How to reclaim space in a thin provisioned LUN using fstrim?

Issue

• A thin-provisioned LUN or LVM volume reports a critical space allocation error in the system logs, even though the guest filesystem (e.g., XFS or EXT4) indicates that there is sufficient free space available:

  kernel: blk_update_request: critical space allocation error, dev sdb, sector 426379264
  kernel: sd 12:0:2:1: [sdh] tag#0 Sense Key : Data Protect [current]
  kernel: sd 12:0:2:1: [sdh] tag#0 Add. Sense: Space allocation failed write protect
  kernel: sd 12:0:2:1: [sdh] tag#0 CDB: Write(10) 2a 00 16 9d a1 90 00 00 08 00