EXT4-fs error (device loop0): ext4_mb_generate_buddy:1289: group 0, block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters
EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 2048 with error 28
EXT4-fs (loop0): This should not happen!! Data will be lost
EXT4-fs (loop0): Total free blocks count 0
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=2415919104
EXT4-fs (loop0): dirty_blocks=8192
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=512
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1043 at fs/ext4/ext4_jbd2.c:79 ext4_journal_check_start+0x25a/0x2b0 fs/ext4/ext4_jbd2.c:79
Modules linked in:
CPU: 0 UID: 0 PID: 1043 Comm: kworker/u4:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:ext4_journal_check_start+0x25a/0x2b0 fs/ext4/ext4_jbd2.c:79
Code: cc cc cc cc cc e8 c6 ab 4e ff 41 bf fb ff ff ff eb e0 e8 b9 ab 4e ff eb d3 e8 b2 ab 4e ff 90 0f 0b 90 eb c8 e8 a7 ab 4e ff 90 <0f> 0b 90 43 80 7c 25 00 00 0f 85 fb fe ff ff e9 fe fe ff ff 44 89
RSP: 0018:ffffc900025f6b98 EFLAGS: 00010293
RAX: ffffffff82716869 RBX: ffff888036404000 RCX: ffff888032fa4900
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 0000000000000004 R08: ffff888042446387 R09: 1ffff11008488c70
R10: dffffc0000000000 R11: ffffed1008488c71 R12: dffffc0000000000
R13: 1ffff11006c808c7 R14: ffff888036404638 R15: ffff888036404338
FS:  0000000000000000(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 000000003eb41000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __ext4_journal_start_sb+0x16b/0x5c0 fs/ext4/ext4_jbd2.c:108
 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline]
 ext4_do_writepages+0xf6c/0x4610 fs/ext4/inode.c:2913
 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025
 do_writepages+0x32e/0x550 mm/page-writeback.c:2604
 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197
 wb_check_background_flush fs/fs-writeback.c:2267 [inline]
 wb_do_writeback fs/fs-writeback.c:2355 [inline]
 wb_workfn+0xb63/0xef0 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>