[patch] ext4: underflow in alignment check

[Dan Carpenter]

My static checker complains that this can underflow if arg is negative
which is true.

Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b1a3471..a2a17e9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1576,7 +1576,7 @@ static int handle_mount_opt(struct super_block *sb, char 
*opt, int token,
        } else if (token == Opt_min_batch_time) {
                sbi->s_min_batch_time = arg;
        } else if (token == Opt_inode_readahead_blks) {
-               if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
+               if (arg && (arg > (1U << 30) || !is_power_of_2(arg))) {
                        ext4_msg(sb, KERN_ERR,
                                 "EXT4-fs: inode_readahead_blks must be "
                                 "0 or a power of 2 smaller than 2^31");