[Devel] [PATCH RHEL7 COMMIT] vziolimit: port diff-iolimit-vzctl-api

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-123.1.2-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-123.1.2.vz7.4.9
------>
commit e72e1777eb631b77c97358f821d733d93349b8b6
Author: Dmitry Monakhov <dmonakhov at openvz.org>
Date:   Tue May 5 13:44:35 2015 +0400

    vziolimit: port diff-iolimit-vzctl-api
    
    iolimit: vzctl ioctl interface
    
    Implement iolimit control block allocation, add get and set ioctl.
    
    Signed-off-by: Konstantin Khlebnikov <khlebnikov at openvz.org>
    
    ====================================
    https://jira.sw.ru/browse/PSBM-20104
    
    Signed-off-by: Dmitry Monakhov <dmonakhov at openvz.org>
---
 include/linux/vziolimit.h | 10 +++++++
 kernel/ve/vziolimit.c     | 68 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/include/linux/vziolimit.h b/include/linux/vziolimit.h
index a017b0f..5af8c04 100644
--- a/include/linux/vziolimit.h
+++ b/include/linux/vziolimit.h
@@ -14,4 +14,14 @@
 
 #define VZIOLIMITTYPE 'I'
 
+struct iolimit_state {
+	unsigned int id;
+	unsigned int speed;
+	unsigned int burst;
+	unsigned int latency;
+};
+
+#define VZCTL_SET_IOLIMIT	_IOW(VZIOLIMITTYPE, 0, struct iolimit_state)
+#define VZCTL_GET_IOLIMIT	_IOR(VZIOLIMITTYPE, 1, struct iolimit_state)
+
 #endif /* _LINUX_VZIOLIMIT_H */
diff --git a/kernel/ve/vziolimit.c b/kernel/ve/vziolimit.c
index 949d1a6..ac5abcd 100644
--- a/kernel/ve/vziolimit.c
+++ b/kernel/ve/vziolimit.c
@@ -11,6 +11,7 @@
 #include <linux/virtinfo.h>
 #include <linux/vzctl.h>
 #include <linux/vziolimit.h>
+#include <asm/uaccess.h>
 #include <bc/beancounter.h>
 
 struct throttle {
@@ -132,6 +133,73 @@ static struct vnotifier_block iolimit_virtinfo_nb = {
 
 static int iolimit_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
+	struct user_beancounter *ub;
+	struct iolimit *iolimit, *new_iolimit = NULL;
+	struct iolimit_state state;
+	int err;
+
+	if (cmd != VZCTL_SET_IOLIMIT && cmd != VZCTL_GET_IOLIMIT)
+		return -ENOTTY;
+
+	if (copy_from_user(&state, (void __user *)arg, sizeof(state)))
+		return -EFAULT;
+
+	ub = get_beancounter_byuid(state.id, 0);
+	if (!ub)
+		return -ENOENT;
+
+	iolimit = ub->private_data2;
+
+	switch (cmd) {
+		case VZCTL_SET_IOLIMIT:
+			if (!iolimit) {
+				new_iolimit = kmalloc(sizeof(struct iolimit), GFP_KERNEL);
+				err = -ENOMEM;
+				if (!new_iolimit)
+					break;
+			}
+
+			spin_lock_irq(&ub->ub_lock);
+
+			if (!iolimit && ub->private_data2) {
+				kfree(new_iolimit);
+				iolimit = ub->private_data2;
+			} else if (!iolimit)
+				iolimit = new_iolimit;
+
+			throttle_setup(&iolimit->throttle, state.speed,
+					state.burst, state.latency);
+
+			if (!ub->private_data2)
+				ub->private_data2 = iolimit;
+
+			spin_unlock_irq(&ub->ub_lock);
+
+			err = 0;
+			break;
+		case VZCTL_GET_IOLIMIT:
+			err = -ENXIO;
+			if (!iolimit)
+				break;
+
+			spin_lock_irq(&ub->ub_lock);
+			state.speed = iolimit->throttle.speed;
+			state.burst = iolimit->throttle.burst;
+			state.latency = jiffies_to_msecs(iolimit->throttle.latency);
+			spin_unlock_irq(&ub->ub_lock);
+
+			err = -EFAULT;
+			if (copy_to_user((void __user *)arg, &state, sizeof(state)))
+				break;
+
+			err = 0;
+			break;
+		default:
+			err = -ENOTTY;
+	}
+
+	put_beancounter(ub);
+	return err;
 }
 
 static struct vzioctlinfo iolimit_vzioctl = {