Merge tag 'iommu-updates-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...
[cascardo/linux.git] / fs / nfsd / nfs4state.c
index 9520271..0f1d569 100644 (file)
@@ -777,13 +777,16 @@ hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp)
        list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations);
 }
 
-static void
+static bool
 unhash_delegation_locked(struct nfs4_delegation *dp)
 {
        struct nfs4_file *fp = dp->dl_stid.sc_file;
 
        lockdep_assert_held(&state_lock);
 
+       if (list_empty(&dp->dl_perfile))
+               return false;
+
        dp->dl_stid.sc_type = NFS4_CLOSED_DELEG_STID;
        /* Ensure that deleg break won't try to requeue it */
        ++dp->dl_time;
@@ -792,16 +795,21 @@ unhash_delegation_locked(struct nfs4_delegation *dp)
        list_del_init(&dp->dl_recall_lru);
        list_del_init(&dp->dl_perfile);
        spin_unlock(&fp->fi_lock);
+       return true;
 }
 
 static void destroy_delegation(struct nfs4_delegation *dp)
 {
+       bool unhashed;
+
        spin_lock(&state_lock);
-       unhash_delegation_locked(dp);
+       unhashed = unhash_delegation_locked(dp);
        spin_unlock(&state_lock);
-       put_clnt_odstate(dp->dl_clnt_odstate);
-       nfs4_put_deleg_lease(dp->dl_stid.sc_file);
-       nfs4_put_stid(&dp->dl_stid);
+       if (unhashed) {
+               put_clnt_odstate(dp->dl_clnt_odstate);
+               nfs4_put_deleg_lease(dp->dl_stid.sc_file);
+               nfs4_put_stid(&dp->dl_stid);
+       }
 }
 
 static void revoke_delegation(struct nfs4_delegation *dp)
@@ -990,6 +998,12 @@ release_all_access(struct nfs4_ol_stateid *stp)
        }
 }
 
+static inline void nfs4_free_stateowner(struct nfs4_stateowner *sop)
+{
+       kfree(sop->so_owner.data);
+       sop->so_ops->so_free(sop);
+}
+
 static void nfs4_put_stateowner(struct nfs4_stateowner *sop)
 {
        struct nfs4_client *clp = sop->so_client;
@@ -1000,20 +1014,23 @@ static void nfs4_put_stateowner(struct nfs4_stateowner *sop)
                return;
        sop->so_ops->so_unhash(sop);
        spin_unlock(&clp->cl_lock);
-       kfree(sop->so_owner.data);
-       sop->so_ops->so_free(sop);
+       nfs4_free_stateowner(sop);
 }
 
-static void unhash_ol_stateid(struct nfs4_ol_stateid *stp)
+static bool unhash_ol_stateid(struct nfs4_ol_stateid *stp)
 {
        struct nfs4_file *fp = stp->st_stid.sc_file;
 
        lockdep_assert_held(&stp->st_stateowner->so_client->cl_lock);
 
+       if (list_empty(&stp->st_perfile))
+               return false;
+
        spin_lock(&fp->fi_lock);
-       list_del(&stp->st_perfile);
+       list_del_init(&stp->st_perfile);
        spin_unlock(&fp->fi_lock);
        list_del(&stp->st_perstateowner);
+       return true;
 }
 
 static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
@@ -1063,25 +1080,27 @@ static void put_ol_stateid_locked(struct nfs4_ol_stateid *stp,
        list_add(&stp->st_locks, reaplist);
 }
 
-static void unhash_lock_stateid(struct nfs4_ol_stateid *stp)
+static bool unhash_lock_stateid(struct nfs4_ol_stateid *stp)
 {
        struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
 
        lockdep_assert_held(&oo->oo_owner.so_client->cl_lock);
 
        list_del_init(&stp->st_locks);
-       unhash_ol_stateid(stp);
        nfs4_unhash_stid(&stp->st_stid);
+       return unhash_ol_stateid(stp);
 }
 
 static void release_lock_stateid(struct nfs4_ol_stateid *stp)
 {
        struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
+       bool unhashed;
 
        spin_lock(&oo->oo_owner.so_client->cl_lock);
-       unhash_lock_stateid(stp);
+       unhashed = unhash_lock_stateid(stp);
        spin_unlock(&oo->oo_owner.so_client->cl_lock);
-       nfs4_put_stid(&stp->st_stid);
+       if (unhashed)
+               nfs4_put_stid(&stp->st_stid);
 }
 
 static void unhash_lockowner_locked(struct nfs4_lockowner *lo)
@@ -1129,7 +1148,7 @@ static void release_lockowner(struct nfs4_lockowner *lo)
        while (!list_empty(&lo->lo_owner.so_stateids)) {
                stp = list_first_entry(&lo->lo_owner.so_stateids,
                                struct nfs4_ol_stateid, st_perstateowner);
-               unhash_lock_stateid(stp);
+               WARN_ON(!unhash_lock_stateid(stp));
                put_ol_stateid_locked(stp, &reaplist);
        }
        spin_unlock(&clp->cl_lock);
@@ -1142,21 +1161,26 @@ static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp,
 {
        struct nfs4_ol_stateid *stp;
 
