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-rw-r--r--lib/rhashtable.c98
1 files changed, 56 insertions, 42 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 081be3ba9ea8..6c3c723e902b 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -20,7 +20,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
-#include <linux/hash.h>
+#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/rhashtable.h>
@@ -32,7 +32,7 @@
#ifdef CONFIG_PROVE_LOCKING
int lockdep_rht_mutex_is_held(const struct rhashtable *ht)
{
- return ht->p.mutex_is_held();
+ return ht->p.mutex_is_held(ht->p.parent);
}
EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held);
#endif
@@ -107,13 +107,13 @@ static u32 head_hashfn(const struct rhashtable *ht,
return obj_hashfn(ht, rht_obj(ht, he), hsize);
}
-static struct bucket_table *bucket_table_alloc(size_t nbuckets, gfp_t flags)
+static struct bucket_table *bucket_table_alloc(size_t nbuckets)
{
struct bucket_table *tbl;
size_t size;
size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
- tbl = kzalloc(size, flags);
+ tbl = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (tbl == NULL)
tbl = vzalloc(size);
@@ -200,7 +200,6 @@ static void hashtable_chain_unzip(const struct rhashtable *ht,
/**
* rhashtable_expand - Expand hash table while allowing concurrent lookups
* @ht: the hash table to expand
- * @flags: allocation flags
*
* A secondary bucket array is allocated and the hash entries are migrated
* while keeping them on both lists until the end of the RCU grace period.
@@ -211,7 +210,7 @@ static void hashtable_chain_unzip(const struct rhashtable *ht,
* The caller must ensure that no concurrent table mutations take place.
* It is however valid to have concurrent lookups if they are RCU protected.
*/
-int rhashtable_expand(struct rhashtable *ht, gfp_t flags)
+int rhashtable_expand(struct rhashtable *ht)
{
struct bucket_table *new_tbl, *old_tbl = rht_dereference(ht->tbl, ht);
struct rhash_head *he;
@@ -223,14 +222,14 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags)
if (ht->p.max_shift && ht->shift >= ht->p.max_shift)
return 0;
- new_tbl = bucket_table_alloc(old_tbl->size * 2, flags);
+ new_tbl = bucket_table_alloc(old_tbl->size * 2);
if (new_tbl == NULL)
return -ENOMEM;
ht->shift++;
/* For each new bucket, search the corresponding old bucket
- * for the first entry that hashes to the new bucket, and
+ * for the first entry that hashes to the new bucket, and
* link the new bucket to that entry. Since all the entries
* which will end up in the new bucket appear in the same
* old bucket, this constructs an entirely valid new hash
@@ -248,8 +247,8 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags)
}
/* Publish the new table pointer. Lookups may now traverse
- * the new table, but they will not benefit from any
- * additional efficiency until later steps unzip the buckets.
+ * the new table, but they will not benefit from any
+ * additional efficiency until later steps unzip the buckets.
*/
rcu_assign_pointer(ht->tbl, new_tbl);
@@ -281,7 +280,6 @@ EXPORT_SYMBOL_GPL(rhashtable_expand);
/**
* rhashtable_shrink - Shrink hash table while allowing concurrent lookups
* @ht: the hash table to shrink
- * @flags: allocation flags
*
* This function may only be called in a context where it is safe to call
* synchronize_rcu(), e.g. not within a rcu_read_lock() section.
@@ -289,7 +287,7 @@ EXPORT_SYMBOL_GPL(rhashtable_expand);
* The caller must ensure that no concurrent table mutations take place.
* It is however valid to have concurrent lookups if they are RCU protected.
*/
-int rhashtable_shrink(struct rhashtable *ht, gfp_t flags)
+int rhashtable_shrink(struct rhashtable *ht)
{
struct bucket_table *ntbl, *tbl = rht_dereference(ht->tbl, ht);
struct rhash_head __rcu **pprev;
@@ -300,20 +298,20 @@ int rhashtable_shrink(struct rhashtable *ht, gfp_t flags)
if (ht->shift <= ht->p.min_shift)
return 0;
- ntbl = bucket_table_alloc(tbl->size / 2, flags);
+ ntbl = bucket_table_alloc(tbl->size / 2);
if (ntbl == NULL)
return -ENOMEM;
ht->shift--;
- /* Link each bucket in the new table to the first bucket
+ /* Link each bucket in the new table to the first bucket
* in the old table that contains entries which will hash
* to the new bucket.
