11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Implementation of the hash table type. 31da177e4SLinus Torvalds * 47efbb60bSStephen Smalley * Author : Stephen Smalley, <sds@tycho.nsa.gov> 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/kernel.h> 71da177e4SLinus Torvalds #include <linux/slab.h> 81da177e4SLinus Torvalds #include <linux/errno.h> 9ed1c9642SDave Jones #include <linux/sched.h> 101da177e4SLinus Torvalds #include "hashtab.h" 111da177e4SLinus Torvalds 127c620eceSKyeongdon Kim static struct kmem_cache *hashtab_node_cachep; 137c620eceSKyeongdon Kim 14bb242497SChad Sellers struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key), 15bb242497SChad Sellers int (*keycmp)(struct hashtab *h, const void *key1, const void *key2), 161da177e4SLinus Torvalds u32 size) 171da177e4SLinus Torvalds { 181da177e4SLinus Torvalds struct hashtab *p; 191da177e4SLinus Torvalds u32 i; 201da177e4SLinus Torvalds 2189d155efSJames Morris p = kzalloc(sizeof(*p), GFP_KERNEL); 22cb8d21e3SMarkus Elfring if (!p) 231da177e4SLinus Torvalds return p; 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds p->size = size; 261da177e4SLinus Torvalds p->nel = 0; 271da177e4SLinus Torvalds p->hash_value = hash_value; 281da177e4SLinus Torvalds p->keycmp = keycmp; 292f00e680SMarkus Elfring p->htable = kmalloc_array(size, sizeof(*p->htable), GFP_KERNEL); 30cb8d21e3SMarkus Elfring if (!p->htable) { 311da177e4SLinus Torvalds kfree(p); 321da177e4SLinus Torvalds return NULL; 331da177e4SLinus Torvalds } 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds for (i = 0; i < size; i++) 361da177e4SLinus Torvalds p->htable[i] = NULL; 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds return p; 391da177e4SLinus Torvalds } 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds int hashtab_insert(struct hashtab *h, void *key, void *datum) 421da177e4SLinus Torvalds { 431da177e4SLinus Torvalds u32 hvalue; 441da177e4SLinus Torvalds struct hashtab_node *prev, *cur, *newnode; 451da177e4SLinus Torvalds 46ed1c9642SDave Jones cond_resched(); 47ed1c9642SDave Jones 481da177e4SLinus Torvalds if (!h || h->nel == HASHTAB_MAX_NODES) 491da177e4SLinus Torvalds return -EINVAL; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds hvalue = h->hash_value(h, key); 521da177e4SLinus Torvalds prev = NULL; 531da177e4SLinus Torvalds cur = h->htable[hvalue]; 541da177e4SLinus Torvalds while (cur && h->keycmp(h, key, cur->key) > 0) { 551da177e4SLinus Torvalds prev = cur; 561da177e4SLinus Torvalds cur = cur->next; 571da177e4SLinus Torvalds } 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds if (cur && (h->keycmp(h, key, cur->key) == 0)) 601da177e4SLinus Torvalds return -EEXIST; 611da177e4SLinus Torvalds 627c620eceSKyeongdon Kim newnode = kmem_cache_zalloc(hashtab_node_cachep, GFP_KERNEL); 63cb8d21e3SMarkus Elfring if (!newnode) 641da177e4SLinus Torvalds return -ENOMEM; 651da177e4SLinus Torvalds newnode->key = key; 661da177e4SLinus Torvalds newnode->datum = datum; 671da177e4SLinus Torvalds if (prev) { 681da177e4SLinus Torvalds newnode->next = prev->next; 691da177e4SLinus Torvalds prev->next = newnode; 701da177e4SLinus Torvalds } else { 711da177e4SLinus Torvalds newnode->next = h->htable[hvalue]; 721da177e4SLinus Torvalds h->htable[hvalue] = newnode; 731da177e4SLinus Torvalds } 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds h->nel++; 761da177e4SLinus Torvalds return 0; 771da177e4SLinus Torvalds } 781da177e4SLinus Torvalds 79bb242497SChad Sellers void *hashtab_search(struct hashtab *h, const void *key) 801da177e4SLinus Torvalds { 811da177e4SLinus Torvalds u32 hvalue; 821da177e4SLinus Torvalds struct hashtab_node *cur; 831da177e4SLinus Torvalds 841da177e4SLinus Torvalds if (!h) 851da177e4SLinus Torvalds return NULL; 861da177e4SLinus Torvalds 871da177e4SLinus Torvalds hvalue = h->hash_value(h, key); 881da177e4SLinus Torvalds cur = h->htable[hvalue]; 89dbc74c65SVesa-Matti