From: "Myklebust, Trond" <Trond.Myklebust@netapp.com>
To: "Jim Rees" <rees@umich.edu>
Cc: "Peng Tao" <bergwolf@gmail.com>, <tao.peng@emc.com>,
<linux-nfs@vger.kernel.org>, <bhalevy@tonian.com>
Subject: RE: [PATCH] NFS41: Drop lseg ref before fallthru to MDS
Date: Tue, 26 Jul 2011 09:14:13 -0700 [thread overview]
Message-ID: <2E1EB2CF9ED1CB4AA966F0EB76EAB4430A5182A2@SACMVEXC2-PRD.hq.netapp.com> (raw)
In-Reply-To: <20110726160805.GA1922@merit.edu>
> -----Original Message-----
> From: Jim Rees [mailto:rees@umich.edu]
> Sent: Tuesday, July 26, 2011 12:08 PM
> To: Myklebust, Trond
> Cc: Peng Tao; tao.peng@emc.com; linux-nfs@vger.kernel.org;
> bhalevy@tonian.com
> Subject: Re: [PATCH] NFS41: Drop lseg ref before fallthru to MDS
>
> Myklebust, Trond wrote:
>
> > 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().
>
> My main worry is for aio/dio where there is no good mechanism for
> retrying. I'm still working on that...
>
> What do you suggest we do for the current set of patches that add
block
> layout to pnfs?
If you are calling pnfs_ld_read/write_done, then don't change anything:
it is easier to fix this in one spot rather than several.
However someone needs to start working on fixing the code in
pnfs_ld_read/write_done to do the right thing. If nobody else has the
cycles, then I can do that but I'd prefer to have someone who can easily
test the resulting code do it.
Cheers
Trond
next prev parent reply other threads:[~2011-07-26 16:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-04 1:30 [PATCH] NFS41: Drop lseg ref before fallthru to MDS Peng Tao
2011-07-09 14:10 ` Benny Halevy
2011-07-20 5:52 ` tao.peng
2011-07-25 19:13 ` Trond Myklebust
2011-07-25 21:35 ` Jim Rees
2011-07-26 15:37 ` Peng Tao
2011-07-26 15:50 ` Myklebust, Trond
2011-07-26 16:08 ` Jim Rees
2011-07-26 16:14 ` Myklebust, Trond [this message]
2011-07-26 16:37 ` Benny Halevy
2011-07-26 17:32 ` Peng Tao
2011-07-26 17:37 ` Myklebust, Trond
2011-07-26 17:57 ` Peng Tao
2011-07-27 10:17 ` tao.peng
2011-07-26 16:34 ` Benny Halevy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2E1EB2CF9ED1CB4AA966F0EB76EAB4430A5182A2@SACMVEXC2-PRD.hq.netapp.com \
--to=trond.myklebust@netapp.com \
--cc=bergwolf@gmail.com \
--cc=bhalevy@tonian.com \
--cc=linux-nfs@vger.kernel.org \
--cc=rees@umich.edu \
--cc=tao.peng@emc.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).