#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/rhashtable.h>
+#include <linux/err.h>
#define HASH_DEFAULT_SIZE 64UL
#define HASH_MIN_SIZE 4UL
return &tbl->locks[hash & tbl->locks_mask];
}
-#define ASSERT_RHT_MUTEX(HT) BUG_ON(!lockdep_rht_mutex_is_held(HT))
-#define ASSERT_BUCKET_LOCK(TBL, HASH) \
- BUG_ON(!lockdep_rht_bucket_is_held(TBL, HASH))
-
-#ifdef CONFIG_PROVE_LOCKING
-int lockdep_rht_mutex_is_held(struct rhashtable *ht)
-{
- return (debug_locks) ? lockdep_is_held(&ht->mutex) : 1;
-}
-EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held);
-
-int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash)
-{
- spinlock_t *lock = bucket_lock(tbl, hash);
-
- return (debug_locks) ? lockdep_is_held(lock) : 1;
-}
-EXPORT_SYMBOL_GPL(lockdep_rht_bucket_is_held);
-#endif
-
static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he)
{
return (void *) he - ht->p.head_offset;
return rht_bucket_index(tbl, obj_raw_hashfn(ht, rht_obj(ht, he)));
}
+#ifdef CONFIG_PROVE_LOCKING
+static void debug_dump_buckets(const struct rhashtable *ht,
+ const struct bucket_table *tbl)
+{
+ struct rhash_head *he;
+ unsigned int i, hash;
+
+ for (i = 0; i < tbl->size; i++) {
+ pr_warn(" [Bucket %d] ", i);
+ rht_for_each_rcu(he, tbl, i) {
+ hash = head_hashfn(ht, tbl, he);
+ pr_cont("[hash = %#x, lock = %p] ",
+ hash, bucket_lock(tbl, hash));
+ }
+ pr_cont("\n");
+ }
+
+}
+
+static void debug_dump_table(struct rhashtable *ht,
+ const struct bucket_table *tbl,
+ unsigned int hash)
+{
+ struct bucket_table *old_tbl, *future_tbl;
+
+ pr_emerg("BUG: lock for hash %#x in table %p not held\n",
+ hash, tbl);
+
+ rcu_read_lock();
+ future_tbl = rht_dereference_rcu(ht->future_tbl, ht);
+ old_tbl = rht_dereference_rcu(ht->tbl, ht);
+ if (future_tbl != old_tbl) {
+ pr_warn("Future table %p (size: %zd)\n",
+ future_tbl, future_tbl->size);
+ debug_dump_buckets(ht, future_tbl);
+ }
+
+ pr_warn("Table %p (size: %zd)\n", old_tbl, old_tbl->size);
+ debug_dump_buckets(ht, old_tbl);
+
+ rcu_read_unlock();
+}
+
+#define ASSERT_RHT_MUTEX(HT) BUG_ON(!lockdep_rht_mutex_is_held(HT))
+#define ASSERT_BUCKET_LOCK(HT, TBL, HASH) \
+ do { \
+ if (unlikely(!lockdep_rht_bucket_is_held(TBL, HASH))) { \
+ debug_dump_table(HT, TBL, HASH); \
+ BUG(); \
+ } \
+ } while (0)
+
+int lockdep_rht_mutex_is_held(struct rhashtable *ht)
+{
+ return (debug_locks) ? lockdep_is_held(&ht->mutex) : 1;
+}
+EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held);
+
+int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash)
+{
+ spinlock_t *lock = bucket_lock(tbl, hash);
+
+ return (debug_locks) ? lockdep_is_held(lock) : 1;
+}
+EXPORT_SYMBOL_GPL(lockdep_rht_bucket_is_held);
+#else
+#define ASSERT_RHT_MUTEX(HT)
+#define ASSERT_BUCKET_LOCK(HT, TBL, HASH)
+#endif
+
+
static struct rhash_head __rcu **bucket_tail(struct bucket_table *tbl, u32 n)
{
struct rhash_head __rcu **pprev;
*
* Returns true if no more work needs to be performed on the bucket.
