warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc1-next-20221018 #1 Not tainted
------------------------------------------------------
syz-executor.5/14619 is trying to acquire lock:
ffff88800c918400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x4e/0x470

but task is already holding lock:
ffff88800fff03f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       mutex_lock_io_nested+0x148/0x1310
       jbd2_journal_flush+0x19a/0xc00
       ext4_change_inode_journal_flag+0x38f/0x530
       ext4_fileattr_set+0x1427/0x18c0
       vfs_fileattr_set+0x77c/0xb80
       do_vfs_ioctl+0xfc1/0x1610
       __x64_sys_ioctl+0x10c/0x210
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #2 (&journal->j_barrier){+.+.}-{3:3}:
       __mutex_lock+0x136/0x14d0
       jbd2_journal_lock_updates+0x15e/0x310
       ext4_change_inode_journal_flag+0x17f/0x530
       ext4_fileattr_set+0x1427/0x18c0
       vfs_fileattr_set+0x77c/0xb80
       do_vfs_ioctl+0xfc1/0x1610
       __x64_sys_ioctl+0x10c/0x210
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       percpu_down_write+0x4d/0x350
       ext4_ind_migrate+0x237/0x830
       ext4_fileattr_set+0x144e/0x18c0
       vfs_fileattr_set+0x77c/0xb80
       do_vfs_ioctl+0xfc1/0x1610
       __x64_sys_ioctl+0x10c/0x210
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sb->s_type->i_mutex_key#6){++++}-{3:3}:
       __lock_acquire+0x2a02/0x5e70
       lock_acquire+0x1a2/0x530
       down_read+0x98/0x450
       ext4_bmap+0x4e/0x470
       bmap+0xac/0x120
       jbd2_journal_bmap+0xa8/0x180
       jbd2_journal_flush+0x853/0xc00
       __ext4_ioctl+0x9e9/0x40a0
       __x64_sys_ioctl+0x19a/0x210
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#6 --> &journal->j_barrier --> &journal->j_checkpoint_mutex

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

2 locks held by syz-executor.5/14619:
 #0: ffff88800fff0170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x15e/0x310
 #1: ffff88800fff03f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00

stack backtrace:
CPU: 1 PID: 14619 Comm: syz-executor.5 Not tainted 6.1.0-rc1-next-20221018 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 check_noncircular+0x263/0x2e0
 __lock_acquire+0x2a02/0x5e70
 lock_acquire+0x1a2/0x530
 down_read+0x98/0x450
 ext4_bmap+0x4e/0x470
 bmap+0xac/0x120
 jbd2_journal_bmap+0xa8/0x180
 jbd2_journal_flush+0x853/0xc00
 __ext4_ioctl+0x9e9/0x40a0
 __x64_sys_ioctl+0x19a/0x210
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc3c9ec1b19
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:00007fc3c7437188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc3c9fd4f60 RCX: 00007fc3c9ec1b19
RDX: 0000000020000100 RSI: 000000004004662b RDI: 0000000000000005
RBP: 00007fc3c9f1bf6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcd34e609f R14: 00007fc3c7437300 R15: 0000000000022000
 </TASK>
EXT4-fs: test_dummy_encryption option not supported
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 14634 Comm: syz-executor.1 Not tainted 6.1.0-rc1-next-20221018 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 should_fail.cold+0x5/0xa
 _copy_to_user+0x2a/0x140
 simple_read_from_buffer+0xcc/0x160
 proc_fail_nth_read+0x198/0x230
 vfs_read+0x253/0x930
 ksys_read+0x127/0x250
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fce56dc169c
Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48
RSP: 002b:00007fce54384170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fce56dc169c
RDX: 000000000000000f RSI: 00007fce543841e0 RDI: 0000000000000004
RBP: 00007fce543841d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff2361ac8f R14: 00007fce54384300 R15: 0000000000022000
 </TASK>
EXT4-fs: test_dummy_encryption option not supported