add sysctl helper functions to provide milliseconds-based interfaces.

Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>

include/linux/sysctl.h

@@ -796,6 +796,8 @@ extern int proc_dointvec_jiffies(ctl_table *, int, struct file *,
 				 void __user *, size_t *, loff_t *);
 extern int proc_dointvec_userhz_jiffies(ctl_table *, int, struct file *,
 					void __user *, size_t *, loff_t *);
+extern int proc_dointvec_ms_jiffies(ctl_table *, int, struct file *,
+				    void __user *, size_t *, loff_t *);
 extern int proc_doulongvec_minmax(ctl_table *, int, struct file *,
 				  void __user *, size_t *, loff_t *);
 extern int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int,
@@ -813,6 +815,7 @@ extern int do_sysctl_strategy (ctl_table *table,
 extern ctl_handler sysctl_string;
 extern ctl_handler sysctl_intvec;
 extern ctl_handler sysctl_jiffies;
+extern ctl_handler sysctl_ms_jiffies;
 
 
 /*

kernel/sysctl.c

@@ -1902,6 +1902,27 @@ static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
 	return 0;
 }
 
+static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
+					    int *valp,
+					    int write, void *data)
+{
+	if (write) {
+		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+	} else {
+		int val = *valp;
+		unsigned long lval;
+		if (val < 0) {
+			*negp = -1;
+			lval = (unsigned long)-val;
+		} else {
+			*negp = 0;
+			lval = (unsigned long)val;
+		}
+		*lvalp = jiffies_to_msecs(lval);
+	}
+	return 0;
+}
+
 /**
  * proc_dointvec_jiffies - read a vector of integers as seconds
  * @table: the sysctl table
@@ -1946,6 +1967,28 @@ int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
 }
 
+/**
+ * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @filp: the file structure
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string. 
+ * The values read are assumed to be in 1/1000 seconds, and 
+ * are converted into jiffies.
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
+			     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
+				do_proc_dointvec_ms_jiffies_conv, NULL);
+}
+
 #else /* CONFIG_PROC_FS */
 
 int proc_dostring(ctl_table *table, int write, struct file *filp,
@@ -1990,6 +2033,12 @@ int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
 	return -ENOSYS;
 }
 
+int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
+			     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2119,6 +2168,33 @@ int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
 	return 1;
 }
 
+/* Strategy function to convert jiffies to seconds */ 
+int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
+		void __user *oldval, size_t __user *oldlenp,
+		void __user *newval, size_t newlen, void **context)
+{
+	if (oldval) {
+		size_t olen;
+		if (oldlenp) { 
+			if (get_user(olen, oldlenp))
+				return -EFAULT;
+			if (olen!=sizeof(int))
+				return -EINVAL; 
+		}
+		if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
+		    (oldlenp && put_user(sizeof(int),oldlenp)))
+			return -EFAULT;
+	}
+	if (newval && newlen) { 
+		int new;
+		if (newlen != sizeof(int))
+			return -EINVAL; 
+		if (get_user(new, (int __user *)newval))
+			return -EFAULT;
+		*(int *)(table->data) = msecs_to_jiffies(new);
+	}
+	return 1;
+}
 
 #else /* CONFIG_SYSCTL */
 
@@ -2149,6 +2225,13 @@ int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
 	return -ENOSYS;
 }
 
+int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
+		void __user *oldval, size_t __user *oldlenp,
+		void __user *newval, size_t newlen, void **context)
+{
+	return -ENOSYS;
+}
+
 int proc_dostring(ctl_table *table, int write, struct file *filp,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2185,6 +2268,12 @@ int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
 	return -ENOSYS;
 }
 
+int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
+			     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2219,11 +2308,13 @@ EXPORT_SYMBOL(proc_dointvec);
 EXPORT_SYMBOL(proc_dointvec_jiffies);
 EXPORT_SYMBOL(proc_dointvec_minmax);
 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
+EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
 EXPORT_SYMBOL(proc_dostring);
 EXPORT_SYMBOL(proc_doulongvec_minmax);
 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
 EXPORT_SYMBOL(register_sysctl_table);
 EXPORT_SYMBOL(sysctl_intvec);
 EXPORT_SYMBOL(sysctl_jiffies);
+EXPORT_SYMBOL(sysctl_ms_jiffies);
 EXPORT_SYMBOL(sysctl_string);
 EXPORT_SYMBOL(unregister_sysctl_table);