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openldap/servers/slapd/back-bdb/cache.c

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/* cache.c - routines to maintain an in-core cache of entries */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2000-2005 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
#include "portable.h"
#include <stdio.h>
#include <ac/errno.h>
#include <ac/string.h>
#include <ac/socket.h>
#include "slap.h"
#include "back-bdb.h"
#ifdef BDB_HIER
#define bdb_cache_lru_add hdb_cache_lru_add
#endif
static int bdb_cache_delete_internal(Cache *cache, EntryInfo *e, int decr);
#ifdef LDAP_DEBUG
static void bdb_lru_print(Cache *cache);
#endif
static int bdb_txn_get( Operation *op, DB_ENV *env, DB_TXN **txn, int reset );
/* 4.2.52 */
#if DB_VERSION_FULL == 0x04020034
#define READ_TXN_FLAG ReadFlag
static int ReadFlag = DB_TXN_NOT_DURABLE;
#else
#define READ_TXN_FLAG 0
#endif
static EntryInfo *
bdb_cache_entryinfo_new( Cache *cache )
{
EntryInfo *ei = NULL;
if ( cache->c_eifree ) {
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
if ( cache->c_eifree ) {
ei = cache->c_eifree;
cache->c_eifree = ei->bei_lrunext;
}
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
}
if ( ei ) {
ei->bei_lrunext = NULL;
ei->bei_state = 0;
} else {
ei = ch_calloc(1, sizeof(struct bdb_entry_info));
ldap_pvt_thread_mutex_init( &ei->bei_kids_mutex );
}
return ei;
}
/* Atomically release and reacquire a lock */
int
bdb_cache_entry_db_relock(
DB_ENV *env,
u_int32_t locker,
EntryInfo *ei,
int rw,
int tryOnly,
DB_LOCK *lock )
{
#ifdef NO_THREADS
return 0;
#else
int rc;
DBT lockobj;
DB_LOCKREQ list[2];
if ( !lock ) return 0;
lockobj.data = &ei->bei_id;
lockobj.size = sizeof(ei->bei_id) + 1;
list[0].op = DB_LOCK_PUT;
list[0].lock = *lock;
list[1].op = DB_LOCK_GET;
list[1].lock = *lock;
list[1].mode = rw ? DB_LOCK_WRITE : DB_LOCK_READ;
list[1].obj = &lockobj;
rc = env->lock_vec(env, locker, tryOnly ? DB_LOCK_NOWAIT : 0,
list, 2, NULL );
if (rc && !tryOnly) {
Debug( LDAP_DEBUG_TRACE,
"bdb_cache_entry_db_relock: entry %ld, rw %d, rc %d\n",
ei->bei_id, rw, rc );
} else {
*lock = list[1].lock;
}
return rc;
#endif
}
static int
bdb_cache_entry_db_lock( DB_ENV *env, u_int32_t locker, EntryInfo *ei,
int rw, int tryOnly, DB_LOCK *lock )
{
#ifdef NO_THREADS
return 0;
#else
int rc;
DBT lockobj;
int db_rw;
if ( !lock ) return 0;
if (rw)
db_rw = DB_LOCK_WRITE;
else
db_rw = DB_LOCK_READ;
lockobj.data = &ei->bei_id;
lockobj.size = sizeof(ei->bei_id) + 1;
rc = LOCK_GET(env, locker, tryOnly ? DB_LOCK_NOWAIT : 0,
&lockobj, db_rw, lock);
if (rc && !tryOnly) {
Debug( LDAP_DEBUG_TRACE,
"bdb_cache_entry_db_lock: entry %ld, rw %d, rc %d\n",
ei->bei_id, rw, rc );
}
return rc;
#endif /* NO_THREADS */
}
int
bdb_cache_entry_db_unlock ( DB_ENV *env, DB_LOCK *lock )
{
#ifdef NO_THREADS
return 0;
#else
int rc;
if ( !lock ) return 0;
rc = LOCK_PUT ( env, lock );
return rc;
#endif
}
static int
bdb_cache_entryinfo_destroy( EntryInfo *e )
{
ldap_pvt_thread_mutex_destroy( &e->bei_kids_mutex );
free( e->bei_nrdn.bv_val );
#ifdef BDB_HIER
free( e->bei_rdn.bv_val );
#endif
free( e );
return 0;
}
#define LRU_DELETE( cache, ei ) do { \
if ( (ei)->bei_lruprev != NULL ) { \
(ei)->bei_lruprev->bei_lrunext = (ei)->bei_lrunext; \
} else { \
(cache)->c_lruhead = (ei)->bei_lrunext; \
} \
if ( (ei)->bei_lrunext != NULL ) { \
(ei)->bei_lrunext->bei_lruprev = (ei)->bei_lruprev; \
} else { \
(cache)->c_lrutail = (ei)->bei_lruprev; \
} \
(ei)->bei_lrunext = (ei)->bei_lruprev = NULL; \
} while(0)
#define LRU_ADD( cache, ei ) do { \
(ei)->bei_lrunext = (cache)->c_lruhead; \
if ( (ei)->bei_lrunext != NULL ) { \
(ei)->bei_lrunext->bei_lruprev = (ei); \
} \
(cache)->c_lruhead = (ei); \
(ei)->bei_lruprev = NULL; \
if ( (cache)->c_lrutail == NULL ) { \
(cache)->c_lrutail = (ei); \
} \
} while(0)
/* Do a length-ordered sort on normalized RDNs */
static int
bdb_rdn_cmp( const void *v_e1, const void *v_e2 )
{
const EntryInfo *e1 = v_e1, *e2 = v_e2;
int rc = e1->bei_nrdn.bv_len - e2->bei_nrdn.bv_len;
if (rc == 0) {
rc = strncmp( e1->bei_nrdn.bv_val, e2->bei_nrdn.bv_val,
e1->bei_nrdn.bv_len );
}
return rc;
}
static int
bdb_id_cmp( const void *v_e1, const void *v_e2 )
{
const EntryInfo *e1 = v_e1, *e2 = v_e2;
return e1->bei_id - e2->bei_id;
}
/* Create an entryinfo in the cache. Caller must release the locks later.
