loop5: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc5-syzkaller-00193-g40f92e79b0aa-dirty #0 Not tainted
------------------------------------------------------
syz.5.1288/9835 is trying to acquire lock:
ffff88802a053de0 (&mm->mmap_lock){++++}-{4:4}, at: gup_fast_fallback+0x215/0x2260

but task is already holding lock:
ffff888034a6f1c0 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: ntfs_file_write_iter+0x78/0x820

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}:
       lock_acquire+0x120/0x360
       down_write+0x96/0x1f0
       ntfs_file_mmap+0x525/0x730
       mmap_region+0x127a/0x1f30
       do_mmap+0xc45/0x10d0
       vm_mmap_pgoff+0x31b/0x4c0
       ksys_mmap_pgoff+0x51f/0x760
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       validate_chain+0xb9b/0x2140
       __lock_acquire+0xab9/0xd20
       lock_acquire+0x120/0x360
       gup_fast_fallback+0x22e/0x2260
       iov_iter_extract_pages+0x35a/0x5e0
       __blockdev_direct_IO+0x114f/0x33d0
       ntfs_direct_IO+0x20b/0x410
       generic_file_direct_write+0x1db/0x3e0
       __generic_file_write_iter+0x11d/0x230
       ntfs_file_write_iter+0x71c/0x820
       do_iter_readv_writev+0x56e/0x7f0
       vfs_writev+0x31a/0x960
       __se_sys_pwritev2+0x179/0x290
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#33);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#33);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

2 locks held by syz.5.1288/9835:
 #0: ffff888023406428 (sb_writers#23){.+.+}-{0:0}, at: vfs_writev+0x288/0x960
 #1: ffff888034a6f1c0 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: ntfs_file_write_iter+0x78/0x820

stack backtrace:
CPU: 0 UID: 0 PID: 9835 Comm: syz.5.1288 Not tainted 6.16.0-rc5-syzkaller-00193-g40f92e79b0aa-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_circular_bug+0x2ee/0x310
 check_noncircular+0x134/0x160
 validate_chain+0xb9b/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 gup_fast_fallback+0x22e/0x2260
 iov_iter_extract_pages+0x35a/0x5e0
 __blockdev_direct_IO+0x114f/0x33d0
 ntfs_direct_IO+0x20b/0x410
 generic_file_direct_write+0x1db/0x3e0
 __generic_file_write_iter+0x11d/0x230
 ntfs_file_write_iter+0x71c/0x820
 do_iter_readv_writev+0x56e/0x7f0
 vfs_writev+0x31a/0x960
 __se_sys_pwritev2+0x179/0x290
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e3038e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1e3124d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f1e305b5fa0 RCX: 00007f1e3038e929
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000006
RBP: 00007f1e30410b39 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000002000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1e305b5fa0 R15: 00007ffe0940ef88
 </TASK>
