+ sys_mount_errors(mi->hostname, errno, 1, 1);
+ return EX_BG;
+}
+
+/*
+ * Handle "background" NFS mount [retry daemon]
+ *
+ * Returns a valid mount command exit code: EX_SUCCESS if successful,
+ * EX_FAIL if a failure occurred. There's nothing to catch the
+ * error return, though, so we use sys_mount_errors to log the
+ * failure.
+ */
+static int nfsmount_child(struct nfsmount_info *mi)
+{
+ unsigned int secs = 1;
+ time_t timeout;
+
+ timeout = nfs_parse_retry_option(mi->options,
+ NFS_DEF_BG_TIMEOUT_MINUTES);
+
+ for (;;) {
+ if (sleep(secs))
+ break;
+ secs <<= 1;
+ if (secs > 120)
+ secs = 120;
+
+ if (nfs_try_mount(mi))
+ return EX_SUCCESS;
+
+ /* retry background mounts when the server is not up */
+ if (nfs_is_permanent_error(errno) && errno != EOPNOTSUPP)
+ break;
+
+ if (time(NULL) > timeout)
+ break;
+
+ sys_mount_errors(mi->hostname, errno, 1, 1);
+ };
+
+ sys_mount_errors(mi->hostname, errno, 1, 0);
+ return EX_FAIL;
+}
+
+/*
+ * Handle "background" NFS mount
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfsmount_bg(struct nfsmount_info *mi)
+{
+ if (!mi->child)
+ return nfsmount_parent(mi);
+ else
+ return nfsmount_child(mi);
+}
+
+/*
+ * Usually all that is needed for an NFS remount is to change
+ * generic mount options like "sync" or "ro". These generic
+ * options are controlled by mi->flags, not by text-based
+ * options, and no contact with the server is needed.
+ *
+ * Take care with the /etc/mtab entry for this mount; just
+ * calling update_mtab() will change an "-t nfs -o vers=4"
+ * mount to an "-t nfs -o remount" mount, and that will
+ * confuse umount.nfs.
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfs_remount(struct nfsmount_info *mi)
+{
+ if (nfs_sys_mount(mi, mi->options))
+ return EX_SUCCESS;
+ return EX_FAIL;
+}
+
+/*
+ * Process mount options and try a mount system call.
+ *
+ * Returns a valid mount command exit code.
+ */
+static const char *nfs_background_opttbl[] = {
+ "bg",
+ "fg",
+ NULL,
+};
+
+static int nfsmount_start(struct nfsmount_info *mi)
+{
+ if (!nfs_validate_options(mi))
+ return EX_FAIL;
+
+ /*
+ * Avoid retry and negotiation logic when remounting
+ */
+ if (mi->flags & MS_REMOUNT)
+ return nfs_remount(mi);
+
+ if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
+ return nfsmount_bg(mi);
+ else
+ return nfsmount_fg(mi);
+}
+
+/**
+ * nfsmount_string - Mount an NFS file system using C string options
+ * @spec: C string specifying remote share to mount ("hostname:path")
+ * @node: C string pathname of local mounted-on directory
+ * @type: C string that represents file system type ("nfs" or "nfs4")
+ * @flags: MS_ style mount flags
+ * @extra_opts: pointer to C string containing fs-specific mount options
+ * (input and output argument)
+ * @fake: flag indicating whether to carry out the whole operation
+ * @child: one if this is a mount daemon (bg)
+ *
+ * Returns a valid mount command exit code.
+ */
+int nfsmount_string(const char *spec, const char *node, const char *type,
+ int flags, char **extra_opts, int fake, int child)
+{
+ struct nfsmount_info mi = {
+ .spec = spec,
+ .node = node,
+ .address = NULL,
+ .type = type,
+ .extra_opts = extra_opts,
+ .flags = flags,
+ .fake = fake,
+ .child = child,
+ };
+ int retval = EX_FAIL;
+
+ mi.options = po_split(*extra_opts);
+ if (mi.options) {
+ retval = nfsmount_start(&mi);
+ po_destroy(mi.options);
+ } else
+ nfs_error(_("%s: internal option parsing error"), progname);
+
+ freeaddrinfo(mi.address);
+ free(mi.hostname);
+ return retval;