On Thu, Mar 17, 2022 at 12:43:43AM -0700, Dai Ngo wrote:
> Update find_clp_in_name_tree to check and expire courtesy client.
>
> Update find_confirmed_client_by_name to discard the courtesy
> client by setting CLIENT_EXPIRED.
>
> Update nfsd4_setclientid to expire client with CLIENT_EXPIRED
> state to prevent multiple confirmed clients with the same name
> on the conf_id_hashtbl list.
I could use a little more "why" here.
I'll give it another read, but right now I'm just not understanding how
this is meant to work.
--b.
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 27 ++++++++++++++++++++++++---
> fs/nfsd/state.h | 22 ++++++++++++++++++++++
> 2 files changed, 46 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index c6b5e05c9c34..dc0e60bf694c 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -2834,8 +2834,11 @@ find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
> node = node->rb_left;
> else if (cmp < 0)
> node = node->rb_right;
> - else
> + else {
> + if (nfsd4_courtesy_clnt_expired(clp))
> + return NULL;
> return clp;
> + }
> }
> return NULL;
> }
> @@ -2914,8 +2917,15 @@ static bool clp_used_exchangeid(struct nfs4_client *clp)
> static struct nfs4_client *
> find_confirmed_client_by_name(struct xdr_netobj *name, struct nfsd_net *nn)
> {
> + struct nfs4_client *clp;
> +
> lockdep_assert_held(&nn->client_lock);
> - return find_clp_in_name_tree(name, &nn->conf_name_tree);
> + clp = find_clp_in_name_tree(name, &nn->conf_name_tree);
> + if (clp && clp->cl_cs_client_state == NFSD4_CLIENT_RECONNECTED) {
> + nfsd4_discard_courtesy_clnt(clp);
> + clp = NULL;
> + }
> + return clp;
> }
>
> static struct nfs4_client *
> @@ -4032,12 +4042,19 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> struct nfs4_client *unconf = NULL;
> __be32 status;
> struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
> + struct nfs4_client *cclient = NULL;
>
> new = create_client(clname, rqstp, &clverifier);
> if (new == NULL)
> return nfserr_jukebox;
> spin_lock(&nn->client_lock);
> - conf = find_confirmed_client_by_name(&clname, nn);
> + /* find confirmed client by name */
> + conf = find_clp_in_name_tree(&clname, &nn->conf_name_tree);
> + if (conf && conf->cl_cs_client_state == NFSD4_CLIENT_RECONNECTED) {
> + cclient = conf;
> + conf = NULL;
> + }
> +
> if (conf && client_has_state(conf)) {
> status = nfserr_clid_inuse;
> if (clp_used_exchangeid(conf))
> @@ -4068,7 +4085,11 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> new = NULL;
> status = nfs_ok;
> out:
> + if (cclient)
> + unhash_client_locked(cclient);
> spin_unlock(&nn->client_lock);
> + if (cclient)
> + expire_client(cclient);
> if (new)
> free_client(new);
> if (unconf) {
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index d156ae3ab46c..14b2c158ccca 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -735,6 +735,7 @@ extern void nfsd4_client_record_remove(struct nfs4_client *clp);
> extern int nfsd4_client_record_check(struct nfs4_client *clp);
> extern void nfsd4_record_grace_done(struct nfsd_net *nn);
>
> +/* courteous server */
> static inline bool
> nfsd4_expire_courtesy_clnt(struct nfs4_client *clp)
> {
> @@ -749,4 +750,25 @@ nfsd4_expire_courtesy_clnt(struct nfs4_client *clp)
> return rc;
> }
>
> +static inline void
> +nfsd4_discard_courtesy_clnt(struct nfs4_client *clp)
> +{
> + spin_lock(&clp->cl_cs_lock);
> + clp->cl_cs_client_state = NFSD4_CLIENT_EXPIRED;
> + spin_unlock(&clp->cl_cs_lock);
> +}
> +
> +static inline bool
> +nfsd4_courtesy_clnt_expired(struct nfs4_client *clp)
> +{
> + bool rc = false;
> +
> + spin_lock(&clp->cl_cs_lock);
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_EXPIRED)
> + rc = true;
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_COURTESY)
> + clp->cl_cs_client_state = NFSD4_CLIENT_RECONNECTED;
> + spin_unlock(&clp->cl_cs_lock);
> + return rc;
> +}
> #endif /* NFSD4_STATE_H */
> --
> 2.9.5
