| /* |
| * 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.sun.com/software/products/lustre/docs/GPLv2.pdf |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| * GPL HEADER END |
| */ |
| /* |
| * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. |
| * Use is subject to license terms. |
| * |
| * Copyright (c) 2012, 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__ |
| /* |
| * 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 |
| |
| /* |
| * Ideally we would use HAVE_HASH_LONG for this, but on linux we configure |
| * the linux kernel and user space at the same time, so we need to differentiate |
| * between them explicitely. If this is not needed on other architectures, then |
| * we'll need to move the functions to archi specific headers. |
| */ |
| |
| #include <linux/hash.h> |
| |
| #define cfs_hash_long(val, bits) hash_long(val, bits) |
| |
| /** 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; |
| |
| typedef union { |
| rwlock_t rw; /**< rwlock */ |
| spinlock_t spin; /**< spinlock */ |
| } cfs_hash_lock_t; |
| |
| /** |
| * cfs_hash_bucket is a container of: |
| * - lock, couter ... |
| * - array of hash-head starting from hsb_head[0], hash-head can be one of |
| * . cfs_hash_head_t |
| * . cfs_hash_head_dep_t |
| * . cfs_hash_dhead_t |
| * . cfs_hash_dhead_dep_t |
| * which depends on requirement of user |
| * - some extra bytes (caller can require it while creating hash) |
| */ |
| typedef struct cfs_hash_bucket { |
| cfs_hash_lock_t 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_t; |
| |
| /** |
| * cfs_hash bucket descriptor, it's normally in stack of caller |
| */ |
| typedef struct cfs_hash_bd { |
| cfs_hash_bucket_t *bd_bucket; /**< address of bucket */ |
| unsigned int bd_offset; /**< offset in bucket */ |
| } cfs_hash_bd_t; |
| |
| #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 = 1 << 0, |
| /** no bucket lock, use one spinlock to protect the whole hash */ |
| CFS_HASH_NO_BKTLOCK = 1 << 1, |
| /** rwlock to protect bucket */ |
| CFS_HASH_RW_BKTLOCK = 1 << 2, |
| /** spinlcok to protect bucket */ |
| CFS_HASH_SPIN_BKTLOCK = 1 << 3, |
| /** always add new item to tail */ |
| CFS_HASH_ADD_TAIL = 1 << 4, |
| /** hash-table doesn't have refcount on item */ |
| CFS_HASH_NO_ITEMREF = 1 << 5, |
| /** big name for param-tree */ |
| CFS_HASH_BIGNAME = 1 << 6, |
| /** track global count */ |
| CFS_HASH_COUNTER = 1 << 7, |
| /** rehash item by new key */ |
| CFS_HASH_REHASH_KEY = 1 << 8, |
| /** Enable dynamic hash resizing */ |
| CFS_HASH_REHASH = 1 << 9, |
| /** can shrink hash-size */ |
| CFS_HASH_SHRINK = 1 << 10, |
| /** assert hash is empty on exit */ |
| CFS_HASH_ASSERT_EMPTY = 1 << 11, |
| /** record hlist depth */ |
| CFS_HASH_DEPTH = 1 << 12, |
| /** |
| * rehash is always scheduled in a different thread, so current |
| * change on hash table is non-blocking |
| */ |
| CFS_HASH_NBLK_CHANGE = 1 << 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. |
| */ |
| |
| typedef struct cfs_hash { |
| /** serialize with rehash, or serialize all operations if |
| * the hash-table has CFS_HASH_NO_BKTLOCK */ |
| cfs_hash_lock_t 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 */ |
| cfs_hash_bucket_t **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 */ |
| cfs_workitem_t hs_rehash_wi; |
| /** refcount on this hash table */ |
| atomic_t hs_refcount; |
| /** rehash buckets-table */ |
| cfs_hash_bucket_t **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 */ |
| cfs_workitem_t hs_dep_wi; |
| #endif |
| /** name of htable */ |
| char hs_name[0]; |
