diff --git a/sys-boot/os-prober/files/os-prober-1.78-btrfsfix.patch b/sys-boot/os-prober/files/os-prober-1.78-btrfsfix.patch
new file mode 100644
index 0000000000000..5a74285dc73f0
--- /dev/null
+++ b/sys-boot/os-prober/files/os-prober-1.78-btrfsfix.patch
@@ -0,0 +1,474 @@
+Bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=688336
+
+diff --git a/common.sh b/common.sh
+index c2c5f46..8fb3c5f 100644
+--- a/common.sh
++++ b/common.sh
+@@ -155,6 +155,7 @@ parse_proc_mounts () {
+ 	done
+ }
+ 
++# add forth parameter to pickup btrfs subvol info
+ parsefstab () {
+ 	while read -r line; do
+ 		case "$line" in
+@@ -165,12 +166,22 @@ parsefstab () {
+ 				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 "$1" | \
+ 		sed 's/\\011/	/g; s/\\012/\n/g; s/\\040/ /g; s/\\134/\\/g'
+diff --git a/linux-boot-prober b/linux-boot-prober
+index e32dc84..2a60fa2 100755
+--- a/linux-boot-prober
++++ b/linux-boot-prober
+@@ -5,16 +5,143 @@ set -e
+ 
+ newns "$@"
+ 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 '$partition' does not exist; skipping"
+ 	continue
+@@ -22,8 +149,8 @@ fi
+ 
+ if ! grep -q "^$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 --git a/linux-boot-probes/mounted/common/40grub2 b/linux-boot-probes/mounted/common/40grub2
+index 885614e..db5cbfd 100755
+--- a/linux-boot-probes/mounted/common/40grub2
++++ b/linux-boot-probes/mounted/common/40grub2
+@@ -2,17 +2,30 @@
+ . /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 "$partition" = "$bootpart" ]; then
++		# trim off the leading subvol
++		kernelfile=$(echo "$kernel" | cut -d '/' -f 2- | cut -d '/' -f 2-)
++		if [ "x$rootsv" != "x$bootsv" ]; then
++		   kernelfile="/boot/$kernelfile"
++		fi
++	else
++		kernelfile=$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 --git a/os-prober b/os-prober
+index 8852887..482c3c2 100755
+--- a/os-prober
++++ b/os-prober
+@@ -76,9 +76,12 @@ partitions () {
+ 
+ 	# 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:]]*\(.*\):\(.*\)$|/dev/mapper/\1-\2|")"
+ 	fi
++
++	# now lets make sure we got all of the btrfs partitions and disks
++	blkid | grep 'TYPE="btrfs"' | cut -d ':' -f 1
+ }
+ 
+ parse_proc_swaps () {
+@@ -136,6 +139,8 @@ if [ -f /proc/mdstat ] ; then
+ 	grep "^md" /proc/mdstat | cut -d: -f2- | parse_proc_mdstat >"$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"
+@@ -154,7 +159,26 @@ for partition in $(partitions); do
+ 		continue
+ 	fi
+ 
+-	if ! grep -q "^$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 $mapped || true)
++	if [ "$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 $partition"
+diff --git a/os-probes/common/50mounted-tests b/os-probes/common/50mounted-tests
+index 2951ef9..e33eb82 100755
+--- a/os-probes/common/50mounted-tests
++++ b/os-probes/common/50mounted-tests
+@@ -19,19 +19,31 @@ do_unmount() {
+ 	rmdir "$tmpmnt" || true
+ }
+ 
+-types="$(fs_type "$partition")"
++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 "$1 type not recognised; skipping"
+-	exit 0
++	exit 1
+ elif [ "$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" = LVM2_member ]; then
+ 	debug "$1 is an LVM member; skipping"
+-	exit 0
++	exit 1
