2 Commits

Author	SHA1	Message	Date
Tony Asleson	dd5d865020	lvmdbusd: Fix hang when lvm compiled with 'enable-notify-dbus' ... The following operations would hang if lvm was compiled with 'enable-notify-dbus' and the client specified -1 for the timeout: * LV snapshot merge * VG move * LV move This was caused because the implementation of these three dbus methods is different. Most of the dbus method calls are executed by gathering information needed to fulfill it, placing that information on a thread safe queue and returning. The results later to be returned to the client with callbacks. With this approach we can process an arbitrary number of commands without any of them blocking other dbus commands. However, the 3 dbus methods listed above did not utilize this functionality because they were implemented with a separate thread that handles the fork & exec of lvm. This is done because these operations can be very slow to complete. However, because of this the lvm command that we were waiting on is trying to call back into the dbus service to notify it that something changed. Because the code was blocking the process that handles the incoming dbus activity the lvm command blocked. We were stuck until the client timed-out the connection, which then causes the service to unblock and continue. If the client did not have a timeout, we would have been hung indefinitely. The fix is to always utilize the worker queue on all dbus methods. We need to ensure that lvm is tested with 'enable-notify-dbus' enabled and disabled.	2016-06-28 12:09:28 -05:00
Alasdair G Kergon	5987562cf9	lvmdbus: Add new daemon.	2016-02-17 23:53:35 +00:00