lvresize: add new options and defaults for fs handling

The new option "--fs String" for lvresize/lvreduce/lvextend
controls the handling of file systems before/after resizing
the LV.  --resizefs is the same as --fs resize.

The new option "--fsmode String" can be used to control
mounting and unmounting of the fs during resizing.

Possible --fs values:

checksize
  Only applies to reducing size; does nothing for extend.
  Check the fs size and reduce the LV if the fs is not using
  the affected space, i.e. the fs does not need to be shrunk.
  Fail the command without reducing the fs or LV if the fs is
  using the affected space.

resize
  Resize the fs using the fs-specific resize command.
  This may include mounting, unmounting, or running fsck.
  See --fsmode to control mounting behavior, and --nofsck to
  disable fsck.

resize_fsadm
  Use the old method of calling fsadm to handle the fs
  (deprecated.) Warning: this option does not prevent lvreduce
  from destroying file systems that are unmounted (or mounted
  if prompts are skipped.)

ignore
  Resize the LV without checking for or handling a file system.
  Warning: using ignore when reducing the LV size may destroy the
  file system.

Possible --fsmode values:

manage
  Mount or unmount the fs as needed to resize the fs,
  and attempt to restore the original mount state at the end.

nochange
  Do not mount or unmount the fs. If mounting or unmounting
  is required to resize the fs, then do not resize the fs or
  the LV and fail the command.

offline
  Unmount the fs if it is mounted, and resize the fs while it
  is unmounted. If mounting is required to resize the fs,
  then do not resize the fs or the LV and fail the command.

Notes on lvreduce:

When no --fs or --resizefs option is specified:
. lvextend default behavior is fs ignore.
. lvreduce default behavior is fs checksize
  (includes activating the LV.)

With the exception of --fs resize_fsadm|ignore, lvreduce requires
the recent libblkid fields FSLASTBLOCK and FSBLOCKSIZE.
FSLASTBLOCK*FSBLOCKSIZE is the last byte used by the fs on the LV,
which determines if reducing the fs is necessary.

3 files changed, 472 insertions, 2 deletions

diff --git a/scripts/Makefile.in b/scripts/Makefile.in
index ebcea92f9..9fcff37b0 100644
--- a/scripts/Makefile.in
+++ b/scripts/Makefile.in
@@ -56,7 +56,11 @@ install_device-mapper: $(DM_SCRIPTS:.sh=_install)
 
 install_ocf: $(OCF_SCRIPTS:.ocf=_install)
 
-install: install_lvm2 install_ocf install_device-mapper
+install_libexec:
+	$(Q) $(INSTALL_SCRIPT) lvresize_fs_helper.sh $(libexecdir)/lvresize_fs_helper
+
+install: install_lvm2 install_ocf install_device-mapper install_libexec
+
 
 # FIXME Customise for other distributions
 install_initscripts:
diff --git a/scripts/fsadm.sh b/scripts/fsadm.sh
index 9ae422f55..d22c7d0a6 100755
--- a/scripts/fsadm.sh
+++ b/scripts/fsadm.sh
@@ -164,7 +164,7 @@ cleanup() {
 		export _FSADM_YES _FSADM_EXTOFF
 		unset FSADM_RUNNING
 		test -n "${LVM_BINARY-}" && PATH=$_SAVEPATH
-		dry exec "$LVM" lvresize $VERB $FORCE -r -L"${NEWSIZE_ORIG}b" "$VOLUME_ORIG"
+		dry exec "$LVM" lvresize $VERB $FORCE $YES --fs resize_fsadm -L"${NEWSIZE_ORIG}b" "$VOLUME_ORIG"
 	fi
 
