ITS#6095 experimental fix: avoid purging other cases of in-use EntryInfos,

avoid using purged EntryInfos that have not yet been fully unlinked.

diff --git a/servers/slapd/back-bdb/back-bdb.h b/servers/slapd/back-bdb/back-bdb.h
index 0219e3ff14056d153a3536c058279de30daa2340..16bc3dc3538acfb3404beb20e6f7e5ff07980237 100644 (file)
--- a/servers/slapd/back-bdb/back-bdb.h
+++ b/servers/slapd/back-bdb/back-bdb.h
@@ -92,6 +92,7 @@ typedef struct bdb_entry_info {
 #define        CACHE_ENTRY_ONELEVEL    0x40
 #define        CACHE_ENTRY_REFERENCED  0x80
 #define        CACHE_ENTRY_NOT_CACHED  0x100
+#define        CACHE_ENTRY_PURGED      0x200
        int bei_finders;
 
        /*

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index a20d772026b088dab805783916958dab54c6d497..c5f7a6d8e010f8528a74db6c621972a995d8cd19 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -94,10 +94,14 @@ bdb_cache_entryinfo_free( Cache *cache, EntryInfo *ei )
        ei->bei_kids = NULL;
        ei->bei_lruprev = NULL;
 
+#if 0
        ldap_pvt_thread_mutex_lock( &cache->c_eifree_mutex );
        ei->bei_lrunext = cache->c_eifree;
        cache->c_eifree = ei;
        ldap_pvt_thread_mutex_unlock( &cache->c_eifree_mutex );
+#else
+       ch_free( ei );
+#endif
 }
 
 #define LRU_DEL( c, e ) do { \
@@ -372,13 +376,11 @@ bdb_entryinfo_add_internal(
                        bdb->bi_cache.c_leaves++;
                rc = avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
                        avl_dup_error );
-               if ( rc ) {
-                       /* This should never happen; entry cache is corrupt */
-                       bdb->bi_dbenv->log_flush( bdb->bi_dbenv, NULL );
-                       assert( !rc );
-               }
 #ifdef BDB_HIER
-               ei->bei_parent->bei_ckids++;
+               /* it's possible for hdb_cache_find_parent to beat us to it */
+               if ( !rc ) {
+                       ei->bei_parent->bei_ckids++;
+               }
 #endif
        }
 
@@ -432,6 +434,8 @@ bdb_cache_find_ndn(
                eip->bei_state |= CACHE_ENTRY_REFERENCED;
                ei.bei_parent = eip;
                ei2 = (EntryInfo *)avl_find( eip->bei_kids, &ei, bdb_rdn_cmp );
+               if ( ei2 && ( ei2->bei_state & CACHE_ENTRY_PURGED ))
+                       ei2 = NULL;
                if ( !ei2 ) {
                        DB_LOCK lock;
                        int len = ei.bei_nrdn.bv_len;
@@ -443,6 +447,7 @@ bdb_cache_find_ndn(
 
                        ei.bei_nrdn.bv_len = ndn->bv_len -
                                (ei.bei_nrdn.bv_val - ndn->bv_val);
+                       eip->bei_finders++;
                        bdb_cache_entryinfo_unlock( eip );
 
                        BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Reading %s",
@@ -452,6 +457,7 @@ bdb_cache_find_ndn(
                        rc = bdb_dn2id( op, &ei.bei_nrdn, &ei, txn, &lock );
                        if (rc) {
                                bdb_cache_entryinfo_lock( eip );
+                               eip->bei_finders--;
                                bdb_cache_entry_db_unlock( bdb, &lock );
                                *res = eip;
                                return rc;
@@ -464,6 +470,7 @@ bdb_cache_find_ndn(
                        ei.bei_nrdn.bv_len = len;
                        rc = bdb_entryinfo_add_internal( bdb, &ei, &ei2 );
                        /* add_internal left eip and c_rwlock locked */
+                       eip->bei_finders--;
                        ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
                        bdb_cache_entry_db_unlock( bdb, &lock );
                        if ( rc ) {
@@ -480,8 +487,8 @@ bdb_cache_find_ndn(
                        *res = eip;
                        return DB_NOTFOUND;
                }
-               bdb_cache_entryinfo_unlock( eip );
                bdb_cache_entryinfo_lock( ei2 );
+               bdb_cache_entryinfo_unlock( eip );
 
                eip = ei2;
 
