diff options
Diffstat (limited to 'drivers/staging/lustre/include/linux/libcfs/libcfs_hash.h')
-rw-r--r-- | drivers/staging/lustre/include/linux/libcfs/libcfs_hash.h | 869 |
1 files changed, 0 insertions, 869 deletions
diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_hash.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_hash.h deleted file mode 100644 index be315958a4b3..000000000000 --- a/drivers/staging/lustre/include/linux/libcfs/libcfs_hash.h +++ /dev/null @@ -1,869 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * GPL HEADER START - * - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 only, - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License version 2 for more details (a copy is included - * in the LICENSE file that accompanied this code). - * - * You should have received a copy of the GNU General Public License - * version 2 along with this program; If not, see - * http://www.gnu.org/licenses/gpl-2.0.html - * - * GPL HEADER END - */ -/* - * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. - * Use is subject to license terms. - * - * Copyright (c) 2012, 2015 Intel Corporation. - */ -/* - * This file is part of Lustre, http://www.lustre.org/ - * Lustre is a trademark of Sun Microsystems, Inc. - * - * libcfs/include/libcfs/libcfs_hash.h - * - * Hashing routines - * - */ - -#ifndef __LIBCFS_HASH_H__ -#define __LIBCFS_HASH_H__ - -#include <linux/hash.h> -#include <linux/spinlock.h> -#include <linux/workqueue.h> -#include <linux/libcfs/libcfs.h> - -/* - * Knuth recommends primes in approximately golden ratio to the maximum - * integer representable by a machine word for multiplicative hashing. - * Chuck Lever verified the effectiveness of this technique: - * http://www.citi.umich.edu/techreports/reports/citi-tr-00-1.pdf - * - * These primes are chosen to be bit-sparse, that is operations on - * them can use shifts and additions instead of multiplications for - * machines where multiplications are slow. - */ -/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */ -#define CFS_GOLDEN_RATIO_PRIME_32 0x9e370001UL -/* 2^63 + 2^61 - 2^57 + 2^54 - 2^51 - 2^18 + 1 */ -#define CFS_GOLDEN_RATIO_PRIME_64 0x9e37fffffffc0001ULL - -/** disable debug */ -#define CFS_HASH_DEBUG_NONE 0 -/* - * record hash depth and output to console when it's too deep, - * computing overhead is low but consume more memory - */ -#define CFS_HASH_DEBUG_1 1 -/** expensive, check key validation */ -#define CFS_HASH_DEBUG_2 2 - -#define CFS_HASH_DEBUG_LEVEL CFS_HASH_DEBUG_NONE - -struct cfs_hash_ops; -struct cfs_hash_lock_ops; -struct cfs_hash_hlist_ops; - -union cfs_hash_lock { - rwlock_t rw; /**< rwlock */ - spinlock_t spin; /**< spinlock */ -}; - -/** - * cfs_hash_bucket is a container of: - * - lock, counter ... - * - array of hash-head starting from hsb_head[0], hash-head can be one of - * . struct cfs_hash_head - * . struct cfs_hash_head_dep - * . struct cfs_hash_dhead - * . struct cfs_hash_dhead_dep - * which depends on requirement of user - * - some extra bytes (caller can require it while creating hash) - */ -struct cfs_hash_bucket { - union cfs_hash_lock hsb_lock; /**< bucket lock */ - u32 hsb_count; /**< current entries */ - u32 hsb_version; /**< change version */ - unsigned int hsb_index; /**< index of bucket */ - int hsb_depmax; /**< max depth on bucket */ - long hsb_head[0]; /**< hash-head array */ -}; - -/** - * cfs_hash bucket descriptor, it's normally in stack of caller - */ -struct cfs_hash_bd { - /* address of bucket */ - struct cfs_hash_bucket *bd_bucket; - /* offset in bucket */ - unsigned int bd_offset; -}; - -#define CFS_HASH_NAME_LEN 16 /**< default