*/
static int
bdb_entryinfo_add_internal(
struct bdb_info *bdb,
EntryInfo *ei,
EntryInfo **res )
{
EntryInfo *ei2 = NULL;
*res = NULL;
ei2 = bdb_cache_entryinfo_new( &bdb->bi_cache );
ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
bdb_cache_entryinfo_lock( ei->bei_parent );
ei2->bei_id = ei->bei_id;
ei2->bei_parent = ei->bei_parent;
#ifdef BDB_HIER
ei2->bei_rdn = ei->bei_rdn;
#endif
#ifdef SLAP_ZONE_ALLOC
ei2->bei_bdb = bdb;
#endif
/* Add to cache ID tree */
if (avl_insert( &bdb->bi_cache.c_idtree, ei2, bdb_id_cmp, avl_dup_error )) {
EntryInfo *eix;
eix = avl_find( bdb->bi_cache.c_idtree, ei2, bdb_id_cmp );
bdb_cache_entryinfo_destroy( ei2 );
ei2 = eix;
#ifdef BDB_HIER
/* It got freed above because its value was
* assigned to ei2.
*/
ei->bei_rdn.bv_val = NULL;
#endif
} else {
bdb->bi_cache.c_eiused++;
ber_dupbv( &ei2->bei_nrdn, &ei->bei_nrdn );
avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
avl_dup_error );
#ifdef BDB_HIER
ei->bei_parent->bei_ckids++;
#endif
}
*res = ei2;
return 0;
}
/* Find the EntryInfo for the requested DN. If the DN cannot be found, return
* the info for its closest ancestor. *res should be NULL to process a
* complete DN starting from the tree root. Otherwise *res must be the
* immediate parent of the requested DN, and only the RDN will be searched.
* The EntryInfo is locked upon return and must be unlocked by the caller.
*/
int
bdb_cache_find_ndn(
Operation *op,
DB_TXN *txn,
struct berval *ndn,
EntryInfo **res )
{
struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
EntryInfo ei, *eip, *ei2;
int rc = 0;
char *ptr;
/* this function is always called with normalized DN */
if ( *res ) {
/* we're doing a onelevel search for an RDN */
ei.bei_nrdn.bv_val = ndn->bv_val;
ei.bei_nrdn.bv_len = dn_rdnlen( op->o_bd, ndn );
eip = *res;
} else {
/* we're searching a full DN from the root */
ptr = ndn->bv_val + ndn->bv_len - op->o_bd->be_nsuffix[0].bv_len;
ei.bei_nrdn.bv_val = ptr;
ei.bei_nrdn.bv_len = op->o_bd->be_nsuffix[0].bv_len;
/* Skip to next rdn if suffix is empty */
if ( ei.bei_nrdn.bv_len == 0 ) {
for (ptr = ei.bei_nrdn.bv_val - 2; ptr > ndn->bv_val
&& !DN_SEPARATOR(*ptr); ptr--) /* empty */;
if ( ptr >= ndn->bv_val ) {
if (DN_SEPARATOR(*ptr)) ptr++;
ei.bei_nrdn.bv_len = ei.bei_nrdn.bv_val - ptr;
ei.bei_nrdn.bv_val = ptr;
}
}
eip = &bdb->bi_cache.c_dntree;
}
for ( bdb_cache_entryinfo_lock( eip ); eip; ) {
ei.bei_parent = eip;
ei2 = (EntryInfo *)avl_find( eip->bei_kids, &ei, bdb_rdn_cmp );
if ( !ei2 ) {
int len = ei.bei_nrdn.bv_len;
if ( BER_BVISEMPTY( ndn )) {
*res = eip;
return LDAP_SUCCESS;
}
ei.bei_nrdn.bv_len = ndn->bv_len -
(ei.bei_nrdn.bv_val - ndn->bv_val);
bdb_cache_entryinfo_unlock( eip );
rc = bdb_dn2id( op, txn, &ei.bei_nrdn, &ei );
if (rc) {
bdb_cache_entryinfo_lock( eip );
*res = eip;
return rc;
}
/* DN exists but needs to be added to cache */
ei.bei_nrdn.bv_len = len;
rc = bdb_entryinfo_add_internal( bdb, &ei, &ei2 );
/* add_internal left eip and c_rwlock locked */
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
if ( rc ) {
*res = eip;
return rc;
}
} else if ( ei2->bei_state & CACHE_ENTRY_DELETED ) {
/* In the midst of deleting? Give it a chance to
* complete.
