NFSD: Add nfsd4_encode_fattr4_fs_layout_types()

Refactor the encoder for FATTR4_FS_LAYOUT_TYPES into a helper. In a
subsequent patch, this helper will be called from a bitmask loop.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b840318..36ef7b0 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3293,6 +3293,28 @@ static __be32 nfsd4_encode_fattr4_mounted_on_fileid(struct xdr_stream *xdr,
        return nfsd4_encode_uint64_t(xdr, ino);
 }
 
+#ifdef CONFIG_NFSD_PNFS
+
+static __be32 nfsd4_encode_fattr4_fs_layout_types(struct xdr_stream *xdr,
+                                                 const struct nfsd4_fattr_args *args)
+{
+       unsigned long mask = args->exp->ex_layout_types;
+       int i;
+
+       /* Hamming weight of @mask is the number of layout types to return */
+       if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
+               return nfserr_resource;
+       for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
+               if (mask & BIT(i)) {
+                       /* layouttype4 */
+                       if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
+                               return nfserr_resource;
+               }
+       return nfs_ok;
+}
+
+#endif
+
 /*
  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
  * ourselves.
@@ -3653,7 +3675,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
        }
 #ifdef CONFIG_NFSD_PNFS
        if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
-               status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
+               status = nfsd4_encode_fattr4_fs_layout_types(xdr, &args);
                if (status)
                        goto out;
        }