pNFS: Allow layout drivers to manage private data in struct nfs4_layoutreturn

Cleanup to allow layout drivers to attach private data to layoutreturn,
and manage the data.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -3039,6 +3039,7 @@ struct nfs4_closedata {
 	struct {
 		struct nfs4_layoutreturn_args arg;
 		struct nfs4_layoutreturn_res res;
+		struct nfs4_xdr_opaque_data ld_private;
 		u32 roc_barrier;
 		bool roc;
 	} lr;
@@ -3267,6 +3268,7 @@ int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait)
 	if (IS_ERR(calldata->arg.seqid))
 		goto out_free_calldata;
 	calldata->arg.fmode = 0;
+	calldata->lr.arg.ld_private = &calldata->lr.ld_private;
 	calldata->res.fattr = &calldata->fattr;
 	calldata->res.seqid = calldata->arg.seqid;
 	calldata->res.server = server;
@@ -5599,6 +5601,7 @@ struct nfs4_delegreturndata {
 	struct {
 		struct nfs4_layoutreturn_args arg;
 		struct nfs4_layoutreturn_res res;
+		struct nfs4_xdr_opaque_data ld_private;
 		u32 roc_barrier;
 		bool roc;
 	} lr;
@@ -5735,6 +5738,7 @@ static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, co
 	data->res.fattr = &data->fattr;
 	data->res.server = server;
 	data->res.lr_ret = -NFS4ERR_NOMATCHING_LAYOUT;
+	data->lr.arg.ld_private = &data->lr.ld_private;
 	nfs_fattr_init(data->res.fattr);
 	data->timestamp = jiffies;
 	data->rpc_status = 0;
@@ -8633,6 +8637,8 @@ static void nfs4_layoutreturn_release(void *calldata)
 	nfs4_sequence_free_slot(&lrp->res.seq_res);
 	pnfs_put_layout_hdr(lrp->args.layout);
 	nfs_iput_and_deactive(lrp->inode);
+	if (lrp->ld_private.ops && lrp->ld_private.ops->free)
+		lrp->ld_private.ops->free(&lrp->ld_private);
 	kfree(calldata);
 	dprintk("<-- %s\n", __func__);
 }

fs/nfs/nfs4xdr.c

@@ -2035,7 +2035,9 @@ encode_layoutreturn(struct xdr_stream *xdr,
 	spin_lock(&args->inode->i_lock);
 	encode_nfs4_stateid(xdr, &args->stateid);
 	spin_unlock(&args->inode->i_lock);
-	if (lr_ops->encode_layoutreturn)
+	if (args->ld_private->ops && args->ld_private->ops->encode)
+		args->ld_private->ops->encode(xdr, args, args->ld_private);
+	else if (lr_ops->encode_layoutreturn)
 		lr_ops->encode_layoutreturn(xdr, args);
 	else
 		encode_uint32(xdr, 0);

fs/nfs/pnfs.c

@@ -1086,6 +1086,7 @@ pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
 	}
 
 	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
+	lrp->args.ld_private = &lrp->ld_private;
 	lrp->clp = NFS_SERVER(ino)->nfs_client;
 	lrp->cred = lo->plh_lc_cred;
 

include/linux/nfs_xdr.h

@@ -320,6 +320,7 @@ struct nfs4_layoutreturn_args {
 	struct pnfs_layout_range range;
 	nfs4_stateid stateid;
 	__u32   layout_type;
+	struct nfs4_xdr_opaque_data *ld_private;
 };
 
 struct nfs4_layoutreturn_res {
@@ -335,6 +336,7 @@ struct nfs4_layoutreturn {
 	struct nfs_client *clp;
 	struct inode *inode;
 	int rpc_status;
+	struct nfs4_xdr_opaque_data ld_private;
 };
 
 #define PNFS_LAYOUTSTATS_MAXSIZE 256