make sure __rand_0_1 does not return 0.0

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/lib/rand.h b/lib/rand.h
index 3d78115d48580f3ea5a0afc3e6e4cbcd7206e83a..a95bd28b49041991abb8a1713ad80c9ef086742a 100644 (file)
--- a/lib/rand.h
+++ b/lib/rand.h
@@ -109,11 +109,11 @@ static inline double __rand_0_1(struct frand_state *state)
        if (state->use64) {
                uint64_t val = __rand64(&state->state64);
 
-               return (double) val / (FRAND64_MAX + 1.0);
+               return (val + 1.0) / (FRAND64_MAX + 1.0);
        } else {
                uint32_t val = __rand32(&state->state32);
 
-               return (double) val / (FRAND32_MAX + 1.0);
+               return (val + 1.0) / (FRAND32_MAX + 1.0);
        }
 }