From 2ed7c3ae98aa671d504eba254fdd89ea26fe15c8 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Thu, 7 Mar 2019 16:31:19 +0800
Subject: [PATCH] Use /tmp over /var/lib for transient files

Create transient mount point in directory /tmp rather than /var/lib
which is not available during transactional update. Also clean up the
count_last_label function for not relying on /var/lib/os-prober/labels
file for the caculation.

https://en.opensuse.org/openSUSE:Packaging_for_transactional-updates

v2:
- Fix accidental deletion of btrfs subvolume (boo#1130669).
- Fix detection of btrfs boot subvolume if its /etc/fstab entry contains
  leading slash for subvol= mount option.

---
 common.sh                                | 37 ++++++++++++++------------------
 linux-boot-prober                        |  2 +-
 linux-boot-probes/common/50mounted-tests |  2 +-
 os-prober                                |  3 ---
 os-probes/common/50mounted-tests         |  2 +-
 5 files changed, 19 insertions(+), 27 deletions(-)

Index: os-prober-1.76/common.sh
===================================================================
--- os-prober-1.76.orig/common.sh
+++ os-prober-1.76/common.sh
@@ -21,31 +21,26 @@ require_tmpdir() {
   fi
 }
 
-count_for() {
-  _labelprefix="$1"
-  _result=$(grep "^${_labelprefix} " /var/lib/os-prober/labels 2>/dev/null || true)
-
-  if [ -z "$_result" ]; then
-    return
-  else
-    echo "$_result" | cut -d' ' -f2
-  fi
-}
-
+OS_PROBER_LABELS=""
 count_next_label() {
-  require_tmpdir
-
   _labelprefix="$1"
-  _cfor="$(count_for "${_labelprefix}")"
-
-  if [ -z "$_cfor" ]; then
-    echo "${_labelprefix} 1" >> /var/lib/os-prober/labels
+  _count=""
+  _labels=""
+  for i in $OS_PROBER_LABELS; do
+    _label="`echo $i | cut -d: -f1`"
+    if [ x"$_labelprefix" = x"$_label" ]; then
+      _count=`echo $i | cut -d: -f2`
+      _labels="$_labels $_label:`expr $_count + 1`"
+    else
+      _labels="$_labels $i"
+    fi
+  done
+  if [ -z "$_count" ]; then
+    OS_PROBER_LABELS="$OS_PROBER_LABELS $_labelprefix:1"
   else
-    sed "s/^${_labelprefix} ${_cfor}/${_labelprefix} $(($_cfor + 1))/" /var/lib/os-prober/labels > "$OS_PROBER_TMP/os-prober.tmp"
-    mv "$OS_PROBER_TMP/os-prober.tmp" /var/lib/os-prober/labels
+    OS_PROBER_LABELS="$_labels"
   fi
-  
-  echo "${_labelprefix}${_cfor}"
+  echo "${_labelprefix}${_count}"
 }
 
 progname=
Index: os-prober-1.76/linux-boot-prober
===================================================================
--- os-prober-1.76.orig/linux-boot-prober
+++ os-prober-1.76/linux-boot-prober
@@ -7,11 +7,6 @@ newns "$@"
 require_tmpdir
 ERR="n"
 
-tmpmnt=/var/lib/os-prober/mount
-if [ ! -d "$tmpmnt" ]; then
-	mkdir "$tmpmnt"
-fi
-
 mounted=
 bootmnt=
 bootsv=
@@ -45,23 +40,21 @@ if [ "x$ERR" != xn ]; then
 fi
 
 if [ "$type" = btrfs ]; then
+	tmpmnt="$(mktemp -d /tmp/linux-boot-prober.XXXXXX)"
 	# handle all of the btrfs stuff here
 	if [ ! -e "/proc/self/mountinfo" ]; then
 		warn "/proc/self/mountinfo does not exist, exiting"
-		umount "$tmpmnt" 2>/dev/null
 		rmdir "$tmpmnt" 2>/dev/null
 		exit 1
 	fi
 	mpoint=$(grep "btrfs" /proc/self/mountinfo | grep " /$subvol " | grep " $partition " | cut -d ' ' -f 5)
 	if [ "$mpoint" = "/" ]; then
 		warn "specifying active root not valid, exiting"
-		umount "$tmpmnt" 2>/dev/null
 		rmdir "$tmpmnt" 2>/dev/null
 		exit 1
 	fi
 	if [ "$mpoint" = "$tmpmnt" ]; then
 		warn "btrfs subvol=$subvool, UUID=$UUID, already mounted on $tmpmnt **ERROR**"
-		umount "$tmpmnt" 2>/dev/null
 		rmdir "$tmpmnt" 2>/dev/null
 		exit 1
 	fi
@@ -74,8 +67,6 @@ if [ "$type" = btrfs ]; then
 
