[nilfs2?] WARNING: locking bug in nilfs_bmap_lookup_at_level

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=103441f0480000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=6051b65119f99af35738
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6051b6...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS)
WARNING: CPU: 1 PID: 20151 at kernel/locking/lockdep.c:3393 __lock_acquire+0x1221/0x3ff0 kernel/locking/lockdep.c:3393
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 20151 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
panic+0x26a/0x50e kernel/panic.c:186
__warn.cold+0x20/0x5a kernel/panic.c:541
report_bug+0x262/0x2b0 lib/bug.c:183
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
NILFS (loop1): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__lock_acquire+0x1221/0x3ff0 kernel/locking/lockdep.c:3393
Code: d2 0f 85 2d 1f 00 00 44 8b 3d 5b ed eb 0b 45 85 ff 0f 85 78 ef ff ff 48 c7 c6 e0 43 6a 88 48 c7 c7 40 19 6a 88 e8 54 b3 a7 06 <0f> 0b e9 61 ef ff ff 8b 05 52 2d d9 0b 85 c0 0f 85 4e f9 ff ff 4c
RSP: 0018:ffff88804986f3f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000002deb6 RSI: ffffffff814dff01 RDI: ffffed100930de71
RBP: ffff88809c378e7a R08: 0000000000000000 R09: 0000000000000b7d
R10: 0000000000000006 R11: ffffffff8c66505b R12: 000000000005030a
R13: ffff88809c378580 R14: ffff88809c378e70 R15: 0000000000000000
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
down_read+0x36/0x80 kernel/locking/rwsem.c:24
nilfs_bmap_lookup_at_level+0x7b/0x3e0 fs/nilfs2/bmap.c:68
nilfs_bmap_lookup fs/nilfs2/bmap.h:170 [inline]
nilfs_mdt_submit_block.constprop.0+0x1a5/0xaa0 fs/nilfs2/mdt.c:142
nilfs_mdt_read_block+0x96/0x3e0 fs/nilfs2/mdt.c:175
nilfs_mdt_get_block+0xe6/0xd40 fs/nilfs2/mdt.c:250
nilfs_palloc_get_block+0xc4/0x2b0 fs/nilfs2/alloc.c:216
nilfs_palloc_get_entry_block+0x17b/0x230 fs/nilfs2/alloc.c:318
nilfs_ifile_get_inode_block+0xbf/0x170 fs/nilfs2/ifile.c:143
__nilfs_read_inode fs/nilfs2/inode.c:483 [inline]
nilfs_iget+0x204/0x860 fs/nilfs2/inode.c:592
nilfs_get_root_dentry+0x26/0x250 fs/nilfs2/super.c:908
nilfs_fill_super fs/nilfs2/super.c:1082 [inline]
nilfs_mount+0xac8/0xe70 fs/nilfs2/super.c:1321
mount_fs+0xa3/0x310 fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2492 [inline]
do_mount+0x115c/0x2f50 fs/namespace.c:2822
ksys_mount+0xcf/0x130 fs/namespace.c:3038
__do_sys_mount fs/namespace.c:3052 [inline]
__se_sys_mount fs/namespace.c:3049 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3049
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fc6ae8e660a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc6ace56f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000f35 RCX: 00007fc6ae8e660a
RDX: 0000000020000ec0 RSI: 0000000020000f00 RDI: 00007fc6ace56fe0
RBP: 00007fc6ace57020 R08: 00007fc6ace57020 R09: 0000000000000010
R10: 0000000000000010 R11: 0000000000000202 R12: 0000000020000ec0
R13: 0000000020000f00 R14: 00007fc6ace56fe0 R15: 0000000020000100
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.