From 67a7538475e9e292103a80fed8cff8ab380314a2 Mon Sep 17 00:00:00 2001
From: Lidong Zhong <lzhong@suse.com>
Date: Fri, 6 Mar 2015 18:35:04 +0800
Subject: [Patch v2] fsadm: add support for btrfs

Check: mount the device first and then run`btrfs filesystem scrub start
-B` command
Reisze: find the mount point first and resize the filesystem after get
the device id since there are maybe several devices underneath btrfs
filesystem

---
Hi David,

This is the patch I sent to upstream. It works fine based on our test.
Please shed your light and thank you for taking time to review.

Regards,
Lidong

 scripts/fsadm.sh | 104 ++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 88 insertions(+), 16 deletions(-)

Index: LVM2.2.02.152/scripts/fsadm.sh
===================================================================
--- LVM2.2.02.152.orig/scripts/fsadm.sh
+++ LVM2.2.02.152/scripts/fsadm.sh
@@ -22,6 +22,7 @@
 # ext2/ext3/ext4: resize2fs, tune2fs
 # reiserfs: resize_reiserfs, reiserfstune
 # xfs: xfs_growfs, xfs_info
+# btrfs: btrfs
 #
 # Return values:
 #   0 success
@@ -56,6 +57,7 @@ FSCK=fsck
 XFS_CHECK=xfs_check
 # XFS_REPAIR -n is used when XFS_CHECK is not found
 XFS_REPAIR=xfs_repair
+BTRFS=btrfs
 
 # user may override lvm location by setting LVM_BINARY
 LVM=${LVM_BINARY:-lvm}
@@ -75,6 +77,9 @@ BLOCKCOUNT=
 MOUNTPOINT=
 MOUNTED=
 REMOUNT=
+FINDMNT=
+UUID=
+BTRFS_DEVID=
 PROCMOUNTS="/proc/mounts"
 PROCSELFMOUNTINFO="/proc/self/mountinfo"
 NULL="$DM_DEV_DIR/null"
@@ -148,7 +153,7 @@ cleanup() {
 		export _FSADM_YES _FSADM_EXTOFF
 		unset FSADM_RUNNING
 		test -n "$LVM_BINARY" && PATH=$_SAVEPATH
-		dry exec "$LVM" lvresize $VERB $FORCE -r -L${NEWSIZE}b "$VOLUME_ORIG"
+		dry exec "$LVM" lvresize $VERB $FORCE -r -L${NEWSIZE}b "$VOLUME"
 	fi
 
 	# error exit status for break
@@ -207,6 +212,34 @@ detect_fs() {
 	verbose "\"$FSTYPE\" filesystem found on \"$VOLUME\""
 }
 
+check_findmnt() {
+	FINDMNT=$(which findmnt 2>$NULL)
+	test -n "$FINDMNT"
+}
+
+detect_fs_uuid() {
+	UUID=$($BLKID -o value -c $NULL -s UUID "$VOLUME" 2>$NULL)
+	test -n "$UUID"
+}
+
+#find the mountpoint of this device
+detect_mounted_findmnt() {
+	local TMP
+	local STR_IFS=$IFS
+	IFS=" $(echo -n -e '\t')"
+
+	read -r TMP<<EOF
+$($FINDMNT -nuP -o TARGET,UUID 2>$NULL | $GREP "$UUID")
+EOF
+
+	TMP=${TMP##*TARGET=\"}
+	TMP=${TMP%%\"*}
+	MOUNTED=$TMP
+	test -n "$MOUNTED"
+
+	IFS=$STR_IFS
+}
+
 detect_mounted_with_proc_self_mountinfo()  {
 	MOUNTED=$("$GREP" "^[0-9]* [0-9]* $MAJORMINOR " "$PROCSELFMOUNTINFO")
 
