From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DD3938A711 for ; Wed, 24 Jun 2026 07:12:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285155; cv=none; b=QfGsI97se3O5+QBirEhYK2h5CiICUSb3xp6nSV6pOgjUMvJ434gmkEKzI+ONPb64E2rjcpbH/91CbGDJy+sNAMIN99TEwhy3jfrFB77HbL7OJmj3nsFKSMTUrYQ+CaSa9gw+OEEIfqh4RH5kdZjypbt0v3LhpJPXkLla6uH264k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285155; c=relaxed/simple; bh=T+oTEsZifQSSjkTTm8dieBj546vS01rprc6FRMPpgRY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HJVUivRpwRsWu26/acuKmu/6teS9LnchXO8OFL9ZWa/28ogirTVpl0aMs4fNu+xOxUhinAGzgZnL+WJirrAjGJ0g+ALDJlLXDwFrx93OtffNVoq8UJ0dzl2OBVq+/bjCjFZn6fSH3aTZ5WpHfa678SpX+PQqWtkCWP403urkdTs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=NEk6jZgM; arc=none smtp.client-ip=209.85.221.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NEk6jZgM" Received: by mail-wr1-f44.google.com with SMTP id ffacd0b85a97d-4624c1409c9so537224f8f.3 for ; Wed, 24 Jun 2026 00:12:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1782285153; x=1782889953; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VhG9FcF945Re4Q58PUpr7BwlsxWpmlT6fgah9/vT28s=; b=NEk6jZgMulgJqN17XPHyzxZWrjC3SRgX+YSWsZTjYh/fBnelCNZujLrpG/e+mFyoF7 f1Gq3XqQrb60v77rGI8/iNo2sqx2/b7UaQAXvH3QITshpe3OUojUSyJlLvUAe2/GpKjU SE3hQWJrn17c9XTEnFuUX50Exw4ddu2TEcs+Jh3H2E1/KEmNBi8R2E1viN8X/RS/F8hf ArU9eVXTMzswldd/Um38NKIYizUTz23JNVE2PVtj38Gk/Zuo1ygshyyt6BVLAHby6pN0 x3Dfz9pBCe5euKHjThKElffKbbO9TKgxcg8aVoI/xbwPxYjVbF266rAnHHl+iApuV2NX Ru3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782285153; x=1782889953; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=VhG9FcF945Re4Q58PUpr7BwlsxWpmlT6fgah9/vT28s=; b=C1l2XZCWRNCVL7fiQ2xHyAjQASQ/3KkqYQz9+t+0aiQOHnxnc9mKFa67ihBtLSTgGc 9rBXkF/1dt4SVZRwixmUId4PH6aYx3xoVTVFBFLabrczu/OQ88P+7YgkYFlcRVhNlAl1 mu/NCKY9YCOXC+O68TA01eN2zEJZHjgi5TvQLccu/LLwk5wxp+oQX9RC35cWvP4kYt8U nEHPMMLEZuBuKR6qsB3Hn/hsaxmJ3mwo4hpblvUFrovEQIBuE2fCDfFapXngpX4q6gQ+ Is0kJ28+cACo+FBOLuiTw+0pfmzymSS7NgwPR5WwmXaX67NvG/eqZv2ApJqC+eDnukRe ELiQ== X-Forwarded-Encrypted: i=1; AHgh+RrhFAyOvHIco/lJdOo036drB9C17MyhQd2I11hJq1bUNdYhh1ux8uYonA/0Dc6NvJW2HC3eJ2x5BA3soEcN@vger.kernel.org X-Gm-Message-State: AOJu0YwH5o3iVIlj6UVrbqRWbJ1ZEV/08Qy502kFH49rKpRiAPxW1eqA 7QKU3mBiojBjF/O0UU7O13/Qs40w76d+cukzmJlNgQ0YQVzgKBKZP9nF X-Gm-Gg: AfdE7cnN7W3C0xe3BlDJi4aXi1Fl3L/68CPbuZhKnql0ej5lamzFrCT+ywSS5xxGgpP MUAciYrBSYJFbrUlAatF9Ot6dw/iU1u+1hfbrYD2unITBoFLj5chsy/X3pzaQHsiaGaJcqV9Ahl L8QlD9nzJpKsIW4EfVOj5F3ZiBlh+sMpdHuFy6ztAt9WB0J4R0f1K870A5mBOmGGaNcg39SNWfz lFnA4MKyVoPSyhxf6T54NMpzDOd6d+AsXPzJ/qJdPjQtq7sq4ThBpy7iEzKE2BE3IMnstBimjTN vxfsLCc/THVzPZbHD/rPBiHL3yA8cAGkT6/MQtPtMSPZdwVL0BnVq4MToHapjzpyo8pnQRsvzbu R2sXGa0De+eqgl2NvuYZVNEFgF5xr46C/QiFHJXLk8MQlW8iEC1Eof7nkk8Z7BumPN21DECZ+mo E0A8WqB+ok X-Received: by 2002:a05:6000:4683:b0:46a:1f35:113f with SMTP id ffacd0b85a97d-46a1f35172dmr8359155f8f.21.1782285152523; Wed, 24 Jun 2026 00:12:32 -0700 (PDT) Received: from localhost ([212.73.77.104]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-46c1ee0189esm4296531f8f.9.2026.06.24.00.12.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Jun 2026 00:12:32 -0700 (PDT) From: Askar Safin To: avagin@gmail.com Cc: akpm@linux-foundation.org, alexander@mihalicyn.com, axboe@kernel.dk, bernd@bsbernd.com, brauner@kernel.org, criu@lists.linux.dev, david@kernel.org, dhowells@redhat.com, fuse-devel@lists.linux.dev, hch@infradead.org, jack@suse.cz, joannelkoong@gmail.com, 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, rostedt@goodmis.org, safinaskar@gmail.com, torvalds@linux-foundation.org, val@packett.cool, viro@zeniv.linux.org.uk, willy@infradead.org Subject: Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2 Date: Wed, 24 Jun 2026 10:12:26 +0300 Message-ID: <20260624071226.2272209-1-safinaskar@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Andrei Vagin : > The CRIU fifo test fails with this change. The problem is that vmsplice > with SPLICE_F_NONBLOCK to a fifo file descriptor fails with -EOPNOTSUPP. > > It seems we need a fix like this one: > > diff --git a/fs/pipe.c b/fs/pipe.c > index 429b0714ec57..6fc49e933727 100644 > --- a/fs/pipe.c > +++ b/fs/pipe.c > @@ -1253,6 +1253,7 @@ static int fifo_open(struct inode *inode, struct > file *filp) > > /* We can only do regular read/write on fifos */ > stream_open(inode, filp); > + filp->f_mode |= FMODE_NOWAIT; > > switch (filp->f_mode & (FMODE_READ | FMODE_WRITE)) { > case FMODE_READ: Does CRIU actually rely on ability to do SPLICE_F_NONBLOCK vmsplice into named fifos? Or this is merely a test? If this is just a test, I think we need not to preserve this behavior. I did debian code search with regex "vmsplice.*SPLICE_F_NONBLOCK" and I found very few packages. And it seems all them use pipes, not named fifos. (On speed: I still think that my vmsplice patches are good thing, despite performance regressions in CRIU.) -- Askar Safin