diff options
| author | NeilBrown <neilb@suse.de> | 2014-12-18 16:48:15 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2014-12-18 16:58:44 +1100 |
| commit | 93d3bd3b28486ae3f933b3f94c81d27565d5e89e (patch) | |
| tree | 8931e48a9de4858fb80a0489a43bc1dd5c8ab289 | |
| parent | 16afb1a5efb59b45db9ee46dad7cc410aabbe90e (diff) | |
| download | mdadm-93d3bd3b28486ae3f933b3f94c81d27565d5e89e.tar.gz | |
util: remove rounding error where reporting "human sizes".
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>
| -rw-r--r-- | util.c | 8 |
1 files changed, 4 insertions, 4 deletions
@@ -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); } |