From patchwork Thu Jan 30 15:24:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Heift X-Patchwork-Id: 3557831 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2798A9F2E9 for ; Thu, 30 Jan 2014 15:24:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0EE98201BB for ; Thu, 30 Jan 2014 15:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF3D220123 for ; Thu, 30 Jan 2014 15:24:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753543AbaA3PYZ (ORCPT ); Thu, 30 Jan 2014 10:24:25 -0500 Received: from mail-ee0-f42.google.com ([74.125.83.42]:43516 "EHLO mail-ee0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753532AbaA3PYW (ORCPT ); Thu, 30 Jan 2014 10:24:22 -0500 Received: by mail-ee0-f42.google.com with SMTP id e49so1665941eek.15 for ; Thu, 30 Jan 2014 07:24:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=V8E1h9bhLTiTeYRvhExh8yZKlnu5sNDli77KYfsRop0=; b=RJUY/w9IhmaOajd3Hr0odgs2Sgxak196hbJ7E2H21tZqUKMtTWKTsdyh62YneURVNk hiqO5VKxk2Ygdp1x0NEN710XFFj81ryjIZWPdJUQmCsUDCTQjMpFOURmfEljhLdF+Wqu XyhC220GscjvQvIjP7dFVlU+TVfrV0mrhpeBLvj7Dk5FxhJD+BrM5slgOJOeLRdanrZH UpQok3RrOuiklCtPJuRfzUA2GIjk5Oks6w7qVoB0rwFLGnodIVC+zChhfT9cLwD+jbWT f2D9AHpnKRnVVn7kPw1l+ccYuMjFTn5Suf0hIZRjVLqeMQLXVeMe1ydKUif2sbTdvELX hIvQ== X-Gm-Message-State: ALoCoQlpmOi0c1ApR/RnZ99pUf7eGc2rfUvHR56VSgu6eJGwjNcvxdxqD2Okrt1Zpd5JvPw2A0WZ X-Received: by 10.14.220.193 with SMTP id o41mr18084733eep.22.1391095461577; Thu, 30 Jan 2014 07:24:21 -0800 (PST) Received: from localhost (host-115-115.kawo1.rwth-aachen.de. [134.130.115.115]) by mx.google.com with ESMTPSA id k6sm23770984eep.17.2014.01.30.07.24.20 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 30 Jan 2014 07:24:20 -0800 (PST) From: Gerhard Heift To: linux-btrfs@vger.kernel.org Subject: [PATCH RFCv4 6/7] btrfs: tree_search, search_ioctl: direct copy to userspace Date: Thu, 30 Jan 2014 16:24:02 +0100 Message-Id: <1391095443-20287-7-git-send-email-Gerhard@Heift.Name> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1391095443-20287-1-git-send-email-Gerhard@Heift.Name> References: <1391095443-20287-1-git-send-email-Gerhard@Heift.Name> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP By copying each found item seperatly to userspace, we do not need extra buffer in the kernel. Signed-off-by: Gerhard Heift --- fs/btrfs/ioctl.c | 48 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 1180293..bab8c67 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1855,7 +1855,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, struct btrfs_key *key, struct btrfs_ioctl_search_key *sk, size_t *buf_size, - char *buf, + char __user *ubuf, unsigned long *sk_offset, int *num_found) { @@ -1915,14 +1915,22 @@ static noinline int copy_to_sk(struct btrfs_root *root, sh.transid = found_transid; /* copy search result header */ - memcpy(buf + *sk_offset, &sh, sizeof(sh)); + if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) { + ret = -EFAULT; + goto out; + } + *sk_offset += sizeof(sh); if (item_len) { - char *p = buf + *sk_offset; + char __user *up = ubuf + *sk_offset; /* copy the item */ - read_extent_buffer(leaf, p, - item_off, item_len); + if (read_extent_buffer_to_user(leaf, up, + item_off, item_len)) { + ret = -EFAULT; + goto out; + } + *sk_offset += item_len; } (*num_found)++; @@ -1949,13 +1957,22 @@ advance_key: } else ret = 1; out: + /* + * 0: all items from this leaf copied, continue with next + * 1: * more items can be copied, but unused buffer is too small + * * all items were found + * Either way, it will stops the loop which iterates to the next + * leaf + * -EOVERFLOW: item was to large for buffer + * -EFAULT: could not copy extent buffer back to userspace + */ return ret; } static noinline int search_ioctl(struct inode *inode, struct btrfs_ioctl_search_key *sk, size_t *buf_size, - char *buf) + char __user *ubuf) { struct btrfs_root *root; struct btrfs_key key; @@ -2003,7 +2020,7 @@ static noinline int search_ioctl(struct inode *inode, ret = 0; goto err; } - ret = copy_to_sk(root, path, &key, sk, buf_size, buf, + ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf, &sk_offset, &num_found); btrfs_release_path(path); if (ret) @@ -2021,7 +2038,8 @@ err: static noinline int btrfs_ioctl_tree_search(struct file *file, void __user *argp) { - struct btrfs_ioctl_search_args *args; + struct btrfs_ioctl_search_args __user *uargs; + struct btrfs_ioctl_search_key sk; struct inode *inode; int ret; size_t buf_size; @@ -2029,14 +2047,15 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - args = memdup_user(argp, sizeof(*args)); - if (IS_ERR(args)) - return PTR_ERR(args); + uargs = (struct btrfs_ioctl_search_args __user *)argp; - buf_size = sizeof(args->buf); + if (copy_from_user(&sk, &uargs->key, sizeof(sk))) + return -EFAULT; + + buf_size = sizeof(uargs->buf); inode = file_inode(file); - ret = search_ioctl(inode, &args->key, &buf_size, args->buf); + ret = search_ioctl(inode, &sk, &buf_size, uargs->buf); /* * In the origin implementation an overflow is handled by returning a @@ -2045,9 +2064,8 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, if (ret == -EOVERFLOW) ret = 0; - if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) + if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk))) ret = -EFAULT; - kfree(args); return ret; }