diff -uNr os-prober-1.56-orig-1/common.sh os-prober-1.56/common.sh
--- os-prober-1.56-orig-1/common.sh	2013-01-10 08:33:45.200766262 -0500
+++ os-prober-1.56/common.sh	2013-01-10 08:34:43.644058934 -0500
@@ -127,6 +127,7 @@
 	done
 }
 
+# add forth parameter to pickup btrfs subvol info
 parsefstab () {
 	while read -r line; do
 		case "$line" in
@@ -137,12 +138,22 @@
 				set -f
 				set -- $line
 				set +f
-				printf '%s %s %s\n' "$1" "$2" "$3"
+				printf '%s %s %s %s\n' "$1" "$2" "$3" "$4"
 			;;
 		esac
 	done
 }
 
+#check_btrfs_mounted $bootsv $bootuuid)
+check_btrfs_mounted () {
+	bootsv="$1"
+	bootuuid="$2"
+	bootdev=$(blkid | grep "$bootuuid" | cut -d ':' -f  1)
+	bindfrom=$(grep " btrfs " /proc/self/mountinfo | 
+		   grep " $bootdev " | grep " /$bootsv " | cut -d ' ' -f 5)
+	printf "%s" "$bindfrom"
+}
+
 unescape_mount () {
 	printf %s "$1" | \
 		sed 's/\\011/	/g; s/\\012/\n/g; s/\\040/ /g; s/\\134/\\/g'
diff -uNr os-prober-1.56-orig-1/common.sh.orig os-prober-1.56/common.sh.orig
--- os-prober-1.56-orig-1/common.sh.orig	1969-12-31 19:00:00.000000000 -0500
+++ os-prober-1.56/common.sh.orig	2013-01-10 08:34:43.642058924 -0500
@@ -0,0 +1,293 @@
+newns () {
+  [ "$OS_PROBER_NEWNS" ] || exec /usr/lib/newns "$0" "$@"
+}
+
+cleanup_tmpdir=false
+cleanup_ro_partitions=
+cleanup () {
+  local partition
+  for partition in $cleanup_ro_partitions; do
+    blockdev --setrw "$partition"
+  done
+  if $cleanup_tmpdir; then
+    rm -rf "$OS_PROBER_TMP"
+  fi
+}
+
+require_tmpdir() {
+  if [ -z "$OS_PROBER_TMP" ]; then
+    if type mktemp >/dev/null 2>&1; then
+      export OS_PROBER_TMP="$(mktemp -d /tmp/os-prober.XXXXXX)"
+      cleanup_tmpdir=:
+      trap cleanup EXIT HUP INT QUIT TERM
+    else
+      export OS_PROBER_TMP=/tmp
+    fi
+  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
+}
+
+count_next_label() {
+  require_tmpdir
+
+  _labelprefix="$1"
+  _cfor="$(count_for "${_labelprefix}")"
+
+  if [ -z "$_cfor" ]; then
+    echo "${_labelprefix} 1" >> /var/lib/os-prober/labels
+  else
+    sed "s/^${_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
+  fi
+  
+  echo "${_labelprefix}${_cfor}"
+}
+
+progname=
+cache_progname() {
+  case $progname in
+    '')
+      progname="$(basename "$0")"
+      ;;
+  esac
+}
+
+log() {
+  cache_progname
+  logger -t "$progname" "$@"
+}
+
+error() {
+  log "error: $@"
+}
+
+warn() {
+  log "warning: $@"
+}
+
+debug() {
+  if [ -n "$OS_PROBER_ENABLE_DEBUG" ]; then
+    log "debug: $@" 
+  fi
+}
+
+result () {
+  log "result:" "$@"
+  echo "$@"
+}
+
+# shim to make it easier to use os-prober outside d-i
+if ! type mapdevfs >/dev/null 2>&1; then
+  mapdevfs () {
+    readlink -f "$1"
