mountd: Dynamically allocate exportent that represents junctions

We're now duplicating a real exportent with arbitrary export options
to create a junction exportent.  After a dupexportent() call,
several of the structure's fields can point to dynamically allocated
memory.  We have to be careful about not orphaning that memory.

What's more, returning a pointer to a static structure is as 90's as
a bad mullet.  It's more straightforward to allocate the exportent
dynamically and release it when we are through with it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 9c2b97280e4212b6d46b59d3a4776807f03ce149..457fc9c9d1ac9f7aa42c823504188896c0839686 100644 (file)
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -968,30 +968,36 @@ out_false:
 /*
  * Duplicate the junction's parent's export options and graft in
  * the fslocdata we constructed from the locations list.
- *
- * Returned exportent points to static memory.
  */
 static struct exportent *create_junction_exportent(struct exportent *parent,
                const char *junction, const char *fslocdata, int ttl)
 {
-       static struct exportent ee;
+       static struct exportent *eep;
 
-       dupexportent(&ee, parent);
-       strcpy(ee.e_path, junction);
-       ee.e_hostname = strdup(parent->e_hostname);
-       if (ee.e_hostname == NULL)
-               goto out_nomem;
-       free(ee.e_uuid);
-       ee.e_uuid = NULL;
-       ee.e_ttl = (unsigned int)ttl;
-
-       free(ee.e_fslocdata);
-       ee.e_fslocmethod = FSLOC_REFER;
-       ee.e_fslocdata = strdup(fslocdata);
-       if (ee.e_fslocdata == NULL)
+       eep = (struct exportent *)malloc(sizeof(*eep));
+       if (eep == NULL)
                goto out_nomem;
 
-       return ⅇ
+       dupexportent(eep, parent);
+       strcpy(eep->e_path, junction);
+       eep->e_hostname = strdup(parent->e_hostname);
+       if (eep->e_hostname == NULL) {
+               free(eep);
+               goto out_nomem;
+       }
+       free(eep->e_uuid);
+       eep->e_uuid = NULL;
+       eep->e_ttl = (unsigned int)ttl;
+
+       free(eep->e_fslocdata);
+       eep->e_fslocdata = strdup(fslocdata);
+       if (eep->e_fslocdata == NULL) {
+               free(eep->e_hostname);
+               free(eep);
+               goto out_nomem;
+       }
+       eep->e_fslocmethod = FSLOC_REFER;
+       return eep;
 
 out_nomem:
        xlog(L_ERROR, "%s: No memory", __func__);
@@ -1001,8 +1007,6 @@ out_nomem:
 /*
  * Walk through the set of FS locations and build an exportent.
  * Returns pointer to an exportent if "junction" refers to a junction.
- *
- * Returned exportent points to static memory.
  */
 static struct exportent *locations_to_export(struct jp_ops *ops,
                nfs_fsloc_set_t locations, const char *junction,
@@ -1022,8 +1026,6 @@ static struct exportent *locations_to_export(struct jp_ops *ops,
  * Retrieve locations information in "junction" and dump it to the
  * kernel.  Returns pointer to an exportent if "junction" refers
  * to a junction.
- *
- * Returned exportent points to static memory.
  */
 static struct exportent *invoke_junction_ops(void *handle, char *dom,
                const char *junction, struct addrinfo *ai)
@@ -1085,8 +1087,6 @@ out:
  * Load the junction plug-in, then try to resolve "pathname".
  * Returns pointer to an initialized exportent if "junction"
  * refers to a junction, or NULL if not.
- *
- * Returned exportent points to static memory.
  */
 static struct exportent *lookup_junction(char *dom, const char *pathname,
                struct addrinfo *ai)
@@ -1165,7 +1165,14 @@ static void nfsd_export(FILE *f)
                        dump_to_cache(f, dom, path, NULL);
                }
        } else {
-               dump_to_cache(f, dom, path, lookup_junction(dom, path, ai));
+               struct exportent *eep;
+
+               eep = lookup_junction(dom, path, ai);
+               dump_to_cache(f, dom, path, eep);
+               if (eep != NULL) {
+                       exportent_release(eep);
+                       free(eep);
+               }
        }
  out:
        xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);