From patchwork Thu Jan 30 00:27:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Heift X-Patchwork-Id: 3555431 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8873BC02DC for ; Thu, 30 Jan 2014 00:28:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AB472201B9 for ; Thu, 30 Jan 2014 00:28:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2DFD2018E for ; Thu, 30 Jan 2014 00:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752379AbaA3A2K (ORCPT ); Wed, 29 Jan 2014 19:28:10 -0500 Received: from mail-ee0-f50.google.com ([74.125.83.50]:41505 "EHLO mail-ee0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752159AbaA3A1y (ORCPT ); Wed, 29 Jan 2014 19:27:54 -0500 Received: by mail-ee0-f50.google.com with SMTP id d17so1243943eek.37 for ; Wed, 29 Jan 2014 16:27:53 -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=LdeFAyVQZn9j2F/2dfiaJ9BGoI26vP0x8qxdZ32Zf44=; b=ICtXS7qsLzzHsVQNfgmQDeybAAb1WFsASZoo+y4c47p3/NdhfcqliLQWh0zjWCPvMv MTxPP71mnQpjYYrnp4HUitlo/h3Ms5eik/blk8fCFmE5CSJzddkrcsk4OIxG94HeOJ6m LBvetFrf+FA5gYiIPOnlYHux3JsN8M91gj2vy4DgpnufQDRzWIKkT19wc+FIfMHT5376 /W3dJXgfEB7msjRqj5HNABoPi1tjh7EIQ7ucbYtm/VtHLzQrVPXQZFSdjrvBmS0r2f41 VrOEq8tZv4eGVxIAT72Ew7EfJmZ3ghTb/IKAyiwvVMuv50ZxUwn5+KC/C+KGwm07ryxY cImA== X-Gm-Message-State: ALoCoQkGK46v/Rwqlrf6TOajYYWdaVh+SYlCUBzIZ4i2T83S4moLQXcv5Hkrh+kIZbaJnGFTYyDh X-Received: by 10.14.214.65 with SMTP id b41mr62317eep.105.1391041673520; Wed, 29 Jan 2014 16:27:53 -0800 (PST) Received: from localhost (host-115-115.kawo1.rwth-aachen.de. [134.130.115.115]) by mx.google.com with ESMTPSA id l4sm15358321een.13.2014.01.29.16.27.52 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 29 Jan 2014 16:27:52 -0800 (PST) From: Gerhard Heift To: linux-btrfs@vger.kernel.org Subject: [PATCH RFCv3 5/6] btrfs: search_ioctl: direct copy to userspace Date: Thu, 30 Jan 2014 01:27:30 +0100 Message-Id: <1391041651-15689-6-git-send-email-Gerhard@Heift.Name> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1391041651-15689-1-git-send-email-Gerhard@Heift.Name> References: <1391041651-15689-1-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=-7.4 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 memory in the kernel. This allows to run a large search inside of a single call. Signed-off-by: Gerhard Heift --- fs/btrfs/ioctl.c | 52 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 10b9931..6daf23b 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 *buf, unsigned long *sk_offset, int *num_found) { @@ -1890,7 +1890,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, if (sizeof(sh) + item_len > *buf_size) { if (*num_found) { ret = 1; - goto overflow; + goto err; } /* @@ -1905,7 +1905,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, if (sizeof(sh) + item_len + *sk_offset > *buf_size) { ret = 1; - goto overflow; + goto err; } sh.objectid = key->objectid; @@ -1915,20 +1915,28 @@ 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(buf + *sk_offset, &sh, sizeof(sh))) { + ret = -EFAULT; + goto err; + } + *sk_offset += sizeof(sh); if (item_len) { - char *p = buf + *sk_offset; + char __user *p = buf + *sk_offset; /* copy the item */ - read_extent_buffer(leaf, p, - item_off, item_len); + if (read_extent_buffer_to_user(leaf, p, + item_off, item_len)) { + ret = -EFAULT; + goto err; + } + *sk_offset += item_len; } (*num_found)++; if (ret) /* -EOVERFLOW from above */ - goto overflow; + goto err; if (*num_found >= sk->nr_items) break; @@ -1946,14 +1954,24 @@ advance_key: key->objectid++; } else ret = 1; -overflow: +err: + /* + * 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 *buf) { struct btrfs_root *root; struct btrfs_key key; @@ -2004,6 +2022,7 @@ static noinline int search_ioctl(struct inode *inode, ret = copy_to_sk(root, path, &key, sk, buf_size, buf, &sk_offset, &num_found); btrfs_release_path(path); + if (ret || num_found >= sk->nr_items) break; @@ -2019,7 +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 *args; + struct btrfs_ioctl_search_key sk; struct inode *inode; int ret; size_t buf_size; @@ -2027,14 +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); + args = (struct btrfs_ioctl_search_args __user *)argp; + + if (copy_from_user(&sk, &args->key, sizeof(sk))) + return -EFAULT; buf_size = sizeof(args->buf); inode = file_inode(file); - ret = search_ioctl(inode, &args->key, &buf_size, args->buf); + ret = search_ioctl(inode, &sk, &buf_size, args->buf); /* * In the origin implementation an overflow is handled by returning a @@ -2045,7 +2066,6 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) ret = -EFAULT; - kfree(args); return ret; }