2014-08-02 03:47:44 -06:00
|
|
|
/*
|
|
|
|
* Resizable, Scalable, Concurrent Hash Table
|
|
|
|
*
|
2016-09-19 05:00:09 -06:00
|
|
|
* Copyright (c) 2015-2016 Herbert Xu <herbert@gondor.apana.org.au>
|
2015-03-24 14:42:19 -06:00
|
|
|
* Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
|
2014-08-02 03:47:44 -06:00
|
|
|
* Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
|
|
|
|
*
|
|
|
|
* Code partially derived from nft_hash
|
2015-03-20 04:57:06 -06:00
|
|
|
* Rewritten with rehash code from br_multicast plus single list
|
|
|
|
* pointer as suggested by Josh Triplett
|
2014-08-02 03:47:44 -06:00
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
|
|
* published by the Free Software Foundation.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#ifndef _LINUX_RHASHTABLE_H
|
|
|
|
#define _LINUX_RHASHTABLE_H
|
|
|
|
|
2015-05-14 21:30:47 -06:00
|
|
|
#include <linux/atomic.h>
|
2015-02-03 13:33:23 -07:00
|
|
|
#include <linux/compiler.h>
|
2015-12-03 05:41:29 -07:00
|
|
|
#include <linux/err.h>
|
2015-03-20 16:18:45 -06:00
|
|
|
#include <linux/errno.h>
|
2015-03-23 07:50:21 -06:00
|
|
|
#include <linux/jhash.h>
|
2015-01-02 15:00:21 -07:00
|
|
|
#include <linux/list_nulls.h>
|
2015-01-02 15:00:20 -07:00
|
|
|
#include <linux/workqueue.h>
|
2015-01-04 00:25:09 -07:00
|
|
|
#include <linux/mutex.h>
|
2015-03-20 04:57:00 -06:00
|
|
|
#include <linux/rcupdate.h>
|
2014-08-02 03:47:44 -06:00
|
|
|
|
2015-01-02 15:00:21 -07:00
|
|
|
/*
|
|
|
|
* The end of the chain is marked with a special nulls marks which has
|
|
|
|
* the following format:
|
|
|
|
*
|
|
|
|
* +-------+-----------------------------------------------------+-+
|
|
|
|
* | Base | Hash |1|
|
|
|
|
* +-------+-----------------------------------------------------+-+
|
|
|
|
*
|
|
|
|
* Base (4 bits) : Reserved to distinguish between multiple tables.
|
|
|
|
* Specified via &struct rhashtable_params.nulls_base.
|
|
|
|
* Hash (27 bits): Full hash (unmasked) of first element added to bucket
|
|
|
|
* 1 (1 bit) : Nulls marker (always set)
|
|
|
|
*
|
|
|
|
* The remaining bits of the next pointer remain unused for now.
|
|
|
|
*/
|
|
|
|
#define RHT_BASE_BITS 4
|
|
|
|
#define RHT_HASH_BITS 27
|
|
|
|
#define RHT_BASE_SHIFT RHT_HASH_BITS
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
/* Base bits plus 1 bit for nulls marker */
|
|
|
|
#define RHT_HASH_RESERVED_SPACE (RHT_BASE_BITS + 1)
|
|
|
|
|
2014-08-02 03:47:44 -06:00
|
|
|
struct rhash_head {
|
2014-08-13 08:38:29 -06:00
|
|
|
struct rhash_head __rcu *next;
|
2014-08-02 03:47:44 -06:00
|
|
|
};
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhlist_head {
|
|
|
|
struct rhash_head rhead;
|
|
|
|
struct rhlist_head __rcu *next;
|
|
|
|
};
|
|
|
|
|
2015-01-02 15:00:20 -07:00
|
|
|
/**
|
|
|
|
* struct bucket_table - Table of hash buckets
|
|
|
|
* @size: Number of hash buckets
|
2015-03-13 20:57:24 -06:00
|
|
|
* @rehash: Current bucket being rehashed
|
2015-03-09 16:27:55 -06:00
|
|
|
* @hash_rnd: Random seed to fold into hash
|
2015-01-02 15:00:20 -07:00
|
|
|
* @locks_mask: Mask to apply before accessing locks[]
|
|
|
|
* @locks: Array of spinlocks protecting individual buckets
|
2015-03-13 20:57:20 -06:00
|
|
|
* @walkers: List of active walkers
|
2015-03-13 20:57:23 -06:00
|
|
|
* @rcu: RCU structure for freeing the table
|
2015-03-13 20:57:25 -06:00
|
|
|
* @future_tbl: Table under construction during rehashing
|
2015-01-02 15:00:20 -07:00
|
|
|
* @buckets: size * hash buckets
|
|
|
|
*/
|
2014-08-02 03:47:44 -06:00
|
|
|
struct bucket_table {
|
2015-03-13 20:57:24 -06:00
|
|
|
unsigned int size;
|
|
|
|
unsigned int rehash;
|
2015-03-09 16:27:55 -06:00
|
|
|
u32 hash_rnd;
|
2015-02-20 07:48:57 -07:00
|
|
|
unsigned int locks_mask;
|
|
|
|
spinlock_t *locks;
|
2015-03-13 20:57:20 -06:00
|
|
|
struct list_head walkers;
|
2015-03-13 20:57:23 -06:00
|
|
|
struct rcu_head rcu;
|
2015-02-20 07:48:57 -07:00
|
|
|
|
2015-03-13 20:57:25 -06:00
|
|
|
struct bucket_table __rcu *future_tbl;
|
|
|
|
|
2015-02-20 07:48:57 -07:00
|
|
|
struct rhash_head __rcu *buckets[] ____cacheline_aligned_in_smp;
|
2014-08-02 03:47:44 -06:00
|
|
|
};
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
/**
|
|
|
|
* struct rhashtable_compare_arg - Key for the function rhashtable_compare
|
|
|
|
* @ht: Hash table
|
|
|
|
* @key: Key to compare against
|
|
|
|
*/
|
|
|
|
struct rhashtable_compare_arg {
|
|
|
|
struct rhashtable *ht;
|
|
|
|
const void *key;
|
|
|
|
};
|
|
|
|
|
2014-08-02 03:47:44 -06:00
|
|
|
typedef u32 (*rht_hashfn_t)(const void *data, u32 len, u32 seed);
|
2015-03-25 07:07:45 -06:00
|
|
|
typedef u32 (*rht_obj_hashfn_t)(const void *data, u32 len, u32 seed);
|
2015-03-20 04:57:00 -06:00
|
|
|
typedef int (*rht_obj_cmpfn_t)(struct rhashtable_compare_arg *arg,
|
|
|
|
const void *obj);
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
struct rhashtable;
|
|
|
|
|
|
|
|
/**
|
|
|
|
* struct rhashtable_params - Hash table construction parameters
|
|
|
|
* @nelem_hint: Hint on number of elements, should be 75% of desired size
|
|
|
|
* @key_len: Length of key
|
|
|
|
* @key_offset: Offset of key in struct to be hashed
|
|
|
|
* @head_offset: Offset of rhash_head in struct to be hashed
|
2015-05-14 21:30:47 -06:00
|
|
|
* @insecure_max_entries: Maximum number of entries (may be exceeded)
|
2015-03-18 03:01:16 -06:00
|
|
|
* @max_size: Maximum size while expanding
|
|
|
|
* @min_size: Minimum size while shrinking
|
2015-01-02 15:00:21 -07:00
|
|
|
* @nulls_base: Base value to generate nulls marker
|
2015-03-23 07:50:28 -06:00
|
|
|
* @insecure_elasticity: Set to true to disable chain length checks
|
2015-03-24 14:42:19 -06:00
|
|
|
* @automatic_shrinking: Enable automatic shrinking of tables
|
2015-01-02 15:00:20 -07:00
|
|
|
* @locks_mul: Number of bucket locks to allocate per cpu (default: 128)
|
2015-03-23 07:50:21 -06:00
|
|
|
* @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)
|
2014-08-02 03:47:44 -06:00
|
|
|
* @obj_hashfn: Function to hash object
|
2015-03-20 04:57:00 -06:00
|
|
|
* @obj_cmpfn: Function to compare key with object
|
2014-08-02 03:47:44 -06:00
|
|
|
*/
|
|
|
|
struct rhashtable_params {
|
|
|
|
size_t nelem_hint;
|
|
|
|
size_t key_len;
|
|
|
|
size_t key_offset;
|
|
|
|
size_t head_offset;
|
2015-05-14 21:30:47 -06:00
|
|
|
unsigned int insecure_max_entries;
|
2015-03-18 03:01:16 -06:00
|
|
|
unsigned int max_size;
|
|
|
|
unsigned int min_size;
|
2015-01-02 15:00:21 -07:00
|
|
|
u32 nulls_base;
|
2015-03-23 07:50:28 -06:00
|
|
|
bool insecure_elasticity;
|
2015-03-24 14:42:19 -06:00
|
|
|
bool automatic_shrinking;
|
2015-01-02 15:00:20 -07:00
|
|
|
size_t locks_mul;
|
2014-08-02 03:47:44 -06:00
