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linux-boot: Resume from hibernation.

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* gnu/build/linux-boot.scm (resume-if-hibernated): New procedure.
(boot-system): Call it.
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Tobias Geerinckx-Rice 2020-11-05 11:03:21 +01:00
parent e87471dc51
commit b9abb301d0
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59
gnu/build/linux-boot.scm
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@ -1,5 +1,6 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016, 2017, 2019, 2020 Tobias Geerinckx-Rice <me@tobias.gr>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2019 Guillaume Le Vaillant <glv@posteo.net>
;;;
@ -110,6 +111,58 @@ (define (find-long-options option arguments)
(substring arg (+ 1 (string-index arg #\=)))))
arguments)))
(define (resume-if-hibernated device)
"Resume from hibernation if possible. This is safe ONLY if no on-disk file
systems have been mounted; calling it later risks severe file system corruption!
See <Documentation/swsusp.txt> in the kernel source directory. This is the
caller's responsibility, as is catching exceptions if resumption was supposed to
happen but didn't.
Resume only from DEVICE if it's a string. If it's #f, use the kernel's default
hibernation device (CONFIG_PM_STD_PARTITION). Never return if resumption
succeeds. Return nothing otherwise. The kernel logs any details to dmesg."
(define (string->major:minor string)
"Return a string with MAJOR:MINOR numbers of the device specified by STRING"
;; The "resume=" kernel command-line option always provides a string, which
;; can represent a device, a UUID, or a label. Check for all three.
(let* ((spec (cond ((string-prefix? "/" string) string)
((uuid string) => identity)
(else (file-system-label string))))
;; XXX The kernel's swsusp_resume_can_resume() waits if ‘resumewait’
;; is found on the command line; our canonicalize-device-spec gives
;; up after 20 seconds. We could emulate the former by looping…
(device (canonicalize-device-spec spec))
(rdev (stat:rdev (stat device)))
;; For backwards compatibility, device numbering is a baroque affair.
;; This is the full 64-bit scheme used by glibc's <sys/sysmacros.h>.
(major (logior (ash (logand #x00000000000fff00 rdev) -8)
(ash (logand #xfffff00000000000 rdev) -32)))
(minor (logior (logand #x00000000000000ff rdev)
(ash (logand #x00000ffffff00000 rdev) -12))))
(format #f "~a:~a" major minor)))
;; Write the resume DEVICE to this magic file, using the MAJOR:MINOR device
;; numbers if possible. The kernel will immediately try to resume from it.
(let ((resume "/sys/power/resume"))
(when (file-exists? resume) ; this kernel supports hibernation
;; Honour the kernel's default device (only) if none other was given.
(let ((major:minor (if device
(or (false-if-exception (string->major:minor
device))
;; We can't parse it. Maybe the kernel can.
device)
(let ((default (call-with-input-file resume
read-line)))
;; Don't waste time echoing 0:0 to /sys.
(if (string=? "0:0" default)
#f
default)))))
(when major:minor
(call-with-output-file resume ; may throw an ‘Invalid argument’
(cut display major:minor <>))))))) ; may never return
(define* (make-disk-device-nodes base major #:optional (minor 0))
"Make the block device nodes around BASE (something like \"/root/dev/sda\")
with the given MAJOR number, starting with MINOR."
@ -507,6 +560,12 @@ (define (device-string->file-system-device device-string)
(load-linux-modules-from-directory linux-modules
linux-module-directory)
(unless (member "noresume" args)
;; Try to resume immediately after loading (storage) modules
;; but before any on-disk file systems have been mounted.
(false-if-exception ; failure is not fatal
(resume-if-hibernated (find-long-option "resume" args))))
(when keymap-file
(let ((status (system* "loadkeys" keymap-file)))
(unless (zero? status)