diff mbox series

[net,v2,2/2] net: avoid false positive warnings in __net_mp_close_rxq()

Message ID 20250403013405.2827250-3-kuba@kernel.org (mailing list archive)
State Accepted
Commit 34f71de3f548eba0604c9cbabc1eb68b2f81fa0f
Delegated to: Netdev Maintainers
Headers show
Series net: make memory provider install / close paths more common | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 42 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-04-04--15-00 (tests: 911)

Commit Message

Jakub Kicinski April 3, 2025, 1:34 a.m. UTC 
Commit under Fixes solved the problem of spurious warnings when we
uninstall an MP from a device while its down. The __net_mp_close_rxq()
which is used by io_uring was not fixed. Move the fix over and reuse
__net_mp_close_rxq() in the devmem path.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Fixes: a70f891e0fa0 ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v2:
 - don't split the registration check, it may cause a race if we just
   bail on the registration state and not on the MP being present,
   as we drop and re-take the instance lock after setting reg_state
v1: https://lore.kernel.org/20250331194308.2026940-1-kuba@kernel.org
---
 net/core/devmem.c          | 12 +++++-------
 net/core/netdev_rx_queue.c |  4 +++-
 2 files changed, 8 insertions(+), 8 deletions(-)

Comments

Mina Almasry April 3, 2025, 9:37 p.m. UTC | #1 
On Wed, Apr 2, 2025 at 6:34 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> Commit under Fixes solved the problem of spurious warnings when we
> uninstall an MP from a device while its down. The __net_mp_close_rxq()
> which is used by io_uring was not fixed. Move the fix over and reuse
> __net_mp_close_rxq() in the devmem path.
>
> Acked-by: Stanislav Fomichev <sdf@fomichev.me>
> Fixes: a70f891e0fa0 ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Mina Almasry <almasrymina@google.com>
diff mbox series

Patch

diff --git a/net/core/devmem.c b/net/core/devmem.c
index f2ce3c2ebc97..6e27a47d0493 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -116,21 +116,19 @@  void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding)
 	struct netdev_rx_queue *rxq;
 	unsigned long xa_idx;
 	unsigned int rxq_idx;
-	int err;
 
 	if (binding->list.next)
 		list_del(&binding->list);
 
 	xa_for_each(&binding->bound_rxqs, xa_idx, rxq) {
-		WARN_ON(rxq->mp_params.mp_priv != binding);
-
-		rxq->mp_params.mp_priv = NULL;
-		rxq->mp_params.mp_ops = NULL;
+		const struct pp_memory_provider_params mp_params = {
+			.mp_priv	= binding,
+			.mp_ops		= &dmabuf_devmem_ops,
+		};
 
 		rxq_idx = get_netdev_rx_queue_index(rxq);
 
-		err = netdev_rx_queue_restart(binding->dev, rxq_idx);
-		WARN_ON(err && err != -ENETDOWN);
+		__net_mp_close_rxq(binding->dev, rxq_idx, &mp_params);
 	}
 
 	xa_erase(&net_devmem_dmabuf_bindings, binding->id);
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
index 556b5393ec9f..d126f10197bf 100644
--- a/net/core/netdev_rx_queue.c
+++ b/net/core/netdev_rx_queue.c
@@ -154,6 +154,7 @@  void __net_mp_close_rxq(struct net_device *dev, unsigned int ifq_idx,
 			const struct pp_memory_provider_params *old_p)
 {
 	struct netdev_rx_queue *rxq;
+	int err;
 
 	if (WARN_ON_ONCE(ifq_idx >= dev->real_num_rx_queues))
 		return;
@@ -173,7 +174,8 @@  void __net_mp_close_rxq(struct net_device *dev, unsigned int ifq_idx,
 
 	rxq->mp_params.mp_ops = NULL;
 	rxq->mp_params.mp_priv = NULL;
-	WARN_ON(netdev_rx_queue_restart(dev, ifq_idx));
+	err = netdev_rx_queue_restart(dev, ifq_idx);
+	WARN_ON(err && err != -ENETDOWN);
 }
 
 void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,