Re: [PATCH 02/11] tools/xenstored: add central quota check functions

[Jürgen Groß <jgross@xxxxxxxx>]

On 13.03.26 16:01, Anthony PERARD wrote:
> On Thu, Mar 05, 2026 at 02:51:59PM +0100, Juergen Gross wrote:
> > Add central functions for checking a value (either an absolute one or
> > the current domain value plus an offset) against a specific quota.
> >
> > This is in preparation of introducing per-domain quota.
> >
> > The required changes allow to drop the "update" parameter from
> > domain_nbentry_fix().
> This patch changes the return value of do_watch(), from E2BIG to ENOSPC,
> but that's not mention.
I can add a remark to the commit message.

> > diff --git a/tools/xenstored/domain.c b/tools/xenstored/domain.c
> > index e453b3061f..1df9265ad5 100644
> > --- a/tools/xenstored/domain.c
> > +++ b/tools/xenstored/domain.c
> > @@ -490,10 +509,9 @@ static bool domain_can_read(struct connection *conn)
> >         if (domain_is_unprivileged(conn)) {
> >                 if (domain->wrl_credit < 0)
> >                         return false;
> > -               if (domain->acc[ACC_OUTST].val >= hard_quotas[ACC_OUTST].val)
> > +               if (domain_check_quota_add(domain, ACC_OUTST, 0))
> Is this change fixing a potential bug? As now we check if there's a
> quota for OUTST.
This is just changing how the quota is tested.

> >                         return false;
> > -               if (domain->acc[ACC_MEM].val >= hard_quotas[ACC_MEM].val &&
> > -                   hard_quotas[ACC_MEM].val)
> > +               if (domain_check_quota_add(domain, ACC_MEM, 0))
> >                         return false;
> >         }
> >   
> > diff --git a/tools/xenstored/watch.c b/tools/xenstored/watch.c
> > index b66a9f1a39..36e4d33f22 100644
> > --- a/tools/xenstored/watch.c
> > +++ b/tools/xenstored/watch.c
> > @@ -220,8 +220,8 @@ int do_watch(const void *ctx, struct connection *conn, 
> > struct buffered_data *in)
> >                         return EEXIST;
> >         }
> >   
> > -	if (domain_watch(conn) > hard_quotas[ACC_WATCH].val)
> > -               return E2BIG;
> > +       if (domain_check_quota_add(conn->domain, ACC_WATCH, 1))
> > +               return ENOSPC;
> Change of return value here not mentionned, even if it now aligned with
> the value returned in other places.
>
> >   
> >   	watch = add_watch(conn, vec[0], vec[1], relative, false);
> >         if (!watch)
> Patch looks fine to me:
> Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
Thanks


Juergen

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