Commit ebd0cb1a authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
Browse files

[PATCH] knfsd: Unexport cache_fresh and fix a small race 



Cache_fresh is now only used in cache.c, so unexport it.

Part of cache_fresh (setting CACHE_VALID) should really be done under the
lock, while part (calling cache_revisit_request etc) must be done outside the
lock.  So we split it up appropriately.

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 4d90452c

include/linux/sunrpc/cache.h

+0 −2
Original line number Diff line number Diff line
@@ -165,8 +165,6 @@ static inline int cache_put(struct cache_head *h, struct cache_detail *cd) 
}



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);

net/sunrpc/cache.c

+30 −21
Original line number Diff line number Diff line
@@ -96,6 +96,27 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, 
}

EXPORT_SYMBOL(sunrpc_cache_lookup);





static void queue_loose(struct cache_detail *detail, struct cache_head *ch);



static int cache_fresh_locked(struct cache_head *head, time_t expiry)

{

	head->expiry_time = expiry;

	head->last_refresh = get_seconds();

	return !test_and_set_bit(CACHE_VALID, &head->flags);

}



static void cache_fresh_unlocked(struct cache_head *head,

			struct cache_detail *detail, int new)

{

	if (new)

		cache_revisit_request(head);

	if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {

		cache_revisit_request(head);

		queue_loose(detail, head);

	}

}



struct cache_head *sunrpc_cache_update(struct cache_detail *detail,

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

{
@@ -105,6 +126,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	 */

	struct cache_head **head;

	struct cache_head *tmp;

	int is_new;



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

		write_lock(&detail->hash_lock);
@@ -113,9 +135,9 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
				set_bit(CACHE_NEGATIVE, &old->flags);

			else

				detail->update(old, new);

			/* FIXME cache_fresh should come first */

			is_new = cache_fresh_locked(old, new->expiry_time);

			write_unlock(&detail->hash_lock);

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

			cache_fresh_unlocked(old, detail, is_new);

			return old;

		}

		write_unlock(&detail->hash_lock);
@@ -138,9 +160,11 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	tmp->next = *head;

	*head = tmp;

	cache_get(tmp);

	is_new = cache_fresh_locked(tmp, new->expiry_time);

	cache_fresh_locked(old, 0);

	write_unlock(&detail->hash_lock);

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

	cache_fresh(detail, old, 0);

	cache_fresh_unlocked(tmp, detail, is_new);

	cache_fresh_unlocked(old, detail, 0);

	detail->cache_put(old, detail);

	return tmp;

}
@@ -192,7 +216,8 @@ int cache_check(struct cache_detail *detail, 
				clear_bit(CACHE_PENDING, &h->flags);

				if (rv == -EAGAIN) {

					set_bit(CACHE_NEGATIVE, &h->flags);

					cache_fresh(detail, h, get_seconds()+CACHE_NEW_EXPIRY);

					cache_fresh_unlocked(h, detail,

					     cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));

					rv = -ENOENT;

				}

				break;
@@ -213,22 +238,6 @@ int cache_check(struct cache_detail *detail, 
	return rv;

}



static void queue_loose(struct cache_detail *detail, struct cache_head *ch);



void cache_fresh(struct cache_detail *detail,

		 struct cache_head *head, time_t expiry)

{



	head->expiry_time = expiry;

	head->last_refresh = get_seconds();

	if (!test_and_set_bit(CACHE_VALID, &head->flags))

		cache_revisit_request(head);

	if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {

		cache_revisit_request(head);

		queue_loose(detail, head);

	}

}



/*

 * caches need to be periodically cleaned.

 * For this we maintain a list of cache_detail and

net/sunrpc/sunrpc_syms.c

+0 −1
Original line number Diff line number Diff line
@@ -105,7 +105,6 @@ EXPORT_SYMBOL(auth_unix_lookup); 
EXPORT_SYMBOL(cache_check);

EXPORT_SYMBOL(cache_flush);

EXPORT_SYMBOL(cache_purge);

EXPORT_SYMBOL(cache_fresh);

EXPORT_SYMBOL(cache_init);

EXPORT_SYMBOL(cache_register);

EXPORT_SYMBOL(cache_unregister);

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