+  }
+fi
+
+item_in_dir () {
+	if [ "$1" = "-q" ]; then
+		q="-q"
+		shift 1
+	else
+		q=""
+	fi
+	[ -d "$2" ] || return 1
+	# find files with any case
+	ls -1 "$2" | grep $q -i "^$1$"
+}
+
+# We can't always tell the filesystem type up front, but if we have the
+# information then we should use it. Note that we can't use block-attr here
+# as it's only available in udebs.
+fs_type () {
+	if (export PATH="/lib/udev:$PATH"; type vol_id) >/dev/null 2>&1; then
+		PATH="/lib/udev:$PATH" vol_id --type "$1" 2>/dev/null
+	elif type blkid >/dev/null 2>&1; then
+		blkid -o value -s TYPE "$1" 2>/dev/null
+	else
+		return 0
+	fi
+}
+
+parse_proc_mounts () {
+	while read -r line; do
+		set -f
+		set -- $line
+		set +f
+		printf '%s %s %s\n' "$(mapdevfs "$1")" "$2" "$3"
+	done
+}
+
+parsefstab () {
+	while read -r line; do
+		case "$line" in
+			"#"*)
+				:	
+			;;
+			*)
+				set -f
+				set -- $line
+				set +f
+				printf '%s %s %s\n' "$1" "$2" "$3"
+			;;
+		esac
+	done
+}
+
+unescape_mount () {
+	printf %s "$1" | \
+		sed 's/\\011/	/g; s/\\012/\n/g; s/\\040/ /g; s/\\134/\\/g'
+}
+
+ro_partition () {
+	if type blockdev >/dev/null 2>&1 && \
+	   [ "$(blockdev --getro "$1")" = 0 ] && \
+	   blockdev --setro "$1"; then
+		cleanup_ro_partitions="${cleanup_ro_partitions:+$cleanup_ro_partitions }$1"
+		trap cleanup EXIT HUP INT QUIT TERM
+	fi
+}
+
+find_label () {
+	local output
+	if type blkid >/dev/null 2>&1; then
+		# Hopefully everyone has blkid by now
+		output="$(blkid -o device -t LABEL="$1")" || return 1
+		echo "$output" | head -n1
+	elif [ -h "/dev/disk/by-label/$1" ]; then
+		# Last-ditch fallback
+		readlink -f "/dev/disk/by-label/$1"
+	else
+		return 1
+	fi
+}
+
+find_uuid () {
+	local output
+	if type blkid >/dev/null 2>&1; then
+		# Hopefully everyone has blkid by now
+		output="$(blkid -o device -t UUID="$1")" || return 1
+		echo "$output" | head -n1
+	elif [ -h "/dev/disk/by-uuid/$1" ]; then
+		# Last-ditch fallback
+		readlink -f "/dev/disk/by-uuid/$1"
+	else
+		return 1
+	fi
+}
+
+# Sets $mountboot as output variable.  (We do this rather than requiring a
+# subshell so that we can run ro_partition without the cleanup trap firing
+# when the subshell exits.)
+linux_mount_boot () {
+	partition="$1"
+	tmpmnt="$2"
+
+	bootpart=""
+	mounted=""
+	lvboot=""
+	if [ -e "$tmpmnt/etc/fstab" ]; then
+		# Try to mount any /boot partition.
+		bootmnt=$(parsefstab < "$tmpmnt/etc/fstab" | grep " /boot ") || true
+		if [ -n "$bootmnt" ]; then
+			set -f
+			set -- $bootmnt
+			set +f
+			boottomnt=""
+
+			# Try to map labels and UUIDs ourselves if possible,
+			# so that we can check whether they're already
+			# mounted somewhere else.