 	# error exit status for break
diff --git a/scripts/lvresize_fs_helper.sh b/scripts/lvresize_fs_helper.sh
new file mode 100755
index 000000000..031b8453b
--- /dev/null
+++ b/scripts/lvresize_fs_helper.sh
@@ -0,0 +1,466 @@
+#!/bin/bash
+#
+# Copyright (C) 2022 Red Hat, Inc. All rights reserved.
+#
+# This file is part of LVM2.
+#
+# This copyrighted material is made available to anyone wishing to use,
+# modify, copy, or redistribute it subject to the terms and conditions
+# of the GNU General Public License v.2.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+errorexit() {
+	echo "$1" >&2
+	exit 1
+}
+
+logmsg() {
+	echo "$1"
+	logger "${SCRIPTNAME}: $1"
+}
+
+# Set to 1 while the fs is temporarily mounted on $TMPDIR
+TMP_MOUNT_DONE=0
+# Set to 1 if the fs resize command fails
+RESIZEFS_FAILED=0
+
+fsextend() {
+	if [ "$DO_UNMOUNT" -eq 1 ]; then
+		logmsg "unmount ${MOUNTDIR}"
+		umount "$MOUNTDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "unmount done"
+		else
+			logmsg "unmount failed"
+			exit 1
+		fi
+	fi
+
+	if [ "$DO_FSCK" -eq 1 ]; then
+		logmsg "e2fsck ${DEVPATH}"
+		e2fsck -f -p "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "e2fsck done"
+		else
+			logmsg "e2fsck failed"
+			exit 1
+		fi
+	fi
+	
+	if [ "$DO_CRYPTRESIZE" -eq 1 ]; then
+		logmsg "cryptsetup resize ${DEVPATH}"
+		cryptsetup resize "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "cryptsetup done"
+		else
+			logmsg "cryptsetup failed"
+			exit 1
+		fi
+	fi
+
+	if [ "$DO_MOUNT" -eq 1 ]; then
+		logmsg "mount ${DEVPATH} ${TMPDIR}"
+		mount -t "$FSTYPE" "$DEVPATH" "$TMPDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "mount done"
+			TMP_MOUNT_DONE=1
+		else
+			logmsg "mount failed"
+			exit 1
+		fi
+	fi
+
+	if [[ "$FSTYPE" == "ext"* ]]; then
+		logmsg "resize2fs ${DEVPATH}"
+		resize2fs "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "resize2fs done"
+		else
+			logmsg "resize2fs failed"
+			RESIZEFS_FAILED=1
+		fi
+	elif [[ "$FSTYPE" == "xfs" ]]; then
+		logmsg "xfs_growfs ${DEVPATH}"
+		xfs_growfs "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "xfs_growfs done"
+		else
+			logmsg "xfs_growfs failed"
+			RESIZEFS_FAILED=1
+		fi
+	fi
+
+	# If the fs was temporarily mounted, now unmount it.
+	if [ $TMP_MOUNT_DONE -eq 1 ]; then
+		logmsg "cleanup unmount ${TMPDIR}"
+		umount "$TMPDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "cleanup unmount done"
+			TMP_MOUNT_DONE=0
+			rmdir "$TMPDIR"
+		else
+			logmsg "cleanup unmount failed"
+			exit 1
+		fi
+	fi
+
+	# If the fs was temporarily unmounted, now remount it.
+	# Not considered a command failure if this fails.
+	if [[ $DO_UNMOUNT -eq 1 && $REMOUNT -eq 1 ]]; then
+		logmsg "remount ${DEVPATH} ${MOUNTDIR}"
+		mount -t "$FSTYPE" "$DEVPATH" "$MOUNTDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "remount done"
+		else
+			logmsg "remount failed"
+		fi
+	fi
+
+	if [ $RESIZEFS_FAILED -eq 1 ]; then
+		logmsg "File system extend failed."
+		exit 1
+	fi
+
+	exit 0
+}
+
+fsreduce() {
+	if [ "$DO_UNMOUNT" -eq 1 ]; then
+		logmsg "unmount ${MOUNTDIR}"
+		umount "$MOUNTDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "unmount done"
+		else
+			logmsg "unmount failed"
+			exit 1
+		fi
+	fi
+
+	if [ "$DO_FSCK" -eq 1 ]; then
+		logmsg "e2fsck ${DEVPATH}"
+		e2fsck -f -p "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "e2fsck done"
+		else
+			logmsg "e2fsck failed"
+			exit 1
+		fi
+	fi
+	
+	if [ "$DO_MOUNT" -eq 1 ]; then
+		logmsg "mount ${DEVPATH} ${TMPDIR}"
+		mount -t "$FSTYPE" "$DEVPATH" "$TMPDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "mount done"
