loop0: detected capacity change from 0 to 64
------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1183 at mark_buffer_dirty+0x299/0x3f0 fs/buffer.c:1183, CPU#0: syz.0.0/5356
Modules linked in:
CPU: 0 UID: 0 PID: 5356 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 04/01/2014
RIP: 0010:mark_buffer_dirty+0x299/0x3f0 fs/buffer.c:1183
Code: 4c 89 f7 e8 09 d7 da ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 84 7f fb ff e8 5f f9 70 ff eb 8c e8 58 f9 70 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 4a f9 70 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc9000d187608 EFLAGS: 00010293
RAX: ffffffff82538d98 RBX: ffff888047c34bc8 RCX: ffff888036404980
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff88801fd9a001 R08: ffff888047c34bcf R09: 1ffff11008f86979
R10: dffffc0000000000 R11: ffffed1008f8697a R12: ffff888055439400
R13: ffff888047c33cb0 R14: ffff888047c34bc8 R15: 000000000000000a
FS:  00007f2b1a0f36c0(0000) GS:ffff88808ccea000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdde718dd30 CR3: 0000000011e42000 CR4: 0000000000352ef0
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:2145
 block_write_begin+0x8d/0x120 fs/buffer.c:2256
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4314
 generic_file_write_iter+0x14a/0x680 mm/filemap.c:4457
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:686
 ksys_write+0x150/0x270 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b1919aeb9
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:00007f2b1a0f3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2b19415fa0 RCX: 00007f2b1919aeb9
RDX: 000000000000fecc RSI: 00002000000008c0 RDI: 0000000000000008
RBP: 00007f2b19208c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b19416038 R14: 00007f2b19415fa0 R15: 00007ffd99754c68
 </TASK>