On Mon, 2024-07-15 at 17:14 +1000, NeilBrown wrote:
> If there are more non-courteous clients than the calculated limit, we
> should fail the request rather than report a soft failure and
> encouraging the client to retry indefinitely.
>
> If there a courteous clients which push us over the limit, then expedite
> their removal.
>
> This is not known to have caused a problem is production use, but
> testing of lots of clients reports repeated NFS4ERR_DELAY responses
> which doesn't seem helpful.
>
> Also remove an outdated comment - we do use a slab cache.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index a20c2c9d7d45..88936f3189e1 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -2212,21 +2212,20 @@ STALE_CLIENTID(clientid_t *clid, struct nfsd_net *nn)
> return 1;
> }
>
> -/*
> - * XXX Should we use a slab cache ?
> - * This type of memory management is somewhat inefficient, but we use it
> - * anyway since SETCLIENTID is not a common operation.
> - */
> static struct nfs4_client *alloc_client(struct xdr_netobj name,
> struct nfsd_net *nn)
> {
> struct nfs4_client *clp;
> int i;
>
> - if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients) {
> + if (atomic_read(&nn->nfs4_client_count) -
> + atomic_read(&nn->nfsd_courtesy_clients) >= nn->nfs4_max_clients)
> + return ERR_PTR(-EREMOTEIO);
> +
nit: I know it gets remapped, but why EREMOTEIO? From nfsd's standpoint
this would seem to imply a problem on the client. Maybe:
#define EUSERS 87 /* Too many users */
...instead?
> + if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients &&
> + atomic_read(&nn->nfsd_courtesy_clients) > 0)
> mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
> - return NULL;
> - }
> +
> clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
> if (clp == NULL)
> return NULL;
> @@ -3115,8 +3114,8 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
> struct dentry *dentries[ARRAY_SIZE(client_files)];
>
> clp = alloc_client(name, nn);
> - if (clp == NULL)
> - return NULL;
> + if (IS_ERR_OR_NULL(clp))
> + return clp;
>
> ret = copy_cred(&clp->cl_cred, &rqstp->rq_cred);
> if (ret) {
> @@ -3498,6 +3497,8 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> new = create_client(exid->clname, rqstp, &verf);
> if (new == NULL)
> return nfserr_jukebox;
> + if (IS_ERR(new))
> + return nfserr_resource;
> status = copy_impl_id(new, exid);
> if (status)
> goto out_nolock;
> @@ -4416,6 +4417,8 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> new = create_client(clname, rqstp, &clverifier);
> if (new == NULL)
> return nfserr_jukebox;
> + if (IS_ERR(new))
> + return nfserr_resource;
> spin_lock(&nn->client_lock);
> conf = find_confirmed_client_by_name(&clname, nn);
> if (conf && client_has_state(conf)) {
Patch looks fine otherwise though.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
