| Message ID | yrjG3wstz9GpyH32kV3JqsEiG-KdxmP9_JHe6ghdMoizrBWpIZhd3hl2VPjFuWagt1WLPXMqSGdMZZWTcvE6J7qxVjdcvq3zTK-Wccd3wEs=@protonmail.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | None | expand |
Hi! I agree with 宋文武. Still… raid5atemyhomework <raid5atemyhomework@protonmail.com> skribis: > (service-type (name 'file-systems) > (extensions > (list (service-extension shepherd-root-service-type > - file-system-shepherd-services) > + (lambda (value) > + (file-system-shepherd-services > + (filter file-system? value) > + (filter symbol? value)))) > (service-extension fstab-service-type > - file-system-fstab-entries) > + (lambda (value) > + (file-system-fstab-entries > + (filter file-system? value)))) > > ;; Have 'user-processes' depend on 'file-systems'. > (service-extension user-processes-service-type > (const '(file-systems))))) > + > + ;; Extensions consist of lists of <file-system> objects or > + ;; shepherd services’ names (symbols). In the latter case, > + ;; the provided shepherd services supposed to mount and > + ;; unmount some file systems themself. Why do we need to extend with symbols? In general it’s much clearer if extensions receive only one type of object (<file-system> records in this case). It’s also best to avoid passing around symbolic names (that’s why we extend with <file-system> records rather than with Shepherd service names or whatever.) Ludo’.
> Why do we need to extend with symbols? > > In general it’s much clearer if extensions receive only one type of > object (<file-system> records in this case). It’s also best to avoid > passing around symbolic names (that’s why we extend with <file-system> > records rather than with Shepherd service names or whatever.) For this case, how would it be done? ZFS file system, on other operating systems and distributions, is documented as automatically mounting filesystems, without management in an `fstab` or similar file, because the intent is that you would make lots of filesystems for various uses and managing an `fstab` would be too onerous. Thus, ZFS file system expects to mount multiple file systems with a single `zfs mount -a` command at startup. Would the below sketch be acceptable? ```scheme ; gnu/system/file-systems.scm (define-record-type* file-system #;... #;... (has-fstab-entry? file-system-has-fstab-entry? (default #t))) ;... ; gnu/services/base,scm (define file-system-service-type (service-type #;... (extensions (list #;... (service-extension fstab-service-type (lambda (file-systems) (filter file-system-has-fstab-entry? file-systems))) #;...)) #;...)) ;... ; gnu/services/file-systems.scm (define zfs-service-type (service-type #;... (extensions (list #;... (service-extension file-system-service-type (const (list (file-system (device "dummy") (mount-point "zfs/*") (has-fstab-entry? #f))))))) #;...)) ``` Then there will be a Shepherd service providing `file-system-zfs/*` which would perform `zfs mount -a -l` on `start` and `zfs unmount -a -f` on `stop`. Would that be acceptable? I am wary of this since it creates a dummy file-system and needs an additional field on every `file-system` record, one which is *only* used by ZFS. I feel the `file-system-target-service-type` is more generic and does not use trickery. Thanks raid5atemyhomework
From 44ee1e470a2f9d4985af4d51654d9f943caa0f24 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=AE=8B=E6=96=87=E6=AD=A6?= <iyzsong@member.fsf.org> Date: Sat, 23 Jan 2021 20:39:06 +0800 Subject: [PATCH] services: Allow 'file-system-service-type' extensible by service name. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * gnu/services/base.scm (file-system-shepherd-services): Add 'extra-services-names' paramater. (file-system-service-type): Handle services’ names from extensions. --- gnu/services/base.scm | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/gnu/services/base.scm b/gnu/services/base.scm index f6a490f712..7bddef5034 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -364,15 +364,16 @@ FILE-SYSTEM." (gnu system file-systems) ,@%default-modules))))))) -(define (file-system-shepherd-services file-systems) +(define (file-system-shepherd-services file-systems extra-services-names) "Return the list of Shepherd services for FILE-SYSTEMS." (let* ((file-systems (filter file-system-mount? file-systems))) (define sink (shepherd-service (provision '(file-systems)) - (requirement (cons* 'root-file-system 'user-file-systems - (map file-system->shepherd-service-name - file-systems))) + (requirement (append '(root-file-system user-file-systems) + (map file-system->shepherd-service-name + file-systems) + extra-services-names)) (documentation "Target for all the initially-mounted file systems") (start #~(const #t)) (stop #~(const #f)))) @@ -429,13 +430,23 @@ FILE-SYSTEM." (service-type (name 'file-systems) (extensions (list (service-extension shepherd-root-service-type - file-system-shepherd-services) + (lambda (value) + (file-system-shepherd-services + (filter file-system? value) + (filter symbol? value)))) (service-extension fstab-service-type - file-system-fstab-entries) + (lambda (value) + (file-system-fstab-entries + (filter file-system? value)))) ;; Have 'user-processes' depend on 'file-systems'. (service-extension user-processes-service-type (const '(file-systems))))) + + ;; Extensions consist of lists of <file-system> objects or + ;; shepherd services’ names (symbols). In the latter case, + ;; the provided shepherd services supposed to mount and + ;; unmount some file systems themself. (compose concatenate) (extend append) (description -- 2.29.2