@@ -543,32 +550,44 @@ hdb_cache_find_parent(
                /* This node is not fully connected yet */
                ein->bei_state |= CACHE_ENTRY_NOT_LINKED;
 
+               /* If this is the first time, save this node
+                * to be returned later.
+                */
+               if ( eir == NULL ) eir = ein;
+
+again:
                /* Insert this node into the ID tree */
                ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
                if ( avl_insert( &bdb->bi_cache.c_idtree, (caddr_t)ein,
                        bdb_id_cmp, bdb_id_dup_err ) ) {
                        EntryInfo *eix = ein->bei_lrunext;
 
+                       if ( eix->bei_state & CACHE_ENTRY_PURGED ) {
+                               ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+                               ldap_pvt_thread_yield();
+                               goto again;
+                       }
+
                        /* Someone else created this node just before us.
                         * Free our new copy and use the existing one.
                         */
                        bdb_cache_entryinfo_free( &bdb->bi_cache, ein );
-                       ein = eix;
-                       
-                       /* Link in any kids we've already processed */
-                       if ( ei2 ) {
-                               bdb_cache_entryinfo_lock( ein );
-                               avl_insert( &ein->bei_kids, (caddr_t)ei2,
-                                       bdb_rdn_cmp, avl_dup_error );
-                               ein->bei_ckids++;
-                               bdb_cache_entryinfo_unlock( ein );
+
+                       /* if it was the node we were looking for, just return it */
+                       if ( eir == ein ) {
+                               *res = eix;
+                               rc = 0;
+                               bdb_cache_entryinfo_lock( eix );
+                               ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+                               break;
                        }
-               }
 
-               /* If this is the first time, save this node
-                * to be returned later.
-                */
-               if ( eir == NULL ) eir = ein;
+                       ein = ei2;
+                       ei2 = eix;
+
+                       /* otherwise, link up what we have and return */
+                       goto gotparent;
+               }
 
                /* If there was a previous node, link it to this one */
                if ( ei2 ) ei2->bei_parent = ein;
@@ -583,17 +602,19 @@ hdb_cache_find_parent(
                bdb->bi_cache.c_eiused++;
                if ( ei2 && ( ei2->bei_kids || !ei2->bei_id ))
                                bdb->bi_cache.c_leaves++;
+
+gotparent:
                ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 
                /* Got the parent, link in and we're done. */
                if ( ei2 ) {
-                       bdb_cache_entryinfo_lock( eir );
                        bdb_cache_entryinfo_lock( ei2 );
+                       bdb_cache_entryinfo_lock( eir );
                        ein->bei_parent = ei2;
 
-                       avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
-                               avl_dup_error);
-                       ei2->bei_ckids++;
+                       if ( avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
+                               avl_dup_error) == 0 )
+                               ei2->bei_ckids++;
 
                        /* Reset all the state info */
                        for (ein = eir; ein != ei2; ein=ein->bei_parent)
@@ -724,12 +745,18 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
                 * or this node is being deleted, skip it.
                 */
                if (( elru->bei_state & ( CACHE_ENTRY_NOT_LINKED |
-                       CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING )) ||
+                       CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING |
+                       CACHE_ENTRY_ONELEVEL )) ||
                        elru->bei_finders > 0 ) {
                        bdb_cache_entryinfo_unlock( elru );
                        goto bottom;
                }
 
+               if ( bdb_cache_entryinfo_trylock( elru->bei_parent )) {
+                       bdb_cache_entryinfo_unlock( elru );
+                       goto bottom;
+               }
+
                /* entryinfo is locked */
                islocked = 1;
 
