Hi,
Thanks for your patch.
FYI: kernel test robot notices the stable kernel rule is not satisfied.
Rule: 'Cc: stable@vger.kernel.org' or 'commit <sha1> upstream.' Subject: [PATCH] writeback: fix dereferencing NULL mapping->host on writeback_page_template Link: https://lore.kernel.org/stable/20230606233613.1290819-1-aquini%40redhat.com
The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html