lfsr: ensure we don't generate an offset + buflen that exceeds the max size

[fio.git] / io_u.c

diff --git a/io_u.c b/io_u.c
index 91d1290f388ef53a2b9ebd55302c051df8f8983b..94fd1234650d658fe9fdd6db3143710665283614 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -49,11 +49,11 @@ static void mark_random_map(struct thread_data *td, struct io_u *io_u)
                io_u->buflen = nr_blocks * min_bs;
 }
 
-static unsigned long long last_block(struct thread_data *td, struct fio_file *f,
-                                    enum fio_ddir ddir)
+static uint64_t last_block(struct thread_data *td, struct fio_file *f,
+                          enum fio_ddir ddir)
 {
-       unsigned long long max_blocks;
-       unsigned long long max_size;
+       uint64_t max_blocks;
+       uint64_t max_size;
 
        assert(ddir_rw(ddir));
 
@@ -77,14 +77,14 @@ static unsigned long long last_block(struct thread_data *td, struct fio_file *f,
 static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
                                  enum fio_ddir ddir, unsigned long long *b)
 {
-       unsigned long long r;
+       unsigned long long r, lastb;
 
-       if (td->o.random_generator == FIO_RAND_GEN_TAUSWORTHE) {
-               unsigned long long rmax, lastb;
+       lastb = last_block(td, f, ddir);
+       if (!lastb)
+               return 1;
 
-               lastb = last_block(td, f, ddir);
-               if (!lastb)
-                       return 1;
+       if (td->o.random_generator == FIO_RAND_GEN_TAUSWORTHE) {
+               unsigned long long rmax;
 
                rmax = td->o.use_os_rand ? OS_RAND_MAX : FRAND_MAX;
 
@@ -102,7 +102,7 @@ static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
        } else {
                uint64_t off = 0;
 
-               if (lfsr_next(&f->lfsr, &off))
+               if (lfsr_next(&f->lfsr, &off, lastb))
                        return 1;
 
                *b = off;