+			TMP_MOUNT_DONE=1
+		else
+			logmsg "mount failed"
+			exit 1
+		fi
+	fi
+
+	if [[ "$FSTYPE" == "ext"* ]]; then
+		NEWSIZEKB=$(($NEWSIZEBYTES/1024))
+		logmsg "resize2fs ${DEVPATH} ${NEWSIZEKB}k"
+		resize2fs "$DEVPATH" "$NEWSIZEKB"k
+		if [ $? -eq 0 ]; then
+			logmsg "resize2fs done"
+		else
+			logmsg "resize2fs failed"
+			# will exit after cleanup unmount
+			RESIZEFS_FAILED=1
+		fi
+	fi
+
+	# If the fs was temporarily mounted, now unmount it.
+	if [ $TMP_MOUNT_DONE -eq 1 ]; then
+		logmsg "cleanup unmount ${TMPDIR}"
+		umount "$TMPDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "cleanup unmount done"
+			TMP_MOUNT_DONE=0
+			rmdir "$TMPDIR"
+		else
+			logmsg "cleanup unmount failed"
+			exit 1
+		fi
+	fi
+
+	if [ $RESIZEFS_FAILED -eq 1 ]; then
+		logmsg "File system reduce failed."
+		exit 1
+	fi
+
+	if [ "$DO_CRYPTRESIZE" -eq 1 ]; then
+		NEWSIZESECTORS=$(($NEWSIZEBYTES/512))
+		logmsg "cryptsetup resize ${NEWSIZESECTORS} sectors ${DEVPATH}"
+		cryptsetup resize --size "$NEWSIZESECTORS" "$DEVPATH"
+		if [ $? -eq 0 ]; then
+			logmsg "cryptsetup done"
+		else
+			logmsg "cryptsetup failed"
+			exit 1
+		fi
+	fi
+
+	# If the fs was temporarily unmounted, now remount it.
+	# Not considered a command failure if this fails.
+	if [[ $DO_UNMOUNT -eq 1 && $REMOUNT -eq 1 ]]; then
+		logmsg "remount ${DEVPATH} ${MOUNTDIR}"
+		mount -t "$FSTYPE" "$DEVPATH" "$MOUNTDIR"
+		if [ $? -eq 0 ]; then
+			logmsg "remount done"
+		else
+			logmsg "remount failed"
+		fi
+	fi
+
+	exit 0
+}
+
+cryptresize() {
+	NEWSIZESECTORS=$(($NEWSIZEBYTES/512))
+	logmsg "cryptsetup resize ${NEWSIZESECTORS} sectors ${DEVPATH}"
+	cryptresize resize --size "$NEWSIZESECTORS" "$DEVPATH"
+	if [ $? -eq 0 ]; then
+		logmsg "cryptsetup done"
+	else
+		logmsg "cryptsetup failed"
+		exit 1
+	fi
+
+	exit 0
+}
+
+usage() {
+	echo "${SCRIPTNAME}: helper script called by lvresize to resize file systems."
+	echo ""
+	echo "${SCRIPTNAME} --fsextend --fstype name --lvpath path"
+	echo "    [ --mountdir path ]"
+	echo "    [ --mount ]"
+	echo "    [ --unmount ]"
+	echo "    [ --remount ]"
+	echo "    [ --fsck ]"
+	echo "    [ --cryptresize ]"
+	echo "    [ --cryptpath path ]"
+	echo ""
+	echo "${SCRIPTNAME} --fsreduce --fstype name --lvpath path"
+	echo "    [ --newsizebytes num ]"
+	echo "    [ --mountdir path ]"
+	echo "    [ --mount ]"
+	echo "    [ --unmount ]"
+	echo "    [ --remount ]"
+	echo "    [ --fsck ]"
+	echo "    [ --cryptresize ]"
+	echo "    [ --cryptpath path ]"
+	echo ""
+	echo "${SCRIPTNAME} --cryptresize --cryptpath path --newsizebytes num"
+	echo ""
+	echo "Options:"
+	echo "    --fsextend"
+	echo "        Extend the file system."
+	echo "    --fsreduce"
+	echo "        Reduce the file system."
+	echo "    --fstype name"
+	echo "        The type of file system (ext*, xfs)."
+	echo "    --lvpath path"
+	echo "        The path to the LV being resized."
+	echo "    --mountdir path"
+	echo "        The file system is currently mounted here."
+	echo "    --mount"
+	echo "        Mount the file system on a temporary directory before resizing."
+	echo "    --unmount"
+	echo "        Unmount the file system before resizing."
+	echo "    --remount"
+	echo "        Remount the file system after resizing if unmounted."
+	echo "    --fsck"
+	echo "        Run fsck on the file system before resizing (only with ext*)."
+	echo "    --newsizebytes num"
+	echo "        The new size of the file system."
+	echo "    --cryptresize"
+	echo "        Resize the crypt device between the LV and file system."
