bcachefs (loop0): check_subvol_children... done
bcachefs (loop0): delete_dead_snapshots... done
bcachefs (loop0): check_inodes... done
bcachefs (loop0): check_extents... done
bcachefs (loop0): check_indirect_extents... done
bcachefs (loop0): check_dirents... done
bcachefs (loop0): check_xattrs... done
bcachefs (loop0): check_root... done
bcachefs (loop0): check_unreachable_inodes... done
bcachefs (loop0): check_subvolume_structure... done
bcachefs (loop0): check_directory_structure... done
bcachefs (loop0): check_nlinks...
bcachefs (loop0): inode 536870914 type reg has wrong i_nlink (2780562353, should be 1), fixing
 done
bcachefs (loop0): check_rebalance_work... done
bcachefs (loop0): resume_logged_ops... done
bcachefs (loop0): delete_dead_inodes... done
bcachefs (loop0): set_fs_needs_rebalance... done
bcachefs (loop0): Fixed errors, running fsck a second time to verify fs is clean
bcachefs (loop0): check_alloc_info... done
bcachefs (loop0): check_lrus... done
bcachefs (loop0): check_btree_backpointers... done
bcachefs (loop0): check_backpointers_to_extents... done
bcachefs (loop0): check_extents_to_backpointers...
bcachefs (loop0): scanning for missing backpointers in 1/128 buckets
 done
bcachefs (loop0): check_alloc_to_lru_refs... done
bcachefs (loop0): bucket_gens_init... done
bcachefs (loop0): check_snapshot_trees... done
bcachefs (loop0): check_snapshots... done
bcachefs (loop0): check_subvols... done
bcachefs (loop0): check_subvol_children... done
bcachefs (loop0): delete_dead_snapshots... done
bcachefs (loop0): check_inodes... done
bcachefs (loop0): check_extents... done
bcachefs (loop0): check_indirect_extents... done
bcachefs (loop0): check_dirents... done
bcachefs (loop0): check_xattrs... done
bcachefs (loop0): check_root... done
bcachefs (loop0): check_unreachable_inodes... done
bcachefs (loop0): check_subvolume_structure... done
bcachefs (loop0): check_directory_structure... done
bcachefs (loop0): check_nlinks... done
bcachefs (loop0): check_rebalance_work... done
bcachefs (loop0): resume_logged_ops... done
bcachefs (loop0): delete_dead_inodes... done
bcachefs (loop0): set_fs_needs_rebalance... done
bcachefs (loop0): done starting filesystem
------------[ cut here ]------------
truncate spotted in mem i_size < btree i_size: 10 < 1048576
WARNING: CPU: 0 PID: 5358 at fs/bcachefs/fs-io.c:474 bchfs_truncate+0xa3b/0xc20 fs/bcachefs/fs-io.c:471
Modules linked in:
CPU: 0 UID: 0 PID: 5358 Comm: syz.0.0 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
RIP: 0010:bchfs_truncate+0xa3b/0xc20 fs/bcachefs/fs-io.c:471
Code: 00 74 0a 48 8b 7c 24 20 e8 72 4e e3 fd 4c 8b 7c 24 20 49 8b 37 48 8b 94 24 00 01 00 00 48 c7 c7 00 2d f5 8b e8 26 de 41 fd 90 <0f> 0b 90 90 e9 95 fa ff ff e8 27 52 7e fd 4c 8b 7c 24 50 4c 89 ff
RSP: 0018:ffffc9000d407540 EFLAGS: 00010246
RAX: 964e228514b4e800 RBX: 1ffff1100a5ee988 RCX: ffff888032814880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc9000d4077d0 R08: ffff88801fc24253 R09: 1ffff11003f8484a
R10: dffffc0000000000 R11: ffffed1003f8484b R12: ffff888052f74c40
R13: ffff888052f74d00 R14: 000000000000000a R15: ffff888052f747e8
FS:  00007fe183b466c0(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000042de9000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 notify_change+0xb36/0xe40 fs/attr.c:552
 do_truncate+0x1a4/0x220 fs/open.c:68
 handle_truncate fs/namei.c:3508 [inline]
 do_open fs/namei.c:3891 [inline]
 path_openat+0x306c/0x3830 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_creat fs/open.c:1528 [inline]
 __se_sys_creat fs/open.c:1522 [inline]
 __x64_sys_creat+0x8f/0xc0 fs/open.c:1522
 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
RIP: 0033:0x7fe182d8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe183b46038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fe182fe5fa0 RCX: 00007fe182d8eec9
RDX: 0000000000000000 RSI: 00000000000000bc RDI: 00002000000000c0
RBP: 00007fe182e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe182fe6038 R14: 00007fe182fe5fa0 R15: 00007ffcb6f2cfb8
 </TASK>