nvme-tcp: fix memory leak when freeing a queue

Release the page frag cache when tearing down the io queues
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/tcp.c

@@ -1225,6 +1225,7 @@ static int nvme_tcp_alloc_async_req(struct nvme_tcp_ctrl *ctrl)
 
 static void nvme_tcp_free_queue(struct nvme_ctrl *nctrl, int qid)
 {
+	struct page *page;
 	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
 	struct nvme_tcp_queue *queue = &ctrl->queues[qid];
 
@@ -1234,6 +1235,11 @@ static void nvme_tcp_free_queue(struct nvme_ctrl *nctrl, int qid)
 	if (queue->hdr_digest || queue->data_digest)
 		nvme_tcp_free_crypto(queue);
 
+	if (queue->pf_cache.va) {
+		page = virt_to_head_page(queue->pf_cache.va);
+		__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
+		queue->pf_cache.va = NULL;
+	}
 	sock_release(queue->sock);
 	kfree(queue->pdu);
 	mutex_destroy(&queue->send_mutex);