From 95b9dc631b74fd0c6b96ecaae382c7f4b9845fb3 Mon Sep 17 00:00:00 2001
From: Quanah Gibson-Mount <quanah@openldap.org>
Date: Wed, 18 Nov 2009 02:22:22 +0000
Subject: [PATCH] ITS#6380
---
CHANGES | 1 +
servers/slapd/sl_malloc.c | 95 +++++++++++++++++++++++++++------------
servers/slapd/syncrepl.c | 7 +--
3 files changed, 71 insertions(+), 32 deletions(-)
diff --git a/CHANGES b/CHANGES
index 29c9a6259f..544a0189e9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -17,6 +17,7 @@ OpenLDAP 2.4.20 Engineering
Fixed slapd inclusion of ac/unistd.h (ITS#6342)
Fixed slapd invalid dn log message (ITS#6309)
Fixed slapd lockup on shutdown (ITS#6372)
+ Fixed slapd sl_free to better reclaim memory (ITS#6380)
Fixed slapd termination for one level DNs (ITS#6338)
Fixed slapd tls_accept to retry in certain cases (ITS#6304)
Fixed slapd unused parameter (ITS#6356)
diff --git a/servers/slapd/sl_malloc.c b/servers/slapd/sl_malloc.c
index 998d50bd8a..b4e0ac6146 100644
--- a/servers/slapd/sl_malloc.c
+++ b/servers/slapd/sl_malloc.c
@@ -90,6 +90,14 @@ slap_sl_mem_init()
static struct slab_heap *slheap;
#endif
+/* This allocator always returns memory aligned on a 2-int boundary.
+ *
+ * The stack-based allocator stores the size as a ber_len_t at both
+ * the head and tail of the allocated block. When freeing a block, the
+ * tail length is ORed with 1 to mark it as free. Freed space can only
+ * be reclaimed from the tail forward. If the tail block is never freed,
+ * nothing else will be reclaimed until the slab is reset...
+ */
void *
slap_sl_mem_create(
ber_len_t size,
@@ -114,7 +122,7 @@ slap_sl_mem_create(
sh = sh_tmp;
#endif
- if ( !new )
+ if ( sh && !new )
return sh;
/* round up to doubleword boundary */
@@ -138,7 +146,12 @@ slap_sl_mem_create(
if ( newptr == NULL ) return NULL;
sh->sh_base = newptr;
}
- sh->sh_last = sh->sh_base;
+ /* insert dummy len */
+ {
+ ber_len_t *i = sh->sh_base;
+ *i++ = 0;
+ sh->sh_last = i;
+ }
sh->sh_end = (char *) sh->sh_base + size;
sh->sh_stack = stack;
return sh;
@@ -258,13 +271,8 @@ slap_sl_malloc(
)
{
struct slab_heap *sh = ctx;
- ber_len_t size_shift;
int pad = 2*sizeof(int)-1, pad_shift;
- int order = -1, order_start = -1;
- struct slab_object *so_new, *so_left, *so_right;
ber_len_t *ptr, *newptr;
- unsigned long diff;
- int i, j;
#ifdef SLAP_NO_SL_MALLOC
newptr = ber_memalloc_x( size, NULL );
@@ -281,8 +289,8 @@ slap_sl_malloc(
exit( EXIT_FAILURE );
}
- /* round up to doubleword boundary */
- size += sizeof(ber_len_t) + pad;
+ /* round up to doubleword boundary, plus space for len at head and tail */
+ size += 2*sizeof(ber_len_t) + pad;
size &= ~pad;
if (sh->sh_stack) {
@@ -293,10 +301,18 @@ slap_sl_malloc(
return ch_malloc(size);
}
newptr = sh->sh_last;
- *newptr++ = size - sizeof(ber_len_t);
sh->sh_last = (char *) sh->sh_last + size;
+ size -= sizeof(ber_len_t);
+ *newptr++ = size;
+ *(ber_len_t *)((char *)sh->sh_last - sizeof(ber_len_t)) = size;
return( (void *)newptr );
} else {
+ struct slab_object *so_new, *so_left, *so_right;
+ ber_len_t size_shift;
+ int order = -1, order_start = -1;
+ unsigned long diff;
+ int i, j;
+
size_shift = size - 1;
do {
order++;
