======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc3-next-20220829 #1 Not tainted
------------------------------------------------------
systemd-journal/112 is trying to acquire lock:
ffff8880100a43f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x234/0x460

but task is already holding lock:
ffff8880100a0530 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x1a0/0x4f0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (sb_pagefaults){.+.+}-{0:0}:
       ext4_page_mkwrite+0x1f8/0x1a70
       do_page_mkwrite+0x1a0/0x4f0
       __handle_mm_fault+0x12ac/0x34c0
       handle_mm_fault+0x2e6/0xa20
       do_user_addr_fault+0x536/0x1300
       exc_page_fault+0x98/0x1a0
       asm_exc_page_fault+0x22/0x30

-> #2 (&mm->mmap_lock#2){++++}-{3:3}:
       internal_get_user_pages_fast+0x133a/0x2ec0
       get_user_pages_fast+0x66/0xa0
       __iov_iter_get_pages_alloc+0x38d/0x2290
       iov_iter_get_pages2+0xa4/0x100
       bio_iov_iter_get_pages+0x1da/0x10b0
       iomap_dio_bio_iter+0x92f/0x1510
       __iomap_dio_rw+0xe14/0x1bd0
       iomap_dio_rw+0x3c/0xa0
       ext4_file_read_iter+0x268/0x400
       vfs_read+0x683/0x930
       ksys_read+0x127/0x250
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&sb->s_type->i_mutex_key#6){++++}-{3:3}:
       down_read+0x98/0x450
       ext4_bmap+0x4e/0x470
       bmap+0xac/0x120
       jbd2_journal_bmap+0xa8/0x180
       jbd2_journal_flush+0x853/0xc00
       __ext4_ioctl+0x9e9/0x4090
       __x64_sys_ioctl+0x19a/0x210
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       __lock_acquire+0x2a02/0x5e70
       lock_acquire+0x1a2/0x530
       mutex_lock_io_nested+0x148/0x1310
       __jbd2_log_wait_for_space+0x234/0x460
       add_transaction_credits+0xa42/0xb80
       start_this_handle+0x3ac/0x14c0
       jbd2__journal_start+0x390/0x8d0
       __ext4_journal_start_sb+0x391/0x470
       ext4_dirty_inode+0x9d/0x110
       __mark_inode_dirty+0x455/0xf00
       generic_update_time+0x26b/0x410
       file_update_time+0x22b/0x280
       ext4_page_mkwrite+0x2ea/0x1a70
       do_page_mkwrite+0x1a0/0x4f0
       __handle_mm_fault+0x12ac/0x34c0
       handle_mm_fault+0x2e6/0xa20
       do_user_addr_fault+0x536/0x1300
       exc_page_fault+0x98/0x1a0
       asm_exc_page_fault+0x22/0x30

other info that might help us debug this:

Chain exists of:
  &journal->j_checkpoint_mutex --> &mm->mmap_lock#2 --> sb_pagefaults

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_pagefaults);
                               lock(&mm->mmap_lock#2);
                               lock(sb_pagefaults);
  lock(&journal->j_checkpoint_mutex);

 *** DEADLOCK ***

2 locks held by systemd-journal/112:
 #0: ffff8880085a9658 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x337/0x1300
 #1: ffff8880100a0530 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x1a0/0x4f0

stack backtrace:
CPU: 0 PID: 112 Comm: systemd-journal Not tainted 6.0.0-rc3-next-20220829 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 check_noncircular+0x263/0x2e0
 __lock_acquire+0x2a02/0x5e70
 lock_acquire+0x1a2/0x530
 mutex_lock_io_nested+0x148/0x1310
 __jbd2_log_wait_for_space+0x234/0x460
 add_transaction_credits+0xa42/0xb80
 start_this_handle+0x3ac/0x14c0
 jbd2__journal_start+0x390/0x8d0
 __ext4_journal_start_sb+0x391/0x470
 ext4_dirty_inode+0x9d/0x110
 __mark_inode_dirty+0x455/0xf00
 generic_update_time+0x26b/0x410
 file_update_time+0x22b/0x280
 ext4_page_mkwrite+0x2ea/0x1a70
 do_page_mkwrite+0x1a0/0x4f0
 __handle_mm_fault+0x12ac/0x34c0
 handle_mm_fault+0x2e6/0xa20
 do_user_addr_fault+0x536/0x1300
 exc_page_fault+0x98/0x1a0
 asm_exc_page_fault+0x22/0x30
RIP: 0033:0x7f6607ffca71
Code: fa ff 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 0f 82 b8 00 00 00 48 83 fa 40 0f 87 1b 01 00 00 c5 fe 6f 06 c5 fe 6f 4c 16 e0 <c5> fe 7f 07 c5 fe 7f 4c 17 e0 c5 f8 77 c3 90 48 39 d1 0f 82 b7 95
RSP: 002b:00007ffdc6256798 EFLAGS: 00010283
RAX: 00007f6606e1bff8 RBX: 0000558eee8b0970 RCX: 00007f6606e1bfb8
RDX: 0000000000000025 RSI: 0000558eee8b0970 RDI: 00007f6606e1bff8
RBP: 0000558eee8af2b0 R08: 0000000000000001 R09: 0000000000361fb8
R10: 0000000000000002 R11: 00000000000a70c8 R12: 0000000000000025
R13: 58329e277cc1a5cd R14: 0000000000000000 R15: 00007ffdc62567c0
 </TASK>
netlink: 60 bytes leftover after parsing attributes in process `syz-executor.7'.
netlink: 60 bytes leftover after parsing attributes in process `syz-executor.7'.
netlink: 60 bytes leftover after parsing attributes in process `syz-executor.7'.
netlink: 60 bytes leftover after parsing attributes in process `syz-executor.7'.
netlink: 60 bytes leftover after parsing attributes in process `syz-executor.7'.
dns_resolver: Unsupported server list version (0)
dns_resolver: Unsupported server list version (0)
dns_resolver: Unsupported server list version (0)
dns_resolver: Unsupported server list version (0)
netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'.