On Mon, 11 Feb, at 03:22:21PM, Al Viro wrote:
> > + /*
> > + * If the string we're being asked to compare doesn't match
> > + * the expected format return "no match".
> > + */
> > + if (!efivarfs_valid_name(str, len))
> > + return 1;
> > + if (!(q = strchr(name->name, '-')))
> > + return 1;
>
> No. Why check that again, when we'd already called ->d_hash() on the
> incoming name *and* candidate dentry? And buggered off on any potential
> errors.
Good point.
> > +
> > + /* Find part 1, the variable name. */
> > + guid = q - (const char *)name->name;
>
> No need to do strchr() for that - you know that name passes
> efivarfs_valid_name(), so you know how far from the end will GUID part begin.
Right.
> > + /* Case-sensitive compare for the variable name */
> > + if (memcmp(str, name->name, guid))
> > + return 1;
> > +
> > + /* Case-insensitive compare for the GUID */
> > + return strcasecmp(&name->name[guid], &str[guid]);
> > +}
>
> > +static int efivarfs_d_hash(const struct dentry *dentry,
> > + const struct inode *inode, struct qstr *qstr)
> > +{
> Egads, man...
> [snip the horror with copying the name]
>
> unsigned long hash = init_name_hash();
> const unsigned char *s = qstr->name;
> int len = qstr->len;
>
> if (!efivarfs_valid_name(s, len))
> return -EINVAL;
> while (len-- > GUID_LEN)
> hash = partial_name_hash(*s++, hash);
> /* GUID is case-insensitive. */
> while (len--)
> hash = partial_name_hash(tolower(*s++), hash);
> return end_name_hash(hash);
Oh, wow, yes that is much nicer. I didn't realise we could build the
hash incrementally like that. Very cool.
--
Matt Fleming, Intel Open Source Technology Center
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