services: user-processes: Remove support for /etc/shepherd/do-not-kill.

The /etc/shepherd/do-not-kill feature has been unused since commit
c828969036, which switched from
unionfs (FUSE) to overlayfs.

* gnu/services/shepherd.scm (%do-not-kill-file): Remove.
(user-processes-shepherd-service): In ‘stop’ action, remove
‘kill-except’, ‘omitted-pids’, and ‘lset=’.  Remove conditionals on
‘omitted-pids’ being non-empty.

Change-Id: Id7c6031fc12fd8ff0a3fde955fb01e373751e2d0
This commit is contained in:
Ludovic Courtès 2025-01-25 12:45:58 +01:00
parent ba9af3e151
commit 5f6fdadb4a
No known key found for this signature in database
GPG key ID: 090B11993D9AEBB5

View file

@ -553,11 +553,6 @@ need to be restarted to complete their upgrade."
;;; User processes.
;;;
(define %do-not-kill-file
;; Name of the file listing PIDs of processes that must survive when halting
;; the system. Typical example is user-space file systems.
"/etc/shepherd/do-not-kill")
(define (user-processes-shepherd-service requirements)
"Return the 'user-processes' Shepherd service with dependencies on
REQUIREMENTS (a list of service names).
@ -575,48 +570,15 @@ system mounts, etc. This is similar to the 'sysvinit' target in systemd."
(requirement requirements)
(start #~(const #t))
(stop #~(lambda _
(define (kill-except omit signal)
;; Kill all the processes with SIGNAL except those listed
;; in OMIT and the current process.
(let ((omit (cons (getpid) omit)))
(for-each (lambda (pid)
(unless (memv pid omit)
(false-if-exception
(kill pid signal))))
(processes))))
(define omitted-pids
;; List of PIDs that must not be killed.
(if (file-exists? #$%do-not-kill-file)
(map string->number
(call-with-input-file #$%do-not-kill-file
(compose string-tokenize
(@ (ice-9 rdelim) read-string))))
'()))
(define lset= (@ (srfi srfi-1) lset=))
(display "sending all processes the TERM signal\n")
(if (null? omitted-pids)
(begin
;; Easy: terminate all of them.
(kill -1 SIGTERM)
(sleep #$grace-delay)
(kill -1 SIGKILL))
(begin
;; Kill them all except OMITTED-PIDS. XXX: We would
;; like to (kill -1 SIGSTOP) to get a fixed list of
;; processes, like 'killall5' does, but that seems
;; unreliable.
(kill-except omitted-pids SIGTERM)
(sleep #$grace-delay)
(kill-except omitted-pids SIGKILL)
(delete-file #$%do-not-kill-file)))
(kill -1 SIGTERM)
(sleep #$grace-delay)
(kill -1 SIGKILL)
(let wait ()
(let ((pids (processes)))
(unless (lset= = pids (cons 1 omitted-pids))
(unless (equal? '(1) pids)
(format #t "waiting for process termination\
(processes left: ~s)~%"
pids)