From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E6E527FB35; Thu, 2 Apr 2026 05:05:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775106344; cv=none; b=Uz7Qz8vWznmkqQ1O3TySKfoeHNFz3P0exmR7or+aCs0uExdOqfYy47kaMsGkRmjzERJ7VA23Bf/oXTtrodk2pVtXqK+vn0oDAPUqIy9SLKaIquajk1gEY/rwhPAFcbB5RQ4149n9sT2xd2Tm27Z719kGnTvTO6zmGSkMFtINuFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775106344; c=relaxed/simple; bh=WrmP4xeitwaKkiK20UoChpSUaMTop6qzPNxEiPcXA7M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BPIOmRv11ROW6xwBsOtDLfIgOtHz9ULIXT9TaCvvbpyEKqyjScOkGmGDhqczcps7dtWYGKAZgZOfeyIDEWif5vGtCujYCfaLsWvx8mxqTIfS6DzCTj9zXSxdeMDgHsgIb5B9olRtlNWh5bZLpFYfOpGagTBvkrLa+yuwVlJpsLY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=PGAw8ToE; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PGAw8ToE" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=KHrQDLTxrZsF/4RAZbeKe9eCtH4wciflhWZFWGPkUH4=; b=PGAw8ToEYuMge9U2EGmcvROZ6g iMSIKpljCOcbCdPTgWjkxQlXP9VgMWw1WPI8v6AMYPXZPY1TMpJlWT/obu8prrqvX81M+QSpAWgNk aY5P6wvRrFfmliTvTE5s/0dx7YurnLmFHZBTO+umln+UXW/hJU6+kvO0vDJYrKiAiz4BcsqRoKyd0 4/bxOD1j5Wb5480eAuv4BbPYT2IUmmowbqTQVwSv7xHJWtikjYfjE5sWt68sl8A3cMCLCbNSn37jZ X29rTpulNrUC2pKo6pFmIKdRpBlUL3bn+G0zXxJN2NZ5nSP1jdt1hXeNI86QOGissn5HlxTcBnGLa bmG2t8OA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1w8AFM-0000000Gn9Y-0yDk; Thu, 02 Apr 2026 05:05:36 +0000 Date: Wed, 1 Apr 2026 22:05:36 -0700 From: Christoph Hellwig To: Pranjal Shrivastava Cc: trond.myklebust@hammerspace.com, anna@kernel.org, davem@davemloft.net, kuba@kernel.org, edumazet@google.com, pabeni@redhat.com, chuck.lever@oracle.com, jlayton@kernel.org, tom@talpey.com, okorniev@redhat.com, neil@brown.name, dai.ngo@oracle.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC PATCH 4/4] nfs: allow P2PDMA in direct I/O path Message-ID: References: <20260401194501.2269200-1-praan@google.com> <20260401194501.2269200-5-praan@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260401194501.2269200-5-praan@google.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Apr 01, 2026 at 07:45:00PM +0000, Pranjal Shrivastava wrote: > Migrate the NFS Direct I/O path from the legacy iov_iter_get_pages_alloc2() > API to the modern iov_iter_extract_pages() API. This migration enables > support for PCI Peer-to-Peer DMA (P2PDMA) by allowing the setting the > ITER_ALLOW_P2PDMA flag. > > Pass ITER_ALLOW_P2PDMA to iov_iter_extract_pages() only if the local > mount indicates support via the NFS_CAP_P2PDMA capability bit (detected > at mount time for RDMA transports). Please split theconversion to iov_iter_extract_pages into a separate preparation patch, and even series. That is a long overdue change that fixes potential data corruption in XFS.