__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
INFO: task kworker/u4:1:21 blocked for more than 140 seconds.
      Not tainted 4.20.0-rc6+ #151
device loop0 blocksize: 4096
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
__find_get_block_slow() failed. block=1, b_blocknr=8
kworker/u4:1    D13576    21      2 0x80000000
b_state=0x00000029, b_size=512
Workqueue: writeback wb_workfn (flush-7:0)
device loop0 blocksize: 4096
Call Trace:
__find_get_block_slow() failed. block=1, b_blocknr=8
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 schedule+0xfe/0x460 kernel/sched/core.c:3516
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 inode_sleep_on_writeback+0x1f9/0x240 fs/fs-writeback.c:1229
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 wb_writeback+0x60a/0xfc0 fs/fs-writeback.c:1788
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 wb_check_start_all fs/fs-writeback.c:1882 [inline]
 wb_do_writeback fs/fs-writeback.c:1908 [inline]
 wb_workfn+0xee9/0x1790 fs/fs-writeback.c:1942
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
 kthread+0x35a/0x440 kernel/kthread.c:246
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
b_state=0x00000029, b_size=512

Showing all locks held in the system:
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
2 locks held by kworker/u4:1/21:
b_state=0x00000029, b_size=512
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 000000002979507b ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124
device loop0 blocksize: 4096
 #1: 000000000513edc4 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128
__find_get_block_slow() failed. block=1, b_blocknr=8
1 lock held by khungtaskd/1021:
b_state=0x00000029, b_size=512
 #0: 00000000238003f6 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
device loop0 blocksize: 4096
2 locks held by rs:main Q:Reg/6052:
__find_get_block_slow() failed. block=1, b_blocknr=8
 #0: 000000004b447360 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
 #1: 000000001ddd00c4 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2810 [inline]
 #1: 000000001ddd00c4 (sb_writers#4){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548
b_state=0x00000029, b_size=512
1 lock held by rsyslogd/6054:
2 locks held by getty/6176:
 #0: 0000000043d6c684 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
device loop0 blocksize: 4096
 #1: 00000000729342a7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
__find_get_block_slow() failed. block=1, b_blocknr=8
2 locks held by getty/6177:
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 #0: 0000000005456045 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000f7290a11 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
__find_get_block_slow() failed. block=1, b_blocknr=8
2 locks held by getty/6178:
b_state=0x00000029, b_size=512
 #0: 000000007948bc67 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 #1: 00000000aa34d199 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
b_state=0x00000029, b_size=512
2 locks held by getty/6179:
device loop0 blocksize: 4096
 #0: 0000000099c05c96 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
__find_get_block_slow() failed. block=1, b_blocknr=8
 #1: 000000007c03e22d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
b_state=0x00000029, b_size=512
2 locks held by getty/6180:
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
 #0: 0000000014c5d8dd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
b_state=0x00000029, b_size=512
 #1: 00000000e818ac50 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
device loop0 blocksize: 4096
2 locks held by getty/6181:
 #0: 00000000ee2aa06e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
__find_get_block_slow() failed. block=1, b_blocknr=8
 #1: 000000002ddbc091 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
b_state=0x00000029, b_size=512
2 locks held by getty/6182:
 #0: 00000000e5df3156 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000a2c1d8d2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
device loop0 blocksize: 4096
6 locks held by syz-executor0/29274:
__find_get_block_slow() failed. block=1, b_blocknr=8

b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
=============================================

