Hi, Feifei

Sorry for the delayed review.
I think it is a good catch, thank you for the patch.

Acked-by: Viacheslav Ovsiienko <redacted>

With best regards,
Slava

-----Original Message-----
From: Feifei Wang <redacted>
Sent: Tuesday, June 22, 2021 4:54
To: Feifei Wang <redacted>; Matan Azrad
[off-list ref]; Shahaf Shuler [off-list ref]; Slava Ovsiienko
[off-list ref]
Cc: dev@dpdk.org; nd <redacted>; Shahaf Shuler <redacted>;
stable@dpdk.org; Ruifeng Wang [off-list ref]; nd
[off-list ref]
Subject: 回复: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap

Hi, Slava

Would you please help review this patch?
Thanks.

Best Regards
Feifei

quoted

-----邮件原件-----
发件人: Feifei Wang [off-list ref]
发送时间: 2021年5月27日 17:48
收件人: Matan Azrad [off-list ref]; Shahaf Shuler
[off-list ref]; Viacheslav Ovsiienko [off-list ref]
抄送: dev@dpdk.org; nd [off-list ref]; Feifei Wang

[off-list ref];

quoted

shahafs@mellanox.com; stable@dpdk.org; Ruifeng Wang
[off-list ref]
主题: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap

For mlx5 DMA unmap, write lock should be used for rebuilding memory
region cache table rather than read lock.

Fixes: 989e999d9305 ("net/mlx5: support PCI device DMA map and unmap")
Cc: shahafs@mellanox.com
Cc: stable@dpdk.org

Signed-off-by: Feifei Wang <redacted>
Reviewed-by: Ruifeng Wang <redacted>
---
 drivers/net/mlx5/mlx5_mr.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c

index
e791b6338d..45a122f4f9 100644

--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c

@@ -395,10 +395,10 @@ mlx5_dma_unmap(struct rte_pci_device *pdev,

void

quoted

*addr,
 	}
 	priv = dev->data->dev_private;
 	sh = priv->sh;
-	rte_rwlock_read_lock(&sh->share_cache.rwlock);
+	rte_rwlock_write_lock(&sh->share_cache.rwlock);
 	mr = mlx5_mr_lookup_list(&sh->share_cache, &entry,

(uintptr_t)addr);

quoted

 	if (!mr) {
-		rte_rwlock_read_unlock(&sh->share_cache.rwlock);
+		rte_rwlock_write_unlock(&sh->share_cache.rwlock);
 		DRV_LOG(WARNING, "address 0x%" PRIxPTR " wasn't

registered "

quoted

 				 "to PCI device %p", (uintptr_t)addr,
 				 (void *)pdev);

@@ -423,7 +423,7 @@ mlx5_dma_unmap(struct rte_pci_device *pdev, void

*addr,
 	DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
 	      sh->share_cache.dev_gen);
 	rte_smp_wmb();
-	rte_rwlock_read_unlock(&sh->share_cache.rwlock);
+	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
 	return 0;
 }

--
2.25.1