|
|
|
rht_hashfn_t hashfn;
|
|
|
|
rht_obj_hashfn_t obj_hashfn;
|
2015-03-20 04:57:00 -06:00
|
|
|
rht_obj_cmpfn_t obj_cmpfn;
|
2014-08-02 03:47:44 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
|
|
* struct rhashtable - Hash table handle
|
|
|
|
* @tbl: Bucket table
|
|
|
|
* @nelems: Number of elements in table
|
2015-03-23 07:50:21 -06:00
|
|
|
* @key_len: Key length for hashfn
|
2015-03-23 07:50:28 -06:00
|
|
|
* @elasticity: Maximum chain length before rehash
|
2014-08-02 03:47:44 -06:00
|
|
|
* @p: Configuration parameters
|
2016-09-19 05:00:09 -06:00
|
|
|
* @rhlist: True if this is an rhltable
|
2015-01-02 15:00:20 -07:00
|
|
|
* @run_work: Deferred worker to expand/shrink asynchronously
|
|
|
|
* @mutex: Mutex to protect current/future table swapping
|
2015-03-23 16:53:17 -06:00
|
|
|
* @lock: Spin lock to protect walker list
|
2014-08-02 03:47:44 -06:00
|
|
|
*/
|
|
|
|
struct rhashtable {
|
|
|
|
struct bucket_table __rcu *tbl;
|
2015-01-02 15:00:20 -07:00
|
|
|
atomic_t nelems;
|
2015-03-23 07:50:21 -06:00
|
|
|
unsigned int key_len;
|
2015-03-23 07:50:28 -06:00
|
|
|
unsigned int elasticity;
|
2014-08-02 03:47:44 -06:00
|
|
|
struct rhashtable_params p;
|
2016-09-19 05:00:09 -06:00
|
|
|
bool rhlist;
|
rhashtable: Fix race in rhashtable_destroy() and use regular work_struct
When we put our declared work task in the global workqueue with
schedule_delayed_work(), its delay parameter is always zero.
Therefore, we should define a regular work in rhashtable structure
instead of a delayed work.
By the way, we add a condition to check whether resizing functions
are NULL before cancelling the work, avoiding to cancel an
uninitialized work.
Lastly, while we wait for all work items we submitted before to run
to completion with cancel_delayed_work(), ht->mutex has been taken in
rhashtable_destroy(). Moreover, cancel_delayed_work() doesn't return
until all work items are accomplished, and when work items are
scheduled, the work's function - rht_deferred_worker() will be called.
However, as rht_deferred_worker() also needs to acquire the lock,
deadlock might happen at the moment as the lock is already held before.
So if the cancel work function is moved out of the lock covered scope,
this will avoid the deadlock.
Fixes: 97defe1 ("rhashtable: Per bucket locks & deferred expansion/shrinking")
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-15 20:13:09 -07:00
|
|
|
struct work_struct run_work;
|
2015-01-02 15:00:20 -07:00
|
|
|
struct mutex mutex;
|
2015-03-23 16:53:17 -06:00
|
|
|
spinlock_t lock;
|
2014-08-02 03:47:44 -06:00
|
|
|
};
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* struct rhltable - Hash table with duplicate objects in a list
|
|
|
|
* @ht: Underlying rhtable
|
|
|
|
*/
|
|
|
|
struct rhltable {
|
|
|
|
struct rhashtable ht;
|
|
|
|
};
|
|
|
|
|
2015-02-03 13:33:23 -07:00
|
|
|
/**
|
|
|
|
* struct rhashtable_walker - Hash table walker
|
|
|
|
* @list: List entry on list of walkers
|
2015-03-13 20:57:20 -06:00
|
|
|
* @tbl: The table that we were walking over
|
2015-02-03 13:33:23 -07:00
|
|
|
*/
|
|
|
|
struct rhashtable_walker {
|
|
|
|
struct list_head list;
|
2015-03-13 20:57:20 -06:00
|
|
|
struct bucket_table *tbl;
|
2015-02-03 13:33:23 -07:00
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
2016-09-19 05:00:09 -06:00
|
|
|
* struct rhashtable_iter - Hash table iterator
|
2015-02-03 13:33:23 -07:00
|
|
|
* @ht: Table to iterate through
|
|
|
|
* @p: Current pointer
|
2016-09-19 05:00:09 -06:00
|
|
|
* @list: Current hash list pointer
|
2015-02-03 13:33:23 -07:00
|
|
|
* @walker: Associated rhashtable walker
|
|
|
|
* @slot: Current slot
|
|
|
|
* @skip: Number of entries to skip in slot
|
|
|
|
*/
|
|
|
|
struct rhashtable_iter {
|
|
|
|
struct rhashtable *ht;
|
|
|
|
struct rhash_head *p;
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhlist_head *list;
|
2016-08-18 02:50:56 -06:00
|
|
|
struct rhashtable_walker walker;
|
2015-02-03 13:33:23 -07:00
|
|
|
unsigned int slot;
|
|
|
|
unsigned int skip;
|
|
|
|
};
|
|
|
|
|
2015-01-02 15:00:21 -07:00
|
|
|
static inline unsigned long rht_marker(const struct rhashtable *ht, u32 hash)
|
|
|
|
{
|
|
|
|
return NULLS_MARKER(ht->p.nulls_base + hash);
|
|
|
|
}
|
|
|
|
|
|
|
|
#define INIT_RHT_NULLS_HEAD(ptr, ht, hash) \
|
|
|
|
((ptr) = (typeof(ptr)) rht_marker(ht, hash))
|
|
|
|
|
|
|
|
static inline bool rht_is_a_nulls(const struct rhash_head *ptr)
|
|
|
|
{
|
|
|
|
return ((unsigned long) ptr & 1);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr)
|
|
|
|
{
|
|
|
|
return ((unsigned long) ptr) >> 1;
|
|
|
|
}
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
static inline void *rht_obj(const struct rhashtable *ht,
|
|
|
|
const struct rhash_head *he)
|
|
|
|
{
|
|
|
|
return (char *)he - ht->p.head_offset;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline unsigned int rht_bucket_index(const struct bucket_table *tbl,
|
|
|
|
unsigned int hash)
|
|
|
|
{
|
|
|
|
return (hash >> RHT_HASH_RESERVED_SPACE) & (tbl->size - 1);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline unsigned int rht_key_hashfn(
|
|
|
|
struct rhashtable *ht, const struct bucket_table *tbl,
|
|
|
|
const void *key, const struct rhashtable_params params)
|
|
|
|
{
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int hash;
|
2015-03-23 07:50:20 -06:00
|
|
|
|
2015-03-23 07:50:21 -06:00
|
|
|
/* params must be equal to ht->p if it isn't constant. */
|
|
|
|
if (!__builtin_constant_p(params.key_len))
|
|
|
|
hash = ht->p.hashfn(key, ht->key_len, tbl->hash_rnd);
|
|
|
|
else if (params.key_len) {
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int key_len = params.key_len;
|
2015-03-23 07:50:21 -06:00
|
|
|
|
|
|
|
if (params.hashfn)
|
|
|
|
hash = params.hashfn(key, key_len, tbl->hash_rnd);
|
|
|
|
else if (key_len & (sizeof(u32) - 1))
|
|
|
|
hash = jhash(key, key_len, tbl->hash_rnd);
|
|
|
|
else
|
|
|
|
hash = jhash2(key, key_len / sizeof(u32),
|
|
|
|
tbl->hash_rnd);
|
|
|
|
} else {
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int key_len = ht->p.key_len;
|
2015-03-23 07:50:21 -06:00
|
|
|
|
|
|
|
if (params.hashfn)
|
|
|
|
hash = params.hashfn(key, key_len, tbl->hash_rnd);
|
|
|
|
else
|
|
|
|
hash = jhash(key, key_len, tbl->hash_rnd);
|
|
|
|
}
|
|
|
|
|
|
|
|
return rht_bucket_index(tbl, hash);
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline unsigned int rht_head_hashfn(
|
|
|
|
struct rhashtable *ht, const struct bucket_table *tbl,
|
|
|
|
const struct rhash_head *he, const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
const char *ptr = rht_obj(ht, he);
|
|
|
|
|
|
|
|
return likely(params.obj_hashfn) ?
