linux-ext4 - [PATCH]An inlinedata bug in ext4_destroy_inline_data

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Message-ID: <CACKVGOZQn1S3nrF_p7sNnV8Z0Y--dnLFgt5P4TB56DP_yB0_-A@mail.gmail.com>
Date:	Tue, 8 Oct 2013 23:32:05 +0800
From:	baixing quan <quanbaixin@...il.com>
To:	linux-ext4@...r.kernel.org
Subject: [PATCH]An inlinedata bug in ext4_destroy_inline_data_nolock()

Filesystem with inlinedata will be remounted with read only mode as
follow steps:

1.mkdir tmp
2.cd tmp
3.mkdir a12345 a23456 a34567 a45678 a67890 a78901
4.reboot
5.cd tmp
6.mv a23456 a23456aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

The bug happened in ext4_rename()
3122         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
3123             old_de->name_len != old_dentry->d_name.len ||
3124             strncmp(old_de->name, old_dentry->d_name.name,
old_de->name_len) ||
3125             (retval = ext4_delete_entry(handle, old_dir,
3126                                         old_de, old_bh)) == -ENOENT)

ext4_delete_entry-> ext4_generic_delete_entry-> ext4_check_dir_entry()
 find the inode number is illegal and the system is remounted with
read only mode.

When the inlinedata is cleared in
ext4_destroy_inline_data_nolock(),ext4_inode->i_block[] is set to 0,
but ext4_inode->i_block[] is assigned as ext4_inode_info->i_block[] in
ext4_mark_iloc_dirty().Therefore, the inlinedata still exist in
ext4_inode->i_block[] and result in ext4_delete_entry() in line 3125
is executed.


>From d0e24fc2c0817fafe816b510060c711e56b6b645 Mon Sep 17 00:00:00 2001
From: qbx <quanbaixin@....com>
Date: Tue, 8 Oct 2013 07:04:13 -0700
Subject: [PATCH] inlinedata rename bug

---
 fs/ext4/inline.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index d9ecbf1..cc6375e 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -434,6 +434,7 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle,

        memset((void *)ext4_raw_inode(&is.iloc)->i_block,
                0, EXT4_MIN_INLINE_DATA_SIZE);
+       memset(ei->i_data,0, sizeof(ei->i_data));

        if (EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
                                      EXT4_FEATURE_INCOMPAT_EXTENTS)) {
-- 
1.7.9.4
--
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