+ dentry = fhp->fh_dentry;
+ exp = fhp->fh_export;
+ /*
+ * We still have to do all these permission checks, even when
+ * fh_dentry is already set:
+ * - fh_verify may be called multiple times with different
+ * "access" arguments (e.g. nfsd_proc_create calls
+ * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
+ * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
+ * - in the NFSv4 case, the filehandle may have been filled
+ * in by fh_compose, and given a dentry, but further
+ * compound operations performed with that filehandle
+ * still need permissions checks. In the worst case, a
+ * mountpoint crossing may have changed the export
+ * options, and we may now need to use a different uid
+ * (for example, if different id-squashing options are in
+ * effect on the new filesystem).
+ */
+ error = nfsd_setuser_and_check_port(rqstp, exp);
+ if (error)
+ goto out;