- if (strncmp(type, "nfs4", 4) == 0)
- return try_nfs4mount(spec, node, flags,
- options, fake, extra_opts);
- else
- return try_nfs23mount(spec, node, flags,
- options, fake, extra_opts);
+ struct addrinfo *ai;
+ int ret = 0;
+
+ for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
+ ret = nfs_do_mount_v4(mi, ai->ai_addr, ai->ai_addrlen);
+ if (ret != 0)
+ return ret;
+
+ switch (errno) {
+ case ECONNREFUSED:
+ case EHOSTUNREACH:
+ continue;
+ default:
+ break;
+ }
+ }
+ return ret;
+}
+
+/*
+ * Handle NFS version and transport protocol
+ * autonegotiation.
+ *
+ * When no version or protocol is specified on the
+ * command line, mount.nfs negotiates with the server
+ * to determine appropriate settings for the new
+ * mount point.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_autonegotiate(struct nfsmount_info *mi)
+{
+ int result;
+
+ result = nfs_try_mount_v4(mi);
+ if (result)
+ return result;
+
+ switch (errno) {
+ case EPROTONOSUPPORT:
+ /* A clear indication that the server or our
+ * client does not support NFS version 4. */
+ goto fall_back;
+ case ENOENT:
+ /* Legacy Linux servers don't export an NFS
+ * version 4 pseudoroot. */
+ goto fall_back;
+ case EPERM:
+ /* Linux servers prior to 2.6.25 may return
+ * EPERM when NFS version 4 is not supported. */
+ goto fall_back;
+ default:
+ return result;
+ }
+
+fall_back:
+ return nfs_try_mount_v3v2(mi);
+}
+
+/*
+ * This is a single pass through the fg/bg loop.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_mount(struct nfsmount_info *mi)
+{
+ int result = 0;
+
+ switch (mi->version) {
+ case 0:
+ result = nfs_autonegotiate(mi);
+ break;
+ case 2:
+ case 3:
+ result = nfs_try_mount_v3v2(mi);
+ break;
+ case 4:
+ result = nfs_try_mount_v4(mi);
+ break;
+ default:
+ errno = EIO;
+ }
+
+ return result;
+}
+
+/*
+ * Distinguish between permanent and temporary errors.
+ *
+ * Basically, we retry if communication with the server has
+ * failed so far, but fail immediately if there is a local
+ * error (like a bad mount option).
+ *
+ * ESTALE is also a temporary error because some servers
+ * return ESTALE when a share is temporarily offline.
+ *
+ * Returns 1 if we should fail immediately, or 0 if we
+ * should retry.
+ */
+static int nfs_is_permanent_error(int error)
+{
+ switch (error) {
+ case ESTALE:
+ case ETIMEDOUT:
+ case ECONNREFUSED:
+ case EHOSTUNREACH:
+ return 0; /* temporary */
+ default:
+ return 1; /* permanent */
+ }