Reworks the series to Option B from the design discussion: no mount
options, no sysfs toggles, single well-known socket per scoutfs
volume at /run/scoutfs/<fsid>/notify.sock.
Changes vs v1.29-notify-1:
- Kmod: dropped notify_events / notify_ring_kb mount options and
their sysfs attrs. Ring is always allocated at mount with a
compile-time 64 KiB size. notify_enabled is now flipped by the
ioctl handler on reader attach / detach, so emit hooks are
zero-cost unless a watcher is connected.
- New third patch: scoutfs-notifyd userspace relay. Single-threaded
epoll daemon that drains the ioctl and broadcasts each record as
a SOCK_SEQPACKET message to connected clients. Shipped with a
systemd template unit and man page.
- Packaging: utils/Makefile and scoutfs-utils.spec.in install the
daemon at /usr/sbin/scoutfs-notifyd and the unit at
/usr/lib/systemd/system/scoutfs-notifyd@.service.
Patches 1 and 2 have been re-scoped; re-apply expected to succeed
on scoutfs v1.29.
William Gill
94a4fd53c6