Hi, Trond, > -----Original Message----- > From: linux-nfs-owner@xxxxxxxxxxxxxxx [mailto:linux-nfs-owner@xxxxxxxxxxxxxxx] > On Behalf Of Myklebust, Trond > Sent: Tuesday, July 26, 2011 11:50 PM > To: Peng Tao > Cc: Peng, Tao; linux-nfs@xxxxxxxxxxxxxxx; bhalevy@xxxxxxxxxx > Subject: RE: [PATCH] NFS41: Drop lseg ref before fallthru to MDS > > > -----Original Message----- > > From: Peng Tao [mailto:bergwolf@xxxxxxxxx] > > Sent: Tuesday, July 26, 2011 11:37 AM > > To: Myklebust, Trond > > Cc: tao.peng@xxxxxxx; linux-nfs@xxxxxxxxxxxxxxx; bhalevy@xxxxxxxxxx > > Subject: Re: [PATCH] NFS41: Drop lseg ref before fallthru to MDS > > > > Hi, Trond, > > > > On Tue, Jul 26, 2011 at 3:13 AM, Trond Myklebust > > <Trond.Myklebust@xxxxxxxxxx> wrote: > > > On Wed, 2011-07-20 at 01:52 -0400, tao.peng@xxxxxxx wrote: > > >> Hi, Trond, > > >> > > >> Any comments on this patch? I still get kernel crash when pnfs write > > is attempted but fails and calls pnfs_ld_write_done(). It seems object > > layout uses the same code path as well. But I don't find the patch in > > either your tree or Benny's tree. Are there any concerns? > > >> > > >> Thanks, > > >> Tao > > > > > > The whole pnfs_ld_write_done thing is bogus and needs to be replaced > > > with something sane. It is trying to initiate a WRITE RPC call with > > the > > > wrong block size, and is calling the MDS rpc_call_done() and > > > rpc_release() with an uninitialised rpc task pointer. > > > > > > Ditto for pnfs_ld_read_done. > > Thanks for your explanation. Is there any plan on how to fix > > pnfs_ld_read/write_done? Basically, we would need an interface that > > can redirect the IO to MDS if pnfs_error is set or do all necessary > > cleanup work to end read/write if pnfs_error is 0. IMHO, the > > recoalesce logic need to access nfs_pageio_descriptor but we do not > > have that information at pnfs_ld_read/write_done. > > As far as I can see, the right thing to do is to mark the layout as invalid and then > redirty the page. It should be easy to have fsync() re-send the pages in this case. > These should be extremely rare events, since we expect to catch most of the pNFS > failures when we do the actual LAYOUTGET in the ->pg_init(). Another problem that just comes into my head is readpage failures. How do we reschdule read failures if not re-sending it to MDS? Thanks, Tao > > My main worry is for aio/dio where there is no good mechanism for retrying. I'm still > working on that... > > Cheers > Trond > �{.n�+�������+%��lzwm��b�맲��r��zX��߲)���w* > jg��� �����ݢj/���z�ޖ��2�ޙ���&�)ߡ�a���� �G���h��j:+v���w�٥ ��.n��������+%������w��{.n�����{��w��� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
