Mailing List Archive

Author: des
Date: 2007-08-03 20:50:05 +0200 (Fri, 03 Aug 2007)
New Revision: 1794

Modified:
trunk/varnish-cache/bin/varnishd/storage_file.c
Log:
Try harder to avoid integer overflows in cache file size calculations
on 32-bit platforms.


Modified: trunk/varnish-cache/bin/varnishd/storage_file.c
===================================================================
--- trunk/varnish-cache/bin/varnishd/storage_file.c 2007-08-03 18:46:43 UTC (rev 1793)
+++ trunk/varnish-cache/bin/varnishd/storage_file.c 2007-08-03 18:50:05 UTC (rev 1794)
@@ -118,7 +118,7 @@
static void
smf_calcsize(struct smf_sc *sc, const char *size, int newfile)
{
- uintmax_t l;
+ uintmax_t l, fssize;
unsigned bs;
char suff[2];
int i, explicit;
@@ -127,6 +127,7 @@

AN(sc);
AZ(fstat(sc->fd, &st));
+ xxxassert(S_ISREG(st.st_mode));

#if defined(HAVE_SYS_MOUNT_H) || defined(HAVE_SYS_VFS_H)
struct statfs fsst;
@@ -137,9 +138,10 @@
bs = sc->pagesize;
if (bs < fsst.f_bsize)
bs = fsst.f_bsize;
+ xxxassert(bs % sc->pagesize == 0);
+ xxxassert(bs % fsst.f_bsize == 0);
+ fssize = fsst.f_bsize * fsst.f_bavail;

- xxxassert(S_ISREG(st.st_mode));
-
i = sscanf(size, "%ju%1s", &l, suff); /* can return -1, 0, 1 or 2 */

explicit = i;
@@ -179,7 +181,7 @@
l *= (uintmax_t)(1024UL * 1024UL) *
(uintmax_t)(1024UL * 1024UL);
else if (suff[0] == '%') {
- l *= fsst.f_bsize * fsst.f_bavail;
+ l *= fssize;
l /= 100;
}
}
@@ -200,14 +202,14 @@

if (l < st.st_size) {
AZ(ftruncate(sc->fd, l));
- } else if (l - st.st_size > fsst.f_bsize * fsst.f_bavail) {
- l = ((uintmax_t)fsst.f_bsize * fsst.f_bavail * 80) / 100;
+ } else if (l - st.st_size > fssize) {
+ l = fssize * 80 / 100;
fprintf(stderr, "WARNING: storage file size reduced"
" to %ju (80%% of available disk space)\n", l);
}
}

- /* round down to of filesystem blocksize or pagesize */
+ /* round down to multiple of filesystem blocksize or pagesize */
l -= (l % bs);

if (l < MINPAGES * (uintmax_t)sc->pagesize) {