Return-Path: Received: from fieldses.org ([173.255.197.46]:54118 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751546AbeAZV7m (ORCPT ); Fri, 26 Jan 2018 16:59:42 -0500 Date: Fri, 26 Jan 2018 16:59:42 -0500 To: Olga Kornievskaia Cc: bfields@redhat.com, linux-nfs@vger.kernel.org Subject: Re: [PATCH v6 07/10] NFSD create new stateid for async copy Message-ID: <20180126215942.GC7770@fieldses.org> References: <20171024174752.74910-1-kolga@netapp.com> <20171024174752.74910-8-kolga@netapp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20171024174752.74910-8-kolga@netapp.com> From: bfields@fieldses.org (J. Bruce Fields) Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Oct 24, 2017 at 01:47:49PM -0400, Olga Kornievskaia wrote: > Generate a new stateid to be used for reply to the asynchronous > COPY (this would also be used later by COPY_NOTIFY as well). > Associate the stateid with the parent OPEN/LOCK/DELEG stateid > that can be freed during the free of the parent stateid. However, > right now deciding to bind the lifetime to when the vfs copy > is done. This way don't need to keep the nfsd_net structure for > the callback. The drawback is that time copy state information > is available for query by OFFLOAD_STATUS is slightly less. > > Signed-off-by: Olga Kornievskaia > --- > fs/nfsd/netns.h | 8 +++++++ > fs/nfsd/nfs4proc.c | 32 +++++++++++++++++++------- > fs/nfsd/nfs4state.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/nfsd/nfsctl.c | 1 + > fs/nfsd/state.h | 14 ++++++++++++ > fs/nfsd/xdr4.h | 2 ++ > 6 files changed, 115 insertions(+), 8 deletions(-) > > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h > index 3714231..2c88a95 100644 > --- a/fs/nfsd/netns.h > +++ b/fs/nfsd/netns.h > @@ -119,6 +119,14 @@ struct nfsd_net { > u32 clverifier_counter; > > struct svc_serv *nfsd_serv; > + > + /* > + * clientid and stateid data for construction of net unique COPY > + * stateids. > + */ > + u32 s2s_cp_cl_id; > + struct idr s2s_cp_stateids; > + spinlock_t s2s_cp_lock; > }; > > /* Simple check to find out if a given net was properly initialized */ > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index a020533..6876080 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -1039,7 +1039,8 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write) > static __be32 > nfsd4_verify_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > stateid_t *src_stateid, struct file **src, > - stateid_t *dst_stateid, struct file **dst) > + stateid_t *dst_stateid, struct file **dst, > + struct nfs4_stid **stid) > { > __be32 status; > > @@ -1053,7 +1054,7 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write) > > status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh, > dst_stateid, WR_STATE, dst, NULL, > - NULL); > + stid); > if (status) { > dprintk("NFSD: %s: couldn't process dst stateid!\n", __func__); > goto out_put_src; > @@ -1084,7 +1085,7 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write) > __be32 status; > > status = nfsd4_verify_copy(rqstp, cstate, &clone->cl_src_stateid, &src, > - &clone->cl_dst_stateid, &dst); > + &clone->cl_dst_stateid, &dst, NULL); > if (status) > goto out; > > @@ -1117,8 +1118,6 @@ static int nfsd4_cb_offload_done(struct nfsd4_callback *cb, > > static int nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync) > { > - memcpy(©->cp_res.cb_stateid, ©->cp_dst_stateid, > - sizeof(copy->cp_dst_stateid)); > copy->cp_res.wr_stable_how = NFS_UNSTABLE; > copy->cp_consecutive = 1; > copy->cp_synchronous = sync; > @@ -1180,10 +1179,15 @@ static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst) > atomic_inc(&dst->cp_clp->cl_refcount); > dst->fh_dst = get_file(src->fh_dst); > dst->fh_src = get_file(src->fh_src); > + dst->stid = src->stid; > + dst->cps = src->cps; > } > > static void cleanup_async_copy(struct nfsd4_copy *copy) > { > + list_del(©->cps->cp_list); > + nfs4_free_cp_state(copy->cps); > + nfs4_put_stid(copy->stid); > fput(copy->fh_dst); > fput(copy->fh_src); > spin_lock(©->cp_clp->async_lock); > @@ -1225,7 +1229,7 @@ static int nfsd4_do_async_copy(void *data) > > status = nfsd4_verify_copy(rqstp, cstate, ©->cp_src_stateid, > ©->fh_src, ©->cp_dst_stateid, > - ©->fh_dst); > + ©->fh_dst, ©->stid); > if (status) > goto out; > > @@ -1234,15 +1238,27 @@ static int nfsd4_do_async_copy(void *data) > sizeof(struct knfsd_fh)); > copy->net = SVC_NET(rqstp); > if (!copy->cp_synchronous) { > + struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); > + > status = nfsd4_init_copy_res(copy, 0); > async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL); > if (!async_copy) { > status = nfserrno(-ENOMEM); > goto out; > } > + copy->cps = nfs4_alloc_init_cp_state(nn, copy->stid); > + if (!copy->cps) { > + status = nfserrno(-ENOMEM); > + kfree(async_copy); > + goto out; > + } > + /* take a reference on the parent stateid so it's not > + * not freed by the copy compound > + */ > + atomic_inc(©->stid->sc_count); > + memcpy(©->cp_res.cb_stateid, ©->cps->cp_stateid, > + sizeof(copy->cps->cp_stateid)); > dup_copy_fields(copy, async_copy); > - memcpy(©->cp_res.cb_stateid, ©->cp_dst_stateid, > - sizeof(copy->cp_dst_stateid)); > spin_lock(&async_copy->cp_clp->async_lock); > list_add(&async_copy->copies, > &async_copy->cp_clp->async_copies); > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index af40762..f9151f2 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -658,6 +658,7 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla > /* Will be incremented before return to client: */ > atomic_set(&stid->sc_count, 1); > spin_lock_init(&stid->sc_lock); > + INIT_LIST_HEAD(&stid->sc_cp_list); > > /* > * It shouldn't be a problem to reuse an opaque stateid value. > @@ -674,6 +675,66 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla > return NULL; > } > > +/* > + * Create a unique stateid_t to represent each COPY. Hang the copy > + * stateids off the OPEN/LOCK/DELEG stateid from the client open > + * the source file. > + */ > +struct nfs4_cp_state *nfs4_alloc_init_cp_state(struct nfsd_net *nn, > + struct nfs4_stid *p_stid) > +{ > + struct nfs4_cp_state *cps; > + int new_id; > + > + cps = kzalloc(sizeof(struct nfs4_cp_state), GFP_KERNEL); > + if (!cps) > + return NULL; > + idr_preload(GFP_KERNEL); > + spin_lock(&nn->s2s_cp_lock); > + new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, cps, 0, 0, GFP_NOWAIT); > + spin_unlock(&nn->s2s_cp_lock); > + idr_preload_end(); > + if (new_id < 0) > + goto out_free; > + cps->cp_stateid.si_opaque.so_id = new_id; > + cps->cp_stateid.si_opaque.so_clid.cl_boot = nn->boot_time; > + cps->cp_stateid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id; > + cps->cp_p_stid = p_stid; > + INIT_LIST_HEAD(&cps->cp_list); > + list_add(&cps->cp_list, &p_stid->sc_cp_list); > + > + return cps; > +out_free: > + kfree(cps); > + return NULL; > +} > + > +void nfs4_free_cp_state(struct nfs4_cp_state *cps) > +{ > + struct nfsd_net *nn; > + > + nn = net_generic(cps->cp_p_stid->sc_client->net, nfsd_net_id); > + spin_lock(&nn->s2s_cp_lock); > + idr_remove(&nn->s2s_cp_stateids, cps->cp_stateid.si_opaque.so_id); > + spin_unlock(&nn->s2s_cp_lock); > + > + kfree(cps); > +} > + > +static void nfs4_free_cp_statelist(struct nfs4_stid *stid) > +{ > + struct nfs4_cp_state *cps; > + > + might_sleep(); > + > + while (!list_empty(&stid->sc_cp_list)) { > + cps = list_first_entry(&stid->sc_cp_list, struct nfs4_cp_state, > + cp_list); > + list_del(&cps->cp_list); > + nfs4_free_cp_state(cps); > + } > +} > + > static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp) > { > struct nfs4_stid *stid; > @@ -819,6 +880,9 @@ static void block_delegations(struct knfsd_fh *fh) > } > idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); > spin_unlock(&clp->cl_lock); > + > + nfs4_free_cp_statelist(s); Is this really safe if there are still ongoing copies? I think the copies take a reference count on the parent stateid, so I think we should never actually get here: perhaps this could just be a WARN_ON(!list_empty(&s->s_cp_list)). Though nfsd4_copy puts things on this list before bumping the sc_count, so there may be a race there. What is supposed to happen, by the way, if a close arrives for a stateid with a copy in progress? Do we cancel the copy before returning from the close, or do we fail the close? (Same question for unlock and delegation return, I guess.) --b.