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[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: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown 2006-03-27 01:15:08 -08:00 committed by Linus Torvalds
parent 4d90452cb2
commit ebd0cb1af3
3 changed files with 30 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/sunrpc/cache.h
View File

@ -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);

51
net/sunrpc/cache.c
View File

@ -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

1
net/sunrpc/sunrpc_syms.c
View File

@ -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);