diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 5559dac9e7f4..ee665f13a2e4 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -981,7 +981,7 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla * Create a unique stateid_t to represent each COPY. */ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid, - unsigned char cs_type) + unsigned char cs_type, struct nfs4_stid *p_stid) { int new_id; @@ -991,19 +991,34 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid, idr_preload(GFP_KERNEL); spin_lock(&nn->s2s_cp_lock); new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, stid, 0, 0, GFP_NOWAIT); - stid->cs_stid.si_opaque.so_id = new_id; - stid->cs_stid.si_generation = 1; + if (new_id >= 0) { + stid->cs_stid.si_opaque.so_id = new_id; + stid->cs_stid.si_generation = 1; + /* + * Set cs_type and link onto sc_cp_list under the same lock + * that installed the IDR entry, so a concurrent + * manage_cpntf_state() sees either no entry or a fully + * linked cp_list. + */ + stid->cs_type = cs_type; + if (p_stid) { + struct nfs4_cpntf_state *cps = + container_of(stid, struct nfs4_cpntf_state, + cp_stateid); + + list_add(&cps->cp_list, &p_stid->sc_cp_list); + } + } spin_unlock(&nn->s2s_cp_lock); idr_preload_end(); if (new_id < 0) return 0; - stid->cs_type = cs_type; return 1; } int nfs4_init_copy_state(struct nfsd_net *nn, struct nfsd4_copy *copy) { - return nfs4_init_cp_state(nn, ©->cp_stateid, NFS4_COPY_STID); + return nfs4_init_cp_state(nn, ©->cp_stateid, NFS4_COPY_STID, NULL); } struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn, @@ -1014,13 +1029,13 @@ struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn, cps = kzalloc_obj(struct nfs4_cpntf_state); if (!cps) return NULL; + /* So a stale list_del_init() before linking is a no-op. */ + INIT_LIST_HEAD(&cps->cp_list); cps->cpntf_time = ktime_get_boottime_seconds(); refcount_set(&cps->cp_stateid.cs_count, 1); - if (!nfs4_init_cp_state(nn, &cps->cp_stateid, NFS4_COPYNOTIFY_STID)) + if (!nfs4_init_cp_state(nn, &cps->cp_stateid, NFS4_COPYNOTIFY_STID, + p_stid)) goto out_free; - spin_lock(&nn->s2s_cp_lock); - list_add(&cps->cp_list, &p_stid->sc_cp_list); - spin_unlock(&nn->s2s_cp_lock); return cps; out_free: kfree(cps); @@ -7959,7 +7974,7 @@ _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps) WARN_ON_ONCE(cps->cp_stateid.cs_type != NFS4_COPYNOTIFY_STID); if (!refcount_dec_and_test(&cps->cp_stateid.cs_count)) return; - list_del(&cps->cp_list); + list_del_init(&cps->cp_list); idr_remove(&nn->s2s_cp_stateids, cps->cp_stateid.cs_stid.si_opaque.so_id); kfree(cps);