[PATCH 2/2] Refer td->loops instead of td->o.loops to fix loop count issue

From: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
To: fio@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>,
	Dmitry Fomichev <Dmitry.Fomichev@wdc.com>,
	Niklas Cassel <niklas.cassel@wdc.com>,
	Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Subject: [PATCH 2/2] Refer td->loops instead of td->o.loops to fix loop count issue
Date: Fri,  1 Oct 2021 19:32:57 +0900	[thread overview]
Message-ID: <20211001103257.4130231-3-shinichiro.kawasaki@wdc.com> (raw)
In-Reply-To: <20211001103257.4130231-1-shinichiro.kawasaki@wdc.com>

In the github issues #1093 and #1278, it was reported that the loops
option does not work as expected when do_verify=0 option is specified.
Per analysis by Sowmya Ravi, the cause was as follows:

1) keep_running() decrements td->o.loops at job repetition, then
   td->o.loops has zero value when the last loop is executed.
2) clear_io_state() is called at the beginning of the thread_main loop
   for each repetition for loops option.
3) clear_io_state() calls reset_io_counters() which resets
   td->nr_done_files to zero when td->o.loops is non-zero.
4) For the last loop of loops option, clear_io_state() call does not
   clear td->nr_done_files since td->l.loops is zero. This results in a
   setup error in do_io().

To fix the issue, modify reset_io_counters() to refer td->loops instead
of td->o.loops. td->o.loops is not a good reference since it is updated
in keep_running(). td->loops is not updated during fio run, and safe to
refer.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
---
 libfio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libfio.c b/libfio.c
index 6144a474..ed5906d4 100644
--- a/libfio.c
+++ b/libfio.c
@@ -104,7 +104,7 @@ static void reset_io_counters(struct thread_data *td, int all)
 	/*
 	 * reset file done count if we are to start over
 	 */
-	if (td->o.time_based || td->o.loops || td->o.do_verify)
+	if (td->o.time_based || td->loops > 1 || td->o.do_verify)
 		td->nr_done_files = 0;
 }
 
-- 
2.31.1

