From patchwork Wed Feb 15 15:40:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13141814 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 3F9ACC636CC for ; Wed, 15 Feb 2023 15:42:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbjBOPmW (ORCPT ); Wed, 15 Feb 2023 10:42:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229728AbjBOPmU (ORCPT ); Wed, 15 Feb 2023 10:42:20 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39C023866B for ; Wed, 15 Feb 2023 07:41:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676475669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Us0zCop2bZgqcPW/JXsl5O/r2nwlZx53CdefM19JIrA=; b=O1bfMbTkva/nAHkOFP6VlwmPxkeINoo9LNoNsKbSxwqtkhZMp86Fz7+RE8NsSdYtiqWf9u EiX9A+iOKRBb25II7NFbn1cowzeckeRkYGsI/QUsr2HTLjZQfKRn545Z4GthoUufqcgAOH E7Jb45NfWkMl+tO7TzL4gHNO17OpFRk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-630-LVpfoPQGNw6GNKM_irhueg-1; Wed, 15 Feb 2023 10:41:02 -0500 X-MC-Unique: LVpfoPQGNw6GNKM_irhueg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A2A5E885620; Wed, 15 Feb 2023 15:41:01 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1BF9418EC1; Wed, 15 Feb 2023 15:40:58 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20230214171330.2722188-1-dhowells@redhat.com> <20230214171330.2722188-6-dhowells@redhat.com> To: Miklos Szeredi Cc: dhowells@redhat.com, Jens Axboe , Al Viro , Christoph Hellwig , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard , linux-unionfs@vger.kernel.org Subject: [PATCH v15 05/17] overlayfs: Implement splice-read MIME-Version: 1.0 Content-ID: <3370084.1676475658.1@warthog.procyon.org.uk> Date: Wed, 15 Feb 2023 15:40:58 +0000 Message-ID: <3370085.1676475658@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org How about the attached then? David --- overlayfs: Implement splice-read Implement splice-read for overlayfs by passing the request down a layer rather than going through generic_file_splice_read() which is going to be changed to assume that ->read_folio() is present on buffered files. Signed-off-by: David Howells cc: Christoph Hellwig cc: Jens Axboe cc: Al Viro cc: John Hubbard cc: David Hildenbrand cc: Matthew Wilcox cc: Miklos Szeredi cc: linux-unionfs@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- Notes: ver #15) - Remove redundant FMODE_CAN_ODIRECT check on real file. - Do rw_verify_area() on the real file, not the overlay file. - Fix a file leak. fs/overlayfs/file.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index c9d0c362c7ef..72a545da51a2 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -419,6 +419,37 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) return ret; } +static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + const struct cred *old_cred; + struct fd real; + ssize_t ret; + + ret = ovl_real_fdget(in, &real); + if (ret) + return ret; + + ret = -EINVAL; + if (!real.file->f_op->splice_read) + goto out_fdput; + + ret = rw_verify_area(READ, real.file, ppos, len); + if (unlikely(ret < 0)) + goto out_fdput; + + old_cred = ovl_override_creds(file_inode(in)->i_sb); + ret = real.file->f_op->splice_read(real.file, ppos, pipe, len, flags); + + revert_creds(old_cred); + ovl_file_accessed(in); +out_fdput: + fdput(real); + + return ret; +} + /* * Calling iter_file_splice_write() directly from overlay's f_op may deadlock * due to lock order inversion between pipe->mutex in iter_file_splice_write() @@ -695,7 +726,7 @@ const struct file_operations ovl_file_operations = { .fallocate = ovl_fallocate, .fadvise = ovl_fadvise, .flush = ovl_flush, - .splice_read = generic_file_splice_read, + .splice_read = ovl_splice_read, .splice_write = ovl_splice_write, .copy_file_range = ovl_copy_file_range,