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 B2765C433F5 for ; Wed, 4 May 2022 08:49:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346495AbiEDIwl (ORCPT ); Wed, 4 May 2022 04:52:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346435AbiEDIwh (ORCPT ); Wed, 4 May 2022 04:52:37 -0400 Received: from mail-oa1-x29.google.com (mail-oa1-x29.google.com [IPv6:2001:4860:4864:20::29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DECF24BE5 for ; Wed, 4 May 2022 01:49:01 -0700 (PDT) Received: by mail-oa1-x29.google.com with SMTP id 586e51a60fabf-e5e433d66dso542779fac.5 for ; Wed, 04 May 2022 01:49:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vFIh1CyhYoOEEs8kbWR5yCunmbCgcWGITL6fTjmMnQw=; b=g3ePdZbj07z/SQtZ3q6Rvxl3hsnUQAUpl5+QnU/2JrBT5r6FbJnGqMdBolz8IJYg/a MnPEplvJnmewM04s9hF7speIY4qJveoHobQV4IiZQ3BPczLXKnYohQHLx5mxO7+cqyB2 FTkJSbHIOs64B5/Dq2JQwiyYBt9EWvy3GEEA7JM0EwcvsYHrrUYbsTdrUESd4T0+77It g8SYWDsbdnQX3zKUVrmHv6EUWSDWU7GzP9lmDfebbBYw0oGgUxJeuAwCSVA9KR+mXFTk /AMqtYj4N0RR6o6yQCPoYXrNsYt6JlLNYN2lSOqRFSMWpD/LhNLsqGKXTJxY30nWaYwj pcWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vFIh1CyhYoOEEs8kbWR5yCunmbCgcWGITL6fTjmMnQw=; b=e8SqjlcK0qUpz73EKs7HPsCAbLGzvFH+s8KXugLnDSweVAAiDuetaL/xdbhf17O588 is57al6jhFWfSsXiMuQu+uZxYzNHJsfXv6uso/zM0qmVG7LRxzzZNGSVVNbqtpcGIR5b O2stgQgDCdjpFudCSrhoScxKw6Fp08JjC9b2z8EuEu8pzVFEh9HxUiIIYjWVoR5Nd3kE AzZJG65kfEcSxFoCkWdRMxXS0Gmf/S9YcY5sYsSF3FZ5lZ6usYktZFGtginIJYRl1eb6 UL9C95V61Tb7y5wpzEQxO82XcWDGV6ByZbKmO0TECIqR9wHVfl/YHQw9O81272FAt2SQ Eq/Q== X-Gm-Message-State: AOAM533Iv2K7ftWBo59W+8e8G6XIc+qzuPw2pe7ePLdl328IrFK+6Onj +G/7gFgKBY/cyMqeVAf7f/aJgXYmB31v17+0JCR6iOiZ8M3qIYM2 X-Google-Smtp-Source: ABdhPJwEx0kAfrKjWjHXKJcaJcRGuuwzouzNqXc0CoN/T++pLVvZwPv9SFOZUZ531V61Al+1pH/gUzwuBPJSvDTlur0= X-Received: by 2002:a05:6870:c392:b0:e9:f20:fa8a with SMTP id g18-20020a056870c39200b000e90f20fa8amr3234278oao.15.1651654140641; Wed, 04 May 2022 01:49:00 -0700 (PDT) MIME-Version: 1.0 References: <20220503184831.78705-1-p.raghav@samsung.com> <20220503184831.78705-2-p.raghav@samsung.com> <20220503205202.GA9567@lst.de> In-Reply-To: From: Kanchan Joshi Date: Wed, 4 May 2022 08:48:35 -0700 Message-ID: Subject: Re: [PATCH v3 1/5] fs,io_uring: add infrastructure for uring-cmd To: Christoph Hellwig Cc: Pankaj Raghav , Jens Axboe , io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, Pavel Begunkov , Ming Lei , Luis Chamberlain , Stefan Roesch , gost.dev@samsung.com, Kanchan Joshi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org > > @@ -27,7 +27,6 @@ struct io_uring_sqe { > > union { > > __u64 addr; /* pointer to buffer or iovecs */ > > __u64 splice_off_in; > > - __u16 cmd_len; > > }; > > __u32 len; /* buffer size or number of iovecs */ > > union { > > @@ -64,16 +63,19 @@ struct io_uring_sqe { > > __u32 file_index; > > }; > > union { > > - __u64 addr3; > > - __u64 cmd; > > + struct { > > + __u64 addr3; > > + __u64 __pad2[1]; > > + } small; > > Thinking if this can cause any issue for existing users of addr3, i.e. > in the userspace side? Since it needs to access this field with > small.addr3. > Jens - is xattr infra already frozen? If this breaks anything, we can avoid that by not touching addr3 at all. And instead keep "__u64 __pad2[1]" and "__u8 cmd[0]" in the union. That means 72 bytes of space, but it is enough for the new nvme struct (nvme_uring_cmd) which is also 72 bytes. Does this sound fine?