From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 13 Mar 2007 13:16:08 +0000 (+0100)
Subject: Obscure file randommap fix
X-Git-Tag: fio-1.14~13
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=5afa0d9b2e14194d34001a24007d96536608e651;ds=sidebyside

Obscure file randommap fix

If file size < block and no size is given, we could be generating
a random offset within -1 and deref ->file_map[] beyond its size.

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

diff --git a/io_u.c b/io_u.c
index 10fa188d..fead400c 100644
--- a/io_u.c
+++ b/io_u.c
@@ -109,6 +109,9 @@ static int get_next_offset(struct thread_data *td, struct io_u *io_u)
 		unsigned long long max_blocks = f->file_size / td->min_bs[ddir];
 		int loops = 5;
 
+		if (!max_blocks)
+			return 1;
+
 		do {
 			r = os_random_long(&td->random_state);
 			b = ((max_blocks - 1) * r / (unsigned long long) (RAND_MAX+1.0));