fix fs.fakeudev, do not source uevent file

Author: reith

src/ugrd/fs/fakeudev.py

@@ -13,9 +13,16 @@ def fake_dm_udev(self) -> str:
     """returns a shell function to fake udev for dm devices."""
     return r"""
     for dm in /sys/block/dm-*; do
-        source "${dm}/uevent"
-        einfo "Faking udev for: ${DEVNAME}"
-        udev_db_file="/run/udev/data/b${MAJOR}:${MINOR}"
+        if [ ! -e "${dm}/dev" ]; then
+            continue
+        fi
+        if [ ! -e "${dm}/dm/name" ]; then
+            continue
+        fi
+        dev_name=$(cat ${dm}/dm/name)
+        majmin=$(cat "${dm}/dev")
+        einfo "Faking udev for: ${dev_name}"
+        udev_db_file="/run/udev/data/b${majmin}"
         printf 'E:DM_UDEV_PRIMARY_SOURCE_FLAG=1\n' > "${udev_db_file}"
     done
     """