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fix lock heirachy in zone_shutdown()

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Mark Andrews 2000-12-29 13:20:46 +00:00
parent 3f160155da
commit 02bad0bd51
1 changed files with 19 additions and 5 deletions
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24
lib/dns/zone.c
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@ -15,7 +15,7 @@
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/ */
/* $Id: zone.c,v 1.284 2000/12/29 01:04:10 marka Exp $ */ /* $Id: zone.c,v 1.285 2000/12/29 13:20:46 marka Exp $ */
#include <config.h> #include <config.h>
@ -247,6 +247,7 @@ struct dns_zone {
#define DNS_ZONEFLG_NOREFRESH 0x00010000U #define DNS_ZONEFLG_NOREFRESH 0x00010000U
#define DNS_ZONEFLG_DIALNOTIFY 0x00020000U #define DNS_ZONEFLG_DIALNOTIFY 0x00020000U
#define DNS_ZONEFLG_DIALREFRESH 0x00040000U #define DNS_ZONEFLG_DIALREFRESH 0x00040000U
#define DNS_ZONEFLG_SHUTDOWN 0x00080000U
#define DNS_ZONE_OPTION(z,o) (((z)->options & (o)) != 0) #define DNS_ZONE_OPTION(z,o) (((z)->options & (o)) != 0)
@ -1258,11 +1259,11 @@ exit_check(dns_zone_t *zone) {
REQUIRE(LOCKED_ZONE(zone)); REQUIRE(LOCKED_ZONE(zone));
if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) && if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SHUTDOWN) &&
zone->irefs == 0) zone->irefs == 0)
{ {
/* /*
* DNS_ZONEFLG_EXITING can only be set if erefs == 0. * DNS_ZONEFLG_SHUTDOWN can only be set if erefs == 0.
*/ */
INSIST(zone->erefs == 0); INSIST(zone->erefs == 0);
return (ISC_TRUE); return (ISC_TRUE);
@ -3576,21 +3577,28 @@ zone_shutdown(isc_task_t *task, isc_event_t *event) {
INSIST(event->ev_type == DNS_EVENT_ZONECONTROL); INSIST(event->ev_type == DNS_EVENT_ZONECONTROL);
INSIST(zone->erefs == 0); INSIST(zone->erefs == 0);
zone_log(zone, "zone_shutdown", ISC_LOG_DEBUG(3), "shutting down"); zone_log(zone, "zone_shutdown", ISC_LOG_DEBUG(3), "shutting down");
/*
* Stop things being restarted after we cancel them below.
*/
LOCK_ZONE(zone); LOCK_ZONE(zone);
DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXITING); DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXITING);
UNLOCK_ZONE(zone);
/* /*
* If we were waiting for xfrin quota, step out of * If we were waiting for xfrin quota, step out of
* the queue. * the queue.
*/ */
RWLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
if (zone->statelist == &zone->zmgr->waiting_for_xfrin) { if (zone->statelist == &zone->zmgr->waiting_for_xfrin) {
RWLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
ISC_LIST_UNLINK(zone->zmgr->waiting_for_xfrin, zone, ISC_LIST_UNLINK(zone->zmgr->waiting_for_xfrin, zone,
statelink); statelink);
RWUNLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
zone->statelist = NULL; zone->statelist = NULL;
} }
RWUNLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
LOCK_ZONE(zone);
if (zone->xfr != NULL) if (zone->xfr != NULL)
dns_xfrin_shutdown(zone->xfr); dns_xfrin_shutdown(zone->xfr);
@ -3612,6 +3620,12 @@ zone_shutdown(isc_task_t *task, isc_event_t *event) {
if (zone->view != NULL) if (zone->view != NULL)
dns_view_weakdetach(&zone->view); dns_view_weakdetach(&zone->view);
/*
* We have now canceled everything set the flag to allow exit_check()
* to succeed. We must not unlock between setting this flag and
* calling exit_check().
*/
DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SHUTDOWN);
free_needed = exit_check(zone); free_needed = exit_check(zone);
UNLOCK_ZONE(zone); UNLOCK_ZONE(zone);
if (free_needed) if (free_needed)