*/
bdb_cache_entryinfo_unlock( eip );
ldap_pvt_thread_yield();
bdb_cache_entryinfo_lock( eip );
*res = eip;
return DB_NOTFOUND;
}
bdb_cache_entryinfo_unlock( eip );
bdb_cache_entryinfo_lock( ei2 );
eip = ei2;
/* Advance to next lower RDN */
for (ptr = ei.bei_nrdn.bv_val - 2; ptr > ndn->bv_val
&& !DN_SEPARATOR(*ptr); ptr--) /* empty */;
if ( ptr >= ndn->bv_val ) {
if (DN_SEPARATOR(*ptr)) ptr++;
ei.bei_nrdn.bv_len = ei.bei_nrdn.bv_val - ptr - 1;
ei.bei_nrdn.bv_val = ptr;
}
if ( ptr < ndn->bv_val ) {
*res = eip;
break;
}
}
return rc;
}
#ifdef BDB_HIER
/* Walk up the tree from a child node, looking for an ID that's already
* been linked into the cache.
*/
static int
hdb_cache_find_parent(
Operation *op,
DB_TXN *txn,
ID id,
EntryInfo **res )
{
struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
EntryInfo ei, eip, *ei2 = NULL, *ein = NULL, *eir = NULL;
int rc;
int addlru = 1;
ei.bei_id = id;
ei.bei_kids = NULL;
ei.bei_ckids = 0;
for (;;) {
rc = hdb_dn2id_parent( op, txn, &ei, &eip.bei_id );
if ( rc ) break;
/* Save the previous node, if any */
ei2 = ein;
/* Create a new node for the current ID */
ein = bdb_cache_entryinfo_new( &bdb->bi_cache );
ein->bei_id = ei.bei_id;
ein->bei_kids = ei.bei_kids;
ein->bei_nrdn = ei.bei_nrdn;
ein->bei_rdn = ei.bei_rdn;
ein->bei_ckids = ei.bei_ckids;
#ifdef SLAP_ZONE_ALLOC
ein->bei_bdb = bdb;
#endif
ei.bei_ckids = 0;
/* This node is not fully connected yet */
ein->bei_state = CACHE_ENTRY_NOT_LINKED;
/* 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, avl_dup_error ) ) {
/* Someone else created this node just before us.
* Free our new copy and use the existing one.
*/
bdb_cache_entryinfo_destroy( ein );
ein = (EntryInfo *)avl_find( bdb->bi_cache.c_idtree,
(caddr_t) &ei, bdb_id_cmp );
/* 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 ( !eir ) {
addlru = 0;
}
}
/* If this is the first time, save this node
* to be returned later.
*/
if ( eir == NULL ) eir = ein;
/* If there was a previous node, link it to this one */
if ( ei2 ) ei2->bei_parent = ein;
/* Look for this node's parent */
if ( eip.bei_id ) {
ei2 = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
(caddr_t) &eip, bdb_id_cmp );
} else {
ei2 = &bdb->bi_cache.c_dntree;
}
bdb->bi_cache.c_eiused++;
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( ei2 );
ein->bei_parent = ei2;
avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
avl_dup_error);
ei2->bei_ckids++;
bdb_cache_entryinfo_unlock( ei2 );
bdb_cache_entryinfo_lock( eir );
/* Reset all the state info */
for (ein = eir; ein != ei2; ein=ein->bei_parent)
ein->bei_state &= ~CACHE_ENTRY_NOT_LINKED;
*res = eir;
break;
}
ei.bei_kids = NULL;
ei.bei_id = eip.bei_id;
ei.bei_ckids = 1;
avl_insert( &ei.bei_kids, (caddr_t)ein, bdb_rdn_cmp,
avl_dup_error );
}
return rc;
}
/* Used by hdb_dn2idl when loading the EntryInfo for all the children
* of a given node
*/
int hdb_cache_load(
struct bdb_info *bdb,
EntryInfo *ei,
EntryInfo **res )
{
EntryInfo *ei2;
int rc;
/* See if we already have this one */
bdb_cache_entryinfo_lock( ei->bei_parent );
ei2 = (EntryInfo *)avl_find( ei->bei_parent->bei_kids, ei, bdb_rdn_cmp );
bdb_cache_entryinfo_unlock( ei->bei_parent );
if ( !ei2 ) {
/* Not found, add it */
struct berval bv;
/* bei_rdn was not malloc'd before, do it now */
ber_dupbv( &bv, &ei->bei_rdn );
ei->bei_rdn = bv;
rc = bdb_entryinfo_add_internal( bdb, ei, res );
bdb_cache_entryinfo_unlock( ei->bei_parent );
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
} else {
/* Found, return it */
*res = ei2;
return 0;
}
return rc;
}
#endif
/* caller must have lru_mutex locked. mutex
* will be unlocked on return.