Kari while (cur && h->keycmp(h, key, cur->key) > 0) 901da177e4SLinus Torvalds cur = cur->next; 911da177e4SLinus Torvalds 92cb8d21e3SMarkus Elfring if (!cur || (h->keycmp(h, key, cur->key) != 0)) 931da177e4SLinus Torvalds return NULL; 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds return cur->datum; 961da177e4SLinus Torvalds } 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds void hashtab_destroy(struct hashtab *h) 991da177e4SLinus Torvalds { 1001da177e4SLinus Torvalds u32 i; 1011da177e4SLinus Torvalds struct hashtab_node *cur, *temp; 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds if (!h) 1041da177e4SLinus Torvalds return; 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds for (i = 0; i < h->size; i++) { 1071da177e4SLinus Torvalds cur = h->htable[i]; 108dbc74c65SVesa-Matti Kari while (cur) { 1091da177e4SLinus Torvalds temp = cur; 1101da177e4SLinus Torvalds cur = cur->next; 1117c620eceSKyeongdon Kim kmem_cache_free(hashtab_node_cachep, temp); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds h->htable[i] = NULL; 1141da177e4SLinus Torvalds } 1151da177e4SLinus Torvalds 1161da177e4SLinus Torvalds kfree(h->htable); 1171da177e4SLinus Torvalds h->htable = NULL; 1181da177e4SLinus Torvalds 1191da177e4SLinus Torvalds kfree(h); 1201da177e4SLinus Torvalds } 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds int hashtab_map(struct hashtab *h, 1231da177e4SLinus Torvalds int (*apply)(void *k, void *d, void *args), 1241da177e4SLinus Torvalds void *args) 1251da177e4SLinus Torvalds { 1261da177e4SLinus Torvalds u32 i; 1271da177e4SLinus Torvalds int ret; 1281da177e4SLinus Torvalds struct hashtab_node *cur; 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds if (!h) 1311da177e4SLinus Torvalds return 0; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds for (i = 0; i < h->size; i++) { 1341da177e4SLinus Torvalds cur = h->htable[i]; 135dbc74c65SVesa-Matti Kari while (cur) { 1361da177e4SLinus Torvalds ret = apply(cur->key, cur->datum, args); 1371da177e4SLinus Torvalds if (ret) 1381da177e4SLinus Torvalds return ret; 1391da177e4SLinus Torvalds cur = cur->next; 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds } 1421da177e4SLinus Torvalds return 0; 1431da177e4SLinus Torvalds } 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvalds 1461da177e4SLinus Torvalds void hashtab_stat(struct hashtab *h, struct hashtab_info *info) 1471da177e4SLinus Torvalds { 1481da177e4SLinus Torvalds u32 i, chain_len, slots_used, max_chain_len; 1491da177e4SLinus Torvalds struct hashtab_node *cur; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds slots_used = 0; 1521da177e4SLinus Torvalds max_chain_len = 0; 1535794ed76SColin Ian King for (i = 0; i < h->size; i++) { 1541da177e4SLinus Torvalds cur = h->htable[i]; 1551da177e4SLinus Torvalds if (cur) { 1561da177e4SLinus Torvalds slots_used++; 1571da177e4SLinus Torvalds chain_len = 0; 1581da177e4SLinus Torvalds while (cur) { 1591da177e4SLinus Torvalds chain_len++; 1601da177e4SLinus Torvalds cur = cur->next; 1611da177e4SLinus Torvalds } 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds if (chain_len > max_chain_len) 1641da177e4SLinus Torvalds max_chain_len = chain_len; 1651da177e4SLinus Torvalds } 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds info->slots_used = slots_used; 1691da177e4SLinus Torvalds info->max_chain_len = max_chain_len; 1701da177e4SLinus Torvalds } 1717c620eceSKyeongdon Kim void hashtab_cache_init(void) 1727c620eceSKyeongdon Kim { 1737c620eceSKyeongdon Kim hashtab_node_cachep = kmem_cache_create("hashtab_node", 1747c620eceSKyeongdon Kim sizeof(struct hashtab_node), 1757c620eceSKyeongdon Kim 0, SLAB_PANIC, NULL); 1767c620eceSKyeongdon Kim } 1777c620eceSKyeongdon Kim 1787c620eceSKyeongdon Kim void hashtab_cache_destroy(void) 1797c620eceSKyeongdon Kim { 1807c620eceSKyeongdon Kim kmem_cache_destroy(hashtab_node_cachep); 1817c620eceSKyeongdon Kim } 182