Subject: [PATCH net-next 1/3] SUNRPC: add netns refcount tracker to struct svc_xprt

From: Eric Dumazet <[email-masked]>
Date: Thu, 27 Jan 2022 12:09:35 -0800

From: Eric Dumazet <[email-masked]>

struct svc_xprt holds a long lived reference to a netns,
it is worth tracking it.

Signed-off-by: Eric Dumazet <[email-masked]>
---
 include/linux/sunrpc/svc_xprt.h | 1 +
 net/sunrpc/svc_xprt.c           | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 571f605bc91ef8fa190e7fd5504efb76ec3fa89e..382af90320acc3a7b3817bf66f65fbb15447ae7d 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -88,6 +88,7 @@ struct svc_xprt {
 	struct list_head	xpt_users;	/* callbacks on free */
 
 	struct net		*xpt_net;
+	netns_tracker		ns_tracker;
 	const struct cred	*xpt_cred;
 	struct rpc_xprt		*xpt_bc_xprt;	/* NFSv4.1 backchannel */
 	struct rpc_xprt_switch	*xpt_bc_xps;	/* NFSv4.1 backchannel */
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index b21ad79941474685597c9c7c07b862ef7e98ad74..db878e833b672864551bc9ef884a3cd6ca6c2603 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -162,7 +162,7 @@ static void svc_xprt_free(struct kref *kref)
 	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
 		svcauth_unix_info_release(xprt);
 	put_cred(xprt->xpt_cred);
-	put_net(xprt->xpt_net);
+	put_net_track(xprt->xpt_net, &xprt->ns_tracker);
 	/* See comment on corresponding get in xs_setup_bc_tcp(): */
 	if (xprt->xpt_bc_xprt)
 		xprt_put(xprt->xpt_bc_xprt);
@@ -198,7 +198,7 @@ void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
 	mutex_init(&xprt->xpt_mutex);
 	spin_lock_init(&xprt->xpt_lock);
 	set_bit(XPT_BUSY, &xprt->xpt_flags);
-	xprt->xpt_net = get_net(net);
+	xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC);
 	strcpy(xprt->xpt_remotebuf, "uninitialized");
 }
 EXPORT_SYMBOL_GPL(svc_xprt_init);
-- 
2.35.0.rc0.227.g00780c9af4-goog