------------[ cut here ]------------
sb_rdonly(sb)
WARNING: fs/ext4/ext4_jbd2.c:83 at ext4_journal_check_start+0x24f/0x2b0 fs/ext4/ext4_jbd2.c:83, CPU#0: syz.6.838/19898
Modules linked in:
CPU: 0 UID: 0 PID: 19898 Comm: syz.6.838 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:ext4_journal_check_start+0x24f/0x2b0 fs/ext4/ext4_jbd2.c:83
Code: 5b 41 5c 41 5d 41 5e 41 5f 5d e9 8c 50 dd 08 cc e8 96 3e 47 ff 41 bf fb ff ff ff eb e0 e8 89 3e 47 ff eb d3 e8 82 3e 47 ff 90 <0f> 0b 90 eb c8 e8 77 3e 47 ff 90 0f 0b 90 43 80 7c 25 00 00 0f 85
RSP: 0018:ffffc90006836e58 EFLAGS: 00010283
RAX: ffffffff827f99ae RBX: ffff88805ef4c000 RCX: 0000000000080000
RDX: ffffc90017310000 RSI: 0000000000003242 RDI: 0000000000003243
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1003659081 R12: dffffc0000000000
R13: 1ffff1100bde9905 R14: ffff88805ef4c828 R15: 0000000000000001
FS:  00007f43070666c0(0000) GS:ffff888125bc2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb628881000 CR3: 0000000026488000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __ext4_journal_start_sb+0x14b/0x780 fs/ext4/ext4_jbd2.c:115
 __ext4_journal_start fs/ext4/ext4_jbd2.h:238 [inline]
 ext4_dirty_inode+0x93/0x110 fs/ext4/inode.c:6733
 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2744
 mark_inode_dirty include/linux/fs.h:2206 [inline]
 dquot_alloc_space include/linux/quotaops.h:312 [inline]
 dquot_alloc_block include/linux/quotaops.h:329 [inline]
 ext4_mb_new_blocks+0x27ee/0x4540 fs/ext4/mballoc.c:6277
 ext4_ext_map_blocks+0x13f1/0x5680 fs/ext4/extents.c:4469
 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:630
 ext4_map_blocks+0x791/0x12c0 fs/ext4/inode.c:823
 ext4_getblk+0x1c3/0x7c0 fs/ext4/inode.c:991
 ext4_bread+0x2a/0x180 fs/ext4/inode.c:1054
 ext4_append+0x2b6/0x560 fs/ext4/namei.c:83
 ext4_init_new_dir+0x11f/0x1c0 fs/ext4/namei.c:2988
 ext4_mkdir+0x4ba/0xce0 fs/ext4/namei.c:3024
 vfs_mkdir+0x408/0x620 fs/namei.c:5410
 cachefiles_get_directory+0x23c/0xa30 fs/cachefiles/namei.c:132
 cachefiles_add_cache+0xb06/0xde0 fs/cachefiles/cache.c:127
 cachefiles_daemon_write+0x608/0x6c0 fs/cachefiles/daemon.c:284
 vfs_write+0x29f/0xbb0 fs/read_write.c:685
 ksys_write+0x156/0x270 fs/read_write.c:739
 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: 0033:0x7f4308e0e159
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:00007f4307066028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4309095fa0 RCX: 00007f4308e0e159
RDX: 0000000000000004 RSI: 0000200000000700 RDI: 0000000000000004
RBP: 00007f4308ea506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4309096038 R14: 00007f4309095fa0 R15: 00007fff32af5cd8
 </TASK>