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Date: Thu, 9 May 2024 19:15:27 +0200
From: Andrea Righi <andrea.righi@canonical.com>
To: David Howells <dhowells@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>, Steve French <smfrench@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	Marc Dionne <marc.dionne@auristor.com>,
	Paulo Alcantara <pc@manguebit.com>,
	Shyam Prasad N <sprasad@microsoft.com>, Tom Talpey <tom@talpey.com>,
	Dominique Martinet <asmadeus@codewreck.org>,
	Eric Van Hensbergen <ericvh@kernel.org>,
	Ilya Dryomov <idryomov@gmail.com>,
	Christian Brauner <christian@brauner.io>, linux-cachefs@redhat.com,
	linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org,
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	v9fs@lists.linux.dev, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, Latchesar Ionkov <lucho@ionkov.net>,
	Christian Schoenebeck <linux_oss@crudebyte.com>
Subject: Re: [PATCH v5 40/40] 9p: Use netfslib read/write_iter
Message-ID: <Zj0ErxVBE3DYT2Ea@gpd>
References: <20231221132400.1601991-1-dhowells@redhat.com>
 <20231221132400.1601991-41-dhowells@redhat.com>
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On Thu, Dec 21, 2023 at 01:23:35PM +0000, David Howells wrote:
> Use netfslib's read and write iteration helpers, allowing netfslib to take
> over the management of the page cache for 9p files and to manage local disk
> caching.  In particular, this eliminates write_begin, write_end, writepage
> and all mentions of struct page and struct folio from 9p.
> 
> Note that netfslib now offers the possibility of write-through caching if
> that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
> v9inode->netfs.flags in v9fs_set_netfs_context().
> 
> Note also this is untested as I can't get ganesha.nfsd to correctly parse
> the config to turn on 9p support.

It looks like this patch has introduced a regression with autopkgtest,
see: https://bugs.launchpad.net/bugs/2056461

I haven't looked at the details yet, I just did some bisecting and
apparently reverting this one seems to fix the problem.

Let me know if you want me to test something in particular or if you
already have a potential fix. Otherwise I'll take a look.

Thanks,
-Andrea