| } cfs_hash_t; |
| |
| typedef struct cfs_hash_lock_ops { |
| /** lock the hash table */ |
| void (*hs_lock)(cfs_hash_lock_t *lock, int exclusive); |
| /** unlock the hash table */ |
| void (*hs_unlock)(cfs_hash_lock_t *lock, int exclusive); |
| /** lock the hash bucket */ |
| void (*hs_bkt_lock)(cfs_hash_lock_t *lock, int exclusive); |
| /** unlock the hash bucket */ |
| void (*hs_bkt_unlock)(cfs_hash_lock_t *lock, int exclusive); |
| } cfs_hash_lock_ops_t; |
| |
| typedef struct cfs_hash_hlist_ops { |
| /** return hlist_head of hash-head of @bd */ |
| struct hlist_head *(*hop_hhead)(cfs_hash_t *hs, cfs_hash_bd_t *bd); |
| /** return hash-head size */ |
| int (*hop_hhead_size)(cfs_hash_t *hs); |
| /** add @hnode to hash-head of @bd */ |
| int (*hop_hnode_add)(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, struct hlist_node *hnode); |
| /** remove @hnode from hash-head of @bd */ |
| int (*hop_hnode_del)(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, struct hlist_node *hnode); |
| } cfs_hash_hlist_ops_t; |
| |
| typedef struct cfs_hash_ops { |
| /** return hashed value from @key */ |
| unsigned (*hs_hash)(cfs_hash_t *hs, const void *key, unsigned 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)(cfs_hash_t *hs, struct hlist_node *hnode); |
| /** release refcount of item */ |
| void (*hs_put)(cfs_hash_t *hs, struct hlist_node *hnode); |
| /** release refcount of item, always called with holding bucket-lock */ |
| void (*hs_put_locked)(cfs_hash_t *hs, struct hlist_node *hnode); |
| /** it's called before removing of @hnode */ |
| void (*hs_exit)(cfs_hash_t *hs, struct hlist_node *hnode); |
| } cfs_hash_ops_t; |
| |
| /** total number of buckets in @hs */ |
| #define CFS_HASH_NBKT(hs) \ |
| (1U << ((hs)->hs_cur_bits - (hs)->hs_bkt_bits)) |
| |
| /** total number of buckets in @hs while rehashing */ |
| #define CFS_HASH_RH_NBKT(hs) \ |
| (1U << ((hs)->hs_rehash_bits - (hs)->hs_bkt_bits)) |
| |
| /** number of hlist for in bucket */ |
| #define CFS_HASH_BKT_NHLIST(hs) (1U << (hs)->hs_bkt_bits) |
| |
| /** total number of hlist in @hs */ |
| #define CFS_HASH_NHLIST(hs) (1U << (hs)->hs_cur_bits) |
| |
| /** total number of hlist in @hs while rehashing */ |
| #define CFS_HASH_RH_NHLIST(hs) (1U << (hs)->hs_rehash_bits) |
| |
| static inline int |
| cfs_hash_with_no_lock(cfs_hash_t *hs) |
| { |
| /* caller will serialize all operations for this hash-table */ |
| return (hs->hs_flags & CFS_HASH_NO_LOCK) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_no_bktlock(cfs_hash_t *hs) |
| { |
| /* no bucket lock, one single lock to protect the hash-table */ |
| return (hs->hs_flags & CFS_HASH_NO_BKTLOCK) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_rw_bktlock(cfs_hash_t *hs) |
| { |
| /* rwlock to protect hash bucket */ |
| return (hs->hs_flags & CFS_HASH_RW_BKTLOCK) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_spin_bktlock(cfs_hash_t *hs) |
| { |
| /* spinlock to protect hash bucket */ |
| return (hs->hs_flags & CFS_HASH_SPIN_BKTLOCK) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_add_tail(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_ADD_TAIL) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_no_itemref(cfs_hash_t *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) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_bigname(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_BIGNAME) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_counter(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_COUNTER) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_rehash(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_REHASH) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_rehash_key(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_REHASH_KEY) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_shrink(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_SHRINK) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_assert_empty(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_ASSERT_EMPTY) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_depth(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_DEPTH) != 0; |
| } |
| |
| static inline int |
| cfs_hash_with_nblk_change(cfs_hash_t *hs) |
| { |
| return (hs->hs_flags & CFS_HASH_NBLK_CHANGE) != 0; |
| } |
| |
| static inline int |
| cfs_hash_is_exiting(cfs_hash_t *hs) |
| { /* cfs_hash_destroy is called */ |
| return hs->hs_exiting; |
| } |
| |
| static inline int |
| cfs_hash_is_rehashing(cfs_hash_t *hs) |
| { /* rehash is launched */ |
| return hs->hs_rehash_bits != 0; |
| } |
| |
| static inline int |
| cfs_hash_is_iterating(cfs_hash_t *hs) |
| { /* someone is calling cfs_hash_for_each_* */ |
| return hs->hs_iterating || hs->hs_iterators != 0; |
| } |
| |
| static inline int |
| cfs_hash_bkt_size(cfs_hash_t *hs) |
| { |
| return offsetof(cfs_hash_bucket_t, hsb_head[0]) + |
| hs->hs_hops->hop_hhead_size(hs) * CFS_HASH_BKT_NHLIST(hs) + |
| hs->hs_extra_bytes; |
| } |
| |
| #define CFS_HOP(hs, op) (hs)->hs_ops->hs_ ## op |
| |
| static inline unsigned |
| cfs_hash_id(cfs_hash_t *hs, const void *key, unsigned mask) |
| { |
| return CFS_HOP(hs, hash)(hs, key, mask); |
| } |
| |
| static inline void * |
| cfs_hash_key(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| return CFS_HOP(hs, key)(hnode); |
| } |
| |
| static inline void |
| cfs_hash_keycpy(cfs_hash_t *hs, struct hlist_node *hnode, void *key) |
| { |
| if (CFS_HOP(hs, keycpy) != NULL) |
| CFS_HOP(hs, keycpy)(hnode, key); |
| } |
| |
| /** |
| * Returns 1 on a match, |
| */ |
| static inline int |
| cfs_hash_keycmp(cfs_hash_t *hs, const void *key, struct hlist_node *hnode) |
| { |
| return CFS_HOP(hs, keycmp)(key, hnode); |
| } |
| |
| static inline void * |
| cfs_hash_object(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| return CFS_HOP(hs, object)(hnode); |
| } |
| |
| static inline void |
| cfs_hash_get(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| return CFS_HOP(hs, get)(hs, hnode); |
| } |
| |
| static inline void |
| cfs_hash_put_locked(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| LASSERT(CFS_HOP(hs, put_locked) != NULL); |
| |
| return CFS_HOP(hs, put_locked)(hs, hnode); |
| } |
| |
| static inline void |
| cfs_hash_put(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| LASSERT(CFS_HOP(hs, put) != NULL); |
| |
| return CFS_HOP(hs, put)(hs, hnode); |
| } |
| |
| static inline void |
| cfs_hash_exit(cfs_hash_t *hs, struct hlist_node *hnode) |
| { |
| if (CFS_HOP(hs, exit)) |
| CFS_HOP(hs, exit)(hs, hnode); |
| } |
| |
| static inline void cfs_hash_lock(cfs_hash_t *hs, int excl) |
| { |
| hs->hs_lops->hs_lock(&hs->hs_lock, excl); |
| } |
| |
| static inline void cfs_hash_unlock(cfs_hash_t *hs, int excl) |
| { |
| hs->hs_lops->hs_unlock(&hs->hs_lock, excl); |
| } |
| |
| static inline int cfs_hash_dec_and_lock(cfs_hash_t *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(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, int excl) |
| { |
| hs->hs_lops->hs_bkt_lock(&bd->bd_bucket->hsb_lock, excl); |
| } |
| |
| static inline void cfs_hash_bd_unlock(cfs_hash_t *hs, |