*/
static void
bdb_cache_lru_add(
struct bdb_info *bdb,
u_int32_t locker,
EntryInfo *ei )
{
DB_LOCK lock, *lockp;
if ( locker ) {
lockp = &lock;
} else {
lockp = NULL;
}
/* See if we're above the cache size limit */
if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
EntryInfo *elru, *elprev;
int i = 0;
/* Look for an unused entry to remove */
for (elru = bdb->bi_cache.c_lrutail; elru; elru = elprev, i++ ) {
elprev = elru->bei_lruprev;
/* Too many probes, not enough idle, give up */
if (i > 10)
break;
/* If we can successfully writelock it, then
* the object is idle.
*/
if ( bdb_cache_entry_db_lock( bdb->bi_dbenv,
bdb->bi_cache.c_locker, elru, 1, 1, lockp ) == 0 ) {
int stop = 0;
/* If there's no entry, or this node is in
* the process of linking into the cache,
* or this node is being deleted, skip it.
*/
if ( !elru->bei_e || (elru->bei_state &
( CACHE_ENTRY_NOT_LINKED | CACHE_ENTRY_DELETED ))) {
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
continue;
}
LRU_DELETE( &bdb->bi_cache, elru );
elru->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( bdb, elru->bei_e, elru->bei_zseq );
#else
bdb_entry_return( elru->bei_e );
#endif
elru->bei_e = NULL;
ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
--bdb->bi_cache.c_cursize;
if (bdb->bi_cache.c_cursize <= bdb->bi_cache.c_maxsize)
stop = 1;
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
if (stop) break;
}
}
}
LRU_ADD( &bdb->bi_cache, ei );
ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_mutex );
}
EntryInfo *
bdb_cache_find_info(
struct bdb_info *bdb,
ID id )
{
EntryInfo ei = { 0 },
*ei2;
ei.bei_id = id;
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 );
ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
return ei2;
}
/*
* cache_find_id - find an entry in the cache, given id.
* The entry is locked for Read upon return. Call with islocked TRUE if
* the supplied *eip was already locked.
*/
int
bdb_cache_find_id(
Operation *op,
DB_TXN *tid,
ID id,
EntryInfo **eip,
int islocked,
u_int32_t locker,
DB_LOCK *lock )
{
struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
Entry *ep = NULL;
int rc = 0, load = 0;
EntryInfo ei = { 0 };
ei.bei_id = id;
#ifdef SLAP_ZONE_ALLOC
slap_zh_rlock(bdb->bi_cache.c_zctx);
#endif
/* If we weren't given any info, see if we have it already cached */
if ( !*eip ) {
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 the lock attempt fails, the info is in use */
if ( ldap_pvt_thread_mutex_trylock(
&(*eip)->bei_kids_mutex )) {
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 ) {
return DB_NOTFOUND;
}
/* otherwise, wait for the info to free up */
ldap_pvt_thread_yield();
goto again;
}
/* If this info isn't hooked up to its parent yet,
* unlock and wait for it to be fully initialized
*/
if ( (*eip)->bei_state & CACHE_ENTRY_NOT_LINKED ) {
bdb_cache_entryinfo_unlock( *eip );
ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
ldap_pvt_thread_yield();
goto again;
}
islocked = 1;
}
ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
}
/* See if the ID exists in the database; add it to the cache if so */
if ( !*eip ) {
#ifndef BDB_HIER
rc = bdb_id2entry( op->o_bd, tid, id, &ep );
if ( rc == 0 ) {
rc = bdb_cache_find_ndn( op, tid,
&ep->e_nname, eip );
if ( *eip ) islocked = 1;
if ( rc ) {
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( bdb, ep, (*eip)->bei_zseq );
#else
bdb_entry_return( ep );
#endif
ep = NULL;
}
}
#else
rc = hdb_cache_find_parent(op, tid, id, eip );
if ( rc == 0 && *eip ) islocked = 1;
#endif
}
/* Ok, we found the info, do we have the entry? */
if ( *eip && rc == 0 ) {
if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
rc = DB_NOTFOUND;
} else {
/* Make sure only one thread tries to load the entry */
load1:
#ifdef SLAP_ZONE_ALLOC
if ((*eip)->bei_e && !slap_zn_validate(
bdb->bi_cache.c_zctx, (*eip)->bei_e, (*eip)->bei_zseq)) {
(*eip)->bei_e = NULL;
(*eip)->bei_zseq = 0;
}
#endif
if ( !(*eip)->bei_e && !((*eip)->bei_state & CACHE_ENTRY_LOADING)) {
load = 1;
(*eip)->bei_state |= CACHE_ENTRY_LOADING;
}
if ( islocked ) {
bdb_cache_entryinfo_unlock( *eip );
islocked = 0;
}
rc = bdb_cache_entry_db_lock( bdb->bi_dbenv, locker, *eip, 0, 0, lock );
if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
rc = DB_NOTFOUND;
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
} else if ( rc == 0 ) {
if ( load ) {
DB_TXN *ltid;
u_int32_t locker2 = locker;
/* We don't wrap entire read operations in txn's, but
* we need our cache entry lock and any DB page locks
* to be associated, in order for deadlock detection
* to work properly. So if we need to read from the DB,
* we use a long-lived per-thread txn for this step.