|
2015-03-25 07:07:45 -06:00
|
|
|
rht_bucket_index(tbl, params.obj_hashfn(ptr, params.key_len ?:
|
|
|
|
ht->p.key_len,
|
|
|
|
tbl->hash_rnd)) :
|
2015-03-20 04:57:00 -06:00
|
|
|
rht_key_hashfn(ht, tbl, ptr + params.key_offset, params);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_grow_above_75 - returns true if nelems > 0.75 * table-size
|
|
|
|
* @ht: hash table
|
|
|
|
* @tbl: current table
|
|
|
|
*/
|
|
|
|
static inline bool rht_grow_above_75(const struct rhashtable *ht,
|
|
|
|
const struct bucket_table *tbl)
|
|
|
|
{
|
|
|
|
/* Expand table when exceeding 75% load */
|
|
|
|
return atomic_read(&ht->nelems) > (tbl->size / 4 * 3) &&
|
|
|
|
(!ht->p.max_size || tbl->size < ht->p.max_size);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_shrink_below_30 - returns true if nelems < 0.3 * table-size
|
|
|
|
* @ht: hash table
|
|
|
|
* @tbl: current table
|
|
|
|
*/
|
|
|
|
static inline bool rht_shrink_below_30(const struct rhashtable *ht,
|
|
|
|
const struct bucket_table *tbl)
|
|
|
|
{
|
|
|
|
/* Shrink table beneath 30% load */
|
|
|
|
return atomic_read(&ht->nelems) < (tbl->size * 3 / 10) &&
|
|
|
|
tbl->size > ht->p.min_size;
|
|
|
|
}
|
|
|
|
|
2015-03-23 07:50:28 -06:00
|
|
|
/**
|
|
|
|
* rht_grow_above_100 - returns true if nelems > table-size
|
|
|
|
* @ht: hash table
|
|
|
|
* @tbl: current table
|
|
|
|
*/
|
|
|
|
static inline bool rht_grow_above_100(const struct rhashtable *ht,
|
|
|
|
const struct bucket_table *tbl)
|
|
|
|
{
|
2015-04-23 08:38:43 -06:00
|
|
|
return atomic_read(&ht->nelems) > tbl->size &&
|
|
|
|
(!ht->p.max_size || tbl->size < ht->p.max_size);
|
2015-03-23 07:50:28 -06:00
|
|
|
}
|
|
|
|
|
2015-05-14 21:30:47 -06:00
|
|
|
/**
|
|
|
|
* rht_grow_above_max - returns true if table is above maximum
|
|
|
|
* @ht: hash table
|
|
|
|
* @tbl: current table
|
|
|
|
*/
|
|
|
|
static inline bool rht_grow_above_max(const struct rhashtable *ht,
|
|
|
|
const struct bucket_table *tbl)
|
|
|
|
{
|
|
|
|
return ht->p.insecure_max_entries &&
|
|
|
|
atomic_read(&ht->nelems) >= ht->p.insecure_max_entries;
|
|
|
|
}
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
/* The bucket lock is selected based on the hash and protects mutations
|
|
|
|
* on a group of hash buckets.
|
|
|
|
*
|
|
|
|
* A maximum of tbl->size/2 bucket locks is allocated. This ensures that
|
|
|
|
* a single lock always covers both buckets which may both contains
|
|
|
|
* entries which link to the same bucket of the old table during resizing.
|
|
|
|
* This allows to simplify the locking as locking the bucket in both
|
|
|
|
* tables during resize always guarantee protection.
|
|
|
|
*
|
|
|
|
* IMPORTANT: When holding the bucket lock of both the old and new table
|
|
|
|
* during expansions and shrinking, the old bucket lock must always be
|
|
|
|
* acquired first.
