[PATCH 2/5] 9p: store req details and callback in struct p9_req_t

[Stefano Stabellini <sstabellini@kernel.org>]

Add a few fields to struct p9_req_t. Callback is the function which will
be called upon requestion completion. offset, rsize, pagevec and kiocb
store important information regarding the read or write request,
essential to complete the request.

Currently not utilized, but they will be used in a later patch.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 include/net/9p/client.h | 8 ++++++++
 net/9p/client.c         | 9 ++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index aef19c6..69fc2f0 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -110,6 +110,7 @@ enum p9_req_status_t {
  *
  */
 
+struct p9_client;
 struct p9_req_t {
 	int status;
 	int t_err;
@@ -118,6 +119,13 @@ struct p9_req_t {
 	struct p9_fcall *rc;
 	void *aux;
 
+    /* Used for async requests */
+	void (*callback)(struct p9_client *c, struct p9_req_t *req, int status);
+	size_t offset;
+	u64 rsize;
+	struct page **pagevec;
+	struct kiocb *kiocb;
+
 	struct list_head req_list;
 };
 
diff --git a/net/9p/client.c b/net/9p/client.c
index b5ea9a3..bfe1715 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -405,6 +405,10 @@ static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 	int tag = r->tc->tag;
 	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 
+	r->offset = 0;
+	r->rsize = 0;
+	r->kiocb = NULL;
+	r->callback = NULL;
 	r->status = REQ_STATUS_IDLE;
 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 		p9_idpool_put(tag, c->tagpool);
@@ -427,7 +431,10 @@ void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 	smp_wmb();
 	req->status = status;
 
-	wake_up(req->wq);
+	if (req->callback != NULL)
+		req->callback(c, req, status);
+	else
+		wake_up(req->wq);
 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 }
 EXPORT_SYMBOL(p9_client_cb);
-- 
1.9.1