- * In any case, the new entry is returned with a reference count.
- *
- *
- * RTN is a struct type for a cache entry
- * MEMBER is the member of the cache which is cache_head, which must be first
- * FNAME is the name for the function
- * ARGS are arguments to function and must contain RTN *item, int set. May
- * also contain something to be usedby SETUP or DETAIL to find cache_detail.
- * SETUP locates the cache detail and makes it available as...
- * DETAIL identifies the cache detail, possibly set up by SETUP
- * HASHFN returns a hash value of the cache entry "item"
- * TEST tests if "tmp" matches "item"
- * INIT copies key information from "item" to "new"
- * UPDATE copies content information from "item" to "tmp"
- * INPLACE is true if updates can happen inplace rather than allocating a new structure
- *
- * WARNING: any substantial changes to this must be reflected in
- * net/sunrpc/svcauth.c(auth_domain_lookup)
- * which is a similar routine that is open-coded.
- */
-#define DefineCacheLookup(RTN,MEMBER,FNAME,ARGS,SETUP,DETAIL,HASHFN,TEST,INIT,UPDATE,INPLACE) \
-RTN *FNAME ARGS \
-{ \
- RTN *tmp, *new=NULL; \
- struct cache_head **hp, **head; \
- SETUP; \
- head = &(DETAIL)->hash_table[HASHFN]; \
- retry: \
- if (set||new) write_lock(&(DETAIL)->hash_lock); \
- else read_lock(&(DETAIL)->hash_lock); \
- for(hp=head; *hp != NULL; hp = &tmp->MEMBER.next) { \
- tmp = container_of(*hp, RTN, MEMBER); \
- if (TEST) { /* found a match */ \
- \
- if (set && !INPLACE && test_bit(CACHE_VALID, &tmp->MEMBER.flags) && !new) \
- break; \
- \
- if (new) \
- {INIT;} \
- if (set) { \
- if (!INPLACE && test_bit(CACHE_VALID, &tmp->MEMBER.flags))\
- { /* need to swap in new */ \
- RTN *t2; \
- \
- new->MEMBER.next = tmp->MEMBER.next; \
- *hp = &new->MEMBER; \
- tmp->MEMBER.next = NULL; \
- t2 = tmp; tmp = new; new = t2; \
- } \
- if (test_bit(CACHE_NEGATIVE, &item->MEMBER.flags)) \
- set_bit(CACHE_NEGATIVE, &tmp->MEMBER.flags); \
- else { \
- UPDATE; \
- clear_bit(CACHE_NEGATIVE, &tmp->MEMBER.flags); \
- } \
- } \
- cache_get(&tmp->MEMBER); \
- if (set||new) write_unlock(&(DETAIL)->hash_lock); \
- else read_unlock(&(DETAIL)->hash_lock); \
- if (set) \
- cache_fresh(DETAIL, &tmp->MEMBER, item->MEMBER.expiry_time); \
- if (set && !INPLACE && new) cache_fresh(DETAIL, &new->MEMBER, 0); \
- if (new) (DETAIL)->cache_put(&new->MEMBER, DETAIL); \
- return tmp; \
- } \
- } \
- /* Didn't find anything */ \
- if (new) { \
- INIT; \
- new->MEMBER.next = *head; \
- *head = &new->MEMBER; \
- (DETAIL)->entries ++; \
- cache_get(&new->MEMBER); \
- if (set) { \
- tmp = new; \
- if (test_bit(CACHE_NEGATIVE, &item->MEMBER.flags)) \
- set_bit(CACHE_NEGATIVE, &tmp->MEMBER.flags); \
- else {UPDATE;} \
- } \
- } \
- if (set||new) write_unlock(&(DETAIL)->hash_lock); \
- else read_unlock(&(DETAIL)->hash_lock); \
- if (new && set) \
- cache_fresh(DETAIL, &new->MEMBER, item->MEMBER.expiry_time); \
- if (new) \
- return new; \
- new = kmalloc(sizeof(*new), GFP_KERNEL); \
- if (new) { \
- cache_init(&new->MEMBER); \
- goto retry; \
- } \
- return NULL; \
-}