diff options
| -rw-r--r-- | include/linux/rhashtable.h | 386 | ||||
| -rw-r--r-- | lib/rhashtable.c | 163 |
2 files changed, 436 insertions, 113 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index c85363c45fc0..a7188eeb135b 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -22,6 +22,7 @@ #include <linux/list_nulls.h> #include <linux/workqueue.h> #include <linux/mutex.h> +#include <linux/rcupdate.h> /* * The end of the chain is marked with a special nulls marks which has @@ -42,6 +43,9 @@ #define RHT_HASH_BITS 27 #define RHT_BASE_SHIFT RHT_HASH_BITS +/* Base bits plus 1 bit for nulls marker */ +#define RHT_HASH_RESERVED_SPACE (RHT_BASE_BITS + 1) + struct rhash_head { struct rhash_head __rcu *next; }; @@ -72,8 +76,20 @@ struct bucket_table { struct rhash_head __rcu *buckets[] ____cacheline_aligned_in_smp; }; +/** + * 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; +}; + typedef u32 (*rht_hashfn_t)(const void *data, u32 len, u32 seed); typedef u32 (*rht_obj_hashfn_t)(const void *data, u32 seed); +typedef int (*rht_obj_cmpfn_t)(struct rhashtable_compare_arg *arg, + const void *obj); struct rhashtable; @@ -89,6 +105,7 @@ struct rhashtable; * @locks_mul: Number of bucket locks to allocate per cpu (default: 128) * @hashfn: Function to hash key * @obj_hashfn: Function to hash object + * @obj_cmpfn: Function to compare key with object */ struct rhashtable_params { size_t nelem_hint; @@ -101,6 +118,7 @@ struct rhashtable_params { size_t locks_mul; rht_hashfn_t hashfn; rht_obj_hashfn_t obj_hashfn; + rht_obj_cmpfn_t obj_cmpfn; }; /** @@ -165,6 +183,83 @@ static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr) return ((unsigned long) ptr) >> 1; } +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) +{ + return rht_bucket_index(tbl, params.hashfn(key, params.key_len ?: + ht->p.key_len, + tbl->hash_rnd)); +} + +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) ? + rht_bucket_index(tbl, params.obj_hashfn(ptr, tbl->hash_rnd)) : + 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; +} + +/* 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]; +} + #ifdef CONFIG_PROVE_LOCKING int lockdep_rht_mutex_is_held(struct rhashtable *ht); int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash); @@ -184,6 +279,9 @@ static inline int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, int rhashtable_init(struct rhashtable *ht, const struct rhashtable_params *params); +int rhashtable_insert_slow(struct rhashtable *ht, const void *key, + struct rhash_head *obj, + struct bucket_table *old_tbl); void rhashtable_insert(struct rhashtable *ht, struct rhash_head *node); bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *node); @@ -356,4 +454,292 @@ void rhashtable_destroy(struct rhashtable *ht); rht_for_each_entry_rcu_continue(tpos, pos, (tbl)->buckets[hash],\ tbl, hash, member) +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); +} + +/** + * rhashtable_lookup_fast - search hash table, inlined version + * @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. + * + * 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) +{ + struct rhashtable_compare_arg arg = { + .ht = ht, + .key = key, + }; + const struct bucket_table *tbl; + struct rhash_head *he; + unsigned hash; + + rcu_read_lock(); + + 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; + rcu_read_unlock(); + return rht_obj(ht, he); + } + + /* Ensure we see any new tables. */ + smp_rmb(); + + tbl = rht_dereference_rcu(tbl->future_tbl, ht); + if (unlikely(tbl)) + goto restart; + rcu_read_unlock(); + + return NULL; +} + +static inline int __rhashtable_insert_fast( + struct rhashtable *ht, const void *key, struct rhash_head *obj, + const struct rhashtable_params params) +{ + struct rhashtable_compare_arg arg = { + .ht = ht, + .key = key, + }; + int err = -EEXIST; + struct bucket_table *tbl, *new_tbl; + struct rhash_head *head; + spinlock_t *lock; + unsigned hash; + + rcu_read_lock(); + + tbl = rht_dereference_rcu(ht->tbl, ht); + hash = rht_head_hashfn(ht, tbl, obj, params); + lock = rht_bucket_lock(tbl, hash); + + spin_lock_bh(lock); + + /* Because we have already taken the bucket lock in tbl, + * if we find that future_tbl is not yet visible then + * that guarantees all other insertions of the same entry + * will also grab the bucket lock in tbl because until + * the rehash completes ht->tbl won't be changed. + */ + new_tbl = rht_dereference_rcu(tbl->future_tbl, ht); + if (unlikely(new_tbl)) { + err = rhashtable_insert_slow(ht, key, obj, new_tbl); + goto out; + } + + if (!key) + goto skip_lookup; + + rht_for_each(head, tbl, hash) { + if (unlikely(!