|
|
|
|
*/
|
|
|
|
static inline spinlock_t *rht_bucket_lock(const struct bucket_table *tbl,
|
|
|
|
unsigned int hash)
|
|
|
|
{
|
|
|
|
return &tbl->locks[hash & tbl->locks_mask];
|
|
|
|
}
|
|
|
|
|
2014-08-02 03:47:44 -06:00
|
|
|
#ifdef CONFIG_PROVE_LOCKING
|
2015-01-02 15:00:20 -07:00
|
|
|
int lockdep_rht_mutex_is_held(struct rhashtable *ht);
|
2015-01-02 15:00:16 -07:00
|
|
|
int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash);
|
2014-08-02 03:47:44 -06:00
|
|
|
#else
|
2015-01-02 15:00:20 -07:00
|
|
|
static inline int lockdep_rht_mutex_is_held(struct rhashtable *ht)
|
2014-08-02 03:47:44 -06:00
|
|
|
{
|
|
|
|
return 1;
|
|
|
|
}
|
2015-01-02 15:00:16 -07:00
|
|
|
|
|
|
|
static inline int lockdep_rht_bucket_is_held(const struct bucket_table *tbl,
|
|
|
|
u32 hash)
|
|
|
|
{
|
|
|
|
return 1;
|
|
|
|
}
|
2014-08-02 03:47:44 -06:00
|
|
|
#endif /* CONFIG_PROVE_LOCKING */
|
|
|
|
|
2015-03-20 04:56:59 -06:00
|
|
|
int rhashtable_init(struct rhashtable *ht,
|
|
|
|
const struct rhashtable_params *params);
|
2016-09-19 05:00:09 -06:00
|
|
|
int rhltable_init(struct rhltable *hlt,
|
|
|
|
const struct rhashtable_params *params);
|
2014-08-02 03:47:44 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
void *rhashtable_insert_slow(struct rhashtable *ht, const void *key,
|
|
|
|
struct rhash_head *obj);
|
2014-08-02 03:47:44 -06:00
|
|
|
|
2016-08-18 02:50:56 -06:00
|
|
|
void rhashtable_walk_enter(struct rhashtable *ht,
|
|
|
|
struct rhashtable_iter *iter);
|
2015-02-03 13:33:23 -07:00
|
|
|
void rhashtable_walk_exit(struct rhashtable_iter *iter);
|
|
|
|
int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);
|
|
|
|
void *rhashtable_walk_next(struct rhashtable_iter *iter);
|
|
|
|
void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU);
|
|
|
|
|
2015-03-24 07:18:20 -06:00
|
|
|
void rhashtable_free_and_destroy(struct rhashtable *ht,
|
|
|
|
void (*free_fn)(void *ptr, void *arg),
|
|
|
|
void *arg);
|
2015-01-02 15:00:20 -07:00
|
|
|
void rhashtable_destroy(struct rhashtable *ht);
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
#define rht_dereference(p, ht) \
|
|
|
|
rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht))
|
|
|
|
|
|
|
|
#define rht_dereference_rcu(p, ht) \
|
|
|
|
rcu_dereference_check(p, lockdep_rht_mutex_is_held(ht))
|
|
|
|
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_dereference_bucket(p, tbl, hash) \
|
|
|
|
rcu_dereference_protected(p, lockdep_rht_bucket_is_held(tbl, hash))
|
2014-08-02 03:47:44 -06:00
|
|
|
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_dereference_bucket_rcu(p, tbl, hash) \
|
|
|
|
rcu_dereference_check(p, lockdep_rht_bucket_is_held(tbl, hash))
|
|
|
|
|
|
|
|
#define rht_entry(tpos, pos, member) \
|
|
|
|
({ tpos = container_of(pos, typeof(*tpos), member); 1; })
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
/**
|
2015-01-02 15:00:16 -07:00
|
|
|
* rht_for_each_continue - continue iterating over hash chain
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @head: the previous &struct rhash_head to continue from
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
2014-08-02 03:47:44 -06:00
|
|
|
*/
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_for_each_continue(pos, head, tbl, hash) \
|
|
|
|
for (pos = rht_dereference_bucket(head, tbl, hash); \
|
2015-01-02 15:00:21 -07:00
|
|
|
!rht_is_a_nulls(pos); \
|
2015-01-02 15:00:16 -07:00
|
|
|
pos = rht_dereference_bucket((pos)->next, tbl, hash))
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each - iterate over hash chain
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
*/
|
|
|
|
#define rht_for_each(pos, tbl, hash) \
|
|
|
|
rht_for_each_continue(pos, (tbl)->buckets[hash], tbl, hash)
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_entry_continue - continue iterating over hash chain
|
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @head: the previous &struct rhash_head to continue from
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
* @member: name of the &struct rhash_head within the hashable struct.
|
|
|
|
*/
|
|
|
|
#define rht_for_each_entry_continue(tpos, pos, head, tbl, hash, member) \
|
|
|
|
for (pos = rht_dereference_bucket(head, tbl, hash); \
|
2015-01-02 15:00:21 -07:00
|
|
|
(!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
|
2015-01-02 15:00:16 -07:00
|
|
|
pos = rht_dereference_bucket((pos)->next, tbl, hash))
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_entry - iterate over hash chain of given type
|
2015-01-02 15:00:16 -07:00
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
* @member: name of the &struct rhash_head within the hashable struct.
|
2014-08-02 03:47:44 -06:00
|
|
|
*/
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_for_each_entry(tpos, pos, tbl, hash, member) \
|
|
|
|
rht_for_each_entry_continue(tpos, pos, (tbl)->buckets[hash], \
|
|
|
|
tbl, hash, member)
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_entry_safe - safely iterate over hash chain of given type
|
2015-01-02 15:00:16 -07:00
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @next: the &struct rhash_head to use as next in loop cursor.
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
* @member: name of the &struct rhash_head within the hashable struct.
|
2014-08-02 03:47:44 -06:00
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive allows for the looped code to
|
|
|
|
* remove the loop cursor from the list.
|
|
|
|
*/
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \
|
|
|
|
for (pos = rht_dereference_bucket((tbl)->buckets[hash], tbl, hash), \
|
2015-01-02 15:00:21 -07:00
|
|
|
next = !rht_is_a_nulls(pos) ? \
|
|
|
|
rht_dereference_bucket(pos->next, tbl, hash) : NULL; \
|
|
|
|
(!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
|
2015-01-21 04:12:13 -07:00
|
|
|
pos = next, \
|
|
|
|
next = !rht_is_a_nulls(pos) ? \
|
|
|
|
rht_dereference_bucket(pos->next, tbl, hash) : NULL)
|
2015-01-02 15:00:16 -07:00
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_rcu_continue - continue iterating over rcu hash chain
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @head: the previous &struct rhash_head to continue from
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive may safely run concurrently with
|
|
|
|
* the _rcu mutation primitives such as rhashtable_insert() as long as the
|
|
|
|
* traversal is guarded by rcu_read_lock().
|
|
|
|
*/
|
|
|
|
#define rht_for_each_rcu_continue(pos, head, tbl, hash) \
|
|
|
|
for (({barrier(); }), \
|
|
|
|
pos = rht_dereference_bucket_rcu(head, tbl, hash); \
|
2015-01-02 15:00:21 -07:00
|
|
|
!rht_is_a_nulls(pos); \
|
2015-01-02 15:00:16 -07:00
|
|
|
pos = rcu_dereference_raw(pos->next))
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_rcu - iterate over rcu hash chain
|
2015-01-02 15:00:16 -07:00
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
2014-08-02 03:47:44 -06:00
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive may safely run concurrently with
|
2015-01-02 15:00:16 -07:00
|
|
|
* the _rcu mutation primitives such as rhashtable_insert() as long as the
|
2014-08-02 03:47:44 -06:00
|
|
|
* traversal is guarded by rcu_read_lock().
|
|
|
|
*/
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_for_each_rcu(pos, tbl, hash) \
|
|
|
|
rht_for_each_rcu_continue(pos, (tbl)->buckets[hash], tbl, hash)
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_entry_rcu_continue - continue iterating over rcu hash chain
|
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @head: the previous &struct rhash_head to continue from
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
* @member: name of the &struct rhash_head within the hashable struct.
|
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive may safely run concurrently with
|
|
|
|
* the _rcu mutation primitives such as rhashtable_insert() as long as the
|
|
|
|
* traversal is guarded by rcu_read_lock().
|
|
|
|
*/
|
|
|
|
#define rht_for_each_entry_rcu_continue(tpos, pos, head, tbl, hash, member) \
|
|
|
|
for (({barrier(); }), \
|
|
|
|
pos = rht_dereference_bucket_rcu(head, tbl, hash); \
|
2015-01-02 15:00:21 -07:00
|
|
|
(!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
|
2015-01-02 15:00:16 -07:00
|
|
|
pos = rht_dereference_bucket_rcu(pos->next, tbl, hash))
|
2014-08-02 03:47:44 -06:00
|
|
|
|
|
|
|
/**
|
|
|
|
* rht_for_each_entry_rcu - iterate over rcu hash chain of given type
|
2015-01-02 15:00:16 -07:00
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rhash_head to use as a loop cursor.
|
|
|
|
* @tbl: the &struct bucket_table
|
|
|
|
* @hash: the hash value / bucket index
|
|
|
|
* @member: name of the &struct rhash_head within the hashable struct.