b_state=0x00000029, b_size=512
NMI backtrace for cpu 1
device loop0 blocksize: 4096
CPU: 1 PID: 1021 Comm: khungtaskd Not tainted 4.20.0-rc6+ #151
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
__find_get_block_slow() failed. block=1, b_blocknr=8
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62
b_state=0x00000029, b_size=512
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xb51/0x1060 kernel/hung_task.c:289
device loop0 blocksize: 4096
__find_get_block_slow() failed. block=1, b_blocknr=8
b_state=0x00000029, b_size=512
device loop0 blocksize: 4096
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
__find_get_block_slow() failed. block=1, b_blocknr=8
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.519 msecs
NMI backtrace for cpu 0
CPU: 0 PID: 29274 Comm: syz-executor0 Not tainted 4.20.0-rc6+ #151
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:more_used drivers/virtio/virtio_ring.c:679 [inline]
RIP: 0010:vring_interrupt+0x9e/0x170 drivers/virtio/virtio_ring.c:940
Code: 8d 7c 24 02 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 a7 00 00 00 45 0f b7 64 24 02 <44> 89 ef 45 31 f6 44 89 e6 e8 e4 df af fd 66 45 39 e5 74 7c e8 69
RSP: 0018:ffff8881dae07858 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff8881d0980140 RCX: ffffffff8166084a
RDX: 0000000000000000 RSI: ffffffff83cfa463 RDI: ffff8881d08e5002
RBP: ffff8881dae07878 R08: ffff8881d1d92500 R09: ffffed103b5c5b5f
R10: ffffed103b5c5b5f R11: ffff8881dae2dafb R12: 0000000000007dd9
R13: 0000000000007dd8 R14: ffff8881dae07a80 R15: ffffffff8a163e20
FS:  00007fb1a9370700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001b81a5000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __handle_irq_event_percpu+0x195/0xb30 kernel/irq/handle.c:149
 handle_irq_event_percpu+0xa0/0x1d0 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
 handle_edge_irq+0x227/0x880 kernel/irq/chip.c:791
 generic_handle_irq_desc include/linux/irqdesc.h:154 [inline]
 handle_irq+0x252/0x3d8 arch/x86/kernel/irq_64.c:78
 do_IRQ+0x98/0x1c0 arch/x86/kernel/irq.c:246
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:583
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:771 [inline]
RIP: 0010:__do_softirq+0x2c3/0xb7e kernel/softirq.c:276
Code: c7 c0 00 01 52 89 48 c1 e8 03 42 80 3c 38 00 0f 85 f0 07 00 00 48 83 3d 4a fe 51 01 00 0f 84 24 07 00 00 fb 66 0f 1f 44 00 00 <48> c7 85 60 fe ff ff 00 91 40 89 b8 ff ff ff ff 0f bc 85 74 fe ff
RSP: 0018:ffff8881dae07c90 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffda
RAX: 1ffffffff12a4020 RBX: ffff8881d1d92500 RCX: 1ffff1103a3b25be
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881d1d92d7c
RBP: ffff8881dae07e70 R08: ffff8881d1d92df0 R09: 0000000000000002
R10: 0000000000000000 R11: ffff8881d1d92500 R12: 1ffff1103b5c0fd4
R13: ffff8881dae07fc0 R14: 0000000000000000 R15: dffffc0000000000
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x17f/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline]
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1688 [inline]
RIP: 0010:vprintk_emit+0x87d/0x990 kernel/printk/printk.c:1921
Code: 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 de 00 00 00 48 83 3d 33 44 ec 07 00 74 34 e8 ac c7 19 00 48 8b bd 90 fe ff ff 57 9d <0f> 1f 44 00 00 e9 aa fe ff ff e8 94 c7 19 00 0f 0b e8 8d c7 19 00
RSP: 0018:ffff8881b40de690 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: 1ffff1103681bcd8 RCX: ffffc9000be9a000
RDX: 0000000000040000 RSI: ffffffff8165bcc4 RDI: 0000000000000246
RBP: ffff8881b40de808 R08: ffff8881d1d92df0 R09: 0000000000000006
R10: 0000000000000000 R11: ffff8881d1d92500 R12: 0000000000000200
R13: 0000000000000000 R14: ffffed103681bcec R15: ffff8881b40de7e0
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964
 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398
 printk+0xa7/0xcf kernel/printk/printk.c:1997
 __find_get_block_slow fs/buffer.c:231 [inline]
 __find_get_block.cold.57+0x3a/0xff fs/buffer.c:1294
 __getblk_slow fs/buffer.c:1039 [inline]
 __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320
 __bread_gfp+0x2d/0x310 fs/buffer.c:1354
 sb_bread include/linux/buffer_head.h:307 [inline]
 __fat_write_inode+0x347/0xb60 fs/fat/inode.c:859
 fat_write_inode+0x97/0x180 fs/fat/inode.c:908
 write_inode fs/fs-writeback.c:1176 [inline]
 __writeback_single_inode+0xf56/0x1660 fs/fs-writeback.c:1375
 writeback_single_inode+0x3c2/0x590 fs/fs-writeback.c:1429
 sync_inode fs/fs-writeback.c:2463 [inline]
 sync_inode_metadata+0x120/0x190 fs/fs-writeback.c:2483
 __generic_file_fsync+0x16f/0x200 fs/libfs.c:988
 generic_file_fsync+0x77/0x120 fs/libfs.c:1018
 fat_file_fsync+0x77/0x180 fs/fat/file.c:198
 vfs_fsync_range+0x140/0x220 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2781 [inline]
 generic_file_write_iter+0x4ff/0x6b0 mm/filemap.c:3297
 call_write_iter include/linux/fs.h:1857 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 __kernel_write+0x10c/0x370 fs/read_write.c:506
 write_pipe_buf+0x180/0x240 fs/splice.c:797
 splice_from_pipe_feed fs/splice.c:503 [inline]
 __splice_from_pipe+0x38b/0x7c0 fs/splice.c:627
 splice_from_pipe+0x1ec/0x340 fs/splice.c:662
 default_file_splice_write+0x3c/0x90 fs/splice.c:809
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x128/0x190 fs/splice.c:1023
 splice_direct_to_actor+0x3ad/0x9d0 fs/splice.c:978
 do_splice_direct+0x2d4/0x420 fs/splice.c:1066
 do_sendfile+0x62a/0xe20 fs/read_write.c:1439
 __do_sys_sendfile64 fs/read_write.c:1494 [inline]
 __se_sys_sendfile64 fs/read_write.c:1486 [inline]
 __x64_sys_sendfile64+0x15d/0x250 fs/read_write.c:1486
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 ? trace_hardirqs_off_th
Lost 10 message(s)!