Bug#865586: live-build: binary_hdd failed with mkfs.vfat error

[Matthijs Kooijman <matthijs@stdin.nl>]

Package: live-build
Version: 1:20170807
Followup-For: Bug #865586

Hi,

I also ran into this same error a while ago. It is caused by partition
devices being created when parted creates partitions, which are not
cleaned up when the loop devices are cleaned up. I'm attaching a patch
that fixes this, by passing --partscan to losetup to clear out any
lingering partition devices when the partition itself is mounted.

It would be more correct to clean up the partition devices when the loop
device is removed, but I'm not quite sure whose responsibility that
would be.

Gr.

Matthijs

>From 05e0703d82e0189e40d88f5070b1c2f955a0ad9e Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Tue, 29 Aug 2017 15:04:31 +0200
Subject: [PATCH 3/4] Pass --partscan to losetup

Recent versions of Linux, parted or some other bit of software cause
partition devices, like /dev/loop0p1 to be created when running parted
mkpart. However, these devices are not cleaned up when running
losetup -d to remove /dev/loop0 later, so they linger around and confuse
mkfs (which refuses to make a filesystem, thinking there are partitions):

	mkfs.fat 4.1 (2017-01-24)
	mkfs.vfat: Partitions or virtual mappings on device '/dev/loop0', not making filesystem (use -I to override)

To prevent this behaviour, pass --partscan to losetup when adding a new
partition, to clean up any lingering partitions. It seems losetup does not
accept --partscan when deleting a loop device, to clean up at that point, but
since binary_hdd mounts the partition last, there should not be any lingering
partition devices after live-build is done.

The --partscan option is available since util-linux 2.21 (released in 2012), so
it should be fairly safe to pass it unconditionally.
---
 functions/losetup.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/functions/losetup.sh b/functions/losetup.sh
index 0346ff677..9d9b46e5d 100755
--- a/functions/losetup.sh
+++ b/functions/losetup.sh
@@ -40,7 +40,7 @@ Losetup ()
 	FILE="${2}"
 	PARTITION="${3:-1}"
 
-	${LB_LOSETUP} --read-only "${DEVICE}" "${FILE}"
+	${LB_LOSETUP} --read-only --partscan "${DEVICE}" "${FILE}"
 	FDISK_OUT="$(${LB_FDISK} -l -u ${DEVICE} 2>&1)"
 	Lodetach "${DEVICE}"
 
@@ -50,14 +50,14 @@ Losetup ()
 	then
 		Echo_message "Mounting %s with offset 0" "${DEVICE}"
 
-		${LB_LOSETUP} "${DEVICE}" "${FILE}"
+		${LB_LOSETUP} --partscan "${DEVICE}" "${FILE}"
 	else
 		SECTORS="$(echo "$FDISK_OUT" | sed -ne "s|^$LOOPDEVICE[ *]*\([0-9]*\).*|\1|p")"
 		OFFSET="$(expr ${SECTORS} '*' 512)"
 
 		Echo_message "Mounting %s with offset %s" "${DEVICE}" "${OFFSET}"
 
-		${LB_LOSETUP} -o "${OFFSET}" "${DEVICE}" "${FILE}"
+		${LB_LOSETUP} --partscan -o "${OFFSET}" "${DEVICE}" "${FILE}"
 	fi
 }
 
-- 
2.11.0