|
2014-08-02 03:47:44 -06:00
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive may safely run concurrently with
|
2015-01-02 15:00:16 -07:00
|
|
|
* the _rcu mutation primitives such as rhashtable_insert() as long as the
|
2014-08-02 03:47:44 -06:00
|
|
|
* traversal is guarded by rcu_read_lock().
|
|
|
|
*/
|
2015-01-02 15:00:16 -07:00
|
|
|
#define rht_for_each_entry_rcu(tpos, pos, tbl, hash, member) \
|
|
|
|
rht_for_each_entry_rcu_continue(tpos, pos, (tbl)->buckets[hash],\
|
|
|
|
tbl, hash, member)
|
2014-08-02 03:47:44 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* rhl_for_each_rcu - iterate over rcu hash table list
|
|
|
|
* @pos: the &struct rlist_head to use as a loop cursor.
|
|
|
|
* @list: the head of the list
|
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive should be used on the
|
|
|
|
* list returned by rhltable_lookup.
|
|
|
|
*/
|
|
|
|
#define rhl_for_each_rcu(pos, list) \
|
|
|
|
for (pos = list; pos; pos = rcu_dereference_raw(pos->next))
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhl_for_each_entry_rcu - iterate over rcu hash table list of given type
|
|
|
|
* @tpos: the type * to use as a loop cursor.
|
|
|
|
* @pos: the &struct rlist_head to use as a loop cursor.
|
|
|
|
* @list: the head of the list
|
|
|
|
* @member: name of the &struct rlist_head within the hashable struct.
|
|
|
|
*
|
|
|
|
* This hash chain list-traversal primitive should be used on the
|
|
|
|
* list returned by rhltable_lookup.
|
|
|
|
*/
|
|
|
|
#define rhl_for_each_entry_rcu(tpos, pos, list, member) \
|
|
|
|
for (pos = list; pos && rht_entry(tpos, pos, member); \
|
|
|
|
pos = rcu_dereference_raw(pos->next))
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
static inline int rhashtable_compare(struct rhashtable_compare_arg *arg,
|
|
|
|
const void *obj)
|
|
|
|
{
|
|
|
|
struct rhashtable *ht = arg->ht;
|
|
|
|
const char *ptr = obj;
|
|
|
|
|
|
|
|
return memcmp(ptr + ht->p.key_offset, arg->key, ht->p.key_len);
|
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/* Internal function, do not use. */
|
|
|
|
static inline struct rhash_head *__rhashtable_lookup(
|
2015-03-20 04:57:00 -06:00
|
|
|
struct rhashtable *ht, const void *key,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
struct rhashtable_compare_arg arg = {
|
|
|
|
.ht = ht,
|
|
|
|
.key = key,
|
|
|
|
};
|
|
|
|
const struct bucket_table *tbl;
|
|
|
|
struct rhash_head *he;
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int hash;
|
2015-03-20 04:57:00 -06:00
|
|
|
|
|
|
|
tbl = rht_dereference_rcu(ht->tbl, ht);
|
|
|
|
restart:
|
|
|
|
hash = rht_key_hashfn(ht, tbl, key, params);
|
|
|
|
rht_for_each_rcu(he, tbl, hash) {
|
|
|
|
if (params.obj_cmpfn ?
|
|
|
|
params.obj_cmpfn(&arg, rht_obj(ht, he)) :
|
|
|
|
rhashtable_compare(&arg, rht_obj(ht, he)))
|
|
|
|
continue;
|
2016-09-19 05:00:09 -06:00
|
|
|
return he;
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Ensure we see any new tables. */
|
|
|
|
smp_rmb();
|
|
|
|
|
|
|
|
tbl = rht_dereference_rcu(tbl->future_tbl, ht);
|
|
|
|
if (unlikely(tbl))
|
|
|
|
goto restart;
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* rhashtable_lookup - search hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @key: the pointer to the key
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Computes the hash value for the key and traverses the bucket chain looking
|
|
|
|
* for a entry with an identical key. The first matching entry is returned.
|
|
|
|
*
|
|
|
|
* This must only be called under the RCU read lock.
|
|
|
|
*
|
|
|
|
* Returns the first entry on which the compare function returned true.
|
|
|
|
*/
|
|
|
|
static inline void *rhashtable_lookup(
|
|
|
|
struct rhashtable *ht, const void *key,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
struct rhash_head *he = __rhashtable_lookup(ht, key, params);
|
|
|
|
|
|
|
|
return he ? rht_obj(ht, he) : NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhashtable_lookup_fast - search hash table, without RCU read lock
|
|
|
|
* @ht: hash table
|
|
|
|
* @key: the pointer to the key
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Computes the hash value for the key and traverses the bucket chain looking
|
|
|
|
* for a entry with an identical key. The first matching entry is returned.
|
|
|
|
*
|
|
|
|
* Only use this function when you have other mechanisms guaranteeing
|
|
|
|
* that the object won't go away after the RCU read lock is released.
|
|
|
|
*
|
|
|
|
* Returns the first entry on which the compare function returned true.
|
|
|
|
*/
|
|
|
|
static inline void *rhashtable_lookup_fast(
|
|
|
|
struct rhashtable *ht, const void *key,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
void *obj;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
obj = rhashtable_lookup(ht, key, params);
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
return obj;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhltable_lookup - search hash list table
|
|
|
|
* @hlt: hash table
|
|
|
|
* @key: the pointer to the key
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Computes the hash value for the key and traverses the bucket chain looking
|
|
|
|
* for a entry with an identical key. All matching entries are returned
|
|
|
|
* in a list.
|
|
|
|
*
|
|
|
|
* This must only be called under the RCU read lock.
|
|
|
|
*
|
|
|
|
* Returns the list of entries that match the given key.
|
|
|
|
*/
|
|
|
|
static inline struct rhlist_head *rhltable_lookup(
|
|
|
|
struct rhltable *hlt, const void *key,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params);
|
|
|
|
|
|
|
|
return he ? container_of(he, struct rhlist_head, rhead) : NULL;
|
|
|
|
}
|
|
|
|
|
2016-08-24 04:31:31 -06:00
|
|
|
/* Internal function, please use rhashtable_insert_fast() instead. This
|
|
|
|
* function returns the existing element already in hashes in there is a clash,
|
|
|
|
* otherwise it returns an error via ERR_PTR().
|
|
|
|
*/
|
|
|
|
static inline void *__rhashtable_insert_fast(
|
2015-03-20 04:57:00 -06:00
|
|
|
struct rhashtable *ht, const void *key, struct rhash_head *obj,
|
2016-09-19 05:00:09 -06:00
|
|
|
const struct rhashtable_params params, bool rhlist)
|
2015-03-20 04:57:00 -06:00
|
|
|
{
|
|
|
|
struct rhashtable_compare_arg arg = {
|
|
|
|
.ht = ht,
|
|
|
|
.key = key,
|
|
|
|
};
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhash_head __rcu **pprev;
|
|
|
|
struct bucket_table *tbl;
|
2015-03-20 04:57:00 -06:00
|
|
|
struct rhash_head *head;
|
|
|
|
spinlock_t *lock;
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int hash;
|
2016-09-19 05:00:09 -06:00
|
|
|
int elasticity;
|
|
|
|
void *data;
|
2015-03-20 04:57:00 -06:00
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
|
|
|
tbl = rht_dereference_rcu(ht->tbl, ht);
|
2016-09-19 05:00:09 -06:00
|
|
|
hash = rht_head_hashfn(ht, tbl, obj, params);
|
|
|
|
lock = rht_bucket_lock(tbl, hash);
|
|
|
|
spin_lock_bh(lock);
|
2015-03-20 04:57:00 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
if (unlikely(rht_dereference_bucket(tbl->future_tbl, tbl, hash))) {
|
|
|
|
slow_path:
|
2015-03-23 07:50:26 -06:00
|
|
|
spin_unlock_bh(lock);
|
2016-09-19 05:00:09 -06:00
|
|
|
rcu_read_unlock();
|
|
|
|
return rhashtable_insert_slow(ht, key, obj);
|
2015-03-23 07:50:26 -06:00
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
elasticity = ht->elasticity;
|
|
|
|
pprev = &tbl->buckets[hash];
|
|
|
|
rht_for_each(head, tbl, hash) {
|
|
|
|
struct rhlist_head *plist;
|
|
|
|
struct rhlist_head *list;
|
|
|
|
|
|
|
|
elasticity--;
|
|
|
|
if (!key ||
|
|
|
|
(params.obj_cmpfn ?
