ext4: properly align shifted xattrs when expanding inodes

BugLink: http://bugs.launchpad.net/bugs/1624037

commit 443a8c41 upstream.

We did not count with the padding of xattr value when computing desired
shift of xattrs in the inode when expanding i_extra_isize. As a result
we could create unaligned start of inline xattrs. Account for alignment
properly.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

fs/ext4/xattr.c

@@ -1429,7 +1429,7 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 		if (entry_size + EXT4_XATTR_SIZE(size) >= isize_diff)
 			shift_bytes = isize_diff;
 		else
-			shift_bytes = entry_size + size;
+			shift_bytes = entry_size + EXT4_XATTR_SIZE(size);
 		/* Adjust the offsets and shift the remaining entries ahead */
 		ext4_xattr_shift_entries(entry, -shift_bytes,
 			(void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +