On Tuesday 07 December 2004 04:38, Patrick Caulfield wrote: > On Mon, Dec 06, 2004 at 04:13:50PM -0800, Daniel McNeil wrote: > > On Mon, 2004-12-06 at 11:45, Ken Preslan wrote: > > > On Fri, Dec 03, 2004 at 03:08:00PM -0800, Daniel McNeil wrote: > > > > Looking at the stack trace above and dissabling dlm.ko, > > it looks like dlm_lock+0x319 is the call to dlm_lock_stage1(). > > looking at dlm_lock_stage1(), it looks like it is sleeping on > > down_write(&rsb->res_lock) > > > > So now I have to find who is holding the res_lock. > > That's consistent with the hang you reported before - in fact it's > almost certainly the same thing. My guess is thet there is a dealock > on res_lock somewhere . In which case I suspect it's going to be > easier to find that one by reading code rather than running tests. > res_lock should never be held for any extended period of time, but in > your last set of tracebacks there was nothing obviously holding it - > so I suspect something is sleeping with it. Hi Patrick, Last week I had a bug in the cluster snapshot failover code that exposed a bug in dlm or libdlm I think. My code inadvertently acquired a lock twice, first in PW mode, then later in CR mode (because I wasn't checking to see if it already had the PW lock). This caused dlm_unlock_wait to wait forever. Are these locks supposed to be recursive or not? In any event, waiting forever has got to be a bug. It might have something to do with a lkid tangle, since I never provided separate lkids for the unlock. This should be easily reproducible. Regards, Daniel
