======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.354/9310 is trying to acquire lock:
ffff8881bfb20778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0

but task is already holding lock:
ffff888172dd40b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock/1){+.+.}-{4:4}:
       lock_acquire+0x120/0x360
       __mutex_lock+0x187/0x1350
       hfs_find_init+0x18e/0x2c0
       hfs_extend_file+0x2f6/0x14c0
       hfs_bmap_reserve+0x107/0x430
       hfs_cat_create+0x1c5/0x730
       hfs_create+0x66/0xe0
       path_openat+0x14f4/0x3830
       do_filp_open+0x1fa/0x410
       do_sys_openat2+0x121/0x1c0
       __x64_sys_openat+0x138/0x170
       do_syscall_64+0xfa/0xfa0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}:
       validate_chain+0xb9b/0x2140
       __lock_acquire+0xab9/0xd20
       lock_acquire+0x120/0x360
       __mutex_lock+0x187/0x1350
       hfs_extend_file+0xda/0x14c0
       hfs_bmap_reserve+0x107/0x430
       __hfs_ext_write_extent+0x1fa/0x470
       __hfs_ext_cache_extent+0x6b/0x9b0
       hfs_extend_file+0x31e/0x14c0
       hfs_get_block+0x3d7/0xbd0
       __blockdev_direct_IO+0x16ff/0x3490
       hfs_direct_IO+0x119/0x220
       generic_file_direct_write+0x1db/0x3e0
       __generic_file_write_iter+0x11d/0x230
       generic_file_write_iter+0x117/0x550
       iter_file_splice_write+0x975/0x10e0
       direct_splice_actor+0x101/0x160
       splice_direct_to_actor+0x5a8/0xcc0
       do_splice_direct+0x181/0x270
       do_sendfile+0x4da/0x7e0
       __se_sys_sendfile64+0x13e/0x190
       do_syscall_64+0xfa/0xfa0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

4 locks held by syz.2.354/9310:
 #0: ffff88816d056420 (sb_writers#14){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff8881bfb229a0 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: generic_file_write_iter+0xeb/0x550
 #2: ffff8881bfb227f8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0
 #3: ffff888172dd40b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0

stack backtrace:
CPU: 1 UID: 0 PID: 9310 Comm: syz.2.354 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_circular_bug+0x2ee/0x310
 check_noncircular+0x134/0x160
 validate_chain+0xb9b/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 __mutex_lock+0x187/0x1350
 hfs_extend_file+0xda/0x14c0
 hfs_bmap_reserve+0x107/0x430
 __hfs_ext_write_extent+0x1fa/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x31e/0x14c0
 hfs_get_block+0x3d7/0xbd0
 __blockdev_direct_IO+0x16ff/0x3490
 hfs_direct_IO+0x119/0x220
 generic_file_direct_write+0x1db/0x3e0
 __generic_file_write_iter+0x11d/0x230
 generic_file_write_iter+0x117/0x550
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd130f8f749
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd131d7b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fd1311e5fa0 RCX: 00007fd130f8f749
RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000009
RBP: 00007fd131013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd1311e6038 R14: 00007fd1311e5fa0 R15: 00007ffdee418c78
 </TASK>