name length */ -#define CFS_HASH_BIGNAME_LEN 64 /**< bigname for param tree */ - -#define CFS_HASH_BKT_BITS 3 /**< default bits of bucket */ -#define CFS_HASH_BITS_MAX 30 /**< max bits of bucket */ -#define CFS_HASH_BITS_MIN CFS_HASH_BKT_BITS - -/** - * common hash attributes. - */ -enum cfs_hash_tag { - /** - * don't need any lock, caller will protect operations with it's - * own lock. With this flag: - * . CFS_HASH_NO_BKTLOCK, CFS_HASH_RW_BKTLOCK, CFS_HASH_SPIN_BKTLOCK - * will be ignored. - * . Some functions will be disabled with this flag, i.e: - * cfs_hash_for_each_empty, cfs_hash_rehash - */ - CFS_HASH_NO_LOCK = BIT(0), - /** no bucket lock, use one spinlock to protect the whole hash */ - CFS_HASH_NO_BKTLOCK = BIT(1), - /** rwlock to protect bucket */ - CFS_HASH_RW_BKTLOCK = BIT(2), - /** spinlock to protect bucket */ - CFS_HASH_SPIN_BKTLOCK = BIT(3), - /** always add new item to tail */ - CFS_HASH_ADD_TAIL = BIT(4), - /** hash-table doesn't have refcount on item */ - CFS_HASH_NO_ITEMREF = BIT(5), - /** big name for param-tree */ - CFS_HASH_BIGNAME = BIT(6), - /** track global count */ - CFS_HASH_COUNTER = BIT(7), - /** rehash item by new key */ - CFS_HASH_REHASH_KEY = BIT(8), - /** Enable dynamic hash resizing */ - CFS_HASH_REHASH = BIT(9), - /** can shrink hash-size */ - CFS_HASH_SHRINK = BIT(10), - /** assert hash is empty on exit */ - CFS_HASH_ASSERT_EMPTY = BIT(11), - /** record hlist depth */ - CFS_HASH_DEPTH = BIT(12), - /** - * rehash is always scheduled in a different thread, so current - * change on hash table is non-blocking - */ - CFS_HASH_NBLK_CHANGE = BIT(13), - /** - * NB, we typed hs_flags as u16, please change it - * if you need to extend >=16 flags - */ -}; - -/** most used attributes */ -#define CFS_HASH_DEFAULT (CFS_HASH_RW_BKTLOCK | \ - CFS_HASH_COUNTER | CFS_HASH_REHASH) - -/** - * cfs_hash is a hash-table implementation for general purpose, it can support: - * . two refcount modes - * hash-table with & without refcount - * . four lock modes - * nolock, one-spinlock, rw-bucket-lock, spin-bucket-lock - * . general operations - * lookup, add(add_tail or add_head), delete - * . rehash - * grows or shrink - * . iteration - * locked iteration and unlocked iteration - * . bigname - * support long name hash - * . debug - * trace max searching depth - * - * Rehash: - * When the htable grows or shrinks, a separate task (cfs_hash_rehash_worker) - * is spawned to handle the rehash in the background, it's possible that other - * processes can concurrently perform additions, deletions, and lookups - * without being blocked on rehash completion, because rehash will release - * the global wrlock for each bucket. - * - * rehash and iteration can't run at the same time because it's too tricky - * to keep both of them safe and correct. - * As they are relatively rare operations, so: - * . if iteration is in progress while we try to launch rehash, then - * it just giveup, iterator will launch rehash at the end. - * . if rehash is in progress while we try to iterate the hash table, - * then we just wait (shouldn't be very long time), anyway, nobody - * should expect iteration of whole hash-table to be non-blocking. - * - * During rehashing, a (key,object) pair may be in one of two buckets, - * depending on whether the worker task has yet to transfer the object - * to its new location in the table. Lookups and deletions need to search both - * locations; additions must take care to only insert into the new bucket. - */ - -struct cfs_hash { - /** - * serialize with rehash, or serialize all operations if - * the hash-table has CFS_HASH_NO_BKTLOCK - */ - union cfs_hash_lock