From: Akira Fujita Subject: [PATCH 3/4]ext4: Add null extent check to ext_get_path() Date: Mon, 14 Sep 2009 17:17:23 +0900 Message-ID: <4AADFC13.4070101@rs.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit To: Theodore Tso , linux-ext4@vger.kernel.org, Peng Tao Return-path: Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:64901 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754983AbZINITM (ORCPT ); Mon, 14 Sep 2009 04:19:12 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: ext4: Add null extent check to ext_get_path From: Akira Fujita There is the possibility that path structure which is taken by ext4_ext_find_extent() indicates null extents. Because during data block exchanging in ext4_move_extents(), constitution of an extent tree may be changed. As a solution, the patch adds null extent check to ext_get_path(). Reported-by: Peng Tao　 Signed-off-by: Akira Fujita --- fs/ext4/move_extent.c | 28 +++++++++++++--------------- 1 files changed, 13 insertions(+), 15 deletions(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 6d126d0..7c26c74 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -39,7 +39,9 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock, if (IS_ERR(*path)) { ret = PTR_ERR(*path); *path = NULL; - } + } else if ((*path)[ext_depth(inode)].p_ext == NULL) + ret = -ENODATA; + return ret; } @@ -316,7 +318,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, if (new_flag) { err = get_ext_path(orig_inode, eblock, &orig_path); - if (orig_path == NULL) + if (err) goto out; if (ext4_ext_insert_extent(handle, orig_inode, @@ -327,7 +329,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, if (end_flag) { err = get_ext_path(orig_inode, le32_to_cpu(end_ext->ee_block) - 1, &orig_path); - if (orig_path == NULL) + if (err) goto out; if (ext4_ext_insert_extent(handle, orig_inode, @@ -673,12 +675,12 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, /* Get the original extent for the block "orig_off" */ err = get_ext_path(orig_inode, orig_off, &orig_path); - if (orig_path == NULL) + if (err) goto out; /* Get the donor extent for the head */ err = get_ext_path(donor_inode, donor_off, &donor_path); - if (donor_path == NULL) + if (err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; @@ -733,7 +735,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, if (orig_path) ext4_ext_drop_refs(orig_path); err = get_ext_path(orig_inode, orig_off, &orig_path); - if (orig_path == NULL) + if (err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; @@ -747,7 +749,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, if (donor_path) ext4_ext_drop_refs(donor_path); err = get_ext_path(donor_inode, donor_off, &donor_path); - if (donor_path == NULL) + if (err) goto out; depth = ext_depth(donor_inode); dext = donor_path[depth].p_ext; @@ -1230,20 +1232,16 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, len -= block_end - file_end; ret1 = get_ext_path(orig_inode, block_start, &orig_path); - if (orig_path == NULL) + if (ret1) goto out2; /* Get path structure to check the hole */ ret1 = get_ext_path(orig_inode, block_start, &holecheck_path); - if (holecheck_path == NULL) + if (ret1) goto out; depth = ext_depth(orig_inode); ext_cur = holecheck_path[depth].p_ext; - if (ext_cur == NULL) { - ret1 = -EINVAL; - goto out; - } /* * Get proper extent whose ee_block is beyond block_start @@ -1372,7 +1370,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, if (holecheck_path) ext4_ext_drop_refs(holecheck_path); ret1 = get_ext_path(orig_inode, seq_start, &holecheck_path); - if (holecheck_path == NULL) + if (ret1) break; depth = holecheck_path->p_depth; @@ -1380,7 +1378,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, if (orig_path) ext4_ext_drop_refs(orig_path); ret1 = get_ext_path(orig_inode, seq_start, &orig_path); - if (orig_path == NULL) + if (ret1) break; ext_cur = holecheck_path[depth].p_ext;