======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.503/8727 is trying to acquire lock:
ffff888120f8a7f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0

but task is already holding lock:
ffff88810b5f40b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}:
       __mutex_lock+0x19f/0x1300
       hfs_find_init+0x18e/0x300
       hfs_extend_file+0x35c/0x15e0
       hfs_bmap_reserve+0x107/0x430
       hfs_cat_create+0x20f/0x800
       hfs_create+0x66/0xe0
       path_openat+0x18dd/0x3e20
       do_filp_open+0x22d/0x490
       do_sys_openat2+0x12f/0x220
       __x64_sys_creat+0x8f/0xc0
       do_syscall_64+0xe2/0xf80
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}:
       __lock_acquire+0x15a5/0x2cf0
       lock_acquire+0x106/0x330
       __mutex_lock+0x19f/0x1300
       hfs_extend_file+0xf2/0x15e0
       hfs_bmap_reserve+0x107/0x430
       __hfs_ext_write_extent+0x1fa/0x470
       __hfs_ext_cache_extent+0x6b/0x9b0
       hfs_extend_file+0x39b/0x15e0
       hfs_get_block+0x412/0xc50
       __block_write_begin_int+0x6c6/0x1910
       cont_write_begin+0x737/0xae0
       hfs_write_begin+0x66/0xb0
       generic_perform_write+0x2e2/0x8f0
       generic_file_write_iter+0x14a/0x680
       vfs_write+0x61d/0xb90
       __x64_sys_pwrite64+0x199/0x230
       do_syscall_64+0xe2/0xf80
       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#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

4 locks held by syz.1.503/8727:
 #0: ffff888112fc8420 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff888120f8bd20 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: generic_file_write_iter+0x11e/0x680
 #2: ffff888120f8bb78 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0
 #3: ffff88810b5f40b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300

stack backtrace:
CPU: 0 UID: 0 PID: 8727 Comm: syz.1.503 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+0xe8/0x150
 print_circular_bug+0x2e1/0x300
 check_noncircular+0x12e/0x150
 __lock_acquire+0x15a5/0x2cf0
 lock_acquire+0x106/0x330
 __mutex_lock+0x19f/0x1300
 hfs_extend_file+0xf2/0x15e0
 hfs_bmap_reserve+0x107/0x430
 __hfs_ext_write_extent+0x1fa/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x39b/0x15e0
 hfs_get_block+0x412/0xc50
 __block_write_begin_int+0x6c6/0x1910
 cont_write_begin+0x737/0xae0
 hfs_write_begin+0x66/0xb0
 generic_perform_write+0x2e2/0x8f0
 generic_file_write_iter+0x14a/0x680
 vfs_write+0x61d/0xb90
 __x64_sys_pwrite64+0x199/0x230
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64c879acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f64c969e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f64c8a15fa0 RCX: 00007f64c879acb9
RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f64c8808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64c8a16038 R14: 00007f64c8a15fa0 R15: 00007fffe1fc3508
 </TASK>
