[bug#41143] [PATCH 1/2] mapped-devices: Allow target to be list of strings

[tsmish]

(let ...) stuff should be in function, but I don't know in which
module it should go.
Code is somewhat untested, proceed with caution.

---
 gnu/services/base.scm         |  5 ++++-
 gnu/system.scm                | 13 ++++++++-----
 gnu/system/mapped-devices.scm |  2 +-
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 0c154d1c4e..3d09e8220c 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -408,7 +408,10 @@ FILE-SYSTEM."
 (define (mapped-device->shepherd-service-name md)
   "Return the symbol that denotes the shepherd service of MD, a
<mapped-device>."
   (symbol-append 'device-mapping-
-                 (string->symbol (mapped-device-target md))))
+                 (string->symbol (string-join
+                                  (let ((t (mapped-device-target md)))
+                                    (if (list? t) t (list t)))
+                                  "-"))))

 (define dependency->shepherd-service-name
   (match-lambda
diff --git a/gnu/system.scm b/gnu/system.scm
index 01baa248a2..75632c5e8a 100644
--- a/gnu/system.scm
+++ b/gnu/system.scm
@@ -390,9 +390,10 @@ marked as 'needed-for-boot'."
     (let ((device (file-system-device fs)))
       (if (string? device)                        ;title is 'device
           (filter (lambda (md)
-                    (string=? (string-append "/dev/mapper/"
-                                             (mapped-device-target md))
-                              device))
+                    (any (cut string=? device <>)
+                         (map (cut string-append "/dev/mapper" <>)
+                              (let ((t (mapped-device-target md)))
+                                (if (list? t) t (list t))))))
                   (operating-system-mapped-devices os))
           '())))

@@ -412,11 +413,13 @@ marked as 'needed-for-boot'."

 (define (mapped-device-users device file-systems)
   "Return the subset of FILE-SYSTEMS that use DEVICE."
-  (let ((target (string-append "/dev/mapper/" (mapped-device-target device))))
+  (let ((targets (map (cut string-append "/dev/mapper/" <>)
+                      (let ((t (mapped-device-target device)))
+                        (if (list? t) t (list t))))))
     (filter (lambda (fs)
               (or (member device (file-system-dependencies fs))
                   (and (string? (file-system-device fs))
-                       (string=? (file-system-device fs) target))))
+                       (any (cut string=? (file-system-device fs) <>)
targets))))
             file-systems)))

 (define (operating-system-user-mapped-devices os)
diff --git a/gnu/system/mapped-devices.scm b/gnu/system/mapped-devices.scm
index 7c58f876a3..3339e509e0 100644
--- a/gnu/system/mapped-devices.scm
+++ b/gnu/system/mapped-devices.scm
@@ -72,7 +72,7 @@
   make-mapped-device
   mapped-device?
   (source    mapped-device-source)                ;string | list of strings
-  (target    mapped-device-target)                ;string
+  (target    mapped-device-target)                ;string | list of strings
   (type      mapped-device-type)                  ;<mapped-device-kind>
   (location  mapped-device-location
              (default (current-source-location)) (innate)))
-- 
2.26.2