Re: [PATCH] Store sysfs dirent structs in rbtree

From: Nathan Fontenot
Date: Thu Jun 24 2010 - 21:59:16 EST


On 06/24/2010 01:04 PM, Cornelia Huck wrote:
> On Wed, 23 Jun 2010 21:56:04 -0500,
> Nathan Fontenot <nfont@xxxxxxxxxxxxxx> wrote:
>
>> +static void sysfs_dirent_insert(struct sysfs_dirent *sd)
>> +{
>> + struct sysfs_dirent *parent_sd = sd->s_parent;
>> + struct sysfs_dirent *d;
>> + struct rb_node **p = &parent_sd->s_dir.rb_root.rb_node;
>> + struct rb_node *parent = NULL;
>> +
>> + while (*p) {
>> + int cmp_val;
>> + parent = *p;
>> + d = to_sysfs_dirent(parent);
>> +
>> + cmp_val = strcmp(d->s_name, sd->s_name);
>> + if (cmp_val < 0)
>> + p = &parent->rb_left;
>> + if (cmp_val > 0)
>> + p = &parent->rb_right;
>> + }
>> +
>> + rb_link_node(&sd->s_dir.rb_node, parent, p);
>> + rb_insert_color(&sd->s_dir.rb_node, &parent_sd->s_dir.rb_root);
>> +}
>
> This will run into trouble if you have duplicate names in different
> namespaces. You won't see it with your patch though, since...
>
>> @@ -536,14 +572,24 @@
>> const void *ns,
>> const unsigned char *name)
>> {
>> - struct sysfs_dirent *sd;
>> -
>> - for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) {
>> - if (ns && sd->s_ns && (sd->s_ns != ns))
>> - continue;
>> - if (!strcmp(sd->s_name, name))
>> - return sd;
>> + struct sysfs_dirent *d;
>> + struct rb_node **p = &parent_sd->s_dir.rb_root.rb_node;
>> + struct rb_node *parent = NULL;
>> +
>> + while (*p) {
>> + int cmp_val;
>> + parent = *p;
>> + d = to_sysfs_dirent(parent);
>> +
>> + cmp_val = strcmp(d->s_name, name);
>> + if (cmp_val == 0)
>> + return d;
>> + else if (cmp_val < 0)
>> + p = &parent->rb_left;
>> + else /* (cmp_val > 0) */
>> + p = &parent->rb_right;
>> }
>> +
>> return NULL;
>> }
>
> ...you removed the namespace check down here.

Yep, I missed namespaces completely with this patch. I'll try again.

> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/