This is a note to let you know that I've just added the patch titled
ext2: Fix link count corruption under heavy link+rename load
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
ext2-fix-link-count-corruption-under-heavy-link-rename-load.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
>From e8a80c6f769dd4622d8b211b398452158ee60c0b Mon Sep 17 00:00:00 2001
From: Josh Hunt <[email protected]>
Date: Thu, 24 Feb 2011 11:48:22 +0100
Subject: ext2: Fix link count corruption under heavy link+rename load
From: Josh Hunt <[email protected]>
commit e8a80c6f769dd4622d8b211b398452158ee60c0b upstream.
vfs_rename_other() does not lock renamed inode with i_mutex. Thus changing
i_nlink in a non-atomic manner (which happens in ext2_rename()) can corrupt
it as reported and analyzed by Josh.
In fact, there is no good reason to mess with i_nlink of the moved file.
We did it presumably to simulate linking into the new directory and unlinking
from an old one. But the practical effect of this is disputable because fsck
can possibly treat file as being properly linked into both directories without
writing any error which is confusing. So we just stop increment-decrement
games with i_nlink which also fixes the corruption.
CC: Al Viro <[email protected]>
Signed-off-by: Josh Hunt <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/ext2/namei.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -327,7 +327,6 @@ static int ext2_rename (struct inode * o
new_de = ext2_find_entry (new_dir, &new_dentry->d_name,
&new_page);
if (!new_de)
goto out_dir;
- inode_inc_link_count(old_inode);
ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
new_inode->i_ctime = CURRENT_TIME_SEC;
if (dir_de)
@@ -339,12 +338,9 @@ static int ext2_rename (struct inode * o
if (new_dir->i_nlink >= EXT2_LINK_MAX)
goto out_dir;
}
- inode_inc_link_count(old_inode);
err = ext2_add_link(new_dentry, old_inode);
- if (err) {
- inode_dec_link_count(old_inode);
+ if (err)
goto out_dir;
- }
if (dir_de)
inode_inc_link_count(new_dir);
}
@@ -352,12 +348,11 @@ static int ext2_rename (struct inode * o
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
- * inode_dec_link_count() will mark the inode dirty.
*/
old_inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(old_inode);
ext2_delete_entry (old_de, old_page);
- inode_dec_link_count(old_inode);
if (dir_de) {
if (old_dir != new_dir)
Patches currently in longterm-queue-2.6.32 which might be from
[email protected] are
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