From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (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 694113955DC for ; Wed, 29 Jul 2026 17:46:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785347181; cv=none; b=avEjVTk00yruFsVQgB148rwYSEuDnMP0OfwfqIJ8WoLin4kI9Xauv5IPUC27hlyDqjnEzWZLV5h1gbkcZxeCx9zzpQTw8vFFVnP4s3d6Cw+Bz7uiYaYLf0TihgQTuXVbqeZlQrhp47/PYjY8cuspZjgDG3EUJaSatvA5GbEeTUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785347181; c=relaxed/simple; bh=UidFeDXv81Ur5iK25hdw53vt+RFWGx9NnnGs3apTKJM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=PDRkDfZw6hHs5nsdtXFGqyzhUIDPnE09h8mkz2KT+AUJnUq3zoQrTOtGAR3tjHN1yyN9iR2HZ5cjciIehiNv3YKeV7Y/GcMOI9jGdZYFXZlm9q8MUoUbwUeW8l0SWL5eUUt6ARFtSE4ORD8/oV13aoVG7VLpHhEW6AUY8g9B3DQ= 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=LhtNhxku; arc=none smtp.client-ip=209.85.128.50 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="LhtNhxku" Received: by mail-wm1-f50.google.com with SMTP id 5b1f17b1804b1-4954afac04bso13987295e9.0 for ; Wed, 29 Jul 2026 10:46:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785347168; x=1785951968; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=WKE9xNdjsRTW2zyuw6/ikQhgmzmnupdLH1iSl4caYw4=; b=LhtNhxkutVb/rQ1a9tAjPqKS+PDo91gQzXUzhrAppUhes7wCBEtJlmBszRWptzX92P wX9M7VrN5dJQBY9YL+kcNbAKxHdLKpFnosAfFsgl71SDaYzQYZfc398fOvi1JKDaqoHI Mtay1Qdc/JnUL59ypsHrWWoZb85CA3sIiyipMb2U7BFRXgz+zPg1YJx/YTGbShyP7S6H F4QnP9aOsxZ91Y88DL1EIBcYtcWXvXS2O/rFN2M4KOtit3fPOLDgPEiCGFks1udshJqY XMtXDO9ISMyh7B6RHX4Hw+OYY+VXibFRwRhYEtyrZMJBpjC29yLUNVys6GuWV+pYjIDE FRdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785347168; x=1785951968; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=WKE9xNdjsRTW2zyuw6/ikQhgmzmnupdLH1iSl4caYw4=; b=aDrocK/rF+bifu47vN1EJAvmTyAd3I3DG42l40Si0TyiTKN7J6AA76m7aukA/b6KBL DwC7YXshvlqKuFGeIC6NfMJOQyHFvdadWAUIdZpRZo7Il1WfNszoqkUm0KFfs6jvETZe 9fAu54v+LnH3cm3Zi2RAOGRaEJby46VTvDNkhGeD7m8220Fo8IBgqQ1Vd/oB0BJh/3+J a63sUAASwUCY2sdtqCGLgoTcpW/HlglIImxyDzFviN7FQs0UXUpKvLkE/CYqexxJOfh8 4pajKCanhPD1/P07iDlyPzY3LCkE8EedpyqgsVjP7MN34gO6srTgMIBJpYMtNLnvot60 4fnA== X-Forwarded-Encrypted: i=1; AHgh+Rq9vpVTOcvHZzH7EVmtG6OJ7Ub/mOPb88iI9RPx/gj1VlfFtTIOOJ8MsGpiBx8kmErfdB+Jvah0e1ASvw==@vger.kernel.org X-Gm-Message-State: AOJu0Yy1SCA63ZF38xrLh7MFSkOgZ8/Xiktih1Ydb+8V5tX9pqxThPix 7qw7yWDiPJ1OMsUv72gFUdHOxTs84Dxn90ypmifqhsv9Yx1taW/ZihBJ X-Gm-Gg: AR+sD11ujqi3JL7kTtKN2fqa4/tqkFzUcUIiugxYcumnPYpFNcHQKEECUCUjVE+e06y WDbOoPowhBxznrQ4EnH8AcPl15asY+jN7Vg1jxJ//qqRBpLsPEbZUffGY/cvGq3vL2grBhmCaRb f1YA9pUpe71BKWowbh5IkN/XN+7QR5EgPRJR74zCHf9lL481r0fUh+i5oNC8vNVME5xKIJbxEhw DykWKAHf5meexnK/1lOSoFhTABelqmwBCliyRu48Zlm7prMZPQa+YXrw8M7DORLPxL15ubFn9ed 1u++SnxS7tqz7gnDKXB50sminq03yD3hMm7AK1Yv2TgREQNzb7dXA9cjQ1vKeK0FjtwuwxUx1cS TMO6Xg3v6fjXCdi8/2ulk/iblJ59LyvV3hE7qwLZeCd6rrGBV3M50XnBAXpk5b9Wvzllblr94Wh P47k4Fbc6jTR8C5WrkMHJvdHRYUqu0TazR0FmiitdayFLMDWl2cKUlziGipo9mmEiFaYCfxjZSv