ITS#6716: Keep sessionlog sorted by csn, compare mincsn with head.

diff --git a/servers/slapd/overlays/syncprov.c b/servers/slapd/overlays/syncprov.c
index db300cbc9a7a74f73aef560598a6452a23ea58a7..b457f4d0e5719aa1de5ee7b3b8873316a5af1c77 100644 (file)
--- a/servers/slapd/overlays/syncprov.c
+++ b/servers/slapd/overlays/syncprov.c
@@ -113,7 +113,6 @@ typedef struct slog_entry {
 } slog_entry;
 
 typedef struct sessionlog {
-       struct berval   sl_mincsn;
        int             sl_num;
        int             sl_size;
        slog_entry *sl_head;
@@ -1501,6 +1500,23 @@ syncprov_add_slog( Operation *op )
 
        sl = si->si_logs;
        {
+               if ( BER_BVISEMPTY( &op->o_csn ) ) {
+                       /* During the syncrepl refresh phase we can receive operations
+                        * without a csn.  We cannot reliably determine the consumers
+                        * state with respect to such operations, so we ignore them and
+                        * wipe out anything in the log if we see them.
+                        */
+                       ldap_pvt_thread_mutex_lock( &sl->sl_mutex );
+                       while ( se = sl->sl_head ) {
+                               sl->sl_head = se->se_next;
+                               ch_free( se );
+                       }
+                       sl->sl_tail = NULL;
+                       sl->sl_num = 0;
+                       ldap_pvt_thread_mutex_unlock( &sl->sl_mutex );
+                       return;
+               }
+
                /* Allocate a record. UUIDs are not NUL-terminated. */
                se = ch_malloc( sizeof( slog_entry ) + opc->suuid.bv_len + 
                        op->o_csn.bv_len + 1 );
@@ -1519,17 +1535,29 @@ syncprov_add_slog( Operation *op )
 
                ldap_pvt_thread_mutex_lock( &sl->sl_mutex );
                if ( sl->sl_head ) {
-                       sl->sl_tail->se_next = se;
+                       /* Keep the list in csn order. */
+                       if ( ber_bvcmp( &sl->sl_tail->se_csn, &se->se_csn ) <= 0 ) {
+                               sl->sl_tail->se_next = se;
+                               sl->sl_tail = se;
+                       } else {
+                               slog_entry **sep;
+
+                               for ( sep = &sl->sl_head; *sep; sep = &(*sep)->se_next ) {
+                                       if ( ber_bvcmp( &se->se_csn, &(*sep)->se_csn ) < 0 ) {
+                                               se->se_next = *sep;
+                                               *sep = se;
+                                               break;
+                                       }
+                               }
+                       }
                } else {
                        sl->sl_head = se;
+                       sl->sl_tail = se;
                }
-               sl->sl_tail = se;
                sl->sl_num++;
                while ( sl->sl_num > sl->sl_size ) {
                        se = sl->sl_head;
                        sl->sl_head = se->se_next;
-                       strcpy( sl->sl_mincsn.bv_val, se->se_csn.bv_val );
-                       sl->sl_mincsn.bv_len = se->se_csn.bv_len;
                        ch_free( se );
                        sl->sl_num--;
                }
@@ -2566,7 +2594,7 @@ no_change:                if ( !(op->o_sync_mode & SLAP_SYNC_PERSIST) ) {
                        /* Are there any log entries, and is the consumer state
                         * present in the session log?
                         */
-                       if ( sl->sl_num > 0 && ber_bvcmp( &mincsn, &sl->sl_mincsn ) >= 0 ) {
+                       if ( sl->sl_num > 0 && ber_bvcmp( &mincsn, &sl->sl_head->se_csn ) >= 0 ) {
                                do_present = 0;
                                /* mutex is unlocked in playlog */
                                syncprov_playlog( op, rs, sl, srs, ctxcsn, numcsns, sids );
@@ -2908,9 +2936,7 @@ sp_cf_gen(ConfigArgs *c)
                }
                sl = si->si_logs;
                if ( !sl ) {
-                       sl = ch_malloc( sizeof( sessionlog ) + LDAP_PVT_CSNSTR_BUFSIZE );
-                       sl->sl_mincsn.bv_val = (char *)(sl+1);
-                       sl->sl_mincsn.bv_len = 0;
+                       sl = ch_malloc( sizeof( sessionlog ) );
                        sl->sl_num = 0;
                        sl->sl_head = sl->sl_tail = NULL;
                        ldap_pvt_thread_mutex_init( &sl->sl_mutex );