Hi all, At weekend, I read the kernel code about aio & direction. For close(), it don't wait aio to complete. But for fsync(), it will wait all aio to complete. Mark used this patch(which using fsync() on write_thread_entry) and the result is looks good. I want to revert the patch which don't use aio when closing journal. And using fsync(). It make the code simple. How about this?
Thanks! Jianpeng > [email protected] > Subject: Re: Deadlock in ceph journal > > On 23/08/14 10:22, Somnath Roy wrote: > > I think it is using direct io for non-aio mode as well. > > > > Thanks & Regards > > Somnath > > > > > One thing that does still concern me - if I understand what is happening > > here > correctly: we write to the journal using aio until we want to stop doing > writes > (presumably pre closing it), then use normal io to write at that point. > > > > Given that we appear to be using direct io whenever we use aio, does this > mean we end up mixing direct and buffered io to the journal [1] (or is the > normal i.e non aio write still using direct io)? > > > > > > Thanks Somnath, > > I think you are correct (I missed the bit in FileJournal::_open that seems to > cover this): > > > if (forwrite) { > flags = O_RDWR; > if (directio) > flags |= O_DIRECT | O_DSYNC; > > > i.e the journal is opened with DIRECT, so all writes (async or not) will > be direct. > > Cheers > > Mark -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
