* bug#47681: [PATCH] services: udev: Use a fixed location for the rules directory and config.
2021-04-09 22:05 bug#47681: Reloading udev rules requires a system restart Maxim Cournoyer
@ 2022-02-01 18:10 ` Maxim Cournoyer
2022-02-21 1:43 ` bug#47681: Reloading udev rules requires a system restart Maxim Cournoyer
0 siblings, 1 reply; 3+ messages in thread
From: Maxim Cournoyer @ 2022-02-01 18:10 UTC (permalink / raw)
To: 47681; +Cc: Maxim Cournoyer
Fixes <https://issues.guix.gnu.org/47681>.
This change adjusts the location of the udev configuration file and rules
directory to a fixed location. Since udev relies on inotify to discover
change to its rules directory (/etc/udev/rules.d), by using a fixed directory
layout, new udev rules can be automatically picked up without restarting the
service.
* gnu/services/base.scm (udev-rules-union): Build rules output directly
in #$output.
(udev-shepherd-service)[start]: Adjust the UDEV_CONFIG_FILE and
EUDEV_RULES_DIRECTORY environment variables.
[actions]: Remove field. The 'rules' action is no longer useful.
(udev.conf): New variable.
(udev-etc): New procedure.
(udev-service-type): Extend the etc-service-type with it.
---
gnu/services/base.scm | 210 +++++++++++++++++++++---------------------
1 file changed, 104 insertions(+), 106 deletions(-)
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index fbd01e84d6..4c8a840156 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -15,7 +15,7 @@
;;; Copyright © 2020, 2021 Brice Waegeneire <brice@waegenei.re>
;;; Copyright © 2021 qblade <qblade@protonmail.com>
;;; Copyright © 2021 Hui Lu <luhuins@163.com>
-;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2021, 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2022 Guillaume Le Vaillant <glv@posteo.net>
;;;
;;; This file is part of GNU Guix.
@@ -1995,8 +1995,7 @@ (define (rules-sub-directory directory)
(find directory-exists?
(map (cut string-append directory <>) %standard-locations)))
- (mkdir-p (string-append #$output "/lib/udev"))
- (union-build (string-append #$output "/lib/udev/rules.d")
+ (union-build #$output
(filter-map rules-sub-directory '#$packages)))))
(computed-file "udev-rules" build))
@@ -2045,116 +2044,115 @@ (define kvm-udev-rule
(define udev-shepherd-service
;; Return a <shepherd-service> for UDEV with RULES.
+ (match-lambda
+ (($ <udev-configuration> udev)
+ (list
+ (shepherd-service
+ (provision '(udev))
+
+ ;; Udev needs /dev to be a 'devtmpfs' mount so that new device nodes can
+ ;; be added: see
+ ;; <http://www.linuxfromscratch.org/lfs/view/development/chapter07/udev.html>.
+ (requirement '(root-file-system))
+
+ (documentation "Populate the /dev directory, dynamically.")
+ (start
+ (with-imported-modules (source-module-closure
+ '((gnu build linux-boot)))
+ #~(lambda ()
+ (define udevd
+ ;; 'udevd' from eudev.
+ #$(file-append udev "/sbin/udevd"))
+
+ (define (wait-for-udevd)
+ ;; Wait until someone's listening on udevd's control
+ ;; socket.
+ (let ((sock (socket AF_UNIX SOCK_SEQPACKET 0)))
+ (let try ()
+ (catch 'system-error
+ (lambda ()
+ (connect sock PF_UNIX "/run/udev/control")
+ (close-port sock))
+ (lambda args
+ (format #t "waiting for udevd...~%")
+ (usleep 500000)
+ (try))))))
+
+ ;; Allow udev to find the modules.
+ (setenv "LINUX_MODULE_DIRECTORY"
+ "/run/booted-system/kernel/lib/modules")
+
+ (let* ((kernel-release
+ (utsname:release (uname)))
+ (linux-module-directory
+ (getenv "LINUX_MODULE_DIRECTORY"))
+ (directory
+ (string-append linux-module-directory "/"
+ kernel-release))
+ (old-umask (umask #o022)))
+ ;; If we're in a container, DIRECTORY might not exist,
+ ;; for instance because the host runs a different
+ ;; kernel. In that case, skip it; we'll just miss a few
+ ;; nodes like /dev/fuse.
+ (when (file-exists? directory)
+ (make-static-device-nodes directory))
+ (umask old-umask))
+
+ (let ((pid (fork+exec-command
+ (list udevd)
+ #:environment-variables
+ (cons*
+ ;; The first one is for udev, the second one for
+ ;; eudev.
+ "UDEV_CONFIG_FILE=/etc/udev/udev.conf"
+ "EUDEV_RULES_DIRECTORY=/etc/udev/rules.d"
+ (string-append "LINUX_MODULE_DIRECTORY="
+ (getenv "LINUX_MODULE_DIRECTORY"))
+ (default-environment-variables)))))
+ ;; Wait until udevd is up and running. This appears to
+ ;; be needed so that the events triggered below are
+ ;; actually handled.
+ (wait-for-udevd)
+
+ ;; Trigger device node creation.
