============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.0/5317 is trying to acquire lock:
ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4940 fs/ocfs2/suballoc.c:857

but task is already holding lock:
ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4940 fs/ocfs2/suballoc.c:857

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]);
  lock(&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz.0.0/5317:
 #0: ffff888044e1a420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff88800bb2b480 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #1: ffff88800bb2b480 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline]
 #1: ffff88800bb2b480 (&type->i_mutex_dir_key#8){+.+.}-{4:4}, at: path_openat+0xb4c/0x3860 fs/namei.c:4827
 #2: ffff88800bb242c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #2: ffff88800bb242c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4940 fs/ocfs2/suballoc.c:857
 #3: ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #3: ffff88800bb25f40 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4940 fs/ocfs2/suballoc.c:857

stack backtrace:
CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain kernel/locking/lockdep.c:3895 [inline]
 __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 down_write+0x96/0x200 kernel/locking/rwsem.c:1590
 inode_lock include/linux/fs.h:1028 [inline]
 ocfs2_reserve_suballoc_bits+0x16a/0x4940 fs/ocfs2/suballoc.c:857
 ocfs2_reserve_cluster_bitmap_bits fs/ocfs2/suballoc.c:1203 [inline]
 ocfs2_reserve_clusters_with_limit+0x3bc/0xc20 fs/ocfs2/suballoc.c:1248
 ocfs2_mknod+0x111f/0x2290 fs/ocfs2/namei.c:358
 ocfs2_create+0x195/0x490 fs/ocfs2/namei.c:677
 lookup_open fs/namei.c:4483 [inline]
 open_last_lookups fs/namei.c:4583 [inline]
 path_openat+0x1395/0x3860 fs/namei.c:4827
 do_file_open+0x23e/0x4a0 fs/namei.c:4859
 do_sys_openat2+0x113/0x200 fs/open.c:1366
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6dc9d9bf79
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:00007f6dcad0e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6dca016090 RCX: 00007f6dc9d9bf79
RDX: 0000000000105040 RSI: 0000200000000640 RDI: ffffffffffffff9c
RBP: 00007f6dc9e327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6dca016128 R14: 00007f6dca016090 R15: 00007ffcde456b88
 </TASK>