|
|
|
|
params.obj_cmpfn(&arg, rht_obj(ht, head)) :
|
|
|
|
rhashtable_compare(&arg, rht_obj(ht, head))))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
data = rht_obj(ht, head);
|
2015-12-03 05:41:29 -07:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
if (!rhlist)
|
|
|
|
goto out;
|
2016-08-24 04:31:31 -06:00
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
list = container_of(obj, struct rhlist_head, rhead);
|
|
|
|
plist = container_of(head, struct rhlist_head, rhead);
|
2015-05-14 21:30:47 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
RCU_INIT_POINTER(list->next, plist);
|
|
|
|
head = rht_dereference_bucket(head->next, tbl, hash);
|
|
|
|
RCU_INIT_POINTER(list->rhead.next, head);
|
|
|
|
rcu_assign_pointer(*pprev, obj);
|
2015-03-23 07:50:28 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
goto good;
|
2015-03-23 07:50:28 -06:00
|
|
|
}
|
2015-03-20 04:57:00 -06:00
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
if (elasticity <= 0)
|
|
|
|
goto slow_path;
|
|
|
|
|
|
|
|
data = ERR_PTR(-E2BIG);
|
|
|
|
if (unlikely(rht_grow_above_max(ht, tbl)))
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
if (unlikely(rht_grow_above_100(ht, tbl)))
|
|
|
|
goto slow_path;
|
2015-03-20 04:57:00 -06:00
|
|
|
|
|
|
|
head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash);
|
|
|
|
|
|
|
|
RCU_INIT_POINTER(obj->next, head);
|
2016-09-19 05:00:09 -06:00
|
|
|
if (rhlist) {
|
|
|
|
struct rhlist_head *list;
|
|
|
|
|
|
|
|
list = container_of(obj, struct rhlist_head, rhead);
|
|
|
|
RCU_INIT_POINTER(list->next, NULL);
|
|
|
|
}
|
2015-03-20 04:57:00 -06:00
|
|
|
|
|
|
|
rcu_assign_pointer(tbl->buckets[hash], obj);
|
|
|
|
|
|
|
|
atomic_inc(&ht->nelems);
|
|
|
|
if (rht_grow_above_75(ht, tbl))
|
|
|
|
schedule_work(&ht->run_work);
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
good:
|
|
|
|
data = NULL;
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
out:
|
|
|
|
spin_unlock_bh(lock);
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
return data;
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhashtable_insert_fast - insert object into hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @obj: pointer to hash head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Will take a per bucket spinlock to protect against mutual mutations
|
|
|
|
* on the same bucket. Multiple insertions may occur in parallel unless
|
|
|
|
* they map to the same bucket lock.
|
|
|
|
*
|
|
|
|
* It is safe to call this function from atomic context.
|
|
|
|
*
|
|
|
|
* Will trigger an automatic deferred table resizing if the size grows
|
|
|
|
* beyond the watermark indicated by grow_decision() which can be passed
|
|
|
|
* to rhashtable_init().
|
|
|
|
*/
|
|
|
|
static inline int rhashtable_insert_fast(
|
|
|
|
struct rhashtable *ht, struct rhash_head *obj,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
2016-08-24 04:31:31 -06:00
|
|
|
void *ret;
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
ret = __rhashtable_insert_fast(ht, NULL, obj, params, false);
|
2016-08-24 04:31:31 -06:00
|
|
|
if (IS_ERR(ret))
|
|
|
|
return PTR_ERR(ret);
|
|
|
|
|
|
|
|
return ret == NULL ? 0 : -EEXIST;
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* rhltable_insert_key - insert object into hash list table
|
|
|
|
* @hlt: hash list table
|
|
|
|
* @key: the pointer to the key
|
|
|
|
* @list: pointer to hash list head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Will take a per bucket spinlock to protect against mutual mutations
|
|
|
|
* on the same bucket. Multiple insertions may occur in parallel unless
|
|
|
|
* they map to the same bucket lock.
|
|
|
|
*
|
|
|
|
* It is safe to call this function from atomic context.
|
|
|
|
*
|
|
|
|
* Will trigger an automatic deferred table resizing if the size grows
|
|
|
|
* beyond the watermark indicated by grow_decision() which can be passed
|
|
|
|
* to rhashtable_init().
|
|
|
|
*/
|
|
|
|
static inline int rhltable_insert_key(
|
|
|
|
struct rhltable *hlt, const void *key, struct rhlist_head *list,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
return PTR_ERR(__rhashtable_insert_fast(&hlt->ht, key, &list->rhead,
|
|
|
|
params, true));
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhltable_insert - insert object into hash list table
|
|
|
|
* @hlt: hash list table
|
|
|
|
* @list: pointer to hash list head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Will take a per bucket spinlock to protect against mutual mutations
|
|
|
|
* on the same bucket. Multiple insertions may occur in parallel unless
|
|
|
|
* they map to the same bucket lock.
|
|
|
|
*
|
|
|
|
* It is safe to call this function from atomic context.
|
|
|
|
*
|
|
|
|
* Will trigger an automatic deferred table resizing if the size grows
|
|
|
|
* beyond the watermark indicated by grow_decision() which can be passed
|
|
|
|
* to rhashtable_init().
|
|
|
|
*/
|
|
|
|
static inline int rhltable_insert(
|
|
|
|
struct rhltable *hlt, struct rhlist_head *list,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
const char *key = rht_obj(&hlt->ht, &list->rhead);
|
|
|
|
|
|
|
|
key += params.key_offset;
|
|
|
|
|
|
|
|
return rhltable_insert_key(hlt, key, list, params);
|
|
|
|
}
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
/**
|
|
|
|
* rhashtable_lookup_insert_fast - lookup and insert object into hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @obj: pointer to hash head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Locks down the bucket chain in both the old and new table if a resize
|
|
|
|
* is in progress to ensure that writers can't remove from the old table
|
|
|
|
* and can't insert to the new table during the atomic operation of search
|
|
|
|
* and insertion. Searches for duplicates in both the old and new table if
|
|
|
|
* a resize is in progress.
|
|
|
|
*
|
|
|
|
* This lookup function may only be used for fixed key hash table (key_len
|
|
|
|
* parameter set). It will BUG() if used inappropriately.
|
|
|
|
*
|
|
|
|
* It is safe to call this function from atomic context.
|
|
|
|
*
|
|
|
|
* Will trigger an automatic deferred table resizing if the size grows
|
|
|
|
* beyond the watermark indicated by grow_decision() which can be passed
|
|
|
|
* to rhashtable_init().
