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 <kolga@xxxxxxxxxx>
> ---
> 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.
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