*/
for (i = 0; i < ntbl->size; i++) {
ntbl->buckets[i] = tbl->buckets[i];
- /* Link each bucket in the new table to the first bucket
+ /* Link each bucket in the new table to the first bucket
* in the old table that contains entries which will hash
* to the new bucket.
*/
@@ -341,7 +339,6 @@ EXPORT_SYMBOL_GPL(rhashtable_shrink);
* rhashtable_insert - insert object into hash hash table
* @ht: hash table
* @obj: pointer to hash head inside object
- * @flags: allocation flags (table expansion)
*
* Will automatically grow the table via rhashtable_expand() if the the
* grow_decision function specified at rhashtable_init() returns true.
@@ -349,8 +346,7 @@ EXPORT_SYMBOL_GPL(rhashtable_shrink);
* The caller must ensure that no concurrent table mutations occur. It is
* however valid to have concurrent lookups if they are RCU protected.
*/
-void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj,
- gfp_t flags)
+void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj)
{
struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
u32 hash;
@@ -363,7 +359,7 @@ void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj,
ht->nelems++;
if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size))
- rhashtable_expand(ht, flags);
+ rhashtable_expand(ht);
}
EXPORT_SYMBOL_GPL(rhashtable_insert);
@@ -372,14 +368,13 @@ EXPORT_SYMBOL_GPL(rhashtable_insert);
* @ht: hash table
* @obj: pointer to hash head inside object
* @pprev: pointer to previous element
- * @flags: allocation flags (table expansion)
*
* Identical to rhashtable_remove() but caller is alreayd aware of the element
* in front of the element to be deleted. This is in particular useful for
* deletion when combined with walking or lookup.
*/
void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj,
- struct rhash_head __rcu **pprev, gfp_t flags)
+ struct rhash_head __rcu **pprev)
{
struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
@@ -390,7 +385,7 @@ void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj,
if (ht->p.shrink_decision &&
ht->p.shrink_decision(ht, tbl->size))
- rhashtable_shrink(ht, flags);
+ rhashtable_shrink(ht);
}
EXPORT_SYMBOL_GPL(rhashtable_remove_pprev);
@@ -398,7 +393,6 @@ EXPORT_SYMBOL_GPL(rhashtable_remove_pprev);
* rhashtable_remove - remove object from hash table
* @ht: hash table
* @obj: pointer to hash head inside object
- * @flags: allocation flags (table expansion)
*
* Since the hash chain is single linked, the removal operation needs to
* walk the bucket chain upon removal. The removal operation is thus
@@ -410,8 +404,7 @@ EXPORT_SYMBOL_GPL(rhashtable_remove_pprev);
* The caller must ensure that no concurrent table mutations occur. It is
* however valid to have concurrent lookups if they are RCU protected.
*/
-bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj,
- gfp_t flags)
+bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj)
{
struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
struct rhash_head __rcu **pprev;
@@ -429,7 +422,7 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj,
continue;
}
- rhashtable_remove_pprev(ht, he, pprev, flags);
+ rhashtable_remove_pprev(ht, he, pprev);
return true;
}
@@ -531,8 +524,10 @@ static size_t rounded_hashtable_size(struct rhashtable_params *params)
* .head_offset = offsetof(struct test_obj, node),
* .key_offset = offsetof(struct test_obj, key),
* .key_len = sizeof(int),
- * .hashfn = arch_fast_hash,
+ * .hashfn = jhash,
+ * #ifdef CONFIG_PROVE_LOCKING
* .mutex_is_held = &my_mutex_is_held,
+ * #endif
* };
*
* Configuration Example 2: Variable length keys
@@ -550,9 +545,11 @@ static size_t rounded_hashtable_size(struct rhashtable_params *params)
*
* struct rhashtable_params params = {
* .head_offset = offsetof(struct test_obj, node),