|
|
|
|
*/
|
|
|
|
static inline int rhashtable_lookup_insert_fast(
|
|
|
|
struct rhashtable *ht, struct rhash_head *obj,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
const char *key = rht_obj(ht, obj);
|
2016-08-24 04:31:31 -06:00
|
|
|
void *ret;
|
2015-03-20 04:57:00 -06:00
|
|
|
|
|
|
|
BUG_ON(ht->p.obj_hashfn);
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
ret = __rhashtable_insert_fast(ht, key + ht->p.key_offset, obj, params,
|
|
|
|
false);
|
2016-08-24 04:31:31 -06:00
|
|
|
if (IS_ERR(ret))
|
|
|
|
return PTR_ERR(ret);
|
|
|
|
|
|
|
|
return ret == NULL ? 0 : -EEXIST;
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhashtable_lookup_insert_key - search and insert object to hash table
|
|
|
|
* with explicit key
|
|
|
|
* @ht: hash table
|
|
|
|
* @key: key
|
|
|
|
* @obj: pointer to hash head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Locks down the bucket chain in both the old and new table if a resize
|
|
|
|
* is in progress to ensure that writers can't remove from the old table
|
|
|
|
* and can't insert to the new table during the atomic operation of search
|
|
|
|
* and insertion. Searches for duplicates in both the old and new table if
|
|
|
|
* a resize is in progress.
|
|
|
|
*
|
|
|
|
* Lookups may occur in parallel with hashtable mutations and resizing.
|
|
|
|
*
|
|
|
|
* Will trigger an automatic deferred table resizing if the size grows
|
|
|
|
* beyond the watermark indicated by grow_decision() which can be passed
|
|
|
|
* to rhashtable_init().
|
|
|
|
*
|
|
|
|
* Returns zero on success.
|
|
|
|
*/
|
|
|
|
static inline int rhashtable_lookup_insert_key(
|
|
|
|
struct rhashtable *ht, const void *key, struct rhash_head *obj,
|
|
|
|
const struct rhashtable_params params)
|
2016-08-24 04:31:31 -06:00
|
|
|
{
|
|
|
|
void *ret;
|
|
|
|
|
|
|
|
BUG_ON(!ht->p.obj_hashfn || !key);
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
ret = __rhashtable_insert_fast(ht, key, obj, params, false);
|
2016-08-24 04:31:31 -06:00
|
|
|
if (IS_ERR(ret))
|
|
|
|
return PTR_ERR(ret);
|
|
|
|
|
|
|
|
return ret == NULL ? 0 : -EEXIST;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhashtable_lookup_get_insert_key - lookup and insert object into hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @obj: pointer to hash head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
* @data: pointer to element data already in hashes
|
|
|
|
*
|
|
|
|
* Just like rhashtable_lookup_insert_key(), but this function returns the
|
|
|
|
* object if it exists, NULL if it does not and the insertion was successful,
|
|
|
|
* and an ERR_PTR otherwise.
|
|
|
|
*/
|
|
|
|
static inline void *rhashtable_lookup_get_insert_key(
|
|
|
|
struct rhashtable *ht, const void *key, struct rhash_head *obj,
|
|
|
|
const struct rhashtable_params params)
|
2015-03-20 04:57:00 -06:00
|
|
|
{
|
|
|
|
BUG_ON(!ht->p.obj_hashfn || !key);
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
return __rhashtable_insert_fast(ht, key, obj, params, false);
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
2015-03-24 07:18:18 -06:00
|
|
|
/* Internal function, please use rhashtable_remove_fast() instead */
|
2016-09-19 05:00:09 -06:00
|
|
|
static inline int __rhashtable_remove_fast_one(
|
2015-03-20 04:57:00 -06:00
|
|
|
struct rhashtable *ht, struct bucket_table *tbl,
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhash_head *obj, const struct rhashtable_params params,
|
|
|
|
bool rhlist)
|
2015-03-20 04:57:00 -06:00
|
|
|
{
|
|
|
|
struct rhash_head __rcu **pprev;
|
|
|
|
struct rhash_head *he;
|
|
|
|
spinlock_t * lock;
|
2015-03-24 07:18:17 -06:00
|
|
|
unsigned int hash;
|
2015-03-20 04:57:00 -06:00
|
|
|
int err = -ENOENT;
|
|
|
|
|
|
|
|
hash = rht_head_hashfn(ht, tbl, obj, params);
|
|
|
|
lock = rht_bucket_lock(tbl, hash);
|
|
|
|
|
|
|
|
spin_lock_bh(lock);
|
|
|
|
|
|
|
|
pprev = &tbl->buckets[hash];
|
|
|
|
rht_for_each(he, tbl, hash) {
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhlist_head *list;
|
|
|
|
|
|
|
|
list = container_of(he, struct rhlist_head, rhead);
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
if (he != obj) {
|
2016-09-19 05:00:09 -06:00
|
|
|
struct rhlist_head __rcu **lpprev;
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
pprev = &he->next;
|
2016-09-19 05:00:09 -06:00
|
|
|
|
|
|
|
if (!rhlist)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
do {
|
|
|
|
lpprev = &list->next;
|
|
|
|
list = rht_dereference_bucket(list->next,
|
|
|
|
tbl, hash);
|
|
|
|
} while (list && obj != &list->rhead);
|
|
|
|
|
|
|
|
if (!list)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
list = rht_dereference_bucket(list->next, tbl, hash);
|
|
|
|
RCU_INIT_POINTER(*lpprev, list);
|
|
|
|
err = 0;
|
|
|
|
break;
|
2015-03-20 04:57:00 -06:00
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
obj = rht_dereference_bucket(obj->next, tbl, hash);
|
|
|
|
err = 1;
|
|
|
|
|
|
|
|
if (rhlist) {
|
|
|
|
list = rht_dereference_bucket(list->next, tbl, hash);
|
|
|
|
if (list) {
|
|
|
|
RCU_INIT_POINTER(list->rhead.next, obj);
|
|
|
|
obj = &list->rhead;
|
|
|
|
err = 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
rcu_assign_pointer(*pprev, obj);
|
2015-03-20 04:57:00 -06:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock_bh(lock);
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
if (err > 0) {
|
|
|
|
atomic_dec(&ht->nelems);
|
|
|
|
if (unlikely(ht->p.automatic_shrinking &&
|
|
|
|
rht_shrink_below_30(ht, tbl)))
|
|
|
|
schedule_work(&ht->run_work);
|
|
|
|
err = 0;
|
|
|
|
}
|
|
|
|
|
2015-03-20 04:57:00 -06:00
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/* Internal function, please use rhashtable_remove_fast() instead */
|
|
|
|
static inline int __rhashtable_remove_fast(
|
2015-03-20 04:57:00 -06:00
|
|
|
struct rhashtable *ht, struct rhash_head *obj,
|
2016-09-19 05:00:09 -06:00
|
|
|
const struct rhashtable_params params, bool rhlist)
|
2015-03-20 04:57:00 -06:00
|
|
|
{
|
|
|
|
struct bucket_table *tbl;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
|
|
|
tbl = rht_dereference_rcu(ht->tbl, ht);
|
|
|
|
|
|
|
|
/* Because we have already taken (and released) the bucket
|
|
|
|
* lock in old_tbl, if we find that future_tbl is not yet
|
|
|
|
* visible then that guarantees the entry to still be in
|
|
|
|
* the old tbl if it exists.
|
|
|
|
*/
|
2016-09-19 05:00:09 -06:00
|
|
|
while ((err = __rhashtable_remove_fast_one(ht, tbl, obj, params,
|
|
|
|
rhlist)) &&
|
2015-03-20 04:57:00 -06:00
|
|
|
(tbl = rht_dereference_rcu(tbl->future_tbl, ht)))
|
|
|
|
;
|
|
|
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* rhashtable_remove_fast - remove object from hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @obj: pointer to hash head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Since the hash chain is single linked, the removal operation needs to
|
|
|
|
* walk the bucket chain upon removal. The removal operation is thus
|
|
|
|
* considerable slow if the hash table is not correctly sized.
