Re: [PATCH v4 8/8] NFSD add nfs4 inter ssc to nfsd4_copy

[Anna Schumaker <schumaker.anna@gmail.com>]

Hi Olga,

On Mon, 2019-07-08 at 15:23 -0400, Olga Kornievskaia wrote:
> Given a universal address, mount the source server from the
> destination
> server.  Use an internal mount. Call the NFS client nfs42_ssc_open to
> obtain the NFS struct file suitable for nfsd_copy_range.
> 
> Ability to do "inter" server-to-server depends on the an nfsd kernel
> parameter "inter_copy_offload_enabled".
> 
> Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> ---
>  fs/nfsd/nfs4proc.c  | 291
> ++++++++++++++++++++++++++++++++++++++++++++++++----
>  fs/nfsd/nfs4state.c |  17 ++-
>  fs/nfsd/nfssvc.c    |   6 ++
>  fs/nfsd/state.h     |   4 +
>  fs/nfsd/xdr4.h      |   5 +
>  5 files changed, 299 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 1039528..caf046f 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1153,6 +1153,209 @@ void nfsd4_shutdown_copy(struct nfs4_client
> *clp)
>  	while ((copy = nfsd4_get_copy(clp)) != NULL)
>  		nfsd4_stop_copy(copy);
>  }
> +#ifdef CONFIG_NFSD_V4_2_INTER_SSC
> +
> +extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
> +				   struct nfs_fh *src_fh,
> +				   nfs4_stateid *stateid);
> +extern void nfs42_ssc_close(struct file *filep);
> +
> +extern void nfs_sb_deactive(struct super_block *sb);
> +
> +#define NFSD42_INTERSSC_MOUNTOPS "vers=4.2,addr=%s,sec=sys"
> +
> +/**
> + * Support one copy source server for now.
> + */
> +static __be32
> +nfsd4_interssc_connect(struct nl4_server *nss, struct svc_rqst
> *rqstp,
> +		       struct vfsmount **mount)
> +{
> +	struct file_system_type *type;
> +	struct vfsmount *ss_mnt;
> +	struct nfs42_netaddr *naddr;
> +	struct sockaddr_storage tmp_addr;
> +	size_t tmp_addrlen, match_netid_len = 3;
> +	char *startsep = "", *endsep = "", *match_netid = "tcp";
> +	char *ipaddr, *dev_name, *raw_data;
> +	int len, raw_len, status = -EINVAL;
> +
> +	naddr = &nss->u.nl4_addr;
> +	tmp_addrlen = rpc_uaddr2sockaddr(SVC_NET(rqstp), naddr->addr,
> +					 naddr->addr_len,
> +					 (struct sockaddr *)&tmp_addr,
> +					 sizeof(tmp_addr));
> +	if (tmp_addrlen == 0)
> +		goto out_err;
> +
> +	if (tmp_addr.ss_family == AF_INET6) {
> +		startsep = "[";
> +		endsep = "]";
> +		match_netid = "tcp6";
> +		match_netid_len = 4;
> +	}
> +
> +	if (naddr->netid_len != match_netid_len ||
> +		strncmp(naddr->netid, match_netid, naddr->netid_len))
> +		goto out_err;
> +
> +	/* Construct the raw data for the vfs_kern_mount call */
> +	len = RPC_MAX_ADDRBUFLEN + 1;
> +	ipaddr = kzalloc(len, GFP_KERNEL);
> +	if (!ipaddr)
> +		goto out_err;
> +
> +	rpc_ntop((struct sockaddr *)&tmp_addr, ipaddr, len);
> +
> +	/* 2 for ipv6 endsep and startsep. 3 for ":/" and trailing
> '/0'*/
> +
> +	raw_len = strlen(NFSD42_INTERSSC_MOUNTOPS) + strlen(ipaddr);
> +	raw_data = kzalloc(raw_len, GFP_KERNEL);
> +	if (!raw_data)
> +		goto out_free_ipaddr;
> +
> +	snprintf(raw_data, raw_len, NFSD42_INTERSSC_MOUNTOPS, ipaddr);
> +
> +	status = -ENODEV;
> +	type = get_fs_type("nfs");
> +	if (!type)
> +		goto out_free_rawdata;
> +
> +	/* Set the server:<export> for the vfs_kern_mount call */
> +	dev_name = kzalloc(len + 5, GFP_KERNEL);
> +	if (!dev_name)
> +		goto out_free_rawdata;
> +	snprintf(dev_name, len + 5, "%s%s%s:/", startsep, ipaddr,
> endsep);
> +
> +	/* Use an 'internal' mount: SB_KERNMOUNT -> MNT_INTERNAL */
> +	ss_mnt = vfs_kern_mount(type, SB_KERNMOUNT, dev_name,
> raw_data);
> +	module_put(type->owner);
> +	if (IS_ERR(ss_mnt))
> +		goto out_free_devname;
> +
> +	status = 0;
> +	*mount = ss_mnt;
> +
> +out_free_devname:
> +	kfree(dev_name);
> +out_free_rawdata:
> +	kfree(raw_data);
> +out_free_ipaddr:
> +	kfree(ipaddr);
> +out_err:
> +	return status;
> +}
> +
> +static void
> +nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
> +{
> +	nfs_sb_deactive(ss_mnt->mnt_sb);
> +	mntput(ss_mnt);
> +}
> +
> +/**
> + * nfsd4_setup_inter_ssc
> + *
> + * Verify COPY destination stateid.
