From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.43 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793862024; b=vV647dYsRGQk8NpFVWXHJlYRpbSN1dfzsHe/anpwyVx4GjuRb0n9WC4zouWVl3kenMbW E5FzvQuOmJXpQ8tuzkzqSQzU4D+tokPLgUmSUuuxWGvIsh/XFH1QWcGdAgjJjLh8mqDyg LPIlAxMMWDSpKdmaIeSEvZXSioX94jg9PlhDTU7XPmsm8iSXsX0i1wGAydioOsd5CpAxw bdYLQGe/buw2HfhQVoxu4hVUf+SMdnsAG5KX0jJt8X16bnFCaGfUjiNww8KxKoYpZqfdG 2t1wQ9IO14XZG9DHqD46DmH8k+O52XxVgdADZ4RTfO6lz0OlVF6Lj6kNjBRparPN9cQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793862024; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=Kx5WUkjnErrix8wXibd1Wzcuh2GC05qD7z4XDKSCne4=; b=jNARGasDjTTRVWQf2FO5PHX7+kjcyzO+U+zaS29saUzY1FjtuEO50G7UYtQ3Yez2vTbS w202mp4WGE0ZMGr96gNt38GIYNTDn4xzO6mvvEUC97yKMVtf4cLuzg3J4oYamT9yAHoK2 2y7y6VR4NRmFon6azd5qARUWP0D37NruTq/brLE619K2ZYb5zD3rnmtwmKgisBQFH6dtM FiV+/pR8a/OBBQQjbnS3hHbW9qG6bKnBrCdxvC5cMV+b1raYFAeXlc4HVJXa2qLfcKWp8 sYxambvdB5cU6y/moIX8lO+0L2hh4peXVzYAtM1Uv/JZ2Bak4/pgEo0Y94fsUc4FWuA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=tLEI0IyM; arc=none smtp.remote-ip=95.215.58.43 Received: from mta1.migadu.com (out-43.mta1.migadu.com [95.215.58.43]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86E8A606A335 for ; Thu, 5 Nov 2026 07:00:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 86E8A606A335 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=tLEI0IyM X-Envelope-To: linux-ext4@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=J78YU5ZFO0YkJHWe7jsk/frJ8JTGoObKjxZIdpWIbcM=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793862021; v=1; x=1794466821; b=tLEI0IyM03Jx9PdNIr3UD/tEvPDKgYoO7sQaffewF3sLN+sjQl9i0vtYzf+JFZBfMVImQxHf k1Fg3YCSvdSSRiFTKJfj8Xr/R5UM2WP9vkOBMbRE6zUHlO8Ky4+K3wYrJdJAdnm7SdJ1dnhe5dT Mi3iTWH7mh7XM0ZeseSWInl4= X-Envelope-To: linux-ext4@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 56e7aac47ff0582e; Thu, 05 Nov 2026 07:00:19 +0000 X-Mizu-Trace-ID: 56e7aac47ff0582e X-Migadu-Flow: FLOW_OUT From: Mengmeng Zhao To: Jens Axboe , Dan Williams , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , tytso@mit.edu, Andreas Dilger , Baokun Li , Ojaswin Mujoo , "Ritesh Harjani (IBM)" , Zhang Yi , "Darrick J. Wong" , Andrew Morton , asml.silence@gmail.com, hch@lst.de, Anuj Gupta Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, Li Wang Subject: [RFC 5/6] iomap: refuse dmabuf iterators on contents-encrypted inodes Date: Thu, 5 Nov 2026 14:58:46 +0800 Message-ID: <20261105065847.196540-6-mengmeng.zhao@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261105065847.196540-1-mengmeng.zhao@linux.dev> References: <20261105065847.196540-1-mengmeng.zhao@linux.dev> X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Mengmeng Zhao Contents encryption needs the crypto layer to reach the data pages of the bio: blk-crypto_fallback kmaps and memcpys them, which a device mapping does not allow. Refuse the iterator in __iomap_dio_rw() before any bio is submitted instead of depending on each filesystem to keep dmabuf away from encrypted inodes, and in iomap_file_init_dma_buf_io_ctx() so that registration on an encrypted file fails up front. Signed-off-by: Mengmeng Zhao Signed-off-by: Li Wang --- fs/iomap/direct-io.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index fc40f4367ee7..aec47b70b084 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -728,6 +728,14 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iov_iter_is_dmabuf_map(iter) && (dio_flags & IOMAP_DIO_BOUNCE)) return ERR_PTR(-EOPNOTSUPP); + /* + * Contents encryption walks the bio pages in the crypto layer, which + * a dmabuf bio has none of. Reject before any bio is submitted. + */ + if (iov_iter_is_dmabuf_map(iter) && + fscrypt_needs_contents_encryption(inode)) + return ERR_PTR(-EOPNOTSUPP); + dio = kmalloc_obj(*dio); if (!dio) return ERR_PTR(-ENOMEM); @@ -940,6 +948,8 @@ int iomap_file_init_dma_buf_io_ctx(struct file *file, struct block_device *bdev, if (IS_DAX(inode)) return -EOPNOTSUPP; + if (fscrypt_needs_contents_encryption(inode)) + return -EOPNOTSUPP; return bdev_init_dma_buf_io_ctx(file, bdev, ctx); } EXPORT_SYMBOL_GPL(iomap_file_init_dma_buf_io_ctx); -- 2.43.0