I am using Dolphin with Nemo. I would like to use Dolphin only, but Dolphin passes the raw SMB address to applications when dragging a file from an SMB share to an application, which does not work for almost all non-KDE apps, so I have to Nemo when browsing SMB directory, because Nemo passes a locally-mapped path, in this case. For example, in Dolphin, if I drag a video file on a SMB share into MPV, MPV crashes, but in Nemo, it works.
Anyway, so when there are mounted gvfs SMB shares, and the SMB server is offline, Dolphin hangs. It hangs when I start Dolphin, and it hangs whenever I try to navigate to ANY directory, even it’s a local directory that has nothing to do with SMB.
Happens to me too. Whenever I am rebooting my smb fileshare for updates, dolphin and its associated file-open dialogs slow to a crawl. Journalctl doesn’t show anything relevant, other than a 4-minute gap between initiating a file-open dialog request and that request being completed, even though only local paths are directly involved.
Alright, I’ve just spent about an hour perusing the many, many duplicate bug reports regarding this issue. At its root this has to do with FUSE-mounted filesystems becoming unavailable while still mounted. This bug report is the most contemporary: