9pfs: Fix divide by zero bug

Some filesystems may return 0s in statfs (trivially, a FUSE filesystem
can do so). QEMU should handle this gracefully and just behave the
same as if statfs failed.

Signed-off-by: Dan Schatzberg <dschatzberg@fb.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
This commit is contained in:
Dan Schatzberg 2019-11-22 12:00:34 -08:00 committed by Greg Kurz
parent 2061735ff0
commit 68d654daee

View File

@ -1834,8 +1834,10 @@ static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path)
* and as well as less than (client msize - P9_IOHDRSZ))
*/
if (!v9fs_co_statfs(pdu, path, &stbuf)) {
iounit = stbuf.f_bsize;
iounit *= (s->msize - P9_IOHDRSZ)/stbuf.f_bsize;
if (stbuf.f_bsize) {
iounit = stbuf.f_bsize;
iounit *= (s->msize - P9_IOHDRSZ) / stbuf.f_bsize;
}
}
if (!iounit) {
iounit = s->msize - P9_IOHDRSZ;