In the attached patch, I've edited debian/changelog to include the LP bug # as requested. I also went ahead and added some description/reference links to the patch itself--I ended up creating a new debdiff to do this since I wasn't sure how to manually update line numbers in a way that would be safe. I renamed the original patch to 1-gvfs for clarity. The substance of the patch is unchanged.
I'll update the bug description momentarily. Sorry for the delay! ** Patch added: "2-gvfs.debdiff" https://bugs.launchpad.net/ubuntu/+source/gvfs/+bug/1927100/+attachment/5548854/+files/2-gvfs.debdiff ** Description changed: + [Description] + glib GFileMonitors can cause deadlocks if not explicitly cancelled before unref-ing (as of Dec 2021; see https://gitlab.gnome.org/GNOME/glib/-/issues/1941). In gvfs <1.46.2, gvfsd-trash can cause this deadlock, leading to 25s delays in spawning gtk+ dialogs system-wide. The best userspace workaround is explicitly pkill-ing gvfsd-trash at a sometimes frequent interval. + + This issue was reported and fixed in gvfs + issue: https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 + commit: https://gitlab.gnome.org/GNOME/gvfs/-/commit/dc21a0948bcbe8a6d79d674bd1e4d63ded57d340 + merge: https://gitlab.gnome.org/GNOME/gvfs/-/merge_requests/96 + + + [Test Case] + To my knowledge, there is not a 100% reproducer for gvfs from userspace as this is a probable lock-ordering issue in lower-level code. https://gitlab.gnome.org/GNOME/glib/-/issues/1941 contains a reproducer for the underlying glib issue. + + User reports of gvfsd-trash manifesting this deadlock exist for Focal and Focal-based distributions, and it has been acknowledged and worked-around in gvfs. See: + https://forums.linuxmint.com/viewtopic.php?f=47&t=328966 (Linux Mint forums) + https://github.com/linuxmint/nemo/issues/2497 (Linux Mint nemo -- file manager) + https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 (gvfs bug report, includes diagnosis and stacktrace showing the gvfsd-trash thread) + + The code change patched-in here has propagated to various other projects. See: + https://bugs.launchpad.net/ubuntu/+source/libxmlb/+bug/1890313 + https://github.com/fwupd/fwupd/issues/2350 + + + [Regression Potential] + This patch explicitly cancels GFileMonitors before "unreferencing" them to workaround a known glib issue. Absent any currently-unknown issues with the GFileMonitor framework, code added by this patch should be entirely within valid usage of GFileMonitors, is already present in gvfs releases in wide distribution, and, at worst, should become superfluous if/when the underlying glib issue is fixed. + + In the event that gvfsd-trash had some (currently unknown) mismanagement + of its file watchers, it's possible that attempting to cancel an invalid + monitor might behave differently than unref-ing it (which was already + happening), but, this scenario would likely be bad either way. + + + [Original Description] + On Ubuntu Mate 20.04. Sometime the Open and Save dialogs in GTK applications will over 20 seconds to display. I found https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 , which suggested this due to gvfsd-trash, and running `killall gvfsd-trash` which does temporary solve the problem. The issue is apparently fixed in gvfs 1.46.2 Please could 1.46.2 or the fix https://gitlab.gnome.org/GNOME/gvfs/-/merge_requests/96 be backported to Ubuntu 20.04 ** Description changed: - [Description] + [Description/Impact] glib GFileMonitors can cause deadlocks if not explicitly cancelled before unref-ing (as of Dec 2021; see https://gitlab.gnome.org/GNOME/glib/-/issues/1941). In gvfs <1.46.2, gvfsd-trash can cause this deadlock, leading to 25s delays in spawning gtk+ dialogs system-wide. The best userspace workaround is explicitly pkill-ing gvfsd-trash at a sometimes frequent interval. - This issue was reported and fixed in gvfs + This issue was reported and fixed in gvfs issue: https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 commit: https://gitlab.gnome.org/GNOME/gvfs/-/commit/dc21a0948bcbe8a6d79d674bd1e4d63ded57d340 merge: https://gitlab.gnome.org/GNOME/gvfs/-/merge_requests/96 - [Test Case] To my knowledge, there is not a 100% reproducer for gvfs from userspace as this is a probable lock-ordering issue in lower-level code. https://gitlab.gnome.org/GNOME/glib/-/issues/1941 contains a reproducer for the underlying glib issue. User reports of gvfsd-trash manifesting this deadlock exist for Focal and Focal-based distributions, and it has been acknowledged and worked-around in gvfs. See: https://forums.linuxmint.com/viewtopic.php?f=47&t=328966 (Linux Mint forums) https://github.com/linuxmint/nemo/issues/2497 (Linux Mint nemo -- file manager) https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 (gvfs bug report, includes diagnosis and stacktrace showing the gvfsd-trash thread) The code change patched-in here has propagated to various other projects. See: https://bugs.launchpad.net/ubuntu/+source/libxmlb/+bug/1890313 https://github.com/fwupd/fwupd/issues/2350 - [Regression Potential] This patch explicitly cancels GFileMonitors before "unreferencing" them to workaround a known glib issue. Absent any currently-unknown issues with the GFileMonitor framework, code added by this patch should be entirely within valid usage of GFileMonitors, is already present in gvfs releases in wide distribution, and, at worst, should become superfluous if/when the underlying glib issue is fixed. In the event that gvfsd-trash had some (currently unknown) mismanagement of its file watchers, it's possible that attempting to cancel an invalid monitor might behave differently than unref-ing it (which was already happening), but, this scenario would likely be bad either way. - [Original Description] On Ubuntu Mate 20.04. Sometime the Open and Save dialogs in GTK applications will over 20 seconds to display. I found https://gitlab.gnome.org/GNOME/gvfs/-/issues/485 , which suggested this due to gvfsd-trash, and running `killall gvfsd-trash` which does temporary solve the problem. The issue is apparently fixed in gvfs 1.46.2 Please could 1.46.2 or the fix https://gitlab.gnome.org/GNOME/gvfs/-/merge_requests/96 be backported to Ubuntu 20.04 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gvfs in Ubuntu. https://bugs.launchpad.net/bugs/1927100 Title: Slow file dialogs, open and save To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gvfs/+bug/1927100/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