hs_lock; - /** hash operations */ - struct cfs_hash_ops *hs_ops; - /** hash lock operations */ - struct cfs_hash_lock_ops *hs_lops; - /** hash list operations */ - struct cfs_hash_hlist_ops *hs_hops; - /** hash buckets-table */ - struct cfs_hash_bucket **hs_buckets; - /** total number of items on this hash-table */ - atomic_t hs_count; - /** hash flags, see cfs_hash_tag for detail */ - u16 hs_flags; - /** # of extra-bytes for bucket, for user saving extended attributes */ - u16 hs_extra_bytes; - /** wants to iterate */ - u8 hs_iterating; - /** hash-table is dying */ - u8 hs_exiting; - /** current hash bits */ - u8 hs_cur_bits; - /** min hash bits */ - u8 hs_min_bits; - /** max hash bits */ - u8 hs_max_bits; - /** bits for rehash */ - u8 hs_rehash_bits; - /** bits for each bucket */ - u8 hs_bkt_bits; - /** resize min threshold */ - u16 hs_min_theta; - /** resize max threshold */ - u16 hs_max_theta; - /** resize count */ - u32 hs_rehash_count; - /** # of iterators (caller of cfs_hash_for_each_*) */ - u32 hs_iterators; - /** rehash workitem */ - struct work_struct hs_rehash_work; - /** refcount on this hash table */ - atomic_t hs_refcount; - /** rehash buckets-table */ - struct cfs_hash_bucket **hs_rehash_buckets; -#if CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1 - /** serialize debug members */ - spinlock_t hs_dep_lock; - /** max depth */ - unsigned int hs_dep_max; - /** id of the deepest bucket */ - unsigned int hs_dep_bkt; - /** offset in the deepest bucket */ - unsigned int hs_dep_off; - /** bits when we found the max depth */ - unsigned int hs_dep_bits; - /** workitem to output max depth */ - struct work_struct hs_dep_work; -#endif - /** name of htable */ - char hs_name[0]; -}; - -struct cfs_hash_lock_ops { - /** lock the hash table */ - void (*hs_lock)(union cfs_hash_lock *lock, int exclusive); - /** unlock the hash table */ - void (*hs_unlock)(union cfs_hash_lock *lock, int exclusive); - /** lock the hash bucket */ - void (*hs_bkt_lock)(union cfs_hash_lock *lock, int exclusive); - /** unlock the hash bucket */ - void (*hs_bkt_unlock)(union cfs_hash_lock *lock, int exclusive); -}; - -struct cfs_hash_hlist_ops { - /** return hlist_head of hash-head of @bd */ - struct hlist_head *(*hop_hhead)(struct cfs_hash *hs, - struct cfs_hash_bd *bd); - /** return hash-head size */ - int (*hop_hhead_size)(struct cfs_hash *hs); - /** add @hnode to hash-head of @bd */ - int (*hop_hnode_add)(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode); - /** remove @hnode from hash-head of @bd */ - int (*hop_hnode_del)(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode); -}; - -struct cfs_hash_ops { - /** return hashed value from @key */ - unsigned int (*hs_hash)(struct cfs_hash *hs, const void *key, - unsigned int mask); - /** return key address of @hnode */ - void * (*hs_key)(struct hlist_node *hnode); - /** copy key from @hnode to @key */ - void (*hs_keycpy)(struct hlist_node *hnode, void *key); - /** - * compare @key with key of @hnode - * returns 1 on a match - */ - int (*hs_keycmp)(const void *key, struct hlist_node *hnode); - /** return object address of @hnode, i.e: container_of(...hnode) */ - void * (*hs_object)(struct hlist_node *hnode); - /** get refcount of item, always called with holding bucket-lock */ - void (*hs_get)(struct cfs_hash *hs, struct hlist_node *hnode); - /** release refcount of item */ - void (*hs_put)(struct cfs_hash *hs, struct hlist_node *hnode); - /** release refcount of item, always called with holding bucket-lock */ - void (*hs_put_locked)(struct cfs_hash *hs, - struct hlist_node *hnode); - /** it's called before removing of @hnode */ - void (*hs_exit)(struct cfs_hash *hs, struct hlist_node *hnode); -}; - -/** total number of buckets in @hs */ -#define CFS_HASH_NBKT(hs) \ - BIT((hs)->hs_cur_bits - (hs)->hs_bkt_bits) - -/** total number of buckets in @hs while rehashing */ -#define CFS_HASH_RH_NBKT(hs) \ - BIT((hs)->hs_rehash_bits - (hs)->hs_bkt_bits) - -/** number of hlist for in bucket */ -#define CFS_HASH_BKT_NHLIST(hs) BIT((hs)->hs_bkt_bits) - -/** total number of hlist in @hs */ -#define CFS_HASH_NHLIST(hs) BIT((hs)->hs_cur_bits) - -/** total number of hlist in @hs while rehashing */ -#define CFS_HASH_RH_NHLIST(hs) BIT((hs)->hs_rehash_bits) - -static inline int -cfs_hash_with_no_lock(struct cfs_hash *hs) -{ - /* caller will serialize all operations for this hash-table */ - return hs->hs_flags & CFS_HASH_NO_LOCK; -} - -static inline int -cfs_hash_with_no_bktlock(struct cfs_hash *hs) -{ - /* no bucket lock, one single lock to protect the hash-table */ - return hs->hs_flags & CFS_HASH_NO_BKTLOCK; -} - -static inline int -cfs_hash_with_rw_bktlock(struct cfs_hash *hs) -{ - /* rwlock to protect hash bucket */ - return hs->hs_flags & CFS_HASH_RW_BKTLOCK; -} - -static inline int -cfs_hash_with_spin_bktlock(struct cfs_hash *hs) -{ - /* spinlock to protect hash bucket */ - return hs->hs_flags & CFS_HASH_SPIN_BKTLOCK; -} - -static inline int -cfs_hash_with_add_tail(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_ADD_TAIL; -} - -static inline int -cfs_hash_with_no_itemref(struct cfs_hash *hs) -{ - /* - * hash-table doesn't keep refcount on item, - * item can't be removed from hash unless it's - * ZERO refcount - */ - return hs->hs_flags & CFS_HASH_NO_ITEMREF; -} - -static inline int -cfs_hash_with_bigname(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_BIGNAME; -} - -static inline int -cfs_hash_with_counter(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_COUNTER; -} - -static inline int -cfs_hash_with_rehash(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_REHASH; -} - -static inline int -cfs_hash_with_rehash_key(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_REHASH_KEY; -} - -static inline int -cfs_hash_with_shrink(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_SHRINK; -} - -static inline int -cfs_hash_with_assert_empty(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_ASSERT_EMPTY; -} - -static inline int -cfs_hash_with_depth(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_DEPTH; -} - -static inline int -cfs_hash_with_nblk_change(struct cfs_hash *hs) -{ - return hs->hs_flags & CFS_HASH_NBLK_CHANGE; -} - -static inline int -cfs_hash_is_exiting(struct cfs_hash *hs) -{ - /* cfs_hash_destroy is called */ - return hs->hs_exiting; -} - -static inline int -cfs_hash_is_rehashing(struct cfs_hash *hs) -{ - /* rehash is launched */ - return !!hs->hs_rehash_bits; -} - -static inline int -cfs_hash_is_iterating(struct cfs_hash *hs) -{ - /* someone is calling cfs_hash_for_each_* */ - return hs->hs_iterating || hs->hs_iterators; -} - -static inline int -cfs_hash_bkt_size(struct cfs_hash *hs) -{ - return offsetof(struct cfs_hash_bucket, hsb_head[0]) + - hs->hs_hops->hop_hhead_size(hs) * CFS_HASH_BKT_NHLIST(hs) + - hs->hs_extra_bytes; -} - -static inline unsigned -cfs_hash_id(struct cfs_hash *hs, const void *key, unsigned int mask) -{ - return hs->hs_ops->hs_hash(hs, key, mask); -} - -static inline void * -cfs_hash_key(struct cfs_hash *hs, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_key(hnode); -} - -static inline void -cfs_hash_keycpy(struct cfs_hash *hs, struct hlist_node *hnode, void *key) -{ - if (hs->hs_ops->hs_keycpy) - hs->hs_ops->hs_keycpy(hnode, key); -} - -/** - * Returns 