From 0d7489b9089c8cb5766cc689d8c414f166b4d84e Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Fri, 13 Oct 2017 17:25:29 +0100 Subject: [PATCH] ITS#8752 fix syncrepl deadlock from updateCookie Must release cookieState->cs_mutex before invoking backend. Add a condvar to serialize calls of updateCookie, so we can release the mutex and still update sequentially. Also added tid logging, useful in conjunction with 7ab0e1aff0cc48cdfb299ca7dbd27900a9e3d1a8 --- servers/slapd/syncrepl.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/servers/slapd/syncrepl.c b/servers/slapd/syncrepl.c index 6e157e700c..60e5e7c13e 100644 --- a/servers/slapd/syncrepl.c +++ b/servers/slapd/syncrepl.c @@ -46,11 +46,13 @@ struct nonpresent_entry { typedef struct cookie_state { ldap_pvt_thread_mutex_t cs_mutex; + ldap_pvt_thread_cond_t cs_cond; struct berval *cs_vals; int *cs_sids; int cs_num; int cs_age; int cs_ref; + int cs_updating; /* pending changes, not yet committed */ ldap_pvt_thread_mutex_t cs_pmutex; @@ -2447,6 +2449,9 @@ syncrepl_message_to_op( op->o_callback = &cb; slap_op_time( &op->o_time, &op->o_tincr ); + Debug( LDAP_DEBUG_SYNC, "syncrepl_message_to_op: %s tid %x\n", + si->si_ridtxt, op->o_tid, 0 ); + switch( op->o_tag ) { case LDAP_REQ_ADD: case LDAP_REQ_MODIFY: @@ -2954,8 +2959,8 @@ syncrepl_entry( int freecsn = 1; Debug( LDAP_DEBUG_SYNC, - "syncrepl_entry: %s LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_%s)\n", - si->si_ridtxt, syncrepl_state2str( syncstate ), 0 ); + "syncrepl_entry: %s LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_%s) tid %x\n", + si->si_ridtxt, syncrepl_state2str( syncstate ), op->o_tid ); if (( syncstate == LDAP_SYNC_PRESENT || syncstate == LDAP_SYNC_ADD ) ) { if ( !si->si_refreshPresent && !si->si_refreshDone ) { @@ -3950,6 +3955,8 @@ syncrepl_updateCookie( mod.sml_next = NULL; ldap_pvt_thread_mutex_lock( &si->si_cookieState->cs_mutex ); + while ( si->si_cookieState->cs_updating ) + ldap_pvt_thread_cond_wait( &si->si_cookieState->cs_cond, &si->si_cookieState->cs_mutex ); #ifdef CHECK_CSN for ( i=0; inumcsns; i++ ) { @@ -4012,6 +4019,10 @@ syncrepl_updateCookie( ch_free( sc.sids ); return 0; } + + si->si_cookieState->cs_updating = 1; + ldap_pvt_thread_mutex_unlock( &si->si_cookieState->cs_mutex ); + op->o_bd = si->si_wbe; slap_queue_csn( op, &first ); @@ -4050,6 +4061,7 @@ syncrepl_updateCookie( op->orm_no_opattrs = 0; op->o_dont_replicate = 0; + ldap_pvt_thread_mutex_lock( &si->si_cookieState->cs_mutex ); if ( rs_modify.sr_err == LDAP_SUCCESS ) { slap_sync_cookie_free( &si->si_syncCookie, 0 ); @@ -4082,6 +4094,8 @@ syncrepl_updateCookie( } #endif + si->si_cookieState->cs_updating = 0; + ldap_pvt_thread_cond_broadcast( &si->si_cookieState->cs_cond ); ldap_pvt_thread_mutex_unlock( &si->si_cookieState->cs_mutex ); op->o_bd = be; @@ -4746,6 +4760,7 @@ syncinfo_free( syncinfo_t *sie, int free_all ) if ( !sie->si_cookieState->cs_ref ) { ch_free( sie->si_cookieState->cs_sids ); ber_bvarray_free( sie->si_cookieState->cs_vals ); + ldap_pvt_thread_cond_destroy( &sie->si_cookieState->cs_cond ); ldap_pvt_thread_mutex_destroy( &sie->si_cookieState->cs_mutex ); ch_free( sie->si_cookieState->cs_psids ); ber_bvarray_free( sie->si_cookieState->cs_pvals ); @@ -5552,6 +5567,7 @@ add_syncrepl( si->si_cookieState = ch_calloc( 1, sizeof( cookie_state )); ldap_pvt_thread_mutex_init( &si->si_cookieState->cs_mutex ); ldap_pvt_thread_mutex_init( &si->si_cookieState->cs_pmutex ); + ldap_pvt_thread_cond_init( &si->si_cookieState->cs_cond ); c->be->be_syncinfo = si; }