======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc1-syzkaller-00001-gfa08a7b61dff #0 Not tainted
------------------------------------------------------
syz-executor.7/5556 is trying to acquire lock:
ffff88814aae20e0 (&type->s_umount_key
#32){++++}-{3:3}, at: __x64_sys_quotactl_fd+0x2c1/0x500

but task is already holding lock:
ffff88814aae2460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_quotactl_fd+0x159/0x500

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#4){.+.+}-{0:0}:
       write_mmp_block+0xca/0x800
       ext4_multi_mount_protect+0x51a/0xad0
       ext4_reconfigure+0x2369/0x2a60
       reconfigure_super+0x25c/0xa60
       __do_sys_fsconfig+0xb15/0xda0
       do_syscall_64+0x38/0xb0
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&type->s_umount_key#32){++++}-{3:3}:
       __lock_acquire+0x2e37/0x5cf0
       lock_acquire+0x1ae/0x510
       down_read+0x3d/0x50
       __x64_sys_quotactl_fd+0x2c1/0x500
       do_syscall_64+0x38/0xb0
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_writers#4);
                               lock(&type->s_umount_key#32);
                               lock(sb_writers#4);
  rlock(&type->s_umount_key#32);

 *** DEADLOCK ***

1 lock held by syz-executor.7/5556:
 #0: ffff88814aae2460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_quotactl_fd+0x159/0x500

stack backtrace:
CPU: 1 PID: 5556 Comm: syz-executor.7 Not tainted 6.4.0-rc1-syzkaller-00001-gfa08a7b61dff #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 dump_stack_lvl+0xd9/0x1b0
 check_noncircular+0x268/0x310
 __lock_acquire+0x2e37/0x5cf0
 lock_acquire+0x1ae/0x510
 down_read+0x3d/0x50
 __x64_sys_quotactl_fd+0x2c1/0x500
 do_syscall_64+0x38/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f994ee7ca19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f994fcc50c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001bb
RAX: ffffffffffffffda RBX: 00007f994ef9bf80 RCX: 00007f994ee7ca19
RDX: ffffffffffffffff RSI: ffffffff80000802 RDI: 0000000000000003
RBP: 00007f994eed8c88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f994ef9bf80 R15: 00007ffd6df00b68
 </TASK>