(params.obj_cmpfn ? + params.obj_cmpfn(&arg, rht_obj(ht, head)) : + rhashtable_compare(&arg, rht_obj(ht, head))))) + goto out; + } + +skip_lookup: + err = 0; + + head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash); + + RCU_INIT_POINTER(obj->next, head); + + rcu_assign_pointer(tbl->buckets[hash], obj); + + atomic_inc(&ht->nelems); + if (rht_grow_above_75(ht, tbl)) + schedule_work(&ht->run_work); + +out: + spin_unlock_bh(lock); + rcu_read_unlock(); + + return err; +} + +/** + * 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) +{ + return __rhashtable_insert_fast(ht, NULL, obj, params); +} + +/** + * 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); + + BUG_ON(ht->p.obj_hashfn); + + return __rhashtable_insert_fast(ht, key + ht->p.key_offset, obj, + params); +} + +/** + * 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) +{ + BUG_ON(!ht->p.obj_hashfn || !key); + + return __rhashtable_insert_fast(ht, key, obj, params); +} + +static inline int __rhashtable_remove_fast( + struct rhashtable *ht, struct bucket_table *tbl, + struct rhash_head *obj, const struct rhashtable_params params) +{ + struct rhash_head __rcu **pprev; + struct rhash_head *he; + spinlock_t * lock; + unsigned hash; + 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) { + if (he != obj) { + pprev = &he->next; + continue; + } + + rcu_assign_pointer(*pprev, obj->next); + err = 0; + break; + } + + spin_unlock_bh(lock); + + return err; +} + +/** + * 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) +{ + 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_remove_fast(ht, tbl, obj, params)) && + (tbl = rht_dereference_rcu(tbl->future_tbl, ht))) + ; + + if (err) + goto out; + + atomic_dec(&ht->nelems); + if (rht_shrink_below_30(ht, tbl)) + schedule_work(&ht->run_work); + +out: + rcu_read_unlock(); + + return err; +} + #endif /* _LINUX_RHASHTABLE_H */ diff --git a/lib/rhashtable.c b/lib/rhashtable.c index e0a9d59f80d6..d1d23fb58525 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -1,13 +1,13 @@ /* * Resizable, Scalable, Concurrent Hash Table * + * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch> * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> * - * Based on the following paper: - * https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf - * * Code partially derived from nft_hash + * Rewritten with rehash code from br_multicast plus single list + * pointer as suggested by Josh Triplett * * 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 @@ -30,53 +30,11 @@ #define HASH_MIN_SIZE 4U #define BUCKET_LOCKS_PER_CPU 128UL -/* Base bits plus 1 bit for nulls marker */ -#define HASH_RESERVED_SPACE (RHT_BASE_BITS + 1) - -/* 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 spinlock_t *bucket_lock(const struct bucket_table *tbl, u32 hash) -{ - return &tbl->locks[hash & tbl->locks_mask]; -} - -static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he) -{ - return (void *) he - ht->p.head_offset; -} - -static u32 rht_bucket_index(const struct bucket_table *tbl, u32 hash) -{ - return (hash >> HASH_RESERVED_SPACE) & (tbl->size - 1); -} - -static u32 key_hashfn(struct rhashtable *ht, const struct bucket_table *tbl, - const void *key) -{ - return rht_bucket_index(tbl, ht->p.hashfn(key, ht->p.key_len, - tbl->hash_rnd)); -} - static u32 head_hashfn(struct rhashtable *ht, const struct bucket_table *tbl, const struct rhash_head *he) { - const char *ptr = rht_obj(ht, he); - - return likely(ht->p.key_len) ? - key_hashfn(ht, tbl, ptr + ht->p.key_offset) : - rht_bucket_index(tbl, ht->p.obj_hashfn(ptr, tbl->hash_rnd)); + return rht_head_hashfn(ht, tbl, he, ht->p); } #ifdef CONFIG_PROVE_LOCKING @@ -90,7 +48,7 @@ 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); + spinlock_t *lock = rht_bucket_lock(tbl, hash); return (debug_locks) ? lockdep_is_held(lock) : 1; } @@ -178,32 +136,6 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht, return tbl; } -/** - * rht_grow_above_75 - returns true if nelems > 0.75 * table-size - * @ht: hash table - * @tbl: current table - */ -static 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 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; -} - static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash) { struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht); @@ -230,7 +162,7 @@ static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash) new_hash = head_hashfn(ht, new_tbl, entry); - new_bucket_lock = bucket_lock(new_tbl, new_hash); + new_bucket_lock = rht_bucket_lock(new_tbl, new_hash); spin_lock_nested(new_bucket_lock, SINGLE_DEPTH_NESTING); head = rht_dereference_bucket(new_tbl->buckets[new_hash], @@ -255,7 +187,7 @@ static void