Backport of the three notify patches onto scoutfs v1.29 as its own
long-lived branch. Rebase was clean: v1.29 -> v1.30 touches
btree/forest/quota/totl/triggers/wkic/xattr, none of which our
patches modify, so the three commits apply unchanged.
Branch purpose: scoutfs-build's multi-version pipeline checks out
this branch (via SCOUTFS_NOTIFY_REF=v1.29-notify-1) when building
kmod RPMs for scoutfs v1.29. Each currently-supported scoutfs
version has its own branch in this repo.
William Gill
5730d95892