postgres.git / summary / log / commit / refs

commit    13ec0bda2a127c3af85ed5f08e8d69c9082dccf5
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Apr 25 20:22:20 2011 +0000
First released in: 9.1.0, 8.2.22, 8.3.16, 8.4.9, 9.0.5

    Fix pg_size_pretty() to avoid overflow for inputs close to INT64_MAX.
    
    The expression that tried to round the value to the nearest TB could
    overflow, leading to bogus output as reported in bug #5993 from Nicola
    Cossu.  This isn't likely to ever happen in the intended usage of the
    function (if it could, we'd be needing to use a wider datatype instead);
    but it's not hard to give the expected output, so let's do so.


 src/backend/utils/adt/dbsize.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 3a85292f057..ab50c06171e 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -402,9 +402,15 @@ pg_size_pretty(PG_FUNCTION_ARGS)
 							 (size + mult / 2) / mult);
 				else
 				{
+					/* Here we have to worry about avoiding overflow */
+					int64	val;
+
 					mult *= 1024;
+					val = size / mult;
+					if ((size % mult) >= (mult / 2))
+						val++;
 					snprintf(buf, sizeof(buf), INT64_FORMAT " TB",
-							 (size + mult / 2) / mult);
+							 val);
 				}
 			}
 		}


[parent: 622077b8bc07]