From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C101DC433F5 for ; Fri, 20 May 2022 14:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344850AbiETOee (ORCPT ); Fri, 20 May 2022 10:34:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233904AbiETOe3 (ORCPT ); Fri, 20 May 2022 10:34:29 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03E475DA36 for ; Fri, 20 May 2022 07:34:28 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id n8so7535036plh.1 for ; Fri, 20 May 2022 07:34:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=gNY/3AVbHNu09hERUfx0oPdssKWIVZqHzBoDv8banCY=; b=qHOzlvJ+z/BVRREh7Ra71FFppaeMOeQzKsb18Qv3l11S2rTZei13xD57YHJvdVLWpF 7XkeaJ6A/ZtFwEhbO3JFSNyIsN/cG5GjDPuor7osKNQwv4wtXOk7XZerpQI09EwKDbJk 9snLMnuWL1wYNMwduurukpHTbsS15BhOnEeuXAbjo1i8w/n7gJV0Cez2JUkSjwRKIZAq 43aCPgDPJii9AnPvs0Ikw/8xwAV6RTK/RJour7vD34faKKVJrXGbdbHh/Io/hZ0axYrx sIZVHQsxdj5m2gxmnNjZx1D6k1jPbFk+W6e2sczW6iK0fpyvYoHFHvtGNFy82uup0vjF qb1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=gNY/3AVbHNu09hERUfx0oPdssKWIVZqHzBoDv8banCY=; b=ZS7II04J6fcJYWLSRuw5eNSHcwsDaYwHNgIxd6Y1Mi1z8Zbw7zrW7E3Hw3Pxj8dyIw 4pI7RzmT/yoxiyMUp1yUYpva8fFFif7rvo1UmzaqjBakImJIxcsUNlVlj9eCtOKpcYOJ kA0VPWC8Efy+m9xsKMSI1QheyImEhc90pNombYL7kbnUCM4E4aAt5y7qhrfsBwOdfUx7 ilNRNx939elk95PfgxjNf9wZ8EL+05yqofSlOh1Vcfr2442HHmH2X1G+lbl3mexgRf+J OHwAGsUPxcOUf63pfxfiWoL6AFMEET9byMzDC003dzhbzIBjMVvxEpyCqTx3M3xg+01d WKaw== X-Gm-Message-State: AOAM532EwTza4ZXNF9KqlvJIOUh2eq7CABXHK17l+8d2lY/psLr/IFTE otdtMV028qbKHQvCTZJUmCDGYg== X-Google-Smtp-Source: ABdhPJzwluIjV6EurcBVvKlETIs9IsuXQhq0Wdlfkue8UtyQ+jr1/6tDPXhZ/7GJIBRXyUL7cK3gdA== X-Received: by 2002:a17:902:bd01:b0:161:ef0f:9da8 with SMTP id p1-20020a170902bd0100b00161ef0f9da8mr4738809pls.147.1653057267335; Fri, 20 May 2022 07:34:27 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id x137-20020a62868f000000b0050dc76281b0sm1882011pfd.138.2022.05.20.07.34.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 May 2022 07:34:26 -0700 (PDT) Message-ID: <938111ca-d3c7-9888-24f8-0017a989002b@kernel.dk> Date: Fri, 20 May 2022 08:34:25 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH] splice: allow direct splicing with chardevs Content-Language: en-US To: "Jason A. Donenfeld" , linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: Jens Axboe References: <20220520095747.123748-1-Jason@zx2c4.com> From: Jens Axboe In-Reply-To: <20220520095747.123748-1-Jason@zx2c4.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/20/22 3:57 AM, Jason A. Donenfeld wrote: > The original direct splicing mechanism from Jens required the input to > be a regular file because it was avoiding the special socket case. It > also recognized blkdevs as being close enough to a regular file. But it > forgot about chardevs, which behave the same way and work fine here. > > This commit adds the missing S_ISCHR condition so that chardevs such as > /dev/urandom can be directly spliced without strangely returning > -EINVAL. Should be fine to turn this on for char devices: Reviewed-by: Jens Axboe -- Jens Axboe