lvmlockd: unlock lv if command fails before lock completes

If lvmlockd acquires an lv lock for a command, but the
command exits before the reply, then the command has
not activated the lv and lvmlockd should unlock it.
This only applies when the lv was not already locked.

(There will always be a chance that the lv lock is held
while the lv is not active, i.e. if the command fails in
the small window between getting the lv lock and before
doing the activation.  In that case, rerunning the
activation command corrects the inconsistency.)

This commit helps by automatically clearing the
inconsistency (lv locked by not activated) in the most
common case when the lv lock operation is slow to
complete and the command is canceled by the user.

This commit also adds and cleans up references to the
client id in a bunch of log messages, which is useful
to follow processing on each independent lock request.
2 files changed