From c259d4d9552b816d770e90fd4b29184eb0cd0fba Mon Sep 17 00:00:00 2001
From: Andrew Cady <d@cryptonomic.net>
Date: Tue, 2 Mar 2021 13:58:28 -0500
Subject: partvi: do not rely on part image file to get size

When partvi writes directly to a boot medium, it shouldn't
copy part files, because these involve copying the unused
parts of the filesystems.  Instead, it should create a new
filesystem on the target and copy files into it.

This change moves in that direction.
---
 src/partvi | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/partvi b/src/partvi
index 2a32851..b718dba 100755
--- a/src/partvi
+++ b/src/partvi
@@ -174,12 +174,30 @@ format_guid()
     printf '%s\n' "${1:0:8}-${1:8:4}-${1:12:4}-${1:16:4}-${1:20:12}"
 }
 
+get_partition_size()
+{
+    case "$type" in
+        dm-verity-hashes|dm-verity-data)
+            stat -L -c '%s' "$builddir"/"${f%.conf}"
+            ;;
+        *)
+            require_var allocation
+            case "$allocation" in
+                *K) echo $(( ${allocation%?} * 1024 )) ;;
+                *M) echo $(( ${allocation%?} * 1024 * 1024 )) ;;
+                *G) echo $(( ${allocation%?} * 1024 * 1024 * 1024 )) ;;
+                *) return 1 ;;
+            esac
+            ;;
+    esac
+}
+
 create_ptable_conf()
 {
         unset partuuid
         inquire_var partuuid
-        part=$builddir/${f%.conf}
-        devsz=$(stat -L -c '%s' "$part") || return
+        devsz=$(get_partition_size) || return
+
         [ "$start" -a "$devsz" ] || return
 
         [ "$((devsz % 512))" -eq 0 ]
@@ -275,8 +293,9 @@ cleanup()
     fi
 }
 
-copy_data_to_mounted_target_filesystems()
+mount_part()
 {
+    local source_dev="$1"
     case "$type" in
         efi-system-partition|boot|samizdat-keys) ;;
         dm-verity-hashes|partition-table|bios-grub) return ;;
@@ -284,12 +303,15 @@ copy_data_to_mounted_target_filesystems()
     esac
 
     img=${f%.conf}
-    dev=/dev/mapper/${whole#/dev/}p${img#part}
     mnt=${f%.conf}.mnt
 
     mkdir -p "$mnt"
-    loudly $sudo mount "$dev" "$mnt"
+    loudly $sudo mount "$source_dev" "$mnt"
+}
 
+copy_data_to_mounted_target_filesystems()
+{
+    mount_part "/dev/mapper/${whole#/dev/}p${img#part}"
     case "$type" in
         boot)
             BOOT_DIR=$mnt
@@ -350,7 +372,6 @@ fi
 
 
 
-
 if whole=$(losetup -j "$target" -O NAME --noheadings)
 then
     cleanup
-- 
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