[PATCH net-next v3] net/smc: fix compile warning for smc_sysctl

Dust Li
2022-03-07T01:54:31Z

kernel test robot reports multiple warning for smc_sysctl:

In file included from net/smc/smc_sysctl.c:17:
>> net/smc/smc_sysctl.h:23:5: warning: no previous prototype \
for function 'smc_sysctl_init' [-Wmissing-prototypes]
int smc_sysctl_init(void)
^
and
>> WARNING: modpost: vmlinux.o(.text+0x12ced2d): Section mismatch \
in reference from the function smc_sysctl_exit() to the variable
.init.data:smc_sysctl_ops
The function smc_sysctl_exit() references
the variable __initdata smc_sysctl_ops.
This is often because smc_sysctl_exit lacks a __initdata
annotation or the annotation of smc_sysctl_ops is wrong.

and
net/smc/smc_sysctl.c: In function 'smc_sysctl_init_net':
net/smc/smc_sysctl.c:47:17: error: 'struct netns_smc' has no member named 'smc_hdr'
47 | net->smc.smc_hdr = register_net_sysctl(net, "net/smc", table);

Since we don't need global sysctl initialization. To make things
clean and simple, remove the global pernet_operations and
smc_sysctl_{init|exit}. Call smc_sysctl_net_{init|exit} directly
from smc_net_{init|exit}.

Also initialized sysctl_autocorking_size if CONFIG_SYSCTL it not
set, this make sure SMC autocorking is enabled by default if
CONFIG_SYSCTL is not set.

Fixes: 462791bbfa35 ("net/smc: add sysctl interface for SMC")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>

---
v3: 1. add __net_{init|exit} annotation for smc_sysctl_net_{init|exit}
sugguested by Jakub Kicinski
2. Remove static inline for smc_sysctl_net_{init|exit} if
CONFIG_SYSCTL not defined
v2: 1. Removes pernet_operations and smc_sysctl_{init|exit}
2. Initialize sysctl_autocorking_size if CONFIG_SYSCTL not set
---
net/smc/Makefile | 3 ++-
net/smc/af_smc.c | 15 ++++++---------
net/smc/smc_sysctl.c | 19 ++-----------------
net/smc/smc_sysctl.h | 9 +++++----
4 files changed, 15 insertions(+), 31 deletions(-)

diff --git a/net/smc/Makefile b/net/smc/Makefile
index 640af9a39f9c..875efcd126a2 100644
--- a/net/smc/Makefile
+++ b/net/smc/Makefile
@@ -4,4 +4,5 @@ obj-$(CONFIG_SMC) += smc.o
obj-$(CONFIG_SMC_DIAG) += smc_diag.o
smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o smc_llc.o
smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o smc_netlink.o smc_stats.o
-smc-y += smc_tracepoint.o smc_sysctl.o
+smc-y += smc_tracepoint.o
+smc-$(CONFIG_SYSCTL) += smc_sysctl.o
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index e508e4f3a073..f0d118e9f155 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3179,11 +3179,17 @@ unsigned int smc_net_id;

static __net_init int smc_net_init(struct net *net)
{
+ int rc;
+
+ rc = smc_sysctl_net_init(net);
+ if (rc)
+ return rc;
return smc_pnet_net_init(net);
}

static void __net_exit smc_net_exit(struct net *net)
{
+ smc_sysctl_net_exit(net);
smc_pnet_net_exit(net);
}

@@ -3296,17 +3302,9 @@ static int __init smc_init(void)
goto out_ib;
}

- rc = smc_sysctl_init();
- if (rc) {
- pr_err("%s: sysctl_init fails with %d\n", __func__, rc);
- goto out_ulp;
- }
-
static_branch_enable(&tcp_have_smc);
return 0;

-out_ulp:
- tcp_unregister_ulp(&smc_ulp_ops);
out_ib:
smc_ib_unregister_client();
out_sock:
@@ -3336,7 +3334,6 @@ static int __init smc_init(void)
static void __exit smc_exit(void)
{
static_branch_disable(&tcp_have_smc);
- smc_sysctl_exit();
tcp_unregister_ulp(&smc_ulp_ops);
sock_unregister(PF_SMC);
smc_core_exit();
diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
index 3b59876aaac9..bae19419e755 100644
--- a/net/smc/smc_sysctl.c
+++ b/net/smc/smc_sysctl.c
@@ -28,7 +28,7 @@ static struct ctl_table smc_table[] = {
{ }
};

-static __net_init int smc_sysctl_init_net(struct net *net)
+int __net_init smc_sysctl_net_init(struct net *net)
{
struct ctl_table *table;

@@ -59,22 +59,7 @@ static __net_init int smc_sysctl_init_net(struct net *net)
return -ENOMEM;
}

-static __net_exit void smc_sysctl_exit_net(struct net *net)
+void __net_exit smc_sysctl_net_exit(struct net *net)
{
unregister_net_sysctl_table(net->smc.smc_hdr);
}
-
-static struct pernet_operations smc_sysctl_ops __net_initdata = {
- .init = smc_sysctl_init_net,
- .exit = smc_sysctl_exit_net,
-};
-
-int __init smc_sysctl_init(void)
-{
- return register_pernet_subsys(&smc_sysctl_ops);
-}
-
-void smc_sysctl_exit(void)
-{
- unregister_pernet_subsys(&smc_sysctl_ops);
-}
diff --git a/net/smc/smc_sysctl.h b/net/smc/smc_sysctl.h
index 49553ac236b6..1d554300604d 100644
--- a/net/smc/smc_sysctl.h
+++ b/net/smc/smc_sysctl.h
@@ -15,17 +15,18 @@

#ifdef CONFIG_SYSCTL

-int smc_sysctl_init(void);
-void smc_sysctl_exit(void);
+int __net_init smc_sysctl_net_init(struct net *net);
+void __net_exit smc_sysctl_net_exit(struct net *net);

#else

-int smc_sysctl_init(void)
+int __net_init smc_sysctl_net_init(struct net *net)
{
+ net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
return 0;
}

-void smc_sysctl_exit(void) { }
+void __net_exit smc_sysctl_net_exit(struct net *net) { }

#endif /* CONFIG_SYSCTL */

--
2.19.1.3.ge56e4f7