+			tmppart="$1"
+			if echo "$1" | grep -q "^/dev/mapper/"; then
+				lvboot="$tmppart"
+			elif echo "$1" | grep -q "LABEL="; then
+				label="$(echo "$1" | cut -d = -f 2)"
+				if tmppart="$(find_label "$label")"; then
+					debug "mapped LABEL=$label to $tmppart"
+				else
+					debug "found boot partition LABEL=$label for Linux system on $partition, but cannot map to existing device"
+					mountboot="$partition 0"
+					return
+				fi
+			elif echo "$1" | grep -q "UUID="; then
+				uuid="$(echo "$1" | cut -d = -f 2)"
+				if tmppart="$(find_uuid "$uuid")"; then
+					debug "mapped UUID=$uuid to $tmppart"
+				else
+					debug "found boot partition UUID=$uuid for Linux system on $partition, but cannot map to existing device"
+					mountboot="$partition 0"
+					return
+				fi
+			fi
+			shift
+			set -- "$(mapdevfs "$tmppart")" "$@"
+
+			if grep -q "^$1 " "$OS_PROBER_TMP/mounted-map"; then
+				bindfrom="$(grep "^$1 " "$OS_PROBER_TMP/mounted-map" | head -n1 | cut -d " " -f 2)"
+				bindfrom="$(unescape_mount "$bindfrom")"
+				if [ "$bindfrom" != "$tmpmnt/boot" ]; then
+					if mount --bind "$bindfrom" "$tmpmnt/boot"; then
+						mounted=1
+						bootpart="$1"
+					else
+						debug "failed to bind-mount $bindfrom onto $tmpmnt/boot"
+					fi
+				fi
+			fi
+			if [ "$mounted" ]; then
+				:
+			elif [ -e "$1" ]; then
+				bootpart="$1"
+				boottomnt="$1"
+			elif [ -e "$tmpmnt/$1" ]; then
+				bootpart="$1"
+				boottomnt="$tmpmnt/$1"
+			elif [ -e "/target/$1" ]; then
+				bootpart="$1"
+				boottomnt="/target/$1"
+			else
+				bootpart=""
+			fi
+
+			if [ ! "$mounted" ]; then
+				if [ -z "$bootpart" ]; then
+					debug "found boot partition $1 for linux system on $partition, but cannot map to existing device"
+				else
+					debug "found boot partition $bootpart for linux system on $partition"
+					if type grub-mount >/dev/null 2>&1 && \
+					   grub-mount "$boottomnt" "$tmpmnt/boot" 2>/dev/null; then
+						mounted=1
+					else
+						ro_partition "$boottomnt"
+						if mount -o ro "$boottomnt" "$tmpmnt/boot" -t "$3"; then
+							mounted=1
+						else
+							error "failed to mount $boottomnt on $tmpmnt/boot"
+						fi
+					fi
+				fi
+			fi
+		fi
+	fi
+	if [ -n "$lvboot" ]; then
+		bootpart="$lvboot"
+	fi
+	if [ -z "$bootpart" ]; then
+		bootpart="$partition"
+	fi
+	if [ -z "$mounted" ]; then
+		mounted=0
+	fi
+
+	mountboot="$bootpart $mounted"
+}
diff -uNr os-prober-1.56-orig-1/linux-boot-prober os-prober-1.56/linux-boot-prober
--- os-prober-1.56-orig-1/linux-boot-prober	2012-03-27 10:39:42.000000000 -0400
+++ os-prober-1.56/linux-boot-prober	2013-01-10 08:34:43.644058934 -0500
@@ -5,16 +5,143 @@
 
