INFO: task syz.0.17:5519 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:22536 pid:5519  tgid:5519  ppid:5478   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 io_schedule+0x80/0xd0 kernel/sched/core.c:7871
 __lock_metapage fs/jfs/jfs_metapage.c:52 [inline]
 lock_metapage+0x1f3/0x400 fs/jfs/jfs_metapage.c:66
 __get_metapage+0x497/0xde0 fs/jfs/jfs_metapage.c:748
 xtSplitPage+0x284/0x21a0 fs/jfs/jfs_xtree.c:989
 xtSplitUp+0x31b/0x1f40 fs/jfs/jfs_xtree.c:786
 xtInsert+0x415/0xe30 fs/jfs/jfs_xtree.c:608
 extAlloc+0xa9a/0xfb0 fs/jfs/jfs_extent.c:150
 jfs_get_block+0x346/0xab0 fs/jfs/inode.c:254
 get_more_blocks fs/direct-io.c:648 [inline]
 do_direct_IO fs/direct-io.c:936 [inline]
 __blockdev_direct_IO+0x16ff/0x3490 fs/direct-io.c:1243
 blockdev_direct_IO include/linux/fs.h:3509 [inline]
 jfs_direct_IO+0x119/0x220 fs/jfs/inode.c:339
 generic_file_direct_write+0x1db/0x3e0 mm/filemap.c:4188
 __generic_file_write_iter+0x11d/0x230 mm/filemap.c:4357
 generic_file_write_iter+0x117/0x550 mm/filemap.c:4397
 iter_file_splice_write+0x975/0x10e0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x101/0x160 fs/splice.c:1161
 splice_direct_to_actor+0x5a8/0xcc0 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x181/0x270 fs/splice.c:1230
 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b1c58f6c9
RSP: 002b:00007ffe488ba688 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f9b1c7e5fa0 RCX: 00007f9b1c58f6c9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007f9b1c611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000080000000c R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b1c7e5fa0 R14: 00007f9b1c7e5fa0 R15: 0000000000000004
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u4:3/43:
 #0: ffff888030f4e948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff888030f4e948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc900005e7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc900005e7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffff8880118320e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
 #3: ffff88801221b8b8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5106:
 #0: ffff88803ec040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000018e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz.0.17/5519:
 #0: ffff888011832420 (sb_writers#12){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160
 #1: ffff88801221ceb8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
 #1: ffff88801221ceb8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: generic_file_write_iter+0xeb/0x550 mm/filemap.c:4394
 #2: ffff88801221ca78 (&jfs_ip->rdwrlock#3){++++}-{4:4}, at: jfs_get_block+0x141/0xab0 fs/jfs/inode.c:219
 #3: ffff88801221cb08 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: extAlloc+0x13c/0xfb0 fs/jfs/jfs_extent.c:86
1 lock held by syz.1.100/5664:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>