 		if ! mount $opts -t btrfs -U $UUID "$tmpmnt" 2>/dev/null; then
 			warn "error mounting btrfs subvol=$subvol UUID=$UUID"
-			umount "$tmpmnt/boot" 2>/dev/null
-			umount "$tmpmnt" 2>/dev/null
 			rmdir "$tmpmnt" 2>/dev/null
 			exit 1
 		fi
@@ -83,8 +74,6 @@ if [ "$type" = btrfs ]; then
 		# bind-mount
 		if ! mount -o bind "$mpoint" "$tmpmnt" 2>/dev/null; then
 			warn "error mounting btrfs bindfrom=$mpoint subvol=$subvol UUID=$UUID"
-			umount "$tmpmnt/boot" 2>/dev/null
-			umount "$tmpmnt" 2>/dev/null
 			rmdir "$tmpmnt" 2>/dev/null
 			exit 1
 		fi
@@ -103,27 +92,34 @@ if [ "$type" = btrfs ]; then
 		bootsv="$subvol"
 	elif echo "$bootmnt" | cut -d ' ' -f 3 | grep -q "btrfs"; then
 		# separate btrfs /boot subvolume
-		bootsv=$(echo "$bootmnt" | cut -d ' ' -f 4 | grep "^subvol=" | sed "s/subvol=//" )
-		bootuuid=$(echo "$bootmnt" | cut -d ' ' -f 1 | grep "^UUID=" | sed "s/UUID=//" )
+		bootsv=$(echo "$bootmnt" | cut -d ' ' -f 4 | sed -n 's!\(^subvol=\|.*,subvol=\)\([^,]\+\).*!\2!p')
+		if [ -z "$bootsv" ]; then
+			warn "no subvolume in entry: $bootmnt"
+			umount "$tmpmnt" 2>/dev/null
+			rmdir "$tmpmnt" 2>/dev/null
+			exit 1
+		fi
+		bootuuid=$(echo "$bootmnt" | cut -d ' ' -f 1 | sed -n 's/UUID=\("\(.*\)"\|\(.*\)\)/\2\3/p')
 		debug "mounting btrfs $tmpmnt/boot UUID=$bootuuid subvol=$bootsv"
 		bindfrom=$(check_btrfs_mounted $bootsv $bootuuid)
 		if [ -n "$bindfrom" ]; then
 			# already mounted some place
 			if ! mount -o bind $bindfrom "$tmpmnt/boot" 2>/dev/null; then
 				warn "error bind mounting btrfs boot subvol=$bootsv, from=$bindfrom"
-				umount "$tmpmnt/boot" 2>/dev/null
 				umount "$tmpmnt" 2>/dev/null
 				rmdir "$tmpmnt" 2>/dev/null
 				exit 1
 			fi
 		elif ! mount -o subvol=$bootsv -t btrfs -U $bootuuid "$tmpmnt/boot" 2>/dev/null; then
 			warn "error mounting btrfs boot partition subvol=$bootsv, UUID=$bootuuid"
-			umount "$tmpmnt/boot" 2>/dev/null
 			umount "$tmpmnt" 2>/dev/null
 			rmdir "$tmpmnt" 2>/dev/null
 			exit 1
 		fi
-		bootpart=$(grep " btrfs " /proc/self/mountinfo | grep " /$bootsv " | cut -d ' ' -f 10)
+		bootpart=$(grep " btrfs " /proc/self/mountinfo | grep " `echo /$bootsv | tr -s /` " | cut -d ' ' -f 10)
+		if [ -z "$bootpart" ]; then
+			warn "no bootpart for $bootsv in /proc/self/mountinfo"
+		fi
 	else
 		# non-btrfs partition or logical volume
 		linux_mount_boot $partition $tmpmnt
Index: os-prober-1.76/linux-boot-probes/common/50mounted-tests
===================================================================
--- os-prober-1.76.orig/linux-boot-probes/common/50mounted-tests
+++ os-prober-1.76/linux-boot-probes/common/50mounted-tests
@@ -42,10 +42,7 @@ elif [ -z "$types" ]; then
 	types="$(grep -v nodev /proc/filesystems)"
 fi
 