+ (system* #$(file-append udev "/bin/udevadm")
+ "trigger" "--action=add")
+
+ ;; Wait for things to settle down.
+ (system* #$(file-append udev "/bin/udevadm")
+ "settle")
+ pid))))
+ (stop #~(make-kill-destructor))
+
+ ;; When halting the system, 'udev' is actually killed by
+ ;; 'user-processes', i.e., before its own 'stop' method was called.
+ ;; Thus, make sure it is not respawned.
+ (respawn? #f)
+ ;; We need additional modules.
+ (modules `((gnu build linux-boot) ;'make-static-device-nodes'
+ ,@%default-modules)))))))
+
+(define udev.conf
+ (computed-file "udev.conf"
+ #~(call-with-output-file #$output
+ (lambda (port)
+ (format port "udev_rules=\"/etc/udev/rules.d\"~%")))))
+
+(define udev-etc
(match-lambda
(($ <udev-configuration> udev rules)
- (let* ((rules (udev-rules-union (cons* udev kvm-udev-rule rules)))
- (udev.conf (computed-file "udev.conf"
- #~(call-with-output-file #$output
- (lambda (port)
- (format port
- "udev_rules=\"~a/lib/udev/rules.d\"\n"
- #$rules))))))
- (list
- (shepherd-service
- (provision '(udev))
-
- ;; Udev needs /dev to be a 'devtmpfs' mount so that new device nodes can
- ;; be added: see
- ;; <http://www.linuxfromscratch.org/lfs/view/development/chapter07/udev.html>.
- (requirement '(root-file-system))
-
- (documentation "Populate the /dev directory, dynamically.")
- (start
- (with-imported-modules (source-module-closure
- '((gnu build linux-boot)))
- #~(lambda ()
- (define udevd
- ;; 'udevd' from eudev.
- #$(file-append udev "/sbin/udevd"))
-
- (define (wait-for-udevd)
- ;; Wait until someone's listening on udevd's control
- ;; socket.
- (let ((sock (socket AF_UNIX SOCK_SEQPACKET 0)))
- (let try ()
- (catch 'system-error
- (lambda ()
- (connect sock PF_UNIX "/run/udev/control")
- (close-port sock))
- (lambda args
- (format #t "waiting for udevd...~%")
- (usleep 500000)
- (try))))))
-
- ;; Allow udev to find the modules.
- (setenv "LINUX_MODULE_DIRECTORY"
- "/run/booted-system/kernel/lib/modules")
-
- (let* ((kernel-release
- (utsname:release (uname)))
- (linux-module-directory
- (getenv "LINUX_MODULE_DIRECTORY"))
- (directory
- (string-append linux-module-directory "/"
- kernel-release))
- (old-umask (umask #o022)))
- ;; If we're in a container, DIRECTORY might not exist,
- ;; for instance because the host runs a different
- ;; kernel. In that case, skip it; we'll just miss a few
- ;; nodes like /dev/fuse.
- (when (file-exists? directory)
- (make-static-device-nodes directory))
- (umask old-umask))
-
- (let ((pid (fork+exec-command (list udevd)
- #:environment-variables
- (cons*
- ;; The first one is for udev, the second one for
- ;; eudev.
- (string-append "UDEV_CONFIG_FILE=" #$udev.conf)
- (string-append "EUDEV_RULES_DIRECTORY="
- #$(file-append
- rules "/lib/udev/rules.d"))
- (string-append "LINUX_MODULE_DIRECTORY="
- (getenv "LINUX_MODULE_DIRECTORY"))
- (default-environment-variables)))))
- ;; Wait until udevd is up and running. This appears to
- ;; be needed so that the events triggered below are
- ;; actually handled.
- (wait-for-udevd)
-
- ;; Trigger device node creation.
- (system* #$(file-append udev "/bin/udevadm")
- "trigger" "--action=add")
-
- ;; Wait for things to settle down.
- (system* #$(file-append udev "/bin/udevadm")
- "settle")
- pid))))
- (stop #~(make-kill-destructor))
-
- ;; When halting the system, 'udev' is actually killed by
- ;; 'user-processes', i.e., before its own 'stop' method was called.
- ;; Thus, make sure it is not respawned.
- (respawn? #f)
- ;; We need additional modules.
- (modules `((gnu build linux-boot) ;'make-static-device-nodes'
- ,@%default-modules))
-
- (actions (list (shepherd-action
- (name 'rules)
- (documentation "Display the directory containing
-the udev rules in use.")
- (procedure #~(lambda (_)
- (display #$rules)
- (newline))))))))))))
+ `(("udev"
+ ,(file-union
+ "udev" `(("udev.conf" ,udev.conf)
+ ("rules.d" ,(udev-rules-union (cons* udev kvm-udev-rule
+ rules))))))))))
(define udev-service-type
(service-type (name 'udev)
(extensions
(list (service-extension shepherd-root-service-type
- udev-shepherd-service)))
-
+ udev-shepherd-service)
+ (service-extension etc-service-type udev-etc)))
(compose concatenate) ;concatenate the list of rules
(extend (lambda (config rules)
(match config
--
2.34.0
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