> + * Connect to the source server with NFSv4.1.
> + * Create the source struct file for nfsd_copy_range.
> + * Called with COPY cstate:
> + *    SAVED_FH: source filehandle
> + *    CURRENT_FH: destination filehandle
> + *
> + * Returns errno (not nfserrxxx)
> + */
> +static __be32
> +nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
> +		      struct nfsd4_compound_state *cstate,
> +		      struct nfsd4_copy *copy, struct vfsmount **mount)
> +{
> +	struct svc_fh *s_fh = NULL;
> +	stateid_t *s_stid = &copy->cp_src_stateid;
> +	__be32 status = -EINVAL;
> +
> +	/* Verify the destination stateid and set dst struct file*/
> +	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate-
> >current_fh,
> +					    &copy->cp_dst_stateid,
> +					    WR_STATE, &copy->file_dst,
> NULL,
> +					    NULL);
> +	if (status)
> +		goto out;
> +
> +	status = nfsd4_interssc_connect(&copy->cp_src, rqstp, mount);
> +	if (status)
> +		goto out;
> +
> +	s_fh = &cstate->save_fh;
> +
> +	copy->c_fh.size = s_fh->fh_handle.fh_size;
> +	memcpy(copy->c_fh.data, &s_fh->fh_handle.fh_base, copy-
> >c_fh.size);
> +	copy->stateid.seqid = s_stid->si_generation;
> +	memcpy(copy->stateid.other, (void *)&s_stid->si_opaque,
> +	       sizeof(stateid_opaque_t));
> +
> +	status = 0;
> +out:
> +	return status;
> +}
> +
> +static void
> +nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct file *src,
> +			struct file *dst)
> +{
> +	nfs42_ssc_close(src);
> +	fput(src);
> +	fput(dst);
> +	mntput(ss_mnt);
> +}
> +
> +#else /* CONFIG_NFSD_V4_2_INTER_SSC */
> +
> +static __be32
> +nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
> +		      struct nfsd4_compound_state *cstate,
> +		      struct nfsd4_copy *copy,
> +		      struct vfsmount **mount)
> +{
> +	*mount = NULL;
> +	return -EINVAL;
> +}
> +
> +static void
> +nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct file *src,
> +			struct file *dst)
> +{
> +}
> +
> +static void
> +nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
> +{
> +}
> +
> +static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
> +				   struct nfs_fh *src_fh,
> +				   nfs4_stateid *stateid)
> +{
> +	return NULL;
> +}
> +#endif /* CONFIG_NFSD_V4_2_INTER_SSC */
> +
> +static __be32
> +nfsd4_setup_intra_ssc(struct svc_rqst *rqstp,
> +		      struct nfsd4_compound_state *cstate,
> +		      struct nfsd4_copy *copy)
> +{
> +	return nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
> +				 &copy->file_src, &copy-
> >cp_dst_stateid,
> +				 &copy->file_dst, NULL);
> +}
> +
> +static void
> +nfsd4_cleanup_intra_ssc(struct file *src, struct file *dst)
> +{
> +	fput(src);
> +	fput(dst);
> +}
>  
>  static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
>  {
> @@ -1217,12 +1420,16 @@ static __be32 nfsd4_do_copy(struct nfsd4_copy
> *copy, bool sync)
>  		status = nfs_ok;
>  	}
>  
> -	fput(copy->file_src);
> -	fput(copy->file_dst);
> +	if (!copy->cp_intra) /* Inter server SSC */
> +		nfsd4_cleanup_inter_ssc(copy->ss_mnt, copy->file_src,
> +					copy->file_dst);
> +	else
> +		nfsd4_cleanup_intra_ssc(copy->file_src, copy-
> >file_dst);
> +
>  	return status;
>  }
>  
> -static void dup_copy_fields(struct nfsd4_copy *src, struct
> nfsd4_copy *dst)
> +static int dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy
> *dst)
>  {
>  	dst->cp_src_pos = src->cp_src_pos;
>  	dst->cp_dst_pos = src->cp_dst_pos;
> @@ -1232,8 +1439,17 @@ static void dup_copy_fields(struct nfsd4_copy
> *src, struct nfsd4_copy *dst)
