======================================================
WARNING: possible circular locking dependency detected
5.15.98-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/28805 is trying to acquire lock:
ffff88814aab03f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:110

but task is already holding lock:
ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:510 [inline]
ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_file_write_iter+0x5c4/0x1990 fs/ext4/file.c:685

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#9){++++}-{3:3}:
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       down_read+0x3b/0x50 kernel/locking/rwsem.c:1480
       inode_lock_shared include/linux/fs.h:797 [inline]
       ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3159
       bmap+0xa1/0xd0 fs/inode.c:1714
       jbd2_journal_bmap fs/jbd2/journal.c:978 [inline]
       __jbd2_journal_erase fs/jbd2/journal.c:1786 [inline]
       jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2492
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:847 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1265 [inline]
       ext4_ioctl+0x335b/0x5db0 fs/ext4/ioctl.c:1277
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       mutex_lock_io_nested+0x45/0x60 kernel/locking/mutex.c:777
       __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:110
       add_transaction_credits+0x950/0xc00 fs/jbd2/transaction.c:303
       start_this_handle+0x747/0x1590 fs/jbd2/transaction.c:427
       jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:525
       __ext4_journal_start_sb+0x1eb/0x440 fs/ext4/ext4_jbd2.c:105
       __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
       ext4_handle_inode_extension+0x1a7/0x8b0 fs/ext4/file.c:325
       ext4_dio_write_iter fs/ext4/file.c:581 [inline]
       ext4_file_write_iter+0x15ed/0x1990 fs/ext4/file.c:685
       do_iter_readv_writev+0x594/0x7a0
       do_iter_write+0x1ea/0x760 fs/read_write.c:855
       iter_file_splice_write+0x806/0xfa0 fs/splice.c:689
       do_splice_from fs/splice.c:767 [inline]
       direct_splice_actor+0xe3/0x1c0 fs/splice.c:936
       splice_direct_to_actor+0x500/0xc10 fs/splice.c:891
       do_splice_direct+0x285/0x3d0 fs/splice.c:979
       do_sendfile+0x625/0xff0 fs/read_write.c:1249
       __do_sys_sendfile64 fs/read_write.c:1317 [inline]
       __se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1303
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#9);
                               lock(&journal->j_checkpoint_mutex);
                               lock(&sb->s_type->i_mutex_key#9);
  lock(&journal->j_checkpoint_mutex);

 *** DEADLOCK ***

2 locks held by syz-executor.4/28805:
 #0: ffff88814aaac460 (sb_writers#5){.+.+}-{0:0}, at: do_sendfile+0x600/0xff0 fs/read_write.c:1248
 #1: ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:510 [inline]
 #1: ffff888026d967a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_file_write_iter+0x5c4/0x1990 fs/ext4/file.c:685

stack backtrace:
CPU: 0 PID: 28805 Comm: syz-executor.4 Not tainted 5.15.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
 lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
 mutex_lock_io_nested+0x45/0x60 kernel/locking/mutex.c:777
 __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:110
 add_transaction_credits+0x950/0xc00 fs/jbd2/transaction.c:303
 start_this_handle+0x747/0x1590 fs/jbd2/transaction.c:427
 jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:525
 __ext4_journal_start_sb+0x1eb/0x440 fs/ext4/ext4_jbd2.c:105
 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
 ext4_handle_inode_extension+0x1a7/0x8b0 fs/ext4/file.c:325
 ext4_dio_write_iter fs/ext4/file.c:581 [inline]
 ext4_file_write_iter+0x15ed/0x1990 fs/ext4/file.c:685
 do_iter_readv_writev+0x594/0x7a0
 do_iter_write+0x1ea/0x760 fs/read_write.c:855
 iter_file_splice_write+0x806/0xfa0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0xe3/0x1c0 fs/splice.c:936
 splice_direct_to_actor+0x500/0xc10 fs/splice.c:891
 do_splice_direct+0x285/0x3d0 fs/splice.c:979
 do_sendfile+0x625/0xff0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1317 [inline]
 __se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1303
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fd8084cc0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd806a3e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fd8085ebf80 RCX: 00007fd8084cc0f9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007fd808527ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000f03afffe R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddf65b3ff R14: 00007fd806a3e300 R15: 0000000000022000
 </TASK>