The High Performance File-System (HPFS) that was originally designed for the OS/2 operating system now has SSD TRIM support for its Linux kernel support while reading/writing from these old partitions.

While I don't know of anyone off-hand still relying upon the OS/2 HPFS file-system support in Linux, it was updated in the post-merge-window (due to waiting on related patches, the original work was sent during the merge window but not committed) of the Linux 4.2 kernel merge window.

Most interesting was adding FSTRIM support to HPFS. FSTRIM is used to discard/trim blocks not in use by the file-system, mainly for solid-state drives.

So in case you are running any OS/2 HPFS file-system still and it happens to be on an SSD, you'll be in better shape with Linux 4.2.