.org/show_bug.cgi?id=200981 Bug ID: 200981 Summary: hypervisor fs hangs at heavy write activity on VM (kvm, qcow2 image) having a reflink disk copy Product: File System Version: 2.5 Kernel Version: 4.18.5 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: XFS Assignee: filesystem_xfs@xxxxxxxxxxxxxxxxxxxxxx Reporter: git.user@xxxxxxxxx Regression: No Created attachment 278203 --> https://bugzilla.kernel.org/attachment.cgi?id=278203&action=edit dmesg kernel: vanilla 4.18.5 gcc (Ubuntu 7.3.0-16ubuntu3) 7.3.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. More or less reproducible for me using next sequence: - on host: create LV of appropriate size (20g in my case) mkfs.xfs -m reflink=1 /dev/data/LV mount /dev/data/LV /mnt/ run kvm VM with qcow2 image (/mnt/disk) - inside vm: sysbench --test=fileio --file-total-size=9G prepare - on host: cp --reflink=always disk disk.b - inside vm: sysbench --test=fileio --file-total-size=9G --file-test-mode=seqwr --max-time=6000 --max-requests=0 --threads=16 run Some time after i/o on /dev/data/LV fall to zero and fs become completely unavailable and then I see a bunch of records: [ 2580.058205] INFO: task worker:6343 blocked for more than 120 seconds. [ 2580.064719] Not tainted 4.18.5 #1 [ 2580.068614] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2580.076496] worker D 0 6343 1 0x00000000 [ 2580.082034] Call Trace: [ 2580.084532] ? __schedule+0x386/0xc50 [ 2580.088248] ? xlog_grant_head_wait+0xa3/0x3a0 [ 2580.092741] schedule+0x2f/0x90 [ 2580.095932] xlog_grant_head_wait+0x53/0x3a0 [ 2580.100256] xlog_grant_head_check+0xb3/0x160 [ 2580.104662] xfs_log_reserve+0x108/0x3f0 [ 2580.108682] xfs_trans_reserve+0x1b4/0x2b0 [ 2580.112948] xfs_trans_alloc+0xbe/0x220 [ 2580.116952] xfs_vn_update_time+0xcb/0x2b0 [ 2580.121220] ? current_time+0x4d/0x90 [ 2580.125047] file_update_time+0xe0/0x120 [ 2580.129139] xfs_file_aio_write_checks+0x14f/0x2d0 [ 2580.134099] xfs_file_dio_aio_write+0xcc/0x420 [ 2580.138715] xfs_file_write_iter+0x7b/0xa0 [ 2580.142978] do_iter_readv_writev+0x139/0x190 [ 2580.147502] do_iter_write+0x7f/0x1c0 [ 2580.151329] vfs_writev+0x98/0x110 [ 2580.154907] ? lock_acquire+0x8e/0x230 [ 2580.158823] ? __fget+0x5/0x200 [ 2580.162131] ? do_pwritev+0x9c/0xe0 [ 2580.165782] ? __fget_light+0x51/0x60 [ 2580.169614] do_pwritev+0x9c/0xe0 [ 2580.173095] do_syscall_64+0x5a/0x190 [ 2580.176922] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 2580.182138] RIP: 0033:0x7fe1937b784a [ 2580.185836] Code: Bad RIP value. [ 2580.189239] RSP: 002b:00007fe05e1f5850 EFLAGS: 00000246 ORIG_RAX: 0000000000000128 [ 2580.197058] RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 00007fe1937b784a [ 2580.204361] RDX: 000000000000001e RSI: 0000564bf126f200 RDI: 0000000000000014 [ 2580.211660] RBP: 0000564bf126f200 R08: 0000000000000000 R09: 0000000000000000 [ 2580.218968] R10: 00000000dccf0000 R11: 0000000000000246 R12: 000000000000001e [ 2580.226265] R13: 00000000dccf0000 R14: 0000564bf13312a0 R15: 00007fe05e9f67a0 Full dmesg attached -- You are receiving this mail because: You are watching the assignee of the bug.
