From 49fc819889fb6151c8fa7ee2684dad50d6726838 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Vavru=C5=A1a?= <marek.vavrusa@nic.cz>
Date: Tue, 8 Apr 2014 14:46:54 +0200
Subject: [PATCH] ddns: excluded ddns/zone discard, release the zone after the
ddns lock
---
src/knot/nameserver/update.c | 30 ++++++++++++++++++------------
src/knot/server/zone-load.c | 2 --
src/knot/zone/zonedb.c | 6 +++++-
3 files changed, 23 insertions(+), 15 deletions(-)
diff --git a/src/knot/nameserver/update.c b/src/knot/nameserver/update.c
index ac3b18c13..afa4e8199 100644
--- a/src/knot/nameserver/update.c
+++ b/src/knot/nameserver/update.c
@@ -142,6 +142,12 @@ int update_answer(knot_pkt_t *pkt, struct query_data *qdata)
return NS_PROC_FAIL;
}
+ /* Check if the zone is not discarded. */
+ if (zone->flags & ZONE_DISCARDED) {
+ pthread_mutex_unlock(&zone->ddns_lock);
+ return NS_PROC_FAIL;
+ }
+
struct timeval t_start = {0}, t_end = {0};
gettimeofday(&t_start, NULL);
UPDATE_LOG(LOG_INFO, "Started (serial %u).", knot_zone_serial(qdata->zone->contents));
@@ -149,10 +155,22 @@ int update_answer(knot_pkt_t *pkt, struct query_data *qdata)
/* Reserve space for TSIG. */
knot_pkt_reserve(pkt, tsig_wire_maxsize(qdata->sign.tsig_key));
+ /* Retain zone for the whole processing so it doesn't disappear
+ * for example during reload.
+ * @note This is going to be fixed when this is made a zone event. */
+ zone_retain(zone);
+
/* Process UPDATE. */
+ rcu_read_unlock();
int ret = update_process(pkt, qdata);
+ rcu_read_lock();
+ /* Since we unlocked RCU read lock, it is possible that the
+ * zone was modified/removed in the background. Therefore,
+ * we must NOT touch the zone after we release it here. */
pthread_mutex_unlock(&zone->ddns_lock);
+ zone_release(zone);
+ qdata->zone = NULL;
/* Evaluate */
switch(ret) {
@@ -335,7 +353,6 @@ static int zones_process_update_auth(struct query_data *qdata)
}
// Apply changeset to zone created by DDNS processing
-
if (zone_config->dnssec_enable) {
/*!
* Check if the UPDATE changed DNSKEYs. If yes, resign the whole
@@ -436,10 +453,7 @@ static int zones_process_update_auth(struct query_data *qdata)
}
// Switch zone contents.
- zone_retain(zone); /* Retain pointer for safe RCU unlock. */
- rcu_read_unlock(); /* Unlock for switch. */
ret = xfrin_switch_zone(zone, new_contents, XFR_TYPE_UPDATE);
- rcu_read_lock(); /* Relock */
if (ret != KNOT_EOK) {
log_zone_error("%s: Failed to replace current zone (%s)\n",
msg, knot_strerror(ret));
@@ -449,8 +463,6 @@ static int zones_process_update_auth(struct query_data *qdata)
/* Free changesets, but not the data. */
zones_free_merged_changesets(chgsets, sec_chs);
- zone_release(zone);
- qdata->zone = NULL;
return KNOT_ERROR;
}
@@ -479,12 +491,6 @@ static int zones_process_update_auth(struct query_data *qdata)
zones_schedule_zonefile_sync(zone, 0);
}
- /* Since we unlocked RCU read lock, it is possible that the
- * zone was modified/removed in the background. Therefore,
- * we must NOT touch the zone after we release it here. */
- zone_release(zone);
- qdata->zone = NULL;
-
return ret;
}
diff --git a/src/knot/server/zone-load.c b/src/knot/server/zone-load.c
index 919d20071..226df6502 100644
--- a/src/knot/server/zone-load.c
+++ b/src/knot/server/zone-load.c
@@ -519,8 +519,6 @@ static int remove_old_zonedb(const knot_zonedb_t *db_new, knot_zonedb_t *db_old)
knot_zonedb_iter_next(&it);
}
- synchronize_rcu();
-
/* Delete all deprecated zones and delete the old database. */
knot_zonedb_deep_free(&db_old);
diff --git a/src/knot/zone/zonedb.c b/src/knot/zone/zonedb.c
index e152a6e0d..4915969bb 100644
--- a/src/knot/zone/zonedb.c
+++ b/src/knot/zone/zonedb.c
@@ -40,8 +40,12 @@
/*! \brief Discard zone in zone database. */
static void discard_zone(zone_t *zone)
{
- synchronize_rcu();
+ /* @note Exclude DDNS. */
+ pthread_mutex_lock(&zone->ddns_lock);
zone->flags |= ZONE_DISCARDED;
+ pthread_mutex_unlock(&zone->ddns_lock);
+ /* Wait for current operations. */
+ synchronize_rcu();
zone_release(zone);
}
--
GitLab