mapped-devices: Add 'lvm-device-mapping'.

* gnu/system/mapped-devices.scm (lvm-device-mapping, open-lvm-device,
close-lvm-device): New variables.

* gnu/tests/install.scm (%lvm-separate-home-os,
%lvm-separate-home-os-source, %lvm-separate-home-installation-script,
%test-lvm-separate-home-os): New variables.

* gnu/system/linux-initrd.scm (raw-initrd): Add (srfi srfi-1) to initrd expression.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

2 files changed, 24 insertions, 2 deletions

diff --git a/gnu/system/linux-initrd.scm b/gnu/system/linux-initrd.scm
index 3e2f1282ccc..85e493fecb9 100644
--- a/gnu/system/linux-initrd.scm
+++ b/gnu/system/linux-initrd.scm
@@ -217,6 +217,7 @@ upon error."
                       (gnu system file-systems)
                       ((guix build utils) #:hide (delete))
                       (guix build bournish)   ;add the 'bournish' meta-command
+                      (srfi srfi-1)           ;for lvm-device-mapping
                       (srfi srfi-26)
 
                       ;; FIXME: The following modules are for
diff --git a/gnu/system/mapped-devices.scm b/gnu/system/mapped-devices.scm
index 8b5aec983d1..559c27bb28c 100644
--- a/gnu/system/mapped-devices.scm
+++ b/gnu/system/mapped-devices.scm
@@ -36,7 +36,7 @@
   #:autoload   (gnu build linux-modules)
                  (missing-modules)
   #:autoload   (gnu packages cryptsetup) (cryptsetup-static)
-  #:autoload   (gnu packages linux) (mdadm-static)
+  #:autoload   (gnu packages linux) (mdadm-static lvm2-static)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:use-module (srfi srfi-34)
@@ -64,7 +64,8 @@
             check-device-initrd-modules           ;XXX: needs a better place
 
             luks-device-mapping
-            raid-device-mapping))
+            raid-device-mapping
+            lvm-device-mapping))
 
 ;;; Commentary:
 ;;;
@@ -304,4 +305,24 @@ TARGET (e.g., \"/dev/md0\"), using 'mdadm'."
    (open open-raid-device)
    (close close-raid-device)))
 
+(define (open-lvm-device source targets)
+  #~(and
+     (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+                     "vgchange" "--activate" "ay" #$source))
+     ; /dev/mapper nodes are usually created by udev, but udev may be unavailable at the time we run this. So we create them here.
+     (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+                     "vgscan" "--mknodes"))
+     (every file-exists? (map (lambda (file) (string-append "/dev/mapper/" file))
+                              '#$targets))))
+
+
+(define (close-lvm-device source targets)
+  #~(zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+                    "vgchange" "--activate" "n" #$source)))
+
+(define lvm-device-mapping
+  (mapped-device-kind
+   (open open-lvm-device)
+   (close close-lvm-device)))
+
 ;;; mapped-devices.scm ends here