+       lockdep_assert_held(&open_stp->st_stid.sc_client->cl_lock);
+
        while (!list_empty(&open_stp->st_locks)) {
                stp = list_entry(open_stp->st_locks.next,
                                struct nfs4_ol_stateid, st_locks);
-               unhash_lock_stateid(stp);
+               WARN_ON(!unhash_lock_stateid(stp));
                put_ol_stateid_locked(stp, reaplist);
        }
 }
 
-static void unhash_open_stateid(struct nfs4_ol_stateid *stp,
+static bool unhash_open_stateid(struct nfs4_ol_stateid *stp,
                                struct list_head *reaplist)
 {
+       bool unhashed;
+
        lockdep_assert_held(&stp->st_stid.sc_client->cl_lock);
 
-       unhash_ol_stateid(stp);
+       unhashed = unhash_ol_stateid(stp);
        release_open_stateid_locks(stp, reaplist);
+       return unhashed;
 }
 
 static void release_open_stateid(struct nfs4_ol_stateid *stp)
@@ -1164,8 +1188,8 @@ static void release_open_stateid(struct nfs4_ol_stateid *stp)
        LIST_HEAD(reaplist);
 
        spin_lock(&stp->st_stid.sc_client->cl_lock);
-       unhash_open_stateid(stp, &reaplist);
-       put_ol_stateid_locked(stp, &reaplist);
+       if (unhash_open_stateid(stp, &reaplist))
+               put_ol_stateid_locked(stp, &reaplist);
        spin_unlock(&stp->st_stid.sc_client->cl_lock);
        free_ol_stateid_reaplist(&reaplist);
 }
@@ -1210,8 +1234,8 @@ static void release_openowner(struct nfs4_openowner *oo)
        while (!list_empty(&oo->oo_owner.so_stateids)) {
                stp = list_first_entry(&oo->oo_owner.so_stateids,
                                struct nfs4_ol_stateid, st_perstateowner);
-               unhash_open_stateid(stp, &reaplist);
-               put_ol_stateid_locked(stp, &reaplist);
+               if (unhash_open_stateid(stp, &reaplist))
+                       put_ol_stateid_locked(stp, &reaplist);
        }
        spin_unlock(&clp->cl_lock);
        free_ol_stateid_reaplist(&reaplist);
@@ -1714,7 +1738,7 @@ __destroy_client(struct nfs4_client *clp)
        spin_lock(&state_lock);
        while (!list_empty(&clp->cl_delegations)) {
                dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt);
-               unhash_delegation_locked(dp);
+               WARN_ON(!unhash_delegation_locked(dp));
                list_add(&dp->dl_recall_lru, &reaplist);
        }
        spin_unlock(&state_lock);
@@ -1894,7 +1918,7 @@ static void gen_confirm(struct nfs4_client *clp, struct nfsd_net *nn)
         * __force to keep sparse happy
         */
        verf[0] = (__force __be32)get_seconds();
-       verf[1] = (__force __be32)nn->clientid_counter;
+       verf[1] = (__force __be32)nn->clverifier_counter++;
        memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data));
 }
 
