syzbot

INFO: task kworker/u8:2:36 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:23048 pid:36    tgid:36    ppid:2      task_flags:0x4248160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-2)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 __closure_sync+0x163/0x220 lib/closure.c:146
 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline]
 __bch2_write+0x31ef/0x3900 fs/bcachefs/io_write.c:1593
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:486 [inline]
 __bch2_writepage+0x1536/0x2790 fs/bcachefs/fs-io-buffered.c:633
 write_cache_pages+0x64/0x100 mm/page-writeback.c:2612
 bch2_writepages+0xf9/0x2d0 fs/bcachefs/fs-io-buffered.c:666
 do_writepages+0x32e/0x550 mm/page-writeback.c:2634
 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
 wb_do_writeback fs/fs-writeback.c:2315 [inline]
 wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.0.17:6231 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:17448 pid:6231  tgid:6231  ppid:6013   task_flags:0x440140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 __closure_sync+0x163/0x220 lib/closure.c:146
 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline]
 __bch2_write+0x31ef/0x3900 fs/bcachefs/io_write.c:1593
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:486 [inline]
 __bch2_writepage+0x1536/0x2790 fs/bcachefs/fs-io-buffered.c:633
 write_cache_pages+0x64/0x100 mm/page-writeback.c:2612
 bch2_writepages+0xf9/0x2d0 fs/bcachefs/fs-io-buffered.c:666
 do_writepages+0x32e/0x550 mm/page-writeback.c:2634
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 file_write_and_wait_range+0x23e/0x340 mm/filemap.c:794
 bch2_fsync+0x127/0x330 fs/bcachefs/fs-io.c:245
 generic_write_sync include/linux/fs.h:3042 [inline]
 bch2_write_iter+0x2822/0x2b90 fs/bcachefs/fs-io-buffered.c:1089
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f