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Wed, 03 Jun 2026 16:01:26 -0700 (PDT) From: Askar Safin To: luto@amacapital.net Cc: akpm@linux-foundation.org, axboe@kernel.dk, brauner@kernel.org, david@kernel.org, dhowells@redhat.com, hch@infradead.org, jack@suse.cz, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, miklos@szeredi.hu, netdev@vger.kernel.org, patches@lists.linux.dev, pfalcato@suse.de, safinaskar@gmail.com, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, willy@infradead.org Subject: Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2 Date: Thu, 4 Jun 2026 02:00:25 +0300 Message-ID: <20260603230122.851517-1-safinaskar@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: 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: 8bit Andy Lutomirski : > On Wed, Jun 3, 2026 at 3:43 PM Askar Safin wrote: > > Finally, we can degrade tee(2) to copy, and hopefully this will > > allow us to always be sure that pipe buffers are not shared with anything. > > This is possible future direction. > > I'm a bit nervous that, if I've read the code correctly (a big if), > then iscsi and nvme will still send *shared* buffers via > MSG_SPLICE_PAGES, but that normal user code will not be able to do > this, and that something will bitrot. As well as I understand you correctly, you mean that if we remove tee(2), then there still will be subsystems, which will be able to send shared pages. Yes, I totally agree. So, if we remove tee(2), then we will probably need to remove all non-standard implementations of pipe_buf_operations. -- Askar Safin