parent_dirname() return the wrong filename for files in the root directory of a share. In notify responses every modified file is reported to the client as empty file name. I noticed this because the SMB2-NOTIFY tests notifies in the root directory. The RAW-NOTIFY test doesn't notice this because it operates on a subdirectory.
Created attachment 4394 [details] Patch for v3-4
Created attachment 4395 [details] Patch for v3-3
Created attachment 4396 [details] Patch for v3-2
b292af0c38c6aa2167adb5803ced03cf51a81a9c and c229239ea4799bb18973d4bdcb4cb499043d6f15 show that only the notify code cared about the filename output of parent_dirname()
Patches have been pushed to v3-4-test, v3-3-test and v3-2-test. Closing out bug report. Thanks!