+	echo "    --cryptpath path"
+	echo "        The path to the crypt device."
+	echo ""
+}
+
+#
+# BEGIN SCRIPT
+#
+PATH="/sbin:/usr/sbin:/bin:/usr/sbin:$PATH"
+SCRIPTNAME=$(basename "$0")
+
+# These are the only commands that this script will run.
+# Each is enabled (1) by the corresponding command options:
+# --fsextend, --fsreduce, --cryptresize, --mount, --unmount, --fsck
+DO_FSEXTEND=0
+DO_FSREDUCE=0
+DO_CRYPTRESIZE=0
+DO_MOUNT=0
+DO_UNMOUNT=0
+DO_FSCK=0
+
+# --remount: attempt to remount the fs if it was originally
+# mounted and the script unmounted it.
+REMOUNT=0
+
+if [ "$UID" != 0 ] && [ "$EUID" != 0 ]; then
+	errorexit "${SCRIPTNAME} must be run as root."
+fi
+
+GETOPT="getopt"
+
+OPTIONS=$("$GETOPT" -o h -l help,fsextend,fsreduce,cryptresize,mount,unmount,remount,fsck,fstype:,lvpath:,newsizebytes:,mountdir:,cryptpath: -n "${SCRIPTNAME}" -- "$@")
+eval set -- "$OPTIONS"
+
+while true
+do
+	case $1 in
+	--fsextend)
+		DO_FSEXTEND=1
+		shift
+		;;
+	--fsreduce)
+		DO_FSREDUCE=1
+		shift
+		;;
+	--cryptresize)
+		DO_CRYPTRESIZE=1
+		shift
+		;;
+	--mount)
+		DO_MOUNT=1
+		shift
+		;;
+	--unmount)
+		DO_UNMOUNT=1
+		shift
+		;;
+	--fsck)
+		DO_FSCK=1
+		shift
+		;;
+	--remount)
+		REMOUNT=1
+		shift
+		;;
+	--fstype)
+		FSTYPE=$2;
+		shift; shift
+		;;
+	--lvpath)
+		LVPATH=$2;
+		shift; shift
+		;;
+	--newsizebytes)
+		NEWSIZEBYTES=$2;
+		shift; shift
+		;;
+	--mountdir)
+		MOUNTDIR=$2;
+		shift; shift
+		;;
+	--cryptpath)
+		CRYPTPATH=$2;
+		shift; shift
+		;;
+	-h|--help)
+		usage
+		shift
+		exit 0
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		errorexit "Unknown option \"$1\."
+		exit 1
+		;;
+    esac
+done
+
+#
+# Input arg checking
+#
+
+# There are three top level commands: --fsextend, --fsreduce, --cryptresize.
+if [[ "$DO_FSEXTEND" -eq 0 && "$DO_FSREDUCE" -eq 0 && "$DO_CRYPTRESIZE" -eq 0 ]]; then
+	errorexit "Missing --fsextend|--fsreduce|--cryptresize."
+fi
+
+if [[ "$DO_FSEXTEND" -eq 1 || "$DO_FSREDUCE" -eq 1 ]]; then
+	case "$FSTYPE" in
+	  ext[234]) ;;
+	  "xfs")    ;;
+	  *) errorexit "Cannot resize --fstype \"$FSTYPE\"."
+	esac
+
+	if [ -z "$LVPATH" ]; then
+		errorexit "Missing required --lvpath."
+	fi
+fi
+
+if [[ "$DO_CRYPTRESIZE" -eq 1 && -z "$CRYPTPATH" ]]; then
+	errorexit "Missing required --cryptpath for --cryptresize."
+fi
+
+if [ "$DO_CRYPTRESIZE" -eq 1 ]; then
+	DEVPATH=$CRYPTPATH
+else
+	DEVPATH=$LVPATH
+fi
+
+if [ -z "$DEVPATH" ]; then
+	errorexit "Missing path to device."
+fi
+
+if [ ! -e "$DEVPATH" ]; then
+	errorexit "Device does not exist \"$DEVPATH\"."
+fi
+
+if [[ "$DO_UNMOUNT" -eq 1 && -z "$MOUNTDIR" ]]; then
+	errorexit "Missing required --mountdir for --unmount."
+fi
+
+if [[ "$DO_FSREDUCE" -eq 1 && "$FSTYPE" == "xfs" ]]; then
+	errorexit "Cannot reduce xfs."
+fi
+
+if [[ "$DO_FSCK" -eq 1 && "$FSTYPE" == "xfs" ]]; then
+	errorexit "Cannot use --fsck with xfs."
+fi
+
+if [ "$DO_MOUNT" -eq 1 ]; then
+	TMPDIR=$(mktemp --suffix _lvresize_$$ -d -p /tmp)
+	if [ ! -e "$TMPDIR" ]; then
+		errorexit "Failed to create temp dir."
+	fi
+	# In case the script terminates without doing cleanup
+	function finish {
+		if [ "$TMP_MOUNT_DONE" -eq 1 ]; then
+			logmsg "exit unmount ${TMPDIR}"
+			umount "$TMPDIR"
+			rmdir "$TMPDIR"
+		fi
+	}
+	trap finish EXIT
+fi
+
+#
+# Main program function:
+# - the two main functions are fsextend and fsreduce.
+# - one special case function is cryptresize.
+#
+
+if [ "$DO_FSEXTEND" -eq 1 ]; then
+	fsextend
+elif [ "$DO_FSREDUCE" -eq 1 ]; then
+	fsreduce
+elif [ "$DO_CRYPTRESIZE" -eq 1 ]; then
+	cryptresize
+fi
+