linux-kernel - [PATCH 01/30] drbd: bitmap bulk IO: do not always suspend IO

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Date:	Mon, 13 Jun 2016 16:08:49 +0200
From:	Philipp Reisner <philipp.reisner@...bit.com>
To:	Jens Axboe <axboe@...com>, linux-kernel@...r.kernel.org
Cc:	drbd-dev@...ts.linbit.com
Subject: [PATCH 01/30] drbd: bitmap bulk IO: do not always suspend IO

From: Lars Ellenberg <lars.ellenberg@...bit.com>

The intention was to only suspend IO if some normal bitmap operation is
supposed to be locked out, not always. If the bulk operation is flaged
as BM_LOCKED_CHANGE_ALLOWED, we do not need to suspend IO.

Signed-off-by: Philipp Reisner <philipp.reisner@...bit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
---
 drivers/block/drbd/drbd_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 2ba1494..4c64cb9 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3585,18 +3585,20 @@ void drbd_queue_bitmap_io(struct drbd_device *device,
 int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *),
 		char *why, enum bm_flag flags)
 {
+	/* Only suspend io, if some operation is supposed to be locked out */
+	const bool do_suspend_io = flags & (BM_DONT_CLEAR|BM_DONT_SET|BM_DONT_TEST);
 	int rv;
 
 	D_ASSERT(device, current != first_peer_device(device)->connection->worker.task);
 
-	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
+	if (do_suspend_io)
 		drbd_suspend_io(device);
 
 	drbd_bm_lock(device, why, flags);
 	rv = io_fn(device);
 	drbd_bm_unlock(device);
 
-	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
+	if (do_suspend_io)
 		drbd_resume_io(device);
 
 	return rv;
-- 
2.7.4