| cfs_hash_bd_t *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(cfs_hash_t *hs, const void *key, cfs_hash_bd_t *bd); |
| |
| static inline void cfs_hash_bd_get_and_lock(cfs_hash_t *hs, const void *key, |
| cfs_hash_bd_t *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(cfs_hash_t *hs, cfs_hash_bd_t *bd) |
| { |
| return bd->bd_offset | (bd->bd_bucket->hsb_index << hs->hs_bkt_bits); |
| } |
| |
| static inline void cfs_hash_bd_index_set(cfs_hash_t *hs, |
| unsigned index, cfs_hash_bd_t *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(cfs_hash_t *hs, cfs_hash_bd_t *bd) |
| { |
| return (void *)bd->bd_bucket + |
| cfs_hash_bkt_size(hs) - hs->hs_extra_bytes; |
| } |
| |
| static inline __u32 |
| cfs_hash_bd_version_get(cfs_hash_bd_t *bd) |
| { |
| /* need hold cfs_hash_bd_lock */ |
| return bd->bd_bucket->hsb_version; |
| } |
| |
| static inline __u32 |
| cfs_hash_bd_count_get(cfs_hash_bd_t *bd) |
| { |
| /* need hold cfs_hash_bd_lock */ |
| return bd->bd_bucket->hsb_count; |
| } |
| |
| static inline int |
| cfs_hash_bd_depmax_get(cfs_hash_bd_t *bd) |
| { |
| return bd->bd_bucket->hsb_depmax; |
| } |
| |
| static inline int |
| cfs_hash_bd_compare(cfs_hash_bd_t *bd1, cfs_hash_bd_t *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(cfs_hash_t *hs, cfs_hash_bd_t *bd, |
| struct hlist_node *hnode); |
| void cfs_hash_bd_del_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd, |
| struct hlist_node *hnode); |
| void cfs_hash_bd_move_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd_old, |
| cfs_hash_bd_t *bd_new, struct hlist_node *hnode); |
| |
| static inline int cfs_hash_bd_dec_and_lock(cfs_hash_t *hs, cfs_hash_bd_t *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(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd) |
| { |
| return hs->hs_hops->hop_hhead(hs, bd); |
| } |
| |
| struct hlist_node *cfs_hash_bd_lookup_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, const void *key); |
| struct hlist_node *cfs_hash_bd_peek_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, const void *key); |
| struct hlist_node *cfs_hash_bd_findadd_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, const void *key, |
| struct hlist_node *hnode, |
| int insist_add); |
| struct hlist_node *cfs_hash_bd_finddel_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bd, const void *key, |
| struct hlist_node *hnode); |
| |
| /** |
| * operations on cfs_hash bucket (bd: bucket descriptor), |
| * they are safe for hash-table with rehash |
| */ |
| void cfs_hash_dual_bd_get(cfs_hash_t *hs, const void *key, cfs_hash_bd_t *bds); |
| void cfs_hash_dual_bd_lock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl); |
| void cfs_hash_dual_bd_unlock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl); |
| |
| static inline void cfs_hash_dual_bd_get_and_lock(cfs_hash_t *hs, const void *key, |
| cfs_hash_bd_t *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(cfs_hash_t *hs, |
| cfs_hash_bd_t *bds, |
| const void *key); |
| struct hlist_node *cfs_hash_dual_bd_findadd_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bds, |
| const void *key, |
| struct hlist_node *hnode, |
| int insist_add); |
| struct hlist_node *cfs_hash_dual_bd_finddel_locked(cfs_hash_t *hs, |
| cfs_hash_bd_t *bds, |
| const void *key, |
| struct hlist_node *hnode); |
| |
| /* Hash init/cleanup functions */ |
| cfs_hash_t *cfs_hash_create(char *name, unsigned cur_bits, unsigned max_bits, |
| unsigned bkt_bits, unsigned extra_bytes, |
| unsigned min_theta, unsigned max_theta, |
| cfs_hash_ops_t *ops, unsigned flags); |
| |
| cfs_hash_t *cfs_hash_getref(cfs_hash_t *hs); |
