From 7fdceda2475605b383dfc7a700446030ded06667 Mon Sep 17 00:00:00 2001
From: Marcel Partap <mpartap@gmx.net>
Date: Sat, 23 Jan 2021 19:16:35 +0100
Subject: [PATCH 1/2] Make unmounting of /proc and /sys more resilient

.. against concurrent ephemeral accesses (f.e. by git status calls from
inside ranger file manager)
---
 scripts/build/chroot_proc  | 8 ++++----
 scripts/build/chroot_sysfs | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/scripts/build/chroot_proc b/scripts/build/chroot_proc
index fcc866932..60317a527 100755
--- a/scripts/build/chroot_proc
+++ b/scripts/build/chroot_proc
@@ -63,10 +63,10 @@ case "${_ACTION}" in
 		fi
 
 		# Unmounting /proc
-		if [ -e chroot/proc/version ]
-		then
-			umount chroot/proc
-		fi
+		while [ -e chroot/proc/version ] && sleep 1
+		do
+			umount -v chroot/proc || fuser --verbose --ismountpoint chroot/proc || true
+		done
 
 		# Removing stage file
 		Remove_stagefile
diff --git a/scripts/build/chroot_sysfs b/scripts/build/chroot_sysfs
index a9ac0290c..1dc9e2734 100755
--- a/scripts/build/chroot_sysfs
+++ b/scripts/build/chroot_sysfs
@@ -57,10 +57,10 @@ case "${_ACTION}" in
 		Acquire_lockfile
 
 		# Unmounting /sys
-		if [ -e chroot/sys/class ]
-		then
-			umount chroot/sys
-		fi
+		while [ -e chroot/sys/class ] && sleep 1
+		do
+			umount -v chroot/sys || fuser --verbose --ismountpoint chroot/sys || true
+		done
 
 		# Removing stage file
 		Remove_stagefile

From bf331e5e653f6083cbedee28013344055bf64aa3 Mon Sep 17 00:00:00 2001
From: Marcel Partap <mpartap@gmx.net>
Date: Sat, 23 Jan 2021 20:42:58 +0100
Subject: [PATCH 2/2] Put a limit on chroot_proc/chroot_sysfs unmount loops

(now with more counter increment and less test b0rkazoid)
(morale: don't rely on the assumption that a shellcheck warning you
choose to ignore could not possible mask another error)
(vim expandtab!)
---
 scripts/build/chroot_proc  | 7 +++++--
 scripts/build/chroot_sysfs | 7 +++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/scripts/build/chroot_proc b/scripts/build/chroot_proc
index 60317a527..47c2df827 100755
--- a/scripts/build/chroot_proc
+++ b/scripts/build/chroot_proc
@@ -63,10 +63,13 @@ case "${_ACTION}" in
 		fi
 
 		# Unmounting /proc
-		while [ -e chroot/proc/version ] && sleep 1
+		ATTEMPT=0
+		while [ -e chroot/proc/version ] && [ ${ATTEMPT} -lt 42 ]
 		do
-			umount -v chroot/proc || fuser --verbose --ismountpoint chroot/proc || true
+			umount -v chroot/proc && break || { fuser --verbose --ismountpoint chroot/proc && sleep 1; }
+			ATTEMPT=$(( ATTEMPT + 1 ))
 		done
+		unset ATTEMPT
 
 		# Removing stage file
 		Remove_stagefile
diff --git a/scripts/build/chroot_sysfs b/scripts/build/chroot_sysfs
index 1dc9e2734..412194a19 100755
--- a/scripts/build/chroot_sysfs
+++ b/scripts/build/chroot_sysfs
@@ -57,10 +57,13 @@ case "${_ACTION}" in
 		Acquire_lockfile
 
 		# Unmounting /sys
-		while [ -e chroot/sys/class ] && sleep 1
+		ATTEMPT=0
+		while [ -e chroot/sys/class ] && [ ${ATTEMPT} -lt 42 ]
 		do
-			umount -v chroot/sys || fuser --verbose --ismountpoint chroot/sys || true
+			umount -v chroot/sys && break || { fuser --verbose --ismountpoint chroot/sys && sleep 1; }
+			ATTEMPT=$(( ATTEMPT + 1 ))
 		done
+		unset ATTEMPT
 
 		# Removing stage file
 		Remove_stagefile