XYf30DJQu9w8Kkd3Bz4RXUvQQylcr5ncjYnAJThR3+GswhZEzhM6QRoNKmmvn+0CDwHY+kdA8qD IGOd+mZCq5GrbnYl6K53W40Zg17iqxBYHJ56BoU= X-Received: by 2002:a05:600c:4fd2:b0:493:e79e:da6b with SMTP id 5b1f17b1804b1-496c6590660mr98300165e9.21.1785347168019; Wed, 29 Jul 2026 10:46:08 -0700 (PDT) Received: from ?IPV6:2a01:4b00:bd21:4f00:7cc6:d3ca:494:116c? ([2a01:4b00:bd21:4f00:7cc6:d3ca:494:116c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-496c45b1c2asm171605965e9.5.2026.07.29.10.46.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Jul 2026 10:46:07 -0700 (PDT) Message-ID: <5afa3726-6c15-41c8-af19-766eb76b4b46@gmail.com> Date: Wed, 29 Jul 2026 18:45:58 +0100 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 14/14] io_uring/rsrc: add dmabuf backed registered buffers To: Anuj gupta Cc: Anuj Gupta/Anuj Gupta , Jens Axboe , Keith Busch , Christoph Hellwig , Sagi Grimberg , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, Alexander Viro , Christian Brauner , Andrew Morton , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , Nitesh Shetty , Kanchan Joshi , Jason Gunthorpe , Damien Le Moal , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , David Sterba , Ilya Dryomov , dm-devel@lists.linux.dev, nvdimm@lists.linux.dev, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org References: <26dcd0ae5c87a3ada5710b14b6894ef343cec6fe.1785274111.git.asml.silence@gmail.com> <583fdfb2-5368-467f-a388-6d388859c995@samsung.com> <0df2f832-e8a8-4fdd-a5b6-e08657c2891f@gmail.com> Content-Language: en-US From: Pavel Begunkov In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 7/29/26 17:52, Anuj gupta wrote: > On Wed, Jul 29, 2026 at 7:37 PM Pavel Begunkov wrote: >>>> +static int io_import_dmabuf(struct io_kiocb *req, >>>> + int ddir, struct iov_iter *iter, >>>> + struct io_mapped_ubuf *imu, >>>> + size_t len, size_t offset, >>>> + unsigned issue_flags) >>>> +{ >>>> + struct io_regbuf_dma *db = imu->priv; >>>> + struct dma_buf_io_map *map; >>>> + >>>> + if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) >>>> + return -EOPNOTSUPP; >>>> + if (!len) >>>> + return -EFAULT; >>>> + if (req->file != db->target_file) >>>> + return -EBADF; >>>> + >>>> + if (req->flags & REQ_F_DROP_DMABUF) { >>>> + map = req->dmabuf_map; >>>> + goto init_iter; >>>> + } >>> >>> O_DIRECT is checked only during registration; we should recheck >>> (file->f_flags & O_DIRECT) per request. >> >> Nobody should be able to clear O_DIRECT, unless I missed something? >> And fwiw, io_uring wouldn't be the right place to do it. >> > > fcntl(fd, F_SETFL, flags & ~O_DIRECT) on an already registered, already > open fd succeeds. The consequence is that subsequent I/Os switch to Very exciting. > buffered I/O and cause silent data loss. Something on this path needs > to reject this combination. Yeah, I'll fix it, thanks -- Pavel Begunkov