+/*
+ * Distinguish between permanent and temporary errors.
+ *
+ * Returns 0 if the passed-in error is temporary, thus the
+ * mount system call should be retried; returns one if the
+ * passed-in error is permanent, thus the mount system call
+ * should not be retried.
+ */
+static int is_permanent_error(int error)
+{
+ switch (error) {
+ case ESTALE:
+ case ETIMEDOUT:
+ case ECONNREFUSED:
+ return 0; /* temporary */
+ default:
+ return 1; /* permanent */
+ }
+}
+
+/*
+ * Reconstruct the mount option string based on a portmapper probe
+ * of the server. Returns one if the server's portmapper returned
+ * something we can use, otherwise zero.
+ *
+ * To handle version and transport protocol fallback properly, we
+ * need to parse some of the mount options in order to set up a
+ * portmap probe. Mount options that rewrite_mount_options()
+ * doesn't recognize are left alone.
+ *
+ * Returns a new group of mount options if successful; otherwise
+ * NULL is returned if some failure occurred.
+ */
+static struct mount_options *rewrite_mount_options(char *str)
+{
+ struct mount_options *options;
+ char *option, new_option[64];
+ clnt_addr_t mnt_server = { };
+ clnt_addr_t nfs_server = { };
+ int p;
+
+ errno = EIO;
+
+ options = po_split(str);
+ if (!options)
+ return NULL;
+
+ option = po_get(options, "addr");
+ if (option) {
+ nfs_server.saddr.sin_family = AF_INET;
+ if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
+ goto err;
+ } else
+ goto err;
+
+ option = po_get(options, "mountaddr");
+ if (option) {
+ mnt_server.saddr.sin_family = AF_INET;
+ if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
+ goto err;
+ } else
+ memcpy(&mnt_server.saddr, &nfs_server.saddr,
+ sizeof(mnt_server.saddr));
+
+ option = po_get(options, "mountport");
+ if (option)
+ mnt_server.pmap.pm_port = atoi(option);
+ mnt_server.pmap.pm_prog = MOUNTPROG;
+ option = po_get(options, "mountvers");
+ if (option)
+ mnt_server.pmap.pm_vers = atoi(option);
+
+ option = po_get(options, "port");
+ if (option) {
+ nfs_server.pmap.pm_port = atoi(option);
+ po_remove_all(options, "port");
+ }
+ nfs_server.pmap.pm_prog = NFS_PROGRAM;
+
+ option = po_get(options, "nfsvers");
+ if (option) {
+ nfs_server.pmap.pm_vers = atoi(option);
+ po_remove_all(options, "nfsvers");
+ }
+ option = po_get(options, "vers");
+ if (option) {
+ nfs_server.pmap.pm_vers = atoi(option);
+ po_remove_all(options, "vers");
+ }
+ option = po_get(options, "proto");
+ if (option) {
+ if (strcmp(option, "tcp") == 0) {
+ nfs_server.pmap.pm_prot = IPPROTO_TCP;
+ po_remove_all(options, "proto");
+ }
+ if (strcmp(option, "udp") == 0) {
+ nfs_server.pmap.pm_prot = IPPROTO_UDP;
+ po_remove_all(options, "proto");