This is a note to let you know that I've just added the patch titled
ext4: fix overflow when counting used blocks on 32-bit architectures
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-overflow-when-counting-used-blocks-on-32-bit-architectures.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8af8eecc1331dbf5e8c662022272cf667e213da5 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Fri, 31 May 2013 19:39:56 -0400
Subject: ext4: fix overflow when counting used blocks on 32-bit architectures
From: Jan Kara <jack@xxxxxxx>
commit 8af8eecc1331dbf5e8c662022272cf667e213da5 upstream.
The arithmetics adding delalloc blocks to the number of used blocks in
ext4_getattr() can easily overflow on 32-bit archs as we first multiply
number of blocks by blocksize and then divide back by 512. Make the
arithmetics more clever and also use proper type (unsigned long long
instead of unsigned long).
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4221,7 +4221,7 @@ int ext4_getattr(struct vfsmount *mnt, s
struct kstat *stat)
{
struct inode *inode;
- unsigned long delalloc_blocks;
+ unsigned long long delalloc_blocks;
inode = dentry->d_inode;
generic_fillattr(inode, stat);
@@ -4238,7 +4238,7 @@ int ext4_getattr(struct vfsmount *mnt, s
*/
delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
- stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
+ stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits-9);
return 0;
}
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-3.4/ext4-fix-data-offset-overflow-in-ext4_xattr_fiemap-on-32-bit-archs.patch
queue-3.4/ext4-fix-overflow-when-counting-used-blocks-on-32-bit-architectures.patch
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