9P: Add cancelled() to the transport functions.

RDMA needs to post a buffer for each incoming reply.
Hence it needs to keep count of these and needs to be
aware of whether a flushed request has received a reply
or not.

This patch adds the cancelled() callback to the transport modules.
It is called when RFLUSH has been received and that the corresponding
request will never receive a reply.

Signed-off-by: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Simon Derr 2013-06-21 15:32:43 +02:00 committed by Eric Van Hensbergen
parent 1cff33069a
commit 80b45261a0
3 changed files with 23 additions and 3 deletions

View file

@ -40,6 +40,8 @@
* @close: member function to discard a connection on this transport
* @request: member function to issue a request to the transport
* @cancel: member function to cancel a request (if it hasn't been sent)
* @cancelled: member function to notify that a cancelled request will not
* not receive a reply
*
* This is the basic API for a transport module which is registered by the
* transport module with the 9P core network module and used by the client
@ -58,6 +60,7 @@ struct p9_trans_module {
void (*close) (struct p9_client *);
int (*request) (struct p9_client *, struct p9_req_t *req);
int (*cancel) (struct p9_client *, struct p9_req_t *req);
int (*cancelled)(struct p9_client *, struct p9_req_t *req);
int (*zc_request)(struct p9_client *, struct p9_req_t *,
char *, char *, int , int, int, int);
};

View file

@ -658,12 +658,18 @@ static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
/*
* if we haven't received a response for oldreq,
* remove it from the list.
* remove it from the list, and notify the transport
* layer that the reply will never arrive.
*/
spin_lock(&c->lock);
if (oldreq->status == REQ_STATUS_FLSH)
if (oldreq->status == REQ_STATUS_FLSH) {
list_del(&oldreq->req_list);
spin_unlock(&c->lock);
spin_unlock(&c->lock);
if (c->trans_mod->cancelled)
c->trans_mod->cancelled(c, req);
} else {
spin_unlock(&c->lock);
}
p9_free_req(c, req);
return 0;

View file

@ -588,6 +588,17 @@ static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
return 1;
}
/* A request has been fully flushed without a reply.
* That means we have posted one buffer in excess.
*/
static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
{
struct p9_trans_rdma *rdma = client->trans;
atomic_inc(&rdma->excess_rc);
return 0;
}
/**
* trans_create_rdma - Transport method for creating atransport instance
* @client: client instance