======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc3-next-20221107 #1 Not tainted
------------------------------------------------------
syz-executor.7/56016 is trying to acquire lock:
ffff88800b0f0400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x52/0x470

but task is already holding lock:
ffff88800fb9c3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       mutex_lock_io_nested+0x14c/0x1330
       __jbd2_log_wait_for_space+0x238/0x460
       add_transaction_credits+0xa42/0xb80
       start_this_handle+0x3ac/0x14c0
       jbd2__journal_start+0x394/0x8d0
       __ext4_journal_start_sb+0x395/0x470
       ext4_unlink+0x4e8/0x8c0
       vfs_unlink+0x35e/0x930
       do_unlinkat+0x398/0x620
       __x64_sys_unlink+0xca/0x110
       do_syscall_64+0x3f/0x90
       entry_SYSCALL_64_after_hwframe+0x72/0xdc

-> #0 (&sb->s_type->i_mutex_key#6){++++}-{3:3}:
       __lock_acquire+0x2a02/0x5e70
       lock_acquire+0x1a6/0x530
       down_read+0x9c/0x450
       ext4_bmap+0x52/0x470
       bmap+0xb0/0x130
       jbd2_journal_bmap+0xac/0x190
       jbd2_journal_flush+0x857/0xc10
       __ext4_ioctl+0x9c1/0x4140
       __x64_sys_ioctl+0x19e/0x210
       do_syscall_64+0x3f/0x90
       entry_SYSCALL_64_after_hwframe+0x72/0xdc

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&journal->j_checkpoint_mutex);
                               lock(&sb->s_type->i_mutex_key#6);
                               lock(&journal->j_checkpoint_mutex);
  lock(&sb->s_type->i_mutex_key#6);

 *** DEADLOCK ***

2 locks held by syz-executor.7/56016:
 #0: ffff88800fb9c170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x162/0x310
 #1: ffff88800fb9c3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10

stack backtrace:
CPU: 1 PID: 56016 Comm: syz-executor.7 Not tainted 6.1.0-rc3-next-20221107 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8f/0xb7
 check_noncircular+0x263/0x2e0
 __lock_acquire+0x2a02/0x5e70
 lock_acquire+0x1a6/0x530
 down_read+0x9c/0x450
 ext4_bmap+0x52/0x470
 bmap+0xb0/0x130
 jbd2_journal_bmap+0xac/0x190
 jbd2_journal_flush+0x857/0xc10
 __ext4_ioctl+0x9c1/0x4140
 __x64_sys_ioctl+0x19e/0x210
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fe9e2b76b19
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe9e00ec188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe9e2c89f60 RCX: 00007fe9e2b76b19
RDX: 0000000020000000 RSI: 000000004004662b RDI: 0000000000000003
RBP: 00007fe9e2bd0f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdcf5f2faf R14: 00007fe9e00ec300 R15: 0000000000022000
 </TASK>
Bluetooth: hci2: link tx timeout
Bluetooth: hci2: killing stalled connection 10:aa:aa:aa:aa:aa
Bluetooth: hci2: link tx timeout
Bluetooth: hci2: killing stalled connection 10:aa:aa:aa:aa:aa
Process accounting resumed
Process accounting resumed
Process accounting resumed
Process accounting resumed
Process accounting resumed
capability: warning: `syz-executor.7' uses deprecated v2 capabilities in a way that may be insecure
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'.
tmpfs: Bad value for 'mpol'
tmpfs: Bad value for 'mpol'
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'.
tmpfs: Bad value for 'mpol'
tmpfs: Bad value for 'mpol'
tmpfs: Bad value for 'mpol'