From 806a45e78be86ffb600647238d398d4279057c3a Mon Sep 17 00:00:00 2001
From: Marek Vavrusa <marek.vavrusa@nic.cz>
Date: Fri, 25 May 2012 14:59:43 +0200
Subject: [PATCH] Added missing RCU unlocks, resolved lock order violations.
---
src/knot/server/xfr-handler.c | 2 +-
src/knot/server/zones.c | 35 +++++++++++++++-------------
src/libknot/hash/cuckoo-hash-table.c | 2 ++
src/libknot/nameserver/name-server.c | 2 ++
4 files changed, 24 insertions(+), 17 deletions(-)
diff --git a/src/knot/server/xfr-handler.c b/src/knot/server/xfr-handler.c
index 136448d7c3..a31d76833c 100644
--- a/src/knot/server/xfr-handler.c
+++ b/src/knot/server/xfr-handler.c
@@ -698,11 +698,11 @@ int xfr_process_event(xfrworker_t *w, int fd, knot_ns_xfr_t *data, uint8_t *buf,
"in %d seconds.\n",
data->msgpref, tmr_s / 1000);
}
- rcu_read_unlock();
/* Update timers. */
server_t *server = (server_t *)knot_ns_get_data(w->ns);
zones_timers_update(zone, zd->conf, server->sched);
+ rcu_read_unlock();
} else {
/* Cleanup */
diff --git a/src/knot/server/zones.c b/src/knot/server/zones.c
index 0143a58e1f..1dacd8f11b 100644
--- a/src/knot/server/zones.c
+++ b/src/knot/server/zones.c
@@ -242,6 +242,7 @@ static uint32_t zones_soa_timer(knot_zone_t *zone,
knot_zone_contents_t * zc = knot_zone_get_contents((zone));
if (!zc) {
+ rcu_read_unlock();
return 0;
}
@@ -295,7 +296,6 @@ static uint32_t zones_soa_expire(knot_zone_t *zone)
*/
static int zones_expire_ev(event_t *e)
{
- rcu_read_lock();
dbg_zones("zones: EXPIRE timer event\n");
knot_zone_t *zone = (knot_zone_t *)e->data;
if (zone == NULL || zone->data == NULL) {
@@ -608,6 +608,7 @@ static int zones_notify_send(event_t *e)
log_server_notice("NOTIFY query maximum number of retries "
"for zone '%s' exceeded.\n",
zd->conf->name);
+ rcu_read_unlock();
pthread_mutex_lock(&zd->lock);
rem_node(&ev->n);
evsched_event_free(e->parent, e);
@@ -620,16 +621,15 @@ static int zones_notify_send(event_t *e)
int retry_tmr = ev->timeout * 1000;
/* Reschedule. */
- conf_read_lock();
evsched_schedule(e->parent, e, retry_tmr);
dbg_notify("notify: Query RETRY after %u secs (zone '%s')\n",
retry_tmr / 1000, zd->conf->name);
- conf_read_unlock();
/* Prepare buffer for query. */
uint8_t *qbuf = malloc(SOCKET_MTU_SZ);
if (qbuf == NULL) {
log_zone_error("Not enough memory to allocate NOTIFY query.\n");
+ rcu_read_unlock();
return KNOTD_ENOMEM;
}
@@ -639,9 +639,6 @@ static int zones_notify_send(event_t *e)
int ret = notify_create_request(contents, qbuf, &buflen);
if (ret == KNOTD_EOK && zd->server) {
- /* Lock RCU. */
- rcu_read_lock();
-
/* Create socket on random port. */
int sock = socket_create(ev->addr.family, SOCK_DGRAM);
@@ -666,9 +663,6 @@ static int zones_notify_send(event_t *e)
}
- /* Unlock RCU */
- rcu_read_unlock();
-
/* Mark as finished to prevent stalling. */
evsched_event_finished(e->parent);
@@ -1261,6 +1255,7 @@ static int zones_journal_apply(knot_zone_t *zone)
knot_zone_contents_t *contents = knot_zone_get_contents(zone);
zonedata_t *zd = (zonedata_t *)knot_zone_data(zone);
if (!contents || !zd) {
+ rcu_read_unlock();
return KNOTD_ENOENT;
}
@@ -1273,6 +1268,7 @@ static int zones_journal_apply(knot_zone_t *zone)
soa_rr = knot_rrset_rdata(soa_rrs);
int64_t serial_ret = knot_rdata_soa_serial(soa_rr);
if (serial_ret < 0) {
+ rcu_read_unlock();
return KNOTD_EINVAL;
}
uint32_t serial = (uint32_t)serial_ret;
@@ -1310,6 +1306,7 @@ static int zones_journal_apply(knot_zone_t *zone)
rcu_read_unlock();
apply_ret = xfrin_switch_zone(zone, contents,
XFR_TYPE_IIN);
+ rcu_read_lock();
if (apply_ret == KNOT_EOK) {
xfrin_cleanup_successful_update(
&chsets->changes);
@@ -1329,10 +1326,10 @@ static int zones_journal_apply(knot_zone_t *zone)
} else {
dbg_zones("zones: failed to load changesets - %s\n",
knotd_strerror(ret));
- rcu_read_unlock();
}
/* Free changesets and return. */
+ rcu_read_unlock();
knot_free_changesets(&chsets);
return ret;
}
@@ -1925,12 +1922,14 @@ int zones_update_db_from_config(const conf_t *conf, knot_nameserver_t *ns,
if (*db_old == NULL) {
log_server_error("Missing zone database in nameserver structure"
".\n");
+ rcu_read_unlock();
return KNOTD_ERROR;
}
/* Create new zone DB */
knot_zonedb_t *db_new = knot_zonedb_new();
if (db_new == NULL) {
+ rcu_read_unlock();
return KNOTD_ERROR;
}
@@ -1964,13 +1963,14 @@ int zones_update_db_from_config(const conf_t *conf, knot_nameserver_t *ns,
* All other have been loaded again so that the old must be destroyed.
