5.4-stable review patch. If anyone has any objections, please let me know.
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From: Maher Sanalla msanalla@nvidia.com
[ Upstream commit 37826f0a8c2f6b6add5179003b8597e32a445362 ]
The ib_post_receive_mads() function handles posting receive work requests (WRs) to MAD QPs and is called in two cases: 1) When a MAD port is opened. 2) When a receive WQE is consumed upon receiving a new MAD.
Whereas, if MADs arrive during the port open phase, a race condition might cause an extra WR to be posted, exceeding the QP’s capacity. This leads to failures such as: infiniband mlx5_0: ib_post_recv failed: -12 infiniband mlx5_0: Couldn't post receive WRs infiniband mlx5_0: Couldn't start port infiniband mlx5_0: Couldn't open port 1
Fix this by checking the current receive count before posting a new WR. If the QP’s receive queue is full, do not post additional WRs.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Maher Sanalla msanalla@nvidia.com Link: https://patch.msgid.link/c4984ba3c3a98a5711a558bccefcad789587ecf1.1741875592... Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/core/mad.c | 38 ++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c index 2284930b5f915..92d9e314238a2 100644 --- a/drivers/infiniband/core/mad.c +++ b/drivers/infiniband/core/mad.c @@ -2926,11 +2926,11 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info, struct ib_mad_private *mad) { unsigned long flags; - int post, ret; struct ib_mad_private *mad_priv; struct ib_sge sg_list; struct ib_recv_wr recv_wr; struct ib_mad_queue *recv_queue = &qp_info->recv_queue; + int ret = 0;
/* Initialize common scatter list fields */ sg_list.lkey = qp_info->port_priv->pd->local_dma_lkey; @@ -2940,7 +2940,7 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info, recv_wr.sg_list = &sg_list; recv_wr.num_sge = 1;
- do { + while (true) { /* Allocate and map receive buffer */ if (mad) { mad_priv = mad; @@ -2948,10 +2948,8 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info, } else { mad_priv = alloc_mad_private(port_mad_size(qp_info->port_priv), GFP_ATOMIC); - if (!mad_priv) { - ret = -ENOMEM; - break; - } + if (!mad_priv) + return -ENOMEM; } sg_list.length = mad_priv_dma_size(mad_priv); sg_list.addr = ib_dma_map_single(qp_info->port_priv->device, @@ -2960,37 +2958,41 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info, DMA_FROM_DEVICE); if (unlikely(ib_dma_mapping_error(qp_info->port_priv->device, sg_list.addr))) { - kfree(mad_priv); ret = -ENOMEM; - break; + goto free_mad_priv; } mad_priv->header.mapping = sg_list.addr; mad_priv->header.mad_list.mad_queue = recv_queue; mad_priv->header.mad_list.cqe.done = ib_mad_recv_done; recv_wr.wr_cqe = &mad_priv->header.mad_list.cqe; - - /* Post receive WR */ spin_lock_irqsave(&recv_queue->lock, flags); - post = (++recv_queue->count < recv_queue->max_active); - list_add_tail(&mad_priv->header.mad_list.list, &recv_queue->list); + if (recv_queue->count >= recv_queue->max_active) { + /* Fully populated the receive queue */ + spin_unlock_irqrestore(&recv_queue->lock, flags); + break; + } + recv_queue->count++; + list_add_tail(&mad_priv->header.mad_list.list, + &recv_queue->list); spin_unlock_irqrestore(&recv_queue->lock, flags); + ret = ib_post_recv(qp_info->qp, &recv_wr, NULL); if (ret) { spin_lock_irqsave(&recv_queue->lock, flags); list_del(&mad_priv->header.mad_list.list); recv_queue->count--; spin_unlock_irqrestore(&recv_queue->lock, flags); - ib_dma_unmap_single(qp_info->port_priv->device, - mad_priv->header.mapping, - mad_priv_dma_size(mad_priv), - DMA_FROM_DEVICE); - kfree(mad_priv); dev_err(&qp_info->port_priv->device->dev, "ib_post_recv failed: %d\n", ret); break; } - } while (post); + }
+ ib_dma_unmap_single(qp_info->port_priv->device, + mad_priv->header.mapping, + mad_priv_dma_size(mad_priv), DMA_FROM_DEVICE); +free_mad_priv: + kfree(mad_priv); return ret; }