File 0041-util-remove-rounding-error-where-reporting... of Package mdadm.5365

Overview Repositories Revisions Requests Users Attributes Meta

File 0041-util-remove-rounding-error-where-reporting-human-siz.patch of Package mdadm.5365

From 93d3bd3b28486ae3f933b3f94c81d27565d5e89e Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Thu, 18 Dec 2014 16:48:15 +1100
Subject: [PATCH 051/359] util: remove rounding error where reporting "human
 sizes".
References: bsc#1081910

The division
 1<<20 / 200
is not exact, so dividing by this to convert bytes into half-megs
is wrong and results in incorrect output.

As we are doing "long long" arithmetic, there is no risk of an overflow
until we reach 64 petabytes.
So change to
   * 200 / (1<<20).

Reported-by: Jan Echternach <jan@goneko.de>
Resolved-debian-bug: 763917
Url: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=763917
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Coly Li <colyli@suse.de>

---
 util.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/util.c b/util.c
index 37c6e0d..89f6b0f 100644
--- a/util.c
+++ b/util.c
@@ -671,13 +671,13 @@ char *human_size(long long bytes)
 	if (bytes < 5000*1024)
 		buf[0] = 0;
 	else if (bytes < 2*1024LL*1024LL*1024LL) {
-		long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
+		long cMiB = (bytes * 200LL / (1LL<<20) + 1) / 2;
 		long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 		snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 			cMiB/100 , cMiB % 100,
 			cMB/100, cMB % 100);
 	} else {
-		long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
+		long cGiB = (bytes * 200LL / (1LL<<30) +1) / 2;
 		long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 		snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 			cGiB/100 , cGiB % 100,
@@ -706,11 +706,11 @@ char *human_size_brief(long long bytes, int prefix)
 		buf[0] = 0;
 	else if (prefix == IEC) {
 		if (bytes < 2*1024LL*1024LL*1024LL) {
-			long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
+			long cMiB = (bytes * 200LL / (1LL<<20) +1) /2;
 			snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 				cMiB/100 , cMiB % 100);
 		} else {
-			long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
+			long cGiB = (bytes * 200LL / (1LL<<30) +1) /2;
 			snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 					cGiB/100 , cGiB % 100);
 		}
-- 
2.16.1

Places

File 0041-util-remove-rounding-error-where-reporting-human-siz.patch of Package mdadm.5365

Places