 newns "$@"
 require_tmpdir
+ERR="n"
+
+tmpmnt=/var/lib/os-prober/mount
+if [ ! -d "$tmpmnt" ]; then
+	mkdir "$tmpmnt"
+fi
+
+mounted=
+bootmnt=
+bootsv=
+bootuuid=
 
 grep "^/dev/" /proc/mounts | parse_proc_mounts >"$OS_PROBER_TMP/mounted-map" || true
 
-partition="$1"
+if [ -z "$1" ]; then
+	ERR=y
+elif [ "$1" = btrfs -a -z "$2" ]; then
+	ERR=y
+elif [ "$1" = btrfs -a -z "$3" ]; then
+	ERR=y
+elif [ "$1" = btrfs ]; then
+	type=btrfs
+	echo "$2" | grep -q "^UUID=" || ERR=y
+	echo "$3" | grep -q "^subvol=" || ERR=y	
+	export "$2"
+	export "$3"
+	partition=$(blkid | grep "$UUID" | cut -d ':' -f 1 | tr '\n' ' ' | cut -d ' ' -f 1)
+	debug "btrfs: partition=$partition, UUID=$UUID, subvol=$subvol"
+else
+	partition="$1"
+	type=other
+fi
 
-if [ -z "$partition" ]; then
+if [ "x$ERR" != xn ]; then
 	echo "usage: linux-boot-prober partition" >&2
+	echo "       linux-boot-prober btrfs UUID=<> subvol=<>" >&2
 	exit 1
 fi
 
+if [ "$type" = btrfs ]; then
+	# handle all of the btrfs stuff here
+	if [ ! -e "/proc/self/mountinfo" ]; then
+		warn "/proc/self/mountinfo does not exist, exiting"
+		umount "$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 "$tmpmnt" 2>/dev/null
+		exit 1
+	fi
+	if [ -z "$mpoint" ]; then
+		# mount the btrfs root
+		if ! mount -o subvol=$subvol -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 "$tmpmnt" 2>/dev/null
+			exit 1
+		fi
+	else
+		# bind-mount
+		if ! mount -o bind "$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
+	fi
+	debug "mounted btrfs $partition, subvol=$subvol on $tmpmnt"
+	if [ ! -e "$tmpmnt/etc/fstab" ]; then
+		warn "btrfs subvol=$subvol not root"
+		umount "$tmpmnt" 2>/dev/null
+		rmdir "$tmpmnt" 2>/dev/null
+		exit 1
+	fi
+	bootmnt=$(parsefstab < "$tmpmnt/etc/fstab" | grep " /boot ") || true
+	if [ -z "$bootmnt" ]; then
+		# /boot is part of the root
+		bootpart="$partition"
+		bootsv="$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=//" )
+		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)
+	else
+		# non-btrfs partition or logical volume
+		linux_mount_boot $partition $tmpmnt
+		bootpart="${mountboot%% *}"
+		bootsv=
+	fi
+	
+	test="/usr/lib/linux-boot-probes/mounted/40grub2"
+	if [ -f $test ] && [ -x $test ]; then
+		debug "running $test $partition $bootpart $tmpmnt $type $subvol $bootsv"
+		if $test "$partition" "$bootpart" "$tmpmnt" "$type" "$subvol" "$bootsv"; then
+			debug "$test succeeded"
+		fi
+	fi
+	umount "$tmpmnt/boot" 2>/dev/null || true
+	if ! umount "$tmpmnt" 2>/dev/null; then
+		warn "problem umount $tmpmnt"
+	fi
+	rmdir "$tmpmnt" 2>/dev/null || true
+
+	exit 0
+fi
+
 if ! mapped="$(mapdevfs "$partition")"; then
 	log "Device '$partition' does not exist; skipping"
 	continue
@@ -22,8 +149,8 @@
 
 if ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map"; then
 	for test in /usr/lib/linux-boot-probes/*; do
-		debug "running $test"
 		if [ -x $test ] && [ -f $test ]; then
+			debug "running $test"
 			if $test "$partition"; then
 				debug "linux detected by $test"
 				break
diff -uNr os-prober-1.56-orig-1/linux-boot-probes/mounted/common/40grub2 os-prober-1.56/linux-boot-probes/mounted/common/40grub2
--- os-prober-1.56-orig-1/linux-boot-probes/mounted/common/40grub2	2012-09-17 13:32:52.000000000 -0400
+++ os-prober-1.56/linux-boot-probes/mounted/common/40grub2	2013-01-10 08:34:43.644058934 -0500
@@ -2,17 +2,27 @@
 . /usr/share/os-prober/common.sh
 set -e
 
