NFSD: Make @lgp parameter of ->encode_layoutget a const pointer

This enables callers to be passed const pointer parameters.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/blocklayoutxdr.c

@@ -16,9 +16,9 @@
 
 __be32
 nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
-		struct nfsd4_layoutget *lgp)
+		const struct nfsd4_layoutget *lgp)
 {
-	struct pnfs_block_extent *b = lgp->lg_content;
+	const struct pnfs_block_extent *b = lgp->lg_content;
 	int len = sizeof(__be32) + 5 * sizeof(__be64) + sizeof(__be32);
 	__be32 *p;
 

fs/nfsd/blocklayoutxdr.h

@@ -53,7 +53,7 @@ struct pnfs_block_deviceaddr {
 __be32 nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
 		struct nfsd4_getdeviceinfo *gdp);
 __be32 nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
-		struct nfsd4_layoutget *lgp);
+		const struct nfsd4_layoutget *lgp);
 int nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
 		u32 block_size);
 int nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,

fs/nfsd/flexfilelayoutxdr.c

@@ -17,9 +17,9 @@ struct ff_idmap {
 
 __be32
 nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
-		struct nfsd4_layoutget *lgp)
+		const struct nfsd4_layoutget *lgp)
 {
-	struct pnfs_ff_layout *fl = lgp->lg_content;
+	const struct pnfs_ff_layout *fl = lgp->lg_content;
 	int len, mirror_len, ds_len, fh_len;
 	__be32 *p;
 

fs/nfsd/flexfilelayoutxdr.h

@@ -45,6 +45,6 @@ struct pnfs_ff_layout {
 __be32 nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
 		struct nfsd4_getdeviceinfo *gdp);
 __be32 nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
-		struct nfsd4_layoutget *lgp);
+		const struct nfsd4_layoutget *lgp);
 
 #endif /* _NFSD_FLEXFILELAYOUTXDR_H */

fs/nfsd/pnfs.h

@@ -31,8 +31,8 @@ struct nfsd4_layout_ops {
 
 	__be32 (*proc_layoutget)(struct inode *, const struct svc_fh *fhp,
 			struct nfsd4_layoutget *lgp);
-	__be32 (*encode_layoutget)(struct xdr_stream *,
-			struct nfsd4_layoutget *lgp);
+	__be32 (*encode_layoutget)(struct xdr_stream *xdr,
+			const struct nfsd4_layoutget *lgp);
 
 	__be32 (*proc_layoutcommit)(struct inode *inode,
 			struct nfsd4_layoutcommit *lcp);