| void cfs_hash_putref(cfs_hash_t *hs); |
| |
| /* Hash addition functions */ |
| void cfs_hash_add(cfs_hash_t *hs, const void *key, |
| struct hlist_node *hnode); |
| int cfs_hash_add_unique(cfs_hash_t *hs, const void *key, |
| struct hlist_node *hnode); |
| void *cfs_hash_findadd_unique(cfs_hash_t *hs, const void *key, |
| struct hlist_node *hnode); |
| |
| /* Hash deletion functions */ |
| void *cfs_hash_del(cfs_hash_t *hs, const void *key, struct hlist_node *hnode); |
| void *cfs_hash_del_key(cfs_hash_t *hs, const void *key); |
| |
| /* Hash lookup/for_each functions */ |
| #define CFS_HASH_LOOP_HOG 1024 |
| |
| typedef int (*cfs_hash_for_each_cb_t)(cfs_hash_t *hs, cfs_hash_bd_t *bd, |
| struct hlist_node *node, void *data); |
| void *cfs_hash_lookup(cfs_hash_t *hs, const void *key); |
| void cfs_hash_for_each(cfs_hash_t *hs, cfs_hash_for_each_cb_t, void *data); |
| void cfs_hash_for_each_safe(cfs_hash_t *hs, cfs_hash_for_each_cb_t, void *data); |
| int cfs_hash_for_each_nolock(cfs_hash_t *hs, |
| cfs_hash_for_each_cb_t, void *data); |
| int cfs_hash_for_each_empty(cfs_hash_t *hs, |
| cfs_hash_for_each_cb_t, void *data); |
| void cfs_hash_for_each_key(cfs_hash_t *hs, const void *key, |
| cfs_hash_for_each_cb_t, void *data); |
| typedef int (*cfs_hash_cond_opt_cb_t)(void *obj, void *data); |
| void cfs_hash_cond_del(cfs_hash_t *hs, cfs_hash_cond_opt_cb_t, void *data); |
| |
| void cfs_hash_hlist_for_each(cfs_hash_t *hs, unsigned hindex, |
| cfs_hash_for_each_cb_t, void *data); |
| int cfs_hash_is_empty(cfs_hash_t *hs); |
| __u64 cfs_hash_size_get(cfs_hash_t *hs); |
| |
| /* |
| * Rehash - Theta is calculated to be the average chained |
| * hash depth assuming a perfectly uniform hash funcion. |
| */ |
| void cfs_hash_rehash_cancel_locked(cfs_hash_t *hs); |
| void cfs_hash_rehash_cancel(cfs_hash_t *hs); |
| int cfs_hash_rehash(cfs_hash_t *hs, int do_rehash); |
| void cfs_hash_rehash_key(cfs_hash_t *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(cfs_hash_t *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(cfs_hash_t *hs, cfs_hash_bd_t *bd, |
| struct hlist_node *hnode) |
| { |
| cfs_hash_bd_t 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(cfs_hash_t *hs, const void *key, |
| struct hlist_node *hnode) {} |
| |
| static inline void |
| cfs_hash_bucket_validate(cfs_hash_t *hs, cfs_hash_bd_t *bd, |
| struct hlist_node *hnode) {} |
| |
| #endif /* CFS_HASH_DEBUG_LEVEL */ |
| |
| #define CFS_HASH_THETA_BITS 10 |
| #define CFS_HASH_MIN_THETA (1U << (CFS_HASH_THETA_BITS - 1)) |
| #define CFS_HASH_MAX_THETA (1U << (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(cfs_hash_t *hs) |
| { |
| return (atomic_read(&hs->hs_count) << |
| CFS_HASH_THETA_BITS) >> hs->hs_cur_bits; |
| } |
| |
| static inline void __cfs_hash_set_theta(cfs_hash_t *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; |
| int cfs_hash_debug_header(struct seq_file *m); |
| int cfs_hash_debug_str(cfs_hash_t *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 mask) |
| { |
| unsigned i, hash = 5381; |
| |
| LASSERT(key != NULL); |
| |
| 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 mask) |
| { |
| return ((key * CFS_GOLDEN_RATIO_PRIME_32) & mask); |
| } |
| |
| /* |
| * Generic u64 hash algorithm. |
| */ |
| static inline unsigned |
| cfs_hash_u64_hash(const __u64 key, unsigned mask) |
| { |
| return ((unsigned)(key * CFS_GOLDEN_RATIO_PRIME_64) & mask); |
| } |
| |
| /** iterate over all buckets in @bds (array of cfs_hash_bd_t) */ |
| #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 |