From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f48.google.com ([74.125.83.48]:65258 "EHLO mail-ee0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752215AbaA3A1v (ORCPT ); Wed, 29 Jan 2014 19:27:51 -0500 Received: by mail-ee0-f48.google.com with SMTP id t10so1240774eei.35 for ; Wed, 29 Jan 2014 16:27:50 -0800 (PST) Received: from localhost (host-115-115.kawo1.rwth-aachen.de. [134.130.115.115]) by mx.google.com with ESMTPSA id k41sm15292156eey.0.2014.01.29.16.27.49 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 29 Jan 2014 16:27:49 -0800 (PST) From: Gerhard Heift To: linux-btrfs@vger.kernel.org Subject: [PATCH RFCv3 3/6] btrfs: tree_search returns needed size on EOVERFLOW Date: Thu, 30 Jan 2014 01:27:28 +0100 Message-Id: <1391041651-15689-4-git-send-email-Gerhard@Heift.Name> 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 List-ID: If an item in tree_search is too large to be stored in the given buffer, return the needed size (including the header). Signed-off-by: Gerhard Heift --- fs/btrfs/ioctl.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 04e1a98..10b9931 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1854,7 +1854,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key, struct btrfs_ioctl_search_key *sk, - size_t buf_size, + size_t *buf_size, char *buf, unsigned long *sk_offset, int *num_found) @@ -1887,7 +1887,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, if (!key_in_sk(key, sk)) continue; - if (sizeof(sh) + item_len > buf_size) { + if (sizeof(sh) + item_len > *buf_size) { if (*num_found) { ret = 1; goto overflow; @@ -1898,11 +1898,12 @@ static noinline int copy_to_sk(struct btrfs_root *root, * handle -EOVERFLOW */ + *buf_size = sizeof(sh) + item_len; item_len = 0; ret = -EOVERFLOW; } - if (sizeof(sh) + item_len + *sk_offset > buf_size) { + if (sizeof(sh) + item_len + *sk_offset > *buf_size) { ret = 1; goto overflow; } @@ -1951,7 +1952,7 @@ overflow: static noinline int search_ioctl(struct inode *inode, struct btrfs_ioctl_search_key *sk, - size_t buf_size, + size_t *buf_size, char *buf) { struct btrfs_root *root; @@ -1962,8 +1963,10 @@ static noinline int search_ioctl(struct inode *inode, int num_found = 0; unsigned long sk_offset = 0; - if (buf_size < sizeof(struct btrfs_ioctl_search_header)) + if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) { + *buf_size = sizeof(struct btrfs_ioctl_search_header); return -EOVERFLOW; + } path = btrfs_alloc_path(); if (!path) @@ -2016,9 +2019,10 @@ err: static noinline int btrfs_ioctl_tree_search(struct file *file, void __user *argp) { - struct btrfs_ioctl_search_args *args; - struct inode *inode; - int ret; + struct btrfs_ioctl_search_args *args; + struct inode *inode; + int ret; + size_t buf_size; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -2027,8 +2031,10 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, if (IS_ERR(args)) return PTR_ERR(args); + buf_size = sizeof(args->buf); + inode = file_inode(file); - ret = search_ioctl(inode, &args->key, sizeof(args->buf), args->buf); + ret = search_ioctl(inode, &args->key, &buf_size, args->buf); /* * In the origin implementation an overflow is handled by returning a -- 1.8.5.3