+# add support for btrfs with no separate /boot
+# that is, rootsv = bootsv
 partition="$1"
 bootpart="$2"
 mpoint="$3"
 type="$4"
+rootsv="$5"
+bootsv="$6"
 
 found_item=0
 
 entry_result () {
+	if [ "x$type" = "xbtrfs" -a "$rootsv" = "$bootsv" ]; then
+		# trim off the leading subvol
+		kernelfile=$(echo "$kernel" | cut -d '/' -f 2- | cut -d '/' -f 2-)
+	else
+		kernelfile=$kernel
+	fi
 	if [ "$ignore_item" = 0 ] && \
 	   [ -n "$kernel" ] && \
-	   [ -e "$mpoint/$kernel" ]; then
+	   [ -e "$mpoint/$kernelfile" ]; then
 		result "$rootpart:$bootpart:$title:$kernel:$initrd:$parameters"
 		found_item=1
 	fi
diff -uNr os-prober-1.56-orig-1/os-prober os-prober-1.56/os-prober
--- os-prober-1.56-orig-1/os-prober	2013-01-10 08:33:45.193766227 -0500
+++ os-prober-1.56/os-prober	2013-01-10 08:34:43.645058939 -0500
@@ -64,9 +64,12 @@
 
 	# Also detect OSes on LVM volumes (assumes LVM is active)
 	if type lvs >/dev/null 2>&1; then
-		echo "$(LVM_SUPPRESS_FD_WARNINGS=1 log_output lvs --noheadings --separator : -o vg_name,lv_name |
+		echo "$(LVM_SUPPRESS_FD_WARNINGS=1 log_output lvs --noheadings --separator : -o vg_name,lv_name 2>/dev/null |
 			sed "s|-|--|g;s|^[[:space:]]*\(.*\):\(.*\)$|/dev/mapper/\1-\2|")"
 	fi
+
+	# now lets make sure we got all of the btrfs partitions and disks
+	blkid | grep btrfs | cut -d ':' -f 1
 }
 
 parse_proc_swaps () {
@@ -124,6 +127,8 @@
 	grep "^md" /proc/mdstat | cut -d: -f2- | parse_proc_mdstat >"$OS_PROBER_TMP/raided-map" || true
 fi
 
+: >"$OS_PROBER_TMP/btrfs-vols"
+
 for partition in $(partitions); do
 	if ! mapped="$(mapdevfs "$partition")"; then
 		log "Device '$partition' does not exist; skipping"
@@ -142,7 +147,26 @@
 		continue
 	fi
 
-	if ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map" ; then
+	# do btrfs processing here; both mounted and unmounted will
+	# be handled by 50mounted-tests so we can do a subvol only once.
+	type=$(blkid -o value -s TYPE $mapped)
+	if [ "$type" = btrfs ]; then
+		uuid=$(blkid -o value -s UUID $mapped)
+		if grep -q "^$uuid" "$OS_PROBER_TMP/btrfs-vols" ; then
+			continue
+		fi
+		debug "btrfs volume uuid=$uuid partition=$partition"
+		echo "$uuid" >>"$OS_PROBER_TMP/btrfs-vols"
+		test="/usr/lib/os-probes/50mounted-tests"
+		if [ -f "$test" ] && [ -x "$test" ]; then
+			debug "running $test on btrfs $partition"
+			if "$test" btrfs "$uuid" "$partition"; then
+				debug "os detected by $test"
+		   		continue
+			fi
+		fi
+
+	elif ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map" ; then
 		for test in /usr/lib/os-probes/*; do
 			if [ -f "$test" ] && [ -x "$test" ]; then
 				debug "running $test on $partition"
diff -uNr os-prober-1.56-orig-1/os-probes/common/50mounted-tests os-prober-1.56/os-probes/common/50mounted-tests
--- os-prober-1.56-orig-1/os-probes/common/50mounted-tests	2012-09-17 11:08:12.000000000 -0400
+++ os-prober-1.56/os-probes/common/50mounted-tests	2013-01-10 08:34:43.645058939 -0500
@@ -1,20 +1,36 @@
 #!/bin/sh
 # Sub-tests that require a mounted partition.
 set -e
-partition="$1"
 