1 on a match, - */ -static inline int -cfs_hash_keycmp(struct cfs_hash *hs, const void *key, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_keycmp(key, hnode); -} - -static inline void * -cfs_hash_object(struct cfs_hash *hs, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_object(hnode); -} - -static inline void -cfs_hash_get(struct cfs_hash *hs, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_get(hs, hnode); -} - -static inline void -cfs_hash_put_locked(struct cfs_hash *hs, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_put_locked(hs, hnode); -} - -static inline void -cfs_hash_put(struct cfs_hash *hs, struct hlist_node *hnode) -{ - return hs->hs_ops->hs_put(hs, hnode); -} - -static inline void -cfs_hash_exit(struct cfs_hash *hs, struct hlist_node *hnode) -{ - if (hs->hs_ops->hs_exit) - hs->hs_ops->hs_exit(hs, hnode); -} - -static inline void cfs_hash_lock(struct cfs_hash *hs, int excl) -{ - hs->hs_lops->hs_lock(&hs->hs_lock, excl); -} - -static inline void cfs_hash_unlock(struct cfs_hash *hs, int excl) -{ - hs->hs_lops->hs_unlock(&hs->hs_lock, excl); -} - -static inline int cfs_hash_dec_and_lock(struct cfs_hash *hs, - atomic_t *condition) -{ - LASSERT(cfs_hash_with_no_bktlock(hs)); - return atomic_dec_and_lock(condition, &hs->hs_lock.spin); -} - -static inline void cfs_hash_bd_lock(struct cfs_hash *hs, - struct cfs_hash_bd *bd, int excl) -{ - hs->hs_lops->hs_bkt_lock(&bd->bd_bucket->hsb_lock, excl); -} - -static inline void cfs_hash_bd_unlock(struct cfs_hash *hs, - struct cfs_hash_bd *bd, int excl) -{ - hs->hs_lops->hs_bkt_unlock(&bd->bd_bucket->hsb_lock, excl); -} - -/** - * operations on cfs_hash bucket (bd: bucket descriptor), - * they are normally for hash-table without rehash - */ -void cfs_hash_bd_get(struct cfs_hash *hs, const void *key, - struct cfs_hash_bd *bd); - -static inline void -cfs_hash_bd_get_and_lock(struct cfs_hash *hs, const void *key, - struct cfs_hash_bd *bd, int excl) -{ - cfs_hash_bd_get(hs, key, bd); - cfs_hash_bd_lock(hs, bd, excl); -} - -static inline unsigned -cfs_hash_bd_index_get(struct cfs_hash *hs, struct cfs_hash_bd *bd) -{ - return bd->bd_offset | (bd->bd_bucket->hsb_index << hs->hs_bkt_bits); -} - -static inline void -cfs_hash_bd_index_set(struct cfs_hash *hs, unsigned int index, - struct cfs_hash_bd *bd) -{ - bd->bd_bucket = hs->hs_buckets[index >> hs->hs_bkt_bits]; - bd->bd_offset = index & (CFS_HASH_BKT_NHLIST(hs) - 1U); -} - -static inline void * -cfs_hash_bd_extra_get(struct cfs_hash *hs, struct cfs_hash_bd *bd) -{ - return (void *)bd->bd_bucket + - cfs_hash_bkt_size(hs) - hs->hs_extra_bytes; -} - -static inline u32 -cfs_hash_bd_version_get(struct cfs_hash_bd *bd) -{ - /* need hold cfs_hash_bd_lock */ - return bd->bd_bucket->hsb_version; -} - -static inline u32 -cfs_hash_bd_count_get(struct cfs_hash_bd *bd) -{ - /* need hold cfs_hash_bd_lock */ - return bd->bd_bucket->hsb_count; -} - -static inline int -cfs_hash_bd_depmax_get(struct cfs_hash_bd *bd) -{ - return bd->bd_bucket->hsb_depmax; -} - -static inline int -cfs_hash_bd_compare(struct cfs_hash_bd *bd1, struct cfs_hash_bd *bd2) -{ - if (bd1->bd_bucket->hsb_index != bd2->bd_bucket->hsb_index) - return bd1->bd_bucket->hsb_index - bd2->bd_bucket->hsb_index; - - if (bd1->bd_offset != bd2->bd_offset) - return bd1->bd_offset - bd2->bd_offset; - - return 0; -} - -void cfs_hash_bd_add_locked(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode); -void cfs_hash_bd_del_locked(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode); -void cfs_hash_bd_move_locked(struct cfs_hash *hs, struct cfs_hash_bd *bd_old, - struct cfs_hash_bd *bd_new, - struct