rhashtable_rehash_chain(struct rhashtable *ht, unsigned old_hash) struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht); spinlock_t *old_bucket_lock; - old_bucket_lock = bucket_lock(old_tbl, old_hash); + old_bucket_lock = rht_bucket_lock(old_tbl, old_hash); spin_lock_bh(old_bucket_lock); while (!rhashtable_rehash_one(ht, old_hash)) @@ -376,6 +308,37 @@ unlock: mutex_unlock(&ht->mutex); } +int rhashtable_insert_slow(struct rhashtable *ht, const void *key, + struct rhash_head *obj, + struct bucket_table *tbl) +{ + struct rhash_head *head; + unsigned hash; + int err = -EEXIST; + + hash = head_hashfn(ht, tbl, obj); + spin_lock_nested(rht_bucket_lock(tbl, hash), SINGLE_DEPTH_NESTING); + + if (key && rhashtable_lookup_fast(ht, key, ht->p)) + goto exit; + + err = 0; + + head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash); + + RCU_INIT_POINTER(obj->next, head); + + rcu_assign_pointer(tbl->buckets[hash], obj); + + atomic_inc(&ht->nelems); + +exit: + spin_unlock(rht_bucket_lock(tbl, hash)); + + return err; +} +EXPORT_SYMBOL_GPL(rhashtable_insert_slow); + static bool __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, bool (*compare)(void *, void *), void *arg) { @@ -390,7 +353,7 @@ static bool __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, old_tbl = rht_dereference_rcu(ht->tbl, ht); hash = head_hashfn(ht, old_tbl, obj); - old_lock = bucket_lock(old_tbl, hash); + old_lock = rht_bucket_lock(old_tbl, hash); spin_lock_bh(old_lock); @@ -403,7 +366,8 @@ static bool __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, tbl = rht_dereference_rcu(old_tbl->future_tbl, ht) ?: old_tbl; if (tbl != old_tbl) { hash = head_hashfn(ht, tbl, obj); - spin_lock_nested(bucket_lock(tbl, hash), SINGLE_DEPTH_NESTING); + spin_lock_nested(rht_bucket_lock(tbl, hash), + SINGLE_DEPTH_NESTING); } if (compare && @@ -430,7 +394,7 @@ static bool __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, exit: if (tbl != old_tbl) - spin_unlock(bucket_lock(tbl, hash)); + spin_unlock(rht_bucket_lock(tbl, hash)); spin_unlock_bh(old_lock); @@ -471,7 +435,7 @@ static bool __rhashtable_remove(struct rhashtable *ht, bool ret = false; hash = head_hashfn(ht, tbl, obj); - lock = bucket_lock(tbl, hash); + lock = rht_bucket_lock(tbl, hash); spin_lock_bh(lock); @@ -537,19 +501,6 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj) } EXPORT_SYMBOL_GPL(rhashtable_remove); -struct rhashtable_compare_arg { - struct rhashtable *ht; - const void *key; -}; - -static bool rhashtable_compare(void *ptr, void *arg) -{ - struct rhashtable_compare_arg *x = arg; - struct rhashtable *ht = x->ht; - - return !memcmp(ptr + ht->p.key_offset, x->key, ht->p.key_len); -} - /** * rhashtable_lookup - lookup key in hash table * @ht: hash table @@ -565,14 +516,7 @@ static bool rhashtable_compare(void *ptr, void *arg) */ void *rhashtable_lookup(struct rhashtable *ht, const void *key) { - struct rhashtable_compare_arg arg = { - .ht = ht, - .key = key, - }; - - BUG_ON(!ht->p.key_len); - - return rhashtable_lookup_compare(ht, key, &rhashtable_compare, &arg); + return rhashtable_lookup_fast(ht, key, ht->p); } EXPORT_SYMBOL_GPL(rhashtable_lookup); @@ -591,7 +535,8 @@ EXPORT_SYMBOL_GPL(rhashtable_lookup); * Returns the first entry on which the compare function returned true. */ void *rhashtable_lookup_compare(struct rhashtable *ht, const void *key, - bool (*compare)(void *, void *), void *arg) + bool (*compare)(void *, void *), + void *arg) { const struct bucket_table *tbl; struct rhash_head *he; @@ -601,7 +546,7 @@ void *rhashtable_lookup_compare(struct rhashtable *ht, const void *key, tbl = rht_dereference_rcu(ht->tbl, ht); restart: - hash = key_hashfn(ht, tbl, key); + hash = rht_key_hashfn(ht, tbl, key, ht->p); rht_for_each_rcu(he, tbl, hash) { if (!compare(rht_obj(ht, he), arg)) continue; @@ -643,15 +588,7 @@ EXPORT_SYMBOL_GPL(rhashtable_lookup_compare); */ bool rhashtable_lookup_insert(struct rhashtable *ht, struct rhash_head *obj) { - struct rhashtable_compare_arg arg = { - .ht = ht, - .key = rht_obj(ht, obj) + ht->p.key_offset, - }; - - BUG_ON(!ht->p.key_len); - - return rhashtable_lookup_compare_insert(ht, obj, &rhashtable_compare, - &arg); + return rhashtable_lookup_insert_fast(ht, obj, ht->p); } EXPORT_SYMBOL_GPL(rhashtable_lookup_insert); @@ -927,8 +864,8 @@ int rhashtable_init(struct rhashtable *ht, size = HASH_DEFAULT_SIZE; - if ((params->key_len && !params->hashfn) || - (!params->key_len && !params->obj_hashfn)) + if ((!(params->key_len && params->hashfn) && !params->obj_hashfn) || + (params->obj_hashfn && !params->obj_cmpfn)) return -EINVAL; if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT)) |