Buffer I/O error on dev loop0, logical block 32, lost sync page write
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!buffer_uptodate(bh)
WARNING: fs/buffer.c:991 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:991, CPU#0: syz.0.0/5328
Modules linked in:
CPU: 0 UID: 0 PID: 5328 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+0x299/0x410 fs/buffer.c:991
Code: 4c 89 f7 e8 69 fa d7 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 74 52 fb ff e8 3f 4a 66 ff eb 8c e8 38 4a 66 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 2a 4a 66 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc9000e10f490 EFLAGS: 00010293
RAX: ffffffff8261d628 RBX: ffff888012268ee0 RCX: ffff88801fb62580
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: dffffc0000000001 R08: ffff888012268ee7 R09: 1ffff1100244d1dc
R10: dffffc0000000000 R11: ffffed100244d1dd R12: ffffffff8c28b200
R13: ffff888013364248 R14: dffffc0000000000 R15: ffff88800e8e4788
FS:  00007fc16518e6c0(0000) GS:ffff88808c2bb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1645c2b60 CR3: 000000001205c000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 mmb_mark_buffer_dirty+0x2c/0x1f0 fs/buffer.c:624
 fat_ent_write+0xb8/0x190 fs/fat/fatent.c:422
 fat_chain_add+0x409/0x8e0 fs/fat/misc.c:140
 fat_add_entries+0x1aa4/0x2320 fs/fat/dir.c:1435
 vfat_add_entry+0x2dd3/0x3570 fs/fat/namei_vfat.c:675
 vfat_mkdir+0x16c/0x300 fs/fat/namei_vfat.c:866
 vfs_mkdir+0x40c/0x620 fs/namei.c:5410
 filename_mkdirat+0x285/0x510 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc16439cfc7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007fc16518de18 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fc16518dea0 RCX: 00007fc16439cfc7
RDX: 00000000000001ff RSI: 00002000000005c0 RDI: 00000000ffffff9c
RBP: 0000200000000b00 R08: 0000200000000140 R09: 0000000000000000
R10: 0000200000000b00 R11: 0000000000000246 R12: 00002000000005c0
R13: 00007fc16518de60 R14: 0000000000000000 R15: 0000000000000000
 </TASK>