[PATCH v3 7/7] kobject: convert uevent_seqnum to seqnum_ops

[Shuah Khan]

Sequence Number api provides interfaces for unsigned atomic up counters
leveraging atomic_t and atomic64_t ops underneath.

Convert uevent_seqnum atomic counter to use seqnum_ops.

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
 include/linux/kobject.h | 3 ++-
 kernel/ksysfs.c         | 3 ++-
 lib/kobject_uevent.c    | 9 ++++++---
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index ea30529fba08..8990e40344a2 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -27,6 +27,7 @@
 #include <linux/atomic.h>
 #include <linux/workqueue.h>
 #include <linux/uidgid.h>
+#include <linux/seqnum_ops.h>
 
 #define UEVENT_HELPER_PATH_LEN		256
 #define UEVENT_NUM_ENVP			64	/* number of env pointers */
@@ -38,7 +39,7 @@ extern char uevent_helper[];
 #endif
 
 /* counter to tag the uevent, read only except for the kobject core */
-extern u64 uevent_seqnum;
+extern struct seqnum64 uevent_seqnum;
 
 /*
  * The actions here must match the index to the string array
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 35859da8bd4f..15836f6e5998 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -17,6 +17,7 @@
 #include <linux/sched.h>
 #include <linux/capability.h>
 #include <linux/compiler.h>
+#include <linux/seqnum_ops.h>
 
 #include <linux/rcupdate.h>	/* rcu_expedited and rcu_normal */
 
@@ -31,7 +32,7 @@ static struct kobj_attribute _name##_attr = \
 static ssize_t uevent_seqnum_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
+	return sprintf(buf, "%llu\n", seqnum64_get(&uevent_seqnum));
 }
 KERNEL_ATTR_RO(uevent_seqnum);
 
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 7998affa45d4..3a7b2648f084 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -28,9 +28,10 @@
 #include <net/sock.h>
 #include <net/netlink.h>
 #include <net/net_namespace.h>
+#include <linux/seqnum_ops.h>
 
 
-u64 uevent_seqnum;
+struct seqnum64  uevent_seqnum;
 #ifdef CONFIG_UEVENT_HELPER
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
 #endif
@@ -584,7 +585,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 
 	mutex_lock(&uevent_sock_mutex);
 	/* we will send an event, so request a new sequence number */
-	retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum);
+	retval = add_uevent_var(env, "SEQNUM=%llu",
+				seqnum64_inc(&uevent_seqnum));
 	if (retval) {
 		mutex_unlock(&uevent_sock_mutex);
 		goto exit;
@@ -687,7 +689,8 @@ static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb,
 	int ret;
 
 	/* bump and prepare sequence number */
-	ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum);
+	ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu",
+			seqnum64_inc(&uevent_seqnum));
 	if (ret < 0 || (size_t)ret >= sizeof(buf))
 		return -ENOMEM;
 	ret++;
-- 
2.27.0