On Sun, Sep 07, 2014 at 05:12:31PM +0200, Benoît Canet wrote: > The Monday 01 Sep 2014 à 15:43:06 (+0800), Liu Yuan wrote : > > This patch set mainly add mainly two logics to implement device recover > > - notify qourum driver of the broken states from the child driver(s) > > - dirty track and sync the device after it is repaired > > > > Thus quorum allow VMs to continue while some child devices are broken and > > when > > the child devices are repaired and return back, we sync dirty bits during > > downtime to keep data consistency. > > > > The recovery logic is based on the driver state bitmap and will sync the > > dirty > > bits with a timeslice window in a coroutine in this prtimive implementation. > > > > Simple graph about 2 children with threshold=1 and read-pattern=fifo: > > (similary to DRBD) > > > > + denote device sync iteration > > - IO on a single device > > = IO on two devices > > > > sync complete, release dirty bitmap > > ^ > > | > > ====-----------------++++----++++----++========== > > | | > > | v > > | device repaired and begin to sync > > v > > device broken, create a dirty bitmap > > > > This sync logic can take care of nested broken problem, that devices are > > broken while in sync. We just start a sync process after the devices are > > repaired again and switch the devices from broken to sound only when the > > sync > > completes. > > > > For read-pattern=quorum mode, it enjoys the recovery logic without any > > problem. > > > > Todo: > > - use aio interface to sync data (multiple transfer in one go) > > - dynamic slice window to control sync bandwidth more smoothly > > - add auto-reconnection mechanism to other protocol (if not support yet) > > - add tests > > > > Cc: Eric Blake <ebl...@redhat.com> > > Cc: Benoit Canet <ben...@irqsave.net> > > Cc: Kevin Wolf <kw...@redhat.com> > > Cc: Stefan Hajnoczi <stefa...@redhat.com> > > > > Liu Yuan (8): > > block/quorum: initialize qcrs.aiocb for read > > block: add driver operation callbacks > > block/sheepdog: propagate disconnect/reconnect events to upper driver > > block/quorum: add quorum_aio_release() helper > > quorum: fix quorum_aio_cancel() > > block/quorum: add broken state to BlockDriverState > > block: add two helpers > > quorum: add basic device recovery logic > > > > block.c | 17 +++ > > block/quorum.c | 324 > > +++++++++++++++++++++++++++++++++++++++++----- > > block/sheepdog.c | 9 ++ > > include/block/block.h | 9 ++ > > include/block/block_int.h | 6 + > > trace-events | 5 + > > 6 files changed, 336 insertions(+), 34 deletions(-) > > > > -- > > 1.9.1 > > > > Hi liu, > > Had you noticed that your series conflict with one of Fam's series in the > quorum cancel > function fix patch ?
Not yet, thanks for reminding. > Could you find an arrangement with Fam so the two patches don't collide > anymore ? > > Do you intend to respin your series ? Yes, I'll rebase the v2 later before more possible reviews. Thanks Yuan