[syzbot] [bcachefs?] kernel BUG in __bch2_trans_commit (3)

[syzbot <syzbot+b6ef9edaba01d5b4e43f@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    40f92e79b0aa Merge tag 'block-6.16-20250710' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=169a7bd4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b309c907eaab29da
dashboard link: https://syzkaller.appspot.com/bug?extid=b6ef9edaba01d5b4e43f
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-40f92e79.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8022f6fa9a48/vmlinux-40f92e79.xz
kernel image: https://storage.googleapis.com/syzbot-assets/565fa9fa3299/bzImage-40f92e79.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b6ef9edaba01d5b4e43f@syzkaller.appspotmail.com

bcachefs (loop0): btree ptr not marked in member info btree allocated bitmap
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c0bef60d07ceb940 written 16 min_key POS_MIN durability: 1 ptr: 0:35:0 gen 0, fixing
bcachefs (loop0): bucket 0:35 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c0bef60d07ceb940 written 16 min_key POS_MIN durability: 1 ptr: 0:35:0 gen 0, fixing
bcachefs (loop0): btree ptr not marked in member info btree allocated bitmap
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq ebb8d5a9e3463bdb written 16 min_key POS_MIN durability: 1 ptr: 0:32:0 gen 0, fixing
bcachefs (loop0): btree ptr not marked in member info btree allocated bitmap
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq e81e1ed936acf3df written 32 min_key POS_MIN durability: 1 ptr: 0:29:0 gen 0, fixing
bcachefs (loop0): bucket 0:29 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq e81e1ed936acf3df written 32 min_key POS_MIN durability: 1 ptr: 0:29:0 gen 0, fixing
bcachefs (loop0): bucket 0:1 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:1 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:2 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:2 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:3 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:3 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:4 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:4 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:5 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:5 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:6 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:6 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:7 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:7 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:8 gen 0 has wrong data_type: got free, should be sb, fixing
bcachefs (loop0): bucket 0:8 gen 0 data type sb has wrong dirty_sectors: got 0, should be 8, fixing
bcachefs (loop0): bucket 0:9 gen 0 has wrong data_type: got free, should be journal, fixing
bcachefs (loop0): bucket 0:9 gen 0 data type journal has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:10 gen 0 has wrong data_type: got free, should be journal, fixing
bcachefs (loop0): bucket 0:10 gen 0 data type journal has wrong dirty_sectors: got 0, should be 256, fixing
bcachefs (loop0): bucket 0:11 gen 0 has wrong data_type: got free, should be journal, fixing
  Ratelimiting new instances of previous error
bcachefs (loop0): bucket 0:11 gen 0 data type journal has wrong dirty_sectors: got 0, should be 256, fixing
  Ratelimiting new instances of previous error
 done
bcachefs (loop0): going read-write
bcachefs (loop0): journal_replay... done
bcachefs (loop0): check_extents_to_backpointers...
bcachefs (loop0): scanning for missing backpointers in 4/128 buckets
 done
bcachefs (loop0): check_inodes... done
bcachefs (loop0): resume_logged_ops... done
bcachefs (loop0): delete_dead_inodes... done
bcachefs (loop0): done starting filesystem
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
------------[ cut here ]------------
kernel BUG at fs/bcachefs/btree_trans_commit.c:348!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5344 Comm: syz.0.0 Not tainted 6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #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:btree_insert_entry_checks fs/bcachefs/btree_trans_commit.c:343 [inline]
RIP: 0010:bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:725 [inline]
RIP: 0010:do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline]
RIP: 0010:__bch2_trans_commit+0x86e5/0x8870 fs/bcachefs/btree_trans_commit.c:1085
Code: 97 fd eb 0c e8 2c 78 97 fd eb 05 e8 25 78 97 fd 49 bd 00 00 00 00 00 fc ff df 4c 8b 64 24 48 e9 e1 af ff ff e8 0c 78 97 fd 90 <0f> 0b e8 04 78 97 fd 90 0f 0b e8 fc 77 97 fd 90 0f 0b e8 f4 77 97
RSP: 0018:ffffc9000d357780 EFLAGS: 00010287
RAX: ffffffff8428be64 RBX: ffffffff84288035 RCX: 0000000000100000
RDX: ffffc9000df42000 RSI: 0000000000004ab7 RDI: 0000000000004ab8
RBP: ffffc9000d357a70 R08: 0000000000000000 R09: ffffffff84288035
R10: dffffc0000000000 R11: ffffed100a6a9309 R12: ffff8880525b4020
R13: dffffc0000000000 R14: ffff8880525b64d8 R15: 0000000000000001
FS:  00007fe567cac6c0(0000) GS:ffff88808d21b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f10bffd2000 CR3: 000000003f923000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline]
 __bch2_unlink+0x2b9/0x530 fs/bcachefs/fs.c:827
 bch2_unlink+0xb1/0xf0 fs/bcachefs/fs.c:864
 vfs_unlink+0x391/0x650 fs/namei.c:4595
 do_unlinkat+0x350/0x560 fs/namei.c:4659
 __do_sys_unlink fs/namei.c:4705 [inline]
 __se_sys_unlink fs/namei.c:4703 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4703
 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: 0033:0x7fe566d8e929
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:00007fe567cac038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fe566fb5fa0 RCX: 00007fe566d8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fe566e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe566fb5fa0 R15: 00007fff2f8fbd98
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:btree_insert_entry_checks fs/bcachefs/btree_trans_commit.c:343 [inline]
RIP: 0010:bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:725 [inline]
RIP: 0010:do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline]
RIP: 0010:__bch2_trans_commit+0x86e5/0x8870 fs/bcachefs/btree_trans_commit.c:1085
Code: 97 fd eb 0c e8 2c 78 97 fd eb 05 e8 25 78 97 fd 49 bd 00 00 00 00 00 fc ff df 4c 8b 64 24 48 e9 e1 af ff ff e8 0c 78 97 fd 90 <0f> 0b e8 04 78 97 fd 90 0f 0b e8 fc 77 97 fd 90 0f 0b e8 f4 77 97
RSP: 0018:ffffc9000d357780 EFLAGS: 00010287
RAX: ffffffff8428be64 RBX: ffffffff84288035 RCX: 0000000000100000
RDX: ffffc9000df42000 RSI: 0000000000004ab7 RDI: 0000000000004ab8
RBP: ffffc9000d357a70 R08: 0000000000000000 R09: ffffffff84288035
R10: dffffc0000000000 R11: ffffed100a6a9309 R12: ffff8880525b4020
R13: dffffc0000000000 R14: ffff8880525b64d8 R15: 0000000000000001
FS:  00007fe567cac6c0(0000) GS:ffff88808d21b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe567c8afc8 CR3: 000000003f923000 CR4: 0000000000352ef0


---
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