Commit 3ffbe78a authored by Long Li's avatar Long Li Committed by Steve French
Browse files

cifs: smbd: Check send queue size before posting a send 



Sometimes the remote peer may return more send credits than the send queue
depth. If all the send credits are used to post senasd, we may overflow the
send queue.

Fix this by checking the send queue size before posting a send.

Signed-off-by: default avatarLong Li <longli@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 072a14ec

fs/cifs/smbdirect.c

+10 −1
Original line number Diff line number Diff line
@@ -287,6 +287,7 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc) 
	if (atomic_dec_and_test(&request->info->send_pending))

		wake_up(&request->info->wait_send_pending);



	wake_up(&request->info->wait_post_send);



	mempool_free(request, request->info->request_mempool);

}
@@ -939,7 +940,14 @@ static int smbd_post_send(struct smbd_connection *info, 
	send_wr.opcode = IB_WR_SEND;

	send_wr.send_flags = IB_SEND_SIGNALED;



	atomic_inc(&info->send_pending);

wait_sq:

	wait_event(info->wait_post_send,

		atomic_read(&info->send_pending) < info->send_credit_target);

	if (unlikely(atomic_inc_return(&info->send_pending) >

				info->send_credit_target)) {

		atomic_dec(&info->send_pending);

		goto wait_sq;

	}



	rc = ib_post_send(info->id->qp, &send_wr, NULL);

	if (rc) {
@@ -1733,6 +1741,7 @@ static struct smbd_connection *_smbd_get_connection( 
	init_waitqueue_head(&info->wait_send_pending);

	atomic_set(&info->send_pending, 0);



	init_waitqueue_head(&info->wait_post_send);



	INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work);

	INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits);

fs/cifs/smbdirect.h

+1 −0
Original line number Diff line number Diff line
@@ -114,6 +114,7 @@ struct smbd_connection { 
	/* Activity accoutning */

	atomic_t send_pending;

	wait_queue_head_t wait_send_pending;

	wait_queue_head_t wait_post_send;



	/* Receive queue */

	struct list_head receive_queue;

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