hlist_node *hnode); - -static inline int -cfs_hash_bd_dec_and_lock(struct cfs_hash *hs, struct cfs_hash_bd *bd, - atomic_t *condition) -{ - LASSERT(cfs_hash_with_spin_bktlock(hs)); - return atomic_dec_and_lock(condition, &bd->bd_bucket->hsb_lock.spin); -} - -static inline struct hlist_head * -cfs_hash_bd_hhead(struct cfs_hash *hs, struct cfs_hash_bd *bd) -{ - return hs->hs_hops->hop_hhead(hs, bd); -} - -struct hlist_node * -cfs_hash_bd_lookup_locked(struct cfs_hash *hs, struct cfs_hash_bd *bd, - const void *key); -struct hlist_node * -cfs_hash_bd_peek_locked(struct cfs_hash *hs, struct cfs_hash_bd *bd, - const void *key); - -/** - * operations on cfs_hash bucket (bd: bucket descriptor), - * they are safe for hash-table with rehash - */ -void cfs_hash_dual_bd_get(struct cfs_hash *hs, const void *key, - struct cfs_hash_bd *bds); -void cfs_hash_dual_bd_lock(struct cfs_hash *hs, struct cfs_hash_bd *bds, - int excl); -void cfs_hash_dual_bd_unlock(struct cfs_hash *hs, struct cfs_hash_bd *bds, - int excl); - -static inline void -cfs_hash_dual_bd_get_and_lock(struct cfs_hash *hs, const void *key, - struct cfs_hash_bd *bds, int excl) -{ - cfs_hash_dual_bd_get(hs, key, bds); - cfs_hash_dual_bd_lock(hs, bds, excl); -} - -struct hlist_node * -cfs_hash_dual_bd_lookup_locked(struct cfs_hash *hs, struct cfs_hash_bd *bds, - const void *key); -struct hlist_node * -cfs_hash_dual_bd_findadd_locked(struct cfs_hash *hs, struct cfs_hash_bd *bds, - const void *key, struct hlist_node *hnode, - int insist_add); -struct hlist_node * -cfs_hash_dual_bd_finddel_locked(struct cfs_hash *hs, struct cfs_hash_bd *bds, - const void *key, struct hlist_node *hnode); - -/* Hash init/cleanup functions */ -struct cfs_hash * -cfs_hash_create(char *name, unsigned int cur_bits, unsigned int max_bits, - unsigned int bkt_bits, unsigned int extra_bytes, - unsigned int min_theta, unsigned int max_theta, - struct cfs_hash_ops *ops, unsigned int flags); - -struct cfs_hash *cfs_hash_getref(struct cfs_hash *hs); -void cfs_hash_putref(struct cfs_hash *hs); - -/* Hash addition functions */ -void cfs_hash_add(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode); -int cfs_hash_add_unique(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode); -void *cfs_hash_findadd_unique(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode); - -/* Hash deletion functions */ -void *cfs_hash_del(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode); -void *cfs_hash_del_key(struct cfs_hash *hs, const void *key); - -/* Hash lookup/for_each functions */ -#define CFS_HASH_LOOP_HOG 1024 - -typedef int (*cfs_hash_for_each_cb_t)(struct cfs_hash *hs, - struct cfs_hash_bd *bd, - struct hlist_node *node, - void *data); -void * -cfs_hash_lookup(struct cfs_hash *hs, const void *key); -void -cfs_hash_for_each(struct cfs_hash *hs, cfs_hash_for_each_cb_t cb, void *data); -void -cfs_hash_for_each_safe(struct cfs_hash *hs, cfs_hash_for_each_cb_t cb, - void *data); -int -cfs_hash_for_each_nolock(struct cfs_hash *hs, cfs_hash_for_each_cb_t cb, - void *data, int start); -int -cfs_hash_for_each_empty(struct cfs_hash *hs, cfs_hash_for_each_cb_t cb, - void *data); -void -cfs_hash_for_each_key(struct cfs_hash *hs, const void *key, - cfs_hash_for_each_cb_t cb, void *data); -typedef int (*cfs_hash_cond_opt_cb_t)(void *obj, void *data); -void -cfs_hash_cond_del(struct cfs_hash *hs, cfs_hash_cond_opt_cb_t cb, void *data); - -void -cfs_hash_hlist_for_each(struct cfs_hash *hs, unsigned int hindex, - cfs_hash_for_each_cb_t cb, void *data); -int cfs_hash_is_empty(struct cfs_hash *hs); -u64 cfs_hash_size_get(struct cfs_hash *hs); - -/* - * Rehash - Theta is