On Mon, 17 Jul 2017 17:53:51 +0200
David Hildenbrand <david@xxxxxxxxxx> wrote:
> > + add_uevent_var(env, "CREATED=%llu", created);
> > + add_uevent_var(env, "COUNT=%llu", active);
>
> I like that much better.
>
> > +
> > + if (type == KVM_EVENT_CREATE_VM)
> > + add_uevent_var(env, "EVENT=create");
> > + else if (type == KVM_EVENT_DESTROY_VM)
> > + add_uevent_var(env, "EVENT=destroy");
> > +
> > + if (kvm->debugfs_dentry) {
> > + char p[ITOA_MAX_LEN];
>
> I'd move this also to the top of the function. Or move tmp and pathbuf
> in here, so you could also move them to this place.
yeah it would probably look cleaner, I'll fix it.
> > +
> > + snprintf(p, sizeof(p), "%s",
> > kvm->debugfs_dentry->d_name.name);
>
> Probably just me, but I prefer ARRAY_SIZE() instead of sizeof() for
> any kind of array sizes.
I'll fix that too
> > + tmp = strchrnul(p + 1, '-');> +
> > *tmp = '\0';
> > + add_uevent_var(env, "PID=%s", p);
> > + pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
> > + if (pathbuf) {
> > + /* sizeof counts the final '\0' */
> > + int len = sizeof("STATS_PATH=") - 1;
> > + const char *pvar = "STATS_PATH=";
>
> Can't you avoid that? See next paragraph.
>
>
> > +
> > + tmp = dentry_path_raw(kvm->debugfs_dentry,
> > + pathbuf + len,
> > + PATH_MAX - len);
> > + if (!IS_ERR(tmp)) {
>
> Why not
>
> tmp = dentry_path_raw(kvm->debugfs_dentry, pathbuf, PATH_MAX);
> if (!IS_ERR(tmp)) {
> add_uevent_var(env, "STATS_PATH=s", tmp);
> }
>
> and avoid len / pvar / memcpy? And keep internal env size checking
> consistent.
that would be true, but then we would copy the buffer with the path
twice, once for dentry_path_raw and once for add_uevent_var.
the env size is consistent, since that would count the bytes
effectively present in the buffer, and note that kobject_uevent_env only
wants a char**, no length, so there are no consistency issues.
I agree that your solution looks better (and I had actually considered
implementing it like that initially), but it can potentially be slower.
I don't really have any strong preference.
Paolo: which solution do you like the most?
[...]