*/
-static bool hashtable_chain_unzip(const struct rhashtable *ht,
+static bool hashtable_chain_unzip(struct rhashtable *ht,
const struct bucket_table *new_tbl,
struct bucket_table *old_tbl,
size_t old_hash)
struct rhash_head *he, *p, *next;
unsigned int new_hash, new_hash2;
- ASSERT_BUCKET_LOCK(old_tbl, old_hash);
+ ASSERT_BUCKET_LOCK(ht, old_tbl, old_hash);
/* Old bucket empty, no work needed. */
p = rht_dereference_bucket(old_tbl->buckets[old_hash], old_tbl,
return false;
new_hash = head_hashfn(ht, new_tbl, p);
- ASSERT_BUCKET_LOCK(new_tbl, new_hash);
+ ASSERT_BUCKET_LOCK(ht, new_tbl, new_hash);
/* Advance the old bucket pointer one or more times until it
* reaches a node that doesn't hash to the same bucket as the
*/
rht_for_each_continue(he, p->next, old_tbl, old_hash) {
new_hash2 = head_hashfn(ht, new_tbl, he);
- ASSERT_BUCKET_LOCK(new_tbl, new_hash2);
+ ASSERT_BUCKET_LOCK(ht, new_tbl, new_hash2);
if (new_hash != new_hash2)
break;
return !rht_is_a_nulls(p);
}
-static void link_old_to_new(struct bucket_table *new_tbl,
+static void link_old_to_new(struct rhashtable *ht, struct bucket_table *new_tbl,
unsigned int new_hash, struct rhash_head *entry)
{
+ ASSERT_BUCKET_LOCK(ht, new_tbl, new_hash);
+
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), entry);
}
lock_buckets(new_tbl, old_tbl, new_hash);
rht_for_each(he, old_tbl, old_hash) {
if (head_hashfn(ht, new_tbl, he) == new_hash) {
- link_old_to_new(new_tbl, new_hash, he);
+ link_old_to_new(ht, new_tbl, new_hash, he);
break;
}
}
unlock_buckets(new_tbl, old_tbl, new_hash);
}
- /* 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.
- */
- rcu_assign_pointer(ht->tbl, new_tbl);
-
/* Unzip interleaved hash chains */
while (!complete && !ht->being_destroyed) {
/* Wait for readers. All new readers will see the new
}
}
+ rcu_assign_pointer(ht->tbl, new_tbl);
synchronize_rcu();
bucket_table_free(old_tbl);
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash),
tbl->buckets[new_hash]);
+ ASSERT_BUCKET_LOCK(ht, tbl, new_hash + new_tbl->size);
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash),
tbl->buckets[new_hash + new_tbl->size]);
static void __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj,
struct bucket_table *tbl, u32 hash)
{
- struct rhash_head *head = rht_dereference_bucket(tbl->buckets[hash],
- tbl, hash);
+ struct rhash_head *head;
+
+ hash = rht_bucket_index(tbl, hash);
+ head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash);
+
+ ASSERT_BUCKET_LOCK(ht, tbl, hash);
if (rht_is_a_nulls(head))
INIT_RHT_NULLS_HEAD(obj->next, ht, hash);
tbl = rht_dereference_rcu(ht->future_tbl, ht);
old_tbl = rht_dereference_rcu(ht->tbl, ht);
- hash = head_hashfn(ht, tbl, obj);
+ hash = obj_raw_hashfn(ht, rht_obj(ht, obj));
lock_buckets(tbl, old_tbl, hash);
__rhashtable_insert(ht, obj, tbl, hash);
{
struct bucket_table *tbl, *new_tbl, *old_tbl;
struct rhash_head __rcu **pprev;
- struct rhash_head *he;
+ struct rhash_head *he, *he2;
unsigned int hash, new_hash;
bool ret = false;
rcu_read_lock();
- tbl = old_tbl = rht_dereference_rcu(ht->tbl, ht);
- new_tbl = rht_dereference_rcu(ht->future_tbl, ht);
- new_hash = head_hashfn(ht, new_tbl, obj);
+ old_tbl = rht_dereference_rcu(ht->tbl, ht);
+ tbl = new_tbl = rht_dereference_rcu(ht->future_tbl, ht);
+ new_hash = obj_raw_hashfn(ht, rht_obj(ht, obj));
lock_buckets(new_tbl, old_tbl, new_hash);
restart:
continue;
}
- rcu_assign_pointer(*pprev, obj->next);
+ ASSERT_BUCKET_LOCK(ht, tbl, hash);
+
+ if (old_tbl->size > new_tbl->size && tbl == old_tbl &&
+ !rht_is_a_nulls(obj->next) &&
+ head_hashfn(ht, tbl, obj->next) != hash) {
+ rcu_assign_pointer(*pprev, (struct rhash_head *) rht_marker(ht, hash));
+ } else if (unlikely(old_tbl->size < new_tbl->size && tbl == new_tbl)) {
+ rht_for_each_continue(he2, obj->next, tbl, hash) {
+ if (head_hashfn(ht, tbl, he2) == hash) {
+ rcu_assign_pointer(*pprev, he2);
+ goto found;
+ }
+ }
+
+ rcu_assign_pointer(*pprev, (struct rhash_head *) rht_marker(ht, hash));
+ } else {
+ rcu_assign_pointer(*pprev, obj->next);
+ }
+found:
ret = true;
break;
}
* resizing. Thus traversing both is fine and the added cost is
* very rare.
*/
- if (tbl != new_tbl) {
- tbl = new_tbl;
+ if (tbl != old_tbl) {
+ tbl = old_tbl;
goto restart;
}
rcu_read_lock();
old_tbl = rht_dereference_rcu(ht->tbl, ht);
new_tbl = rht_dereference_rcu(ht->future_tbl, ht);
- new_hash = head_hashfn(ht, new_tbl, obj);
+ new_hash = obj_raw_hashfn(ht, rht_obj(ht, obj));
lock_buckets(new_tbl, old_tbl, new_hash);
projects / firefly-linux-kernel-4.4.55.git / blobdiff