[PATCH net,v2 0/2] fix WARNING when removing file in ipvs

[PATCH net,v2 0/2] fix WARNING when removing file in ipvs

[Zhengchao Shao]

When using strace for fault injection, some warnings are trigged when
files are removed. This is because the file fails to be created during
the initialization, but the initialization continues normally. Therefore,
a WARNING is reported when the file is removed during the exit.

---
v2: add macro isolation
---
Zhengchao Shao (2):
  ipvs: fix WARNING in __ip_vs_cleanup_batch()
  ipvs: fix WARNING in ip_vs_app_net_cleanup()

 net/netfilter/ipvs/ip_vs_app.c  | 10 ++++++++--
 net/netfilter/ipvs/ip_vs_conn.c | 26 +++++++++++++++++++++-----
 2 files changed, 29 insertions(+), 7 deletions(-)

-- 
2.17.1

[PATCH net,v2 1/2] ipvs: fix WARNING in __ip_vs_cleanup_batch()

[Zhengchao Shao]

During the initialization of ip_vs_conn_net_init(), if file ip_vs_conn
or ip_vs_conn_sync fails to be created, the initialization is successful
by default. Therefore, the ip_vs_conn or ip_vs_conn_sync file doesn't
be found during the remove.

The following is the stack information:
name 'ip_vs_conn_sync'
WARNING: CPU: 3 PID: 9 at fs/proc/generic.c:712
remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
Call Trace:
<TASK>
__ip_vs_cleanup_batch+0x7d/0x120
ops_exit_list+0x125/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>

Fixes: 61b1ab4583e2 ("IPVS: netns, add basic init per netns.")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
---
 net/netfilter/ipvs/ip_vs_conn.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 8c04bb57dd6f..fa548c9e6aae 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -1447,20 +1447,36 @@ int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
 {
 	atomic_set(&ipvs->conn_count, 0);
 
-	proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
-			&ip_vs_conn_seq_ops, sizeof(struct ip_vs_iter_state));
-	proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
-			&ip_vs_conn_sync_seq_ops,
-			sizeof(struct ip_vs_iter_state));
+#ifdef CONFIG_PROC_FS
+	if (!proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
+			     &ip_vs_conn_seq_ops,
+			     sizeof(struct ip_vs_iter_state)))
+		goto err_conn;
+
+	if (!proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
+			     &ip_vs_conn_sync_seq_ops,
+			     sizeof(struct ip_vs_iter_state)))
+		goto err_conn_sync;
+#endif
+
 	return 0;
+
+#ifdef CONFIG_PROC_FS
+err_conn_sync:
+	remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
+err_conn:
+	return -ENOMEM;
+#endif
 }
 
 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
 {
 	/* flush all the connection entries first */
 	ip_vs_conn_flush(ipvs);
+#ifdef CONFIG_PROC_FS
 	remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
 	remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
+#endif
 }
 
 int __init ip_vs_conn_init(void)
-- 
2.17.1

[PATCH net,v2 2/2] ipvs: fix WARNING in ip_vs_app_net_cleanup()

[Zhengchao Shao]

During the initialization of ip_vs_app_net_init(), if file ip_vs_app
fails to be created, the initialization is successful by default.
Therefore, the ip_vs_app file doesn't be found during the remove in
ip_vs_app_net_cleanup(). It will cause WRNING.

The following is the stack information:
name 'ip_vs_app'
WARNING: CPU: 1 PID: 9 at fs/proc/generic.c:712 remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
Call Trace:
<TASK>
ops_exit_list+0x125/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>

Fixes: 457c4cbc5a3d ("[NET]: Make /proc/net per network namespace")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
---
 net/netfilter/ipvs/ip_vs_app.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_app.c b/net/netfilter/ipvs/ip_vs_app.c
index f9b16f2b2219..fdacbc3c15be 100644
--- a/net/netfilter/ipvs/ip_vs_app.c
+++ b/net/netfilter/ipvs/ip_vs_app.c
@@ -599,13 +599,19 @@ static const struct seq_operations ip_vs_app_seq_ops = {
 int __net_init ip_vs_app_net_init(struct netns_ipvs *ipvs)
 {
 	INIT_LIST_HEAD(&ipvs->app_list);
-	proc_create_net("ip_vs_app", 0, ipvs->net->proc_net, &ip_vs_app_seq_ops,
-			sizeof(struct seq_net_private));
+#ifdef CONFIG_PROC_FS
+	if (!proc_create_net("ip_vs_app", 0, ipvs->net->proc_net,
+			     &ip_vs_app_seq_ops,
+			     sizeof(struct seq_net_private)))
+		return -ENOMEM;
+#endif
 	return 0;
 }
 
 void __net_exit ip_vs_app_net_cleanup(struct netns_ipvs *ipvs)
 {
 	unregister_ip_vs_app(ipvs, NULL /* all */);
+#ifdef CONFIG_PROC_FS
 	remove_proc_entry("ip_vs_app", ipvs->net->proc_net);
+#endif
 }
-- 
2.17.1

Re: [PATCH net,v2 0/2] fix WARNING when removing file in ipvs

[Julian Anastasov]

	Hello,

On Mon, 31 Oct 2022, Zhengchao Shao wrote:

> When using strace for fault injection, some warnings are trigged when
> files are removed. This is because the file fails to be created during
> the initialization, but the initialization continues normally. Therefore,
> a WARNING is reported when the file is removed during the exit.
> 
> ---
> v2: add macro isolation
> ---
> Zhengchao Shao (2):
>   ipvs: fix WARNING in __ip_vs_cleanup_batch()
>   ipvs: fix WARNING in ip_vs_app_net_cleanup()

	Both patches in v2 look good to me, thanks!

Acked-by: Julian Anastasov <ja@ssi.bg>

>  net/netfilter/ipvs/ip_vs_app.c  | 10 ++++++++--
>  net/netfilter/ipvs/ip_vs_conn.c | 26 +++++++++++++++++++++-----
>  2 files changed, 29 insertions(+), 7 deletions(-)
> 
> -- 
> 2.17.1

Regards

--
Julian Anastasov <ja@ssi.bg>