======================================================
WARNING: possible circular locking dependency detected
6.2.0-rc5-next-20230123 #1 Not tainted
------------------------------------------------------
syz-executor.0/27393 is trying to acquire lock:
ffff88800b5e0400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x52/0x470
but task is already holding lock:
ffff88800fcac3f8 (&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/0x1300
__jbd2_log_wait_for_space+0x238/0x460
add_transaction_credits+0xa42/0xb80
start_this_handle+0x3ac/0x14c0
jbd2__journal_start+0x394/0x6b0
__ext4_journal_start_sb+0x4c2/0x6f0
__ext4_unlink+0x44e/0xcf0
ext4_unlink+0x3ac/0x640
vfs_unlink+0x35e/0x930
do_unlinkat+0x3b9/0x650
__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+0x2a52/0x5e90
lock_acquire.part.0+0x120/0x340
down_read+0x9c/0x450
ext4_bmap+0x52/0x470
bmap+0xb0/0x130
jbd2_journal_bmap+0xac/0x190
jbd2_journal_flush+0x860/0xc10
__ext4_ioctl+0x9fd/0x42a0
__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);
rlock(&sb->s_type->i_mutex_key#6);
*** DEADLOCK ***
2 locks held by syz-executor.0/27393:
#0: ffff88800fcac170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x162/0x310
#1: ffff88800fcac3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10
stack backtrace:
CPU: 1 PID: 27393 Comm: syz-executor.0 Not tainted 6.2.0-rc5-next-20230123 #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+0x2a52/0x5e90
lock_acquire.part.0+0x120/0x340
down_read+0x9c/0x450
ext4_bmap+0x52/0x470
bmap+0xb0/0x130
jbd2_journal_bmap+0xac/0x190
jbd2_journal_flush+0x860/0xc10
__ext4_ioctl+0x9fd/0x42a0
__x64_sys_ioctl+0x19e/0x210
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fc80b61db19
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:00007fc808b93188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc80b730f60 RCX: 00007fc80b61db19
RDX: 0000000020000340 RSI: 000000004004662b RDI: 0000000000000007
RBP: 00007fc80b677f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd55d6513f R14: 00007fc808b93300 R15: 0000000000022000
</TASK>