@@ -2241,6 +2265,9 @@ static bool client_has_state(struct nfs4_client *clp)
         * Also note we should probably be using this in 4.0 case too.
         */
        return !list_empty(&clp->cl_openowners)
+#ifdef CONFIG_NFSD_PNFS
+               || !list_empty(&clp->cl_lo_states)
+#endif
                || !list_empty(&clp->cl_delegations)
                || !list_empty(&clp->cl_sessions);
 }
@@ -2547,11 +2574,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                        goto out_free_conn;
                cs_slot = &conf->cl_cs_slot;
                status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
-               if (status == nfserr_replay_cache) {
-                       status = nfsd4_replay_create_session(cr_ses, cs_slot);
-                       goto out_free_conn;
-               } else if (cr_ses->seqid != cs_slot->sl_seqid + 1) {
-                       status = nfserr_seq_misordered;
+               if (status) {
+                       if (status == nfserr_replay_cache)
+                               status = nfsd4_replay_create_session(cr_ses, cs_slot);
                        goto out_free_conn;
                }
        } else if (unconf) {
@@ -3041,10 +3066,11 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        unconf = find_unconfirmed_client_by_name(&clname, nn);
        if (unconf)
                unhash_client_locked(unconf);
-       if (conf && same_verf(&conf->cl_verifier, &clverifier))
+       if (conf && same_verf(&conf->cl_verifier, &clverifier)) {
                /* case 1: probable callback update */
                copy_clid(new, conf);
-       else /* case 4 (new client) or cases 2, 3 (client reboot): */
+               gen_confirm(new, nn);
+       } else /* case 4 (new client) or cases 2, 3 (client reboot): */
                gen_clid(new, nn);
        new->cl_minorversion = 0;
        gen_callback(new, setclid, rqstp);
@@ -3085,10 +3111,11 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
        /*
         * We try hard to give out unique clientid's, so if we get an
         * attempt to confirm the same clientid with a different cred,
-        * there's a bug somewhere.  Let's charitably assume it's our
-        * bug.
+        * the client may be buggy; this should never happen.
+        *
+        * Nevertheless, RFC 7530 recommends INUSE for this case:
         */
-       status = nfserr_serverfault;
+       status = nfserr_clid_inuse;
        if (unconf && !same_creds(&unconf->cl_cred, &rqstp->rq_cred))
                goto out;
        if (conf && !same_creds(&conf->cl_cred, &rqstp->rq_cred))
@@ -3315,7 +3342,8 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
                hash_openowner(oo, clp, strhashval);
                ret = oo;
        } else
-               nfs4_free_openowner(&oo->oo_owner);
+               nfs4_free_stateowner(&oo->oo_owner);
+
        spin_unlock(&clp->cl_lock);
        return ret;
 }
@@ -3482,6 +3510,9 @@ static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
 {
        struct nfs4_delegation *dp = cb_to_delegation(cb);
 
+       if (dp->dl_stid.sc_type == NFS4_CLOSED_DELEG_STID)
+               return 1;
+
        switch (task->tk_status) {
        case 0:
                return 1;
@@ -3885,12 +3916,6 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c
        return status;
 }
 
-static void
-nfs4_set_claim_prev(struct nfsd4_open *open, bool has_session)
-{
-       open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
-}
-
 /* Should we give out recallable state?: */
 static bool nfsd4_cb_channel_good(struct nfs4_client *clp)
 {
@@ -3923,7 +3948,7 @@ static struct file_lock *nfs4_alloc_init_lease(struct nfs4_file *fp, int flag)
 static int nfs4_setlease(struct nfs4_delegation *dp)
 {
        struct nfs4_file *fp = dp->dl_stid.sc_file;
-       struct file_lock *fl, *ret;
+       struct file_lock *fl;
        struct file *filp;
        int status = 0;
 
@@ -3934,10 +3959,10 @@ static int nfs4_setlease(struct nfs4_delegation *dp)
        if (!filp) {
                /* We should always have a readable file here */
                WARN_ON_ONCE(1);
+               locks_free_lock(fl);
                return -EBADF;
        }
        fl->fl_file = filp;
-       ret = fl;
        status = vfs_setlease(filp, fl->fl_type, &fl, NULL);
        if (fl)
                locks_free_lock(fl);
@@ -4063,7 +4088,8 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open,
                case NFS4_OPEN_CLAIM_FH:
                        /*
                         * Let's not give out any delegations till everyone's
-                        * had the chance to reclaim theirs....
+                        * had the chance to reclaim theirs, *and* until
+                        * NLM locks have all been reclaimed:
                         */
                        if (locks_in_grace(clp->net))
                                goto out_no_deleg;
@@ -4209,7 +4235,7 @@ out:
        if (fp)
                put_nfs4_file(fp);
        if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
-               nfs4_set_claim_prev(open, nfsd4_has_session(&resp->cstate));
+               open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
        /*
        * To finish the open response, we just need to set the rflags.
        */
@@ -4338,14 +4364,12 @@ nfs4_laundromat(struct nfsd_net *nn)
        spin_lock(&state_lock);
        list_for_each_safe(pos, next, &nn->del_recall_lru) {
                dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
-               if (net_generic(dp->dl_stid.sc_client->net, nfsd_net_id) != nn)
-                       continue;
                if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) {
                        t = dp->dl_time - cutoff;
                        new_timeo = min(new_timeo, t);
                        break;
                }
-               unhash_delegation_locked(dp);
+               WARN_ON(!unhash_delegation_locked(dp));
                list_add(&dp->dl_recall_lru, &reaplist);
        }
        spin_unlock(&state_lock);
@@ -4440,7 +4464,7 @@ check_special_stateids(struct net *net, svc_fh *current_fh, stateid_t *stateid,
 {
        if (ONE_STATEID(stateid) && (flags & RD_STATE))
                return nfs_ok;
-       else if (locks_in_grace(net)) {
+       else if (opens_in_grace(net)) {
                /* Answer in remaining cases depends on existence of
                 * conflicting state; so we must wait out the grace period. */
                return nfserr_grace;
@@ -4459,7 +4483,7 @@ check_special_stateids(struct net *net, svc_fh *current_fh, stateid_t *stateid,
 static inline int
 grace_disallows_io(struct net *net, struct inode *inode)
 {
-       return locks_in_grace(net) && mandatory_lock(inode);
+       return opens_in_grace(net) && mandatory_lock(inode);
 }
 
