From: Jens Axboe <axboe@fb.com>
Date: Mon, 9 May 2016 19:31:01 +0000 (-0600)
Subject: io_u: if we're doing backwards IO, wrap to end (not start)
X-Git-Tag: fio-2.10~35
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=b0a84f48509d76032455842f1482901e3ab12afd;p=fio.git

io_u: if we're doing backwards IO, wrap to end (not start)

If we have a job with a start file offset and we're doing holed
IO, we want to wrap to the start offset for forwards holes, but
to the end for backwards holes.

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

diff --git a/io_u.c b/io_u.c
index eb15dc28..f9870e70 100644
--- a/io_u.c
+++ b/io_u.c
@@ -371,10 +371,15 @@ static int get_next_seq_offset(struct thread_data *td, struct fio_file *f,
 			/*
 			 * If we reach beyond the end of the file
 			 * with holed IO, wrap around to the
-			 * beginning again.
+			 * beginning again. If we're doing backwards IO,
+			 * wrap to the end.
 			 */
-			if (pos >= f->real_file_size)
-				pos = f->file_offset;
+			if (pos >= f->real_file_size) {
+				if (o->ddir_seq_add > 0)
+					pos = f->file_offset;
+				else
+					pos = f->real_file_size + o->ddir_seq_add;
+			}
 		}
 
 		*offset = pos;