|
|
|
|
*
|
|
|
|
* Will automatically shrink the table via rhashtable_expand() if the
|
|
|
|
* shrink_decision function specified at rhashtable_init() returns true.
|
|
|
|
*
|
|
|
|
* Returns zero on success, -ENOENT if the entry could not be found.
|
|
|
|
*/
|
|
|
|
static inline int rhashtable_remove_fast(
|
|
|
|
struct rhashtable *ht, struct rhash_head *obj,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
return __rhashtable_remove_fast(ht, obj, params, false);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhltable_remove - remove object from hash list table
|
|
|
|
* @hlt: hash list table
|
|
|
|
* @list: pointer to hash list head inside object
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Since the hash chain is single linked, the removal operation needs to
|
|
|
|
* walk the bucket chain upon removal. The removal operation is thus
|
|
|
|
* considerable slow if the hash table is not correctly sized.
|
|
|
|
*
|
|
|
|
* Will automatically shrink the table via rhashtable_expand() if the
|
|
|
|
* shrink_decision function specified at rhashtable_init() returns true.
|
|
|
|
*
|
|
|
|
* Returns zero on success, -ENOENT if the entry could not be found.
|
|
|
|
*/
|
|
|
|
static inline int rhltable_remove(
|
|
|
|
struct rhltable *hlt, struct rhlist_head *list,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
return __rhashtable_remove_fast(&hlt->ht, &list->rhead, params, true);
|
|
|
|
}
|
|
|
|
|
2015-12-15 16:41:36 -07:00
|
|
|
/* Internal function, please use rhashtable_replace_fast() instead */
|
|
|
|
static inline int __rhashtable_replace_fast(
|
|
|
|
struct rhashtable *ht, struct bucket_table *tbl,
|
|
|
|
struct rhash_head *obj_old, struct rhash_head *obj_new,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
struct rhash_head __rcu **pprev;
|
|
|
|
struct rhash_head *he;
|
|
|
|
spinlock_t *lock;
|
|
|
|
unsigned int hash;
|
|
|
|
int err = -ENOENT;
|
|
|
|
|
|
|
|
/* Minimally, the old and new objects must have same hash
|
|
|
|
* (which should mean identifiers are the same).
|
|
|
|
*/
|
|
|
|
hash = rht_head_hashfn(ht, tbl, obj_old, params);
|
|
|
|
if (hash != rht_head_hashfn(ht, tbl, obj_new, params))
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
lock = rht_bucket_lock(tbl, hash);
|
|
|
|
|
|
|
|
spin_lock_bh(lock);
|
|
|
|
|
|
|
|
pprev = &tbl->buckets[hash];
|
|
|
|
rht_for_each(he, tbl, hash) {
|
|
|
|
if (he != obj_old) {
|
|
|
|
pprev = &he->next;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
rcu_assign_pointer(obj_new->next, obj_old->next);
|
|
|
|
rcu_assign_pointer(*pprev, obj_new);
|
|
|
|
err = 0;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock_bh(lock);
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhashtable_replace_fast - replace an object in hash table
|
|
|
|
* @ht: hash table
|
|
|
|
* @obj_old: pointer to hash head inside object being replaced
|
|
|
|
* @obj_new: pointer to hash head inside object which is new
|
|
|
|
* @params: hash table parameters
|
|
|
|
*
|
|
|
|
* Replacing an object doesn't affect the number of elements in the hash table
|
|
|
|
* or bucket, so we don't need to worry about shrinking or expanding the
|
|
|
|
* table here.
|
|
|
|
*
|
|
|
|
* Returns zero on success, -ENOENT if the entry could not be found,
|
|
|
|
* -EINVAL if hash is not the same for the old and new objects.
|
|
|
|
*/
|
|
|
|
static inline int rhashtable_replace_fast(
|
|
|
|
struct rhashtable *ht, struct rhash_head *obj_old,
|
|
|
|
struct rhash_head *obj_new,
|
|
|
|
const struct rhashtable_params params)
|
|
|
|
{
|
|
|
|
struct bucket_table *tbl;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
|
|
|
tbl = rht_dereference_rcu(ht->tbl, ht);
|
|
|
|
|
|
|
|
/* Because we have already taken (and released) the bucket
|
|
|
|
* lock in old_tbl, if we find that future_tbl is not yet
|
|
|
|
* visible then that guarantees the entry to still be in
|
|
|
|
* the old tbl if it exists.
|
|
|
|
*/
|
|
|
|
while ((err = __rhashtable_replace_fast(ht, tbl, obj_old,
|
|
|
|
obj_new, params)) &&
|
|
|
|
(tbl = rht_dereference_rcu(tbl->future_tbl, ht)))
|
|
|
|
;
|
|
|
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
2016-08-18 02:50:56 -06:00
|
|
|
/* Obsolete function, do not use in new code. */
|
|
|
|
static inline int rhashtable_walk_init(struct rhashtable *ht,
|
|
|
|
struct rhashtable_iter *iter, gfp_t gfp)
|
|
|
|
{
|
|
|
|
rhashtable_walk_enter(ht, iter);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2016-09-19 05:00:09 -06:00
|
|
|
/**
|
|
|
|
* rhltable_walk_enter - Initialise an iterator
|
|
|
|
* @hlt: Table to walk over
|
|
|
|
* @iter: Hash table Iterator
|
|
|
|
*
|
|
|
|
* This function prepares a hash table walk.
|
|
|
|
*
|
|
|
|
* Note that if you restart a walk after rhashtable_walk_stop you
|
|
|
|
* may see the same object twice. Also, you may miss objects if
|
|
|
|
* there are removals in between rhashtable_walk_stop and the next
|
|
|
|
* call to rhashtable_walk_start.
|
|
|
|
*
|
|
|
|
* For a completely stable walk you should construct your own data
|
|
|
|
* structure outside the hash table.
|
|
|
|
*
|
|
|
|
* This function may sleep so you must not call it from interrupt
|
|
|
|
* context or with spin locks held.
|
|
|
|
*
|
|
|
|
* You must call rhashtable_walk_exit after this function returns.
|
|
|
|
*/
|
|
|
|
static inline void rhltable_walk_enter(struct rhltable *hlt,
|
|
|
|
struct rhashtable_iter *iter)
|
|
|
|
{
|
|
|
|
return rhashtable_walk_enter(&hlt->ht, iter);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rhltable_free_and_destroy - free elements and destroy hash list table
|
|
|
|
* @hlt: the hash list table to destroy
|
|
|
|
* @free_fn: callback to release resources of element
|
|
|
|
* @arg: pointer passed to free_fn
|
|
|
|
*
|
|
|
|
* See documentation for rhashtable_free_and_destroy.
|
|
|
|
*/
|
|
|
|
static inline void rhltable_free_and_destroy(struct rhltable *hlt,
|
|
|
|
void (*free_fn)(void *ptr,
|
|
|
|
void *arg),
|
|
|
|
void *arg)
|
|
|
|
{
|
|
|
|
return rhashtable_free_and_destroy(&hlt->ht, free_fn, arg);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void rhltable_destroy(struct rhltable *hlt)
|
|
|
|
{
|
|
|
|
return rhltable_free_and_destroy(hlt, NULL, NULL);
|
|
|
|
}
|
|
|
|
|
2014-08-02 03:47:44 -06:00
|
|
|
#endif /* _LINUX_RHASHTABLE_H */
|