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* [PATCH net-next v1] net/smc: Fix memory leak in percpu refs
@ 2024-10-09  3:55 Kai Shen
  2024-10-10  8:53 ` Wen Gu
  0 siblings, 1 reply; 2+ messages in thread
From: Kai Shen @ 2024-10-09  3:55 UTC (permalink / raw)
  To: kgraul, wenjia, jaka, guwen, kuba
  Cc: davem, tonylu, netdev, linux-s390, linux-rdma

This patch adds missing percpu_ref_exit when releasing percpu refs.
When releasing percpu refs, percpu_ref_exit should be called.
Otherwise, memory leak happens.

Signed-off-by: Kai Shen <KaiShen@linux.alibaba.com>
---
 net/smc/smc_wr.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 0021065a600a..994c0cd4fddb 100644
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -648,8 +648,10 @@ void smc_wr_free_link(struct smc_link *lnk)
 	smc_wr_tx_wait_no_pending_sends(lnk);
 	percpu_ref_kill(&lnk->wr_reg_refs);
 	wait_for_completion(&lnk->reg_ref_comp);
+	percpu_ref_exit(&lnk->wr_reg_refs);
 	percpu_ref_kill(&lnk->wr_tx_refs);
 	wait_for_completion(&lnk->tx_ref_comp);
+	percpu_ref_exit(&lnk->wr_tx_refs);
 
 	if (lnk->wr_rx_dma_addr) {
 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
@@ -912,11 +914,13 @@ int smc_wr_create_link(struct smc_link *lnk)
 	init_waitqueue_head(&lnk->wr_reg_wait);
 	rc = percpu_ref_init(&lnk->wr_reg_refs, smcr_wr_reg_refs_free, 0, GFP_KERNEL);
 	if (rc)
-		goto dma_unmap;
+		goto cancel_ref;
 	init_completion(&lnk->reg_ref_comp);
 	init_waitqueue_head(&lnk->wr_rx_empty_wait);
 	return rc;
 
+cancel_ref:
+	percpu_ref_exit(&lnk->wr_tx_refs);
 dma_unmap:
 	if (lnk->wr_rx_v2_dma_addr) {
 		ib_dma_unmap_single(ibdev, lnk->wr_rx_v2_dma_addr,
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH net-next v1] net/smc: Fix memory leak in percpu refs
  2024-10-09  3:55 [PATCH net-next v1] net/smc: Fix memory leak in percpu refs Kai Shen
@ 2024-10-10  8:53 ` Wen Gu
  0 siblings, 0 replies; 2+ messages in thread
From: Wen Gu @ 2024-10-10  8:53 UTC (permalink / raw)
  To: Kai Shen, kgraul, wenjia, jaka, kuba
  Cc: davem, tonylu, netdev, linux-s390, linux-rdma



On 2024/10/9 11:55, Kai Shen wrote:
> This patch adds missing percpu_ref_exit when releasing percpu refs.
> When releasing percpu refs, percpu_ref_exit should be called.
> Otherwise, memory leak happens.
> 
> Signed-off-by: Kai Shen <KaiShen@linux.alibaba.com>
> ---
>   net/smc/smc_wr.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
> index 0021065a600a..994c0cd4fddb 100644
> --- a/net/smc/smc_wr.c
> +++ b/net/smc/smc_wr.c
> @@ -648,8 +648,10 @@ void smc_wr_free_link(struct smc_link *lnk)
>   	smc_wr_tx_wait_no_pending_sends(lnk);
>   	percpu_ref_kill(&lnk->wr_reg_refs);
>   	wait_for_completion(&lnk->reg_ref_comp);
> +	percpu_ref_exit(&lnk->wr_reg_refs);
>   	percpu_ref_kill(&lnk->wr_tx_refs);
>   	wait_for_completion(&lnk->tx_ref_comp);
> +	percpu_ref_exit(&lnk->wr_tx_refs);
>   
>   	if (lnk->wr_rx_dma_addr) {
>   		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
> @@ -912,11 +914,13 @@ int smc_wr_create_link(struct smc_link *lnk)
>   	init_waitqueue_head(&lnk->wr_reg_wait);
>   	rc = percpu_ref_init(&lnk->wr_reg_refs, smcr_wr_reg_refs_free, 0, GFP_KERNEL);
>   	if (rc)
> -		goto dma_unmap;
> +		goto cancel_ref;
>   	init_completion(&lnk->reg_ref_comp);
>   	init_waitqueue_head(&lnk->wr_rx_empty_wait);
>   	return rc;
>   
> +cancel_ref:
> +	percpu_ref_exit(&lnk->wr_tx_refs);
>   dma_unmap:
>   	if (lnk->wr_rx_v2_dma_addr) {
>   		ib_dma_unmap_single(ibdev, lnk->wr_rx_v2_dma_addr,

Hi, Kai.

I think this is a fix to 79a22238b4f2 ("net/smc: Use percpu ref for wr tx reference").
So send it to net please and add a fix tag. Thanks!

^ permalink raw reply	[flat|nested] 2+ messages in thread

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