We would hang forever when passing a zero to string_get_size(). Furthermore, string_get_size() would produce decimals on a value small enough to be exact. Finally, a few formatting issues are inconsistent with standard SI style guidelines. - If the value is less than the divisor, skip the entire rounding step. This prints out all small values including zero as integers, without decimals. - Add a space between the value and the symbol for the unit, consistent with standard SI practice. - Lower case k in kB since we are talking about powers of 10. - Finally, change "int" to "unsigned int" in one place to shut up a gcc warning when compiling the code out-of-kernel for testing. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
		
			
				
	
	
		
			68 lines
		
	
	
	
		
			1.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
	
		
			1.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * Helpers for formatting and printing strings
 | 
						|
 *
 | 
						|
 * Copyright 31 August 2008 James Bottomley
 | 
						|
 */
 | 
						|
#include <linux/kernel.h>
 | 
						|
#include <linux/math64.h>
 | 
						|
#include <linux/module.h>
 | 
						|
#include <linux/string_helpers.h>
 | 
						|
 | 
						|
/**
 | 
						|
 * string_get_size - get the size in the specified units
 | 
						|
 * @size:	The size to be converted
 | 
						|
 * @units:	units to use (powers of 1000 or 1024)
 | 
						|
 * @buf:	buffer to format to
 | 
						|
 * @len:	length of buffer
 | 
						|
 *
 | 
						|
 * This function returns a string formatted to 3 significant figures
 | 
						|
 * giving the size in the required units.  Returns 0 on success or
 | 
						|
 * error on failure.  @buf is always zero terminated.
 | 
						|
 *
 | 
						|
 */
 | 
						|
int string_get_size(u64 size, const enum string_size_units units,
 | 
						|
		    char *buf, int len)
 | 
						|
{
 | 
						|
	const char *units_10[] = { "B", "kB", "MB", "GB", "TB", "PB",
 | 
						|
				   "EB", "ZB", "YB", NULL};
 | 
						|
	const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB",
 | 
						|
				 "EiB", "ZiB", "YiB", NULL };
 | 
						|
	const char **units_str[] = {
 | 
						|
		[STRING_UNITS_10] =  units_10,
 | 
						|
		[STRING_UNITS_2] = units_2,
 | 
						|
	};
 | 
						|
	const unsigned int divisor[] = {
 | 
						|
		[STRING_UNITS_10] = 1000,
 | 
						|
		[STRING_UNITS_2] = 1024,
 | 
						|
	};
 | 
						|
	int i, j;
 | 
						|
	u64 remainder = 0, sf_cap;
 | 
						|
	char tmp[8];
 | 
						|
 | 
						|
	tmp[0] = '\0';
 | 
						|
	i = 0;
 | 
						|
	if (size >= divisor[units]) {
 | 
						|
		while (size >= divisor[units] && units_str[units][i]) {
 | 
						|
			remainder = do_div(size, divisor[units]);
 | 
						|
			i++;
 | 
						|
		}
 | 
						|
 | 
						|
		sf_cap = size;
 | 
						|
		for (j = 0; sf_cap*10 < 1000; j++)
 | 
						|
			sf_cap *= 10;
 | 
						|
 | 
						|
		if (j) {
 | 
						|
			remainder *= 1000;
 | 
						|
			do_div(remainder, divisor[units]);
 | 
						|
			snprintf(tmp, sizeof(tmp), ".%03lld",
 | 
						|
				 (unsigned long long)remainder);
 | 
						|
			tmp[j+1] = '\0';
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
 | 
						|
		 tmp, units_str[units][i]);
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL(string_get_size);
 |