Merge branch 'offer_filesystem_repair_option' of https://github.com/framps/PiShrink

README.md

@@ -2,9 +2,12 @@
 PiShrink is a bash script that automatically shrink a pi image that will then resize to the max size of the SD card on boot. This will make putting the image back onto the SD card faster and the shrunk images will compress better.
 
 ## Usage ##
-`sudo pishrink.sh [-s] imagefile.img [newimagefile.img]`
+`sudo pishrink.sh [-sdrp] imagefile.img [newimagefile.img]`
 
 If the `-s` option is given the script will skip the autoexpanding part of the process.  If you specify the `newimagefile.img` parameter, the script will make a copy of `imagefile.img` and work off that. You will need enough space to make a full copy of the image to use that option.
+Option `-d` will create a logfile `pishrink.log` which may help for problem analysis.
+Option `-r` will try to recover a corrupted filesystem. You have to specify the `newimagefile.img` parameter and a recovery is done on a copy of the image.
+Option `-p` will try to recover a corrupted filesystem in paranoia mode. You have to specify the `newimagefile.img` parameter and a recovery is done on a copy of the image.
 
 ## Prerequisites ##
 If you are trying to shrink a [NOOBS](https://github.com/raspberrypi/noobs) image it will likely fail. This is due to [NOOBS partitioning](https://github.com/raspberrypi/noobs/wiki/NOOBS-partitioning-explained) being significantly different than Raspbian's. Hopefully PiShrink will be able to support NOOBS in the near future.

pishrink.sh

@@ -1,13 +1,39 @@
 #!/bin/bash
 
-version="v0.1"
+version="v0.1.1"
+
+CURRENT_DIR=$(pwd)
+SCRIPTNAME="${0##*/}"
+LOGFILE=${CURRENT_DIR}/${SCRIPTNAME%.*}.log
 
 function info() {
-	echo "$1..."
+	echo "$SCRIPTNAME: $1..."
+}
+
+# Returns 0 for success, <> 0 for failure
+function retry() { # command maxretry failuretest
+
+		local tries=1
+		local command="$1" # command to retry
+		local maxRetry=$2 # number of retries
+		local successtest="$3" # success test
+
+		while (( tries <= maxRetry )); do
+			info "Trying to recover corrupted filesystem. Trial $tries"
+			eval "$command"
+			rc=$?
+			eval "$successtest"
+			if (( ! $? )); then
+				info "Recovered filesystem error"
+				return 0
+			fi
+			(( tries++ ))
+		done
+		return 1
 }
 
 function error() {
-	echo -n "ERROR occured in line $1: "
+	echo -n "$SCRIPTNAME: ERROR occured in line $1: "
 	shift
 	echo "$@"
 }
@@ -35,24 +61,81 @@ function logVariables() {
 	fi
 }
 
-usage() { echo "Usage: $0 [-sd] imagefile.img [newimagefile.img]"; exit -1; }
+function checkFilesystem() {
+
+	local stdTest="(( rc < 4 ))"
+	[[ $paranoia == true ]] && stdTest="(( rc == 0 ))"
+
+	local rc
+	info "Checking filesystem"
+	retry "e2fsck -pfttv \"$loopback\"" 3 "$stdTest"
+	rc=$?
+
+	(( ! rc )) && return
+
+	info "Filesystem error detected"
+
+	if [[ $paranoia != true ]]; then
+		error $LINENO "e2fsck failed. Filesystem corrupted. Try option -r or option -p."
+		exit -9
+	fi
+
+	info "Trying to recover corrupted filesystem (Phase1)"
+	retry "e2fsck -pftt \"$loopback\"" 3 "stdTest"
+	(( ! $? )) && return
+
+	info "Trying to recover corrupted filesystem (Phase2)."
+	retry "e2fsck -yv \"$loopback\"" 3 "$stdTest"
+	(( ! $? )) && return
+
+	info "Trying to recover corrupted filesystem (Phase3)."
+	retry "e2fsck -fttvy -b 32768 \"$loopback\"" 3 "$stdTest"
+	(( ! $? )) && return
+
+	error $LINENO "Filesystem recoveries failed. Giving up to fix corrupted filesystem."
+	exit -9
+
+}
+
+help() {
+	local help
+	read -r -d '' help << EOM
+-s: Don't expand filesystem when image is booted the first time
+-d: Write debug messages in a debug log file
+-r: Try to repair corrupted filesystem
+-p: Try to repair corrupted filesystem in paranoia mode
+EOM
+	echo $help
+	exit -1
+}
+
+usage() {
+	echo "Usage: $0 [-sdrph] imagefile.img [newimagefile.img]"
+	echo "-s: skip autoexpand"
+	echo "-d: debug mode on"
+	echo "-r: try to repair filesystem errors"
+	echo "-p: try to repair filesystem errors (paranoia mode)"
+	echo "-h: display help text"
+	exit -1
+}
 
 should_skip_autoexpand=false
 debug=false
+repair=false
+paranoia=false
 
-while getopts ":sd" opt; do
+while getopts ":sdrph" opt; do
   case "${opt}" in
     s) should_skip_autoexpand=true ;;
     d) debug=true;;
+    r) repair=true;;
+    p) paranoia=true;;
+    h) help;;
     *) usage ;;
   esac
 done
 shift $((OPTIND-1))
 
-CURRENT_DIR=$(pwd)
-SCRIPTNAME="${0##*/}"
-LOGFILE=${CURRENT_DIR}/${SCRIPTNAME%.*}.log
-
 if [ "$debug" = true ]; then
 	info "Creating log file $LOGFILE"
 	rm $LOGFILE &>/dev/null
@@ -78,6 +161,10 @@ if (( EUID != 0 )); then
   error $LINENO "You need to be running as root."
   exit -3
 fi
+if [[ -z "$2" ]] && [[ $repair == true || $paranoia == true ]]; then
+  error $LINENO "Option -r and -p require to specify newimagefile.img."
+  exit -3
+fi
 
 #Check that what we need is installed
 for command in parted losetup tune2fs md5sum e2fsck resize2fs; do
@@ -194,11 +281,8 @@ else
 fi
 
 #Make sure filesystem is ok
-info "Checking filesystem"
+if [[ $repair == true ]]; then
-if ! e2fsck -p -f "$loopback"; then
+	checkFilesystem
-	rc=$?
-	error $LINENO "fsck failed with rc $rc"
-	exit -9
 fi
 
 if ! minsize=$(resize2fs -P "$loopback"); then