[PATCH 09/10 v7] sunrpc: Support get_ref/put_ref for reference change in cache_head

Kinglong Mee
2015-07-11T12:52:00Z

Add get_ref/put_ref functions in cache_head for processing
reference change (increase/decrease)

v7, new one

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
---
include/linux/sunrpc/cache.h | 15 +++++++++++++--
net/sunrpc/cache.c | 2 ++
2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 5a4b921..77bc623 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -52,6 +52,9 @@ struct cache_head {
* was sent, else this is when update was received
*/
struct kref ref;
+ void (*get_ref)(struct cache_head *);
+ void (*put_ref)(struct cache_head *);
+
unsigned long flags;
};
#define CACHE_VALID 0 /* Entry contains valid data */
@@ -187,7 +190,11 @@ extern void cache_clean_deferred(void *owner);

static inline struct cache_head *cache_get(struct cache_head *h)
{
- kref_get(&h->ref);
+ if (h->get_ref) {
+ h->get_ref(h);
+ } else
+ kref_get(&h->ref);
+
return h;
}

@@ -197,7 +204,11 @@ static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
if (atomic_read(&h->ref.refcount) <= 2 &&
h->expiry_time < cd->nextcheck)
cd->nextcheck = h->expiry_time;
- kref_put(&h->ref, cd->cache_put);
+
+ if (h->put_ref) {
+ h->put_ref(h);
+ } else
+ kref_put(&h->ref, cd->cache_put);
}

static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h)
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 8a27483..1ca88b0 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -49,6 +49,8 @@ static void cache_init(struct cache_head *h)
kref_init(&h->ref);
h->expiry_time = now + CACHE_NEW_EXPIRY;
h->last_refresh = now;
+ h->get_ref = NULL;
+ h->put_ref = NULL;
}

struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
--
2.4.3