Re: [PATCH] ext3: also fix loop in do_split()

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 29 Nov 2008 04:40:42 -0500
roel kluin <roel.kluin@gmail.com> wrote:

> unsigned i >= 0 is always true
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
> index 3e5edc9..8f5e15d 100644
> --- a/fs/ext3/namei.c
> +++ b/fs/ext3/namei.c
> @@ -1188,7 +1188,7 @@ static struct ext3_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
>  	/* Split the existing block in the middle, size-wise */
>  	size = 0;
>  	move = 0;
> -	for (i = count-1; i >= 0; i--) {
> +	for (i = count-1; i < count; i--) {
>  		/* is more than half of this entry in 2nd half of the block? */
>  		if (size + map[i].size/2 > blocksize/2)
>  			break;

A local variable called `i' should always have signed type.  In fact,
it should have `int' type.  Doing

	unsigned i;

is an act of insane vandalism, punishable by spending five additional
years coding in fortran.

I suggest you fix this by giving `i' the type God intended, or by
making it unsigned and then renaming it to something which is not
intended to trick programmers and reviewers.

Sheesh.