@@ -782,8 +809,10 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
                }
 
 next:
-               if ( islocked )
+               if ( islocked ) {
                        bdb_cache_entryinfo_unlock( elru );
+                       bdb_cache_entryinfo_unlock( elru->bei_parent );
+               }
 
                if ( count >= efree && eicount >= eifree ) {
                        if ( count || ecount > bdb->bi_cache.c_cursize ) {
@@ -822,6 +851,15 @@ bdb_cache_find_info(
        ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
        ei2 = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
                                        (caddr_t) &ei, bdb_id_cmp );
+       if ( ei2 ) {
+               if ( ei2->bei_state & CACHE_ENTRY_PURGED ) {
+                       ei2 = NULL;
+               } else {
+                       bdb_cache_entryinfo_lock( ei2 );
+                       ei2->bei_finders++;
+                       bdb_cache_entryinfo_unlock( ei2 );
+               }
+       }
        ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
        return ei2;
 }
@@ -857,13 +895,19 @@ again:    ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
                *eip = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
                        (caddr_t) &ei, bdb_id_cmp );
                if ( *eip ) {
+                       if ( (*eip)->bei_state & CACHE_ENTRY_PURGED ) {
+                               *eip = NULL;
+                               ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
+                               goto purged;
+                       }
                        /* If the lock attempt fails, the info is in use */
                        if ( bdb_cache_entryinfo_trylock( *eip )) {
+                               int del = (*eip)->bei_state & CACHE_ENTRY_DELETED;
                                ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
                                /* If this node is being deleted, treat
                                 * as if the delete has already finished
                                 */
-                               if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
+                               if ( del ) {
                                        return DB_NOTFOUND;
                                }
                                /* otherwise, wait for the info to free up */
@@ -885,6 +929,7 @@ again:      ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
        }
 
        /* See if the ID exists in the database; add it to the cache if so */
+purged:
        if ( !*eip ) {
 #ifndef BDB_HIER
                rc = bdb_id2entry( op->o_bd, tid, id, &ep );
@@ -913,6 +958,11 @@ again:     ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
                if ( !( flag & ID_LOCKED )) {
                        bdb_cache_entryinfo_lock( *eip );
                        flag |= ID_LOCKED;
+                       if ( (*eip)->bei_state & CACHE_ENTRY_PURGED ) {
+                               bdb_cache_entryinfo_unlock( *eip );
+                               *eip = NULL;
+                               goto purged;
+                       }
                }
 
                if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
@@ -1138,10 +1188,12 @@ bdb_cache_add(
        e->e_private = new;
        new->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
        eip->bei_state &= ~CACHE_ENTRY_NO_KIDS;
+       bdb_cache_entryinfo_unlock( eip );
        if (eip->bei_parent) {
+               bdb_cache_entryinfo_lock( eip->bei_parent );
                eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
+               bdb_cache_entryinfo_unlock( eip->bei_parent );
        }
-       bdb_cache_entryinfo_unlock( eip );
 
        ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
        ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
@@ -1320,8 +1372,10 @@ bdb_cache_delete(
        /* Get write lock on the data */
        rc = bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
        if ( rc ) {
+               bdb_cache_entryinfo_lock( ei );
                /* couldn't lock, undo and give up */
                ei->bei_state ^= CACHE_ENTRY_DELETED;
+               bdb_cache_entryinfo_unlock( ei );
                return rc;
        }
 
@@ -1331,7 +1385,10 @@ bdb_cache_delete(
        /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
 
+       bdb_cache_entryinfo_lock( ei->bei_parent );
+       bdb_cache_entryinfo_lock( ei );
        rc = bdb_cache_delete_internal( &bdb->bi_cache, e->e_private, 1 );
+       bdb_cache_entryinfo_unlock( ei );
 
        /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
@@ -1373,11 +1430,12 @@ bdb_cache_delete_internal(
        int decr_leaf = 0;
 