*/
int ret = zones_remove_zones(db_new, *db_old);
+
+ /* Unlock RCU, messing with any data will not affect us now */
+ rcu_read_unlock();
+
if (ret != KNOTD_EOK) {
return ret;
}
- /* Unlock RCU, messing with any data will not affect us now */
- rcu_read_unlock();
-
return KNOTD_EOK;
}
@@ -1999,6 +1999,7 @@ int zones_zonefile_sync(knot_zone_t *zone, journal_t *journal)
knot_zone_contents_t *contents = knot_zone_get_contents(zone);
if (!contents) {
pthread_mutex_unlock(&zd->lock);
+ rcu_read_unlock();
return KNOTD_EINVAL;
}
@@ -2013,6 +2014,7 @@ int zones_zonefile_sync(knot_zone_t *zone, journal_t *journal)
int64_t serial_ret = knot_rdata_soa_serial(soa_rr);
if (serial_ret < 0) {
pthread_mutex_unlock(&zd->lock);
+ rcu_read_unlock();
return KNOTD_EINVAL;
}
uint32_t serial_to = (uint32_t)serial_ret;
@@ -2030,9 +2032,9 @@ int zones_zonefile_sync(knot_zone_t *zone, journal_t *journal)
dbg_zones("zones: failed to sync '%s' to '%s'\n",
zd->conf->name, zd->conf->file);
pthread_mutex_unlock(&zd->lock);
+ rcu_read_unlock();
return ret;
}
-
conf_read_unlock();
/* Update journal entries. */
@@ -2433,10 +2435,10 @@ int zones_process_response(knot_nameserver_t *nameserver,
log_zone_info("SOA query of '%s' to '%s@%d': Answered, no "
"transfer needed.\n",
zd->conf->name, r_addr, r_port);
- rcu_read_unlock();
-
+
/* Reinstall timers. */
zones_timers_update(zone, zd->conf, sched);
+ rcu_read_unlock();
return KNOTD_EOK;
}
@@ -3184,6 +3186,7 @@ int zones_timers_update(knot_zone_t *zone, conf_zone_t *cfzone, evsched_t *sch)
pthread_mutex_unlock(&zd->lock);
/* Check XFR/IN master server. */
+ conf_read_lock();
if (zd->xfr_in.master.ptr) {
/* Schedule REFRESH timer. */
diff --git a/src/libknot/hash/cuckoo-hash-table.c b/src/libknot/hash/cuckoo-hash-table.c
index 50a7a0f5b7..9db32bf30e 100644
--- a/src/libknot/hash/cuckoo-hash-table.c
+++ b/src/libknot/hash/cuckoo-hash-table.c
@@ -1037,6 +1037,7 @@ int ck_update_item(const ck_hash_table_t *table, const char *key, size_t length,
ck_hash_table_item_t **item = ck_find_item_nc(table, key, length);
if (item == NULL || (*item) == NULL) {
+ rcu_read_unlock();
return -1;
}
@@ -1060,6 +1061,7 @@ int ck_delete_item(const ck_hash_table_t *table, const char *key, size_t length,
ck_hash_table_item_t **place = ck_find_item_nc(table, key, length);
if (place == NULL) {
+ rcu_read_unlock();
return -1;
}
diff --git a/src/libknot/nameserver/name-server.c b/src/libknot/nameserver/name-server.c
index a9cde8e4ab..3a2f271d1a 100644
--- a/src/libknot/nameserver/name-server.c
+++ b/src/libknot/nameserver/name-server.c
@@ -2509,6 +2509,7 @@ static int ns_ixfr_from_zone(knot_ns_xfr_t *xfr)
/*! \todo Probably rename the function. */
ns_xfr_send_and_clear(xfr, 1);
// socket_close(xfr->session); /*! \todo Remove for UDP.*/
+ rcu_read_unlock();
return res;
}
@@ -2517,6 +2518,7 @@ static int ns_ixfr_from_zone(knot_ns_xfr_t *xfr)
res = ns_ixfr_put_changeset(xfr, &chgsets->sets[i]);
if (res != KNOT_EOK) {
// answer is sent
+ rcu_read_unlock();
return res;
}
}
--
GitLab