Comment 0 for bug 1702368

Using Ubuntu artful with linux-image-4.10.0-26-generic 4.10.0-26.30 and sshfs 2.8-1. I use "sshfs -o reconnect" and often run gvim against a file on an sshfs filesystem.

Sometimes when I suspend I get:

Jul 4 20:59:08 xps kernel: [46684.608740] PM: Syncing filesystems ... done.
Jul 4 20:59:08 xps kernel: [46684.613278] PM: Preparing system for sleep (mem)
Jul 4 20:59:08 xps kernel: [46684.613788] Freezing user space processes ...
Jul 4 20:59:08 xps kernel: [46704.620140] Freezing of tasks failed after 20.006 seconds (1 tasks refusing to freeze, wq_busy=0):
Jul 4 20:59:08 xps kernel: [46704.620534] gvim D 0 11155 1336 0x00000004
Jul 4 20:59:08 xps kernel: [46704.620541] Call Trace:
Jul 4 20:59:08 xps kernel: [46704.620556] __schedule+0x233/0x6f0
...
Jul 4 20:59:08 xps kernel: [46704.620679] entry_SYSCALL_64_fastpath+0x1e/0xad
...
Jul 4 20:59:08 xps kernel: [46704.620711] Restarting tasks ... done.

...and the system fails to suspend.

AFAICT, this is https://bugzilla.redhat.com/show_bug.cgi?id=656992 and https://lists.debian.org/debian-kernel/2011/10/msg00412.html has an extensive explanation. The corresponding Debian bug was closed long ago due to inactivity. It isn't exactly bug 388419 though since that is about behaviour after resume, rather than failure to suspend.

This affects sshfs-fuse, but it sounds like a full fix would be in the kernel. I wonder if it's possible to work around in userspace packaging in sshfs-fuse, though, by arranging some action in userspace before suspend?

It seems unlikely that this will be addressed any time soon, but it'd be nice to keep a bug open in Launchpad so that users can have a single rallying point.