[syzbot] [bcachefs?] INFO: task hung in __closure_sync

[syzbot <syzbot+7bf808f7fe4a6549f36e@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    f03359bca01b Merge tag 'for-6.9-rc6-tag' of git://git.kern..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1298e660980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d2f00edef461175
dashboard link: https://syzkaller.appspot.com/bug?extid=7bf808f7fe4a6549f36e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a7c31f180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16109450980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e3ee5200440e/disk-f03359bc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c651e70b4ae3/vmlinux-f03359bc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/196f43b316ad/bzImage-f03359bc.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/883314a64ffe/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7bf808f7fe4a6549f36e@syzkaller.appspotmail.com

INFO: task syz-executor334:5078 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor334 state:D stack:15856 pid:5078  tgid:5078  ppid:5075   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 __closure_sync+0x259/0x2f0 lib/closure.c:135
 closure_sync include/linux/closure.h:194 [inline]
 __bch2_write+0x5458/0x5bd0 fs/bcachefs/io_write.c:1486
 bch2_write+0x947/0x1590 fs/bcachefs/io_write.c:1610
 closure_queue include/linux/closure.h:257 [inline]
 closure_call include/linux/closure.h:390 [inline]
 bch2_dio_write_loop fs/bcachefs/fs-io-direct.c:531 [inline]
 bch2_direct_write+0x1a52/0x3050 fs/bcachefs/fs-io-direct.c:652
 bch2_write_iter+0x206/0x2840 fs/bcachefs/fs-io-buffered.c:1143
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa84/0xcb0 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f42713dfdf9
RSP: 002b:00007ffdf34d9c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f42713dfdf9
RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000555500000000 R09: 0000555500000000
R10: 0000555500000000 R11: 0000000000000246 R12: 00000000000f4240
R13: 00007ffdf34d9ec8 R14: 0000000000000001 R15: 00007ffdf34d9c90
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
1 lock held by kworker/u8:3/50:
 #0: ffff8880b953e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
2 locks held by getty/4827:
 #0: ffff88802aba90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
2 locks held by syz-executor334/5078:
 #0: ffff8880730de420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2855 [inline]
 #0: ffff8880730de420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586
 #1: ffff8880779f88b8 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff8880779f88b8 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: bch2_direct_write+0x243/0x3050 fs/bcachefs/fs-io-direct.c:598

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112


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