+ elif [ "$types" = ntfs ]; then
+ 	if type ntfs-3g >/dev/null 2>&1; then
+ 		types='ntfs-3g ntfs'
+@@ -40,7 +52,7 @@ elif [ -z "$types" ]; then
+ 	if type cryptsetup >/dev/null 2>&1 && \
+ 	   cryptsetup luksDump "$partition" >/dev/null 2>&1; then
+ 		debug "$1 is a LUKS partition; skipping"
+-		exit 0
++		exit 1
+ 	fi
+ 	for type in $(grep -v nodev /proc/filesystems); do
+ 		# hfsplus filesystems are mountable as hfs. Try hfs last so
+@@ -63,6 +75,108 @@ if [ ! -d "$tmpmnt" ]; then
+ 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 14)
++        if ! umount "$tmpmnt"; then
++            warn "failed to umount btrfs volume on $tmpmnt"
++            rmdir "$tmpmnt" || true
++            exit 1
++        fi
++
++	found=
++	mounted=
++
++	mpoint="$(grep btrfs /proc/self/mountinfo | grep "$partition " | cut -d ' ' -f 5)"
++	if [ -n "$mpoint" -a "x$mpoint" = "x/" ]; then
++		debug "This is the root for the running system" #running system must be done elsewhere
++	else
++	    #partition was not root of running system, so lets look for bootable subvols
++	    if [ -n "$mpoint" ] ; then
++		mounted=1  #partition was already mounted,so lets not unmount it when done
++	    else
++		# again, do not mount btrfs ro
++		mount -t btrfs -U "$UUID" "$tmpmnt"
++		mpoint="$tmpmnt"
++	    fi
++
++	    test="/usr/libexec/os-probes/mounted/90linux-distro"
++	    if [ -f "$test" ] && [ -x "$test" ]; then
++		debug "running subtest $test"
++		if "$test" "$partition" "$mpoint" btrfs "UUID=$UUID"; then
++		    debug "os found by subtest $test on $partition"
++		    found=1
++		fi
++	    fi
++	    if [ -z "$mounted" ]; then
++		if ! umount "$tmpmnt"; then
++		    warn "failed to umount $tmpmnt"
++		fi
++	    fi
++	fi
++
++	if [ -z "$subvols" ]; then
++	        debug "no subvols found on btrfs volume $UUID"
++	else
++		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 $tmpmnt"
++				fi
++			fi
++		done
++	fi
++	rmdir "$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 --git a/os-probes/mounted/common/90linux-distro b/os-probes/mounted/common/90linux-distro
+index badfbb1..9bc5154 100755
+--- a/os-probes/mounted/common/90linux-distro
++++ b/os-probes/mounted/common/90linux-distro
+@@ -7,6 +7,8 @@ set -e
+ partition="$1"
+ dir="$2"
+ type="$3"
++uuid="$4"
++subvol="$5"
+ 
+ # This test is inaccurate, but given separate / and /boot partitions and the
+ # fact that only some architectures have ld-linux.so, I can't see anything
+@@ -143,7 +145,11 @@ if (ls "$dir"/lib*/ld*.so* && [ -d "$dir/boot" ] || ls "$dir"/usr/lib*/ld*.so*)
+ 	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 --git a/sys-boot/os-prober/os-prober-1.78.ebuild b/sys-boot/os-prober/os-prober-1.78.ebuild
index 0ed65355dd73f..5c4721ad5c0ca 100644
--- a/sys-boot/os-prober/os-prober-1.78.ebuild
+++ b/sys-boot/os-prober/os-prober-1.78.ebuild
@@ -20,7 +20,10 @@ DEPEND=""
 # bug 594250
 QA_MULTILIB_PATHS="usr/lib/os-prober/.*"
 
-PATCHES=( "${FILESDIR}"/${PN}-1.76-exherbo.patch )
+PATCHES=(
+	"${FILESDIR}"/${PN}-1.76-exherbo.patch
+	"${FILESDIR}"/${PN}-1.78-btrfsfix.patch
+)
 
 DOC_CONTENTS="
 	If you intend for os-prober to detect versions of Windows installed on