From: Matthew Wilcox <willy@infradead.org>
To: David Howells <dhowells@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com,
jlayton@redhat.com, dwysocha@redhat.com,
Dominique Martinet <asmadeus@codewreck.org>,
Steve French <sfrench@samba.org>,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
Christoph Hellwig <hch@lst.de>,
dchinner@redhat.com,
Linus Torvalds <torvalds@linux-foundation.org>,
v9fs-developer@lists.sourceforge.net,
linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org,
linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: Redesigning and modernising fscache
Date: Thu, 14 Jan 2021 16:19:29 +0000 [thread overview]
Message-ID: <20210114161929.GQ35215@casper.infradead.org> (raw)
In-Reply-To: <2758811.1610621106@warthog.procyon.org.uk>
On Thu, Jan 14, 2021 at 10:45:06AM +0000, David Howells wrote:
> However, there've been some objections to the approach I've taken to
> implementing this. The way I've done it is to disable the use of fscache by
> the five network filesystems that use it, remove much of the old code, put in
> the reimplementation, then cut the filesystems over. I.e. rip-and-replace.
> It leaves unported filesystems unable to use it - but three of the five are
> done (afs, ceph, nfs), and I've supplied partially-done patches for the other
> two (9p, cifs).
>
> It's been suggested that it's too hard to review this way and that either I
> should go for a gradual phasing in or build the new one in parallel. The
> first is difficult because I want to change how almost everything in there
> works - but the parts are tied together; the second is difficult because there
> are areas that would *have* to overlap (the UAPI device file, the cache
> storage, the cache size limits and at least some state for managing these), so
> there would have to be interaction between the two variants. One refinement
> of the latter would be to make the two implementations mutually exclusive: you
> can build one or the other, but not both.
My reservation with "build fscache2" is that it's going to take some
time to do, and I really want rid of ->readpages as soon as possible.
What I'd like to see is netfs_readahead() existing as soon as possible,
built on top of the current core. Then filesystems can implement
netfs_read_request_ops one by one, and they become insulated from the
transition.
next prev parent reply other threads:[~2021-01-14 16:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-14 10:45 Redesigning and modernising fscache David Howells
2021-01-14 16:19 ` Matthew Wilcox [this message]
2021-01-18 23:36 ` Cut down implementation of fscache new API David Howells
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=20210114161929.GQ35215@casper.infradead.org \
--to=willy@infradead.org \
--cc=anna.schumaker@netapp.com \
--cc=asmadeus@codewreck.org \
--cc=ceph-devel@vger.kernel.org \
--cc=dchinner@redhat.com \
--cc=dhowells@redhat.com \
--cc=dwysocha@redhat.com \
--cc=hch@lst.de \
--cc=jlayton@redhat.com \
--cc=linux-afs@lists.infradead.org \
--cc=linux-cachefs@redhat.com \
--cc=linux-cifs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=sfrench@samba.org \
--cc=torvalds@linux-foundation.org \
--cc=trond.myklebust@hammerspace.com \
--cc=v9fs-developer@lists.sourceforge.net \
/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).