installer: Ignore small devices.

Filter the devices that are smaller than 2GiB in the device selection list.

* gnu/installer/parted.scm (%min-device-size): New variable.
(non-install-devices): Rename it ...
(eligible-devices): ... this way. Filter the install device as well as the
small devices.
* gnu/installer/newt/partition.scm (run-partitioning-page): Adapt it.

gnu/installer/newt/partition.scm

@@ -83,7 +83,8 @@ DEVICES list."
          devices))
 
   (let* ((result (run-listbox-selection-page
-                  #:info-text (G_ "Please select a disk.")
+                  #:info-text (G_ "Please select a \
+disk.  The installation device as well as the small devices are filtered.")
                   #:title (G_ "Disk")
                   #:listbox-items (device-items)
                   #:listbox-item->text cdr
@@ -792,13 +793,13 @@ by pressing the Exit button.~%~%")))
            result-user-partitions)))))
 
   (init-parted)
-  (let* ((non-install-devices (non-install-devices))
+  (let* ((eligible-devices (eligible-devices))
-         (user-partitions (run-page non-install-devices))
+         (user-partitions (run-page eligible-devices))
          (user-partitions-with-pass (prompt-luks-passwords
                                      user-partitions))
          (form (draw-formatting-page user-partitions)))
     ;; Make sure the disks are not in use before proceeding to formatting.
-    (free-parted non-install-devices)
+    (free-parted eligible-devices)
     (format-user-partitions user-partitions-with-pass)
     (syslog "formatted ~a user partitions~%"
             (length user-partitions-with-pass))

gnu/installer/parted.scm

@@ -81,7 +81,7 @@
 
             with-delay-device-in-use?
             force-device-sync
-            non-install-devices
+            eligible-devices
             partition-user-type
             user-fs-type-name
             partition-filesystem-user-type
@@ -356,28 +356,49 @@ fail. See rereadpt function in wipefs.c of util-linux for an explanation."
              (and=> (uuid root)
                     find-partition-by-uuid)))))
 
-(define (non-install-devices)
+;; Minimal installation device size.
-  "Return all the available devices, except the install device."
+(define %min-device-size
+  (* 2 GIBIBYTE-SIZE)) ;2GiB
+
+(define (eligible-devices)
+  "Return all the available devices except the install device and the devices
+which are smaller than %MIN-DEVICE-SIZE."
 
   (define the-installer-root-partition-path
     (installer-root-partition-path))
 
+  (define (small-device? device)
+    (let ((length (device-length device))
+          (sector-size (device-sector-size device)))
+      (and (< (* length sector-size) %min-device-size)
+           (syslog "~a is not eligible because it is smaller than ~a.~%"
+                   (device-path device)
+                   (unit-format-custom-byte device
+                                            %min-device-size
+                                            UNIT-GIGABYTE)))))
+
   ;; Read partition table of device and compare each path to the one
   ;; we're booting from to determine if it is the installation
   ;; device.
   (define (installation-device? device)
     ;; When using CDROM based installation, the root partition path may be the
     ;; device path.
-    (or (string=? the-installer-root-partition-path
+    (and (or (string=? the-installer-root-partition-path
                        (device-path device))
              (let ((disk (disk-new device)))
                (and disk
                     (any (lambda (partition)
                            (string=? the-installer-root-partition-path
                                      (partition-get-path partition)))
-                    (disk-partitions disk))))))
+                         (disk-partitions disk)))))
+         (syslog "~a is not eligible because it is the installation device.~%"
+                 (device-path device))))
 
-  (remove installation-device? (devices)))
+  (remove
+   (lambda (device)
+     (or (installation-device? device)
+         (small-device? device)))
+   (devices)))
 
 
 ;;