Re: [PATCH v2 06/10] NFSD add COPY_NOTIFY operation

[Olga Kornievskaia <olga.kornievskaia@gmail.com>]

On Tue, Feb 19, 2019 at 9:35 PM J. Bruce Fields <bfields@fieldses.org> wrote:
>
> On Fri, Nov 30, 2018 at 03:03:44PM -0500, Olga Kornievskaia wrote:
> > Introducing the COPY_NOTIFY operation.
> >
> > Create a new unique stateid that will keep track of the copy
> > state and the upcoming READs that will use that stateid. Keep
> > it in the list associated with parent stateid.
> >
> > Return single netaddr to advertise to the copy.
> >
> > Signed-off-by: Andy Adamson <andros@netapp.com>
> > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > ---
> >  fs/nfsd/nfs4proc.c  | 72 +++++++++++++++++++++++++++++++++++----
> >  fs/nfsd/nfs4state.c | 64 +++++++++++++++++++++++++++++++----
> >  fs/nfsd/nfs4xdr.c   | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++--
> >  fs/nfsd/state.h     | 18 ++++++++--
> >  fs/nfsd/xdr4.h      | 13 +++++++
> >  5 files changed, 248 insertions(+), 16 deletions(-)
> >
> > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> > index 0152b34..51fca9e 100644
> > --- a/fs/nfsd/nfs4proc.c
> > +++ b/fs/nfsd/nfs4proc.c
> > @@ -37,6 +37,7 @@
> >  #include <linux/falloc.h>
> >  #include <linux/slab.h>
> >  #include <linux/kthread.h>
> > +#include <linux/sunrpc/addr.h>
> >
> >  #include "idmap.h"
> >  #include "cache.h"
> > @@ -1035,7 +1036,8 @@ static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
> >  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;
> >
> > @@ -1052,7 +1054,7 @@ static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
> >
> >       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;
> > @@ -1083,7 +1085,7 @@ static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
> >       __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;
> >
> > @@ -1230,7 +1232,7 @@ static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
> >
> >  static void cleanup_async_copy(struct nfsd4_copy *copy)
> >  {
> > -     nfs4_free_cp_state(copy);
> > +     nfs4_free_copy_state(copy);
> >       fput(copy->file_dst);
> >       fput(copy->file_src);
> >       spin_lock(&copy->cp_clp->async_lock);
> > @@ -1270,7 +1272,7 @@ static int nfsd4_do_async_copy(void *data)
> >
> >       status = nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
> >                                  &copy->file_src, &copy->cp_dst_stateid,
> > -                                &copy->file_dst);
> > +                                &copy->file_dst, NULL);
> >       if (status)
> >               goto out;
> >
> > @@ -1284,7 +1286,7 @@ static int nfsd4_do_async_copy(void *data)
> >               async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
> >               if (!async_copy)
> >                       goto out;
> > -             if (!nfs4_init_cp_state(nn, copy)) {
> > +             if (!nfs4_init_copy_state(nn, copy)) {
> >                       kfree(async_copy);
> >                       goto out;
> >               }
> > @@ -1348,6 +1350,43 @@ struct nfsd4_copy *
> >  }
> >
> >  static __be32
> > +nfsd4_copy_notify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> > +               union nfsd4_op_u *u)
> > +{
> > +     struct nfsd4_copy_notify *cn = &u->copy_notify;
> > +     __be32 status;
> > +     struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
> > +     struct nfs4_stid *stid;
> > +     struct nfs4_cpntf_state *cps;
> > +
> > +     status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
> > +                                     &cn->cpn_src_stateid, RD_STATE, NULL,
> > +                                     NULL, &stid);
> > +     if (status)
> > +             return status;
> > +
> > +     cn->cpn_sec = nn->nfsd4_lease;
> > +     cn->cpn_nsec = 0;
> > +
> > +     status = nfserrno(-ENOMEM);
> > +     cps = nfs4_alloc_init_cpntf_state(nn, stid);
> > +     if (!cps)
> > +             return status;
> > +     memcpy(&cn->cpn_cnr_stateid, &cps->cp_stateid, sizeof(stateid_t));
> > +
> > +     /**
> > +      * For now, only return one server address in cpn_src, the
> > +      * address used by the client to connect to this server.
> > +      */
> > +     cn->cpn_src.nl4_type = NL4_NETADDR;
> > +     status = nfsd4_set_netaddr((struct sockaddr *)&rqstp->rq_daddr,
> > +                              &cn->cpn_src.u.nl4_addr);
> > +     WARN_ON_ONCE(status);
> > +
> > +     return status;
> > +}
> > +
> > +static __be32
> >  nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> >               struct nfsd4_fallocate *fallocate, int flags)
> >  {
