------------[ cut here ]------------
folio expected an open fid inode->i_ino=1ca04c8
WARNING: CPU: 2 PID: 13 at fs/9p/vfs_addr.c:39 v9fs_begin_writeback fs/9p/vfs_addr.c:39 [inline]
WARNING: CPU: 2 PID: 13 at fs/9p/vfs_addr.c:39 v9fs_begin_writeback+0x219/0x290 fs/9p/vfs_addr.c:33
Modules linked in:
CPU: 2 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.16.0-syzkaller-g89748acdf226 #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-9p-305)
RIP: 0010:v9fs_begin_writeback fs/9p/vfs_addr.c:39 [inline]
RIP: 0010:v9fs_begin_writeback+0x219/0x290 fs/9p/vfs_addr.c:33
Code: 00 00 00 00 00 fc ff df 48 8d 7b 40 48 89 fa 48 c1 ea 03 80 3c 02 00 75 66 48 8b 73 40 48 c7 c7 60 c1 f1 8b e8 e8 7a f3 fd 90 <0f> 0b 90 90 e9 5f ff ff ff e8 29 f1 9a fe e9 4e ff ff ff e8 8f f0
RSP: 0018:ffffc900001074b0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88803df6b380 RCX: ffffffff817a2808
RDX: ffff88801de90000 RSI: ffffffff817a2815 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880347b3c90
R13: ffffc900001077e8 R14: dffffc0000000000 R15: ffff8880347b3f08
FS:  0000000000000000(0000) GS:ffff8880d68fb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000740 CR3: 00000000340de000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 netfs_writepages+0x6e4/0x920 fs/netfs/write_issue.c:592
 do_writepages+0x277/0x600 mm/page-writeback.c:2634
 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x60a/0xfa0 fs/fs-writeback.c:1976
 wb_writeback+0x419/0xb70 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x14d/0xbe0 fs/fs-writeback.c:2343
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>