Handle 'crossmnt' when kernel asked for export options for a directory.

If the kernel finds a mountpoint below a 'crossmnt' export, it will ask
mounted what export options to use.  With this patch it will return
the same export options as for the top 'crossmnt' export unless
more specific options have been given.

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 734ddd8f5ea5d50d5493ec90c212462b5ef7480a..2f13f03ec9a61247228d3c4e347488c7393e3af5 100644 (file)
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -515,11 +515,36 @@ void nfsd_export(FILE *f)
                for (exp = exportlist[i]; exp; exp = exp->m_next) {
                        if (!client_member(dom, exp->m_client->m_hostname))
                                continue;
-                       if (strcmp(path, exp->m_export.e_path))
+                       if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
+                               /* if path is a mountpoint below e_path, then OK */
+                               int l = strlen(exp->m_export.e_path);
+                               if (strcmp(path, exp->m_export.e_path) == 0 ||
+                                   (strncmp(path, exp->m_export.e_path, l) == 0 &&
+                                    path[l] == '/' &&
+                                    is_mountpoint(path)))
+                                       /* ok */;
+                               else
+                                       continue;
+                       } else if (strcmp(path, exp->m_export.e_path) != 0)
                                continue;
                        if (!found) {
                                found = exp;
                                found_type = i;
+                               continue;
+                       }
+                       /* If one is a CROSSMOUNT, then prefer the longest path */
+                       if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
+                            (found->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
+                           strlen(found->m_export.e_path) !=
+                           strlen(found->m_export.e_path)) {
+
+                               if (strlen(exp->m_export.e_path) >
+                                   strlen(found->m_export.e_path)) {
+                                       found = exp;
+                                       found_type = i;
+                               }
+                               continue;
+
                        } else if (found_type == i && found->m_warned == 0) {
                                xlog(L_WARNING, "%s exported to both %s and %s, "
                                     "arbitrarily choosing options from first",