[pkg-cryptsetup-devel] Bug#791944: udev: shutdown hangs because of missing swapoff

[Peter Rajnoha]

> `dmsetup udevcookies` lists no cookies. Adding `dmsetup
> udevcomplete_all` before `dmsetup remove` doesn't help.

Well, if dmsetup remove is waiting on a cookie as the log displays,
"dmsetup udevcookies" should display it (otherwise the dmsetup
remove wouldn't hang).

You need to call dmsetup udevcookies *after* the hang happens

A call to "dmsetup udevcomplete_all" *after* the hang would
release it, but the standard way is for "dmsetup udevcomplete <cookie>"
to be called from within udev rule for the udev event
that gets generated (in this case as a result of REMOVE task).

Let's check the udev debug log then - it should contain something
like "starting ... udevcomplete <cookie_number>" and "... udevcomplete
<cookie_number> completed".

To switch udev into debug mode, call "udevadm control --log-priority debug"
before deactivation of the device (the REMOVE task). The log should
go into syslog or so (for systemd, it's in the journal).

-- 
Peter