Hi,
I've discovered a bug in the new lsblk util, which incorrectly reports
the size of a nearly 2TB partition:
NAME MAJ:MIN RM SIZE RO MOUNTPOINT
sda 8:0 0 83.9G 0
ââsda1 8:1 0 100M 0 /boot
ââsda2 8:2 0 83.8G 0 /
sdb 8:16 0 1.171798692T 0
ââsdb1 8:17 0 20G 0 /home
ââsdb2 8:18 0 1.171798692T 0 /mnt/Gluttony
sdc 8:32 0 931.5G 0
ââsdc1 8:33 0 931.5G 0 /mnt/Haven
sr0 11:0 1 2K 0
Looking at size_to_human_string (strutils.c:245), it looks like it's a
simple integer overflow. With the attached patch applied, the output is
now accurate:
NAME MAJ:MIN RM SIZE RO MOUNTPOINT
sda 8:0 0 83.9G 0
ââsda1 8:1 0 100M 0 /boot
ââsda2 8:2 0 83.8G 0 /
sdb 8:16 0 1.8T 0
ââsdb1 8:17 0 20G 0 /home
ââsdb2 8:18 0 1.8T 0 /mnt/Gluttony
sdc 8:32 0 931.5G 0
ââsdc1 8:33 0 931.5G 0 /mnt/Haven
sr0 11:0 1 2K 0
thanks,
dave reisner
>From 78e7c415db74723e8ac5ec696217afe26a05e3d8 Mon Sep 17 00:00:00 2001
From: Dave Reisner <d@xxxxxxxxxxxxxx>
Date: Mon, 14 Feb 2011 12:12:31 -0500
Subject: [PATCH] strutils: avoid integer overflow on large values
This is visible on a 2TB disk via lsblk, where a large partition
incorrectly displays as 1.171798692T instead of 1.8T. This is corrected
by using a uint64_t type instead of a simple int -- consistant with the
type used in lsblk.c to represent the raw size in bytes.
Signed-off-by: Dave Reisner <d@xxxxxxxxxxxxxx>
---
lib/strutils.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/strutils.c b/lib/strutils.c
index 94635b1..303d692 100644
--- a/lib/strutils.c
+++ b/lib/strutils.c
@@ -245,7 +245,8 @@ static int get_exp(uint64_t n)
char *size_to_human_string(uint64_t bytes)
{
char buf[32];
- int dec, frac, exp;
+ int dec, exp;
+ uint64_t frac;
const char *letters = "BKMGTP";
char c;
@@ -267,7 +268,7 @@ char *size_to_human_string(uint64_t bytes)
if (!dp || !*dp)
dp = ".";
- snprintf(buf, sizeof(buf), "%d%s%d%c", dec, dp, frac, c);
+ snprintf(buf, sizeof(buf), "%d%s%jd%c", dec, dp, frac, c);
} else
snprintf(buf, sizeof(buf), "%d%c", dec, c);
--
1.7.4.1
