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yaml
---
r: 24265
b: refs/heads/master
c: 15a5f6b
h: refs/heads/master
i:
  24263: ba5fcf7
v: v3
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NeilBrown authored and Linus Torvalds committed Mar 27, 2006
1 parent 58f1f09 commit 4d7f794
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Showing 3 changed files with 111 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 7d317f2c9f1e9dcf4f632fa98f91d1d4a36c4cae
refs/heads/master: 15a5f6bd23eddd5b3be80366f364be04fb1c1c99
12 changes: 12 additions & 0 deletions trunk/include/linux/sunrpc/cache.h
Original file line number Diff line number Diff line change
Expand Up @@ -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
*/
Expand Down Expand Up @@ -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;}) ; \
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98 changes: 98 additions & 0 deletions trunk/net/sunrpc/cache.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
/*
Expand Down

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