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Commit 15a5f6bd authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] knfsd: Create cache_lookup function instead of using a macro to declare one 



The C++-like 'template' approach proves to be too ugly and hard to work with.

The old 'template' won't go away until all users are updated.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7d317f2c

include/linux/sunrpc/cache.h

+12 −0
Original line number Diff line number Diff line
@@ -81,6 +81,11 @@ 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

	 */
@@ -237,6 +242,13 @@ RTN *FNAME ARGS \ 
	& FUNC##_cache, FUNC##_hash(item), FUNC##_match(item, tmp),	\

	STRUCT##_init(new, item), STRUCT##_update(tmp, item))



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 cache_for_each(pos, detail, index, member) 						\

	for (({read_lock(&(detail)->hash_lock); index = (detail)->hash_size;}) ;		\

net/sunrpc/cache.c

+98 −0
Original line number Diff line number Diff line
@@ -47,6 +47,104 @@ void cache_init(struct cache_head *h) 
	h->last_refresh = now;

}



struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,

				       struct cache_head *key, int hash)

{

	struct cache_head **head,  **hp;

	struct cache_head *new = NULL;



	head = &detail->hash_table[hash];



	read_lock(&detail->hash_lock);



	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {

		struct cache_head *tmp = *hp;

		if (detail->match(tmp, key)) {

			cache_get(tmp);

			read_unlock(&detail->hash_lock);

			return tmp;

		}

	}

	read_unlock(&detail->hash_lock);

	/* Didn't find anything, insert an empty entry */



	new = detail->alloc();

	if (!new)

		return NULL;

	cache_init(new);



	write_lock(&detail->hash_lock);



	/* check if entry appeared while we slept */

	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {

		struct cache_head *tmp = *hp;

		if (detail->match(tmp, key)) {

			cache_get(tmp);

			write_unlock(&detail->hash_lock);

			detail->cache_put(new, detail);

			return tmp;

		}

	}

	detail->init(new, key);

	new->next = *head;

	*head = new;

	detail->entries++;

	cache_get(new);

	write_unlock(&detail->hash_lock);



	return new;

}

EXPORT_SYMBOL(sunrpc_cache_lookup);



struct cache_head *sunrpc_cache_update(struct cache_detail *detail,

				       struct cache_head *new, struct cache_head *old, int hash)

{

	/* The 'old' entry is to be replaced by 'new'.

	 * If 'old' is not VALID, we update it directly,

	 * otherwise we need to replace it

	 */

	struct cache_head **head;

	struct cache_head *tmp;



	if (!test_bit(CACHE_VALID, &old->flags)) {

		write_lock(&detail->hash_lock);

		if (!test_bit(CACHE_VALID, &old->flags)) {

			if (test_bit(CACHE_NEGATIVE, &new->flags))

				set_bit(CACHE_NEGATIVE, &old->flags);

			else

				detail->update(old, new);

			/* FIXME cache_fresh should come first */

			write_unlock(&detail->hash_lock);

			cache_fresh(detail, old, new->expiry_time);

			return old;

		}

		write_unlock(&detail->hash_lock);

	}

	/* We need to insert a new entry */

	tmp = detail->alloc();

	if (!tmp) {

		detail->cache_put(old, detail);

		return NULL;

	}

	cache_init(tmp);

	detail->init(tmp, old);

	head = &detail->hash_table[hash];



	write_lock(&detail->hash_lock);

	if (test_bit(CACHE_NEGATIVE, &new->flags))

		set_bit(CACHE_NEGATIVE, &tmp->flags);

	else

		detail->update(tmp, new);

	tmp->next = *head;

	*head = tmp;

	cache_get(tmp);

	write_unlock(&detail->hash_lock);

	cache_fresh(detail, tmp, new->expiry_time);

	cache_fresh(detail, old, 0);

	detail->cache_put(old, detail);

	return tmp;

}

EXPORT_SYMBOL(sunrpc_cache_update);



static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);

/*