On Wed, Apr 06, 2022 at 03:45:32PM -0700, Dai Ngo wrote:
> static void
> nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
> struct laundry_time *lt)
> {
> struct list_head *pos, *next;
> struct nfs4_client *clp;
> + bool cour;
> + struct list_head cslist;
>
> INIT_LIST_HEAD(reaplist);
> + INIT_LIST_HEAD(&cslist);
> spin_lock(&nn->client_lock);
> list_for_each_safe(pos, next, &nn->client_lru) {
> clp = list_entry(pos, struct nfs4_client, cl_lru);
> if (!state_expired(lt, clp->cl_time))
> break;
> - if (mark_client_expired_locked(clp))
> +
> + if (!client_has_state(clp))
> + goto exp_client;
> +
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_EXPIRED)
> + goto exp_client;
> + cour = (clp->cl_cs_client_state == NFSD4_CLIENT_COURTESY);
> + if (cour && ktime_get_boottime_seconds() >=
> + (clp->cl_time + NFSD_COURTESY_CLIENT_TIMEOUT))
> + goto exp_client;
> + if (nfs4_anylock_blockers(clp)) {
> +exp_client:
> + if (mark_client_expired_locked(clp))
> + continue;
> + list_add(&clp->cl_lru, reaplist);
> continue;
> - list_add(&clp->cl_lru, reaplist);
> + }
> + if (!cour) {
> + spin_lock(&clp->cl_cs_lock);
> + clp->cl_cs_client_state = NFSD4_CLIENT_COURTESY;
> + spin_unlock(&clp->cl_cs_lock);
> + list_add(&clp->cl_cs_list, &cslist);
> + }
> }
> spin_unlock(&nn->client_lock);
> +
> + while (!list_empty(&cslist)) {
> + clp = list_first_entry(&cslist, struct nfs4_client, cl_cs_list);
> + list_del_init(&clp->cl_cs_list);
> + spin_lock(&clp->cl_cs_lock);
> + /*
> + * Client might have re-connected. Make sure it's
> + * still in courtesy state before removing its record.
> + */
Good to be careful, but, then....
> + if (clp->cl_cs_client_state != NFSD4_CLIENT_COURTESY) {
> + spin_unlock(&clp->cl_cs_lock);
> + continue;
> + }
> + spin_unlock(&clp->cl_cs_lock);
.... I'm not seeing what prevents a client from reconnecting right here,
after we drop cl_cs_lock but before we call
nfsd4_client_record_remove().
> + nfsd4_client_record_remove(clp);
> + }
> }
>
> static time64_t
> @@ -5794,6 +5876,13 @@ nfs4_laundromat(struct nfsd_net *nn)
> dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
> if (!state_expired(<, dp->dl_time))
> break;
> + spin_lock(&clp->cl_cs_lock);
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_COURTESY) {
> + clp->cl_cs_client_state = NFSD4_CLIENT_EXPIRED;
> + spin_unlock(&clp->cl_cs_lock);
In an earlier patch you set the client to EXPIRED as soon as we got a
lease break, so isn't this unnecessary?
I guess there could be a case like:
1. lease break comes in
2. client fails to renew, transitions to courtesy
3. delegation callback times out
though it'd seem better to catch that at step 2 if we can.
--b.
> + continue;
> + }
> + spin_unlock(&clp->cl_cs_lock);
> WARN_ON(!unhash_delegation_locked(dp));
> list_add(&dp->dl_recall_lru, &reaplist);
> }
> --
> 2.9.5