*/
if ( !ep && !tid ) {
rc = bdb_txn_get( op, bdb->bi_dbenv, &ltid, 0 );
if ( ltid )
locker2 = TXN_ID( ltid );
} else {
ltid = tid;
}
/* Give up original read lock, obtain write lock with
* (possibly) new locker ID.
*/
if ( rc == 0 ) {
rc = bdb_cache_entry_db_relock( bdb->bi_dbenv, locker2,
*eip, 1, 0, lock );
}
if ( rc == 0 && !ep) {
rc = bdb_id2entry( op->o_bd, ltid, id, &ep );
}
if ( rc == 0 ) {
ep->e_private = *eip;
#ifdef BDB_HIER
bdb_fix_dn( ep, 0 );
#endif
(*eip)->bei_e = ep;
#ifdef SLAP_ZONE_ALLOC
(*eip)->bei_zseq = *((ber_len_t *)ep - 2);
#endif
ep = NULL;
}
(*eip)->bei_state ^= CACHE_ENTRY_LOADING;
if ( rc == 0 ) {
/* If we succeeded, downgrade back to a readlock. */
rc = bdb_cache_entry_db_relock( bdb->bi_dbenv, locker,
*eip, 0, 0, lock );
} else {
/* Otherwise, release the lock. */
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
}
if ( locker2 != locker ) {
/* If we're using the per-thread txn, release all
* of its page locks now.
*/
DB_LOCKREQ list;
list.op = DB_LOCK_PUT_ALL;
list.obj = NULL;
bdb->bi_dbenv->lock_vec( bdb->bi_dbenv, locker2,
0, &list, 1, NULL );
/* If this txn was deadlocked, we must abort it
* and invalidate this per-thread txn.
*/
if ( rc == DB_LOCK_DEADLOCK ) {
bdb_txn_get( op, bdb->bi_dbenv, &ltid, 1 );
}
}
} else if ( !(*eip)->bei_e ) {
/* Some other thread is trying to load the entry,
* give it a chance to finish.
*/
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
ldap_pvt_thread_yield();
bdb_cache_entryinfo_lock( *eip );
islocked = 1;
goto load1;
#ifdef BDB_HIER
} else {
/* Check for subtree renames
*/
rc = bdb_fix_dn( (*eip)->bei_e, 1 );
if ( rc ) {
bdb_cache_entry_db_relock( bdb->bi_dbenv,
locker, *eip, 1, 0, lock );
/* check again in case other modifier did it already */
if ( bdb_fix_dn( (*eip)->bei_e, 1 ) )
rc = bdb_fix_dn( (*eip)->bei_e, 2 );
bdb_cache_entry_db_relock( bdb->bi_dbenv,
locker, *eip, 0, 0, lock );
}
#endif
}
}
}
}
if ( islocked ) {
bdb_cache_entryinfo_unlock( *eip );
}
if ( ep ) {
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( bdb, ep, (*eip)->bei_zseq );
#else
bdb_entry_return( ep );
#endif
}
if ( rc == 0 ) {
if ( load ) {
ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
bdb->bi_cache.c_cursize++;
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
}
ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
/* If the LRU list has only one entry and this is it, it
* doesn't need to be added again.
*/
if ( bdb->bi_cache.c_lruhead == bdb->bi_cache.c_lrutail &&
bdb->bi_cache.c_lruhead == *eip ) {
ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_mutex );
} else {
/* if entry is on LRU list, remove from old spot */
if ( (*eip)->bei_lrunext || (*eip)->bei_lruprev ) {
LRU_DELETE( &bdb->bi_cache, *eip );
}
/* lru_mutex is unlocked for us */
bdb_cache_lru_add( bdb, locker, *eip );
}
}
#ifdef SLAP_ZONE_ALLOC
if (rc == 0 && (*eip)->bei_e) {
slap_zn_rlock(bdb->bi_cache.c_zctx, (*eip)->bei_e);
}
slap_zh_runlock(bdb->bi_cache.c_zctx);
#endif
return rc;
}
int
bdb_cache_children(
Operation *op,
DB_TXN *txn,
Entry *e )
{
int rc;
if ( BEI(e)->bei_kids ) {
return 0;
}
if ( BEI(e)->bei_state & CACHE_ENTRY_NO_KIDS ) {
return DB_NOTFOUND;
}
rc = bdb_dn2id_children( op, txn, e );
if ( rc == DB_NOTFOUND ) {
BEI(e)->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
}
return rc;
}
/* Update the cache after a successful database Add. */
int
bdb_cache_add(
struct bdb_info *bdb,
EntryInfo *eip,
Entry *e,
struct berval *nrdn,
u_int32_t locker )
{
EntryInfo *new, ei;
DB_LOCK lock;
int rc;
#ifdef BDB_HIER
struct berval rdn = e->e_name;
#endif
ei.bei_id = e->e_id;
ei.bei_parent = eip;
ei.bei_nrdn = *nrdn;
ei.bei_lockpad = 0;
/* Lock this entry so that bdb_add can run to completion.
