Centralise the allocation and freeing of cache_request objects instead
of doing it in multiple places. Use a reference count (but not a
kref, that would require adding a backpointer to the cache_detail in
the cache_request).
Signed-off-by: Greg Banks <[email protected]>
---
net/sunrpc/cache.c | 46 +++++++++++++++++++++++++++++++-----------
1 file changed, 35 insertions(+), 11 deletions(-)
Index: bfields/net/sunrpc/cache.c
===================================================================
--- bfields.orig/net/sunrpc/cache.c
+++ bfields/net/sunrpc/cache.c
@@ -688,11 +688,39 @@ void cache_clean_deferred(void *owner)
struct cache_request {
struct list_head list;
+ atomic_t count;
struct cache_head *item;
int len;
char buf[0];
};
+static void
+cache_request_put(struct cache_request *rq, struct cache_detail *cd)
+{
+ if (atomic_dec_and_test(&rq->count)) {
+ cache_put(rq->item, cd);
+ kfree(rq);
+ }
+}
+
+static struct cache_request *
+cache_request_get(struct cache_head *h)
+{
+ struct cache_request *rq;
+
+ rq = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!rq)
+ return NULL;
+
+ memset(rq, 0, sizeof(*rq));
+ INIT_LIST_HEAD(&rq->list);
+ atomic_set(&rq->count, 1);
+ rq->len = PAGE_SIZE - sizeof(*rq);
+ rq->item = cache_get(h);
+
+ return rq;
+}
+
static ssize_t
cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
{
@@ -740,8 +768,7 @@ cache_read(struct file *filp, char __use
error:
/* need to release rq */
- cache_put(rq->item, cd);
- kfree(rq);
+ cache_request_put(rq, cd);
return err;
}
@@ -890,10 +917,8 @@ static void cache_remove_queued(struct c
spin_unlock(&cd->queue_lock);
/* if found, destroy */
- if (rq) {
- cache_put(rq->item, cd);
- kfree(rq);
- }
+ if (rq)
+ cache_request_put(rq, cd);
}
/*
@@ -998,20 +1023,19 @@ static int cache_make_upcall(struct cach
return -EINVAL;
}
- rq = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ rq = cache_request_get(h);
if (!rq)
return -EAGAIN;
bp = rq->buf;
- len = PAGE_SIZE - sizeof(*rq);
+ len = rq->len;
cd->cache_request(cd, h, &bp, &len);
if (len < 0) {
- kfree(rq);
+ cache_request_put(rq, cd);
return -EAGAIN;
}
- rq->item = cache_get(h);
- rq->len = PAGE_SIZE - sizeof(*rq) - len;
+ rq->len -= len;
spin_lock(&cd->queue_lock);
list_add_tail(&rq->list, &cd->to_read);
spin_unlock(&cd->queue_lock);
--
--
Greg Banks, P.Engineer, SGI Australian Software Group.
the brightly coloured sporks of revolution.
I don't speak for SGI.