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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AE0EC10F11 for ; Sat, 13 Apr 2019 20:54:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 530902084E for ; Sat, 13 Apr 2019 20:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727204AbfDMUyq (ORCPT ); Sat, 13 Apr 2019 16:54:46 -0400 Received: from mail-vk1-f194.google.com ([209.85.221.194]:34869 "EHLO mail-vk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727105AbfDMUyq (ORCPT ); Sat, 13 Apr 2019 16:54:46 -0400 Received: by mail-vk1-f194.google.com with SMTP id g24so2888508vki.2; Sat, 13 Apr 2019 13:54:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ognk4lz2NDKt1DvD/X12198HfbOIyneoWr847fqKsa4=; b=PHu1AI7nR3zd4DoKcBAeFTiDvpgzwNs5Im63A5Ykp0n/gcCbgdvzmm4Bmei3nG1HcH eFsRmR9DqeVpgZl5vNJRSnXe1V11tlVPEIifq+Xn57esSCJwxodIjKA3VjCXrqCLZN2F wzsDyr1lQoF41im5Hil+odH7mJLLqYmMZiL9LBu9yX9ln+dYLZDyeUF0NvUb3mPu1QAT X5FBanLKOAmIq7zVPrpQ+br68fsk4h7Tmj8yr4KaUQSpBRT349a/ejxKCXeqZcgyx3hm XT+ABt63RiEgVEIQRy6mpEm3DriYY+bSQX66yEATkBRNWy/oe3Q2ozC2EDsDT89/3EfQ rsDw== X-Gm-Message-State: APjAAAXCfG9uNegTSVoc+lCeCQNAetg1POj1m9GOHyjebaajq4J5h16v kABbcDUnb0VKThlZb5Zg8R8kUR53QXAGZg== X-Google-Smtp-Source: APXvYqwv3V8ZyHxCWYExIpQywnX8nFC3rJdZ1OA3aV4RypgIwI1SHfCFCKjKhnQm6jXi1nKzqGusqQ== X-Received: by 2002:a1f:23c5:: with SMTP id j188mr34821935vkj.39.1555188884730; Sat, 13 Apr 2019 13:54:44 -0700 (PDT) Received: from localhost.localdomain ([201.240.145.139]) by smtp.gmail.com with ESMTPSA id g184sm11132244vkd.31.2019.04.13.13.54.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Apr 2019 13:54:44 -0700 (PDT) From: Shawn Landden Cc: linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Shawn Landden Subject: [PATCH] new flag COPY_FILE_RANGE_FILESIZE for copy_file_range() Date: Sat, 13 Apr 2019 15:54:39 -0500 Message-Id: <20190413205439.9623-1-shawn@git.icu> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If flags includes COPY_FILE_RANGE_FILESIZE then the length copied is the length of the file. off_in and off_out are ignored. len must be 0 or the file size. This implementation saves a call to stat() in the common case of copying files. It does not fix any race conditions, but that is possible in the future with this interface. EAGAIN: If COPY_FILE_RANGE_FILESIZE was passed and len is not 0 or the file size. Signed-off-by: Shawn Landden CC: --- fs/read_write.c | 14 +++++++++++++- include/uapi/linux/stat.h | 4 ++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/read_write.c b/fs/read_write.c index 61b43ad7608e..6d06361f0856 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1557,7 +1557,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, struct inode *inode_out = file_inode(file_out); ssize_t ret; - if (flags != 0) + if ((flags & ~COPY_FILE_RANGE_FILESIZE) != 0) return -EINVAL; if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) @@ -1565,6 +1565,18 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) return -EINVAL; + if (flags & COPY_FILE_RANGE_FILESIZE) { + struct kstat stat; + int error; + error = vfs_getattr(&file_in->f_path, &stat, + STATX_SIZE, 0); + if (error < 0) + return error; + if (!(len == 0 || len == stat.size)) + return -EAGAIN; + len = stat.size; + } + ret = rw_verify_area(READ, file_in, &pos_in, len); if (unlikely(ret)) return ret; diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 7b35e98d3c58..1075aa4666ef 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -170,5 +170,9 @@ struct statx { #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */ +/* + * Flags for copy_file_range() + */ +#define COPY_FILE_RANGE_FILESIZE 0x00000001 /* Copy the full length of the input file */ #endif /* _UAPI_LINUX_STAT_H */ -- 2.20.1