@@ -243,7 +276,11 @@ detect_mounted_with_proc_mounts()  {
 # check if the given device is already mounted and where
 # FIXME: resolve swap usage and device stacking
 detect_mounted()  {
-	if test -e "$PROCSELFMOUNTINFO"; then
+	if test "$FSTYPE" = "btrfs" ; then
+		check_findmnt || error "Need 'findmnt' utility to work with btrfs filesystem"
+		detect_fs_uuid || verbose "Can't get fs UUID from \"$VOLUME\" volume"
+		detect_mounted_findmnt
+	elif test -e "$PROCSELFMOUNTINFO"; then
 		detect_mounted_with_proc_self_mountinfo
 	elif test -e "$PROCMOUNTS"; then
 		detect_mounted_with_proc_mounts
@@ -396,6 +433,31 @@ resize_xfs() {
 	fi
 }
 
+########################
+# Resize btrfs filesystem
+# - mounted for upsize/downsize
+# - cannot resize when unmounted
+########################
+resize_btrfs() {
+	detect_mounted
+	MOUNTPOINT=$MOUNTED
+	if [ -z "$MOUNTED" ]; then
+		MOUNTPOINT=$TEMPDIR
+		temp_mount || error "Cannot mount Btrfs filesystem"
+	fi
+
+	verbose "Parsing $BTRFS filesystem show \"$MOUNTPOINT\""
+	for i in $(LC_ALL=C "$BTRFS" filesystem show "$MOUNTPOINT"); do
+		case "$i" in
+		  *"$VOLUME"*) BTRFS_DEVID=${i##*devid};;
+		esac
+	done
+	BTRFS_DEVID=${BTRFS_DEVID%%size*}
+	BTRFS_DEVID=$(echo $BTRFS_DEVID|sed 's/^[ \t]*//g'|sed 's/[ \t]*$'//g)
+	decode_size $1 1
+	verbose "Resizing filesystem on device \"$VOLUME\" to $NEWSIZE bytes(btrfs devid: $BTRFS_DEVID) "
+	dry "$BTRFS" filesystem resize "$BTRFS_DEVID":"$NEWSIZE" "$MOUNTPOINT"
+}
 ####################
 # Resize filesystem
 ####################
@@ -412,6 +474,7 @@ resize() {
 	  "ext3"|"ext2"|"ext4") resize_ext $NEWSIZE ;;
 	  "reiserfs") resize_reiser $NEWSIZE ;;
 	  "xfs") resize_xfs $NEWSIZE ;;
+	  "btrfs") resize_btrfs $NEWSIZE ;;
 	  *) error "Filesystem \"$FSTYPE\" on device \"$VOLUME\" is not supported by this tool" ;;
 	esac || error "Resize $FSTYPE failed"
 	cleanup 0
@@ -469,6 +532,12 @@ check() {
 			# Think about better way....
 			dry "$XFS_REPAIR" -n -o force_geometry "$VOLUME"
 		 fi ;;
+         "btrfs") #mount the device first and then run scrub
+		 MOUNTPOINT=$TEMPDIR
+		 temp_mount || error "Cannot mount btrfs filesystem"
+		 dry "$BTRFS" scrub start -B "$VOLUME"
+		 test "$MOUNTPOINT" = "$TEMPDIR" && MOUNTPOINT="" temp_umount
+		 ;;
 	  *)    # check if executed from interactive shell environment
 		case "$-" in
 		  *i*) dry "$FSCK" $YES $FORCE "$VOLUME" ;;
@@ -490,7 +559,7 @@ test -n "$FSADM_RUNNING" && exit 0
 for i in "$TUNE_EXT" "$RESIZE_EXT" "$TUNE_REISER" "$RESIZE_REISER" \
 	"$TUNE_XFS" "$RESIZE_XFS" "$MOUNT" "$UMOUNT" "$MKDIR" \
 	"$RMDIR" "$BLOCKDEV" "$BLKID" "$GREP" "$READLINK" \
-	"$DATE" "$FSCK" "$XFS_CHECK" "$XFS_REPAIR" "$LVM" ; do
+	"$DATE" "$FSCK" "$XFS_CHECK" "$XFS_REPAIR" "$LVM" "$BTRFS" ; do
 	test -n "$i" || error "Required command definitions in the script are missing!"
 done