bcachefs (loop0): going read-write
bcachefs (loop0): insufficient writeable journal devices available: have 0, need 1
rw journal devs:
bcachefs (loop0): done starting filesystem
------------[ cut here ]------------
WARNING: CPU: 1 PID: 13123 at fs/bcachefs/fs-io.c:361 __bch2_truncate_folio+0x179c/0x1a30 fs/bcachefs/fs-io.c:361
Modules linked in:
CPU: 1 UID: 0 PID: 13123 Comm: syz.0.1731 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__bch2_truncate_folio+0x179c/0x1a30 fs/bcachefs/fs-io.c:361
Code: 5f 5d e9 b2 41 d0 fc cc e8 81 af 7f fd 48 c7 c7 b7 a3 a3 8d e8 85 61 e9 ff 89 05 cf 3e 86 15 e9 49 ea ff ff e8 65 af 7f fd 90 <0f> 0b 90 e9 26 f9 ff ff e8 67 17 3a 07 e8 52 af 7f fd be 00 10 00
RSP: 0018:ffffc90003eaf9e0 EFLAGS: 00010287
RAX: ffffffff843fff7b RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90004722000 RSI: 0000000000001471 RDI: 0000000000001472
RBP: ffffc90003eafbb0 R08: ffffea0002229b87 R09: 1ffffd4000445370
R10: dffffc0000000000 R11: fffff94000445371 R12: 1ffff110086485bc
R13: dffffc0000000000 R14: ffff888043242de0 R15: 0000000000000000
FS:  00007fdcf3b5c6c0(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdce8a7f000 CR3: 000000009521a000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 bch2_truncate_folios fs/bcachefs/fs-io.c:400 [inline]
 bchfs_fallocate+0x233/0x680 fs/bcachefs/fs-io.c:777
 bch2_fallocate_dispatch+0x28a/0x410 fs/bcachefs/fs-io.c:836
 vfs_fallocate+0x669/0x7e0 fs/open.c:342
 ksys_fallocate fs/open.c:366 [inline]
 __do_sys_fallocate fs/open.c:371 [inline]
 __se_sys_fallocate fs/open.c:369 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:369
 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: 0033:0x7fdcf2d8ebe9
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:00007fdcf3b5c038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fdcf2fc5fa0 RCX: 00007fdcf2d8ebe9
RDX: 0000000000000006 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007fdcf2e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdcf2fc6038 R14: 00007fdcf2fc5fa0 R15: 00007ffc2220e118
 </TASK>