 /* Returns true iff a is later than b: */
@@ -4751,7 +4775,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                if (check_for_locks(stp->st_stid.sc_file,
                                    lockowner(stp->st_stateowner)))
                        break;
-               unhash_lock_stateid(stp);
+               WARN_ON(!unhash_lock_stateid(stp));
                spin_unlock(&cl->cl_lock);
                nfs4_put_stid(s);
                ret = nfs_ok;
@@ -4967,20 +4991,23 @@ out:
 static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
 {
        struct nfs4_client *clp = s->st_stid.sc_client;
+       bool unhashed;
        LIST_HEAD(reaplist);
 
        s->st_stid.sc_type = NFS4_CLOSED_STID;
        spin_lock(&clp->cl_lock);
-       unhash_open_stateid(s, &reaplist);
+       unhashed = unhash_open_stateid(s, &reaplist);
 
        if (clp->cl_minorversion) {
-               put_ol_stateid_locked(s, &reaplist);
+               if (unhashed)
+                       put_ol_stateid_locked(s, &reaplist);
                spin_unlock(&clp->cl_lock);
                free_ol_stateid_reaplist(&reaplist);
        } else {
                spin_unlock(&clp->cl_lock);
                free_ol_stateid_reaplist(&reaplist);
-               move_to_close_lru(s, clp->net);
+               if (unhashed)
+                       move_to_close_lru(s, clp->net);
        }
 }
 
@@ -5045,9 +5072,6 @@ out:
        return status;
 }
 
-
-#define LOFF_OVERFLOW(start, len)      ((u64)(len) > ~(u64)(start))
-
 static inline u64
 end_offset(u64 start, u64 len)
 {
@@ -5139,8 +5163,7 @@ nevermind:
 }
 
 static struct nfs4_lockowner *
-find_lockowner_str_locked(clientid_t *clid, struct xdr_netobj *owner,
-               struct nfs4_client *clp)
+find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
 {
        unsigned int strhashval = ownerstr_hashval(owner);
        struct nfs4_stateowner *so;
@@ -5158,13 +5181,12 @@ find_lockowner_str_locked(clientid_t *clid, struct xdr_netobj *owner,
 }
 
 static struct nfs4_lockowner *
-find_lockowner_str(clientid_t *clid, struct xdr_netobj *owner,
-               struct nfs4_client *clp)
+find_lockowner_str(struct nfs4_client *clp, struct xdr_netobj *owner)
 {
        struct nfs4_lockowner *lo;
 
        spin_lock(&clp->cl_lock);
-       lo = find_lockowner_str_locked(clid, owner, clp);
+       lo = find_lockowner_str_locked(clp, owner);
        spin_unlock(&clp->cl_lock);
        return lo;
 }
@@ -5208,14 +5230,14 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp,
        lo->lo_owner.so_seqid = lock->lk_new_lock_seqid;
        lo->lo_owner.so_ops = &lockowner_ops;
        spin_lock(&clp->cl_lock);
-       ret = find_lockowner_str_locked(&clp->cl_clientid,
-                       &lock->lk_new_owner, clp);
+       ret = find_lockowner_str_locked(clp, &lock->lk_new_owner);
        if (ret == NULL) {
                list_add(&lo->lo_owner.so_strhash,
                         &clp->cl_ownerstr_hashtbl[strhashval]);
                ret = lo;
        } else
-               nfs4_free_lockowner(&lo->lo_owner);
+               nfs4_free_stateowner(&lo->lo_owner);
+
        spin_unlock(&clp->cl_lock);
        return ret;
 }
@@ -5298,8 +5320,8 @@ find_or_create_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fi,
 static int
 check_lock_length(u64 offset, u64 length)
 {
-       return ((length == 0)  || ((length != NFS4_MAX_UINT64) &&
-            LOFF_OVERFLOW(offset, length)));
+       return ((length == 0) || ((length != NFS4_MAX_UINT64) &&
+               (length > ~offset)));
 }
 
 static void get_lock_access(struct nfs4_ol_stateid *lock_stp, u32 access)
@@ -5328,9 +5350,9 @@ lookup_or_create_lock_state(struct nfsd4_compound_state *cstate,
        struct nfs4_lockowner *lo;
        unsigned int strhashval;
 
