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-rw-r--r--lib/rhashtable.c85
1 files changed, 36 insertions, 49 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 9427b5766134..ae4223e0f5bc 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -28,6 +28,7 @@
#include <linux/rhashtable.h>
#include <linux/err.h>
#include <linux/export.h>
+#include <linux/rhashtable.h>
#define HASH_DEFAULT_SIZE 64UL
#define HASH_MIN_SIZE 4U
@@ -115,8 +116,7 @@ static void bucket_table_free_rcu(struct rcu_head *head)
static union nested_table *nested_table_alloc(struct rhashtable *ht,
union nested_table __rcu **prev,
- unsigned int shifted,
- unsigned int nhash)
+ bool leaf)
{
union nested_table *ntbl;
int i;
@@ -127,10 +127,9 @@ static union nested_table *nested_table_alloc(struct rhashtable *ht,
ntbl = kzalloc(PAGE_SIZE, GFP_ATOMIC);
- if (ntbl && shifted) {
- for (i = 0; i < PAGE_SIZE / sizeof(ntbl[0].bucket); i++)
- INIT_RHT_NULLS_HEAD(ntbl[i].bucket, ht,
- (i << shifted) | nhash);
+ if (ntbl && leaf) {
+ for (i = 0; i < PAGE_SIZE / sizeof(ntbl[0]); i++)
+ INIT_RHT_NULLS_HEAD(ntbl[i].bucket);
}
rcu_assign_pointer(*prev, ntbl);
@@ -156,7 +155,7 @@ static struct bucket_table *nested_bucket_table_alloc(struct rhashtable *ht,
return NULL;
if (!nested_table_alloc(ht, (union nested_table __rcu **)tbl->buckets,
- 0, 0)) {
+ false)) {
kfree(tbl);
return NULL;
}
@@ -206,7 +205,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
tbl->hash_rnd = get_random_u32();
for (i = 0; i < nbuckets; i++)
- INIT_RHT_NULLS_HEAD(tbl->buckets[i], ht, i);
+ INIT_RHT_NULLS_HEAD(tbl->buckets[i]);
return tbl;
}
@@ -227,8 +226,7 @@ static struct bucket_table *rhashtable_last_table(struct rhashtable *ht,
static int rhashtable_rehash_one(struct rhashtable *ht, unsigned int old_hash)
{
struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht);
- struct bucket_table *new_tbl = rhashtable_last_table(ht,
- rht_dereference_rcu(old_tbl->future_tbl, ht));
+ struct bucket_table *new_tbl = rhashtable_last_table(ht, old_tbl);
struct rhash_head __rcu **pprev = rht_bucket_var(old_tbl, old_hash);
int err = -EAGAIN;
struct rhash_head *head, *next, *entry;
@@ -298,21 +296,14 @@ static int rhashtable_rehash_attach(struct rhashtable *ht,
struct bucket_table *old_tbl,
struct bucket_table *new_tbl)
{
- /* Protect future_tbl using the first bucket lock. */
- spin_lock_bh(old_tbl->locks);
-
- /* Did somebody beat us to it? */
- if (rcu_access_pointer(old_tbl->future_tbl)) {
- spin_unlock_bh(old_tbl->locks);
- return -EEXIST;
- }
-
/* Make insertions go into the new, empty table right away. Deletions
* and lookups will be attempted in both tables until we synchronize.
+ * As cmpxchg() provides strong barriers, we do not need
+ * rcu_assign_pointer().
