X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fsunrpc%2Fcache.h;h=3699dff7db8fd3c129488745f9e851d7abbf56e1;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=c4e3ea7cf1545e5da79e504c8fabddbc1f4a8d87;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index c4e3ea7cf..3699dff7d 100644 --- a/include/linux/sunrpc/cache.h +++ b/include/linux/sunrpc/cache.h @@ -50,7 +50,7 @@ struct cache_head { time_t last_refresh; /* If CACHE_PENDING, this is when upcall * was sent, else this is when update was received */ - atomic_t refcnt; + struct kref ref; unsigned long flags; }; #define CACHE_VALID 0 /* Entry contains valid data */ @@ -68,8 +68,7 @@ struct cache_detail { atomic_t inuse; /* active user-space update or lookup */ char *name; - void (*cache_put)(struct cache_head *, - struct cache_detail*); + void (*cache_put)(struct kref *); void (*cache_request)(struct cache_detail *cd, struct cache_head *h, @@ -81,6 +80,11 @@ struct cache_detail { struct cache_detail *cd, struct cache_head *h); + struct cache_head * (*alloc)(void); + int (*match)(struct cache_head *orig, struct cache_head *new); + void (*init)(struct cache_head *orig, struct cache_head *new); + void (*update)(struct cache_head *orig, struct cache_head *new); + /* fields below this comment are for internal use * and should not be touched by cache owners */ @@ -123,126 +127,14 @@ struct cache_deferred_req { int too_many); }; -/* - * just like a template in C++, this macro does cache lookup - * for us. - * The function is passed some sort of HANDLE from which a cache_detail - * structure can be determined (via SETUP, DETAIL), a template - * cache entry (type RTN*), and a "set" flag. Using the HASHFN and the - * TEST, the function will try to find a matching cache entry in the cache. - * If "set" == 0 : - * If an entry is found, it is returned - * If no entry is found, a new non-VALID entry is created. - * If "set" == 1 and INPLACE == 0 : - * If no entry is found a new one is inserted with data from "template" - * If a non-CACHE_VALID entry is found, it is updated from template using UPDATE - * If a CACHE_VALID entry is found, a new entry is swapped in with data - * from "template" - * If set == 1, and INPLACE == 1 : - * As above, except that if a CACHE_VALID entry is found, we UPDATE in place - * instead of swapping in a new entry. - * - * If the passed handle has the CACHE_NEGATIVE flag set, then UPDATE is not - * run but insteead CACHE_NEGATIVE is set in any new item. - * 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; \ -} +extern struct cache_head * +sunrpc_cache_lookup(struct cache_detail *detail, + struct cache_head *key, int hash); +extern struct cache_head * +sunrpc_cache_update(struct cache_detail *detail, + struct cache_head *new, struct cache_head *old, int hash); -#define DefineSimpleCacheLookup(STRUCT,INPLACE) \ - DefineCacheLookup(struct STRUCT, h, STRUCT##_lookup, (struct STRUCT *item, int set), /*no setup */, \ - & STRUCT##_cache, STRUCT##_hash(item), STRUCT##_match(item, tmp),\ - STRUCT##_init(new, item), STRUCT##_update(tmp, item),INPLACE) #define cache_for_each(pos, detail, index, member) \ for (({read_lock(&(detail)->hash_lock); index = (detail)->hash_size;}) ; \ @@ -258,22 +150,30 @@ extern void cache_clean_deferred(void *owner); static inline struct cache_head *cache_get(struct cache_head *h) { - atomic_inc(&h->refcnt); + kref_get(&h->ref); return h; } -static inline int cache_put(struct cache_head *h, struct cache_detail *cd) +static inline void cache_put(struct cache_head *h, struct cache_detail *cd) { - if (atomic_read(&h->refcnt) <= 2 && + if (atomic_read(&h->ref.refcount) <= 2 && h->expiry_time < cd->nextcheck) cd->nextcheck = h->expiry_time; - return atomic_dec_and_test(&h->refcnt); + kref_put(&h->ref, cd->cache_put); +} + +static inline int cache_valid(struct cache_head *h) +{ + /* If an item has been unhashed pending removal when + * the refcount drops to 0, the expiry_time will be + * set to 0. We don't want to consider such items + * valid in this context even though CACHE_VALID is + * set. + */ + return (h->expiry_time != 0 && test_bit(CACHE_VALID, &h->flags)); } -extern void cache_init(struct cache_head *h); -extern void cache_fresh(struct cache_detail *detail, - struct cache_head *head, time_t expiry); extern int cache_check(struct cache_detail *detail, struct cache_head *h, struct cache_req *rqstp); extern void cache_flush(void);