* It can only fail if BDB has run out of lock resources.
*/
rc = bdb_cache_entry_db_lock( bdb->bi_dbenv, locker, &ei, 1, 0, &lock );
if ( rc ) {
bdb_cache_entryinfo_unlock( eip );
return rc;
}
#ifdef BDB_HIER
if ( nrdn->bv_len != e->e_nname.bv_len ) {
char *ptr = strchr( rdn.bv_val, ',' );
rdn.bv_len = ptr - rdn.bv_val;
}
ber_dupbv( &ei.bei_rdn, &rdn );
if ( eip->bei_dkids ) eip->bei_dkids++;
#endif
rc = bdb_entryinfo_add_internal( bdb, &ei, &new );
/* bdb_csn_commit can cause this when adding the database root entry */
if ( new->bei_e ) {
new->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( bdb, new->bei_e, new->bei_zseq );
#else
bdb_entry_return( new->bei_e );
#endif
}
new->bei_e = e;
e->e_private = new;
new->bei_state = CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
eip->bei_state &= ~CACHE_ENTRY_NO_KIDS;
if (eip->bei_parent) {
eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
}
bdb_cache_entryinfo_unlock( eip );
++bdb->bi_cache.c_cursize;
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
/* lru_mutex is unlocked for us */
bdb_cache_lru_add( bdb, locker, new );
return rc;
}
int
bdb_cache_modify(
Entry *e,
Attribute *newAttrs,
DB_ENV *env,
u_int32_t locker,
DB_LOCK *lock )
{
EntryInfo *ei = BEI(e);
int rc;
/* Get write lock on data */
rc = bdb_cache_entry_db_relock( env, locker, ei, 1, 0, lock );
/* If we've done repeated mods on a cached entry, then e_attrs
* is no longer contiguous with the entry, and must be freed.
*/
if ( ! rc ) {
if ( (void *)e->e_attrs != (void *)(e+1) ) {
attrs_free( e->e_attrs );
}
e->e_attrs = newAttrs;
}
return rc;
}
/*
* Change the rdn in the entryinfo. Also move to a new parent if needed.
*/
int
bdb_cache_modrdn(
struct bdb_info *bdb,
Entry *e,
struct berval *nrdn,
Entry *new,
EntryInfo *ein,
u_int32_t locker,
DB_LOCK *lock )
{
EntryInfo *ei = BEI(e), *pei;
int rc;
#ifdef BDB_HIER
struct berval rdn;
#endif
/* Get write lock on data */
rc = bdb_cache_entry_db_relock( bdb->bi_dbenv, locker, ei, 1, 0, lock );
if ( rc ) return rc;
/* If we've done repeated mods on a cached entry, then e_attrs
* is no longer contiguous with the entry, and must be freed.
*/
if ( (void *)e->e_attrs != (void *)(e+1) ) {
attrs_free( e->e_attrs );
}
e->e_attrs = new->e_attrs;
if( e->e_nname.bv_val < e->e_bv.bv_val ||
e->e_nname.bv_val > e->e_bv.bv_val + e->e_bv.bv_len )
{
ch_free(e->e_name.bv_val);
ch_free(e->e_nname.bv_val);
}
e->e_name = new->e_name;
e->e_nname = new->e_nname;
/* Lock the parent's kids AVL tree */
pei = ei->bei_parent;
bdb_cache_entryinfo_lock( pei );
avl_delete( &pei->bei_kids, (caddr_t) ei, bdb_rdn_cmp );
free( ei->bei_nrdn.bv_val );
ber_dupbv( &ei->bei_nrdn, nrdn );
#ifdef BDB_HIER
free( ei->bei_rdn.bv_val );
rdn = e->e_name;
if ( nrdn->bv_len != e->e_nname.bv_len ) {
char *ptr = strchr(rdn.bv_val, ',');
rdn.bv_len = ptr - rdn.bv_val;
}
ber_dupbv( &ei->bei_rdn, &rdn );
#endif
if (!ein) {
ein = ei->bei_parent;
} else {
ei->bei_parent = ein;
bdb_cache_entryinfo_unlock( pei );
bdb_cache_entryinfo_lock( ein );
}
#ifdef BDB_HIER
{
/* Record the generation number of this change */
ldap_pvt_thread_mutex_lock( &bdb->bi_modrdns_mutex );
bdb->bi_modrdns++;
ei->bei_modrdns = bdb->bi_modrdns;
ldap_pvt_thread_mutex_unlock( &bdb->bi_modrdns_mutex );
}
#endif
avl_insert( &ein->bei_kids, ei, bdb_rdn_cmp, avl_dup_error );
bdb_cache_entryinfo_unlock( ein );
return rc;
}
/*
* cache_delete - delete the entry e from the cache.
