syzbot

incfs: Can't find or create .index dir in ./file0
BUG: Dentry 000000007364aa64{i=0,n=.index}  still in use (1) [unmount of incremental-fs incremental-fs]
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WARNING: CPU: 0 PID: 363 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 363 Comm: syz-executor190 Not tainted 5.4.93-syzkaller-00590-g1e5f5a14faba #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1dd/0x24e lib/dump_stack.c:118
 panic+0x285/0x750 kernel/panic.c:221
 __warn+0x1fd/0x200 kernel/panic.c:582
 report_bug+0x390/0x4d0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap arch/x86/kernel/traps.c:272 [inline]
 do_invalid_op+0x6e/0x110 arch/x86/kernel/traps.c:291
 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:1029
RIP: 0010:umount_check+0x179/0x1c0 fs/dcache.c:1588
Code: ff 4c 8b 0b 48 81 c5 20 04 00 00 48 c7 c7 63 55 1d 85 4c 89 fe 4c 89 f2 4c 89 f9 45 89 e8 31 c0 55 e8 07 36 b0 ff 48 83 c4 08 <0f> 0b e9 fd fe ff ff 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c d4 fe ff
RSP: 0018:ffff8881e910f710 EFLAGS: 00010292
RAX: 0000000000000067 RBX: ffffffff8548f520 RCX: dd3296738f0bf900
RDX: 0000000000000000 RSI: 0000000080000002 RDI: 0000000000000000
RBP: ffff8881e93f0420 R08: ffffffff814e47a1 R09: ffffed103ee05e08
R10: ffffed103ee05e08 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881eff5b440
 d_walk+0x2e9/0x570 fs/dcache.c:1307
 do_one_tree fs/dcache.c:1604 [inline]
 shrink_dcache_for_umount+0x8a/0x1b0 fs/dcache.c:1620
 generic_shutdown_super+0x63/0x2a0 fs/super.c:447
 incfs_kill_sb+0x3d/0x50 fs/incfs/vfs.c:1659
 deactivate_locked_super+0xaf/0x100 fs/super.c:335
 deactivate_super+0x1b8/0x280 fs/super.c:366
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
 task_work_run+0x176/0x1a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcc2/0x2830 kernel/exit.c:812
 do_group_exit+0x155/0x2b0 kernel/exit.c:910
 get_signal+0x13ec/0x1f00 kernel/signal.c:2745
 do_signal+0x92/0x5d0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x207/0x310 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x44aa19
Code: Bad RIP value.
RSP: 002b:00007f5ecb84dcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006dcc28 RCX: 000000000044aa19
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dcc28
RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc2c
R13: 00007fff2cfb214f R14: 00007f5ecb84e9c0 R15: 00000000006dcc2c
Kernel Offset: disabled
Rebooting in 86400 seconds..