loop2: detected capacity change from 0 to 64
------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1180 at mark_buffer_dirty+0x299/0x440 fs/buffer.c:1180, CPU#1: syz.2.355/8475
Modules linked in:
CPU: 1 UID: 0 PID: 8475 Comm: syz.2.355 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:mark_buffer_dirty+0x299/0x440 fs/buffer.c:1180
Code: 4c 89 f7 e8 39 0b df ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 74 60 fb ff e8 ff 01 79 ff eb 8c e8 f8 01 79 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 ea 01 79 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc90003ef7488 EFLAGS: 00010283
RAX: ffffffff824b5118 RBX: ffff8880616a7818 RCX: 0000000000080000
RDX: ffffc90006fe3000 RSI: 0000000000001b15 RDI: 0000000000001b16
RBP: ffff88803f78a001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100c2d4f04 R12: ffff88806a8c4000
R13: ffff88806b51e5c8 R14: ffff8880616a7818 R15: 000000000000000f
FS:  00007fb1f4c7e6c0(0000) GS:ffff888126443000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000006f212000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 bfs_move_block fs/bfs/file.c:44 [inline]
 bfs_move_blocks fs/bfs/file.c:57 [inline]
 bfs_get_block+0x5da/0xae0 fs/bfs/file.c:126
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
 block_write_begin+0x8d/0x120 fs/buffer.c:2253
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4314
 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4457
 do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1
 vfs_writev+0x345/0x9a0 fs/read_write.c:1059
 do_writev+0x15a/0x2e0 fs/read_write.c:1105
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb1f6a2c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb1f4c7e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fb1f6ca5fa0 RCX: 00007fb1f6a2c799
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007fb1f6ac2bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb1f6ca6038 R14: 00007fb1f6ca5fa0 R15: 00007fff11ac17a8
 </TASK>