When there are some bytes to write in case write overflows the limit, truncate the write instead of sending SIGXFSZ outright.
Send SIGXFSZ when truncating.
Only UFS, msdosfs, tmpfs are handled.
Per-commit view https://kib.kiev.ua/git/gitweb.cgi?p=deviant3.git;a=shortlog;h=refs/heads/ufs
PR: 164793