>  	memcpy(&dst->fh, &src->fh, sizeof(src->fh));
>  	dst->cp_clp = src->cp_clp;
>  	dst->file_dst = get_file(src->file_dst);
> -	dst->file_src = get_file(src->file_src);
> +	dst->cp_intra = src->cp_intra;
> +	if (src->cp_intra) /* for inter, file_src doesn't exist yet */
> +		dst->file_src = get_file(src->file_src);
>  	memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src-
> >cp_stateid));
> +	memcpy(&dst->cp_src, &src->cp_src, sizeof(struct nl4_server));
> +	memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
> +	memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
> +	dst->ss_mnt = src->ss_mnt;
> +
> +	return 0;
> +
>  }
>  
>  static void cleanup_async_copy(struct nfsd4_copy *copy)
> @@ -1252,7 +1468,18 @@ static int nfsd4_do_async_copy(void *data)
>  	struct nfsd4_copy *copy = (struct nfsd4_copy *)data;
>  	struct nfsd4_copy *cb_copy;
>  
> +	if (!copy->cp_intra) { /* Inter server SSC */
> +		copy->file_src = nfs42_ssc_open(copy->ss_mnt, &copy-
> >c_fh,
> +					      &copy->stateid);
> +		if (IS_ERR(copy->file_src)) {
> +			copy->nfserr = nfserr_offload_denied;
> +			nfsd4_interssc_disconnect(copy->ss_mnt);
> +			goto do_callback;
> +		}
> +	}
> +
>  	copy->nfserr = nfsd4_do_copy(copy, 0);
> +do_callback:
>  	cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
>  	if (!cb_copy)
>  		goto out;
> @@ -1276,11 +1503,20 @@ static int nfsd4_do_async_copy(void *data)
>  	__be32 status;
>  	struct nfsd4_copy *async_copy = NULL;
>  
> -	status = nfsd4_verify_copy(rqstp, cstate, &copy-
> >cp_src_stateid,
> -				   &copy->file_src, &copy-
> >cp_dst_stateid,
> -				   &copy->file_dst, NULL);
> -	if (status)
> -		goto out;
> +	if (!copy->cp_intra) { /* Inter server SSC */
> +		if (!inter_copy_offload_enable || copy->cp_synchronous) 
> {
> +			status = nfserr_notsupp;
> +			goto out;
> +		}
> +		status = nfsd4_setup_inter_ssc(rqstp, cstate, copy,
> +					&copy->ss_mnt);
> +		if (status)
> +			return nfserr_offload_denied;
> +	} else {
> +		status = nfsd4_setup_intra_ssc(rqstp, cstate, copy);
> +		if (status)
> +			return status;
> +	}
>  
>  	copy->cp_clp = cstate->clp;
>  	memcpy(&copy->fh, &cstate->current_fh.fh_handle,
> @@ -1291,15 +1527,15 @@ static int nfsd4_do_async_copy(void *data)
>  		status = nfserrno(-ENOMEM);
>  		async_copy = kzalloc(sizeof(struct nfsd4_copy),
> GFP_KERNEL);
>  		if (!async_copy)
> -			goto out;
> -		if (!nfs4_init_copy_state(nn, copy)) {
> -			kfree(async_copy);
> -			goto out;
> -		}
> +			goto out_err;
> +		if (!nfs4_init_copy_state(nn, copy))
> +			goto out_err;
>  		refcount_set(&async_copy->refcount, 1);
>  		memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid,
>  			sizeof(copy->cp_stateid));
> -		dup_copy_fields(copy, async_copy);
> +		status = dup_copy_fields(copy, async_copy);
> +		if (status)
> +			goto out_err;
>  		async_copy->copy_task =
> kthread_create(nfsd4_do_async_copy,
>  				async_copy, "%s", "copy thread");
>  		if (IS_ERR(async_copy->copy_task))
> @@ -1310,13 +1546,17 @@ static int nfsd4_do_async_copy(void *data)
>  		spin_unlock(&async_copy->cp_clp->async_lock);
>  		wake_up_process(async_copy->copy_task);
>  		status = nfs_ok;
> -	} else
> +	} else {
>  		status = nfsd4_do_copy(copy, 1);
> +	}
>  out:
>  	return status;
>  out_err:
>  	cleanup_async_copy(async_copy);
> -	goto out;
> +	status = nfserrno(-ENOMEM);
> +	if (!copy->cp_intra)
> +		nfsd4_interssc_disconnect(copy->ss_mnt);
> +	goto out_err;

Won't this just loop going to the out_err label?

