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Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20260824144130.759997-1-dhowells@redhat.com> <20260824144130.759997-31-dhowells@redhat.com> To: =?us-ascii?Q?=3D=3FUTF-8=3FQ=3FAur=3DC3=3DA9lien=5FCouderc=3F=3D?= Cc: dhowells@redhat.com, Paulo Alcantara , Christian Brauner , Matthew Wilcox , Christoph Hellwig , Jens Axboe , Leon Romanovsky , Namjae Jeon , ChenXiaoSong , Marc Dionne , Stefan Metzmacher , Eric Van Hensbergen , Dominique Martinet , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, Linux NFS Mailing List , ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: READ_PLUS in NetFS? Re: [PATCH v10 30/35] netfs: Simplify read abandonment Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 24 Aug 2026 20:47:30 +0100 Message-ID: <771538.1787600850@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Aur=C3=A9lien Couderc wrote: > What about READ_PLUS, i.e. sparse file reads? If you do this kind of > work of handling partial abandonment, can such a work also benefit > READ_PLUS? READ_PLUS is NFS, right? I'm not sure it would particularly help or hinder. The VFS/VM only asks to read contiguous regions and netfslib breaks that up into subrequests, but currently netfslib doesn't know anything about sparse reads. What I'm looking at with Ceph, for example, is that Ceph knows where the gaps are and will clear them before terminating the subrequest. Partial abandonment is for when some sort of fatal error occurs and we cann= ot finish the request. David