+static u32 nfsd_attrmask[] = {
+ NFSD_WRITEABLE_ATTRS_WORD0,
+ NFSD_WRITEABLE_ATTRS_WORD1,
+ NFSD_WRITEABLE_ATTRS_WORD2
+};
+
+static u32 nfsd41_ex_attrmask[] = {
+ NFSD_SUPPATTR_EXCLCREAT_WORD0,
+ NFSD_SUPPATTR_EXCLCREAT_WORD1,
+ NFSD_SUPPATTR_EXCLCREAT_WORD2
+};
+
+static __be32
+check_attr_support(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ u32 *bmval, u32 *writable)
+{
+ struct dentry *dentry = cstate->current_fh.fh_dentry;
+ struct svc_export *exp = cstate->current_fh.fh_export;
+
+ /*
+ * Check about attributes are supported by the NFSv4 server or not.
+ * According to spec, unsupported attributes return ERR_ATTRNOTSUPP.
+ */
+ if ((bmval[0] & ~nfsd_suppattrs0(cstate->minorversion)) ||
+ (bmval[1] & ~nfsd_suppattrs1(cstate->minorversion)) ||
+ (bmval[2] & ~nfsd_suppattrs2(cstate->minorversion)))
+ return nfserr_attrnotsupp;
+
+ /*
+ * Check FATTR4_WORD0_ACL & FATTR4_WORD0_FS_LOCATIONS can be supported
+ * in current environment or not.
+ */
+ if (bmval[0] & FATTR4_WORD0_ACL) {
+ if (!IS_POSIXACL(dentry->d_inode))
+ return nfserr_attrnotsupp;
+ }
+ if (bmval[0] & FATTR4_WORD0_FS_LOCATIONS) {
+ if (exp->ex_fslocs.locations == NULL)
+ return nfserr_attrnotsupp;
+ }
+
+ /*
+ * According to spec, read-only attributes return ERR_INVAL.
+ */
+ if (writable) {
+ if ((bmval[0] & ~writable[0]) || (bmval[1] & ~writable[1]) ||
+ (bmval[2] & ~writable[2]))
+ return nfserr_inval;
+ }
+
+ return nfs_ok;
+}
+
+static __be32
+nfsd4_check_open_attributes(struct svc_rqst *rqstp,
+ struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
+{
+ __be32 status = nfs_ok;
+
+ if (open->op_create == NFS4_OPEN_CREATE) {
+ if (open->op_createmode == NFS4_CREATE_UNCHECKED
+ || open->op_createmode == NFS4_CREATE_GUARDED)
+ status = check_attr_support(rqstp, cstate,
+ open->op_bmval, nfsd_attrmask);
+ else if (open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1)
+ status = check_attr_support(rqstp, cstate,
+ open->op_bmval, nfsd41_ex_attrmask);
+ }
+
+ return status;
+}
+