[PATCH v3 32/85] NFSD: Add helper to decode OPEN's createhow4 argument

[Chuck Lever <chuck.lever@xxxxxxxxxx>]

Refactor for clarity.

Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
 fs/nfsd/nfs4xdr.c |   78 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 45 insertions(+), 33 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 7254c9e4e825..579139d727ea 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -946,6 +946,48 @@ nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup
 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
 }
 
+static __be32
+nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_createmode) {
+	case NFS4_CREATE_UNCHECKED:
+	case NFS4_CREATE_GUARDED:
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE:
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE4_1:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
 {
 	__be32 *p;
@@ -1046,39 +1088,9 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 	case NFS4_OPEN_NOCREATE:
 		break;
 	case NFS4_OPEN_CREATE:
-		READ_BUF(4);
-		open->op_createmode = be32_to_cpup(p++);
-		switch (open->op_createmode) {
-		case NFS4_CREATE_UNCHECKED:
-		case NFS4_CREATE_GUARDED:
-			status = nfsd4_decode_fattr4(argp, open->op_bmval,
-						     ARRAY_SIZE(open->op_bmval),
-						     &open->op_iattr, &open->op_acl,
-						     &open->op_label, &open->op_umask);
-			if (status)
-				goto out;
-			break;
-		case NFS4_CREATE_EXCLUSIVE:
-			status = nfsd4_decode_verifier4(argp, &open->op_verf);
-			if (status)
-				return status;
-			break;
-		case NFS4_CREATE_EXCLUSIVE4_1:
-			if (argp->minorversion < 1)
-				goto xdr_error;
-			status = nfsd4_decode_verifier4(argp, &open->op_verf);
-			if (status)
-				return status;
-			status = nfsd4_decode_fattr4(argp, open->op_bmval,
-						     ARRAY_SIZE(open->op_bmval),
-						     &open->op_iattr, &open->op_acl,
-						     &open->op_label, &open->op_umask);
-			if (status)
-				goto out;
-			break;
-		default:
-			goto xdr_error;
-		}
+		status = nfsd4_decode_createhow4(argp, open);
+		if (status)
+			return status;
 		break;
 	default:
 		goto xdr_error;