loop6: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.6.787/10049 is trying to acquire lock:
ffff88810828c270 (&wnd->rw_lock){++++}-{4:4}, at: mark_as_free_ex+0x3e/0x390

but task is already holding lock:
ffff88803b16c3c8 (&ni->file.run_lock#2){++++}-{4:4}, at: attr_collapse_range+0x38c/0x1730

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{4:4}:
       lock_acquire+0x120/0x360
       down_read+0x46/0x2e0
       run_unpack_ex+0x7e5/0xba0
       ntfs_iget5+0x232b/0x37c0
       dir_search_u+0x1df/0x2c0
       ntfs_lookup+0xfb/0x1f0
       lookup_one_qstr_excl+0x131/0x360
       filename_create+0x224/0x3c0
       do_mkdirat+0xa0/0x590
       __x64_sys_mkdir+0x6c/0x80
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&wnd->rw_lock){++++}-{4:4}:
       validate_chain+0xb9b/0x2140
       __lock_acquire+0xab9/0xd20
       lock_acquire+0x120/0x360
       down_write_nested+0x9d/0x200
       mark_as_free_ex+0x3e/0x390
       run_deallocate_ex+0x187/0x2f0
       attr_collapse_range+0xc36/0x1730
       ntfs_fallocate+0x7d6/0x10b0
       vfs_fallocate+0x669/0x7e0
       __x64_sys_fallocate+0xc0/0x110
       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(&ni->file.run_lock#2);
                               lock(&wnd->rw_lock);
                               lock(&ni->file.run_lock#2);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

5 locks held by syz.6.787/10049:
 #0: ffff88810622c428 (sb_writers#16){.+.+}-{0:0}, at: vfs_fallocate+0x5f0/0x7e0
 #1: ffff88803b16c5b0 (&sb->s_type->i_mutex_key#22){+.+.}-{4:4}, at: ntfs_fallocate+0x2ee/0x10b0
 #2: ffff88803b16c750 (mapping.invalidate_lock#5){++++}-{4:4}, at: ntfs_fallocate+0x3b8/0x10b0
 #3: ffff88803b16c318 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_fallocate+0x7c4/0x10b0
 #4: ffff88803b16c3c8 (&ni->file.run_lock#2){++++}-{4:4}, at: attr_collapse_range+0x38c/0x1730

stack backtrace:
CPU: 0 UID: 0 PID: 10049 Comm: syz.6.787 Not tainted syzkaller #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
 down_write_nested+0x9d/0x200
 mark_as_free_ex+0x3e/0x390
 run_deallocate_ex+0x187/0x2f0
 attr_collapse_range+0xc36/0x1730
 ntfs_fallocate+0x7d6/0x10b0
 vfs_fallocate+0x669/0x7e0
 __x64_sys_fallocate+0xc0/0x110
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a8d38ec29
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:00007f3a8e1cd038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f3a8d5d5fa0 RCX: 00007f3a8d38ec29
RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000004
RBP: 00007f3a8d411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a8d5d6038 R14: 00007f3a8d5d5fa0 R15: 00007ffea15b22a8
 </TASK>