 . /usr/share/os-prober/common.sh
 
-types="$(fs_type "$partition")" || types=NOT-DETECTED
+if [ "x$1" = xbtrfs ]; then
+	types=btrfs
+	if [ -z "$2" -o -z "$3" ]; then
+		debug "missing btrfs parameters, exiting"
+		exit 1
+	fi
+	UUID="$2"
+	BTRFSDEV="$3"
+else
+	partition="$1"
+	types="$(fs_type "$partition")" || types=NOT-DETECTED
+fi
+
 if [ "$types" = NOT-DETECTED ]; then
 	debug "$1 type not recognised; skipping"
-	exit 0
+	exit 1
+elif [ "x$types" = "x" ]; then
+	exit 1
+elif [ "$types" = LVM2_member ]; then
+	debug "skipping LVM2 Volume Group on $partition"
+	exit 1
 elif [ "$types" = swap ]; then
 	debug "$1 is a swap partition; skipping"
-	exit 0
+	exit 1
 elif [ "$types" = crypto_LUKS ]; then
 	debug "$1 is a LUKS partition; skipping"
-	exit 0
+	exit 1
 elif [ "$types" = ntfs ]; then
 	if type ntfs-3g >/dev/null 2>&1; then
 		types='ntfs-3g ntfs'
@@ -23,7 +39,7 @@
 	if type cryptsetup >/dev/null 2>&1 && \
 	   cryptsetup luksDump "$partition" >/dev/null 2>&1; then
 		debug "$1 is a LUKS partition; skipping"
-		exit 0
+		exit 1
 	fi
 	for type in $(grep -v nodev /proc/filesystems); do
 		# hfsplus filesystems are mountable as hfs. Try hfs last so
@@ -46,6 +62,76 @@
 fi
 
