diff options
Diffstat (limited to 'gnu/services/base.scm')
| -rw-r--r-- | gnu/services/base.scm | 93 |
1 files changed, 89 insertions, 4 deletions
diff --git a/gnu/services/base.scm b/gnu/services/base.scm index 9561995243..ae538ea41c 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -22,14 +22,17 @@ #:use-module (gnu system linux) ; 'pam-service', etc. #:use-module (gnu packages admin) #:use-module ((gnu packages base) - #:select (glibc-final)) + #:select (glibc-final %final-inputs)) + #:use-module (gnu packages linux) #:use-module (gnu packages package-management) #:use-module (guix gexp) #:use-module (guix monads) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) #:use-module (ice-9 format) - #:export (host-name-service + #:export (root-file-system-service + user-processes-service + host-name-service mingetty-service nscd-service syslog-service @@ -43,6 +46,81 @@ ;;; ;;; Code: +(define (root-file-system-service) + "Return a service whose sole purpose is to re-mount read-only the root file +system upon shutdown (aka. cleanly \"umounting\" root.) + +This service must be the root of the service dependency graph so that its +'stop' action is invoked when dmd is the only process left." + (define coreutils + (car (assoc-ref %final-inputs "coreutils"))) + + (with-monad %store-monad + (return + (service + (documentation "Take care of the root file system.") + (provision '(root-file-system)) + (start #~(const #t)) + (stop #~(lambda _ + ;; Return #f if successfully stopped. + (system* (string-append #$coreutils "/bin/sync")) + + (call-with-blocked-asyncs + (lambda () + (let ((null (%make-void-port "w"))) + ;; Close 'dmd.log'. + (display "closing log\n") + ;; XXX: Ideally we'd use 'stop-logging', but that one + ;; doesn't actually close the port as of dmd 0.1. + (close-port (@@ (dmd comm) log-output-port)) + (set! (@@ (dmd comm) log-output-port) null) + + ;; Redirect the default output ports.. + (set-current-output-port null) + (set-current-error-port null) + + ;; Close /dev/console. + (for-each close-fdes '(0 1 2)) + + ;; At this points, there are no open files left, so the + ;; root file system can be re-mounted read-only. + (not (zero? + (system* (string-append #$util-linux "/bin/mount") + "-n" "-o" "remount,ro" + "-t" "dummy" "dummy" "/")))))))) + (respawn? #f))))) + +(define* (user-processes-service #:key (grace-delay 2)) + "Return the service that is responsible for terminating all the processes so +that the root file system can be re-mounted read-only, just before +rebooting/halting. Processes still running GRACE-DELAY seconds after SIGTERM +has been sent are terminated with SIGKILL. + +All the services that spawn processes must depend on this one so that they are +stopped before 'kill' is called." + (with-monad %store-monad + (return (service + (documentation "When stopped, terminate all user processes.") + (provision '(user-processes)) + (requirement '(root-file-system)) + (start #~(const #t)) + (stop #~(lambda _ + ;; When this happens, all the processes have been + ;; killed, including 'deco', so DMD-OUTPUT-PORT and + ;; thus CURRENT-OUTPUT-PORT are dangling. + (call-with-output-file "/dev/console" + (lambda (port) + (display "sending all processes the TERM signal\n" + port))) + + (kill -1 SIGTERM) + (sleep #$grace-delay) + (kill -1 SIGKILL) + + (display "all processes have been terminated\n") + #f)) + (respawn? #f))))) + (define (host-name-service name) "Return a service that sets the host name to NAME." (with-monad %store-monad @@ -66,7 +144,7 @@ ;; Since the login prompt shows the host name, wait for the 'host-name' ;; service to be done. - (requirement '(host-name)) + (requirement '(user-processes host-name)) (start #~(make-forkexec-constructor (string-append #$mingetty "/sbin/mingetty") @@ -87,6 +165,7 @@ (return (service (documentation "Run libc's name service cache daemon (nscd).") (provision '(nscd)) + (requirement '(user-processes)) (start #~(make-forkexec-constructor (string-append #$glibc "/sbin/nscd") "-f" "/dev/null" @@ -126,6 +205,7 @@ (service (documentation "Run the syslog daemon (syslogd).") (provision '(syslogd)) + (requirement '(user-processes)) (start #~(make-forkexec-constructor (string-append #$inetutils "/libexec/syslogd") @@ -161,6 +241,7 @@ BUILD-ACCOUNTS user accounts available under BUILD-USER-GID." #:gid build-user-gid))) (return (service (provision '(guix-daemon)) + (requirement '(user-processes)) (start #~(make-forkexec-constructor (string-append #$guix "/bin/guix-daemon") @@ -189,6 +270,10 @@ This is the GNU operating system, welcome!\n\n"))) (nscd-service) ;; FIXME: Make this an activation-time thing instead of a service. - (host-name-service "gnu")))) + (host-name-service "gnu") + + ;; The "root" services. + (user-processes-service) + (root-file-system-service)))) ;;; base.scm ends here |