- * .hashfn = arch_fast_hash,
+ * .hashfn = jhash,
* .obj_hashfn = my_hash_fn,
+ * #ifdef CONFIG_PROVE_LOCKING
* .mutex_is_held = &my_mutex_is_held,
+ * #endif
* };
*/
int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
@@ -572,7 +569,7 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
if (params->nelem_hint)
size = rounded_hashtable_size(params);
- tbl = bucket_table_alloc(size, GFP_KERNEL);
+ tbl = bucket_table_alloc(size);
if (tbl == NULL)
return -ENOMEM;
@@ -613,10 +610,12 @@ EXPORT_SYMBOL_GPL(rhashtable_destroy);
#define TEST_PTR ((void *) 0xdeadbeef)
#define TEST_NEXPANDS 4
-static int test_mutex_is_held(void)
+#ifdef CONFIG_PROVE_LOCKING
+static int test_mutex_is_held(void *parent)
{
return 1;
}
+#endif
struct test_obj {
void *ptr;
@@ -654,15 +653,15 @@ static int __init test_rht_lookup(struct rhashtable *ht)
return 0;
}
-static void test_bucket_stats(struct rhashtable *ht,
- struct bucket_table *tbl,
- bool quiet)
+static void test_bucket_stats(struct rhashtable *ht, bool quiet)
{
- unsigned int cnt, i, total = 0;
+ unsigned int cnt, rcu_cnt, i, total = 0;
struct test_obj *obj;
+ struct bucket_table *tbl;
+ tbl = rht_dereference_rcu(ht->tbl, ht);
for (i = 0; i < tbl->size; i++) {
- cnt = 0;
+ rcu_cnt = cnt = 0;
if (!quiet)
pr_info(" [%#4x/%zu]", i, tbl->size);
@@ -674,6 +673,13 @@ static void test_bucket_stats(struct rhashtable *ht,
pr_cont(" [%p],", obj);
}
+ rht_for_each_entry_rcu(obj, tbl->buckets[i], node)
+ rcu_cnt++;
+
+ if (rcu_cnt != cnt)
+ pr_warn("Test failed: Chain count mismach %d != %d",
+ cnt, rcu_cnt);
+
if (!quiet)
pr_cont("\n [%#x] first element: %p, chain length: %u\n",
i, tbl->buckets[i], cnt);
@@ -681,6 +687,9 @@ static void test_bucket_stats(struct rhashtable *ht,
pr_info(" Traversal complete: counted=%u, nelems=%zu, entries=%d\n",
total, ht->nelems, TEST_ENTRIES);
+
+ if (total != ht->nelems || total != TEST_ENTRIES)
+ pr_warn("Test failed: Total count mismatch ^^^");
}
static int __init test_rhashtable(struct rhashtable *ht)
@@ -707,18 +716,17 @@ static int __init test_rhashtable(struct rhashtable *ht)
obj->ptr = TEST_PTR;
obj->value = i * 2;
- rhashtable_insert(ht, &obj->node, GFP_KERNEL);
+ rhashtable_insert(ht, &obj->node);
}
rcu_read_lock();
- tbl = rht_dereference_rcu(ht->tbl, ht);
- test_bucket_stats(ht, tbl, true);
+ test_bucket_stats(ht, true);
test_rht_lookup(ht);
rcu_read_unlock();
for (i = 0; i < TEST_NEXPANDS; i++) {
pr_info(" Table expansion iteration %u...\n", i);
- rhashtable_expand(ht, GFP_KERNEL);
+ rhashtable_expand(ht);
rcu_read_lock();
pr_info(" Verifying lookups...\n");
@@ -728,7 +736,7 @@ static int __init test_rhashtable(struct rhashtable *ht)
for (i = 0; i < TEST_NEXPANDS; i++) {
pr_info(" Table shrinkage iteration %u...\n", i);
- rhashtable_shrink(ht, GFP_KERNEL);
+ rhashtable_shrink(ht);
rcu_read_lock();
pr_info(" Verifying lookups...\n");
@@ -736,6 +744,10 @@ static int __init test_rhashtable(struct rhashtable *ht)
rcu_read_unlock();
}
+ rcu_read_lock();
+ test_bucket_stats(ht, true);
+ rcu_read_unlock();
+
pr_info(" Deleting %d keys\n", TEST_ENTRIES);
for (i = 0; i < TEST_ENTRIES; i++) {
u32 key = i * 2;
@@ -743,7 +755,7 @@ static int __init test_rhashtable(struct rhashtable *ht)
obj = rhashtable_lookup(ht, &key);
BUG_ON(!obj);
- rhashtable_remove(ht, &obj->node, GFP_KERNEL);
+ rhashtable_remove(ht, &obj->node);
kfree(obj);
}
@@ -766,8 +778,10 @@ static int __init test_rht_init(void)
.head_offset = offsetof(struct test_obj, node),
.key_offset = offsetof(struct test_obj, value),
.key_len = sizeof(int),
- .hashfn = arch_fast_hash,
+ .hashfn = jhash,
+#ifdef CONFIG_PROVE_LOCKING
.mutex_is_held = &test_mutex_is_held,
+#endif
.grow_decision = rht_grow_above_75,
.shrink_decision = rht_shrink_below_30,
};