calculated to be the average chained - * hash depth assuming a perfectly uniform hash function. - */ -void cfs_hash_rehash_cancel_locked(struct cfs_hash *hs); -void cfs_hash_rehash_cancel(struct cfs_hash *hs); -void cfs_hash_rehash(struct cfs_hash *hs, int do_rehash); -void cfs_hash_rehash_key(struct cfs_hash *hs, const void *old_key, - void *new_key, struct hlist_node *hnode); - -#if CFS_HASH_DEBUG_LEVEL > CFS_HASH_DEBUG_1 -/* Validate hnode references the correct key */ -static inline void -cfs_hash_key_validate(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode) -{ - LASSERT(cfs_hash_keycmp(hs, key, hnode)); -} - -/* Validate hnode is in the correct bucket */ -static inline void -cfs_hash_bucket_validate(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode) -{ - struct cfs_hash_bd bds[2]; - - cfs_hash_dual_bd_get(hs, cfs_hash_key(hs, hnode), bds); - LASSERT(bds[0].bd_bucket == bd->bd_bucket || - bds[1].bd_bucket == bd->bd_bucket); -} - -#else /* CFS_HASH_DEBUG_LEVEL > CFS_HASH_DEBUG_1 */ - -static inline void -cfs_hash_key_validate(struct cfs_hash *hs, const void *key, - struct hlist_node *hnode) {} - -static inline void -cfs_hash_bucket_validate(struct cfs_hash *hs, struct cfs_hash_bd *bd, - struct hlist_node *hnode) {} - -#endif /* CFS_HASH_DEBUG_LEVEL */ - -#define CFS_HASH_THETA_BITS 10 -#define CFS_HASH_MIN_THETA BIT(CFS_HASH_THETA_BITS - 1) -#define CFS_HASH_MAX_THETA BIT(CFS_HASH_THETA_BITS + 1) - -/* Return integer component of theta */ -static inline int __cfs_hash_theta_int(int theta) -{ - return (theta >> CFS_HASH_THETA_BITS); -} - -/* Return a fractional value between 0 and 999 */ -static inline int __cfs_hash_theta_frac(int theta) -{ - return ((theta * 1000) >> CFS_HASH_THETA_BITS) - - (__cfs_hash_theta_int(theta) * 1000); -} - -static inline int __cfs_hash_theta(struct cfs_hash *hs) -{ - return (atomic_read(&hs->hs_count) << - CFS_HASH_THETA_BITS) >> hs->hs_cur_bits; -} - -static inline void -__cfs_hash_set_theta(struct cfs_hash *hs, int min, int max) -{ - LASSERT(min < max); - hs->hs_min_theta = (u16)min; - hs->hs_max_theta = (u16)max; -} - -/* Generic debug formatting routines mainly for proc handler */ -struct seq_file; -void cfs_hash_debug_header(struct seq_file *m); -void cfs_hash_debug_str(struct cfs_hash *hs, struct seq_file *m); - -/* - * Generic djb2 hash algorithm for character arrays. - */ -static inline unsigned -cfs_hash_djb2_hash(const void *key, size_t size, unsigned int mask) -{ - unsigned int i, hash = 5381; - - LASSERT(key); - - for (i = 0; i < size; i++) - hash = hash * 33 + ((char *)key)[i]; - - return (hash & mask); -} - -/* - * Generic u32 hash algorithm. - */ -static inline unsigned -cfs_hash_u32_hash(const u32 key, unsigned int mask) -{ - return ((key * CFS_GOLDEN_RATIO_PRIME_32) & mask); -} - -/* - * Generic u64 hash algorithm. - */ -static inline unsigned -cfs_hash_u64_hash(const u64 key, unsigned int mask) -{ - return ((unsigned int)(key * CFS_GOLDEN_RATIO_PRIME_64) & mask); -} - -/** iterate over all buckets in @bds (array of struct cfs_hash_bd) */ -#define cfs_hash_for_each_bd(bds, n, i) \ - for (i = 0; i < n && (bds)[i].bd_bucket != NULL; i++) - -/** iterate over all buckets of @hs */ -#define cfs_hash_for_each_bucket(hs, bd, pos) \ - for (pos = 0; \ - pos < CFS_HASH_NBKT(hs) && \ - ((bd)->bd_bucket = (hs)->hs_buckets[pos]) != NULL; pos++) - -/** iterate over all hlist of bucket @bd */ -#define cfs_hash_bd_for_each_hlist(hs, bd, hlist) \ - for ((bd)->bd_offset = 0; \ - (bd)->bd_offset < CFS_HASH_BKT_NHLIST(hs) && \ - (hlist = cfs_hash_bd_hhead(hs, bd)) != NULL; \ - (bd)->bd_offset++) - -/* !__LIBCFS__HASH_H__ */ -#endif |