zonemd, unlock xfr lock for auth zone verify of zonemd for mesh new callback.

diff --git a/services/authzone.c b/services/authzone.c
index 0a477442c27ef66b605c788bda63a741dea63cc3..470f490cf9132440d1ed36ec195613dd759e3087 100644 (file)
--- a/services/authzone.c
+++ b/services/authzone.c
@@ -5106,6 +5106,28 @@ xfr_write_after_update(struct auth_xfer* xfr, struct module_env* env)
        lock_rw_unlock(&z->lock);
 }
 
+/** reacquire locks and structures. Starts with no locks, ends
+ * with xfr and z locks, if fail, no z lock */
+static int xfr_process_reacquire_locks(struct auth_xfer* xfr,
+       struct module_env* env, struct auth_zone** z)
+{
+       /* release xfr lock, then, while holding az->lock grab both
+        * z->lock and xfr->lock */
+       lock_rw_rdlock(&env->auth_zones->lock);
+       *z = auth_zone_find(env->auth_zones, xfr->name, xfr->namelen,
+               xfr->dclass);
+       if(!*z) {
+               lock_rw_unlock(&env->auth_zones->lock);
+               lock_basic_lock(&xfr->lock);
+               *z = NULL;
+               return 0;
+       }
+       lock_rw_wrlock(&(*z)->lock);
+       lock_basic_lock(&xfr->lock);
+       lock_rw_unlock(&env->auth_zones->lock);
+       return 1;
+}
+
 /** process chunk list and update zone in memory,
  * return false if it did not work */
 static int
@@ -5115,21 +5137,12 @@ xfr_process_chunk_list(struct auth_xfer* xfr, struct module_env* env,
        struct auth_zone* z;
 
        /* obtain locks and structures */
-       /* release xfr lock, then, while holding az->lock grab both
-        * z->lock and xfr->lock */
        lock_basic_unlock(&xfr->lock);
-       lock_rw_rdlock(&env->auth_zones->lock);
-       z = auth_zone_find(env->auth_zones, xfr->name, xfr->namelen,
-               xfr->dclass);
-       if(!z) {
-               lock_rw_unlock(&env->auth_zones->lock);
+       if(!xfr_process_reacquire_locks(xfr, env, &z)) {
                /* the zone is gone, ignore xfr results */
-               lock_basic_lock(&xfr->lock);
                return 0;
        }
-       lock_rw_wrlock(&z->lock);
-       lock_basic_lock(&xfr->lock);
-       lock_rw_unlock(&env->auth_zones->lock);
+       /* holding xfr and z locks */
 
        /* apply data */
        if(xfr->task_transfer->master->http) {
@@ -5164,16 +5177,35 @@ xfr_process_chunk_list(struct auth_xfer* xfr, struct module_env* env,
                        " (or malformed RR)", xfr->task_transfer->master->host);
                return 0;
        }
+
+       /* release xfr lock while verifying zonemd because it may have
+        * to spawn lookups in the state machines */
+       lock_basic_unlock(&xfr->lock);
+       /* holding z lock */
        auth_zone_verify_zonemd(z, env, &env->mesh->mods, NULL, 0, 0);
        if(z->zone_expired) {
                char zname[256];
-               dname_str(xfr->name, zname);
                /* ZONEMD must have failed */
+               /* reacquire locks, so we hold xfr lock on exit of routine,
+                * and both xfr and z again after releasing xfr for potential
+                * state machine mesh callbacks */
+               lock_rw_unlock(&z->lock);
+               if(!xfr_process_reacquire_locks(xfr, env, &z))
+                       return 0;
+               dname_str(xfr->name, zname);
                verbose(VERB_ALGO, "xfr from %s: ZONEMD failed for %s, transfer is failed", xfr->task_transfer->master->host, zname);
                xfr->zone_expired = 1;
                lock_rw_unlock(&z->lock);
                return 0;
        }
+       /* reacquire locks, so we hold xfr lock on exit of routine,
+        * and both xfr and z again after releasing xfr for potential
+        * state machine mesh callbacks */
+       lock_rw_unlock(&z->lock);
+       if(!xfr_process_reacquire_locks(xfr, env, &z))
+               return 0;
+       /* holding xfr and z locks */
+
        if(xfr->have_zone)
                xfr->lease_time = *env->now;