[PATCH openbmc v6 11/18] initfs: update: check individual mtd partitions for mounts

[OpenBMC Patches]

From: "Milton D. Miller II" <miltonm at us.ibm.com>

Instead of checking for any mtd device, only check mtd devices
that are to be updated.  Include child mtd devices when looking
for mounted filesystems.

If this check is suppressed flash updates are suppressed.
Suppressing the check may be useful to verify a update could
succeed at shutdown.

Signed-off-by: Milton Miller <miltonm at us.ibm.com>
---
 .../obmc-phosphor-initfs/files/obmc-update.sh      | 47 +++++++++++++++++++---
 1 file changed, 41 insertions(+), 6 deletions(-)

diff --git a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
index 4442e5b..22c9dcc 100755
--- a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
+++ b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
@@ -19,11 +19,34 @@ then
 	mount -t devtmpfs dev dev
 fi
 
-if grep mtd /proc/mounts
-then
-	echo 1>&2 "ERROR: A mtd device is mounted."
-	exit 1
-fi
+# mtd number N with mtd name Name can be mounted via mtdN, or mtd:Name
+# (with a mtd aware fs) or by /dev/mtdblockN (with a mtd or block fs).
+mtdismounted() {
+	m=${1##mtd}
+	if grep -s "mtdblock$m " /proc/mounts || grep -s "mtd$m " /proc/mounts
+	then
+		return 0
+	fi
+	n=$(cat /sys/class/mtd/mtd$m/name)
+	if test -n "$n" && grep -s "mtd:$n " /proc/mounts
+	then
+		return 0
+	fi
+	return 1
+}
+
+# Detect child partitions when the whole flash is to be updated.
+# Ignore mtdNro and mtdblockN names in the class subsystem directory.
+childmtds() {
+	for m in /sys/class/mtd/$1/mtd*
+	do
+		m=${m##*/}
+		if test "${m%ro}" = "${m#mtdblock}"
+		then
+			echo $m
+		fi
+	done
+}
 
 findmtd() {
 	m=$(grep -xl "$1" /sys/class/mtd/*/name)
@@ -62,10 +85,10 @@ doclean=
 dosave=y
 dorestore=y
 toram=
+checkmount=y
 
 whitelist=/run/initramfs/whitelist
 image=/run/initramfs/image-
-
 E="ERROR:"
 
 while test "$1" != "${1#-}"
@@ -92,6 +115,10 @@ do
 	--no-flash)
 		doflash=
 		shift ;;
+	--ignore-mount)
+		checkmount=
+		doflash=
+		shift ;;
 	--copy-files)
 		toram=y
 		shift ;;
@@ -135,6 +162,14 @@ do
 		echo 1>&2 "$E Unable to find mtd partiton for ${f##*/}."
 		exit 1
 	fi
+	for s in $m $(childmtds $m)
+	do
+		if test -n "$checkmount" && mtdismounted $s
+		then
+			echo 1>&2 "$E Device $s is mounted, ${f##*/} is busy."
+			exit 1
+		fi
+	done
 done
 
 if test -n "$doflash"
-- 
2.9.0