-tmpmnt=/var/lib/os-prober/mount
-if [ ! -d "$tmpmnt" ]; then
-	mkdir "$tmpmnt"
-fi
+tmpmnt="$(mktemp -d /tmp/linux-boot-probes-50mounted-tests.XXXXXX)"
 
 mounted=
 if type grub2-mount >/dev/null 2>&1 && \
Index: os-prober-1.76/os-prober
===================================================================
--- os-prober-1.76.orig/os-prober
+++ os-prober-1.76/os-prober
@@ -141,9 +141,6 @@ parse_proc_mdstat () {
 	done
 }
 
-# Needed for idempotency
-rm -f /var/lib/os-prober/labels
-
 for prog in /usr/lib/os-probes/init/*; do
 	if [ -x "$prog" ] && [ -f "$prog" ]; then
 		"$prog" || true
Index: os-prober-1.76/os-probes/common/50mounted-tests
===================================================================
--- os-prober-1.76.orig/os-probes/common/50mounted-tests
+++ os-prober-1.76/os-probes/common/50mounted-tests
@@ -58,10 +58,7 @@ elif [ -z "$types" ]; then
 	exit 0
 fi
 
-tmpmnt=/var/lib/os-prober/mount
-if [ ! -d "$tmpmnt" ]; then
-	mkdir "$tmpmnt"
-fi
+tmpmnt="$(mktemp -d /tmp/os-probes-50mounted-tests.XXXXXX)"
 
 mounted=
 
@@ -105,7 +102,7 @@ probe_subvol ()
 	local UUID=$3
 	local tmpmnt=$4
 
-	mounted=
+	local mounted=
 	mpoint="$(grep btrfs /proc/self/mountinfo | grep "$partition " | grep "/$subvol " | cut -d ' ' -f 5)"
 	ret=1
 
@@ -115,13 +112,18 @@ probe_subvol ()
 
 	if [ -n "$mpoint" ]; then
 		if [ "x$mpoint" = "x/" ]; then
-			continue # this is the root for the running system
+			return 1
   		fi
-		mounted=1
 	else
 		# again, do not mount btrfs ro
-		mount -t btrfs $opts -U "$UUID" "$tmpmnt"
-		mpoint="$tmpmnt"
+		if mount -t btrfs $opts -U "$UUID" "$tmpmnt" 2>/dev/null; then
+			debug "btrfs volume $UUID mounted with $opt"
+			mpoint="$tmpmnt"
+			mounted=1
+		else
+			warn "cannot mount btrfs volume $UUID with $opt"
+			return 1
+		fi
 	fi
 	test="/usr/lib/os-probes/mounted/90linux-distro"
 	if [ -f "$test" ] && [ -x "$test" ]; then
@@ -131,7 +133,7 @@ probe_subvol ()
 			ret=0
 		fi
 	fi
-	if [ -z "$mounted" ]; then
+	if [ "$mounted" ]; then
 		if ! umount "$tmpmnt"; then
 			warn "failed to umount $tmpmnt"
 		fi
Index: os-prober-1.76/linux-boot-probes/mounted/common/40grub2
===================================================================
--- os-prober-1.76.orig/linux-boot-probes/mounted/common/40grub2
+++ os-prober-1.76/linux-boot-probes/mounted/common/40grub2
@@ -15,7 +15,7 @@ found_item=0
 
 entry_result () {
 	if [ "x$type" = "xbtrfs" ]; then
-		bsv=${bootsv:+/}${bootsv}
+		bsv=`echo ${bootsv:+/}${bootsv} | tr -s /`
 		# if path is not relative to subvolume make it relative
 		kernel=${kernel#${bsv}}
 		kernelfile=$kernel