> > @@ -2299,6 +2338,21 @@ static inline u32 nfsd4_offload_status_rsize(struct svc_rqst *rqstp,
> >               1 /* osr_complete<1> optional 0 for now */) * sizeof(__be32);
> >  }
> >
> > +static inline u32 nfsd4_copy_notify_rsize(struct svc_rqst *rqstp,
> > +                                     struct nfsd4_op *op)
> > +{
> > +     return (op_encode_hdr_size +
> > +             3 /* cnr_lease_time */ +
> > +             1 /* We support one cnr_source_server */ +
> > +             1 /* cnr_stateid seq */ +
> > +             op_encode_stateid_maxsz /* cnr_stateid */ +
> > +             1 /* num cnr_source_server*/ +
> > +             1 /* nl4_type */ +
> > +             1 /* nl4 size */ +
> > +             XDR_QUADLEN(NFS4_OPAQUE_LIMIT) /*nl4_loc + nl4_loc_sz */)
> > +             * sizeof(__be32);
> > +}
> > +
> >  #ifdef CONFIG_NFSD_PNFS
> >  static inline u32 nfsd4_getdeviceinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
> >  {
> > @@ -2723,6 +2777,12 @@ static inline u32 nfsd4_seek_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
> >               .op_name = "OP_OFFLOAD_CANCEL",
> >               .op_rsize_bop = nfsd4_only_status_rsize,
> >       },
> > +     [OP_COPY_NOTIFY] = {
> > +             .op_func = nfsd4_copy_notify,
> > +             .op_flags = OP_MODIFIES_SOMETHING,
> > +             .op_name = "OP_COPY_NOTIFY",
> > +             .op_rsize_bop = nfsd4_copy_notify_rsize,
> > +     },
> >  };
> >
> >  /**
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index be3e967..eaa136f 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -697,6 +697,7 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla
> >       /* Will be incremented before return to client: */
> >       refcount_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.
> > @@ -716,24 +717,53 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla
> >  /*
> >   * Create a unique stateid_t to represent each COPY.
> >   */
> > -int nfs4_init_cp_state(struct nfsd_net *nn, struct nfsd4_copy *copy)
> > +static int nfs4_init_cp_state(struct nfsd_net *nn, void *ptr, stateid_t *stid)
> >  {
> >       int new_id;
> >
> >       idr_preload(GFP_KERNEL);
> >       spin_lock(&nn->s2s_cp_lock);
> > -     new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, copy, 0, 0, GFP_NOWAIT);
> > +     new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, ptr, 0, 0, GFP_NOWAIT);
> >       spin_unlock(&nn->s2s_cp_lock);
> >       idr_preload_end();
> >       if (new_id < 0)
> >               return 0;
> > -     copy->cp_stateid.si_opaque.so_id = new_id;
> > -     copy->cp_stateid.si_opaque.so_clid.cl_boot = nn->boot_time;
> > -     copy->cp_stateid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
> > +     stid->si_opaque.so_id = new_id;
> > +     stid->si_opaque.so_clid.cl_boot = nn->boot_time;
> > +     stid->si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
> >       return 1;
> >  }
> >
> > -void nfs4_free_cp_state(struct nfsd4_copy *copy)
> > +int nfs4_init_copy_state(struct nfsd_net *nn, struct nfsd4_copy *copy)
> > +{
> > +     return nfs4_init_cp_state(nn, copy, &copy->cp_stateid);
> > +}
> > +
> > +struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
> > +                                                  struct nfs4_stid *p_stid)
> > +{
> > +     struct nfs4_cpntf_state *cps;
> > +
> > +     cps = kzalloc(sizeof(struct nfs4_cpntf_state), GFP_KERNEL);
> > +     if (!cps)
> > +             return NULL;
> > +     if (!nfs4_init_cp_state(nn, cps, &cps->cp_stateid))
> > +             goto out_free;
> > +     cps->cp_p_stid = p_stid;
> > +     cps->cp_active = false;
> > +     cps->cp_timeout = jiffies + (nn->nfsd4_lease * HZ);
> > +     INIT_LIST_HEAD(&cps->cp_list);
> > +     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);
> > +     return NULL;
> > +}
> > +
> > +void nfs4_free_copy_state(struct nfsd4_copy *copy)
> >  {
> >       struct nfsd_net *nn;
> >
> > @@ -743,6 +773,27 @@ void nfs4_free_cp_state(struct nfsd4_copy *copy)
> >       spin_unlock(&nn->s2s_cp_lock);
> >  }
> >
> > +static void nfs4_free_cpntf_statelist(struct net *net, struct nfs4_stid *stid)
> > +{
> > +     struct nfs4_cpntf_state *cps;
> > +     struct nfsd_net *nn;
> > +
> > +     nn = net_generic(net, nfsd_net_id);
> > +
> > +     might_sleep();
>
> What's that for?  Just remove it unless you've got some good reason.

I think this function was using free_ol_stateid_reaplist() as an
example which has might_sleep() in it. I don't really see a reason why
we'd be sleeping in nfs4_free_cpntf_statelist() so I'll remove it.

>
> --b.