From 2cb0b79895ce4bef53869961f5370c9378057d15 Mon Sep 17 00:00:00 2001 From: Tobias Geerinckx-Rice Date: Fri, 26 Feb 2016 17:57:07 +0100 Subject: linux-boot: Resume from hibernation. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * gnu/build/linux-boot.scm (resume-if-hibernated): New procedure. (boot-system): Call it unless ‘noresume’ was specified. --- gnu/build/linux-boot.scm | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/gnu/build/linux-boot.scm b/gnu/build/linux-boot.scm index 05e833c0c6..74e76b6a31 100644 --- a/gnu/build/linux-boot.scm +++ b/gnu/build/linux-boot.scm @@ -1,5 +1,6 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès +;;; Copyright © 2016, 2017, 2019 Tobias Geerinckx-Rice ;;; Copyright © 2017 Mathieu Othacehe ;;; Copyright © 2019 Guillaume Le Vaillant ;;; @@ -110,6 +111,51 @@ OPTION doesn't appear in 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 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 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 loop (ew!) if someone relies on it… + (device (canonicalize-device-spec spec)) + (rdev (stat:rdev (stat device))) + (minor (modulo rdev 256)) + (major (/ (- rdev minor) 256))) + (format #f "~a:~a" major minor))) + + ;; Write the MAJOR:MINOR numbers of the specified or default resume DEVICE to + ;; this magic file. 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 + (string->major:minor device) + (let ((default (call-with-input-file resume + read-line))) + ;; Don't waste time echoing ‘nothing’ 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." @@ -504,6 +550,12 @@ upon error." (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) -- cgit v1.2.3