2005-04-27 Jeremy Katz <katzj@redhat.com>

	* isys/isys.c (doDevSpaceFree): Apply Jindrich Novy's patch to fix
	space calculation on > 2 TB devices (#155709)

1 files changed, 21 insertions, 1 deletions

diff --git a/isys/isys.c b/isys/isys.c
index 1d8f5def3..ec0d4f818 100644
--- a/isys/isys.c
+++ b/isys/isys.c
@@ -881,9 +881,23 @@ static PyObject * doGetRaidChunkSize(PyObject * s, PyObject * args) {
     return Py_BuildValue("i", sb.chunk_size / 1024);
 }
 
+static int get_bits(unsigned long long v) {
+    int  b = 0;
+    
+    if ( v & 0xffffffff00000000LLU ) { b += 32; v >>= 32; }
+    if ( v & 0xffff0000LLU ) { b += 16; v >>= 16; }
+    if ( v & 0xff00LLU ) { b += 8; v >>= 8; }
+    if ( v & 0xf0LLU ) { b += 4; v >>= 4; }
+    if ( v & 0xcLLU ) { b += 2; v >>= 2; }
+    if ( v & 0x2LLU ) b++;
+    
+    return v ? b + 1 : b;
+}
+
 static PyObject * doDevSpaceFree(PyObject * s, PyObject * args) {
     char * path;
     struct statfs sb;
+    unsigned long long size;
 
     if (!PyArg_ParseTuple(args, "s", &path)) return NULL;
 
@@ -892,7 +906,13 @@ static PyObject * doDevSpaceFree(PyObject * s, PyObject * args) {
 	return NULL;
     }
 
-    return Py_BuildValue("l", (long) sb.f_bfree * (sb.f_bsize / 1024) / (1024));
+    /* Calculate a saturated addition to prevent oveflow. */
+    if ( get_bits(sb.f_bfree) + get_bits(sb.f_bsize) <= 64 )
+        size = (unsigned long long)sb.f_bfree * sb.f_bsize;
+    else
+        size = ~0LLU;
+
+    return PyLong_FromUnsignedLongLong(size>>20);
 }
 
 static PyObject * doRaidStop(PyObject * s, PyObject * args) {