net/smc: Fix memory leak when using percpu refs

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.

Fixes: 79a22238b4f2 ("net/smc: Use percpu ref for wr tx reference")
Signed-off-by: Kai Shen <KaiShen@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Link: https://patch.msgid.link/20241010115624.7769-1-KaiShen@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 0021065a600a0379295d642d0830a757d043b894..994c0cd4fddbf17c92a2c99594e713bf4ce62a72 100644 (file)
--- 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,