*
* returns: 0 e was deleted ok
* 1 e was not in the cache
* -1 something bad happened
*/
int
bdb_cache_delete(
Cache *cache,
Entry *e,
DB_ENV *env,
u_int32_t locker,
DB_LOCK *lock )
{
EntryInfo *ei = BEI(e);
int rc;
assert( e->e_private != NULL );
/* Set this early, warn off any queriers */
ei->bei_state |= CACHE_ENTRY_DELETED;
/* Lock the entry's info */
bdb_cache_entryinfo_lock( ei );
/* Get write lock on the data */
rc = bdb_cache_entry_db_relock( env, locker, ei, 1, 0, lock );
if ( rc ) {
/* couldn't lock, undo and give up */
ei->bei_state ^= CACHE_ENTRY_DELETED;
bdb_cache_entryinfo_unlock( ei );
return rc;
}
Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_delete( %ld )\n",
e->e_id, 0, 0 );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
rc = bdb_cache_delete_internal( cache, e->e_private, 1 );
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* Leave entry info locked */
return( rc );
}
void
bdb_cache_delete_cleanup(
Cache *cache,
EntryInfo *ei )
{
if ( ei->bei_e ) {
ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( ei->bei_bdb, ei->bei_e, ei->bei_zseq );
#else
bdb_entry_return( ei->bei_e );
#endif
ei->bei_e = NULL;
}
free( ei->bei_nrdn.bv_val );
ei->bei_nrdn.bv_val = NULL;
#ifdef BDB_HIER
free( ei->bei_rdn.bv_val );
ei->bei_rdn.bv_val = NULL;
ei->bei_modrdns = 0;
ei->bei_ckids = 0;
ei->bei_dkids = 0;
#endif
ei->bei_parent = NULL;
ei->bei_kids = NULL;
ei->bei_lruprev = NULL;
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
ei->bei_lrunext = cache->c_eifree;
cache->c_eifree = ei;
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
bdb_cache_entryinfo_unlock( ei );
}
static int
bdb_cache_delete_internal(
Cache *cache,
EntryInfo *e,
int decr )
{
int rc = 0; /* return code */
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
/* Lock the parent's kids tree */
bdb_cache_entryinfo_lock( e->bei_parent );
#ifdef BDB_HIER
e->bei_parent->bei_ckids--;
if ( decr && e->bei_parent->bei_dkids ) e->bei_parent->bei_dkids--;
#endif
/* dn tree */
if ( avl_delete( &e->bei_parent->bei_kids, (caddr_t) e, bdb_rdn_cmp )
== NULL )
{
rc = -1;
}
/* id tree */
if ( avl_delete( &cache->c_idtree, (caddr_t) e, bdb_id_cmp ) == NULL ) {
rc = -1;
}
if (rc != 0) {
return rc;
}
cache->c_eiused--;
/* lru */
LRU_DELETE( cache, e );
if ( e->bei_e ) cache->c_cursize--;
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
bdb_cache_entryinfo_unlock( e->bei_parent );
return( 0 );
}
static void
bdb_entryinfo_release( void *data )
{
EntryInfo *ei = (EntryInfo *)data;
if ( ei->bei_kids ) {
avl_free( ei->bei_kids, NULL );
}
if ( ei->bei_e ) {
ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( ei->bei_bdb, ei->bei_e, ei->bei_zseq );
#else
bdb_entry_return( ei->bei_e );
#endif
}
bdb_cache_entryinfo_destroy( ei );
}
void
bdb_cache_release_all( Cache *cache )
{
/* set cache write lock */
ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
/* set lru mutex */
ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_release_all\n", 0, 0, 0 );
avl_free( cache->c_dntree.bei_kids, NULL );
avl_free( cache->c_idtree, bdb_entryinfo_release );
for (;cache->c_eifree;cache->c_eifree = cache->c_lruhead) {
cache->c_lruhead = cache->c_eifree->bei_lrunext;
bdb_cache_entryinfo_destroy(cache->c_eifree);
}
cache->c_cursize = 0;
cache->c_eiused = 0;
cache->c_idtree = NULL;
cache->c_lruhead = NULL;
cache->c_lrutail = NULL;
cache->c_dntree.bei_kids = NULL;
/* free lru mutex */
ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
/* free cache write lock */
ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
}
#ifdef LDAP_DEBUG
static void
bdb_lru_print( Cache *cache )
{
EntryInfo *e;
fprintf( stderr, "LRU queue (head to tail):\n" );
for ( e = cache->c_lruhead; e != NULL; e = e->bei_lrunext ) {
fprintf( stderr, "\trdn \"%20s\" id %ld\n",
e->bei_nrdn.bv_val, e->bei_id );
}
fprintf( stderr, "LRU queue (tail to head):\n" );
for ( e = cache->c_lrutail; e != NULL; e = e->bei_lruprev ) {
fprintf( stderr, "\trdn \"%20s\" id %ld\n",
e->bei_nrdn.bv_val, e->bei_id );
}
}
#endif
static void
bdb_txn_free( void *key, void *data )
{
DB_TXN *txn = data;
TXN_ABORT( txn );
}
/* Obtain a long-lived transaction for the current thread.
