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authorGreg Kurz <groug@kaod.org>2018-01-22 22:02:05 +0100
committerMichael S. Tsirkin <mst@redhat.com>2018-02-09 20:08:19 +0200
commit26d99834f89e76514076d9cd06f61e56e6a509b8 (patch)
tree0098d208ff8f3788c37cc4f25087fe5853e7c483 /net/9p
parentd25cc43c6775bff6b8e3dad97c747954b805e421 (diff)
downloadlinux-26d99834f89e76514076d9cd06f61e56e6a509b8.tar.bz2
9p/trans_virtio: discard zero-length reply
When a 9p request is successfully flushed, the server is expected to just mark it as used without sending a 9p reply (ie, without writing data into the buffer). In this case, virtqueue_get_buf() will return len == 0 and we must not report a REQ_STATUS_RCVD status to the client, otherwise the client will erroneously assume the request has not been flushed. Cc: stable@vger.kernel.org Signed-off-by: Greg Kurz <groug@kaod.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'net/9p')
-rw-r--r--net/9p/trans_virtio.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index f3a4efcf1456..3aa5a93ad107 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -160,7 +160,8 @@ static void req_done(struct virtqueue *vq)
spin_unlock_irqrestore(&chan->lock, flags);
/* Wakeup if anyone waiting for VirtIO ring space. */
wake_up(chan->vc_wq);
- p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
+ if (len)
+ p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
}
}