/usr/share/glib-2.0/schemas/ is in cinnamon-desktop-data 2.2.3-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.a11y.applications.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.a11y.keyboard.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.a11y.magnifier.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.a11y.mouse.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.background.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.default-applications.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.enums.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.input-sources.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.interface.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.lockdown.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.media-handling.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.screensaver.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.session.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.sound.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.thumbnail-cache.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.thumbnailers.gschema.xml
/usr/share/glib-2.0/schemas/org.cinnamon.desktop.wm.preferences.gschema.xml