* If reset == 1, remove the current transaction. */
static int
bdb_txn_get( Operation *op, DB_ENV *env, DB_TXN **txn, int reset )
{
int i, rc;
void *ctx, *data = NULL;
if ( slapMode & SLAP_TOOL_MODE ) {
*txn = NULL;
return 0;
}
/* If no op was provided, try to find the ctx anyway... */
if ( op ) {
ctx = op->o_threadctx;
} else {
ctx = ldap_pvt_thread_pool_context();
}
/* Shouldn't happen unless we're single-threaded */
if ( !ctx ) {
*txn = NULL;
return 0;
}
if ( reset ) {
TXN_ABORT( *txn );
return ldap_pvt_thread_pool_setkey( ctx, ((char *)env)+1, NULL, NULL );
}
if ( ldap_pvt_thread_pool_getkey( ctx, ((char *)env)+1, &data, NULL ) ||
data == NULL ) {
for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
rc = TXN_BEGIN( env, NULL, txn, READ_TXN_FLAG );
#if DB_VERSION_FULL == 0x04020034
if ( rc == EINVAL && READ_TXN_FLAG ) {
READ_TXN_FLAG = 0;
Debug( LDAP_DEBUG_ANY,
"bdb_txn_get: BerkeleyDB 4.2.52 library needs TXN patch!\n",
0, 0, 0 );
i--;
continue;
}
#endif
if (rc) ldap_pvt_thread_yield();
}
if ( rc != 0) {
return rc;
}
if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, ((char *)env)+1,
*txn, bdb_txn_free ) ) ) {
TXN_ABORT( *txn );
Debug( LDAP_DEBUG_ANY, "bdb_txn_get: err %s(%d)\n",
db_strerror(rc), rc, 0 );
return rc;
}
} else {
*txn = data;
}
return 0;
}
#ifdef BDB_REUSE_LOCKERS
static void
bdb_locker_id_free( void *key, void *data )
{
DB_ENV *env = key;
int lockid = (int) data;
int rc;
rc = XLOCK_ID_FREE( env, lockid );
if ( rc == EINVAL ) {
DB_LOCKREQ lr;
Debug( LDAP_DEBUG_ANY,
"bdb_locker_id_free: %d err %s(%d)\n",
lockid, db_strerror(rc), rc );
/* release all locks held by this locker. */
lr.op = DB_LOCK_PUT_ALL;
lr.obj = NULL;
env->lock_vec( env, lockid, 0, &lr, 1, NULL );
XLOCK_ID_FREE( env, lockid );
}
}
int
bdb_locker_id( Operation *op, DB_ENV *env, int *locker )
{
int i, rc, lockid;
void *data;
void *ctx;
if ( !env || !locker ) return -1;
/* If no op was provided, try to find the ctx anyway... */
if ( op ) {
ctx = op->o_threadctx;
} else {
ctx = ldap_pvt_thread_pool_context();
}
/* Shouldn't happen unless we're single-threaded */
if ( !ctx ) {
*locker = 0;
return 0;
}
if ( ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
rc = XLOCK_ID( env, &lockid );
if (rc) ldap_pvt_thread_yield();
}
if ( rc != 0) {
return rc;
}
data = (void *)lockid;
if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, env,
data, bdb_locker_id_free ) ) ) {
XLOCK_ID_FREE( env, lockid );
Debug( LDAP_DEBUG_ANY, "bdb_locker_id: err %s(%d)\n",
db_strerror(rc), rc, 0 );
return rc;
}
} else {
lockid = (int)data;
}
*locker = lockid;
return 0;
}
#endif
void
bdb_cache_delete_entry(
struct bdb_info *bdb,
EntryInfo *ei,
u_int32_t locker,
DB_LOCK *lock )
{
ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
if ( bdb_cache_entry_db_lock( bdb->bi_dbenv, bdb->bi_cache.c_locker, ei, 1, 1, lock ) == 0 )
{
if ( ei->bei_e && !(ei->bei_state & CACHE_ENTRY_NOT_LINKED )) {
LRU_DELETE( &bdb->bi_cache, ei );
ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
bdb_entry_return( bdb, ei->bei_e, ei->bei_zseq );
#else
bdb_entry_return( ei->bei_e );
#endif
ei->bei_e = NULL;
--bdb->bi_cache.c_cursize;
}
bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
}
ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
}
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