markdelfunc for lock order problem in lruhash reclaim().

git-svn-id: file:///svn/unbound/trunk@804 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -16,6 +16,8 @@
 	- hardening, if error reply with rcode=0 (noerror) send servfail.
 	- fixup same (*var) error in find_rrset in msgparse, was harmless.
 	- check return value of evtimer_add().
+	- fixup lockorder in lruhash_reclaim(), building up a list of locked
+	  entries one at a time. Instead they are removed and unlocked.
 
 3 December 2007: Wouter
 	- changed checkconf/ to smallapp/ to make room for more support tools.

services/cache/rrset.c

@@ -47,6 +47,14 @@
 #include "util/regional.h"
 #include "util/alloc.h"
 
+/** mark rrset to be deleted */
+static void
+rrset_markdel(void* key)
+{
+	struct ub_packed_rrset_key* r = (struct ub_packed_rrset_key*)key;
+	r->id = 0;
+}
+
 struct rrset_cache* rrset_cache_create(struct config_file* cfg, 
 	struct alloc_cache* alloc)
 {
@@ -57,6 +65,7 @@ struct rrset_cache* rrset_cache_create(struct config_file* cfg,
 	struct rrset_cache *r = (struct rrset_cache*)slabhash_create(slabs,
 		startarray, maxmem, ub_rrset_sizefunc, ub_rrset_compare,
 		ub_rrset_key_delete, rrset_data_delete, alloc);
+	slabhash_setmarkdel(&r->table, &rrset_markdel);
 	return r;
 }
 

util/storage/lruhash.c

@@ -205,6 +205,10 @@ reclaim_space(struct lruhash* table, struct lruhash_entry** list)
 		*list = d;
 		lock_rw_wrlock(&d->lock);
 		table->space_used -= table->sizefunc(d->key, d->data);
+		if(table->markdelfunc)
+			/* TODO fptr_wlist it */
+			(*table->markdelfunc)(d->key);
+		lock_rw_unlock(&d->lock);
 		lock_quick_unlock(&bin->lock);
 	}
 }
@@ -341,7 +345,7 @@ lruhash_insert(struct lruhash* table, hashvalue_t hash,
 	while(reclaimlist) {
 		struct lruhash_entry* n = reclaimlist->overflow_next;
 		void* d = reclaimlist->data;
-		(*table->delkeyfunc)(reclaimlist->key, cb_arg, 1);
+		(*table->delkeyfunc)(reclaimlist->key, cb_arg, 0);
 		(*table->deldatafunc)(d, cb_arg);
 		reclaimlist = n;
 	}
@@ -395,10 +399,14 @@ lruhash_remove(struct lruhash* table, hashvalue_t hash, void* key)
 	table->space_used -= (*table->sizefunc)(entry->key, entry->data);
 	lock_quick_unlock(&table->lock);
 	lock_rw_wrlock(&entry->lock);
+	if(table->markdelfunc)
+		/* TODO fptr wlist it */
+		(*table->markdelfunc)(entry->key);
+	lock_rw_unlock(&entry->lock);
 	lock_quick_unlock(&bin->lock);
 	/* finish removal */
 	d = entry->data;
-	(*table->delkeyfunc)(entry->key, table->cb_arg, 1);
+	(*table->delkeyfunc)(entry->key, table->cb_arg, 0);
 	(*table->deldatafunc)(d, table->cb_arg);
 }
 
@@ -414,7 +422,11 @@ bin_clear(struct lruhash* table, struct lruhash_bin* bin)
 		lock_rw_wrlock(&p->lock);
 		np = p->overflow_next;
 		d = p->data;
-		(*table->delkeyfunc)(p->key, table->cb_arg, 1);
+		if(table->markdelfunc)
+			/* TODO fptr wlist it */
+			(*table->markdelfunc)(p->key);
+		lock_rw_unlock(&p->lock);
+		(*table->delkeyfunc)(p->key, table->cb_arg, 0);
 		(*table->deldatafunc)(d, table->cb_arg);
 		p = np;
 	}
@@ -491,3 +503,11 @@ lruhash_get_mem(struct lruhash* table)
 	s += lock_get_mem(&table->lock);
 	return s;
 }
+
+void 
+lruhash_setmarkdel(struct lruhash* table, lruhash_markdelfunc_t md)
+{
+	lock_quick_lock(&table->lock);
+	table->markdelfunc = md;
+	lock_quick_unlock(&table->lock);
+}

util/storage/lruhash.h

@@ -141,6 +141,10 @@ typedef void (*lruhash_delkeyfunc_t)(void*, void*, int);
 /** old data is deleted. This function is called: func(data, userarg). */
 typedef void (*lruhash_deldatafunc_t)(void*, void*);
 
+/** mark a key as pending to be deleted (and not to be used by anyone). 
+ * called: func(key) */
+typedef void (*lruhash_markdelfunc_t)(void*);
+
 /**
  * Hash table that keeps LRU list of entries.
  */
@@ -155,6 +159,8 @@ struct lruhash {
 	lruhash_delkeyfunc_t delkeyfunc;
 	/** how to delete data. */
 	lruhash_deldatafunc_t deldatafunc;
+	/** how to mark a key pending deletion */
+	lruhash_markdelfunc_t markdelfunc;
 	/** user argument for user functions */
 	void* cb_arg;
 
@@ -294,6 +300,11 @@ struct lruhash_entry* lruhash_lookup(struct lruhash* table, hashvalue_t hash,
  */
 void lru_touch(struct lruhash* table, struct lruhash_entry* entry);
 
+/**
+ * Set the markdelfunction (or NULL)
+ */
+void lruhash_setmarkdel(struct lruhash* table, lruhash_markdelfunc_t md);
+
 /************************* Internal functions ************************/
 /*** these are only exposed for unit tests. ***/
 

util/storage/slabhash.c

@@ -202,3 +202,11 @@ void test_slabhash_deldata(void* data, void* ATTR_UNUSED(arg))
 {
 	deldata((struct slabhash_testdata*)data);
 }
+
+void slabhash_setmarkdel(struct slabhash* sl, lruhash_markdelfunc_t md)
+{
+	size_t i;
+	for(i=0; i<sl->size; i++) {
+		lruhash_setmarkdel(sl->array[i], md);
+	}
+}

util/storage/slabhash.h

@@ -167,6 +167,13 @@ size_t slabhash_get_mem(struct slabhash* table);
  */
 struct lruhash* slabhash_gettable(struct slabhash* table, hashvalue_t hash);
 
+/**
+ * Set markdel function
+ * @param table: slabbed hash table.
+ * @param md: markdel function ptr.
+ */
+void slabhash_setmarkdel(struct slabhash* table, lruhash_markdelfunc_t md);
+
 /* --- test representation --- */
 /** test structure contains test key */
 struct slabhash_testkey {