EXT4-fs warning (device loop4): ext4_da_update_reserve_space:372: ext4_da_update_reserve_space: ino 18, used 1 with only 0 reserved data blocks ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5712 at fs/ext4/inode.c:373 ext4_da_update_reserve_space+0x419/0x730 fs/ext4/inode.c:369 Modules linked in: CPU: 0 PID: 5712 Comm: kworker/u4:8 Not tainted 6.3.0-rc3-syzkaller-00021-ga1effab7a3a3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Workqueue: writeback wb_workfn (flush-7:4) RIP: 0010:ext4_da_update_reserve_space+0x419/0x730 fs/ext4/inode.c:373 Code: 4c 89 ff 48 c7 c6 69 9e 82 8c ba 74 01 00 00 48 c7 c1 c0 3c fc 8a 49 c7 c0 69 9e 82 8c 41 55 41 54 e8 9b bb 0e 00 48 83 c4 10 <0f> 0b 48 bd 00 00 00 00 00 fc ff df 0f b6 04 2b 84 c0 0f 85 8f 01 RSP: 0018:ffffc9000550ecd0 EFLAGS: 00010282 RAX: 33ab5c39bc53b600 RBX: 1ffff1100e8d5d96 RCX: 33ab5c39bc53b600 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880746ae740 R08: ffffffff816dfe9c R09: fffffbfff205be51 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880746ae700 R15: ffff88807be74000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556782848 CR3: 000000001e780000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_map_blocks+0xb64/0x1cf0 fs/ext4/inode.c:672 mpage_map_one_extent fs/ext4/inode.c:2421 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] ext4_do_writepages+0x189f/0x3d20 fs/ext4/inode.c:2876 ext4_writepages+0x1e5/0x290 fs/ext4/inode.c:2964 do_writepages+0x3a6/0x670 mm/page-writeback.c:2551 __writeback_single_inode+0x155/0xfb0 fs/fs-writeback.c:1600 writeback_sb_inodes+0x8ef/0x11d0 fs/fs-writeback.c:1891 wb_writeback+0x458/0xc70 fs/fs-writeback.c:2065 wb_do_writeback fs/fs-writeback.c:2208 [inline] wb_workfn+0x400/0xff0 fs/fs-writeback.c:2248 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2390 worker_thread+0xa63/0x1210 kernel/workqueue.c:2537 kthread+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308