@@ -412,21 +428,26 @@ slap_sl_realloc(void *ptr, ber_len_t size, void *ctx)
size += pad + sizeof( ber_len_t );
size &= ~pad;
+ p--;
+
/* Never shrink blocks */
- if (size <= p[-1]) {
- newptr = p;
+ if (size <= p[0]) {
+ newptr = ptr;
/* If reallocing the last block, we can grow it */
- } else if ((char *)ptr + p[-1] == sh->sh_last &&
+ } else if ((char *)ptr + p[0] == sh->sh_last &&
(char *)ptr + size < (char *)sh->sh_end ) {
- newptr = p;
- sh->sh_last = (char *)sh->sh_last + size - p[-1];
- p[-1] = size;
-
+ newptr = ptr;
+ sh->sh_last = (char *)ptr + size;
+ p[0] = size;
+ p[size/sizeof(ber_len_t)] = size;
+
/* Nowhere to grow, need to alloc and copy */
} else {
- newptr = slap_sl_malloc(size, ctx);
- AC_MEMCPY(newptr, ptr, p[-1]);
+ newptr = slap_sl_malloc(size-sizeof(ber_len_t), ctx);
+ AC_MEMCPY(newptr, ptr, p[0]-sizeof(ber_len_t));
+ /* mark old region as free */
+ p[p[0]/sizeof(ber_len_t)] |= 1;
}
return newptr;
} else {
@@ -447,13 +468,8 @@ void
slap_sl_free(void *ptr, void *ctx)
{
struct slab_heap *sh = ctx;
- int size, size_shift, order_size;
- int pad = 2*sizeof(int)-1, pad_shift;
+ ber_len_t size;
ber_len_t *p = (ber_len_t *)ptr, *tmpp;
- int order_start = -1, order = -1;
- struct slab_object *so;
- unsigned long diff;
- int i, inserted = 0;
if (!ptr)
return;
@@ -465,10 +481,31 @@ slap_sl_free(void *ptr, void *ctx)
if (!sh || ptr < sh->sh_base || ptr >= sh->sh_end) {
ber_memfree_x(ptr, NULL);
- } else if (sh->sh_stack && (char *)ptr + p[-1] == sh->sh_last) {
- p--;
- sh->sh_last = p;
- } else if (!sh->sh_stack) {
+ } else if (sh->sh_stack) {
+ tmpp = (ber_len_t *)((char *)ptr + p[-1]);
+ /* mark it free */
+ tmpp[-1] |= 1;
+ /* reclaim free space off tail */
+ while ( tmpp == sh->sh_last ) {
+ if ( tmpp[-1] & 1 ) {
+ size = tmpp[-1] ^ 1;
+ ptr = (char *)tmpp - size;
+ p = (ber_len_t *)ptr;
+ p--;
+ sh->sh_last = p;
+ tmpp = sh->sh_last;
+ } else {
+ break;
+ }
+ }
+ } else {
+ int size_shift, order_size;
+ int pad = 2*sizeof(int)-1, pad_shift;
+ int order_start = -1, order = -1;
+ struct slab_object *so;
+ unsigned long diff;
+ int i, inserted = 0;
+
size = *(--p);
size_shift = size + sizeof(ber_len_t) - 1;
do {
diff --git a/servers/slapd/syncrepl.c b/servers/slapd/syncrepl.c
index e098251824..4933933935 100644
--- a/servers/slapd/syncrepl.c
+++ b/servers/slapd/syncrepl.c
@@ -579,8 +579,9 @@ do_syncrep1(
{
ber_len_t ssf; /* ITS#5403, 3864 LDAP_OPT_X_SASL_SSF probably ought
to use sasl_ssf_t but currently uses ber_len_t */
- ldap_get_option( si->si_ld, LDAP_OPT_X_SASL_SSF, &ssf );
- op->o_sasl_ssf = ssf;
+ if ( ldap_get_option( si->si_ld, LDAP_OPT_X_SASL_SSF, &ssf )
+ == LDAP_SUCCESS )
+ op->o_sasl_ssf = ssf;
}
op->o_ssf = ( op->o_sasl_ssf > op->o_tls_ssf )
? op->o_sasl_ssf : op->o_tls_ssf;
@@ -1322,7 +1323,7 @@ do_syncrepl(
if ( SLAP_GLUE_SUBORDINATE( be ) && !overlay_is_inst( be, "syncprov" )) {
BackendDB * top_be = select_backend( &be->be_nsuffix[0], 1 );
if ( overlay_is_inst( top_be, "syncprov" ))
- si->si_wbe = select_backend( &be->be_nsuffix[0], 1 );
+ si->si_wbe = top_be;
else
si->si_wbe = be;
} else {
--
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