Why is the tcmu-runner log consuming a lot of space?

Issue

• The tcmu-runner log is spanning several GBs:

  ls -lha /var/log/gluster-block
  total 120G
  120G -rw-------.  1 root root 120G May 28 21:53 tcmu-runner-glfs.log
  

  This is because the following entries are constantly being added to this file, hundreds of times per second:

  [2020-05-28 20:37:37.290333] W [inode.c:1638:inode_table_prune] (-->/lib64/libglusterfs.so.0(fd_unref+0x1d3) [0x7f6567ac0d03] -->/lib64/libglusterfs.so.0(inode_unref+0x36) [0x7f6567aa8676] -->/lib64/libglusterfs.so.0(+0x38607) [0x7f6567aa8607] ) 0-vol_373db344457515f36db17714447245d7-client-2: Empty inode lru list found but with (-1) lru_size
  [2020-05-28 20:37:37.292657] W [inode.c:1638:inode_table_prune] (-->/usr/lib64/glusterfs/6.0/xlator/cluster/replicate.so(+0x5f0c7) [0x7f65170c80c7] -->/lib64/libglusterfs.so.0(inode_unref+0x36) [0x7f6567aa8676] -->/lib64/libglusterfs.so.0(+0x38607) [0x7f6567aa8607] ) 0-vol_373db344457515f36db17714447245d7-replicate-0: Empty inode lru list found but with (-1) lru_size
  [2020-05-28 20:37:37.292766] W [inode.c:1638:inode_table_prune] (-->/usr/lib64/glusterfs/6.0/xlator/features/shard.so(+0x4aca)  [0x7f6516b84aca] -->/lib64/libglusterfs.so.0(inode_unref+0x36) [0x7f6567aa8676] -->/lib64/libglusterfs.so.0(+0x38607)     [0x7f6567aa8607] ) 0-vol_373db344457515f36db17714447245d7-shard: Empty inode lru list found but with (-1) lru_size
  

• Also, the CPU usage of the process is very high:

  $ top
  top - 09:24:20 up 125 days, 22:50,  1 user,  load average: 2.59, 2.49, 2.54                                                                                                         
  Tasks: 24264 total,   2 running, 24262 sleeping,   0 stopped,   0 zombie
  %Cpu(s): 15.8 us, 18.6 sy,  0.0 ni, 60.8 id,  2.5 wa,  0.0 hi,  2.2 si,  0.0 st
  KiB Mem : 16266620 total,   200820 free, 11995632 used,  4070168 buff/cache
  KiB Swap: 16777212 total,   250372 free, 16526840 used.  3073320 avail Mem
  
    PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
  21188 root      20   0   11.7g 125032  92728 S  95.0  0.8  23462:40 tcmu-   runner
  

Why is this so? How to stop these messages to show up?