======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.3.1415/12614 is trying to acquire lock:
ffff8881b7a4a258 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xb6/0x360

but task is already holding lock:
ffff8881b7a4a2e8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xa4/0x360

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&oi->ip_xattr_sem){++++}-{4:4}:
       down_read+0x4a/0x330
       ocfs2_init_acl+0x2fd/0x7e0
       ocfs2_mknod+0x166a/0x2240
       ocfs2_create+0x195/0x460
       path_openat+0x133a/0x3830
       do_file_open+0x23e/0x4a0
       do_sys_openat2+0x115/0x200
       __x64_sys_open+0x11e/0x150
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
       down_read+0x4a/0x330
       ocfs2_start_trans+0x3ab/0x700
       ocfs2_mknod+0x116a/0x2240
       ocfs2_create+0x195/0x460
       path_openat+0x133a/0x3830
       do_file_open+0x23e/0x4a0
       do_sys_openat2+0x115/0x200
       __x64_sys_openat+0x138/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (sb_internal#2){.+.+}-{0:0}:
       ocfs2_start_trans+0x2ac/0x700
       ocfs2_write_begin_nolock+0x277f/0x41f0
       ocfs2_page_mkwrite+0x63d/0xb60
       do_page_mkwrite+0x147/0x310
       do_wp_page+0x1a9c/0x4b80
       handle_mm_fault+0x15d7/0x3750
       do_user_addr_fault+0x744/0x1340
       exc_page_fault+0x6a/0xc0
       asm_exc_page_fault+0x26/0x30

-> #0 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}:
       __lock_acquire+0x15ff/0x2e50
       lock_acquire+0x115/0x350
       down_write+0x96/0x200
       ocfs2_try_remove_refcount_tree+0xb6/0x360
       ocfs2_truncate_file+0xe90/0x14b0
       ocfs2_setattr+0x1641/0x1d10
       notify_change+0xbba/0xea0
       do_truncate+0x1c2/0x250
       do_ftruncate+0x4d4/0x580
       __x64_sys_ftruncate+0x8f/0xe0
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &ocfs2_file_ip_alloc_sem_key --> &journal->j_trans_barrier --> &oi->ip_xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&oi->ip_xattr_sem);
                               lock(&journal->j_trans_barrier);
                               lock(&oi->ip_xattr_sem);
  lock(&ocfs2_file_ip_alloc_sem_key);

 *** DEADLOCK ***

3 locks held by syz.3.1415/12614:
 #0: ffff8881bca42450 (sb_writers#15){.+.+}-{0:0}, at: do_ftruncate+0x474/0x580
 #1: ffff8881b7a4a5a0 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: do_truncate+0x18f/0x250
 #2: ffff8881b7a4a2e8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xa4/0x360

stack backtrace:
CPU: 1 UID: 0 PID: 12614 Comm: syz.3.1415 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x2e2/0x300
 check_noncircular+0x12f/0x150
 __lock_acquire+0x15ff/0x2e50
 lock_acquire+0x115/0x350
 down_write+0x96/0x200
 ocfs2_try_remove_refcount_tree+0xb6/0x360
 ocfs2_truncate_file+0xe90/0x14b0
 ocfs2_setattr+0x1641/0x1d10
 notify_change+0xbba/0xea0
 do_truncate+0x1c2/0x250
 do_ftruncate+0x4d4/0x580
 __x64_sys_ftruncate+0x8f/0xe0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f270a39e0d9
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:00007f27085d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f270a626090 RCX: 00007f270a39e0d9
RDX: 0000000000000000 RSI: 000000000000010d RDI: 0000000000000003
RBP: 00007f270a435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f270a626128 R14: 00007f270a626090 R15: 00007fff98c08168
 </TASK>
