From: Dan Williams <dan.j.williams@intel.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Chinner <david@fromorbit.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-xfs <linux-xfs@vger.kernel.org>,
linux-ext4 <linux-ext4@vger.kernel.org>,
linux-rdma <linux-rdma@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux MM <linux-mm@kvack.org>, Jeff Layton <jlayton@kernel.org>,
Jan Kara <jack@suse.cz>, Theodore Ts'o <tytso@mit.edu>,
John Hubbard <jhubbard@nvidia.com>,
Jason Gunthorpe <jgg@ziepe.ca>, Christoph Hellwig <hch@lst.de>
Subject: Re: Lease semantic proposal
Date: Wed, 2 Oct 2019 06:07:27 -0700 [thread overview]
Message-ID: <CAPcyv4jpLYUcqA6D_qfGF4FQCu-SuH67FHLcH0fCQTQ-D+hWzQ@mail.gmail.com> (raw)
In-Reply-To: <20191001210156.GB5500@iweiny-DESK2.sc.intel.com>
On Tue, Oct 1, 2019 at 2:02 PM Ira Weiny <ira.weiny@intel.com> wrote:
>
> On Mon, Sep 30, 2019 at 06:42:33PM +1000, Dave Chinner wrote:
> > On Wed, Sep 25, 2019 at 04:46:03PM -0700, Ira Weiny wrote:
> > > On Tue, Sep 24, 2019 at 08:26:20AM +1000, Dave Chinner wrote:
> > > > Hence, AFIACT, the above definition of a F_RDLCK|F_LAYOUT lease
> > > > doesn't appear to be compatible with the semantics required by
> > > > existing users of layout leases.
> > >
> > > I disagree. Other than the addition of F_UNBREAK, I think this is consistent
> > > with what is currently implemented. Also, by exporting all this to user space
> > > we can now write tests for it independent of the RDMA pinning.
> >
> > The current usage of F_RDLCK | F_LAYOUT by the pNFS code allows
> > layout changes to occur to the file while the layout lease is held.
>
> This was not my understanding.
I think you guys are talking past each other. F_RDLCK | F_LAYOUT can
be broken to allow writes to the file / layout. The new unbreakable
case would require explicit SIGKILL as "revocation method of last
resort", but that's the new incremental extension being proposed. No
changes to the current behavior of F_RDLCK | F_LAYOUT.
Dave, the question at hand is whether this new layout lease mode being
proposed is going to respond to BREAK_WRITE, or just BREAK_UNMAP. It
seems longterm page pinning conflicts really only care about
BREAK_UNMAP where pages that were part of the file are being removed
from the file. The unbreakable case can tolerate layout changes that
keep pinned pages mapped / allocated to the file.
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2019-10-02 13:07 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 19:08 Lease semantic proposal Ira Weiny
2019-09-23 20:17 ` Jeff Layton
2019-10-01 18:17 ` Ira Weiny
2019-10-02 12:28 ` Jeff Layton
2019-10-02 19:27 ` J. Bruce Fields
2019-10-02 20:35 ` Jeff Layton
2019-10-03 8:43 ` Jan Kara
2019-10-03 15:37 ` J. Bruce Fields
2020-01-21 0:56 ` Steve French
2019-10-03 9:01 ` Jan Kara
2019-10-03 17:05 ` Ira Weiny
2019-09-23 22:26 ` Dave Chinner
2019-09-25 23:46 ` Ira Weiny
2019-09-26 11:29 ` Jeff Layton
2019-09-30 8:42 ` Dave Chinner
2019-10-01 21:01 ` Ira Weiny
2019-10-02 13:07 ` Dan Williams [this message]
2019-10-10 10:39 ` Dave Chinner
2019-10-04 7:51 ` Jan Kara
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=CAPcyv4jpLYUcqA6D_qfGF4FQCu-SuH67FHLcH0fCQTQ-D+hWzQ@mail.gmail.com \
--to=dan.j.williams@intel.com \
--cc=david@fromorbit.com \
--cc=hch@lst.de \
--cc=ira.weiny@intel.com \
--cc=jack@suse.cz \
--cc=jgg@ziepe.ca \
--cc=jhubbard@nvidia.com \
--cc=jlayton@kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=linux-rdma@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=tytso@mit.edu \
/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).