 mounted=
+
+# all btrfs processing here.  Handle both unmounted and
+# mounted subvolumes.
+if [ "$types" = btrfs ]; then
+	partition="$BTRFSDEV"
+	debug "begin btrfs processing for $UUID"
+	# note that the btrfs volume must not be mounted ro
+	if mount -t btrfs -U "$UUID" "$tmpmnt"  2>/dev/null; then
+		debug "btrfs volume $UUID mounted"
+	else
+		warn "cannot mount btrfs volume $UUID, exiting"
+		rmdir "$tmpmnt" || true
+		exit 1
+	fi
+	# besides regular subvols, get ro and snapshot so thet can be excluded
+        subvols=$(btrfs subvolume list "$tmpmnt" | cut -d ' ' -f 9)
+        rosubvols=$(btrfs subvolume list -r "$tmpmnt" | cut -d ' ' -f 9)
+        sssubvols=$(btrfs subvolume list -s "$tmpmnt" | cut -d ' ' -f 9)
+        if ! umount "$tmpmnt"; then
+            warn "failed to umount btrfs volume on $tmpmnt"
+            rmdir "$tmpmnt" || true
+            exit 1
+        fi
+	if [ -z "$subvols" ]; then
+		debug "no subvols found on btrfs volume $UUID"
+		exit 1
+	fi
+	found=
+        for subvol in $subvols; do
+		debug "begin btrfs processing for $UUID subvol=$subvol"
+		if echo "$rosubvols" | grep -q -x "$subvol"; then
+			continue
+		fi
+		if echo "$sssubvols" | grep -q -x "$subvol"; then
+			continue
+		fi
+		mounted=
+		mpoint="$(grep btrfs /proc/self/mountinfo | grep "$partition " | grep "/$subvol " | cut -d ' ' -f 5)"
+		if [ -n "$mpoint" ]; then
+			if [ "x$mpoint" = "x/" ]; then
+				continue # this is the root for the running system
+			fi
+			mounted=1
+		else
+			# again, do not mount btrfs ro
+			mount -t btrfs -o subvol="$subvol" -U "$UUID" "$tmpmnt"
+			mpoint="$tmpmnt"
+		fi
+		test="/usr/lib/os-probes/mounted/90linux-distro"
+		if [ -f "$test" ] && [ -x "$test" ]; then
+			debug "running subtest $test"
+			if "$test" "$partition" "$mpoint" btrfs "UUID=$UUID" "subvol=$subvol"; then
+				debug "os found by subtest $test on subvol $subvol"
+				found=1
+			fi
+		fi
+		if [ -z "$mounted" ]; then
+			if ! umount "$tmpmnt"; then
+			    warn "failed to umount $tmpmnt"
+			fi
+		fi
+	done
+	rmdir "$tmpmnt" || true
+	if [ "$found" ]; then
+		exit 0
+	else
+		exit 1
+	fi
+fi
+
 if type grub-mount >/dev/null 2>&1 && \
    type grub-probe >/dev/null 2>&1 && \
    grub-mount "$partition" "$tmpmnt" 2>/dev/null; then
diff -uNr os-prober-1.56-orig-1/os-probes/mounted/common/90linux-distro os-prober-1.56/os-probes/mounted/common/90linux-distro
--- os-prober-1.56-orig-1/os-probes/mounted/common/90linux-distro	2013-01-10 08:33:45.197766247 -0500
+++ os-prober-1.56/os-probes/mounted/common/90linux-distro	2013-01-10 08:34:43.645058939 -0500
@@ -7,6 +7,8 @@
 partition="$1"
 dir="$2"
 type="$3"
+uuid="$4"
+subvol="$5"
 
 # This test is inaccurate, but given separate / and /boot partitions and the
 # fact that only some architectures have ld-linux.so, I can't see anything
@@ -128,7 +130,11 @@
 	fi
 	
         label="$(count_next_label "$short")"
-	result "$partition:$long:$label:linux"
+	if [ "x$type" = "xbtrfs" -a "x$uuid" != "x" -a "x$subvol" != "x" ]; then
+		result "$partition:$long:$label:linux:$type:$uuid:$subvol"
+	else
+		result "$partition:$long:$label:linux"
+	fi
 	exit 0
 else
 	exit 1
diff -uNr os-prober-1.56-orig-1/README.btrfs os-prober-1.56/README.btrfs
--- os-prober-1.56-orig-1/README.btrfs	1969-12-31 19:00:00.000000000 -0500
+++ os-prober-1.56/README.btrfs	2013-01-10 08:34:43.645058939 -0500
@@ -0,0 +1,15 @@
+BTRFS is a new filesystem which combines the filesystem with logical volume
+management (subvolumes).  For further information, see:
+      https://btrfs.wiki.kernel.org/index.php/Main_Page
+      https://btrfs.wiki.kernel.org/index.php/FAQ
+
+In order to support BTRFS, a number of changes were necessary to os-prober,
+os-probes/common/50mounted-tests, os-probes/mounted/common/90linux-distro,
+linux-boot-prober, and linux-boot-probes/common/50mounted-tests.
+
+The biggest impact will be to grub2 where there is additional information
+output by os-prober and where, if a BTRFS subvolume is being used for root,
+the parameters for linux-boot-prober have changed.
+
+Sun 30 Dec 2012 11:49:52 AM EST Gene Czarcinski <address@hidden>
+