Thanks,
Anna

>  }
>  
>  struct nfsd4_copy *
> @@ -1342,15 +1582,24 @@ struct nfsd4_copy *
>  		     union nfsd4_op_u *u)
>  {
>  	struct nfsd4_offload_status *os = &u->offload_status;
> -	__be32 status = 0;
> +	__be32 status = nfserr_bad_stateid;
>  	struct nfsd4_copy *copy;
>  	struct nfs4_client *clp = cstate->clp;
> +	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
>  
>  	copy = find_async_copy(clp, &os->stateid);
> -	if (copy)
> +	if (!copy) {
> +		struct nfs4_cpntf_state *cps = NULL;
> +
> +		status = find_internal_cpntf_state(nn, &os->stateid,
> &cps);
> +		if (status)
> +			return status;
> +		if (cps) {
> +			free_cpntf_state(nn, &os->stateid, cps);
> +			return nfs_ok;
> +		}
> +	} else
>  		nfsd4_stop_copy(copy);
> -	else
> -		status = nfserr_bad_stateid;
>  
>  	return status;
>  }
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index d7f4b96..c1a0695 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -5232,12 +5232,23 @@ static __be32 nfsd4_validate_stateid(struct
> nfs4_client *cl, stateid_t *stateid)
>  
>  	return 0;
>  }
> +void free_cpntf_state(struct nfsd_net *nn, stateid_t *st,
> +		      struct nfs4_cpntf_state *cps)
> +{
> +	spin_lock(&nn->s2s_cp_lock);
> +	list_del(&cps->cp_list);
> +	idr_remove(&nn->s2s_cp_stateids, cps-
> >cp_stateid.si_opaque.so_id);
> +	nfs4_put_stid(cps->cp_p_stid);
> +	kfree(cps);
> +	spin_unlock(&nn->s2s_cp_lock);
> +}
> +
>  /*
>   * A READ from an inter server to server COPY will have a
>   * copy stateid. Return the parent nfs4_stid.
>   */
> -static __be32 _find_cpntf_state(struct nfsd_net *nn, stateid_t *st,
> -		     struct nfs4_cpntf_state **cps)
> +__be32 find_internal_cpntf_state(struct nfsd_net *nn, stateid_t *st,
> +				 struct nfs4_cpntf_state **cps)
>  {
>  	struct nfs4_cpntf_state *state = NULL;
>  
> @@ -5260,7 +5271,7 @@ static __be32 find_cpntf_state(struct nfsd_net
> *nn, stateid_t *st,
>  	__be32 status;
>  	struct nfs4_cpntf_state *cps = NULL;
>  
> -	status = _find_cpntf_state(nn, st, &cps);
> +	status = find_internal_cpntf_state(nn, st, &cps);
>  	if (status)
>  		return status;
>  
> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> index 18d94ea..033bfcb 100644
> --- a/fs/nfsd/nfssvc.c
> +++ b/fs/nfsd/nfssvc.c
> @@ -30,6 +30,12 @@
>  
>  #define NFSDDBG_FACILITY	NFSDDBG_SVC
>  
> +bool inter_copy_offload_enable;
> +EXPORT_SYMBOL_GPL(inter_copy_offload_enable);
> +module_param(inter_copy_offload_enable, bool, 0644);
> +MODULE_PARM_DESC(inter_copy_offload_enable,
> +		 "Enable inter server to server copy offload. Default:
> false");
> +
>  extern struct svc_program	nfsd_program;
>  static int			nfsd(void *vrqstp);
>  #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 106ed56..7026e2a 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -659,6 +659,10 @@ extern struct nfs4_client_reclaim
> *nfs4_client_to_reclaim(struct xdr_netobj name
>  extern void nfs4_put_copy(struct nfsd4_copy *copy);
>  extern struct nfsd4_copy *
>  find_async_copy(struct nfs4_client *clp, stateid_t *staetid);
> +extern __be32 find_internal_cpntf_state(struct nfsd_net *nn,
> stateid_t *st,
> +				struct nfs4_cpntf_state **cps);
> +extern void free_cpntf_state(struct nfsd_net *nn, stateid_t *st,
> +		      struct nfs4_cpntf_state *cps);
>  static inline void get_nfs4_file(struct nfs4_file *fi)
>  {
>  	refcount_inc(&fi->fi_ref);
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index fbd18d6..bb2f8e5 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -547,7 +547,12 @@ struct nfsd4_copy {
>  	struct task_struct	*copy_task;
>  	refcount_t		refcount;
>  	bool			stopped;
> +
> +	struct vfsmount		*ss_mnt;
> +	struct nfs_fh		c_fh;
> +	nfs4_stateid		stateid;
>  };
> +extern bool inter_copy_offload_enable;
>  
>  struct nfsd4_seek {
>  	/* request */