Re: [PATCH][FAT] FAT dirent scan with hin take #3

[Pekka Enberg <penberg@cs.helsinki.fi>]

Hi,

On 8/31/05, Machida, Hiroyuki <machida@sm.sony.co.jp> wrote:
> +inline
> +static int hint_allocate(struct inode *dir)
> +{
> +       loff_t *hints;
> +       int err = 0;
> +
> +       if (!MSDOS_I(dir)->scan_hints) {
> +               hints = kcalloc(FAT_SCAN_NWAY, sizeof(loff_t), GFP_KERNEL);
> +               if (!hints)
> +                       err = -ENOMEM;

Better to bail out here as...

> +
> +               down(&MSDOS_I(dir)->scan_lock);
> +               if (MSDOS_I(dir)->scan_hints)
> +                       err = -EINVAL;

...you might overwrite -ENOMEM here masking the real problem.

> +               if (!err)
> +                       MSDOS_I(dir)->scan_hints = hints;
> +               up(&MSDOS_I(dir)->scan_lock);
> +               if (err == -EINVAL) {

Gotos would make error handling much cleaner.

> +inline
> +static int hint_index_body(const unsigned char *name, int name_len, int check_null)

Please consider calling this __hint_index() instead as per normal
naming conventions.

> +{
> +       int i;
> +       int val = 0;
> +       unsigned char *p = (unsigned char *) name;
> +       int id = current->pid;
> +
> +       for (i=0; i<name_len; i++) {
> +               if (check_null && !*p) break;

Please put break on separate line. You still have quite a few of these.

> +               val = ((val << 1) & 0xfe) | ((val & 0x80) ? 1 : 0);
> +               val ^= *p;
> +               p ++;
> +       }
> +       id = ((id >> 8) & 0xf) ^ (id & 0xf);
> +       val = (val << 1) | (id & 1);
> +       return val & (FAT_SCAN_NWAY-1);
> +}

                              Pekka