        /* already freed? */
-       if ( !e->bei_parent )
+       if ( !e->bei_parent ) {
+               assert(0);
                return -1;
+       }
 
-       /* Lock the parent's kids tree */
-       bdb_cache_entryinfo_lock( e->bei_parent );
+       e->bei_state |= CACHE_ENTRY_PURGED;
 
 #ifdef BDB_HIER
        e->bei_parent->bei_ckids--;
@@ -1388,6 +1446,7 @@ bdb_cache_delete_internal(
                == NULL )
        {
                rc = -1;
+               assert(0);
        }
        if ( e->bei_parent->bei_kids )
                decr_leaf = 1;
@@ -1402,6 +1461,7 @@ bdb_cache_delete_internal(
                        cache->c_leaves--;
        } else {
                rc = -1;
+               assert(0);
        }
        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 

diff --git a/servers/slapd/back-bdb/dn2id.c b/servers/slapd/back-bdb/dn2id.c
index f4c528fa48646e8b31dfc0f44bbe321b0765ea2f..c09885303bd68d7faefbd865649b70b440622036 100644 (file)
--- a/servers/slapd/back-bdb/dn2id.c
+++ b/servers/slapd/back-bdb/dn2id.c
@@ -1102,7 +1102,7 @@ hdb_dn2idl_internal(
                cx->rc = cx->dbc->c_close( cx->dbc );
 done_one:
                bdb_cache_entryinfo_lock( cx->ei );
-               cx->ei->bei_state ^= CACHE_ENTRY_ONELEVEL;
+               cx->ei->bei_state &= ~CACHE_ENTRY_ONELEVEL;
                bdb_cache_entryinfo_unlock( cx->ei );
                if ( cx->rc )
                        return cx->rc;
@@ -1151,7 +1151,8 @@ gotit:
                                for ( cx->id = bdb_idl_first( save, &idcurs );
                                        cx->id != NOID;
                                        cx->id = bdb_idl_next( save, &idcurs )) {
-                                       cx->ei = bdb_cache_find_info( cx->bdb, cx->id );
+                                       EntryInfo *ei2;
+                                       ei2 = cx->ei = bdb_cache_find_info( cx->bdb, cx->id );
                                        if ( !cx->ei ||
                                                ( cx->ei->bei_state & CACHE_ENTRY_NO_KIDS ))
                                                continue;
@@ -1160,6 +1161,10 @@ gotit:
                                        hdb_dn2idl_internal( cx );
                                        if ( !BDB_IDL_IS_ZERO( cx->tmp ))
                                                nokids = 0;
+                                       bdb_cache_entryinfo_lock( ei2 );
+                                       ei2->bei_finders--;
+                                       bdb_cache_entryinfo_unlock( ei2 );
+
                                }
                                cx->depth--;
                                cx->op->o_tmpfree( save, cx->op->o_tmpmemctx );

diff --git a/servers/slapd/back-bdb/search.c b/servers/slapd/back-bdb/search.c
index def485ec9ee3fd080cef8f53213aa8a36dc1c006..09faf8ebe970d9d6796c9ea12dc98863ae7fb491 100644 (file)
--- a/servers/slapd/back-bdb/search.c
+++ b/servers/slapd/back-bdb/search.c
@@ -569,10 +569,6 @@ dn2entry_retry:
 #ifdef SLAP_ZONE_ALLOC
        slap_zn_runlock(bdb->bi_cache.c_zctx, e);
 #endif
-       if ( e != e_root ) {
-               bdb_cache_return_entry_r(bdb, e, &lock);
-       }
-       e = NULL;
 
        /* select candidates */
        if ( op->oq_search.rs_scope == LDAP_SCOPE_BASE ) {
@@ -595,6 +591,11 @@ cand_retry:
                }
        }
 
+       if ( e != e_root ) {
+               bdb_cache_return_entry_r(bdb, e, &lock);
+       }
+       e = NULL;
+
        /* start cursor at beginning of candidates.
         */
        cursor = 0;