*/
- rcu_assign_pointer(old_tbl->future_tbl, new_tbl);
- spin_unlock_bh(old_tbl->locks);
+ if (cmpxchg(&old_tbl->future_tbl, NULL, new_tbl) != NULL)
+ return -EEXIST;
return 0;
}
@@ -475,7 +466,7 @@ static int rhashtable_insert_rehash(struct rhashtable *ht,
fail:
/* Do not fail the insert if someone else did a rehash. */
- if (likely(rcu_dereference_raw(tbl->future_tbl)))
+ if (likely(rcu_access_pointer(tbl->future_tbl)))
return 0;
/* Schedule async rehash to retry allocation in process context. */
@@ -548,7 +539,7 @@ static struct bucket_table *rhashtable_insert_one(struct rhashtable *ht,
if (PTR_ERR(data) != -EAGAIN && PTR_ERR(data) != -ENOENT)
return ERR_CAST(data);
- new_tbl = rcu_dereference(tbl->future_tbl);
+ new_tbl = rht_dereference_rcu(tbl->future_tbl, ht);
if (new_tbl)
return new_tbl;
@@ -607,7 +598,7 @@ static void *rhashtable_try_insert(struct rhashtable *ht, const void *key,
break;
spin_unlock_bh(lock);
- tbl = rcu_dereference(tbl->future_tbl);
+ tbl = rht_dereference_rcu(tbl->future_tbl, ht);
}
data = rhashtable_lookup_one(ht, tbl, hash, key, obj);
@@ -774,7 +765,7 @@ int rhashtable_walk_start_check(struct rhashtable_iter *iter)
skip++;
if (list == iter->list) {
iter->p = p;
- skip = skip;
+ iter->skip = skip;
goto found;
}
}
@@ -964,8 +955,16 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_stop);
static size_t rounded_hashtable_size(const struct rhashtable_params *params)
{
- return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
- (unsigned long)params->min_size);
+ size_t retsize;
+
+ if (params->nelem_hint)
+ retsize = max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
+ (unsigned long)params->min_size);
+ else
+ retsize = max(HASH_DEFAULT_SIZE,
+ (unsigned long)params->min_size);
+
+ return retsize;
}
static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed)
@@ -994,7 +993,6 @@ static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed)
* .key_offset = offsetof(struct test_obj, key),
* .key_len = sizeof(int),
* .hashfn = jhash,
- * .nulls_base = (1U << RHT_BASE_SHIFT),
* };
*
* Configuration Example 2: Variable length keys
@@ -1022,15 +1020,10 @@ int rhashtable_init(struct rhashtable *ht,
struct bucket_table *tbl;
size_t size;
- size = HASH_DEFAULT_SIZE;
-
if ((!params->key_len && !params->obj_hashfn) ||
(params->obj_hashfn && !params->obj_cmpfn))
return -EINVAL;
- if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT))
- return -EINVAL;
-
memset(ht, 0, sizeof(*ht));
mutex_init(&ht->mutex);
spin_lock_init(&ht->lock);
@@ -1050,8 +1043,7 @@ int rhashtable_init(struct rhashtable *ht,
ht->p.min_size = max_t(u16, ht->p.min_size, HASH_MIN_SIZE);
- if (params->nelem_hint)
- size = rounded_hashtable_size(&ht->p);
+ size = rounded_hashtable_size(&ht->p);
if (params->locks_mul)
ht->p.locks_mul = roundup_pow_of_two(params->locks_mul);
@@ -1095,10 +1087,6 @@ int rhltable_init(struct rhltable *hlt, const struct rhashtable_params *params)
{
int err;
- /* No rhlist NULLs marking for now. */
- if (params->nulls_base)
- return -EINVAL;
-
err = rhashtable_init(&hlt->ht, params);
hlt->ht.rhlist = true;
return err;
@@ -1143,13 +1131,14 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
void (*free_fn)(void *ptr, void *arg),
void *arg)
{
- struct bucket_table *tbl;
+ struct bucket_table *tbl, *next_tbl;
unsigned int i;
cancel_work_sync(&ht->run_work);
mutex_lock(&ht->mutex);
tbl = rht_dereference(ht->tbl, ht);
+restart:
if (free_fn) {
for (i = 0; i < tbl->size; i++) {
struct rhash_head *pos, *next;
@@ -1166,7 +1155,12 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
}
}
+ next_tbl = rht_dereference(tbl->future_tbl, ht);
bucket_table_free(tbl);
+ if (next_tbl) {
+ tbl = next_tbl;
+ goto restart;
+ }
mutex_unlock(&ht->mutex);
}
EXPORT_SYMBOL_GPL(rhashtable_free_and_destroy);
@@ -1216,25 +1210,18 @@ struct rhash_head __rcu **rht_bucket_nested_insert(struct rhashtable *ht,
unsigned int index = hash & ((1 << tbl->nest) - 1);
unsigned int size = tbl->size >> tbl->nest;
union nested_table *ntbl;
- unsigned int shifted;
- unsigned int nhash;
ntbl = (union nested_table *)rcu_dereference_raw(tbl->buckets[0]);
hash >>= tbl->nest;
- nhash = index;
- shifted = tbl->nest;
ntbl = nested_table_alloc(ht, &ntbl[index].table,
- size <= (1 << shift) ? shifted : 0, nhash);
+ size <= (1 << shift));
while (ntbl && size > (1 << shift)) {
index = hash & ((1 << shift) - 1);
size >>= shift;
hash >>= shift;
- nhash |= index << shifted;
- shifted += shift;
ntbl = nested_table_alloc(ht, &ntbl[index].table,
- size <= (1 << shift) ? shifted : 0,
- nhash);
+ size <= (1 << shift));
}
if (!ntbl)
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-09 22:24:55 +0300