Index: os-prober-1.76/os-prober
===================================================================
--- os-prober-1.76.orig/os-prober
+++ os-prober-1.76/os-prober
@@ -161,6 +161,15 @@ fi
 
 : >"$OS_PROBER_TMP/btrfs-vols"
 
+btrfsrootdev=$(sed -n -e 's!\([^\s]\+\)\s\+\(/\|/target/boot\|/target\)\s\+btrfs!\1!p;ta;b;:a;q' "$OS_PROBER_TMP/mounted-map")
+if [ -n "$btrfsrootdev" ] ; then
+	if btrfsrootdev="$(mapdevfs "$btrfsrootdev")"; then
+		btrfsrootdevuuid=$(blkid -o value -s UUID "$btrfsrootdev")
+		debug "btrfs is mounted as root, uuid: $btrfsrootdevuuid"
+		echo "$btrfsrootdevuuid" >>"$OS_PROBER_TMP/btrfs-vols"
+	fi
+fi
+
 for partition in $(partitions); do
 	if ! mapped="$(mapdevfs "$partition")"; then
 		log "Device '$partition' does not exist; skipping"
@@ -183,13 +192,9 @@ for partition in $(partitions); do
 	# be handled by 50mounted-tests so we can do a subvol only once.
 	type=$(blkid -o value -s TYPE $mapped || true)
 	if [ "$type" = btrfs ]; then
-		mpoint=$(grep "^$mapped " "$OS_PROBER_TMP/mounted-map" | head -n1 | cut -d " " -f 2)
-		mpoint="$(unescape_mount "$mpoint")"
-		if [ "$mpoint" = "/target/boot" ] || [ "$mpoint" = "/target" ] || [ "$mpoint" = "/" ]; then
-			continue
-		fi
 		uuid=$(blkid -o value -s UUID $mapped)
 		if grep -q "^$uuid" "$OS_PROBER_TMP/btrfs-vols" ; then
+			debug "skipped btrfs partition=$partition uuid=$uuid"
 			continue
 		fi
 		debug "btrfs volume uuid=$uuid partition=$partition"