-       lo = find_lockowner_str(&cl->cl_clientid, &lock->v.new.owner, cl);
+       lo = find_lockowner_str(cl, &lock->lk_new_owner);
        if (!lo) {
-               strhashval = ownerstr_hashval(&lock->v.new.owner);
+               strhashval = ownerstr_hashval(&lock->lk_new_owner);
                lo = alloc_init_lock_stateowner(strhashval, cl, ost, lock);
                if (lo == NULL)
                        return nfserr_jukebox;
@@ -5391,7 +5413,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        if (lock->lk_is_new) {
                if (nfsd4_has_session(cstate))
                        /* See rfc 5661 18.10.3: given clientid is ignored: */
-                       memcpy(&lock->v.new.clientid,
+                       memcpy(&lock->lk_new_clientid,
                                &cstate->session->se_client->cl_clientid,
                                sizeof(clientid_t));
 
@@ -5409,7 +5431,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                open_sop = openowner(open_stp->st_stateowner);
                status = nfserr_bad_stateid;
                if (!same_clid(&open_sop->oo_owner.so_client->cl_clientid,
-                                               &lock->v.new.clientid))
+                                               &lock->lk_new_clientid))
                        goto out;
                status = lookup_or_create_lock_state(cstate, open_stp, lock,
                                                        &lock_stp, &new);
@@ -5603,8 +5625,7 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                goto out;
        }
 
-       lo = find_lockowner_str(&lockt->lt_clientid, &lockt->lt_owner,
-                               cstate->clp);
+       lo = find_lockowner_str(cstate->clp, &lockt->lt_owner);
        if (lo)
                file_lock->fl_owner = (fl_owner_t)lo;
        file_lock->fl_pid = current->tgid;
@@ -6019,7 +6040,7 @@ nfsd_inject_add_lock_to_list(struct nfs4_ol_stateid *lst,
 
 static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max,
                                    struct list_head *collect,
-                                   void (*func)(struct nfs4_ol_stateid *))
+                                   bool (*func)(struct nfs4_ol_stateid *))
 {
        struct nfs4_openowner *oop;
        struct nfs4_ol_stateid *stp, *st_next;
@@ -6033,9 +6054,9 @@ static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max,
                        list_for_each_entry_safe(lst, lst_next,
                                        &stp->st_locks, st_locks) {
                                if (func) {
-                                       func(lst);
-                                       nfsd_inject_add_lock_to_list(lst,
-                                                               collect);
+                                       if (func(lst))
+                                               nfsd_inject_add_lock_to_list(lst,
+                                                                       collect);
                                }
                                ++count;
                                /*
@@ -6305,7 +6326,7 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max,
                                continue;
 
                        atomic_inc(&clp->cl_refcount);
-                       unhash_delegation_locked(dp);
+                       WARN_ON(!unhash_delegation_locked(dp));
                        list_add(&dp->dl_recall_lru, victims);
                }
                ++count;
@@ -6584,6 +6605,7 @@ nfs4_state_start_net(struct net *net)
                return ret;
        nn->boot_time = get_seconds();
        nn->grace_ended = false;
+       nn->nfsd4_manager.block_opens = true;
        locks_start_grace(net, &nn->nfsd4_manager);
        nfsd4_client_tracking_init(net);
        printk(KERN_INFO "NFSD: starting %ld-second grace period (net %p)\n",
@@ -6602,7 +6624,7 @@ nfs4_state_start(void)
        ret = set_callback_cred();
        if (ret)
                return -ENOMEM;
-       laundry_wq = create_singlethread_workqueue("nfsd4");
+       laundry_wq = alloc_workqueue("%s", WQ_UNBOUND, 0, "nfsd4");
        if (laundry_wq == NULL) {
                ret = -ENOMEM;
                goto out_recovery;
@@ -6635,7 +6657,7 @@ nfs4_state_shutdown_net(struct net *net)
        spin_lock(&state_lock);
        list_for_each_safe(pos, next, &nn->del_recall_lru) {
                dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
-               unhash_delegation_locked(dp);
+               WARN_ON(!unhash_delegation_locked(dp));
                list_add(&dp->dl_recall_lru, &reaplist);
        }
        spin_unlock(&state_lock);