[Devel] [PATCH vz9 05/27] ve/proc/stat: Wire virtualized /proc/stat handler

[Nikita Yushchenko]

From: Konstantin Khorenko <khorenko at virtuozzo.com>

Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
Reviewed-by: Andrey Ryabinin <aryabinin at virtuozzo.com>

(cherry-picked from vz8 commit abac75aaeba1 ("ve/proc/stat: Wire
virtualized /proc/stat handler"))

Signed-off-by: Nikita Yushchenko <nikita.yushchenko at virtuozzo.com>
---
 fs/proc/stat.c     | 10 ++++++++++
 include/linux/ve.h |  2 ++
 kernel/ve/ve.c     | 17 +++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 3f102d658b33..d40f26728c9b 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -14,6 +14,7 @@
 #include <linux/irqnr.h>
 #include <linux/sched/cputime.h>
 #include <linux/tick.h>
+#include <linux/ve.h>
 
 #ifndef arch_irq_stat_cpu
 #define arch_irq_stat_cpu(cpu) 0
@@ -114,6 +115,15 @@ static int show_stat(struct seq_file *p, void *v)
 	u64 sum_softirq = 0;
 	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
 	struct timespec64 boottime;
+	struct ve_struct *ve;
+
+	ve = get_exec_env();
+	if (!ve_is_super(ve)) {
+		int ret;
+		ret = ve_show_cpu_stat(ve, p);
+		if (ret != -ENOSYS)
+			return ret;
+	}
 
 	user = nice = system = idle = iowait =
 		irq = softirq = steal = 0;
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 4dde4cb46d52..47f690c1b8b9 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -199,8 +199,10 @@ static inline int vz_security_protocol_check(struct net *net, int protocol) { re
 struct seq_file;
 
 #if defined(CONFIG_VE) && defined(CONFIG_CGROUP_SCHED)
+int ve_show_cpu_stat(struct ve_struct *ve, struct seq_file *p);
 int ve_show_loadavg(struct ve_struct *ve, struct seq_file *p);
 #else
+static inline int ve_show_cpu_stat(struct ve_struct *ve, struct seq_file *p) { return -ENOSYS; }
 static inline int ve_show_loadavg(struct ve_struct *ve, struct seq_file *p) { return -ENOSYS; }
 #endif
 
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index bd114bd620eb..2e418e72ce62 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -1455,6 +1455,23 @@ bool ve_check_trusted_exec(struct file *file, struct filename *name)
 }
 
 #ifdef CONFIG_CGROUP_SCHED
+int cpu_cgroup_proc_stat(struct cgroup_subsys_state *cpu_css,
+			 struct cgroup_subsys_state *cpuacct_css,
+			 struct seq_file *p);
+
+int ve_show_cpu_stat(struct ve_struct *ve, struct seq_file *p)
+{
+	struct cgroup_subsys_state *cpu_css, *cpuacct_css;
+	int err;
+
+	cpu_css = ve_get_init_css(ve, cpu_cgrp_id);
+	cpuacct_css = ve_get_init_css(ve, cpuacct_cgrp_id);
+	err = cpu_cgroup_proc_stat(cpu_css, cpuacct_css, p);
+	css_put(cpuacct_css);
+	css_put(cpu_css);
+	return err;
+}
+
 int cpu_cgroup_proc_loadavg(struct cgroup_subsys_state *css,
 			    struct seq_file *p);
 
-- 
2.30.2