[PATCH 2/2] 9p/trans_virtio: implement cancelled callback

From: Greg Kurz
Date: Wed Dec 20 2017 - 13:22:27 EST


When 9p requests are successfully flushed, we must manually move the
associated buffers to the virtqueue freelist, since the server doesn't
send a reply.

Signed-off-by: Greg Kurz <groug@xxxxxxxx>
---
net/9p/trans_virtio.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index f3a4efcf1456..d3216af124c4 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -206,6 +206,23 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
return 1;
}

+static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req)
+{
+ struct virtio_chan *chan = client->trans;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (virtqueue_detach_buf(chan->vq, req) != req) {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ return 0;
+ }
+ chan->ring_bufs_avail = 1;
+ spin_unlock_irqrestore(&chan->lock, flags);
+ /* Wakeup if anyone waiting for VirtIO ring space. */
+ wake_up(chan->vc_wq);
+ return 0;
+}
+
/**
* pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
* this takes a list of pages.
@@ -737,6 +754,7 @@ static struct p9_trans_module p9_virtio_trans = {
.request = p9_virtio_request,
.zc_request = p9_virtio_zc_request,
.cancel = p9_virtio_cancel,
+ .cancelled = p9_virtio_cancelled,
/*
* We leave one entry for input and one entry for response
* headers. We also skip one more entry to accomodate, address